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Identifying the environmental factors that control germination is essential to understanding seed traits and their effect on fitness. Glossy buckthorn ( Frangula alnus ) is a shrub or small tree from Eurasia that has become invasive in North America, and which has negative impacts on plant communities and ecosystems. In this study, we analyzed the germination response of glossy buckthorn seeds to different temperatures, various stratification lengths and scarification conditions to measure the impact on breaking seed dormancy, as well as the effect of light in triggering germination. Survival analysis was performed utilizing a Kaplan-Meier estimator and Cox proportional hazard model. Glossy buckthorn seeds exhibited physiological dormancy and required cold stratification to germinate. Germination starts at the end of spring when temperatures reach 12°C and reach a peak later in the season with a germination rate of 70% at 20°C. At warmer temperatures, germination declines, and seeds are induced into dormancy again. Ungerminated seeds will form persistent seed banks that will ensure the survival of F. alnus over time and space as well as enhance its chances of a successful establishment and invasion. Due to climate change, increases in temperatures might impact seeds buried in the soil, shorten the length of stratification periods in some areas of North America and consequently affect the timing of germination resulting in a shift of its germination period.

In this study, the interest of ground penetrating radar (GPR) time-lapse measurements for the estimation of hydrodynamic unsaturated soil parameters is investigated using synthetic infiltration experiments. Water movement and electromagnetic wave propagation in the unsaturated zone are modeled using a one-dimensional hydrogeophysical model. The GPR travel time data are analyzed for different reflectors: a moving reflector (the infiltration wetting front) and three fixed reflectors located at different depths in the soil. Global sensitivity analysis (GSA) is employed to assess the influence of the saturated hydraulic conductivity, the saturated and residual water contents, and the Mualem–van Genuchten shape parameters α and n of the soil on the GPR travel time data of the reflectors. Statistical calibration of the soil parameters is then performed using the Markov chain Monte Carlo (MCMC) method. The impact of the type of reflector (moving or fixed) is then evaluated by analyzing the calibrated model parameters and their confidence intervals for different scenarios. GSA results show that the sensitivities of the moving and fixed reflectors data to the hydrodynamic soil parameters are different whereas the fixed reflectors have similar sensitivities. Results of parameter estimation show that the use of only data from the moving or fixed reflectors does not allow a good identification of all soil parameters. When both data are combined, all soil parameters can be well estimated with narrow confidence intervals.

The investigation of permeable hydrothermally altered and fractured zones and their distribution is a key issue for the understanding of fluid circulation in granitic rocks, on which the success of geothermal projects relies. Based on the use of short-wave infrared (SWIR) spectroscopy applied to rock cuttings coupled with interpretation of geophysical logs, we propose an investigation of the clay signature of fault and fracture zones (FZ) inside the granitic basement. This methodology was applied to two geothermal wells: GRT-2 from the Rittershoffen and GPK-1 from the Soultz-sous-Forêts (Soultz) geothermal sites, both located in the Upper Rhine Graben (URG). A total of 1430 SWIR spectra were acquired and analysed. Variations in the 2200 nm absorption band area are correlated with hydrothermal alteration grades. The 2200 nm absorption band area is found to reflect the illite quantity and its variations in the granitic basement. Low, stable values are observed in the unaltered granite facies, showing good reproducibility of the method, whereas scattered high values are associated with high hydrothermal alteration and FZs. Variations in the 2200 nm absorption band area were correlated with the gamma ray and electrical resistivity logs. This procedure allowed us to confirm that illite mainly controls the resistivity response except inside the permeable FZs, where the resistivity response is controlled by the geothermal brine. Thus, the architecture of these permeable FZs was described precisely by using a combination of the 2200 nm absorption band area data and the electrical resistivity log. Moreover, by correlation with other geophysical logs (temperature (T), porosity, and density), paleo-permeable and currently permeable FZs inside the reservoir were distinguished. The correlation of SWIR spectroscopy with electrical resistivity logs appears to be a robust tool for geothermal exploration in granitic reservoirs in the URG.

Model-based development is becoming an increasingly common development methodology. In important domains like embedded systems already major parts of the code are generated from models specified with domain-specific modelling languages. Hence, such models are nowadays an integral part of the software development and maintenance process and therefore have a major economic and strategic value for the software-developing organisations. Nevertheless almost no work has been done on a quality defect that is known to seriously hamper maintenance productivity in classic code-based development: Cloning. This paper presents an approach for the automatic detection of clones in large models as they are used in model-based development of control systems. The approach is based on graph theory and hence can be applied to most graphical data-flow languages. An industrial case study demonstrates the applicability of our approach for the detection of clones in Matlab/Simulink models that are widely used in model-based development of embedded systems in the automotive domain.

Summary In this study, we conducted a variance-based Global Sensitivity Analysis on time-lapse Ground Penetrating Radar synthetic data. We developed a coupled hydrogeological and geophysical model to compute the GPR two-way travel times during a constant head water infiltration in a homogeneous soil with a fixed water table level. We used a large number of random realizations of the model to conduct surrogate modeling based on Polynomial Chaos Expansion method, in order to perform a Global Sensitivity Analysis based on the Sobol indices. The results show the complementarity of the GPR two-way travel times for reflections occurring at the wetting front and at reflectors of fixed depths. The particular focus on the latter evidenced the three hydrodynamic parameters (using the Mualem – van Genuchten model) of the soil with the largest contribution to the total variance of the data : the saturated hydraulic conductivity, the α parameter and the saturated water content.

Electrolysis is seen by many as the ultimate solution for producing hydrogen with zero emission, assuming the electricity source to be without emission itself. Obviously this depends the context existing in each specific region of the world. This paper will focus on the Canadian context, its electrical generation characteristics, its Hydrogen strategy elements and examine what it would take to ensure the viability of electrolysis in this context. The discussion will bring those considerations down to technical R&D challenges to consider for electrolysis of the future. Lessons learned from R&D in Proton Exchange Membrane fuel cells will be included in the discussion.

In some Earth materials, induced polarization (IP) phenomena are occurring when an electric perturbation is applied. These mechanisms are described by a frequency dependent complex resistivity. The study of relaxation model parameters describing these phenomena allows to access indirectly to several properties of interest of the underground, as properties linked to the pore space geometry, fluid content or presence and discrimination of disseminated metallic particles. Nevertheless, complex resistivity is usually studied using electrical method with a direct current hypothesis, neglecting by the way electromagnetic induction that can occurs in the data. Thus, strong limitations appear to recover a complex resistivity image as EM induction increase with frequencies and larger offset. We implemented a frequency dependent complex resistivity in POLYEM3D, a 3D finite-difference modelling and inversion code for controlled-source electromagnetic data (CSEM) in order to fully recover IP information contained in EM data. CSEM method is a resistivity imaging technique using multi-frequency electromagnetic signals fully taking into account EM induction with larger investigation depth. Following a preliminary sensitivity study, a multi-stages inversion strategy was defined to undertake the multi-parameters problem. Furthermore, to manage the increasing number of parameters, a second order polynomial parametrization is used to describe frequency variation of complex resistivity. We show through 1D synthetic data inversions and preliminary 3D results that we are able to recover a complex resistivity and its frequency variation from CSEM data in the IP/EM coupling domain, when IP signals are sufficiently large compared to EM induction. Our inversion strategy allows then to access to IP parameters of the medium in an extended frequency domain as well as for greater depth of investigation. A 3D CSEM survey was undertaken in December 2020 on the former mining site of La Porte-Aux-Moines (Côtes-d'Armor, France) presenting strong IP responses, to validate our inversion method for a 3D in-situ dataset.

We develop a methodology to estimate soil hydrodynamic parameters from a water infiltration experiment monitored with a GPR (Ground Penetrating Radar). Such an experiment, carried out on both controlled and natural site, consists in applying a water charge in a tank on the soil surface. During the water infiltration, the water layer thickness above the soil surface in the tank and the GPR response on the infiltration water front are monitored. The infiltration experiment is then modelled numerically using hydrogeological parameters which describe the constitutive relationships between water content, pressure and hydraulic conductivity. In that goal, we use the WAMOS-1D code which combines the 1D Richards equation and the Mualem – van Genuchten model. From the hydrogeological models outputs and petrophysical relationships, corresponding GPR velocity models are created to generate the resulting GPR signals. Then, an inversion algorithm couples both the hydrogeological and the geophysical models to seek the optimal hydrodynamic parameters. The inverse problem objective function is calculated from the estimated arrival time of the GPR waves reflected by the water infiltration front and compared to the measured ones. Preliminary inversion tests explore the hydrodynamic parameters space using synthetic data. First results show that the saturated hydraulic conductivity parameter can be estimated. Further tests are performed to improve both our experimental set-up and methodology and allow an estimation of the other hydrodynamic parameters. An emerging idea is to complete the objective function by analyzing the arrival time corresponding to additional reflectors to the water infiltration front.

Echocardiography is a difficult tool to master. Competency requires the supervised interpretation of hundreds of exams. Perceptual learning modules (PLMs) are novel learning tools that aim to speed up this learning process by enabling learners to go online and interpret numerous clinical images, followed systematically by expert feedback. We developed and tested a PLM aimed at improving novices' ability to quickly visually estimate left ventricular ejection fraction (LVEF) on transesophageal echocardiography images, a critical skill in acute care. We hypothesized that using the PLM would improve the accuracy and the speed of learners' estimations.Learners without echocardiography experience were randomly assigned to a group that used the 96-case PLM (n = 26) or a control group (n = 26) that did not. Both groups took a pre-test and an immediate post-test that measured the accuracy of their visual estimations during a first session. At six months, participants also completed a delayed post-test.In the immediate post-test, the PLM group showed significantly better accuracy than the control group (median absolute estimation error 6.1 vs 9.0; difference 95% CI, 1.0 to 4.6; P0.001). Nevertheless, at six months, estimation errors were similar in both groups (median absolute estimation error 10.0 vs 10.0; difference 95% CI, -1.3 to 2.1; P = 0.27).Participation in a short online PLM significantly improved novices' short-term ability to accurately estimate LVEF visually, compared with controls. The effect was not sustained at six months.www.clinicaltrials.gov (NCT03245567); registered 7 August 2017.RéSUMé: OBJECTIF: L’échocardiographie est un outil difficile à maîtriser. Afin d’acquérir cette compétence, l’interprétation supervisée de centaines d’examens est nécessaire. Les modules d’apprentissage perceptuel (MAP) sont des outils d’apprentissage innovants qui visent à accélérer ce processus d’apprentissage en permettant aux apprenants d’aller en ligne et d’interpréter de nombreuses images cliniques, lesquelles sont systématiquement suivies par des rétroactions d’experts. Nous avons mis au point et testé un MAP visant à améliorer la capacité des nouveaux apprenants à rapidement estimer visuellement la fraction d’éjection ventriculaire gauche (FEVG) sur des images d’échocardiographie transœsophagienne, une compétence critique dans les soins aigus. Nous avons émis l’hypothèse que l’utilisation du MAP améliorerait la précision et la rapidité des estimations des apprenants. MéTHODE: Les apprenants sans expérience de lecture d’échocardiographie ont été aléatoirement alloués à un groupe qui a utilisé le MAP de 96 cas (n = 26) ou à un groupe témoin (n = 26) qui ne l’a pas utilisé. Les deux groupes ont passé un prétest et un post-test immédiat qui ont mesuré l’exactitude de leurs estimations visuelles au cours d’une première séance. Six mois plus tard, les participants ont également passé un autre post-test retardé. RéSULTATS: Dans le post-test immédiat, le groupe MAP a démontré une précision significativement meilleure que le groupe témoin (erreur d’estimation absolue médiane, 6,1 vs 9,0; différence de l’IC 95 %, 1,0 à 4,6; P0,001). Néanmoins, à six mois, les erreurs d’estimation étaient similaires dans les deux groupes (erreur d’estimation absolue médiane, 10,0 vs 10,0; différence de l’IC 95 %, -1,3 à 2,1; P = 0,27). CONCLUSION: La participation à un bref MAP en ligne a considérablement amélioré la capacité à court terme des nouveaux apprenants à estimer visuellement et avec précision la FEVG, par rapport à un groupe témoin. L’effet n’était pas maintenu à six mois. ENREGISTREMENT DE L’éTUDE: www.clinicaltrials.gov (NCT03245567); enregistrée le 7 août 2017.

We present results of a feasibility study of a borehole induction-coil sensor for surface-borehole NMR (SBNMR) investigations. This sensor of 7 cm diameter and 180 cm length is connected to a standard MRS (Magnetic Resonance Sounding) instrument. Thus, SBNMR is a cost-effective extension of the MRS method. Using a downhole sensor increases the depth of investigation and the resolution of MRS. In the near-horizontal Earth's magnetic field, the sensitive area of the sensor is represented by a cylinder of a few meters in diameter. A blind zone of 0.5 to 1 m around the borehole is due to the disturbance of the Earth's magnetic field by the magnetic core of the sensor. The relatively large volume investigated with SBNMR and the blind zone around borehole may represent an advantage of SBNMR over the NMR (nuclear magnetic resonance) borehole tool investigating a narrow zone around the borehole. However, using the Earth's magnetic field renders the SBNMR performance site dependent with an inherently low signal-to-noise ratio. Our first results show a good correspondence between SBNMR, MRS and borehole data.

International audience; Many methodologies have been proposed to improve the signal to noise ratio of the magnetic resonance measurements. Nevertheless, in many places MRS remains unrealizable even though it would provide valuable contribution. We propose to combine figure-of-eight shape loops with multichannel equipment to challenge this issue. We propose to use the gradient of the vertical component of the magnetic field measured via a pair of small figure-of-eight loops to estimate the noise in a large eight-shape loop of any orientation. We demonstrate on synthetic data the efficiency and limitation of this approach. The methodology applied on a field dataset allows finding a stable best direction in this case, and underlines a surprising roughly common behavior for the harmonics of the industrial current and frequencies in-between where a less organized structure was expected. This approach proves to be a convenient and efficient way to characterize quickly a site before measuring a MRS sounding, to choose the optimal orientation of the MRS loop, and provide an estimate of the final noise level that can be expected.

Glossy buckthorn (Frangula alnus Mill.) is an alien species in Canada that is invading many forested areas. Glossy buckthorn has impacts on the biodiversity and productivity of invaded forests. Currently, we do not know much about the species’ ecology and no thorough study of its distribution in temperate forests has been performed yet. As is often the case with invasive plant species, the phenology of glossy buckthorn differs from that of other indigenous plant species found in invaded communities. In the forests of eastern Canada, the main phenological difference is a delay in the shedding of glossy buckthorn leaves, which occurs later in the fall than for other indigenous tree species found in that region. Therefore, our objective was to use that phenological characteristic to map the spatial distribution of glossy buckthorn over a portion of southern Québec, Canada, using remote sensing-based approaches. We achieved this by applying a linear temporal unmixing model to a time series of the normalized difference vegetation index (NDVI) derived from Landsat 8 Operational Land Imager (OLI) images to create a map of the probability of the occurrence of glossy buckthorn for the study area. The map resulting from the temporal unmixing model shows an agreement of 69% with field estimates of glossy buckthorn occurrence measured in 121 plots distributed over the study area. Glossy buckthorn mapping accuracy was limited by evergreen species and by the spectral and spatial resolution of the Landsat 8 OLI.

International audience; In headwater catchment, the calibration of hydrological models is complex due to the scarcity of data in mountainous areas. Here, an innovative methodology is developed to condition hydrological model parameters by using magnetic resonance sounding (MRS) measurements in combination with stream flow rate data. MRS has the specificity in the various geophysical imaging techniques of being mainly sensitive to the vertical distribution of water content among the subsurface. In a way very similar to hydraulic head observations, these local distributions of water content may serve as information in a hydrological model to pattern subsurface flow by seeking model parameters. Simulations are run with different sets of parameters of a hydrological model. Each simulation provides as an output a 4-D map (3-D spatial plus time) of the vertical water content distributions over the whole catchment and their fluctuations over time. This output is then used to simulate the MRS signal that would be produced by the estimated water content. The simulated MRS signal is compared to measured MRS data to determine which hydrological simulations (which model parameters) are close to observations. The approach is applied on a hard-rock headwater catchment housing a very shallow and thin aquifer where an MRS survey covers the whole studied site. Hydraulic parameters of an integrated hydrological model of the catchment are spatially distributed by zones with uniform values, the prior delineation of the zones being guided by pedological studies. As MRS measurements supply local but spatially distributed information, the method conditions the various zones on their parameter values in a much better way than the classical (in headwater catchments) measure of the stream flow rate at the outlet of the system. Finally, hydrological simulation and time-dependent MRS forward calculations can help identifying possible locations for MRS stations to monitor the transient behavior of the hydrological state of the catchment.

Projected changes in temperature and drought regime are likely to reduce carbon (C) storage in forests, thereby amplifying rates of climate change. While such reductions are often presumed to be greatest in semi-arid forests that experience widespread tree mortality, the consequences of drought may also be important in temperate mesic forests of Eastern North America (ENA) if tree growth is significantly curtailed by drought. Investigations of the environmental conditions that determine drought sensitivity are critically needed to accurately predict ecosystem feedbacks to climate change. We matched site factors with the growth responses to drought of 10,753 trees across mesic forests of ENA, representing 24 species and 346 stands, to determine the broad-scale drivers of drought sensitivity for the dominant trees in ENA. Here we show that two factors-the timing of drought, and the atmospheric demand for water (i.e., local potential evapotranspiration; PET)-are stronger drivers of drought sensitivity than soil and stand characteristics. Drought-induced reductions in tree growth were greatest when the droughts occurred during early-season peaks in radial growth, especially for trees growing in the warmest, driest regions (i.e., highest PET). Further, mean species trait values (rooting depth and ψ50 ) were poor predictors of drought sensitivity, as intraspecific variation in sensitivity was equal to or greater than interspecific variation in 17 of 24 species. From a general circulation model ensemble, we find that future increases in early-season PET may exacerbate these effects, and potentially offset gains in C uptake and storage in ENA owing to other global change factors.

Background Total knee arthroplasty (TKA) reduces knee extensor muscle strength (KES) in the operated limb for several months after the surgery. Immediately after TKA, compared to either inguinal femoral nerve block or placebo, adductor canal block (ACB) better preserves KES. Whether this short-term increase in KES is maintained several weeks after surgery remains unknown. We hypothesized that 48 hours of continuous ACB immediately after TKA would improve KES 6 weeks after TKA, compared to placebo. Methods Patients scheduled for primary unilateral TKA were randomized to receive either a continuous ACB (group ACB) or a sham block (group SHAM) for 48 hours after surgery. Primary outcome was the difference in maximal KES 6 weeks postoperatively, measured with a dynamometer during maximum voluntary isometric contraction. Secondary outcomes included postoperative day 1 (POD1) and day 2 (POD2) KES, pain scores at rest and peak effort, and opioid consumption; variation at 6 weeks of Knee Osteoarthritis Outcome Score, patient satisfaction, and length of hospital stay. Results Sixty-three subjects were randomized and 58 completed the study. Patients in group ACB had less pain at rest during POD1 and during peak effort on POD1 and POD2, consumed less opioids on POD1 and POD2, and had higher median KES on POD1. There was no significant difference between groups for median KES on POD2, variation of Knee Osteoarthritis Outcome Score, patient satisfaction, and length of stay. There was no difference between groups in median KES 6 weeks after surgery (52 Nm [31-89 Nm] for group ACB vs 47 Nm [30-78 Nm] for group SHAM, P= .147). Conclusions Continuous ACB provides better analgesia and KES for 24-48 hours after surgery, but does not affect KES 6 weeks after TKA. Further research could evaluate whether standardized and optimized rehabilitation over the long term would allow early KES improvements with ACB to be maintained over a period of weeks or months.

Clearcutting practices combined with the predicted increase in fire activity may induce post-fire regeneration failure in boreal forest landscapes. This study aims (1) to evaluate if recently managed landscape by clear cut logging is susceptible to be affected by post-fire regeneration failure; and (2) to explore the ecological drivers of black spruce (Picea mariana (Mill.) BSP) post-fire regeneration. In 2014, we surveyed the regeneration of 36 stands in northwestern Quebec that had burned in a major fire in 2005. Fire severity was evaluated for each site with the differenced Normalized Burn Ratio. Using linear models, we explored the relationship between environmental variables (fire severity, pre-fire stand maturity, nature of the seedbed, and physiographic variables) and black spruce post-fire regeneration. Black spruce post-fire seedling density was highly variable (range: 25–16 000 seedlings/ha; mean ± standard deviation: 4549 seedlings/ha ± 4752) within the studied fire, but did not significantly differ between stands that had been logged 50 years prior to fire and those that were mature prior to the 2005 fire. However, post-fire regeneration failure (defined as 50%) in stands affected by past logging activities. Our study illustrates how biological legacies, environmental conditions and fire severity determine post-fire recovery and resilience of black spruce-dominated ecosystems of eastern Canada. By identifying the drivers of post-fire regeneration success, our study will help forest managers allocating resources where restoration of productive forest are truly needed.

Past feeding activities of the North American porcupine (Erethizon dorsatum L.) in an overmature forest were reconstructed using tree-ring dated feeding scars on jack pine (Pinus banksiana Lamb.) trees in Parc national du Bic (Quebec). Following a long fire-free period, most pines that regenerated after the 1847 fire are currently senescent, moribund, or dead, and the youngest trees are nearly 100 years old. Balsam fir (Abies balsamea (L.) Mill.), the most abundant species in the regeneration layer, is predicted to replace jack pine given the absence of recent fire and present fire protection practices in the park. According to the age structure of feeding scars, porcupine activity has been particularly high during the 1980s, which is coincident with the creation of the park. Porcupine activity was lower before this decade and in the late 20th century and absent in this century (2000–2015). The recent decrease in the number of feeding scars is consistent with the decline of the porcupine population, as shown by censuses of active dens and inventories of individuals. Observed tree death is linked with tree senescence rather than excessive feeding. In the absence of fire, it is probable that the shift from the overmature pine stand to a balsam fir stand will profoundly affect porcupine activity. This research shows how the study of tree rings can unravel some of the ecological relationships structuring a forest ecosystem through fire, succession, and animal browsing.

Background During general anaesthesia, most patients develop atelectasis, which promotes postoperative pulmonary complications. RCTs that investigated perioperative lung protection have failed to reduce postoperative pulmonary complications consistently. Ultrasound imaging could help confirm the effects of different protective ventilatory strategies, but this has not been tested in trials. The objective of this study was to use ultrasonography to evaluate whether lung-protective ventilation measures reduce perioperative atelectasis. Methods We conducted a prospective, randomised patient- and assessor-blinded controlled trial in women undergoing open gynaecological surgery. Subjects were randomised to either lung protection or zero end-expiratory pressure (ZEEP; with no recruitment manoeuvres [RMs]). Lung protection entailed PEEP (7 cm H2O) and RMs every 30 min. Lung ultrasonography was undertaken at five predefined time points. The primary outcome was the difference in lung ultrasonography score (LUS) between groups before emergence; a lower LUS indicates better lung aeration. Results We recruited 45 women (34–85 yr old). Women randomised to lung protection had lower mean (standard deviation) LUS before emergence (6.1 [3.7]), compared with women randomised to ZEEP (11.7 [3.9]; 95% confidence interval for the difference between group means [–7.9 to –3.2]; P Conclusions As assessed by lung ultrasonography, intraoperative PEEP/RMs decreased aeration loss during general anaesthesia. However, similar degrees of aeration loss were observed after tracheal extubation regardless of intraoperative ventilatory strategy. Clinical trial registration NCT02055807.

This study shows how to estimate water content of unsaturated sandy soils from ground-penetrating radar (GPR) data acquired during water drainage experiment. Using the Topp equation, water content can be converted to dielectric permittivity. Afterwards, based on 1D forward modeling method a GPR synthetic trace is generated. Finally, a trial-and-error match of modeled and observed GPR traces was performed to estimate the optimum set of parameters characterizing the materials composing the soil. According to the comparison of the modeling signal and the real signal, we go back to update the water content. Repeating the procedure until the modeling signal fits the real signal very well. We used this procedure to obtain the evolution of water content of unsaturated sandy soils. The method is presented on drainage experiment carried out on unsaturated sandy soil of a large-controlled experimental site. In order to follow the change of the water level, we measured GPR profiles at different times and picked up four GPR profiles, then the same trace (No. 700) were picked up on each GPR profile and estimated the water content from each signal.

International audience; Magnetic Resonance Sounding (MRS) measurements are acquired at 16 stations in the Strengbach headwater catchment (Vosges Mountains – France). These data, rendering the vertical distribution of water contents in the subsurface, are used to show their potential in conditioning a hydrological model of the catchment, as described in the article “Magnetic resonance sounding measurements as posterior information to condition hydrological model parameters: Application to a hard-rock headwater catchment” – Journal of Hydrology (2020). Acquisition protocols follow a free induction decay scheme. Data are filtered by applying a band-pass filter at the Larmor frequency. A filter removing the 50 Hz noise is also applied with the exception of data at a Larmor frequency close to the 50 Hz harmonic. The signal envelopes are then fitted by a decaying exponential function over time to estimate the median characteristic relaxation time of each MRS sounding.

We presented an innovative hydrogeophysical approach that allows numerical modeling of water flow in a variably saturated media. In our model, we approximated the subsurface by horizontally stratified porous media. The model output was a time varying water content profile. Then, we compared the water content provided by the model with the water content measurements carried out using the time-lapse Magnetic Resonance Sounding (MRS) method. Each MRS sounding provided a water content profile in the unsaturated zone down to twenty meters. The time shift between the profiles corresponded to the time lapse between individual MRS soundings. We minimized the discrepancy between the observed and the modeled MRS signals by varying hydraulic parameters of soil layers in the water flow model. For measuring and processing MRS data, we used NUMIS MRS instrument and SAMOVAR software. We carried out water flow modeling with HYDRUS-1D software. This paper reports our results and summarizes the limitations of the MRS method applied to water content measurements in the unsaturated zone.

Research activity associated with various observations at the Strengbach catchment in the Vosges Massif (880-1150 m) addresses many questions in the domains of hydrology and geochemistry. The catchment is the observation and experimental site of the Observatoire Hydro-Geochimique de l'Environnement appointed by the Centre National de la Recherche Scientifique. It also belongs to the research facilities that form the French Network of Critical Zone Observatories (OZCAR), which supports a network of critical zone observatories. The catchment is small (0.8 km(2)) with steep slopes (20-30%) on granitic bedrock that mainly allow for forestry (spruce and beech stands) as the main land cover. Meteorological, hydrological, and geochemical data have been monitored since 1986. The first studies conducted were dedicated to the elucidation of acid rain effects on forest ecosystems and particularly on forest decline. Multidisciplinary research studies conducted on the Strengbach catchment enable exploration of the following issues: (i) hydrological functioning at the scale of a small catchment and questions regarding the evolution and preservation of the water resources in mountainous environments (stock, recharge, infiltration, and water pathways), (ii) exchange processes observed at the soil-plant-atmosphere continuum and in particular weathering processes and the evolution of soil mineral fertility (Ca, Mg, K, P), (iii) processes responsible for the export of water and for associated fluxes (dissolved chemicals, suspended materials, bed loads) and their dynamic at the outlet, and (iv) responses of the ecosystems to environmental disturbances (acid rain, forest management, and climate change) and their current and future modeling.

Alkalinized lidocaine in the endotracheal tube (ETT) cuff decreases the incidence of cough and throat pain on emergence after surgery lasting more than 2 hours. However, alkalinized lidocaine needs 60-120 minutes to cross the ETT cuff membrane; therefore, its usefulness in shorter duration surgery is unknown. This prospective double-blind randomized controlled trial tested the hypothesis that alkalinized lidocaine would reduce the incidence of emergence cough after surgeries lasting120 minutes.After local ethics board approval, American Society of Anesthesiologists I-III patients consented to be randomized into 1 of 2 groups receiving either alkalinized lidocaine (group AL) or saline (group S) to inflate the ETT cuff. Cuffs were prefilled90 minutes before intubation with either 2 mL of 2% lidocaine and 8 mL of 8.4% bicarbonate (group AL) or 10 mL of normal saline (group S). Cuffs were emptied immediately before intubation. After intubation, either 2 mL of 2% lidocaine (AL) or 2 mL of saline (S) were injected into the cuff. Additional 8.4% bicarbonate (AL) or saline (S) was injected into the cuff until there was no air leak. Anesthesia was maintained using desflurane, rocuronium, and either fentanyl or sufentanil to maintain vital signs within 20% of baseline values. Opioids administered in prophylaxis of extubation cough were proscribed. A standardized "no touch" emergence technique was used. A blinded assessor noted any cough above 0.2 minimum alveolar concentration (MAC) of expired desflurane. At 0.2 MAC, once every 30 seconds, the patient was instructed to open his eyes and extubation occurred once a directed response was noted.A total of 213 patients were randomized and 100 patients in each group completed the experimental protocol. The incidence of extubation cough in group AL was 12%, significantly lower (1-sided P = .045) than the 22% incidence in group S. The 1-tailed risk ratio for cough in group AL was 0.55 (0-0.94, P = .045). Total amount of opioids administered (P = .194), ETT cuff preloading times (P = .259), and extubation times (P = .331) were not significantly different between groups. The average duration of surgery was 59 ± 28 minutes in group AL and 52 ± 29 minutes in group S (P = .057).Alkalinized lidocaine in the ETT cuff significantly decreased general anesthesia emergence cough after surgeries with an average duration of slightly1 hour.

BACKGROUND The I-gel (IG) supraglottic airway device is a reliable way to establish an airway. Its large ventilation lumen allows for easy passage of an endotracheal tube. With the use of a flexible bronchoscope, the IG offers a good visualization of the laryngeal inlet. This prospective randomized study aims to compare the success rate of flexible bronchoscope-guided tracheal intubation using either the IG or the LMA-Fastrach (FT) laryngeal masks. METHODS One hundred twenty patients requiring general anesthesia were randomized to 1 of the 2 study groups: IG or FT. After anesthesia induction, the assigned laryngeal mask was inserted to obtain adequate ventilation. We then proceeded to a flexible bronchoscope-guided intubation through the supraglottic device. Tracheal intubation and laryngeal mask insertion success rates were noted, as well as the time required for these manipulations. The view of the laryngeal inlet was graded for each intubation attempt. RESULTS Sixty patients were assigned to each study group. The intubation success rates were similar between the IG and the FT groups (100 % vs 95.0 % at first attempt; P = 0.12). The times required for tracheal intubation were significantly lower in the IG group (30 ± 11 seconds vs 50 ± 21 seconds; P < 0.0001). Glottic visualization was better in the IG group, with a significantly higher percentage of grade 1 visualization (63.3% vs 3.3%; P < 0.0001) and a lower percentage of grade 3 visualization (1.7% vs 60.0%; P < 0.0001), than that in the FT group. CONCLUSIONS The use of the IG supraglottic airway device as a conduit for flexible bronchoscope-guided tracheal intubation results in a success rate equivalent to the use of the LMA-FT. However, the IG allows for shorter intubation times and a better visualization of the glottic opening compared with the LMA-FT.

International audience; Crystalline basement rocks at the surface are both surface water resources and an analogue of deep reservoir used for geothermal exploitation. We present here a geophysical survey realized in the East of France, at an outcrop in a quarry allowing to characterize the transition zone between sediments and basement. We applied electrical resistivity measurements and magnetic resonance soundings and highlighted water-bearing structures in the sandstone and in the basement, showing lateral variations.

With increased rates of climate change, it is imperative for forest managers to have access to models that can take into account the expected effects of climate change on tree growth. To this end, growth function are sometimes used that include climatic variables such as mean annual temperature or precipitation averaged over decades. Such growth models are usually relatively easy to develop but they do not take into account the fact that tree diameter growth on a given year is determined not by climatic conditions that prevailed up to 30 years before but mainly by climatic conditions that prevailed during the current and previous year. Our objective is determine if including climatic variables obtained from dendroclimatic response function will lead to growth models having a better fit to data than versions with 30-year average climatic conditions, or no climate at all. Growth models were developed for Betula alleghaniensis, Acer saccharum, Acer rubrum and Fagus grandifolia using data from south-eastern Quebec. Three types of growth function were compared. A first set of growth function was developed in which the potential growth of a tree was modeled as a function of tree size and site characteristics (vegetation type and drainage) to be further modified as a non-linear function of plot basal area. The effect of climate was not explicitly accounted for in this fort set of growth function, therefore they will be refered to as Climate-implicit models. A second set of growth function was developed in which we explicitly accounted for the effect of climate by incorporating 30-year mean annual temperature and precipitation in the growth function. In a third type of growth function, also climate-explicit, we incorporated the most significant recent climatic variables identified using climatic response function developed for each species based on dendrochronological and climatic data. The three types of models were compared based on the Akaike information criterion (AIC). Our results showed that Climate-explicit growth models with climatic variables obtained from response function analysis outperformed other growth models for three out of four species (B. alleghaniensis, A. saccharum and F. grandifolia). Incorporating climate in the form of 30-year average climatic conditions brought some improvement over a non-climatic function for A. rubrum, but this was not the case for other species. Accounting for growth dependency on climate by including recent monthly climatic variables provided by response function could be a potentially useful approach for the development of a new lineage of tree growth models dealing with climate change.

Few diagnostic tools are available to anesthesiologists when confronted with intraoperative hypoxemia. Lung ultrasonography is a safe and accurate bedside imaging modality. The aim of this study was to evaluate the feasibility of lung ultrasonography during the perioperative period and assess its ability to detect intraoperative respiratory complications and oxygenation changes resulting from perioperative atelectasis.In this prospective observational pilot study, 30 consecutive patients scheduled for laparoscopic surgery were recruited. Mechanical ventilation was standardized. Lung ultrasonography was performed at 5 predefined time points: before induction of general anesthesia (GA), after induction of GA, after pneumoperitoneum insufflation, on arrival in the recovery room, and before recovery room discharge. For each echographic examination, 12 pulmonary quadrants were imaged. From these, a semiquantitative score, the lung ultrasound (LUS) score, was calculated to assess lung aeration at each time point.Lung ultrasonography was possible in all patients. Changes in the LUS score between the postinduction period and arrival in the recovery room were correlated with changes in oxygenation (Spearman r = -0.43, P = .018). Induction of GA was associated with an increase in the LUS score, which gradually worsened at all time points until recovery room discharge. This increase was significantly worse in the basal and dependent lung zones. Lung ultrasonography helped in the detection of 2 capnothoraces, 1 endobronchial intubation, and 1 episode of subclinical pulmonary edema.Lung ultrasonography in the perioperative period is feasible, allows tracking of perioperative atelectasis, and facilitates the diagnosis of respiratory complications. The evolution of aeration loss correlates moderately with changes in oxygenation.

Nuclear magnetic resonance (NMR) measurements provide direct sensitivity to hydrogen-bearing fluids and their interactions with the pore space. As such NMR is used in near-surface geophysics to determine water content and to estimate hydrogeologic properties such as pore size and hydraulic conductivity. This special section covers the recent advances in NMR for near-surface applications. Most of the papers in this issue were first presented at the 6th International Workshop on Magnetic Resonance of the Subsurface held at Aarhus University in Aarhus, Denmark, on 8–10 June 2015. The 11 papers presented in this special section highlight the recent advances in the NMR method as applied to the characterization of the near surface. The studies primarily focus on surface NMR but also include laboratory and borehole NMR. The subject matter covers novel field applications, new methods for data …

International audience; Seismic reflection imaging is a geophysical method that provides greater resolution at depth than other methods and is, therefore, the method of choice for hydrocarbon-reservoir exploration. However, seismic imaging has only sparingly been used to explore and monitor geothermal reservoirs. Yet, detailed images of reservoirs are an essential prerequisite to assess the feasibility of geothermal projects and to reduce the risk associated with expensive drilling programs. The vast experience of hydrocarbon seismic imaging has much to offer in illuminating the route toward improved seismic exploration of geothermal reservoirs - but adaptations to the geothermal problem are required. Specialized seismic acquisition and processing techniques with significant potential for the geothermal case are the use of 3D arrays and multicomponent sensors, coupled with sophisticated processing, including seismic attribute analysis, polarization filtering/migration, converted-wave processing, and the analysis of the diffracted wavefield. Furthermore, full-waveform inversion and S-wave splitting investigations potentially provide quantitative estimates of elastic parameters, from which it may be possible to infer critical geothermal properties, such as porosity and temperature.

Question Recent studies revealed by indirect evidence that lichen–spruce woodlands in the closed-crown boreal forest are an alternative stable state of black spruce–feathermoss stands. This paper aims to demonstrate and quantify black spruce forest cover regression following successive wildfire events in the closed-crown forest zone during the 20th century. A case study in north-eastern North American closed-crown forest zone is presented. Location The study area is at the centre of the closed-crown boreal forest zone of eastern Canada (49°59′ N, 71°59′ W). Methods A burned area of 25 ha was selected in which three tree cohorts were visible. The first cohort contains partly buried trunks and stumps of a stand destroyed by a forest fire in 1920, the second contains standing dead trees from a 1995 forest fire and the third contains seedlings established after the 1995 fire. Fires were dated by scar analyses of living trees at the edge of the site. An array of sample plots was established in autumn 1997 to evaluate each cohort in terms of stocking and tree density. Results Black spruce stocking decreased significantly between cohorts, from 43.5% in Cohort 1 (all coniferous trees) to 25.6% in Cohort 2 and 11.5% in Cohort 3 (2011). Jack pine showed an inverse tendency, from 0% in Cohort 1 (not determined) to 0% in Cohort 2 and 3.8% in Cohort 3. Black spruce stems per hectare also dropped significantly from a minimum of 1322 in Cohort 1 to 1088 in Cohort 2 and 976 in Cohort 3. Conclusions This study is the first quantitative demonstration that lichen–spruce woodlands in the closed-crown boreal forest zone are an alternative stable state of black spruce–feathermoss stands. Stocking levels and densities markedly declined after each of the two fires (1920 and 1995) that both occurred after spruce budworm outbreaks (1910 and 1980) and are most likely responsible for the shift from a closed-crown to an open woodland.

Background— Atrial fibrillation (AF) is common after thoracic surgery. Limited data exist concerning the incidence of AF, its impact on mortality, the effectiveness of therapy, and the risk factors of AF after pulmonary transplantation. Methods and Results— We reviewed the medical files of 224 consecutive lung transplant recipients who underwent surgery over a 10-year period at a large Canadian center. We collected patient characteristics, in-hospital treatments, and outcomes. Time-to-event analysis was used to account for in-hospital follow-up and models generated to assess the impact of AF on mortality and independent risk factors of AF after transplantation. Postoperative AF occurred in 65 patients (29%). AF was more likely to occur with complications such as pneumonia, mediastinitis, and bronchial dehiscence and was not an independent risk factor of mortality (hazard ratio=1.56; 95% confidence interval, 0.52–4.63). Pharmacological or electric therapy for rhythm or rate control of AF was administered to 97% of patients. Intravenous amiodarone was used in 46%, electric cardioversion in 28%, and heparin in 26%. Only 1 patient remained in AF at discharge. Age (hazard ratio=1.08 by year; 95% confidence interval, 1.05–1.12), bilateral transplantation (hazard ratio=1.87; 95% confidence interval, 1.03–3.42), and a history of AF before the transplantation (hazard ratio=4.48; 95% confidence interval, 1.05–19.11) were found to be independently associated with an increased incidence of postoperative AF. Conclusions— AF is fairly common after pulmonary transplantation, transient, and relatively benign. It is not independently associated with increased in-hospital mortality. Most patients return to sinus rhythm before discharge. Age, prior AF, and bilateral transplantation increase the risk of postoperative AF.

Lichen—spruce woodlands occur in the closed-crown forest zone as a divergent type of the spruce—moss forest because of regeneration failure caused by compounded disturbances (fire, insect outbreaks, and logging). From the southern limit of distribution of lichen woodlands (47° 30′ N) to the northern limit of the closed-crown forest zone (52° 40′ N), 53 lichen woodlands were sampled for a detailed dendroecological analysis. Radial, height, and volumetric growth of black spruce (Picea mariana) trees among the woodlands varied significantly according to stand age. Growth rates were similar for all even-aged spruce trees, whereas growth rates of trees 100 y old. No significant differences were found in growth rates of spruces distributed along the latitudinal gradient. Spruce trees were generally small in all the woodlands studied, with only a few trees taller than 12 m. Although spruce budworm may have affected all stands, the timing and intensity of the infestations were not necessarily synchronous among the studied stands. Partial least square response (PLS) functions were calculated to evaluate the impact of climate on tree-rings with latitude. Along the 600-km transect, PLS response functions indicated that growth was strongly influenced by current and previous year climatic conditions, particularly precipitation.

BACKGROUND: Clinicians have adopted a restrictive transfusion threshold (75-80 g/L) after major orthopedic surgery. Anemia may be associated with a decrease in postoperative vigor. We hypothesize that, in these patients, a threshold hemoglobin (Hb) concentration exists below which functional recovery and quality of life (QoL) become difficult. STUDY DESIGN AND METHODS: A prospective, observational cohort study in 305 patients 60 years or older undergoing a total hip or knee arthroplasty was conducted. Major outcome variables were distance walked in 6 minutes (6MWT), score on the Borg Scale for perception of effort, maximal dominant hand strength, and Short Form 36 (SF-36) QoL assessment in the preoperative and early postoperative periods. Patients were categorized according to their Hb level the day of the postoperative 6MWT (≤80, 81-90, 91-100, and >100 g/L). RESULTS: There was no difference between Hb groups in the decrease of the distance walked preoperatively versus postoperatively. For both moments of observation, the 6MWT was not significantly different between Hb groups (p = 0.190). Similar results were found with perception of effort, maximal dominant hand strength, and SF-36 QoL assessment scores. In a regression model, the decrease in Hb concentration could explain only 1.9% of the total variation observed in the 6MWT (p = 0.008). CONCLUSION: Moderate anemia is not associated with an impaired functional recovery or QoL in the immediate postoperative period after major arthroplasties. Further studies will be required to determine the long-term consequences of a restrictive transfusion strategy in these patients.

This paper deals with the electrical resistivity monitoring of the Ketzin CO 2 injection pilot (CO2ReMoVe EC project) through time-lapse CSEM measurements. There, 3 boreholes about 800 m deep have been especially designed for current injection at reservoir (sandstone) depth. CO 2 is directly injected in a saline (∼240 g/l) aquifer. Prior modelling results indicated that the increase of electrical resistivity generated by the CO 2 plume (gaseous and liquid CO 2 phases) supposed to be highly resisitive, would generate measurable changes in the EM fields on the surface, when injecting current directly inside the reservoir. In order to highlight and follow these expected resistivity changes, 3 CSEM surveys were performed in August 2008 (baseline prior to injection), June 2009 and August 2010. Each time, 13 EM stations have been recorded during current injection of a square wave at 3 frequencies (0.125 Hz, 0.5 Hz and 4 Hz) in two configurations (“double mise a la masse” (2×MAM) and “mise a la masse–surface” (MAM-Surface)). This paper only presents results of the 2×MAM configuration at 0.5 Hz. In spite of a very noisy area (gas pipes, high voltage power lines), we measured signal amplitude 10 times higher than noise amplitude. We show that EM fields vectors (both inphase and quadrature components) measured on the surface are very similar to the forward modelling EM responses computed with COMSOL Multiphysics ® . Models also show that electric field spatial distribution is strongly affected by a thin and resistive layer (35 m–200 Ωm) of anhydrite above the reservoir, making E field diverging from the boreholes whereas a dipolar pattern was expected for the dipole current injection used here. Moreover, while June 2009 survey highlighted the expected strong increase of electric field (increase of resistivity), August 2010 survey showed electric field amplitudes similar to the 2008 baseline survey, revealing therefore major changes of the reservoir properties. Finally, the directional sensitivity of the 2×MAM array is tested through modelling residuals computed for five CO 2 plume spatial distributions. Results show that a north-eastward migration of the CO 2 plume is expected to fit field data.

Geophysical methods are adequate for imaging the CO2 plume in order to follow its migration within the reservoir and possible leakages through the caprock formation. In particular, changes in density, seismic velocity or electrical resistivity are associated with changes in the gas saturation and make methods such as gravity, 4D seismic and electrical resistivity tomography (ERT) or CSEM powerful tools to follow up the fate of injected CO2. Respect to the minimum amount of CO2 stored that can be quantified for verification purpose, there is an order of magnitude between 4D seismic (few 100s of Kt) and the other two methods (few Mt). Respect to the detection of leakage at the reservoir level, only 4D seismic could be considered as useful. Using downhole measurements, such as crosshole electric or downhole gravity will increase the resolution of these methods and therefore its ability to detect leakage. In case of CO2 leakage upwards and accumulation within a secondary reservoir located at a few hundreds of meters depth, the resolution of the three methods is increased by several order of magnitude and small amounts of CO2 could be detected, depending whether it is in gaseous phase or dissolved. It is expected that controlled experiments of leaking CO2 at shallow depth will help to define more precisely the conditions of use of the three methods.

Polycyclism, the ability for a plant to produce several flushes in the same growing season, is a key process of plant development. Polycyclism frequency is likely to change with the anticipated climate trend, expected to impact plant growth over the next century. However, polycyclism processes are not well described in the literature, and an important lack of knowledge prevents any possible prediction for the twenty-first century. Aleppo pine is a good model to study polycyclism: it is known to produce up to four annual flushes in one growing season. In this study, we used architectural analysis to describe and reconstruct polycyclism processes, periodicity and frequency on Aleppo pine in a Mediterranean site for the last 15 years. We also assessed relationships between polycyclism frequency and climate. Since 1995, climate was far hotter and drier than normal in South-eastern France: polycyclism was significantly reduced, particularly after 2003 heat-wave, which delayed effect remains till 2008, exacerbated by repeated droughts. Morphologically, polycyclism is primarily influenced by twig vigour, status (principal/secondary and strong axes) and position (low, middle or top crown). Climatically, it depends on summer temperatures of the current and preceding year, rainfall of the first half of preceding year and winter rainfall. Previous year abundant rainfall combined with colder temperatures and high rainfall in spring or at the end of summer of the current year increase tricyclism frequency. Polycyclism is likely to decrease significantly in the twenty-first century due to a hotter and drier climate.

BACKGROUND: The indications for red blood cell (RBC) transfusions remain unclear despite published guidelines. Our hypothesis was that the transfusion practice varies inside the Centre hospitalier de l'Universite de Montreal (CHUM). STUDY DESIGN AND METHODS: A total of 701 charts of patients who underwent a knee or hip arthroplasty or prosthesis revision in three hospitals of the CHUM were reviewed. Demography, hemoglobin (Hb) concentrations, details on transfusions, and postoperative adverse events (AEs) were collected up until discharge. The primary outcome was the presence or absence of RBC transfusion. Secondary outcomes were the nadir Hb, number of units transfused, discharge Hb, blood losses, and postoperative AEs. RESULTS: The rate of postoperative transfusion was 29%. We found no significant difference between odds ratios of each site for sex, coronary artery disease, chronic heart failure, type of procedure, American Society of Anesthesiologists physical status, weight, height, body mass index, body surface area, and estimated blood volume. Overall, patients were transfused at a Hb between 75 and 80 g/L. Eighty-five percent of postoperative transfusions could be predicted using only nadir Hb and adding patient characteristics did not substantially improve the model (86.1%). Discharge Hb was below 100 g/L in 66% of patients. CONCLUSIONS: There was no difference among hospitals regarding the way RBC transfusions are used. Our data suggest that physicians mainly based their decision to transfuse on a single variable, the Hb concentration, with the use of a restrictive strategy. Future trials should focus on the optimal transfusion trigger to adopt in major orthopedic surgery.