Nondestructive Methods for Recovery of Biological Material from Human Teeth for DNA Extraction

The extraction of DNA from human skeletal remains applied to forensic, and evolutionary studies do not exclude risks, which are to be evaluated when working with unique specimens that could be damaged or even destroyed. In the present study were evaluated several nondestructive methods for recovering DNA instead of the most currently used pulverization method. Three different procedures to access inside the dental pieces (occlusal perforation, cervical perforation, and cervical cut) have been compared with the aim of recovering as many cell remains as possible to carry out a DNA extraction. Given the DNA quantitation results, a method was proposed that consists of a cervical cut to facilitate the access to the pulp cavity and a subsequent filing of the root canals down to the apex of the dental root. This methodology allows the recovery of both mitochondrial and nuclear DNA, with the minimum deterioration for the dental pieces.     

Informal Institutions and Judicial Independence in Paraguay, 1954–2011

This article explains how informal institutions have prevented the emergence of autonomous judges in Paraguay between 1954 and 2011. The central argument is that co‐optation, clientelism, and judicial corruption considered as informal institutions, rooted during the dictatorship, have impeded the appearance of an independent judicial branch in the democratic regime. To test this hypothesis, the article relies on historical narratives, surveys, and semistructured interviews. The conclusions suggest that in countries that have experienced the consolidation of informal institutions oriented toward maintaining the ties of subordination of judges to politicians, constitutional reforms and fragmentation of political power are necessary but not sufficient conditions for improving judicial independence.     

Examining Legislative Cue‐Taking in the US Senate

We examine congressional cue‐taking theory to determine its extent, conditionality, and various forms in the US Senate. Using a novel data‐collection technique (timed C‐SPAN footage), we focus on temporal dynamics via event history analysis. Examining the effects of senator characteristics across 16 votes from the 108th Congress, we find that committee leadership and seniority generally predict cue‐giving, while other types of characteristics predict cue‐giving on certain types of votes. Our results underscore the importance of considering the order and timing of voting when studying congressional behavior.     

Decomposition Rate and Pattern in Hanging Pigs

Accurate prediction of the postmortem interval requires an understanding of the decomposition process and the factors acting upon it. A controlled experiment, over 60 days at an outdoor site in the northwest of England, used 20 freshly killed pigs (Sus scrofa) as human analogues to study decomposition rate and pattern. Ten pigs were hung off the ground and ten placed on the surface. Observed differences in the decomposition pattern required a new decomposition scoring scale to be produced for the hanging pigs to enable comparisons with the surface pigs. The difference in the rate of decomposition between hanging and surface pigs was statistically significant (p = 0.001). Hanging pigs reached advanced decomposition stages sooner, but lagged behind during the early stages. This delay is believed to result from lower variety and quantity of insects, due to restricted beetle access to the aerial carcass, and/or writhing maggots falling from the carcass.     

Contribution of Antemortem Computed Tomography Findings to Cause of Death Determination: An Unusual Fatal Stroke

In the case reported here, the antemortem computed tomography scan (CT scan) was essential in the forensic investigation. A 32‐year‐old man was found fully awake with a facial abrasion, after what seemed to be a car accident. He lost consciousness suddenly one hour after initial management. Successive CT scan showed a facial fracture and a metallic foreign body in the carotid canal associated with an occlusion/dissection of the left internal carotid, a pseudoaneurysm, and a carotid‐cavernous fistula. The victim died from a stroke. Autopsy confirmed that the facial abrasion was a gunshot entrance wound, the metallic foreign body being a projectile. Intracranial vascular injuries linked with gunshot wounds are most of the time isolated and due to pelet embolism. The observed vascular injury association has never been described in the existing literature. The CT scan provided a better understanding of the chronology of events that led to death.     

The Application of Flow Cytometry as a Rapid and Sensitive Screening Method to Detect Contamination of Vitreous Humor Samples and Avoid Miscalculation of the Postmortem Interval

Research into maximizing the speed, precision, and reliability of estimating the postmortem interval (PMI) has been a recurring object of investigation and methodologies based on the vitreous humor (VH) have provided good results. However, contamination from causes not readily apparent, such as blood, can occur, and thus lead not only to an erroneous estimation of PMI, but also interfere with the correct identification of other substances in the VH. We have developed a flow cytometry method which quantifies blood contamination and is able to detect erythrocytes in 1:750,000 dilution of contaminated VH which affects the results of hypoxanthine. It is an improvement on the previous more complex mass spectrometry method, being faster, more sensitive, and readily available. As such, it could be proposed for the rapid screening of appropriate samples by detecting and eliminating blood contaminated samples from PMI estimation.