Pig decomposition in lotic aquatic systems: the potential use of algal growth in establishing a postmortem submersion interval (PMSI)

While algal community composition has been examined as a qualitative indicator of postmortem submersion interval (PMSI), there have been no quantitative studies on using algal growth rates as PMSI estimators. The present study was undertaken to examine pig decomposition in streams and to develop a more quantitative approach to estimate a PMSI. Pigs and ceramic tiles were completely submerged and regularly sampled for periphyton growth. Five stages of decomposition were identified for the submerged pig carcasses according to physical characteristics. Algal growth rates, measured quantitatively as a function of chlorophyll-a concentration, were greater on pigs compared with tiles; however, microhabitat (pools versus riffles) did not significantly influence algal growth. Additionally, there was a strong correlation between algal growth rate and time on pigs and tile substrates. This strong correlation was observed after significant rain events. Our study documents for the first time a quantitative technique to determine the length of time a corpse has been submerged in water. We suggest that algal growth rates may be a useful quantitative indicator in criminal investigations involving corpses that are completely submerged in stream or riverine habitats.     

Marine taphonomy: adipocere formation in a series of bodies recovered from a single shipwreck.

Taphonomy of marine environments has been studied mostly from individual cases. The formation of adipocere, or "grave-wax," is an important indicator of the postmortem interval. In the present paper, the conditions and the timing of adipoceric formation are observed in a series of 15 cadavers recovered at different times, over a period of 433 days, from the same contained environment. Initial foci of adipocere on the subcutaneous tissue of the cadavers were detected as early as 38 days from the time of immersion in cold (10-12 degrees C) sea water. The discrepancies between our findings and previous reports on the correlation between time since death and decomposition stages in marine environments are discussed.     

The potential to determine a postmortem submersion interval based on algal/diatom diversity on decomposing mammalian carcasses in brackish ponds in Delaware

Recently botanical evidence has been studied to determine if it is useful in forensic investigations. This study was performed to examine stillborn piglet decomposition in a brackish water environment and to semi-quantitatively document stages of decomposition, degree day accumulation per stage as well as the algal/diatom diversity useful in determining a postmortem submersion interval (PMSI). Piglets and ceramic tiles were submerged in brackish ponds and sampled on a regular basis to document algal diversity and succession between substrates and stages of decomposition. Significantly greater weight was lost from piglet carcasses during the early floating and advanced floating decay stages. Seasonal effects were observed in degree-day accumulations. Diatom diversity was significantly greater on piglet carcasses compared to tile substrates. Algal diversity decreased over time on the piglet carcasses as well as the stage of decomposition. A significant relationship and strong correlation between algal diversity found on the piglet substrate with time was observed. Our results indicate that more research is needed to examine the potential to use diatoms in not only determining manner of death but also the duration of time (PMSI) a victim may have been immersed in an aquatic environment.     

Pleural effusion in bodies recovered from water

Both in saltwater and freshwater drowning cases, a common autopsy sign is pleural effusion. However, the factors that determine the amount of pleural effusion have not been well established. An attempt was therefore made to correlate the amount of pleural fluid in bodies recovered from water with several parameters registered on the judicial files as well as autopsy findings from the years 1994-1998. The number of cases with pleural fluid increase was found to be very high in saltwater drowning (P<0.001). But, when the freshwater and saltwater drowning cases with pleural fluid increase were compared according to pleural fluid amount, no significant difference was detected (521+/-340 and 768+/-536 ml, respectively). Although there was a positive correlation between the decomposition degree and the fluid in the pleural cavity, a relative decrease was detected in the amount of effusion contrary to the expectations in cases of extreme decomposition. Pleural fluid amount provides significant data about the type of water and the cause of death in early postmortem interval. And there is a link between the time spent in water and the amount of pleural effusion. With the advance of the postmortem interval, decomposition level and the duration of immersion should be taken into account in differential diagnosis.     

Spontaneous formation of γ-hydroxybutyric acid from γ-butyrolactone in tap water solutions

The spontaneous conversion of γ-butyrolactone (GBL) to γ-hydroxybutyric acid (GHB) in seven different Swedish tap waters was investigated. The waters used in the study were selected to represent the diversity among Swedish tap waters as well as possible, which was enabled by principal component analysis (PCA) of a number of water quality parameters. GBL solutions (5, 25 and 50% v/v) were prepared in each of the tap waters and in deionized water and the formation of GHB was followed over time. The GHB quantifications were made using a CZE method, employing a carrier electrolyte consisting of 25mM benzoic acid, 54mM tris(hydroxymethyl)aminomethane (Tris) and 1.7mM tetradecyltrimethylammonium bromide (TTAB), which was developed as a part of the current study. Data evaluation showed that the formation of GHB was largely dependent on the type of tap water. For example, there was a negative correlation between the kinetics of the GHB formation and the alkalinity of the tap waters (r(2)=0.990). This could be explained by a faster decrease in pH in the waters with low buffering capacity (i.e. low alkalinity), which catalysed the hydrolysis of GBL. Equilibrium was reached after 40-250 days depending on the initial GBL concentration and the type of tap water. The level of the equilibrium appeared to be dependent on the initial GBL concentration and ranged from 26 to 37%. Gained knowledge on the levels of the GHB/GBL equilibrium and the kinetics of the formation of GHB in tap water solutions of GBL, including the influence of the tap water quality, may be useful information for casework with the GHB/GBL problem in focus.     

Tributary-level transboundary water law in the Syr Darya: overlooked stories of practical water cooperation

Conventional emphasis on basin-wide water management has often resulted in the formation of transboundary water law on the basin or near basin scale. In Central Asia, however, the Syr Darya Basin possesses an abundance of tributary-level cooperative agreements that guide and codify water sharing and management on the sub-basin scale. To understand the volume and nature of this cooperation, this paper compiled and analyzed a set of agreements that apply to small transboundary tributaries (STTs) in the Syr Darya Basin. The paper assembled the largest collection of STT water agreements—123 in total—and classified such documents according to a range of criteria including: purpose and objectives, water management issues, and operational mechanisms. Results of this work highlight a rise in sub-basin-scale cooperation in the first decade of the twenty-first century, a time when large-scale cooperation appeared tenuous; a practical orientation to transboundary water management at a small scale; and an abundance of treaties of short time duration. These findings present options related to scale, time duration and focus of transboundary water law that can help inform future treaty development.     

Cooling rates of the ear and brain in pig heads submerged in water: implications for postmortem interval estimation of cadavers found in still water

The state of the art for determining postmortem interval in submerged bodies reflects a serious lack of studies. The objectives of the present study were therefore to study cerebral and tympanic cooling in water and its relation to cooling in air, in a pig model. First of all, cerebral and tympanic cooling on a single head and on an entire body were compared and proven to be very similar in air and in water. Nine pairs of heads were then exposed to 9 temperature intervals from 0 degrees C to 20 degrees C. For every set temperature, one head was placed in water, the other in "ambient" air in a thermostatic chamber. Ear and brain temperature were simultaneously measured every 10 minutes during 8 hours. Results showed that both in air and in water, cooling curves were almost exponential, regardless of the site (ear or brain) or the environmental temperature. Cooling was always more rapid in water than in air. Cerebral and tympanic cooling always had a correlation coefficient of 0.98-0.99. Assuming that these cooling patterns are applicable to man, this research may provide a starting point for postmortem interval estimation in submerged cadavers.     

The formation of early stage adipocere in submerged remains: a preliminary experimental study

In some circumstances, the presence of adipocere may retard decomposition and complicate postmortem interval estimation. This article explores the correlation between Accumulated Degree Days (ADD) and early stage formation of adipocere. Sixty wild rabbit (Oryctolagus cuniculus) carcasses were used in this experiment; a control group (N = 30) deposited directly on the ground surface and an experimental group (N = 30) completely submersed in water in individual buckets. Data (water and inner body temperature, pH, and total body score) were collected every 100 ADD. Results indicated that early stage adipocere is correlated to ADD and that its formation on submersed remains is more likely to occur after 630 ADD. Skin sloughing promoted the formation of adipocere. No adipocere was formed on any of the control group rabbits. This study also highlights the fact that multiple factors influence adipocere formation and it is suggested that further research needs to be conducted into this area.     

Bodies found in the water. An investigative approach

The determination of the cause of death of a person whose body is found in the water requires careful investigative work on the part of both police and pathologists. Opinions as to cause and manner of death should not be derived from the autopsy alone but must result from a logical correlation of data regarding victim identity, circumstances, autopsy, and laboratory findings.     

Time of death of victims found in cold water environment

Limited data is available on the application of post-mortem temperature methods to non-standard conditions, especially in problematic real life cases in which the body of the victim is found in cold water environment. Here we present our experience on two cases with known post-mortem times. A 14-year-old girl (rectal temperature 15.5 degrees C) was found assaulted and drowned after a rainy cold night (+5 degrees C) in wet clothing (four layers) at the bottom of a shallow ditch, lying in non-flowing water. The post-mortem time turned out to be 15-16 h. Four days later, at the same time in the morning, after a cold (+/- 0 degrees C) night, a young man (rectal temperature 10.8 degrees C) was found drowned in a shallow cold drain (+4 degrees C) wearing similar clothing (four layers) and being exposed to almost similar environmental and weather conditions, except of flow (7.7 l/s or 0.3 m/s) in the drain. The post-mortem time was deduced to be 10-12 h. We tested the applicability of five practical methods to estimate time of death. Henssge's temperature-time of death nomogram method with correction factors was the most versatile and gave also most accurate results, although there is limited data on choosing of correction factors. In the first case, the right correction factor was close to 1.0 (recommended 1.1-1.2), suggesting that wet clothing acted like dry clothing in slowing down body cooling. In the second case, the right correction factor was between 0.3 and 0.5, similar to the recommended 0.35 for naked bodies in flowing water.     

Kinetics of ethanol in biological sections

Ethanol concentration in alveolocapillary blood (ACB), venous blood (VB), capillary blood (CB), saliva and urine was measured in healthy men and women aged 19-45 years 20, 40, 60, 90, 120, 180, 240 and 300 min after a single intake of 20% ethanol solution in soda water in a dose 0.8 g/kg body mass. Two types of kinetic curves were established. Calculations with Vidmark equation for different biomedia were made. Ethanol levels in all BM studied coincided in the resorption phase. In the elimination phase, ethanol concentration forms a sequence: ACB < saliva < VB < urine. Correlations and correlation coefficients of ethanol concentrations in different BM were estimated. The ethanol concentration correlation urine/ACB 1.71 +/- 0.15 and VB/ACB 1.45 +/- 0.07 is proposed for use in tests for alcohol intoxication.     

Amount of postmortem bleeding: an experimental autopsy study

An experimental autopsy study was performed on 64 cases (55 male, 9 female; average age 51.5 +/- 16.2 years) of sudden natural (38 cases) and asphyxic deaths (26 cases). The study objective was the amount of postmortem bleeding from postmortem cutting of the thoracic aorta, related to the time since death. The amount of postmortem bleeding ranged from 100 to 1300 cm, 440.6 +/- 268.1 cm on average. The time since death up to the autopsy time ranged from 4 to 72 hours, 19.4 +/- 12.9 in average. A statistically significant correlation between the amount of postmortem bleeding and postmortem time interval was stated: Pearson correlation test value r = -0.461 (P = 0.000): the shorter the time interval, the larger the amount of bleeding. The formula of linear regression was estimated according to this correlation: amount of postmortem bleeding (cm) = -9.571 x time since death (h) + 626.659. This proves that the amount of postmortem bleeding (eg, from aortic blunt rupture) could be about 620 cm.     

人毛发中36种芬太尼类物质的HPLC-MS/MS检测方法

建立了同时对人毛发中36种芬太尼类物质快速定性定量检测方法,并成功应用于实际案件的检测.利用高效液相色谱-串联质谱(HPLC-MS/MS)技术,采用MRM(多反应监测)模式,用Waters ACQUITY BEH C18(100mm×2.1 mm,1.7 μm)色谱柱,柱温50℃,流动相为甲醇-0.1％甲酸的水溶液(V...     

Hazards of mattresses, beds and bedding in deaths of infants

Of 52 infants who had died suddenly and were referred to autopsy, nine had lain on adult water beds for the first time; five had died as a result of accidents; two had died on water beds; two were in beds with widely spaced slats; and one had died as a result of strangulation. Three deaths were due to overlying. Three other infants had been placed on sheepskin rugs for the first time and were found dead shortly thereafter. These infants ranged in age from 2 to 9 months, except for a severely mentally retarded nine-year-old with spastic paraplegia. We believe that a general warning should be issued concerning water beds and that soft bedding should not be used for infants. Infants should not be placed unattended or left to sleep on water beds; only beds recommended for infants should be used. Overlying of a young infant is most likely to occur on a water bed, or if the parent is obese or has consumed alcohol.     

Postmortem interval estimation by biochemical determination in birds muscle

Experimental postmortem interval estimation was assayed by various biochemical components of hens pectoral muscle. Among them, only percentage of non-protein nitrogen on total soluble protein, asparatic amino transferase activity and creatinine concentration showed significant correlation with time after death. Asparatic amino transferase was negatively correlated and non-protein nitrogen percentage and creatinine were positively correlated to postmortem interval. The stronger correlation (0.925) was found for creatinine.     

家兔血液和尿液中氯胺酮浓度的相关性

目的研究家兔尿液中氯胺酮及代谢物去甲氯胺酮浓度与血药浓度的动态相关性。方法实验家兔分为氯胺酮灌胃组、静脉注射组和对照组,分别于染毒前和染毒后不同时间点收集尿液和血液。气相色谱/质谱联用(GC/MS)全扫描定性、气相色谱(GC)定量分析血液和尿液样品中氯胺酮及去甲氯胺酮的浓度。采用双变量Pearson相关分析研究尿液中药物浓度和血药浓度的相关性。结果氯胺酮灌胃组和静脉注射组给药后各时间点氯胺酮及去甲氯胺酮在尿液和血液中的浓度相关系数范围在0.11～0.69之间。结论氯胺酮及去甲氯胺酮在尿液和血液中的浓度相关性较差,尿液药物浓度并不能直接反映血药浓度,因此用尿液中氯胺酮浓度推断血药浓度时应慎重考虑。     

The estimation of the time of death by non-protein nitrogen (NPN) in cadaveric materials. Report 3: Multiple regression analysis of NPN values in human cadaveric materials

The non-protein nitrogen (NPN) values in brain, lung, liver, and kidney in 79 autopsy cases were determined according to the Micro-Kjeldahl Nessler method. Multiple regression analysis of the data was performed with every possible combination of the time of death and the NPN values in the tissues.The brain NPN showed the best correlation with the postmortem time (r = 0.673), whereas the other correlations were less satisfactory (lung r = 0.422, liver r = 0.397, and kidney r = 0.379, respectively). However, multiple combinations of each tissue NPN value proved to give better correlation coefficients and smaller errors of the estimated time of death.The practical significance of the tissue NPN as a postmortem biochemical indicator of the time of death and the multiple regression analysis of such indicators were extensively discussed in this report.     

Interpretation of postmortem change in cadavers in Spain

Estimating time since death is especially difficult in the examination of poorly preserved cadavers and depends on the experience of the examiner and comparison with previously documented cases showing similar characteristics. The present study reports on information obtained over the past ten years through the work of the Laboratorio de Antropología y Odontología Forense (LAF) of the Instituto Anatómico Forense de Madrid, Spain, in particular evaluating how the type of fracture influences postmortem change. From the original 225 forensic cases examined between 1992 and 2002 in the LAF, a sample of 29 cases were selected from various regions of the Spanish mainland. A data collection protocol was established to reflect factors which the existing specialized literature, documenting the relation existing in the sample analyzed between time since death and the extent of postmortem change, which in the environments examined are distributed into the following phases: Phase 1 (putrefaction): one week to one month on the surface and two months in water. Phase 2 (initial skeletonization): two months on the surface and five to six months in water. Phase 3 (advanced skeltonization): six months to 1.5 years on the surface and 2.5 years buried. Phase 4 (complete skeletonization): about one year on the surface and three years buried. This paper also provide useful information on the impact of carrion insect activity, location, climate, seasonality, and predator.     

A brief study of time

In this paper we describe the first large-scale, long-term study of how hosts connected to the Internet manage their clocks. This is important for forensic investigations when there is a need for correlation of events collected from disparate sources, as well as for the correlation of computer events to “real” time. We have sampled over 8000 web servers on the Internet on a regular basis for a period of over six months. We have found that only about 74% of the hosts we observed were within 10 s of our reference time (UTC). The other hosts exhibited a large variety of different clock behaviors, some of which are explainable by existing clock models, some not, warranting further research in the area of forensic time and clock analysis.     

用乙醇和正丁醇判断豚鼠溺死时间的实验探索

本文以豚鼠为实验动物，溺死后浸泡于水温为２０℃的水缸小。运用气相色谱法测定其溺死后不同浸泡时间在心、肺、肝小＃在的乙醇和正了醇含量。实验结果表明在溺死后８天内，样本中乙醇和正了醇量随浸泡时间的延长而增加，且呈高度的直线相关。其血、肺、矸中乙醇量与溺死时间的回归方程依次为ｙ１＝－１６．８２＋１２．９５Ｘ，ｙ２＝－５８．５３＋１９．２３Ｘ，ｙ３＝－３１．９１＋４７．２９Ｘ。血、肺、肝小正丁醇量与溺死时间的回归方程依次为ｙ４＝－１０．１３＋５．８６ｘ，ｙ５＝－２９．４５＋１６．１７ｘ，ｙ６＝３．７５＋１４．３１ｘ。综合分析溺死后血、肺、肝小乙醇和正丁醇，有可能作为判断溺死时间的新指标。