Statistical inference on patch-specific survival and movement rates from marked animals

Empirical estimates of patch-specific survival and movement rates are needed to parametrize spatially explicit population models, and for inference on the effects of habitat quality and fragmentation on populations. Data from radio-marked animals, in which both the fates and habitat locations of animals are known over time, can be used in conjunction with continuous-time proportional hazards models to obtain inferences on survival rates. Discrete-time conditional logistic models may provide inference on both survival and movement rates. We use Monte Carlo simulation to investigate accuracy of estimates of survival from both approaches, and movement rates from conditional logistic regression, for two habitats. Bias was low (relative bias < 0.04) and interval coverage accurate (close to the nominal 0.95) for estimates of habitat effect on survival based on proportional hazards. Bias was high ( relative bias 0.60) and interval coverage poor ( = 0.26 vs. nominal 0.95) for estimates of habitat effect based on conditional logistic regression; bias was especially influenced by heterogeneity in survival and the shape of the hazard function, whereas both bias and coverage were affected by ‘memory’ effects in movement patterns. Bias estimates of movement rate was low ( relative bias < 0.05), but interval coverage was poor ( = 0.48–0.80), possibly as a result of poor performance of a Taylor series estimate of variance. An example is provided from a radio-telemetry study of 47 wintering American woodcock (Scolopax minor), illustrating practical difficulties in field studies to parametrize these models. We also discuss extensions of continuous-time models to explicitly include a movement process, and further examine tradeoffs between continuous and discrete models.     

生态毒理基因组学——后基因组时代生态毒理学的新领域

基因组学、蛋白组学和代谢组学技术为生态毒理学的发展提供了生物高通量的技术手段,构成了新的交叉学科——生态毒理基因组学.生态毒理基因组学着重研究环境毒物暴露下非靶生物基因和蛋白的表达,能够在基因组水平上更深入地理解环境污染物的致毒机制,同时,它引进生物标志物为生态风险评价提供了平台.论文对生态毒理基因组学的发展历程、技术支持、模式生物及其在生态风险评价方面的应用进行了综述,以推动生态毒理基因组学技术在我国的进一步发展.     

Possible causes and consequences of philopatry and breeding dispersal in red-backed shrikes <Emphasis Type="BoldItalic">Lanius collurio</Emphasis>

Studies of animal breeding dispersal have often focused on possible causes, whereas its adaptive significance has received less attention. Using an information-theoretic approach, we assessed predictions of four hypotheses relating to causes and consequences of breeding dispersal in a migratory passerine, the red-backed shrike Lanius collurio. As predicted by the reproductive performance hypothesis, probability of breeding dispersal in females (though not in males) decreased with increasing annual average number of fledglings produced in the past year, but there was no association with conspecific reproductive performance in either sex. The site choice hypothesis, stating that individuals disperse to improve breeding site quality, received support in males only, as dispersal probability was positively associated to a measure indicating low territory quality. The social constraints hypothesis, referring to dispersal in relation to intraspecific interactions, received little support in either sex. The predation risk hypothesis was hardly supported either. Consequences of dispersal were marginal in both sexes because neither fledgling production in females, nor territory quality in males improved after dispersal. In addition, males settled on territories closer to the forest edge than those occupied predispersal, which is opposite to the prediction of the predation risk hypothesis. We conclude that own reproductive success was the major factor determining dispersal behavior in females, whereas territory quality and possibly predation risk were most important in males. Overall, breeding dispersal appeared not to be adaptive in this dense population inhabiting an optimal habitat.     

Temporal dynamics of arsenic uptake and distribution: food and water risks in the Bengal basin

Abstract

Contaminated food chain is a serious contender for arsenic (As) uptake around the globe. In Nadia, West Bengal, we trace possible means of transfer of As from multiple sources reaching different trophic levels, and associated seasonal variability leading to chronic As uptake. This work considers possible sources-pathways of As transfer through food chain in rural community. Arsenic concentration in groundwater, soil, rice, and vegetable-samples collected detected in different harvest seasons of 2014 and 2016. Arsenic level in shallow groundwater samples ranged from 0.1 to 354?µg/L, with 75% of the sites above the prescribed limit by WHO (10?µg/L) during the boro harvest season. High soil As content (～20.6?mg/kg), resulted in accumulation of As in food crops. A positive correlation in As conc. with increase over period in all sites indicating gradual As accumulation in topsoil. Unpolished rice samples showed high As content (～1.75?mg/kg), polishing reduced 80% of As. Among vegetables, the plant family Poaceae with high irrigation requirements and Solanaceae retaining high moisture, have the highest levels of As. Contaminated animal fodder (Poaceae) and turf water for cattle are shown to contaminate milk (0.06 to 0.24?µg/L) and behoves strategies, practices to minimize As exposure.     

Fecundity as a Basis for Risk Assessment of Nonindigenous Freshwater Molluscs

Abstract:  The most efficient way to reduce future damages from nonindigenous species is to prevent the introduction of harmful species. Although ecologists have long sought to predict the identity of such species, recent methodological advances promise success where previous attempts failed. We applied recently developed risk assessment approaches to nonindigenous freshwater molluscs at two geographic scales: the Laurentian Great Lakes basin and the 48 contiguous states of the United States. We used data on natural history and biogeography to discriminate between established freshwater molluscs that are benign and those that constitute nuisances (i.e., cause environmental and/or economic damage). Two statistical techniques, logistic regression and categorical tree analysis, showed that nuisance status was positively associated with fecundity. Other aspects of natural history and biogeography did not significantly affect likelihood of becoming a nuisance. We then used the derived statistical models to predict the chance that 15 mollusc species not yet in natural ecosystems would cause damage if they become established. We also tested whether time since establishment is related to the likelihood that nonindigenous mollusc species in the Great Lakes and United States would cause negative impacts. No significant relationship was evident at the U.S. scale, but recently established molluscs within the Great Lakes were more likely to cause negative impacts. This may reflect changing environmental conditions, changing patterns of trade, or may be an indication of "invasional meltdown." Our quantitative analyses could be extended to other taxa and ecosystems and offer a number of improvements over the qualitative risk assessments currently used by U.S. (and other) government agencies.     

Incorporating the Effects of Socioeconomic Uncertainty into Priority Setting for Conservation Investment

Abstract:  Uncertainty in the implementation and outcomes of conservation actions that is not accounted for leaves conservation plans vulnerable to potential changes in future conditions. We used a decision-theoretic approach to investigate the effects of two types of investment uncertainty on the optimal allocation of global conservation resources for land acquisition in the Mediterranean Basin. We considered uncertainty about (1) whether investment will continue and (2) whether the acquired biodiversity assets are secure, which we termed transaction uncertainty and performance uncertainty, respectively. We also developed and tested the robustness of different rules of thumb for guiding the allocation of conservation resources when these sources of uncertainty exist. In the presence of uncertainty in future investment ability (transaction uncertainty), the optimal strategy was opportunistic, meaning the investment priority should be to act where uncertainty is highest while investment remains possible. When there was a probability that investments would fail (performance uncertainty), the optimal solution became a complex trade-off between the immediate biodiversity benefits of acting in a region and the perceived longevity of the investment. In general, regions were prioritized for investment when they had the greatest performance certainty, even if an alternative region was highly threatened or had higher biodiversity value. The improved performance of rules of thumb when accounting for uncertainty highlights the importance of explicitly incorporating sources of investment uncertainty and evaluating potential conservation investments in the context of their likely long-term success.     

梯级水库群环境风险分析

为提高梯级水库群环境风险管理水平,加强流域生态环境保护,以溪洛渡-向家坝梯级水库为研究对象,基于灾害系统理论和系统动力学,对溪洛渡-向家坝梯级水库环境风险进行了系统梳理,辨识了梯级水库环境风险承载体、风险源、风险诱因,分析了环境风险传递机理,采用贝叶斯理论进行库区水体藻类爆发概率计算。结果表明:溪洛渡-向家坝梯级水库环境风险通过水流、电流、系统动力学流进行传播,并会影响到电站机组和水工建筑物的安全,由于水动力减弱和库区污染物排放,导致库区水体藻类爆发概率为2.42%,死鱼概率为1.21%,在此基础上,绘制环境风险传递拓扑图,并提出相应的环境风险管控措施。     

Injuries as a Result of California Earthquakes in the Past Decade

The devastating effects of earthquakes have been demonstrated repeatedly in the past decade, through moderate and major earthquakes such as the October 1987 Whittier Narrows earthquake (5.9 on the Richter scale), the October 1989 Loma Prieta earthquake (7.1) and the January 1994 Northridge earthquake (6.7). While 'official' tallies of injuries and deaths are reported for each event, the numbers vary from report to report. For Northridge, the number of injuries vary between 8,000 and 12,000; the number of deaths from 33 to 73 (Peek-Asa et al., 1997; Durkin, 1996).While official estimates are commonly reported following disasters, the study of actual numbers, types and causes of casualties has not developed. In this paper, we identify the numbers and risk factors for injuries within community-based samples across three earthquakes in urban California. We first report the numbers and types of injuries in each earthquake and then identify risk factors specifically associated with the Northridge earthquake     

Environmental Information Systems in Malaria Risk Mapping and Epidemic Forecasting

Every year between one and two million African children under five die of malaria. If one adds to this the contribution of malaria to all-cause infant mortality then clearly the burden of the disease is catastrophic — a disaster quietly happening each and every year. New tools are needed urgently to support those currently available for control of the disease. An effective vaccine remains elusive. This article outlines the potential contribution to malaria control services of satellite information, which is being used by resource managers in other sectors. In particular, it highlights the lessons which can be learned from early warning systems in other areas, especially those designed to respond to famine. An appendix provides a brief introduction to satellite data and their interpretation.     

环境风险评价研究进展

重大环境污染事故常伴有人员伤亡,给社会、经济、人群健康和环境带来巨大破坏,环境风险评价是预防环境污染事故并提供有效应急措施的必要工作.对环境风险评价发展的三个阶段:健康风险评价、事故风险评价和综合风险评价进行了总结,并分析其研究进展、评价方法和研究不足之处,最后探讨了环境风险评价与环境风险管理的关系.结果表明,在未来几十年内,区域环境风险、长期环境风险、不确定性处理和环境毒理学、环境流行病学等方面将成为环境风险评价的重点研究领域.