530 research outputs found

    Propagation of social representations

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    Based on a minimal formalism of social representations as a set of associated cognems, a simple model of propagation of representations is presented. Assuming that subjects share the constitutive cognems, the model proposes that mere focused attention on the set of cognems in the field of common conscience may replicate the pattern of representation from context into subjects, or, from subject to subject, through actualization by language, where cognems are represented by verbal signs. Limits of the model are discussed, and evolutionist perspectives are presented with the support of field data

    Reproduction and adaptation characteristics in D’man sheep

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    D’man breed (D) is found in the oasis of the subsaharian regions of Morocco and reared usually in sedentary type of management with small flocks (< 10 ewes). Preliminary field surveys showed that D is early maturing, prolific and aseasonal. Hence, a multidisciplinary research programme on D was started in 1974. This paper reports the findings of these studies and describes the approach used to (1) characterize and evaluate the performances of D in field and station, (2) study the physiological mechanism involved in its peculiar reproduction and production, (3) study the genetic basis of reproduction parameters, and (4) evaluate use of D in crossbreeding schemes to improve the productivity of other Moroccoan breeds. Results show that D is one of the rare breeds that is simultaneously early maturing, highly prolific and completely aseasonal. However, studies on water turnover and nitrogen recycling show that D is not well adapted to hot climate and poor nutrition. Its reproduction parameters are relatively independent of photoperiod and related to a low sensitivity to negative oestrogen feedback. D male is characterized by high libido and can be used for synchronizing oestruses through the »ram effect». Crossbreeding experiments with non-prolific sheep confirm the heritability of reproductive parameters. However, the genetic basis for these is not yet well known

    Rôle du laboratoire dans le diagnostic virologique de la grippe pandémique A(H1N1)v

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    La nouvelle grippe pandémique, apparue au mois d’avril 2009 au Mexique est encore appelée grippe porcine. Elle est due à un nouveau virus Influenza A(H1N1)v, totalement inédit, jamais identifié auparavant dans aucune espèce et résulte de réassortiments génétiques complexes. Le rôle du laboratoire est fondamental pour le diagnostic virologique de cette grippe émergente. Il permet d’apporter la certitude du diagnostic chez des patients dont le contexte clinico-épidémiologique est évocateur d’une infection par le virus A(H1N)v. La confirmation virologique d’un cas d’infection due à ce virus est apportée par la positivité des tests de laboratoire suivants: RT-PCR et/ou culture virale et/ou multiplication par quatre du taux des anticorps neutralisants spécifiques dirigés contre le virus A(H1N1)v sur une paire de sérums prélevés à deux semaines d'intervalle. La RT-PCR en temps réel, représente à l’heure actuelle un outil de choix en raison de sa rapidité, sensibilité et spécificité. Les tests immunologiques de diagnostic rapide (TDR) permettent de détecter la présence des antigènes de la nucléoprotéine des virus grippaux saisonniers de type A et B. L’évaluation de ces tests a montré, dans le contexte pandémique actuel, une faible sensibilité ne leur conférant pas une valeur prédictive négative compatible avec une utilisation généralisée. Leurs résultats doivent être interprétés avec prudence et malgré leur bonne valeur prédictive positive, ils ne permettent qu’un diagnostic de présomption, une confirmation par RT-PCR en temps réel sera conduite chaque fois que cela est nécessaire

    Chemical composition, antinociceptive and anti-inflammatory effects in rodents of the essential oil of Peperomia serpens (Sw.) Loud

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    AbstractEthnopharmacological relevancePeperomia serpens (Piperaceae), popularly known as “carrapatinho”, is an epiphyte herbaceous liana grown wild on different host trees in the Amazon rainforest. Its leaves are largely used in Brazilian folk medicine to treat inflammation, pain and asthma.Aim of the studyThis study investigated the effects of essential oil of Peperomia serpens (EOPs) in standard rodent models of pain and inflammation.Materials and methodsThe antinociceptive activity was evaluated using chemical (acetic acid and formalin) and thermal (hot plate) models of nociception in mice whereas the anti-inflammatory activity was evaluated by carrageenan- and dextran-induced paw edema tests in rats croton oil-induced ear edema, as well as cell migration, rolling and adhesion induced by carrageenan in mice. Additionally, phytochemical analysis of the EOPs has been also performed.ResultsChemical composition of the EOPs was analyzed by gas chromatography and mass spectrometry (GC/MS). Twenty-four compounds, representing 89.6% of total oil, were identified. (E)-Nerolidol (38.0%), ledol (27.1%), α-humulene (11.5%), (E)-caryophyllene (4.0%) and α-eudesmol (2.7%) were found to be the major constituents of the oil. Oral pretreatment with EOPs (62.5–500mg/kg) significantly reduced the writhing number evoked by acetic acid injection, with an ED50 value of 188.8mg/kg that was used thereafter in all tests. EOPs had no significant effect on hot plate test but reduced the licking time in both phases of the formalin test, an effect that was not significantly altered by naloxone (0.4mg/kg, s.c.). EOPs inhibited the edema formation induced by carrageenan and dextran in rats. In mice, EOPs inhibited the edema formation by croton oil as well as the leukocyte and neutrophil migration, the rolling and the adhesion of leukocytes.ConclusionsThese data show for the first time that EOPs has a significant and peripheral antinociceptive effect that seems unrelated to interaction with the opioid system. EOPs also displays a significant anti-inflammatory effect in acute inflammation models. This effect seems to be related to components which inhibit the production of several inflammatory mediators. These results support the widespread use of Peperomia serpens in popular medicine to treat inflammation and pain

    Focal adhesion kinase contributes to proliferative potential of ErbB2 mammary tumour cells but is dispensable for ErbB2 mammary tumour induction in vivo

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    INTRODUCTION: Activation of focal adhesion kinase (FAK) is hypothesized to play an important role in the pathogenesis of human breast cancer. METHODS: To directly evaluate the role of FAK in mammary tumour progression, we have used a conditional FAK mouse model and mouse mammary tumour virus (MMTV)-driven Cre recombinase strain to inactivate FAK in the mammary epithelium of a transgenic mouse model of ErbB2 breast cancer. RESULTS: Although mammary epithelial disruption of FAK in this model resulted in both a delay in onset and a decrease in the number of neoplastic lesions, mammary tumours occurred in 100% of virgin female mice. All of the tumours and derived metastases that developed were proficient for FAK due to the absence of Cre recombinase expression. The hyperplastic epithelia where Cre-mediated recombination of FAK could be detected exhibited a profound proliferative defect. Consistent with these observations, disruption of FAK in established tumour cells resulted in reduced tumour growth that was associated with impaired proliferation. To avoid the selection for FAK-proficient ErbB2 tumour epithelia through escape of Cre-mediated recombination, we next intercrossed the FAK conditional mice with a separate MMTV-driven ErbB2 strain that co-expressed ErbB2 and Cre recombinase on the same transcriptional unit. CONCLUSIONS: While a delay in tumour induction was noted, FAK-deficient tumours arose in 100% of female animals indicating that FAK is dispensable for ErbB2 tumour initiation. In addition, the FAK-null ErbB2 tumours retained their metastatic potential. We further demonstrated that the FAK-related Pyk2 kinase is still expressed in these tumours and is associated with its downstream regulator p130Cas. These observations indicate that Pyk2 can functionally substitute for FAK in ErbB2 mammary tumour progression

    Developing "personality" taxonomies: Metatheoretical and methodological rationales underlying selection approaches, methods of data generation and reduction principles

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    Taxonomic "personality" models are widely used in research and applied fields. This article applies the Transdisciplinary Philosophy-of-Science Paradigm for Research on Individuals (TPS-Paradigm) to scrutinise the three methodological steps that are required for developing comprehensive “personality” taxonomies: 1) the approaches used to select the phenomena and events to be studied, 2) the methods used to generate data about the selected phenomena and events and 3) the reduction principles used to extract the “most important” individual-specific variations for constructing “personality” taxonomies. Analyses of some currently popular taxonomies reveal frequent mismatches between the researchers’ explicit and implicit metatheories about “personality” and the abilities of previous methodologies to capture the particular kinds of phenomena toward which they are targeted. Serious deficiencies that preclude scientific quantifications are identified in standardised questionnaires, psychology’s established standard method of investigation. These mismatches and deficiencies derive from the lack of an explicit formulation and critical reflection on the philosophical and metatheoretical assumptions being made by scientists and from the established practice of radically matching the methodological tools to researchers’ preconceived ideas and to pre-existing statistical theories rather than to the particular phenomena and individuals under study. These findings raise serious doubts about the ability of previous taxonomies to appropriately and comprehensively reflect the phenomena towards which they are targeted and the structures of individual-specificity occurring in them. The article elaborates and illustrates with empirical examples methodological principles that allow researchers to appropriately meet the metatheoretical requirements and that are suitable for comprehensively exploring individuals’ “personality”

    Vasodilator activity of extracts of field Alpinia purpurata (Vieill) K: Schum and A. zerumbet (Pers.) Burtt et Smith cultured in vitro

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    Nowadays, the high blood pressure is one of the main causes of death and cardiovascular diseases. Vasodilator drugs are frequently used to treat arterial hypertension. Experiments were undertaken to determine whether hydroalcoholic extracts obtained from leaves of field-grown Alpinia purpurata and A. zerumbet cultured in vitro under different plant growth regulators induce a vasodilator effect on Wistar rat mesenteric vascular bed pre-contracted with norepinephrine. Plant extracts were able to induce a long-lasting endothelium-dependent vasodilation. Efficiency on activity of A. purpurata reached 87% at concentration of 60 &#956;g. The extract of A. zerumbet maintained in medium containing IAA, induced the relaxation (17.4%) at 90 &#956;g, as compared to the control (MS0) that showed a better vasodilator effect (60%). These results are in agreement with the quantification of phenolic compounds in the extracts, which were 50% lower for those plants cultured in IAA. A. purpurata was assayed for the first time in relation to its vasodilator activity. This paper showed a strong probability of correlation between the pharmacological activities of A. purpurata with their content in phenolic compounds.Atualmente, a hipertensão arterial é uma das maiores causas de morte e de doenças cardiovasculares. Os vasodilatadores são freqüentemente utilizados no tratamento da hipertensão. Extratos hidroalcoólicos de Alpinia purpurata de campo e de A. zerumbet cultivada in vitro sob diferentes reguladores de crescimento vegetal foram ensaiados no leito mesentérico de ratos Wistar. Os extratos de A. purpurata e A. zerumbet produziram efeito vasodilatador com padrão de resposta dose-dependente de duração prolongada. Extratos da espécie A. purpurata tiveram efeito vasodilatador de 87% na dose de 60 &#956;g. O extrato obtido de folhas de A. zerumbet oriundas das culturas mantidas em meio contendo AIA (ácido indol acético) inibiu o relaxamento (17,4%) na dose de 90 &#956;g em relação ao controle (MS0), com o qual foi verificado melhor efeito vasodilatador (60%). Estes resultados estão de acordo com a concentração de fenóis totais que foi 50% menor para os extratos de plantas cultivadas in vitro em AIA. A espécie A. purpurata foi pela primeira vez ensaiada quanto à atividade vasodilatadora. Os resultados obtidos indicaram a presença de substâncias fenólicas provavelmente correlacionadas à ação terapêutica de A. purpurata

    Conceiving “personality”: Psychologist’s challenges and basic fundamentals of the Transdisciplinary Philosophy-of-Science Paradigm for Research on Individuals

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    Scientists exploring individuals, as such scientists are individuals themselves and thus not independent from their objects of research, encounter profound challenges; in particular, high risks for anthropo-, ethno- and ego-centric biases and various fallacies in reasoning. The Transdisciplinary Philosophy-of-Science Paradigm for Research on Individuals (TPS-Paradigm) aims to tackle these challenges by exploring and making explicit the philosophical presuppositions that are being made and the metatheories and methodologies that are used in the field. This article introduces basic fundamentals of the TPS-Paradigm including the epistemological principle of complementarity and metatheoretical concepts for exploring individuals as living organisms. Centrally, the TPS-Paradigm considers three metatheoretical properties (spatial location in relation to individuals’ bodies, temporal extension, and physicality versus “non-physicality”) that can be conceived in different forms for various kinds of phenomena explored in individuals (morphology, physiology, behaviour, the psyche, semiotic representations, artificially modified outer appearances and contexts). These properties, as they determine the phenomena’s accessibility in everyday life and research, are used to elaborate philosophy-of-science foundations and to derive general methodological implications for the elementary problem of phenomenon-methodology matching and for scientific quantification of the various kinds of phenomena studied. On the basis of these foundations, the article explores the metatheories and methodologies that are used or needed to empirically study each given kind of phenomenon in individuals in general. Building on these general implications, the article derives special implications for exploring individuals’ “personality”, which the TPS-Paradigm conceives of as individual-specificity in all of the various kinds of phenomena studied in individuals

    Bilateral anterior dislocation of the shoulders at the start of a backstroke competition

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    Bilateral anterior dislocation of the shoulders is very rare. A 20-year-old man presented with bilateral anterior shoulder dislocation as a result of a diving incident. He complained of pain and restriction of movement in both shoulders with abducted and externally rotated arms. Radiographs revealed that the shoulders were dislocated. The patient was treated with closed reduction and was able to resume swimming 3 months later. To our knowledge, this is the first bilateral anterior dislocation of the shoulders during a backstroke swimming competition that was caused by this mechanism of injury. The rarity of this lesion and its uncommon mechanism prompted us to relate this observation
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