214 research outputs found

    Fractionally Integrated Moving Average Stable Processes With Long-Range Dependence

    Get PDF
    Long memory processes driven by L\'evy noise with finite second-order moments have been well studied in the literature. They form a very rich class of processes presenting an autocovariance function which decays like a power function. Here, we study a class of L\'evy process whose second-order moments are infinite, the so-called α\alpha-stable processes. Based on Samorodnitsky and Taqqu (2000), we construct an isometry that allows us to define stochastic integrals concerning the linear fractional stable motion using Riemann-Liouville fractional integrals. With this construction, follows naturally an integration by parts formula. We then present a family of stationary SαSS\alpha S processes with the property of long-range dependence, using a generalized measure to investigate its dependence structure. In the end, the law of large number's result for a time's sample of the process is shown as an application of the isometry and integration by parts formula

    Incorporación de ácidos grasos de cadena media a triglicéridos de aceite de pescado por interesterificación química y enzimática

    Get PDF
    Structured triglycerides (STs) containing both medium-chain fatty acids (MCFA) and polyunsaturated fatty acids (PUFA) in the same molecule offer nutritional and therapeutic benefits. The aim of this work was to establish the incorporation of MCFA into fish oil triglycerides (TAGs), while maintaining substantial levels of docosahexaenoic and eicosapentaenoic acids. The effects of different acyl donors (capric acid methyl ester/MeC10 or medium chain triglyceride/TCM) and of the catalyst (chemical or enzymatic) on the fatty acid composition of the reaction product were studied. The fatty acid composition of the fish oil TAG was modified after interesterification to contain MCFA, and it depended on the catalyst and on the substrates. Thermograms obtained by Differential Scanning Calorimetry (DSC) showed that interesterification promoted noteworthy changes in the melting profile of the samples. STs of clinical nutrition interest containing both EPA and DHA obtained from fish oil along with MCFA were successfully produced.Triglicéridos estructurados (SL) conteniendo ácidos grasos de cadena media (MCFA) y ácidos grasos poliinsaturados (PUFA) en la misma molécula de glicerol tienen ventajas nutricionales y terapéuticas. Se establece la incorporación de MCFA a los triglicéridos (TAGs) de aceite de pescado, conservando un contenido considerable de ácidos docosahexaenóico (DHA) y eicosapentaenóico (EPA). El efecto de diferentes acil donadores (éster metílico de ácido cáprico/MeC10 o triglicéridos de cadena media/TCM) y de catalizador (químico o enzimático) sobre la composición del producto de las reacciones fue estudiado. La composición de ácidos grasos de los TAGs del aceite de pescado fue modificada después de las reacciones para contener MCFA y dependió del catalizador y de los substratos. Los termogramas obtenidos por Calorimetría Diferencial de Barrido (DSC) indicaron que la interesterificación provocó alteraciones considerables de los perfiles de fusión de las muestras. Fueron producidos STs de interés en nutrición clínica conteniendo EPA y DHA, además de MCFA

    Estimation of genetic parameters for test-day milk yield in Girolando cows using a random regression model.

    Get PDF
    The objective of this study was to estimate the components of variance and genetic parameters of test-day milk yield in first lactation Girolando cows, using a random regression model. A total of 126,892 test-day milk yield (TDMY) records of 15,351 first-parity Holstein, Gyr, and Girolando breed cows were used, obtained from the Associação Brasileira dos Criadores de Girolando. To estimate the components of (co) variance, the additive genetic functions and permanent environmental covariance were estimated by random regression in three functions: Wilmink, Legendre Polynomials (third order) and Linear spline Polynomials (three knots). The Legendre polynomial function showed better fit quality. The genetic and permanent environment variances for TDMY ranged from 2.67 to 5.14 and from 9.31 to 12.04, respectively. Heritability estimates gradually increased from the beginning (0.13) to mid-lactation (0.19). The genetic correlations between the days of the control ranged from 0.37 to 1.00. The correlations of permanent environment followed the same trend as genetic correlations. The use of Legendre polynomials via random regression model can be considered as a good tool for estimating genetic parameters for test-day milk yield records

    Researching the use of force: The background to the international project

    Get PDF
    This article provides the background to an international project on use of force by the police that was carried out in eight countries. Force is often considered to be the defining characteristic of policing and much research has been conducted on the determinants, prevalence and control of the use of force, particularly in the United States. However, little work has looked at police officers’ own views on the use of force, in particular the way in which they justify it. Using a hypothetical encounter developed for this project, researchers in each country conducted focus groups with police officers in which they were encouraged to talk about the use of force. The results show interesting similarities and differences across countries and demonstrate the value of using this kind of research focus and methodology

    Sensitive Commercial NASBA Assay for the Detection of Respiratory Syncytial Virus in Clinical Specimen

    Get PDF
    The aim of the study was to evaluate the usability of three diagnostic procedures for the detection of respiratory syncytial virus in clinical samples. Therefore, the FDA cleared CE marked NOW® RSV ELISA, the NucliSENS® EasyQ RSV A+B NASBA, and a literature based inhouse RT-PCR protocol were compared for their relative sensitivities. Thereby, NASBA turned out to be the most sensitive method with a total number of 80 RSV positive samples out of a cohort of 251 nasopharyngeal washings from patients suffering from clinical symptoms, followed by the inhouse RT-PCR (62/251) and ELISA (52/251). Thus, NASBA may serve as a rapid and highly sensitive alternative for RSV diagnostics

    Cadherin-23 Mediates Heterotypic Cell-Cell Adhesion between Breast Cancer Epithelial Cells and Fibroblasts

    Get PDF
    In the early stages of breast cancer metastasis, epithelial cells penetrate the basement membrane and invade the surrounding stroma, where they encounter fibroblasts. Paracrine signaling between fibroblasts and epithelial tumor cells contributes to the metastatic cascade, but little is known about the role of adhesive contacts between these two cell types in metastasis. Here we show that MCF-7 breast cancer epithelial cells and normal breast fibroblasts form heterotypic adhesions when grown together in co-culture, as evidenced by adhesion assays. PCR and immunoblotting show that both cell types express multiple members of the cadherin superfamily, including the atypical cadherin, cadherin-23, when grown in isolation and in co-culture. Immunocytochemistry experiments show that cadherin-23 localizes to homotypic adhesions between MCF-7 cells and also to heterotypic adhesions between the epithelial cells and fibroblasts, and antibody inhibition and RNAi experiments show that cadherin-23 plays a role in mediating these adhesive interactions. Finally, we show that cadherin-23 is upregulated in breast cancer tissue samples, and we hypothesize that heterotypic adhesions mediated by this atypical cadherin may play a role in the early stages of metastasis

    ‘The only game in town?’: football match-fixing in Greece

    Get PDF
    The final publication is available at Springer via http://dx.doi.org/10.1007/s12117-014-9239-3Football match-fixing in Greece has a relatively long history, however, from the late 1990s it has been considered as a serious problem for the sport in the country. Despite the history of the phenomenon in the country, Greece has only relatively recently been identified as one of the hotspots for football match-fixing on an international level. Following the recent scandal exposure of fixed matches in Greece in 2011, also known as Koriopolis (a pun name on the Italian scandal Calciopolis and the Greek word ‘korios’ or phone-tap), detailed information about numerous matches played in the 2008/09, 2009/10 and 2010/11 seasons that attracted UEFA’s attention were brought into the public eye. Soon after, legal action was taken against individuals involved in the process, with a number of club officials facing lifelong bans from any footballrelated activity, and football clubs either relegated or excluded from European competitions and the Super League itself for their involvement in the scandal. In May 2013, the number of people facing charges exceeded 200, with some of them having already been imprisoned for their involvement in the scandal. Following the aforementioned scandal exposure, a vast amount of information regarding football match-fixing was made available to the public. The aim of the current article is to provide an account of the social organisation of football match-fixing in Greece. Our account is based on three main sources of data: the telephone conversations that were the result of wiretapping by the National Intelligence Agency in relation to the latest football match-fixing scandal (of 2011), published media sources, and interviews with informed actors from the realm of Greek football
    corecore