82 research outputs found

    The present and future offshore wind resource in the Southwestern African region

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    In the last decades, offshore wind harvesting has increased enormously, and is seen as a renewable energy resource with great potential in many regions of the world. Therefore, it is crucial to understand how this resource will evolve in a warming climate. In the present study, offshore wind resource in the Southwestern African region is analysed for the present and future climates. A ROM (REMO-OASIS-MPIOM) climate simulation in uncoupled and coupled atmosphere–ocean mode, at 25 km horizontal resolution, and a multi-model ensemble built with a set of regional climate models from the CORDEX-Africa experiment at 0.44° resolution were used. The projected changes of the offshore wind energy density throughout the twenty-first century are examined following the RCP4.5 and RCP8.5 greenhouse gas emissions scenarios. Characterised by strong coastal-parallel winds, the Southwestern African offshore region shows high values of wind energy density at 100 m, up to 1500 Wm⁻² near the coast, particularly offshore Namibia and west South Africa. Conversely, along Angola’s coast the available offshore wind energy density is lower. Throughout the twenty-first century, for the weaker climate mitigation scenario (RCP8.5), an increase of the offshore wind resource is projected to occur along Namibia and South African western coasts, more pronounced at the end of the century (+ 24%), while a decrease is projected along Angola’s coasts, reaching a negative anomaly of about − 32%. Smaller changes but with the same pattern are projected for the stronger climate mitigation scenario (RCP4.5). The future deployment of offshore floating hub turbines placed at higher heights may allow higher production of energy in this region. Along offshore Namibia and west South Africa, the wind energy density at 250 m showed differences that range between 30 and 50% relative to wind energy density at 100 m

    Acute Kidney Injury Reduces Phagocytic and Microbicidal Capacities of Alveolar Macrophages

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    Background/Aims: Renal ischaemia-reperfusion injury (IRI) is a systemic inflammatory process in which Th1 responses predominate affecting other organs including the lungs. the present study explored the phagocytic and microbicidal capacity of macrophages in rats with lung inflammation that underwent IRI. Methods: the alveolar macrophages of rats sensitised to OVA were evaluated for phagocytosis and bacterial killing 24h after antigen challenge in animals with or without prior submission to 60 min of renal ischaemia. Results: Bronchoalveolar lavage had a high level of cellular infiltrate in immunised animals (420%) compared with control animals; IRI significantly reduced this infiltration (52%). Macrophages from animals immunised and challenged with OVA presented a 10x increase in phagocytic capacity compared to the control group, whereas immunised animals subjected to IRI showed a reduction in the phagocytic index of 68%. the killing of Klebsiella pneumoniae by macrophages from immunised animals was higher (56%) compared with the control group but reduced in animals submitted to IRI (45%). Immunised and challenged group showed an increase in gene expression levels of IL-10(450%), HO-1 (259%), INF-gamma (460%) and MCP-1 (370%) compared to the immunised group subjected to IRI. Conclusions: Renal ischaemia and reperfusion injury apparently alters the phagocytic and microbicidal capacity of macrophages, reducing lung inflammation to OVA. Copyright (C) 2013 S. Karger AG, BaselFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)INCT Complex FluidsFADA-UNIFESPUniversidade Federal de São Paulo, Disciplina Nefrol, Lab Imunol Clin & Expt, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Lab Inflamacao & Farmacol Vasc, BR-04023900 São Paulo, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Imunol, Lab Imunobiol Transplante, BR-05508 São Paulo, BrazilUniversidade Federal de São Paulo, Disciplina Nefrol, Lab Imunol Clin & Expt, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Lab Inflamacao & Farmacol Vasc, BR-04023900 São Paulo, BrazilFAPESP: 07/07139-3FAPESP: 10/52180-4FAPESP: 10/01404-0FAPESP: 12/02270-0FAPESP: 12/51104-8Web of Scienc

    Adipose Tissue-Derived Stem Cell Treatment Prevents Renal Disease Progression

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    Adipose tissue-derived stem cells (ASCs) are an attractive source of stem cells with regenerative properties that are similar to those of bone marrow stem cells. Here, we analyze the role of ASCs in reducing the progression of kidney fibrosis. Progressive renal fibrosis was achieved by unilateral clamping of the renal pedicle in mice for 1 h; after that, the kidney was reperfused immediately. Four hours after the surgery, 2 x 10(5) ASCs were intraperitoneally administered, and mice were followed for 24 h posttreatment and then at some other time interval for the next 6 weeks. Also, animals were treated with 2 x 10(5) ASCs at 6 weeks after reperfusion and sacrificed 4 weeks later to study their effect when interstitial fibrosis is already present. At 24 h after reperfusion, ASC-treated animals showed reduced renal dysfunction and enhanced regenerative tubular processes. Renal mRNA expression of IL-6 and TNF was decreased in ASC-treated animals, whereas IL-4. IL-10, and HO-1 expression increased despite a lack of ASCs in the kidneys as determined by SRY analysis. As expected, untreated kidneys shrank at 6 weeks, whereas the kidneys of ASC-treated animals remained normal in size, showed less collagen deposition, and decreased staining for FSP-1, type I collagen, and Hypoxyprobe. the renal protection seen in ASC-treated animals was followed by reduced serum levels of TNF-alpha, KC, RANTES, and IL-1 alpha. Surprisingly, treatment with ASCs at 6 weeks, when animals already showed installed fibrosis, demonstrated amelioration of functional parameters, with less tissue fibrosis observed and reduced mRNA expression of type I collagen and vimentin. ASC therapy can improve functional parameters and reduce progression of renal fibrosis at early and later times after injury, mostly due to early modulation of the inflammatory response and to less hypoxia, thereby reducing the epithelial-mesenchymal transition.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)DECIT/Ministerio do SaudeComplex Fluids INCTUniversidade Federal de São Paulo, Div Nephrol, Escola Paulista Med, Expt & Clin Immunol Lab, BR-04023900 São Paulo, BrazilUniv São Paulo, Dept Pathol, São Paulo, BrazilUniv Fed Triangulo Mineiro, Div Pathol, Uberaba, MG, BrazilUniv São Paulo, Dept Immunol, Lab Transplantat Immunobiol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, Escola Paulista Med, Expt & Clin Immunol Lab, BR-04023900 São Paulo, BrazilFAPESP: 09/13251-6FAPESP: 07/07139-3CNPq: 473844/2009-5Web of Scienc

    Performance evaluation of a global CMIP6 single forcing, multi wave model ensemble of wave climate simulations

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    A performance evaluation is conducted for a state-of-the-art Coupled Model Intercomparison Project Phase 6 (CMIP6)-derived ensemble of global wave climate simulations. A single-model (forcing), single-scenario approach is considered to build the ensemble, where the differentiating factor between each member is the wave model or physics parameterization used to simulate waves. The 7-member ensemble is evaluated for the 1995-2014 historical period, highlighting the impact of the multiple source terms on its robustness. The ensemble’s ability to accurately represent the present wave climate is assessed through an extensive comparison with long-term ERA5 reanalysis and in-situ observational data. Relevant aspects such as the depiction of extremes and natural wave climate variability are analyzed, and inter-member uncertainties are quantified. Overall, the results indicate that the ensemble is able to accurately simulate the global wave climate, regarding the significant wave height (), mean and peak wave periods ( and , respectively) and mean wave direction (). However, we show that using multiple wave models and parameterizations should be cautiously considered when building ensembles, even under the same forcing conditions. Model-parameterization-induced ensemble spreads during the historical period are found to be high, compromising the robustness of projected changes in wave parameters towards the end of the 21 century across several areas of the global ocean

    How will a warming climate affect the Benguela coastal low‐level wind jet?

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    The strong coastal upwelling associated to the Benguela eastern boundary upwelling system makes the ocean along coast of this current one of the most productive ecosystems in the world. The Benguela Coastal Low‐Level Jet (BCLLJ) is one of the most important mesoscale feature that shape the climate of this region. The main synoptic forcing of the BCLLJ is the Angola thermal low over land and the St. Helen anticyclone over the ocean, resulting in southwesterly winds along the coast. This study investigates how the BCLLJ might change due to climate warming, with the help of uncoupled and coupled simulations from a 25‐km horizontal resolution regional climate model (ROM). In general, the coupled simulation displays the best performance in representing the present time near‐surface wind speed, with a decrease on the known warm bias of sea surface temperature in the Benguela eastern boundary upwelling system region. The analysis of the projected changes of the BCLLJ climate toward the end of the 21st century (2070–2099), following the RCP8.5 emissions scenario, shows an increase in the frequency of the BCLLJ occurrence along the southern area with higher changes in the coupled simulation (between 6% and 8%). These changes are related to a southerly shift of the St. Helen High, which intensifies the flow offshore the west coast of South Africa and causes a sharpening of the land‐sea thermal contrasts. However, during spring, associated with the decrease in near‐surface wind speed due to higher sea surface temperatures, the future frequency and intensity of the BCLLJ are lower

    On the assessment of the wave modeling uncertainty in wave climate projections

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    This study investigates the epistemic uncertainty associated with the wave propagation modeling in wave climate projections. A single-forcing, single-scenario, seven-member global wave climate projection ensemble is used, developed using three wave models with a consistent numerical domain. The uncertainty is assessed through projected changes in wave height, wave period, and wave direction. The relative importance of the wave model used and its internal parameterization are examined. The former is the dominant source of uncertainty in approximately two-thirds of the global ocean. The study reveals divergences in projected changes from runs of different models and runs of the same model with different parameterizations over 75% of the ensemble mean change in several ocean regions. Projected changes in the wave period shows the most significant uncertainties, particularly in the Pacific Ocean basin, while the wave height shows the least. Over 30% of global coastlines exhibit significant uncertainties in at least two out of the three wave climate variables analyzed. The coasts of western North America, the Maritime Continent and the Arabian Sea show the most significant wave modeling uncertainties

    Adipose Tissue-Derived Mesenchymal Stem Cells Increase Skin Allograft Survival and Inhibit Th-17 Immune Response

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    Adipose tissue-derived mesenchymal stem cells (ADSC) exhibit immunosuppressive capabilities both in vitro and in vivo. Their use for therapy in the transplant field is attractive as they could render the use of immunosuppressive drugs unnecessary. The aim of this study was to investigate the effect of ADSC therapy on prolonging skin allograft survival. Animals that were treated with a single injection of donor allogeneic ADSC one day after transplantation showed an increase in donor skin graft survival by approximately one week. This improvement was associated with preserved histological morphology, an expansion of CD4+ regulatory T cells (Treg) in draining lymph nodes, as well as heightened IL-10 expression and down-regulated IL-17 expression. In vitro, ADSC inhibit naïve CD4+ T cell proliferation and constrain Th-1 and Th-17 polarization. In summary, infusion of ADSC one day post-transplantation dramatically increases skin allograft survival by inhibiting the Th-17 pathogenic immune response and enhancing the protective Treg immune response. Finally, these data suggest that ADSC therapy will open new opportunities for promoting drug-free allograft survival in clinical transplantation

    Wave modeling uncertainty in global wave climate projections: assessment and quantification

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    Ocean wind waves are projected to changeover the twenty-first century under a warming climate. The standard approach to conduct these studies is based on wave climate projections. These products represent future wave climates, for different scenarios, developed using forcing drivers from global climate models (GCMs) or regional climate models (RCMs). Projected changes in wave climate are affected by multiple sources of uncertainty (see Figure): aleatoric uncertainty, socio-economic scenario uncertainty, uncertainty related to GCMs and the epistemic uncertainty associated with the wave modeling
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