230 research outputs found

    CORRELATIONS BETWEEN OIL AND STOCK MARKETS: A WAVELET-BASED APPROACH

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    In a global economy, shocks occurring in one market can spill over to other markets. This paper investigates the impact of oil shocks and stock markets crashes on correlations between stock and oil markets. We test changes in correlations at different scales with non-overlapping confidence intervals based on estimated wavelet correlations. Contrary to other approaches, this method does not need adjustment for heteroskedasticity biases on the correlation coefficients. Our results show that oil shocks affect the correlation between both markets. The evidence on the change of correlation between stock markets after an oil shock is weaker; except in some specific cases during the Kuwait war and the OPEC cutback period. Conversely, we only find weak evidence that stock market crashes change the correlation between oil and stock markets. Overall, the evidence gives support to including oil as an asset class in asset allocation strategies.he authors acknowledge financial support from Financial Research Center–UNIDE and from the Spanish Ministry of Education and Science, research projects MTM2010-17323, ECO2011-25706, ECO2012-32401 and MTM2012-36163-C06-03

    Mecanización del cultivo de forrajes

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    En este artículo se recogen las máquinas más apropiadas y sus capacidades de trabajo en las labores de preparación del suelo, siembra, fertilización, protección del cultivo, recolección, siega, acondicionado, hilerado y transporte de las principales forrajeras cultivadas en España, así como los criterios de elección en función de la capacidad de trabajo y un ejemplo con coste de instalación del cultivo el año de implantació

    Aspectos prácticos para la regulación y puesta a punto de una sembradora

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    La labor de siembra es clave dentro de cualquier proceso productivo. Buena parte del éxito de dicha labor depende de la elección de una sembradora adecuada y de su correcta regulación y puesta a punto. Por lo tanto, es vital realizar una revisión de la máquina antes de la campala de siembra y es aquí donde entra en juego la facilidad de manejo y regulación del equipo

    Características técnicas de las sembradoras convencionales

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    La siembra es una operación clave para optimizar los rendimientos de una explotación, por lo que es muy importante seleccionar la sembradora idónea para cada tipo de cultivo y regularla adecuadamente para establecer la densidad superficial de plantas óptima en cada situación

    Transcriptional regulation os phenylalaline biosynthesis and utilization

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    Conifer trees divert large quantities of carbon into the biosynthesis of phenylpropanoids, particularly to generate lignin, an important constituent of wood. Since phenylalanine is the precursor for phenylpropanoid biosynthesis, the precise regulation of phenylalanine synthesis and utilization should occur simultaneously. This crucial pathway is finely regulated primarily at the transcriptional level. Transcriptome analyses indicate that the transcription factors (TFs) preferentially expressed during wood formation in plants belong to the MYB and NAC families. Craven-Bartle et al. (2013) have shown in conifers that Myb8 is a candidate regulator of key genes in phenylalanine biosynthesis involved in the supply of the phenylpropane carbon skeleton necessary for lignin biosynthesis. This TF is able to bind AC elements present in the promoter regions of these genes to activate transcription. Constitutive overexpression of Myb8 in white spruce increased secondary-wall thickening and led to ectopic lignin deposition (Bomal et al. 2008). In Arabidopsis, the transcriptional network controlling secondary cell wall involves NAC-domain regulators operating upstream Myb transcription factors. Functional orthologues of members of this network described have been identified in poplar and eucalyptus, but in conifers functional evidence had only been obtained for MYBs. We have identified in the P. pinaster genome 37 genes encoding NAC proteins, which 3 NAC proteins could be potential candidates to be involved in vascular development (Pascual et al. 2015). The understanding of the transcriptional regulatory network associated to phenylpropanoids and lignin biosynthesis in conifers is crucial for future applications in tree improvement and sustainable forest management. This work is supported by the projects BIO2012-33797, BIO2015-69285-R and BIO-474 References: Bomal C, et al. (2008) Involvement of Pinus taeda MYB1 and MYB8 in phenylpropanoid metabolism and secondary cell wall biogenesis: a comparative in planta analysis. J Exp Bot. 59: 3925-3939. Craven-Bartle B, et al. (2013) A Myb transcription factor regulates genes of the phenylalanine pathway in maritime pine. Plant J, 74: 755-766. Pascual MB, et al. (2015) The NAC transcription factor family in maritime pine (Pinus pinaster): molecular regulation of two genes involved in stress responses. BMC Plant Biol, 15: 254.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Epicatechin induces NF-kappa B, activator rotein-1 (AP-1) and nuclear transcription factor erythroid 2p45-related factor-2 (Nrf2) via phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and extracellular regulated kinase (ERK) signalling in HepG2 cells

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    The dietary flavonoid epicatechin has been reported to exhibit a wide range of biological activities. The objective of the present study was to investigate the time-dependent regulation by epicatechin on the activity of the main transcription factors (NF-kappa B, activator protein-1 (AP-1) and nuclear transcription factor erythroid 2p45-related factor (Nrf2)) related to antioxidant defence and survival and proliferation pathways in HepG2 cells. Treatment of cells with 10 mu M-epicatechin induced the NF-kappa B pathway in a time-dependent manner characterised by increased levels Of I kappa B kinase (IKK) and phosphorylated inhibitor Of kappa B subunit-a (p-I kappa B alpha) and proteolytic degradation Of I kappa B, which was consistent with an up-regulation of the NF-kappa B-binding activity. Time-dependent activation of the AP-1 pathway, in concert with enhanced c-Jun nuclear levels and induction of Nrf2 translocation and phosphorylation were also demonstrated. Additionally, epicatechin-induced NF-kappa B and Nrf2 were connected to reactive oxygen species intracellular levels and to the activation of cell survival and proliferation pathways, being phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and extracellular regulated kinase (ERK) associated to Nrf2 modulation and ERK to NF-kappa B induction. These data suggest that the epicatechin-induced survival effect occurs by the induction of redox-sensitive transcription factors through a tight regulation of survival and proliferation pathways

    Systematic review of the psychometric properties of patient-reported outcome measures for foot and ankle in rheumatoid arthritis

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    Background Foot problems and pain are common in patients with rheumatoid arthritis. Patient-reported outcome measures provide a standardized method of capturing patients’ perspectives of their functional status and wellbeing. There are many instruments specific to people with feet affected by rheumatoid arthritis but knowledge of their psychometric validation or methodological quality is lacking Objectives To identify patient-reported outcome measures specific to the foot and ankle and rheumatoid arthritis and investigate their methodological quality and psychometric properties Design Systematic review. Data source : A search was conducted for psychometric or validation studies on patient-reported outcomes in Rheumatoid Arthritis published in different languages, by examining the Pubmed; Scopus, CINAHL; PEDro and Google Scholar databases. Review methods . The systematic review performed was based on the following inclusion criteria: psychometric or clinimetric validation studies on patient-reported outcomes specific to the foot and ankle that included patients with Rheumatoid arthritis. Two authors independently assessed the quality of the studies and extracted datas Results Of the initial 431 studies, fourteen instruments met the inclusion criteria. Significant methodological flaws were detected in most with only SEFAS met the COSMIN quality criteria. Conclusion SEFAS had the best quality and was ranked most appropriate for use with patients living with Rheumatoid Arthriti

    Multidisciplinary teaching of Biotechnology and Omics sciences

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    In the last years, there was a great boom in the Omics fields that have developed as multidisciplinary sciences. They use laboratory techniques related to Biology and Chemistry but also Bioinformatics tools. However, the developmental progress of these disciplines has led that much of undergraduate studies related to Biology have curricula that become outdated. From this point of view, it is necessary to focus the students to the fundamentals and techniques of complementary disciplines that will be essentials for the understanding of the Omics sciences. In the present work, we have developed a new teaching approach for Biochemistry, Biology and Bioinformatics students. They formed interdisciplinary working groups. These groups have prepared and presented communications about different techniques or methods in Molecular Biology, Omics or Bioinformatics participating in a technical meeting. This learning strategy “I do and I learn” has enabled to the students a first contact with the scientific communication including the approach to the scientific literature to acquire technical knowledge. The cooperation between students from different disciplines has enriched their point of view and even has been used in some practical master’s works.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Medida no destructiva de la firmeza en melocotón para laboratorios de calidad

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    La medida de firmeza en fruta fresca es un parámetro de calidad clave tanto para el consumidor como para las empresas comercializadoras. Al primero, la estimación de firmeza le orienta sobre la madurez del producto. A la segunda, el conocimiento de la firmeza de los frutos le permite estimar su vida en estantería y, por lo tanto, una adecuada planificación de su comercialización (tiempos de transporte y almacenamiento). El objetivo del trabajo es comparar la posibilidad de aplicar de dos sensores (uno acústico y otro de impacto) para la estimación de firmeza en melocotón, considerando diferentes períodos de almacenamiento del producto

    Aplicación de tecnología NIR portátil a la estimación el parcela de la concentración de azúcares en uva

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    During the 2008 growing season field tests have been carried out on three varieties of wine grape. Over 2500 samples of wine grape berries were scanned with a portable and commercial near infrared (NIR) spectrometer and subsequently processed to determine °Brix using a digital refractometer. The main objectives of this research are to evalúate the potential of a portable NIR equipment to measure the changes in soluble solid contents of grapes during the pre-harvest period, and to establish calibration model for soluble solid contení (°Brix) in grapes, in order to provide a non destructive tool for determining optimal harvest date. A first calibration model has been constructed based on data of three varieties with a R2 of 0.81
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