Forensic estimation of post-mortem interval by means of the spectrophotometric method of cerebrospinal fluid research

Obtaining the most accurate information about an object during its evaluation is one of the most urgent tasks of current forensic medical examination. That is why the application of new technologies in forensic medical expertise becomes an integral part of the technological support of forensic examination institutions. Purpose: To compare the effectiveness of cerebrospinal fluid polycrystalline films, microscopic images, two-dimensional Stokes-polarimetry, and autofluorescent polarimetry in post-mortem interval estimation over long- and short-term time intervals. Material and methods. The object of the study is cerebrospinal fluid donated from 70 corpses (experimental group) and 20 living persons (control group). Methods used: two-dimensional Stokes-polarimetry, autofluorescent polarimetry. Results: Quantitative characteristics of the cerebrospinal fluid’s polycrystalline films statistical moments allows us to establish relations between them and the duration of the post-mortem interval at a significant time interval. However, this method does not consider the morphology of the film of the cerebrospinal fluid and its coordinate structure. In contrast to this method, fluorescence microscopy considers the biochemical composition of the biological fluid and carries information about the concentration of molecular complexes of proteins, NADH, flavins, porphyrins, etc. In the early post-mortem period, changes in the cerebrospinal fluid begin precisely with changes in the concentration of biochemical compounds, and crystalline changes are secondary, so it can be argued that this method is most effective for diagnosing the progression of the time in the first hours after death. Conclusions: Fluorescent laser polarimetric methods allow accurate estimation of the postmortem interval during the first hours after death. While, the polarization methods is more effective during the long-term periods of time, but has less precision.

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Relationship between post-mortem interval and creatine concentration in vitreous humour and cerebrospinal fluid

Australian Journal of Forensic Sciences ◽

10.1080/00450618.2013.824027 ◽

2013 ◽

Vol 46 (2) ◽

pp. 160-165 ◽

Cited By ~ 6

Author(s):

Tomoyo Takata ◽

Takashi Kitao ◽

Satoru Miyaishi

Keyword(s):

Cerebrospinal Fluid ◽

Vitreous Humour ◽

Post Mortem ◽

Post Mortem Interval

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POST-MORTEM INTERVAL ESTIMATION USING POLYCRYSTALLINE CEREBROSPINAL FLUID FILMS TWO-DIMENSIONAL CARTOGRAPHY OF MUTUAL LASER POLARIZATION DISTRIBUTION LEVELS

CBU International Conference Proceedings ◽

10.12955/cbup.v6.1267 ◽

2018 ◽

Vol 6 ◽

pp. 892-897

Author(s):

Marta Garazdiuk ◽

Oleh Wanchuliak ◽

Oleksandr Pavlyukovich ◽

Natalia Pavlyukovich ◽

Oleksandr Garazdiuk

Keyword(s):

Cerebrospinal Fluid ◽

Large Scale ◽

Interval Estimation ◽

Diagnostic Methods ◽

Two Dimensional ◽

Post Mortem ◽

Polycrystalline Films ◽

Fluid Films ◽

Microscopic Images ◽

Post Mortem Interval

Post-mortem interval estimation is one of the most important issues in forensic practice. Optical diagnostic methods of biological tissue structure assessment are perspective in this area.The objects of investigation are polycrystalline films of cerebrospinal fluid, taken from 64 corpses with accurately known times of death and 15 healthy volunteers.The method of two-dimensional stokes-polarimetric mapping of distributions of a complex degree of mutual polarization with spatial-frequency filtration of microscopic images of cerebrospinal fluid films in the time monitoring of post-mortem changes in optical manifestations of polycrystalline networks has been tested in order to estimate the post-mortem interval. The most sensitive post-mortem changes in the optical manifestations of polycrystalline cerebrospinal fluid networks are revealed - statistical moments of the third and fourth orders that characterize the asymmetry and the excess (severity of the peak) of the distributions of values of the complex degree of mutual polarization of large-scale components of cerebrospinal fluid polycrystalline films microscopic images.An interval of 48 hours with the accuracy of the post-mortem interval estimation in ± 30 minutes were established by the method of two-dimensional mapping of distributions of the values of a complex degree of mutual polarization of large-scale component of cerebrospinal fluid films microscopic images.

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Evaluating the utility of time-lapse imaging in the estimation of post-mortem interval: An Australian case study

Forensic Science International Synergy ◽

10.1016/j.fsisyn.2019.08.003 ◽

2019 ◽

Vol 1 ◽

pp. 204-210 ◽

Cited By ~ 1

Author(s):

Alyson Wilson ◽

Stanley Serafin ◽

Dilan Seckiner ◽

Rachel Berry ◽

Xanthé Mallett

Keyword(s):

Time Lapse ◽

Post Mortem ◽

Post Mortem Interval ◽

Australian Case ◽

Time Lapse Imaging

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Impact of Comingled Heterospecific Assemblages on Developmentally Based Estimates of the Post-Mortem Interval—A Study with Lucilia sericata (Meigen), Phormia regina (Meigen) and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae)

Insects ◽

10.3390/insects12040280 ◽

2021 ◽

Vol 12 (4) ◽

pp. 280

Author(s):

Krystal R. Hans ◽

Sherah L. Vanlaerhoven

Keyword(s):

Growth Rate ◽

Development Time ◽

Lucilia Sericata ◽

Phormia Regina ◽

Calliphora Vicina ◽

Immature Stages ◽

Post Mortem ◽

Blow Fly ◽

Blow Flies ◽

Post Mortem Interval

Estimates of the minimum post-mortem interval (mPMI) using the development rate of blow flies (Diptera: Calliphoridae) are common in modern forensic entomology casework. These estimates are based on single species developing in the absence of heterospecific interactions. Yet, in real-world situations, it is not uncommon to have 2 or more blow fly species developing on a body. Species interactions have the potential to change the acceptance of resources as suitable for oviposition, the timing of oviposition, growth rate, size and development time of immature stages, as well as impacting the survival of immature stages to reach adult. This study measured larval development and growth rate of the blow flies Lucilia sericata (Meigen, 1826), Phormia regina (Meigen, 1826) and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae) over five constant temperatures (15, 20, 25, 30, 35 °C), in the presence of conspecifics or two-species heterospecific assemblages. Temperature and species treatment interacted such that L. sericata larvae gained mass more rapidly when in the presence of P. regina at 20 and 30 °C, however only developed faster at first instar. At later stages, the presence of P. regina slowed development of L. sericata immatures. Development time of C. vicina immatures was not affected by the presence of P. regina, however larvae gained mass more slowly. Development time of P. regina immatures was faster in the presence of either L. sericata or C. vicina until third instar, at which point, the presence of L. sericata was neutral whereas C. vicina negatively impacted development time. Phormia regina larvae gained mass more rapidly in the presence of L. sericata at 20 °C but were negatively impacted at 25 °C by the presence of either L. sericata or C. vicina. The results of this study indicate that metrics such as development time or larval mass used for estimating mPMI with blow flies are impacted by the presence of comingled heterospecific blow fly assemblages. As the effects of heterospecific assemblages are not uniformly positive or negative between stages, temperatures or species combinations, more research into these effects is vital. Until then, caution should be used when estimating mPMI in cases with multiple blow fly species interacting on a body.

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