Honey Bees (Hymenoptera: Apidae) Decrease Foraging But Not Recruitment After Neonicotinoid Exposure

Honey bees (Linnaeus, Hymenoptera: Apidae) are widely used as commercial pollinators and commonly forage in agricultural and urban landscapes containing neonicotinoid-treated plants. Previous research has demonstrated that honey bees display adverse behavioral and cognitive effects after treatment with sublethal doses of neonicotinoids. In laboratory studies, honey bees simultaneously increase their proportional intake of neonicotinoid-treated solutions and decrease their total solution consumption to some concentrations of certain neonicotinoids. These findings suggest that neonicotinoids might elicit a suboptimal response in honey bees, in which they forage preferentially on foods containing pesticides, effectively increasing their exposure, while also decreasing their total food intake; however, behavioral responses in semifield and field conditions are less understood. Here we conducted a feeder experiment with freely flying bees to determine the effects of a sublethal, field-realistic concentration of imidacloprid (IMD) on the foraging and recruitment behaviors of honey bees visiting either a control feeder containing a sucrose solution or a treatment feeder containing the same sucrose solution with IMD. We report that IMD-treated honey bees foraged less frequently (–28%) and persistently (–66%) than control foragers. Recruitment behaviors (dance frequency and dance propensity) also decreased with IMD, but nonsignificantly. Our results suggest that neonicotinoids inhibit honey bee foraging, which could potentially decrease food intake and adversely affect colony health.     

Effects of an extreme flash flood on the native fish assemblages across a Mediterranean catchment

Abstract  The effects of an extreme flash flood on the native fish assemblages across a Mediterranean catchment in Southwest Portugal were investigated. The fish community structure and habitat were surveyed at 10 sites pre- and post-flood. Overall species richness and rank abundances changed little after the flood, despite there being a consistent decline in the abundance of small cyprinids. Pre- and post-flood habitat correlates of abundance changed for at least some species, and variability in assemblage structure was associated with flood, depth and pH. These results indicate that extreme floods occurring early in the wet season may have little disruptive effects on the overall structure of native fish assemblages in Mediterranean streams, although may at least partially influence population dynamics for some species. Habitat quality and complexity are likely to play a role in mediating species responses to flooding.     

不同干豆豆浆机制备豆浆的主要品质评价

以大豆为原料选用我国2个主导品牌的3款豆浆机(九阳精磨豆浆机、九阳无网干豆豆浆机、美的无网干豆豆浆机)制作豆浆,从蛋白质含量、蛋白质回收率、豆浆颗粒度及感官特性等方面对豆浆品质进行评价.结果表明:豆浆的蛋白含量为1.72%～2.66%,蛋白回收率为47.13%～68.66%,带有精磨器的豆浆机制备的豆浆蛋白含量及蛋白回...     

高寒区多源降水产品精度与水文模拟效果评估——以雅鲁藏布江流域和拉萨河流域为例

卫星降水产品在缺资料地区开展水文气象研究及径流模拟中发挥着至关重要的作用,然而卫星降水产品的精度可能会影响径流模拟效果。采用多种统计指标和VIC水文模型综合评估5种卫星降水产品(CMORPH-BLD、GSMaP＿Gauge、CMFD、MSWEP和PERSIANN-CDR)在雅鲁藏布江流域的精度和拉萨河流域的水文模拟效果。结果表明：(1)CMORPH＿BLD和GSMaP＿Gauge在少雨季存在低估,CMFD在少雨季与观测值具有很好的一致性。MSWEP和PERSIANN-CDR在多雨季和少雨季存在高估。降水量方面,CMORPH-BLD和CMFD均较为接近观测值,其他降水产品存在不同程度的高估。(2)日尺度上,除CMFD外其他卫星降水数据与观测值具有较小的相关性(0.26～0.45),CMORPH-BLD和CMFD和观测值具有较好的一致性,CMFD和MSWEP探测小降水事件(0.1,0.5,1 mm/d)的能力优于GSMaP＿Gauge。各卫星降水产品在探测强降水(2,5,10 mm/d)方面能力不足。日降水2 mm/d的降水阈值为各分类指数的变化点。(3)月尺度上,各降水产品与观测值具有很...     

沉水植物化感作用抑制藻类生长的研究进展

根据国内外相关报道,重点对9科15种沉水植物化感作用物质的构成及抑制15种藻类的生长,沉水植物化感作用抑制藻类生长的机理等方面的研究进展进行综合评述。     

土豆淀粉废水发酵普鲁兰多糖的研究

普鲁兰多糖是一种具有重要应用价值的微生物胞外多糖。淀粉废水是加工淀粉过程中不可避免的一种产物,成份复杂,营养丰富。利用淀粉废水作为碳源制得普鲁兰多糖,不仅使多糖的生产成本降低,变废为宝,还会减少环境污染。本文通过比较实验获得用土豆淀粉废水(potato starch waste)制多糖产率高于其它碳源,并且确定最佳发酵培养基为(%):土豆淀粉废水10,KH2PO40.6 NaCL0.2(NH4)2SO40.08。     

浙江天童国家森林公园常绿阔叶林生物量研究(Ⅱ)群落生物量及其分配规律

森林生物量测定一直是森林生态系统研究的主要内容,也是地区森林生态系统长期监测所必需的基础性研究。以浙江天童国家森林公园常绿阔叶林为研究对象,于2003年10月份采用收获法(草本层、灌木层)和标准木法(乔木层)相结合的方法,测定了以木荷Schimasuperba,米槠Castanopsis carlesii为优势种的群落地上部分生物量。结果表明:群落地上部分总生物量为(141.0770±17.4298)t.hm-2(平均值±标准差,n=3),其中接近90%集中于乔木层,其他层生物量分配较少。群落及其各层生物量种间分配差异较大,以优势树种木荷和米槠生物量为主,其生物量主要由树干组成,器官分配大小顺序为干>枝>叶。群落萌枝生物量主要集中在灌木层,50%以上由米槠萌枝生物量构成。群落生物量及其分配状况基本体现了以木荷和米槠为优势种的该群落结构特征及常绿阔叶林群落生物量分配特征。表5参15     

兰州大尾羊心脏型脂肪酸结合蛋白（H-FABP） 基因克隆及其同源性比较

【目的】克隆兰州大尾羊心脏型肪酸结合蛋白（H-FABP）基因全长cDNA序列,为研究绵羊H-FABP生物学作用和生产应用提供理论依据。【方法】根据已知哺乳动物H-FABP基因 cDNA 序列,设计5''和3''特异引物,运用cDNA 末端快速扩增（RACE）技术获得兰州大尾羊H-FABP基因全长 cDNA 序列。【结果】 扩增获得兰州大尾羊5''端425 bp、3''端231 bp片段和 177 bp中间片段,拼接获得748 bp兰州大尾羊H-FABP基因全长cDNA 序列（GenBank登录号：JQ780322）。 兰州大尾羊H-FABP基因ORF长 402 bp,编码 133 个氨基酸。核苷酸序列分析显示兰州大尾羊H-FABP基因序列与大多数哺乳动物相似,但其第66位发生的碱基转换（T←→G）引起所编码的第22位天门冬氨酸（N）不同于其它所有物种的赖氨酸（K）。构建的基因进化树分析结果显示兰州大尾羊与山羊亲缘关系最近。预测兰州大尾羊H-FABP蛋白质的空间结构与山羊和牛H-FABP类似,由2个α螺旋和10个反向平行的β折叠组成,10 个折叠片围成一个桶状结构,疏水性残基位于桶内,用于结合脂肪酸。【结论】克隆了兰州大尾羊H-FABP基因,为进一步研究该基因的功能奠定了基础。     

Approaches to pathogen-mediated resistance breeding against plum pox potyvirus in stone-fruit trees1

In a programme for developing systems which allow the transfer of foreign genes into apricot cultivars, we have tested cotyledons of immature embryos, somatic embryos and leaf discs. Apricot plants have been transformed, and then regenerated, with Agrobacterium tumefaciens strain LBA 4404 containing various binary plasmids: pBinGUSint, carrying the marker gene β-glucuronidase (GUS), and pBinPPVm, carrying the coat-protein gene of plum pox potyvirus (PPV). The marker gene GUS was used for visual evaluation of the efficiency of the transformation system. The coat-protein gene was used in the hope of introducing coat protein-mediated resistance to one of the most important stone-fruit pathogens in Europe and the Mediterranean area.     

Isolates of Verticillium dahliae Pathogenic to Crucifers Are of at Least Three Distinct Molecular Types

ABSTRACT Diverse isolates of the soilborne wilt fungi Verticillium dahliae and V. albo-atrum were studied to understand the nature and origins of those infecting cruciferous hosts. All isolates from cruciferous crops produced microsclerotia, and the majority produced long conidia with a high nuclear DNA content; these isolates were divided into two groups by amplified fragment length polymorphism (AFLP) analysis. One group could be subdivided by other criteria such as rRNA sequences and mitochondrial DNA restriction fragment length polymorphism (RFLP) analysis. Two crucifer isolates were short spored and had a low nuclear DNA content. The results are consistent with the crucifer isolates being interspecific hybrids. The long-spored isolates are best regarded as amphihaploids (or allodiploids) with the AFLP groups probably each representing separate interspecific hybridization events. The short-spored crucifer isolates appear to be derived from interspecific hybrids and are here called 'secondary haploids'. Molecular evidence suggests that one parent in the crosses was similar to V. dahliae. The other parent of the amphihaploids seems to have been more similar to V. albo-atrum than to V. dahliae, but was distinct from all isolates of either species so far studied. The implications for the taxonomy of crucifer isolates are discussed and the use of the name V. longisporum, proposed elsewhere for just some of these isolates, is discouraged.