43 research outputs found

    Lidar technology measurements and technology: Report of panel

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    Lidar is ready to make an important contribution to tropospheric chemistry research with a variety of spaceborne measurements that complement the measurements from passive instruments. Lidar can now be considered for near-term and far-term space missions dealing with a number of scientifically important issues in tropospheric chemistry. The evolution in the lidar missions from space are addressed and details of these missions are given. The laser availability for space missions based upon the technical data is assessed

    Quantification of the virus-host interaction in human T lymphotropic virus I infection

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    BACKGROUND: HTLV-I causes the disabling inflammatory disease HAM/TSP: there is no vaccine, no satisfactory treatment and no means of assessing the risk of disease or prognosis in infected people. Like many immunopathological diseases with a viral etiology the outcome of infection is thought to depend on the virus-host immunology interaction. However the dynamic virus-host interaction is complex and current models of HAM/TSP pathogenesis are conflicting. The CD8+ cell response is thought to be a determinant of both HTLV-I proviral load and disease status but its effects can obscure other factors. RESULTS: We show here that in the absence of CD8+ cells, CD4+ lymphocytes from HAM/TSP patients expressed HTLV-I protein significantly more readily than lymphocytes from asymptomatic carriers of similar proviral load (P = 0.017). A high rate of viral protein expression was significantly associated with a large increase in the prevalence of HAM/TSP (P = 0.031, 89% of cases correctly classified). Additionally, a high rate of Tax expression and a low CD8+ cell efficiency were independently significantly associated with a high proviral load (P = 0.005, P = 0.003 respectively). CONCLUSION: These results disentangle the complex relationship between immune surveillance, proviral load, inflammatory disease and viral protein expression and indicate that increased protein expression may play an important role in HAM/TSP pathogenesis. This has important implications for therapy since it suggests that interventions should aim to reduce Tax expression rather than proviral load per se

    Erratum to "The launch of the first-ever Integrated Assessment of Air Pollution and Climate Change for Sustainable Development in Africa"

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    Erratum to "The launch of the first-ever Integrated Assessment of Air Pollution and Climate Change for Sustainable Development in Africa" published in Clean Air Journal, 32(2), 2022, https://doi.org/10.17159/caj/2022/32/2.15320 The original article can be found here: https://cleanairjournal.org.za/article/view/1532

    Development of the Low Emissions Analysis Platform – Integrated Benefits Calculator (LEAP-IBC) tool to assess air quality and climate co-benefits : Application for Bangladesh

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    Low- and middle-income countries have the largest health burdens associated with air pollution exposure, and are particularly vulnerable to climate change impacts. Substantial opportunities have been identified to simultaneously improve air quality and mitigate climate change due to overlapping sources of greenhouse gas and air pollutant emissions and because a subset of pollutants, short-lived climate pollutants (SLCPs), directly contribute to both impacts. However, planners in low- and middle-income countries often lack practical tools to quantify the air pollution and climate change impacts of different policies and measures. This paper presents a modelling framework implemented in the Low Emissions Analysis Platform – Integrated Benefits Calculator (LEAP-IBC) tool to develop integrated strategies to improve air quality, human health and mitigate climate change. The framework estimates emissions of greenhouse gases, SLCPs and air pollutants for historical years, and future projections for baseline and mitigation scenarios. These emissions are then used to quantify i) population-weighted annual average ambient PM2.5 concentrations across the target country, ii) household PM2.5 exposure of different population groups living in households cooking using different fuels/technologies and iii) radiative forcing from all emissions. Health impacts (premature mortality) attributable to ambient and household PM2.5 exposure and changes in global average temperature change are then estimated. This framework is applied in Bangladesh to evaluate the air quality and climate change benefits from implementation of Bangladesh's Nationally Determined Contribution (NDC) and National Action Plan to reduce SLCPs. Results show that the measures included to reduce GHGs in Bangladesh's NDC also have substantial benefits for air quality and human health. Full implementation of Bangladesh's NDC, and National SLCP Plan would reduce carbon dioxide, methane, black carbon and primary PM2.5 emissions by 25%, 34%, 46% and 45%, respectively in 2030 compared to a baseline scenario. These emission reductions could reduce population-weighted ambient PM2.5 concentrations in Bangladesh by 18% in 2030, and avoid approximately 12,000 and 100,000 premature deaths attributable to ambient and household PM2.5 exposures, respectively, in 2030. As countries are simultaneously planning to achieve the climate goals in the Paris Agreement, improve air quality to reduce health impacts and achieve the Sustainable Development Goals, the LEAP-IBC tool provides a practical framework by which planners can develop integrated strategies, achieving multiple air quality and climate benefits

    Smaller limbic structures are associated with greater immunosuppression in over 1000 HIV-infected adults across five continents: Findings from the ENIGMA-HIV Working Group

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    Background: Human immunodeficiency virus type-1 (HIV) infection can be controlled with combination antiretroviral therapy (cART), but neurocognitive impairment remains common even in chronic and treated HIV-infected (HIV+) cohorts. Identifying the neuroanatomical pathways associated with infection has the potential to delineate novel neuropathological processes underlying persisting deficits, yet individual neuroimaging studies have yielded inconsistent findings. The ENIGMA-HIV Working Group was established to harmonize data from diverse studies to identify the common effects of HIV-infection on brain structure. Methods: Data were pooled from 12 independent neuroHIV studies from Africa, Asia, Australia, Europe, and North America. Volume estimates for eight subcortical brain regions were extracted from T1-weighted MRI from 1,044 HIV+ adults (aged 22-81 years; 72.4% on cART; 70.3% male; 41.6% with detectable viral load (dVL)), to identify associations with plasma markers reflecting current immunosuppression (CD4+ T-cell count) or dVL. Follow-up analyses stratified data by cART status and sex. Bonferroni correction was used to determine statistical significance. Findings: LowercurrentCD4+ count was associated with smaller hippocampal (β= 20.3 mm3 per 100 cells/mm3; p = 0.0001) and thalamic volumes (β= 29.3; p = 0.003); in the subset of participants not on cART, it was associated with smaller putamen volumes (β= 65.1; p = 0.0009). On average, a dVL was associated with smaller hippocampal (Cohen’s d = 0.24; p = 0.0003) and amygdala volumes (d = 0.18; p = 0.0058).Interpretation: In HIV+ individuals across five continents, smaller limbic volumes were consistently associated with current plasma markers. As we assessed cohorts with different inclusion/exclusion criteria and demographic distributions, these deficits may represent a generalizable brain-signature of HIV infection in the cART era. Our findings support the importance of achieving viral suppression and immune restoration for maintaining brain health. Funding: This work was supported, in part, by NIH grant U54 EB020403

    Association of Immunosuppression and Viral Load With Subcortical Brain Volume in an International Sample of People Living With HIV

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    International audienceIMPORTANCE Despite more widely accessible combination antiretroviral therapy (cART), HIV-1 infection remains a global public health challenge. Even in treated patients with chronic HIV infection, neurocognitive impairment often persists, affecting quality of life. Identifying the neuroanatomical pathways associated with infection in vivo may delineate the neuropathologic processes underlying these deficits. However, published neuroimaging findings from relatively small, heterogeneous cohorts are inconsistent, limiting the generalizability of the conclusions drawnto date.OBJECTIVE To examine structural brain associations with the most commonly collected clinicalassessments of HIV burden (CD4+T-cell count and viral load), which are generalizable acrossdemographically and clinically diverse HIV-infected individuals worldwide.DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study established the HIV WorkingGroup within the Enhancing Neuro Imaging Genetics Through Meta Analysis (ENIGMA) consortiumto pool and harmonize data from existing HIV neuroimaging studies. In total, data from 1295HIV-positive adults were contributed from 13 studies across Africa, Asia, Australia, Europe, and NorthAmerica. Regional and whole brain segmentations were extracted from data sets as contributingstudies joined the consortium on a rolling basis from November 1, 2014, to December 31, 2019.MAIN OUTCOMES AND MEASURES Volume estimates for 8 subcortical brain regions wereextracted from T1-weighted magnetic resonance images to identify associations with blood plasmamarkers of current immunosuppression (CD4+T-cell counts) or detectable plasma viral load (dVL) inHIV-positive participants. Post hoc sensitivity analyses stratified data by cART status.RESULTS After quality assurance, data from 1203 HIV-positive individuals (mean [SD] age, 45.7 [11.5]years; 880 [73.2%] male; 897 [74.6%] taking cART) remained. Lower current CD4+cell counts wereassociated with smaller hippocampal (mean [SE] β = 16.66 [4.72] mm3per 100 cells/mm3;P< .001)and thalamic (mean [SE] β = 32.24 [8.96] mm3per 100 cells/mm3;P< .001) volumes and largerventricles (mean [SE] β = −391.50 [122.58] mm3per 100 cells/mm3;P= .001); in participants nottaking cART, however, lowercurrent CD4+cell counts were associated with smaller putamen volumes(mean [SE] β = 57.34 [18.78] mm3per 100 cells/mm3;P= .003). A dVL was associated with smallerhippocampal volumes (d= −0.17;P= .005); in participants taking cART, dVL was also associated withsmaller amygdala volumes (d= −0.23;P= .004

    A decision support system for energy planning in developing countries

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