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  • 1
    ISSN: 1432-0827
    Keywords: Bone mineral analysis ; Hip strength analysis ; Age ; Femoral neck stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The greater hip fracture rate among elderly women is generally ascribed to differences in femoral neck strength between the sexes. Strength of a given bone is a function of both its material properties and the magnitudes of mechanical stresses within it. This study examined the hypothesis that these apparent strength differences between the sexes are due to dissimilarities in the restructuring of the femoral neck with age, which result in higher stresses in elderly women. Using Hip Strength Analysis, a computer program developed by the authors, femoral neck cross-sectional geometric properties for stress analyses were derived from bone mineral image data of 409 community living, white subjects ranging from 19 to 93 years of age. Though both sexes show declines in femoral neck bone mineral density (BMD) and cross-sectional area with age, only females show a decline in the cross-sectional moment of inertia (CSMI, a geometric index of bone rigidity). The lack of decline in male CSMI appears to be a result of a small but significant increase in femoral neck girth. Similar age-related changes have been observed in the femoral shaft by others. The net effect of these observed changes is that mechanical stresses in the femoral neck of females appear to increase at three times the rate per decade of those of males. These results lend support to the hypothesis that the higher fracture rate in elderly women is due, at least in part, to elevated levels of mechanical stress, resulting from a combination of greater bone loss and less compensatory geometric restructuring with age.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Oxford journal of archaeology 10 (1991), S. 0 
    ISSN: 1468-0092
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Archaeology
    Notes: Summary. Until comparatively recently the archaeological study of ancient towns had been largely conditioned by urban development or individual research interests. This is especially true of Mediterranean sites whose especial richness has generated most attention upon their monumental aspect. Such work provides us with only partial glimpses of urban landscapes which are by definition complex and dynamic. An increasing awareness of this in recent years has led to archaeologists explicitly adopting sampling based strategies when confronting ancient towns. This paper attempts to outline the sampling-based research design employed at a multi-period town site in southern Spain. The integrated use of topographical survey, systematic surface sherding and geophysics provided a valuable insight into the spatial patterning of surface and sub-surface archaeological features. This allowed a hypothesis about the ancient topography of the town to be proposed and for it to be successfully tested by open-area excavation.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 37 (1990), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The barbel was originally a fish with a relatively restricted range in the British Isles. However, despite the general environmental degradation of many British rivers, and in contrast with some native freshwater fishes, the barbel is now more widely distributed than it was a century ago. It may even be more abundant numerically.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neural transmission 89 (1992), S. 103-110 
    ISSN: 1435-1463
    Keywords: TRH ; hypothalamus ; asymmetry ; suicide patients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The aim of the present study was to investigate the functional and/ or pathological significance of the hemispherical lateralization of TRH using radioimmunoassay to determine the TRH concentration of nuclei and areas within the hypothalamus of suicide patients, with matching measurement being carried out on control subjects. In suicide patients, we found no significant difference in TRH concentration between the left and right intrahypothalamic structures, while the group used as control subjects (see Borson-Chazot, 1986) showed a significant left side predominance in the ventromedial nucleus, paraventricular nucleus and area dorsalis. As regards the TRH concentration in the right intrahypothalamic structures, no significant difference was found between the suicide patients and the control subjects. The absence of the left TRH predominance for the three intra-hypothalamic structures in question may be of pathological significance.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1573-1561
    Keywords: Plant defense ; air pollution ; acidic deposition ; biological indicators ; plant polyphenols ; total phenolics ; proanthocyanidins ; condensed tannins ; secondary metabolites ; Pinus taeda
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Tannin and total phenolic levels in the foliage of loblolly pine (Pinus taeda L.) were examined in order to evaluate the effect of atmospheric pollution on secondary plant metabolism. The trees were exposed to four ozone concentrations and three levels of simulated acid rain. Tannin concentration (quantity per gram) and content (quantity per fascicle) were increased in foliage exposed to high concentrations of ozone in both ozone-sensitive and ozone-tolerant families. No effect of acid rain on tannins was observed. Neither total phenolic concentration nor content was significantly affected by any treatment, indicating that the ozone-related increase in foliar tannins was due to changes in allocation within the phenolic group rather than to increases in total phenolics. The change in allocation of resources in the production of secondary metabolites may have implications in herbivore defense, as well as for the overall energy balance of the plant.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1619-1560
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1615-5947
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract CT imaging of traumatic aortic rupture has been both advocated and disparaged in the current literature as a reliable diagnostic modality. In a retrospective review of blunt chest trauma patients at our institution evaluated by both thoracic CT and arteriography, we found a 17% false negative rate and a 39% false positive rate. Although we feel CT is not sufficiently sensitive at present to evaluate traumatic rupture of the aorta directly, it is an invaluable adjunctive imaging modality for stable blunt chest trauma patients with equivocal chest radiographs or arteriograms.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Human evolution 9 (1994), S. 331-342 
    ISSN: 1824-310X
    Keywords: birth ; bone density ; Neanderthal ; obstetrics ; robusticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Neanderthal pelvic morphology is not well understood, despite the recent find and analysis of the Kebara 2 pelvis. Many of the proposed hypotheses focus on the possible need for a larger birth canal. A previously unexplored aspect involves possible direct obstetric implications of bone robusticity and density. These characteristics ocan affect obstetrics in modern humans, especially the molding of the neonate's head during parturition: engineering studies have shown that denser neonate cranial bones undergo less deformation, and thicker (more robust) cranial bones would also be expected to deform less during the birth process. These bone characteristics may also result in a less flexible birth canal. Thus, more robust or denser bones could result in the need for a larger birth canal or a smaller neonate head, due to decreased flexibility. Examples from modern populations are discussed and the conclusions applied to Neanderthals, who are known to have had high bone robusticity and may have had high bone density, given their heavy musculature. (A positive association between muscle mass and bone density has been observed repeatedly in modern humans.) We conclude that bone robusticity and density may have obstetrical implications for Neanderthals, with particular importance for neonate head molding during birth.
    Type of Medium: Electronic Resource
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