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101.
The systematic relationships of the snake genus Anomochilus 总被引:2,自引:1,他引:1
DAVID CUNDALL V. WALLACH † DOUGLAS A. ROSSMAN 《Zoological Journal of the Linnean Society》1993,109(3):275-299
Phylogenetic analysis of 38 skeletal characters, 12 muscular characters and 15 visceral characters in 17 major snake clades plus Anomochilus suggests that Anomochilus is the sister taxon of all other living alethinophidian snakes. However, skeletal, muscular and visceral character sets analysed separately or in pairs give four groups of nonconcordant tree topologies. Based on the cladogram derived from the total evidence, two families are erected to prevent the existing family Uropeltidae from becoming paraphyletic: Anomochilidae, for the Malaysian and Indonesian genus Anomochilus , and Cylindrophiidae, for the Sri Lankan, Southeast Asian and Indonesian genus Cylindrophis and the Upper Eocene fossil Eoanilius. 相似文献
102.
103.
Juliana Tarquini Néstor Toledo Leopoldo H. Soibelzon Cecilia C. Morgan 《Historical Biology》2018,30(4):496-506
Procyonidae were the first northern placental carnivorans that reached the Neotropics. They are represented by two extinct genera: ?Cyonasua and ?Chapalmalania (late Miocene – early Pleistocene). Postcranial elements are only known for ?Cyonasua and related taxa (?Parahyaenodon argentinus and ?Tetraprothomo argentinus). To obtain highly reliable allometric equations for body mass estimations of fossil procyonids, we performed least squares regressions (multiple and bivariate lineal models) using 51 postcranial linear measurements. The extant sample included 124 taxa corresponding to nine families of Carnivora, with body mass data from the literature. We obtained about 63 equations from diverse combinations of postcranial measurements; 14 of them were selected using several reliability indexes as criteria. Our results show that body masses calculated for ?Cyonasua range between 12.63 and 28.45 kg, ?P. argentinus was estimated at 14.41 kg, while ?T. argentinus at 25.31 kg. Thus, the body mass of ?Cyonasua would have been at least twice as high as the mean of the extant procyonid Procyon cancrivorus. ?Cyonasua was probably able to fend off predators and quite capable of climbing slowly on thick-enough branches. Other palaeoecological and palaeobiological inferences are discussed. 相似文献
104.
Ferdinand Bohlmann Pahup Singh Ravindra K. Singh Krishna C. Joshi Jasmin Jakupovic 《Phytochemistry》1985,24(5):1114-1115
An Indian sample of Solidago altissima afforded in addition to several clerodanes already isolated from other Solidago species, a diterpene with a new carbon skeleton. Furthermore a ketone and a new anethole derivative were present. 相似文献
105.
The relationship between wing kinematics, wing morphology and the brachial index of birds (BI=humerus length/ulna length) was examined. BI was found to differ between three groups of birds, which were classified on the basis of similar wing kinematics. In addition, a comparative analysis of a large dataset, using phylogenetically independent contrasts, suggested a significant, albeit weak, correlation between BI and four measures of wing morphology (wing loading, wing area, wing length and aspect ratio). Although wing kinematics and wing morphology are both correlated with BI in birds, the dominant selective pressure upon this ratio is probably wing kinematics. The previously identified clade specificity of BI within Neornithes is most likely because birds with similar BIs fly with kinematic similarity and closely related birds have similar flight styles. A correlation between BI and wing kinematics means that it may be possible to characterize the wing beat of fossil birds. A more robust relationship between wing morphology and BI may emerge, but only after the relationship between wing kinematics and BI is quantified. A comparative and quantitative study of wing-bone anatomy and wing kinematics is a priority for future studies of avian wing-skeleton evolution and functional morphology. 相似文献
106.
Human hair from various racial groups was investigated using the following techniques: amino acid analysis, acrylamide gel electrophoresis, x-ray diffraction studies, stress-strain analysis. Each of these techniques yielded identical results for all samples, indicating that the variables producing phenotypic differences in human hair form are probably not on the level of primary or secondary biochemical structure. Hair samples of a variety of primates were examined electrophoretically, with each taxonomic family investigated exhibiting a different pattern. These biochemical results are consistent with accepted primate phylogeny. 相似文献
107.
Caroline E. G. Tutin 《Primates; journal of primatology》1999,40(1):249-265
A 17-month study was made of the primates using a 9-ha “island” of forest, surrounded by savanna, in the northern part of
the Lopé Reserve, Gabon. One group ofCercopithecus cephus (plus a young maleCercopithecus nictitans who was in permanent association with them) were resident in the fragment and groups of five other species of primates made
visits during 127 days of observation:Pan troglodytes, 15 visits;Cercocebus albigena, 10;Colobus satanas, 3;Cercopithecus nictitans, 2;C. pogonias, 1. Visits were also made by lone males of three species,C. nictitans, Cercocebus albigena, andMandrillus sphinx. The eighth species of diurnal primate present at Lopé,Gorilla g. gorilla, did not visit the fragment during the study. Compared to conspecific groups in neighbouring continuous forest, primates
in the fragment ate less fruit, seeds and flowers and more insects and leaves. The local population density of primates resident
in the fragment was equivalent to that of the neighbouring continuous forest where all eight species occur, despite the diversity
and abundance of fruit being less in the fragment. The costs imposed on the resident group by the reduced diversity and availability
of preferred fruit foods appeared to be offset by a number of benefits that increased individual feeding efficiency for monkeys
residing within a single fragment. These included lower travel costs, reduced feeding competition between individuals through
group fission, and excellent knowledge of the location and quality of food resources in the small home range. It is also possible
that the overall negative impact of inter-specific feeding competition was lower in fragments than in continuous forest and
that micro-habitat differences resulted in an increased availability of palatable insect and leaf fallback foods in the fragment. 相似文献
108.
Purified nucleoli of HeLa cells were treated sequentially with nonionic detergent, nucleic acid enzyme, low salt and high salt. The residual nucleolar structure termed nucleolar skeleton (nucleolar matrix) was shown as a fine network under electron microscope with DGD embedding-unembedding technique. Such structures of BHK-21 cell and mouse liver cell are similar to that of HeLa cell. The protein composition of the nucleolar skeleton of HeLa cells was analyzed. The protein composition of such nucleolar residual shows obvious difference from the compositions of nuclear matrix and chromosome scaffold. The major protein composition of the nucleolar skeleton of HeLa cells contains 6-7 polypeptides. Their molecular weights are about 48, 43, 36 and 33 ku. Further studies show that actin and fib-rillarin are two major protein components of nucleolar skeleton of HeLa cells. 相似文献
109.
110.
Yoshikazu Watanabe Kohei Hayashida Daisuke Saito Toshihiro Takahashi Junichi Sakai Eriko Nakata Takashi Kanda Takashi Iwai Shigeto Hirayama Hideaki Fujii Tomio Yamakawa Hiroshi Nagase 《Bioorganic & medicinal chemistry letters》2017,27(15):3495-3498
We designed and synthesized novel δ opioid receptor (DOR) agonists 3a–i with an azatricyclodecane skeleton, which was a novel structural class of DOR agonists. Among them, 3b exhibited high values of binding affinity and potent agonistic activity for the DOR that were approximately equivalent to those of 2 which bore an oxazatricyclodecane skeleton. In vitro assays using the blood-brain barrier (BBB) permeability test kit supported the idea that 3b achieved an excellent BBB permeability by converting an oxygen atom of 2 to a carbon atom (methylene group) in the core skeleton. As a result, 3b showed potent antinociceptive effects. 相似文献