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。     

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。     

Visualizing latent fingerprints on color-printed papers using ultraviolet fluorescence

Laser detection of latent fingerprints on a white paper has been performed, previously. Ultraviolet fluorescence from various kinds of printer toner and ink used for home printers were measured to study fluorescence imaging of fingerprints on a color-printed white paper. The experimental system consisted of a nanosecond pulsed tunable laser and a cooled CCD camera. Excitation wavelengths are 230 and 280 nm. Fourteen printers consisting of three color laser printers, three color inkjet printers, five monochrome laser printers, two monochrome copy machines, and a color copy machine were tested. Toner and ink of most printers exhibited fluorescence in the region from 360 to 550 nm. In most cases, clear fluorescence images were obtained by time-resolved imaging with a band-pass filter and 280-nm excitation. However for toners from laser color printers that showed strong fluorescence, better results were obtained with 230-nm excitation. Latent fingerprints on a photograph page and a black-character page of a newspaper were also imaged.     

Visualization of Aged Fingerprints with an Ultraviolet Laser

Detection of aged fingerprints is difficult because they can degrade over time with exposure to light, moisture, and temperature. In this study, aging fingerprints were visualized by time‐resolved spectroscopy with an ultraviolet‐pulsed laser. Fingerprints were prepared on glass slides and paper and then stored under three lighting conditions and two humidity conditions for up to a year. The fluorescence intensities of the fingerprints decreased with time. Samples were stored in the dark degraded less than in sunlight or under a fluorescent lamp. Samples were stored under low humidity degraded less than under moderate humidity. As the storage period increased, a fluorescence emission peak appeared that was at a longer wavelength than the peak visible in earlier spectra. This peak was used for visualization of an aged fingerprint over time. An image of the fingerprint was not initially visible, but an image appeared as the time since deposition of the fingerprint increased.     

Public interest law revisited 1

This article undertakes a detailed examination of the practical desirability and legal validity of arbitration clauses under the Nigerian legal regime. This involves navigating through provisions of the relevant Rent Control and Recovery of Premises Law. Areas of incompatibility (including those bordering on jurisdiction, penal provisions and enforcement of awards) between the latter law and arbitration clauses are then discussed. Finally, recommendations are made to the effect that the Rent Control and Recovery of Premises Law should be amended.     

导入ISO9001:2000背景下地方政府绩效考核指标体系述评

地方政府在导入ISO质量管理体系的背景下,其绩效如何考核?国际标准化组织设计了一套完整的指标体系,包括"好政府的制度发展、经济的可持续发展、全面的社会发展和环境的可持续发展"等四个维度。本文对这套指标进行了介绍,并结合中国的具体情况进行了分析,目的在于为地方政府导入ISO质量管理体系进行理论上的指导。文章认为,导入这套指标体系符合我国建设和谐社会和落实科学发展观的要求,有利于促进政府职能转变,有利于解决当前我国的社会问题。因此,它在我国具有相当强的可适用性。