The taphonomic impact of scavenger guilds in peri-urban and rural regions of central and southern Alberta. Part I – Identification of forensically relevant vertebrate scavengers

As a body decomposes in an outdoor environment, numerous taphonomic agents can act on the process of human decomposition. It is important to understand the impact of these agents as they can vary the rate of soft and hard tissue loss which may alter postmortem interval estimations. One taphonomic factor which has not been extensively investigated in many regions of the world, including Canada, are vertebrate scavengers. The current study aimed to identify scavenger guilds in the peri-urban and rural regions of two major cities in Alberta (Calgary and Edmonton) where human remains are frequently located. Vertebrate scavenger activity was recorded continuously using cellular and noncellular trail cameras. Images were analyzed to determine how the scavenging profiles (i.e., scavenger species, arrival time, and feeding behavior) impacted the loss of soft and hard tissue. We identified a range of mammalian and avian scavengers and found that coyote and black-billed magpie were the predominant scavengers recorded at the Edmonton peri-urban and rural sites, and the Calgary peri-urban sites. In contrast, when a site was within bear territory such as the Calgary rural sites, black and grizzly bears were the predominant scavengers. At all sites, the large mammalian scavengers were responsible for most soft tissue loss and subsequent hard tissue dispersal. None of the scavengers demonstrated a clear preference for open versus closed sites. This taphonomic information is important to consider when searching for human remains at these locations or in other North American regions with comparable scavenger guilds.     

Phenibut screening and quantification with liquid chromatography–tandem mass spectrometry and its application to driving cases

An analytical strategy for identification by an LC–MS/MS multitarget screening method and a suitable LC–MS/MS based quantification were developed for the psychotropic drug phenibut. The samples analyzed were collected during traffic control and were associated with driving under the influence of drugs. A positive sample for phenibut was identified in a single case of driving under the influence. The quantification revealed a drug concentration of 1.9 μg/mL. An interaction with blood alcohol (BAC = 0.10%) was discussed as the explanation of the way of driving and deficit manifestations observed (swaying, nystagmus, quivering of the eyelid, and reddened eyes). According to the available information, the quantified phenibut concentration could be explained by an intake of four tablets (self-reported) during the day containing 250 mg of the drug. Chromatography was performed with a Luna 5 μm C18 (2) 100 A, 150 mm × 2 mm analytical column, and a buffer system consisted of 10 mM ammonium acetate and 0.1% acetic acid (v/v) included in mobile phases marked as A (H₂O/methanol = 95/5, v/v) and B (H₂O/methanol = 3/97, v/v). An effective limit of detection (LOD = 0.002 μg/mL) could be achieved for the multitarget screening method. The quantification of phenibut was performed on a second LC–MS/MS system with LOD/LOQ values of 0.22/0.40 μg/mL. Since phenibut quantification data are rare, the presented information can be used with caution for evaluation of positive cases in the future.     

从利益攸关方到战略再保证:霸权衰落下的中美关系

近五年来,美国对华政策定位经历了从利益攸关方、中美国、G2到战略再保证的转变,也成为当前国际关系领域研究的热门话题。这种转变与美国霸权衰落紧密相连,是美国为了延续霸权,希望中国继续融入其霸权体系的手段之一。面对复杂多变的国际局势,战略选择成为中国当前必须慎之又慎的问题。历史证明,与霸权国的对抗没有出路,因此中国只能选择合作。机制化的双边协调对话必然是今后中美关系保持良性发展的趋势,也是中国努力的方向,但也必须时刻警惕美国对华战略中的陷阱。     

东亚区域的生产分工、产品需求结构与贸易模式转型

东亚区域生产分工经历了产业间、产业内和产品内三种分工形式以及雁行和生产网络两种分工模式的演进路径,并且影响着东亚区域内产品需求结构的变化。对外部最终产品市场的严重依赖是东亚区域产品需求结构的主要特征,东亚区域外需主导型的贸易模式亟待转型。中国在东亚贸易模式转型过程中将发挥重要的作用。     

后美国时代的权力结构变迁与国际制度改革——基于八国集团改革的理论思考

权力结构与制度变革的关系探讨历来是国际问题研究的核心之一。金融危机爆发后,国际权力结构进入一个后美国时代,权力的分散但非匀质化是其显著特征。本文认为,制度改革是权力结构变迁过程中的合理性诉求,结构的变迁会对原有制度框架内的支配国和受益者形成某种改革压力。另一方面,权力结构变迁的长期性决定了制度改革的继承性和包容性。从总体上看,世界权力关系的变迁将会导致国际规则的调整和完善,倾向于制度的不断演化而非完全替代。     

中印油气外交:“新大角逐”、“互利互赢”或“独立平行”

近年来,19世纪的口号"大角逐"在国际能源领域再次抬头。但是,西方学者往往选择少数案例来证明油价上升的主要原因是中国与印度的竞争,以及油田的买卖。本文通过对中印竞争、合作与独立购买案例的实证调研,认为双方的竞争与合作案例的数量不仅少,而且两类交易的数量相当,相比之下,平行独立的中印能源外交案例最多。中印两国能源公司都基本遵照市场规律与游戏规则,而且多数能源行动并不属于过时的份额油"大角逐"。