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M Hubig

Publications and source records attributed to M Hubig.

8 recordsLinked to original sources
PubMed2001

Sex determination and estimation of stature from the long bones of the arm.

The determination of sex and the estimation of stature from bones play an important role in identifying unknown bodies, parts of bodies or skeletal remains. In medico-legal practice statements on the probable sex of a decomposed body or part of a body are often expected even during autopsy. The present study was, therefore, restricted to few easily accessible dimensions from bones which were prepared only by mechanically removing soft tissues, tendons and ligaments. The specimens came from the Anatomical Institutes in Munich and Cologne from the years 1994-1998 including a total of 143 individuals (64 males and 79 females). The mean age was 79 years (46-108), the mean body height 161cm (134-189). The following measurements were taken: maximum humeral length (mean: 33.4cm in males; 30.7cm in females), vertical humeral head diameter (mean: 5.0cm in males, 4.4cm in females), humeral epicondylar width (mean: 6.6cm in males; 5.8cm in females), maximum ulnar length (mean: 26.5cm in males, 23.8cm in females), proximal ulnar width (mean: 3.4cm in males, 2.9cm in females), distal ulnar width (mean: 2.2cm in males; 1.8cm in females), maximum radial length (mean: 24.6cm in males; 22.0cm in females), radial head diameter (mean: 2.6cm in males, 2.2cm in females) and distal radial width (mean: 3.6cm in males; 3.2cm in females). The differences between the means in males and females were significant (P<0.0005). A discriminant analysis was carried out with good results. A percentage of 94.93% of cases were correctly classified when all measures of the radius were applied jointly, followed by humerus (93.15%) and ulna (90.58%). Applied singly, the humeral head diameter allowed the best distinction (90.41% correctly grouped cases), followed by the radial length (89.13%), the radial head diameter (88.57%) and the humeral epicondylar width (88.49%). The linear regression analysis for quantifying the correlation between the bone lengths and the stature led to unsatifactory results with large 95%-confidence intervals for the coefficients and high standard errors of estimate.

Adult↗
PubMed2000

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.

Autopsy↗
PubMed2000

Determination of sex from femora.

The determination of sex from bones or bone fragments considerably contributes to identifying unknown bodies or skeletal remains. Due to temporal change and regional differences anthropometric standards have to be constantly renewed. The present study provides measurements of femoral dimensions in a contemporary German population and analyses sexual dimorphism by discriminant analysis. Maximum length (male: 46.4+/-2.4 cm, female: 43.4+/-2.4 cm), maximum midshaft diameter (male: 3.1+/-0.2 cm, female: 2.8+/-0.2 cm), condylar width (male: 8.4+/-1.0 cm, female: 7.7+/-0.5 cm), vertical head diameter (male: 4.9+/-0.3 cm, female: 4.4+/-0.3 cm), head circumference (male: 15.7+/-0.8 cm, female: 13.8+/-1.0 cm) and transverse head diameter (male: 4.9+/-0.3 cm, female: 4.3+/-0.3 cm) were measured in 170 femora, 100 from male (age: 16-92 years, mean: 60.8 years; body height: 153-190 cm, mean: 171 cm) and 70 from female (age: 20-96 years, mean: 72 years; body height: 146-175 cm, mean: 161 cm) individuals. In the discriminant analysis (leave-one-out-method) 67.7% of cases could be grouped correctly with the maximum length alone, 72.4% with the maximum midshaft diameter, 81.4% with the condylar width, 86.8% with the vertical head diameter, 87.7% with the head circumference and 89.6% with the transverse head diameter. The stepwise procedure with all head measurements showed that the results for the transverse head diameter could not be improved. With all measurements subjected to stepwise procedure 91.7% of cases could be classified correctly combining midshaft diameter and head circumference (D=3.012xmidshaft diameter in cm+0.780xhead circumference in cm 20.569).

Adolescent↗
PubMed1999

Energy loss due to radiation in postmortem cooling. Part B: Energy balance with respect to radiation.

With the help of the law of Stefan and Boltzmann and a model for the cooling of exposed skin derived from the data of Lyle and Cleveland, the radiation energy loss ER can be calculated according to the following formula: [formula in text] where epsilon represents the emissivity of the skin (0.98), sigma the Stefan-Boltzmann constant, AR the radiating surface area, TS(0) the skin temperature at death, TE the environmental temperature and Z' = 0.1017 the gradient of the skin temperature curve. Additionally, an energy loss due to conduction and convection EC has to be taken into account. Comparing the energy losses due to radiation, conduction and convection with the decrease ET of the thermal energy in the body, calculated from mean heat capacity (3.45 kJ/(kg degrees K)), body mass and decrease of mean body temperature, there is a surplus of energy in the very early postmortem period, which can be explained only by an internal source of energy EI. Alltogether the following balance equation can be formulated: ET + EI = ER + EC Since the body temperature decreases in the early postmortem period, EI can be estimated by: EI(t) > or = max (ER(t) - ET(t), 0). The values obtained range up to 500 kJ for a medium sized (175 cm), medium weight (75 kg) body at an environmental temperature of 5 degrees C and are compatible with estimations of Lundquist for supravital energy production by breakdown of glycogen.

Body Mass Index↗
PubMed1999

The significance of the anatomy of the skull base for mechanical modelling: a comparative study.

The present paper aims at analysing the significance of the anatomical structures of the human skull base for mechanical modelling. Three different Finite-Element (FE)-models of the human neurocranium were developed. The most complex model (1242 solid cuboid elements) contains holes and spaces functionally simulating the foramina and fissures and additional element layers for the inner relief of the skull base (petrous temporal and sella). Of the less complex models, one (1256 solid cuboid elements) includes only the 3 cranial fossae, while the other (400 solid cuboid elements) represents a rotationally symmetrical ellipsoid with a hole for the foramen magnum. Two linear static loadcases, one with a transverse loading direction (pressure of 250 kg on the left temporal surface, bearing on the right temporal surface) and the other with a sagittal loading direction (pressure of 250 kg on the frontal surface, bearing on the occipital surface) were computed. The loadcase analyses show, qualitatively and quantitatively, similar equivalent von Mises stress values and distributions in the two more complex models while the elementary geometric model leads to significantly different absolute stress values and distributions. The results of the most complex model are highly compatible with experimental observations on transverse and sagittal fractures of the skull base.

Biomechanical Phenomena↗
PubMed1998

Energy loss due to radiation in postmortem cooling. Part A: quantitative estimation of radiation using the Stefan-Boltzmann law.

Conduction and convection are assumed to account for most of the energy loss from the dead body to the (cooler) environment. There are no quantitative estimations in the literature for the contribution of radiation to heat loss. The aim of the present paper was to estimate the radiation energy loss in postmortem cooling. The Stefan-Boltzmann law is used and combined with a single-exponential model for the cooling process of the skin derived from experimental data of Lyle and Cleveland (1956). The influence of various factors (e.g. skin temperature, environmental temperature, body mass and body height) on the amount of radiation emitted was investigated. The radiation energy is quantitatively described as a function of time. The radiation energy loss ranged from approximately 200 kJ in small (165 cm) and lean (50 kg) bodies at room temperature (20 degrees C) to approximately 600 kJ in tall (185 cm) and over-weight (100 kg) bodies at outdoor temperature (5 degrees C) in the first hour postmortem.

Body Constitution↗
PubMed1997

Finite-element modeling of the human neurocranium under functional anatomical aspects.

Due to its functional significance the human skull plays an important role in biomechanical research. The present work describes a new Finite-Element model of the human neurocranium. The dry skull of a middle-aged woman served as a pattern. The model was developed using only the preprocessor (Mentat) of a commercial FE-system (Marc). Unlike that of other FE models of the human skull mentioned in the literature, the geometry in this model was designed according to functional anatomical findings. Functionally important morphological structures representing loci minoris resistentiae, especially the foramina and fissures of the skull base, were included in the model. The results of two linear static loadcase analyses in the region of the skull base underline the importance of modeling from the functional anatomical point of view.

Female↗