28 research outputs found
Remote Sensing Support for the Gain-Loss Approach for Greenhouse Gas Inventories
For tropical countries that do not have extensive ground sampling programs such as national forest inventories, the gain-loss approach for greenhouse gas inventories is often used. With the gain-loss approach, emissions and removals are estimated as the product of activity data defined as the areas of human-caused emissions and removals and emissions factors defined as the per unit area responses of carbon stocks for those activities. Remotely sensed imagery and remote sensing-based land use and land use change maps have emerged as crucial information sources for facilitating the statistically rigorous estimation of activity data. Similarly, remote sensing-based biomass maps have been used as sources of auxiliary data for enhancing estimates of emissions and removals factors and as sources of biomass data for remote and inaccessible regions. The current status of statistically rigorous methods for combining ground and remotely sensed data that comply with the good practice guidelines for greenhouse gas inventories of the Intergovernmental Panel on Climate Change is reviewed.For tropical countries that do not have extensive ground sampling programs such as national forest inventories, the gain-loss approach for greenhouse gas inventories is often used. With the gain-loss approach, emissions and removals are estimated as the product of activity data defined as the areas of human-caused emissions and removals and emissions factors defined as the per unit area responses of carbon stocks for those activities. Remotely sensed imagery and remote sensing-based land use and land use change maps have emerged as crucial information sources for facilitating the statistically rigorous estimation of activity data. Similarly, remote sensing-based biomass maps have been used as sources of auxiliary data for enhancing estimates of emissions and removals factors and as sources of biomass data for remote and inaccessible regions. The current status of statistically rigorous methods for combining ground and remotely sensed data that comply with the good practice guidelines for greenhouse gas inventories of the Intergovernmental Panel on Climate Change is reviewed.Peer reviewe
Enhanced detection of antigen-specific T cells by a multiplexed AIM assay.
Broadly applicable methods to identify and characterize antigen-specific CD4 <sup>+</sup> and CD8 <sup>+</sup> T cells are key to immunology research, including studies of vaccine responses and immunity to infectious diseases. We developed a multiplexed activation-induced marker (AIM) assay that presents several advantages compared to single pairs of AIMs. The simultaneous measurement of four AIMs (CD69, 4-1BB, OX40, and CD40L) creates six AIM pairs that define CD4 <sup>+</sup> T cell populations with partial and variable overlap. When combined in an AND/OR Boolean gating strategy for analysis, this approach enhances CD4 <sup>+</sup> T cell detection compared to any single AIM pair, while CD8 <sup>+</sup> T cells are dominated by CD69/4-1BB co-expression. Supervised and unsupervised clustering analyses show differential expression of the AIMs in defined T helper lineages and that multiplexing mitigates phenotypic biases. Paired and unpaired comparisons of responses to infections (HIV and cytomegalovirus [CMV]) and vaccination (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) validate the robustness and versatility of the method
Spontaneous HIV expression during suppressive ART is associated with the magnitude and function of HIV-specific CD4+ and CD8+ T cells.
Spontaneous transcription and translation of HIV can persist during suppressive antiretroviral therapy (ART). The quantity, phenotype, and biological relevance of this spontaneously "active" reservoir remain unclear. Using multiplexed single-cell RNAflow-fluorescence in situ hybridization (FISH), we detect active HIV transcription in 14/18 people with HIV on suppressive ART, with a median of 28/million CD4 <sup>+</sup> T cells. While these cells predominantly exhibit abortive transcription, p24-expressing cells are evident in 39% of participants. Phenotypically diverse, active reservoirs are enriched in central memory T cells and CCR6- and activation-marker-expressing cells. The magnitude of the active reservoir positively correlates with total HIV-specific CD4 <sup>+</sup> and CD8 <sup>+</sup> T cell responses and with multiple HIV-specific T cell clusters identified by unsupervised analysis. These associations are particularly strong with p24-expressing active reservoir cells. Single-cell vDNA sequencing shows that active reservoirs are largely dominated by defective proviruses. Our data suggest that these reservoirs maintain HIV-specific CD4 <sup>+</sup> and CD8 <sup>+</sup> T responses during suppressive ART
Remote Sensing Support for the Gain-Loss Approach for Greenhouse Gas Inventories
For tropical countries that do not have extensive ground sampling programs such as national forest inventories, the gain-loss approach for greenhouse gas inventories is often used. With the gain-loss approach, emissions and removals are estimated as the product of activity data defined as the areas of human-caused emissions and removals and emissions factors defined as the per unit area responses of carbon stocks for those activities. Remotely sensed imagery and remote sensing-based land use and land use change maps have emerged as crucial information sources for facilitating the statistically rigorous estimation of activity data. Similarly, remote sensing-based biomass maps have been used as sources of auxiliary data for enhancing estimates of emissions and removals factors and as sources of biomass data for remote and inaccessible regions. The current status of statistically rigorous methods for combining ground and remotely sensed data that comply with the good practice guidelines for greenhouse gas inventories of the Intergovernmental Panel on Climate Change is reviewed
A predictive model of spatial distribution of biological soil crust in the Sahel from local to regional scale [abstract]
EGU.European Geosciences Union General Assembly, Vienne, AUT, 22-/04/2012 - 27/04/201
Developing a predictive environment-based model for mapping biological soil crust patterns at the local scale in the Sahel
Several studies have demonstrated the great range of possibilities offered by remote sensing in identifying, estimating and mapping biological soil crust (BSC) patterns, i.e. a feature recognised to play major functions in drylands. However those techniques are suitable mainly where BSC patterns are abundant ( > 30%) and vegetation cover low ( 75%. Predicted values were obtained with an overall accuracy of 77.7% (kappa = 0.54), classifying the model as good and discriminant. This work is the first step in assessing the local scale ecological functions of BSC. Further work is needed for extrapolation at the regional scale in order to provide a useful tool for ecological surveys and for predictions of soil surface dynamics related to global changes in dryland areas
Venous malformation: update on aetiopathogenesis, diagnosis and management
The aim of this review was to discuss the current knowledge on aetiopathogenesis, diagnosis and therapeutic management of venous malformations (VMs). VMs are slow-flow vascular anomalies. They are simple, sporadic or familial (cutaneomucosal VMs or glomuvenous malformations), combined (e.g. capillaro-venous and capillaro-lymphaticovenous malformations) or syndromic (Klippel-Trenaunay, blue rubber bleb naevus and Maffucci). Genetic studies have identified causes of familial forms and of 40% of sporadic VMs. Another diagnostic advancement is the identification of elevated D-dimer level as the first biomarker of VMs within vascular anomalies. Those associated with pain are often responsive to low-molecular-weight heparin, which should also be used to avoid disseminated intravascular coagulopathy secondary to intervention, especially if fibrinogen level is low. Finally, development of a modified sclerosing agent, ethylcellulose-ethanol, has improved therapy. It is efficient and safe, and widens indications for sclerotherapy to sensitive and dangerous areas such as hands, feet and periocular area
Etude de la corrosion et des interactions entre sollicitations mecaniques et corrosion de materiaux soumis a un environnement type gazeification du charbon
SIGLECNRS AR 11952 (1-2) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Tumor budding outperforms ypT and ypN classification in predicting outcome of rectal cancer after neoadjuvant chemoradiotherapy
A third SARS-CoV-2 mRNA vaccine dose in people receiving hemodialysis overcomes B cell defects but elicits a skewed CD4<sup>+</sup> T cell profile.
Cellular immune defects associated with suboptimal responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccination in people receiving hemodialysis (HD) are poorly understood. We longitudinally analyze antibody, B cell, CD4 <sup>+</sup> , and CD8 <sup>+</sup> T cell vaccine responses in 27 HD patients and 26 low-risk control individuals (CIs). The first two doses elicit weaker B cell and CD8 <sup>+</sup> T cell responses in HD than in CI, while CD4 <sup>+</sup> T cell responses are quantitatively similar. In HD, a third dose robustly boosts B cell responses, leads to convergent CD8 <sup>+</sup> T cell responses, and enhances comparatively more T helper (T <sub>H</sub> ) immunity. Unsupervised clustering of single-cell features reveals phenotypic and functional shifts over time and between cohorts. The third dose attenuates some features of T <sub>H</sub> cells in HD (tumor necrosis factor alpha [TNFα]/interleukin [IL]-2 skewing), while others (CCR6, CXCR6, programmed cell death protein 1 [PD-1], and HLA-DR overexpression) persist. Therefore, a third vaccine dose is critical to achieving robust multifaceted immunity in hemodialysis patients, although some distinct T <sub>H</sub> characteristics endure