云南省两种兽类新纪录——藏鼩鼱(Sorex thibetanus Kast-schenko,1905)和甘肃鼩鼱(Sorex cansulus Thomas,1912)

目前对藏鼩鼱(Sorex thibetanus)和甘肃鼩鼱(Sorex catnsulus)的分布范围和生物学资料了解较少.2017年,在云南省西北部的高山区域采集了 48号鼩鼱属(Sorex)动物标本.用形态学和基于Cyt b基因的分子系统学对采集标本进行了物种鉴定.结果显示来自4个地点的27号标本形态上与藏鼩鼱相符...     

鼩鼱科三物种转录组初步分析

中国是鼩鼱科物种十分丰富的国家,已知有12属61个物种在中国分布,并演化出多种生态适应型.本研究采用高通量测序技术对小纹背鼩鼱、云南长尾鼩鼱和蹼足鼩3个物种的心和肺组织样本进行转录组测序.其中小纹背鼩鼱和云南长尾鼩营地表生活,蹼足鼩适应半水生生活.3个物种的转录组测序一共获得20.5 Gb的Clean Data,拼接后...     

三江并流区树线生境小型兽类多样性多维度评价及其保护启示

三江并流区具有极高的环境异质性和丰富的生物多样性, 树线以上的高山生境是该地区的核心景观之一。本研究拟通过物种、系统发育和功能多样性对高山小型兽类多样性进行评价, 并从保护生物学的角度讨论生物多样性多维度评价的意义。2013年9月至2018年11月对三江并流区树线区域展开规范化野外调查, 收集小型兽类群落信息。从野外采集的组织样品中提取、扩增、测定线粒体CYTB基因序列, 构建小型兽类物种系统发育树。通过α多样性的不同维度以及功能冗余度评价了三江并流区树线生境小型兽类多样性。结果显示, 使用不同数据类型(出现/缺失数据和多度数据)的结果并不一致, 说明仅使用传统的丰富度指数对于描述多样性分布存在较大局限。物种和系统发育多样性在不同地点间的分布相似, 但功能多样性的分布与这两者有所差异, 从另一角度说明综合评价生物多样性的不同维度对于全面保护演化历史和生态功能的必要性。与高黎贡山、云岭相比较, 怒山山脉在5个样带尺度的多样性指数上呈现最高水平, 且具有最低的功能冗余度, 说明怒山的研究和保护力度均亟待加强。     

Adaptive diffusion kernel learning from biological networks for protein function prediction

Background  

Machine-learning tools have gained considerable attention during the last few years for analyzing biological networks for protein function prediction. Kernel methods are suitable for learning from graph-based data such as biological networks, as they only require the abstraction of the similarities between objects into the kernel matrix. One key issue in kernel methods is the selection of a good kernel function. Diffusion kernels, the discretization of the familiar Gaussian kernel of Euclidean space, are commonly used for graph-based data.     

Episodic salinization and freshwater salinization syndrome mobilize base cations,carbon, and nutrients to streams across urban regions

Urbanized watersheds in colder climates experience episodic salinization due to anthropogenic salt inputs and runoff from impervious surfaces. Episodic salinization can be manifested as a ‘pulse’ in concentrations and fluxes of salt ions lasting from hours to days after snowstorms in response to road salting. Episodic salinization contributes to freshwater salinization syndrome, characterized by cascading mobilization of chemicals and shifting acid–base status. We conducted laboratory experiments and analyzed high-frequency sensor data to investigate the water quality impacts of freshwater salinization syndrome and episodic salinization across 12 watersheds draining two major metropolitan regions along the U.S. East Coast. Sediments from 12 watersheds spanning land use gradients across two metropolitan regions, Baltimore, Maryland and Washington DC, were incubated across a range of replicated salinity treatments (0–10 g/L sodium chloride). There were statistically significant linear increasing trends in calcium and potassium concentrations with experimental salinization across all 12 sites and in magnesium concentrations at 11 of 12 sites (p?<?0.05), with mean rates of increase of 1.92?±?0.31 mg-Ca per g-NaCl, 2.80?±?0.67 mg–K per g-NaCl, and 1.11?±?0.19 mg-Mg per g-NaCl, respectively. Similarly, there were statistically significant increasing linear trends in total dissolved nitrogen (TDN) concentrations with experimental salinization at 9 of the 12 sites, with a mean rate of increase of 0.07?±?0.01 mg-N per g-NaCl. There were statistically significant increasing linear trends in soluble reactive phosphorus (SRP) concentrations with experimental salinization at 7 of the 12 sites (p?<?0.05), with a mean rate of increase of 2.34?±?0.66 µg-P per g-NaCl. The response of dissolved inorganic carbon (DIC) and organic carbon (DOC) concentrations to experimental salinization varied between sites, and dissolved silica did not show any significant response. High-frequency sensors near the experimental sites showed statistically significant positive linear relationships between nitrate concentrations, specific conductance, and chloride concentrations similar to relationships observed in laboratory incubations. Our results suggested that episodic salinization and freshwater salinization syndrome can mobilize base cations and nutrients to streams through accelerated ion exchange and stimulate different biogeochemical processes by shifting pH ranges and ionic strength. The growing impacts of freshwater salinization syndrome and episodic salinization on nutrient mobilization, shifting acid–base status, and augmenting eutrophication warrant serious consideration in water quality management.