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271.
The aim of this work is to check whether modifications in the length of the hunting seasons had an effect on the chance of reproduction of different species of ringed birds. We start from a national data set of ringing‐recovered data on three species of game birds. Only data on birds recovered as juveniles are used. Data on recoveries are organized in a 4‐way contingency table. Several generalized linear models are proposed for the counts of recovered birds. Bayesian hierarchical modeling is particularly suitable for this kind of data, for which an over‐dispersion parameter can be introduced at the second level of the hierarchy. Maximum Likelihood and Bayesian solutions are computed for the different models: the Bayesian framework, in particular under an individual modeling of over‐dispersion, exhibits the best fit in terms of Bayesian p‐value. The results show that the modification in the length of the hunting seasons does not produce equal benefits for the three species considered. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
272.
273.
The relationship between short‐term exposure to air pollution and mortality or morbidity has been the subject of much recent research, in which the standard method of analysis uses Poisson linear or additive models. In this paper, we use a Bayesian dynamic generalised linear model (DGLM) to estimate this relationship, which allows the standard linear or additive model to be extended in two ways: (i) the long‐term trend and temporal correlation present in the health data can be modelled by an autoregressive process rather than a smooth function of calendar time; (ii) the effects of air pollution are allowed to evolve over time. The efficacy of these two extensions are investigated by applying a series of dynamic and non‐dynamic models to air pollution and mortality data from Greater London. A Bayesian approach is taken throughout, and a Markov chain monte carlo simulation algorithm is presented for inference. An alternative likelihood based analysis is also presented, in order to allow a direct comparison with the only previous analysis of air pollution and health data using a DGLM. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
274.
J. M. Prada‐Snchez M. Febrero‐Bande T. Cotos‐Yez W. Gonzlez‐Manteiga J. L. Bermúdez‐Cela T. Lucas‐Domínguez 《Environmetrics》2000,11(2):209-225
Atmospheric SO2 concentrations at sampling stations near the fossil fuel fired power station at As Pontes (La Coruña, Spain) were predicted using a model for the corresponding time series consisting of a self‐explicative term and a linear combination of exogenous variables. In a supplementary simulation study, models of this kind behaved better than the corresponding pure self‐explicative or pure linear regression models. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
275.
The generalized linear model (GLM) encompasses many discrete and continuous models and it is particularly useful for analyzing discrete data. However, in many real life applications, the full distributional assumption of the GLM cannot be justified. Further, the GLM cannot accommodate over‐dispersion in the data. Since the inception of the GLM by Nelder and Wedderburn ( 1972 ) a number of its extensions have been proposed in the literature for robust analysis of discrete data. The purpose of this paper is to critically review these extensions. Applications to over‐dispersed Poisson and binomial models are shown. Some simulations are conducted to compare, in terms of bias and efficiency, the estimates of mean and the dispersion parameters by different methods. Applications to some biological and environmental data are given. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
276.
采用土培的试验方法,研究了在不同浓度阴离子表面活性剂——直链烷基苯磺酸钠(LAS)处理后,单季茭\"美人茭\"的生长、茭白叶片中叶绿素含量和抗氧化酶系统活性的变化情况,以及LAS在茭白叶片和土壤中的相对残留量.结果表明,10mg·L-1、100mg·L-1LAS处理浓度对茭白的生长状态没有显著影响;1000mg·L-1LAS处理浓度下美人茭株高和最大叶宽均分别低于对照25.5%(p<0.05)和27.0%(p<0.05),处理过程中叶绿素总含量大幅下降.10mg·L-1、100mg·L-1LAS处理浓度下美人茭的抗坏血酸过氧化物酶(APX)和过氧化氢酶(CAT)活性显著提高,1000mg·L-1LAS处理浓度下美人茭的过氧化物酶(POD)活性受到严重的抑制.丙二醛(MDA)含量呈先上升后下降的趋势,并随着LAS处理浓度的升高而升高.茭白叶片中LAS残留量先下降后上升,10mg·L-1处理浓度下美人茭叶片中LAS含量低;10和100mg·L-1处理浓度下土壤中LAS含量基本在0.1～0.5mg·L-1之间,1000mg·L-1处理浓度下土壤中LAS含量持续上升,达到2.0～3.0mg·L-1,且LAS含量在第28d比第7d时高54.0%(p<0.05).与单纯的土壤环境相比,茭白-土壤系统能够更有效地降低土壤中LAS含量. 相似文献
277.
Measuring biological diversity 总被引：2，自引：0，他引：2
The diversity of a set of species refers to the joint dissimilarity of the species in the set. This paper discusses the measurement
of diversity from the set of pairwise distances between the species in the set. A measure called the effective number of species
is developed from a non-parametric probability inequality and is shown to have a simple interpretation in terms of comparing
linear experiments. 相似文献
278.
Amrita Gupta Bistra Dilkina Dana J. Morin Angela K. Fuller J. Andrew Royle Christopher Sutherland Carla P. Gomes 《Conservation biology》2019,33(5):1023-1034
Ecological distance-based spatial capture–recapture models (SCR) are a promising approach for simultaneously estimating animal density and connectivity, both of which affect spatial population processes and ultimately species persistence. We explored how SCR models can be integrated into reserve-design frameworks that explicitly acknowledge both the spatial distribution of individuals and their space use resulting from landscape structure. We formulated the design of wildlife reserves as a budget-constrained optimization problem and conducted a simulation to explore 3 different SCR-informed optimization objectives that prioritized different conservation goals by maximizing the number of protected individuals, reserve connectivity, and density-weighted connectivity. We also studied the effect on our 3 objectives of enforcing that the space-use requirements of individuals be met by the reserve for individuals to be considered conserved (referred to as home-range constraints). Maximizing local population density resulted in fragmented reserves that would likely not aid long-term population persistence, and maximizing the connectivity objective yielded reserves that protected the fewest individuals. However, maximizing density-weighted connectivity or preemptively imposing home-range constraints on reserve design yielded reserves of largely spatially compact sets of parcels covering high-density areas in the landscape with high functional connectivity between them. Our results quantify the extent to which reserve design is constrained by individual home-range requirements and highlight that accounting for individual space use in the objective and constraints can help in the design of reserves that balance abundance and connectivity in a biologically relevant manner. 相似文献
279.
Michele Jeanette Sanders Laura Miller Shonil A. Bhagwat Jesse Marije Anne van der Grient Alex David Rogers 《Conservation biology》2020,34(1):113-124
A key obstacle to conservation success is the tendency of conservation professionals to tackle each challenge individually rather than collectively and in context. We sought to prioritize barriers to conservation previously described in the conservation literature. We undertook an online survey of 154 practitioners from over 70 countries to ascertain the most important barriers to conservation they faced. We used statistical analyses to identify the key impediments to conservation success and to examine whether these were affected by organizational attributes. Twenty-one barriers were identified. The importance ascribed to those was influenced by continent of operation and organization size, but not by organization age or autonomy (from larger parent organizations). We found the most important barriers to consider when undertaking conservation action were wider issues (e.g., population growth, consumerism, favoring development, and industrial-scale activity), operating environment (e.g., lack of political will, ineffective law enforcement, weak governments, corruption, safety and security), community attributes (e.g., dynamics, conflicts, and education levels), and the way conservation is undertaken (overconfidence, lack of funding, and externally set agendas). However, we advise against applying a one-size-fits-all approach. We propose that conservationists account for the complex socioecological systems they operate in if they are to achieve success. 相似文献
280.