Candidate gene polymorphisms (BoIFNG, TLR4, SLC11A1) as risk factors for paratuberculosis infection in cattle

Paratuberculosis (Johne's disease) imposes a significant problem to the world dairy and beef industries and today is considered a potential zoonosis. The disease is caused by Mycobacterium avium subsp. paratuberculosis and is characterized by progressive weight loss and profuse diarrhoea. Susceptibility to infection is suspected to have a genetic component, and moderated values for heritability of infection have been reported. Interferon gamma is an inducible cytokine with a crucial role in the innate host response to intracellular bacteria. Toll-like receptors are trans-membrane structures responsible for coordination of innate and adaptive immune responses. The solute carrier family 11 member 1 (SLC11A1, formerly NRAMP1) gene plays an important role in innate immunity, preventing bacterial growth in macrophages during the initial stages of infection. The objective of this candidate gene case–control study was to characterize the distribution of polymorphisms in three candidate genes related to the immune function; interferon gamma (BoIFNG), toll-like receptor 4 (TLR4), and SLC11A1 genes and to test their role as potential risk factors for paratuberculosis infection in cattle. The statistical analysis demonstrated significant differences in allelic frequencies between cases and controls for BoIFNG-SNP₁2781 and SLC11A1 microsatellites, indicating a significant association between infection and variant alleles. In the analysis of genotypes, a significant association was also found between infection status and BoIFNG-SNP₁2781 and SLC11A1-275-279-281 microsatellites. However, when variables such as breed and age were included in the multivariate logistic regression analysis, a tendency toward statistical significance for the effect of polymorphisms in the odds of infection was only found for alleles SLC11A1-275 and 279.     

Association between cow reproduction and calf growth traits and ELISA scores for paratuberculosis in a multibreed herd of beef cattle

The objective of this research was to assess the association between 4 cow reproductive and weight traits, and 2 preweaning calf traits and ELISA scores for paratuberculosis (0 = negative, 1 = suspect, 2 = weak-positive, and 3 = positive) in a multibreed herd of cows ranging from 100% Angus (A) to 100% Brahman (B). Cow data were 624 gestation lengths (GL), 358 records of time open (TO), 605 calving intervals (CI), and 1240 weight changes from November to weaning in September (WC) from 502 purebred and crossbred cows. Calf data consisted of 956 birth weights (BWT), and 923 weaning weights adjusted to 205 d of age (WW205) from 956 purebred and crossbred calves. Traits were analyzed individually using multibreed mixed models that assumed homogeneity of variances across breed groups. Covariances among random effects were assumed to be zero. Fixed effects were year, age of cow, sex of calf, year × age of cow interaction (except WC), age of cow × sex of calf interaction (only for WC), and covariates for B fraction of sire and cow, heterosis of cow and calf, and ELISA score. Random effects were sire (except for TO and CI), dam, and residual. Regression estimates of cow and calf traits on ELISA scores indicated that lower cow fertility (longer TO), lower ability of cows to maintain weight (negative WC), lower calf BWT, and lower calf WW205 were associated with higher cow ELISA scores. Further research on the effects of subclinical paratuberculosis in beef cattle at regional and national levels seems advisable considering the large potential economic cost of this disease.     

羊驼皮肤结构基因（原）胶原的表达特点

为了揭示羊驼皮肤胶原蛋白（Collagen）在皮肤结构发生中的分子机制,本研究通过构建羊驼皮肤cD—NA文库并进行大规模测序分析,结果表明：在羊驼皮肤内发现只有纤维类胶原表达,即typeⅠ,typeⅢ,typeⅤ collagen,其中typeⅠ表达最高,typeⅢ和typeⅤ表达低;然而,在羊驼皮肤内未发现各类collagen相对应的原胶原（procollagen）,其成员procollagentype Ⅰ,typeⅢ,typeⅣ,typeⅥ,typeⅦ,typeⅩⅧ在表达,且typeⅠ远远高于其他家族成员的表达,由此推断collagen和procollagentypeⅠ在羊驼皮肤结构发生中起主要作用,羊驼皮肤内的蛋白水解机制可能使procollagen产生不同类型的collagen。     

Fruit fly bioassay to distinguish "sweet" sugar structures

Palatable response to dietary sugars plays a significant role in influencing metabolic health. New structures are being explored with beneficial health properties, although consumer acceptance relies heavily on desirable sensory properties. Despite the importance of behavioral responses, the ability to elucidate structure-preference relationships of sugars is lacking. A wild population of Drosophila melanogaster was used as a model to perform pairwise comparisons across structural groups to characterize a fruit fly bioassay for assessing sugar preference. Preference was successfully described in structurally relevant terms, particularly through the ability to directly test sugars of related structures in addition to standard sucrose comparisons. The fruit fly bioassay also provided the first report on the relative preference for the β-linked sugar alcohol, gentiobiitol. In making reference to well-known human preferences, the bioassay also raises opportunities for greater understanding of behavioral response to sugar structures in general.     

Seroepidemiological studies of bovine babesiosis on Pemba Island, Tanzania.

Serological evidence of infection with Babesia bovis and Babesia bigemina at a number of sites in Pemba was obtained using an enzyme-linked immunosorbent assay (ELISA) capable of detecting the appropriate parasite-specific antibody. Overall, 96% of animals were found to be positive for B. bovis, 88% were positive for B. bigemina and 88% were positive for both Babesia species. Antibody to B. bovis and B. bigemina was detected early in life in a number of calves born on Pemba, and was considered to be of maternal origin. The amount of maternal antibody in the serum of individual animals fell throughout the first 3 months of life. Later in life, antibody levels increased, probably in response to Babesia infection from natural tick challenge. These results suggest that infection with both Babesia parasites is widespread throughout Pemba and that both parasites probably exist in an enzootically stable situation.     

About the inconvenience of handling mixed-breed herds; aspects of social behavior as a potential source of stress and economic losses

Tropical Animal Health and Production - The objective of this study was to assess aspects of the social behavior of a mixed-breed herd of beef cows as a potential source for stress and economic...     

An initial experimental assessment of the influence of substrate depth on floral assemblage for extensive green roofs

Extensive green roofs have the potential to be used as mitigation tools to compensate for urban habitat loss, but there is little information about how closely these systems emulate ground-based habitats. This study investigated the effect of limited substrate depth on plant assemblages in the initial phase of growth in extensive green roof substrates. Five replicate mesocosms (1 m²) for each of three design treatments: (A) 10 cm aggregate depth with green roof drainage and solid floor, (B) 15 cm aggregate depth with green roof drainage and solid floor, and (C) 15 cm aggregate depth on top of bare earth; were positioned at ground level. Each mesocosm had an identical growth substrate and was seeded with the same seed mix. Plant assemblages were analysed using point-quadrat methods. Significant differences in species composition were observed between treatments that seemed to be related to water availability. Even the deep (15 cm) solid floor green roof treatment showed many significant differences in floral assemblage compared to the identical treatment (C) where plants had access to water in the soil profile. Therefore, it is not possible to exactly recreate most ground-based urban habitats on roofs by simply copying the soil characteristics and floral composition found on the ground. Like for mitigation for habitat loss using extensive green roofs requires the careful manipulation of design elements in order to counteract the limited water availability on green roofs.     

真空袋装储藏对荞麦品质影响的试验研究

本文针对荞麦在收获后到食用时品质下降过快的问题，在理论分析的基础上，采用真空袋装方法对荞麦米就储藏期间的品质保持问题进行了研究。试验结果表明：真空袋装能有效地抑制荞麦米储藏期间游离脂肪酸浓度的增长。真空度保持在80Kpa以上时，其游离脂肪酸浓度下降为同期常规储藏的42％左右：在荞麦米的色泽保持方面，避光条件下，真空袋装能很好地保持荞麦米原有色泽，但在光照条件下，它的护绿效果却很不明显，只略好于常规储藏。     

Observations of extreme upwelling filaments in the southeast atlantic ocean

Cold oceanic water upwells along the western coastline of most major continents. The thermal front that demarcates the farthest seaward extent of this upwelled water is sometimes characterized by extensive whisps or cross-frontal filaments. These may play an important role in the functioning of the upwelling ecosystem as a whole. Satellite observations on filaments of the Benguela upwelling system show filaments that exceed 1000 kilometers in length. Two mechanisms that may produce the exceptional length of these filaments are interaction with Agulhas rings and the effect of intense berg winds.     

Impact of lower atmospheric carbon dioxide on tropical mountain ecosystems

Carbon-isotope values of bulk organic matter from high-altitude lakes on Mount Kenya and Mount Elgon, East Africa, were 10 to 14 per mil higher during glacial times than they are today. Compound-specific isotope analyses of leaf waxes and algal biomarkers show that organisms possessing CO2-concentrating mechanisms, including C4 grasses and freshwater algae, were primarily responsible for this large increase. Carbon limitation due to lower ambient CO2 partial pressures had a significant impact on the distribution of forest on the tropical mountains, in addition to climate. Hence, tree line elevation should not be used to infer palaeotemperatures.