The determination of time since death or the postmortem interval(PMI)is one of the most important and frequently asked questions in forensic medicine.Medicolegal scholars and forensic pathologists around the world hav...The determination of time since death or the postmortem interval(PMI)is one of the most important and frequently asked questions in forensic medicine.Medicolegal scholars and forensic pathologists around the world have studied the estimation of PMI extensively in the past,and many novel methods and advanced technologies have now been applied in the field.For several centuries,Chinese forensic examiners have also worked on the estimation of the PMI,and there are a large number of excellent studies published in Chinese rather than in English,and these are not easily accessible or known internationally.Therefore we have conducted a review of relevant studies published by Chinese forensic scholars in the last few decades.The scope of this review is to provide a concise summary of the current progress in the estimation of PMI by Chinese forensic researchers using molecular biology,spectroscopic technology,entomological methods,energy changes,thanatochemistry and other methods.展开更多
The electrical conductivity(EC)of extracted muscle fluid has been extensively used to evaluate meat freshness and shelf life in the field of food sanitation for decades.The opposite of freshness is the corruption that...The electrical conductivity(EC)of extracted muscle fluid has been extensively used to evaluate meat freshness and shelf life in the field of food sanitation for decades.The opposite of freshness is the corruption that increases with time.Based on the freshness/corruption principle,we investigated the relationship between long postmortem intervals(PMIs)and EC in cadaver skeletal muscle.EC values of extracted fluid from rat muscles were measured at different PMIs for 10 days.The results indicate that there was a significant correlation between PMI and EC,and the data fit well to the cubic polynomial regression equation y=‑0.01x3+0.264x2‑13.657x+1769.148(R2=0.925).In addition,the EC of different dilutions of these muscle extracts showed strict quadratic correlation(R2=1)with the dilution ratios,suggesting that EC can be measured with very small quantities of muscle sample.Our study suggests that determination of the EC of cadaver skeletal muscle extracts may be a useful method for estimating long PMIs.展开更多
Previous research has found that electrical conductivity(EC),an important index to predict meat freshness and shelflife,is very promising for estimating the late postmortem interval(PMI).However,whether it has potenti...Previous research has found that electrical conductivity(EC),an important index to predict meat freshness and shelflife,is very promising for estimating the late postmortem interval(PMI).However,whether it has potential use in the early PMI has not been fully studied yet.To test this possibility in the present study,EC of three internal organs of rat liver,spleen,and kidney were determined within 24 postmortem hows,and then,EC changes at different PMIs were carefully analyzed.The overall results showed that EC of liver and spleen increased significantly with PMI while EC of kidney had minor changes during the same period.Specifically,significant linear positive correlations between EC of liver and spleen and PMI were found and the coefficients of their regression functions were R^(2)=0.98 and R^(2)=0.95,respectively.It can be concluded that determination of EC in certain internal organs such as liver and spleen may be a potential tool in the early PMI estimation.However,more researches on its influencing factors are needed to facilitate its final use in practice.展开更多
Estimation of postmortem interval(PMI)has been an important and difficult subject in the forensic study.It is a primary task of forensic work,and it can help guide the work in field investigation.With the development ...Estimation of postmortem interval(PMI)has been an important and difficult subject in the forensic study.It is a primary task of forensic work,and it can help guide the work in field investigation.With the development of computed tomography(CT)technology,CT imaging techniques are now being more frequently applied to the field of forensic medicine.This study used CT imaging techniques to observe area changes in different tissues and organs of rabbits after death and the changing pattern of the average CT values in the organs.The study analyzed the relationship between the CT values of different organs and PMI with the imaging software Max Viewer and obtained multiparameter nonlinear regression equation of the different organs,and the study provided an objective and accurate method and reference information for the estimation of PMI in the forensic medicine.In forensic science,PMI refers to the time interval between the discovery or inspection of corpse and the time of death.CT,magnetic resonance imaging,and other imaging techniques have become important means of clinical examinations over the years.Although some scholars in our country have used modem radiological techniques in various fields of forensic science,such as estimation of injury time,personal identification of bodies,analysis of the cause of death,determination of the causes of injury,and identification of the foreign substances of bodies,there are only a few studies on the estimation of time of death.We detected the process of subtle changes in adult rabbits after death,the shape and size of tissues and organs,and the relationship between adjacent organs in three-dimensional space in an efiort to develop new method for the estimation of PMI.The bodies of the dead rabbits were stored at 20℃ room temperature,sealed condition,and prevented exposure to flesh flies.The dead rabbits were randomly divided into comparison group and experimental group.The whole-body CT scans were performed on the experimental group of rabbits at different PMIs.NeuViz dual-slice spiral CT scanner(made by Neusoft Medical in China,2 mm×10 mm high-speed rare earth ceramic detector)is a 360°scan that could obtain two images,capable of providing a wide range of high-speed continuous spiral scan.Max Viewer(Version:1.0.0131,Neusoft,Shenyang,China)is a CT image viewing software developed by Neusoft Medical.The software can be used to view and process images in various common methods and to measure a number of parameters,such as length,area,angle,and CT values.Statistical analysis was performed using SPSS1 Statistics 19.0(SPSS,Inc.,Chicago,IL,USA).AP<0.05 was considered statistically significant.We obtained the binomial regression equation of the CT values and the related coefficient(R^(2)).In the future,we suggests that comprehensive analyses of various indicators of different organs could establish a diversified pattern to remedy the deficiencies and make the study of PMI estimation more scientific and enhance the operability.展开更多
Background:The estimation of postmortem interval(PMI)is one of the most important topics in forensic medicine research.We speculate that with an increased PMI,the computed tomography(CT)values of different tissues may...Background:The estimation of postmortem interval(PMI)is one of the most important topics in forensic medicine research.We speculate that with an increased PMI,the computed tomography(CT)values of different tissues may show regular changes.Purpose:To use postmortem computed tomography(PMCT)to measure the myocardial CT value(unit:Hounsfield Unit,HU)of the heart to explore its pattern in postmortem change,and to discuss whether it can serve as a new parameter for PMI estimation.Methods:A total of 10 healthy adult New Zealand rabbits were selected and then put into a 20℃ incubator after being sacrificed.Within 0-156 h after death,CT scans were performed every 12 h to detect changes in the myocardial CT value of the heart over time.Regression analysis was used to determine the relationship between the myocardial CT value of the heart and PMI.At the same time,HE and Masson were used to stain the cardiac tissue sections detected by PMCT at Oh,48h and 156h,respectively.Results:During 0-156 h,the overall myocardial CT value showed a trend of first rising and then decreasing with the increase of PMI.The fitting regression equation was y=-2873.193+143.866x-1.728x2(x:myocardial CT value,unit:Hu;y:PMI,unit:h,R2=0.466,P<0.05).During 48-156 h,the overall myocardial CT value decreased gradually with the increase of PMI.The fitting regression equation was y=-93.038+18.700x-0.321x2(x:myocardial CT value,unit:Hu;y:PMI,unit:h,R2=0.963,P<0.001).The results of the morphological changes of the myocardial tissue structure after death showed that the myocardial cell structure was relatively complete at 0-48 hours after death;and the myocardial cell structure disappeared at 156 hours after death.Conclusions:Our results revealed evident postmortem changes in the myocardial CT value of the heart.Accordingly,measuring the myocardial CT value through PMCT shows promise for being used as a parameter for PMI estimation in forensic medicine and is worthy of further studies.The morphological changes of the myocardial tissue structure after death provide morphological basis for postmortem changes of tissue density,and further prove the reasons for the changes of CT value.展开更多
In forensic medical examinations,estimating the postmortem interval(PMI)is an important factor.Methamphetamine(MA)is a synthetic stimulant that is commonly abused,and estimation of the PMI after MA abuse has become on...In forensic medical examinations,estimating the postmortem interval(PMI)is an important factor.Methamphetamine(MA)is a synthetic stimulant that is commonly abused,and estimation of the PMI after MA abuse has become one of the main tasks in forensic investigation.Microorganisms play a vital role in carrion decomposition.Analysing the bacterial succession patterns can be used as a forensic tool to estimate the PMI.The present study aimed to analyse bacterial succession changes during the decomposition of MA to estimate the PMI.We analysed bacterial communities in rabbits treated with three different concentrations of MA(0,22.5,and 90 mg/kg)under the natural conditions of 20°C and 70%humidity by sequencing 16S rRNA gene amplicons using the Illumina MiSeq system.We obtained 2374209 high-quality sequences and 2937 operational taxonomic units(OTUs).The relative abundances of the bacterial communities varied markedly in response to different MA concentrations.Interestingly,in response to the different concentrations of MA,Bacteroidetes became disparate in the rectum in the late PMI.Increased numbers of bacterial taxa were identified in the rectum and buccal cavity samples,except at the highest concentration of MA in the rectum samples when PMI was 0-h,than were present in live rabbits.Meanwhile,the PMI correlated significantly with bacterial succession at different taxonomic levels.Our results suggested that bacterial community succession could be used as a“microbial clock”to estimate the PMI in cases of MA-related death;however,further study is required to gain a deeper understanding of this concept.展开更多
Insects have an important role in minimum postmortem interval(PMImin)estimation.An accurate PMImin estimation relies on a comprehensive study of the development and succes-sion of local carrion insects.No published re...Insects have an important role in minimum postmortem interval(PMImin)estimation.An accurate PMImin estimation relies on a comprehensive study of the development and succes-sion of local carrion insects.No published research on carrion insect succession exists for tropical north Queensland.To address this,we aimed to obtain preliminary observational data concerning the rate of decomposition and insect succession on pig carcasses in Townsville and compare these with other regions of Australia and overseas.Adult insects were collected daily from three pig carcasses for 30d during summer and identified to fa-mily level.Observations of decomposition rate were made each day and progression through the stages of decomposition were recorded.Adult insects were identified to family and their presence/absence used as a proxy for arrival at/departure from the remains,respectively.These preliminary data highlight several interesting trends that may be inform-ative for forensic PMImin estimation.Decomposition was rapid:all carcasses were at the dry/remains stage by Day 5,which was substantially quicker than all other regions in the com-parison.Differences were also observed in the presence/absence of insect families and their arrival and departure times.Given the rapid progression through early decomposition,we argue that later-arriving coleopteran taxa may be more forensically informative in tropical Australia,in contrast with temperate regions where Diptera appear most useful.This research contributes preliminary observational data to understanding insect succession pat-terns in tropical Australia and demonstrates the critical need for comprehensive local succes-sion data for each climatic region of Australia to enable accurate PMImin estimation.These data will inform future research targeted at gaining a more comprehensive understanding of insect succession in the Australian tropics.展开更多
It is observed that there is not enough literature to support the usefulness of dental tissue in forensic medicine for the estimation of postmortem interval(PMI).Therefore,the authors of this article have systematical...It is observed that there is not enough literature to support the usefulness of dental tissue in forensic medicine for the estimation of postmortem interval(PMI).Therefore,the authors of this article have systematically reviewed the available literature to understand the most used dental tissues,the methods employed to evaluate these tissues,and their reliability in PMI estimation.A MEDLINE-PubMed search engine was used to review the literature using the keywords“teeth,”“dental tissues,”“post‑mortem interval,”and“forensic dentistry”from 2001 until 2020.The most used tissue was dental pulp,but other cellular‑.and molecular‑level dental tissues such as enamel,dentin,cementum,periodontal ligament,odontoblast,and mitochondrial and nuclear DNA and RNA were also used.Based on this observation,the authors have provided the categorical classification to evaluate these dental tissues into morphological,histopathological,and molecular‑level examination to understand the reliability of these dental tissues.The molecular examinations to evaluate these tissues were widely employed and emerging in the estimation of PMI as this method could provide a reliable outcome when compared with others.Since the literature reviewed was not enough to answer our questions,however,to conclude,the dental pulp is the widely used tissue so far.Further,more studies are required to authenticate the role of other dental tissues to predict the PMI at an early stage with cost‑effective and most convenient techniques.展开更多
Estimation of the postmortem interval(PMI)is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved.In this study,we analyzed volatile organic compounds(VOCs)in rat muscle s...Estimation of the postmortem interval(PMI)is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved.In this study,we analyzed volatile organic compounds(VOCs)in rat muscle samples collected at different PMIs and studied the feasibility of muscle VOC fingerprinting as a new method for PMI estimation.In total,110 rats were sacrificed and stored at a constant temperature(25℃).Rat skeletal muscle samples were collected at 0-10‑day postmortem,and then the VOCs were determined using a method of headspace solid‑phase microextraction coupled with gas chromatography‑mass spectrometry.The correlations between the VOCs(species and quantities)and PMIs were carefully analyzed and standard muscle VOC fingerprints at 25℃were established for different PMIs.To further test the accuracy of muscle VOC fingerprinting as a method for PMI estimation,ten additional rats with known PMIs were studied.We identified 15 kinds of VOCs and the number of VOC species increased with the PMI.The total peak areas of the VOCs increased significantly with the postmortem day(adjusted R^(2)=0.96-0.97).The mean error of the VOC fingerprinting for PMI estimation was 0.5 days and the mean relative error was 8.33%.We concluded that muscle VOC fingerprinting combining the use of VOC species and peak areas is accurate and effective and could be used as an alternative approach for PMI estimation in forensic practice.Although the preliminary results are encouraging,further studies in human cadavers under real case conditions are needed.展开更多
Postmortem changes in the biochemical constituents of the vitreous humor have been widely used to estimate the postmortem interval(PMI)over the past several decades.However,few reviews have summarized the relationship...Postmortem changes in the biochemical constituents of the vitreous humor have been widely used to estimate the postmortem interval(PMI)over the past several decades.However,few reviews have summarized the relationship between the postmortem vitreous biochemical constituents and time of death.Herein,the relationship between PMI and single biochemical components,including vitreous potassium,hypoxanthine,and amino acids,as well as comparisons of each statistical parameter in the formula,is summarized.We also discuss other compounds such as urea and uric acid,which have no direct relationship with PMI.Utility of multiple constituent simultaneous analysis for estimating PMI is being increasingly investigated.The promising idea of using simultaneous analysis of multiple constituents to determine PMI is proposed as a future research direction.展开更多
Accurate estimation of the postmortem interval(PMI)is an important task in forensic practice.In the last half-century,the use of postmortem biochemistry has become an important ancillary method in determining the time...Accurate estimation of the postmortem interval(PMI)is an important task in forensic practice.In the last half-century,the use of postmortem biochemistry has become an important ancillary method in determining the time of death.The present study was carried out to determine the correlation between blood oxidation-reduction potential(ORP)values and PMIs,and to develop a three-dimensional surface equation to estimate the PMI under various temperature conditions.A total of 48 rabbits were placed into six groups and sacrificed by air embolism.Blood was obtained from the right ventricle of each rabbit,and specimens were stored at 10℃,15℃,20℃,25℃,30℃,and 35℃.At different PMIs(once every 4 h),the blood ORP values were measured using a PB-21 electrochemical analyzer.Statistical analysis and curve fitting of the data yielded cubic polynomial regression equations and a surface equation at different temperatures.Result:The results showed that there was a strong positive correlation between the blood ORP values at different temperatures and the PMI.This study provides another example of using a three-dimensional surface equation as a tool to estimate the PMI at various temperature conditions.展开更多
Estimation of postmortem interval(PMI)is vitally important in forensic investigations.Although many studies have examined the chemical changes of various tissues over time,no reports using spectroscopic methods in adi...Estimation of postmortem interval(PMI)is vitally important in forensic investigations.Although many studies have examined the chemical changes of various tissues over time,no reports using spectroscopic methods in adipose tissue are available.In this study,attenuated total reflectance-Fourier transform infrared(ATR-FTIR)spectroscopy was utilized to collect comprehensive biochemical information from human adipose tissues in vitro at different times.Thereafter,mice were used as samples for in vivo experiments for more detailed studies on PMI.Then,partial least squares(PLS)model for PMI estimation was established based on the acquired spectral dataset of mouse samples.The spectral variable associated with C=O arising from lipids and free fatty acids was most susceptible to PMI.Moreover,the PLS model appeared to achieve a satisfactory prediction with a root mean square error of cross‑validation of 1.78 days,and the reliability of the model was determined in an external validation set with a root mean square error of prediction of 1.87 days.The study shows the possibility of application of ATR-FTIR methods in PMI estimation using adipose tissue.展开更多
Background:In forensic investigations,accurate estimation of the postmortem interval(PMI)is an important task,but also an ongoing challenge.Especially in cases where the cadaver has been specially treated,for example,...Background:In forensic investigations,accurate estimation of the postmortem interval(PMI)is an important task,but also an ongoing challenge.Especially in cases where the cadaver has been specially treated,for example,by boiling,the determination of PMI becomes extremely difficult.Previous studies have shown that the succession of the microbial community after decomposition of the cadaver can be used to infer PMI.However,the feasibility of determining the PMI of boiled cadavers has not yet been demonstrated.Aims and Objectives:The main objective of this study was to test whether we can infer PMI of boiled cadavers based on the succession of microbial communities.Materials and Methods:SD rats were killed by cervical dislocation.Subsequently,the rat cadavers were divided into the case(boiled cadavers)and control(unboiled cadavers)groups.Rectal samples were collected from the rats for 45 days and at nine time points.High-throughput sequencing of the 16S rRNA gene was performed to characterize the microbial community in the rectum.Results:The results showed that the composition and relative abundance of bacterial communities at the phylum level were significantly different between the case and control groups.The alpha diversity of the microbial community showed a decreasing trend with the decomposition process.Principal coordinate analysis showed that the case and control groups had obvious patterns along the succession of microbial communities.The rectal microbial communities showed a significant linear trend in the time course of decomposition.A random forest model was used to infer PMI.The goodness-of-fit(R2)of the model was 68.00%and 84.00%,and the mean absolute errors were 2.05 and 1.48 days within 45 days of decomposition for the case and control groups,respectively.Conclusions:Our results suggest that microbial community succession could be a potential method to infer PMI of boiled cadavers.展开更多
Anthropologists are often the custodians of long-term unidentified human remains though their positions as curators of university or museum skeletal collections.Various factors decrease the solvability of these legacy...Anthropologists are often the custodians of long-term unidentified human remains though their positions as curators of university or museum skeletal collections.Various factors decrease the solvability of these legacy cases including the passage of time,the loss of provenience for specific cases,and lack of documentation or case records.While anthropologists can contribute important information toward identification,it is often necessary to explore novel and cross-disciplinary strategies to resolve difficult cold cases.In long cold cases,the postmortem interval,in particular,may be difficult to estimate leading to further challenges in achieving identification.Modern advances in radiocarbon bomb pulse dating,isotope analysis,and actualistic studies have contributed to positive identification of unidentified human remains in some legacy cases,but may not be available to all forensic practitioners and law enforcement from resource-poor agencies.Pooling resources,as well as collaborating with professionals outside of forensic anthropology,is a useful strategy to pursue when anthropological methods are exhausted.The case study presented here demonstrates a collaborative approach between forensic anthropologists,forensic genetic genealogists,and law enforcement in a century-old homicide.The dismembered and mummified parts of a male body were recovered in a remote cave in 1979 and again in 1991.Despite forensic anthropologists creating and updating the biological profile over the decades from recovery to present,no identification was made until the application of forensic genetic genealogy(FGG)to the case in 2019.New interpretations of bone microstructure and trauma analysis are presented for the case,alongside the historical documentation and“proof of life”evidence used by the genealogy team.A review of the FGG methods underscores the challenges in this case(e.g.significant endogamy,multiple aliases used by the victim)and the steps taken toward resolution.Ultimately,a combined anthropology and genealogy approach resulted in a confirmed identity for a man who was murdered in 1916.展开更多
The value of the Formicidae (Insecta,Hymenoptera) community in forensic investigations is poorly studied in Portugal.In order to better understand the structure and dynamics of this group of insects in cadavers and th...The value of the Formicidae (Insecta,Hymenoptera) community in forensic investigations is poorly studied in Portugal.In order to better understand the structure and dynamics of this group of insects in cadavers and their putative value in forensic investigations,studies were carried out in Lisbon area during one year.Piglet carcasses were used as a model of human decomposition.The entomofauna attracted to the carcasses was collected over a period of about 2 months in each season of the year.The collection of ants was performed at regular intervals,daily in the first 23 days and then with intervals of 2,3 or 5 days until the end of the experiment.Five stages of cadaveric decomposition were recognized with the ants being present in all of them.Three hundred and nine specimens were captured: 7 in autumn,6 in winter,90 in spring and 206 in summer.These specimens belong to three subfamilies and seven different species.Four of them had never been mentioned before as being associated to cadavers in this geographical area.Spring and summer had the greater diversity of species and a larger number of individuals.Temnothorax luteus was the dominant species in spring and Tapinoma nigerrimum in summer.Corroborating the information of other similar studies carried out in the Iberian Peninsula,the sarcosaprophagous Formicidae community found in Lisbon is unique and different from other studied locations,which supports the need to perform regional studies.Our results shown that ants do not present a definite pattern of succession,but some species have the potential to be seasonal or geographic indicators.展开更多
In forensic entomology,insects are used mainly to obtain information about the time since death.This information is obtained studying the developmental rate of the first colonizers,principally species in the families ...In forensic entomology,insects are used mainly to obtain information about the time since death.This information is obtained studying the developmental rate of the first colonizers,principally species in the families Calliphoridae,Sarcophagidae,Muscidae,Stratiomyidae and Phoridae.However,species belonging to other families can provide information about body transfer or the season of the death.Among them Milichiidae are flies rarely reported from human cases despite the larvae of some species are known as saprophagous feeding on plant and animal decomposing matter.A potential cause of the lack of records of these species from forensic cases can be related with the paucity of descriptions and illustrations of the immature stages.In this article,the entomological samples collected from a human body found inside an apartment in a Maghreb country,in Northern Africa,is reported and Leptometopa latipes(Diptera:Milichiidae)is described in detail.Molecular analysis is also reported to confirm the morphological analysis.展开更多
There is currently a dearth of research investigating the progression and rate of decomposition for juvenile remains.It is thought that juveniles and infants decompose at an increased rate relative to adults due simpl...There is currently a dearth of research investigating the progression and rate of decomposition for juvenile remains.It is thought that juveniles and infants decompose at an increased rate relative to adults due simply to body mass and that skeletal preservation is commonly dependent on intrinsic levels of bone mineral density(BMD).This study investigates the environmental variables important in driving juvenile decomposition as well as examining if currently accepted methodology for quantifying adult decomposition can be applied to juvenile remains.Furthermore,histological analysis is undertaken to test the Histological Index(HI)as a semi-quantitative indicator of decomposition.Thirty-five Sus scrofa ranging between 1.8 and 22.7 kg were deposited to simulate body mass of human infant and juvenile remains.Pigs were deposited every season over two years in the southeastern US with five depositional types:bagged,blanket wrapped,and surface control foetal remains,surface,and buried juvenile remains.Remains were scored quantitatively throughout soft tissue decomposition.Following study completion and skeletonization,a femur was selected from each set of remains for histological analysis.Thick sections were assessed under standard brightfield light and scored using Oxford Histological Index(OHI).Results indicate that seasonal variation is an important factor to consider even when using a standardized time variable such as accumulated degree days(ADD),particularly variation in soil moisture.Soil moisture was a consistent significant variable in the mixed effects model.The pattern of decomposition using total body score(TBS)was similar to that observed by others prior to log transformation with a rapid incline early in decomposition with levelling off.The correlation between time in days,ADD,and TBS was not as strong as those previously reported(R^(2)=0.317 and 0.499,respectively)suggesting that TBS as it is currently formulated cannot be directly applied to juvenile remains.Finally,the OHI model performed moderately well,but was variable even within seasons across multiple years.展开更多
Hanging is one of the most common methods of suicide worldwide.Despite the high incidence,only a little knowledge about the pattern of cadaver colonization by insects on hanging corpse is available.Different types of ...Hanging is one of the most common methods of suicide worldwide.Despite the high incidence,only a little knowledge about the pattern of cadaver colonization by insects on hanging corpse is available.Different types of hanging can alter the body decomposition process as well as the pattern and rate of insect colonization.Two case studies where the hanging occurred with a similar postmortem interval of 34 days are described.The two bodies showed different patterns of insect colonization and decomposition scored using the Total Body Score (TBS) and the TBS for hanging (TBShang).The first case was about the body of a 24-years-old male,with mummification of the unclothed upper anatomical parts.A TBS of 14 and a TBShang of 18 were assigned.The second body,belonging to a 1 S-years-old male,was found pre-skeletonized lying on the ground with the skull disarticulated.A TBS of 31 and a TBShang of 32 were assigned.Average temperatures of (21.5 ± 2.5) ℃ for the first body and (25.1 ± 2.7) ℃ for the second body were recorded in the 34 days preceding the bodies' discovery for a total of 731 and 853 Accumulated Degree Days (ADD) respectively.According to previous studies,the different decomposition patterns were related to temperatures of exposition and to the diversity of arthropod community found on the bodies because of the different types of hanging: totally suspended vs.in contact with the soil.The limited insect activity caused by hanging explains the delay in decomposition of hanging bodies in which mummification can take place,especially on the upper body parts.In vertical body position,the body fluids accumulated in the lower body parts accelerating the desiccation of soft tissues on the upper parts.The effect of gravity can also explain the decrease of internal maggot mass as larvae easily fall from the hanging body to the drip zones below where they are unable to recolonize the body if totally suspended.Furthermore,in a hanging body a greater surface is exposed to wind and sun with a quicker skin drying preventing the additional Diptera colonization.This paper shows the weaknesses of scoring scales and regression models developed to predict ADD when irregular decomposition and mummification have not taken into account.展开更多
Decomposition research is still in its infancy,but significant advances have occurred within forensic anthropology and other disciplines in the past several decades.Decomposition research in forensic anthropology has ...Decomposition research is still in its infancy,but significant advances have occurred within forensic anthropology and other disciplines in the past several decades.Decomposition research in forensic anthropology has primarily focused on estimating the postmortem interval(PMI),detecting clandestine remains,and interpreting the context of the scene.Additionally,while much of the work has focused on forensic-related questions,an interdisciplinary focus on the ecology of decomposition has also advanced our knowledge.The purpose of this article is to highlight some of the fundamental shifts that have occurred to advance decomposition research,such as the role of primary extrinsic factors,the application of decomposition research to the detection of clandestine remains and the estimation of the PMI in forensic anthropology casework.Future research in decomposition should focus on the collection of standardized data,the incorporation of ecological and evolutionary theory,more rigorous statistical analyses,examination of extended PMIs,greater emphasis on aquatic decomposition and interdisciplinary or transdisciplinary research,and the use of human cadavers to get forensically reliable data.展开更多
基金supported by National Sciences Foundation of China(NSFC)[grant numbers 81601645,81671869,81072509,81273339 and 81273335]the Science and Technology Commission of Shanghai Municipality[grant number 14DZ2270800].
文摘The determination of time since death or the postmortem interval(PMI)is one of the most important and frequently asked questions in forensic medicine.Medicolegal scholars and forensic pathologists around the world have studied the estimation of PMI extensively in the past,and many novel methods and advanced technologies have now been applied in the field.For several centuries,Chinese forensic examiners have also worked on the estimation of the PMI,and there are a large number of excellent studies published in Chinese rather than in English,and these are not easily accessible or known internationally.Therefore we have conducted a review of relevant studies published by Chinese forensic scholars in the last few decades.The scope of this review is to provide a concise summary of the current progress in the estimation of PMI by Chinese forensic researchers using molecular biology,spectroscopic technology,entomological methods,energy changes,thanatochemistry and other methods.
文摘The electrical conductivity(EC)of extracted muscle fluid has been extensively used to evaluate meat freshness and shelf life in the field of food sanitation for decades.The opposite of freshness is the corruption that increases with time.Based on the freshness/corruption principle,we investigated the relationship between long postmortem intervals(PMIs)and EC in cadaver skeletal muscle.EC values of extracted fluid from rat muscles were measured at different PMIs for 10 days.The results indicate that there was a significant correlation between PMI and EC,and the data fit well to the cubic polynomial regression equation y=‑0.01x3+0.264x2‑13.657x+1769.148(R2=0.925).In addition,the EC of different dilutions of these muscle extracts showed strict quadratic correlation(R2=1)with the dilution ratios,suggesting that EC can be measured with very small quantities of muscle sample.Our study suggests that determination of the EC of cadaver skeletal muscle extracts may be a useful method for estimating long PMIs.
基金This study was supported by the Basic and Frontier Study of Technology Project of Henan Province(Grant No.112300410082)the Doctor Foundation and the Youngs'Foundation of Henan University of Science and Technology(Grant No.09001309,2013ZCX024 and 2011QN52)Key Laboratory of Forensic Medicine Identification in Luoyang(No.11550002).
文摘Previous research has found that electrical conductivity(EC),an important index to predict meat freshness and shelflife,is very promising for estimating the late postmortem interval(PMI).However,whether it has potential use in the early PMI has not been fully studied yet.To test this possibility in the present study,EC of three internal organs of rat liver,spleen,and kidney were determined within 24 postmortem hows,and then,EC changes at different PMIs were carefully analyzed.The overall results showed that EC of liver and spleen increased significantly with PMI while EC of kidney had minor changes during the same period.Specifically,significant linear positive correlations between EC of liver and spleen and PMI were found and the coefficients of their regression functions were R^(2)=0.98 and R^(2)=0.95,respectively.It can be concluded that determination of EC in certain internal organs such as liver and spleen may be a potential tool in the early PMI estimation.However,more researches on its influencing factors are needed to facilitate its final use in practice.
文摘Estimation of postmortem interval(PMI)has been an important and difficult subject in the forensic study.It is a primary task of forensic work,and it can help guide the work in field investigation.With the development of computed tomography(CT)technology,CT imaging techniques are now being more frequently applied to the field of forensic medicine.This study used CT imaging techniques to observe area changes in different tissues and organs of rabbits after death and the changing pattern of the average CT values in the organs.The study analyzed the relationship between the CT values of different organs and PMI with the imaging software Max Viewer and obtained multiparameter nonlinear regression equation of the different organs,and the study provided an objective and accurate method and reference information for the estimation of PMI in the forensic medicine.In forensic science,PMI refers to the time interval between the discovery or inspection of corpse and the time of death.CT,magnetic resonance imaging,and other imaging techniques have become important means of clinical examinations over the years.Although some scholars in our country have used modem radiological techniques in various fields of forensic science,such as estimation of injury time,personal identification of bodies,analysis of the cause of death,determination of the causes of injury,and identification of the foreign substances of bodies,there are only a few studies on the estimation of time of death.We detected the process of subtle changes in adult rabbits after death,the shape and size of tissues and organs,and the relationship between adjacent organs in three-dimensional space in an efiort to develop new method for the estimation of PMI.The bodies of the dead rabbits were stored at 20℃ room temperature,sealed condition,and prevented exposure to flesh flies.The dead rabbits were randomly divided into comparison group and experimental group.The whole-body CT scans were performed on the experimental group of rabbits at different PMIs.NeuViz dual-slice spiral CT scanner(made by Neusoft Medical in China,2 mm×10 mm high-speed rare earth ceramic detector)is a 360°scan that could obtain two images,capable of providing a wide range of high-speed continuous spiral scan.Max Viewer(Version:1.0.0131,Neusoft,Shenyang,China)is a CT image viewing software developed by Neusoft Medical.The software can be used to view and process images in various common methods and to measure a number of parameters,such as length,area,angle,and CT values.Statistical analysis was performed using SPSS1 Statistics 19.0(SPSS,Inc.,Chicago,IL,USA).AP<0.05 was considered statistically significant.We obtained the binomial regression equation of the CT values and the related coefficient(R^(2)).In the future,we suggests that comprehensive analyses of various indicators of different organs could establish a diversified pattern to remedy the deficiencies and make the study of PMI estimation more scientific and enhance the operability.
基金supported by the General Program of National Natural Science Foundation of China(grant number 81971796),Bering Natural Science Foundation(grant number 7192121)Chinese Academy of Engineering Advisory Project(grant number 2019-XZ-31)Production-Study-Research Project for graduate students of China University of Political Science and Law(grant number CXY2012).
文摘Background:The estimation of postmortem interval(PMI)is one of the most important topics in forensic medicine research.We speculate that with an increased PMI,the computed tomography(CT)values of different tissues may show regular changes.Purpose:To use postmortem computed tomography(PMCT)to measure the myocardial CT value(unit:Hounsfield Unit,HU)of the heart to explore its pattern in postmortem change,and to discuss whether it can serve as a new parameter for PMI estimation.Methods:A total of 10 healthy adult New Zealand rabbits were selected and then put into a 20℃ incubator after being sacrificed.Within 0-156 h after death,CT scans were performed every 12 h to detect changes in the myocardial CT value of the heart over time.Regression analysis was used to determine the relationship between the myocardial CT value of the heart and PMI.At the same time,HE and Masson were used to stain the cardiac tissue sections detected by PMCT at Oh,48h and 156h,respectively.Results:During 0-156 h,the overall myocardial CT value showed a trend of first rising and then decreasing with the increase of PMI.The fitting regression equation was y=-2873.193+143.866x-1.728x2(x:myocardial CT value,unit:Hu;y:PMI,unit:h,R2=0.466,P<0.05).During 48-156 h,the overall myocardial CT value decreased gradually with the increase of PMI.The fitting regression equation was y=-93.038+18.700x-0.321x2(x:myocardial CT value,unit:Hu;y:PMI,unit:h,R2=0.963,P<0.001).The results of the morphological changes of the myocardial tissue structure after death showed that the myocardial cell structure was relatively complete at 0-48 hours after death;and the myocardial cell structure disappeared at 156 hours after death.Conclusions:Our results revealed evident postmortem changes in the myocardial CT value of the heart.Accordingly,measuring the myocardial CT value through PMCT shows promise for being used as a parameter for PMI estimation in forensic medicine and is worthy of further studies.The morphological changes of the myocardial tissue structure after death provide morphological basis for postmortem changes of tissue density,and further prove the reasons for the changes of CT value.
基金This study was supported by the National Natural Science Foundation of China[Grant No.81772026,820721140].
文摘In forensic medical examinations,estimating the postmortem interval(PMI)is an important factor.Methamphetamine(MA)is a synthetic stimulant that is commonly abused,and estimation of the PMI after MA abuse has become one of the main tasks in forensic investigation.Microorganisms play a vital role in carrion decomposition.Analysing the bacterial succession patterns can be used as a forensic tool to estimate the PMI.The present study aimed to analyse bacterial succession changes during the decomposition of MA to estimate the PMI.We analysed bacterial communities in rabbits treated with three different concentrations of MA(0,22.5,and 90 mg/kg)under the natural conditions of 20°C and 70%humidity by sequencing 16S rRNA gene amplicons using the Illumina MiSeq system.We obtained 2374209 high-quality sequences and 2937 operational taxonomic units(OTUs).The relative abundances of the bacterial communities varied markedly in response to different MA concentrations.Interestingly,in response to the different concentrations of MA,Bacteroidetes became disparate in the rectum in the late PMI.Increased numbers of bacterial taxa were identified in the rectum and buccal cavity samples,except at the highest concentration of MA in the rectum samples when PMI was 0-h,than were present in live rabbits.Meanwhile,the PMI correlated significantly with bacterial succession at different taxonomic levels.Our results suggested that bacterial community succession could be used as a“microbial clock”to estimate the PMI in cases of MA-related death;however,further study is required to gain a deeper understanding of this concept.
文摘Insects have an important role in minimum postmortem interval(PMImin)estimation.An accurate PMImin estimation relies on a comprehensive study of the development and succes-sion of local carrion insects.No published research on carrion insect succession exists for tropical north Queensland.To address this,we aimed to obtain preliminary observational data concerning the rate of decomposition and insect succession on pig carcasses in Townsville and compare these with other regions of Australia and overseas.Adult insects were collected daily from three pig carcasses for 30d during summer and identified to fa-mily level.Observations of decomposition rate were made each day and progression through the stages of decomposition were recorded.Adult insects were identified to family and their presence/absence used as a proxy for arrival at/departure from the remains,respectively.These preliminary data highlight several interesting trends that may be inform-ative for forensic PMImin estimation.Decomposition was rapid:all carcasses were at the dry/remains stage by Day 5,which was substantially quicker than all other regions in the com-parison.Differences were also observed in the presence/absence of insect families and their arrival and departure times.Given the rapid progression through early decomposition,we argue that later-arriving coleopteran taxa may be more forensically informative in tropical Australia,in contrast with temperate regions where Diptera appear most useful.This research contributes preliminary observational data to understanding insect succession pat-terns in tropical Australia and demonstrates the critical need for comprehensive local succes-sion data for each climatic region of Australia to enable accurate PMImin estimation.These data will inform future research targeted at gaining a more comprehensive understanding of insect succession in the Australian tropics.
文摘It is observed that there is not enough literature to support the usefulness of dental tissue in forensic medicine for the estimation of postmortem interval(PMI).Therefore,the authors of this article have systematically reviewed the available literature to understand the most used dental tissues,the methods employed to evaluate these tissues,and their reliability in PMI estimation.A MEDLINE-PubMed search engine was used to review the literature using the keywords“teeth,”“dental tissues,”“post‑mortem interval,”and“forensic dentistry”from 2001 until 2020.The most used tissue was dental pulp,but other cellular‑.and molecular‑level dental tissues such as enamel,dentin,cementum,periodontal ligament,odontoblast,and mitochondrial and nuclear DNA and RNA were also used.Based on this observation,the authors have provided the categorical classification to evaluate these dental tissues into morphological,histopathological,and molecular‑level examination to understand the reliability of these dental tissues.The molecular examinations to evaluate these tissues were widely employed and emerging in the estimation of PMI as this method could provide a reliable outcome when compared with others.Since the literature reviewed was not enough to answer our questions,however,to conclude,the dental pulp is the widely used tissue so far.Further,more studies are required to authenticate the role of other dental tissues to predict the PMI at an early stage with cost‑effective and most convenient techniques.
基金This research was partially supported by China Scholarship Council(CSC 201707070113).
文摘Estimation of the postmortem interval(PMI)is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved.In this study,we analyzed volatile organic compounds(VOCs)in rat muscle samples collected at different PMIs and studied the feasibility of muscle VOC fingerprinting as a new method for PMI estimation.In total,110 rats were sacrificed and stored at a constant temperature(25℃).Rat skeletal muscle samples were collected at 0-10‑day postmortem,and then the VOCs were determined using a method of headspace solid‑phase microextraction coupled with gas chromatography‑mass spectrometry.The correlations between the VOCs(species and quantities)and PMIs were carefully analyzed and standard muscle VOC fingerprints at 25℃were established for different PMIs.To further test the accuracy of muscle VOC fingerprinting as a method for PMI estimation,ten additional rats with known PMIs were studied.We identified 15 kinds of VOCs and the number of VOC species increased with the PMI.The total peak areas of the VOCs increased significantly with the postmortem day(adjusted R^(2)=0.96-0.97).The mean error of the VOC fingerprinting for PMI estimation was 0.5 days and the mean relative error was 8.33%.We concluded that muscle VOC fingerprinting combining the use of VOC species and peak areas is accurate and effective and could be used as an alternative approach for PMI estimation in forensic practice.Although the preliminary results are encouraging,further studies in human cadavers under real case conditions are needed.
基金This research was supported by the National Natural Science Foundation of China(No.81772025)the Natural Science Foundation of Hunan Province(No.2017JJ3511).
文摘Postmortem changes in the biochemical constituents of the vitreous humor have been widely used to estimate the postmortem interval(PMI)over the past several decades.However,few reviews have summarized the relationship between the postmortem vitreous biochemical constituents and time of death.Herein,the relationship between PMI and single biochemical components,including vitreous potassium,hypoxanthine,and amino acids,as well as comparisons of each statistical parameter in the formula,is summarized.We also discuss other compounds such as urea and uric acid,which have no direct relationship with PMI.Utility of multiple constituent simultaneous analysis for estimating PMI is being increasingly investigated.The promising idea of using simultaneous analysis of multiple constituents to determine PMI is proposed as a future research direction.
基金This study was supported by the Key Projects in the National Science and Technology Pillar Program during the Eleventh Five‑year Plan Period(2012BAK16B02)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,the State Education Ministry[(2013)1792]+2 种基金the Training Programmers Foundation for the Beijing Talents(2013D002023000002)the Beijing Planning Project of Philosophy and Social Science(13FXC032)the Project of Young Teachers’Academic Innovation Team by China University of Political Science and Law(2014CXTD04).
文摘Accurate estimation of the postmortem interval(PMI)is an important task in forensic practice.In the last half-century,the use of postmortem biochemistry has become an important ancillary method in determining the time of death.The present study was carried out to determine the correlation between blood oxidation-reduction potential(ORP)values and PMIs,and to develop a three-dimensional surface equation to estimate the PMI under various temperature conditions.A total of 48 rabbits were placed into six groups and sacrificed by air embolism.Blood was obtained from the right ventricle of each rabbit,and specimens were stored at 10℃,15℃,20℃,25℃,30℃,and 35℃.At different PMIs(once every 4 h),the blood ORP values were measured using a PB-21 electrochemical analyzer.Statistical analysis and curve fitting of the data yielded cubic polynomial regression equations and a surface equation at different temperatures.Result:The results showed that there was a strong positive correlation between the blood ORP values at different temperatures and the PMI.This study provides another example of using a three-dimensional surface equation as a tool to estimate the PMI at various temperature conditions.
基金This study was funded by the Council of the National Natural Science Foundation of China(No.81730056).
文摘Estimation of postmortem interval(PMI)is vitally important in forensic investigations.Although many studies have examined the chemical changes of various tissues over time,no reports using spectroscopic methods in adipose tissue are available.In this study,attenuated total reflectance-Fourier transform infrared(ATR-FTIR)spectroscopy was utilized to collect comprehensive biochemical information from human adipose tissues in vitro at different times.Thereafter,mice were used as samples for in vivo experiments for more detailed studies on PMI.Then,partial least squares(PLS)model for PMI estimation was established based on the acquired spectral dataset of mouse samples.The spectral variable associated with C=O arising from lipids and free fatty acids was most susceptible to PMI.Moreover,the PLS model appeared to achieve a satisfactory prediction with a root mean square error of cross‑validation of 1.78 days,and the reliability of the model was determined in an external validation set with a root mean square error of prediction of 1.87 days.The study shows the possibility of application of ATR-FTIR methods in PMI estimation using adipose tissue.
基金supported by the National Natural Science Foundation of China(82030058,82101977,82130056).
文摘Background:In forensic investigations,accurate estimation of the postmortem interval(PMI)is an important task,but also an ongoing challenge.Especially in cases where the cadaver has been specially treated,for example,by boiling,the determination of PMI becomes extremely difficult.Previous studies have shown that the succession of the microbial community after decomposition of the cadaver can be used to infer PMI.However,the feasibility of determining the PMI of boiled cadavers has not yet been demonstrated.Aims and Objectives:The main objective of this study was to test whether we can infer PMI of boiled cadavers based on the succession of microbial communities.Materials and Methods:SD rats were killed by cervical dislocation.Subsequently,the rat cadavers were divided into the case(boiled cadavers)and control(unboiled cadavers)groups.Rectal samples were collected from the rats for 45 days and at nine time points.High-throughput sequencing of the 16S rRNA gene was performed to characterize the microbial community in the rectum.Results:The results showed that the composition and relative abundance of bacterial communities at the phylum level were significantly different between the case and control groups.The alpha diversity of the microbial community showed a decreasing trend with the decomposition process.Principal coordinate analysis showed that the case and control groups had obvious patterns along the succession of microbial communities.The rectal microbial communities showed a significant linear trend in the time course of decomposition.A random forest model was used to infer PMI.The goodness-of-fit(R2)of the model was 68.00%and 84.00%,and the mean absolute errors were 2.05 and 1.48 days within 45 days of decomposition for the case and control groups,respectively.Conclusions:Our results suggest that microbial community succession could be a potential method to infer PMI of boiled cadavers.
基金Funding was provided for DNA extraction/sequencing and forensic genetic genealogy through donations to the DNA Doe Project.
文摘Anthropologists are often the custodians of long-term unidentified human remains though their positions as curators of university or museum skeletal collections.Various factors decrease the solvability of these legacy cases including the passage of time,the loss of provenience for specific cases,and lack of documentation or case records.While anthropologists can contribute important information toward identification,it is often necessary to explore novel and cross-disciplinary strategies to resolve difficult cold cases.In long cold cases,the postmortem interval,in particular,may be difficult to estimate leading to further challenges in achieving identification.Modern advances in radiocarbon bomb pulse dating,isotope analysis,and actualistic studies have contributed to positive identification of unidentified human remains in some legacy cases,but may not be available to all forensic practitioners and law enforcement from resource-poor agencies.Pooling resources,as well as collaborating with professionals outside of forensic anthropology,is a useful strategy to pursue when anthropological methods are exhausted.The case study presented here demonstrates a collaborative approach between forensic anthropologists,forensic genetic genealogists,and law enforcement in a century-old homicide.The dismembered and mummified parts of a male body were recovered in a remote cave in 1979 and again in 1991.Despite forensic anthropologists creating and updating the biological profile over the decades from recovery to present,no identification was made until the application of forensic genetic genealogy(FGG)to the case in 2019.New interpretations of bone microstructure and trauma analysis are presented for the case,alongside the historical documentation and“proof of life”evidence used by the genealogy team.A review of the FGG methods underscores the challenges in this case(e.g.significant endogamy,multiple aliases used by the victim)and the steps taken toward resolution.Ultimately,a combined anthropology and genealogy approach resulted in a confirmed identity for a man who was murdered in 1916.
基金Ricardo Dinis-Oliveira acknowledges Fundacao para a Cien-cia e a Tecnologia(FCT)for his Investigator Grant Igrantnumber IF/01147/1013.
文摘The value of the Formicidae (Insecta,Hymenoptera) community in forensic investigations is poorly studied in Portugal.In order to better understand the structure and dynamics of this group of insects in cadavers and their putative value in forensic investigations,studies were carried out in Lisbon area during one year.Piglet carcasses were used as a model of human decomposition.The entomofauna attracted to the carcasses was collected over a period of about 2 months in each season of the year.The collection of ants was performed at regular intervals,daily in the first 23 days and then with intervals of 2,3 or 5 days until the end of the experiment.Five stages of cadaveric decomposition were recognized with the ants being present in all of them.Three hundred and nine specimens were captured: 7 in autumn,6 in winter,90 in spring and 206 in summer.These specimens belong to three subfamilies and seven different species.Four of them had never been mentioned before as being associated to cadavers in this geographical area.Spring and summer had the greater diversity of species and a larger number of individuals.Temnothorax luteus was the dominant species in spring and Tapinoma nigerrimum in summer.Corroborating the information of other similar studies carried out in the Iberian Peninsula,the sarcosaprophagous Formicidae community found in Lisbon is unique and different from other studied locations,which supports the need to perform regional studies.Our results shown that ants do not present a definite pattern of succession,but some species have the potential to be seasonal or geographic indicators.
基金The work of G.Giordani and F.Tuccia was funded by the Leverhulme Trust Doctoral Scholarship program.
文摘In forensic entomology,insects are used mainly to obtain information about the time since death.This information is obtained studying the developmental rate of the first colonizers,principally species in the families Calliphoridae,Sarcophagidae,Muscidae,Stratiomyidae and Phoridae.However,species belonging to other families can provide information about body transfer or the season of the death.Among them Milichiidae are flies rarely reported from human cases despite the larvae of some species are known as saprophagous feeding on plant and animal decomposing matter.A potential cause of the lack of records of these species from forensic cases can be related with the paucity of descriptions and illustrations of the immature stages.In this article,the entomological samples collected from a human body found inside an apartment in a Maghreb country,in Northern Africa,is reported and Leptometopa latipes(Diptera:Milichiidae)is described in detail.Molecular analysis is also reported to confirm the morphological analysis.
基金supported by a National Institute of Justice Grant[2012-DN-BX-K049].
文摘There is currently a dearth of research investigating the progression and rate of decomposition for juvenile remains.It is thought that juveniles and infants decompose at an increased rate relative to adults due simply to body mass and that skeletal preservation is commonly dependent on intrinsic levels of bone mineral density(BMD).This study investigates the environmental variables important in driving juvenile decomposition as well as examining if currently accepted methodology for quantifying adult decomposition can be applied to juvenile remains.Furthermore,histological analysis is undertaken to test the Histological Index(HI)as a semi-quantitative indicator of decomposition.Thirty-five Sus scrofa ranging between 1.8 and 22.7 kg were deposited to simulate body mass of human infant and juvenile remains.Pigs were deposited every season over two years in the southeastern US with five depositional types:bagged,blanket wrapped,and surface control foetal remains,surface,and buried juvenile remains.Remains were scored quantitatively throughout soft tissue decomposition.Following study completion and skeletonization,a femur was selected from each set of remains for histological analysis.Thick sections were assessed under standard brightfield light and scored using Oxford Histological Index(OHI).Results indicate that seasonal variation is an important factor to consider even when using a standardized time variable such as accumulated degree days(ADD),particularly variation in soil moisture.Soil moisture was a consistent significant variable in the mixed effects model.The pattern of decomposition using total body score(TBS)was similar to that observed by others prior to log transformation with a rapid incline early in decomposition with levelling off.The correlation between time in days,ADD,and TBS was not as strong as those previously reported(R^(2)=0.317 and 0.499,respectively)suggesting that TBS as it is currently formulated cannot be directly applied to juvenile remains.Finally,the OHI model performed moderately well,but was variable even within seasons across multiple years.
文摘Hanging is one of the most common methods of suicide worldwide.Despite the high incidence,only a little knowledge about the pattern of cadaver colonization by insects on hanging corpse is available.Different types of hanging can alter the body decomposition process as well as the pattern and rate of insect colonization.Two case studies where the hanging occurred with a similar postmortem interval of 34 days are described.The two bodies showed different patterns of insect colonization and decomposition scored using the Total Body Score (TBS) and the TBS for hanging (TBShang).The first case was about the body of a 24-years-old male,with mummification of the unclothed upper anatomical parts.A TBS of 14 and a TBShang of 18 were assigned.The second body,belonging to a 1 S-years-old male,was found pre-skeletonized lying on the ground with the skull disarticulated.A TBS of 31 and a TBShang of 32 were assigned.Average temperatures of (21.5 ± 2.5) ℃ for the first body and (25.1 ± 2.7) ℃ for the second body were recorded in the 34 days preceding the bodies' discovery for a total of 731 and 853 Accumulated Degree Days (ADD) respectively.According to previous studies,the different decomposition patterns were related to temperatures of exposition and to the diversity of arthropod community found on the bodies because of the different types of hanging: totally suspended vs.in contact with the soil.The limited insect activity caused by hanging explains the delay in decomposition of hanging bodies in which mummification can take place,especially on the upper body parts.In vertical body position,the body fluids accumulated in the lower body parts accelerating the desiccation of soft tissues on the upper parts.The effect of gravity can also explain the decrease of internal maggot mass as larvae easily fall from the hanging body to the drip zones below where they are unable to recolonize the body if totally suspended.Furthermore,in a hanging body a greater surface is exposed to wind and sun with a quicker skin drying preventing the additional Diptera colonization.This paper shows the weaknesses of scoring scales and regression models developed to predict ADD when irregular decomposition and mummification have not taken into account.
文摘Decomposition research is still in its infancy,but significant advances have occurred within forensic anthropology and other disciplines in the past several decades.Decomposition research in forensic anthropology has primarily focused on estimating the postmortem interval(PMI),detecting clandestine remains,and interpreting the context of the scene.Additionally,while much of the work has focused on forensic-related questions,an interdisciplinary focus on the ecology of decomposition has also advanced our knowledge.The purpose of this article is to highlight some of the fundamental shifts that have occurred to advance decomposition research,such as the role of primary extrinsic factors,the application of decomposition research to the detection of clandestine remains and the estimation of the PMI in forensic anthropology casework.Future research in decomposition should focus on the collection of standardized data,the incorporation of ecological and evolutionary theory,more rigorous statistical analyses,examination of extended PMIs,greater emphasis on aquatic decomposition and interdisciplinary or transdisciplinary research,and the use of human cadavers to get forensically reliable data.
