152 research outputs found

    Temporal changes in cardiac oxidative stress, inflammation and remodeling induced by exercise in hypertension: Role for local angiotensin II reduction

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    Exercise training reduces renin-angiotensin system (RAS) activation, decreases plasma and tissue oxidative stress and inflammation in hypertension. However, the temporal nature of these phenomena in response to exercise is unknown. We sought to determine in spontaneously hypertensive rats (SHR) and age-matched WKY controls the weekly effects of training on blood pressure (BP), plasma and left ventricle (LV) Ang II and Ang-(1–7) content (HPLC), LV oxidative stress (DHE staining), gene and protein expression (qPCR and WB) of pro-inflammatory cytokines, antioxidant enzymes and their consequence on hypertension-induced cardiac remodeling. SHR and WKY were submitted to aerobic training (T) or maintained sedentary (S) for 8 weeks; measurements were made at weeks 0, 1, 2, 4 and 8. Hypertension-induced cardiac hypertrophy was accompanied by acute plasma Ang II increase with amplified responses during the late phase of LV hypertrophy. Similar pattern was observed for oxidative stress markers, TNF alpha and interleukin-1β, associated with cardiomyocytes’ diameter enlargement and collagen deposition. SHR-T exhibited prompt and marked decrease in LV Ang II content (T1 vs T4 in WKY-T), normalized oxidative stress (T2), augmented antioxidant defense (T4) and reduced both collagen deposition and inflammatory profile (T8), without changing cardiomyocytes’ diameter and LV hypertrophy. These changes were accompanied by decreased plasma Ang II content (T2-T4) and reduced BP (T8). SHR-T and WKY-T showed parallel increases in LV and plasma Ang-(1–7) content. Our data indicate that early training-induced downregulation of LV ACE-AngII-AT1 receptor axis is a crucial mechanism to reduce oxidative/pro-inflammatory profile and improve antioxidant defense in SHR-T, showing in addition this effect precedes plasma RAS deactivation

    Multi-scale assessment of human-induced changes to Amazonian instream habitats

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    Context Land use change and forest degradation have myriad effects on tropical ecosystems. Yet their consequences for low-order streams remain very poorly understood, including in the world´s largest freshwater basin, the Amazon. Objectives Determine the degree to which physical and chemical characteristics of the instream habitat of low-order Amazonian streams change in response to past local- and catchment-level anthropogenic disturbances. Methods To do so, we collected field instream habitat (i.e., physical habitat and water quality) and landscape data from 99 stream sites in two eastern Brazilian Amazon regions. We used random forest regression trees to assess the relative importance of different predictor variables in determining changes in instream habitat response variables. Results Multiple drivers, operating at multiple spatial scales, were important in determining changes in the physical habitat and water quality of the sites. Although we found few similarities in modelled relationships between the two regions, we observed non-linear responses of specific instream characteristics to landscape change; for example 20 % of catchment deforestation resulted in consistently warmer streams. Conclusions Our results highlight the importance of local riparian and catchment-scale forest cover in shaping instream physical environments, but also underscore the importance of other land use changes and activities, such as road crossings and upstream agriculture intensification. In contrast to the property-scale focus of the Brazilian Forest code, which governs environmental regulations on private land, our results reinforce the importance of catchment-wide management strategies to protect stream ecosystem integrity

    Genotoxic effect of photodynamic therapy mediated by curcumin on Candida albicans

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    Photodynamic therapy (PDT) is a promising method for localized and speci c inactivation of fungi and bacteria. A nontoxic light-sensitive compound is taken up by cells, which are then exposed selectively to light, which activates toxicity of the compound. We investigated the potential of sublethal PDT using light-sensitive curcumin (CUR) in combination with blue (455 nm) light to promote reactive oxygen species (ROS) formation in the form of singlet oxygen and DNA damage of Candida albicans. Surprisingly, CUR-mediated PDT but also light alone caused signi cantly longer comet tails, an indication of DNA damage of C. albicans when compared with the negative control. The intracellular ROS production was also signi cantly higher for the group treated only with light. However, PDT compared to blue light alone signi cantly slowed DNA repair. Comet tails decreased during 30 min visualized as a 90% reduction in length in the absence of light for cells treated with light alone, while comet tails of cells treated with PDT only diminished in size about 45%. These results indicate that complex mechanisms may result in PDT in a way that should be considered when choosing the photosensitive compound and other aspects of the treatment design.FAPESP grants number 2012/17468–2; UID/AGR/04033/2013info:eu-repo/semantics/publishedVersio

    The numbers of the beast: Valuation of jaguar (Panthera onca) tourism and cattle depredation in the Brazilian Pantanal

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    Large carnivores fascinate people because of their beauty and potential as human predators and have therefore become focal species for the ecotourism industry. Wildlife tourism has grown exponentially and has often been used as a financial argument for species conservation. However, carnivores depredate livestock, leading to a direct economic conflict with rural livelihoods, often resulting in lethal retaliation action. Here we show that jaguar ecotourism represents a gross annual income of US6,827,392inlanduserevenueacrossarepresentativeportiontheBrazilianPantanal,theworldslargestwetland.Consideringtheaggregatecostsofjaguardepredationonlivestockwithinthesamearea,weestimatethattheresidentjaguarpopulationwouldinduceahypotheticaldamageofonlyUS6,827,392 in land-use revenue across a representative portion the Brazilian Pantanal, the world's largest wetland. Considering the aggregate costs of jaguar depredation on livestock within the same area, we estimate that the resident jaguar population would induce a hypothetical damage of only US121,500 per year in bovine cattle losses. This large discrepancy between economic gains and losses reinforces the importance of wildlife tourism as a conservation tool in boosting tolerance of jaguars in private ranches. We also evaluate the partnership between ecotourism and cattle ranchers, in which cattle losses induced by jaguars could be compensated by a system of voluntary donations from tourists, ensuring that both traditional livestock husbandry and ecotourism can co-exist within the same ranches, thereby promoting landscape-scale jaguar conservation

    Thresholds of riparian forest use by terrestrial mammals in a fragmented Amazonian deforestation frontier

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    Species persistence in fragmented landscapes is intimately related to the quality, structure, and context of remaining habitat remnants. Riparian vegetation is legally protected within private landholdings in Brazil, so we quantitatively assessed occupancy patterns of terrestrial mammals in these remnants, examining under which circumstances different species effectively use them. We selected 38 riparian forest patches and five comparable riparian sites within continuous forest, at which we installed four to five camera-traps per site (199 camera-trap stations). Terrestrial mammal assemblages were sampled for 60 days per station during the dry seasons of 2013 and 2014. We modelled species occupancy and detection probabilities within riparian forest remnants, and examined the effects of patch size, habitat quality, and landscape structure on occupancy probabilities. We then scaled-up modelled occupancies to all 1915 riparian patches throughout the study region to identify which remnants retain the greatest potential to work as habitat for terrestrial vertebrates. Of the ten species for which occupancy was modelled, six responded to forest quality (remnant degradation, cattle intrusion, palm aggregations, and understorey density) or structure (remnant width, isolation, length, and area of the patch from which it originates). Patch suitability was lower considering habitat quality than landscape structure, and virtually all riparian remnants were unsuitable to maintain a high occupancy probability for all species that responded to forest patch quality or structure. Beyond safeguarding legal compliance concerning riparian remnant amount, ensuring terrestrial vertebrate persistence in fragmented landscapes will require curbing the drivers of forest degradation within private landholdings

    Different Behavior of Enteric Bacteria and Viruses in Clay and Sandy Soils after Biofertilization with Swine Digestate

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    Enteric pathogens from biofertilizer can accumulate in the soil, subsequently contaminating water and crops. We evaluated the survival, percolation and leaching of model enteric pathogens in clay and sandy soils after biofertilization with swine digestate: PhiX-174, mengovirus (vMC0), Salmonella enterica Typhimurium and Escherichia coli O157:H7 were used as biomarkers. The survival of vMC0 and PhiX-174 in clay soil was significantly lower than in sandy soil (ıPT90 values of 10.520 0.600 vs. 21.270 1.100 and 12.040 0.010 vs. 43.470 1.300, respectively) and PhiX- 174 showed faster percolation and leaching in sandy soil than clay soil (ıPT90 values of 0.46 and 2.43, respectively). S. enterica Typhimurium was percolated and inactivated more slowly than E. coli O157:H7 (ıPT90 values of 9.340 0.200 vs. 6.620 0.500 and 11.900 0.900 vs. 10.750 0.900 in clay and sandy soils, respectively), such that E. coli O157:H7 was transferred more quickly to the deeper layers of both soils evaluated (percolation). Our findings suggest that E. coli O157:H7 may serve as a useful microbial biomarker of depth contamination and leaching in clay and sandy soil and that bacteriophage could be used as an indicator of enteric pathogen persistence. Our study contributes to development of predictive models for enteric pathogen behavior in soils, and for potential water and food contamination associated with biofertilization, useful for risk management and mitigation in swine digestate recycling.RTA2014-00024-C04-01 from the Spanish Ministry of Economy and Innovation and the Brazilian CNPq Project number 472804/2013-8, an dby CAPES/PNPD and CAPES/PDSE

    Einführung in z/OS

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    FSF: Applying machine learning techniques to data forwarding in socially selfish Opportunistic Networks

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    [EN] Opportunistic networks are becoming a solution to provide communication support in areas with overloaded cellular networks, and in scenarios where a fixed infrastructure is not available, as in remote and developing regions. A critical issue, which still requires a satisfactory solution, is the design of an efficient data delivery solution trading off delivery efficiency, delay, and cost. To tackle this problem, most researchers have used either the network state or node mobility as a forwarding criterion. Solutions based on social behaviour have recently been considered as a promising alternative. Following the philosophy from this new category of protocols, in this work, we present our ¿FriendShip and Acquaintanceship Forwarding¿ (FSF) protocol, a routing protocol that makes its routing decisions considering the social ties between the nodes and both the selfishness and the device resources levels of the candidate node for message relaying. When a contact opportunity arises, FSF first classifies the social ties between the message destination and the candidate to relay. Then, by using logistic functions, FSF assesses the relay node selfishness to consider those cases in which the relay node is socially selfish. To consider those cases in which the relay node does not accept receipt of the message because its device has resource constraints at that moment, FSF looks at the resource levels of the relay node. By using the ONE simulator to carry out trace-driven simulation experiments, we find that, when accounting for selfishness on routing decisions, our FSF algorithm outperforms previously proposed schemes, by increasing the delivery ratio up to 20%, with the additional advantage of introducing a lower number of forwarding events. We also find that the chosen buffer management algorithm can become a critical element to improve network performance in scenarios with selfish nodes.This work was partially supported by the "Camilo Batista de Souza/Programa Doutorado-sanduiche no Exterior (PDSE)/Processo 88881.133931/2016-01" and by the Ministerio de Ciencia, Innovacion y Universidades, Programa Estatal de Investigacion, Desarrollo e Innovacion Orientada a los Retos de la Sociedad, Proyectos I+D+I 2018, Spain, under Grant RTI2018-096384-B-I00".Souza, C.; Mota, E.; Soares, D.; Manzoni, P.; Cano, J.; Tavares De Araujo Cesariny Calafate, CM.; Hernández-Orallo, E. (2019). FSF: Applying machine learning techniques to data forwarding in socially selfish Opportunistic Networks. Sensors. 19(10):1-26. https://doi.org/10.3390/s19102374S1261910Trifunovic, S., Kouyoumdjieva, S. T., Distl, B., Pajevic, L., Karlsson, G., & Plattner, B. (2017). 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    Communicating generators in Javascript

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    This paper outlines the design, performance, and use of an application programming interface and library for concurrent programming with CSP in JavaScript. The implementation harnesses ECMAScript 6 Generators to provide cooperative scheduling and channel communication within a single JavaScript engine. External channels lie atop WebSockets, amongst other web technologies, to enable multicore and distributed execution across standard web browsers and Node.js servers. Low-level benchmarks indicate that scheduling and messaging performance is within expectations for this dynamic and diverse execution environment. Sample code snippets highlight the applicability of CSP to contemporary web development in hiding the location of computation and state through the channel abstraction. The ”callback hell” scenario common to many JavaScript applications is alleviated by using channels instead of callbacks, and the possibility of performing parallel and scientific computing is explored with promising results. Finally, the limitations of the present design are discussed, and possible enhancements such as the dynamic migration of state and code are considered.peer-reviewe
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