A comprehensive regression tree to estimate body weight from the skeleton

The purpose of this research is to estimate actual body weight (in particular obesity) from the human skeleton. Known individuals (total n=187) were studied from the Bass Collection from the University of Tennessee, Knoxville. This research combines bone density, cross-sectional geometry of the femur and skeletal pathologies. Bone mineral density was calculated for the proximal femur. Three-dimensional bone surface models were created from computed tomographic scans. Cross-sectional geometry of the femur was calculated at five locations along the diaphysis. The pathologies analyzed were heel spurs, diffuse idiopathic skeletal hyperostosis (DISH), and tibial osteoarthritis. The best regression tree model included only four variables. The first split to estimate body weight was the minimum moment of inertia (I(y) ) at the distal femur, the second was midshaft width, then anteroposterior thickness at the proximal slice and the final split was the degree of DISH (SD 17.1-31.0 kg). The ability to estimate body weight from the skeleton is one more useful tool for the osteologist.     

Can whale-fall studies inform human forensics?

Experimental knowledge of human body decomposition in the deep ocean is very limited, partly due to the logistical challenges of deep-sea research. The literature on ecological responses to the arrival of naturally sunk and implanted whale carcasses on the seafloor represents a potential source of information relevant to questions of human body survival and recovery in the deep ocean. Whale falls trigger the formation of complex, localized, and dense biological communities that have become a point of interest for marine biologists for the past 2–3 decades. Researchers have documented whale falls by whale type, size, geographic location, water depth and water chemistry, and there have been some comparative analyses of decomposition rates and faunal presence on carcasses. We undertook a review and meta-analysis of the whale-fall literature to identify and statistically model trends relevant to human forensics. Results from studies using deep-sea cameras baited with pig carcasses and simulated carrion provided further validation of noted trends. The stages of whale carcass decomposition most relevant to human forensics are those characterised by mobile scavengers that strip the soft tissues from carcasses, and to a lesser degree, other biota that degrade skeletal material. Our statistical models used the number of faunal taxa attracted to the whale carcasses as a measure of the ecological response and the potential rate of decomposition. Negative binomial models identified significant influences of carcass age and dissolved oxygen concentration on the ecological response (taxon numbers). The strongest environmental effects were identified in data from experimental studies that implanted whale carcasses across a broad range of dissolved-oxygen conditions. We propose directions for further experimental research to refine models of environmental controls on decomposition in the deep sea. Our results also highlight the potential use of publicly available global databases on environmental conditions in the deep ocean for informing body scavenging activity and thus body survival. Applying a forensic lens to whale-fall studies provides a window into an otherwise unseen world from the standpoint of human forensic taphonomy.     

Forensic Biomechanical Analysis of Falls from Height Using Numerical Human Body Models*

Abstract: This article describes the method of using human body models developed originally for the use in automotive safety in forensic reconstructions of falls from height. The MADYMO^® software package and multibody human body models were used in forensic analyses of two real cases—a fatal fall from a window c. 13.8 m above the ground and a fall into a c. 2.5‐m deep cellar pit resulting in isolated ankle joint injury. The performed series of numerical simulations helped to reconstruct the events and to resolve legally relevant questions concerning various aspects of the falls. The benefits as well as limitations and potential biases associated with the use of numerical simulation in forensic biomechanical settings are discussed. The method has proven to be effective under specific circumstances, though the cost (both financial and temporal) still prevents it from wider use.     

Cardiac Changes Due to Electronic Control Devices? A Computer‐Based Analysis of Electrical Effects at the Human Heart Caused by an ECD Pulse Applied to the Body's Exterior

Electronic control devices (ECDs) deliver high‐voltage, low‐current energy pulses temporarily paralyzing a person. For the ECD–human interaction, we have developed a computer model using the SEMCAD program within which to simulate the electrical effects throughout the body resulting from the imposition of an ECD pulse at a particular point on the body surface. Our human body models were based on cross‐sectional MRIs and CT scans, with the dielectric properties of the various tissues assigned based on previously published values. We simulated the application of a single ECD pulse and calculated the resulting electric field strength and current and charge densities at different body locations. The results were compared with corresponding values obtained by other researchers in similar simulations. Furthermore, we simulated an application of a pulse of 20‐millisecond duration equal to the European household current of 50 Hz and to the ventricular fibrillation threshold. The resulting current level indicated at the heart muscle was 1/5 the level considered the threshold for triggering ventricular fibrillation.     

Determination of the time of death according to rectal thermometry data using computer calculations

A mathematic model of estimation of time of death (TD) in newborns is proposed. This computer method of TD timing by changes of body temperature differs from earlier developed mathematical models by possibility to consider individual anthropometric and thermophysical characteristics of the body. It is more precise, shorter and easy to perform.     

有限元方法在交通损伤中的应用及其法医学前景

有限元方法(finite element method,FEM)是一种基于计算机技术的数值计算方法,目前已逐渐被应用于医学及生物力学领域。通过有限元分析,可以研究交通损伤中人体结构的受力过程分析和受伤机制,为交通损伤的法医学鉴定提供帮助。本文综述了近年来国内外在交通损伤中颅脑、颈椎、胸腹部、骨盆及四肢的有限元建模和分析进展。     

Determination of time-dependent skin temperature decrease rates in the case of abrupt changes of environmental temperature

The present study deals with the development of a method for determining time-dependent temperature decrease rates and its application to postmortem surface cooling. The study concentrates on evaluating skin cooling behavior since data on skin cooling in the forensic literature are scarce. Furthermore, all heat transfer mechanisms strongly depend on the temperature gradient between body surface and environment. One of the main problems in modelling postmortem cooling processes is the dependence on the environmental temperature. All models for postmortem rectal cooling essentially presuppose a constant environmental temperature. In medico-legal practice, the temperature of the surrounding of a corpse mostly varies; therefore, an approach for extending the models to variable environmental temperatures is desirable. It consists in 'localizing' them to infinitesimal small intervals of time. An extended model differential equation is obtained and solved explicitly. The approach developed is applied to the single-exponential Newtonian model of surface cooling producing the following differential equation:T(S)'(t)=-lambda(t)(T(S)(t)-T(E)(t))(with T(S)(t) the surface/skin temperature, T(E)(t) the environmental temperature, lambda(t) the temperature decrease rate and T(S)'(t) the actual change of skin temperature or first-order derivative of T(S)). The differential equation directly provides an estimator:lambda(t)=-T(S)'(t)T(S)(t)-T(E)(t)for the time-dependent temperature decrease rate. The estimator is applied to two skin cooling experiments with different types of abrupt changes of environmental temperature, peak-like and step-like; the values of the time-dependent temperature decrease rate function were calculated. By reinserting them, the measured surface temperature curve could be accurately reconstructed, indicating that the extended model is well suited for describing surface cooling in the case of abrupt changes of environmental temperature.     

Offshore Wind: Government Control and the Regulatory Landscape

The open ocean, especially off the eastern seaboard of the United States, presents a significant opportunity for the generation of electricity with the development of offshore wind projects. The first offshore wind project commenced operation during 2016 with a five-turbine project in Rhode Island. It is anticipated this is the first of many offshore wind projects that are expected along the East Coast of the United States. The legal and regulatory landscape for the development of offshore wind projects is complex and expensive. Projects are typically fifteen miles offshore where the federal government has jurisdiction and is responsible for leasing the ocean bottom for projects. Additionally, the U.S. Army Corps of Engineers has jurisdiction with regard to the disturbance of the ocean bottom. The state's jurisdiction commences within three miles of the coast, where the principal role for the states will be permitting for transmission lines both offshore and onshore.     

The Influence of Preburial Insect Access on the Decomposition Rate

Abstract: This study compared total body score (TBS) in buried remains (35 cm depth) with and without insect access prior to burial. Sixty rabbit carcasses were exhumed at 50 accumulated degree day (ADD) intervals. Weight loss, TBS, intra‐abdominal decomposition, carcass/soil interface temperature, and below‐carcass soil pH were recorded and analyzed. Results showed significant differences (p << 0.001) in decomposition rates between carcasses with and without insect access prior to burial. An approximately 30% enhanced decomposition rate with insects was observed. TBS was the most valid tool in postmortem interval (PMI) estimation. All other variables showed only weak relationships to decomposition stages, adding little value to PMI estimation. Although progress in estimating the PMI for surface remains has been made, no previous studies have accomplished this for buried remains. This study builds a framework to which further comparable studies can contribute, to produce predictive models for PMI estimation in buried human remains.     

Response surface methodology and improved interval analysis method-For analyzing uncertainty in accident reconstruction

Methods used to calculate intervals of accident reconstruction results are research hotspot in the word. The response surface methodology-interval analysis method (RSM-IAM) is a useful method for analyzing uncertainty of simulation results in this field, but there are two problems in this method because of the interval extension problem and inaccurate response surface models. In order to tackle these two problems, based on subinterval analysis thought and response surface methodology, an improved interval analysis method (RSM-IIAM) is proposed. In RSM-IIAM, the stepwise regression technique is used to obtain a reasonable response surface mode of the simulation model; and then, intervals of uncertain parameters are divided into several subintervals; after that, intervals of simulation results in accident reconstruction are calculated according to these subintervals. Finally, four numerical cases were given. Results showed that the RSM-IIAM is simple and high accuracy, which will be useful in analyzing uncertainty of simulation results in accident reconstruction.     

Rates of putrefaction of dental pulp in the Northwest coast environment

Cytological stability is of interest to criminal investigators in instances where remnants of soft tissue have been preserved, since such tissue can aid in the identification of human remains, helping to determine either the sex of the individual or his or her identity. This study based on seven experiments shows that, in Northwest coast outdoor environments in both summer (three experiments) and winter (three experiments), the stability of dental pulp nuclei ranges from 4 days to 2 weeks. The seventh experiment serves to describe the morphological sequence observed in nuclear putrefaction. The specimens included human and pig extracted teeth and unextracted pig teeth. Deposition of the specimens was made both on the surface and in the subsurface (30-cm depth), and the environmental variables were recorded.     

Evaluating Simulant Materials for Understanding Cranial Backspatter from a Ballistic Projectile

In cranial wounds resulting from a gunshot, the study of backspatter patterns can provide information about the actual incidents by linking material to surrounding objects. This study investigates the physics of backspatter from a high‐speed projectile impact and evaluates a range of simulant materials using impact tests. Next, we evaluate a mesh‐free method called smoothed particle hydrodynamics (SPH) to model the splashing mechanism during backspatter. The study has shown that a projectile impact causes fragmentation at the impact site, while transferring momentum to fragmented particles. The particles travel along the path of least resistance, leading to partial material movement in the reverse direction of the projectile motion causing backspatter. Medium‐density fiberboard is a better simulant for a human skull than polycarbonate, and lorica leather is a better simulant for a human skin than natural rubber. SPH is an effective numerical method for modeling the high‐speed impact fracture and fragmentations.     

Measuring Desiccation Using Qualitative Changes: A Step Toward Determining Regional Decomposition Sequences

The creation of a regional decomposition scoring system for western Colorado provides a model for the creation of regional systems. The development of a scoring system requires: (1) human remains, not proxies, (2) longitudinal observations, and (3) large sample size. First, an enhanced system (total body desiccation score; TBDS) was developed through observations of 40 human remains. This effort produced a categorical scoring model augmented by qualitative categories of gross tissue change. The new model was tested with retrospective photographic packets. A sample of eight donors with data collected over 3 years was selected. Monthly data points over a maximum of a 3‐year period yielded 112 data points. Correlations between TBDS and accumulated degree‐days (ADD), and total body score (TBS) and ADD were approximately equal for a TBS below ~20, but the TBDS correlated better with ADD at higher TBS scores >20. The TBDS may be used to refine postmortem interval (PMI) models in areas where remains desiccate.     

Predicting the postmortem interval using human intestinal microbiome data and random forest algorithm

Gradual changes in microbial communities in a human body after death can be used to determine postmortem interval (PMI). In this study, gut microflora samples were collected from the vermiform appendix and the transverse colon of human cadavers with PMIs between 5 and 192 h. The results revealed that the appendix might be an excellent intestinal sampling site and the appendix flora had an inferred succession rule during human body decomposition. Firmicutes, Bacteroidetes, and their respective subclasses showed a predictable succession rule in relative abundance over time. A Random Forest regression model was developed to correlate human gut microbiota with PMI. We believe that our findings have increased the knowledge of the composition and abundance of the gut microbiota in human corpses, and suggest that the use of the human appendix microbial succession may be a potential method for forensic estimation of the time of death.     

Observations and 3D Analysis of Controlled Cast-Off Stains

Cast-off stains are common patterns found at crime scenes involving blood shedding events. However, the analysis and interpretation of cast-off patterns remains an area lacking tools for crime scene investigators. Analyzing cast-off patterns may allow investigators to interpret the area from where an object may have been swung and thus determine the approximate location of a suspect or victim. This study looked at the position and distribution of cast-off patterns and area of origin as a starting point for the development of a method to analyze cast-off patterns. Through a series of tests using a controlled cast-off rig (n = 10), it was observed that a Path Volume Envelope (PVE) may be identified where the swinging path is contained in a volume along with an area of exclusion. The calculated center, linear position of the PVE was found to have an average error of just over 3.2 cm when compared to the known object swing path position. The maximum deviation of the PVE to the known swing path was found to be 5.0 cm with a standard deviation of 1.4 cm. Additional studies are required to investigate the effects of partial cast-off stains, wielded object velocity, direction of swing, distance from the projected surface, and other factors. The observations and analysis from this study were seen to be predictable and repeatable and may provide a possible new method for investigators to interpret cast-off stains.     

一个案例引发的思考——海上货物运输中“电放”法律问题探究

在海上货物运输中,提单通常是承运人在目的港交付货物的凭证,如果承运人无正本提单放货,则要承担相应的民事责任。在电放的情况下,承运人应当如何在目的港交付货物,没有相应的法律法规之规定,进而导致理论观点不一,判决各异。通过青岛泰达集团进出口有限公司诉青岛大通联运国际货运代理有限公司海上货物运输合同纠纷案,从电放概念入手,层层剖析电放情况下承运人在目的港交付货物的义务和责任。