Loss of integrity of the cuticle and epithelial cells of the integumentary and tracheal systems in T. molitor larvae due to densovirus infection may not only cause dehydration via excessive water loss, but also secondary infection by bacteria and fungi as a result of the loss of their primary defense barrier against infection. One limitation encountered in this study was the interpretation of a dark discoloration presented by densovirus-infected T. molitor larvae. Further investigation into the mechanism of this change is suggested as there remains uncertainty to whether this is in fact hemocyte granule prophenoloxidase-mediated melanization or some other possible explanation, such as the collection of debris over an unshed and desiccated cuticle. InI is the most important microscopical feature of the densovirus infection in T. molitor. InI observed on bright-field microscopy represents the DRAC observed on electron microscopy. The infection with TmDNV induces homogeneous basophilic- and eosinophilic-texturized InIs. Feulgen staining confirmed the DNA-dominant nature of the basophilic InIs, which correlates with DRACs accumulating maturing and mature virions on TEM as is shown in Figs. 6d and 7a. On the other hand, a great number of eosinophilic-texturized InIs presented with a fainter staining after the Feulgen reaction, which correlates with DRACs shown in TEM photomicrographs in Fig. 7c–f. Eosinophilic-texturized inclusions represented DRACs that ultrastructurally displayed an evolving mixture of heterogeneous viral matrix, maturing and mature virions, and ribosomes. Viral matrix observed in DARC was composed of electron-dense fibrillar small-aggregating-to-long-anastomosing streams, which evolved into a large compact mass that resembles the shape of a “rotary dial” . Similar structures were described in early studies of G. mellonella infected with densovirus. Later, H-1 parvovirus studies indicated that H-1 parvovirus–associated replication bodies, square plastic planter which are not uncommonly observed in DRAC in T. molitor , are composed of nucleolar fibrils and serve as the location of viral DNA replication. Differentiating maturing and mature virions from ribosomes in the infected nucleus on conventional plastic-embedded preparations posed a challenge.

However, the large number of virus particles recovered on direct TEM supports the observation that large quantities of round vesicles/ particles of about 18 to 24 nm in diameter found within the DRAC were in fact maturing and mature densovirus virions rather than ribosomes. The DRAC displayed a very pleomorphic morphology, which varied from accumulation of maturing and mature virions to dense virus matrix that mimicked nucleolar structures and paracrystalline arrays. This heterogeneous appearance of the DRAC is an important feature that characterizes and facilitates TmDNV diagnosis at the ultrastructural level. Initial TEM studies on the G. mellonella densovirus demonstrated that the nucleoplasm is completely replaced by virions during the first 20 hours of infection. As in other autonomous parvoviruses that depend on the S phase of the infected cells, TmDNV replication and assembly is a unique and dynamic process that demands a deeper understanding. Nonetheless, crystallization of the DRAC forming “paracrystalline arrays” was interpreted as the final stage of nuclear infection with densovirus in T. molitor. Numerous infected cells presented cytoplasmic membrane–bound vesicles containing virus particles or paracrystalline arrays. Intracytoplasmic paracrystalline arrays have been considered a distinct feature of Densovirinae infections. The origin of the structures is not well understood, but it should be considered as a process of infected nuclear breakdown, heterophagia, or autophagia. Ultrastructural changes of the nuclei and cytoplasm in TmDNV–infected epithelial cells suggest apoptosis as the mechanism of cell death, although studies on viruses of the Parvoviridae family suggest that the mechanisms of Parvoviridae-induced cell death are unique and complex, warranting further investigation. Fruit, nut, and berry crops are commonly grouped into one of three categories: temperate, subtropical, and tropical. Temperate zone crops include almond, apple, apricot, peach, grape, blueberry, and strawberry . Avocado, citrus, and guava are considered to be subtropical, while banana, cashew, and pineapple are tropical . Generally, temperate and subtropical crops can be grown in San Mateo and San Francisco Counties , but tropical crops are rarely successful.

This publication focuses on temperate and subtropical crops. Temperate zone crops generally require a period of cold temperature during the winter months for successful flower and fruit development. This cold temperature period is measured in “chill hours” . Some crops require many chill hours, while others require few. This is called the crop’s “chill requirement.” When selecting temperate zone crops, it is important to choose only those crops that have a chill requirement that will be met at your location. Subtropical crops, such as citrus, loquat, and guava, require little or no chilling. Native to warm-climate regions, these crops can be injured by cold temperatures during winter and spring months, and they require heat during the growing season for fruit maturation and flavor.Selecting climate zones and meeting chill requirements are not the only factors necessary for good fruit production. Pollination, sunlight, heat accumulation, and wind are all important considerations. For fruit development to occur, flowers have to be pollinated; that is, pollen must move from the male organs to the female organs . Pollen transfer can be facilitated by bees, beetles, flies, butterflies, moths, birds, bats, wind, and water. The pollen can come from flowers on the same tree , or from flowers of other trees of the same species . In some cases, a crop may require another tree of a specific variety for pollination. For information on pollination requirements, see the “Crop and Variety Selection Table” at the end of this publication. For further details, see “Notes on Crops and Varieties” below. Note that even in self fertile crops, cross-pollination can increase fruit set. Also, poor pollination can occur as a result of insufficient pollinator activity, such as during cool and wet weather in the spring when bees may be less active . For most crops, plentiful sunlight and warm temperatures during the growing season are needed. Factors such as fog, wind, elevation, aspect , and distance from the ocean affect sunlight level and temperature.In recent years, a variety of novel two-dimensional van der Waals magnets have been discovered, founding the active field of 2D magnetism.

Among these prospective compounds, binary chromium tellurides Cr1–δTe are attractive owing to their rich magnetic properties, as well as inherent chemical and structural compatibility when forming heterostructures with other topological systems, such as tetradymite-type topological insulators or chalcogenide-based Dirac/ Weyl semimetals. Furthermore, the broken time-reversal symmetry and spin-orbit coupling offer unique opportunities for the interplay between spin configurations and reciprocal-space topology. In this regard, ferromagnetic Cr2Te3 with strong perpendicular magnetic anisotropy is an intriguing platform to host non-trivial topological physics, particularly for the high-quality thin films grown by molecular beam epitaxy. The intrinsic AHE is topological in nature and a hallmark of itinerant ferromagnets, which has also been observed in more exotic systems even without a net magnetization, such as spin liquids, antiferromagnets, and Weyl semimetals. When SOC coexists with long-range magnetic order, square plastic plant pot the Berry curvature can be significantly influenced near avoided band crossings, rendering the system an incredibly rich playground combining topology and magnetism. Here, we report the unique magnetotransport signatures of highquality quasi-2D Cr2Te3 MBE-grown thin films governed by non-trivial band topologies. Via synergetic structural, magnetic, and transport measurements, together with first-principles simulations, we have uncovered novel Berry-curvature-induced magnetism featuring an extraordinary sign reversal of the AHE as we modulate the temperature and the strain for the thin films containing 3–24 unit cells on Al2O3 or SrTiO3 substrates. Moreover, a hump-shaped Hall feature emerges, most likely due to the presence of multiple magnetic layers/domains under different levels of interfacial strain. This work identifies pristine ferromagnetic Cr2Te3 thin films as a fascinating platform for further engineering topological effects, given their nontrivial Berry curvature physics.The crystalline structure of Cr2Te3 thin films is described first, followed by the development of strain at the substrate/film interface by the epitaxy. Bulk Cr2Te3 crystalizes in a three-dimensional lattice with space group P31c ðD2 3d,No:163Þ, as shown in Fig. 1a–c, where each unit cell contains four vertically stacked hexagonal layers of Cr. There are three symmetrically unique sites for Cr, labeled Cr1, Cr2, and Cr3, respectively: The Cr1 atoms are sparsely arranged in a weakly antiferromagnetic sublattice, while the Cr2/Cr3 atoms form ferromagnetic layers similar to those in CrTe2. Since the Cr1 sites are often only partially filled , Cr2Te3 behaves essentially as a quasi-2D magnet. This quasi-2D nature of Cr2Te3 allows for high-quality, layer-by-layer epitaxial growth of c-oriented films on a variety of substrates. The hexagonal c axis is the easy magnetic axis, leading to PMA for the films. The sixfold in-plane symmetry is seen in the honeycombs visualized by atomic resolution scanning tunneling microscopy and scanning transmission electron microscopy high-angle annular dark-field imaging, as well as in the reflection high-energy electron diffraction and X-ray diffraction patterns.

The sharp substrate/film interface is confirmed by the cross-sectional HAADF and the corresponding integrated differential phase contrast images. The intrinsic random distribution of Cr atoms on the Cr1 sites is resolved in the enlarged view of the atoms in Fig. 1k–m, shown overlaid with red circles, while the overall chemical composition of the thin film is uniform within the resolution of energy dispersive X-ray spectroscopy . Figure 1f illustrates the basic sample architecture, where the strain in the Cr2Te3 thin films is governed by the interface with the substrate.Upon reducing the thickness t, films grown on Al2O3 can develop an IP compressive strain up to −0.15%, as determined by XRD and summarized in Fig. 1d. A higher strain level can be sustained using SrTiO3 substrates. Such control of strain is well suited for exploring interface-sensitive properties in Cr2Te3 thin films.The magnetic properties of Cr2Te3 thin films with selected thicknesses were assessed using vibrating sample magnetometry . Figure 2a shows the temperature dependence of the magnetization M for a t = 24 u.c. film on Al2O3 substrate with an out-of-plane applied magnetic field μ0H = 0.1 T. Under the field-cool condition, M rises below the Curie temperature TC ~ 180 K, reaching M ~2.50 μB per Cr at 2 K in the 0.1 T field. The zero-FC scan, on the other hand, deviates from the FC curve below the blocking temperature Tb, signaling the freezing out of domains in a random direction in the absence of an aligning field. As illustrated in Fig. 2b, Cr2Te3 favors PMA with coercive field μ0Hc = 0.76 T and saturation magnetization Ms ~2.83 μB per Cr at 2 K for t = 24 u.c., whereas the IP measurements have weaker ferromagnetic hysteresis loops. The low-T zero-field kink feature in the OOP M becomes more prominent with reduced thickness . The multistep hysteresis attests to the presence of varied layer-dependent magnetic anisotropies, despite the overall chemical and phase homogeneity of the films34. This is consistent with the interfacial strain-driven magnetic profiles revealed by the depth-sensitive polarized neutron reflectometry as described below. The PNR experiments, responsive to the IP magnetization, were carried out at chosen T and H on samples with t = 24 and 6 u.c. to uncover the impact of interfacial strain and the details of the stepwise hysteresis loops due to the interplay between anisotropy and the Zeeman energies in an applied external magnetic field. The PNR spin asymmetry ratio SA = /, measured as a function of the wave vector transfer Q = 4πsin/λ with R+ and R− being the reflectivity for the neutron spin parallel or antiparallel to the external field, evidently confirms the magnetization . By simultaneously refining PNR and X-ray reflectivity data, the depth profiles of nuclear and magnetic scattering length densities at μ0H = 1 T, 0.8 T and 0.05 T for t = 24 u.c. were obtained and are shown in Fig. 2c. The uniform MSLD profile at the IP saturation field μ0H = 1 T attests to the high quality of the magnetic Cr2Te3 film with well-defined interfaces of 0.5 nm roughness. Remarkably, at reduced IP field μ0H = 0.8 T and 0.05 T, M develops a non-uniform depth-dependent profile with two distinct regions, possessing a lower IP magnetization value close to the substrate. Given that the NSLD depth profile of the Cr2Te3 layer is uniform and no changes are detected in the structure and chemical composition of the film, we attribute the reduced IP magnetization approaching the substrate to a canting of the magnetization vector towards the OOP direction .