干旱对不同地力水平、不同品种小麦生育性状及产量的影响

在相同的水分条件下 ,对不同地力水平、不同品种小麦的生育性状及产量进行比较。研究结果表明 ,小麦品种 9350 31在高肥力条件下表现突出 ,鲁麦 2 1适应性广 ,在中、低肥力地块上表现最佳     

PP_(333)对温室葡萄枝条次生木质部细胞解剖结构的影响

为了研究设施栽培条件下葡萄木质部细胞的特征性结构及其受PP_(333)的影响,试验通过对温室葡萄喷施PP_(333)后的枝条次生木质部细胞的解离、观察,经统计分析,结果表明:(1)不同浓度PP333处理对各类型细胞的X形态结构没有明显影响;(2)浓度不同对各类细胞的长度和直径抑制作用不同,喷施1500mg/L浓度的PP_(333)对其营养生长的抑制效果最好。通过该试验的研究,为更好地探索设施栽培条件下果树的生理生态特征和化学调控技术提供了依据。     

Cohabitation of tree holes by ants and breeding birds in a temperate deciduous forest

A previously unknown association of ants with birds breeding in tree holes is described. Ants Lasius brunneus Latreille (Hymenoptera: Formicidae) were found in c. 15% of nests of Parus major L. and Poecile palustris L. (Paridae) breeding in tree holes in the primeval deciduous forest located in the Bia?owie?a National Park (Poland). The ants preferably used holes located higher above the ground. As such holes are warmer than the unused holes or other nest sites, it is suggested that the ants cohabit holes utilized by the tits to gain thermal benefits.     

国有林场木材产、销、存计算机辅助管理系统

阐述国有林场木材产、销、存计算机辅助管理系统的设计目标、运行环境、运行特点、数据流程图及系统功能。运用该系统可进行进出仓材积、价格、金额计算 ,各种报表生成和打印 ,完全避免木材生产销售中的计算差错和损失 ,从而提高林场的经营管理水平 ,也便于快速获取各种数据 ,为经营决策提供科学依据。     

硒蛋白X基因克隆、定点突变、原核表达及多克隆抗体制备

本试验旨在克隆鉴定猪硒蛋白X(Sel X)基因,将其定点突变后进行原核表达,获得重组蛋白,并制备猪Sel X多克隆抗体,为以猪为模型Sel X功能研究奠定基础。利用c DNA末端快速克隆(3'-RACE)技术从猪肝脏总RNA扩增出含开放阅读框(ORF)至poly(A)共1 215 bp的Sel X基因c DNA片段,其348 bp的ORF编码区和对应的氨基酸残基与人相应序列分别有88%和91%序列同源性,猪Sel X基因提交NCBI Gen Bank数据库,序列号为EF113597。ORF编码氨基酸残基中硒代半胱氨酸(Sec)位于C-端第95个残基,其编码密码子TGA经定点突变为半胱氨酸(Cys)的TGT后,将其插入载体p ET30,转入大肠杆菌BL21(DE3)中,在0.5 mmol/L异丙基硫代-β-D-半乳糖苷(IPTG)诱导2 h获得融合表达产物,经His-tag亲和层析后,获得分子质量为18.0 ku的纯化蛋白。将纯化获得的Sel X基因突变体融合蛋白(Sel Xm)免疫兔子,得到效价高达1∶20 000的多克隆抗体,免疫印迹(Western-blot)结果显示该抗体能特异性识别纯化的Sel Xm和猪肝脏中相应Sel X。本试验成功克隆并鉴定了猪Sel X基因,并制备了其多克隆抗体。     

紫苏籽提取物对蛋鸡产蛋高峰后期生产性能、生殖激素及免疫功能的影响

为了探讨在饲粮中添加不同水平紫苏籽提取物对蛋鸡产蛋高峰后期生产性能、生殖激素及免疫功能的影响,本试验选用体重、产蛋率基本一致的48周龄海兰褐蛋鸡480只,采用单因素完全随机试验设计,随机分为4组,每组6个重复,每个重复20只。对照组饲喂基础饲粮,试验Ⅰ、Ⅱ、Ⅲ组分别在基础饲粮中添加0.01%、0.02%、0.03%的紫苏籽提取物,试验期30 d。结果表明:1)与对照组相比,饲粮中添加0.01%、0.02%、0.03%紫苏籽提取物均能降低料蛋比,但差异不显著(P0.05),4组间日均采食量、破软蛋率无显著差异(P0.05),添加0.03%紫苏籽提取物能极显著提高蛋鸡产蛋率和日均产蛋量(P0.01);2)与对照组相比,添加0.01%、0.02%、0.03%紫苏籽提取物能极显著提高蛋鸡血清中孕酮(第15天)和雌二醇(第15和30天)的含量(P0.01),添加0.03%紫苏籽提取物能极显著降低蛋鸡血清中睾酮含量(P0.01);3)与对照组相比,添加0.01%、0.02%、0.03%紫苏籽提取物能极显著提高蛋鸡血清中白细胞介素-2(IL-2)含量(P0.01),添加0.02%、0.03%紫苏籽提取物能极显著提高蛋鸡血清中免疫球蛋白G(Ig G)含量(P0.01),添加0.03%紫苏籽提取物能极显著提高蛋鸡血清中免疫球蛋白A(Ig A)含量(P0.01)。由此可知,饲粮中紫苏籽提取物添加水平为0.03%时,能极显著提高蛋鸡产蛋高峰后期产蛋率、日均产蛋量和免疫功能。     

Frozen bread dough: Effects of freezing storage and dough improvers

This review focuses on the effects of freezing storage on the microstructure and baking performance of frozen doughs, and provides an overview of the activities of dough improvers, including emulsifiers, hydrocolloids and other improvers used in frozen dough applications. The overall quality of bread baked from frozen dough deteriorates as the storage of the dough at sub-zero temperatures increases due to several factors which are discussed. Lipid-related emulsifiers such as diacetyl tartaric acid esters of mono and diglycerides and sucrose esters employed as anti-staling agents, dough modifiers, shortening sparing agents, and as improvers for the production of high-protein bread have also been employed in frozen doughs. Hydrocolloids are gaining importance in the baking industry as dough improvers due to their ability to induce structural changes in the main components of wheat flour systems during breadmaking steps and bread storage Their effects in frozen doughs is discussed. Other dough improvers, such as ascorbic acid, honey and green tea extract, are also reviewed in the context of frozen doughs.     

靶向甲型流感病毒血凝素的人源单克隆抗体研究进展

甲型流感病毒感染性强,宿主广泛,主要感染禽类,其次为哺乳动物。当跨物种传染事件发生时,有可能造成流感大流行,因此,对病毒实施及时有效的监控,以及研发抗流感病毒药物刻不容缓。流感病毒表面的糖蛋白血凝素在病毒入侵宿主细胞的过程中发挥了关键的作用,可作为单克隆抗体药物的主要靶点。针对血凝素的单克隆抗体能够有效抑制病毒传播,保护宿主。因此,本文综述了目前报道的针对甲型流感病毒血凝素糖蛋白的人单克隆抗体,为后续抗流感药物的研发提供新的思路和展望。     

Congenital cataracts in an Ayrshire herd: a herd case report

Background

Microbiological standards within pork slaughter processing plants in the European Union are currently governed by Commission Regulation (EC) 2073/2005, which describes detailed performance criteria at specific stages of the procedure (following carcass dressing and before chilling) for total viable counts (TVC), Enterobacteriaceae (EB) and Salmonella spp. In this study, 95 carcasses from an Irish pork slaughter plant were sampled by swabbing 100 cm² of surface at three sites (belly, ham, jowl) to examine the effects of eight processing stages (stunning, bleeding, scalding, singeing, polishing, evisceration, final inspection and chilling) on contamination levels.

Results

TVC ranged from approximately 1.7–6.3 log cfu cm² during sampling. There were significant reductions in TVC for all sites after scalding and singeing (p < 0.05), whilst there was a significant increase in counts after polishing and evisceration (p < 0.05) compared with preceding stages. EB counts indicated hygienic weak points in the examined slaughter plant leading to faecal (cross)-contamination, with elevated counts after stunning, bleeding and evisceration (p < 0.05), compared with final counts after chilling.

Conclusions

Although the bacterial numbers reported in this study may reflect specific plant practices and temporal influences, results show that contamination can be introduced at various steps in the process and highlight the importance of monitoring locations other than those required by legislation within the process. Monitoring can be used to establish baseline levels for high-risk stages specific to each plant and to assess the effectiveness of additional interventions.     

Risk-based surveillance of antimicrobial residues in pigs – Identification of potential risk indicators

Around 20,000 samples are analysed each year for the presence of antibacterial residues in Danish finisher pigs, and between zero and five samples are detected positive above the maximum residue level (MRL). The intention was to develop a risk-based surveillance programme involving fewer samples while ensuring equal sensitivity. Therefore, risk indicators were searched for. Data were obtained from the Danish slaughterhouse database covering the period from July 2010 to December 2012. Residues were found or suspected in 17 incidents. In nine of these, the farmer had called in to prevent the pigs from being slaughtered. Hence, eight suspect cases were found through the surveillance programme, and two of these were above MRL. For these eight case herds, the number of pigs slaughtered and the number in which each of the following lesions were found were included in a statistical analysis: chronic pleuritis, tail bite, chronic pericarditis, chronic pneumonia, chronic peritonitis, osteomyelitis, abscess in hindquarters, abscess in leg/toe and abscess in forequarters. Only chronic pleuritis was associated with the presence of residues. Next, data from all herds delivering pigs for slaughter to the same abattoir were included covering a 3-month period prior to the residue finding. The prevalence of chronic pleuritis was on average 1.7 times higher in the eight case herds compared to all other herds. In two herds, the prevalence was significantly higher (P ≤ 0.05), and in one herd substantially higher, but only borderline significant (P = 0.1). In the remaining herds, the prevalence did not differ from the other herds delivering pigs to the abattoir. This indicates that chronic pleuritis might be considered as a risk indicator for use in surveillance. Other risk indicators/factors – reported in the cases where the farmers called in – were inadequate marking of treated animals and incorrect use of medication dispensers. These factors are not suited for use in surveillance and should be dealt with otherwise.