A report of the 1997, 1998 and 1999 Paternity Testing Workshops of the English Speaking Working Group of the International Society for Forensic Genetics

We present the results of the 1997, 1998 and 1999 Paternity Testing Workshops of the English Speaking Working Group of the International Society for Forensic Genetics. The numbers of participating laboratories were 24 (1997), 31 (1998) and 32 (1999). In 1997, all laboratories drew the correct conclusion that the alleged father was the biological father of the child. In 1998, the alleged father was the biological brother of the child and all laboratories excluded him. The scenario in 1999 was a deficiency case consisting of mother, child and the parents of the alleged father and all but one laboratory drew the correct conclusion.The percentage of laboratories routinely performing variable number of tandem repeat (VNTR) investigations using single locus probes (SLPs) and restriction fragment length polymorphism (RFLP) decreased from 83% in 1997 to 66% in 1999. In the three workshops, more than 90% of the laboratories used polymerase chain reaction (PCR) based systems. In 1999, 80% of the laboratories performing PCR, used commercially available short tandem repeat (STR) kits. Other commonly used systems were HLA and PolyMarker investigated with PCR. Conventional systems and RFLP investigations of VNTRs with multi loci probes (MLPs) were used routinely by approximately 20% of the participating laboratories.All laboratories submitting results in the three workshops used RFLP-based VNTRs or/and PCR based VNTRs/STRs. Inter-laboratory comparisons of the results showed a very high concordance. The overall coefficients of variation between the laboratories of the results of RFLP typing of the commonly used VNTRs D2S44, D7S21, D7S22 and D12S11 were 1.2-1.3%. Consistent results were obtained in the great majority of the systems investigated by PCR and typing errors counted for less than 0.3% of the PCR based results.     

The 1998-1999 collaborative exercises and proficiency testing program on DNA typing of the Spanish and Portuguese Working Group of the International Society for Forensic Genetics (GEP-ISFG)

A total of 28 laboratories (labs) submitted results for the 1998 collaborative exercise and the proficiency testing program of the Spanish and Portuguese Working Group of the International Society for Forensic Genetics (GEP-ISFG) group. This number increased to 46 labs in 1999. Six bloodstains were submitted, each one with 200 microl soaked in cotton except the sample no. 6 submitted for DNA quantification which had 2 microl. One of the samples was a mixed stain. A paternity testing case and a criminal case in the 1998 trial (GEP'98) and two paternity testing cases in 1999 (GEP'99) were included and the statistical evaluation of the evidence was requested in both cases. In the GEP'99 trial, a theoretical paternity testing case was included. A total of 52 DNA genetic markers were used by the participants in the GEP'98 trial, which increased to 101 in GEP'99. Despite this increasing number of participating labs, results remained quite satisfactory. All the labs used PCR-based DNA polymorphisms with an increasing number of markers, obtaining good results. SLPs were used by a decreasing number of labs but the results indicated a good level of expertise despite the different protocols used.Good results were also obtained for mtDNA despite the difficulties presented by the samples due to the presence of length heteroplasmy in some samples in both trials. The detection of heteroplasmy should, however, be improved.Similar conclusions were reached for both, the paternity and the criminal case by all the labs. Common methodologies for the statistical evaluation of the paternity case were used and the paternity index and the probability of paternity (with an a priori value of 0.5) reported by most of the labs. Also, a great uniformity was found in the evaluation of the criminal case despite the lack of a specific hypothesis in the design of the exercise. Some errors in statistical programs or in calculations were detected in a theoretical paternity case included in the GEP'99 trial for statistical analysis.     

Size calculation of restriction enzyme HaeIII-generated fragments detected by probe YNH24 by comparison of data from two laboratories: the generation of fragment-size frequencies.

Restriction fragment-length polymorphism of locus D2S44 detected by the highly polymorphic probe YNH24 and restriction endonuclease HaeIII can be used to improve parentage testing when representative fragment-size frequencies can be obtained. By joining the results of different laboratories, it is possible to set up a meaningful databank. Therefore, the same randomly chosen samples were tested for the HaeIII RFLP detected by probe YNH24 in Düsseldorf (DUS) and Amsterdam (AMS). The results of the different fragment-size calculations obtained by using internal markers and a computerized system (DUS-cad and AMS-cad), and by using external markers and manual calculations (DUS-man), were analyzed. Comparing these results, no statistically significant differences were seen. The results obtained with probe YNH24 and enzyme HaeIII in Düsseldorf and Amsterdam can be used to attain a sufficient number of samples to generate relevant fragment-size frequencies.     

Fn-EIIIA金标试纸条进行损伤时间推断的效果评价

目的评价Fn-EIIIA金标单克隆抗体试纸条在人体皮肤组织损伤时间推断中的有效性和灵敏度。方法提取不同损伤时间人体皮肤组织,匀浆,用Fn-EIIIA金标单克隆抗体试纸条检测其Fn-EIIIA的表达,对其结果进行评价;同时,将大鼠挫伤皮肤组织置于自然环境中,分别提取不同自溶时间段的皮肤样本进行检测,对自溶变化对检测结果的影响进行观察。结果正常皮肤组织样本中试纸条检测线不显色,损伤1h后即显色,随损伤时间延长,试纸条检测线有显色逐渐加深的趋势;在观察时间段内,组织自溶对检测结果无显著影响。结论Fn-EIIIA金标单克隆抗体试纸条可作为法医学损伤时间推断敏感、稳定的检测手段。     

A fatal forensic intoxication with fenarimol: analysis by HPLC/DAD/MSD

Fenarimol (Rubigan) is a pyrimidine ergosterol biosynthesis inhibitor used as a systemic fungicide. The authors present a fatal fenarimol intoxication case analysed in the Forensic Toxicology Service of the National Institute of Legal Medicine. The results were used to compare two different HPLC techniques, regarding selectivity and sensitivity: an HPLC system with a diode array detector (DAD) and an HPLC system with a DAD and a mass spectrometry detector (MSD) with an electrospray interface. All biological samples were submitted to a solid-phase extraction procedure. The detection and quantification limits of fenarimol, linearity, precision and accuracy were evaluated. The fenarimol concentration levels determined were of 89.0 mg/ml in gastric contents, 1.9 mg/g in liver and 0.4 mg/g in kidney. Blood was not available at autopsy. No published data related to fenarimol self-poisoning were found, so it was not possible to interpret the results obtained by comparison with toxic/lethal levels.     

Development of a Library Search‐Based Screening System for 3,4‐Methylenedioxymethamphetamine in Ecstasy Tablets Using a Portable Near‐Infrared Spectrometer

This is the first report on development of a library search‐based screening system for 3,4‐methylenedioxymethamphetamine (MDMA) in ecstasy tablets using a portable near‐infrared (NIR) spectrometer. The spectrum library consisted of spectra originating from standard substances as well as mixtures of MDMA hydrochloride (MDMA‐HCl) and diluents. The raw NIR spectra were mathematically pretreated, and then, a library search was performed using correlation coefficient. To enhance the discrimination ability, the wavelength used for the library search was limited. Mixtures of MDMA‐HCl and diluents were used to decide criteria to judge MDMA‐positive or MDMA‐negative. Confiscated MDMA tablets and medicinal tablets were used for performance check of the criteria. Twenty‐two of 27 MDMA tablets were truly judged as MDMA‐positive. Five false‐negative results may be caused by compounds not included in the library. No false‐positive results were obtained for medicinal tablets. This system will be a useful tool for on‐site screening of MDMA tablets.     

Report on the third EDNAP collaborative STR exercise

This report describes an inter-laboratory exercise completed on behalf of the European DNA Profiling (EDNAP) group. The exercise is one in a series designed to identify STR loci which could be used for harmonisation between participating European forensic science laboratories. Participants were asked to identify the alleles present in five bloodstains at the STR loci HUMTHO1 and HUMVWFA31/A. Two of the stains were prepared from mixtures of two different blood samples. There were no special instructions and each laboratory was requested to use the methodology normally employed for crime case investigations. All participating laboratories achieved the same results for both loci. In addition, the laboratories were also requested to report the results obtained from any other loci which would normally be used in crime case investigations. A comparison of these results showed some inter-laboratory variation.     

What does a digital forensics opinion look like? A comparative study of digital forensics and forensic science reporting practices

This study explores digital forensics (DF) reporting practices and compares the results with other forensic science disciplines. Forty reports were obtained from a quasi-experiment involving DF examiners, and a quantitative content analysis was performed to determine which conclusion types they applied and which content they included with relevance to the credibility of the reported results. A qualitative analysis was performed to examine the certainty expressions used in the conclusions. The results were compared to a study of eight forensic science disciplines performed by Bali et al. [24,26]. The results show that the DF examiners tend to present their conclusions either as Categorical conclusion or Strength of support (SoS) conclusion types and that they address source, activity, and offence level issues in their conclusions. The content analysis indicates deficiencies in DF reporting practices, and several of the challenges seem to be shared with other FS disciplines. The analysis of certainty expressions showed that a plethora of expressions was used, and that they lacked reference to an established framework. The results indicate that more research on DF evaluation and reporting practices is necessary and justifies a need for enhanced focus on quality control and peer review within the DF discipline.     

A comparison of efficiency of manual and automatic fibres search with the Maxcan fibre finder

The aim of this work was to study the efficiency of automatic fibre searching with the Maxcan fibre finder (Cox Analytical Systems, Sweden) in comparison to manual searching. The influence of some parameters (color, thickness, background noise) on the results of a fibre search was considered. Eighteen experimental tapes with different target fibres and different background noises were prepared in the laboratory. Searching of fibres was performed manually and with the Maxcan fibre finder by different operators from four European laboratories. Two laboratories have the Maxcan fibre finder system and the two instruments were used and compared in this study. The results show that searching with the Maxcan is generally as efficient as manual searching, except for very pale or very dark fibres. Note that the tapes used for these experiments were prepared in laboratory, and are not completely representative of the tape that could be obtained in real cases. To generalize the results obtained, further research on real case samples would be necessary.     

A comparison of efficiency of manual and automatic fibres search with the Maxcan fibre finder

The aim of this work was to study the efficiency of automatic fibre searching with the Maxcan fibre finder (Cox Analytical Systems, Sweden) in comparison to manual searching. The influence of some parameters (color, thickness, background noise) on the results of a fibre search was considered. Eighteen experimental tapes with different target fibres and different background noises were prepared in the laboratory. Searching of fibres was performed manually and with the Maxcan fibre finder by different operators from four European laboratories. Two laboratories have the Maxcan fibre finder system and the two instruments were used and compared in this study. The results show that searching with the Maxcan is generally as efficient as manual searching, except for very pale or very dark fibres. Note that the tapes used for these experiments were prepared in laboratory, and are not completely representative of the tape that could be obtained in real cases. To generalize the results obtained, further research on real case samples would be necessary.     

A report of the 2000 and 2001 paternity testing workshops of the English speaking working group of the international society for forensic genetics

During the last 10 years, the English Speaking Working Group (ESWG) of the International Society for Forensic Genetics (ISFG) has once a year arranged a Paternity Testing Workshop in which blood samples as well as a questionnaire concerning laboratory strategies were distributed to the participating laboratories. In 2000 and 2001, paper challenges were included in the workshops. Here, we present the results of the 2000 and 2001 Paternity Testing Workshops. The numbers of participating laboratories were 33 (2000) and 36 (2001). A total of 36% (2000) and 31% (2001) of the laboratories submitted typing results of variable number of tandem repeats (VNTRs) investigated with restriction fragment length polymorphism (RFLP) and single locus probes (SLPs). A total of 91% (2000) and 86% (2001) submitted typing results of polymerase chain reaction (PCR) based systems. Typing errors occurred in 0.3% of the submitted PCR-based results in 2000 and in 0.1% in 2001. The results of the paper challenges showed a high degree of variation in the formulas used for calculation of the weight of evidence of rare events such as inconsistencies or possible silent alleles. The majority of the laboratories used the same formulas for calculations of frequently occurring events.     

Relative Advantages of Person- and Variable-Based Approaches for Predicting Problem Behaviors from Kindergarten Assessments

Kindergarten teacher ratings of physical aggression, hyperactivity,inattention, anxiety, and prosocial behavior were used to predictself-reported delinquency, peer-rated social withdrawal, and schoolplacement in preadolescence (ages 10 to 12 years) in a large longitudinalsample of boys from low socio-economic neighborhoods. Two analyticstrategies were used: person-oriented and variable-oriented approaches. Inthe person approach, eight clusters, based on the kindergarten behaviors,were used to predict delinquency, social withdrawal, and schoolplacement. In the variable approach, the kindergarten behaviors were used asdimensions in logistic regressions. Family adversity was used as the firstpredictor in both approaches; it significantly predicted all the outcomes inpreadolescence. The results obtained using the two approaches were partly inaccordance. In both sets of results, kindergarten teacher-ratedexternalizing behavior problems were most related to later self-reporteddelinquency, and internalizing problems to peer-rated socialwithdrawal. However, the person approach showed that all patterns ofkindergarten behavior problems increased the risk for placement out of anage-appropriate regular classroom, while only inattention and lack ofprosocial behavior were the significant dimensional predictors of thisnegative outcome according to the variable approach. Also, the personapproach showed that the Multiproblem kindergarten boys had the highestpercentage of comorbidity of preadolescent problems. The ROC curvesindicated that prediction of delinquency, social withdrawal, and schoolplacement were equally accurate using the cluster and variableapproaches. Advantages and limits of both approaches are discussed withreference to their usefulness for clinicians.     

Strontium-90 as an indicator of time since death: a pilot investigation.

The results of a pilot investigation are presented. The study aimed to show that the presence of radioactive strontium-90 in human bone could be used as evidence of active uptake during life. In this way the time since death of the individual could be identified as occurring before or after the date when atmospheric levels of radioactive strontium were at a peak in the early 1960s. The results of this initial investigation were encouraging but further detailed analysis is required on a substantially larger sample of material spanning a more controlled time period.     

猫脑震荡与脑损伤的实验性研究

了解轻型颅脑损伤和脑震荡的脑组织病理形态学及生理功能的变化情况。以流体液压冲击法及胶锤打击的方式 ,分别造成闭合性脑外伤及脑震荡的动物模型。结果显示 :较大的钝性外力可造成脑组织明显的病理形态学改变和脑电、心电等生理功能的持续性改变 ,即脑损伤 ;较小的钝力则只能造成动物意识的一过性丧失 ( 3 0min以内 )及脑电、心电的可复性变化 ,脑组织光镜下病理形态学改变不明显。区别脑震荡与轻型脑损伤应以有无明显的病理形态学改变为“界” ,以脑电、心电、意识障碍等改变是否可复为“度”来划分脑震荡与脑损伤     

Evaluation of breath-alcohol instruments. III. Controlled field trial with Alcolmeter pocket model

A breath-alcohol screening device, Alcolmeter pocket model, was evaluated in a controlled field trial with policeman operating the instruments. The results of tests made with subjects before they drank alcohol were always zero. The standard deviation (S.D.) of breath alcohol determinations increased with increase in the concentration of alcohol in the sample, being 0.036 mg/ml at a mean blood-ethanol concentration of 0.53 mg/ml. The S.D. varied among subjects tested (from 0.022 to 0.053 mg/ml) as well as among the instruments used (from 0.023 to 0.054 mg/ml). The breath test results were on average less than the actual blood-ethanol concentrations when a 2100: 1 blood/breath ratio was used to calibrate the Alcolmeter device. Blood ethanol (x) and Alcolmeter readings (y) were highly correlated (r = 0.95 +/- 0.018) and the regression equation was y = -0.017 + 0.95x. At a mean blood-ethanol concentration of 0.50 mg/ml, the Alcolmeter instrument will indicate 0.46 mg/ml on average. The standard error estimate was 0.085 mg/ml, being 17% of the mean Alcolmeter reading and this corresponds to 95% confidence limits of +/- 0.17 mg/ml. The results of this study show that Alcolmeter pocket-model is a useful device for breath-alcohol screening purposes at a blood-alcohol level of 0.50 mg/ml. A blood/breath ratio of 2300 should be used to calibrate the Alcolmeter device.     

烟蒂DNA分型的研究

目的 研究烟蒂中DNA提取及其检验。方法 用Chelex-100法提取170枚烟蒂样本的DNA,进行PCR扩增及STR检验。结果 除1名志愿者提供的21枚烟蒂外层纸未能检出STR基因分型外,其余烟蒂外层纸均得到分型结果。加入少许烟丝的样本未能检出STR分型,与口唇接触的海绵有时可检出基因型,6个月内的烟蒂可检出小片段基因座。结论 烟蒂能进行DNA分型,在法医检案中具有应用价值。     

Metric sex determination from the pelvis in modern Greeks

The ability to determine sex from unknown skeletal remains is vital, and methods to do this on the various bones of the human skeleton have been researched extensively. Many researchers have emphasized the need for population specific data for methods which are based on measurements, as there are vast differences in body size in various populations. The pelvis is known to be the most sexually dimorphic part of the human body, and no discriminant function formulae for this bone are available for Greek or other Mediterranean groups. The purpose of this study was therefore to develop discriminant functions which can be used for sex determination on measurements of the pelvis of modern Greeks. A sample of 97 male and 95 female pelves in a skeletal collection housed in Heraklion, Crete, was used. Measurements were taken from the articulated pelvis, single os coxae and the sacrum. Discriminant function formulae for all measurements and various combinations were used in order to assess the degree of sexual dimorphism in various parts of the pelvis, and to make the formulae usable on fragmented remains. For the single os coxae, average accuracies of 79.7-95.4% (79.1-93.5% on cross-validation) were found. However, it was found that measurements of the sciatic notch were unreliable and yielded poor results, and it is advisable that this characteristic must only be used as a last resort. Dimensions of the sacrum were not very dimorphic (average accuracy 60.9%), while measurements from the articulated pelvis yielded poorer results than that from single innominate bones. The diameter of the acetabulum was the single most dimorphic characteristic, providing on average 83.9% accuracy when used in isolation.     

Analysis of morphine by RIA and HPLC in fingernail clippings obtained from heroin users

Heroin is abused around the world and is frequently reported as the cause of death in overdose cases. Analysis of morphine in hair has been used in the past in forensic toxicology to study the addiction history of heroin addicts. The purpose of the present study was to evaluate the usefulness of the nail as an analytical specimen in the identification and quantification of morphine in fingernail clippings of known heroin users. Fingernail clippings were obtained from 26 consenting patients of the Glasgow Drug Problem Service. At the time of sampling, the participants provided answers to a questionnaire regarding their drug use patterns. Samples were decontaminated by sonication in SDS, deionized water and methanol, and the methanolic washes were screened for analyte presence. The washed nail clippings were then hydrolyzed and extracted. RIA was used for the screening and HPLC for the confirmation of morphine. Positive RIA results were obtained with nail clippings from 25 of the 26 heroin users. The levels ranged from 0.06 to 4.69 ng/mg with a mean morphine concentration of 1.67 ng/mg. HPLC results were positive for 22 of the 26 nail samples. The mean morphine level by HPLC was 2.11 ng/mg with a range from 0.14 to 6.90 ng/mg. Based on these results, we suggest that nails have the potential of becoming a powerful alternative to hair for the detection of past heroin use in forensic cases.     

Two Simple Formulas for Evaluating the Lower Bound of the Impact Velocity in Vehicle–pedestrian Accidents

Formulas for evaluating the lower bound of the impact velocity are valuable in vehicle–pedestrian accident reconstruction. The theory of classical mechanics and four hypotheses were employed to derive formulas; the research results and simulation/accident tests were employed to validate their feasibility. Then, two simple formulas were developed according to the distance between the rest positions of the vehicle and the pedestrian and the flight‐phase distance. The results showed that the evaluated results by the two proposed formulas are inferior to the existing results. The influence of a roadside step on the impact velocity, which decreased with an increase in the flight‐phase distance and a reduction in the road slope, was evaluated. Based on a real accident, the study concludes that the lower bound can be easily obtained with the proposed formulas, which can be used to determine the evaluated impact velocity during simulations.