西藏部分地区藏猪戊型肝炎病毒血清流行病学调查

为了解西藏地区藏猪戊型肝炎流行情况,在拉萨、林芝、昌都、日喀则和山南等5个市,采集305份藏猪血清,利用酶联免疫吸附(ELISA)法进行戊型肝炎病毒血清抗体检测,并用SPSS 21.0方法进行不同性别、不同区域间的显著性差异分析。结果显示:从305份藏猪血清中检测到81份抗体阳性,总抗体阳性率为26.6%(81/305);拉萨市和林芝市的抗体阳性率最高,达32.8%(20/61),其次为昌都市、日喀则市和山南市,阳性率分别为29.5%(18/61)、26.2%(16/61)、11.5%(7/61);山南市阳性率与其他4个市相比差异显著(P0.05),公猪和母猪的抗体阳性率分别为23.3%(35/150)和29.7%(46/155),无显著差异(P0.05)。结果表明,西藏地区藏猪群中存在不同程度的猪戊型肝炎病毒感染。鉴于当地存在食用生或半生猪肉和猪肝的习俗,建议加强宣传,倡导健康饮食,同时加强高发区疫病防治,降低人类感染风险。     

信号肽对溶血素在大肠杆菌中跨膜转运的影响

信号肽在引导外源蛋白的跨膜转运过程中具有重要作用。本试验通过PCR方法获得带有信号肽序列和不带有信号肽序列的溶血素基因,构建表达载体在大肠杆菌中进行诱导表达。经过溶血试验和免疫印迹试验证明缺失了信号肽的重组溶血素不能被跨膜转运至细胞外;带有信号肽的重组溶血素能够跨膜转运大肠杆菌细胞外。本试验为猪链球菌2型基因缺失弱毒疫苗的研究、细菌信号肽以及基因工程重组蛋白的可溶性表达进行了有益探索。     

两种诊断制品对临床样品中布鲁氏菌抗体的检测比较

本研究以国家标准《动物布鲁氏菌病诊断技术》(GB/T 18646-2018)中的试管凝集试验方法为确诊金标准,对353份临床牛、羊和猪血清样品进行确诊,然后分别采用虎红平板凝集试验抗原和抗体检测试纸条,对该353份临床血清进行检测,比较两种诊断制品在布鲁氏菌病初筛中的差异。经统计分析发现,虎红平板凝集试验抗原敏感性为100%(23/23),特异性为97.88%(323/330),与确诊结果间的Kappa值为0.86;布鲁氏菌抗体检测试纸条敏感性为100%(23/23),特异性为99.39%(328/330),与确诊结果间的Kappa值为0.95,两种方法的重复性试验结果均一致。试验结果证明,布鲁氏菌抗体检测试纸条和布鲁氏菌虎红平板凝集试验抗原都能满足布鲁氏菌病初筛的需求;由于布鲁氏菌抗体检测试纸条的储存、运输和操作的便捷性,在部分地区或特殊环境下可替代布鲁氏菌虎红平板凝集试验抗原用于布鲁氏菌病初筛。     

A rapid assessment of landscape biodiversity using diversity profiles of arthropod morphospecies

Context

The assessment of land-use impacts on biodiversity is one of the central themes of landscape ecology and conservation biology. However, due to the complexity of biodiversity, it is impossible to obtain complete information about the diversity of all species even for small areas, necessitating the selection of individual species or assemblages thereof as species surrogate. In parts of the world where taxonomic expertise is lacking, species identification has hindered progress in biodiversity conservation, and the only practical, relatively-accurate option, is the use of taxonomic minimalism.

Objective

We carried out a rapid biodiversity assessment based on three surrogates—land-use (driver-surrogate), terrestrial arthropods (species-surrogate) and morphospecies (taxonomic-surrogate)—to determine the impacts of land-use on biodiversity of the Western Region (Ghana), an area covering ~4 % of the West African biodiversity hotspot.

Method

We used diversity profiles to visualize the distribution of a total of 8848 arthropod individuals over seven land-use types which define the complete heterogeneity of the landscape.

Results

Here, we present both sample and asymptotic diversity profiles of arthropod morphospecies for each land-use type and the potential of each land-use type for conserving arthropods.

Conclusions

We conclude that (1) the morphospecies approach is useful for detecting differences in species diversity of land-use types; (2) the concept of asymptotic diversity may not be necessary for land-use based biodiversity comparison; and (3) maximum diversity profiles are useful for determining the land-use conservation values in cases where pristine areas are not available.

     

Increasing selenium supply during the close-up dry period improves nutrient metabolism and attenuates inflammatory response after calving in dairy cows

The objective of this study was to investigate whether feeding selenium (Se)-replete cows a Se-yeast supplement in late pregnancy affects nutrient metabolism and inflammatory response during the periparturient period. Twenty cows were randomly assigned to two groups with 10 cows each. Cows in one group received Se-yeast at 0.3 mg Se/kg DM during the last 4 weeks before calving in addition to fed a TMR containing supplemented sodium selenite at 0.3 mg Se/kg DM (Se-yeast), while cows in another group were only fed a TMR containing supplemented sodium selenite at 0.3 mg Se/kg DM (Control). Blood samples were collected and analyzed for nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), glucose, insulin, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, serum amyloid A (SAA), haptoglobin (Hp), and albumin. In control cows, plasma NEFA, IL-1β, IL-6, SAA, and Hp levels increased after calving, but glucose, insulin, and albumin levels decreased after parturition. Se-yeast supplemental cows had lower postpartum concentrations of NEFA, TNF-α, IL-1β, IL-6, SAA, and Hp, and higher postpartum levels of glucose, insulin, and albumin compared with control cows. The results indicate that feeding Se-replete cows a Se-yeast supplement in late pregnancy improves nutrient metabolism and attenuates the inflammatory response after calving.     

Identification of Differentially Expressed Genes and Lipid Metabolism Signaling Pathways between Muscle and Fat Tissues in Broiler Chickens

In this study, signaling pathways and key differentially expressed genes (DEGs) involved in lipid metabolism in muscle and fat tissues were investigated. Muscle and abdominal fat tissues were obtained from 35-day-old female broilers for RNA sequencing. DEGs between muscle and fat tissues were identified. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of DEGs were performed. A total of 6130 DEGs were identified to be significantly enriched in 365 GO terms, most of which were involved in biological processes, cellular components, and molecular functions in muscle and fat tissues. Three important lipid signaling pathways (pyruvate metabolism, the insulin signaling pathway, and the adipocytokine signaling pathway) were identified among the fat and muscle tissues of broilers. The key common DEGs in these pathways included phosphoenolpyruvate carboxykinase 2 (PCK2), acetyl-CoA carboxylase 1 alpha and beta (ACACA and ACACB), and the mitogen-activated protein kinase (AMPK) gene family. Hence, our findings revealed the pathways and key genes and gene families involved in the regulation of fat deposition in the muscle and fat tissues of broilers.     

宁夏玉米营养成分近红外分析模型建立与应用

研究采集宁夏区内各市县(固原、海原、同心、中卫、中宁、永宁、平罗)抽取玉米样品120批,用近红外分析仪扫描定标样品集获得玉米近红外光谱图,利用偏最小二乘法建立模型,并分别经过无预处理、均值中心化、标准正态变量转换、一阶导数、标准正态变量转换结合去趋势校正(SNV+D)预处理光谱,获得水分、粗蛋白、粗脂肪、粗纤维预测模型,分别是经过MC、SNV+D、SNV+D、SNV+D光谱预处理后效果最好。预测决定系数R² _p分别为0.951、0.976、0.728、0.897,相对分析误差RPD除粗脂肪为2.62外,其他均大于3的近红外预测模型,通过预测模型验证集验证后,并对模型预测值与实测值进行U检验,结果为差异不显著(P>0.05)。该近红外预测模型对玉米中水分、粗蛋白、粗纤维具有较佳预测效果,粗脂肪的预测精度有待进一步提高。     

Effects of late planting on fiber quality and within-boll yield components as mediated by sucrose metabolism in cotton bolls

ABSTRACT

The objective of this study was to examine the effect of late planting on sucrose metabolism in cotton bolls and the relationship to fiber properties and within-boll yield components. Two cotton lines A201 and A705 were employed in a sowing date experiment where two temperature regimes during boll maturation period were created at mean daily temperature of 26.8°C, 28.3°C for early planting and 25.2°C, 23.1°C for late planting in 2016 and 2017, respectively. Boll size, seed mass per boll, seed index and fiber length were increased, and lint percentage was decreased by late planting. Greater cell wall invertase activity and the resultant hexose concentration in fibers were observed in late planting, and thus led to decreased osmotic potential accounting for the enhanced fiber length. Similarly, late planting increased the maximum of vacuolar invertase activity in ovules occurring at 5 days post anthesis (DPA) and hexose concentrations in embryos from 10 DPA afterwards which may favor embryo cell division, and thus increase final seed size. Our data indicate that acid invertase and hexose are implicated in the formation of within-boll yield components and fiber properties as affected by the lower temperature regime due to late planting.     

烤烟带电育苗病虫害与生长调查

利用双层带电育苗技术，研究其对烟苗育苗期间常见的病虫害预防效果以及苗的生长状况。结果表明:带电育苗对根茎类和气传病害有预防效果。烟苗生长速度快，能有效缩短成苗时间、提高烟苗质量；但底层有无人工补光和营养液碳酸氢根离子浓度高低对预防白粉病影响很大，对调控生长效果影响显著。带电育苗时底层补光并在原液中添加碳酸氢钾或在环境中增施烟气CO2，对预防白粉病效果显著。带电育苗上、下层在蚜虫密集环境中仍然不能有效趋避蚜虫，而使用物理植保液防治蚜虫非常有效。      

中喙丽金龟成虫对不同植物种类的危害程度

调查了近年来在上海局部区域严重发生的农林害虫——中喙丽金龟成虫对不同植物种类的危害程度。共计调查243个植物种类,其中109种植物受害,占调查植物种类数量的44.86%。109种受害植物隶属于39个科,以蔷薇科、豆科植物种类最多。