I021 Impact du polymorphisme génétique C(-260)T du CD14 sur la pression pulsée en fonction d’autres facteurs de risque cardiovasculaires : etude populationnelle transversale à partir du registre monica

Objectif de l’étudeLe CD14 est à l’intersection entre l’inflammation, les maladies infectieuses et le syndrome métabolique. Une corrélation positive entre la concentration plasmatique du CD14 soluble (sCD14) et la rigidité aortique a été décrite dans une étude transversale. Mais différents résultats ont été retrouvés sur l’incidence des évènements cardiovasculaires en fonction du polymorphisme C(-260)T du gène du CD14.L’objectif de cette étude est d’étudier l’influence du polymorphisme C(-260)T du CD14 sur la pression pulsée et indirectement sur le risque cardiovasculaire à partir de l’étude populationnelle transversale MONICA.Déroulement de l’étude1 155 sujets âgés entre 35 et 64 ans, en prévention primaire, ont été recrutés à partir des listes électorales de la Haute Garonne entre 1995 et 1997.MéthodesLa pression pulsée brachiale était mesurée au repos à 2 reprises puis moyennée. La concentration plasmatique du sCD14 a été mesurée par méthode immunoenzymatique. La randomisation est de type mendélienne. Les sujets ont été répartis en fonction du polymorphisme C(-260)T du CD14 après génotypage : homozygotes CC, homozygotes TT ou hétérozygotes CT.RésultatsLes sujets homozygotes TT ont une pression pulsée (PP) significativement plus basse et une concentration en sCD14 significativement plus élevée. Après ajustement avec les principaux facteurs confondants (âge, sexe, facteurs de risque cardiovasculaires traités), seul le génotype du CD14 reste corrélé à la PP. Cette corrélation n’intervient qu’en présence de facteurs de risque traités. Les diabétiques traités homozygotes TT sont ceux qui bénéficient de la plus importante baisse de PP par rapport aux homozygotes diabétiques CC (− 19,4mmHg, p=0,006).ConclusionCette étude suggère que les facteurs de risque ont un impact différent sur la pression pulsée en fonction du polymorphisme C(-260)T du CD14. Cette observation pourrait contribuer à affiner le risque cardiovasculaire absolu individuel, les sujets homozygotes TT ayant un risque cardiovasculaire moindre

Modelling the contribution of short-range atmospheric and hydrological transfers to nitrogen fluxes, budgets and indirect emissions in rural landscapes

Spatial interactions within a landscape may lead to large inputs of reactive nitrogen (N<sub>r</sub>) transferred from cultivated areas and farms to oligotrophic ecosystems and induce environmental threats such as acidification, nitric pollution or eutrophication of protected areas. The paper presents a new methodology to estimate N<sub>r</sub> fluxes at the landscape scale by taking into account spatial interactions between landscape elements. This methodology includes estimates of indirect N<sub>r</sub> emissions due to short-range atmospheric and hydrological transfers. We used the NitroScape model which integrates processes of N<sub>r</sub> transformation and short-range transfer in a dynamic and spatially distributed way to simulate N<sub>r</sub> fluxes and budgets at the landscape scale. Four configurations of NitroScape were implemented by taking into account or not the atmospheric, hydrological or both pathways of N<sub>r</sub> transfer. We simulated N<sub>r</sub> fluxes, especially direct and indirect N<sub>r</sub> emissions, within a test landscape including pig farms, croplands and unmanaged ecosystems. Simulation results showed the ability of NitroScape to simulate patterns of N<sub>r</sub> emissions and recapture for each landscape element and the whole landscape. NitroScape made it possible to quantify the contribution of both atmospheric and hydrological transfers to N<sub>r</sub> fluxes, budgets and indirect N<sub>r</sub> emissions. For instance, indirect N<sub>2</sub>O emissions were estimated at around 21% of the total N<sub>2</sub>O emissions. They varied within the landscape according to land use, meteorological and soil conditions as well as topography. This first attempt proved that the NitroScape model is a useful tool to estimate the effect of spatial interactions on N<sub>r</sub> fluxes and budgets as well as indirect N<sub>r</sub> emissions within landscapes. Our approach needs to be further tested by applying NitroScape to several spatial arrangements of agro-ecosystems within the landscape and to real and larger landscapes

An inter-model assessment of the role of direct air capture in deep mitigation pathways

The feasibility of large-scale biological CO2 removal to achieve stringent climate targets remains unclear. Direct Air Carbon Capture and Storage (DACCS) offers an alternative negative emissions technology (NET) option. Here we conduct the first inter-model comparison on the role of DACCS in 1.5 and 2°C scenarios, under a variety of techno-economic assumptions. Deploying DACCS significantly reduces mitigation costs, and it complements rather than substitutes other NETs. The key factor limiting DACCS deployment is the rate at which it can be scaled up. Our scenarios’ average DACCS scale-up rates of 1.5 GtCO2/yr would require considerable sorbent production and up to 300 EJ/yr of energy input by 2100. The risk of assuming that DACCS can be deployed at scale, and finding it to be subsequently unavailable, leads to a global temperature overshoot of up to 0.8°C. DACCS should therefore be developed and deployed alongside, rather than instead of, other mitigation options

Neuropathic complications after 157 procedures of continuous popliteal nerve block for hallux valgus surgery. A retrospective study

SummaryBackgroundContinuous peripheral nerve block (CPNB), in particular at the popliteal fossa, is widely used in orthopedic surgery, allowing good postoperative analgesia. Possible neuropathic complications, however, remain poorly known.ObjectiveTo review the characteristics of peripheral neuropathy (PN) after sciatic CPNB at the popliteal fossa, estimating prevalence, severity, evolution and possible risk factors, especially those relating to the procedure.MethodsRetrospective study of PN associated with popliteal fossa CPNB for hallux valgus surgery, between November 1st, 2005 and November 1st, 2009. All procedures were analyzed (type of anesthesia, approach, nerve location technique, number of procedures by operator) with, for each case of PN, analysis of clinical and electromyographic data.ResultsOne hundred and fifty seven sciatic CPNBs were performed (92% women; mean age, 55 years). The approach was lateral (n=62), posterior (n=74) or unknown (n=21). Ultrasound guidance was combined to neurostimulation for 69 patients (44%). Three women (prevalence=1.91%), aged 19, 24 and 65 years respectively, developed associated common superficial peroneal and sural nerve injury (2), axonal on electromyography, with motor (n=1) and/or sensory (n=3) residual dysfunction.DiscussionThe higher prevalence found in the present study than in the literature (0 to 0.5%) raises questions of methodological bias or technical problems. The common peroneal and sural nerves seem to be exposed, unlike the tibial. Several mechanisms can be suggested: anesthetic neurotoxicity, direct mechanical lesion, or tourniquet-related ischemia and conduction block. Further studies are necessary to determine the ideal anesthetic procedure.ConclusionPatients should be informed of the potential risk, however rare, even during mild surgery. The best possible technique should be implemented, with reinforced surveillance.Level of evidenceLevel IV retrospective study

Meeting well-below 2°C target would increase energy sector jobs globally

To limit global warming to well-below 2°C (WB2C), fossil fuels must be replaced by low-carbon energy sources. Support for this transition is often dampened by the impact on fossil fuel jobs. Previous work shows that pro-climate polices could increase employment by 20 million net energy jobs, but these studies rely on Organisation for Economic Co-operation and Development (OECD) jobs data, assumptions about jobs in non-OECD countries, and a single baseline assumption. Here we combine a global dataset of job intensities across 11 energy technologies and five job categories in 50 countries with an integrated assessment model under three shared socioeconomic pathways. We estimate direct energy jobs under a WB2C scenario and current policy scenarios. We find that, by 2050, energy sector jobs would grow from today's 18 million to 26 million under a WB2C scenario compared with 21 million under the current policy scenario. Fossil fuel extraction jobs would rapidly decline, but losses will be compensated by gains in solar and wind jobs, particularly in the manufacturing sector (totaling 7.7 million in 2050)

Using a Crop Model to Benchmark Miscanthus and Switchgrass

Crop yields are important items in the economic performance and the environmental impacts of second-generation biofuels. Since they strongly depend on crop management and pedoclimatic conditions, it is important to compare candidate feedstocks to select the most appropriate crops in a given context. Agro-ecosystem models offer a prime route to benchmark crops, but have been little tested from this perspective thus far. Here, we tested whether an agro-ecosystem model (CERES-EGC) was specific enough to capture the differences between miscanthus and switchgrass in northern Europe. The model was compared to field observations obtained in seven long-term trials in France and the UK, involving different fertilizer input rates and harvesting dates. At the calibration site (Estrées-Mons), the mean deviations between simulated and observed crop biomass yields for miscanthus varied between −0.3 t DM ha−1 and 4.2 t DM ha−1. For switchgrass, simulated yields were within 1.0 t DM ha−1 of the experimental data. Observed miscanthus yields were higher than switchgrass yields in most sites and for all treatments, with one exception. Overall, the model captured the differences between both crops adequately, with a mean deviation of 0.46 t DM ha−1, and could be used to guide feedstock selections over larger biomass supply areas

Coupling climate and economic models in a cost-benefit framework: a convex optimization approach

In this paper we present a general method, based on a convex optimisation technique, that facilitates the coupling of climate and economic models in a cost-benefit framework. As a demonstration of the method, we couple an economic growth model à la Ramsey adapted from DICE-99 with an efficient intermediate complexity climate model, C-GOLDSTEIN, which has highly simplified physics, but fully 3-D ocean dynamics. As in DICE-99 we assume that an economic cost is associated with global temperature change: this change is obtained from the climate model which is driven by the GHG concentrations computed from the economic growth path. The work extends a previous paper in which these models were coupled in cost-effectiveness mode. Here we consider the more intricate cost-benefit coupling in which the climate impact is not fixed a priori. We implement the coupled model using an oracle-based optimisation technique. Each model is contained in an oracle which supplies model output and information on its sensitivity to a master program. The algorithm Proximal-ACCPM guarantees the convergence of the procedure under sufficient convexity assumptions. Our results demonstrate the possibility of a consistent, cost-benefit, climate-damage optimisation analysis with a 3-D climate model

Assessing the challenges of global long-term mitigation scenarios

The implications of global mitigation to achieve different long-term temperature goals (LTTGs) can be investigated in integrated assessment models (IAMs), which provide a large number of outputs including technology deployment levels, economic costs, carbon prices, annual rates of decarbonisation, degree of global net negative emissions required, as well as utilisation levels for fossil fuel plants. All of these factors can be considered in detail when judging the real-world feasibility of the mitigation scenarios produced by these models. This study presents a model inter-comparison of three widely used IAMs (TIAM, MESSAGE and WITCH) to analyse multiple mitigation scenarios exploring a range of LTTGs and a range of constraints, including delayed mitigation action, limited end-use electrification and delayed deployment of carbon capture technologies. The scenario outputs across the three models are examined and discussed and a matrix of the different factors concerning scenario feasibility is presented

Apatites in Gale Crater

ChemCam is an active remote sensing instrument suite that has operated successfully on MSL since landing Aug. 6th, 2012. It uses laser pulses to remove dust and to analyze rocks up to 7 m away. Laser-induced breakdown spectroscopy (LIBS) obtains emission spectra of materials ablated from the samples in electronically excited states. The intensities of the emission lines scale with the abundances of the related element. ChemCam is sensitive to most major rock-forming elements as well as to a set of minor and trace elements such as F, Cl, Li, P, Sr, Ba, and Rb. The measured chemical composition can then be used to infer the mineralogical composition of the ablated material. Here, we report a summary of inferred apatite detections along the MSL traverse at Gale Crater. We present the geologic settings of these findings and derive some interpretations about the formation conditions of apatite in time and space