Cultivar‐specific effects of pathogen testing on storage root yield of sweetpotato,Ipomoea batatas

The accumulation and perpetuation of viral pathogens over generations of clonal propagation in crop species such as sweetpotato, Ipomoea batatas, inevitably result in a reduction in crop yield and quality. This study was conducted at Bundaberg, Australia to compare the productivity of field‐derived and pathogen‐tested (PT) clones of 14 sweetpotato cultivars and the yield benefits of using healthy planting materials. The field‐derived clonal materials were exposed to the endemic viruses, while the PT clones were subjected to thermotherapy and meristem‐tip culture to eliminate viral pathogens. The plants were indexed for viruses using nitrocellulose membrane‐enzyme‐linked immunosorbent assay and graft‐inoculations onto Ipomoea setosa. A net benefit of 38% in storage root yield was realised from using PT materials in this study. Conversely, in a similar study previously conducted at Kerevat, Papua New Guinea (PNG), a net deficit of 36% was realised. This reinforced our finding that the response to pathogen testing was cultivar dependent and that the PNG cultivars in these studies generally exhibited increased tolerance to the endemic viruses present at the respective trial sites as manifested in their lack of response from the use of PT clones. They may be useful sources for future resistance breeding efforts. Nonetheless, the potential economic gain from using PT stocks necessitates the use of pathogen testing on virus‐susceptible commercial cultivars.     

High‐Voltage‐Driven Surface Structuring and Electrochemical Stabilization of Ni‐Rich Layered Cathode Materials for Li Rechargeable Batteries

Layered lithium–nickel–cobalt–manganese oxide (NCM) materials have emerged as promising alternative cathode materials owing to their high energy density and electrochemical stability. Although high reversible capacity has been achieved for Ni‐rich NCM materials when charged beyond 4.2 V versus Li⁺/Li, full lithium utilization is hindered by the pronounced structural degradation and electrolyte decomposition. Herein, the unexpected realization of sustained working voltage as well as improved electrochemical performance upon electrochemical cycling at a high operating voltage of 4.9 V in the Ni‐rich NCM LiNi_0.895Co_0.085Mn_0.02O₂ is presented. The improved electrochemical performance at a high working voltage at 4.9 V is attributed to the removal of the resistive Ni²⁺O rock‐salt surface layer, which stabilizes the voltage profile and improves retention of the energy density during electrochemical cycling. The manifestation of the layered Ni²⁺O rock‐salt phase along with the structural evolution related to the metal dissolution are probed using in situ X‐ray diffraction, neutron diffraction, transmission electron microscopy, and X‐ray absorption spectroscopy. The findings help unravel the structural complexities associated with high working voltages and offer insight for the design of advanced battery materials, enabling the realization of fully reversible lithium extraction in Ni‐rich NCM materials.     

Compositionally Graded Cathode Material with Long‐Term Cycling Stability for Electric Vehicles Application

Al is introduced into a compositionally graded cathode with average composition of Li[Ni_0.61Co_0.12Mn_0.27]O₂ (FCG61) whose Ni and Mn concentrations are designed to vary continuously within the cathode particle. The Al‐substituted full concentration gradient (Al‐FCG61) cathode is tested for 3000 cycles in a full‐cell, mainly to gauge its viability for daily charge/discharge cycles during the service life of electric vehicles (≈10 years). The Al‐substitution enables the Al‐FCG61 cathode to maintain 84% of its initial capacity even after 3000 cycles. It is demonstrated that the Al‐substitution strengthens the grain boundaries, substantiated by the mechanical strength data, thereby delaying the nucleation of microcracks at the phase boundaries which is shown to be the main reason for the cathode failure during long‐term cycling. It also shows that the Al‐substitution decreases the cation mixing and suppresses the deleterious formation of the secondary phase that likely initiates the microcracks. Unlike an NCA cathode, whose depth of discharge (DOD) must be limited to 60% for long‐term cycling, the proposed Al‐FCG61 cathode is cycled at 100% DOD for 3000 cycles to fully utilize its available capacity for maximum energy density and subsequent reduction in cost of the battery.     

Aberrant,ectopic expression of VEGF and VEGF receptors 1 and 2 in malignant colonic epithelial cells. Implications for these cells growth via an autocrine mechanism

Vascular endothelial growth factor A (referred to as VEGF) is implicated in colon cancer growth. Currently, the main accepted mechanism by which VEGF promotes colon cancer growth is via the stimulation of angiogenesis, which was originally postulated by late Judah Folkman. However, the cellular source of VEGF in colon cancer tissue; and, the expression of VEGF and its receptors VEGF-R1 and VEGF-R2 in colon cancer cells are not fully known and are subjects of controversy.     

Species differences in auditory processing dynamics in songbird auditory telencephalon

The caudomedial nidopallium (NCM) of songbirds is a telencephalic area involved in the auditory processing and memorization of complex vocal communication signals. We used pure tone stimuli and multiunit electrophysiological recordings in awake birds to investigate whether the basic properties of song-responding circuits in NCM differ between canaries and zebra finches, two species whose songs are markedly different in their spectral and temporal organization. We found that the responses in zebra finch NCM are characterized by broad tuning and sustained responses that may facilitate the integration of zebra finch song syllables and call notes that are of long duration and have a broad harmonic structure. In contrast, we found that the responses in canary NCM show narrower tuning and less sustained responses over the time periods analyzed. These characteristics may contribute to enhanced processing of the narrow-band whistles, rapid trills, and steep frequency modulations that are prominent features of canary song. These species differences are much less pronounced in field L2, the direct thalamorecipient region that represents a preceding station in the central avian auditory pathway. NCM responses did not differ across sexes of either species, but field L2 did show wider tuning in zebra finch females relative to males. In sum, species differences in the response properties of NCM likely reflect selectivity for the acoustic elements of each species' vocal repertoire.     

应用Dot—ELISA检测PVX,PVY和PVS

以ＮＣＭ为固相载体、应用间接ＥＬＩＳＡ法测定了纯化的ＰＶＸ、ＰＶＹ和ＰＶＳ;对接种的烟草,马铃薯块茎的芽、休眠块茎顶端的稀释度ＰＶＸ分别为：１／２０４８０－１／８１９２０、１／５１２０;ＰＶＹ分别为１／８１９２０、１／２０４８０和１／５１２０;ＰＶＳ分别为１／８１９２０－１／３２７６８０、１／２０４８０－１／８１９２０和１／５１２０－１／２０４８０,和Ｃｏｃｋｔａｉｌ－ＥＬＩＳＡ相关,检测ＰＶＸ和     

Visualizing the localization of sulfoglycolipids in lipid raft domains in model membranes and sperm membrane extracts

Sulfogalactosylglycerolipid (SGG) is found in detergent-resistant lipid raft fractions isolated from sperm plasma membranes and has been shown to be important in sperm-egg adhesion. In order to provide more direct evidence for the association of sulfoglycolipids with lipid raft domains, we have examined the distribution of two sulfoglycolipids in supported membranes prepared from artificial lipid mixtures and cellular lipid extracts. Atomic force microscopy has been used to visualize the localization of SGG and sulfogalactosylceramide (SGC) in liquid-ordered domains in supported bilayers of ternary lipid mixtures comprised of dipalmitoylphosphatidylcholine, cholesterol and palmitoyldocosahexaenoylphosphatidylcholine. The localization of SGC/SGG in the liquid-ordered raft domains is demonstrated by changes in bilayer morphology in the presence of sulfoglycolipid, by selective antibody labeling of the domains with anti-SGC/SGG and by the effects of the cholesterol-sequestering agent, methyl-β-cyclodextrin, on the supported membranes. In addition, we use a combination of atomic force microscopy and immunofluorescence to show that supported bilayers made from lipids extracted from sperm anterior head plasma membranes (APM) and isolated APM vesicles exhibit small SGG-rich domains that are similar to those observed in bilayers of artificial lipid mixtures. The possible implications of these results for the involvement of SGG-rich lipid rafts in modulating sperm-egg interactions in vivo and the utility of model membranes for studying the behavior of lipid rafts are discussed.     

A possible relation between new neuronal recruitment and migratory behavior in Acrocephalus warblers

Evidence suggests a possible correlation between learning abilities of adults and new neuronal recruitment into their brains. The hypothesis is that this brain plasticity enables animals to adapt to environmental changes. We examined whether there are differences in neuronal recruitment between resident and migrant birds. We predicted that migrants, which are more exposed to spatial changes than residents, will recruit more new neurons. To test this, we compared neuronal recruitment in two closely related bird species ‐ the migrant reed warbler (Acrocephalus scirpaceus), and the resident Clamorous warbler (A. Stentoreus) ‐ during spring, summer, and autumn. Wild birds were caught, treated with BrdU and sacrificed five weeks later. New neurons were recorded in the Hippocampus and Nidopallium caudolateral. The results support our hypothesis, as more new neurons were found in the migrant species, in both brain regions and all seasons. We suggest that this phenomenon enables enhanced navigational abilities, which are required for the migratory lifestyle. However, in contrast to our hypothesis, in spring we found less new neurons in adults of both species, as compared to other seasons. We suggest that in spring, when birds settle in breeding territories, they require less spatial skills, and this might enable to reduce the cost of neuronal recruitment, as reflected by less new neurons in their brains. We also found age differences, with overall higher neuronal recruitment in juveniles. Finally, we advocate the importance of studying wild populations, for a better understanding of the adaptive significance of neuronal replacement in the vertebrate brain. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 74: 1194–1209, 2014