1,457 research outputs found

    Urban Green Spaces, Greenness Exposure and Species Richness in Residential Environments and Relations with Physical Activity and BMI in Portuguese Adolescents

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    Environmental factors play an important role in obesity-related behaviors. Evidence indicates significant associations between weight and urban green spaces in adults, but it is not clear whether this relationship applies to adolescents. Therefore, our aim was to determine the associations between urban green spaces, greenness exposure and species richness in residential environments with physical activity and body mass index. Sixty-two adolescents between 12 and 18 years of age answered a self-administered questionnaire, providing information on height, weight, age, sex and home address. Data on socioeconomic deprivation were obtained from the European Index of Deprivation for Small Portuguese Areas. Physical activity levels were assessed using accelerometers. Urban green space counts and the normalized difference vegetation index values were measured using buffers along the roads with distances of 300, 500, 1000 and 1500 m from each participant’s residence. To quantify the species richness, the species richness index was used. Linear regression models were fitted to analyze whether urban green spaces, exposure to green spaces and species richness counts for each distance were associated with physical activity and self-reported body mass index. We did not find significant associations between the independent variables and the probability of overweight or obesity. The relationship between environmental variables, adolescents’ physical activity and body weight seems to be complex and further studies may contribute to better understanding of the topic.This research was funded by FEDER through the Operational Program for Competitiveness and Internationalization and received national funding from the Foundation for Science and Technology—FCT (Portuguese Ministry of Science, Technology and Higher Education), under the Research Center in Physical Activity, Health and Leisure (CIAFEL) (UIDB/00617/2020) and also under the Epidemiology Research Unit (EPIUnit)—Institute of Public Health of the University of Porto (info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB/04750/2020/PT). Ana Isabel Ribeiro was supported by national funds through FCT, under the ‘Stimulus of Scientific Employment—Individual Support’ program within the contract info:eu-repo/grantAgreement/FCT/CEEC IND 2018/CEECIND/02386/2018/CP1538/CT0001/PT

    Mineralocorticoid receptor antagonists eplerenone and spironolactone modify adrenal cortex morphology and physiology

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    Mineralocorticoid receptor antagonists (MRAs) are a class of anti-hypertensive drugs that act by blocking aldosterone action. The aim of this study was to evaluate whether the MRAs spironolactone and eplerenone influence adrenal cortical physiology and morphology. Spontaneous hypertensive rats (SHR, n = 18) and normotensive rats (WKY, n = 18) were randomly exposed to a daily dose of spironolactone (n = 6), eplerenone (n = 6), or no drug (n = 6) over 28 days. After that, aldosterone, corticosterone, and 11-deoxycorticosterone plasma concentrations were quantified. Adrenal glands were subjected to morphological analysis to assess lipid droplets content, capsular width, cell proliferation, and steroidogenic proteins expression. The adrenal cortex in untreated SHR showed higher lipid droplet content as than in WKY. In SHR, MRA treatment was associated with higher circulating aldosterone levels and Ki-67 expression in aldosterone-secreting cells. In WKY, the only difference observed after MRA spironolactone treatment was a narrower capsule. There was no difference in abundance of steroidogenic enzyme between groups. In conclusion, MRAs modify adrenal gland function and morphology in SHR. The effects observed within the adrenal glomerulosa with aldosterone-secreting cell proliferation and higher circulating aldosterone levels suggests that MRA treatment provokes activation of the renin angiotensin system. The prognostic value of hyperaldosteronism secondary to MRAs blockade requires further investigation.Funding: This research was funded by the Associação dos Amigos do Serviço de Endocrinologia do Hospital de São João (2020–2021). Unit for Multidisciplinary Research in Biomedicine (UMIB) is funded by the Foundation for Science and Technology (FCT)-Portugal (UIDB/00215/2020 and UIDP/00215/2020—approval date: 2019)

    Stereology shows that damaged liver recovers after protein refeeding

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    Objective: The aim of the present study was to investigate the putative effects of a low-protein diet on the three-dimensional structure of hepatocytes and determine whether this scenario could be reversed by restoring the adequate levels of protein to the diet. Methods: Using design-based stereology, the total number and volume of hepatocytes were estimated in the liver of mice in healthy and altered (by protein malnutrition) conditions and after protein renutrition. Results: This study demonstrated a 65% decrease in the liver volume (3302 mm3 for the control for undernourished versus 1141 mm3 for the undernourished group) accompanied by a 46% reduction in the hepatocyte volume (8223 μm3 for the control for undernourished versus 4475 μm3 for the undernourished group) and a 90% increase in the total number of binucleate hepatocytes (1 549 393 for the control for undernourished versus 2 941 353 for the undernourished group). Reinstating a normoproteinic diet (12% casein) proved to be effective in restoring the size of hepatocytes, leading to an 85% increase in the total number of uninucleate hepatocytes (15 988 560 for the undernourished versus 29 600 520 for the renourished group), and partially reversed the liver atrophy. Conclusions: Awareness of these data will add to a better morphologic understanding of malnutrition-induced hepatopathies and will help clinicians improve the diagnosis and treatment of this condition in humans and in veterinary practice

    A Factorization Law for Entanglement Decay

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    We present a simple and general factorization law for quantum systems shared by two parties, which describes the time evolution of entanglement upon passage of either component through an arbitrary noisy channel. The robustness of entanglement-based quantum information processing protocols is thus easily and fully characterized by a single quantity.Comment: 4 pages, 5 figure

    Analyzing Ideological Communities in Congressional Voting Networks

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    We here study the behavior of political party members aiming at identifying how ideological communities are created and evolve over time in diverse (fragmented and non-fragmented) party systems. Using public voting data of both Brazil and the US, we propose a methodology to identify and characterize ideological communities, their member polarization, and how such communities evolve over time, covering a 15-year period. Our results reveal very distinct patterns across the two case studies, in terms of both structural and dynamic properties
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