418 research outputs found

    A closure concept in factor-critical graphs

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    AbstractA graph G is called n-factor-critical if the removal of every set of n vertices results in a~graph with a~1-factor. We prove the following theorem: Let G be a~graph and let x be a~locally n-connected vertex. Let {u,v} be a~pair of vertices in V(G)−{x} such that uv∉E(G), x∈NG(u)∩NG(v), and NG(x)⊂NG(u)∪NG(v)∪{u,v}. Then G is n-factor-critical if and only if G+uv is n-factor-critical

    On 1-factors and matching extension

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    AbstractWe prove the following: (1) Let G be a graph with a 1-factor and let F be an arbitrary 1-factor of G. If G⧹{a,b} is k-extendable for each ab∈F, then G is k-extendable. (2) Let G be a graph and let M be an arbitrary maximal matching of G. If G⧹{a,b} is k-factor-critical for each ab∈M, then G is k-factor-critical

    DEVELOPMENT OF SOUND PROOF WINDOWS FOR HOUSE IN VIETNAM

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    Joint Research on Environmental Science and Technology for the Eart

    PRELIMINARY SURVEY ON COMMUNITY RESPONSE TO ROAD TRAFFIC NOISE IN HANOI

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    Joint Research on Environmental Science and Technology for the Eart

    Allometry and Interspecific Differences in the Facial Cranium of Two Closely Related Macaque Species

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    Interpreting evolutionary history of macaque monkeys from fossil evidence is difficult, because their evolutionary fluctuations in body size might have removed or formed important morphological features differently in each lineage. We employed geometric morphometrics to explore allometric trajectories of craniofacial shape in two closely related species, Macaca fascicularis and M. fuscata. These two species exhibit a single shared allometric trajectory in superoinferior deflection of the anterior face, indicating that the differences in this feature can be explained by size variation. In contrast, two parallel trajectories are demonstrated in craniofacial protrusion, indicating that even if they are comparable in size, M. fuscata has a higher and shorter face than M. fascicularis. The degree of facial protrusion is most likely a critical feature for phyletic evaluation in the fascicularis group. Such analyses in various macaques would help to resolve controversies regarding phyletic interpretations of fossil macaques

    ANNOYANCE SCALES IN VIETNAMESE

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    Joint Research on Environmental Science and Technology for the Eart

    Phenotypic plasticity in the mandibular morphology of Japanese macaques: captive–wild comparison

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    Despite the accumulating evidence suggesting the importance of phenotypic plasticity in diversification and adaptation, little is known about plastic variation in primate skulls. The present study evaluated the plastic variation of the mandible in Japanese macaques by comparing wild and captive specimens. The results showed that captive individuals are square-jawed with relatively longer tooth rows than wild individuals. We also found that this shape change resembles the sexual dimorphism, indicating that the mandibles of captive individuals are to some extent masculinized. By contrast, the mandible morphology was not clearly explained by ecogeographical factors. These findings suggest the possibility that perturbations in the social environment in captivity and resulting changes of androgenic hormones may have influenced the development of mandible shape. As the high plasticity of social properties is well known in wild primates, social environment may cause the inter- and intra-population diversity of skull morphology, even in the wild. The captive–wild morphological difference detected in this study, however, can also be possibly formed by other untested sources of variation (e.g. inter-population genetic variation), and therefore this hypothesis should be validated further
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