吸毒案件中的尿吗啡检测

目的　研究吸毒人员停止使用毒品海洛因后 ,尿吗啡含量自然递减的一般规律。方法　对确证的 1 82名吸毒 (海洛因 )人员在停止使用毒品后连续 9天采集尿样 ,用放射免疫分析法检测尿吗啡含量。结果　 1 82名吸毒 (海洛因 )人员在停止吸毒后第 8天 ,尿吗啡平均含量降至 30ng/ml。 结论　在办案中 ,吸毒 (海洛因 )人员的尿样检测 ,建议最好在末次使用海洛因 8天之内     

Quantitative and qualitative analysis of DNA extracted from postmortem muscle tissues

DNA extracted from 33 postmortem muscle specimens was analyzed using MZ 1.3, a hypervariable minisatellite probe, as well as locus-specific minisatellite probes (g3, MS1 and MS43). After storage at -25 degrees C for 10 months, DNA from all the samples was partially (approximately 21% of total DNA) degraded even when autopsy was performed 1 day postmortem. However, more than 90% of DNA samples up to at least 3 days postmortem were suitable to obtain good restriction fragment length polymorphism (RFLP) patterns. When small strips of specimen were stored for 8 days at room temperature in moist chambers, approximately 42% of total DNA was degraded. Only 30% of these DNA samples still showed good RFLP patterns. However, no obvious relation between qualities of DNA analyzed by detection of RFLP and quantities of total and high-MW DNA became apparent. A case of familial relationship was ascertained by DNA fingerprints. Since DNA of good quality can be recovered from muscle tissues in large quantities, DNA extraction from muscle tissues and detection of RFLP patterns should be very useful for individual identification in autopsy cases.     

Quantitative analysis of proinflammatory cytokines (IL-1beta, IL-6, TNF-alpha) in human skin wounds

Proinflammatory cytokines play an important role in the mediation of inflammation and trauma. They could be useful for the determination of vitality and wound age. In the present study, 144 human skin wounds due to sharp force were investigated. The material was collected during operations (N=96) and postmortem examinations (N=48). The wound age varied from several seconds or minutes to 9 days. Control skin was available in each individual. The tissue specimens were homogenized and extracted in a solution of PBS and protease inhibitors. Interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-alpha) were measured by quantitative ELISA analysis. Statistical evaluation was performed by the t-test using the quotients of levels (wound sample/control skin). In surgical specimens the cytokine levels revealed a clear tendency to increase with wound age. IL-1beta in early skin wounds (24 h, P<0.05). The quantitative analysis of proinflammatory cytokines in wound extracts can contribute to the determination of vitality and wound age, in particular in the very early post-traumatic interval (classic stab wounds).     

Race, conventional crime, and criminal justice: The declining importance of skin color

Blacks in the United States are arrested, prosecuted, convicted, and incarcerated in numbers disproportionate to their percentage of the population. One explanation is that racial discrimination against Blacks pervades the American system of criminal justice. This study examined the nature and extent of racial discrimination in the criminal justice system by evaluating five propositions using data from extant literature. Little evidence was found to support the allegation that the criminal justice system systematically discriminates against Blacks.     

废水样中总硝基化合物的定量分析

利用气相色谱/质谱联用法对废水样中的2、4-二硝基甲苯和TNT进行了定性和定量分析,测定了废水中总硝基化合物的浓度.     

Quantitative analysis of glasses used within Australia

An initial 134 glasses have been collected from eleven classifications of glass used within Australia. These include both local and imported glasses. Quantitative elemental analyses of the glasses have been determined using a scanning electron microscope equipped with an energy dispersive X-ray spectrometer. The current program provides for an elemental analysis for Na, Mg, Al, Si, P, S or Pb, Cl, K, Ca, Ba or Ti, V, Cr, Fe, Mn and Zn expressed as oxides, and has a sensitivity down to approximately 0.1%. The data for the six most commonly occurring elements, namely, Na, Mg, Al, Si, K and Ca, together with the refractive index are presented for each class of glass in terms of their mean value and standard deviation from the mean, and also in histogram form.     

Single source DNA profile recovery from single cells isolated from skin and fabric from touch DNA mixtures in mock physical assaults

The ability to obtain DNA profiles from trace biological evidence is routinely demonstrated with so-called ‘touch DNA evidence’, which is generally perceived to be the result of DNA obtained from shed skin cells transferred from a donor's hands to an object or person during direct physical contact. Current methods for the recovery of trace DNA employ swabs or adhesive tape to sample an area of interest. While of practical utility, such ‘blind-swabbing’ approaches will necessarily co-sample cellular material from the different individuals whose cells are present on the item, even though the individuals' cells are principally located in topographically dispersed, but distinct, locations on the item. Thus the act of swabbing itself artifactually creates some of the DNA mixtures encountered in touch DNA samples. In some instances involving transient contact between an assailant and victim, the victim's DNA may be found in such significant excess as to preclude the detection and typing of the perpetrator's DNA. In order to circumvent the challenges with standard recovery and analysis methods for touch DNA evidence, we reported previously the development of a ‘smart analysis’ single cell recovery and DNA analysis method that results in enhanced genetic analysis of touch DNA evidence. Here we use the smart single cell analysis method to recover probative single source profiles from individual and agglomerated cells from various touched objects and clothing items belonging to known donors. We then use the same approach for the detection of single source male donor DNA in simulated physical contact/assault mixture samples (i.e. male ‘assailant’ grabbing the wrist, neck or clothing from the female ‘victim’, or being in transient contact with bedding from the ‘victim’). DNA profiles attributable to the male or female known donors were obtained from 31% and 35% of the single and agglomerated bio-particles (putative cells) tested. The known male donor ‘assailant’ DNA profile was identified in the cell sampling from every mixture type tested. The results of this work demonstrate the efficacy of an alternative strategy to recover single source perpetrator DNA profiles in physical contact/assault cases involving trace perpetrator/victim cellular admixtures.     

The detection and analysis of ignitable liquid residues extracted from human skin using SPME/GC

A simple, fast, inexpensive, and sensitive technique for the detection and identification of flammable or combustible liquid residues on the skin of arson suspects is presented. The use of solid phase microextraction (SPME) for the analysis of ignitable liquid residues has been demonstrated and it is shown in this work that this technique is effective in extracting these liquid residues at extremely low quantities. Microliter quantities of controlled spikes of gasoline, diesel fuel, and charcoal lighter fluid were deposited on the hands of a volunteer and extracted after several time intervals. The SPME technique can recover very small amounts of liquid deposits on skin up to 3.5 h after exposure, depending on the class of the ignitable liquid residue used.     

Cytokinetics of epidermic cells in skin from human cadavers. I. Dependency on the postmortal interval

Punch biopsies taken from the extensor side of the thigh of 35 human cadavers were incubated in vitro with radioactively labeled thymidine (3H-thymidine = 3H-TdR, 14C-thymidine = 14C-TdR) to determine whether a relationship exists between changes in the proliferative activity of the skin and the postmortal interval after irreversible cardiac arrest. The cadavers were stored at 4 degrees C. Cadavers with indeterminable time of death or presence of intoxication, drug therapy with cytostatic agents, or a skin disease were excluded from the study. Single, double, or multiple biopsies were performed on the same cadaver; single labeling with 3H-TdR was done in all cases; double labeling with 3H-TdR and 14C-TdR in selected cases. No relevant changes in the labeling index (mean, 2.39 +/- 1.03%) were demonstrable within the examined postmortal interval of 77.75 h. The DNA synthesis time (ts) was, on the average, 4.75 +/- 1.44 h; a certain relationship to the postmortal interval existed since ts declined with increasing storage time. The potential doubling time (tpot) decreased accordingly, beginning with 181.7 h (mean storage time, 29.9 h) and ending with 137.7 h (mean storage time, 41.7 h). No statistically relevant differences, however, were established at the 1% level. Whereas both labeling index and tpot during the early postmortal interval are comparable with observations in live humans, ts was relatively short as compared to that for the epidermis of live humans.     

致伤工具微量残留物提取和检验研究

目的研究猪皮损伤创口内微量物证提取检验方法,探索致伤工具残留物成分认定方法。方法用锤子打击猪皮,并用滤纸、棉花棒提取损伤创口的微量物质,应用扫描电镜X射线能谱技术检验,确定致伤工具成分。结果猪皮残留微小颗粒可以定量地与锤子成分进行比对检验,扫描电镜X射线能谱技术可对微小颗粒成分分析。结论该方法可以作为致伤工具成分认定的参考,对致伤工具推断具有现实意义。     

Under the skin of probation: A statewide analysis

This analysis examines the inter- and intra-racial/ethnicity effects of skin tone variations in a sample of probationers across three dependent variables: probation length, successful completion, and revocation due to technical violations. Darker tones were linked to shorter probation terms with the exception of African Americans, among whom no effect was found. Darker tones were also associated with a decreased likelihood of successful probation completion. Conversely, probation success likelihood was higher among light skinned Hispanics. Finally, lighter tones were also associated with increased risks of probation revocation. Importantly, across the analysis any significant effects for Whites dissipated once Hispanics were removed from the analysis. Explanations of the contrary findings are offered drawing from scholarship on normal crimes and racial threat.     

Prediction of eye color from genetic data using Bayesian approach

Prediction of visible traits from genetic data in certain forensic cases may provide important information that can speed up the process of investigation. Research that has been conducted on the genetics of pigmentation has revealed polymorphisms that explain a significant proportion of the variation observed in human iris color. Here, on the basis of genetic data for the six most relevant eye color predictors, two alternative Bayesian network model variants were developed and evaluated for their accuracy in prediction of eye color. The first model assumed eye color to be categorized into blue, brown, green, and hazel, while the second variant assumed a simplified classification with two states: light and dark. It was found that particularly high accuracy was obtained for the second model, and this proved that reliable differentiation between light and dark irises is possible based on analysis of six single nucleotide polymorphisms and a Bayesian procedure of evidence interpretation.     

A content analysis of fingerprint literature for educational curricula

Forensic science is being required to justify and elucidate its scientific foundations. One way of doing this is through academic curricula. For many native forensic sciences, these curricula do not exist. A content analysis of nine major books in fingerprints was conducted to develop a structure for curricula in that field. The results of this study can be used to organize course content and serve as a model for other disciplines with published materials but no coherent or standard curricula.     

Post-mortem analysis of apoptotic changes associated with human skin bruises

The estimation of the age of skin bruises is of importance in forensic medicine, especially in child abuse cases. Time-dependent changes in bruise colour and/or associated histological features have been used with a limited degree of success. An increased rate of apoptosis in the injured tissue has been considered as a novel time-dependent marker of cell death, by injury inflicted in a rat model. The object of the present study was to apply the TUNEL method of DNA end labelling to identify and enumerate apoptotic cells in bruised and normal skin in order to study the relationship of apoptotic cell density with the age of the bruise. A commercially available DNA end labelling kit, TUNEL method, was standardised, validated and used for this purpose. Twenty unselected post-mortem cases with bruises due to a variety of causes were studied. The apoptotic cells stained with TUNEL reaction were counted in 10 high power fields in the epidermis, as well as in the dermis of formaldehyde-fixed paraffin-embedded skin specimens. The mean positive cell densities (+/- 1 S.E.) were compared with respect to the age of the bruise. In the epidermis, the mean apoptotic cell count was statistically significantly greater in the bruised skin compared to normal skin in 2- to 6-day-old bruises; whilst in the dermis the same was true in 3- to 8-day-old bruises. The overall findings suggest that there is a quiescent period prior to the increase in the apoptotic cell activity that is seen following skin bruising. This is so provided the post-mortem skin samples were collected within a lapse of 6 days or less between the time of death and formalin fixation and paraffin embedding to avoid the bias made by the difference of length of post-mortem interval.     

An integrated technique for the analysis of skin bite marks

The high number of murder, rape, and child abuse cases in South Africa has led to increased numbers of bite mark cases being heard in high courts. Objective analysis to match perpetrators to bite marks at crime scenes must be able to withstand vigorous cross-examination to be of value in conviction of perpetrators. An analysis technique is described in four stages, namely determination of the mark to be a human bite mark, pattern association analysis, metric analysis and comparison with the population data, and illustrated by a real case study. New and accepted techniques are combined to determine the likelihood ratio of guilt expressed as one of a range of conclusions described in the paper. Each stage of the analysis adds to the confirmation (or rejection) of concordance between the dental features present on the victim and the dentition of the suspect. The results illustrate identification to a high degree of certainty.     

Statistical examination of hair color as a potential biasing factor in hair analysis

We review eight different data sets in this paper for the purposes of assessing the possibility that reported color of hair can produce a systematic bias in the interpretation of hair assays. We review studies or data sets that include heroin and its metabolites, cocaine and its metabolites, MDMA and its analogs, and amphetamine and methamphetamine. The studies have utilized a variety of different degrees of color categorization, ranging from the simple dichotomy of brown and black, to a high of 12 categories. The mean number of categories reported approaches 6 (mean = 5.875). There are a total of 2791 data points in this analysis. We utilize two major statistical techniques for assessing significance; one-way analysis of variance, and Tukey's Honestly Significant Difference procedure. In circumstances were only dichotomous contrasts are possible, one-way analysis of variance is used. In contrasts involving three or more categorical groups, Tukey's procedure is used. In circumstances where the homogeneity of group variances is not sustained by the Levene statistic, we use the Tamahane procedure, allowing an assessment that assumes unequal variances. The analysis of this data fails to discern a significant color effect. We speculate that it may be that variance is large in many domains affecting analyte recovery from hair. In large groups these variations tend to regress towards a typical or mean value. Thus the data here show that while there are group or aggregate differences in these 'typical' values, they are not great when considered in relation to the within-group variations which exist for those values. It is our view that color may play a role in the accumulation of drugs in hair, however it is likely to account for only a very small part of the complex process of drug accumulation.     

Criminal justice pioneers: A content analysis of biographical data

This study used relational content analysis to assess the relative importance of criminal justice pioneers (N = 44) as identified by Jones (2005). Comparisons were made in terms of race, gender, area of focus, level of education, era of birth, longevity, and the amount of space (i.e., pages) devoted to each biography. The results were threefold: (1) most of the designated pioneers were born between 1901 and 1950 where a significant number contributed in the area of law enforcement, (2) all women pioneers were Caucasian and outnumbered African American pioneers by more than more than a 2:1 ratio, and (3) men were ten times more likely than women to be regarded as pioneers. The implications of these findings are discussed regarding the perceived relative importance of certain personalities based on the amount of space devoted to their bibliography.