645 research outputs found

    Higher Body Mass Index Values Do Not Impact Physical Function and Lower-Extremity Muscle Strength Performance in Active Older Individuals

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    International Journal of Exercise Science 15(3): 330-340, 2022. This study examined the potential impact of BMI on physical function and lower-extremity muscle strength (leg extension and flexion peak torque) performance in active/trained older individuals. Sixty-four active/trained older individuals were enrolled, and later allocated to groups according to BMI categories (normal [≤ 24.9 kg/m2], overweight [25 to 29.9 kg/m2] and obese [≥ 30 kg/m2]). Sixty-four active/trained older individuals were enrolled, and later allocated to groups according to BMI categories (normal [≤ 24.9 kg/m2], overweight [25 to 29.9 kg/m2] and obese [≥ 30 kg/m2]). Assessments were conducted in two separate visits to the laboratory. In the first visit, participants underwent measures of height, body mass, and peak torque leg extension and flexion using an isokinetic dynamometer. On visit two, participants performed the 30-second Sit and Stand test (30SST), Timed Up and Go (TUG), and 6-minute Walk (6MW) tests. ANOVA one-way was used to analyze the data and significance was set at P \u3c .05. One-way ANOVAs did not reveal significance differences among BMI categories for leg extension peak torque (F(2,61) = 1.11; P = 0.336), leg flexion peak torque (F(2,61) = 1.22; P = 0.303), 30SST (F(2,61) =1.28; P = 0.285), TUG (F(2,61) = 0.238; P = 0.789), and 6MW (F(2,61) = 2.52; P = 0.089)]. Our findings indicated that for older individuals who exercise regularly, physical function tests which mimic ordinary activities of daily living, are not impacted by BMI status. Thus, being physically active may counteract some of the negative effects of high BMI observed in the older adult population

    Gene duplication in an African cichlid adaptive radiation

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    Background Gene duplication is a source of evolutionary innovation and can contribute to the divergence of lineages; however, the relative importance of this process remains to be determined. The explosive divergence of the African cichlid adaptive radiations provides both a model for studying the general role of gene duplication in the divergence of lineages and also an exciting foray into the identification of genomic features that underlie the dramatic phenotypic and ecological diversification in this particular lineage. We present the first genome-wide study of gene duplication in African cichlid fishes, identifying gene duplicates in three species belonging to the Lake Malawi adaptive radiation (Metriaclima estherae, Protomelas similis, Rhamphochromis “chilingali”) and one closely related species from a non-radiated riverine lineage (Astatotilapia tweddlei). Results Using Astatotilapia burtoni as reference, microarray comparative genomic hybridization analysis of 5689 genes reveals 134 duplicated genes among the four cichlid species tested. Between 51 and 55 genes were identified as duplicated in each of the three species from the Lake Malawi radiation, representing a 38%–49% increase in number of duplicated genes relative to the non-radiated lineage (37 genes). Duplicated genes include several that are involved in immune response, ATP metabolism and detoxification. Conclusions These results contribute to our understanding of the abundance and type of gene duplicates present in cichlid fish lineages. The duplicated genes identified in this study provide candidates for the analysis of functional relevance with regard to phenotype and divergence. Comparative sequence analysis of gene duplicates can address the role of positive selection and adaptive evolution by gene duplication, while further study across the phylogenetic range of cichlid radiations (and more generally in other adaptive radiations) will determine whether the patterns of gene duplication seen in this study consistently accompany rapid radiation

    Homologous Flares and Magnetic Field Topology in Active Region NOAA 10501 on 20 November 2003

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    We present and interpret observations of two morphologically homologous flares that occurred in active region (AR) NOAA 10501 on 20 November 2003. Both flares displayed four homologous H-alpha ribbons and were both accompanied by coronal mass ejections (CMEs). The central flare ribbons were located at the site of an emerging bipole in the center of the active region. The negative polarity of this bipole fragmented in two main pieces, one rotating around the positive polarity by ~ 110 deg within 32 hours. We model the coronal magnetic field and compute its topology, using as boundary condition the magnetogram closest in time to each flare. In particular, we calculate the location of quasiseparatrix layers (QSLs) in order to understand the connectivity between the flare ribbons. Though several polarities were present in AR 10501, the global magnetic field topology corresponds to a quadrupolar magnetic field distribution without magnetic null points. For both flares, the photospheric traces of QSLs are similar and match well the locations of the four H-alpha ribbons. This globally unchanged topology and the continuous shearing by the rotating bipole are two key factors responsible for the flare homology. However, our analyses also indicate that different magnetic connectivity domains of the quadrupolar configuration become unstable during each flare, so that magnetic reconnection proceeds differently in both events.Comment: 24 pages, 10 figures, Solar Physics (accepted

    Pressure-driven instabilities in astrophysical jets

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    Astrophysical jets are widely believed to be self-collimated by the hoop-stress due to the azimuthal component of their magnetic field. However this implies that the magnetic field is largely dominated by its azimuthal component in the outer jet region. In the fusion context, it is well-known that such configurations are highly unstable in static columns, leading to plasma disruption. It has long been pointed out that a similar outcome may follow for MHD jets, and the reasons preventing disruption are still not elucidated, although some progress has been accomplished in the recent years. In these notes, I review the present status of this open problem for pressure-driven instabilities, one of the two major sources of ideal MHD instability in static columns (the other one being current-driven instabilities). I first discuss in a heuristic way the origin of these instabilities. Magnetic resonances and magnetic shear are introduced, and their role in pressure-driven instabilities discussed in relation to Suydam's criterion. A dispersion relation is derived for pressure-driven modes in the limit of large azimuthal magnetic fields, which gives back the two criteria derived by Kadomtsev for this instability. The growth rates of these instabilities are expected to be short in comparison with the jet propagation time. What is known about the potential stabilizing role of the axial velocity of jets is then reviewed. In particular, a nonlinear stabilization mechanism recently identified in the fusion literature is discussed. Key words: Ideal MHD: stability, pressure-driven modes; Jets: stabilityComment: 20 pages, 3 figures. Lecture given at the JETSET European school "Numerical MHD and Instabilities". To be published by Springer in the "Lectures notes in physics" serie

    Epidemiological factors related to slow progression of the acquired immune deficiency syndrome (AIDS)

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    Com o objetivo de identificação de fatores envolvidos na progressão lenta para aids, realizou-se estudo transversal para avaliação de dados epidemiológicos de indivíduos infectados pelo Vírus da Imunodeficiência Humana tipo 1 (HIV-1), atendidos no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto-USP. Foram selecionados pacientes, conforme critérios definidos, constituindo duas populações: população 1, composta por lentos progressores (P1), que possuía anticorpos anti-HIV há mais de oito anos e com ocorrência de menos de duas doenças oportunistas no último ano, e a população 2 (P2), pacientes rápidos progressores, com diagnóstico de infecção pelo HIV e doença manifesta a menos de dois anos e com mais de duas doenças oportunistas, diagnosticadas no último ano. Todos os indivíduos foram submetidos a questionário, contendo dados demográficos, profissão, ocorrência de outras doenças sexualmente transmissíveis, forma de contágio, data de diagnóstico e hábitos. O período do estudo foi de março de 1998 a outubro de 1999. Obtivemos na P1: doze homens e quatro mulheres, idade média 30,7 anos, forma de contágio predominantemente sangüínea, tempo de progressão da doença 10,5 anos; P2: 12 homens e 4 mulheres; idade média 34,8 anos, forma de contágio predominantemente sexual, tempo de progressão da doença de 1,5 anos. Tabagismo foi o principal vício em ambas as populações. Quando interrogados sobre a causa do bom estado de saúde, os indivíduos da P1 responderam estar ela relacionada à fé e ao uso adequado das medicações. Os pacientes da P2 não foram interrogados sobre a causa de seu estado de saúde. Quanto à prática sexual, nove pacientes da P1 mantinham relações, sendo cinco sem uso regular do preservativo. Na P2, apenas um paciente utilizava preservativo. Dois pacientes da P1 e um da P2 revelaram ter apresentado DST, Sífilis e Papiloma Vírus Humano. Em vista do reduzido número de pacientes, não foi possível estabelecer associação entre as variáveis estudadas e os padrões de progressão da doença. Os dados sobre hábitos não parecem contribuir para o padrão de desenvolvimento da doença. O estudo oferece um perfil epidemiológico dessas populações de pacientes.To determine the factors involved in slow progression to aids, a transverse study was conducted for the evaluation of the epidemiological data of individuals infected with type 1 human immunodeficiency virus seen at the University Hospital of the Faculty of Medicine of Ribeirão Preto-USP. Patients were choosed in conformity some judgment, establish two populations: population 1, consisting of slow progressors (P1), had been carrying HIV antibodies for more than 8 years, with the occurrence of less than 2 opportunistic diseases in the last year, and population 2 (P2), consisting of rapid progressors, had a diagnosis of HIV infection and overt disease detected less than 2 years before and more than 2 opportunistic diseases diagnosed during the last year. All patients responded to a questionnaire concerning demographic data, profession, occurrence of other sexually transmissible diseases, form of contagion, date of diagnosis, and habits. The study was conducted from March 1998 to October 1999. We obtain in the P1: 12 men and 4 women, mean age 30.7 years, predominant form of contagion: blood route, time of disease progression 10.5 years; P2 12 men and 4 women; mean age 34,8 years, predominant form of contagion: sexual, time of disease progression 1.5 years. Tabagisme was the principal vice in about populations. When asked about motivation yours good health, the subjects of P1 answered to be relationed the faith and medications use. The patients of the P2 did not answer about yours health state. Whatever the sexual custom, 9 patients of the P1 had sexual relations, five without regular use of condom. In the P2 only um patient used condom. Two patients of the P1 and one of P2 declared to have STD, syphilis and Human Papiloma Virus (HPV). Because there are reduces number of patients it’s impossible to make asociation between the variables studies and mesures of the disease progression. The dates about habits don’t contribute for the disease development. The study offers an epidemiological profile of these patient populations

    Soccer and homosexuality: the conflicts that lie within the affective game of the coach-adolescent athlete relationship

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    Discussions regarding homosexuality within a sports context are mediated by emotional nuances, especially in the world of soccer, where practitioners are required to have attributes such as strength, masculinity and aggressiveness. As a consequence, this work aimed to analyze the symbolic representation of homosexual relationships between adolescent soccer players and their coaches; and, furthermore, to understand the intention behind homoerotic relationships that are established between members of the management team and its players. In this study, researchers used the life history methodology, with participation from three adolescent athletes, ages 14, 15 and 16, and three former athletes, ages 26, 28 and 45, who we called speakers. Based on the collection and analysis of research participants’ testimonies, homosexual relations were found to have occurred between athletes and coaches, or between athletes and other members of the management team, as a part of a “social contract” that is exclusively linked to their professional objectives. These relationships appear to be purely objective; authentic affective links are absent, due apparently to the transient nature of the athletes in these groups. Too, this context is usually marked by the athlete’s physical and emotional vulnerability, and the agreements he makes within this context are accompanied with moral dilemmas, because such adolescents idealize the coach as a paternal archetype.“Futebol e homossexualidade: Os conflitos que se encontram dentro do jogo afetivo da relação treinador-atleta adolescente.” As discussões a respeito da homossexualidade no contexto esportivo são mediadas por nuanças emocionais, especialmente no mundo do futebol que exige de seus praticantes atributos de força, virilidade e agressividade. Por este motivo este trabalho teve como objetivos diagnosticar existência de relações homossexuais entre atletas adolescentes da modalidade de futebol e seus técnicos e sua representação simbólica e ainda, compreender a intencionalidade das relações homoafetivas que se estabelecem entre componentes da equipe diretiva e os jogadores. Esta pesquisa é de natureza qualitativa e a técnica adotada foi a “história de vida” e a participação de três atletas adolescentes em atividade, com idade de 14, 15 e 16 anos e três ex-atletas profissionais, com idades 26, 28 e 45 anos serviram de base metodológica. A partir da análise e tratamento dos depoimentos verificou-se que ocorreram relações homossexuais nas categorias de base envolvendo técnico e atleta, ou com outros membros da equipe diretiva, como parte dos contratos sociais, ligados exclusivamente a objetivos profissionais. Estas relações parecem ser puramente objetais, não parecendo existir vínculos afetivos duradouros, aparentemente, devido à natureza transitória de atletas nesses grupos. Também, nesses ambientes, muitas vezes marcados pela vulnerabilidade física e emocional dos atletas, os acertos para as relações homossexuais são permeadas por dilemas morais, tendo em vista que os atletas adolescentes idealizam o treinador como o arquétipo paterno ideal.“El fútbol y la homosexualidad: Los conflictos que se encuentran dentro del juego afectivo de la relación atleta-entrenador de los adolescentes.” Las discusiones sobre la homosexualidad en contexto deportivo están mediadas por matices emocionales, sobre todo en el mundo del fútbol que exige a sus jugadores atributos como la fuerza, la virilidad y los jugadores. En este estudio, los investigadores utilizaron la metodología de la historia de vida, con la participación de tres atletas adolescentes, con 14, 15 y 16 años, y tres ex atletas con 26, 28 y 45 años, que llamamos ‘oradores’. Basado en la recogida y análisis de testimonios de participantes en la investigación, se encontró que las relaciones homosexuales que se han producido entre los atletas y entrenadores, o entre atletas y otros miembros del equipo de gestión, son como parte de un “contrato social” que está vinculado exclusivamente a sus objetivos profesionales. Estas relaciones parecen ser solamente como un objeto; porque a veces no hay vínculos afectivos auténticos, debido aparentemente a la naturaleza transitoria de los atletas en estos grupos. Demasiado, este contexto es generalmente marcado por la vulnerabilidad física y emocional del deportista, y los acuerdos que hace dentro de este contexto se acompañan con dilemas morales, debido a que tales adolescentes idealizan el entrenador como un arquetipo paterno. la agresividad. Por lo tanto, este estudio tuvo como objetivo diagnosticar la existencia de relaciones homosexuales entre adolescentes atletas de fútbol y sus entrenadores y la representación simbólica de estas relaciones. También comprender la intencionalidad de las relaciones homoafetivas que se intercambian entre algunos componentes del equipo directivo y(undefined
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