275 research outputs found

    Assessing local acid mine drainage impacts on natural regeneration-revegetation of São Domingos mine (Portugal) using a mineralogical, biochemical and textural approach

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    São Domingos sulfide mine was shut down more than 50 years ago leaving behind eroded and depositional surfaces due to acid mine drainage (AMD). The aim of this study was to assess six selected sites subjected to AMD, considered phytotoxic regions characterized by vegetation scarcity. Two main criteria, nature and composition of soluble fractions and total chemistry of surficial products related to jarosites presence, enabled to set up an overall dichotomy between superficial proximal/discharge and distal/sedimentation areas. Wet and dry sieving results comparison revealed that samples have a predominant sandy texture and lithic (phyllite, quartzite and volcanic country rocks) composition. Quartz, and subordinate feldspar enrichment is also detected in the coarse silt fraction. The results also suggest that the materials under study, when subjected to the local torrential hydrologic regime, have a high mechanical vulnerability, facilitating erosion and mud transport, both critical for vegetation support, and triggering contamination transfer and dispersion. The vicinity and ground-level surfaces of discharging areas are enriched in the jarosite group minerals whereas the sedimentation ones present hypersaline aluminous tendency. The formation of jarosite is considered as an efficient positive environmental contribution to metals and metalloids sequestration/immobilization. The remediation/revegetation solutions to be adopted in each location must have into consideration these differentiating aspects

    Nosema ceranae (Microsporidia: Nosematidae) Does Not Cause Collapse of Colonies of Africanized Apis mellifera (Hymenoptera: Apidae) in Tropical Climate

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    Nosemosis is an important disease that affects honey bees (Apis mellifera Lineu), caused by obligate intracellular parasites, Nosema  apis  and/or  Nosema  ceranae. Since the initial detection of N. ceranae in A. mellifera coincided with recent large-scale losses of bee colonies worldwide, the impacts of this parasite under field conditions are of great interest. Here we test two hypotheses, the first one, whether the climatic variables (temperature, air humidity and precipitation) influence the intensity of infection of the microsporidium Nosema spp. in Africanized honey bees (Apis mellifera), and the second, whether the local of hive installation (outdoor or roofed) influences the intensity of infection of these spores in Africanized honey bees. Between August 2013 and August 2016, samples of Africanized bees were collected weekly from 20 colonies, of which ten were located in an open area (outdoor apiary) and ten under a roof on a concrete floor (roofed apiary). N.  ceranae was the only species present. The type of apiary did not influence (p > 0.05) the number of spores of N. ceranae in Africanized bees. However, the infection intensities of the roofed apiary colonies were lower in the autumn. Regarding the meteorological parameters, there was a negative correlation between the winter infection intensities and the minimum temperature in the roofed apiary and the humidity in the outdoor apiary. The highest infection intensities occurred in both apiaries in the spring and summer, which may be related to higher pollen production. On average, the infection intensity was 16.19 ± 15.81 x 105, ranging from zero to 100.5 x105, and there were no records of collapse during the three years

    Topical Hpmc/s-nitrosoglutathione Solution Decreases Inflammation And Bone Resorption In Experimental Periodontal Disease In Rats

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)S-nitrosoglutathione (GSNO) is a nitric oxide (NO) donor, which exerts antioxidant, anti-inflammatory, and microbicidal actions. Intragingival application of GSNO was already shown to decrease alveolar bone loss, inflammation and oxidative stress in an experimental periodontal disease (EPD) model. In the present study, we evaluated the potential therapeutic effect of topical applications of hydroxypropylmethylcellulose (HPMC)/GSNO solutions on EPD in Wistar rats. EPD was induced by placing a sterilized nylon (3.0) thread ligature around the cervix of the second left upper molar of the animals, which received topical applications of a HPMC solutions containing GSNO 2 or 10 mM or vehicle (HPMC solution), 1 h prior to the placement of the ligature and then twice daily until sacrifice on day 11. Treatment with HPMC/ GSNO 10 mM solution significantly reduced alveolar bone loss, oxidative stress and TNF-alpha e IL-1 beta levels in the surrounding gingival tissue, and led to a decreased transcription of RANK and TNF-alpha genes and elevated bone alkaline phosphatase, compared to the HPMC group. In conclusion, topical application of HPMC/GSNO solution is a potential treatment to reduce inflammation and bone loss in periodontal disease.114National Council for Scientific and Technological Development - CNPq [478380/2011-9, 309390/2011-7]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Mechanisms underlying skeletal muscle insulin resistance induced by fatty acids: importance of the mitochondrial function

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    Insulin resistance condition is associated to the development of several syndromes, such as obesity, type 2 diabetes mellitus and metabolic syndrome. Although the factors linking insulin resistance to these syndromes are not precisely defined yet, evidence suggests that the elevated plasma free fatty acid (FFA) level plays an important role in the development of skeletal muscle insulin resistance. Accordantly, in vivo and in vitro exposure of skeletal muscle and myocytes to physiological concentrations of saturated fatty acids is associated with insulin resistance condition. Several mechanisms have been postulated to account for fatty acids-induced muscle insulin resistance, including Randle cycle, oxidative stress, inflammation and mitochondrial dysfunction. Here we reviewed experimental evidence supporting the involvement of each of these propositions in the development of skeletal muscle insulin resistance induced by saturated fatty acids and propose an integrative model placing mitochondrial dysfunction as an important and common factor to the other mechanisms

    Preparation of novel trifluoroacetylketene O,N-acetals and trifluoromethyl-containing S,S-sulfoximido N-substituted heterocycles

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    Two new trifluoroacetylketene O,N-acetals [CF3C(O)CH=C(OEt)(NS(O)R2), where R = CH3, Ph] derived from the reaction of 4,4-diethoxy-1,1,1-trifluorobut-3-en-2-one [CF3C(O)CH=C(OEt)2] with S,S-dimethyl- and S-methyl-S-phenyl-sulfoximide [HN=S(O)R2], in the presence of triethylamine, have been obtained, in 60-72% yields, and applied in the synthesis of S,S-dimethylsulfoximido-substituted pyrazoles, isoxazoles and pyrimidines, in 55-89% yields, from the reactions of 4-ethoxy-4-(S,S-dimethylsulfoximido)-1,1,1-trifluorobut-3-en-2-one with hydrazines, hydroxylamine hydrochloride and acetylguanidine

    Educational inequality in consumption of in natura or minimally processed foods and ultra-processed foods: The intersection between sex and race/skin color in Brazil

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    BackgroundIt remains uncertain how the intersection between educational, gender, and race/skin color inequalities influences food consumption in Brazil. In this study, we examined the educational inequality in the consumption of in natura/minimally processed and ultra-processed foods by Brazilians with an intersectional perspective between sex and race/color.MethodsWe used cross-sectional data from the Telephone Surveillance System (VIGITEL 2019), comprising 52,443 participants ≥ 18 years. Daily food consumption was considered high when consumption of ≥5 foods for each food group was reported the day before the survey. Educational inequality in food consumption was assessed by the slope index of inequality (SII) and the relative index of inequality (RII) according to sex and race/color (White; Black/Brown). Positive SII and RII values > 1.0 indicate higher food consumption among more educated participants.ResultsThe consumptions of in natura/minimally processed and ultra-processed foods were more prevalent in those with the highest level of education (≥12 years) and intermediate education (9–11 years), respectively. However, highly educated White women had higher consumption of in natura/minimally processed foods than Black women with the same education level, and White men in low and intermediate school levels had higher consumption of these foods than Black men with the same education levels. We found higher absolute educational inequality for in natura/minimally processed foods among White women (SII 21.8, 95% CI 15.3, 28.4) and Black/Brown men (SII 19.3, 95% CI 12.5, 26.1). Black/Brown men (SII 7.3, 95% CI 0.5, 14.0) and Black/Brown women (SII 5.6, 95% CI 1.0, 10.2) had higher absolute educational inequality than White men (SII −3.3, 95% CI −10.9, 4.3; P = 0.04) in the consumption of ultra-processed foods.ConclusionEducational inequalities influenced the consumption of in natura/minimally processed more than ultra-processed foods, and, for the latter, inequalities were greater among Black/Brown men and women than among White men

    Phylogeography of red muntjacs reveals three distinct mitochondrial lineages

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    Background: The members of the genus Muntiacus are of particular interest to evolutionary biologists due to their extreme chromosomal rearrangements and the ongoing discussions about the number of living species. Red muntjacs have the largest distribution of all muntjacs and were formerly considered as one species. Karyotype differences led to the provisional split between the Southern Red Muntjac (Muntiacus muntjak) and the Northern Red Muntjac (M. vaginalis), but uncertainties remain as, so far, no phylogenetic study has been conducted. Here, we analysed whole mitochondrial genomes of 59 archival and 16 contemporaneous samples to resolve uncertainties about their taxonomy and used red muntjacs as model for understanding the evolutionary history of other species in Southeast Asia. Results: We found three distinct matrilineal groups of red muntjacs: Sri Lankan red muntjacs (including the Western Ghats) diverged first from other muntjacs about 1.5 Mya; later northern red muntjacs (including North India and Indochina) and southern red muntjacs (Sundaland) split around 1.12 Mya. The diversification of red muntjacs into these three main lineages was likely promoted by two Pleistocene barriers: one through the Indian subcontinent and one separating the Indochinese and Sundaic red muntjacs. Interestingly, we found a high level of gene flow within the populations of northern and southern red muntjacs, indicating gene flow between populations in Indochina and dispersal of red muntjacs over the exposed Sunda Shelf during the Last Glacial Maximum. Conclusions: Our results provide new insights into the evolution of species in South and Southeast Asia as we found clear genetic differentiation in a widespread and generalist species, corresponding to two known biogeographical barriers: The Isthmus of Kra and the central Indian dry zone. In addition, our molecular data support either the delineation of three monotypic species or three subspecies, but more importantly these data highlight the conservation importance of the Sri Lankan/South Indian red muntjac
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