770 resultados para taxonomic relationships
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Based on the variables relationship and knowledge, this article aimed at analyzing how a multinational enterprise selects an entry mode to operate in a particular international market and how this initial choice evolves over time. We devised a rather new theoretical framework to address it by combining three theoretical approaches that have dealt with the firm internationalization: the Uppsala model, the relational approach, and the subsidiary development literature. We constructed a qualitative backward-looking longitudinal case study of the internationalization process of a North-American multinational enterprise in the Brazilian market. Results show that four types of relationships and three types of knowledge played the role in the events that characterized the internationalization of this firm. Based on these results, five new hypotheses concerning the interplay between relationships and knowledge in the internationalization process of the firm are suggested for future empirical tests.
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To elucidate the evolutionary history of snow voles, genus Chionomys, we studied the phylogeography of Chionomysnivalis across its range and investigated its relationships with two congeneric species, Chionomysgud and Chionomysroberti, using independent molecular markers. Analyses were based on mitochondrial (~940 bp cyt b) and Y-chromosomal (~2020 bp from three introns) genetic variation. Our data provide conclusive evidence for a Caucasian and Middle Eastern origin for the three species and a subsequent westward expansion of C.nivalis. In addition, we discuss the taxonomic status of the genus Chionomys in relation to the genus Microtus.
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Epidemiological studies have recognized a genetic diathesis for suicidal behavior, which is independent of other psychiatric disorders. Genome-wide association studies (GWAS) on suicide attempt (SA) and ideation have failed to identify specific genetic variants. Here, we conduct further GWAS and for the first time, use polygenic score analysis in cohorts of patients with mood disorders, to test for common genetic variants for mood disorders and suicide phenotypes. Genome-wide studies for SA were conducted in the RADIANT and GSK-Munich recurrent depression samples and London Bipolar Affective Disorder Case-Control Study (BACCs) then meta-analysis was performed. A GWAS on suicidal ideation during antidepressant treatment had previously been conducted in the Genome Based Therapeutic Drugs for Depression (GENDEP) study. We derived polygenic scores from each sample and tested their ability to predict SA in the mood disorder cohorts or ideation status in the GENDEP study. Polygenic scores for major depressive disorder, bipolar disorder and schizophrenia from the Psychiatric Genomics Consortium were used to investigate pleiotropy between psychiatric disorders and suicide phenotypes. No significant evidence for association was detected at any SNP in GWAS or meta-analysis. Polygenic scores for major depressive disorder significantly predicted suicidal ideation in the GENDEP pharmacogenetics study and also predicted SA in a combined validation dataset. Polygenic scores for SA showed no predictive ability for suicidal ideation. Polygenic score analysis suggests pleiotropy between psychiatric disorders and suicidal ideation whereas the tendency to act on such thoughts may have a partially independent genetic diathesis. © 2014 Wiley Periodicals, Inc.
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We sequenced 2167 base pairs (bp) of mitochondrial DNA cytochrome b and 16S, and 1390 bp of nuclear genes BRCA1 and ApoB in shrews taxa (Eulipotyphla, family Soricidae). The aim was to study the relationships at higher taxonomic levels within this family, and in particular the position of difficult clades such as Anourosorex and Myosorex. The data confirmed two monophyletic subfamilies, Soricinae and Crocidurinae. In the former, the tribes Anourosoricini, Blarinini, Nectogalini, Notiosoricini, and Soricini were supported. The latter was formed by the tribes Myosoricini and Crocidurini. The genus Suncus appeared to be paraphyletic and included Sylvisorex. We further suggest a biogeographical hypothesis, which shows that North America was colonized by three independent lineages of Soricinae during middle Miocene. Our hypothesis is congruent with the first fossil records for these taxa. Using molecular dating, the first exchanges between Africa and Eurasia occurred during the middle Miocene. The last one took place in the Late Miocene, with the dispersion of the genus Crocidura through the old world.
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Invasive species may carry with them parasites from their native range, differing from parasite taxa found in the invaded range. Host switching by parasites (either from the invader to native fauna or from native fauna to the invader) may have important consequences for the viability of either type of host (e.g., their survivorship, fecundity, dispersal ability, or geographic distribution). Rhabdias pseudosphaerocephala (Nematoda) is a common parasite of cane toads (Rhinella marina) in the toad's native range (South and Central America) and also in its introduced Australian range. This lungworm can depress host viability and is capable of infecting Australian frogs in laboratory trials. Despite syntopy between toads and frogs for up to 75 yr, our analyses, based on DNA sequence data of lungworms from 80 frogs and 56 toads, collected from 2008 to 2011, did not reveal any cases of host switching in nature: toads and native frogs retain entirely different lungworm faunas. All lungworms in cane toads were the South and Central American species Rhabdias pseudosphaerocephala, whereas Australian frogs contained at least four taxa (mostly undescribed and currently lumped under the name Rhabdias cf. hylae). General patterns of prevalence and intensity, based on the dissection of 1,315 frogs collected between 1989 and 2011 across the toads' Australian range, show that these Australian endemic Rhabdias spp. are widely distributed geographically and across host taxa but are more common in some frog species (especially, large-bodied species) than they are in others.
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In the scientific literature, the term of addiction is currently used to describe a whole range of phenomena characterized by an irresistible urge to engage in a series of behaviors carried out in a repetitive and persistent manner despite accruing adverse somatic, psychological and social consequences for the individual. It has been suggested that subjects presenting such behaviors would share specific features of personality which support the appearance or are associated with these addictive behaviors. Dimensions such as alexithymia and depression have been particularly well investigated. The aim of this study was to explore the hypothesis of a specific psychopathological model relating alexithymia and depression in different addictive disorders such as alcoholism, drug addiction or eating disorders. Alexithymic and depressive dimensions were explored and analyzed through the statistical tool of path analysis in a large clinical sample of addicted patients and controls. The results of this statistical method, which tests unidirectional causal relationships between a certain number of observed variables, showed a good adjustment between the observed data and the ideal model, and support the hypothesis that a depressive dimension can facilitate the development of dependence in vulnerable alexithymic subjects. These results can have clinical implications in the treatment of addictive disorders.
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We karyotyped and sequenced 1,140 base pairs of the mitochondrial DNA cytochrome b of a specimen of Zarudny's rock shrew (Crocidura zarudnyi) from Baluchestan, southeastern Iran, to clarify its cytogenetic and molecular relationships with other Eurasian species of Crocidura. According to the karyotype (2N = 40, FN = 50), Zarudny's rock shrew belongs to the group of the lesser white-toothed shrew (C. suaveolens), which is different from other known crocidurine karyotypes, considering the combination of the diploid and fundamental number of chromosomes. Molecular results revealed that C. zarudnyi is included in a monophyletic clade with the C. suaveolens group, where it is a sister taxon to the others (mean Kimura 2-parameter distance = 9.7%).
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In recent years, previously unsuspected roles of astrocytes have been revealed, largely owing to the development of new tools enabling their selective study in situ. These exciting findings add to the large body of evidence demonstrating that astrocytes play a central role in brain homeostasis, in particular via the numerous cooperative metabolic processes they establish with neurons, such as the supply of energy metabolites and neurotransmitter recycling functions. Furthermore, impairments in astrocytic function are increasingly being recognized as an important contributor to neuronal dysfunction and, in particular, neurodegenerative processes. In this review, we discuss recent evidence supporting important roles for astrocytes in neuropathological conditions such as neuroinflammation, amyotrophic lateral sclerosis and Alzheimer's disease. We also explore the potential for neuroprotective therapeutics based on the modulation of astrocytic functions.
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The shape of alliance processes over the course of psychotherapy has already been studied in several process-outcome studies on very brief psychotherapy. The present study applies the shape-of-change methodology to short-term dynamic psychotherapies and complements this method with hierarchical linear modeling. A total of 50 psychotherapies of up to 40 sessions were included. Alliance was measured at the end of each session. The results indicate that a linear progression model is most adequate. Three main patterns were found: stable, linear, and quadratic growth. The linear growth pattern, along with the slope parameter, was related to treatment outcome. This study sheds additional light on alliance process research, underscores the importance of linear alliance progression for outcome, and also fosters a better understanding of its limitations.
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The shrews of the Sorex araneus group, characterized by the sexual chromosome complex XY1, Y2 have been intensively studied by morphological, karyotypical, and biochemical analyses. Nevertheless, the phylogenetic relationships among the species belonging to the araneus complex are still under debate, as different approaches gave often contradictory results. In this paper, partial nucleotide sequences of the mitochondrial DNA cytochrome b gene (1011 bp) were determined for 6 species of the araneus group from Eurasia and North America. We also included in the data set the sequences of Sorex samniticus, whose relationships with the araneus group remain controversial. Three other species representing two major karyological groups were also examined. Both parsimony and distance trees strongly support the monophyly of the araneus group. Sorex sumniticus is significantly more closely related to the araneus complex than to the other species included in the analysis. Based on the branching pattern within the araneus group, an attempt has been made to reconstruct the colonization history of the Holarctic region.
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Traditionally, the Drosophila guarani species group has been divided into two subgroups: the guarani and the guaramunu subgroups. Two, out of the four species included in this research, are members of the guarani subgroup (D. ornatifrons Duda, 1927 and D. subbadia Paterson & Mainland, 1943) and two are included in the guaramunu subgroup (D. maculifrons Duda, 1927 and D. griseolineata Duda, 1927). However, some authors have suggested that D. maculifrons and D. griseolineata are much closer to some species of the Drosophila tripunctata group than to some of the species of the guarani group. To add new data to the matter under dispute, Polyacrylamide Gel Eletrophoresis (PAGE-SDS) was used for the analysis and comparison of protein composition and Random Amplified Polymorphic DNA (RAPD) analysis to find differences in genomic DNA, in addition to the analysis of quantitative morphological characters previously described. Analysis of PAGE-SDS results in a dendrogram that pointed out D. subbadia as being the most distant within the Drosophila guarani group. However, these results were not supported either by RAPD analysis or by the analysis of continuous morphological characters, which supplied the clustering of D. subbadia with D. ornatifrons. Although our data give strong support to the clustering of D. subbadia and D. ornatifrons, none of the dendrograms provided a clade comprising D. maculifrons and D. griseolineata. Thus, this research does not support the traditional subdivision of the D. guarani group into those two subgroups.
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Introduction: Pain and beliefs have an influence on the patient's course in rehabilitation, pain causes fears and fears influence pain perception. The aim of this study is to understand pain and beliefs evolutions during rehabilitation taking into account of bio-psycho-social complexity.Patients and methods: 631 consecutive patients admitted in rehabilitation after a musculoskeletal traumatism were included and assessed at admission and at discharge. Pain was measured by VAS (Visual Analogical Scale), bio-psycho-social complexity by Intermed scale, and beliefs by judgement on Lickert scales. Four kinds of beliefs were evaluated: fear of a severe origin of pain, fear of movement, fear of pain and feeling of distress (loss of control). The association between the changes in pain and beliefs during the hospitalization was assessed by linear regressions.Results: After adjustment for gender, age, education and native language, patients with a decrease in pain during rehabilitation have higher probability of decreasing their fears. For the distress feeling, this relationship is weaker among bio-psycho-socially complex patients (odds-ratio 1.22 for each decreasing of 10mm/100 VAS) than among non-complex patients (OR 1.47). Patients with a pain decrease of 30% or more during hospitalization have higher probability of seeing their fears decrease, this relationship being stronger in complex patient for fear of a severe origin of pain.Discussion: The relationships between evolution of pain and beliefs move in the same direction. The higher a patient feels pain, the less they could be able to modify their dysfunctional beliefs. When the pain diminishes of 30% or more, the probability to challenge the beliefs is increased. The prognostic with regard to feeling of distress and fear of a severe origin of pain, is worse among bio-psycho-socially complex patients.
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Cordiluroides Albuquerque is a genus of Neotropical Coenosiinae (Muscidae), known from six species. The genus is here recorded for the first time from Costa Rica, on the basis of three species: C. listrata Albuquerque, 1954, C. insularis (Willliston, 1896) and C. bistriata (Wulp, 1896) sp. rev.. We provide a key for the identification of these Costa Rican species, redescribe and illustrate their external morphological characters and terminalia. C. bistriata and C. vittifera (Stein, 1904) are both considered to be good species and are re-instated from the synonymy of C. insularis. The type material of C. listrata (Museu Nacional, Rio de Janeiro), of C. insularis and C. bistriata (The Natural History Museum, London) and of C. vittifera (Museum für Naturkunde, Humboldt-Universität zu Berlin) has been examined.