The predatory beetle is Azya orbigera, in the family Coccinelidae. Without a doubt, this observation can easily lead to the conclusion that the relatively rare scale insect is kept under control by the relatively common coccinellid beetle. But a closer look reveals a dramatic variability: Some bushes are very heavily laden with the scale insects, and some have none at all. There is another classical ecological notion that emerges in this system. Surrounding the tree in which an Azteca nest is located is a region containing coffee plants that are routinely patrolled by the Azteca ants that were described above. The ants harvest the sweet secretions the scale insects produce and, in turn, scare away or kill the natural enemies seeking to attack the scales , a well-known mutualism . Because the coffee bushes located near the shade trees that contain Azteca nests are where the scale insect is at leastpartially protected from the predatory beetle and various parasitoids, this area represents a refuge for the scale insect. It is therefore tempting to conclude that the ant itself is an indirect herbivore on the coffee . Although such is the case at a very local level , because of the complexities induced by the beetle predator, such is not the case at a larger scale. The ants effectively provide an area of high food availability for the beetle. Furthermore, the ants protecting the scale insects also, inadvertently, protect the beetle larvae from its own parasitoids, providing an effective refuge for the beetle as well . Predator–prey systems that contain a refuge are well studied in theoretical ecology , usually with an emphasis on their stabilizing properties. Expanding our view to a larger spatial scale, we deduce an evident contradiction from easily observable patterns. However, round planter pot the ants cannot provide protection if they have not yet created a foraging pattern at the site where the scales are located.

Therefore, the scale insect is unable to form a successful population unless under protection from the ants but is unable to attract the ant protection unless it builds up at least a small population. This pattern is well known in ecology as an Allee effect: An organism cannot form a successful population unless a critical number of individuals first become established, a mechanism generally understood to frequently be involved with the idea of critical transitions. In figure 4, we illustrate the system with a cartoon diagram approximately summarizing a simple population model . On one hand, as the dispersion of scales moves from aposition far removed from the refuge toward it, the adult beetle predators that have already located the scales will tend to move with it, until they encounter the protective ants , as is presented in figure 4a. A snapshot at some particular time therefore might look like the pattern in figure 4b. On the other hand, as the dispersion of scales moves from a position within the refuge away from it, the encounter with the beetle predators will not occur until the scales are far removed from the refuge, as is presented in figure 4c. A snapshot at some particular time therefore might look like the pattern in figure 4d. Finally, combining the pattern of figure 4b with that of figure 4d, we obtain the combined graph presented in figure 4e. Note that there is a broad region in which the scales could be very high while at the same time could be very low, effectively depending on where the scales are dispersing from, a structure typically referred to as hysteresis. Selecting 20 different shade trees containing Azteca nests, we examined all coffee bushes within 2 meters of the nest and a number of bushes further removed . We estimated the activity of Azteca ants on each of the bushes before counting the scale insects, to get an estimate of where the actual refuge was located . Note that the ant activity within 1 meter of the nest was high for almost all bushes surveyed , although positions greater than 1 meter awaty were highly variable, with some bushes having high activity levels and others having none. Further than 4 meters from the nest, ant activity was effectively nonexistant, and bushes further than about 4 meters from the nest were completely out of the refuge.

Plotting the number of bushes with a saturated density of scale insects and those with less than 10 scales, we obtain a pattern corresponding quite closely to what is expected from the hysteretic pattern predicted by the theoretical considerations . A further complication enters with a more complete natural history understanding of the beetles and their larvae. Although the adult beetle can fly and therefore forage over long distances for its food source, the larvae are largely restricted to terrestrial movement; that is, they are restricted in space . Female beetles therefore must choose their oviposition sites in such a way that the larvae will mature in an environment that contains a locally abundant food source. One major food source for predatory beetles is the general kinds of insects that are relatively sessile and suck the juices from plants, precisely the characteristics of the green coffee scale. They are easy targets for predators because they are normally slow moving and have few defenses. The problem for a potential predator is that they are very frequently defended by ants, precisely in areas where they are good sources of food for a beetle larva. Consequently, a whole group of beetles has evolved the habit of seeking out ants and ovipositing in areas where ants are abundant and defending the hemipterans. These myrmecophilous beetles must obviously have a strategy of protecting their larvae from the aggressive action of the ants and of enabling oviposition in sites of high ant activity . In the case of the beetleA. orbigera, the larva is covered with waxy filaments that tend to stick in the ants’ mandibles whenever they try to attack it . But more importantly, female beetles take advantage of an unusual behavioral pattern of the ants in order to oviposit where the scales are abundant . When a phorid fly attacks an ant, that ant exudes a pheromone that effectively says to the other ants in the general vicinity “Look out! Phorids attacking,” and the surrounding sisters all adopt a sort of catatonic posture, heads up, mandibles open, and stationary . Although the phorid is able to detect the alarm pheromones of the ant and is therefore attracted to it, it is unable to actually oviposit on the ant unless it sees some movement . Therefore, not only the ant under potential phorid attack, but also the sisters surrounding her assume this semistationary posture, a result of the very specific pheromone that alerts all ants in the vicinity that a phorid is lurking about. Remarkably, the adult female beetle is able to detect and react to this specific chemical, apparently using it as a cue that the time is propitious to enter into the ant-protected zone to sneak in some ovipositions . Therefore the phorid, in addition to being an important player in the Turing process that forms the basic spatial structure of the system, imposes a trait-mediated indirect interaction , in which the effect of the ant on the beetle is reduced. There is more to this story: first, from simple theoretical considerations and, second, round pot for plants from some evident natural history observations of the system. The theoretical considerations emerge from the knowledge that the refuge is dynamic. That is, past ecological theory has shown that when a prey species is able to retreat from its predator in a fixed refuge space, the basic instabilities of the predator–prey arrangement can be cancelled. But, in the present example, the refuge is effectively a pattern formed by another element in the system , the Azteca ant. And the Azteca ant is dynamic in the system, increasing its numbers in proportion to the resources it gains . If the scale insect population increases, there is more food for the ant, and it will therefore make more nests and expand its territory, creating even more refuge area for the scale insect. However, as the ant expands its area of influence , an increasing fraction of the area becomes refuge and, therefore, not available to the adult beetles . At the extreme, there must be some point at which the beetle is unable to find enough prey to continue its population expansion, because almost all of the area would now be a refuge for the scale insect.

Therefore, theoretically, the inevitable expansion of the refuge would lead to the eventual local extinction of the beetle predator. It could, of course, be the case that this expected instability of the system does not express itself for diverse reasons or perhaps for an excessively long time. However, purely theoretically, it represents a potential problem for persistence of this control agent. The theoretical problem is resolved by some very simple natural history observations. A fungal disease, known as the white halo fungus , almost inevitably becomes epizootic , especially when local population densities of the scale insect become large . The fungus can occasionally be found on isolated scale insects, but almost always is most evident when scale insects have built up a significant local population density, and such a buildup can only happen when they are under the protective custody of the Azteca ant.In the end, we see that the Azteca ant plays a key role in the control of this pest. On one hand it protects the scale insect from its adult beetle predator but only in the area of the refuge of the scale, which is defined by the ant itself . On the other hand, it permits the scale insect to build up such large local populations that the white halo fungus frequently becomes epizootic and drives the scale insect to local extinction. It is a curious inverse application of Gause’s traditional competitive exclusion principle, which might be expected to apply between the fungus and the beetle because they share this same food source. It seems unlikely, however, that the scale could be controlled completely by either the beetle or the fungal disease, except in the context of a spatial pattern generated by the Azteca ant . The massive expansion of the ants that might be expected theoretically never happens, partly because of the local effect of the fungal disease and the beetle larvae together reducing the scale insect population locally. Therefore, the dynamic nature of the ant cluster mosaic , always provides a small set of refuges that allows the beetle predator to be maintained throughout the coffee farm. From the point of view of the beetle, it is perhaps ironic that the beetle itself may be involved in the organization of the spatial pattern that is required for its own persistence . There is yet an additional complication. The fungal disease, once it arrives, multiplies extremely rapidly. But, as was noted above, it does not arrive in the first place unless the scale population is large and locally concentrated. Therefore, once the disease gets there, it increases to epidemic levels and wipes out the entire population of scale insects , creating a classical situation of boom and bust and hysteresis in space . Although it is a somewhat complicated argument that has been made in a couple of different ways elsewhere , the disease can clearly generate a locally chaotic dynamic trajectory. Its population dynamics over time are therefore expected to be both oscillatory and unpredictable. Furthermore, as the relevant population gets closer to the ant nest , the oscillations with its disease are expected to be more and more extreme. Eventually, they become so extreme that they transcend the boundaries of a critical value and both scales and disease completely disappear. Note that chaotic trajectories have boundaries , and the equilibrium point at zero is constrained within a basin of attraction. As the system gets closer to the refuge, the combination of a lower bound on the scale population and the rapidity with which it can increase when under protection from the ants combine to frequently produce chaotic oscillations, and the collision between the boundary of the chaos and the basin edge causes the population to crash, in a basin or boundary collision .

Conversely in 2021, total free anthocyanin concentrations were the highest in D4, C0, and D1 wines. Anthocyanin modifications due to shading treatments were more varied in 2021 compared to 2020. Overall, wines from D4 had the most 3-glucosides and 3-acetylated glucosides, while C0 and D5 consistently had less. Coumarylated anthocyanin concentrations were reduced in D3 and D5 wines compared to C0 wines. This was not consistent with the concentrations observed in 2020. Likewise, there was no statistically significant effect on the anthocyanin hydroxylation ratio in 2021 wines, while shading had an impact on anthocyanin hydroxylation in wines in 2020. Nine flavonol compounds were monitored in wines using HPLC . For all monitored flavonol compounds except myricetin-3- glucuronide, C0 wines consistently had the highest concentrations in 2020 compared to shaded wines, with D4 and D5 wines following in flavonol concentration. Subsequently, C0 also had the highest wine flavonol concentration when calculated as total flavonols in 2020. A similar trend occurred in 2021. C0 wines from 2021 also contained greater concentrations of each flavonol compared to shaded treatments, as well as total flavonol concentration.The wine aroma profiles from the 2020 and 2021 vintages were analyzed with and 29 volatile compounds were identified and categorized into their respective compound classes . The aromas profiles of wines depended highly on vintage, resulting in distinct aroma profiles. Generally, in 2020, total higher alcohols were unaffected by shade treatments, except for isoamyl alcohol and benzyl alcohol. Wines produced from shaded fruit had similar concentrations of isoamyl alcohol while the C0 had the lowest isoamyl alcohol concentration. Benzyl alcohol concentrations were reduced in D3 and D5 wines compared to C0, D1 and D4 wines. In 2021, black plastic plant pots shading treatments did not impact the concentration of higher alcohols in the resulting wines except for benzyl alcohol, which increased in 2021 D3 wines compared to all other treatments.

Acetate esters and fatty acid ethyl esters showed varied effects in wines due to shading in 2020. C0 and D5 had the lowest ethyl acetate concentrations compared to the other shade treatments. Likewise, isoamyl acetate was reduced in C0, D4 and D5 wines compared to D1 and D3 wines. Among the shade film treatments , ethyl hexanoate and ethyl octanoate concentrations were comparable between D1 and D5 wines and were greater than concentrations found in D3 wines. C0 and D5 wines were indistinguishable in ethyl butyrate, ethyl-2-methylbutyrate and ethyl valerate in 2020, with D1 and D3 wines having the highest concentrations of each these ester compounds. Isobutyric acid increased in D4 in 2020. In 2021, there were no significant impacts of shading on acetate esters, fatty acid ethyl esters, ethyl butyrate, ethyl-2-methylbutyrate or ethyl valerate. The effect of shade films on various terpenes and norisoprenoids was highly dependent on vintage conditions. Alpha-terpinene was highest in D5 wines but was significantly reduced in D1 and D3 wines in 2020. The D4 wines had the most cis-rose-oxide while C0 wines had the least. Linalool concentrations were reduced in C0, D4 and D5 wines. Among the shaded treatments, nerol concentrations were enhanced in D5 wines in 2020, while there was no effect of shading on nerol concentration in 2021. D5 did not differ from the C0 in nerol concentration in 2020. Farnesol in D3 was reduced in 2020 whereas farnesol concentrations were not affected in 2021 wines. Conversely, nerolidol was unaffected by shade films in 2020, whereas significant decreases in nerolidol concentrations were observed in D4 and D5 wines in 2021. It was observed that b-damascenone were elevated in 2020 in C0 wines, yet differences in b-damascenone concentrations were nonsignificant between shade film treatments. In 2021, only significant differences in b-damascenone concentrations were observed in wines, with C0 wines containing the most bdamascenone and D5 wines containing the least. b-ionone concentrations were not statistically significant between all treatments in 2020 and 2021.

To determine the effects of partial solar shading on wine chemistry, flavonoid composition and aromatic profiles of wines we conducted a principal components analysis for both vintages . In 2020, PCA indicated that PC1 accounted for 30.8%, and PC2 accounted for 22.1% of the total variance. The C0 treatments clustered together, separately from the partial solar shading treatments. The separation along PC1 was explained by the ratio of di- to tri-hydroxylated anthocyanins in wines, norisoprenoids and flavonols, as well as lower CI, alcohol content and TPI. The separation along PC2 was explained by TA, pH, terpenes and the percentage of polymeric anthocyanins in wine samples. In 2021, PCA indicated PC1 accounted for 29.9%, and PC2 accounted for 22.2% of the total variance. The C0 treatments again separated from shade film treatments, but less so than in 2020. The separation in PC1 was again explained by the ratio of di- to tri-hydroxylated anthocyanins, along with the total glucosides, total methylated anthocyanins and total anthocyanins. The separation of C0 was along PC2 and thus was associated with higher concentrations of flavonols, terpenes, norisoprenoids, and polymeric anthocyanins in wine. We analyzed the relationships further between the variables monitored with a correlation analysis in wines . In 2020, CI in wines had the strongest positive correlation with TPI and acids. Alcohol percentage and ketones were also positively correlated to TPI and acids, although less so than CI. Ketones also were very strongly positively correlated with higher alcohols, while higher alcohols were less strongly correlated to acids. Conversely, flavonols were strongly negatively correlated with acetate esters and other esters in wines. Norisporenoids and pH were less negatively correlated to acetate esters. Fatty acid ethyl esters particularly showed to be negatively correlated with TA. In 2021, the strongest positive correlations in wines were between total anthocyanins and total glucosides and total methylated anthocyanins .

Total coumarylated anthocyanins were significantly and positively correlated to total anthocyanins, methylated anthocyanins, and total glucosides. Strong negative correlations were found between hue and ester compounds including fatty acid ethyl esters and acetate esters. Alcohol percentage and norisoprenoids were also negatively correlated witheach other. A strong negative correlation existed between the ration of di- to tri-hydroxylated anthocyanins and total acetylated anthocyanins. Lastly, total higher alcohols and pH were strongly negatively correlated with each other.In hot viticulture regions, there is a desire to reduce excessive alcohol content in wines due to marketability and taxation concerns . Numerous studies have demonstrated that partial solar radiation exclusion is an effective method for reducing the amount of ethanol in wines by reducing TSS in shaded clusters . However, in the present study, C0 wines consistently had the lowest alcohol content and the lowest concentration of residual sugars in 2020 compared to shaded fruit, despite grapes at harvest having similar TSS values across the treatments . This may be due to the composition of sugars in the grape berry being affected by excessive cluster temperatures in C0 fruit. Sepulveda and Kliewer showed that heat stress at 40°C post-veraison decreases glucose and fructose in the grape berry. During heat wave events post-veraison, cluster temperatures in C0 reached a maximum temperature of 58°C, exceeding the point at which glucose and fructose content is altered . Additionally, the production of non-fermentable sugars such as arabinose, raffinose and xylose are known to be present in the grape berry . Genes involved in the production of these sugars have been shown to be upregulated under heat stress conditions in grapevine . While the grape berry is 95-99% glucose and fructose at harvest, these non-fermentable sugars are included in the metric of total soluble solids . As a result, while TSS was unaffected by shade films , the proportion of fermentable to nonfermentable sugars may be impacted, thus leading to 2020 C0 wines with reduced alcohol content. This difference in alcohol content between 2021 wines was not observed most likely due to the 2021 growing season being cooler with less GDDs than 2020 . While C0 wines in this study demonstrated lower alcohol content than shaded wines, black plastic garden pots previous literature corroborates cluster temperature reduction by partial solar radiation exclusion as an effective method to lessen sugar content in the grape berry and thus reduce alcohol content of wines . The effect of partial solar radiation exclusion in semi-arid climates on berry pH and TA is mixed. Previous work demonstrates partial solar radiation exclusion to reduce pH and increase TA in grape berries by reducing the thermal degradation of organic acids . However, in the present study, berry pH and TA at harvest were unaffected in either year by shade films . Nonetheless, there were apparent effects on wine pH and TA that were vintage dependent. In the present study, D3 wines had the lowest pH and highest TA, while C0 wines did not differ from the shade films D1, D4 or D5 in pH or TA in 2020. Differences observed in pH between the wines ultimately affect the colorimetric properties of these wines.

In 2021, D4 and D5 wines showed the highest pH values. It is understood that the pH of the wines can shift the anthocyanin equilibrium in wine solution between the flavylium and quinoidal base forms . In the present study, D4 wines had the highest pH and the highest CI. In many cases, when pH rises, CI will decline as anthocyanin equilibrium shifts away from the flavylium form towards the colorless quinoidal forms . However, this was not the case in the present study. Rather, improved color intensity at elevated wine pH could be attributed to co-pigmentation in the wine matrix. Co-pigmentation refers to non-covalent interactions between anthocyanins and cofactors such as flavonols, flavan-3-ols and proanthocyaninidins, that results in greater absorbance of the wine than color what would be indicated by anthocyanin content and pH conditions . In the hotter 2020 vintage, the total flavonols in grape berries were increased in D4 fruit compared to other treatments . This increased berry flavonol content was transmissible during winemaking, as D4 wines also showed the highest total flavonols with similar concentrations as C0 wines in 2020. TPI was also enhanced in D4 wines. As such, this increased the abundance of cofactors in the wine matrix. Thus, improved color intensity documented in D4 wines in both vintages could be due to the enhancement of absorbance from increased flavonol content by reducing thermal degradation in the vineyard . In the cooler 2021 growing season, shade films produced wines with less flavonols than C0, but greater anthocyanin content, thus leading to improved color intensity in D4 wines. The increase of phenolic cofactors in D4 wines not only enhanced color and hue, but also led to a higher percentage of polymeric anthocyanins when compared to other shade treatments. Phenolic and polyphenolic compounds from grape skins and seeds can form polymeric pigments in wine with anthocyanins . These polymeric anthocyanins are more stable than monomeric anthocyanins and help to stabilize wine color. This occurs as the proportion of monomeric anthocyanins decreases, leaving color to be maintained by polymeric anthocyanins . Across both vintages, the percentage of polymeric anthocyanins was maximized in D4 wines, indicating that these wines may have greater aging potential than wines from C0 and other shading treatments.In the present study, partial solar radiation exclusion modified the composition of anthocyanins in wine. Partial solar radiation exclusion resulted in increased anthocyanin glycosides in wine from shade film treatments except for D4 wines in 2020. In 2021, D4 consistently showed the lowest cluster temperatures post-veraison and as a result, demonstrated the highest concentration of glucosides in resultant wines. Excessive berry temperatures post-veraison in both vintages led to C0 fruit with reduced total anthocyanin content atharvest and this carried over into resultant wines . The reduction of near-infrared radiation by at least 15% produced a cluster temperature conducive to anthocyanin accumulation, as these compounds are susceptible to thermal degradation above 35°C . When comparing total anthocyanin and flavonol concentrations between 2020 and 2021, regardless of treatment, 2020 wines had anthocyanin and flavonol concentrations six to seven times less than those in 2021 wines. As flavonoids are susceptible to thermal degradation, this drastic difference in total flavonoid concentrations may be attributed to hotter vintage air temperatures in 2020 compared to 2021.

The filter papers containing ovisacs were pinned to the underside of the aforementioned infected source plants, which were then kept in a growth chamber until the first instar mealybug crawlers hatched. Approximately 72 h after hatching on the infected source plants, mealybugs were transferred to mature vines in the vineyard and to uninfected vines in the laboratory, for a 48 h inoculation access period. The timing of hatching led us to perform field inoculations on 18 July 2011, which coincided with the emergence of the new Ps. maritimus generation in Napa Valley. Twenty replicate source vines were propagated and used, with one to five recipient test vines inoculated per source plant in each inoculation experiment . All recipient test vines were treated with an insecticide upon completion of the inoculation access period.The experimental field inoculations were located in three rows of a vineyard block of V. vinifera cv. Cabernet Franc clone 01 grafted to 110R rootstock, obtained from Duarte Nursery and planted in Oakville, Napa Valley, CA in 1994. No vines in the experimental area were symptomatic for grapevine leafroll disease prior to our experimental inoculations. To confirm initial GLRaV-3-free status prior to inoculations, three petioles were collected from each experimental vine in July 2011 before inoculations were performed, for diagnostic testing . The block consisted of 8315 vines planted at 588 vines per hectare. Row spacing was 1.8 m, and vine spacing was 1.5 m, with a vertical shoot positioning trellis system and bilateral pruning. Row direction was northwest-southeast. Drip irrigation was provided using one 3.8 – L·h–1 emitter every 1.5 m. A minimum of five buffer vines were left untreated at each end of the rows. Experimental vines were spaced every third vine, and treatments were fully randomized. The three treatments included inoculations with no leaf cages, plastic grow pots inoculations using mesh leaf cages, and negative controls for which no experimental manipulation was performed. Each treatment included 30 replicate vines, for a total of 90 experimental vines.

The experiment comprised an area including 360 total vines, including the 90 experimental vines plus the spacer vines. The spacer vines were monitored periodically throughout the study for symptoms of grapevine leafroll disease. A survey for any signs of mealybugs was performed in October 2012. On 11 October 2012, 15 months postinoculation, a commercial testing service collected and analyzed material from some vines that were symptomatic for grapevine leafroll disease in the experiment and tested for a broad panel of known grape pathogens: GLRaV-1, GLRaV-2, GLRaV-2 strain Red Globe, GLRaV-3, GLRaV-4, GLRaV-4 strain 5, GLRaV-4 strain 6, GLRaV-4 strain 9, GLRaV-7, Syrah virus 1, Grapevine virus A, GVB, Grapevine virus D, Grapevine fanleaf virus, Xylella fastidiosa, GFkV, Rupestris stem pitting-associated virus, Rupestris stem pitting-associated virus strain Syrah, and Grapevine red blotch-associated virus. For inoculations, ten Ps. maritimus first instar insects were gently moved with a paintbrush from leaves of infected source plants onto the underside of one fully expanded mid-height leaf, located on a vertical cane growing from a middle spur on the south cordon of each grapevine. For the caged treatment, a cloth mesh cage was placed over the inoculated leaf and secured at the petiole using a twist tie. For the uncaged treatment, no covering was used on the inoculated vine. The experimental area was commercially treated with spirotetramat insecticide on 20 July 2011, after a 48 h inoculation access period. After inoculations the experimental area was managed following standard commercial practices.Three months after inoculations, the petiole of the inoculated leaf was collected on 14 October 2011 for diagnostic testing. In the instance where that petiole had fallen off the vine or could not be found, a petiole near the inoculated leaf was collected; inoculated petioles were missing from 9 of 60 inoculated vines.

Immediately following the first appearance of symptoms in 2012 and 2013, petioles were collected from each experimental vine and tested for presence of GLRaV-3. Petioles were collected from each experimental vine in September 2014, and tested for the presence of GLRaV-3, GVB, and GFkV. On each sampling date, three petioles were collected from each vine and pooled for diagnostic testing. If a vine had symptomatic leaves at the time of sample collection, symptomatic leaves were preferentially collected over asymptomatic leaves. During each growing season in 2011 through 2014 , experimental vines were surveyed regularly for visible leaf roll disease symptoms, beginning immediately after inoculations. On each survey date vines were marked as either asymptomatic or symptomatic, with surveys beginning in May and continuing through October. Shortly after symptoms first emerged in 2012, a detailed symptom survey of each symptomatic vine was performed to determine possible variation in disease symptom severity among vines and if there was an association between location of inoculation and initial appearance of symptoms within vines. For this survey, the position of each spur and the number of symptomatic and asymptomatic leaves on each spur were recorded. In Year Two, berry quality of all vines was measured three times during the weeks immediately preceding commercial harvest. Degrees Brix , pH, and titratable acidity were measured on 31 August, 21 September, and 3 October 2012, and harvest was 4 October 2012. In Year Three, berry quality of a randomly selected subset of 30 vines was measured on 28 August and 14 September, and harvest was 14 September 2013. The 30 vines were evenly divided between uninfected negative controls, uninfected and infected vines from the caged inoculation treatment, and uninfected and infected vines from the uncaged inoculated treatment. For berry quality analysis, on each sampling date approximately 200 berries were collected from each vine to minimize variance in measurements .

Within each grapevine, berries were collected from the top, middle, and bottom of each harvestable cluster of grapes and pooled for laboratory analysis. All samples were processed by Constellation Laboratories in California, USA. Total soluble solids as °Brix were measured using an Atago refractometer, and pH was measured using an Orion pH meter. Titratable acidity of the juice was measured via direct titration with 0.1 N NaOH, using phenolphthalein as an indicator.To test whether the newly infected field vines could be a source of GLRaV-3 one season after mealybug inoculations, a transmission experiment was performed in the laboratory from cuttings of these newly infected fieldvines. Ps. maritimus were not used because of the above mentioned difficulty in obtaining virus-free first in stars for transmission experiments. Instead we used first instars of Planococcus ficus, which are easily maintained in colonies and therefore can be ready for use in transmission studies at any time. Furthermore, Pl. ficus is a known vector of GLRaV-3 . Field cuttings were collected on 4 October 2012 and the stem bases were placed in flasks of water. First instar Pl. ficus were allowed a 24 h acquisition access period on the field cuttings, then transferred to the underside of a leaf of virus- free V. vinifera cv. Pinot noir recipient test vines; ten insects per recipient test vine were confined using a leaf cage for a 24 h inoculation access period. Following inoculations, plants were treated with a contact insecticide and then kept in a greenhouse for four months until petiole sample collection for diagnostic detection of GLRaV-3. For this experiment, a randomly selected subset of experimental field vines of each treatment was tested as a potential GLRaV-3 source. In total, nine symptomatic vines were tested; five from the caged inoculation treatment and four from the open inoculation treatment, and seven recipient test vines were inoculated in the laboratory from each symptomatic field vine. One of these 63 recipient test vines died before petiole sample collection to test for infection with GLRaV-3. Eleven total asymptomatic field vines were tested as a negative control: three from the caged inoculation treatment, three from the open inoculation treatment, big plastic pots and five uninoculated negative control vines. There were no symptomatic negative control vines in the field experiment. For each asymptomatic field vine, three replicate recipient test plants were inoculated, for a total of 33 recipient test vines from asymptomatic field vines. Additionally twenty uninoculated test vines were included with the recipient test vines in the experiment as negative controls, for a total of 116 experimental and control test plants.For each field and laboratory experiment, proportions of resulting successful inoculations from replicate source plants were compared using a Pearson chi-square test; proportions of successful inoculations did not differ, and therefore infected source plants were pooled for further analyses. A chi-square test revealed that caged and uncaged treatments did not differ in the field or laboratory studies, and data from caged and uncaged treatments were therefore pooled for all analyses. For each transmission experiment, proportions of recipient test plants that became infected with GLRaV-3 in each treatment were compared using chi-square tests. We calculated the estimated probability of transmission bya single insect following Swallow . The Swallow estimator can be used to estimate the probability that one insect will transmit a pathogen based on the number of insects used per recipient test plant, the number of recipient plants tested, and the proportion of recipient test plants that become infected. For the detailed symptom survey in Year Two on symptomatic vines only, we tested for a difference in the proportion of leaves that were symptomatic among spurs, using a generalized linear model with a Gaussian distribution; proportion data were arcsine-transformed prior to analysis to better meet the assumptions of the model. All above analyses were conducted using R Version 3.2.0. To assess the effects of GLRaV-3 infection on berry quality, °Brix, pH, and titratable acidity of symptomatic and asymptomatic vines were compared using a repeated measures ANOVA, using SPSS Version 23.

We found no effect of GVB infection on any of the variables measured in our field experiment; therefore the four vines that became infected with both GVB and GLRaV-3 were included with GLRaV-3-infected vines in our analyses.Our vineyard inoculations provide the first mealybugborne GLRaV-3 transmission study under realistic commercial vineyard conditions, providing corroboration that other laboratory transmission studies of GLRaV-3 are predictive of mealybug-borne transmission in commercial vineyards. In the field study, three months after vector inoculation, GLRaV-3 infections were detected in the petiole of the inoculated leaf of approximately two thirds of all vines that ultimately became infected, indicating that early localized infections in commercial vineyards can be detected using diagnostics well before the appearance of disease symptoms. Grapevine leafroll disease symptoms first appeared early in the year of the growing season following mealybug-mediated inoculations, and were present in all infected vines within a two week time frame. Appearance of disease symptoms was more consistent and narrow in timing than was diagnostic detection, which increased for two years following inoculations. Symptoms first appeared without localization to the point of inoculation, indicating that systemic infection had established before the first expression of symptoms. Furthermore, newly infected field vines were effective sources for mealybug-borne transmission one year after inoculation, providing additional evidence of rapid establishment of systemic infection. Berry quality was also affected one year after inoculations, indicating that infection had an effect on vine physiology as early as one growing season following inoculations. Only vines that were infected with GLRaV-3 also tested positive for GVB, indicating that GVB may have some dependence on GLRaV-3 during transmission or establishment in a new host. There were much fewer infections with GVB than with GLRaV-3. There was no evidence that GVB affected disease symptoms or progression compared with vines that were infected only with GLRaV-3. Results of laboratory-based transmission studies can differ from realistic field conditions , and there is considerable variation in estimates of transmission efficiency of GLRaV-3 among laboratory studies . The laboratory and field studies were consistent with each other in that there was no effect of caging the insect vectors on the recipient test vines on virus transmission. There was higher transmission efficiency based on our laboratory experiment compared with our field study. This may have been due in part to the controlled conditions indoors compared with outdoors, and the improved ability of first instar mealybugs to settle and feed on recipient test vines in the laboratory.

However, the present study of three human excised larynges with a larger range of applied adduction forces showed a large impact. In fact, for larynges L1 and L2, the results yielded a decrease in flow rate at equal subglottal pressure for increasing adduction level . This relationship is consistent with results presented by Alipour and colleagues, who performed experiments with excised animal larynges in a full larynx setup. The effect is caused by an increase in the glottal flow resistance computed as RB , and also RA . From an aerodynamic point of view, a high degree of adduction causes a high flow resistance and therefore a high energy transfer from the glottal flow to the vocal fold tissues. This yields a large transglottal pressure drop. As a consequence, high subglottal pressures can be generated at relatively low flow rates for L1 and L2 . Considering the limited lung volume for glottal flow generation, a high adduction level is desirable for effective and economic phonation. In contrast, the results for larynx L3 show the opposite behavior. On increasing the adduction level, the flow resistance RB tends to decrease, as shown in Fig. 4. Thus, at equal subglottal pressure, the glottal flow rate rises for larger adduction levels, as displayed in Fig. 3, which reduces the efficiency of the phonation process. Considering the glottal flow resistance RA based on Alipour et al., it also shows a slightly increasing tendency for rising adduction levels. However, as RA is defined as a derivative of the subglottal flow with respect to the flow rate, flow resistance generated by non-vibrating vocal folds in the low subglottal pressure range is not taken into account by RA. Therefore, garden pots square the authors suggest that RB might better describe the relationship between subglottal pressure and flow rate.

Although the adduction has a large impact on the flowpressure relationship, its influence on the fundamental frequency and the generated SPL is negligible and non-systematic. Similar findings for SPL were presented by Alipour et al. However, on performing a spectral analysis of the generated sound, they found an enhancement of the sound intensity of higher harmonics, especially the second harmonic. This spectral analysis was not possible with our acoustic data due to the high ambient noise level. Local parameters: Displacement and velocity values are in similar ranges to earlier ex-vivo and in-vivo canine hemilarynx studies, in-vivo human investigations, and synthetic models. The displacement ratios for L1 and L2 are up to 2.1, as seen in other studies. In contrast, for L3 , lateral components are much more pronounced. Similar to Boessenecker et al., an increase in subglottal pressure resulted in increased vocal fold velocities. In contrast to assumptions by Boessenecker et al., vocal fold adduction forces appear to influence the absolute values of vocal fold displacements and velocities, especially at high PS. For L1 and L2 the dynamical amplitudes increase, whereas for L3 the dynamic amplitudes decrease. This behavior of L3 might be related to increased tissue stiffness induced by the applied adduction forces, or just greater than normal overall stiffness of the vocal tissue in principle. For assessing mucosal wave propagation, phase delays in the range of 129 to 257 were found between the vocal fold edge and the most inferior suture l1 . Hence, the phase delays correspond to values of 16 /mm to 32 /mm. Similarly high lateral phase delays were found at 182 before. Even higher phase delays were reported for canines, see Table I in Titze et al. They computed phase delays between 24 /mm and 61 /mm where the phase delay was determined over a distance of 2 mm around the vocal fold edge in ex-vivo caninemodels. Also, for an in-vivo canine model, phase delay values between 25 /mm and 59 /mm were computed when converting their values to ours.

Additionally, phase delay values reported in our study coincide with values found for synthetic and computational multi-layer models of human vocal folds. In summary, our computed phase delay values are in the lower region of canines and match previous results for excised humans, synthetic, and computational models. However, the actual and exact positions and distances where these values were obtained were not given. EEFs: Several previous studies have shown that the primary power of the method of EEFs is derived from its data reduction capability . That is, by reducing complex vibratory motion to essential dynamics, fundamental laryngeal vibration patterns are often revealed. For example, previously the method of empirical functions demonstrated physical mechanisms for transferring energy from the glottal airflow to the vocal fold tissues, and for distinguishing aerodynamically and acoustically induced vocal fold vibrations. As displayed in Fig. 8, the trajectories of larynges L1 and L2 exhibit superposed vertical and lateral motion during vibration. Decomposing the oscillatory motion, the two largest EEFs of L1 and L2 describe a balanced vertical-lateral oscillation whose amplitudes increase with increasing adduction. This is accompanied by increased PS for equal airflow rates. Qualitatively, the characteristics of the increasing vertical-lateral motion are described by stronger prominence of the Fig. 8-shape of EEF1, defined by the Min and Max amplitude contours as also reported previously. For larynx L1, the vertical-lateral balanced vibration is a result of the superposition of EEF1 and EEF2 for all three adduction levels. An increasing adduction level for constant airflow results in increasing amplitudes in both the lateral and vertical directions, which is most pronounced in the higher range of subglottal pressure, as depicted in Fig. 6. Furthermore, the amplitude increase for L1 becomes apparent in both EEF1 and EEF2, Fig. 9. In contrast, for larynx L2, the balanced vertical-lateral motion is mainly included in EEF1 whereas EEF2 describes mainly the lateral vibratory motion. In this case, the stronger characteristic of a balanced vertical-lateral motion is generated by an energy transfer from EEF2 to EEF1 during the adduction increase. The reason for the differences in the EEFs of L1 and L2 might be the less periodic oscillation of L1, which results in a homogeneous energy distribution in EEF1 and EEF2. However, this aperiodicity in the case of L1 did not influence the efficiency of the fluid-structure interaction between the glottal flow and the vocal fold tissues because the flow-pressure relationships for L1 and L2 are systematically equivalent. In comparison with L1 and L2, EEF1 and EEF2 of larynx L3 exhibit primarily lateral vibrational components. This is most obvious when comparing the diagrams of vertical and lateral amplitudes in Fig. 6. For both of the EEFs, the amplitudes decrease at constant airflow with increasing adduction and decreasing PS, reflecting the decreasing energy transfer from the glottal flow to the vocal fold tissues. Hence the authors suggest that an effective energy transfer might be favored by a balanced vertical-lateral oscillation pattern which produces the distinctive convergent-divergent shape change in the glottal duct. Furthermore, this seems to be valid also in cases of slightly aperiodic but still balanced vertical-lateral oscillations of the vocal fold. In cases with an overemphasis of just a single direction of motion , square pots the energy transfer might be disturbed, resulting in a low effi- ciency of the fluid-structure interaction between the airflow and vocal fold tissue. As a result, the effort to sustain phonation may increase significantly.The application of topology in condensed matter physics has become widely embraced and has renewed our understanding of electronic band structures of materials. This framework enables the understanding of symmetry-protected features in reciprocal space found in topological insulators and semimetals. Combining nontrivial topology with time-reversal symmetry breaking can lead to large Berry curvatures that enable sizable macroscopic responses such as the anomalous Hall effect and the related anomalous Nernst effect with great potential applications ranging from thermoelectrics to spin-based storage. In fact, the key step to understanding the intrinsic origins of the AHE was in identifying the relationship between the AHE and the Berry curvature of the occupied electronic bands in a crystal. Antiperovskite transition-metal nitrides, especially Mn4N, have a diverse range of magnetic properties and emergent phases which make them interesting for both understanding fundamental physics and for spin-based applications.

Mn4N has a high N´eel temperature , small saturation magnetization, and high uniaxial magnetic anisotropy, making it particularly appealing for thermoelectric applications based on the ANE . Mn4N is also predicted to host a wealth of realspace magnetic topological features including spin textures, hedgehog-anti-hedgehog pairs and skyrmion tubes. These non-trivial spin structures were found to be mainly stabilized by the frustration induced by the magnetic exchange interaction between fourth-nearest neighbors. More recently, measurements of the AHE and ANE were reported for Mn4N, however, they do not agree on the origin of the AHE in Mn4N, and importantly, do not address how it can be enhanced through experimentally viable routes such as strain. In particular, the microscopic origins of the AHE can either be extrinsic or intrinsic . Recent experimental work studied transport signatures of the AHE in epitaxial Mn4N films of different thickness, and concluded that the AHE has competing contributions from skew scattering, side jump, and intrinsic mechanisms. According to the conventional scaling law ρAHE ∝ ρ γ xx, where ρAHE is anomalous Hall resistivity and ρ γ xx is longitudinal resistivity, γ was found to be larger than 2 for all Mn4N films, indicating that the side jump and intrinsic mechanisms are dominant in these films. On the other hand, Isogami et al. report a dominant intrinsic contribution to AHE and ANE based on transport and ab initio calculations. Surprisingly, we are not aware of a comprehensive study of the electronic origins of the AHE and ANE from the perspective of first-principles based calculations, or nor a discussion of how these properties can be enhanced. Moreover, the range of competing, frustrated magnetic states in ferrimagnetic Mn4N motivates us to explore the range of tunability of the topological responses in this system. The antiperovskite structure of Mn4N can be viewed as Mn3MnN with Mn ions on three inequivalent cation sublattices and N taking the anion site . These three different Mn sublattices have unequal magnetic moments leading to its ferrimagnetic nature and small saturation magnetization. Neutron diffraction experiments identified two different magnetic configurations in Mn4N. In the “Type-A” structure, the spins of Mn II and Mn III are aligned parallel to each other but antiparallel to those of Mn I, whereas in the “Type-B” structure, the spins of Mn I and Mn II are aligned parallel to each other while being antiparallel to the spins of Mn III. Previous theoretical works found the Type-B to be the ground state, though both have been observed in experiment . All first-principles calculations were carried out within the framework of Density Functional Theory as implemented in Vienna Ab-Initio Software Package using the projector augmented-wave potentials.Osmotic Demyelination Syndrome , also known as Central Pontine Myelinolysis, is a serious—and often irreversible—complication of rapid correction of serum sodium. Patients with cirrhosis experience labile serum sodium levels related to portal hypertension and diuretic use, often with rapid correction—intentional or unintentional—during hospitalizations. Studies on ODS in cirrhosis have focused on patients undergoing liver transplantation. These findings may not generalize to the cirrhosis population as a whole, yet the risk of ODS for inpatients with cirrhosis outside of the context of liver transplantation is not well-characterized. Such information is critical to inform management of severe hyponatremia in patients with cirrhosis, a common clinical scenario. Therefore, we aimed to characterize the prevalence and risk factors of ODS in this population.We performed a cross-sectional study to determine overall prevalence of ODS in hospitalized patients with cirrhosis not receiving liver transplants, to compare those with and without ODS, and to determine whether cirrhosis and general illness severity correlated with prevalence of ODS. We used data from the Healthcare Cost and Utilization Project National Inpatient Sample , a nationally representative dataset of a stratified sample of US community hospitals, from years 2009-2013. This study was exempt from the need for informed consent. It was approved by the University of California, San Francisco institutional review board. To develop our study sample, we selected all patients 18 years or older with any discharge diagnosis of cirrhosis using International Classification of Diseases, Ninth Revision codes for cirrhosis, which have been previously validated for identifying inpatients with cirrhosis with a positive predictive power of 90% and a negative predictive value of 87%, as well as validated for identifying individual signs and severity of cirrhotic decompensation. 

Results from the pseudo mixed model indicated the interaction effect was more important than the treatment effect. Thus, “alcohol hotness” will not be included in any further discussion of significant attributes for BA wines. The significant difference in malic acid content in the wines among treatments appears to have had little impact on sensory evaluation given that there was no significant difference in the perception of sourness in the wines. From the PCA generated from BA descriptive analysis results , the control and sort wines appear to be correlated more closely with “alcohol” . Wines made from these treatments were higher in ethanol content, which may explain this trend. However, the small number of significant attributes indicate that BA wines made by different treatments were very similar in sensory properties.Analysis of wine color revealed that there were perceivable differences among treatments for all three varieties . For BA the reject treatments were rated lighter in color compared to the control and sort treatments, whereas a similar trend was observed in the CS treatments. This was expected because berries with less color were removed by the optical sorter and included in the reject fermentations. This agrees with results from Table 6; the rejected treatments were significantly lower in anthocyanin content for BA and CS, which can explain the difference in color perception. For GN wines, the control treatment was perceived to be slightly darker than the sort and reject treatments. Although fermentations were prepared to have similar solid-to-juice ratios in the must among treatments, grow bag for tomato it is possible that variations between replicates may have resulted in the control treatments being slightly more concentrated, which could provide an explanation for this result.

It can be concluded that optical sorting was generally successful in removing berries with less color; however, this did not lead to a large difference in the final color of the wines between the sort and control treatments.Multiple Factor Analysis was performed for each variety using all sensory attributes and only volatile compounds that differed significantly among treatments . This was done to observe the association, if any, of the significant volatile compounds and sensory attributes. For GN wines, the only significant attribute was “SO2”. From Figure 7, isobutanol, which can impart a solvent like aroma in wine, is grouped closely with “SO2”. It is possible that wines with a higher isobutanol concentration were perceived to be higher in “SO2” aroma. For BA wines, there does not appear to be a trend among sensory attributes and volatile compounds . For CS wines, “apple” is grouped closely with ethyl esters , which provides evidence that this may have caused the increased perception of this attribute in the control and sort treatments .Overall, optical sorting had minimal impact on the sensory properties of the three varieties tested. It is possible that the chemical differences noted earlier were too small to result in consistent differences by descriptive analysis. Even though the wines made from reject material contained significantly higher concentrations of higher alcohols, it did not result in a difference in sensory perception. Higher alcohols have a relatively high sensory threshold . It is possible that the concentration of these compounds in the reject wines was below the sensory threshold.The purpose of this study was to determine what effects, if any, optical berry sorting had on wine made from different red grape varieties, and to investigate the potential to use optical sorters to sort for different ripeness levels using color as a main criterion.

Given the observed differences in Brix and final ethanol content, optical sorting seemed to be successful in removing underripe berries for CS and possibly for BA; however, this did not result in a significant difference in the final ethanol content between the sort and control treatments. The removal of underripe berries was also evident by the difference in color among treatments. For BA, the rejected treatments were significantly lighter in color; however, the color of the sort and control treatments was very similar, whereas a similar trend was observed in the CS treatments. Wines made from GN generally did not follow these trends; possibly because sorting parameters were too aggressive for this cultivar, resulting in a high percent rejection of optimal berries. This may have minimized potential differences between reject wine with the other treatments. Another possibility is that color differences in the GN fruit did not correspond to differences in sugar content. From these results, it may be concluded that, when using color as a criterion, optical sorting based on ripeness level was successful but may be dependent on variety and fruit variability. Additionally, the impact on the resulting wine is likely dependent on the initial variability in grape ripeness. The optical sorter was successful in removing MOG. This result was reflected in the phenolic analyses; reject treatments were generally higher in total phenolics and tannin, most likely due to the greater proportion of MOG included in the must. The decrease in anthocyanins is likely due to the higher percentage of green, underripe berries in the reject treatment musts. A study that made wine with the addition of MOG found that this addition significantly increased the phenolic and tannin content in the resulting wines. Despite the differences observed in the phenolic composition of the reject wines, the control and sort treatments were very similar for all three varieties. This is in contrast with some previous studies that have found wine made from optical sorted fruit had significantly different levels of phenolics.

One study found that optical sorting led to wines with higher levels of total phenolics. It should be mentioned that the researchers here did whole cluster pressing for their control wines , whereas the sorted wines were destemmed. It is possible that higher levels of phenolics were extracted due to the damage caused by the destemming process on the seeds and skins. Another study found that wine made from optically sorted grapes that were machine harvested generally had lower levels of phenolics; levels that were similar to the same wines made from a handpick treatment. Given that the rejects were, in general, significantly higher in total phenolics and tannin than the control and sort treatments, it can be suggested that optical sorting has the potential to decrease the phenolic content in wine; however, there was not enough MOG to show a large impact in the current study. Optical sorting likely has a greater impact on mechanically harvest fruit due to generally higher levels of MOG observed from this harvest method. Some differences were found among treatments in the aroma profiles of the wines. Few compounds differed significantly between sort and control treatment and, in general, the reject treatments had greater concentrations of higher alcohols and control and sort treatments had greater concentrations of ethyl esters. The higher ethanol content of the sort and control treatments as well as their lower pH can lead to a higher production of esters. In general, reject treatments contained significantly more suspended solids then the control and sort treatments for all varieties studied. Research has shown that high levels of suspended solids during fermentation can lead to greater production of higher alcohols. Descriptive analysis indicated only one significantly different attribute among GN treatments and only two significantly different attributes among BA treatments. BA control and sort wines were associated with the “alcohol” descriptor which correlated with the higher ethanol levels in these treatments compared to the reject treatment. Similarly, there were only three significant attributes among the CS treatments. “Alcohol hotness” related to ethanol content as previously described. The control and sort treatments were also rated significantly higher in “apple” and “sweet” aromas compared to the reject treatment. Some studies have shown that higher levels of ethanol can increase the perception of sweetness in a wine. However, as King et al. noted, grow bag for blueberry plants there is disagreement in this regard, as other studies have shown that ethanol content can either decrease or have no effect on the perception of sweetness. Thus, this may not be a sufficient explanation as to why the control and sort wines were rated significantly higher in sweetness. Perhaps the higher concentration of total phenolics and tannin in reject wines could explain the difference given that phenolics in wine contribute to bitterness and astringency. From the PCA in Figure 6, it can be noted that “bitter” and “drying” are more associated with reject wines. Although these attributes are not significantly different among the treatments there appears to be a trend which could impact the perception of sweetness.

One study found that increasing bitterness in coffee decreased the perception of sweetness. It is possible that reject wines were rated lower in “sweet” due to the higher concentration of phenolic compounds thus decreasing the perception of sweetness. The higher perception of sweetness in the control and sort wines may also be attributed to the higher intensity of the “apple” aroma, which the judges could have associated with a sweet taste. One study found that retronasal aromaperception of fruity compounds increased with an increasing level of sweetness in a model wine solution. The authors also noted several other studies which found that aroma compounds can enhance the perception of sweetness in different foods and beverages. Another study found that samples described as “fruity” were also often associated with a “sweet” aroma. This provides further evidence that the judges in the current study may have associated these attributes together. The overall sensory differences were minimal, and the wines were determined to be similar. The results from this study largely agree with results from previous studies investigating the effects of optical sorters. It is possible that there was not enough variation in the starting material of the current study for optical sorting to have a large impact. Optical sorters may be used to greater effect during vintages with inconsistent ripening, issues with raisining, or large amounts of berry damage, possibly caused by either birds and/or fungal infections. Future research should investigate the impact of optical sorters in these scenarios.Grapevine has indeterminate growth habits compared to other perennial fruit crops. Latent growth of the dormant grapevine bud may be induced by favorable conditions with little to no dormancy period required . Therefore, semi-tropical regions may raise two crops a year, and in fact, it is not uncommon for the latent bud to produce some fruit when correlative inhibition is removed in temperate regions. Furthermore, the grape berry does not have the same fruit abscission mechanism as apple or peach revealed under carbon starvation. It is therefore possible for grapevine canopy size and crop level manipulations leading to a wider range of source or sink limiting conditions within a growing season. The crop level of a perennial crop is initially determined by organogenesis at the basal buds. The number and size of the flower primordia is associated with number of clusters and berries per cluster through the formation flowers and fruit set . However, fruit set is largely variable among years, weather, location, and cultivars . Poor fruit set may be a limitation to crop yield, although weather is often considered to be the leading cause. However, the mechanism of poor fruit set is not fully understood. Carbon supply or mineral nutrition are related to the amount of fruit set , which is an acclimation mechanism to unfavorable conditions. Ultimately, yield of grapevine is affected by berry size, and within the berry, pulp enlargement is the largest contributor to yield gain rather than skin or seed biomass . Conversely, vegetative growth is far less influenced by latent bud formation, as competition amongst growing buds tends to buffer the impact of growing shoot tips on its length and total leaf area . This is likely due to the great limiting effect of nitrogen among other nutrients or hydraulic pressure . The ratio between leaf area and fruit mass is closely related to the amount of carbohydrates accumulated in the must . Thus, an excessive crop level or less than ideal canopy size may result in over cropping and may lead to delayed ripening . Conversely, in under cropping, where there is excessive vigor or reduced crop level, this is not necessarily deleterious for speed of ripening . However, it may be a wasteful management of resources if there is not a trade-off with farm-gate prices.

While ant activity only significantly increased after string placement on connected coffee plants, we also observed lesser increases in ant activity on control coffee plants and nest trees . This unexpected result could mean that strings, a novel element in the environment, acted as a form of habitat modification or disturbance, which increased overall ant activity in the local area. However, if our manipulation was the cause, we would have expected the ants to attack the jute strings , a behavior that we did not observe during the experiment. Experiments in tropical forests have shown that the long-term removal of lianas can influence ant richness on trees , and therefore may possibly also affect overall ant abundance and activity when promoted. It is also possible that other factors could potentially explain this result in control plants, such as changes in local abiotic factors that we did not measure systematically in our experiment. Future research which expands on the temporal scope of this study may be useful in assessing the long-term effects of artificial connectivity in this system. Ant activity after string placement was negatively affected by distance to the nesting tree . This result is consistent with previous studies suggesting that within 5 m A. sericeasur dominance in the leaf litter decreases with distance to the nesting tree . However, in our study, grow bag the effect of distance after string placement was significant only on control plants, but not on connected plants. This suggests that connections could buffer the negative effects that larger distances from the nesting tree pose to ant activity and potentially increase antprovided biological control services in these plants. Connected coffee plants also had significantly higher CBB removal than control plants .

Overall, greater ant activity on coffee plants was associated with higher CBB removal rates , suggesting that ant activity directly influenced CBB removal rates. However, while this effect was significant on control coffee plants, it was only marginally significant on connected plants. While we believe that these results support the hypothesis that connectivity enhances ant foraging and bio-control services on coffee, the use of dead CBB in this experiment as a proxy to measure bio-control may explain the only marginally significant effect of ant activity on CBB removal in connected plants. It is possible that dead prey exhibit more variable recruitment responses from ants than live prey. Despite this, it is likely that strings facilitated ant movement to coffee plants by providing a smooth, linear substrate and indirectly increased CBB removal . In other systems, the leaf-cutting ant Atta cephalotes uses fallen branches to rapidly move between areas and thereby quickly discover new food resources . Similarly, these resources allow scouts to return quickly to the colony, minimizing the time taken for information transfer and recruitment of other foraging workers . The role of trunk trails and fallen branches has received extensive attention in the leaf-cutting ant system; however, fewer studies have looked at the influence of connectivity resources on foraging behavior of predatory arboreal ants. Surprisingly, CBB removal did not follow the same trend as ant activity with distance to the nesting tree. While control plants tended to have lower CBB removal rates than connected plants as distance to the tree increased, we did not find a significant effect of distance on CBB removal in either control or connected plant groups. Collectively, these results suggest that connections in the arboreal stratum have the potential to increase ant activity and therefore enhance plant protection from CBB attack, particularly in connected plants.

Further studies should assess the effect of distance on CBB removal using plants located at distances larger than 3.5 m from the tree. It is important to note that enhanced ant activity on coffee plants could lead to increases in the density of ant-tended hemipterans, such as the green coffee scale, which if severe enough could reduce the productivity of coffee plants. However, the green coffee scale is not a major pest in the region of study, in contrast to the economically significant coffee berry borer . Furthermore, a recent study evaluating the benefits associated with the indirect Azteca–Coffea mutualism found that the protective benefit ants provide to coffee plants is positively associated with high densities of the scale . This suggests that the enhanced CBB control by ants outweighs the costs associated with scale damage. However, these interactions may be context-dependent and still need to be fully evaluated in the field to provide a holistic understanding of the impact of connectivity on scale density and coffee yield. Other ant species could also benefit from the addition of connections between coffee plants and shade trees, such as C. basalis and P. simplex, which were observed using these connections during our study. The ant P. simplex has been previously reported as an important CBB bio-control agent, acting in conjunction with other species of ants to effectively suppress CBB at various life stages . Therefore, this technique could support Azteca ants as well as other ant species that play an important role in suppressing CBB populations. Our results support the general hypothesis that connectivity, one measure of habitat complexity, can sustain important ecological processes in natural and managed ecosystems. In aquatic systems, more complex habitats with macrophytes allow for greater food capture and maintain higher levels of diversity . In terrestrial systems, higher complexity can influence trophic dynamics . In coffee agroecosystems, ants are highly sensitive to habitat change and management intensification, generally expressed as the reduction of shade, elimination of epiphytes, and use of chemical inputs . Such intensification can have a negative effect not only on vegetation connectivity and ant foraging, but may also cascade to affect ecosystem services, such as biological control.

Our study supports the idea that promoting complexity at a local scale, in this case providing structural resources for ants in agroecosystems, can significantly enhance connectivity within the arboreal strata, and potentially improve biological control of coffee pests. This idea has already been successfully implemented in other agricultural systems, placing “ant bridges” made of bamboo strips or strings connecting neighboring trees in , and could be incorporated as a management strategy in coffee systems. Future research should evaluate the practical feasibility of adding connections between vegetation strata to enhance bio-control. For example, studies in timber plantations have estimated that the presence of ants increases timber production by 40%, and that ants can be maintained at lower costs by providing intra-colony host tree connections using rope, poles or lianas . It is important that future studies in coffee also consider the costs of other CBB control methods, such as the application of the pesticide endosulfan, which can lead to the development of resistance, can negatively impact natural enemies, and can have harmful impacts on human health . Further investigation into promoting ant bio-control with artificial connections in coffee should: assess economic trade-offs, management applicability, and farmers’ perceptions of this method in large and small coffee plantations, compare the cost between string placement and other management approaches , grow bag gardening and assess coffee yields on connected and not connected plants to provide management recommendations. More broadly, incorporating conservation bio-control strategies in combination with vegetation connectivity is consistent with criteria identified as key for the sustainability of biological control, such as increasing local habitat quality and enhancing species’ dispersal ability . Generally, the maintenance of shade trees and natural vegetation in agroforestry systems may increase vegetation complexity and natural connectivity between plants to promote ant foraging and subsequent biological pest control.The HPA axis maintains a diurnal rhythm marked by a daily peak after waking, a subsequent decline over the course of the day, and a nadir shortly after onset of continuous sleep . The diurnal pattern of HPA activity plays important roles in a variety of metabolic, immunological, and psychological processes that support our day-to-day functioning . In studies of children, the preferred assessment method of HPA axis activity is the collection of saliva and the measurement of cortisol . Cortisol is the “end-product” hormone released into the bloodstream from the adrenal glands—the final step in a biological cascade initiated by the hypothalamus and perpetuated by the pituitary gland. In addition to supporting the orchestration of several other processes , moderate cortisol levels are thought to support effective neural transmission and optimal learning and high-order cognition . In times of acute physiological or psychological stress, the HPA axis mounts a particularly pronounced response, culminating in high levels of cortisol that reach glucocorticoid receptors throughout the body and brain. Working with the ANS, these acute HPA stress responses coordinate the physiological and psychological resources needed to overcome the stressor . Yet, given negative feedback processes, high cortisol levels also play important regulatory roles in down-regulating HPA axis activation, allowing it and other systems to return to baseline . Collectively, these complex within- and cross-system dynamics support an organism’s ability to both respond to and recover from the effects of environmental stressors . HPA axis reactivity and regulation are evident very early in life. Newborn infants can mount an HPA axis response to environmental stimuli , and normative circadian rhythms tend to stabilize as infants begin to forego their afternoon naps .

However, the span from infancy through early childhood is also a time of meaningful developmental change. Indeed, a growing theoretical and empirical literature indicates that children’s early experiences play a critical role in the organization of their emerging adrenocortical systems .Low-income ecologies present a confluence of distal and proximal risk factors thought to influence children’s developing physiological stress systems and undermine optimal cognitive and social development . For example, children growing up in low-income contexts are more likely to face distal stressors, such as inhospitable and dangerous neighborhoods and inadequate access to services and social capital . Such distal risks are known to have trickle-down effects that undermine parents’ abilities to effectively read, interpret, and respond to their children’s needs . In turn, a convergent literature comprising experimental work with animals as well as observational studies of young children indicates that sensitive and responsive caregiving can support adaptive HPA axis functioning . This is evident with respect to children’s acute stress responses. For example, young children with secure attachment relationships and more sensitive caregivers tend to show better regulated HPA axis responses when faced with acute psychological stressors . Changes in the quality of children’s caregiving environments have also been linked with their baseline, or resting levels of HPA axis activity. For example, at the more extreme end, children who are moved from very high-risk households into foster care have been found to evince comparatively lower resting cortisol levels than their peers who remain in high-risk homes . For instance, in prior work with the same sample as used in the present study, our group showed that higher levels of maternal sensitivity in infancy are predictive lower levels of resting cortisol, after adjusting for income and a number of potential confounds . Beyond psychosocial risks, children growing in the context of economic adversity are more apt be exposed to households that are more densely populated, noisy, disorganized, and unpredictable—aspects typically discussed under the umbrella term chaos . A growing literature suggests that chaotic environments may alter children’s ANS and HPA axis functioning in early and middle childhood. Recent work by researchers in our laboratory suggests similar effects with respect to infants and toddlers , with within-child increases in chaos predictive of contemporaneous increases in resting salivary cortisol in later infancy and toddlerhood.Notably, young children growing up in low-income contexts spend substantial amounts of time in settings outside of their homes—such as non-parental child care. Indeed, in the United States approximately 43% of children in poverty attend regular non-parental care by 9 months of age . A well-developed literature indicates that young children’s early child care experiences also play a meaningful role in their HPA axis functioning. Meta-analytic findings indicate that—compared to their normal diurnal patterns experienced at home—children tend to show cortisol increases across the day on days when they attend child care . Some work suggests these patterns are particularly strong in toddlerhood and the beginning of the early childhood years and for children who attend lower quality child care . There is also some, albeit limited, evidence of long-term effects; for example, Roisman and colleagues found that spending greater proportions of time in center-based care in infancy and early childhood was predictive of children’s subsequent cortisol awakening response in adolescence.

Consistent with studies affirming the influence of vegetation connectivity on predatory arthropod movement and predation range, our results illustrate how vegetation connectivity facilitates A. sericeasur foraging mobility and pest removal. In coffee systems, higher degrees of vegetation connectivity are associated with shade trees, as well as more heterogeneous habitat complexity and variability in plant structure. In other studies, ants generally increase predation services in shaded systems as compared to monocultures and, in coffee plants, more effectively remove CBB in shaded coffee systems as compared to sun monoculture systems. Interestingly, most studies find the opposite effect of structural complexity on parasitoid behavior, with higher degrees of plant structural complexity leading to decreased parasitoid foraging efficiency. This negative relationship between parasitism and habitat complexity transfers to coffee systems, where the parasitic phorid flies exert a greater inhibiting effect on Azteca ants in simple, low-shade farms than in complex, high-shade farms. Together with the aforementioned study, our combined results illustrate how habitat complexity at the landscape scale and vegetation connectivity at the plot scale dually facilitate A. sericeasur-mediated pest removal: by facilitating ant mobility and by reducing the efficiency of the parasitoid that interferes with their pest removal ability. In order for A. sericeasur to provide ant-mediated pest removal services, coffee agroforests must include enough shade trees to provide sufficient habitats for ant nests. Planting coffee plants close enough to shade trees to allow for direct connectivity and leaving some vegetation connections between coffee plants and shade trees rather than chopping them or relying on herbicides can facilitate ant-provided ecosystem services by providing foraging paths through naturally occurring structural connectivity.

By enhancing the A. sericeasur effectiveness in controlling CBB populations, vegetation connectivity can potentially reduce chemical pesticide use. Our results offer management insight into one piece of a complex ecological puzzle. Because A. sericeasur tend C. viridis, square black flower bucket they could indirectly reduce coffee plant growth by contributing to high-scale densities and an associated damaging sooty mold. However, high densities of C. viridis also beneficially attract Lecanicillium lecanii, which attacks coffee leaf rust, a devastating coffee fungal disease. Moreover, the CBB is regarded as a far more damaging coffee pest than C. viridis. Furthermore, facilitating the mobility of A. sericeasur as a single ant species is not necessarily the most effective pest management approach, as higher ant diversity can improve pest control through the cooperation of complementary predatory species. Enhanced A. sericeasur activity on coffee plants could alter the behavior of other ant species, which could have positive or negative effects on overall pest control services due to spatial complementarity or potential negative interactions between predators. However, studies find that increasing connectivity generally increases species richness, and so, vegetation connections that increase A. sericeasur mobility likely facilitate the mobility of other predatory ants in coffee systems, even by providing alternative paths to avoid aggressive altercations with A. sericeasur. Although A. sericeasur occupies only 3–5% of the shade trees at our research site, other ants known to contribute to CBB regulation would likely also use vegetation pathways, facilitating additional pest control. Future research should examine how vegetation connectivity impacts the abundance and diversity of other ant species on coffee plants and the associated spatial complementarity between specific predators of the CBB. Future studies could also investigate how phorid attacks on Azteca vary on different foraging pathways to better understand the mechanisms behind their preference for vegetation pathways.

Connectivity affects arboreal ant distribution, behavior, and interactions with other organisms in agroecosystems, profoundly impacting ant community diversity and ant provided ecosystem services. Our results demonstrate how vegetation connectivity increases A. sericeasur activity, recruitment to resources, and CBB removal, and that naturally occurring vegetation connectivity, in the form of branches and natural substrates, accounts for this enhancement. As climate change increases coffee’s susceptibility to CBB damage, agroecological and economically feasible forms of pest control are increasingly necessary for coffee-producing communities. Farm management conducive to forest conservation, habitat and structural complexity, and the associated higher degrees of vegetation connectivity will facilitate ant-provided pest control services in coffee agroecosystems.Wild birds provide many ecosystem services that are economically, ecologically, and culturally important to humans . On a global scale, insectivorous birds consume an estimated 400–500 million tons of insects annually and have the capacity to decrease arthropod populations and increase crop yields of both temperate and tropical farms . While these beneficial effects are not always observed , attention has focused on promoting avian diversity and abundance on farms to leverage these benefits . The fact that birds consume agricultural pests does not ensure that they can control them, in the sense of substantially reducing densities of rapidly-growing pests. Here, we evaluate the capacity of birds to suppress agricultural pests, specifically the coffee berry borer, aninvasive pest found in almost every coffee-producing region worldwide. The coffee berry borer is one of the most economically significant pests of coffee worldwide , causing an estimated annual global loss of US $500 million . These small beetles damage coffee crops when a female bores into a coffee cherry and excavates chambers for larvae to grow, consuming the coffee bean. Control of CBB can be accomplished by spraying fungal bioinsecticide Beauvaria bassinia, increasing harvest frequency or continually removing, by hand, over-ripe and fallen cherries, which serve as reservoirs for infestations .

The last, and most laborious, control method appears to be the most economically effective In addition to human-mediated control, natural predators such as ants, parasitoid wasps, and nematodes are being explored as potential bio-control agents . Birds have also been identified as a significant biological control agent of CBB . Field experiments in Central America have shown that CBB infestation dramatically decreases when birds are present . For example, Karp et al. reported that bird predation suppresses CBB infestation by 50% and saves farmers US $75– 310/ha per year; another estimate values bird predation at US $584/ha . Suppression is done by both resident foliage-gleaning insectivores, such as rufous-capped warblers , and Neotropical migrants like the yellow warbler . Similar to other agriculture systems, avian abundance is higher on farms with heterogenous landscapes in close proximity to native habitat , suggesting low-intensity shade coffee farms are better not only for supporting biodiversity, but also in providing pestmediating ecosystem services . Several lines of evidence support the notion that birds depredate CBB in coffee plantations, and that their effects are biologically significant. Firstly, we know that a variety of bird species consume CBB from assays of avian fecal and regurgitant samples , though the detection rate is quite low . Low detection rates might be due to low consumption rates; detectability of DNA in feces depends on number of CBB eaten, and time since feeding, as well as fecal mass . Secondly, bird and bat exclosure experiments are associated with greater CBB infestation within enclosures . At the same time, it is not clear how birds can effectively suppress CBB at most sites, and throughout the season. Exclosure experiments that report avian suppression appear to be at sites with relatively low CBB infestations , whereas coffee-producing regions with more recent introduction of CBB have infestations of up to 500,000 CBB in a season . We also do not know whether suppression is effective throughout the reproductive cycle of the CBB, or just when abundances are relatively low. Finally, CBB field traps often capture large numbers of CBB, even in the presence of birds . Consequently, while there is clear evidence that birds consume CBB, the degree to which CBB populations can be suppressed is less clear, particularly because of the species’ population growth potential . Here, square black flower bucket wholesale we use a CBB population growth model to assess the capacity of birds at naturally occurring densities to reduce CBB populations, as a function of a starting infestation size. We created an age-based population growth model for CBB using data from a life-stage transition matrix published by Mariño et al. . We converted their matrix into a female-only, daily time-step, deterministic Leslie matrix; we could not estimate population growth directly from the original matrix because it did not use a common time step . We incorporated a skewed adult sex ratio to mimic real populations , and added a life-stage for dispersing females, the stage at which CBB are vulnerable to predation by birds. Since the entire CBB lifecycle occurs within the coffee cherry, CBB are vulnerable to predation by birds for a short time window when adult females disperse between plants and burrow into a new cherry .

Birds do not eat coffee cherries, with the exception of the Jacu , which is found in southeastern South America. Consequently, we assumed that only adult CBB females are vulnerable to bird predation. With our Leslie matrix, we projected population growth for a closed population during a single CBB breeding season. We projected growth at three levels of initial starting populations of CBB , calculated from published estimates of CBB densities from alcohol lure traps in coffee farms from Colombia, Hawaii and Costa Rica. We then determined the degree to which dispersing female survival rate would have to be decreased to result in a 50% depression in the adult population size at the end of the coffee season at all three infestation levels. Finally, we assessed the plausibility of this degree of CBB suppression by birds as a function of avian energy requirements, reported avian densities on coffee farms, prey composition of avian diets, estimated caloric value of CBB, and the starting population size of CBB females.Coffee phenology is directly related to rainfall patterns that differ among coffee producing regions, leading to distinct seasons, and timing of harvest. Our model assumes environmental conditions of Costa Rica, and thus describe the coffee phenology of this region. In regions of Costa Rica with marked seasonality, coffee flowering is triggered during the dry to wet season transition by the onset of acute precipitation . Areas with relatively consistent rain patterns have more continuous flowering events and a longer harvest season In the Central Valley of Costa Rica, flowering typically begins in March, with three flowering events spread over a month . Flowers are short-lived, lasting only a few days before fruit begin to develop. Maturation of coffee cherries is slow, with immature green cherries taking up to 240 days to develop into red, ripe fruit that is ready for harvest in mid-October through January . After harvest, coffee plants are left to recuperate until flowering is initiated again the following year by the next onset of rain.Following the coffee flowering period and initiation of cherry growth, adult female CBB emerge and disperse via flight in search of new cherries to colonize . Timing of emergence appears to be driven primarily by relative humidity and temperature, with dispersal peaks occurring around the end of the coffee harvest, from December through March . Females begin ovipositing in chambers carved out of the coffee endosperm roughly 120–150 days after coffee flowering, when the dry content of the seed is 20% or higher . It is this dispersal period, and subsequent drilling into the coffee cherry, when CBB are vulnerable to predation by birds, as the remainder of the CBB life cycle occurs within the coffee cherry. There are five main CBB developmental stages: egg, larva, pupa, juvenile, and adult. Females can oviposit daily for up to 40 days, averaging 1–2 eggs per day . After a week, eggs hatch and larva take 17 days to develop into pupa. Following pupation , juveniles emerge and reach sexual maturity after about 4 days . The length of the CBB life cycle can be slowed and accelerated depending on average temperature ; the developmental times used here are based on 25 C rearing conditions . Offspring sex ratio is skewed toward females, ranging from 1:5 to 1:494 . Since males are flightless, mating occurs between siblings within the natal cherry. Fertilized females then disperse to colonize other cherries, though multigenerational oviposition within the natal cherry is possible. The prolonged maturation of the coffee crop allows continual reproduction, with 2–8 CBB generations feasible in a single season if environmental conditions and food availability be favorable . With the removal of cherries during harvest, adult CBB will enter diapause in coffee cherries that remain on the plant or fall to the ground .

Flies were constantly provided with water and artificial diet that served as both a food source and an oviposition medium. Before their use in experiments, all flies were allowed to mate for 8 d in mixed-sex cages. Some small fruit varieties were numbered since this information is proprietary.This trial was conducted in Oxnard, California, USA on highbush blueberry plots during 2020. Plants were irrigated with three drip stakes per plot ten times a day for ten-minute intervals delivering 1.1 liters of water per hour. Screenhouses were fully enclosed with screen material to prevent insects from entering. There were three 70 m x 5 m screenhouses with GUM or UTC treatment randomly assigned to the north or south end of each screenhouse for a total of 6 plots. Within each screenhouse, treatment plots contained twelve plants in two rows, and plots were separated by 45 m. one-hundred flies were released in each plot four times, once per week. Three GUM deployment plots were compared with three UTC plots. GUM dispensers were installed in every other plant with irrigation stakes placed directly through the pads. The GUM application was completed on 14 April. Plots were sampled every seven days from 14 April to 12 May. One sample consisted of 50 berries.Ten field trials were conducted from September to November 2020 across multiple coastal production regions in California, USA , at different ranches and on multiple varieties being grown under high tunnels. Each location was a replicate consisting of two plots and were randomly assigned at each ranch to GUM or to UTC. Plots within a ranch received similar irrigation, fertilizer, flower buckets wholesale and insecticides. Each plot received a minimum of four spinosad sprays timed 7-10 days apart during the cropping period and based on monitoring trends from fruit collections.

Additional peroxyacetic acid applications were applied at 2-3 day intervals after each spinosad application, followed by a C. subtsugae application 1-2 d after each peroxyacetic acid application. Throughout the experimental periods, GUM dispensers were distributed evenly throughout each plot and replaced every 21 days. GUM dispensers were staked directly under the drip line in soil plots, and irrigation stakes were placed directly through the dispenser in substrate plantings. Six fruit samples were collected from each treatment plot every week for 4 to 12 weeks. Samples were collected at least 2 m from each edge of the tunnel as well as from the center of the tunnel approximately 20- 30 m from the edge of the tunnel and at ~0.75 m from the ground. Each sample consisted of 50 berries. Sample berries were incubated at room temperature for 2-4 days to allow for larval growth and facilitate detection. Samples were evaluated by crushing fruit and submerging them in a saltwater solution . The crushed fruit solution was then poured into a tray where D. suzukii larvae subsequently floated to the top of the solution and were counted.The buildup of D. suzukii populations was modeled under four scenarios i.e.; no intervention , GUM only, insecticide , and GUM and insecticide . The model parameters were obtained from experimental work and iterations of the model have been used in previous studies . Recorded D. suzukii population levels and weather data were used as model inputs. Outputs from the model were directly compared with D. suzukii infestation data of the blueberry field trial 1 . This trial was selected because of its relatively long duration and is most suitable for describing population build-up. Ambient temperature influences the fecundity rates, mortality rates, and maturation delays of the four principal life stages . The simulations were based on daily mean temperature data recorded at Aurora, Oregon, USA, between June and September 2020. We assumed that the flies had access to unlimited fruit and that no other factors affected population dynamics .

Parameter values, including for fecundity rates, mortality rates, and maturation delays, were obtained from laboratory experiments on blueberry . The simulations were initialized on 30 June with a population composed equally of adult males and females. The model simulations track relative population densities, and the initial adult density was chosen so that the simulated egg density matched the final eggs/berry in the UTC treatment. The GUM dispensers were assumed to reduce D. suzukii fecundity by 49%, according to data from Tait et al. . Insecticide induced mortality rates caused by GS were calculated from laboratory data . Spinosad was used as insecticide model. The effects of GUM and GS were assumed to start on 9 July in accordance with the model design. Details on the model and on how the GS and GUM treatments were implemented can be found in the Supplementary Material. The simulations were implemented using Wolfram Mathematica 13.0 . The code for the simulations is available online1 .The current study supports findings from previous laboratory and small-scale field cage trials. Here we show through field collected and modeled data that food-grade gum use can reduce D. suzukii fruit damage . The aim of this work was to acquire detailed knowledge about limitations of food-grade gum in a range of commercial cropping systems including blueberry, blackberry, cherry, raspberry, strawberry, and winegrape. These studies were conducted in two key production regions i.e., California and Oregon in the USA. The overall results supported initial findings and provided additional evidence that this tool can reduce D. suzukii crop damage especially when applied together with the grower standard. Both field-collected data and model simulations indicates that there is a synergistic effect of food-grade gum when used in combination with a conventional insecticide. For most of the experiments , field plots receiving the food-grade gum resulted in either numerical or statistical differences in D. suzukii damage compared to untreated control plots. This was not recorded for the cherry, strawberry, and blackberry trials. Reasonable hypothesis about these data are discussed below. In trials where D. suzukii infestations were measured in buffer plots , there was evidence of a reduction in damage, but not at the same level as in plots treated by the food-grade gum. Overall, considering all the trials, crop damage was reduced up to 78% over a period of up to 21 days post application of the food-grade gum. The results from the current study indicate that the food-grade gum can be used in combination with standard insecticides , and in some cases as a stand-alone treatment to reduce the infestation level of D. suzukii. Similar reductions in D. suzukii damage were reported under laboratory and controlled semi-field conditions , suggesting that the food-grade gum resulted in lower damage due to oviposition. These findings support earlier results where the effects of semiochemical volatiles emanating from the food-grade gum resulted in significant behavioral changes . In several trials, data lower oviposition and fruit infestation in the presence of the food-grade gum under field conditions. Reasons of why in multiple trials a statistical difference was not reached, can be explained by multiple parameters observed by scientists and growers such as animals removing the cottons pads, water-irrigation issues, and wind. These factors are addressed in a future publication . In the Hood River cherry trial, constant windy conditions may have resulted in dispersion of volatiles, flower harvest buckets ultimately resulting in impacts that were less pronounced. There is little doubt that efficiency of the food-grade gum can vary depending on production conditions and crop . Host preference of D.suzukii was ranked 4th for cherry, followed by blueberry and winegrape . Such differences in host preference should be considered when applying food-grade gum.

Synthetic blends can be less attractive compared to the actual fruit; thus, additional adjustments may be required to minimize egg-laying in the fruit. Results showed that the application of the food-grade gum in grape shows clear impacts to protect berries from D. suzukii attack. Considering the vulnerability of several winegrape cultivars towards D. suzukii and the encouraging results collected, we have reasons to believe that the food-grade gum can be a useful tool for the winegrape production. For the food-grade gum applications in blueberry in open field experiments, the infestation rate for the food-grade gum and grower standard were 70% and 85% lower than that for untreated control respectively, with the food-grade gum treatment resulted in a significantly lower infestation rate compared with the control. Open and semi-field experiments conducted in California provide similar outcomes to those in Oregon. Blueberry experiments conducted in California within a screenhouse provided 45.5% egg reduction. There were sequential applications with differing timing and the results indicated that early applications resulted in lower egg reductions . A potential hypothesis for this phenomenon could be related to environmental conditions including temperature and humidity that could significantly change the emission of plant volatiles . Egg reduction in raspberry and blackberry varied from 42-90% and 24-70% respectively. Two cultivars of raspberry have been subjected to the trial and in both cases there was reduction in egg infestation. For blackberry the same cultivar has been evaluated but in three different farms. Results were consistent between the different locations. For strawberry, in several cases results showed numerically increased larval levels compared in the food-grade gum treatments. A potential hypothesis for this phenomenon could be related to either unreported production practices or environmental conditions that could significantly change the emission of plant volatiles or the food-grade gum. Other reasons that can justify the negative results, range from lack of irrigation to rodents removing food-grade gum within a day of placement . The trial run in Watsonville, California, showed a numerical reduction of eggs when the foodgrade gum was applied as standalone and in combination with pesticide. As discussed previously, multiple factors may have impacted the trial. Meta-analysis to determine differences between food-grade gum and untreated control and mean larvae resulted in a highly significant difference. Despite the non-statistical significant results gotten in multiple trials, the meta-analysis showed that by analyzing together all the trials, the food-grade gum has a significant positive effect on protecting fruits from D. suzukii infestation. The data originated clearly indicate that the presence of the food-grade gum substrate is a valid approach to keep D. suzukii away from berries. This analysis seems extremely valuable because it provides a general idea of how, overall, the use of the new tool has the potential to bring benefits to the small berry industries all over the world. For this study, the initial D. suzukii adult densities were fitted to match the untreated control treatment. The relatively similar trends displayed between simulations and real data suggest that model assumptions are close to representative of treatments. Simulation outputs however differed slightly from the field data in the earlier phase of the season. The simulations suggest an earlier buildup of D. suzukii populations compared to the sudden increase of infestation in the field trial. A reason for this difference could be that the model output was compared with the experimental data by assuming that the simulated egg population is proportional to the mean number of eggs found per fruit in the experiments. This assumption is reasonable for constant fruit levels, but the availability of ripe fruit in the trials were not constant. Under commercial field conditions, fruit is harvested every 7-10 days for this cultivar. This means that less susceptible fruit is available directly after every harvest event, likely negatively impacting D. suzukii population levels. Therefore, a high availability of ripe fruit in the middle portion of the experiment likely resulted in fewer eggs laid per berry compared to later in the season when fruit are less available. These differences in ovipositional resources likely resulted in the sudden increase in recorded infestation levels towards the latter portion of the experiment. Future work should focus on these relationships of pest population level and crop availability to determine risk. Finally, data collected under different environmental conditions over periods ranging from 10 to 60 days do not appear to impact the efficacy of the food-grade gum. Treated fruits were less damaged by D. suzukii. Additional factors such as active distance, commercial field longevity and improved formulation will result in additional improvements and future adoption.The Berry phase has played significant roles in many aspects of physics, ranging from atoms to molecules to condensed-matter systems.

Though there is a paucity of human research linking endogenous measures of dopamine function with reinforcement learning, dopaminergic drugs modulate RPE-like fMRI signals . Beyond reinforcement learning, dopamine has been linked to a multitude of cognitive processes thought to support complex, goal-directed decision-making such as episodic memory , working memory , flexibility , and valuation . Therefore, it would be reasonable to expect that deficits in dopamine function would negatively impact decision-making, and possibly through multiple paths. Aging is accompanied by alterations in multiple components of the dopamine system, including loss of dopamine-producing neurons in the substantia nigra , and losses in dopamine receptors and transporters . However, there is accumulating evidence from in vivo PET imaging in humans indicating that dopamine changes in aging are more heterogenous than previously thought. In this review, we focus on three aspects of intra and inter individual variability and consider how they may obscure evidence of systematic changes in decision-making with age. First, declines in the dopamine system vary substantially across individuals . Second, pre and post synaptic components of the dopamine system may decline at different rates and in different directions . Third, declines in the dopamine system may be spatially heterogeneous . We provide examples for how these factors may affect decision-making processes relying on reinforcement learning as well as goal-directed processes thought to rely on working memory . We posit that incorporating in vivo imaging to account for intraindividual and inter individual variability in dopamine function may explain some of the null or conflicting age effects in the decision sciences.Perhaps reflecting the complex relationship between dopamine function and aging, black plastic plant pots wholesale there is surprisingly little consensus on the nature of age-related changes in value-based decision making using laboratory-based tasks.

For example, studies in animal models strongly implicate dopamine in risk-taking . However, meta-analyses of tasks assessing risk-taking in young and older adults found no effect of age , or small effects indicating greater risk aversion in older adults when potential financial gains are at stake . Previous discussions of the mixed effects in the decision making literature have emphasized how variability in task framing and difficulty have profound effects on performance in older adults and can potentially alter the direction of observed age differences . For example, a recent meta-analysis of the Iowa gambling task suggests risk aversion in aging may develop progressively over the course of a single experimental session . Therefore, older adults may appear more risk seeking or more risk averse depending on a given task’s demands on learning. While previous discussions have brought to light the importance of between-study task differences in interpreting inconsistencies in the direction of reported age-group differences, here we emphasize the ways in which inter individual variability in older adults preclude the identification of systematic age-group differences within a single study. One limitation of previous studies is the absence of in vivo assessment of dopamine function using methods such as PET. PET imaging has been critical for clarifying essential questions in cognitive aging. For example, relevant to the field of Alzheimer’s disease research, PET imaging is being used to resolve conflicting accounts of the pathological mechanisms affecting memory. Recent PET findings have demonstrated preferential relationships between the accumulation of tau and memory . Similarly, dopamine PET imaging has been central for resolving controversies regarding the neural basis of cognitive training gains and mechanisms of transfer.

Backman and colleagues have demonstrated 5 weeks of working memory training increases striatal dopamine release during performance of the training task as well during performance on untrained working memory tasks . Incorporation of neurochemical and neuropathological quantitation allows for unique insights into the mechanisms underlying cognitive decline or enhancement in humans that are not possible using fMRI, electroencephalography, or structural imaging alone. Here, we discuss how the addition of in vivo dopamine measures to behavioral and structural and functional imaging studies will be useful for organizing the range of age effects reported in the decision sciences. We first provide background on in vivo dopamine imaging, and describe the strengths and limitations of these methods. We next identify three sources of inter individual and intra individual variability in age-related changes in brain dopamine, which have been revealed through PET imaging. Using specific examples to illustrate how these sources of variability can produce inconsistent age group effects, we propose ways in which in vivo imaging can clarify the neural basis for these findings. Finally, we address the possibility that changes in dopamine function join with age-related alterations in affective attention to increase inter individual variability in decision-making performance. We suggest that age-related changes in affective attention influence decision-making, and may, at times, oppose the effects of altered dopamine function on performance. We propose that accounting for interactions between dopamine and affective attention will be useful for explaining apparent noise in decision-making performance between individuals and between tasks.In this section, we briefly review methods for in vivo dopamine imaging in humans, which we hope provides useful background information for our discussion of how these methods can bolster our understanding of decision-making in aging.

PET imaging allows for the assessment of multiple components of dopamine function in vivo in animal models and humans. Here, we focus our review on PET imaging methods, though similar principles apply to SPECT imaging. Radiotracers have been developed that target dopamine receptors, transporters, and enzymes involved in dopamine synthesis . Commonly, PET imaging is conducted while subjects are not cognitively engaged in a specific task, but are in baseline resting conditions. Examples of how dopamine PET is paired with simultaneous cognitive task performance is described below. In a typical experiment, a subject is injected with a single bolus of the radiotracer and undergoes imaging over the course of 60–90 minutes. Kinetic modeling is applied to the data to provide a single whole-brain image . This image provides a static snapshot of the occupancy of specific dopamine receptors or transporters, or enzymatic function underlying dopamine synthesis capacity within an individual . Similarly, neuromelanin-sensitive MR approaches provide a static snapshot of the health of the nigral dopamine system , though relationships between MR and PET measures have not yet been established . Region of interest analyses can test how these measures vary across individuals and correlate with specific behaviors or other neural measures. For imaging receptors and transporters, radiotracers that act as competitive agonists or antagonists are used. It is worth noting that while most tracers give good quantitation in the striatum where the concentration of dopamine targets is high, fewer tracers allow for measurement in regions such as thalamus, amygdala, hippocampus, and cortex, where concentrations may be 10-fold less. Therefore, higher affinity tracers for D1 and D2/3 receptors must be used for research aimed at delineating contributions of cortical dopamine in decision-making. Tracers targeting receptors and transporters are characterized as “reversible,” meaning they bind to their target but can also dissociate until they reach a steady state during which the flux of tracer tissue binding equals the flux of dissociation back into blood. Calculations of non-displaceable binding potential are common for assessing individual difference in the availability of dopamine receptors and transporters . In a given region of interest, BPND reflects the density and affinity of the targeted receptor or transporter. However, as the tracer is in competition with endogenous dopamine to bind to its target, BPND is also sensitive to individual differences in the concentration of endogenous dopamine. Therefore,BPND comprises both the density/affinity of the receptor/transporter of interest as well as the concentration of competing dopamine particularly for lower affinity tracers. Thus, there is no “pure” PET measure of dopamine receptor density or transporter density. There are established PET methods for assessing dopamine release within individual subjects, which capitalize on the competitive displacement of radiotracers by endogenous dopamine . Specifically, decreases in receptor BPND accompany increases in extracellular dopamine concentration, which has been validated by simultaneous microdialysis . Due to slow tracer kinetics, black plastic plant pots bulk current PET imaging methods do not allow for event-related measurement of dopamine release for single trials. Therefore, direct comparison with phasic dopamine release afforded by fast scan cyclic voltammetry in animal models is untenable. In humans, PET measures of dopamine release reflect changes in extracellular dopamine across 10–60 minutes, depending on study design.

One approach is to collect two PET scans per subject and compare baseline BPND with BPND during task performance , or following administration of a drug that increases synaptic dopamine concentration by blocking dopamine reuptake or stimulating release . A second approach is to measure alteration in dopamine release across a single session. These protocols are somewhat more onerous and usually require constant infusion of the radiotracer, but have demonstrated increases in dopamine release associated with cognitive task performance . In addition to PET imaging, it is possible to assess dopaminergic function in vivo using neuromelanin-sensitive MR. This approach enables the visualization of monoaminergic nuclei in the substantia nigra pars compacta and locus ceruleus . Neuromelanin’s binding to iron and copper facilitates the visualization of neuromelanin-rich regions in using MR approaches . Its sequestration of heavy metals is likely neuroprotective, though after neuronal death, the release of toxins into extracellular space may be detrimental . Supporting the validity of this measure for assessing individual differences in the integrity of substantia nigra dopaminergic function, there is evidence that neuromelanin MR signal is reduced in Parkinson’s disease and distinguishes healthy controls from people with schizophrenia and depression . Consistent with PET dopamine synthesis findings, healthy aging is associated with elevation of neuromelanin . Individual differences in neuromelanin MR signal in healthy aging have been linked to variability in reward learning , memory performance , and fMRI activation during encoding . To date, there has been little investigation characterizing relationships between neuromelanin MR signal and dopamine PET measures within subject in young or older adults. One study reported a positive relationship between neuromelanin signal and D2/3 BPND in VTA/substantia nigra, but failed to find a relationship with dopaminesynthesis capacity . However, this study may have been underpowered , and used L-[β− 11C]DOPA to measure dopamine synthesis capacity, which complicates data analysis compared to the fluoro-l-mtyrosine PET measure of dopamine synthesis capacity . While the neuromelanin MR imaging approach is still under active development , it represents a low-cost and easily implemented way to approximate individual differences in the integrity of neurochemical systems relevant to cognition.In vivo imaging has the advantage of providing a within-subject, continuous measure of dopamine function that can be used to assess individual differences and offers a perspective of which brain regions may be preferentially associated with specific aspects of cognitive performance. What has emerged in the study of aging is the observation that changes are not monotonic. Different components of the dopamine system appear to change at different rates, in different directions, or not at all. Further, age-related changes in dopamine receptors may be spatially nonuniform. Below, we summarize these findings, which together speak to the limitations of experimental approaches that do not seek to account for such heterogeneity in the effects of aging on the neural systems supporting decision-making. A recent meta-analysis examining age-related changes in dopamine PET measures found consistent evidence that D1 and D2/3 BPND decline with aging . Though the studies examined in this meta-analysis were cross-sectional rather than longitudinal, the magnitude of age-related reductions was illustrated by the estimation of the percent reduction per decade of life. D1 receptors declined at a rate of ~14% per decade while D2/3 receptors and the dopamine transporter declined at a rate of 8%–9% per decade. These estimations derived from human PET imaging studies are generally consistent with, though in some cases are slightly higher than quantitation from postmortem human tissue and nonhuman animal studies . While receptor BPND is lower in older adults relative to young, studies consistently reveal substantial inter-individual variability in D1 and D2/3 BPND in older adults. For example, D2/3 BPND is relatively preserved in people who are more physically active . Such interindividual variability appears to be relevant to cognition, as it correlated with differences in psychomotor function , executive function , and memory in older adults. While dopamine receptor BPND declines in aging, there is accumulating evidence that dopamine synthesis capacity is elevated in older adults .

The mobile phase consisted of isocratic elution with acetonitrile:water at a flow rate of 1.0 ml/min with a run time of 22 min. Standard solutions of 10 mg/L of D-glucose, D-fructose, Dsucrose, and D-raffinose were injected to obtain the retention time for each compound, and detection was conducted by RID. Sugar standards were purchased from VWR International . Sugar concentration of each sample was determined by comparison of the peak area and retention time with standard sample curves. Starch content of the roots, shoots, and leaves was conducted using the Starch Assay Kit SA-20 in accordance with the manufacturer’s instructions. Briefly, pellets of different tissues were dissolved in 1 ml DMSO and incubated for 5 min in a water bath at 100◦C. Starch digestion commenced with the addition of 10 µl α-amylase and then incubated in boiling water for another 5 min. Then, the ddH2O was added to a total volume of 5 ml. Next, 500 µl of the above sample and 500 µl of starch assay reagent were mixed and incubated for 15 min at 60◦C. Negative controls with the starch assay reagent blank, sample blank, and glucose assay reagent blank and positive controls with starch from wheat and corn were performed. Reaction started with the incubation of 500 µl of each sample and 1 ml of glucose assay reagent at 37◦C and was stopped with the addition of 1 ml of 6 M sulfuric acid after 30 min. The reaction was followed with a Cary 100 Series UVV is Spectrophotometer and starch content was expressed as percent of starch per tissue dried weight.In spite of the warming trends recorded for the study area within the two growing seasons covered by this study, 30 planter pot the plant water status recorded in both growing seasons was optimal for grapevine growth as indicated by the midday SWP and the gs . Thus, seasonal integrals of SWP ranged between -0.8 and -1.1 MPa, while gs ranged between 150 and 250 mmol m−2 s −1 , in accordance to the midday SWP and gs values considered as well-watered conditions .

Moreover, water status of the grapevines subjected to less applied water amount never reached values lower than -1.5 MPa for SWP and/or 50 mmol m−2 s −1 for gs , which have been reported to impair grapevine performance and berry ripening . As Keller et al. reported before, in warmer years, 100% ETc treatment may suffer from mild water deficit. Thus, under our experimental conditions, at the end of the season, especially in 2020, grapevines reached SWP values to ca. -1.2 MPa; however, they are not sufficient to impair grapevine physiology and metabolism in warm climates . Previous studies highlighted that plant water status is closely related to leaf gas exchange parameters . Thus, low values of SWP were related to decreased gs likely because plants subjected to mild to moderate water deficit close their stomata as an early response to water scarcity to diminish water loss and carbon assimilation . Accordingly, in both growing seasons, a higher SWP promoted increased stomatal conductance and, consequently, net carbon assimilation rates in grapevines subjected to 100% ETc. AN and gs peaked around veraison and then declined in all the treatments similar to several studies conducted in a warm climate before . Thus, previous studies have pointed out that limited photosynthetic performance, hence lower gs and AN values, may be triggered by passive or active signals . Nevertheless, AN in 50% ETc treatment was not severely decreased presumably by increases in WUE, which have been related to improvements in stomatal sensitivity to water loss and vapor pressure despite the hormonal signaling from roots to shoots . Likewise, Tortosa et al. suggested that differences in WUE between Tempranillo grapevine clones were more explanatory of the variations in carbon assimilation rather than a different stomatal control. Finally, it is worth mentioning that WUE was significantly lower in the driest and hotter growing season regardless of the irrigation treatment as previously reported . Regarding intrinsic WUE , no effect due to growing conditions was observed in contrast to previous studies on vines subjected to mild water stress .

The water deficits applied in this study were from moderate to severe based on SWP values; thus, it is expected that the vegetative and reproductive growth of vines will be impacted accordingly. Thus, in previous studies, higher water deficits resulted in reductions of yield and berry size . The reduction in berry mass has been associated with the inhibition of cell expansion and the diminution of inner mesocarp cell sap . The detrimental effects of 25% ETc were reported previously, suggesting that this applied water amount may not be adequate for hot climates with very little or no summer precipitation . Vegetative growth was also impaired by water deficits applied in this study, as indicated in the decrease of leaf and root dry bio-masses measured in 25 and 50% ETc treatments. Diminution of root growth under water stress has been related to the loss of cell turgor and increased penetration resistance of dried soils . In addition, a recent study suggested that the loss of leaves could decrease the supply of carbohydrates and/or growth hormones to meristematic regions, thereby inhibiting growth . In accordance with previous studies, severe water deficits led to lower shoot to root ratio because root growth is generally less affected than shoot growth in drought-stressed grapevines . Given that grapevine vegetative growth occurs soon after bud break in springtime, our results corroborated the crucial role of water availability during that period on vine development, physiological performance, and yield components reported in previous studies . Thus, irrigation of grapevines during summer could not be sufficient to fulfill water requirements when rainfall has been scarce in spring , and precipitation amounts prior to bud break result in cascading effects for the rest of the growing season that cannot be overcome with supplemental irrigation .The allocation of NSC varied between organs for which roots accounted 30%, shoots 25%, and leaves 40% of the whole plant NSCs at harvest, slightly differing from those reported for several fruit trees but similar to theworks in grapevine . The NSC composition was highly dependent on the grapevine organs, with starch being the main NSC in the roots and shoots.

Previous studies reported that roots accumulated the largest amounts of starch in plastids, namely amyloplasts, which is fundamental to allow rapid vegetative development during the next spring . Our results also corroborated with this finding. Our results indicated that, apart from fruits, SS were mainly accumulated in the leaves at harvest, which accounted for about 90% of the total leaf NSC. Thus, the allocation of NSCs in different organs allowed the plants to persist when respiration rate was higher than photo assimilation in annual events, but also aided in responding to abiotic stresses such as drought . Our results indicated that plants that received 100% ETc had higher NSC content. Similarly, a previous study with potted grapevines reported increased starch and SS contents in the leaves from the grapevines with higher leaf area to fruit ratio that were well-watered . In shoots, sucrose and raffinose proportions were higher in 50 and 100% ETc treatments compared with 25% ETc. As a great part of the shoot biomass is vascular tissue, this may suggest an increase in NSC translocation in these treatments. Although sucrose is the main sugar for carbon translocation through the phloem into the sink tissues, recent research highlighted the roles of other sugars, such as raffinose, in carbon translocation and storage . On the other hand, plastic growers pots previous research reported less NSC accumulation in grapevine canes under carbon starvation at a low leaf to fruit ratios, suggesting that sucrose may control starch accumulation through adjustment of the sink strength . Furthermore, Rossouw et al. also highlighted the role of raffinose toward root carbohydrate source functioning in grapevines with significantly lower leaf to fruit ratio due to defoliation from carbon starvation . When the photosynthetic supply of carbohydrates is limited, remobilization from perennial tissues can provide an alternative carbon source . Thus, previous research conducted on potted grapevines reported a concurrent starch remobilization from roots with a rapid berry sugar accumulation . Conversely, under our experimental conditions , no effect of water deficits on NSC remobilization from roots to berries was observed despite the decreased leaf to fruit ratio. Likewise, Keller et al. did not observe higher amounts of sugars in berries from field-grown Cabernet Sauvignon subjected to 25% ETc compared with 70 or 100% ETc under field conditions.Under our experimental conditions, yield per plant was strongly related to shoot, leaf, and root BM. Similarly, Field et al. found that grapevines with the lowest shoot growth rate before veraison had significantly less fruit set than the other treatments, attributing these effects to the restoration of root carbohydrate reserves that occurred at the same time. Grapevines subjected to 25% ETc had reduced photo assimilates due to lower AN in both seasons resulting in less NSC in the source leaves available for new growth and exported to sinks. This resulted in a general lower plantBM . Contrarily, grapevines subjected to 100% ETc had higher photo assimilation rates throughout the course of the study that led to higher SS and starch content and, consequently, to the improvement of BM and, therefore, higher harvest index. Therefore, the reduced growth rate of both sink and source organs in response to water deficits indicated that the availability of carbon is a major growth constraint. The yield per plant of 50% ETc was lower than 100% ETc, but not as low as 25% ETc. However, canopy BM was greatly reduced in both 50% ETc and 25% ETc compared with 100% ETc. Accordingly, Field et al. reported that grapevine grown under warm soil conditions favored shoot and fruit development over carbohydrate reserve accumulation. In contrast, Candolfi-Vasconcelos et al. reported that a lower leaf area to fruit ratio increased the translocation of carbohydrates from permanent structures to reproductive organs to support grape ripening. The shoot to root ratio revealed a positive relationship with the total BM, leaf and root NSC, and N contents. Thus, the distribution of biomass relies on the C:N ratio as highlighted by the negative relationship between shoot to root and the sucrose:nitrogen ratios. Similarly, a linear relationship between NSC and root to shoot ratio in grapevines grown under stressful conditions was previously reported . From a molecular point of view, the alterations of source:sink ratios led to transcriptional adjustments of genes involved in starch metabolism, including the upregulation of VvGPT1 and VvNTT for lower leaf area to fruit ratios . Furthermore, enhanced root biomass in 100% ETc likely resulted from higher sugar content in the roots as our data supported. It was recently reported that increases in root elongation and hexose contents were due to the VvSWEET4 overexpression, a gene implied as a grapevine response to abiotic stress . Similarly, Medici et al. reported up- or downregulation of the genes encoding hexose transporters in grapevines subjected to water deficits corroborating this result. Therefore, although some genes may be expressed under water deficit, lack of carbon accumulation impaired the growth. The relationship between root to shoot ratio and plant nitrogen content was previously reported for grapevines, suggesting that dry matter partitioning is largely a function of the internal status of the plants . We found decreased N content in grapevines facing water deficits, which resulted in a decrease of total BM. Similarly, Romero et al. reported reductions in leaf nitrogen content when vines were subjected to water deficits. These authors suggested that nutrient uptake may be reduced due to deficits in soil water profile, and the slow root growth under these conditions consequently inhibited grapevine growth. In our study, N content was strongly related to photosynthetic pigments. Accordingly, previous studies reported lower leaf N and leaf chlorophyll in deficit-irrigated grapevines, suggesting quantitative losses in the photosynthetic apparatus and/or damage to the biochemical photosynthetic machinery, decreasing photosynthetic capacity as corroborated with the lower NSC leaf content with water deficits. Finally, molecular research over the last decades has suggested the important regulatory functions of sucrose and N metabolites in metabolism at the cellular and subcellular levels and/or in gene expression patterns, giving new insights into how plants may modulate over a longer period its growth and biomass allocation in response to fluctuating environmental conditions .