Synthetic rat scotophobin induces dark avoidance in mice

Two independent research groups replicate alteration of dark preference to dark avoidance by mice injected with synthetic scotophobin, a pentadecapeptide.     

Cytochrome P-450 mediated O-dealkylation of 7-alkoxycoumarins in liver microsomes from rainbow trout (Salmo gairdneri)

Evidence has recently been presented for variation in the inducibility of various 7-alkoxycoumarin-O-dealkylase activities in liver microsomes from a number of mammalian species by -naphthoflavone (NF). In the present study we have investigated the inducibility of hepatic microsomal 7-methoxycoumarin-O-demethylase, 7-ethoxycoumarin-O-deethylase, 7-propoxycoumarin-O-depropylase and 7-butoxycoumarin-O-debutylase activities in rainbow trout by NF. O-demethylase activity was increased approximately 17-fold, O-deethylase and O-depropylase activities approximately 9-fold and O-debutylase activity approximately 25-fold. The kinetics of the various hepatic microsomal 7-alkoxycoumarin-O-dealkylase activities were investigated in control and NF-treated rainbow trout. The O-demethylase-, O-depropylase- and O-debutylase activities exhibited monophasic Michaelis-Menten kinetics in liver microsomes from both control and NF-treated rainbow trout, whereas the O-deethylase activity exhibited biphasic Michaelis-Menten kinetics in control liver microsomes and monophasic Michaelis-Menten kinetics in liver microsomes from NF-treated rainbow trout.     

Evaluation of PCR systems for the identification and differentiation of Mycoplasma agalactiae and Mycoplasma bovis: a collaborative trial

Diagnostic differentiation between the ruminant pathogens Mycoplasma agalactiae and Mycoplasma bovis is known to be problematic when only conventional serological and biochemical tests are used. The main reason for this is that both agents share a considerable number of related proteins and common epitopes. DNA-based detection methods offer advantages in terms of specificity and sensitivity. However, there is an urgent need to compare currently used PCR assays because they target different genomic regions and, therefore, may perform differently. In the present work, five laboratories, which use PCR routinely, evaluated the specificity of four different PCR systems for M. agalactiae and three systems for M. bovis on a total of 41 strains of the two Mycoplasma species including six previously unidentified strains. As the vast majority of PCR examinations (97.1% of all tests) correctly identified the strains the specificity of all seven detection systems appears to be high. In four cases, incorrect identification by conventional diagnostic methods was rectified by PCR. Isolates from non-typical hosts, i.e. three M. bovis strains from small ruminants and two M. agalactiae strains from cattle, were characterised by sequencing the 16S and part of the 23S ribosomal RNA genes.     

Nutritional restriction in utero programs postnatal muscle development in lambs

The effect of nutritional programming during late gestation on evoked compound muscle action potentials (CMAP) during early postnatal life was examined. Lambs were born to ewes that were fed either an adequate or low nutrient supply during the last trimester of gestation. Lambs were born to either a ram with a high genetic potential for daily live weight gain, or a ram with a high genetic potential for both daily gain and lean content. CMAP signals were evoked by electrical stimulation and recordings were analyzed in terms of area, amplitude, width at 50% maximal height and both leading and trailing slopes. Significant effects of nutrient restriction during late gestation were measured for lamb birthweight, bodyweight at day 21 and growth rate (P < 0.001), as well as CMAP area, corrected peak and slope for Musculus longissimus dorsi at day 21 and as early as day 10 for Musculus biceps femoris. In conclusion, nutrient restriction during the last trimester of gestation influences evoked CMAP signal parameters postnatally in a muscle‐specific fashion, and muscle development may be related to paternal genetic background.     

广州地区猫泛白细胞减少症病毒分离鉴定及全基因组遗传分析

【目的】分析广州地区猫泛白细胞减少症病毒(Feline panleukopenia virus,FPLV)的自然重组、跨宿主传播以及流行变异情况。【方法】采集疑似感染猫泛白细胞减少症病毒的猫粪便样品进行细胞分离,并对阳性病料提取基因组DNA,PCR扩增获得病毒的全基因组序列,并与Gen Bank中相关的参考毒株序列进行遗传进化分析,同时对VP2基因与NS1基因的主要氨基酸位点进行差异分析。【结果】成功获得2株猫泛白细胞减少症病毒及其全基因组序列。遗传进化分析显示,广州地区分离的猫泛白细胞减少症病毒FPLV-GZ01、FPLV-GZ02与我国其他分离毒株FPLV-XJ01、FPLV-HRB属同一分支,提示FPLV-GZ01、FPLV-GZ02由FPLV-XJ1进化而来;NS1基因系统进化树显示,FPLV存在与CPV-447重组的可能。主要氨基酸位点分析显示,FPLV在VP2基因中的主要氨基酸位点上的遗传变异比CPV保守;在NS1基因上发现FPLV-GZ01、FPLV-GZ02分别存在不同程度的氨基酸位点突变。【结论】广州地区分离的猫泛白细胞减少症病毒仍在不断地重组进化。     

对提升科研院所惠农服务能力的思考

科技惠农服务是推动科技创新和成果转化、支撑农业提质增效的有效载体。地方科研院立足现代农业发展特点,通过完善科技惠农服务管理体系、创新服务模式和机制,深化了科研与产业合作。根据都市型现代农业转型发展需求、科技惠农服务"四种功能"发挥和"三个服务"目标要求,该研究从强化科技惠农工作的统筹布局、深化产学研用合作、提升基地示范展示水平、深化科技培训和普及工作、推动科技协同服务等方面,继续提升科技惠农服务能力。     

农机需求下降“十大原因”深度分析

2010年1月-4月,国内农机行业度过了一个漫长的市场低迷期,没有再现2009年同期的繁荣景象,市场的冷清出乎许多人的意料.从终端市场统计回来的资料分析,截止4月底,大中轮拖国内行业实际销售约5200台,同比下降50%以上,社会库存与实销比约4:1;有收获机行业风向标之称的小麦联合收获机实销量仅有8000台左右;另外全喂入水稻收获机销量也只有2000台左右,而2009年同期小麦联合收获机销量已经达到了35000台,全喂入水稻联合收获机销售量13500台,两种产品实销量同比分别下降75%、80%,主销产品社会实销量下降幅度之大,令人震惊.面对急转直下的市场销售现状,需要我们认真思考,深入探究,寻找问题根源和解决办法.     

From Molecules to Products: Some Aspects of Structure–Function Relationships in Cereal Starches

In this review, starch behavior is described from molecules in solution to the use of starch in products. The determination of molecular characteristics with asymmetrical flow field‐flow fractionation is described, and the behavior of starch in binary solutions is discussed. The organization of starch in granules and the changes in organization during gelatinization and retrogradation are then described. The role of starch retrogradation in bread staling is described in some detail, and the influence of water mobility and distribution is discussed in relation to amylopectin retrogradation. Finally, the use of starch as emulsifier is described. Hydrophobically modified starch is one possibility for emulsion stabilization; also, the starch granule as such can be used to stabilize emulsions (so‐called Pickering emulsions).     

新形势下北京种业发展的路径研究

掌握种业发展现状和科学判断发展形势是探索新型种业体系建立路径的重要内容。北京籽种产业具有基础性、战略性、知识性和辐射性等特点。促进北京种业壮大,对"种业之都"建设和保障国家粮食安全具有重要意义。该研究总结了"十二五"以来北京籽种产业发展取得成效及问题,在对现代农业、科技创新、市场环境等发展趋势进行判断基础上,从深化机制、优化环境、建设育种体系、推动产业化等方面提出北京种业发展的路径。