Quantitative trait locus mapping for Verticillium wilt resistance in a backcross inbred line population of cotton (Gossypium hirsutum × Gossypium barbadense) based on RGA-AFLP analysis

Verticillium wilt (VW), caused by Verticillium dahliae Kleb., is one of the most important diseases in cotton. The objective of this study was to map quantitative trait loci (QTLs) conferring VW resistance using resistance gene analog (RGA)-targeted amplified fragment length polymorphism (RGA-AFLP) markers in an interspecific backcross inbred line mapping population, consisting of 146 lines from a susceptible Sure-Grow 747 (Gossypium hirsutum L.) × resistant Pima S-7 (G. barbadense L.) cross. VW resistance was evaluated in replicated tests based on disease incidence in the field, and disease incidence and severity in the greenhouse. Of 160 polymorphic RGA-AFLP markers, 42 were significantly correlated with one or more VW traits and 41 were placed on a linkage map which covered 1,226 cM of the cotton genome and contained 251 other molecular markers. Three QTLs for VW resistance were detected, each of which explained 12.0–18.6 % of the phenotypic variation. Two of these QTLs for disease incidence and severity detected in the greenhouse inoculation tests using root wounding are located on chromosome c4. Both are closely linked to four RGA-AFLP markers and therefore considered as the same QTL for VW resistance. The other QTL detected in the field test was located on c19 and flanked by several RGA-AFLP markers. The desirable QTL allele on c4 for VW resistance detected in the greenhouse was from the VW susceptible Upland parent and absent from the resistant Pima parent which was more VW susceptible due to the disarmament of the first line of defense mechanism due to root wounding during inoculation. The other desirable VW resistance QTL allele, on c19, was from the resistant parent Pima S-7, consistent with the fact that Pima cotton was more resistant to VW when naturally infected in the field. The results should facilitate the development of more sequence specific markers and the transfer of VW resistance from Pima to Upland cotton through marker-assisted selection.     

Relative susceptibility of Salix clones to chrysomelid beetles: evidence from the Stott willow collection at Ness

Willow species and hybrids growing in the Stott willow collection at Ness, UK, differed markedly in their susceptibility to leaf damage by insects, predominantly chrysomelid beetles, with the rank order of susceptibility remaining relatively constant over 2 years. Some species displayed a wide range of variation in susceptibility amongst clones; others very little. The range of susceptibilities of hybrids tended to mirror those of the parent species, with the hybrid usually sustaining leaf damage levels intermediate between those of the parents. Leaf damage in most species was higher on the lower leaf surface up to mid-season, beyond which leaf perforation damage became prevalent. Damage levels did not appear related to leaf toughness. Apparent levels of leaf damage were lower in October versus July/August samples across nearly all species. Heavy leaf damage in one year did not appear to induce the production of leaves that were more resistant to insect attack in the following year.     

The chemistry of water on alumina surfaces: reaction dynamics from first principles

Aluminas and their surface chemistry play a vital role in many areas of modern technology. The behavior of adsorbed water is particularly important and poorly understood. Simulations of hydrated alpha-alumina (0001) surfaces with ab initio molecular dynamics elucidate many aspects of this problem, especially the complex dynamics of water dissociation and related surface reactions. At low water coverage, free energy profiles established that molecularly adsorbed water is metastable and dissociates readily, even in the absence of defects, by a kinetically preferred pathway. Observations at higher water coverage revealed rapid dissociation and unanticipated collective effects, including water-catalyzed dissociation and proton transfer reactions between adsorbed water and hydroxide. The results provide a consistent interpretation of the measured coverage dependence of water heats of adsorption, hydroxyl vibrational spectra, and other experiments.     

Exploring tropical fisheries through fishers’ perceptions: Fishing down the food web in the Tonlé Sap,Cambodia

Tropical fisheries are among the most productive fisheries in the world, often providing the primary source of protein for the local population. Despite their importance, data on these systems are relatively limited, thus hampering management and policy development. Here, the implications of increasing fishing pressure are explored by critically evaluating the perceptions of the fishers who rely on these ecosystems to survive. A total of 169 fishers in 26 different fish‐dependent communities in the Tonlé Sap Lake, Cambodia, were surveyed to understand their perceptions of the impact that fishing has had on the ecosystem. The Tonlé Sap is one of the largest, yet poorest studied, freshwater fisheries in the world. Consistent with “fishing down the food web” theory of fisheries, survey data revealed that although fishers observed the total size of fish catch remaining consistent over recent years there has been a drastic decline in the size of individual fish, as well as a reduction in the diversity of species caught. These perceptions are examined with reference to food web theories that explore how fishing pressure leads to ecosystem change, including the more recent “indiscriminate fisheries” theory.     

Should I stay or should I go? Fishers’ ability and willingness to adapt to environmental change in Cambodia's Tonle Sap Lake

The livelihoods of people dependent on the Tonle Sap floodplain ecosystem in Cambodia are expected to be affected by changes in economic conditions, social circumstances, environmental perturbations, demographic shifts and political climates. This study assesses how small‐scale fisheries’ livelihoods are changing in response to social and environmental conditions using the opinions of fishers collected through an intensive family survey of 514 households from Pursat and Battambang Provinces in Cambodia. Probit modelling approach was used to assess whether a fisher would continue fishing or not in the future when subjected to a variety of shifting conditions and identify the factors associated with their response. It was found that in any future condition about 50% of fishers would likely continue to fish, which suggests how much they love their traditional livelihood of fishing. The remaining 50% considered to diversify their livelihood strategy by shifting towards a combination of fishing, farming, and off‐farm jobs. Furthermore, the analysis found that the fishers will change their fishing practices depending on how other sectors in the region develop. The model showed increasing access to agricultural activities decreased the likelihood of continuing to fish, whereas finding an off‐farm job corresponded to increased likelihood of continuing to fish.     

美国胶合板市场:进口暴涨!

图1示出3个主要供应国的针叶材胶合板进入美国市场的情况,自1997年以来(不含1997年)已经突破100万m3,这3个国家是巴西、加拿大和智利.特别值得注意的是,由于各种原因,过去2年里从巴西进口针叶材胶合板增长非常明显,我们对此要进行讨论,对此中国的生产商们可能会很有兴趣.     

给海外买家留个好印象

因为和中国木业国际公司之间亲密的合作．我知道中国木业国际公司正在考虑帮助国内的木产品企业成功地开拓外方市场。那么,在海外买家参观企业的工厂时,怎样给他们留下好的印象呢？我提出如下的建议。请不要认为．这是一个典型西方人提出的中国企业必须照做的建议,我相信这些有助于您的商务。     

Microtubule stabilization reduces scarring and causes axon regeneration after spinal cord injury

Hypertrophic scarring and poor intrinsic axon growth capacity constitute major obstacles for spinal cord repair. These processes are tightly regulated by microtubule dynamics. Here, moderate microtubule stabilization decreased scar formation after spinal cord injury in rodents through various cellular mechanisms, including dampening of transforming growth factor-β signaling. It prevented accumulation of chondroitin sulfate proteoglycans and rendered the lesion site permissive for axon regeneration of growth-competent sensory neurons. Microtubule stabilization also promoted growth of central nervous system axons of the Raphe-spinal tract and led to functional improvement. Thus, microtubule stabilization reduces fibrotic scarring and enhances the capacity of axons to grow.     

Loss of M2 muscarine receptors in the cerebral cortex in Alzheimer's disease and experimental cholinergic denervation

Cerebral cortex samples from patients with Alzheimer's disease and from rats after experimental cholinergic denervation of the cerebral cortex exhibited reductions in the presynaptic marker choline acetyltransferase activity and in the number of M2 muscarine receptors, with no change in the number of M1 receptors. These results are in keeping with evidence that M2 receptors function in cholinergic nerve terminals to regulate the release of acetylcholine, whereas M1 receptors are located on postsynaptic cells and facilitate cellular excitation. New M1-selective agonists and M2-selective antagonists directed at post- or presynaptic sites deserve consideration as potential agents for the treatment of the disease.