23 research outputs found

    A 50 l CYGNO prototype overground characterization

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    The nature of dark matter is still unknown and an experimental program to look for dark matter particles in our Galaxy should extend its sensitivity to light particles in the GeV mass range and exploit the directional information of the DM particle motion (Vahsen et al. in CYGNUS: feasibility of a nuclear recoil observatory with directional sensitivity to dark matter and neutrinos, arXiv:2008.12587, 2020). The CYGNO project is studying a gaseous time projection chamber operated at atmospheric pressure with a Gas Electron Multiplier (Sauli in Nucl Instrum Meth A 386:531, https://doi.org/10.1016/S0168-9002(96)01172-2, 1997) amplification and with an optical readout as a promising technology for light dark matter and directional searches. In this paper we describe the operation of a 50 l prototype named LIME (Long Imaging ModulE) in an overground location at Laboratori Nazionali di Frascati (LNF) of INFN. This prototype employs the technology under study for the 1 cubic meter CYGNO demonstrator to be installed at the Laboratori Nazionali del Gran Sasso (LNGS) (Amaro et al. in Instruments 2022, 6(1), https://www.mdpi.com/2410-390X/6/1/6, 2022). We report the characterization of LIME with photon sources in the energy range from few keV to several tens of keV to understand the performance of the energy reconstruction of the emitted electron. We achieved a low energy threshold of few keV and an energy resolution over the whole energy range of 10–20%, while operating the detector for several weeks continuously with very high operational efficiency. The energy spectrum of the reconstructed electrons is then reported and will be the basis to identify radio-contaminants of the LIME materials to be removed for future CYGNO detectors

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Influence of lipid microparticle encapsulation on in vitro efficacy, photostability and water resistance of the sunscreen agents, octyl methoxycinnamate and butyl methoxydibenzoylmethane

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    Context: Essential requirements for the efficacy of sunscreen agents are optimal UV absorption, high photostability and resistance against water removal. Objective: Aim of this study was to investigate the effect of encapsulation in lipid microparticles (LMs) on the overall performance of the two most commonly used sunscreen agents, octyl methoxycinnamate (OMC) and butyl methoxydibenzoylmethane (BMDBM). Methods: LMs loaded with OMC and BMDBM were prepared by melt emulsification and characterized by optical microscopy, UV filter content and release studies. The LMs incorporating OMC and BMDBM or the nonencapsulated sunscreen agents were introduced into a model cream (oil-in-water emulsion). Results: No significant differences were observed between the sun protection factor (SPF) of the formulations containing the free (SPF, 9.4±1.9) or microencapsulated (SPF, 9.6±1.3) UV filters. Irradiation of the creams with a solar simulator, demonstrated that the photodecomposition of OMC and BMDBM was significantly decreased by encapsulation in LMs, from 55.7±5.3% to 46.1±5.1% and 36.3±3.9% to 20.1±4.7%, respectively. However, in vitro water resistance studies showed that entrapment in the LMs significantly enhanced the sunscreen agent removal caused by watering (the losses for OMC and BMDBM were 45.1±6.3% and 49.2±8.4%, respectively), as compared to the formulation with the nonencapsulated sunscreen agents (the losses for OMC and BMDBM were 26.7±6.1% and 28.0±6.7%, respectively). Conclusion: Incorporation in LMs can have controversial effects on UV filter efficacy. In particular, the water resistance properties of sun-care formulations containing sunscreens loaded in LMs should be verified to assure that the photoprotective activity is maintained during usage

    Factors associated with leisure-time physical activity among patients undergoing hemodialysis

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    Background: End-stage renal disease patients are characterized by low levels of physical activity, especially during leisure time. However, the recognition of variables associated with patterns of physical activity in this population has been little explored. Thus, the objective was to assess factors associated with levels of physical activity during leisure time among patients on haemodialysis. Methods: Ninety-eight patients (51.6 ± 15.7 years, 57 M/41 F) from two dialysis centres in São Paulo, Brazil participated in this cross-sectional study. Participants were divided into those who never exercised during leisure-time (inactive) and those who exercised at least once a week (active). The independent factors assessed were: socio-demographic data, comorbidities, personal barriers to exercise and physical activity records from childhood to adulthood (tracking of physical activity). Results: Only 27 % of patients were engaged in PA during their leisure time at least once a week. Patients who engaged in regular physical activity during adulthood before the initiation of the hemodialysis treatment (adjusted OR: 7.24 95 % IC: 1.99; 26.50), those who developed the renal disease through diseases other than diabetes or hypertension (adjusted OR: 4.82; 95 % IC: 1.48; 15.68), and those who had no cardiovascular diseases (adjusted OR: 11.33; 95 % IC: 1.23; 103.8) where more likely to be active during their leisure-time. Conclusion: Comorbidities such as cardiovascular disease, hypertension and diabetes mellitus as well as the level of physical activity prior to end-stage renal disease could predict leisure-time physical activity among patients receiving hemodialysis therapy. © 2015 Rosa et al

    Investigation of liver tissue and biochemical parameters of adult wistar rats treated with Arctium lappa L.

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    This study was carried out to evaluate the effects of Arctium lappa L. (burdock) on the liver of adult male Wistar rats as measured by light microscopy and biochemical parameters. The rats received the extract in water bottles at doses of 10 or 20 g/L daily for 40 days. There were no significant changes in the plasma levels of albumin, aspartate transaminase (AST), alanine transaminase (ALT), gamma glutamyl transferase (GGT), total protein, total cholesterol, urea, uric acid, triacylglycerol, calcium, phosphorus, chlorine and direct bilirubin. The morphological analysis did not reveal histopathological alterations in liver tissue. Both biochemical and morphological data did not indicate A. lappa toxicity.<br>A bardana (Arctium lappa L) é uma planta trazida do Japão e aclimatada no Brasil, e é extensamente utilizada na medicina popular em todo mundo. Este estudo foi realizado para avaliar os possíveis efeitos da A. lappa no fígado e nos parâmetros bioquímicos plasmáticos em ratos Wistar adultos. Estes receberam a infusão de bardana nas doses de 10 ou 20 g de folhas secas /L de água, por 40 dias. Não houve alteração significativa nos níveis plasmáticos de albumina, aspartato transaminase (AST), alanina transaminase (ALT), gamma glutamil transferase (GGT), proteínas totais, colesterol total, uréia, ácido úrico, triglicérides, cálcio, fósforo, bilirrubina direta e cloro. A análise morfológica não revelou alterações histopatológicas no fígado. Os dados bioquímicos e morfológicos não indicaram a toxicidade da bardana

    O efeito da floresta alagada na alimentação de três espécies de peixes onívoros em lagos de várzea da Amazônia Central, Brasil Effects of flooded forest in the diet of three fish species in floodplain lakes of Central Amazon, Brazil

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    As enchentes anuais dos rios na Amazônia alagam extensas áreas de floresta conhecidas como várzeas ou igapós. Estas áreas têm papel importante na vida dos peixes da região, pois são fontes de alimento e de abrigo. Acreditamos que o desmatamento destas áreas ocasiona prejuízos à ictiofauna principalmente pela diminuição da quantidade e diversidade de alimento disponível. O estudo da relação entre a quantidade de floresta e a dieta de Parauchenipterus galeatus (Auchenipteridae, Siluriformes), Mylossoma duriventre (Characidae, Characiformes)e Triportheus elongatus (Characidae, Characiformes)permitiu registrar pela primeira vez a influência direta da floresta alagada na ecologia alimentar de peixes na Amazônia Central.<br>The annual flooding of the rivers in the Amazonia extends over large forest areas known as várzeas or igapós. These areas play an important role in the life of the fishes, as a source of food and shelter. We believe that the deforestation of these areas may affect negatively the fish fauna mainly by decreasing the amount of food resources and consequently the diversity of food types available. The study of the relationship between the riparian forest cover and the diet of Parauchenipterus galeatus (Auchenipteridae, Siluriformes), Mylossoma duriventre (Characidae, Characiformes) and Triportheus elongatus (Characidae, Characiformes) allowed to refer for the first time on the direct influence of the flooded forest in the feeding ecology of fishes in Central Amazonia
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