5,194 research outputs found

    Semi-parametric seasonal unit root tests

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    We extend the M class of unit root tests introduced by Stock (1999, Cointegration, Causality and Forecasting. A Festschrift in Honour of Clive W.J. Granger. Oxford University Press), Perron and Ng (1996, Review of Economic Studies 63, 435–463) and Ng and Perron (2001, Econometrica 69, 1519–1554) to the seasonal case, thereby developing semi-parametric alternatives to the regression-based augmented seasonal unit root tests of Hylleberg, Engle, Granger, and Yoo (1990, Journal of Econometrics 44, 215–238). The success of this class of unit root tests to deliver good finite sample size control even in the most problematic (near-cancellation) case where the shocks contain a strong negative moving average component is shown to carry over to the seasonal case as is the superior size/power trade-off offered by these tests relative to other available tests

    Diurnal variability of inner-shelf circulation in the lee of a cape under upwelling conditions.

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    The nearshore circulation in the lee of a cape under upwelling conditions was studied using in-situ data from 3 consecutive summers (2006–2008). Focus was given to a period between 20 July and 04 August 2006 to study the diurnal variability of the cross-shelf circulation. This period was chosen because it had a steady upwellingfavourable wind condition modulated by a diurnal cycle much similar to sea breeze. The daily variability of the observed cross-shelf circulation consisted of three distinct periods: a morning period with a 3-layer vertical structure with onshore velocities at mid-depth, a mid-day period where the flow is reversed and has a 2-layer structure with onshore velocities at the surface and offshore flow below, and, lastly, in the evening, a 2-layer period with intensified offshore velocities at the surface and onshore flow at the bottom. The observed cross-shelf circulation showed a peculiar vertical shape and diurnal variability different from several other systems described in literature. We hypothesize that the flow reversal of the cross-shelf circulation results as a response to the rapid change of the wind magnitude and direction at mid-day with the presence of the cape north of the mooring site influencing this response. A numerical modelling experiment exclusively forced by winds simulated successfully most of the circulation at the ADCP site, especially the mid-day reversal and the evening's upwelling-type structure. This supports the hypothesis that the cross-shelf circulation at diurnal timescales is mostly wind-driven. By analysing the 3D circulation in the vicinity of Cape Sines we came to the conclusion that the diurnal variability of the wind and the flow interaction with topography are responsible for the circulation variability at the ADCP site, though only a small region in the south of the cape showed a similar diurnal variability. The fact that the wind diurnally undergoes relaxation and intensification strongly affects the circulation, promoting superficial onshore flows in the leeside of Cape Sines. Despite the small-scale nature of the observed cross-shelf circulation, onshore flows as the ones described in this study can be particularly helpful to understand the transport and settlement of larvae in this region and in other regions with similar topography and wind characteristics.We thank D. Jacinto and T. Silva for help during field work and the Port of Sines Authority (APS) for providing oceanographic and meteorological data. Financial support was provided by FCT (POCI/ MAR/57630/2004; PTDC/BIA-BEC/103734/2008 and PEst-OE/ MAR/UIO199/2011). The simulations were preformed in the computational facilities provided under FCT contract RECI/GEO-MET/0380/ 2012. Luísa Lamas was funded by the FCT under a Ph.D. grant (SFRH/ BD/69533/2010)

    High AN1 variability and interaction with basic helix-loop-helix co-factors related to anthocyanin biosynthesis in potato leaves

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    AN1 is a regulatory gene that promotes anthocyanin biosynthesis in potato tubers and encodes a R2R3 MYB transcription factor. However, no clear evidence implicates AN1 in anthocyanin production in leaves, where these pigments might enhance environmental stress tolerance. In our study we found that AN1 displays intraspecific sequence variability in both coding/non-coding regions and in the promoter, and that its expression is associated with high anthocyanin content in leaves of commercial potatoes. Expression analysis provided evidence that leaf pigmentation is associated to AN1 expression and that StJAF13 acts as putative AN1 co-regulator for anthocyanin gene expression in leaves of the red leaf variety "Magenta Love", while a concomitant expression of StbHLH1 may contribute to anthocyanin accumulation in leaves of "Double Fun". Yeast two-hybrid experiments confirmed that AN1 interacts with StbHLH1 and StJAF13 and the latter interaction was verified and localized in the cell nucleus by bimolecular fluorescence complementation assays. In addition, transgenic tobacco (Nicotiana tabacum) overexpressing a combination of either AN1 with StJAF13 or AN1 with StbHLH1 showed deeper purple pigmentation with respect to AN1 alone. This further confirmed AN1/StJAF13 and AN1/StbHLH1 interactions. Our findings demonstrate that the classical loci identified for potato leaf anthocyanin accumulation correspond to AN1 and may represent an important step to expand our knowledge on the molecular mechanisms underlying anthocyanin biosynthesis in different plant tissues. This article is protected by copyright. All rights reserved

    Decisiones razonables y razonadas sobre medicamentos convencionales y de uso tradicional. El Seguimiento Farmacoterapéutico, integrador de la perspectiva del paciente.

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    Se presenta un caso de una paciente con síndrome metabólico y comorbilidades asociadas que acude a un consultorio farmacéutico del nivel primario de Atención en Salud en Bogotá (Colombia), donde recibe seguimiento farmacoterapéutico. La paciente usa tratamientos prescritos por sus médicos y se automedica con productos naturales, como son el extracto de balsamina para regular niveles de glucosa, el extracto de arándano azul europeo para problemas oculares y el uso de lecitina de soja para control de triglicéridos. Para la evaluación de la farmacoterapia, se localizó evidencia científica sobre el uso y conveniencia de cada producto en el tratamiento de sus problemas de salud, realizándose las siguientes intervenciones: continuar con la toma de la balsamina, el Bilberry y la lecitina de soja, ya que existen reportes de su utilidad como coadyuvantes en el control de las enfermedades que presenta y la elaboración de un plan de medicación para reforzar la adherencia a los tratamientos. Cuando se evalúan las intervenciones, encontramos que las cifras de glicemia, presión arterial y función hepática se encuentran dentro de objetivos terapéuticos. En este caso, el químico farmacéutico tiene una labor integradora de las terapias de los pacientes, basados en la valoración del riesgo-beneficio y a través del seguimiento farmacoterapéutico obtiene información clínica que permite tomar decisiones sustentadas para el futuro, más aún en el contexto de Latinoamérica, donde los productos naturales son ampliamente usados en la población

    Evolutionary history of Podarcis tiliguerta on Corsica and Sardinia.

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    BACKGROUND: Podarcis tiliguerta is a wall lizard endemic to the Mediterranean islands of Corsica and Sardinia. Previous findings of high mtDNA and morphological diversity have led to the suggestion that it may represent a species complex. Here, we analysed mitochondrial and nuclear markers (mtDNA, 3110 bp; 6 nDNA loci, 3961 bp) in P. tiliguerta sampled from thirty-two localities across Corsica and Sardinia. RESULTS: We find much greater intraspecific genetic divergence than between sister species of other Mediterranean island Podarcis, i.e., between P. lilfordi and P. pityusensis. We detected three mtDNA clusters in Corsica (North, South-East and South-West) and either two or three in Sardinia (North vs. South) depending on the clustering method. Only one or two nDNA groups were identified within each main island (again, depending on the method). A Bayesian time-calibrated multispecies coalescent tree was obtained from mtDNA and provided statistical support for a Miocene origin of the species (13.87 Ma, 95% HPD: 18.30-10.77 Ma). The posterior mean divergence time for the Corsican and Sardinian lineages was 12.75 Ma ago (95% HPD: 16.94-9.04 Ma). CONCLUSION: The results support the evolutionary distinctiveness of Corsican and Sardinian populations and also indicate a lack of post-divergence migration despite periods of contact being possible. Further to this, species delimitation analyses of Corsican and Sardinian lineages provided statistical support for their recognition as distinct (sister) taxa. Our results provide new insights into the biogeography of the Mediterranean biodiversity hotspot, and contribute important findings relevant to the systematics and evolution of this speciose lizard genus

    Decisiones razonables y razonadas sobre medicamentos convencionales y de uso tradicional. El Seguimiento Farmacoterapéutico, integrador de la perspectiva del paciente.

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    Se presenta un caso de una paciente con síndrome metabólico y comorbilidades asociadas que acude a un consultorio farmacéutico del nivel primario de Atención en Salud en Bogotá (Colombia), donde recibe seguimiento farmacoterapéutico. La paciente usa tratamientos prescritos por sus médicos y se automedica con productos naturales, como son el extracto de balsamina para regular niveles de glucosa, el extracto de arándano azul europeo para problemas oculares y el uso de lecitina de soja para control de triglicéridos. Para la evaluación de la farmacoterapia, se localizó evidencia científica sobre el uso y conveniencia de cada producto en el tratamiento de sus problemas de salud, realizándose las siguientes intervenciones: continuar con la toma de la balsamina, el Bilberry y la lecitina de soja, ya que existen reportes de su utilidad como coadyuvantes en el control de las enfermedades que presenta y la elaboración de un plan de medicación para reforzar la adherencia a los tratamientos. Cuando se evalúan las intervenciones, encontramos que las cifras de glicemia, presión arterial y función hepática se encuentran dentro de objetivos terapéuticos. En este caso, el químico farmacéutico tiene una labor integradora de las terapias de los pacientes, basados en la valoración del riesgo-beneficio y a través del seguimiento farmacoterapéutico obtiene información clínica que permite tomar decisiones sustentadas para el futuro, más aún en el contexto de Latinoamérica, donde los productos naturales son ampliamente usados en la población

    Terapia por caja espejo y autonomía en el autocuidado después de un accidente cerebrovascular: programa de intervención

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    Enquadramento: Nos doentes com acidente vascular cerebral (AVC) da artéria cerebral média (ACM), a alteração da função do membro superior conduz à dependência no autocuidado. No processo de reconstrução da autonomia/independência, existe evidência da efetividade dos métodos com estímulos sensoriais na recuperação motora após o AVC. Objetivo: Avaliar o contributo da terapia por caixa de espelho para a autonomia no autocuidado nos doentes com hemiplegia/hemiparesia, por AVC da ACM. Metodologia: Estudo transversal, quase-experimental, com abordagem quantitativa, desenho pré-programa/pós- -programa com grupo controlo não equivalente. Amostra não probabilística de 30 participantes. Resultados: Verificaram-se ganhos na força de preensão, amplitude articular e destreza manual do membro superior, mais expressivos no grupo experimental mas sem diferenças estatisticamente significativas entre grupos. Conclusão: Apesar da evolução mais expressiva do grupo experimental, a terapia por caixa de espelho não se revelou efetiva na recuperação motora do membro superior, pelo que, é necessário continuar a investigação nesta área com desenhos randomizados, amostras maiores e direcionada para o autocuidado.Background: In patients with middle cerebral artery (MCA) stroke, changes in upper limb function lead to dependence on others for self-care. In the process of recovering autonomy/independence, there is evidence on the effectiveness of sensory stimulation techniques in the motor recovery after stroke. Objective: To assess the effect of mirror therapy on the self-care autonomy of patients with hemiplegia/hemiparesis due to MCA stroke. Methodology: Cross-sectional and quasi-experimental study with a quantitative approach, a before-and-after design, and a non-equivalent control group. A nonprobability sample of 30 participants was selected. Results: Gains in grip strength, joint range of motion, and manual dexterity of the upper limb were more significant in the experimental group but without statistically significant differences between groups. Conclusion: Despite the more significant evolution of the experimental group, mirror therapy was not effective in the motor recovery of the upper limb. Further studies are needed in this area using randomized designs, larger samples, and focused on self-care.Marco contextual: En los pacientes que han sufrido un accidente cerebrovascular (ACV) en la arteria cerebral media (ACM), la alteración de la función del miembro superior lleva a ser dependientes en el autocuidado. En el proceso de reconstrucción de la autonomía/independencia, existen pruebas de la efectividad de los métodos con estímulos sensoriales en la recuperación motora después del ACV. Objetivo: Evaluar la contribución de la terapia por caja espejo para la autonomía en el autocuidado en los pacientes con hemiplejia/hemiparesia por ACV de la ACM. Metodología: Estudio basado en el paradigma cuantitativo, de naturaleza transversal y carácter cuasiexperimental, con un diseño preprograma/posprograma con un grupo de control no equivalente. Muestra de 30 participantes sin repartir aleatoriamente. Resultados: Se observaron beneficios en la fuerza de prensión, amplitud articular y destreza manual del miembro superior, más llamativos en el grupo experimental pero sin diferencias estadísticamente significativas entre grupos. Conclusión: A pesar de la evolución más llamativa del grupo experimental, la terapia por caja espejo no se mostró efectiva en la recuperación motora del miembro superior, por lo que es necesario continuar la investigación en esta área con diseños aleatorizados, muestras mayores y dirigida al autocuidado.info:eu-repo/semantics/publishedVersio

    Influence of apical oxygen on the extent of in-plane exchange interaction in cuprate superconductors

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    In high Tc superconductors the magnetic and electronic properties are determined by the probability that valence electrons virtually jump from site to site in the CuO2 planes, a mechanism opposed by on-site Coulomb repulsion and favored by hopping integrals. The spatial extent of the latter is related to transport properties, including superconductivity, and to the dispersion relation of spin excitations (magnons). Here, for three antiferromagnetic parent compounds (single-layer Bi2Sr0.99La1.1CuO6+delta, double-layer Nd1.2Ba1.8Cu3O6 and infinite-layer CaCuO2) differing by the number of apical atoms, we compare the magnetic spectra measured by resonant inelastic x-ray scattering over a significant portion of the reciprocal space and with unprecedented accuracy. We observe that the absence of apical oxygens increases the in-plane hopping range and, in CaCuO2, it leads to a genuine 3D exchange-bond network. These results establish a corresponding relation between the exchange interactions and the crystal structure, and provide fresh insight into the materials dependence of the superconducting transition temperature.Comment: 9 pages, 4 figures, 1 Table, 42 reference
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