Morphology of Modern Arrowhead Tips on Human Skin Analog

Archery has experienced a recent resurgence in participation and has seen increases in archery range attendance and in children and young adults seeking archery lessons. Popular literature and movies prominently feature protagonists well versed in this form of weaponry. Periodic homicide cases in the United States involving bows are reported, and despite this and the current interest in the field, there are no manuscripts published on a large series of arrow wounds. This experiment utilizes a broad selection of modern arrowheads to create wounds for comparison. While general appearances mimicked the arrowhead shape, details such as the presence of abrasions were greatly influenced by the design of the arrowhead tip. Additionally, in the absence of projectiles or available history, arrowhead injuries can mimic other instruments causing penetrating wounds. A published resource on arrowhead injuries would allow differentiation of causes of injury by forensic scientists.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141548/1/jfo13502.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141548/2/jfo13502_am.pd

The Modern Compound Bow

Bows and arrows are ancient weapons that have risen and fallen as the preeminent armaments used by man. Because of the ubiquity of firearms, fatalities from archery injuries in the United States have radically declined. However, when deaths involving this weapon do present themselves, the paucity of reference materials can be a hurdle for forensic pathologists and other forensic scientists. This article will provide a brief history of the origins of the bow and the inception of the compound bow. Comparing and contrasting the structures comprising a traditional bow to those of the modern compound bow will provide insight into how these components function in unison to propel arrows.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141095/1/jfo13503.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141095/2/jfo13503_am.pd

Commode Cardiaâ Death by Valsalva Maneuver: A Case Series

The Valsalva maneuver is used in clinical medicine for the diagnosis and/or treatment of various cardiovascular conditions. It can also be used in activities of daily living, such as defecation. Due to the cardiovascular effects produced during the Valsalva maneuver, it may be contraindicated in certain medical conditions and could be a trigger of sudden cardiac death. The incidence and prevalence of death following Valsalva maneuver in the presence of underlying cardiovascular disease, or â commode cardia,â has not been examined. In 2012, the Wayne County Medical Examiner’s Office (Detroit, MI) investigated 21 deaths that occurred on the toilet, fourteen of which were due to cardiovascular disease. In another 31 deaths in the bathroom due to cardiovascular disease, the possibility that the decedent defecated immediately prior to death could not be excluded. Hence, the incidence of commode cardia in this population ranges from 2.3 to 7.4% of all cardiovascularâ related deaths.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134829/1/jfo13196_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134829/2/jfo13196.pd

Significant differences in postmortem heart weight before and after dissection using the short-axis dissecting method

Correctly assessing heart weight can be critical at postmortem examination. The current international guidelines advocate using the short-axis method in dissecting the heart and the heart weighed when the blood is emptied. However, it did not specify at what point the heart should be weighed or how the blood should be emptied. This study compared heart weights at three different time points during the heart examination (immediately after dissecting out of the pericardial sac with blood still in chambers, blood washed/removed from heart chambers without the heart opened, and the heart completely opened, blood emptied, and pad dried). This was to illustrate the variation in measurement and potential errors when the heart is weighed at different time of dissection. The results show that there were statistical and clinical significant differences between the heart weights at each weighing points. We recommend the heart to be completely dissected with any blood and residual washing/rinsing water emptied before being weighed. Although performed in this study, the effect of pad drying the heart on heart weight was not explored and was a limitation in this study

Identifying fatal head injuries on postmortem computed tomography using convolutional neural network/deep learning : a feasibility study

Postmortem computed tomography (PMCT) is a relatively recent advancement in forensic pathology practice that has been increasingly used as an ancillary investigation and screening tool. One area of clinical CT imaging that has garnered a lot of research interest recently is the area of “artificial intelligence” (AI), such as in screening and computer-assisted diagnostics. This feasibility study investigated the application of convolutional neural network, a form of deep learning AI, to PMCT head imaging in differentiating fatal head injury from controls. PMCT images of a transverse section of the head at the level of the frontal sinus from 25 cases of fatal head injury were combined with 25 nonhead-injury controls and divided into training and testing datasets. A convolutional neural network was constructed using Keras and was trained against the training data before being assessed against the testing dataset. The results of this study demonstrated an accuracy of between 70% and 92.5%, with difficulties in recognizing subarachnoid hemorrhage and in distinguishing congested vessels and prominent falx from head injury. These results are promising for potential applications as a screening tool or in computer-assisted diagnostics in the future

Postmortem vitreous humor magnesium does not elevate in salt water drowning when the immersion time is less than an hour

Background Elevation in postmortem vitreous humor sodium and chloride (PMVSC) in salt water drowning (SWD) when the immersion time is less than 1 hour (SWD1) is hypothesized to result from electrolyte changes in blood from salt water inhalation/ingestion during drowning. After approximately 1 hour after death, electrolytes may diffuse into the vitreous humor via the eye coverings. Another abundant element in salt water is magnesium, which is approximately 50 times higher in concentration than the blood and vitreous humor magnesium levels. Magnesium is able to diffuse across the eye coverings but not as easily through the blood-ocular barrier. With these properties, we hypothesize that postmortem vitreous magnesium (PMVM) would not be elevated in SWD1 but become elevated in SWD with immersion times greater than 1 hour (SWD>1). Aim The aim of this article was to investigate the differences in PMVM and PMVSC between nonimmersion deaths, SWD1, and SWD>1. Methods This is a 1-year retrospective study comparing PMVM and PMVSC in nonimmersion deaths, SWD1, and SWD>1. Results Postmortem vitreous magnesium is significantly higher in SWD>1 than SWD1 and nonimmersion deaths, with no significant difference between SWD1 and nonimmersion deaths. Postmortem vitreous humor sodium chloride is statistically higher in SWD1 and SWD>1 than nonimmersion deaths. Conclusions As a conclusion, PMVSC elevates and PMVM does not elevate in SWD1

Postmortem Vitreous Humor Magnesium Does Not Elevate in Salt Water Drowning When the Immersion Time Is Less Than an Hour

Background Elevation in postmortem vitreous humor sodium and chloride (PMVSC) in salt water drowning (SWD) when the immersion time is less than 1 hour (SWD1) is hypothesized to result from electrolyte changes in blood from salt water inhalation/ingestion during drowning. After approximately 1 hour after death, electrolytes may diffuse into the vitreous humor via the eye coverings. Another abundant element in salt water is magnesium, which is approximately 50 times higher in concentration than the blood and vitreous humor magnesium levels. Magnesium is able to diffuse across the eye coverings but not as easily through the blood-ocular barrier. With these properties, we hypothesize that postmortem vitreous magnesium (PMVM) would not be elevated in SWD1 but become elevated in SWD with immersion times greater than 1 hour (SWD>1). Aim The aim of this article was to investigate the differences in PMVM and PMVSC between nonimmersion deaths, SWD1, and SWD>1. Methods This is a 1-year retrospective study comparing PMVM and PMVSC in nonimmersion deaths, SWD1, and SWD>1. Results Postmortem vitreous magnesium is significantly higher in SWD>1 than SWD1 and nonimmersion deaths, with no significant difference between SWD1 and nonimmersion deaths. Postmortem vitreous humor sodium chloride is statistically higher in SWD1 and SWD>1 than nonimmersion deaths. Conclusions As a conclusion, PMVSC elevates and PMVM does not elevate in SWD1

Identifying gross post-mortem organ images using a pre-trained convolutional neural network

Identifying organs/tissue and pathology on radiological and microscopic images can be performed using convolutional neural networks (CNN). However, there are scant studies on applying CNN to post-mortem gross images of visceral organs. This proof-of-concept study used 537 gross post-mortem images of dissected brain, heart, lung, liver, spleen, and kidney, which were randomly divided into a training and teaching datasets for the pre-trained CNN Xception. The CNN was trained using the training dataset and subsequently tested on the testing dataset. The overall accuracies were >95% percent for both training and testing datasets and have an F1 score of >0.95 for all dissected organs. This study showed that small datasets of post-mortem images can be classified with a very high accuracy using a pre-trained CNN. This novel area has the potential for future application in data mining, education and teaching, case review, research, quality assurance, auditing purposes, and identifying pathology

Significant Differences in PostMortem Heart Weight Before and After Dissection Using the Short‐Axis Dissecting Method

Correctly assessing heart weight can be critical at postmortem examination. The current international guidelines advocate using the short-axis method in dissecting the heart and the heart weighed when the blood is emptied. However, it did not specify at what point the heart should be weighed or how the blood should be emptied. This study compared heart weights at three different time points during the heart examination (immediately after dissecting out of the pericardial sac with blood still in chambers, blood washed/removed from heart chambers without the heart opened, and the heart completely opened, blood emptied, and pad dried). This was to illustrate the variation in measurement and potential errors when the heart is weighed at different time of dissection. The results show that there were statistical and clinical significant differences between the heart weights at each weighing points. We recommend the heart to be completely dissected with any blood and residual washing/rinsing water emptied before being weighed. Although performed in this study, the effect of pad drying the heart on heart weight was not explored and was a limitation in this study

Higher heart weight in New Zealand Maori and Pacific Islanders

Heart weight is dependent on sex, age, height, and weight. Although previous autopsy studies showed no differences in heart weight between different ethnic groups, none have examined the New Zealand population of Māori and Pacific Islanders (Polynesians). The presented study compared heart weights between 101 European and 85 Polynesian suicide hanging deaths from New Zealand. Univariate linear regression coefficients for age, male sex, height, body weight, body mass index, and Polynesian ethnicity were positive and significant (P < 0.05). Apart from body mass index, subsequent multivariate analysis showed that all regression coefficients remained positive and significant (P < 0.05). Polynesian ethnicity seemed to be an independent predictor for increased heart weight in the study population. Apart from possible genetic factors, the higher heart weight in Polynesians may have other underlying reasons. Caution is required when interpreting heart weight in cases of sudden natural deaths, especially in this population