3,132 research outputs found

    On the massive gluon propagator, the PT-BFM scheme and the low-momentum behaviour of decoupling and scaling DSE solutions

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    We study the low-momentum behaviour of Yang-Mills propagators obtained from Landau-gauge Dyson-Schwinger equations (DSE) in the PT-BFM scheme. We compare the ghost propagator numerical results with the analytical ones obtained by analyzing the low-momentum behaviour of the ghost propagator DSE in Landau gauge, assuming for the truncation a constant ghost-gluon vertex and a simple model for a massive gluon propagator. The asymptotic expression obtained for the regular or decoupling ghost dressing function up to the order O(q2){\cal O}(q^2) is proven to fit pretty well the numerical PT-BFM results. Furthermore, when the size of the coupling renormalized at some scale approaches some critical value, the numerical PT-BFM propagators tend to behave as the scaling ones. We also show that the scaling solution, implying a diverging ghost dressing function, cannot be a DSE solution in the PT-BFM scheme but an unattainable limiting case.Comment: 16 pages, 2 figs., 2 tabs (updated version to be published in JHEP

    Injury prevention, drowning prevention habits and resuscitation knowledge of Portuguese surfing instructors. A cross-sectional study

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    Surfing instructors can play an important role both in preventing sport related injuries and as first responders in water emergencies events. Even though Portugal is a predominantly oceanic country, with many people enrolling in water sports activities, we still don’t have a clear insight of the knowledge and educational practices of surfing instructors concerning both injury prevention and first response actions. This study aimed to analyze the educational practices on prevention of surf-related injuries of Portuguese surfing instructors and their knowledge and experience acting as first responders in the sea. A cross-sectional study was designed, using an online survey distributed by all surfing schools registered at Portuguese Surfing Federation to their instructors. The survey included a brief demographic characterization, questions regarding teaching practices about prevention of surfing-related injuries and knowledge/experience acting as first responders at the sea. Data was collected anonymously using Google Forms. A total of 102 instructors participated in the study. The analysis of the survey responses showed that 93.2% of surfing instructors are aware of the importance of prevention habits for teaching but skip some major preventive measures when teaching novice surfers. Nevertheless, the instructors with more than 15 years of experience provide more feedback on prevention habits during classes than instructors with less experience (p=0.019). When looking at self-perceptions of own competence to act in a drowning event, the instructors who have attended a basic life support course asserted to be more competent than those who never attended a course (p<0.05). These findings suggest that it would be very positive that all surfing schools followed the same protocol, giving due importance to prevention measures. Moreover, surfing instructors can play an important role in first response to drowning events but might have some training flaws that should be considered as part of a Water Safety National Strategy. © JPES

    Microesferas de alginato para uso dermatofarmacéutico

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    Simple and reproducible methods were developed to microencapsulate all-trans-retinoic acid (RA) and salicylic acid (SA)in solution. The objectives of the present study were to improve their therapeutic applications and to establish comparativecriteria concerning the different methodologies that have been used. The objective of RA and SA microencapsulationon the one hand, is to modulate AR release in an attempt to protect skin from AR and AS irritation and, on the other,is to protect RA from environmental hazards such as air, light and moisture.Se desarrollaron métodos simples y reproducibles para la microencapsulación de ácido all-trans-retinoico (AR) yácido salicílico (AS) en forma disuelta, con el objeto de mejorar sus aplicaciones terapéuticas y establecer criterioscomparativos de las distintas metodologías empleadas. Se caracterizaron los sistemas microparticulados mediantemicrofotografía y distribución del tamaño de las partículas obtenidas. El desarrollo galénico de microesferas dealginato sódico, tiene como objetivo modular la liberación del AR, ya que es de interés dermatofarmacéutico optimizarla eficacia terapéutica y minimizar las reacciones secundarias, y proteger a la piel de la acción irritante del AR ydel AS, preservando al AR, de la acción deletérea de agentes externos tales como el aire, la luz y la humedad

    Micropartículas de alginato conteniendo paracetamol

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    Micropartículas conteniendo paracetamol (PCT) han sido obtenidas por emulsificación/gelificación interna de unasolución de alginato dispersada en un aceite vegetal. La morfología y la distribución de tamaño de partícula fuerondeterminadas. Se estudió la concentración de ión calcio resultando ser un parámetro crítico en la producción de lasmicropartículas. Se observó que el incremento en la concentración de calcio produce un aumento en el rendimientototal de micropartículas y en el encapsulación de PCT. La técnica desarrollada permite obtener un sistema concaracterísticas micrométricas óptimas y una mayor eficacia de encapsulación de PCT

    Anthracological evidence suggests naturalness of Pinus pinaster in inland southwestern Iberia

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    The study of well-preserved archaeological charcoals in the pre-Roman Iron Age settlement of Castillejos II (Badajoz, Spain) is used to reconstruct environmental conditions and land-use practices in vegetation landscapes in the southwest of the Iberian Peninsula before the arrival of Roman civilization. The results support that, while evergreen Quercus forests dominated during the Holocene, Pinus pinaster existed as a natural element of southwestern Iberian Peninsula vegetation. Although its presence could be linked to anthropogenic disturbance or fire history, it is suggested that P. pinaster populations survived during the Holocene in the region, mixed with oaks or in monospecific stands in mountain enclaves. This hypothesis contrasts with previous assumptions that P. pinaster was not autochthonous in the area

    The Boom of cohabitation in Colombia and in the Andean Region : social and spatial patterns

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    In this chapter we use census microdata to document the rise in cohabitation in Colombia and in the Andean countries of Ecuador, Bolivia, Perú and Venezuela over the last four decades. We use multilevel logistic regression models to examine the effect of individual and contextual variables on cohabitation. We show the individual and contextual effects of social stratification, ethnicity and religion on cohabitation. Cohabitation levels follow a negative gradient with education and vary according to ethnic background. The Bolivian, Ecuadorian and Peruvian censuses reveal that the two largest ethnic groups (i.e. the Quechua and Aymara) have, controlling for other characteristics, the lowest incidence of cohabitation. By contrast, Afro-American populations show the highest levels of cohabitation. The joint use of individual- and contextual-level explanatory variables is sufficient to account for the majority of Bolivia's internal diversity regarding cohabitation, but not sufficient to account for the internal diversity identified in Colombia, Peru or Ecuador. Even after controls, residence in the Andes mountain areas continues to be a factor associated with lower levels of cohabitation. This invites further investigations on how the institutionalization of marriage occurred in the Andes

    Low Sensitivity of BinaxNOW RSV in Infants

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    BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of hospitalization in infants. Early detection of RSV can optimize clinical management and minimize use of antibiotics. BinaxNOW RSV (BN) is a rapid antigen detection test that is widely used. We aimed to validate the sensitivity of BN in hospitalized and nonhospitalized infants against the gold standard of molecular diagnosis. METHODS: We evaluated the performance of BN in infants with acute respiratory tract infections with different degrees of disease severity. Diagnostic accuracy of BN test results were compared with molecular diagnosis as reference standard. RESULTS: One hundred sixty-two respiratory samples from 148 children from October 2017 to February 2019 were studied. Sixty-six (40.7%) samples tested positive for RSV (30 hospitalizations, 31 medically attended episodes not requiring hospitalization, and 5 nonmedically attended episodes). Five of these samples tested positive with BN, leading to an overall sensitivity of BN of 7.6% (95% confidence interval [CI], 3.3%-16.5%) and a specificity of 100% (95% CI, 96.2%-100%). Sensitivity was low in all subgroups. CONCLUSIONS: We found a low sensitivity of BN for point-of-care detection of RSV infection. BinaxNOW RSV should be used and interpreted with caution

    CoVITEST: A Fast and Reliable Method to Monitor Anti-SARS-CoV-2 Specific T Cells From Whole Blood

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    Cellular and humoral immune responses are essential for COVID-19 recovery and protection against SARS-CoV-2 reinfection. To date, the evaluation of SARS-CoV-2 immune protection has mainly focused on antibody detection, generally disregarding the cellular response, or placing it in a secondary position. This phenomenon may be explained by the complex nature of the assays needed to analyze cellular immunity compared with the technically simple and automated detection of antibodies. Nevertheless, a large body of evidence supports the relevance of the T cell's role in protection against SARS-CoV-2, especially in vulnerable individuals with a weakened immune system (such as the population over 65 and patients with immunodeficiencies). Here we propose to use CoVITEST (Covid19 anti-Viral Immunity based on T cells for Evaluation in a Simple Test), a fast, affordable and accessible in-house assay that, together with a diagnostic matrix, allows us to determine those patients who might be protected with SARS-CoV-2-reactive T cells. The method was established using healthy SARS-CoV-2-naïve donors pre- and post-vaccination (n=30), and further validated with convalescent COVID-19 donors (n=51) in a side-by-side comparison with the gold standard IFN-? ELISpot. We demonstrated that our CoVITEST presented reliable and comparable results to those obtained with the ELISpot technique in a considerably shorter time (less than 8 hours). In conclusion, we present a simple but reliable assay to determine cellular immunity against SARS-CoV-2 that can be used routinely during this pandemic to monitor the immune status in vulnerable patients and thereby adjust their therapeutic approaches. This method might indeed help to optimize and improve decision-making protocols for re-vaccination against SARS-CoV-2, at least for some population subsets.Copyright © 2022 Egri, Olivé, Hernández-Rodríguez, Castro, De Guzman, Heredia, Segura, Fernandez, de Moner, Torradeflot, Ballús, Martinez, Vazquez, Costa, Dobaño, Mazza, Mazzotti, Pascal, Juan, González-Navarro and Calderón
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