Search PubMed⌕ Search

Biomedical subjects

D P Van Gerven

Publications and source records attributed to D P Van Gerven.

At least 19 recordsLinked to original sources
PubMed1997

Patterns of femoral bone remodeling dynamics in a Medieval Nubian population.

The relationship between age, sex and histomorphometry in femoral cortical bone was examined in a skeletal population of late Medieval antiquity (AD 1250-1450) from Kulubnarti, in Sudanese Nubia. These skeletal remains are naturally mummified and in an excellent state of preservation. The study sample consisted of femoral cross sections from 24 females and 19 males ranging in age from 20 to 50+ years. Femoral cross sections were examined using an image analysis system. Numbers of secondary osteons and osteon fragments were counted, osteon area and Haversian canal area were measured, and several variables were calculated to assess differences between sexes and among age groups in bone remodeling variables. The results indicate significant differences between the sexes in osteon number and size. Males had significantly more intact osteons than females, whereas females had significantly larger osteons than males. Haversian canal dimensions were not statistically significant between the sexes. Sex differences in activity patterns in which males were involved in more physically strenuous tasks may have contributed to differences in remodeling variables. Interpopulational comparisons suggest that mechanical strain affects the microstructural features examined in this study. In particular, small Haversian canals in some archaeological skeletal populations are associated with higher bone volume, which may result from high levels of mechanical strain.

Adult↗
PubMed1994

Developmental, diachronic, and demographic analysis of cribra orbitalia in the medieval Christian populations of Kulubnarti.

Previous analysis of cribra orbitalia in the medieval populations of Kulubnarti focused only on the presence or absence of the lesion relative to age, sex, and cultural period. Demographic consideration of the lesion was limited to a gross comparison of lesion frequencies and probabilities of dying by age group. The scope of the earlier work has been expanded in the present research to include the consideration of cribra orbitalia from a developmental, demographic, and diachronic perspective. The sample consisted of the same 334 crania analyzed by Van Gerven et al. ([1981] J. Hum. Evol. 10:395-408). All skulls showing the lesion were dichotomized as active or healing, and separate life tables were constructed for those with lesions and those without. The results demonstrate that active lesions are confined entirely to infancy and childhood with formation beginning as early as six months and ending by the twelfth year. This childhood pattern is consistent with the iron deficiency anemia hypothesis proposed by Carlson et al. ([1974] J. Hum. Evol. 3:405-410). Among young adults (16-40), healing lesions occur more frequently in males than females. In the older age categories, however, females exhibit a higher frequency of partially healed lesions than males. A life table comparison of those with and those without cribra orbitalia reveals a dramatic reduction in mean life expectancy for those with the lesion across the formative childhood years (birth-16). This reduction peaks at age 5 where 78% of the children exhibit lesions and where they, as a group, have a mean life expectancy 15.5 years below those without the lesion.

Anemia, Hypochromic↗
PubMed1992

Obstetric dimensions of the true pelvis in a medieval population from Sudanese Nubia.

Functional analysis of the true pelvis (defined as that portion lying below and including the pelvic brim) was undertaken on a sample of 36 females from the Medieval site of Kulubnarti in Sudanese Nubia. Standard obstetric measurements were taken and compared to four additional prehistoric skeletal samples and to modern American standards for the same obstetric dimensions. Relative to the other prehistoric populations, the Kulubnarti pelves are smaller in most dimensions and, when compared to modern American standards, from one-third to one-half would be diagnosed as contracted in one or more planes. Given the meager, fluctuating resources of these Medieval Nubians' harsh desert environment, pelvic size reduction is a likely result of body size reduction as one biological response to nutritional stress (Mittler and Van Gerven, 1989; Moore et al., 1986; Van Gerven et al., 1981). It is argued, however, that size reduction created a high potential for either maternal-neonatal morbidity and mortality due to fetopelvic disproportion or neonatal loss due to low birth weight. In either case, it is suggested that the Kulubnarti population paid a significant biological price for this aspect of size reduction.

Adult↗
PubMed1991

Biomechanical association of dental and temporomandibular pathology in a medieval Nubian population.

An analysis of the relationship between oral pathology and degenerative change at the temporomandibular joint (TMJ) was undertaken on an archaeological sample of 122 adult crania from the Medieval site of Kulubnarti in Sudanese Nubia. The crania were sorted into 2 groups: those demonstrating clearly visible bony changes at the joint (TMJ+) and those without visible change (TMJ-). These groups were compared according to 1) age; 2) sex; 3) active dental pathologies (abscesses, caries, partial socket resorption); 4) tooth loss with complete socket resorption; and 5) dental attrition. No statistically significant association was evident between degenerative change at the TMJ and age, active dental pathologies, or dental attrition; however, sex differences and posterior tooth loss with complete socket resorption revealed a significant correspondence to degenerative TMJ changes. Both of these factors agree with the clinical literature and with biomechanical models (most notably that of Hylander) based upon modern populations. Furthermore, the results support the contention that paleopathological conditions can be analyzed from a clinical and functional biomechanical perspective.

History, Medieval↗
PubMed1990

Patterns of enamel hypoplasia in two medieval populations from Nubia's Batn el Hajar.

Analysis of enamel hypoplasia frequencies for two medieval populations representing the earliest and latest Christian periods of ancient Nubia reveals important diachronic shifts in childhood stress. The mean frequency for hypoplastic bands among the early Christians is 4.2, while the late Christian sample has a mean frequency of 3.7. In addition, the earlier Christians show a prolongation of hypoplastic occurrences through childhood corresponding to a prolonged period of intensified childhood mortality. The modal time interval between hypoplastic occurrences is also shorter for the early Christian children. A comparison of hypoplasia frequencies by sex also reveals a pattern of considerable interest. Females show both lower frequencies of hypoplasias as well as a delay in onset. The diachronic differences are consistent with other indications from paleopathology and paleodemography that childhood stress decreased in later Christian times. The sex differences suggest that during the infancy and early childhood females were more resilient than their male counterparts.

Age Factors↗
PubMed1985

Cortical bone maintenance and geometry of the tibia in prehistoric children from Nubia's Batn el Hajar.

The relationship between advancing age in adults and patterns of cortical bone maintenance has been extensively documented for archaeological populations (Dewey, et al., 1969; Van Gerven et al., 1969; Perzigian, 1973). Most recently, this research has been expanded to include a more thorough consideration of the geometric properties of bone in relationship to adult age changes (Martin and Atkinsin, 1977; Ruff and Hayes, 1983). To date, however, few studies have documented subadult patterns of cortical bone maintenance in archaeological populations and none have incorporated the relationship between patterns of cortical bone loss and gain and the changing geometric properties of growing bone. Using a sample of 172 tibias from children excavated from the Medieval Christian site of Kulubnarti, located in Nubia's Batn el Hajar, the present research examines the relationship between percent cortical area, bone mineral content, and cross-sectional moments of inertia. Among these children, bone mineral content increases steadily from birth in spite of a reduction in percent cortical area during early and late childhood. It appears, therefore, that tissue quality of the bone is not adversely affected by the reduction. Furthermore, the reduction in percent cortical area in later childhood corresponds to a dramatic increase in bending strength measured by cross-sectional moments of inertia. Thus, whether this cortical reduction is due entirely or in part to either normal modeling or nutritional stress, the tissue and organ quality of the bone is not adversely affected.

Aging↗
PubMed1985

Observations on the formation and persistence of radiopaque transverse lines.

The formation and persistence of radiopaque transverse lines have been assessed in the living in clinical studies of growth, nutrition, and disease. Lines have also been used by many researchers in the analysis of patterns of childhood stress in prehistoric skeletal materials, although most of this research has been undertaken on adult bones. However, how reliable and useful are transverse lines for interpretations of stress? The precise etiologies for their appearance are varied and controversial, and lines are also known to resorb during both childhood and the adult years. Sex differences in both their formation and persistence have also been reported. To assess better the viability of lines as indicators of stress, the present research analyzes rates of formation, distribution frequencies, and the persistence of transverse lines in individuals aged birth to 50+ years from a single archaeological population. The results suggest that while transverse lines may be analytically useful as subsidiary criteria for more fully understanding the biological well-being of prehistoric populations, caution should be exercised in the interpretations made concerning childhood stress, particularly when using adult bones.

Adolescent↗
PubMed1982

The contribution of time and local geography to craniofacial variation in Nubia's Batn el Hajar.

While the history of Lower Nubia has traditionally been explained in terms of racial migrations and mixture, recent studies of craniofacial variation have emphasized the biological continuity in Lower Nubia over the past 12,000 years. Carlson and Van Gerven for example have demonstrated a trend among the populations for changes in craniofacial form that are best explained by changing masticatory function and in situ evolution independent of major racial migrations. The purpose of the present research is to extend the analysis of craniofacial variation in Lower Nubia to a culturally and geographically distinctive region to the south known as the Batn el Hajar. Data for Lower Nubia were obtained in the field from 44 Meroitic, 94 X-Group, and 36 Christian crania during the 1964 Colorado Expedition to Nubia. Data from the Batn el Hajar were obtained from 188 crania excavated in 1979 at the Christian site of Kulubnarti which spans the entire Christian era from 550 to 1450+. Analysis of 12 metric variables using discriminant function revealed two sources of variation. The first is temporal and reflects the pattern of facial reduction previously reported for Lower Nubia. The second is geographic and suggests a morphological convergence between the people of Kulubnarti and Lower Nubia during late Christian times. This convergence reflects the southward migration of Lower Nubian Christians following the annexation of Lower Nubia by Islamic Egypt in the middle 15th century.

Biological Evolution↗
PubMed1977

Masticatory function and post-Pleistocene evolution in Nubia.

The present research focuses on craniofacial variation in Nubia over approximately 10,000 years. Samples were grouped according to their temporal location and subsistence pattern, and represent a transition from a hunting-gathering adaptation (Mesolithic) to a transitional hunting-gathering-agricultural adaptation (A-C Group) and finally to a fully agricultural adaptation (Meroitic/X-Group/Christian). The purposes were: (1) to compare the Mesolithic sample with the later Nubian populations; and (2) to evaluate further the hypothesis that change in Nubian craniofacial morphology was due to changing functional demands associated with the progressive change in subsistence adaptation and associated behavior. The results tend to support recent views that the Nubian Mesolithic population is probably ancestral to later Nubian groups, and that the masticatory-functional hypothesis can best account for craniofacial change among the Nubians since 12,000 B.P. According to this hypothesis systematic reduction in functional demand placed on the masticatory complex from the Mesolithic led, secondarily, to an alteration of the growth of the maxillomandibular complex such that the face became progressively less robust and more inferoposteriorly located relative to the cranial vault. Both the increase in the height of the vault relative to its length, producing a more "globular" appearance, and the reduction in dental size were tertiary, compensatory responses to altered facial size and position.

Biological Evolution↗
PubMed1977

Sexual dimorphism and mechanics of the human hip: a multivariate assessment.

The present research was undertaken to determine the effects of sexual dimorphism in the human pelvis and femur on the mechanics of human locomotion. The analysis was based on six biomechanical variables determined from 25 male and 32 female skeletal remains from the Dickson Mound site. Discriminant function analysis indicates that the mechanical variables which primarily contribute to dimorphism are the moment arm of the gluteus medius and the torque produced by the abductors at the hip. These mechanical aspects of hip function produce greater pressure on the femoral head in females.

Anthropometry↗
PubMed1976

The effect of size variation on univariate assessments of morphological difference in human crania.

The present research was undertaken to determine the contribution of general size to craniometric variation in two previously described Paleo-Amerindian series, and to evaluate the effect of size variation on univariate assessments of morphological difference between the two. The analysis was based upon 19 measurements of 81 crania representing the Iswanid and Fort Ancient Muskogid varieties. The results of principal components analysis indicate that the 19 measurements can be represented as five principal component variates. Inspection of component eigenvectors indicates that variation in body size accounts for 40% of the variation within the metric data. Analysis of covariance lends support to the hypothesis that this size variation contributes substantially to statistical tests of difference between the two groups based on Student's t.

Analysis of Variance↗