Facial approximation: globe projection guideline falsified by exophthalmometry literature

The projection of the cornea from the bony orbit has been determined, in facial approximation, by centrally locating the eyeball in the orbit and positioning the cornea so that its most anterior point falls in line with a tangent dropped from the mid-superior to the mid-inferior orbital rim. However, there appears to be no scientific evidence to justify this guideline; yet, there have been numerous studies that measure globe projection in living subjects, from the lateral orbit using an exophthalmometer. The aim of this study was to determine if the traditional facial approximation guideline is consistent with the exophthalmometry literature. MRI research shows that corneal projection is underestimated using the traditional facial approximation guideline. An underestimation is also strongly supported by statistical comparisons of globe projection measures taken using more traditional instruments (e.g., Hertel's exophthalmometer) to skull morphology (p < 0.006). It is suggested that the traditional facial approximation guideline not be used in future facial approximations since it appears to under-predict anterior globe projection by 4 mm on average. It is also suggested that average exophthalmometer values be used until more accurate and precise ways of determining globe projection have been determined.     

Validation of a 16-locus fluorescent multiplex system

STR multiplexes have been indispensable for the efficient genotyping of forensic samples. The PowerPlex 16 System contains the coreCODIS loci, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, CSF1PO, FGA, THOI, TPOX, vWA, the sex determinant locus, amelogenin, and two pentanucleotide STR loci, Penta D and Penta E. This multiplex satisfies the locus requirements for most national databases and is the most efficient currently available system due to its single PCR amplification. To provide the groundwork for judicial acceptance, including the publication of primer sequences, and to evaluate laboratory-to-laboratory variation, a developmental validation for casework on this commercially available system was performed in 24 laboratories and produced the following conclusions. Amplification was reliable on a variety of thermal cyclers and product could be analyzed on either an ABI PRISM 310 Genetic Analyzer or an ABI PRISM 377 DNA Sequencer. Genotyping using single source samples was consistent between 0.25 and 2 ng of input DNA template with a few laboratories obtaining complete genotypes at 0.0625 ng. However, heterozygote allele imbalance (<60% peak height balance) caused by stochastic effects was observed at a rate of 13% with 0.125 ng DNA and 22% at 0.0625 ng DNA. Mixture analyses were done using a total of 1 ng of DNA template. Most alleles were detected in mixtures of 4 to 1 and some minor alleles were detected in mixtures of 19 to 1. Optimum amplification cycle number was dependent on the sensitivity of the detection instrument used and could also be adjusted to accommodate larger amounts of DNA on solid supports such as FTA paper. Reaction conditions including volume, annealing temperature, and concentrations of primer, AmpliTaq Gold, and magnesium were shown to be optimal yet robust enough to withstand moderate variations without affecting genotype analysis. Environmental, matrix and standard source analyses revealed an ability to obtain complete genotypes in all sample types except those exposed to 80 degrees C for 12-48 days. Finally, comparison of genotype results from the PowerPlex 16 System with other commercially available systems on non-probative reference and forensic samples showed consistent results.     

An improved method for post-PCR purification for mtDNA sequence analysis

Mitochondrial DNA (mtDNA) analysis of forensic samples typically is performed when the quantity and quality of DNA are insufficient for nuclear DNA analysis or when maternal relatives may be the only reference source. Many of the steps required in the analytical process are both lengthy and labor intensive. Therefore, improvements in the process that reduce labor without compromising the quality of the data are desirable. The current procedure requires purification of the amplicons by centrifugal filtration after PCR and prior to cycle sequencing. Because this method requires several manipulations to perform, alternate cleanup procedures were investigated. These include the use of 1) Qiagen QlAquick PCR Purification columns, 2) Concert Rapid PCR Purification columns, and 3) ExoSAP-IT reagent. When the yield of purified amplicons, quality of the sequence profile, and ease of assay were evaluated, the use of ExoSAP-IT reagent for post-amplification purification was chosen to replace the filtration method.     

Role of alcohol in heroin overdose

The relationship between ethanol and risk of heroin overdosage was studied. Statistical processing of the results of forensic chemical analysis (460 expert evaluations) carried out in Chelyabinsk Regional Bureau of Forensic Medical Expert Evaluations in 2000 was carried out. The results of morphine and ethanol measurements in the blood and urine from corpses where deaths ensued from narcotic or ethanol poisoning, were analyzed. The concentrations of morphine in the blood and urine were measured on a gaseous chromatographer with mass-selective detector (Hewlett Packard HP 6890/HP-5972). Methods for measuring urinary and blood morphine are described. The results of statistical analysis demonstrated relationships between the age and ethanol concentrations in the blood and urine; blood ethanol and total urinary and blood morphine concentrations; blood concentration of free morphine and presence of 6-monoacetylmorphine in the blood. The authors conclude that the presence of ethanol in the blood together with morphine drastically augments the risk of rapid death from respiration arrest. It can also lead to a relatively high risk of overdosage in experienced narcomaniacs using heroin and ethanol.     

Crystallization of cerebrospinal fluid in cases of death from ischemic heart disease and ethanol poisoning

Crystallographic analysis of the cerebrospinal fluid (CSF) was carried out in 18 cases of death from coronary disease and 19 cases of death from ethanol poisoning. The crystallograms were evaluated visually and by the stereoscopic picture. Specific features of the CSF crystal colonies growth in subjects dead from the above conditions are determined.     

Population genetics of nine short tandem repeat loci: allele frequency distribution in a Brazilian population sample

Gene and genotype frequencies in relation to the D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, and D7S820 loci were determined in a sample of 290 unrelated individuals (204 Caucasians and 86 mulattoes) living in the city of S?o Paulo, Brazil. The sex test Amelogenin was also performed in all subjects from our sample, revealing the expected sex in all instances. Allele frequency data obtained from the analysis of these samples were in the usual range of other population groups with similar racial background. In the sample of Caucasian individuals, panmictic proportions were ruled out in relation to TPOX and CSF1PO loci, but only in the latter was the overall frequency of heterozygotes significantly less than expected. In the sample of mulattoes, Hardy-Weinberg proportions were rejected in relation to FGA and CSF1PO loci, but in no instance were the overall numbers of heterozygotes different from the corresponding expected ones under panmixia. Taking into account all this and also the number of tests performed, the degree of genetic heterogeneity of Brazilian populations, and the critical level reached by the significant results (1% < alpha<5%), the departures from panmixia here observed can be considered to be negligible in altering significantly biologic relationship odds calculated under the assumption of random matings.     

Diagnostic problems associated with cadaveric trauma from animal activity

Analysis of a series of deaths between 1986 and 2001 resulting from natural disease, accidents, suicides, and homicide, where postmortem animal activity had traumatized bodies, was undertaken at the Forensic Science Center in Adelaide to demonstrate the range of lesions that may occur and problems in interpretation that result. Tissue damage had been caused by a variety of animals, including fly larvae, ants, birds, dogs, rodents, sea lice, and sharks. Postmortem animal activity had disguised injuries, modified wounds, and created the appearances of inflicted injury. Problems with identification occurred after postmortem facial trauma, and loss of organ parenchyma had interfered with, or precluded, the precise determination of the manner of death in some cases. Specific kinds of tissue and organ damage may occur after death, necessitating careful assessment of lesions in a search for characteristic features of animal activity. The pattern of lesions may enable identification of the particular species of animal involved.     

Understanding Children's Use of Secrecy in the Context of Eyewitness Reports

To investigate socioemotional influences on children's eyewitness accuracy, we examined children's reports for activities they were motivated to conceal. Forty-eight 3–6-year-old children participated in a standardized play session with their mothers. Half of the children were told by an experimenter not to play with certain toys, but did so at the urging of their mothers, who told their children to keep the play activities secret. The remaining children were not restricted from playing with the toys, nor told by their mothers to keep the play activities secret. Later, all children were interviewed about the activities with free narrative and detailed questions. Half were given an interview that consisted of highly suggestive questions; half were given an interview consisting of specific, less suggestive questions. Results indicated that older children who were instructed to keep events secret withheld more information than did older children not told to keep events secret. Younger children's reports were not significantly affected by the secret manipulation. There were no significant effects associated with interview type. We discuss implications for understanding the development of children's knowledge and use of secrecy, and applications of the research to issues that arise when child witnesses give reports in legal contexts.