尸温相关因素推断死亡时间的研究

目的 统计分析影响尸体温度下降多因素和死亡时间的相关性,探索尸温推断死亡时间的创新应用.方法 建立影响尸体温度(直肠温度)下降相关因素的采集标准,收集实践工作中的157例明确死亡时间真实案例的相关数据,根据实际工作经验结合统计学的基本要求对各因素进行量化评分,利用EXCEL和SPSS软件对数据进行处理,采用多元线性回归的方法统计分析各影响系数同死亡时间的相关性.结果 获得了具有统计学意义的回归方程,Y=25.993+0.04X1+0.172X2+0.88X3+0.047X4+0.373X5+0.347X6-0.766X7,决定系数R2=0.876.结论 该方法为尸温推断死亡时间的创新应用,经测试可用于实际工作.     

SJDY-1型存储式电子压力计的设计与实现

地层压力测量是油气田开发过程中必不可少的工作。本文介绍了SJDY-1型存储式电子压力计的系统工作原理和系统结构组成,阐述了系统的软硬件设计,着重分析了系统的上位机程序,并给出了对系统实现非线性和温度补偿的方法。     

Abnormal Daily Temperature and Concern about Climate Change Across the United States

The relatively low level of concern about climate change among Americans has important implications for climate policy. While many studies have examined individual characteristics associated with climate change attitudes, fewer studies have considered the effects of environmental conditions on such attitudes. Here, we use two national samples of American adults to explore the impact of abnormal daily temperatures on levels of concern about climate change. We test the hypotheses that (1) abnormally warm temperatures, and (2) both abnormally warm and abnormally cool temperatures are associated with higher levels of concern. Using a generalized ordinal logit, we find that the quadratic form of deviation from mean temperature on the date of the survey is significantly associated with higher levels of concern, thus supporting the second hypothesis. We discuss several theoretical frameworks that may explain this result including availability bias, mental models, and implicit stimuli, and the implications for climate policy.     

Use of Postmortem Temperature Decay Response Surface Plots of Heat Transport in the Human Eye to Predict Time of Death

A finite element heat transfer model of the human eye was previously constructed and applied to experimental postmortem temperature decay curves collected in eyeballs of ten human bodies. The model was applied in the early postmortem period of 0–24 h under conditions of natural convection–radiation. Based upon this previous model, response surfaces for postmortem temperature decay were constructed based upon variable ranges of the natural convective–radiation heat transfer coefficient from 7–13 W/m² K, ambient temperatures of 10–33°C, and times of 0–24 h. Mathematical equations to describe these response surfaces have been developed. This response surface method is demonstrated for use by coroners/medical personnel to estimate time of death from recorded field temperature data collected over a 30‐min period. Sensitivity of the model to small changes in the key variable of ambient temperature is explored. The response surface model is applied to two cases of previously collected experimental eyeball temperature data. This response surface model method is only valid for constant surrounding temperatures, conditions of natural convection, no radiation effects, and postmortem times of 0–24 h.     

Tracking Movement and Temperature Selection of Larvae of Two Forensically Important Blow Fly Species Within a “Maggot Mass”

The current study responds to the lack of understanding about the temperatures experienced by individual blow fly larvae within “maggot masses.” The temperature selection of both aggregating (in a mass) and nonaggregating larvae was compared and their pattern of movement assessed. Infrared imaging determined the temperatures within a mass and in the vicinity of the constituent individual larvae, whose movements were tracked by dyeing their tissues red. Individual Chrysomya rufifacies larvae selected temperatures above 27°C, significantly higher than the temperature selected by Calliphora vicina larvae (24.5°C). However, this same difference was not seen within a mass, with both species selecting temperatures around 28°C. Larval movement in a mass was nonrandom, indicating that larvae actively select their position in a mass. Furthermore, larvae have a strong tendency to select the hottest part of a mass; therefore, maximum mass temperatures might provide a reliable proxy for the actual temperatures experienced by larvae.     

Maggot development during morgue storage and its effect on estimating the post-mortem interval

When insect evidence is obtained during autopsy, forensic entomologists make decisions regarding the effects of low-temperature (-1 degrees C to 4 degrees C) storage of the body and associated insects when estimating the post-mortem interval (PMI). To determine the effects of storage in a morgue cooler on the temperature of maggot masses, temperatures inside and outside of body bags containing a human cadaver and porcine cadavers (seven replicates) were measured during storage. Temperatures remained significantly higher (p<0.05) inside of the body bags relative to the cooler, and remained at levels sufficient for maggot feeding and development. If the assumption that no insect development takes place during preautopsy refrigeration is made, potential error rates in PMI estimation of 8.6-12.8% occur. The potential for blow fly larvae to undergo significant development while being stored in the morgue is a possibility that forensic entomologists should consider during an investigation involving samples collected from autopsy. Case and experimental evidence also demonstrate that substantial tissue loss can occur from maggot feeding during morgue storage.     

Estimating the Time of Death in Domestic Canines

Abstract:  Because 36.1% of U.S. households have dogs, the time of death (TOD) of dogs at crime scenes can be useful to forensic investigators. However, there are few published studies based on postmortem changes in dogs. This study, conducted indoors in still air at approximately room temperature, monitored the postmortem reduction in rectal, liver, brain, and aural temperatures in 16 dogs for 32 h after death. Graphs of temperature reduction were prepared to estimate the TOD of dogs within the first 32 h postmortem. Sex, body mass, and hair coat density did not affect the rate of body temperature reduction, but increased body weight and volume slowed it. Rectal temperature was the most convenient, reasonable site for measuring body temperature. Vitreous humor potassium ion concentration [K⁺] was measured in both eyes at c.  1.5 and 7 h after death. Both eyes had the same [K⁺] when measured simultaneously, and [K⁺] increased after death.     

根据蛆长推断死亡时间的回归方程

用最小二乘法原理对有关数据进行处理，得出一个根据蛆长推断死亡时间的回归方程。并通过对一百余条成熟粪蛆的变蛹情况观察，利用该方程归纳出了蛹的生长情况所相当于的蛆长，扩大了推断方程的应用范围，可推断变蛹后的死亡时间。     

积温法则进行死亡时间推断

应用昆虫发育历期和积温法则推测死亡时间是法医学重要技术。本文对蝇蛆和蛹应用倒计积温的方法进行死亡时间推断,获得与实际死亡时间一致的结果。     

Comment on the Marshall-Hoare-Henssge model for estimating the time since death

Timewise temperature variations in objects that are undergoing unsteady heating or cooling is a commonly encountered problem in the thermal sciences. One particular area of application is the cooling of a body post-death and the use of body temperatures to estimate the time of death. Here, a new approach based on the theory of transient heat transfer is formulated to allow efficient calculation of unsteady conduction problems. The theoretically derived unsteady temperature models are compared with experimentally based correlations (the Marshall-Hoare-Henssge model). The two approaches are found to agree very well. With this new theoretically based approach, timewise temperature variation can be calculated for both large and small Biot number transient problems.