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

Fossil extraction bans and carbon taxes: Assessing their interplay through multiple models

Given concerns about the ambition and effectiveness of current climate policies, a case has been made for the combination of demand side policies such as carbon pricing with supply side bans on fossil fuel extraction. However, little is known about their interplay in the context of climate stabilization strategies. Here, we present a multi-model assessment quantifying the effectiveness of supply side policies and their interactions with demand-side ones. We explore a variety of fossil fuel bans with four integrated assessment models and find that international supply side policies reduce carbon emissions but not at sufficient levels to stabilize temperature increase to well below 2°C. When combined with demand side policies, supply side policies reduce the required carbon price, dampen reliance on CO2 removal technologies, and increase investment in renewable energy. The results indicate the opportunity to integrate fossil fuel bans alongside price-based policies when exploring pathways to reach ambitious mitigation targets

Phosphates du Protérozoïque supérieur dans la chaîne des Dahomeyides (circa 600 Ma) de la région de Bassar (Nord-Togo, Afrique de l'Ouest)

Les phosphates de Bassar (nord du Togo) sont situés dans la partie tectonisée de la couverture du craton ouest-africain, et plus précisément dans les schistes de l'unité structurale de l'Atacora de la chaîne des Dahomeyides. Les roches phosphatées se présentent comme des intercalations d'épaisseur variables (< 30 m). Elles sont généralement constituées de pellets d'apatite plus ou moins pure et recristallisée enrobés dans une matrice essentiellement phosphatée. Ce gisement s'ajoute notamment aux indices d'Aloub Djouana et de Pagala et démontre ainsi une extension fort intéressante des phosphates précambriens dans les unités tectonisées au front des Dahomeyide

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

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

A new physiological model for studying the effect of chest compression and ventilation during cardiopulmonary resuscitation: The Thiel cadaver

BACKGROUND: Studying ventilation and intrathoracic pressure (ITP) induced by chest compressions (CC) during Cardio Pulmonary Resuscitation is challenging and important aspects such as airway closure have been mostly ignored. We hypothesized that Thiel Embalmed Cadavers could constitute an appropriate model. METHODS: We assessed respiratory mechanics and ITP during CC in 11 cadavers, and we compared it to measurements obtained in 9 out-of-hospital cardiac arrest patients and to predicted values from a bench model. An oesophageal catheter was inserted to assess chest wall compliance, and ITP variation (ΔITP). Airway pressure variation (ΔPaw) at airway opening and ΔITP generated by CC were measured at decremental positive end expiratory pressure (PEEP) to test its impact on flow and ΔPaw. The patient\u27s data were derived from flow and airway pressure captured via the ventilator during resuscitation. RESULTS: Resistance and Compliance of the respiratory system were comparable to those of the out-of-hospital cardiac arrest patients (C 42 ± 12 vs C 37.3 ± 10.9 mL/cmHO and Res 17.5 ± 7.5 vs Res 20.2 ± 5.3 cmHO/L/sec), and remained stable over time. During CC, ΔITP varied from 32 ± 12 cmHO to 69 ± 14 cmHO with manual and automatic CC respectively. Transmission of ΔITP at the airway opening was significantly affected by PEEP, suggesting dynamic small airway closure at low lung volumes. This phenomenon was similarly observed in patients. CONCLUSION: Respiratory mechanics and dynamic pressures during CC of cadavers behave as predicted by a theoretical model and similarly to patients. The Thiel model is a suitable to assess ITP variations induced by ventilation during CC

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

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

Language intermediaries and local agency: peacebuilding, translation/interpreting and political disempowerment in 'mature' post-Dayton Bosnia-Herzegovina

The peace negotiations that ended the 1992–95 war in Bosnia-Herzegovina established a constitutional system of ethnic power-sharing that satisfied its signatories (the presidents of Serbia, Croatia and Bosnia) enough for war to cease and provided for international military and civilian peacebuilding to play a significant role in post-conflict Bosnia’s governance and economy. This indefinite peacebuilding mission, still ongoing in a downsized form, depended – like any other form of intervention where foreigners work across linguistic boundaries – on interlinguistic mediation by locally-recruited translators/interpreters, an aspect of knowledge production that even current peace and conflict research into peacebuilding’s micropolitics often neglects. On an individual level, locally-recruited interpreters’ frequently-overlooked agency was integral to peacebuilding practice. Yet theorising their agency must also acknowledge the macrosocial level, where the post-war constitutional system has often been argued to have stripped Bosnians of political agency, since it foreclosed political participation as anything but an ethnic subject corresponding to the three institutionalised ethnic identities (Bosniak, Croat or Serb). The entrenched and growing disconnect between political elites and the public, expressed through social protest in 2014, foregrounds the problem of agency and dis/empowerment in Bosnian society more sharply than research on the politics of translation/interpreting and peacebuilding in Bosnia before 2014 took into account, yet reveals further articulations of how international peacebuilding and domestic political contestation were intertwined

Milk and milk-derived peptides combat against hypertension and vascular dysfunction : a review

Epidemiological studies have revealed that consumption of milk and fermented dairy products is inversely associated with elevated blood pressure and with many of the risk factors of the metabolic syndrome. Previously, calcium was thought to be behind this phenomenon, but during the last 20 years, convincing evidence emerging from experimental, epidemiological and intervention studies has highlighted the important role of the small peptides formed during fermentation processes. This review provides an overview of the potential blood pressure lowering components present in dairy products with a special focus on casein-derived tripeptides.Peer reviewe