1,216 research outputs found

    Nanosized patterns as reference structures for macroscopic transport properties and vortex phases in YBCO films

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    This paper studies the striking correlation between nanosized structural patterns in YBCO films and macroscopic transport current. A nanosized network of parallel Josephson junctions laced by insulating dislocations is almost mimicking the grain boundary structural network. It contributes to the macroscopic properties and accounts for the strong intergranular pinning across the film in the intermediate temperature range. The correlation between the two networks enables to find out an outstanding scaling law in the (Jc,B) plane and to determine meaningful parameters concerning the matching between the vortex lattice and the intergranular defect lattice. Two asymptotic behaviors of the pinning force below the flux flow regime are checked: the corresponding vortex phases are clearly individuated.Comment: 4 pages, 4 figure

    Hydrodynamic lift of vesicles under shear flow in microgravity

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    The dynamics of a vesicle suspension in a shear flow between parallel plates has been investigated under microgravity conditions, where vesicles are only submitted to hydrodynamic effects such as lift forces due to the presence of walls and drag forces. The temporal evolution of the spatial distribution of the vesicles has been recorded thanks to digital holographic microscopy, during parabolic flights and under normal gravity conditions. The collected data demonstrates that vesicles are pushed away from the walls with a lift velocity proportional to γ˙R3/z2\dot{\gamma} R^3/z^2 where γ˙\dot{\gamma} is the shear rate, RR the vesicle radius and zz its distance from the wall. This scaling as well as the dependence of the lift velocity upon vesicle aspect ratio are consistent with theoretical predictions by Olla [J. Phys. II France {\bf 7}, 1533--1540 (1997)].Comment: 6 pages, 8 figure

    Tuberculosis treatment in a refugee and migrant population: 20 years of experience on the Thai-Burmese border.

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    Although tuberculosis (TB) is a curable disease, it remains a major global health problem and an important cause of morbidity and mortality among vulnerable populations, including refugees and migrants

    Case-Control Study of Risk Factors for Sporadic Giardiasis and Parasite Assemblages in North West England

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    Giardia duodenalis is a major cause of infectious gastroenteritis worldwide, and it is diversified into eight genetic assemblages (A to H), which are distinguishable only by molecular typing. There is some evidence that the assemblages infecting humans (assemblages A and B) may have different transmission routes, but systematically acquired data, combining epidemiological and molecular findings, are required. We undertook a case-control study with Giardia genotyping in North West England, to determine general and parasite assemblage-specific risk factors. For people without a history of foreign travel, swimming in swimming pools and changing diapers were the most important risk factors for the disease. People infected with assemblage B reported a greater number of symptoms and higher frequencies of vomiting, abdominal pain, swollen stomach, and loss of appetite, compared with people infected with assemblage A. More importantly, keeping a dog was associated only with assemblage A infections, suggesting the presence of a potential zoonotic reservoir for this assemblage. This is the first case-control study to combine epidemiological data with Giardia genotyping, and it shows the importance of integrating these two levels of information for better understanding of the epidemiology of this pathogen

    hypomyelination and congenital cataract neuroimaging features of a novel inherited white matter disorder

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    BACKGROUND AND PURPOSE: Hypomyelination and congenital cataract (HCC) is an autosomal recessive white matter disease caused by deficiency of hyccin, a membrane protein implicated in both central and peripheral myelination. We aimed to describe the neuroimaging features of this novel entity. MATERIALS AND METHODS: A systematic analysis of patients with unclassified leukoencephalopathies admitted to our institutions revealed 10 children with congenital cataract, slowly progressive neurologic impairment, and diffuse white matter abnormalities on neuroimaging. Psychomotor developmental delay was evident after the first year of life. Peripheral neuropathy was demonstrated by neurophysiologic studies in 9 children. The available neuroimaging studies were retrospectively reviewed. RESULTS: In all patients, neuroimaging revealed diffuse involvement of the supratentorial white matter associated with preservation of both cortical and deep gray matter structures. Supratentorial white matter hypomyelination was detected in all patients; 7 patients also had evidence of variably extensive areas of increased white matter water content. Deep cerebellar white matter hypomyelination was found in 6 patients. Older patients had evidence of white matter bulk loss and gliosis. Proton MR spectroscopy showed variable findings, depending on the stage of the disease. Sural nerve biopsy revealed hypomyelinated nerve fibers. Mutations in the DRCTNNB1A gene on chromosome 7p15.3, causing complete or severe deficiency of hyccin, were demonstrated in all patients. CONCLUSIONS: HCC is characterized by a combined pattern of primary myelin deficiency and secondary neurodegenerative changes. In the proper clinical setting, recognition of suggestive neuroimaging findings should prompt appropriate genetic investigations

    Inestabilidad ambiental y seguridad alimentaria global

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    Se analiza el impacto de condiciones climáticas extremas de los últimos años sobre los precios internacionales de los alimentos, encuadrados éstos dentro del proceso de Cambio Climático (CC). El objetivo directo es mostrar como un grupo de sequías en regiones productoras de granos puede inestabilizar el precio de los mismos y su impacto en la seguridad alimentaria global. Se utilizan métodos estadísticos corrientes de series temporales. En el trabajo se muestra que el alza de precios de los alimentos manifiesta como una función de Dirac fueron resultados de una sequía intensa ocurrida simultáneamente en diversas regiones de la Tierra y muertes masivas de especies animales, sumado a un efecto especulativo. Los dos primeros factores configuran un cuadro de inestabilidad ambiental que puede estar asociado al CC y la destrucción de la capa de ozono que habría permitido el ingreso de radiación nociva del espacio. Se concluye que las agencias estatales vinculadas al CC deberían integrar equipos multidisciplinarios que analicen los diversos factores intervinientes en la toma de decisiones políticas sobre la mitigación o atenuación de los efectos del fenómeno. Solamente de esta manera se lograrían resultados que permitan mantener la sustentabilidad del planeta.Eje: Economía, producción y tecnología.Universidad Nacional de La Plat

    Inestabilidad ambiental y seguridad alimentaria global

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    Se analiza el impacto de condiciones climáticas extremas de los últimos años sobre los precios internacionales de los alimentos, encuadrados éstos dentro del proceso de Cambio Climático (CC). El objetivo directo es mostrar como un grupo de sequías en regiones productoras de granos puede inestabilizar el precio de los mismos y su impacto en la seguridad alimentaria global. Se utilizan métodos estadísticos corrientes de series temporales. En el trabajo se muestra que el alza de precios de los alimentos manifiesta como una función de Dirac fueron resultados de una sequía intensa ocurrida simultáneamente en diversas regiones de la Tierra y muertes masivas de especies animales, sumado a un efecto especulativo. Los dos primeros factores configuran un cuadro de inestabilidad ambiental que puede estar asociado al CC y la destrucción de la capa de ozono que habría permitido el ingreso de radiación nociva del espacio. Se concluye que las agencias estatales vinculadas al CC deberían integrar equipos multidisciplinarios que analicen los diversos factores intervinientes en la toma de decisiones políticas sobre la mitigación o atenuación de los efectos del fenómeno. Solamente de esta manera se lograrían resultados que permitan mantener la sustentabilidad del planeta.Eje: Economía, producción y tecnología.Universidad Nacional de La Plat

    Inestabilidad ambiental y seguridad alimentaria global

    Get PDF
    Se analiza el impacto de condiciones climáticas extremas de los últimos años sobre los precios internacionales de los alimentos, encuadrados éstos dentro del proceso de Cambio Climático (CC). El objetivo directo es mostrar como un grupo de sequías en regiones productoras de granos puede inestabilizar el precio de los mismos y su impacto en la seguridad alimentaria global. Se utilizan métodos estadísticos corrientes de series temporales. En el trabajo se muestra que el alza de precios de los alimentos manifiesta como una función de Dirac fueron resultados de una sequía intensa ocurrida simultáneamente en diversas regiones de la Tierra y muertes masivas de especies animales, sumado a un efecto especulativo. Los dos primeros factores configuran un cuadro de inestabilidad ambiental que puede estar asociado al CC y la destrucción de la capa de ozono que habría permitido el ingreso de radiación nociva del espacio. Se concluye que las agencias estatales vinculadas al CC deberían integrar equipos multidisciplinarios que analicen los diversos factores intervinientes en la toma de decisiones políticas sobre la mitigación o atenuación de los efectos del fenómeno. Solamente de esta manera se lograrían resultados que permitan mantener la sustentabilidad del planeta.Eje: Economía, producción y tecnología.Universidad Nacional de La Plat

    Health-related quality of life and functional changes in DMD:A 12-month longitudinal cohort study

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    Family caregivers of people with amyotrophic lateral sclerosis (ALS) live stressful lives in which they spend most of their time caring for their loved ones and managing difficult situations, thereby reducing the time spent in taking care of themselves. This situation may last several years. Previous literature has widely highlighted that this situation reduces caregivers' quality of life and increases their psychological distress and risk of health problems, but there is a lack of studies that focus on psychological interventions for these situations. This qualitative study examined a pilot experience of two mutual support groups for family caregivers of people with ALS. The aim was to identify caregivers' needs, the prominent aspects of their experience, and to understand whether and how this intervention strategy might help them. Six partners (four men and two women) and six adult children (five women and one man) participated in the groups, which were conducted in northern Italy. After the support groups finished, participants underwent semi-structured interviews. The authors conducted a content analysis of the transcripts of the interviews and the 20 group sessions. The thematic areas identified were "caregiving," "being the son/daughter of a person with ALS," "being the partner of a person with ALS," "group experience" and "group evaluation." The caregiving experience was profoundly different depending on whether the caregiver was a son/daughter or a partner of a patient with ALS. Moreover, comparison with peers and mutual support helped participants to better cope with ALS and its consequences, to improve their care for their relatives and to overcome typical caregiver isolation. These results suggest the usefulness of involving communities in caregiver support in order to create new networks and activate personal and social resources for well-being
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