Biomechanical response targets for physical and computational models of the pediatric trunk

Objectives: This paper quantifies pediatric thoracoabdominal response to belt loading to guide the scaling of existing adult response data and to assess the validity of a juvenile porcine abdominal model for application to the development of physical and computational models of the human child. Methods: Table-top belt-loading experiments were performed on 6, 7, and 15 year-old pediatric post-mortem human subjects (PMHS). Response targets are reported for diagonal belt and distributed loading of the anterior thorax and for horizontal belt loading of the abdomen. Results: The pediatric PMHS exhibited abdominal response similar to the swine, including the degree of rate sensitivity. The thoraces of the PMHS were as stiff as, or slightly more stiff than, published adult corridors. Conclusions: An assessment of age-related changes in thoracic stiffness suggests that the effective stiffness of the chest increases through the fourth decade of life and then decreases, resulting in stiffness values similar for children and elderly adults.     

Independence, not conflict, characterizes dart-shooting and sperm exchange in a hermaphroditic snail

Although the sexes are united in hermaphrodites, conflict can still occur because the male and female functions have separate interests. We examined the evidence for conflict in the mating system of the terrestrial snail Cantareus aspersus (formerly Helix aspersa) where sharp, calcareous darts are ‘shot’ during courtship. We predicted that the use of the dart would either reflect or create conflict and this would be evident in either the courtship behavior or the transference of sperm. Previous studies demonstrated that the dart functions after sperm transfer to increase sperm survival. Using detailed observations of mating snails, we examined the factors that determine dart shooting order, the behavioral responses after being hit by a dart, the accuracy of dart shooting, and the allocation of sperm resources. We found that each dart was shot independently, and each animal appeared to be interested only in getting off the best possible shot, probably one that penetrates deeply near the genital pore. There is no evidence of mating conflict. Every snail transfers sperm to its partner, and the size of the donation does not depend on the success or failure of either snail’s dart shot. Although the receipt of a dart does not appear to cause harm, it may produce indirect costs due to the partial loss of control over fertilization. We conclude that mating in C. aspersus is a partnership in which independent actors demonstrate unconditional reciprocity during courtship and sperm transfer.     

Degradation of RPA 202248 [U-14C-phenyl]alpha(-(cyclopropylcarbonyl)-2-(methylsulfonyl)-beta-oxo-4-(trifluromethyl)benzenepropanenitrile), the primary degradation product of isoxaflutole, in an outdoor aquatic microcosm system

Isoxaflutole, the active ingredient in BALANCE WDG and BALANCE PRO corn herbicides and a co-formulant with the herbicide flufenacet in the product EPIC, is readily degraded in soil and water to RPA 202248 alpha(-(cyclopropylcarbonyl)-2-(methyvlsulfonyl)-beta-oxo-4-(trifluromethyl)benzenepropanenitrile). Because RPA 202248 is responsible at the molecular level for isoxaflutole's herbicidal activity it is important to understand the environmental behavior of the degradation product. Laboratory studies suggest that RPA 202248 is stable to hydrolysis and photolysis in aqueous systems and hence poses a possible environmental concern. As part of a program of work towards understanding the actual field situation, an outdoor microcosm study was carried out. Over the course of the 29-day study, residues remained predominantly in the aqueous phase. A slow but steady degradation of RPA 202248 was observed leading to the formation of RPA 203328 (2-methylsulfonyl-4-trifluoromethylbenzoic acid), which has no herbicidal activity. The half-life of RPA 202248 was calculated to be 103 days. These findings indicate that aqueous degradation should be considered as a potential route of dissipation when assessing the fate of RPA 202248 in large scale impounded water bodies, such as ponds, lakes, or reservoirs in the Mid-West Corn Belt.     

A theoretical model of air and steam co-injection to prevent the downward migration of DNAPLs during steam-enhanced extraction

When steam is injected into soil containing a dense volatile non-aqueous phase liquid contaminant the DNAPL vaporized within the heated soil region condenses and accumulates ahead of the steam condensation front. If enough DNAPL accumulates, gravitational forces can overcome trapping forces allowing the liquid contaminant to flow downward. By injecting air with steam, a portion of the DNAPL vapor remains suspended in equilibrium with the air, decreasing liquid contaminant accumulation ahead of the steam condensation front, and thus reducing the possibility of downward migration. In this work, a one-dimensional theoretical model is developed to predict the injection ratio of air to steam that will prevent the accumulation of volatile DNAPLs. The contaminated region is modeled as a one-dimensional homogeneous porous medium with an initially uniform distribution of a single component contaminant. Mass and energy balances are combined to determine the injection ratio of air to steam that eliminates accumulation of the contaminant ahead of the steam condensation front, and hence reduces the possibility of downward migration. The minimum injection ratio that eliminates accumulation is defined as the optimum injection ratio. Example calculations are presented for three DNAPLs, carbon tetrachloride (CCl4), trichloroethylene (TCE), and perchloroethylene (PCE). The optimum injection ratio of air to steam is shown to depend on the initial saturation and the volatility of the liquid contaminant. Numerical simulation results are presented to validate the model, and to illustrate downward migration for ratios less than optimum. Optimum injection ratios determined from numerical simulations are shown to be in good agreement with the theoretical model.     

Implementing wildlife-management strategies into road infrastructure in southern Ontario: a critical success factors approach

Wildlife-road conflict has profound negative impacts on both wildlife populations and society. Despite a long-held understanding of this problem, in most regions the wildlife-management strategies (WMS) available to mitigate this conflict are still relatively underutilized. This study examines the implementation of these strategies into road infrastructure, using Southern Ontario as a case study, in order to develop an understanding of what leads to successful WMS implementation. The project management concept of critical success factors was applied and interviews with project decision-makers and key stakeholders were conducted. Nine factors were identified and a comparison between a ‘smooth’ and ‘rough’ project is used to illustrate the cumulative effects that these factors, and their interrelationships, have on project implementation success. Practitioners can use these findings to evaluate WMS projects based on likelihood of success and allocate resources accordingly, ultimately leading to increased chances of implementation and overall benefit to conservation and society.     

Energy's role in the extraversion (dis)advantage: How energy ties and task conflict help clarify the relationship between extraversion and proactive performance

While academic and practitioner literatures have proposed that extraverts are at an advantage in team‐based work, it remains unclear exactly what that advantage might be, how extraverts attain such an advantage, and under which conditions. Theory highlighting the importance of energy in the coordination of team efforts helps to answer these questions. We propose that extraverted individuals are able to develop more energizing relationships with their teammates and as a result are seen as proactively contributing to their team. However, problems in coordination (i.e., team task conflict) can reverse this extraversion advantage. We studied 27 project‐based teams at their formation, peak performance, and after disbandment. Results suggest that when team task conflict is low, extraverts energize their teammates and are viewed by others as proactively contributing to the team. However, when team task conflict is high, extraverts develop energizing relationships with fewer of their teammates and are not viewed as proactively contributing to the team. Our findings regarding energizing relationships and team task conflict clarify why extraversion is related to proactive performance and in what way, how, and when extraverts may be at a (dis)advantage in team‐based work. Copyright © 2016 John Wiley & Sons, Ltd.     

Modeling affective and cognitive responses to soft-target terrorism over time

Environment Systems and Decisions - There is great value in understanding the public’s reactions to terror attacks, though such reactions pose stark challenges for sound psychological...     

21世纪可替代脊椎动物进行生态毒性测试的方法：过去二十年的发展和现状综述

替代脊椎动物进行化学物质和污染物危害评估的方法已成为越来越重要的需求。现在首先要考虑的是当启动一个脊椎动物生态毒性测试,必须确保不必要的脊椎动物生物的使用尽可能最小化。对于一些监管目的,脊椎动物的使用对环境风险评估(ERA)已经被禁止,而在其他情况下生物测试的数量已经大大减少了,或者测试程序严格精简了。然而,想要获得能够完全替代脊椎动物提供环境危害数据的方法仍有很长的路要走。动物替代品的发展不仅仅是基于道德的考虑,也可以降低执行脊椎动物生态毒性测试的成本以及在某些情况下能够提供更好的信息旨在改进环境风险评估。本文集中综述了在过去的几十年里生态毒性评估替代方法所发生的重大的进展。
精选自Adam Lillicrap, Scott Belanger, Natalie Burden, David Du Pasquier, Michelle R. Embry, Marlies Halder, Mark A. Lampi, Lucy Lee, Teresa Norberg-King, Barnett A. Rattner, Kristin Schirmer, Paul Thomas. Alternative approaches to vertebrate ecotoxicity tests in the 21st century: a review of developments over the last two decades and current status. Environmental Toxicology and Chemistry: Volume 35, Issue 11, pages 2637–2646, November 2016. DOI: 10.1002/etc.3603
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3603/full