Biomedical subjects

N Lynnerup

Publications and source records attributed to N Lynnerup.

23 records · Page 2Linked to original sources

PubMed1993

A computer program for the estimation of time of death.

In the 1960s Marshall and Hoare presented a "Standard Cooling Curve" based on their mathematical analyses on the postmortem cooling of bodies. Although fairly accurate under standard conditions, the "curve" or formula is based on the assumption that the ambience temperature is constant and that the temperature at death is known. Also, Marshall and Hoare's formula expresses the temperature as a function of time, and not vice versa, the latter being the problem most often encountered by forensic scientists. A simple BASIC program that enables solving of Marshall and Hoare's equation for the postmortem cooling of bodies is presented. It is proposed that by having a computer program that solves the equation, giving the length of the cooling period in response to a certain rectal temperature, and which allows easy comparison of multiple solutions, the uncertainties related to ambience temperature and temperature at death can be quantified, substantiating estimations of time of death.

Body Temperature↗

PubMed1992

A computer program for planimetric analysis of digitized images.

Planimetrical measurements are made to calculate the area of an entity. By digitizing the entity the planimetrical measurements may be done by computer. This computer program was developed in conjunction with a research project involving measurement of the pneumatized cell system of the temporal bones as seen on X-rays. By placing the X-rays on a digitizer tablet and tracing the outline of the cell system, the area was calculated by the program. The calculated data and traced images could be stored and printed. The program is written in BASIC; necessary hardware is an IBM-compatible personal computer, a digitizer tablet and a printer.

Anthropometry↗

PubMed1992

CT-scanning of ancient Greenlandic Inuit temporal bones.

Additional morphological evidence of former infectious middle ear disease (IMED) was found by CT-scanning in 5 of 6 Greenlandic Inuit crania strongly suspected for former IMED due to earlier examination revealing either bilateral hypocellularity or asymmetry of the pneumatized area of the temporal bones. The CT-scans showed sclerosing and obliteration of the air cells and even destruction of the cellular septae, and a high degree of irregularity of the cells. Sclerosing of the surrounding bone tissue was also found. The findings in one cranium were dubious and could both be regarded as a congenital malformation or an infection in infanthood. CT-scan confirms and even adds to the results of conventional X-ray of temporal bones making hypotheses of paleopathology more reliable. The findings also support the environmental theory of pneumatization of the air cell system in the temporal bones.

Air↗

PubMed1991

Pneumatization of the temporal bones in a Greenlandic Inuit anthropological material.

The degree of pneumatization of the temporal bones correlates with exposure during childhood and adolescence to infectious middle ear diseases (IMED), both acute and chronic. The pneumatized area as seen on cranial X-rays can be measured. This was applied to an anthropological material in order to develop methods for assessing ancient populations' exposure to IMED. Fifty-six Greenlandic Inuit (Eskimo) crania were examined. The crania were sexed and measured. X-rays were taken bilaterally, using the projection of Runström II, and the pneumatized area was measured planimetrically by computer. In blind trials it was found that the inter- and intraobserver variation was non-significant; that the degree of pneumatization of the temporal ossa did not reflect cranial size or sexual dimorphism; and that the pneumatized areas correlated bilaterally. Asymmetry in the size of the pneumatized areas, an indicator of exposure to IMED, was found in 5 crania (9%).

Female↗

PubMed1990

A non-invasive technique for age at death determination.

Several methods for age at death determination of human skeletal remains have been developed. These methods have, especially in combination, proved to be useful in making individual identification of skeletal material in forensic cases. This study is based on the known correlation between actual age and structural changes in trabecular bone tissue. Using X-rays taken from live individuals, it provides a useful non-invasive ageing technique for the forensic examiner. An initial pilot study defined five phases of age-related changes in the trabecular tissue of the proximal end of the femur. A total of 60 X-rays, randomly selected, and covering an age span from 14 years to 94 years, were subsequently scored in blind trials. The results demonstrate a clear relationship between age and changes in the trabecular structures. Based on this relationship it is possible to obtain an age estimate by identification of one of the five phases. An exact age determination of a single individual was not possible, but could be approximated to within 20 years. In forensic cases, however, where the removal of soft tissue is not always possible, this method can contribute to the final age determination when used in conjunction with other well-known methods, and thereby strengthen the final age estimate.

Adolescent↗