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41.
Jelani Wiltshire Fred W. Huffer William C. Parker 《Journal of applied statistics》2014,41(9):2028-2043
Van Valen's Red Queen hypothesis states that within a homogeneous taxonomic group the age is statistically independent of the rate of extinction. The case of the Red Queen hypothesis being addressed here is when the homogeneous taxonomic group is a group of similar species. Since Van Valen's work, various statistical approaches have been used to address the relationship between taxon age and the rate of extinction. We propose a general class of test statistics that can be used to test for the effect of age on the rate of extinction. These test statistics allow for a varying background rate of extinction and attempt to remove the effects of other covariates when assessing the effect of age on extinction. No model is assumed for the covariate effects. Instead we control for covariate effects by pairing or grouping together similar species. Simulations are used to compare the power of the statistics. We apply the test statistics to data on Foram extinctions and find that age has a positive effect on the rate of extinction. A derivation of the null distribution of one of the test statistics is provided in the supplementary material. 相似文献
42.
Small area statistics obtained from sample survey data provide a critical source of information used to study health, economic, and sociological trends. However, most large-scale sample surveys are not designed for the purpose of producing small area statistics. Moreover, data disseminators are prevented from releasing public-use microdata for small geographic areas for disclosure reasons; thus, limiting the utility of the data they collect. This research evaluates a synthetic data method, intended for data disseminators, for releasing public-use microdata for small geographic areas based on complex sample survey data. The method replaces all observed survey values with synthetic (or imputed) values generated from a hierarchical Bayesian model that explicitly accounts for complex sample design features, including stratification, clustering, and sampling weights. The method is applied to restricted microdata from the National Health Interview Survey and synthetic data are generated for both sampled and non-sampled small areas. The analytic validity of the resulting small area inferences is assessed by direct comparison with the actual data, a simulation study, and a cross-validation study. 相似文献
43.
Randall Lutter Linda Abbott Rick Becker Chris Borgert Ann Bradley Gail Charnley Susan Dudley Alan Felsot Nancy Golden George Gray Daland Juberg Mary Mitchell Nancy Rachman Lorenz Rhomberg Keith Solomon Stephen Sundlof Kate Willett 《Risk analysis》2015,35(2):186-192
Federal and other regulatory agencies often use or claim to use a weight of evidence (WoE) approach in chemical evaluation. Their approaches to the use of WoE, however, differ significantly, rely heavily on subjective professional judgment, and merit improvement. We review uses of WoE approaches in key articles in the peer‐reviewed scientific literature, and find significant variations. We find that a hypothesis‐based WoE approach, developed by Lorenz Rhomberg et al., can provide a stronger scientific basis for chemical assessment while improving transparency and preserving the appropriate scope of professional judgment. Their approach, while still evolving, relies on the explicit specification of the hypothesized basis for using the information at hand to infer the ability of an agent to cause human health impacts or, more broadly, affect other endpoints of concern. We describe and endorse such a hypothesis‐based WoE approach to chemical evaluation. 相似文献
44.
宋晓英 《西南交通大学学报(社会科学版)》2011,12(3):77-81
海外华人的网络写作越来越普遍,大多以非功利的"民间"立场、"性灵性"写作特点与多元文化视角独树一帜。网名"寒胭"者写作中对家国文化传承、城市现代化进程、人性变异与现代人精神实质的追溯与揭示颇具代表性,其感伤情结、家国情怀和忧患意识体现于哀国、殇城、感人、忧世四个方面。此类写作的意义在于,当一个民族身为"弱国"的历史未过百年,被强势文化浸濡的现状尚在延续,物质的发展建构在一定道德文明代价的付出之上,而多数人已在现代化进程中麻痹自满时,作为愈是远离而乡情愈重的海外儿女,他们的民族危机意识对"人的存在"与"现代化"真正涵义的质询与考辨,无论是对于祖国民族道德传承,还是精神物质文明建构,均有着弥足轻重的镜鉴意义。 相似文献
45.
弗洛伊德民族心理学思想述论 总被引:1,自引:0,他引:1
心理学大师弗洛伊德也是西方民族心理学的奠基者之一,他的俄底普斯情结、图腾与禁忌和民族群体领袖等理论,打开了民族学和心理学交叉研究的大门,对宗教思想和民族心理密切关系的阐释,补充了民族心理学的研究内容。 相似文献
46.
Software packages usually report the results of statistical tests using p-values. Users often interpret these values by comparing them with standard thresholds, for example, 0.1, 1, and 5%, which is sometimes reinforced by a star rating (***, **, and *, respectively). We consider an arbitrary statistical test whose p-value p is not available explicitly, but can be approximated by Monte Carlo samples, for example, by bootstrap or permutation tests. The standard implementation of such tests usually draws a fixed number of samples to approximate p. However, the probability that the exact and the approximated p-value lie on different sides of a threshold (the resampling risk) can be high, particularly for p-values close to a threshold. We present a method to overcome this. We consider a finite set of user-specified intervals that cover [0, 1] and that can be overlapping. We call these p-value buckets. We present algorithms that, with arbitrarily high probability, return a p-value bucket containing p. We prove that for both a bounded resampling risk and a finite runtime, overlapping buckets need to be employed, and that our methods both bound the resampling risk and guarantee a finite runtime for such overlapping buckets. To interpret decisions with overlapping buckets, we propose an extension of the star rating system. We demonstrate that our methods are suitable for use in standard software, including for low p-value thresholds occurring in multiple testing settings, and that they can be computationally more efficient than standard implementations. 相似文献
47.
根据2002-2012年北京市投入产出的直接消耗系数,结合共引网络的建模思想,构建一类加权无向网络——产业需求竞争网络,并引入边权、单位权和差异性作为衡量网络中竞争关系的指标。通过研究发现:INCN-BJ网络的边权反映了产业链环节的完善程度,单位权反映了产品部门对产业系统的促进作用,差异性则区分出产业系统中需要加大产业政策指导的落后产品部门。 相似文献
48.
“波特假说”预言环境保护和经济发展可以实现双赢。研究认为,人力资本是实现环境友好型技术进步以及环境-经济综合绩效提升的支撑和匹配条件,亦即人力资本是“波特假说”成立的重要条件变量。实证结果显示:人力资本水平对环境-经济综合绩效存在直接的正向影响,且在东部和中部地区较为显著;全样本估计中环境规制对环境-经济综合绩效直接影响不显著,而人力资本可以改善环境规制的影响效应,间接作用于环境-经济综合绩效;进一步依据人力资本水平的分组检验,证实“波特假说”在人力资本水平较高地区的成立性,人力资本对环境-经济综合绩效的直接和间接影响均显著,验证了人力资本是“波特假说”成立条件这一分析结论。“新常态”下,应加强人力资本积累,健全人力资本流动机制,并依据地区人力资本条件科学实施环境规制,才能推动环境-经济综合绩效稳步提升。 相似文献
49.
段京雨 《西昌学院学报(社会科学版)》2016,(3):101-105
现代汉语中存在着这样一种特殊的复合时间结构——T1+(的)+T2,T1、T2均是具有指示性的时点。在言语交际过程中,
人们常使用“T1+(的)+T2”这类复合时间结构的语言表达式,将原来具有一定距离的“事件”(包括已然事件和未然事件)拉回
到现时,从而产生加强现场感的语用效果,且站在说话人角度,具有积极的交际效果。 相似文献
50.
Marcel de Toledo Vieira Maria de Fátima Salgueiro Peter W. F. Smith 《Journal of applied statistics》2016,43(7):1310-1321
We investigate the impacts of complex sampling on point and standard error estimates in latent growth curve modelling of survey data. Methodological issues are illustrated with empirical evidence from the analysis of longitudinal data on life satisfaction trajectories using data from the British Household Panel Survey, a national representative survey in Great Britain. A multi-process second-order latent growth curve model with conditional linear growth is used to study variation in the two perceived life satisfaction latent factors considered. The benefits of accounting for the complex survey design are considered, including obtaining unbiased both point and standard error estimates, and therefore correctly specified confidence intervals and statistical tests. We conclude that, even for the rather elaborated longitudinal data models that were considered, estimation procedures are affected by variance-inflating impacts of complex sampling. 相似文献