The use of SEM/EDS analysis to distinguish dental and osseus tissue from other materials

With increasing frequency, relatively small, fragmentary evidence thought to be osseous or dental tissue of human origin is submitted to the forensic laboratory for DNA analysis with the request for positive identification. Prior to performing DNA analysis, however, it is prudent to first perform a presumptive test or "screen" to determine whether the questioned material may be eliminated from further consideration. When material is shown not to be consistent with bone/teeth, DNA testing is not performed. When such determinations cannot be made from gross morphological features, elemental analysis can be indicative. This presumptive test is made possible by applying scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) in conjunction with an X-ray spectral database recently developed by the FBI laboratory. This database includes spectra for many different materials including known examples of bone and tooth from many different contexts and representing the full range of taphonomic conditions. Results of SEM/EDS analysis of evidence can be compared to these standards to determine if they are consistent with bone and/or tooth and, if not, then what the material might represent. Analysis suggests that although the proportions and amounts of calcium and phosphorus are particularly important in differentiating bone and tooth from other materials, other minor differences in spectral profile can also provide significant discrimination. Analysis enables bone and tooth to be successfully distinguished from other materials in most cases. Exceptions appear to be ivory, mineral apatite, and perhaps some types of corals.     

Analysis of ionic ratios in myocardial tissue and their relation to cardiac damage

The authors evaluated the usefulness of the postmortem biochemical analysis of ionic ratios in different parts of the heart and their relation to cardiac damage caused by chest trauma, as observed by anatomopathologic study. Fifty-nine 59 cases were studied, selected from routine necropsies, and samples were taken from different sites of cardiac tissue. The cause of death was trauma in 40 cases and nontraumatic causes in 19 cases. The object of this study was to analyze the levels of Na+, K+, Ca+2, Mg+2, and Zn+2 in different zones of the heart, and the relationship between intracellular and extracellular ion ratios and the different causes of death and any anatomopathologic alterations observed. The biochemical tests revealed a possible relation between the ionic values and cause of death. Alterations in cell membrane permeability and corresponding modification of the ionic ratios were produced earlier than histologic alterations, which need longer to establish themselves whether or not they follow a traumatic process.     

Population genetics of nine short tandem repeat loci: allele frequency distribution in a Brazilian population sample

Gene and genotype frequencies in relation to the D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, and D7S820 loci were determined in a sample of 290 unrelated individuals (204 Caucasians and 86 mulattoes) living in the city of S?o Paulo, Brazil. The sex test Amelogenin was also performed in all subjects from our sample, revealing the expected sex in all instances. Allele frequency data obtained from the analysis of these samples were in the usual range of other population groups with similar racial background. In the sample of Caucasian individuals, panmictic proportions were ruled out in relation to TPOX and CSF1PO loci, but only in the latter was the overall frequency of heterozygotes significantly less than expected. In the sample of mulattoes, Hardy-Weinberg proportions were rejected in relation to FGA and CSF1PO loci, but in no instance were the overall numbers of heterozygotes different from the corresponding expected ones under panmixia. Taking into account all this and also the number of tests performed, the degree of genetic heterogeneity of Brazilian populations, and the critical level reached by the significant results (1% < alpha<5%), the departures from panmixia here observed can be considered to be negligible in altering significantly biologic relationship odds calculated under the assumption of random matings.     

Testing a Model of Resistance to Peer Pressure Among Mexican-Origin Adolescents

This study examined the factors associated with resistance to peer pressure toward antisocial behaviors among a sample of Mexican-origin adolescents (n=564) living in a large Southwestern city in the U.S. A model examining the influence of generational status, emotional autonomy from parents, and self-esteem on resistance to peer pressure was tested independently for boys and girls. Gender differences emerged in the factors that influenced resistance to peer pressure. Results indicated that resistance to peer pressure was influenced by generational status and emotional autonomy from parents for both boys and girls. However, self-esteem was found to influence resistance to peer pressure only for boys.Mayra Y. Bámaca is a graduate student in Family and Human Development at Arizona State University. Her research interests include adolescent development among ethnically diverse populations, the influence of contextual factors in development, parenting adolescents, and resiliency among Latino adolescents and their families. This work was based on the master’s thesis of the first author.Adriana J. Uma?a-Taylor received her Ph.D. from the University of Missouri-Columbia and is currently an Assistant Professor of Family and Human Development at Arizona State University. Her research interests include ethnic identity formation during adolescence and resilience among Latino adolescents and their families.This study was supported, in part, by a grant to the second author from the Fahs Beck Fund for Research and Experimentation of the New York Community Trust.     

关注贫困女大学生的心理问题及心理救助

贫困女大学生面对沉重的生存压力和日趋激烈的竞争环境,不仅物质生活困窘,其心理压力也十分值得关注。因此,了解这一特定群体身心发展的特点,在为贫困女大学生提供积极的经济帮助的同时,重视她们的心理问题及心理救助,加强对她们的心理健康教育,是高校教育工作者义不容辞的职责。     

如何对青年进行励志教育

本文针对当前一些青年对自己生存环境存在较大的心理压力,对未来前途忧心忡忡,但又缺乏明确志向、处于一种无目标的状态,提出在继承中华优秀传统、借鉴国外经验的基础上,积极引导青年匡正误区,明确励志,在教育中学会赏识、学会激励、正确对待挫折、积极自我暗示。     

论档案的为民服务

本着档案为民服务的理念,本文通过论证得出档案的开放和利用是档案工作的出发点与归宿的结论。在当前,要特别关注档案的公平利用问题,通过改革创新,扩大档案为民服务的范围,让档案真正为促进社会和谐发挥效力。     

来自HMONG人的思考--读《跨国苗族研究--民族与国家的边界》

本文对石茂明博士的新著《跨国苗族研究———民族与国家的边界》进行了一定的评述。在评价该著重要的学术价值同时,还指出了其中存在的一些不足。     

香港警方办理未成年人遭受性侵害案件的做法及启示

针对未成年人的生理和心理特点,香港警方在办理未成年人遭受性侵害案件时,特别强调对未成年被害人的关爱和保护,减少对未成年被害人的再次伤害。具体体现在:多机构的合作模式、专门的办案程序、家居录影式的调查访问、一站式的调查取证、支持被害人出庭作证、多专业的治疗辅导服务等。