Implications of simian retroviruses for captive primate population management and the occupational safety of primate handlers.

Nonhuman primates can be naturally infected with a plethora of viruses with zoonotic potential, including retroviruses. These simian viruses present risks to both captive nonhuman primate populations and persons exposed to nonhuman primates. Simian retroviruses, including simian immunodeficiency virus, simian type D retrovirus, simian T-lymphotropic virus, and gibbon ape leukemia virus, have been shown to cause clinical disease in nonhuman primates. In contrast, simian foamy virus, a retrovirus that is highly prevalent in most nonhuman primates, has not been associated with clinical disease in naturally infected primates. Although it has been shown that human retrovirus infections with human T-lymphotropic virus and human immunodeficiency virus originated through multiple independent introductions of simian retroviruses into human populations that then spread globally, little is known about the frequency of such zoonotic events. In this article, exogenous simian retroviruses are reviewed as a concern for zoo and wildlife veterinarians, primate handlers, other persons in direct contact with nonhuman primates, and other nonhuman primates in a collection. The health implications for individual animals as well as managed populations in zoos and research institutions are discussed, the cross-species transmission and zoonotic disease potential of simian retroviruses are described, and suggestions for working safely with nonhuman primates are provided.     

Plasma protein levels as potential marker traits for resistance to furunculosis

Abstract. The feasibility of including individual records on correlated traits in a family selection programme which aims to increase resistance to furunculosis in Atlantic salmon was studied; markers were selected because of their potential role in the pathogenesis of the disease. Fibrinogen and α₂-antiplasmin both show genetic variation; both are correlated with survival after challenge with Aeromonas salmonicida , the correlation being 0·44 and 0·37 ( P < 0·05), respectively, and it is possible to measure both on a large scale at low costs. Contrary to α₂-antiplasmin, fibrinogen was negatively correlated with survival due to furunculosis within the 10 most resistant families and within the 10 most susceptible families in contrast to an overall positive correlation. This inconsistency could be attributable to the presence of different allelic phases in different families, and of major linked loci influencing survival and fibrinogen levels. Thus, only α₂-antiplasmin fulfils the requirements for a marker trait for resistance to the disease suitable for individual selection at the population level, whereas the use of fibrinogen would be restricted to within family selection. The full statistical model explained 51% of the variation in resistance to furunculosis, and α₂-antiplasmin contributed 15% to this variation when considered as a separate entity. Thus, the additional gain from including individual records on α₂-antiplasmin in a family selection programme could be significant.     

Electrodeposited ceramic superlattices

Ceramic superlattices have been produced by electrodeposition with modulation wavelengths in the range from 5 to 10 nanometers. The TlaPbbOc/TldPbeOf superlattices were deposited from a single aqueous solution at room temperature, and the layer thicknesses were galvanostatically controlled. The films showed strong preferred orientation and distinct first-order satellites around the Bragg reflections in the x-ray diffraction pattem. The modulation wavelengths calculated from the satellite spacings were in agreement with those calculated from Faraday's law. Because the modulation wavelengths are of electron mean free path dimensions, this dass of degenerate semiconductor metal-oxide superlattices may exhibit thickness-dependent quantum optical, electronic, or optoelectronic effects.     

Adaptation of a latex agglutination tube test for diagnosis of Mycoplasma hyopneumoniae swine pneumonia

A tube latex agglutination test (LAT) for diagnosis of Mycoplasma hyopneumoniae swine pneumonia was developed. In pigs inoculated with M. hyopneumoniae, LAT antibodies were generally detected 2–3 weeks post-inoculation, which was 1 week or more before complement-fixing antibodies were first detected in the corresponding pigs. Correlation of LAT results and gross and microscopic lung lesions of corresponding pigs revealed that LAT titers persisted after the pneumonic lesions had resolved.Latex agglutination titers in pigs exposed by contact with M. hyopneumoniae inoculated pigs were demonstrated 4–12 weeks post-contact.Latex agglutination antibodies were detected up to 48 weeks post-inoculation in pigs inoculated with M. hyopneumoniae and this was similar to the duration of detectable indirect hemagglutination titers. Complement-fixation titers, however, were demonstrated no longer than 28 weeks post-inoculation in corresponding pigs.Evaluation of repeatability of LAT results revealed some variation of LAT titers of sera titered on four different occasions.Sera from pigs inoculated with other swine mycoplasmas, including M. hyosynoviae and M. hyorhinis, did not react in the M. hyopneumoniae LAT. In addition, no detectable titers were demonstrated in the M. hyopneumoniae LAT using sera from pigs infected with Metastrongylus spp., Ascaris suum, or in sera from pigs vaccinated with any of four commonly used swine vaccines.     

美国本地阔叶材获得新的市场地位

木地板行业显现的趋势之一就是其产品将从采用进口树种回归至国内树种。在过去几年中由于非法采伐造成价格下降,燃起了人们对进口树种的热情,但是行业主管人员相信今年春季逐步实施的雷斯法案正在拉平价格,国外树种价格将会上升,从而促使国外树种需求下降。     

秋季国外地板全扫描

尽管近来购买者多是看得多买得少,但是商家不乏推介新产品以引起购买者的关注。供应商力争使其产品与众不同,并且帮助商家利用新的盈利手段来推动秋季销售。其中最值得关注的是：     

基于改进Bayes抠图算法的麦穗小穗自动计数方法

小麦产量评估需人工获取田间单位面积的麦穗数和麦穗小穗数，往往耗时耗力。为了实现高效、自动地麦穗小穗计数，提出一种基于改进Bayes抠图算法的麦穗小穗自动计数方法。该方法首先利用改进Bayes抠图算法对获取地自然生长条件下的麦穗图像进行抠图，将麦穗从自然背景中分割出来。然后对该图像进行平滑滤波和二值化，运用迭代极限腐蚀运算对二值化图像进行腐蚀处理，去除麦穗图像中的麦芒，分离出麦穗上每个单独的麦穗小穗。再运用面积滤波滤除掉面积过小的区域，对剩余区域的黑洞进行填充，由此每个单独的麦穗小穗形成一个单独的连通区域，最后对连通区域进行标记和计数，完成麦穗小穗的自动计数。使用4个小麦品种的麦穗图像对麦穗上的小穗进行计数验证，结果表明，该方法在识别4个品种田间麦穗单幅图像中小穗数量的平均计数精度达到94.53%，平均相对误差为5.47%，对比已有麦穗小穗自动计数方法，计数精度显著提高，这对于小麦在线产量预估具有重要意义。     

在系统可编程技术分析

在系统可编程技术将数字系统的设计过程由书面设计──硬件搭配──制做样机改变为书面设计──仿真──制做样机,避免了搭试的诸多弊端。其关键环节仿真,是计算机发展和可编程器件使用的共同结果。