506 research outputs found

    Suscetibilidade dos solos à erosão na área de entorno do reservatório da Usina Hidrelétrica de Tombos (MG).

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    O objetivo deste trabalho foi avaliar a suscetibilidade dos solos à erosão na área de entorno do reservatório da UHE de Tombos. As variáveis de análise constaram de mapas temáticos dos elemento físico-bióticos, através da superposição temática em SIG e, atribuição de valores específicos a cada um deles, segundo a importância dos fatores em relação à erosão. Um mapa de 1:10.000, estratificado em sete classes de susceptibilidade à erosão foi gerado

    Estudo de erosão dos solos na área do médio alto curso do Rio Grande, Região Serrana do Estado do Rio de Janeiro.

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    O objetivo deste trabalho foi avaliar a suscetibilidade dos solos à erosão, na área de influência do médio alto curso do Rio Grande, região serrana do estado do Rio de Janeiro. Os procedimentos adotados envolveram a superposição temática em SIG, aliada à atribuição de valores específicos para cada parâmetro, segundo a importância dos fatores em relação à erosão. O mapa final produzido na escala 1:50.000, estratifica a área de estudo em 7 classes de suscetibilidade à erosão

    Hyperoside Supplementation in Preservation Media Surpasses Vitamin C Protection Against Oxidative Stress-Induced Damages in Human Spermatozoa

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    Background/Aims: Oxidative Stress (OS) is reported as one of the main causes of male infertility. Infertile couples often resort to assisted reproductive technology (ART) to achieve parenthood. However, preparation for ART protocols increases the exposer of gametes to OS. Thus, it is crucial to find suitable preservation media that can counteract the OS-induced damages in spermatozoa. In this work, we tested and compared the efficiency of vitamin C (VC) and hyperoside (HYP) as potential antioxidant supplements for sperm preservation media. Methods: We evaluated the cytotoxicity of HYP (0, 5, 50, 100, and 500 µM) in spermatozoa. After incubation of sperm cells with VC (600 µM) and HYP (100 and 500 µM), in the presence and absence of H2O2 (300 µM), the following parameters were assessed: total sperm motility and vitality, OS biomarkers expression, total antioxidant capacity (TAC) of the media, percentage of DNA fragmentation, mitochondrial membrane potential (MMP), and metabolite quantification of the media by proton nuclear magnetic resonance (1H-NMR). Results: The supplementation with VC (600 µM) and HYP (100 and 500 µM) did not induce any deleterious effects to the physiology and metabolism of the spermatozoa, after 1-hour of treatment. In the presence of H2O2 (300 µM), both VC and HYP were able to prevent some of the deleterious effects of H2O2 in sperm, which were represented by an increase in sperm motility, a decrease in DNA fragmentation, and a decreasing trend in lipid peroxidation levels. However, these antioxidants were not able to prevent the decrease of MMP associated with H2O2 treatment, nor were able to prevent the conversion of pyruvate into acetate (a reaction promoted by H2O2). Conclusion: The supplementation of sperm preservation media with VC and HYP could be beneficial for the preservation of sperm physiology. From the antioxidant conditions tested, the supplementation of media with HYP (100 µM) demonstrated the best results regarding sperm preservation, evidencing the higher antioxidant capacity of HYP compared to VC. Nevertheless, none of the antioxidants used was able to prevent the metabolic alterations promoted by H2O2 in spermatozoa.This work was supported by Fundação para a Ciência e a Tecnologia - FCT to Sara C. Pereira (2021.05487.BD); David F. Carrageta (SFRH/BD/136779/2018); Marco G. Alves (IFCT2015 and PTDC/MEC-AND/28691/2017); LAQV-REQUIMTE (UIDB/50006/2020); UMIB (UIDB/00215/2020, and UIDP/00215/2020); ITR - Laboratory for Integrative and Translational Research in Population Health (LA/P/0064/2020). Pedro F. Oliveira was funded by national funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., under the Scientific Employment Stimulus - Institutional Call - reference CEECINST/00026/2018

    Origin and main ramifications of coeliac artery in Cerdocyon thous

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    Background: Cerdocyon thous is the canid with the greatest geographical coverage in South America. The aim of this study was to describe the origin, skeletopy, length and main branches of the coeliac artery in C. thous. Materials and methods: The dissections were performed on 14 cadavers of adult specimens, 6 males and 8 females, with a rostrosacral length average of 67.00 ± 4.7 cm and 62.09 ± 5.7 cm, respectively. The specimens were collected dead on highways on the banks of the Atlantic Forest (Rio de Janeiro) and the Pampa biome (Rio Grande do Sul) in Brazil. The cadavers were fixed and preserved in a formaldehyde solution until dissection. The coeliac artery was dissected, the length was measured “in situ” and its main branches were recorded. The coeliac artery emerged as a single artery in all dissected animals. Results: The average length of the coeliac artery was 1.43 ± 0.17 cm in males and 1.39 mm ± 0.24 cm in females, with no significant difference in this measurement between sexes. The predominant skeletopy was at the level of the second lumbar vertebra (57.1%), positioned on average 1.43 cm cranially to the cranial mesenteric artery. In most individuals (92.9%), the classic trifurcation was formed: the coeliac artery branched into the hepatic, left gastric, and lienal arteries. Only 1 male animal presented a bifurcation formed between the hepatic artery and a gastrolienal trunk. Conclusions: These anatomical characteristics are similar to those of other species of the Canidae family, possibly due to their phylogenetic proximity

    Serological, parasitological and molecular assessment of Babesia bovis and Babesia bigemina in cattle from State Maranhão.

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    The aim of the present study was to determine the prevalence of Babesia bovis and Babesia bigemina in dairy cattle from São Luis Island in the state of Maranhão, Brazil. A total of 281 blood samples were collected. In total, 275 (97.9%) animals were B. bovis-reactive and B. bigemina-reactive in the Enzyme-Linked Immunosorbent Assay (ELISA). The microscopy examination detected 22 (7.8%) animals that were positive for Babesia sp. and the Polymerase Chain Reaction (PCR) analysis showed that 91 animals (32.38%) and 23 animals (8.18%) were positive for B. bovis and B. bigemina, respectively, while 17 animals (6.04%) were co-infected. There is a high level of transmission of these protozoa in Maranhão, and the animals were naturally exposed. Therefore, it is possible to characterize the island as enzootic stability for babesiosis, indicat-ing a risk of financial losses when susceptible animals are introduced from areas of enzootic instability or free regions of B. bovis and B. bigemina.Título em português: Avaliação sorológica, parasitológica e molecular de Babesia bovis e Babesia bigemina no gado do Estado do Maranhão

    What kinds of value motives guide people in their moral attitudes? The role of personal and prescriptive values at the culture level and individual level

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    Opinions about moralized issues are arguably one of the most difficult issues in interpersonal dialogues given that they can result in intolerance and prejudicial behavior toward those with divergent moral beliefs. Recent research has shown that moral attitudes vary not only depending on the individual's characteristics but also as a function of culture. Individuals from individualistic-oriented cultures exhibit more lenient judgments toward moralized issues than those from collectivistic-oriented cultures. What is unclear to date is what kinds of cultural value motives underlie these attitudesAre they driven only by intrinsic value motives (personal values) or also by extrinsic value motives (prescriptive values in the form of societal expectations about what should be valued)? The cultural press to conform is arguably stronger if moral attitudes are predicted by the latter. Participants from eight countries (N = 1,456) responded to a questionnaire containing a modified version of the Schwartz Value Survey assessing personal and prescriptive values. The results showed that personal value ratings of openness-to-change versus conservation at the culture and individual levels were predictive of individuals' moral attitudes consistent with previous findings. Prescriptive value ratings of openness-to-change versus conservation also predicted individuals' moral attitudes, but only at the aggregated culture level. This suggests that the prescriptive values concept is a truly group-level phenomenon and that attitudes toward moralized issues are guided by cultural values with normative qualities. We discuss the implications for intercultural contact situations.info:eu-repo/semantics/acceptedVersio

    Caracterização geoambiental de paisagens rurais montanhosas com suporte de SIG, subsídios ao planejamento.

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    A partir de unidades geoambientais delimitadas, foi feita a caracterização geoambiental e a indicação de alternativas sustentáveis de utilização das terras de uma microbacia inserida em paisagens rurais montanhosas na Serra dos Órgãos, ocupada com agricultura familiar. Com suporte de geoprocessamento e SIG, montou-se uma base de dados espaciais, composta de mapas temáticos do meio físico, para a geração de mapas interpretativos úteis ao planejamento. Os procedimentos utilizados permitiram efetuar análise de ofertas e restrições ambientais apresentadas em cada unidade, sugerir formas de usos mais condizentes com a realidade local, com base nas vocações agro-ecológicas de cada compartimento. Os resultados mostram áreas agricultáveis e não agricultáveis e de potencial para uso e conservação. Os resultados contribuem para o desenvolvimento da cartografia ambiental, em escala de detalhe, da paisagem da Serra do Mar
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