943 resultados para Franco-american relations


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Amblycipitidae Day, 1873 is an Asian family of catfishes (Siluriformes) usually considered to contain 28 species placed in three genera: Amblyceps (14 spp.), Liobagrus (12 spp.) and Xiurenbagrus (2 spp.). Morphology-based systematics has supported the monophyly of this family, with some authors placing Amblycipitidae within a larger group including Akysidae, Sisoridae and Aspredinidae, termed the Sisoroidea. Here we investigate the phylogenetic relationships among four species of Amblyceps, six species of Liobagrus and the two species of Xiurenbagrus with respect to other sisoroid taxa as well as other catfish groups using 6100 aligned base pairs of DNA sequence data from the rag1 and rag2 genes of the nuclear genome and from three regions (cyt b, COL ND4 plus tRNA-His and tRNA-Ser) of the mitochondrial genome. Parsimony and Bayesian analyses of the data indicate strong support for a diphyletic Amblycipitidae in which the genus Amblyceps is the sister group to the Sisoridae and a clade formed by genera Liobagrus and Xiurenbagrus is the sister group to Akysidae. These taxa together form a well supported monophyletic group that assembles all Asian sisoroid taxa, but excludes the South American Aspredinidae. Results for aspredinids are consistent with previous molecular studies that indicate these catfishes are not sisoroids, but the sister group to the South American doradoid catfishes (Auchenipteridae + Doradidae). The redefined sisoroid clade plus Bagridae, Horabagridae and (Ailia + Laides) make up a larger monophyletic group informally termed "Big Asia." Likelihood-based SH tests and Bayes Factor comparisons of the rag and the mitochondrial data partitions considered separately and combined reject both the hypothesis of amblycipitid monophyly and the hypothesis of aspredinid inclusion within Sisoroidea. This result for amblycipitids conflicts with a number of well documented morphological synapomorphies that we briefly review. Possible nomenclatural changes for amblycipitid taxa are noted.

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A theoretical model about the size-dependent interface energy between two thin films with different materials is developed by considering the chemical bonding contribution based on the thermodynamic expressions and the structure strain contribution based on the mechanical characteristics. The interface energy decreases with reducing thickness of thin films, and is determined by such available thermodynamic and mechanical parameters as the melting entropy, the melting enthalpy, the shear modulus of two materials, etc. The predicted interface energies of some metal/MgO and metal/Al2O3 interfaces based on the model are consistent with the results based on the molecular mechanics calculation. Furthermore, the interface fracture properties of Ag/MgO and Ni/Al2O3 based on the atomistic simulation are further compared with each other. The fracture strength and the toughness of the interface with the smaller structure interface energy are both found to be lower. The intrinsic relations among the interface energy, the interface strength, and the fracture toughness are discussed by introducing the related interface potential and the interface stress. The microscopic interface fracture toughness is found to equal the structure interface energy in nanoscale, and the microscopic fracture strength is proportional to the fracture toughness. (C) 2010 American Institute of Physics. [doi:10.1063/1.3501090]

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Polychaete Neanthes japonica is a species geographically specific in China and Japan with important scientific implication and commercial value. In this study, the relations of body weight, salinity and temperature to oxygen consumption and ammonia excretion of N. japonica were determined. Three different groups in body weight (large: 2.34 +/- 0.36 g, middle: 1.50 +/- 0.21 g and small: 0.62 +/- 0.12 g) were set for all experiments. Results show that the body weight is negatively related to the rates of oxygen consumption and ammonia excretion; and the relationship is significant. The oxygen consumption and ammonia excretion at 24A degrees C decreased at salinity from 5 to 30 and increased above 30, indicating that both lower and higher salinity are adverse and certain degree of salinity stress is necessary for enhancing the energy demand. At salinity 30, rising temperature from 18A degrees C to 30A degrees C, the oxygen consumption increased before 27A degrees C and then decreased. However, the relation of ammonia excretion and temperature seems more complex. Two-way ANOVA shows that salinity, temperature and body weight all have a significant effect on the oxygen consumption and ammonia excretion of the worm. Moreover, interaction between salinity/temperature and body weight is also significant. O:N (oxygen/nitrogen) ratio varies greatly in this case from 5.97 to 463.22, indicating that N. japonica can regulate the type of metabolic substrate against environment changes.

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This paper examines the effect of inbreeding level of population on the magnitude of inbreeding depression expressed by comparing them between two cultured populations (A and B) in the hermaphroditic animal of the bay scallop Argopecten irradians irradians. Population A is expected to have less genetic variations and higher inbreeding level due to longer cultured history (20 generations) and less "ancestral" individuals (26 individuals) than population B due to shorter cultured history (4 generations) and more "ancestral" individuals (406 individuals). Two groups within each population were produced, one using self-fertilization and one using mass-mating within the same population. Selfed offspring (AS and BS) from two populations both had lower fitness components than their mass-mated counterparts (AM and BM) and exhibited inbreeding depression for all examined traits, e.g. lower hatching, less viability and slower growth, indicating that inbreeding depression is a common feature in this animal. Fitness components in all traits of offspring from population A significantly differed those from population B and the magnitude of inbreeding depression for all traits in population A with higher inbreeding level was significantly smaller than that in population B with lower inbreeding level, indicating that both fitness components and magnitude of inbreeding depression were significantly affected by inbreeding level of populations and genetic load harbored in population A may be partially purged through inbreeding. Moreover, the magnitude of inbreeding depression in the two populations both varied among traits and life history stages. The present results support the partial-dominance hypothesis of inbreeding depression. (C) 2008 Elsevier B.V. All rights reserved.

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The presumed pair relationships of intercontinental vicariad species in the Podophyllum group (Sinopodophyllum hexandrum vs. Podophyllum pelatum and Diphylleia grayi vs. D. cymosa) were recently, considered to be paraphyletic. In the present paper, the trnL-F and ITS gene sequences of the representatives were used to examine the sister relationships of these two vicariad species. A heuristic parsimony analysis based on the trnLF data identified Diphylleia as the basal clade of the other three genera, but provided poor resolution of their inter-relationships. High sequence divergence was found in the ITS data. ITS1 region, more variable but parsimonyuninformative. has no phylogenetic value, Sequence divergence of the ITS2 region provided abundant, phylogenetically informative variable characters. Analysis of ITS2 sequences confirmeda sister relationship between the presumable vicariad species, in spite of a low bootstrap support for Sinopodophyllum hexandrum vs. Podophyllum pelatum. The combined ITS2 and trnL-F data enforced a sister relationship between Sinopodophyllum hexandrum and Podophyllum pelatum with an elevated bootstrap support of 100%. Based on molecular phylogeny, the morphological evolution of this group was discussed. The self-pollination might have evolved from cross-fertilization two times in this group. The different pollination and seed dispersal systems of Sinopodophyllum hexandrum and Podophlyllum pelatum resulted from their adaptations to different ecological habitats. The divergence time of Sinopodophyllum hexandrum-Podophyllum pelatum is estimated to be 6.52+/-1.89 myr based on the ITS divergence. The divergence of this species pair predated or co-occurred with the recent uplift of the Himalayas 4-3 myr during the late Miocene and the formation of the alpine habitats. Sinopodophyllum hexandrum developed a host of specialized characters in its subsequent adaptation to the arid alpine surroundings. The present study confirmed the different patterns of species relationship between Asian-North American disjuncts. The isolation of plant elements between North America and eastern Asia must have been a gradual process, resulting in the different phylogenetic patterns and divergence times of the disjuncts.

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This paper deals with the relations between the Machangqing rockbody which corresponds to the A-type granites and porphyry copper mineralization in terms of petrochemistry, trace element geochemistry, fluid inclusion geochemistry and isotope geochemistry. The results show that the Machangqing porphyry copper deposit was formed from the fluid predominated by mag-matic fluid. This kind of ore-forming fluid was just differentiated from the magma responsible for the A-type granites. therefore,as viewed from whereer they contain water or not,the A-type granites can,at least,be divided into two types: water-bearing and water-free.The water-bearing A-type granites can serve as the host ofporphyry copper deposits under certain geological conditions.

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2007

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A procedure is given for recognizing sets of inference rules that generate polynomial time decidable inference relations. The procedure can automatically recognize the tractability of the inference rules underlying congruence closure. The recognition of tractability for that particular rule set constitutes mechanical verification of a theorem originally proved independently by Kozen and Shostak. The procedure is algorithmic, rather than heuristic, and the class of automatically recognizable tractable rule sets can be precisely characterized. A series of examples of rule sets whose tractability is non-trivial, yet machine recognizable, is also given. The technical framework developed here is viewed as a first step toward a general theory of tractable inference relations.

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The aim of this study was to conduct a systematic review to identify the randomized clinical studies that had investigated the following research question: Is the mandibular manipulation technique an effective and safe technique for the treatment of the temporomandibular joint disk displacement without reduction? the systematic search was conducted in the electronic databases: PubMed (Medical Publications), LILACS (Latin American and Caribbean Literature in Health Sciences), EMBASE (Excerpta Medica Database), PEDro (Physiotherapy Evidence Database), BBO (Brazilian Library of Odontology), CENTRAL (Library Cochrane), and SciELO (Scientific Electronic Library Online). the abstracts of presentations in physical therapy meetings were manually selected, and the articles of the ones that meet the requirements were investigated. No language restrictions were considered. Only randomized and controlled clinical studies were included. Two studies of medium quality fulfilled all the inclusion criteria. There is no sufficient evidence to support the effectiveness of the mandibular manipulation therapy, and therefore its use remains questionable. Being minimally invasive, this therapy is attractive as an initial approach, especially considering the cost of the alternative approaches. the analysis of the results suggests that additional high-quality randomized clinical trials are necessary on the topic, and they should focus on methods for data randomization and allocation, on clearly defined outcomes, on a priori calculated sample size, and on an adequate follow-up strategy.