Suicide in parachuting: A case report and review of the literature

International audienceSkydiving fatalities are mostly accidental and the result of human errors. However, suicides may be greatly underreported in skydivers. We present the case of a young civilian skydiver who committed suicide by jumping from an altitude of 4000m without activating his chutes. Witnesses reported that the victim had remained in a freefall position until ground impact. Besides an extensive blunt trauma, the autopsy showed an antero-posterior flattening of the body with symmetrical abrasions on its front, which were consistent with a high-energy impact on the ground in a "belly-down" position. Police investigation revealed that the victim had expressed suicidal thoughts in text messages before jumping from the airplane, and examination of his equipment showed that he had disabled the security system allowing the reserve chute to be automatically deployed at low altitude. To the best of our knowledge, this is the first case of suicide of a skydiver that has been described in the scientific literature. A suicidal intent should be assumed in skydiving fatalities involving jumpers with operable but un-activated parachutes on their back. This case highlights the importance of a thorough forensic investigation in such circumstances to ascertain the manner of death

Insights into paradoxical (REM) sleep homeostatic regulation in mice using an innovative automated sleep deprivation method

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Efficient paradoxical (REM) sleep homeostatic regulation in mice: reports on sleep architecture and neuronal activation

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Age estimation at death using pubic bone analysis of a virtual reference sample

International audienceAge at death estimation is a major part of forensic anthropology, but is often poor in the latter decades of life and should benefit from specific population standards. The aim of this study was to test a virtual reference sample with a uniform age distribution in order to improve the accuracy of age estimation for individuals over 40~years of age. We retrospectively built a random virtual reference sample of pubic symphyses from 1100 clinical cases using computed tomography at two French hospitals; this was compared with a test sample (pubic symphyses from 75 corpses undergoing post-mortem computed tomography at a French forensic department) and with the sample originally used in the Suchey-Brooks (SB) system. Inaccuracy and bias were calculated and the proportions of cases in which the real age fell within~the estimated age \textpm~1 standard deviation were calculated. Compared to using the SB sample, using our French sample resulted in a lower inaccuracy for males over 55~years and bias showed that that for males aged 56 to 70~years were less underestimated. Compared to using the SB sample, using our French sample resulted in a lower inaccuracy for females over 70~years and bias showed that that for females aged 56 and older were less underestimated. This study presents a large data set of pubic symphyseal phases from a French virtual sample that allows for improving age estimation accuracy at death, particularly for individuals over 40~years. This kind of material can be useful to improve the age estimation accuracy in a specific region. However, the reliability remains poor and the variability of pubic symphysis morphology related to bone degeneration seems to be an unavoidable limit of the method

Tau protein in cerebrospinal fluid: a novel biomarker of the time of death?

International audienceBackground: Tau proteins are recognized biomarkers of neurodegeneration and neuronal damage in the cerebrospinal fluid (CSF). It has also been suggested that these CSF proteins could increase post-mortem due to neuronal death. The aim of this study was to investigate the changes in CSF total and phosphorylated tau (p-tau) levels in the early post-mortem interval (PMI), to determine whether these proteins could be relevant biomarkers of time since death.Methods: Tau and p-tau levels were measured by ELISA in lumbar and cisternal CSF samples from 82 corpses (46 men, 36 women, mean age: 72.4 ± 15.2 years) with a PMI 6 h versus PMI ≤ 6 h, the discriminatory power of the biomarkers being higher in the subgroup of neurologically healthy patients. Based on cut-off values obtained by ROC curve analysis, the CSF biomarkers could rectify or adjust the time interval provided by the temperature-based methods in a significant number of cases. A predictive model combining tympanic temperature and cisternal tau values was found to be particularly accurate to assign individuals according to their PMI (≤ or > 6 h), with a Se of 83% and a Sp of 100% (AUC = 0.95).Conclusion: Our findings suggest that CSF tau and p-tau proteins could serve as potential biomarkers of time since death, in association with tympanic temperature. The practical applicability of such an integrated approach has to be assessed by further studies

Paradoxical (REM) sleep deprivation in mice using the small-platforms-over-water method: polysomnographic analyses and melanin-concentrating hormone and hypocretin/orexin neuronal activation before, during and after deprivation

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Glacier, permafrost and thermokarst interactions in Alpine terrain: Insights from seven decades of reconstructed dynamics of the Chauvet glacial and periglacial system (Southern French Alps)

International audienceThis study analyses the long-term dynamics in the Chauvet glacial and periglacial system (southern French Alps) over seven decades (1948-2020), where several lake outburst floods have been documented since 1930. To accurately describe an

Cytokines as new biomarkers of skin wound vitality

International audienceBackground: The diagnosis of skin wound vitality is currently based on standard histology, but histological findings lack sensitivity in case of a short survival time. New reliable biomarkers of vitality are therefore strongly needed. We assessed the ability of 10 candidate cytokines (IFN-γ, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, TNF-α) to discriminate between vital and early post-mortem wounds.Methods: Twenty-four cadavers with a recent open skin wound (< 3 h) were included (20 men, 4 women, mean age = 51.0 ± 24.3 years). An early post-mortem wound was performed in an uninjured skin area, and both wounds were sampled at the autopsy (post-mortem interval (PMI) = 66.3 ± 28.3 h). Needle-puncture sites related to resuscitation cares were included as very early post-mortem wounds (n = 6). In addition to standard histology, cytokines levels were simultaneously measured in each sample using a multiplex sandwich immunoassay, then normalized on healthy skin levels. A quantitative evaluation of IL-8-positive cells in ante- and post-mortem wound samples was also performed.Results: In the training set of samples (n = 72), cytokine levels were significantly higher in vital wounds (mean age = 47 ± 53 min) than in post-mortem wounds (mean PMI = 6.9 ± 9.0 h) (p < 0.2), except for two cytokines (IFN-γ and IL-2). IL-8 was the best discriminatory cytokine (Se = 54%, Sp = 100%, AUC = 0.79), while a multivariate model combining IL-4 and IL12p70 was a bit more discriminant (Se = 55%, Sp = 100%, AUC = 0.84). In the validation set (n = 72), the discriminatory power of the cytokines and the predictive model was slightly lower, with IL-8 remaining the best cytokine (Se = 46%, Sp = 96%, AUC = 0.75). The predictive model remained highly specific (Sp = 100%). Both the cytokines and the predictive model allowed the iatrogenic injuries to be correctly classified as post-mortem wounds. Standard histology and immunohistochemistry showed 21% sensitivity and a specificity of 79% and 100%, respectively. Only two iatrogenic wounds could be properly categorized histologically.Conclusion: This study suggests that cytokines could be useful biomarkers of skin wound vitality and that the immunoassay method could be more sensitive than immunohistochemistry to identify wounds with a short survival time. Further research is underway to confirm these preliminary data