Patella sex determination by 3D statistical shape models and nonlinear classifiers

Sex determination is one of the essential steps in personal identification of an individual from skeletal remains. Most elements of the skeleton have been subjected to discriminant function analysis for sex estimation, but little work has been done in terms of the patella. This paper proposes a new sex determination method from the patella using a novel automated feature extraction technique. A dataset of 228 patellae (95 females and 133 males) was amassed from the William M. Bass Donated Skeletal Collection from the University of Tennessee and was subjected to noninvasive high resolution computed tomography (CT). After the CT data were segmented, a set of features was automatically extracted, normalized, and ranked. The segmentation process with surface smoothing minimizes the noise from enthesophytes and ultimately allows our methods to distinguish variations in patellar morphology. These features include geometric features, moments, principal axes, and principal components. A feature vector of dimension 45 for each subject was then constructed. A set of statistical and supervised neural network classification methods were used to classify the sex of the patellar feature vectors. Nonlinear classifiers such as neural networks have been used in previous research to analyze several medical diagnosis problems, including quantitative tissue characterization and automated chromosome classification. In this paper, different classification methods were compared. Classification success ranged from 83.77% average classification rate using labels from a Fuzzy C-Means (FCM) clustering step, to 90.3% for linear discriminant classification (LDC). We obtained results of 96.02% and 93.51% training and testing classification rates, respectively, using feed-forward backpropagation neural networks (NN). These promising results using newly developed features and the application of nonlinear classifiers encourage the usage of these methods in forensic anthropology for identifying the sex of an individual from incomplete skeletons retaining at least one patella.     

Migration of a Kirschner wire used in the fixation of a subcapital humeral fracture, causing cardiac tamponade: case report and review of literature

Metallic pins and wires are frequently used for fixation of fractures and dislocations. Migration is one of the potential complications of such fixation methods. Usually, migration of the pins causes only minor complications, but if the device migrates to a vital cavity, serious damage and even death may ensue. The shoulder girdle is one of the areas in which pins and wires are mostly used, the humeral neck fractures being one of them. We report a case in which a Kirschner wire migrated from a subcapital humeral fracture site into the aorta and pericardium, causing sudden cardiac tamponade and death.     

Lethal paradoxical cerebral vein thrombosis due to suspicious anticoagulant rodenticide intoxication with chlorophacinone

Superwarfarin exposure is a growing health problem, described in many countries. The authors report a case of suspicious chlorophacinone poisoning with a problematic diagnosis. They review the literature and discuss particularities of anticoagulant rodenticide intoxication, as well as the apparent contradiction between anticoagulant intoxication and lethal thrombosis.     

Forensic drug intelligence: an important tool in law enforcement

Organised criminality is a great concern for national/international security. The demonstration of complex crimes is increasingly dependant on knowledge distributed within law-enforcement agencies and scientific disciplines. This separation of knowledge creates difficulties in reconstructing and prosecuting such crimes. Basic interdisciplinary research in drug intelligence combined with crime analysis, forensic intelligence, and traditional law enforcement investigation is leading to important advances in crime investigation support. Laboratory results constitute one highly dependable source of information that is both reliable and testable. Their operational use can support investigation and even provide undetected connections or organisation of structure. The foremost difficulties encountered by drug analysts are not principally of a chemical or analytical nature, but methodologies to extract parameters or features that are deemed to be crucial for handling and contextualising drug profiling data. An organised memory has been developed in order to provide accurate, timely, useful and meaningful information for linking spatially and temporally distinct events on a national and international level (including cross-border phenomena). Literature has already pointed out that forensic case data are amenable for use in an intelligence perspective if data and knowledge of specialised actors are appropriately organised, shared and processed. As a particular form of forensic case data, the authors' research focuses on parameters obtained through the systematic physical and chemical profiling of samples of illicit drugs. The procedure is used to infer and characterise links between samples that originate from the same and different seizures. The discussion will not, however, focus on how samples are actually analysed and compared as substantial literature on this topic already exists. Rather, attention is primarily drawn to an active and close collaboration between magistrates, forensic scientists, law enforcement investigators and crime analysts from different institutions with the aim of generating, using and validating relevant profiling case data as integral part of investigative and crime analysis processes. Original advances are highlighted through experiences from criminal investigations of offences related to the unlawful importation, exportation, supply and possession of illicit drugs.     

Population genetic data of 15 tetrameric short tandem repeats (STRs) in Berbers from Morocco

The allele frequency distribution of 15 short tandem repeats (STR) loci contained in the AmpFlSTR Identifiler PCR Amplification Kit (Applied Biosystems), was determined in two Berber populations from Asni and Bouhria, in Central and Eastern Morocco, respectively. A total of 209 individuals were typed. No deviations from the Hardy-Weinberg equilibrium were observed for Asni at the 15 STRs loci whereas for the Bouhria samples, two loci (D5S818 and TH01) showed significant departures from Hardy-Weinberg expectations (after Bonferroni's correction). All loci are highly polymorphic and population differentiation tests showed that the Moroccan samples from Asni and Bouhria have significant differences in 4 out of 15 loci (D21S11, D7S820, D16S539 and TPOX). The aim of the study was to obtain accurate allele frequencies relevant for forensic applications. Comparative analyses between our population data and other population samples gathered from the literature are also presented.     

Allele frequencies for nine STR loci (D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820) in the Italian population

Genotype and allele frequencies for STR loci D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820 were investigated in 289 unrelated Italian Caucasian individuals from the North and South regions. After co-amplification by polymerase chain reaction, automatic DNA profiling of these nine STR loci was performed by ABI PRISM((R)) 310 DNA Genetic Analyzer. For each locus, statistical parameters for forensic and paternity purposes were then calculated; the combined power of discrimination and the combined power of exclusion of all nine loci were 0.9999999999917 and 0.99992 for the Northern population and 0.9999999999921 and 0.99991 for the Southern population.     

"Life expectancy" of "ecstasy" tablets in Israel in the years 2001-2003

3,4-Methylenedioxymethamphetamine (MDMA) tablets known as "ecstasy" became a very popular drug amongst Israeli youth in the last decade. The ecstasy tablets have a simple design impressed on them (logos) making it relatively easy to distinguish between various logos. The life expectancy of ecstasy tablet logos, defined as the period between the first seizure by the police of a certain logo until the last seizure of the same logo, was monitored during the years 2001-2003. During this time interval, 58 different tablet logos were seized. A total of 26 logos, defined as common logos with at least 10 independent seizures, were observed. At any given time interval during this period, 8-10 common logos were found with an average life expectancy of approximately 9 months. Five of the observed 26 common logos were defined as the most common logos that appeared in at least 200 independent seizures each. Plots of the number of seizures and number of tablets seized as a function of time are presented and discussed as well as explanations for the high turnover rate of any given logo.     

Age estimation by pulp/tooth ratio in canines by peri-apical X-rays

Estimation of age in individuals has received considerable attention in forensic science, in which it is a widely used method for individual identification, together with paleo-demographic analyses to establish mortality patterns in past populations. The present investigation, which is a continuation of a previously published pilot study, was conducted to examine the possible application of the pulp/tooth area ratio by peri-apical images as an indicator of age at death. A total of 200 peri-apical X-rays of upper and lower canines were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. They belong to the Frassetto osteological collection of Sassari (Sardinia) and are housed in the Museum of Anthropology, Department of Experimental and Evolutionistic Biology, University of Bologna. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio on upper (x(1)) and lower (x(2)) canines. Very good agreement was found between intraobserver measurements. Statistical analysis was performed in order to obtain multiple regression formulae for dental age calculation, with chronological age as dependent variable, and gender, and upper and lower canines as independent variables. Stepwise regression analysis showed that gender did not contribute significantly to the fit (p=0.881) whereas variables x(1) and x(2) and the first-order interaction between them did. These two variables explained 92.5% of variations in estimated chronological age and the residual standard error was 4.06 years. Lastly, two simple linear regression equations were obtained for age estimation using canines from the maxilla and mandible separately. Both models explained 86% of variations in estimated chronological age and allowed an age-at-death estimate with a residual standard error of about 5.4 years.     

Alternative fuels in fire debris analysis: biodiesel basics

Alternative fuels are becoming more prominent on the market today and, soon, fire debris analysts will start seeing them in liquid samples or in fire debris samples. Biodiesel fuel is one of the most common alternative fuels and is now readily available in many parts of the United States and around the world. This article introduces biodiesel to fire debris analysts. Biodiesel fuel is manufactured from vegetable oils and/or animal oils/fats. It is composed of fatty acid methyl esters (FAMEs) and is sold pure or as a blend with diesel fuel. When present in fire debris samples, it is recommended to extract the debris using passive headspace concentration on activated charcoal, possibly followed by a solvent extraction. The gas chromatographic analysis of the extract is first carried out with the same program as for regular ignitable liquid residues, and second with a program adapted to the analysis of FAMEs.