Suicide by a circular saw

The case of a suicide of a 32-year-old female using an electric circular saw is herein described. The decedent was suffering from depression and was found dead in her room. Beside her right hand was lying a circular saw, which was not running. The autopsy revealed a large gaping wound measuring 15.5 cm in length on the right side of her neck. The right external carotid artery, the right internal jugular vein, and the right internal carotid artery were cut and the injury reached to the cervical vertebra. Therefore, the cause of death was exsanguination. An individual who commits suicide with an electric saw, such as a chain saw, band saw, and circular saw is rare; in particular females rarely select this method as the means of suicide. However, we herein report the case of a female patient with a psychiatric disease who successfully committed suicide with a circular saw.     

Bloodstain pattern analysis--casework experience

The morphology of bloodstain distribution patterns at the crime scene carries vital information for a reconstruction of the events. Contrary to experimental work, case reports where the reconstruction has been verified have rarely been published. This is the reason why a series of four illustrative cases is presented where bloodstain pattern analysis at the crime scene made a reconstruction of the events possible and where this reconstruction was later verified by a confession of the offender. The cases include various types of bloodstains such as contact and smear stains, drop stains, arterial blood spatter and splash stains from both impact and cast-off pattern. Problems frequently encountered in practical casework are addressed, such as unfavourable environmental conditions or combinations of different bloodstain patterns. It is also demonstrated that the analysis of bloodstain morphology can support individualisation of stains by directing the selection of a limited number of stains from a complex pattern for DNA analysis. The complexity of real situations suggests a step-by-step approach starting with a comprehensive view of the overall picture. This is followed by a differentiation and analysis of single bloodstain patterns and a search for informative details. It is ideal when the expert inspecting the crime scene has also performed the autopsy, but he definitely must have detailed knowledge of the injuries of the deceased/injured and of the possible mechanisms of production.     

Haplotype of 12 Y-STR loci of the PowerPlex Y-system in Sichuan Han ethnic group in west China

Haplotypes and allele frequencies for 12 Y-STR loci were determined in Sichuan Han ethnic population samples of 237 unrelated males living in west China. Only one haplotype was encountered in triple. Twelve of the haplotypes were encountered in duplicate, while 210 haplotypes were unique. The gene diversity was 0.9952. This study provides an essential precondition for identification of male DNA and tracing of paternal lineages.     

Adipocere formation via hydrogenation of linoleic acid in a victim kept under dry concealment

Adipocere formation is well known as a later post-mortem change. We experienced a female victim who had been sealed up in a clothes box for approximately 4 years. We collected several subcutaneous fats as well as visceral fats from the victim to investigate adipocere formation. Fresh subcutaneous fats of one female and five male victims who suddenly died were used as the control. These samples were homogenized and the lipids were extracted with chloroform and methanol followed by injection into gas chromatography-mass spectrometry and gas chromatography. We detected a hydroxy fatty acid in the fat of the case, but not in the controls. Using standard synthetic hydroxy fatty acid, the lipid extract component was identified as 10-hydroxyoctadecanoic acid (10-OH 18:0) and this concentration was quantified. Consequently we confirmed that adipocere was formed much slowly in dry concealment. In addition, the fatty acid composition was compared with the control. Most of the linoleic acid (18:2) disappeared and a peak developed instead. Using standard synthetic fatty acid, this peak was identified as cis-12-octadecenoic acid (cis-12-18:1). This suggests that linoleic acid is hydrogenated to cis-12-octadecenoic acid in the process of adipocere formation.     

The use of rapid diagnostic test of procalcitonin serum levels for the postmortem diagnosis of sepsis

Because serum Procalcitonin is reported to be a valid postmortem marker of sepsis, this prospective study was carried out to determine whether the semi-quantitative PCT-Q((R))-Test (B.R.A.H.M.S., Germany) is a reliable indicator of postmortem Procalcitonin (PCT) serum levels, thus enabling a quick "tableside" diagnosis of sepsis. Postmortem PCT-levels of 70 forensic and 78 clinical-pathological autopsy cases (n=148) were examined using the B.R.A.H.M.S-PCT-Q-Test during autopsy. 27 cases were categorized as the cases of sepsis according to the ACCP/SCCM Consensus Conference criteria. 121 cases were assigned to the non-sepsis group. Among the 148 cases, 18 samples could not be analyzed by the reason of strong hemolysis. Using a cut-off point of 2 ng/ml, 20 cases of sepsis were identified (true positive) whereas 3 cases of sepsis were not detected (false negative). In the non-sepsis group (107 cases) 6 cases showed a positive testing (false positive). When applied within 48 h postmortem, the PCT-Q-Test showed a sensitivity of 86.96% and a specificity of 94.39% (at cut-off 2 ng/ml). Likelihood ratios and positive predictive values proved to be lower in the forensic autopsy group (PPV: 59.3% in forensic case vs. 85.1% in clinicopathological cases; NPV: 98.73% in forensic cases vs. 95.2% in clinicopathological cases). The PPVs using a cut-off point of 10 ng/ml were 100% in both groups independent of sepsis prevalences. The results show, that a high NPV for prevalences ranging from 3% to 30% can be reached using a 2 ng/ml cut-off point, whereas a cut-off of 10 ng/ml ensures a high PPV for the respective prevalences in the absence of exclusion criteria. The study provides strong evidence that the introduction of rapid diagnostic test (RDTs) of postmortem PCT serum levels may be useful in achieving rapid distinction between sepsis and non-sepsis-related causes of death, especially in conjunction with the medical case history and further autopsy results. In addition, the use of RDTs enables clinicians to conduct an evidence-based validation of clinical diagnosis, thus facilitating future clinical decision-making.     

Application of discriminant analysis to differentiate between incorporation of cocaine and its congeners into hair and contamination

The requirement to differentiate between incorporation and external contamination of drugs into hair is undisputed, in particular when dealing with compounds which are administered by sniffing or inhalation (e.g. cocaine). With the aim of making this discrimination, hair samples from cocaine (COC) users (group IN) and seized cocaine samples (group OUT) were compared regarding the parameters benzoylecgonine (BZE), ecgonine methyl ester (EME), ecgonine (ECG), anhydroecgonine methyl ester (AEME), cocaethylene (CE) and norcocaine (NCOC). Since most of these compounds may be minor by-products of COC or be formed by biotransformation or chemical degradation, the stability of each substance was carefully examined. COC was found to be converted into significant amounts of BZE, EME and ECG even under mild extraction conditions, while traces of NCOC proved to be a ubiquitous by-product of COC. Cocaine positive hairs and seized cocaine samples (diluted to relevant concentrations) were equally preprocessed and analyzed by LC-MS-MS. Out of the metabolites listed above, NCOC, CE and AEME (each normalised to COC) were significantly increased in the incorporation group (i.e. hair samples from cocaine users). Based on this approach, a statistical discriminant analysis enabled us to make a prediction (and estimation of uncertainty) for each cocaine positive hair sample as to its likelihood of belonging to the group of cocaine users or of being contaminated.     

基于六边形理论的学生领导力发展观

在充满复杂性的时代,关注领导力是有必要的。在以快速变化、高度工业化为特征的第三个千年中,通讯与信息技术时代与数字世界需要能够推进世界革新的领导人。由于教育系统已经将培养政治领导、社会、经济、文化和科技等领域的领导人涵盖其中,而这些领导人将把握社会方向,促进世界发展。因此,学生领导力成为现阶段的重要学科。学生领导力发展六边形理论,内涵丰富,从个人、集体和社会各个角度出发,建立系统性观点,旨在进一步推进学生领导力发展理论。     

Family Cohesion and Romantic and Sexual Initiation: A Three Wave Longitudinal Study

Although the relation between family relationships and the timing of sexual debut has been the focus of many studies, research on mediating factors is scarce. This study examines whether low levels of family cohesion result in an earlier onset of romantic and sexual experiences, and whether the link between family cohesion and an early sexual debut is mediated by early romantic initiation. A longitudinal sample of 314 adolescent girls and 222 boys, aged 12–17 at Wave 1, completed questionnaires at three measurement points with three year intervals. The results showed that sexual debut followed romantic initiation for 77% of the participants. For early adolescent females (aged 12–14), high levels of family cohesion resulted in a later sexual debut and this association was fully mediated by a delay of romantic initiation. Among boys and older girls, timing of romantic initiation did not mediate the link between family cohesion and timing of sexual initiation. Early adolescent girls who have negative relationships with their parents turn to romantic relationships for intimacy and support, which subsequently provide the opportunity for an early sexual debut. Low levels of family cohesion thus primarily precipitate romantic initiation and sexual initiation appears to be secondary to this process among girls in this age group.