考虑逆向物流的应急物资配置流程SPN建模分析

应急物资的高效快速配置是降低灾害损失和顺利实施应急救援的有力保障。应急逆向物流包括废旧物资的回收利用以及可重复利用物资的回收再利用,能起到缓解应急物资匮乏,减少环境污染的作用。本文根据随机Petri网理论,构建考虑逆向物流的应急物资配置模型,通过对同构于该模型的马尔可夫链进行仿真,求得各种状态的稳态概率,结合马尔可夫链性质对关键因素进行静态分析和动态分析;通过“雅安地震”的案例应用表明,当地震灾害发生时,此模型可以反映各因素对应急物资配置整体流程的影响,并通过数值变化趋势反映不同条件下应急物资配置的关键环节,可以为灾后救援和应急物资的利用提供理论支持。     

Elk decision-making rules are simplified in the presence of wolves

The risk of predation drives many behavioral responses in prey. However, few studies have directly tested whether predation risk alters the way other variables influence prey behavior. Here we use information theory (Akaike’s Information Criterion, AICc) in a novel way to test the hypothesis that the decision-making rules governing elk behavior are simplified by the presence of wolves. With elk habitat use as the dependent variable, we test whether the number of independent variables (i.e., the size of the models) that best predict this behavior differ when wolves are present vs absent. Thus, we use AICc scores simply to determine the number of variables to which elk respond when making decisions. We measured habitat use using 2,288 locations from GPS collars on 14 elk, over two winters (14 elk winters), in the Gallatin Canyon portion of the Greater Yellowstone Ecosystem. We found that the use of three major habitat components (grass, conifer, sage) was sensitive to many variables on days that wolves were locally absent, with the best models (ΔAICc≤2) averaging 7.4 parameters. In contrast, habitat use was sensitive to few variables on days when wolves were present: the best models averaged only 2.5 parameters. Because fewer variables affect elk behavior in the presence of wolves, we conclude that elk use simpler decision-making rules in the presence of wolves. This simplification of decision-making rules implies that predation risk imposes selection pressures that do not allow prey to respond to other pressures in ways that they otherwise would. If the affected processes are important, then this indirect effect of predation is likely to be important.     

Coordinating a group departure: who produces the piping signals on honeybee swarms?

A swarm of honeybees provides a striking example of an animal group performing a synchronized departure for a new location; in this case, thousands of bees taking off at once to fly to a new home. However, the means by which this is achieved remain unclear. Shortly before takeoff, one hears a crescendo of a high-pitched mechanical signal—worker piping—so we explored the role of this signal in coordinating a swarm’s mass takeoff. Specifically, we examined whether exclusively nest site scouts produce the worker piping signal or whether it is produced in a relay or chain reaction fashion. We found no evidence that bees other than the scouts that have visited the swarm’s chosen nest site produce piping signals. This absence of relay communication in piping suggests that it is a signal that only primes swarms for takeoff and that the release of takeoff is triggered by some other signal or cue; perhaps the takeoff of bees on the swarm periphery as they reach flight temperature in response to piping.     

Rank-related partner choice in the fission–fusion society of the spotted hyena (<Emphasis Type="Italic">Crocuta crocuta</Emphasis>)

When social partners vary in their relative value, individuals should theoretically initiate partnerships with conspecifics of the highest value. Here, we tested this prediction in a wild population of spotted hyenas (Crocuta crocuta). Crocuta live in complex, fission–fusion societies structured by dominance hierarchies in which individuals vary greatly in their value as social companions. Because patterns of association among Crocuta reflect social preferences, we calculated association indices (AIs) to examine how social rank influences intrasexual partner choice among unrelated adults of both sexes. The highest-ranking individuals were generally most gregarious in both sexes. Females associated most often with dominant and adjacent-ranking females. Females joined subgroups based on the presence of particular conspecifics such that subordinates joined focal females at higher rates than did dominants. Dominants benefit from associations with subordinates by enjoying priority of access to resources obtained and defended by multiple group members, but the benefits of these associations to subordinates are unknown. To investigate this, we tested three hypotheses suggesting how subordinates might benefit from rank-related partner choice among unrelated females. We found that subordinates who initiated group formation benefited by gaining social and feeding tolerance from dominants. However, rates at which dominants provided coalitionary support to subordinates did not vary with AIs. Overall, our data resemble those documenting patterns of association among cercopithecine primates. We consider our results in light of optimal reproductive skew theory, Seyfarth’s rank attractiveness model, and biological market theory. Our data are more consistent with the predictions of Seyfarth’s model and of biological market theory than with those of skew theory.     

Different habitats, different habits? Response to foraging information in the parasitic wasp Venturia canescens

The parasitic wasp, Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae), has two reproductive modes, namely, thelytoky or arrhenotoky, and occurs in habitats with highly variable or relatively stable host abundances, respectively. Since information processing is costly, we expected that information indicating resource availability would be mainly used by the thelytokous wasps and less so by the arrhenotokous type. This idea was explored by two different approaches. In a study on patch-time allocation, we used females from ten populations and measured patch-residence times of individuals that visited multiple patches at different encounter rates. In a more detailed approach, thelytokous and arrhenotokous females from a single location were observed continuously while foraging, and all behaviors were recorded. Wasps of both reproductive modes (i.e., both habitat types) used information for the assessment of habitat quality. However, the way that the information was used differed between them. Whereas thelytokous females used foraging information to maximize their efficiency at high patch-encounter rates, arrhenotokous females merely reduced the number of offspring produced without changing patch times. The behavior of the arrhenotokous females should result in a spreading of offspring across the habitat and, thus, reduced sib-mating. The foraging strategy of these wasps might therefore be an adaptation to reduce costs associated with inbreeding.     

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.     

纳污水体周围地下水污染特征浅析

通过对接纳石油化工废水的水体周围地下潜水的监测,发现纳污水体周围地下水污染因素与地表纳污水体中较高含量污染物一致,即都主要为有机污染,纳污水体中污染物浓度高,则潜水中该污染物浓度相应较高.说明纳污水体所接纳的含高浓度的石油类、化学耗氧量和五日生化需氧量的有机污染废水对周围地下水产生了比较明显的污染作用.污染范围是以泡子为中心,向四周呈椭圆形扩散形成污染晕,随着距离纳污水体距离的增加,污染物浓度呈下降趋势,在泡子溢流口和进水口处污染晕向外延伸.     

基于时空指示克里格的PM2.5不确定性分布

以山东省2014年PM_2.5浓度监测数据为对象,利用时空指示克里格理论和方法,实现对PM_2.5时空分布的不确定性分析.结果表明,山东省境内PM_2.5的空间自相关范围大于100km,时间自相关范围为3d左右.此外,山东省境内各空间位置全年空气质量以大于0.8的概率达到空气质量"优"级别的时空占比为7%,以大于0.8的概率达到轻度污染级别的时空占比为34%,以大于0.8的概率超过严重污染级别的时空占比为1%;东部沿海地域空气质量达到轻度污染的概率明显高于中西部,夏季空气质量也明显优于其它季节.     

基于FLAC3D的复合煤岩受载破裂数值模拟及试验研究

采用FLAC~(3D)对复合煤岩模型的单轴压缩破裂进行数值模拟及试验,研究复合煤岩受载破裂应力与应变关系变化规律。针对煤样厚度、复合煤岩组合比、煤层参数、顶底板岩性等参数,对复合煤岩模型进行加载仿真研究,仿真及试验结果表明:单一煤样模型随着高度的减小,应力应变曲线整体阶段存在尺寸效应;改变煤岩组合比例时,其抗压强度基本不变,随煤样比例增大,复合煤岩的整体弹性模量减小,整体刚度减小;单一改变复合煤岩的煤样参数时,随煤样弹性模量增大,复合煤岩的弹性模量越强,应力应变曲线峰值点越高,对应应变越小;单一改变顶底板岩性,对复合煤岩模型的应力应变曲线影响不大。试验结果和仿真结果变化趋势一致,表明所建模型具有一定正确性和适用性。     

Improved recovery of repeat intoxicated drivers using fingernails and blood spots to monitor alcohol and other substance abuse

Objectives: This study reports the results of a pilot program in Kenosha County that used a combination of direct biomarkers extracted from blood spots and nails to monitor repeat intoxicated drivers for their use of alcohol and drugs with a detection window spanning from 3 weeks to several months. The objectives were to test whether the direct biomarkers phosphatidylethanol (PEth), ethylglucuronide (EtG), and 5 drug metabolites would (1) help assessors obtain a more objective evaluation of repeat offenders during the assessment interview, (2) allow for timely identification of relapses and improve classification of drivers into risk categories, and (3) predict recidivism by identifying offenders most likely to obtain a subsequent operating while intoxicated (OWI) offense within 4 years of enrollment in the program.

Methods: All (N = 261) repeat offenders were tested using PEth obtained from blood spots and EtG obtained from fingernails; 159 participants were also tested for a 5 drugs of abuse nail panel. Drivers were tested immediately after the assessment interview (baseline) and at 3, 6, 9, and 12 months after baseline. Based on biomarker results and self-reports of abstinence, offenders were classified into different risk categories and required to follow specific testing timelines based on the program's decision tree.

Results: The baseline analysis shows that 60% of drivers tested positive for alcohol biomarkers (EtG, PEth, or both) at the assessment interview, with lower detection rates (0–11%) for the 5 drug metabolites. The comparison of biomarkers results to self-reports of abstinence identified 28% of all offenders as high risk and assigned them to more frequent testing and more intense monitoring. The longitudinal analysis shows that 56% (completers) of participants completed the program successfully and the remaining 44% (noncompliant) terminated prematurely. Two thirds (68%) of the completers were able to reduce or control their drinking and one third relapsed at least one time during their mandated monitoring periods. After a brief intervention by the assessors, 79% of relapsers tested negative for biomarkers in their repeat tests. The rearrest analysis showed that offenders classified in the noncompliant and relapsers groups were 7 times more likely to receive a new OWI 4 years after enrollment compared to drivers classified as abstainers or controllers. Refractory drivers were monitored the longest and reported no subsequent rearrests.

Conclusion: These findings demonstrate the benefits of more individualized interventions with repeat OWI offenders and calls for further development of multimodal approaches in traffic medicine including those that use direct alcohol biomarkers as evidence-based practices to reduce recidivism.