Life in Suspension with Death: Biocultural Ontologies, Perceptual Cues, and Biomarkers for the Tibetan Tukdam Postmortem Meditative State

This article presents two cases from a collaborative study among Tibetan monastic populations in India on the postdeath meditative state called tukdam (thugs dam). Entered by advanced Tibetan Buddhist practitioners through a variety of different practices, this state provides an ontological frame that is investigated by two distinct intellectual traditions-the Tibetan Buddhist and medical tradition on one hand and the Euroamerican biomedical and scientific tradition on the other-using their respective means of inquiry. Through the investigation, the traditions enact two paradigms of the body at the time of death alongside attendant conceptualizations of what constitutes life itself. This work examines when epistemologies of these two traditions might converge, under what ontological contexts, and through which correlated indicators of evidence. In doing so, this work explores how these two intellectual traditions might answer how the time course and characteristics of physiological changes during the postmortem period might exhibit variation across individuals. Centrally, this piece presents an epistemological inquiry delineating the types of valid evidence that constitute exceptional processes post-clinical death and their potential ontological implications.

Effects of aluminium phosphide on larval morphometry of two important Chrysomya species

Chrysomya megacephala and C. rufifacies are globally predominant species of blowflies that are amongst the primary colonisers of decomposing carcasses. The development of blowflies has been studied extensively to estimate the minimum postmortem interval (PMImin). This article evaluates the effect of aluminium phosphide (AlP) on the larval morphometry and life cycles of C. megacephala and C. rufifacies. The rabbits were given different dosages of AlP and their livers were excised to rear C. megacephala and C. rufifacies. Through multiple-regression analysis, we assessed the overall impact of varying dosages of AlP on larvae of both species. AlP accelerated development until pupation, whilst the time until emergence remained the same. At higher concentrations, AlP had a positive effect on the development of these species. Since both species are abundant, forensic entomology studies examining the effect of AlP on morphometry and developmental stages would provide valuable information to investigators assessing PMImin.

Estimation of Late Postmortem Interval: Where Do We Stand? A Literature Review

Estimating time since death can be challenging for forensic experts, and is one of the most challenging activities concerning the forensic world. Various methods have been assessed to calculate the postmortem interval on dead bodies in different stages of decomposition and are currently widely used. Nowadays, the only well-recognized dating technique is carbon-14 radioisotope measurement, whereas other methods have been tested throughout the years involving different disciplines with different and sometimes not univocal results. Today, there is no precise and secure method to precisely determine time since death, and late postmortem interval estimation remains one of the most debated topics in forensic pathology. Many proposed methods have shown promising results, and it is desirable that with further studies some of them might become acknowledged techniques to resolve such a difficult and important challenge. The present review aims at presenting studies about the different techniques that have been tested in order to find a valuable method for estimating time since death for skeletal remains. By providing a comprehensive overview, the purpose of this work is to offer readers new perspectives on postmortem interval estimation and to improve current practice in the management of skeletal remains and decomposed bodies.

Review on forensic importance of myiasis: Focus on medicolegal issues on post-mortem interval estimation and neglect evaluation

Myiasis is the infestation of live vertebrates by dipterous larvae that feed on living or necrotic tissues, liquid body substances or ingested food and develop in or on the vertebrate body. In both animals and humans, myiasis plays a fundamental role in forensic practice because of its implications in the evaluation of cases of neglect and in the mPMI (minimum post-mortem interval) estimation. The present study aims to provide a review of forensic issues related to myiasis. A retrospective analysis was conducted by exploring major electronic literature databases. Methodological evaluation of each study was performed according to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) standards. Sixty-one papers were included in this review. Entomology shows great potentiality in forensic investigations, mostly because of its contributory role in mPMI estimation. Such evaluation, however, requires a careful consideration of the possibility of an ante-mortem myiasis infestation, which could complicate the correct assessment of the mPMI. Hence, forensic pathologists should pay attention to the entomological fauna on a corpse, in both fresh and decomposed bodies. Moreover, in cases with poor nutritional or hygienic conditions, myiasis should be carefully evaluated as an indicator of neglect.

Succession study on forensically important Coleoptera from India: a preliminary study and its forensic implications

Background

Coleoptera is the second most important group of entomofauna associated with decomposition, yet little is known about its role in decomposition and postmortem colonization of carcasses in India and other parts of the world. Consequently, a preliminary study was conducted to study the succession of forensically important Coleoptera using goat carrion as an animal model.

Results

Five decomposition stages were observed during the experiment. A total of 1174 adult coleopterans belonging to 21 species and seven families were collected during this study. Throughout faunal succession, Histeridae and Silphidae were the dominant Coleopteran families, and they occurred mainly during the bloated and decay stages of decomposition; Necrophila (Calosilpha) ioptera was the dominant species present from the bloated to dry stage of putrescence. Two species, Pachylister bellicus and Saprinus sternifossa were reported for the first time from India.

Conclusion

This study provides baseline data regarding Coleopteran species associated with different decomposition stages, but more extensive studies need to be performed to develop a geographical database on arthropod succession from as many habitats as possible so that this kind of data can be used in forensic cases.

Evaluation of Insect Succession Patterns and Carcass Weight Loss for the Estimation of Postmortem Interval

This study assesses the succession of insects on rabbit carcass. The study was conducted in sunny and shaded sites in the west of Iran during four seasons in 2016 and 2017. Based on the results of this study, various factors such as body size, carcass location, and carcass injury could affect the pattern of insect succession on carcass. In this study, we estimated the elapsed time since death (R2 > 0.98, P = 0.00) based on carcass weight loss during the stages of decomposition and the cubic method. Jaccard analysis was performed to determine the similarity of insect taxa during decomposition of rabbit carrion in two different sites during a period of four seasons. Succession pattern analysis for necrophagous insects in both habitats showed a similarity between bloat and decay stages for each habitat. On the other hand, pairwise similarities in taxa were low at the fresh and dry stages, however increased at bloat and decay stages of decomposition. This study shows that succession has some limitations in determining the elapsed time of death. Therefore, the use of source of information such as a weight loss model seems to be essential.

Characterizing forensically important insect and microbial community colonization patterns in buried remains

During violent criminal actions in which the perpetrator disposes of the victim's remains by burial, the analysis of insects and bacterial colonization patterns could be necessary for postmortem interval (PMI) estimation. Our research aimed to assess the decomposition process of buried rat carcasses from shallow graves (40 cm), the diversity and dynamics of insects and bacteria throughout the decomposition stages, and the environmental parameters' influence on these variations. The results provide further insight on decomposition in soil and contribute to a broader understanding of the factors involved in decomposition by qualitatively and quantitatively analysing the decomposer community (bacteria and insects). Additionally, two bacterial taxa, Enterococcus faecalis and Clostridium paraputrificum that were investigated for the first time as PMI indicators using quantitative polymerase chain reaction (qPCR) showed differential abundance over time, promising data for PMI estimation. The current study on the decomposition of buried rat carcasses in a natural environment will strengthen the current knowledge on decomposed remains from shallow graves and represents an effort to quantify insect and bacterial taxa as PMI estimators.

Abiotic and Biotic Factors Regulating Inter-Kingdom Engagement between Insects and Microbe Activity on Vertebrate Remains

Abstract: A number of abiotic and biotic factors are known to regulate arthropod attraction, colonization, and utilization of decomposing vertebrate remains. Such information is critical when assessing arthropod evidence associated with said remains in terms of forensic relevance. Interactions are not limited to just between the resource and arthropods. There is another biotic factor that has been historically overlooked; however, with the advent of high-throughput sequencing, and other molecular techniques, the curtain has been pulled back to reveal a microscopic world that is playing a major role with regards to carrion decomposition patterns in association with arthropods. The objective of this publication is to review many of these factors and draw attention to their impact on microbial, specifically bacteria, activity associated with these remains as it is our contention that microbes serve as a primary mechanism regulating associated arthropod behavior.

Insect succession on remains of human and animals in Shenzhen, China

Most forensic entomological succession studies have been carried out using pig or rabbit carcasses; however, there have been few studies on the differences between insect succession patterns on human cadavers and on animal carcasses. In order to clarify the differences between decomposition and insect succession patterns of human cadavers and animal carcasses, one 49.5kg human cadaver, two large pig carcasses (45 and 48kg), two small pig carcasses (23 and 25kg) and two rabbit carcasses (both 1.75kg) were placed in the same field conditions in Shenzhen, China for a comparative study on August, 2013. The results indicated that: (1) The duration from fresh to skeletonization is in order of human cadaver>large pig carcasses>small pig carcasses>rabbit carcasses; (2) insect assemblages (including developmental stages) are more complex on larger carcasses, in order of human cadaver=large pig carcasses>small pig carcasses>rabbit carcasses; (3) the developmental rates of the same forensically important fly species on all carcasses are consistent; (4) all identified species of Calliphoridae can complete development of one generation on human cadaver, and both large and small pig carcasses, while on rabbit carcasses, only a subset of the Calliphoridae species can finish development of one generation; (5) beetles can generate offspring on human cadaver, and both large and small pig carcasses, while they do not generate offspring on rabbit carcasses. This study provides useful comparative data for decomposition and insect succession pattern of human cadaver with animal carcasses.

The Importance of Habitat in the Ecology of Decomposition on Rabbit Carcasses in Malaysia: Implications in Forensic Entomology

The stages of decomposition and the faunal succession on rabbit carcasses in three different habitats, namely jungle, rural, and highland areas, were studied. Three New Zealand White rabbit (Oryctolagus cuniculus) carcasses weighing ∼2 kg were sampled daily until the decomposition process was completed. Representative specimens of adult flies, larvae, pupa, and mites were collected from the carcasses and processed in the laboratory. There were differences in decomposition rate and faunal succession between the carcasses. The fastest rate of decomposition was recorded in rural area, and the slowest rate of decomposition was recorded in highland area. The carcasses exhibited the same pattern of colonization by adult flies, but the dominant species of larvae and adult flies on each carcass in specific habitats were different. The primary species of flies recorded in jungle were Chrysomya megacephala F., Chrysomya rufifacies (Macquart), Chrysomya chani Kurahashi, Chrysomya villenuevi Patton, Chrysomya nigripes Aubertin, Chrysomya pinguis (Walker), Hemipyrellia ligurriens (Wiedemann), Hemipyrellia tagaliana (Bigot), Hypopyiopsis fumipennis (Walker), Hypopygiopsis violacea (Macquart), and Hydrotaea spinigera Stein represented by both adults and larvae. Musca domestica L., Atherigona sp., Lioproctia pattoni (Senior-White), Lioproctia saprianovae Pape & Bänziger, and Seniorwhitea princeps (Wiedemann) were represented by adults only. The biodiversity of flies in the rural area were C. megacephala, C. rufifacies, H. ligurriens, Fannia canicularis L., Hydrotaea chalcogaster (Wiedemann), and Hyd. spinigera represented by both adults and larvae, meanwhile M. domestica, Atherigona sp., Boettcherisca peregrina (Robineau-Desvoidy), Parasarcophaga taenionota Wiedemann, Parasarcophaga scopariiformis Senior-White, and S. princeps were represented by adults only. The species of flies collected in the highland area were Lucilia porphyrina (Walker), C. megacephala, C. rufifacies, C. villenuevi, C. pinguis, H. ligurriens, Hyd. spinigera, Hyd. chalcogaster, F. canicularis, and Boettcherisca highlandica Kurahashi & Tan represented by both adults and larvae, whereas C. nigripes, Chrysomya thanomthini Kurahashi & Tumrasvin, M. domestica, Atherigona sp., Parasarcophaga albiceps Meigen, P. taenionota, Sepsidae, Phoridae, and Millichidae were represented by adults only. Faunal succession followed the sequence of dominant flies, i.e., Calliphoridae, Sarcophagidae, Muscidae, Sepsidae, and lastly Stratiomyidae for jungle, or Sepsidae for rural and highland studies. Mites, from suborders Mesostigmata, Prostigmata, Astigmatina, and Oribatida, were also recovered throughout decomposition, which could be used for future implementation in forensic investigations. The data obtained from this study could provide more accurate indicators for local forensic scientists in solving criminal cases especially on the determination of time and primary location of death.

Insect succession and carrion decomposition in selected forests of Central Europe. Part 3: Succession of carrion fauna

The succession of insects on pig carrion was monitored in spring, summer and autumn, in three forest types and 2 years in Western Poland (Central Europe). In most forensically useful taxa, significant differences between seasons, forests and years in time of appearance on carrion were found. The lowest values of appearance time were recorded in summer and the highest in spring. In alder forest insects appeared on carcasses significantly earlier than in pine-oak forest and hornbeam-oak forest. In summer periods of insect presence on carrion were significantly shorter than in spring and autumn. In most taxa no significant effect of forest type or year on length of the presence period was found. In all seasons assemblages of adult taxa were clearly more aggregated than assemblages of larval taxa. Sequence of insects' appearance on carcasses was very similar in different seasons, forests and years. General seasonal models of insect succession on carrion are proposed for forests of Central Europe. Data on appearance time and length of the presence period in particular seasons, forests and years are presented for forensically useful taxa. Implications for methods of PMI estimation (particularly the succession-based method) are discussed.

Developmental Stages of Hypopygiopsis violacea (Family: Calliphoridae), a Forensically Important Blowfly on Rat Carcass

A study on blowfly developmental stages to estimate the time of death (TOD) of small mammal had been conducted during a rainy season. During this study, fresh Muller’s rat (Sundamys muelleri) carcasses were used as the host sample, and the developmental duration of every larval stage, decomposition stages of host animal, ambient temperature and relative humidity were recorded. Hypopygiopsis violacea (Family: Calliphoridae) was recorded to be the first blowfly visiting and ovipositing on the carcass after the carcass being deposited, while Chrysomya megacephala and C. ruffacies were recorded as the most dominant calliphorids present during the decomposition process. This study estimated that the time for calliphorids to complete their life cycle, from an egg to an adult was approximately twenty-three days, and the decomposition of Sundamys muelleri took about nine days. Useful information on succession and rate of development of blowfly could enhance the knowledge of the length of time elapsed since death in particular host animal.