染色体易位重组位点的自动识别方法研究

染色体易位重组位点的识别对很多染色体遗传性疾病的诊断有着重要的意义.本文基于实际诊断中采集到的24类染色体数据和9号正常与异常染色体数据,构建了一套自动识别染色体易位重组位点的模型和方法.首先,对染色体图像进行预处理,得到了方向梯度直方图特征(HOG)和局部二值模式特征(LBP),构建了基于纹理特征的染色体24分类多通...     

α/β类蛋白质折叠类型的分类方法研究

蛋白质折叠规律的研究是生命科学重大前沿课题之一,折叠分类是蛋白质折叠研究的基础。本文基于LIFCA数据库,选取样本量大于2的55种α/β类蛋白质折叠类型为研究对象。结合蛋白质折叠类型的定义及其保守拓扑结构特征,确定了55种蛋白质折叠类型的模板及其对应的特征参数。建立了基于模板的打分函数Mul-Fscore,并结合二级结构参数信息,给出了55种α/β类蛋白质折叠类型的多模板分类方法。用此方法对LIFAC数据库中的931个样本进行检验,分类结果的平均特异性、平均敏感性、MCC值分别为99.58%、79.47%、79.39%。与TM-score分类结果对比发现,Mul-Fscore分类的敏感性与MCC值好于TM-score的相应结果,平均特异性相近。     

四川省鸟类种类记叙

按《世界鸟类分类及分布名录》的分类体系,结合四川省近年来发现的新记录,统讣四川省鸟类有20目78科647种,占全国鸟类目的83．3％,科的77．2％,种的50．0％。其中非雀形目有19H4l科264种,雀形目有37科383种。在目级水平上的变化是将原沙鸡科和戴胜科分别提升为目。在科级水平上的变化较大,新增了许多科。近年来四川省新发现增加的科是鹈鹕科和盔鹏科。四川省有国家Ⅰ级保护鸟类15种,Ⅱ级保护鸟类82种;列入CITES(2003)附录I的有9种,附录n的有57种;IUCN(2002)红色名录的物种有33种;有中国鸟类特有种37种,占全国鸟类特有种的53．6％。     

Direct and Indirect Classification in Clinical Research

We investigate if the use of a priori knowledge allows an improvement of medical decision making. We compare two frameworks of classification – direct and indirect classification – with respect to different classification errors: differential misclassification, observed misclassification and true misclassification. We analyze general behaviors of the classifiers in an artificial example and furthermore as being interested in the diagnosis of early glaucoma we adapt a simulation model of the optic nerve head. Indirect classifiers outperform direct classifiers in certain parameter situations of a Monte‐Carlo study. In summary, we demonstrate that indirect classification provides a flexible framework to improve diagnostic rules by using explicit a priori knowledge in clinical research.     

Sex-specific indicators of landscape use by servals: Consequences of living in fragmented landscapes

The conversion of wetlands and its associated habitat for farming, residential development and commercial purposes has led to many small disconnected patches of native vegetation surrounded by generally inhospitable human altered land uses. Such human interventions pose a serious threat to the survival of wetland dependent indicator species such as the serval (Leptailurus serval) in the Drakensberg Midlands of KwaZulu-Natal, South Africa. To address the effects of habitat fragmentation on serval space use we used GPS fixes of collared individuals for 100 days between May 2013 and January 2014. We tracked five females and eleven male servals with GPS-UHF collars. Fragmentation indices at the class level (wetland, forest with bushland, grassland and cropland) were measured within the collared serval's minimum convex polygon area (MCP) of home range. Serval use points and fragmentation indices were extracted to each sub-landscape unit of 2 km² falling within the MCP home range. The response of serval population to fragmentation indices was analyzed using generalized linear models at three levels: male, female and the overall population. We found that core area of wetland positively explained landscape use by servals. Effects of forest core area, forest proximity and patch richness were important for landscape use by male servals. Male and female serval use declined with increase in complex shapes of forest and grassland, wetland clumpiness for females and overall, and cropland patches for servals overall. Our results showed that wetland is a key determinant for the survival of male and female servals in fragmented landscapes therefore effective conservation of serval population demands adequate viable native habitat.