Thermal development of latent fingermarks on porous surfaces—Further observations and refinements

In a further study of the thermal development of fingermarks on paper and similar surfaces, it is demonstrated that direct contact heating of the substrate using coated or ceramic surfaces at temperatures in excess of 230 °C produces results superior to those obtained using hot air. Fingermarks can also be developed in this way on other cellulose-based substrates such as wood and cotton fabric, though ridge detail is difficult to obtain in the latter case. Fluorescence spectroscopy indicates that the phenomena observed during the thermal development of fingermarks can be reproduced simply by heating untreated white copy paper or filter paper, or these papers treated with solutions of sodium chloride or alanine. There is no evidence to suggest that the observed fluorescence of fingermarks heated on paper is due to a reaction of fingermark constituents on or with the paper. Instead, we maintain that the ridge contrast observed first as fluorescence, and later as brown charring, is simply an acceleration of the thermal degradation of the paper. Thermal degradation of cellulose, a major constituent of paper and wood, is known to give rise to a fluorescent product if sufficient oxygen is available [1], [2], [3], [4], [5]. However, the absence of atmospheric oxygen has only a slight effect on the thermal development of fingermarks, indicating that there is sufficient oxygen already present in paper to allow the formation of the fluorescent and charred products. In a depletion study comparing thermal development of fingermarks on paper with development using ninhydrin, the thermal technique was found to be as sensitive as ninhydrin for six out of seven donors. When thermal development was used in sequence with ninhydrin and DFO, it was found that only fingermarks that had been developed to the fluorescent stage (a few seconds of heating) could subsequently be developed with the other reagents. In the reverse sequence, no useful further development was noted for fingermarks that were treated thermally after having been developed with ninhydrin or DFO. Aged fingermarks, including marks from 1-year-old university examination papers were successfully developed using the thermal technique.     

A study of distribution of ethyl glucuronide in different keratin matrices

Ethyl glucuronide (EtG) is a direct metabolite of ethanol, frequently used as a biomarker of alcohol abuse. To this purpose, EtG is preferentially determined in hair samples, using a cut-off value of 30pg/mg to discriminate between social and heavy drinkers, as recently fixed by an international consensus conference. Although this cut-off value is assumed for head hair, alternative matrices, such as pubic, axillary and chest hair, are often analyzed when head hair is not available. Previous studies suggested that determination of EtG in various keratin matrices may lead to different results; growth cycle and rate, urine contamination, distribution of sebum glands and other environmental factors are likely to contribute to these differences. We analyzed more than 2700 samples (head, pubic, chest and axillary hair) to evaluate the inter- and intra-individual distribution of the EtG concentration in the different keratin matrices. The data were interpreted on a statistical basis, on the assumption that large population data-sets will level off the average alcohol consumption of each group. From both inter- and intra-individual distribution data, significant differences were observed in EtG concentrations recorded in head, axillary and pubic hair samples. It is concluded that pubic hair cannot be utilized alternatively to head hair to prove chronic alcohol abuse, nor is axillary hair, since positive and negative biases respectively affect these determinations. In contrast, for chest hair, EtG distributions similar to head hair were found, although the large discrepancy between the examined population dimensions presently prevents any definitive conclusion. Thus, chest hair represents a promising alternative to head hair for EtG determinations, deserving further investigation on samples collected from the same individuals, in order to establish a clear correlation between their respective EtG concentrations.     

关于我国民族乡经济社会发展的思考

民族乡是民族区域自治制度的一种补充形式,民族乡制度是我国解决民族问题的一项政治制度,也是党和国家民族政策的重要组成部分。本文坚持以“三个代表”重要思想为指导,深入分析民族乡工作面临的形势和存在的问题,探索和研究加快民族乡经济和社会发展的思路和措施。     

Unusual neck lesion in a pedestrian caused by a road accident

The authors describe a road accident that occurred in the Trieste region of Italy in 1998, wherein a pedestrian experienced a mortal injury. During the on-site examination, the forensic officer in charge noticed, in addition to dispersed abrasions, bruises, and fractures, an unusual position of the head with a highly unusual motility of the cervical rachis and, above all, an apparent whitish fibrous elastic cord, 7-8 cm long, which came out of the mouth. The cord was found to be a segment of the spinal cord, expelled and driven into the mouth cavity by the impact. This represents an interesting case because of the specific dynamics of the accident and the type of lesion involved. This kind of spinal cord injury, in particular, is infrequent among pedestrians involved in road accidents in comparison with other road casualties.     

Everyday stressors in the lives of Anglo and Hispanic learning handicapped adolescent

The sociocultural context of the lives of 10 learning handicapped adolescents was closely monitored over an entire school year using participant observation techniques. Everyday stressors and coping strategies of 5 Hispanic and 5 Anglo adolescents matched on age, sex, SES, class placement, and family intactness, were documented in lengthy field notes. Data revealed that in addition to concerns typical of all adolescents (i.e., family, work, recreation, appearance), cross pressure from cultural conflicts and the learning handicapped status were major sources of stress for these adolescent subgroups. It was concluded that we need to understand stressful events as a function of the context in which lives are situated in order to develop intervention programs designed to teach stress management and strategies for coping with relevant real-life problems.This research was supported in part by National Institute of Child Health and Human Development Grant No. HD23097.Received Ed.D. from Columbia University. Current interests include social competence and family relations of culturally diverse learning handicapped populations.     

A case of electrocution during illegal fishing activities

The passage of electric current through the human body causes variable harm, ranging from loss of consciousness to death caused by paralysis of the bulbar nerve centers. This report describes a fatal case caused by an illegal fishing practice involving stunning fish with electric shocks produced by an electric generator carried through the water inside the carcass of an old refrigerator to keep it afloat. This occurrence is unusual because of the circumstances giving rise to the use of electric current and the cause of death, which resulted from the combination of the electric current produced by the generator and the saltwater, bringing about death by drowning.     

Death following atypical compression of the neck

The authors present 3 cases of asphyxia caused by atypical compression of the neck by the metal bed bars fitted at the sides of the bed to prevent falling out. These occurred in 3 elderly women living in nursing homes, confined to bed by severe neuropsychiatric disturbances. In all 3 cases, the minor nature of the skin lesions and absence of blood infiltrations in the anatomic structures of the neck had made it difficult to diagnose the cause of death. Inspection of the rest homes, together with the autopsy findings (acute pulmonary emphysema, conjunctival petechiae, and dark, fluid blood), enabled identification of asphyxia as the cause of death and its causal agent as the bed bars.     

The 2000-2001 GEP-ISFG Collaborative Exercise on mtDNA: assessing the cause of unsuccessful mtDNA PCR amplification of hair shaft samples

We report the results of Spanish and Portuguese working group (GEP) of International Society of Forensic Genetics (ISFG) Collaborative Exercise 2001-2002 on mitochondrial DNA (mtDNA) analysis. 64 laboratories from Spain, Portugal and several Latin-American countries participated in this quality control exercise. Five samples were sent to the participating laboratories, four blood stains (M1-M4) and a sample (M5) consisting of two hair shaft fragments. M4 was non-human (Felis catus) in origin; therefore, the capacity of the labs to identify the biological source of this sample was an integral part of the exercise. Some labs detected the non-human origin of M4 by carrying out immuno-diffussion techniques using antihuman serum, whereas others identified the specific animal origin by testing the sample against a set of animal antibodies or by means of the analysis of mtDNA regions (Cyt-b, 12S, and 16S genes). The results of the other three human blood stains (M1-M3) improved in relation to the last Collaborative Exercises but those related to hairs yielded a low rate of success which clearly contrasts with previous results. As a consequence of this, some labs performed additional analysis showing that the origin of this low efficiency was not the presence of inhibitors, but the low quantity of DNA present in these specific hair samples and the degradation.As a general conclusion the results emphasize the need of external proficiency testing as part of the accreditation procedure for the labs performing mtDNA analysis in forensic casework.