Sex Determination by Discriminant Function Analysis of Lumbar Vertebrae

Sex determination is critical for developing the biological profile of unidentified skeletal remains. When more commonly used elements (os coxa, cranium) for sexing are not available, methods utilizing other skeletal elements are needed. This study aims to assess the degree of sexual dimorphism of the lumbar vertebrae and develop discriminant functions for sex determination from them, using a sample of South African blacks from the Raymond A. Dart Collection (47 males, 51 females). Eleven variables at each lumbar level were subjected to univariate and multivariate discriminant function analyses. Univariate equations produced classification rates ranging from 57.7% to 83.5%, with the highest accuracies associated with dimensions of the vertebral body. Multivariate stepwise analysis generated classification rates ranging from 75.9% to 88.7%. These results are comparable to other methods for sexing the skeleton and indicate that measures of the lumbar vertebrae can be used as an effective tool for sex determination.     

A Silver‐Stain Modification of Standard Histological Slide Preparation for Use in Anthropology Analyses

The traditional histology method typically employed by forensic anthropologists involves plastic embedding of undecalcified bone. The embedded sample is then cut by a diamond blade saw and ground to the required thickness of ~50–100 microns using a grinder. There are several limitations to this method: Cement lines may be blurred; depth‐of‐field artifacts may result from viewing thick sections; and medicolegal offices with limited budgets may not be able to invest in additional equipment or training for this method. A silver nitrate stain modification of the standard histology preparation technique of decalcified bone is presented. The benefits of this technique are that: Cement lines are viewed clearly; no depth‐of‐field artifacts are present; and because this is a modification of the standard technique used by histology laboratories typically employed by medicolegal offices, no additional equipment or training is required.     

Animal Scavenging and Scattering and the Implications for Documenting the Deaths of Undocumented Border Crossers in the Sonoran Desert,

Since 1998, over 5500 people have died while attempting to cross the U.S.–Mexico border without authorization. These deaths have primarily occured in the Arizona desert. Despite the high volume of deaths, little experimental work has been conducted on Sonoran Desert taphonomy. In this study, pig carcasses were used as proxies for human remains and placed in different depositional contexts (i.e., direct sunlight and shade) that replicate typical sites of migrant death. Decomposition was documented through daily site visits, motion-sensitive cameras and GIS mapping, while skeletal preservation was investigated through the collection of the remains and subsequent faunal analysis. Our results suggest that vultures and domestic dogs are underappreciated members of the Sonoran scavenging guild and may disperse skeletal remains and migrant possessions over 25 m from the site of death. The impact of scavengers and the desert environment on the decomposition process has significant implications for estimating death rates and identifying human remains along the Arizona/Mexico border.     

Comparing Electronic News Media Reports of Potential Bioterrorism-Related Incidents Involving Unknown White Powder to Reports Received by the United States Centers for Disease Control and Prevention and the Federal Bureau of Investigation: U.S.A., 2009–2011

There have been periodic electronic news media reports of potential bioterrorism-related incidents involving unknown substances (often referred to as “white powder”) since the 2001 intentional dissemination of Bacillus anthracis through the U.S. Postal System. This study reviewed the number of unknown “white powder” incidents reported online by the electronic news media and compared them with unknown “white powder” incidents reported to the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Federal Bureau of Investigation (FBI) during a 2-year period from June 1, 2009 and May 31, 2011. Results identified 297 electronic news media reports, 538 CDC reports, and 384 FBI reports of unknown “white powder.” This study showed different unknown “white powder” incidents captured by each of the three sources. However, the authors could not determine the public health implications of this discordance.     

Differences in Handwritings of Schizophrenia Patients and Examination of the Change after Treatment

The aim of this study was to analyze the differences between the handwritings of schizophrenia patients and healthy subjects in addition to the changes that occurred in schizophrenia patients' handwriting in response to the treatment. The test subjects were 29 schizophrenia patients and 29 healthy individuals with the same age, gender, and dominant hand. The changes in the handwritings were examined according to 14 different parameters. On the day of admittance, the percentage of extra letters was 16.7%, and after 7–10 days of hospitalization, it rose to 33.3%. The percentage of skipped words decreased from 29.2% to 16.7% after 7–10 days of hospitalization, and to 10% after 3 weeks. The letters written by schizophrenia patients are significantly larger in height and width compared to the control group. The schizophrenia patients showed a higher incidence of crossed-out letters, adding extra words, missing punctuation as well as missing words.     

Sudden Death Due To Acute Cocaine Toxicity—Excited Delirium in a Body Packer

Excited delirium denotes a life-threatening medical condition characterized by the acute onset of agitated and violent behavior that often results in a sudden and unexplained death. Cocaine-induced excited delirium refers to fatal cocaine intoxication with the following symptoms occurring sequentially: hyperthermia, delirium with agitation, respiratory arrest, and death. We present a case of cocaine-induced excited delirium in a cocaine “body packer” or a “mule”, specifically an individual who attempts to smuggle cocaine within the body. Investigators at the scene initially suspected homicide due to the victim's sharp and blunt force injuries. Three rubber packets containing cocaine were removed from the victim's rectum. Blood toxicological analysis revealed an alcohol concentration of 0.016 g/100 and cocaine >1 mg/L. The forensic pathologist should consider cocaine-induced excited delirium when an individual exhibits aggressive behavior, unexpected strength, and resistance to pain who dies suddenly. Further analysis should be performed during the scene investigation and autopsy for evidence of body packing.     

Objective Analysis of Impressed Chisel Toolmarks

Historical and recent challenges to the practice of comparative forensic examination have created a driving force for the formation of objective methods for toolmark identification. In this study , fifty sequentially manufactured chisels were used to create impression toolmarks in lead (500 toolmarks total). An algorithm previously used to statistically separate known matching and nonmatching striated screwdriver marks and quasi-striated plier marks was used to evaluate the chisel marks. Impression toolmarks, a more complex form of toolmark, pose a more difficult test for the algorithm that was originally designed for striated toolmarks. Results show in this instance that the algorithm can separate matching and nonmatching impression marks, providing further validation of the assumption that toolmarks are identifiably unique.     

Death from Nitrous Oxide

Nitrous oxide is an inflammable gas that gives no smell or taste. It has a history of abuse as long as its clinical use, and deaths, although rare, have been reported. We describe two cases of accidental deaths related to voluntary inhalation of nitrous oxide, both found dead with a gas mask covering the face. In an attempt to find an explanation to why the victims did not react properly to oncoming hypoxia, we performed experiments where a test person was allowed to breath in a closed system, with or without nitrous oxide added. Vital signs and gas concentrations as well as subjective symptoms were recorded. The experiments indicated that the explanation to the fact that neither of the descendents had reacted to oncoming hypoxia and hypercapnia was due to the inhalation of nitrous oxide. This study raises the question whether nitrous oxide really should be easily, commercially available.     

A Simple Digestion Method with a Lefort Aqua Regia Solution for Diatom Extraction

Presence of diatoms in tissues has been considered as a significant sign of drowning. However, there are limitations in the present extraction methods. We developed a new digestion method using the Lefort aqua regia solution (3:1 nitric acid to hydrochloric acid) for diatom extraction and evaluated the digestive capability, diatom destruction, and diatoms' recovery of this new method. The kidney tissues from rabbit mixed with water rich in diatoms were treated by the Lefort aqua regia digestion method (n = 10) and the conventional acid digestion method (n = 10). The results showed that the digestive capability of Lefort aqua regia digestion method was superior to conventional acid digestion method (p < 0.01); the structure of diatom remained almost intact; and the recovery of diatom was comparable to the conventional acid digestion method (p > 0.05). The Lefort aqua regia reagent is an improvement over the conventional acid digestion for recovery of diatoms from tissue samples.