122 research outputs found

    Evaluation de l'applicabilité d'outils de communication du risque en prévention cardiovasculaire auprès de patients dyslipidémiques

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    Contexte : Dans le contexte de la prévention des maladies cardiovasculaires (MCV), il est recommandé d'estimer quantitativement le risque cardiovasculaire (RCV) global des patients, en tenant compte de l'ensemble de leurs facteurs de risque cardiovasculaire (FRCV). Le manque d'implication des patients dans les prises de décision, pouvant notamment provenir de la difficulté à expliquer et comprendre le RCV, est un obstacle majeur à une prévention efficace. Or, le partage de la décision entre patients et médecins relève d'une importance particulière lorsqu'il est question de prévention cardiovasculaire, du fait des changements de mode de vie évoqués. La façon de présenter aux patients l'information concernant leur risque médical, et en particulier le format de présentation, influencent leurs perceptions, opinions, décisions et comportements. Des outils d'aide à la décision, dont des outils de communication du risque, ont donc été développés afin d'aider à surmonter les barrières au partage décisionnel. Leur utilisation pourrait ainsi améliorer l'adhésion des patients aux mesures préventives, augmenter l'efficacité de la prévention cardiovasculaire et, ultimement, réduire le fardeau des MCV. But et objectifs : Evaluer l'applicabilité de deux outils de communication du risque en prévention cardiovasculaire, auprès de patients dyslipidémiques. Plus particulièrement, étudier les effets de ces outils sur la vision des patients de leur RCV et sur leur implication dans le processus décisionnel. Méthodologie : Les patients dyslipidémiques de la consultation des lipides de la PMU de Lausanne ont été randomisés dans un groupe « Intervention » (présentation du RCV par les deux outils de communication lors d'un entretien personnel à la suite d'une consultation spécialisée) et un groupe « Témoin » (consultation spécialisée ordinaire). Des données anthropométriques, ainsi que sur les paramètres vitaux, le profil lipidique et les FRCV des participants ont été compilées. Un questionnaire soumis aux patients a permis de récolter des informations sociodémographiques ainsi que des données sur la perception de leur RCV, l'inquiétude au sujet de leur RCV, la compréhension de leur RCV, leur implication dans le processus décisionnel et l'utilité des outils le cas échéant. Résultats : 82 patients ont pris part à l'étude, dont 42 ont bénéficié de l'intervention. Les groupes « Intervention » et « Témoin » ont été randomisés de façon homogène et ne différaient pas significativement quant aux données sociodémographiques, données anthropométriques, paramètres vitaux, profil lipidique, FRCV et RCV. L'utilisation des outils de communication dans le groupe « Intervention » a permis d'améliorer la justesse de la perception du RCV (i.e. la concordance entre le risque réel et le risque perçu par les patients). Aucune différence significative n'a été mise en évidence entre les deux groupes en ce qui concerne l'inquiétude au sujet du RCV, l'adéquation de cette inquiétude (i.e. la relation positive entre le RCV et l'inquiétude), ainsi que la compréhension du RCV. L'implication subjective des patients dans le processus décisionnel ne diffère pas de façon statistiquement significative après l'emploi des outils de communication. Enfin, la majorité des patients interrogés voient les outils de communication présentés comme des aides utiles, que ce soit pour la communication de leur RCV ou pour leur implication future dans le partage de la décision médicale. Conclusion : Les résultats de cette étude semblent montrer que les outils de communication du risque évalués sont applicables en prévention cardiovasculaire et qu'ils sont bien perçus par les patients. Ils représentent une aide à la communication du RCV très intéressante, en permettant notamment d'améliorer la perception du risque des patients. Ils ne paraissent pas modifier l'inquiétude, la compréhension ni l'implication subjectives des patients, du moins à court terme. Par conséquent, nous sommes persuadés que le développement et l'étude de tels outils doivent être encouragés, dans l'optique d'offrir de nouvelles possibilités de communication et d'impliquer les patients dans le partage de la décision

    Temperature dependence of the coercive field in single-domain particle systems

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    The magnetic properties of Cu97Co3 and Cu90Co10 granular alloys were measured over a wide temperature range (2 to 300K). The measurements show an unusual temperature dependence of the coercive field. A generalized model is proposed and explains well the experimental behavior over a wide temperature range. The coexistence of blocked and unblocked particles for a given temperature rises difficulties that are solved here by introducing a temperature dependent blocking temperature. An empirical factor gamma arise from the model and is directly related to the particle interactions. The proposed generalized model describes well the experimental results and can be applied to other single-domain particle system.Comment: 7 pages, 8 figures, revised version, accepted to Physical Review B on 29/04/200

    Effects of Learning Rate on the Performance of the Population Based Incremental Learning Algorithm

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    The effect of learning rate (LR) on the performance of a newly introduced evolutionary algorithm called population-based incremental learning (PBIL) is investigated in this paper. PBIL is a technique that combines a simple genetic algorithm (GA) with competitive learning (CL). Although CL is often studied in the context of artificial neural networks (ANNs), it plays a vital role in PBIL in that the idea of creating a prototype vector in learning vector quantization (LVQ) is central to PBIL. In PBIL, the crossover operator of GAs is abstracted away and the role of population is redefined. PBIL maintains a real-valued probability vector (PV) or prototype vector from which solutions are generated. The probability vector controls the random bitstrings generated by PBIL and is used to create other individuals through learning. The setting of the learning rate (LR) can greatly affect the performance of PBIL. However, the effect of the learning rate in PBIL is not yet fully understood. In this paper, PBIL is used to design power system stabilizers (PSSs) for a multi-machine power system. Four cases studies with different learning rate patterns are investigated. These include fixed LR; purely adaptive LR; fixed LR followed by adaptive LR; and adaptive LR followed by fixed LR. It is shown that a smaller learning rate leads to more exploration of the algorithm which introduces more diversity in the population at the cost of slower convergence. On the other hand, a higher learning rate means more exploitation of the algorithm and hence, this could lead to a premature convergence in the case of fixed LR. Therefore, in setting the LR, a trade-off is needed between exploitation and exploration

    Poincar\'e and sl(2) algebras of order 3

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    In this paper we initiate a general classification for Lie algebras of order 3 and we give all Lie algebras of order 3 based on sl(2,C)\mathfrak{sl}(2,\mathbb C) and iso(1,3)\mathfrak{iso}(1,3) the Poincar\'e algebra in four-dimensions. We then set the basis of the theory of the deformations (in the Gerstenhaber sense) and contractions for Lie algebras of order 3.Comment: Title and presentation change

    Growing towards disparity: geometric morphometrics reveals sexual and allometric differences in Aparasphenodon brunoi (Anura: Hylidae: Lophyohylinae) head shape

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    Sexual dimorphism and allometry feature is the main categories of intraspecific variation found in the animal kingdom, and techniques such as Geometric Morphometrics are effective to investigate variations in shape. Considering that many vertebrates exhibit substantial allometry and sexual dimorphism, we test the hypotheses that (1) Aparasphenodon brunoi displays ontogenetic and static allometry; and that (2) there is sexual dimorphism in head shape in this species. We analyzed 75 specimens of A. brunoi from Parque Nacional da Restinga de Jurubatiba and found significant ontogenetic and static allometries in head shape, as well as sexual dimorphism after size correction. Regarding sexual dimorphism, females tend to have larger heads, besides slightly anteriorly positioned nostrils, smaller eyes, larger canthal ridges, narrower and longer frontoparietal ridges, and larger and laterally shifted squamosal ridges. We discuss the relevance of head morphology variation in the species, as well as the presumed consequences on the species fitness.Dimorfismo sexual e alometria são as principais categorias de variação intraespecífica encontradas em metazoários e técnicas como a Morfometria Geométrica são eficazes para investigar variações na forma. Considerando que muitos vertebrados exibem considerável alometria e dimorfismo sexual, testamos as seguintes hipóteses: (1) Aparasphenodon brunoi exibe alometria ontogenética e estática; e (2) existe dimorfismo sexual na forma da cabeça nesta espécie. Analisamos 75 espécimes de A. brunoi do Parque Nacional da Restinga de Jurubatiba e encontramos alometrias ontogenética e estática significativas na forma da cabeça, além de dimorfismo sexual após a correção do tamanho. Em relação ao dimorfismo sexual, as fêmeas tendem a ter cabeças maiores, além de narinas ligeiramente posicionadas mais anteriormente, olhos menores, cristas cantais maiores, cristas frontoparietais mais estreitas e mais longas e cristas esquamosais maiores e deslocadas lateralmente. Discutimos a relevância da variação da morfologia da cabeça na espécie, bem como as consequências presumidas na aptidão da mesma.Asociación Herpetológica Argentin

    Growing towards disparity: geometric morphometrics reveals sexual and allometric differences in Aparasphenodon brunoi (Anura: Hylidae: Lophyohylinae) head shape

    Get PDF
    Sexual dimorphism and allometry feature is the main categories of intraspecific variation found in the animal kingdom, and techniques such as Geometric Morphometrics are effective to investigate variations in shape. Considering that many vertebrates exhibit substantial allometry and sexual dimorphism, we test the hypotheses that (1) Aparasphenodon brunoi displays ontogenetic and static allometry; and that (2) there is sexual dimorphism in head shape in this species. We analyzed 75 specimens of A. brunoi from Parque Nacional da Restinga de Jurubatiba and found significant ontogenetic and static allometries in head shape, as well as sexual dimorphism after size correction. Regarding sexual dimorphism, females tend to have larger heads, besides slightly anteriorly positioned nostrils, smaller eyes, larger canthal ridges, narrower and longer frontoparietal ridges, and larger and laterally shifted squamosal ridges. We discuss the relevance of head morphology variation in the species, as well as the presumed consequences on the species fitness.Dimorfismo sexual e alometria são as principais categorias de variação intraespecífica encontradas em metazoários e técnicas como a Morfometria Geométrica são eficazes para investigar variações na forma. Considerando que muitos vertebrados exibem considerável alometria e dimorfismo sexual, testamos as seguintes hipóteses: (1) Aparasphenodon brunoi exibe alometria ontogenética e estática; e (2) existe dimorfismo sexual na forma da cabeça nesta espécie. Analisamos 75 espécimes de A. brunoi do Parque Nacional da Restinga de Jurubatiba e encontramos alometrias ontogenética e estática significativas na forma da cabeça, além de dimorfismo sexual após a correção do tamanho. Em relação ao dimorfismo sexual, as fêmeas tendem a ter cabeças maiores, além de narinas ligeiramente posicionadas mais anteriormente, olhos menores, cristas cantais maiores, cristas frontoparietais mais estreitas e mais longas e cristas esquamosais maiores e deslocadas lateralmente. Discutimos a relevância da variação da morfologia da cabeça na espécie, bem como as consequências presumidas na aptidão da mesma.Asociación Herpetológica Argentin

    Growing towards disparity: geometric morphometrics reveals sexual and allometric differences in Aparasphenodon brunoi (Anura: Hylidae: Lophyohylinae) head shape

    Get PDF
    Sexual dimorphism and allometry feature is the main categories of intraspecific variation found in the animal kingdom, and techniques such as Geometric Morphometrics are effective to investigate variations in shape. Considering that many vertebrates exhibit substantial allometry and sexual dimorphism, we test the hypotheses that (1) Aparasphenodon brunoi displays ontogenetic and static allometry; and that (2) there is sexual dimorphism in head shape in this species. We analyzed 75 specimens of A. brunoi from Parque Nacional da Restinga de Jurubatiba and found significant ontogenetic and static allometries in head shape, as well as sexual dimorphism after size correction. Regarding sexual dimorphism, females tend to have larger heads, besides slightly anteriorly positioned nostrils, smaller eyes, larger canthal ridges, narrower and longer frontoparietal ridges, and larger and laterally shifted squamosal ridges. We discuss the relevance of head morphology variation in the species, as well as the presumed consequences on the species fitness.Dimorfismo sexual e alometria são as principais categorias de variação intraespecífica encontradas em metazoários e técnicas como a Morfometria Geométrica são eficazes para investigar variações na forma. Considerando que muitos vertebrados exibem considerável alometria e dimorfismo sexual, testamos as seguintes hipóteses: (1) Aparasphenodon brunoi exibe alometria ontogenética e estática; e (2) existe dimorfismo sexual na forma da cabeça nesta espécie. Analisamos 75 espécimes de A. brunoi do Parque Nacional da Restinga de Jurubatiba e encontramos alometrias ontogenética e estática significativas na forma da cabeça, além de dimorfismo sexual após a correção do tamanho. Em relação ao dimorfismo sexual, as fêmeas tendem a ter cabeças maiores, além de narinas ligeiramente posicionadas mais anteriormente, olhos menores, cristas cantais maiores, cristas frontoparietais mais estreitas e mais longas e cristas esquamosais maiores e deslocadas lateralmente. Discutimos a relevância da variação da morfologia da cabeça na espécie, bem como as consequências presumidas na aptidão da mesma.Asociación Herpetológica Argentin

    Symmetries, Associated First Integrals, and Double Reduction of Difference Equations

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    We determine the symmetry generators of some ordinary difference equations and proceeded to find the first integral and reduce the order of the difference equations. We show that, in some cases, the symmetry generator and first integral are associated via the "invariance condition. " That is, the first integral may be invariant under the symmetry of the original difference equation. When this condition is satisfied, we may proceed to double reduction of the difference equation

    Susceptibility of Aedes albopictus and Culex quinquefasciatus to Japanese encephalitis virus; 35710580

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    Background: Japanese encephalitis virus (JEV) is the principal cause of mosquito-borne encephalitis in human populations within Asia. If introduced into new geographic areas, it could have further implications for public and animal health. However, potential mosquito vectors for virus transmission have not been fully investigated. The Asian tiger mosquito, Aedes albopictus, has emerged in Europe and is now expanding its geographical range into more northerly latitudes. Culex quinquefasciatus, although absent from Europe, has been detected in Turkey, a country with territory in Europe, and could act as a vector for JEV in other regions. To assess the risk of these invasive species acting as vectors for JEV and therefore potentially contributing to its geographical expansion, we have investigated the vector competence of Ae. albopictus and Cx. quinquefasciatus. Methods: Two colonised lines of Ae. albopictus (Italy and Spain) and a line of Cx. quinquefasciatus (Tanzania) were compared for susceptibility to infection by oral feeding with JEV strain SA-14, genotype III at 106 PFU/ml and maintained at 25 °C. Specimens were processed at 7 and 14 days post-inoculation (dpi). Rates of infection, dissemination and transmission were assessed through detection of viral RNA by real-time polymerase chain reaction (RT-PCR) in mosquito body, legs and saliva, respectively, at each time point. Where possible, infection and dissemination were confirmed by immunohistochemical (IHC) detection of the JEV envelope protein. Results: Aedes albopictus from Italy showed no susceptibility to infection with JEV strain SA-14. Conversely, Ae. albopictus colonised in Spain was susceptible and 100% of infected mosquitoes that were subjected to saliva screening expressed viral RNA at 14 dpi. Culex quinquefasciatus was highly susceptible to infection as early as 7 dpi and 50% of infected mosquitoes that were subjected to saliva screening expressed viral RNA at 14 dpi. Infection and dissemination were confirmed in Cx. quinquefasciatus by IHC detection of JEV envelope protein in both the mid-gut and salivary glands. Conclusions: Aedes albopictus from two different locations in Europe range from being susceptible to JEV and capable of transmission through to being resistant. Culex quinquefasciatus also appears highly susceptible; therefore, both species could potentially act as vectors for JEV and facilitate the emergence of JEV into new regions. Graphical Abstract: Figure not available: see fulltext.] © 2022, The Author(s)
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