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Skeletal Morphology (skeletal + morphology)
Selected AbstractsSearching for new morphological characters in the systematics of scleractinian reef corals: comparison of septal teeth and granules between Atlantic and Pacific MussidaeACTA ZOOLOGICA, Issue 2 2009Ann F. Budd Abstract Recent molecular analyses have challenged the traditional classification of scleractinian corals at all taxonomic levels suggesting that new morphological characters are needed. Here we tackle this problem for the family Mussidae, which is polyphyletic. Most of its members belong to two molecular clades composed of: (1) Atlantic Mussidae and Faviidae (except Montastraea) and (2) Pacific Mussidae (Cynarina, Lobophyllia, Scolymia, Symphyllia) and Pectiniidae. Other Pacific mussids (e.g. Acanthastrea) belong to additional clades. To discover new characters that would better serve as phylogenetic markers, we compare the skeletal morphology of mussid genera in different molecular-based clades. Three sets of characters are considered: (1) macromorphology (budding; colony form; size and shape of corallites; numbers of septal cycles), (2) micromorphology (shapes and distributions of septal teeth and granules), and (3) microstructure (arrangement of calcification centres and thickening deposits within costosepta). Although most traditional macromorphological characters exhibit homoplasy, several new micromorphological characters are effective at distinguishing clades, including the shapes and distribution of septal teeth and granules, the area between teeth, and the development of thickening deposits. Arrangements of calcification centres and fibres differ among clades, but the fine-scale structure of thickening deposits does not. [source] The first complete skeleton of Megaloceros verticornis (Dawkins, 1868) Cervidae, Mammalia, from Bilshausen (Lower Saxony, Germany): description and phylogenetic implicationsFOSSIL RECORD-MITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE, Issue 1 2002Thekla Pfeiffer Abstract The first well preserved, articulated skeleton of a young male deer of Megaloceros verticornis (Dawkins, 1868) was excavated from early Middle Pleistocene sediments of the clay pit of Bilshausen (Unter-Eichsfeld, Lower Saxony). This find made it possible, for the first time, to establish, using cladistic techniques, the systematic position of Megaloceros verticornis among Pleistocene and Holocene plesiometacarpal and telemetacarpal cervids. By contrast to the antler and tooth characters, the postcranial characters, in particular, are suitable for phylogeny reconstruction. Megaloceros verticornis from Bilshausen shows great similarity with M. giganteus of the Upper Pleistocene of Europe in its skeletal morphology, and bootstrap values (BP = 100) show strong support for the monophyly of M. giganteus and M. verticornis. The analysis yields no evidence, however, of a close relationship between Dama and Megaloceros, which has been widely discussed in the literature because of the presence of large, palmated antlers in both genera. Aus der Tongrube von Bilshausen (Unter-Eichsfeld, Niedersachsen) konnte das erste, vollständige Skelett eines jugen Hirsches von Megaloceros verticornis (Dawkins, 1868) aus mittelpleistozänen Sedimentablagerungen geborgen werden. Dieser Fund ermöglichte es erstmalig, die systematische Stellung von Megaloceros verticornis im System plesiometacarpaler und telemetacarpaler Hirsche des Pleistozäns und Holozäns auf breiter Basis zu untersuchen. Im Gegensatz zu den Geweih- und Zahnmerkmalen eignen sich die postcranialen Merkmale des Skelettes besonders gut für eine phylogenetische Rekonstruktion der Hirsche. Die Gemeinsamkeit Großer Schaufelgeweihe bei Dama dama und dem Riesenhirsch Megaloceros giganteus hat dazu geführt, beide in eine enge phylogenetische Beziehung zu setzen, was in der Literatur zu einer anhaltenden Kontroverse geführt hat. Die Analyse der Morphologie der postcranialen Elemente zeigt jedoch, dass es keine enge Verwandtschaft zwischen Dama und Megaloceros gibt. [source] Sperm characteristics and teratology in rats following vas deferens occlusion with RISUG and its reversalINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2010N. K. Lohiya Summary The functional success of the reversal of vas occlusion by styrene maleic anhydride (RISUG), using the solvent vehicle, Dimethyl Sulphoxide (DMSO), has been investigated. Reversal with DMSO was carried out in Wistar albino rats 90 days after bilateral vas occlusion. The body weight, organ weight, sperm characteristics, fertility test and teratology, including skeletal morphology were evaluated in vas occlusion and reversal animals and in F1 progenies to assess the functional success of the occlusion and reversal. Body weight, organ weight and the cauda epididymal sperm characteristics of vas occlusion and reversal animals and of F1 progenies were comparable to control. Ejaculated spermatozoa in the vaginal smear showed detached head/tail, acrosomal damage, bent midpiece, bent tail and morphological aberrations in sperm head after vas occlusion, which returned to normal, 90 days after reversal. Monthly fertility test, post-injection showed 0% fertility, which improved gradually and 100% fertility was achieved 90 days after reversal. The fertility/pregnancy/implantation record and skeletal morphology of the offspring were comparable to control. The results suggest functional success and safety of vas occlusion reversal by DMSO. [source] Targeted Deletion of the Sclerostin Gene in Mice Results in Increased Bone Formation and Bone Strength,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2008Xiaodong Li Abstract Introduction: Sclerosteosis is a rare high bone mass genetic disorder in humans caused by inactivating mutations in SOST, the gene encoding sclerostin. Based on these data, sclerostin has emerged as a key negative regulator of bone mass. We generated SOST knockout (KO) mice to gain a more detailed understanding of the effects of sclerostin deficiency on bone. Materials and Methods: Gene targeting was used to inactivate SOST and generate a line of SOST KO mice. Radiography, densitometry, ,CT, histomorphometry, and mechanical testing were used to characterize the impact of sclerostin deficiency on bone in male and female mice. Comparisons were made between same sex KO and wildtype (WT) mice. Results: The results for male and female SOST KO mice were similar, with differences only in the magnitude of some effects. SOST KO mice had increased radiodensity throughout the skeleton, with general skeletal morphology being normal in appearance. DXA analysis of lumbar vertebrae and whole leg showed that there was a significant increase in BMD (>50%) at both sites. ,CT analysis of femur showed that bone volume was significantly increased in both the trabecular and cortical compartments. Histomorphometry of trabecular bone revealed a significant increase in osteoblast surface and no significant change in osteoclast surface in SOST KO mice. The bone formation rate in SOST KO mice was significantly increased for trabecular bone (>9-fold) at the distal femur, as well as for the endocortical and periosteal surfaces of the femur midshaft. Mechanical testing of lumbar vertebrae and femur showed that bone strength was significantly increased at both sites in SOST KO mice. Conclusions:SOST KO mice have a high bone mass phenotype characterized by marked increases in BMD, bone volume, bone formation, and bone strength. These results show that sclerostin is a key negative regulator of a powerful, evolutionarily conserved bone formation pathway that acts on both trabecular and cortical bone. [source] Fallback foraging as a way of life: Using dietary toughness to compare the fallback signal among capuchins and implications for interpreting morphological variationAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Barth W. Wright Abstract The genus Cebus is one of the best extant models for examining the role of fallback foods in primate evolution. Cebus includes the tufted capuchins, which exhibit skeletal features for the exploitation of hard and tough foods. Paradoxically, these seemingly "specialized" taxa belong to the most ubiquitous group of closely related primates in South America, thriving in a range of different habitats. This appears to be a consequence of their ability to exploit obdurate fallback foods. Here we compare the toughness of foods exploited by two tufted capuchin species at two ecologically distinct sites; C. apella in a tropical rainforest, and C. libidinosus in a cerrado forest. We include dietary data for one untufted species (C. olivaceus) to assess the degree of difference between the tufted species. These data, along with information on skeletal morphology, are used to address whether or not a fallback foraging species exhibits a given suite of morphological and behavioral attributes, regardless of habitat. Both tufted species ingest and masticate a number of exceedingly tough plant tissues that appear to be used as fallback resources, however, C. libidinosus has the toughest diet both in terms of median and maximal values. Morphologically, C. libidinosus is intermediate in absolute symphyseal and mandibular measurements, and in measures of postcranial robusticity, but exhibits a higher intermembral index than C. apella. We propose that this incongruence between dietary toughness and skeletal morphology is the consequence of C. libidinosus' use of tools while on the ground for the exploitation of fallback foods. Am J Phys Anthropol 140:687,699, 2009. © 2009 Wiley-Liss, Inc. [source] Understanding race and human variation: Why forensic anthropologists are good at identifying raceAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2009Stephen Ousley Abstract American forensicanthropologists uncritically accepted the biological race concept from classic physical anthropology and applied it to methods of human identification. Why and how the biological race concept might work in forensic anthropology was contemplated by Sauer (Soc Sci Med 34 1992 107,111), who hypothesized that American forensic anthropologists are good at what they do because of a concordance between social race and skeletal morphology in American whites and blacks. However, Sauer also stressed that this concordance did not validate the classic biological race concept of physical anthropology that there are a relatively small number of discrete types of human beings. Results from Howells (Papers of the Peabody Museum of Archaeology and Ethnology 67 1973 1,259; Papers of the Peabody Museum of Archaeology and Ethnology 79 1989 1,189; Papers of the Peabody Museum of Archaeology and Ethnology 82 1995 1,108) and others using craniometric and molecular data show strong geographic patterning of human variation despite overlap in their distributions. However, Williams et al. (Curr Anthropol 46 2005 340,346) concluded that skeletal morphology cannot be used to accurately classify individuals. Williams et al. cited additional support from Lewontin (Evol Biol 6 1972 381,398), who analyzed classic genetic markers. In this study, multivariate analyses of craniometric data support Sauer's hypothesis that there are morphological differences between American whites and blacks. We also confirm significant geographic patterning in human variation but also find differences among groups within continents. As a result, if biological races are defined by uniqueness, then there are a very large number of biological races that can be defined, contradicting the classic biological race concept of physical anthropology. Further, our results show that humans can be accurately classified into geographic origin using craniometrics even though there is overlap among groups. Am J Phys Anthropol 2009. © 2009 Wiley-Liss, Inc. [source] Middle phalanx skeletal morphology in the hand: Can it predict flexor tendon size and attachments?AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2007Mary W. Marzke Abstract Specific sites on the palmar diaphysis of the manual middle phalanges provide attachment for the flexor digitorum superficialis (FDS) tendon. It has been assumed in the literature that lateral palmar fossae on these bones reflect locations for these attachments and offer evidence for relative size of the flexor tendon. This assumption has led to predictions about relative FDS muscle force potential from sizes of fossae on fossil hominin middle phalanges. Inferences about locomotor capabilities of fossil hominins in turn have been drawn from the predicted force potential of the flexor muscle. The study reported here provides a critical first step in evaluating hypotheses about behavioral implications of middle phalangeal morphology in fossil hominins, by testing the hypothesis that the lateral fossae reflect the size of the FDS tendon and the location of the terminal FDS tendon attachments on the middle phalanx. The middle phalangeal region was dissected in 43 individuals from 16 primate genera, including humans. Qualitative observations were made of tendon attachment locations relative to the lateral fossae. Length measurements of the fossae were tested as predictors of FDS tendon cross-sectional area and of FDS attachment tendon lengths. Our results lead to the conclusion that the hypothesis must be rejected, and that future attention should focus on functional implications of the palmar median bar associated with the lateral fossae. Am J Phys Anthropol, 2007. © 2007 Wiley-Liss, Inc. [source] Optimization of Volumetric Computed Tomography for Skeletal Analysis of Model Genetic OrganismsTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 5 2008Sergio X. Vasquez Abstract Forward and reverse genetics now allow researchers to understand embryonic and postnatal gene function in a broad range of species. Although some genetic mutations cause obvious morphological change, other mutations can be more subtle and, without adequate observation and quantification, might be overlooked. For the increasing number of genetic model organisms examined by the growing field of phenomics, standardized but sensitive methods for quantitative analysis need to be incorporated into routine practice to effectively acquire and analyze ever-increasing quantities of phenotypic data. In this study, we present platform-independent parameters for the use of microscopic x-ray computed tomography (microCT) for phenotyping species-specific skeletal morphology of a variety of different genetic model organisms. We show that microCT is suitable for phenotypic characterization for prenatal and postnatal specimens across multiple species. Anat Rec, 291:475,487, 2008. © 2008 Wiley-Liss, Inc. [source] | |||||||||||||