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101.
We present a robust sampling methodology to estimate population size using line transect and capture-recapture procedures for aerial surveys. Aerial surveys usually underestimate population density due to animals being missed. A combination of capture-recapture and line transect sampling methods with multiple observers allows violation of the assumption that all animals on the centreline are sighted from the air. We illustrate our method with an example of inanimate objects which shows evidence of failure of the assumption that all objects on the centreline have probability 1 of being detected. A simulation study is implemented to evaluate the performance of three variations of the Lincoln-Petersen estimator: the overall estimator, the stratified estimator, and the general stratified estimator based on the combined likelihood proposed in this paper. The stratified Lincoln-Petersen estimator based on the combined likelihood is found to be generally superior to the other estimators.  相似文献   
102.
Kin-biased social tolerance among house mice has been interpreted in terms of kin discrimination. However, several lines of evidence suggest it may instead be an incidental artifact of group member discrimination. This leads to very different predictions about the social consequences of relatedness within and between social groups. Social interactions between wild-stock adult female and juvenile house mice (Mus domesticus) established in neighbouring territorial groups within enclosures reveal relatedness to dominant males within groups as the major factor determining social tolerance of juveniles by females. Relatedness to the female herself had no significant independent effect on responses indicating tolerance. Females were generally more aggressive toward neighbouring-group juveniles (all unrelated to females) compared with those from their own group (all related to females), but were most aggressive toward neighbouring juveniles sired by the neighbouring dominant male. They were also more aggressive toward their own-group juveniles that had been sired by the neighbouring dominant but only when encountered in the neighbouring territory and with a greater bias against female juveniles. Females were least aggressive toward own-group juveniles sired by their own-group dominant male. The sire-bias in tolerance among females is similar to that reported among the dominant males themselves in an earlier study. As a result of the combined sire-bias in tolerance by adult males and females, juveniles sired by their own-group dominant males become less likely to intrude into a neighbouring territory with time. Overall, the results suggest that differences in social tolerance reflect discrimination on the basis of social group membership rather than relatedness between interactants and thus provide strong experimental evidence in support of incidental kin bias rather than kin discrimination.  相似文献   
103.
国内外高浓度煤粉燃烧技术综述   总被引:2,自引:0,他引:2  
分析我国浓淡燃烧器的类型和现状,借鉴国外几种清洁稳燃的高浓度煤粉燃烧技术的特点和应用范围。对我国浓淡燃烧器的开发和利用提供有益的参考和指导。  相似文献   
104.
环境政策边缘化现实与改革方向辨析   总被引:8,自引:3,他引:5  
本文认为由于中国现行环境政策的设计、执行和实施不能有效纳入到社会经济发展和决策过程的主流。不能从根源上解决环境与发展的矛盾.因而呈规出边缘化特征,表现在环境政策的末端管理特征、尚未建立一体化的政策体系、公平与效率准则未纳入政策设计过程、缺乏综合绩效评估、环境投资总量不足与低效率等。从政策的设计、作用环境、作用对象、作用范围的变化分析了边缘化的产生原因以及所导致的中国环境保护的误区和问题.包括技术、经济.生态、社会效率的分离.环境资源的区域配置低效率、近动式管理以及政策实施效果与政策目标的偏离等。本文提出改变现存问题的突破点在于构建基于环境权益以及全成本的政策体系和管理制度,并分析了需要解决和突破的关键性理论和实践问题。  相似文献   
105.
Three studies draw from evolutionary theory to assess whether sleepiness increases interpretive biases in workplace social judgments. Study 1 established a relationship between sleepiness and interpretive bias using ambiguous interpersonal scenarios from a measure commonly used in personnel selection (N = 148). Study 2 explored the boundary conditions of the sleepiness–interpretive bias link via an experimental online field survey of U.S. adults (N = 433). Sleepiness increased interpretive bias when social threats were clearly present (unfair workplace) but did not affect bias in the absence of threat (fair workplace). Study 3 replicated and extended findings from the previous two studies using objective measures of sleep loss and a quasi‐experimental manipulation of minor sleep loss (N = 175). Negative affect, ego depletion, or personality variables did not influence the observed relationships. Overall, results suggest that a self‐protection/evolutionary perspective best explains the effects of sleepiness on workplace interpretive biases. These studies advance the current research on sleep in organizations by adding a cognitive “threat interpretation” bias approach to past work examining the emotional reaction/behavioral side of sleep disruption. Interpretive biases due to sleepiness may have significant implications for employee health and counterproductive behavior. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
106.
Abstract: As a result of global declines in amphibian populations, interest in the conservation of amphibians has grown. This growth has been fueled partially by the recent discovery of other potential causes of declines, including chytridiomycosis (the amphibian chytrid, an infectious disease) and climate change. It has been proposed that researchers have shifted their focus to these novel stressors and that other threats to amphibians, such as habitat loss, are not being studied in proportion to their potential effects. We tested the validity of this proposal by reviewing the literature on amphibian declines, categorizing the primary topic of articles within this literature (e.g., habitat loss or UV‐B radiation) and comparing citation rates among articles on these topics and impact factors of journals in which the articles were published. From 1990 to 2009, the proportion of papers on habitat loss remained fairly constant, and although the number of papers on chytridiomycosis increased after the disease was described in 1998, the number of published papers on amphibian declines also increased. Nevertheless, papers on chytridiomycosis were more highly cited than papers not on chytridiomycosis and were published in journals with higher impact factors on average, which may indicate this research topic is more popular in the literature. Our results were not consistent with a shift in the research agenda on amphibians. We believe the perception of such a shift has been supported by the higher citation rates of papers on chytridiomycosis.  相似文献   
107.
Abstract: The ability of a population to adapt to changing environments depends critically on the amount and kind of genetic variability it possesses. Mutations are an important source of new genetic variability and may lead to new adaptations, especially if the population size is large. Mutation rates are extremely variable between and within species, and males usually have higher mutation rates as a result of elevated rates of male germ cell division. This male bias affects the overall mutation rate. We examined the factors that influence male mutation bias, and focused on the effects of classical life‐history parameters, such as the average age at reproduction and elevated rates of sperm production in response to sexual selection and sperm competition. We argue that human‐induced changes in age at reproduction or in sexual selection will affect male mutation biases and hence overall mutation rates. Depending on the effective population size, these changes are likely to influence the long‐term persistence of a population.  相似文献   
108.
Stated-preference surveys for the economic valuation of environmental resources typically assume no uncertainty in the hypothetical valuation scenarios. However, the outcomes of environmental policies are uncertain. We explored the effects of including information on probabilities of attribute improvement and provision in choice experiments. Our results suggest that stating explicitly a high probability for the occurrence of the valuation scenario can improve the goodness of fit of choice models and the consistency of choices. As the general public becomes more aware of the uncertainty of environmental outcomes under global change, omitting information on scenario risk may contribute to hypothetical bias and impair the validity of stated-preference valuations.  相似文献   
109.
Environmental economists have long used surveys to gather information about people's preferences. A recent innovation in survey methodology has been the advent of web-based surveys. While the Internet appears to offer a promising alternative to conventional survey administration modes, concerns exist over potential sampling biases associated with web-based surveys and the effect these may have on valuation estimates. This paper compares results obtained from a travel cost questionnaire of visitors to Fraser Island, Australia, that was conducted using two alternate survey administration modes; conventional mail and web-based. It is found that response rates and the socio-demographic make-up of respondents to the two survey modes are not statistically different. Moreover, both modes yield similar consumer surplus estimates.  相似文献   
110.
The role of nature documentaries in shaping public attitudes and behavior toward conservation and wildlife issues is unclear. We analyzed the emotional content of over 2 million tweets related to Our Planet, a major nature documentary released on Netflix, with dictionary and rule-based automatic sentiment analysis. We also compared the sentiment associated with species mentioned in Our Planet and a set of control species with similar features but not mentioned in the documentary. Tweets were largely negative in sentiment at the time of release of the series. This effect was primarily linked to the highly skewed distributions of retweets and, in particular, to a single negatively valenced and massively retweeted tweet (>150,000 retweets). Species mentioned in Our Planet were associated with more negative sentiment than the control species, and this effect coincided with a short period following the airing of the series. Our results are consistent with a general negativity bias in cultural transmission and document the difficulty of evoking positive sentiment, on social media and elsewhere, in response to environmental problems.  相似文献   
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