Evaluating the discriminating power of amino acid ratios on distinguishing dark colored hair samples

Human hairs are one of the most commonly encountered items of trace evidence. Currently, conventional methods for hair analysis include microscopic comparison and DNA analysis (nuclear and mitochondrial). Each approach has its own drawbacks. Hair proteins are stable and offer an alternative to DNA testing, as demonstrated with proteomics for distinguishing humans. However, proteomics is complicated and requires identifying peptides to remain intact following harsh sample preparation methods. Alternatively, the actual amino acid content of a hair sample may also offer important identifying information and actually requires proteins and peptides to be broken down completely rather than remaining intact. This study evaluated the discriminating power of using hair amino acid ratios to differentiate hair samples from 10 unrelated individuals with dark colored hair. Hair proteins were digested, derivatized, and analyzed using gas chromatography–mass spectrometry. Amino acid ratios were calculated for each individual and comparisons using ANOVA and post-hoc pairwise t-test with Bonferroni correction were made with amino acid ratios for individuals. Overall, out of the 45 possible pairwise comparisons between all hair samples, 38 (84%) were differentiable. Out of the 36 possible pairwise comparisons between brown haired individuals, 32 (89%) were considered differentiable using univariate statistics. Multivariate statistics were also attempted but, overall, univariate models were sufficient for exclusionary purposes. These results indicate that amino acid ratio analysis can potentially be used as an exclusionary method using hair if DNA analysis cannot be performed, or to corroborate conclusions made following microscopic analysis.     

Evaluating the sensitivity,stability, and cross-reactivity of commercial fentanyl immunoassay test strips

Illicit fentanyl has flooded the United States' drug market, increasing the risk of overdose and poisonings throughout the general population and accidental exposure among law enforcement officers confiscating the increasing number of seizures. Fentanyl test strips (FTS) are used to obtain presumptive information about the presence of fentanyl in a suspected sample. However, their adoption by law enforcement personnel and seized-drug analysts has been limited because most products are advertised for urine testing, not for assays using water solutions. This study presents an evaluation of four commercial FTS: Rapid Response from BTNX, Inc.; T-Dip Fentanyl (FTY) Urine Dip Cards obtained from Amazon.com ; Premier BioDip FYL10 from Premier Biotech Inc.; and MobileDetect Fentanyl strips from DetectaChem, Inc. Performance characteristics curves were used to compare the products' sensitivity, showing that all can reliably detect fentanyl in aqueous solutions at concentrations below 1 μg/mL, with some of the tests able to reliably detect the drug at 200 ng/mL. A stability study demonstrates the performance of all four FTS brands was only slightly affected after 30 days of storage at two extreme environmental conditions. Fentanyl-related substances are also evaluated using the Rapid Response FTS, which showed high cross-reactivity with para-fluorofentanyl and acetylfentanyl, but lower with ortho-chlorofentanyl, carfentanil, and 4-ANPP. Users should be aware that FTS may give false-negative results even when potentially dangerous levels of carfentanil are present. When testing other common drugs, adulterants, and diluents frequently encountered in seized tablets, concentration-dependent results were obtained and multiple instances of false positives were recorded.     

体系、社会和国家:理解《美韩自由贸易协定》

2007年6月,美韩双方签署了《美韩自由贸易协定》。美韩之间为什么要签署该协定?该协定对两国国内分别产生了哪些影响?该协定为何至今没能获得美国国会的通过?针对上述问题,本文结合美国贸易政策理论,从体系、国家和社会三个层面对其进行了分析。《美韩自由贸易协定》的签署及其实施,在体系层面上将会为双方带来经济、政治和战略上的多重收益,而在社会层面上却产生了不同的反应。尽管由于国内经济困难和利益集团的掣制使得协定的通过还面临不小的阻力,但基于协定所蕴含的重要价值和两国政府对此认识的高度一致,协定获得通过只是时间上的问题。     

东亚-北美经济失衡与再平衡分析

本文从国别结构和产品结构分析了20世纪90年代以来东亚—北美经济失衡的变化,认为美国贸易逆差不断扩大是其对外产业转移的结果,东亚地区贸易顺差与日俱增是其承接产业转移的结果。其中,东亚内部再次产业转移导致中国顺差迅速膨胀。为了实现东亚—北美经济再平衡,美国需要采取一些措施扩大出口,控制过度的信贷消费,并对美元采取更加负责的政策;东亚地区需要努力实现由外需驱动型向内需驱动型增长方式的转变,加快产业调整与升级,并把产业链向其他地区延伸。     

人本性价值取向与国际关系理论范式

人本性价值取向决定国际理论范式的生成。西方社会主体所崇奉的人性本恶价值取向,决定了在西方国际关系理论中的现实主义处于主体地位的状况。中国国际理论范式的建构也必须以中国传统文化中的人性本善的主体价值取向为基础。     

国际法中健康权的产生、内涵及实施机制

健康权作为二战后兴起的一项重要人权,其发展路径具有从国际法向国内法扩展的特点。"人身的固有尊严"是健康权的正当性基础所在,也决定着健康权的基本内涵。《经济、社会和文化权利国际公约》第12条第1款规定的健康权既是自由权,也是社会权,既指获得卫生保健的权利,也包括获得构成健康基础条件的权利;第12条第2款规定只是列举了公约起草者认为特别重要的四项义务,而非缔约国的全部义务。缔约国义务的性质和范围必须结合公约第2条规定的一般义务条款加以判定。健康权的实施机制包括缔约国报告机制、书面申诉机制,以及调查报告机制三种,不同机制对缔约国的约束力不同,综合运用多种机制确保健康权的有效实施是今后的发展趋势。     

《苏日中立条约》与战时国民外交

1941年,中日战争僵持之际,苏、日两国于4月13日签订了<苏日中立条约>.条约的签订,犹如一石激起千层浪,引起了国际社会的广泛关注.中国民众也没有置之度外,纷纷通过报纸、杂志等媒体表达自己的意见,在民众舆论的配合下,中国政府经过交涉,终于弄清了苏联签约的真正意图,明确了以后的外交方向.     

浅析韩国的绿色增长战略

绿色增长正在成为世界谋求经济社会可持续发展的重要经济模式,各国都在寻求实现绿色增长的发展战略。1997亚洲金融风暴、2008年以来的世界性经济衰退促使积极探索经济转型新路的韩国加快了战略转型的步伐。韩国政府为此提出并开始实施“低碳绿色增长战略”,制订并发表了“绿色增长国家战略与五年计划”以及相关的法规,详细阐述了韩国推进这一战略计划的长远规划、战略目标、实施计划、政策措施等,并建立了从中央到地方的组织实施机构。韩国积极推动的绿色增长战略充分揭示了其未来经济发展的基本方向,意在谋求实现经济增长方式的转变、构建未来经济长期稳定发展的新增长模式和动力。     

证券虚假陈述民事责任性质之界定

虚假陈述是一种典型的证券欺诈行为,历来成为各国证券法规制的重点。我国2005年修改的《证券法》明确规定了虚假陈述的民事责任,但未明确责任的性质。本文从虚假陈述民事责任性质三种学说的评析入手,结合案例分析了我国实践中存在的问题,并提出了相应的解决办法。