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.     

Blow Flies from Forest Fragments Embedded in Different Land Uses: Implications for Selecting Indicators in Forensic Entomology

Given the general expectation that forest loss can alter biodiversity patterns, we hypothesize that blow fly species abundances differ in a gradient of native vegetation cover. This study was conducted in 17 fragments across different landscapes in central Brazil. Different land cover type proportions were used to represent landscape structure. In total, 2334 specimens of nine species of Calliphoridae were collected. We used principal component analysis (PCA) to reduce dimensionality and multicollinearity of the landscape data. The first component explained 70%, and it represented a gradient of forest‐pasture land uses. Alien species showed a wide distribution in different fragments with no clear relationship between the abundance values and the scores of PCA axes, whereas native species occurred only in areas with a predominance of forest cover. Our study revealed that certain native species may be sensitive to forest loss at the landscape scale, and they represent a bioindicator in forensic entomology.     

Combinatorics in the theory of utility

It used to be thought that the utility or pleasure that goods gave consumers depended on the whole on the nature of the goods and, particularly, on its quantity. This is half true, half false. The utility obtained from a set of goods depends mainly on how the goods are ordered and combined within the dynamic time sequence represented by consumption. In other words, it depends less on what the goods are and more on how the goods are positioned. Understanding this offers huge possibilities within the theory of utility--and thus of consumption--as it allows us to apply the arsenal of tools available to us in the mathematic speciality known as combinatorics, as applied to utility. If each combination of goods poses a utility, we can rank these combinations differently using ordinal criteria and real transitive preferences. From there we can establish a set of menus, from best to least poor, and, armed with this information, work out a theory of individual choice. This is in brief the purpose of this work.     

Three paradigms in a single monetary circulation

The nature of money is simple and easy to understand, both what it is and what it was; it is the ＂law of gravity＂ we all understand. Many macroeconomic concepts and operations are based on money. Without it, they would be impossible to comprehend and, in fact, can only be understood by methodically tracking the circulation of money. There are three core paradigms of money and money circulation： the money multiplier, the velocity of circulation of money income and the money-income multiplier. In this paper, we try to demystify or decouple some of these circulatory mechanisms in order to establish, to the extent that is possible, a single comprehensive theory. A comprehensive theory or an approximation to such demands that the three economic operations corresponding to the above three paradigms form part of the same monetary macroeconomic phenomenon. To prove workable, it requires that the formulae arrived at being represented by a single mathematical expression. This paper shows that there is a conflict between, on one hand, the inevitable and persistent economic intuition that relates the three paradigms and, on the other, the mathematical formulae （and their components） that occasionally negate this.     

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。     

The impact of student-generated digital flashcards on student learning of constitutional law

This article describes, evaluates and reflects upon student creation of cloud-based digital flashcards as an authentic formative and summative assessment task designed for the deep learning of constitutional law. The usefulness of digital flashcards in online legal education is explored. The undergraduate law student participants in the study responded differently to the assessment task depending upon the constitutional law topic they were assigned, the perceived relevance of constructing digital flashcards to professional practice and how they reacted to this creative task. Building digital flashcards provides a potentially powerful authentic assessment task for the study of constitutional law provided it is designed to support semester long creation, validation and sharing of digital flashcards that students perceive as professionally relevant and educationally useful. Student recommendations for designing an assessment task involving the creation of digital flashcards are evaluated.     

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。