Interpreting the Effects of Burning on Pre-incineration Saw Marks in Bone

This study examined the effects of fire on the features associated with saw marks in bone. Both class and individual characteristics were examined using stereomicroscopy and scanning electron microscopy (SEM). Twenty-four semifleshed Sus scrofa L. tibiae were sawed into three sections with the middle section having deep and shallow false starts. Twelve saw blades of varying age and type were each used to cut two tibiae. In each case, the first tibia was burned in an outdoor open fire to the point of partial calcination. The second tibia, our control, was macerated using a heated enzyme solution. Controls and burned specimens were examined for the following characteristics: breakaway spur, tooth hop, false start, exit chipping, tooth imprint, breakaway notch, pull out striae, kerf flare, and blade drift. In general, there was parity in the observed characteristics in the burned samples using the SEM and the stereomicroscope. SEM observation, however, provided enhanced images, with the addition of observing individual tooth imprints, previously not visible. Therefore, this study recommends using an SEM for the examination of saw cuts in burnt bone.     

Angular Determination of Toolmarks Using a Computer‐Generated Virtual Tool

A blind study to determine whether virtual toolmarks created using a computer could be used to identify and characterize angle of incidence of physical toolmarks was conducted. Six sequentially manufactured screwdriver tips and one random screwdriver were used to create toolmarks at various angles. An apparatus controlled tool angle. Resultant toolmarks were randomly coded and sent to the researchers, who scanned both tips and toolmarks using an optical profilometer to obtain 3D topography data. Developed software was used to create virtual marks based on the tool topography data. Virtual marks generated at angles from 30 to 85° (5° increments) were compared to physical toolmarks using a statistical algorithm. Twenty of twenty toolmarks were correctly identified by the algorithm. On average, the algorithm misidentified the correct angle of incidence by ?6.12°. This study presents the results, their significance, and offers reasons for the average angular misidentification.     

Forensic Use of A Subtropical Blowfly: The First Case Indicating Minimum Postmortem Interval (mPMI) in Southern Brazil and First Record of Sarconesia Chlorogaster from a Human Corpse

Southern Brazil is unique due to its subtropical climate. Here, we report on the first forensic entomology case and the first record of Sarconesia chlorogaster (Wiedemann) in a human corpse in this region. Flies' samples were collected from a body indoors at 20°C. Four species were found, but only Chrysomya albiceps (Wiedemann) and S. chlorogaster were used to estimate the minimum postmortem interval (mPMI). The mPMI was calculated using accumulated degree hour (ADH) and developmental time. The S. chlorogaster puparium collected was light in color, so we used an experiment to establish a more accurate estimate for time since initiation of pupation where we found full tanning after 3 h. Development of C. albiceps at 20°C to the end of the third instar is 7.4 days. The mPMI based on S. chlorogaster (developmental time until the third instar with no more than 3 h of pupae development) was 7.6 days.     

The Politics of Obstruction: Republican Holds in the U.S. Senate

A defining feature of the modern US Senate is obstruction. Almost all pieces of legislation considered in the Senate are affected either directly or indirectly by obstruction. Obstruction takes many forms in the modern Senate, but one of the most prevalent, yet least studied, is the hold. Using a newly created dataset on Republican Senate holds, we cast light on this important practice. Our results suggest that a variety of factors including timing, party status, and a senator's voting record are related to both the prevalence of holds and the success of legislation subject to holds in the Senate.     

It depends whose data are being shared: considerations for genomic data sharing policies

There is an urgent need for consistent data sharing policies that promote the advancement of science while respecting the values and interests of those providing their genetic data for research. Responding to the article of Jalayne J. Arias, Genevieve Pham-Kanter, and Eric G. Campbell, ‘The Growth and Gaps of Genetic Data Sharing Policies in the United States’, this commentary further explores the challenges of human subjects’ protection in existing data sharing policies. We will elaborate on the need for data sharing policies to accommodate variation in individual and group preferences around data sharing and privacy concerns by comparing our previously published data on patients’ and parents’ consent to data sharing and attitudes about privacy to data from focus groups with HIV-positive, underserved individuals who were asked about their willingness to participate in genetic research and share their data broadly. These studies support the observation of Arias, Pham-Kanter, and Campbell that researchers, and funding agencies will need to balance the privacy interests of groups as well as individuals in future genomic data sharing policies.