Impoverishment of YOY‐fish assemblages by intense commercial navigation in a large Lowland river

Navigation‐induced physical forces have been suggested to modify the structure of riverine fish assemblages by impeding especially the recruitment of littoral bound species. To investigate the effect of vessel frequency on fish, we compared the composition and seasonal succession of young‐of‐the‐year (YOY) fish assemblages in three similarly degraded river reaches differing in average vessel passages (2, 6 and 41 per day). Fish were caught by electrofishing biweekly between May and September. Multivariate tests were used to analyse differences between YOY‐fish assemblages and hurdle regression models applied to determine abiotic factors predicting fish occurrence and abundance. Roach (Rutilus rutilus) and perch (Perca fluviatilis) densities were compared. Roach larvae remain in the littoral zone while perch larvae shift to the pelagic zone immediately after hatch. YOY‐fish assemblage structure substantially changed along the traffic intensity gradient. In the high traffic intensity reach, species number and total fish density were markedly reduced compared to the other reaches. Roach densities were lowest in the high traffic intensity reach whereas perch densities did not decline along the gradient. Hurdle regressions confirmed a stronger effect of commercial navigation traffic intensity on roach than on perch. The total zooplankton biomass was highest in the high traffic intensity reach. Our results provide empirical evidence that intensive commercial navigation impoverishes fish assemblages in width‐restricted waterways. They underlined that in particular those species that have their first nursery habitats in shoreline areas were more affected by intensive commercial navigation than species whose larvae live predominantly pelagic. The results indicate that the negative effect of intensive navigation on riverine fish results primarily from the navigation‐induced hydraulic disturbances along the banks. Therefore, mitigation of navigation‐induced hydraulic forces is required to prevent degradation of fish communities in waterways. Copyright © 2010 John Wiley & Sons, Ltd.     

基于能量特征的脑电信号特征提取与分类

为了快速、有效地提取脑电特征,提高分类正确率,采用带通滤波和小波包分析的方法提取Mu、Beta节律对应的脑电信号,在时域范围内,将信号幅度的平方作为能量特征值;在频域范围内,采用AR模型功率谱估计法所得的功率谱密度作为能量特征值.根据运动想象脑电信号特点,构造左右通道信号能量差值的符号特性作为分类判别依据,进行分类测试,方法简单.初步实验结果表明,所利用的两种方法的分类正确率达87.857%.     

微博走进公安工作

微博这种新兴的网络交流方式越来越受到公众的关注,正在成为继博客之后网民们相互交流的新平台,这种集发布信息、互动交流于一体的网络工具也为公安机关所关注,各级公安机关纷纷对公安微博表现出了极大的热情,给新形势下的公安工作带来了新的契机。公安机关开设微博可以带来以下好处:首先,公安微博拉近了警民距离,提高了警察自身的公信力;其次,公安微博能使公安机关站在信息发布的制高点,及时消除谣言,还原真相;最后,公安微博能为侦查提供线索,为破案开辟新思路。总之,公安微博的开辟为公安工作带来了可喜的变化,小小的"微博110"正在为社会的稳定,人民的安居乐业贡献自己的力量。     

信息检索中相关实体发现综述

实体是Web页面中的重要信息载体,用户通过搜索引擎进行信息检索中时一般想得到某个具体的实体,而不是某些文档的列表,因而信息检索中的相关实体发现研究就具有非常重要的意义。对信息检索中的相关实体发现的基本过程进行了综述,重点描述了相关实体发现的重要组成部分:全文检索、实体识别、实体分级,主页查找及其各部分所涉及到的关键问题。     

Visual Foxpro中防止关联数据库的不彻底数据更新

提出如何利用 TTS技术防止关联数据库关联更新的不彻底 ,并以一个实例对其实现过程进行了具体的说明。     

A proteome analysis of the dorsolateral prefrontal cortex in human alcoholic patients

Alcoholic patients commonly experience cognitive decline. It is postulated that cognitive dysfunction is caused by an alcohol-induced region-selective brain damage, particularly to the prefrontal region, and grey and white matter may be affected differently. We used a proteomics-based approach to compare protein expression profiles of the dorsolateral prefrontal cortex (Brodmann area 9 (BA9)) from human alcoholic and healthy control brains. Changes in the relative expression of 110 protein 'spots' were identified in the BA9 grey matter, of which 54 were identified as 44 different proteins. In our recent article, 60 protein spots were differentially expressed in the BA9 white matter and 18 of these were identified (Alexander-Kaufman, K., James, G., Sheedy, D., Harper, C., Matsumoto, I., Mol. Psychiatry 2006, 11, 56-65). Additional BA9 white matter proteins are identified here and discussed in conjunction to our grey matter results. Thiamine-dependent enzymes transketolase and pyruvate dehydrogenase (E1β ubunit) were among the proteins identified. To our knowledge, this is the first time a disruption in thiamine-dependent enzymes has been demonstrated in the brains of 'neurologically uncomplicated' alcoholics. By identifying protein expression changes in prefrontal grey and white matter separately, hypotheses may draw upon more mechanistic explanations as to how alcoholism causes the structural alterations associated with alcohol-related brain damage and cognitive dysfunction.     

Cognitive processes in complex tasks: introduction and discussion

This paper points out that the fusional limits of binocular stereoscopic viewing are an important factor, not only determining the reproduction range of stereoscopic images, but also the conformity between the stereoscopic display and stereoscopic vision. Experimental results showed that fusional limits increase in proportion to the field of view angle, and that they are affected not only by the size of the viewing target, but also by the effects that the environment has on the target. These findings explain the differences between binocular vision in real space and binocular vision in a stereoscopic display. Finally, the conditions under which observers arc able to view images of stereoscopic displays without excessive visual strain are discussed.     

基于事件关联电位脑机接口的电视遥控异步系统

本文设计了基于事件关联电位脑机接口的脑电信号预处理、特征提取、分类识别实时算法,开发了具有通讯功能的遥控器,实现了脑机接口电视遥控的异步系统.受试者可以用脑电波来遥控电视选择频道和调整音量,这为重症瘫痪病人拓展其与自然的直接交流开辟了新的通道.5位健康的受试者参与了训练实验和在线实验,实验结果表明经过特定的训练,受试者均可有效控制该脑机接口电视遥控系统,其统计平均准确率达87％,平均传输速率(ITR)达35 bits/min.     

Self-Reported Gambling-Related Suicidality Among Gambling Helpline Callers.

Problem gamblers often attribute suicidal ideation or attempts to their gambling. Logistic regression analyses were applied to data from problem gamblers (N = 986) calling a helpline. Problem gamblers reporting gambling-related suicidality (n = 252; 25.6%) were more likely than those denying it (n = 734; 74.4%) to acknowledge family, financial, legal, and mental and substance-related problems. Of problem gamblers acknowledging gambling-related suicidality, those reporting gambling-related suicide attempts (n = 53; 21.5%) were more likely than those denying them (n = 193; 78.5%) to acknowledge gambling-related illegal behaviors, mental health and substance abuse treatment, and family histories of alcohol problems, and were less likely to report prior gambling treatment. The findings suggest that increased gambling severity is associated with gambling-related suicidality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Olfactory and auditory event-related potentials in Huntington's disease.

The influence of Huntington's disease (HD) on the olfactory event-related potential (OERP), an electrophysiological measure of olfactory information processing, has not been reported to date. In the present study, olfactory and auditory event-related potentials (ERPs) were recorded monopolarly from Fz, Cz, and Pz electrode sites in 8 patients with HD and 8 age- and gender-matched control participants. Results demonstrated that individuals with HD were delayed compared with controls on the P3 component of the OERP (p