Comparison of methods to determine sex by evaluating the greater sciatic notch: Visual, angular and geometric morphometrics

Sex estimation is the first step for biological profile reconstruction of an unknown skeleton (archaeological or contemporary) and consequently for positive identification of skeletal remains recovered from forensic settings. Several tools have been developed using different osseous structures. With the intention to provide an objective method comparison, we reported the analysis of three different methods (visual, metric and geometric morphometrics) for sex assessment of the greater sciatic notch. One hundred and thirty pelvic bones (45.4% females and 54.6% males) from the National Autonomous University of Mexico Skeletal Collection pertaining to the contemporary Mexican population were analyzed. We used the ROC-analysis to test between desired false positive thresholds (1-specificity) and expected true positive rates (sensitivity) in order to predict the best approach to sex assessment. The comparison of the area under the ROC-curves shows significant differences among visual and metric methods. At the same time, the analysis suggested that higher morphological variation among the sexes is independent of the methodological approach. The results indicate that the metric (angle), with a high percent of indeterminate cases (34.6%), and visual, with 26.2% of the cases allocated as intermediate cases, were poorly accurate; we cannot recommend these techniques for sexing an unknown specimen. On the other hand, the geometric morphometrics approach improves sex estimation in 82.3% of correctly classified individuals with more than 95% of posterior probability. In addition to the method comparison, the major sexual variation of the greater sciatic notch was determined to be located on its posterior border.     

Why is methenamine detected in Goma-2 dynamites originally methenamine free? An interpretation of relevant forensic results

After the train bombing in Madrid (Spain) on 11 March 2004, methenamine was detected in some of the specimens of Goma-2 ECO dynamite submitted to the forensic laboratories when analyzed by gas chromatography coupled with mass spectrometry detection (GC-MS). Methenamine is synthesized from formaldehyde and ammonia through a condensation reaction. However, neither methenamine nor any of these compounds were used to manufacture Goma-2 ECO dynamite. Four different experiments were designed in order to explain the presence of methenamine detected in the dynamite samples analyzed. In the first one, GC-MS was used to analyze the individual components of Goma-2 ECO provided by the manufacturer and the components mixed in a raw paste. Methenamine was detected in the manufacturer's ammonium nitrate and in the raw paste. The other experiments were designed to find the precursors sources for methenamine generation in Goma-2 ECO. Results revealed that these sources could be ammonium nitrate for ammonia and sawdust for formaldehyde. Under heating conditions, dynamite could produce these precursors, which could condense in the injection port of the GC-MS system and generate methenamine. However, methenamine was not always detected in these dynamites. This was explained by the existence of two opposite effects: (a) dynamite stability makes difficult that ammonium nitrate releases ammonia and (b) there is a gradual loss of formaldehyde in sawdust along the time. Both effects can prevent the formation of an amount of methenamine large enough to be detected.     

Seasonal structure and dynamics of sarcosaprophagous fauna on pig carrion in a rural area of Cordoba (Argentina): their importance in forensic science

Four experiments, one in each season, were carried out during 2004 in a rural area of Córdoba, central Argentina. Two pigs (Sus scrofa L.), weighing approximately 8 kg each, were used in each of the four experiments. The animals were killed by a sharp blow to the head and immediately placed in an appropriate arthropod trap. One pig was placed in the shade and the other under direct sunlight. This research was conducted to determine the seasonal structure and dynamics of arthropods that constitute the sarcosaprophagous community in a given area of the central region of Argentina. The decomposition process was divided into five stages: fresh, bloated, decay, advanced decay and dry. The duration of each stage varied in different seasons, showing that the temperature and humidity are the most important variables that influence this process. A total of 51,500 adults and 36,909 immature were collected. More than 80% of the specimens collected belong to Insecta, and within this, Diptera were the most abundant order. The flies were mainly represented by adults and immature of the following species: Chrysomya albiceps (Wiedemann) (Calliphoridae), Musca domestica Linnaeus (Muscidae) and Fannia femoralis (Stein) (Fanniidae). Coleoptera were mainly represented by adults and immature of the species Creophilus maxillosus (Linnaeus) (Staphylinidae) and Dermestes maculatus (Geer) (Dermestidae). More than 50% of hymenopteran fauna collected belong to Formicidae. The trophic levels associated with the decomposition of the remains included five categories: necrophagous, parasites and predators of the necrophagous species, omnivores, opportunists and adventives. During faunal succession a strong dominance of the necrophagous species of the family Calliphoridae and Muscidae was observed, mainly during the early stages of decay process in all seasons.     

Identification process in mass graves from the Spanish Civil War II

The identification process of a mass grave from the Spanish Civil War (1936-1939) is presented. The presumed location of the grave, as well as the presumed number and identities of the persons buried in the grave were obtained exclusively from witnesses' and relatives' testimonies. In agreement with the testimonies, the grave was located at the indicated location and five skeletons were exhumed. Also in agreement with the testimonies, the osteological and DNA study led investigators to propose the identification of two kin groups, a father and his son and a pair of brothers. But the genetic study did not support the identification of a fifth man presumed to have been buried in the grave. The differences and similarities between this case and another case reported earlier are discussed.     

Permanent teeth development in a Spanish sample. Application to dental age estimation

The purpose of this study is to clarify the chronology of different stages of dental development, according to Demirjian, in a sample of Spanish children, which will enable us to build a database that will be used as a reference in regard to the dental development of individuals of our socio-geographic environment. In the same studied sample, a calculation of the dental age according to Demirjian was carried out. This study was conducted in a final sample consisting of 1010 orthopantograms, corresponding to Spanish children (485 boys and 525 girls) ages 2-16. Comparing the age of onset of the different stages among the children, evidence was found that girls had an earlier general development than boys. These differences were only statistically significant in teeth and concrete stages. The canine teeth revealed greater gender dimorphism, with significant differences in all stages compared with the upper canines. The method proposed by Demirjian for dental age calculation resulted in a significant overestimation of dental age in relation to the chronological age in boys (average of 0.87 years) and girls (average of 0.55 years). Data from this study may be used as reference for dental maturity, as well as a standard for estimating age in Spanish children.     

Predicting discharge in forensic psychiatry: the legal and psychosocial factors associated with long and short stays in forensic psychiatric hospitals

In Germany, both the number of patients treated in forensic psychiatric hospitals and the average inpatient treatment period have been increasing for over thirty years. Biographical and clinical factors, e.g., the number of prior offences, type of offence, and psychiatric diagnosis, count among the factors that influence the treatment duration and the likelihood of discharge. The aims of the current study were threefold: (1) to provide an estimate of the German forensic psychiatric patient population with a low likelihood of discharge, (2) to replicate a set of personal variables that predict a relatively high, as opposed to a low, likelihood of discharge from forensic psychiatric hospitals, and (3) to describe a group of other factors that are likely to add to the existing body of knowledge. Based on a sample of 899 patients, we applied a battery of primarily biographical and other personal variables to two subgroups of patients. The first subgroup of patients had been treated in a forensic psychiatric hospital according to section 63 of the German legal code for at least ten years (long-stay patients, n=137), whereas the second subgroup had been released after a maximum treatment period of four years (short-stay patients, n=67). The resulting logistic regression model had a high goodness of fit, with more than 85% of the patients correctly classified into the groups. In accordance with earlier studies, we found a series of personal variables, including age at first admission and type of offence, to be predictive of a short or long-stay. Other findings, such as the high number of immigrants among the short-stay patients and the significance of a patient's work time before admission to a forensic psychiatric hospital, are more clearly represented than has been observed in previous research.     

Are there population differences in minutiae frequencies? A comparative study of two Argentinian population samples and one Spanish sample

In recent years, both scientific and judicial sources have highlighted the need for more knowledge about minutiae variability, in order to improve their statistical application to fingerprint identification. In line with this trend toward improving our knowledge of this subject, the aim of the present study was to calculate the frequency with which 20 types of minutiae appeared in 2780 fingerprint impressions obtained from 278 individuals from two Argentinian population samples (100 individuals from Ramal and 178 from Puna-Quebrada). The different types of minutiae were located, identified, and quantified visually in two areas on the fingerprint, the inside and outside of a circle, the radius of which cut fifteen ridges perpendicularly, starting from the center cut of the axes defining the sectors. The non-equiprobability found in both population samples for the different minutiae types studied demonstrated that the evidential weight provided by these characteristics is not the same when applied in identification processes, whether used quantitatively (numerical standard) or qualitatively (holistic method). The results obtained for both populations were compared statistically with those published previously for a Spanish population sample, which had been collected using the same methodology. This comparison has enabled us to demonstrate, for the first time, the existence of significant differences between populations in minutiae frequencies, independently from the main pattern type.     

腹腔连续注射低剂量氯胺酮后大鼠海马LC3和Beclin1的表达

目的研究腹腔连续注射低剂量氯胺酮后大鼠海马自噬相关蛋白LC3、Beclin1的表达及其意义。方法 SD大鼠30只随机分为用药组和对照组,用药组大鼠以5mg/kg的剂量腹腔注射氯胺酮,每间隔30min 1次,共5次。对照组予以等量生理盐水。用药组大鼠按用药后时间不同分为6小组,分别于末次给药后1,3,6,12,24,48h后取海马组织备用,用免疫荧光技术和Western blot技术检测大鼠海马组织中LC3、Beclin1的表达,应用统计学处理,比较用药组与对照组的蛋白表达差异。结果与对照组比较,用药组大鼠海马组织中LC3Ⅱ/LC3Ⅰ值在1h表达开始增多,6h呈强表达,Beclinl的表达在6h开始增多,12,24,48h都呈强表达(P<0.05)。结论腹腔连续注射低剂量氯胺酮能促进海马组织发生自噬,自噬增强是对氯胺酮毒性的反应。     

Cathepsin-L在缺血心肌中的表达

目的检测cathepsin-L(CTSL)在大鼠早期缺血心肌中的表达变化,并探讨其法医学意义。方法建立大鼠早期心肌缺血模型,设置早期缺血组(early ischemic myocardium,EIM)、非缺血组(non-ischemic myocardium,NIM)、假手术组以及空白对照组,采用real-time PCR方法检测大鼠缺血后15min,30min,1h和2h CTSL mRNA的表达量,并进行组内和组间比较。收集心源性猝死者缺血心肌和机械性损伤致死者正常心肌样本,采用免疫组化染色方法观察心肌组织中CTSL蛋白表达。结果 EIM组CTSL mRNA表达量与NIM组、假手术组及空白组相比,在15min时无统计学意义(P>0.05),在30min、1h和2h时分别升高1.4、3.1和4.5倍(P<0.05);其余3组间差异无统计学意义(P>0.05)。观察10例冠脉狭窄程度Ⅲ～Ⅳ级的心源性猝死(SCD)者缺血心肌,CTSL表达增强。结论大鼠心肌缺血后早期即可检测到CTSL mRNA的升高,并在SCD冠脉狭窄死者缺血心肌中高表达,提示CTSL可作为心肌缺血与SCD的参考指标。     

人身侵权之债债权人在破产清偿中的优先权分析

在破产案件,特别是由大规模侵权引发的破产案件之中,人身侵权之债的债权人是否享有优先权是一个非常重要又颇具争议的问题。从优先权的价值取向、人身侵权之债的特殊性以及社会现实的需求等方面综合分析,人身侵权之债在破产中理应具有一定的优先性。从各国的司法实践来看,许多国家都对破产中的人身侵权之债给予了特殊保护,而且有越来越多的国家开始重视人身侵权之债的优先保护问题。