Insect succession and decomposition patterns on shaded and sunlit carrion in Saskatchewan in three different seasons

A study was conducted on decomposition and insect succession in the Prairie Ecozone of Saskatchewan in the year 2000. Eighteen domestic pig carcasses (42-79 kg) were employed as human models for applications to future homicide investigations in this region. Two major variables were considered including the effect of season and habitat (sun versus shade). Research was conducted over 25 weeks, spanning three seasons: spring, summer and fall. Ambient temperature, internal carcass temperature, faunistic succession over time, and the rate of decay were all compared for each experimental variable. Results indicated that habitat was only a factor in the decompositional rate of carrion in the spring season. The ambient temperature was the chief factor determining the seasonal variations in decay rate. Maximum internal carcass temperatures always coincided with the presence of 3rd instar larvae. Patterns of insect succession occurred in a predictable sequence that varied across different habitats and seasons and was unique compared to previously published studies. Carcasses placed in spring and fall attracted a more diverse assemblage of insects than summer-placed carrion. Sun-exposed carrion also had greater variation in fauna than shaded carrion in spring and fall. Members of Silphidae were the first coleopteran colonizers in all habitats and seasons. This paper also marks the first record for Cochliomyia macellaria (Fabricius) in Saskatchewan.     

The recovery of latent fingermarks and DNA using a silicone-based casting material

There are many techniques available for the recovery of fingermarks at scenes of crime including the possibility of taking casts of the marks. Casts can be advantageous in cases where other destructive recovery techniques might not be suitable, such as when recovering finger marks deposited on valued or immobile items. In this research, Isomark (a silicone-based casting material) was used to recover casts of finger marks placed on a variety of substrates. Casts were enhanced using cyanoacrylate fuming. Good quality marks were successfully recovered from a range of smooth, non-porous surfaces. Recovery from semi-porous surfaces was shown to be inefficient. DNA was subsequently extracted from the casts using QIAamp Mini extraction kits, amplified and profiled. Full DNA profiles were obtained 34% of samples extracted.     

Investigative and autopsy findings in sport aircraft-related deaths in southwest Florida

Aircraft designated for sport or recreational use only, including ultralights, experimental aircraft and light-sport aircraft, have become increasingly popular. Because of their relative safety and the rarity of fatalities resulting from crashes of these aircraft, the forensic literature contains little information concerning the pathologic findings in such deaths. We report 9 deaths resulting from 6 sport aircraft crashes in southwest Florida, 6 pilots and 3 passengers. The vehicles involved 3 experimental aircraft, 1 ultralight and 2 "ultralight-like" aircraft. The patterns of injuries included trauma predominantly to the chest (3 cases), abdomen (1) or head (1), as well as multiple blunt force injuries involving the chest and abdomen (1) or the head and torso (3). Extremity fractures were found in only 2 cases, whereas injuries to the symphysis pubis were found in six. No "control-type" injuries were identified. These cases illustrate the varied pathologies associated with deaths due to crashes of sport aircraft and reveal the lack of uniformity associated with the investigations of such deaths.     

Case report of suicide by inhalation of nitrogen gas

Nitrogen is an inert gas that is a normal constituent of the air that we breathe. It is a suffocating gas that does not support life and that can be a cause of death by the displacement of oxygen in the atmosphere. The majority of deaths associated with nitrogen have occurred in the setting of scuba diving. Although other suffocating gases have been used as a means of committing suicide, the literature contains little information about the use of nitrogen as a suicidal agent. A case of a 50-year-old man who committed suicide using a homemade suicide device and nitrogen gas is presented.     

One Approach to Formulating and Evaluating Student Work Groups in Legal Environment of Business Courses

The principal focus of this study is an investigation of whether students' grade point average (GPA) is a viable criterion for forming student work groups in the undergraduate Legal Environment of Business course. More specifically, the research focuses on the impact of: (1) GPA-homogeneous (HO) and GPA-heterogeneous (HE) groups upon student satisfaction with group processes and (2) the impact on individual student performance in both group and nongroup assignments. Data obtained from fourteen HE and fourteen HO student groups, in four separate Legal Environment of Business classes consisting of a mix of Management, Marketing, Computer Information Systems, International Business, Financial Services, and Accounting majors, generated a number of significant results. The most surprising observations dealt with the behavior of low achievers whose individual grades showed substantial improvement after working in HO groups. Researchers who are assessing pedagogical methods which serve to engage a student's active learning and motivation should find these results to be of interest. In addition, the beneficial impact on task and relationship behaviors observed in this study should provide solace or a sense of reward to the larger set of academicians, across disciplines, who attempt to impart realistic organizational skills to their classes.