17 research outputs found

    Finding the niche: A review of market assessment methodologies for rural electrification with small scale wind power

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    The mass roll out of solar PV across the Global South has enabled electricity access for millions of people. In the right context, Small Wind Turbines (SWTs) can be complementary, offering the potential to generate at times of low solar resource (night, monsoon season, winter, etc.) and increasing the proportion of the total energy system that can be manufactured locally. However, many contextual factors critically affect the viability of the technology, such as the extreme variability in the wind resource itself and the local availability of technical support. Therefore, performing a detailed market analysis in each new context is much more important. The Wind Empowerment Market Assessment Methodology (WEMAM) is a multi-scalar, transdisciplinary methodology for identifying the niche contexts where small wind can make a valuable contribution to rural electrification. This paper aims to inform the development of WEMAM with a critical review of existing market assessment methodologies. By breaking down WEMAM into its component parts, reflecting upon its practical applications to date and drawing upon insights from the literature, opportunities where it could continue to evolve are highlighted. Key opportunities include shifting the focus towards development outcomes; creating community archetypes; localised studies in high potential regions; scenario modelling and MCDA ranking of proposed interventions; participatory market mapping; and applying socio-technical transitions theory to understand how the small wind niche can break through into the mainstream

    Association of mixed hematopoietic chimerism with elevated circulating autoantibodies and chronic graft-versus-host disease occurrence.

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    International audienceBACKGROUND: Use of a reduced-intensity conditioning regimen before an allogeneic hematopoietic cell transplantation is frequently associated with an early state of mixed hematopoietic chimerism. Such a coexistence of both host and donor hematopoietic cells may influence posttransplant alloreactivity and may affect the occurrence and severity of acute and chronic graft-versus-host disease (GVHD) as well as the intensity of the graft-versus-leukemia effect. Here we evaluated the relation between chimerism state after reduced-intensity conditioning transplantation (RICT), autoantibody production, and chronic GVHD (cGVHD)-related pathology. METHODS: Chimerism state, circulating anticardiolipin, and antidouble stranded DNA autoantibody (Ab) titers as well as occurrence of cGVHD-like lesions were investigated in a murine RICT model. RESULTS: We observed a novel association between mixed chimerism state, high levels of pathogenic IgG autoantibodies, and subsequent development of cGVHD-like lesions. Furthermore, we found that the persistence of host B cells, but not dendritic cell origin or subset, was a factor associated with the appearance of cGVHD-like lesions. The implication of host B cells was confirmed by a host origin of autoantibodies. CONCLUSION: Recipient B cell persistence may contribute to the frequency and/or severity of cGVHD after RICT

    Immune Activation and CD8(+) T-Cell Differentiation towards Senescence in HIV-1 Infection

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    Progress in the fight against the HIV/AIDS epidemic is hindered by our failure to elucidate the precise reasons for the onset of immunodeficiency in HIV-1 infection. Increasing evidence suggests that elevated immune activation is associated with poor outcome in HIV-1 pathogenesis. However, the basis of this association remains unclear. Through ex vivo analysis of virus-specific CD8(+) T-cells and the use of an in vitro model of naïve CD8(+) T-cell priming, we show that the activation level and the differentiation state of T-cells are closely related. Acute HIV-1 infection induces massive activation of CD8(+) T-cells, affecting many cell populations, not only those specific for HIV-1, which results in further differentiation of these cells. HIV disease progression correlates with increased proportions of highly differentiated CD8(+) T-cells, which exhibit characteristics of replicative senescence and probably indicate a decline in T-cell competence of the infected person. The differentiation of CD8(+) and CD4(+) T-cells towards a state of replicative senescence is a natural process. It can be driven by excessive levels of immune stimulation. This may be part of the mechanism through which HIV-1-mediated immune activation exhausts the capacity of the immune system

    Expression of CD4 by human hematopoietic progenitors [see comments]

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    Engraftment of NOD/SCID Mice with Human CD34(+) Cells Transduced by Concentrated Oncoretroviral Vector Particles Pseudotyped with the Feline Endogenous Retrovirus (RD114) Envelope Protein

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    Oncoretrovirus vectors pseudotyped with the feline endogenous retrovirus (RD114) envelope protein produced by the FLYRD18 packaging cell line have previously been shown to transduce human hematopoietic progenitor cells with a greater efficiency than similar amphotropic envelope-pseudotyped vectors. In this report, we describe the production and efficient concentration of RD114-pseudotyped murine leukemia virus (MLV)-based vectors. Following a single round of centrifugation, vector supernatants were concentrated approximately 200-fold with a 50 to 70% yield. Concentrated vector stocks transduced prestimulated human CD34(+) (hCD34(+)) cells with approximately 69% efficiency (n = 7, standard deviation = 4.4%) using a single addition of vector at a low multiplicity of infection (MOI = 5). Introduction of transduced hCD34(+) cells into irradiated NOD/SCID recipients resulted in multilineage engraftment with long-term transgene expression. These data demonstrate that RD114-pseudotyped MLV-based vectors can be efficiently concentrated to high titers and that hCD34(+) cells transduced with concentrated vector stocks retain in vivo repopulating potential. These results highlight the potential of RD114-pseudotyped oncoretrovirus vectors for future clinical implementation in hematopoietic stem cell gene transfer

    Early and Persistent Bone Marrow Hematopoiesis Defect in Simian/Human Immunodeficiency Virus-Infected Macaques despite Efficient Reduction of Viremia by Highly Active Antiretroviral Therapy during Primary Infection

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    The hematological abnormalities observed in human immunodeficiency virus (HIV)-infected patients appear to be mainly due to bone marrow dysfunction. A macaque models of AIDS could greatly facilitate an in vivo approach to the pathogenesis of such dysfunction. Here, we evaluated in this model the impact of infection with a pathogenic simian/human immunodeficiency virus (SHIV) on bone marrow hematopoiesis. Three groups of macaques were inoculated with 50 50% median infective doses of pathogenic SHIV 89.P, which expresses env of dual-tropic HIV type 1 (HIV-1) 89.6 primary isolate. During the primary phase of infection, animals were treated with either a placebo or highly active antiretroviral therapy (HAART) combining zidovudine, lamivudine, and indinavir, initiated 4 or 72 h postinfection (p.i.) and administered twice a day until day 28 p.i. In both placebo-treated and HAART-treated animals, bone marrow colony-forming cells (CFC) progressively decreased quite early, during the first month p.i. One year p.i., both placebo- and HAART-treated animals displayed decreases in CFC to about 56% of preinfection values. At the same time, a dramatic decrease (greater than 77%) of bone marrow CD34(+) long-term culture-initiating cells was noted in all animals were found. No statistically significant differences between placebo- and HAART-treated monkeys were found. These data argue for an early and profound alteration of myelopoiesis at the level of the most primitive CD34(+) progenitor cells during SHIV infection, independently of the level of viremia, circulating CD4(+) cell counts, or antiviral treatment
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