1,612 research outputs found

    Weighted norm inequalities for polynomial expansions associated to some measures with mass points

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    Fourier series in orthogonal polynomials with respect to a measure ν\nu on [1,1][-1,1] are studied when ν\nu is a linear combination of a generalized Jacobi weight and finitely many Dirac deltas in [1,1][-1,1]. We prove some weighted norm inequalities for the partial sum operators SnS_n, their maximal operator SS^* and the commutator [Mb,Sn][M_b, S_n], where MbM_b denotes the operator of pointwise multiplication by b \in \BMO. We also prove some norm inequalities for SnS_n when ν\nu is a sum of a Laguerre weight on R+\R^+ and a positive mass on 00

    Calorimetric study of water's two glass transitions in the presence of LiCl

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    A DSC study of dilute glassy LiCl aqueous solutions in the water-dominated regime provides direct evidence of a glass-to-liquid transition in expanded high density amorphous (eHDA)-type solutions. Similarly, low density amorphous ice (LDA) exhibits a glass transition prior to crystallization to ice Ic. Both glass transition temperatures are independent of the salt concentration, whereas the magnitude of the heat capacity increase differs. By contrast to pure water, the glass transition endpoint for LDA can be accessed in LiCl aqueous solutions above 0.01 mole fraction. Furthermore, we also reveal the endpoint for HDA's glass transition, solving the question on the width of both glass transitions. This suggests that both equilibrated HDL and LDL can be accessed in dilute LiCl solutions, supporting the liquid-liquid transition scenario to understand water's anomalies.Fil: Ruiz, Guadalupe N.. Universidad de Innsbruck; Austria. Universidad Politécnica de Catalunya; EspañaFil: Amann Winkel, Katrin. AlbaNova University Center; Suecia. Universidad de Innsbruck; AustriaFil: Bove, Livia E.. Université Pierre et Marie Curie; FranciaFil: Corti, Horacio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad de Buenos Aires; ArgentinaFil: Loerting, Thomas. Universidad de Innsbruck; Austri

    Tuning molecular dynamics by hydration and confinement: Antiplasticizing effect of water in hydrated prilocaine nanoclusters

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    In glass-forming substances, the addition of water tends to produce the effect of lowering the glass transition temperature, Tg. In a previous work by some of us (Ruiz et al., Sci. Rep., 2017, 7, 7470) we reported on a rare anti-plasticizing effect of water on the molecular dynamics of a simple molecular system, the pharmaceutically active prilocaine molecule, for which the addition of water leads to an increase of Tg. In the present work, we study pure and hydrated prilocaine confined in 0.5 nm and 1 nm pore size molecular sieves, and carry out a comparison with the bulk compounds in order to gain a better understanding of the microscopic mechanisms that result in this rare effect. We find that the Tg of the drug under nanometric confinement can be lower than the bulk value by as much as 17 K. Through the concurrent use of differential scanning calorimetry and broadband dielectric spectroscopy we are able to observe the antiplasticizing effect of water in prilocaine also under nanometric confinement, finding an increase of Tg of up to almost 6 K upon hydration. The extension of our analysis to nanoconfined systems provides a plausible explanation for the very uncommon antiplasticizing effect, based on the formation of water-prilocaine molecular complexes. Moreover, this study deepens the understanding of the behavior of drugs under confinement, which is of relevance not only from a fundamental point of view, but also for practical applications such as drug delivery.Peer ReviewedPostprint (author's final draft

    Racial Stratification in Self-Rated Health Among Black Mexicans and White Mexicans

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    How do Mexicans of distinct racial backgrounds fit into the recognized patterns of racial health disparities? We conduct regression analyses using data from the 2000-2017 National Health Interview Survey to determine if Mexicans who self-identify as White or Black have a relative advantage or disadvantage in self-rated health in relation to Non-Hispanic (NH) Whites and Blacks in the U.S. Our results indicate that both Black Mexicans and White Mexicans have a significant disadvantage in relation to NH-Whites while White Mexicans have a slight advantage in relation to both NH-Blacks and Black Mexicans. Overall, our results suggest that studying health outcomes among Hispanics without considering race may mask inequalities not observed in the aggregate

    Effects of threat and motivation on classical musicians’ professional performance practice during the Covid-19 pandemic

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    In the past 2 years our world has experienced huge disruptions because of COVID-19. The performing arts has not been insulated from these tumultuous events with the entire music industry being thrown into a state of instability due to the paralyzing effects of the COVID-19 pandemic. In this study, we examined how classical professional musicians’ ability to cope with uncertainty, economic struggles, and work-life interplay during COVID-19 was influenced by various factors that affect a crucial part of the development and sustainment of music careers: musicians’ practice. We analyzed responses to an online survey of 309 classical performing musicians from 41 countries in Europe and Latin America across three pandemic stages: immediately before the pandemic, during the pandemic, and when vaccines were being made available and lockdowns were being reduced or lifted. Structural equation modeling indicates relationships between perceptions of threat at the peak of the pandemic and the musicians Self- or External-Based Motivation for the three periods in which respondents were asked to reflect. Findings suggest that musicians who are more internally self-motivated seemed to be more resilient to the pandemic threats and more capable of managing their practicing routines, whereas more externally motivated musicians experienced a reduction in their dedicated time to practice during lockdown. We suggest pedagogical and policy implications, as well as future lines of research that are oriented toward supporting professional musicians in assessing and understanding their motivational drives so that they can cope with situations that disrupt their professional lives

    A methodology for transparent knowledge specification in a dynamic tuning environment

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    The increasing use of parallel/distributed applications demands a continuous support to take significant advantages from parallel power. This includes the evolution of performance analysis and tuning tools which automatically allows for obtaining a better behavior of the applications. Different approaches and tools have been proposed and they are continuously evolving to cover the requirements and expectations of users. One such tool is MATE (Monitoring Analysis and Tuning Environment), which provides automatic and dynamic tuning for parallel/distributed applications. The knowledge used by MATE to analyze and take decisions is based on performance models which include a set of performance parameters and a set of mathematical expressions modeling the solution of the performance problem. These elements are used by the tuning environment to conduct the monitoring and analysis steps, respectively. The tuning phase depends on the results of the performance analysis. This paper presents a methodology to specify performance models. Each performance model specification can be automatically and transparently translated into a piece of software code encapsulating the knowledge to be straightforwardly included in MATE. Applying this methodology, the user does not have to be involved in the implementation details of MATE, which makes the usage of the tool more transparent.Fil: Caymes Scutari, Paola Guadalupe. Universidad Tecnológica Nacional. Facultad Regional de Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Morajko, A.. Universitat Autònoma de Barcelona; EspañaFil: Margalef, T.. Universitat Autònoma de Barcelona; EspañaFil: Luque, E.. Universitat Autònoma de Barcelona; Españ

    Bait Stations for Control of Mexican Fruit Flies (Anastrepha ludens), First Year

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    The Mexican fruit fly, Anastrepha ludens (Loew) (Mexfly), is a pest of economic importance with the potential to cause millions of dollars in damage to citrus and other fruits. This chapter presents the first-year results from a three-year field study (2014–2017) conducted to evaluate the effectiveness of bait stations with Spinosad embedded in a wax matrix to control Mexfly. Spinosad is produced by a naturally occurring bacteria, Saccharopolyspora spinosa, and is considered an organic insecticide acceptable for use by organic growers. The flies feed on the wax matrix, and the Spinosad acts as a stomach poison killing the flies. Each bait station contains a two-component lure consisting of the attractants, putrescine, and ammonium acetate. The study used 500 bait stations strategically placed based on historic wild fly capture data at 12 locations in the Lower Rio Grande Valley in south Texas, United States. Results indicate that a hat or protective covering over the bait station extends the residual killing effect with fly mortality of up to 3 months from aged bait stations taken from the field. In addition, a reduction in wild Mexfly capture was observed in the areas where the bait stations were used. Potential uses would be around wild fly finds, in abandoned or poorly maintained groves, in organic groves, or with permission, in residential citrus plantings. This study indicates that bait stations are another valuable integrated pest management (IPM) tool for program managers in their effort to control Mexfly

    Phosphorylation by Inorganic Phosphate of the Plasma Membrane H +

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