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With the best lightweight potential of all metallic construction materials, magnesium primarily helps to increase energy efficiency over the lifecycle of automotive and non-automotive industrial products. Yet to assess overall energy efficiency, the production process must also be taken into account. This paper provides an insight into the energy-efficient production of magnesium strips up to 0,8 mm in thickness based on twin-roll casting and strip rolling on an industrial scale, as developed at the Institute of Metal Forming at the Technical University Bergakademie Freiberg (Germany) in cooperation with MgF Magnesium Flachprodukte GmbH (Germ any). The technology of twin-roll casting and strip rolling on a four-high reversing mill is described.

Background and Aims: Data on the prevalence and characteristics of so-called rare HCV genotypes (GTs) in larger cohorts is limited. This study investigates the frequency of rare GT and resistance-associated substitutions and the efficacy of retreatment in a European cohort. Methods: A total of 129 patients with rare GT1-6 were included from the European resistance database. NS3, NS5A, and NS5B were sequenced and clinical parameters and retreatment efficacies were collected retrospectively. Results: Overall 1.5% (69/4,656) of direct-acting antiviral (DAA)-naive and 4.4% (60/1,376) of DAA-failure patients were infected with rare GT. Although rare GTs were almost equally distributed throughout GT1-6 in DAA-naive patients, we detected mainly rare GT4 (47%, 28/60 GT4; of these n = 17, subtype 4r) and GT3 (25%, 15/60 GT3, of these n = 8, subtype 3b) among DAA-failures. A total of 62% (37/60) of DAA failures had not responded to first-generation regimes and the majority was infected with rare GT4 (57%, 21/37). In contrast, among patients with failure to pangenotypic DAA regimens (38%, 23/60), infections with rare GT3 were overrepresented (57%, 13/23). Although NS5A RASs were uncommon in rare GT2, GT5a, and GT6, we observed combined RASs in rare GT1, GT3, and GT4 at positions 28, 30, 31, which can be considered as inherent. DAA failures with completed follow-up of retreatment, achieved a high SVR rate (94%, 45/48 modified intention-to-treat analysis; 92%, 45/49 intention-to-treat). Three patients with GT4f, 4r, or 3b, respectively, had virological treatment failure. Conclusions: In this European cohort, rare HCV GT were uncommon. Accumulation of specific rare GT in DAA-failure patients suggests reduced antiviral activities of DAA regimens. The limited global availability of pangenotypic regimens for first line therapy as well as multiple targeted regimens for retreatment could result in HCV elimination targets being delayed. Impact and implications: Data on the prevalence and characteristics of rare HCV genotypes (GT) in larger cohorts are still scarce. This study found low rates of rare HCV GTs among European HCV-infected patients. In direct-acting antiviral (DAA)-failure patients, rare GT3 subtypes accumulated after pangenotypic DAA treatment and rare GT4 after first generation DAA failure and viral resistance was detected at NS5A positions 28, 30, and 31. The limited global availability of pangenotypic DAA regimens for first line therapy as well as multiple targeted regimens for retreatment could result in HCV elimination targets being delayed.

Nature-based solutions (NbS) offer ways to preserve, restore and manage ecosystems to meet today's societal challenges by combining benefits for society and biodiversity. They incorporate natural features and processes into projects to ensure their sustainable development while investing in the integrity of ecosystems. “Forest-based solutions” (FbS) can be identified as NbS forests that provide both human well-being and biodiversity benefits. In this paper, we intend to consider FbS as solutions that help reconcile natural hazard control with biodiversity benefits, and especially highlight the practices and research needs in this field. FbS in this article correspond specifically to forests used or managed for mitigating natural hazards linked to gravity (rockfalls and avalanches) or to water (floods and drought), while preserving, restoring or managing biodiversity. Firstly, we review the definition and development of FbS applied to natural hazard reduction, while stressing issues concerning the design, implementation, and monitoring of these kinds of actions. Secondly, we point out the need to combine natural hazard control with restoration, preservation and management of ecosystems, by posing novel practice and research questions.

We introduce an aerodynamic rotor concept for an offshore wind turbine which is tailored for an increased power feed-in at low wind speeds by a substantial increase in the rotor diameter while maintaining the rated power. The main objective of the conceptual design is to limit the steady-inflow loads (blade flapwise root bending moment (RBM) and thrust) to the maximum values of a reference turbine. The outer part of the blade (i.e. outer 30 % span) is designed for a higher design tip speed ratio (TSR) and a lower axial induction than the inner part. By operating at the high TSR in light winds, the slender outer part fully contributes to the increased power capture. In stronger winds the TSR is reduced and the torque generation is shifted to the inner section of the rotor. Moreover, the blade design efficiently reduces the power losses when the flapwise RBM is limited through peak shaving, below rated wind speed. This is of high importance, given the wind speed distribution at offshore sites. The characteristics of the rotor are first investigated with stationary blade element momentum simulations and further analysed with aeroelastic simulations, considering the flexibility of blades and tower to show that a structural design is feasible even for a blade of this size and complexity. The economic revenue and the cost of valued energy of the turbine are estimated and compared to the IEA 15 MW offshore reference turbine, considering a fictitious wind-speed-dependent feed-in price. Our results for the turbine concept with an increase in rotor diameter by 36 % show that the revenue can be increased by 30 % and the cost of valued energy can be reduced by 16 % compared to the reference turbine.

Forests strongly modify the accumulation, metamorphism and melting of snow in midlatitude and high-latitude regions. Recently, snow routines in hydrological and land surface models were improved to incorporate more accurate representations of forest snow processes, but model intercomparison projects have identified deficiencies, partly due to incomplete knowledge of the processes controlling snow cover in forests. The Snow Under Forest (SnoUF) project was initiated to enhance knowledge of the complex interactions between snow and vegetation. Two field campaigns, during the winters 2016–2017 and 2017–2018, were conducted in a coniferous forest bordering the snow study at Col de Porte (1325 m a.s.l., French Alps) to document the snow accumulation and ablation processes. This paper presents the field site, the instrumentation and the collection and postprocessing methods. The observations include distributed forest characteristics (tree inventory, lidar measurements of forest structure, subcanopy hemispherical photographs), meteorology (automatic weather station and an array of radiometers), snow cover and depth (snow pole transect and laser scan) and snow interception by the canopy during precipitation events. The weather station installed under dense canopy during the first campaign has been maintained since then and has provided continuous measurements throughout the year since 2018. Data are publicly available from the repository of the Observatoire des Sciences de l'Univers de Grenoble (OSUG) data center at https://doi.org/10.17178/SNOUF.2022 (Sicart et al., 2022).

The dynamic inflow effect describes the unsteady aerodynamic response to fast changes in rotor loading due to the inertia of the wake. Fast changes in turbine loading due to pitch actuation or rotor speed transients lead to load overshoots. The phenomenon is suspected to be also relevant for gust situations; however, this was never shown, and thus the actual load response is also unknown. The paper's objectives are to prove and explain the dynamic inflow effect due to gusts, and compare and subsequently improve a typical dynamic inflow engineering model to the measurements. An active grid is used to impress a 1.8 m diameter model turbine with rotor uniform gusts of the wind tunnel flow. The influence attributed to the dynamic inflow effect is isolated from the comparison of two experimental cases. Firstly, dynamic measurements of loads and radially resolved axial velocities in the rotor plane during a gust situation are performed. Secondly, corresponding quantities are linearly interpolated for the gust wind speed from lookup tables with steady operational points. Furthermore, simulations with a typical blade element momentum code and a higher-fidelity free-vortex wake model are performed. Both the experiment and higher-fidelity model show a dynamic inflow effect due to gusts in the loads and axial velocities. An amplification of induced velocities causes reduced load amplitudes. Consequently, fatigue loading would be lower. This amplification originates from wake inertia. It is influenced by the coherent gust pushed through the rotor like a turbulent box. The wake is superimposed on that coherent gust box, and thus the inertia of the wake and consequently also the flow in the rotor plane is affected. Contemporary dynamic inflow models inherently assume a constant wind velocity. They filter the induced velocity and thus cannot predict the observed amplification of the induced velocity. The commonly used Øye engineering model predicts increased gust load amplitudes and thus higher fatigue loads. With an extra filter term on the quasi-steady wind velocity, the qualitative behaviour observed experimentally and numerically can be caught. In conclusion, these new experimental findings on dynamic inflow due to gusts and improvements to the Øye model enable improvements in wind turbine design by less conservative fatigue loads.

The dynamic inflow effect denotes the unsteady aerodynamic response to fast changes in rotor loading due to a gradual adaption of the wake. This does lead to load overshoots. The objective of the paper was to increase the understanding of that effect based on pitch step experiments on a 1.8 m diameter model wind turbine, which are performed in the large open jet wind tunnel of ForWind – University of Oldenburg. The flow in the rotor plane is measured with a 2D laser Doppler anemometer, and the dynamic wake induction factor transients in axial and tangential direction are extracted. Further, integral load measurements with strain gauges and hot-wire measurements in the near and close far wake are performed. The results show a clear gradual decay of the axial induction factors after a pitch step, giving the first direct experimental evidence of dynamic inflow due to pitch steps. Two engineering models are fitted to the induction factor transients to further investigate the relevant time constants of the dynamic inflow process. The radial dependency of the axial induction time constants as well as the dependency on the pitch direction is discussed. It is confirmed that the nature of the dynamic inflow decay is better described by two rather than only one time constant. The dynamic changes in wake radius are connected to the radial dependency of the axial induction transients. In conclusion, the comparative discussion of inductions, wake deployment and loads facilitate an improved physical understanding of the dynamic inflow process for wind turbines. Furthermore, these measurements provide a new detailed validation case for dynamic inflow models and other types of simulations.

Abstract Background Circulatory efficiency reflects the ratio between total left ventricular work and the work required for maintaining cardiovascular circulation. The effect of severe aortic valve stenosis (AS) and aortic valve replacement (AVR) on left ventricular/circulatory mechanical power and efficiency is not yet fully understood. We aimed to quantify left ventricular (LV) efficiency in patients with severe AS before and after surgical AVR. Methods Circulatory efficiency was computed from cardiovascular magnetic resonance (CMR) imaging derived volumetric data, echocardiographic and clinical data in patients with severe AS (n = 41) before and 4 months after AVR and in age and sex-matched healthy subjects (n = 10). Results In patients with AS circulatory efficiency was significantly decreased compared to healthy subjects (9 ± 3% vs 12 ± 2%; p = 0.004). There were significant negative correlations between circulatory efficiency and LV myocardial mass (r = − 0.591, p

Abstract Purpose Response assessment to definitive non-surgical treatment for head and neck squamous cell carcinoma (HNSCC) is centered on the role of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET-CT) 12 weeks after treatment. The 5-point Hopkins score is the only qualitative system available for standardized reporting, albeit limited by suboptimal positive predictive value (PPV). The aim of our study was to explore the feasibility and assess the diagnostic accuracy of an experimental 6-point scale (“Cuneo score”). Methods We performed a retrospective, multicenter study on HNSCC patients who received a curatively-intended, radiation-based treatment. A centralized, independent qualitative evaluation of post-treatment FDG-PET/CT scans was undertaken by 3 experienced nuclear medicine physicians who were blinded to patients’ information, clinical data, and all other imaging examinations. Response to treatment was evaluated according to Hopkins, Cuneo, and Deauville criteria. The primary endpoint of the study was to evaluate the PPV of Cuneo score in assessing locoregional control (LRC). We also correlated semi-quantitative metabolic factors as included in PERCIST and EORTC criteria with disease outcome. Results Out of a total sample of 350 patients from 11 centers, 119 subjects (oropharynx, 57.1%; HPV negative, 73.1%) had baseline and post-treatment FDG-PET/CT scans fully compliant with EANM 1.0 guidelines and were therefore included in our analysis. At a median follow-up of 42 months (range 5-98), the median locoregional control was 35 months (95% CI, 32-43), with a 74.5% 3-year rate. Cuneo score had the highest diagnostic accuracy (76.5%), with a positive predictive value for primary tumor (Tref), nodal disease (Nref), and composite TNref of 42.9%, 100%, and 50%, respectively. A Cuneo score of 5-6 (indicative of residual disease) was associated with poor overall survival at multivariate analysis (HR 6.0; 95% CI, 1.88-19.18; p = 0.002). In addition, nodal progressive disease according to PERCIST criteria was associated with worse LRC (OR for LR failure, 5.65; 95% CI, 1.26-25.46; p = 0.024) and overall survival (OR for death, 4.81; 1.07-21.53; p = 0.04). Conclusions In the frame of a strictly blinded methodology for response assessment, the feasibility of Cuneo score was preliminarily validated. Prospective investigations are warranted to further evaluate its reproducibility and diagnostic accuracy.

Seismic monitoring of mass movements can significantly help to mitigate the associated hazards; however, the link between event dynamics and the seismic signals generated is not completely understood. To better understand these relationships, we conducted controlled releases of single blocks within a soft-rock (black marls) gully of the Rioux-Bourdoux torrent (French Alps). A total of 28 blocks, with masses ranging from 76 to 472 kg, were used for the experiment. An instrumentation combining video cameras and seismometers was deployed along the travelled path. The video cameras allow reconstructing the trajectories of the blocks and estimating their velocities at the time of the different impacts with the slope. These data are compared to the recorded seismic signals. As the distance between the falling block and the seismic sensors at the time of each impact is known, we were able to determine the associated seismic signal amplitude corrected for propagation and attenuation effects. We compared the velocity, the potential energy lost, the kinetic energy and the momentum of the block at each impact to the true amplitude and the radiated seismic energy. Our results suggest that the amplitude of the seismic signal is correlated to the momentum of the block at the impact. We also found relationships between the potential energy lost, the kinetic energy and the seismic energy radiated by the impacts. Thanks to these relationships, we were able to retrieve the mass and the velocity before impact of each block directly from the seismic signal. Despite high uncertainties, the values found are close to the true values of the masses and the velocities of the blocks. These relationships allow for gaining a better understanding of the physical processes that control the source of high-frequency seismic signals generated by rockfalls.

A diversity of T helper (Th) subsets (Th1, Th2, Th17) has been identified in the human tumor microenvironment. In breast cancer, the role of Th subsets remains controversial, and a systematic study integrating Th subset diversity, T cell inflammation, breast cancer molecular subtypes, and patient prognosis, is lacking. In primary untreated breast cancer samples, we analyzed 19 Th cytokines at the protein level. Eight were T cell-specific, and subsequently measured in 106 prospectively-collected untreated samples. The dominant Th cytokines across all breast cancer samples were IFN-γ and IL-2. Th2 cytokines (IL-4, IL-5, IL-13) were expressed at low levels and not associated with any breast cancer subtype. Th17 cytokines (IL-17A and IL-17F) were up-regulated in triple negative breast cancer (TNBC), specifically in T cell non-inflamed tumors. In order to get insight into prognosis, we exploited the METABRIC transcriptomic dataset. We derived Th1, Th2, and Th17 metagenes based on manually curated Th signatures, and found that a high Th17 metagene was of good prognosis in T cell non-inflamed TNBC. Multivariate Cox modeling selected the Nottingham Prognostic Index (NPI), Th2 and Th17 metagenes as additive predictors of breast cancer-specific survival, which defined novel and highly distinct prognostic groups within TNBC. Our results reveal that Th17 is a novel prognostic composite biomarker in T cell non-inflamed TNBC. Integrating immune cell and tumor molecular diversity is an efficient strategy for prognostic stratification of cancer patients.

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La forêt occupe près de 30 % du territoire français et fournit de nombreux services de production, de régulation et culturels. L'évaluation de ces services écosystémiques et de leurs évolutions pose des défis majeurs pour les scientifiques et les décideurs, qui plus est à l'échelle des petits territoires pour lesquels les données ou indicateurs élaborés à l'échelle nationale ne sont guère transposables. Des progrès importants ont toutefois été réalisés ces dernières années, reposant le plus souvent sur l'utilisation conjointe de bases de données, d'outils de télédétection et de modèles démographiques appliqués à différentes échelles. Cet article illustre, au travers de trois cas d'étude qui concernent la forêt de montagne, les avantages et limites de certaines de ces approches et propose ensuite des voies d'amélioration dans l'objectif d'appuyer les prises de décision pour des projets de développement territorial.

Rockfall is an extremely rapid process involving long travel distances. Due to these features, when an event occurs, the ability to take evasive action is practically zero and, thus, the risk of injury or loss of life is high. Damage to buildings and infrastructure is quite likely. In many cases, therefore, suitable protection measures are necessary. This contribution provides an overview of previous and current research on the main topics related to rockfall. It covers the onset of rockfall and runout modelling approaches, as well as hazard zoning and protection measures. It is the aim of this article to provide an in-depth knowledge base for researchers and practitioners involved in projects dealing with the rockfall protection of infrastructures, who may work in the fields of civil or environmental engineering, risk and safety, the earth and natural sciences.

Hydrogeomorphic processes are a major threat in many parts of the Alps, where they periodically damage infrastructure, disrupt transportation corridors or even cause loss of life. Nonetheless, past torrential activity and the analysis of areas affected during particular events remain often imprecise. It was therefore the purpose of this study to reconstruct spatio-temporal patterns of past debris-flow activity in abandoned channels on the forested cone of the Manival torrent (Massif de la Chartreuse, French Prealps). A Light Detecting and Ranging (LiDAR) generated Digital Elevation Model (DEM) was used to identify five abandoned channels and related depositional forms (lobes, lateral levees) in the proximal alluvial fan of the torrent. A total of 156 Scots pine trees (Pinus sylvestris L.) with clear signs of debris flow events was analyzed and growth disturbances (GD) assessed, such as callus tissue, the onset of compression wood or abrupt growth suppression. In total, 375 GD were identified in the tree-ring samples, pointing to 13 debris-flow events for the period 1931–2008. While debris flows appear to be very common at Manival, they have only rarely propagated outside the main channel over the past 80 years. Furthermore, analysis of the spatial distribution of disturbed trees contributed to the identification of four patterns of debris-flow routing and led to the determination of three preferential breakout locations. Finally, the results of this study demonstrate that the temporal distribution of debris flows did not exhibit significant variations since the beginning of the 20th century.

Many slopes in the Alps are prone to rockfall and forests play a vital role in protecting objects such as (rail) roads and infrastructure against rockfall. Decision support tools are required to assess rockfall processes and to quantify the rockfall protection effect of forest stands. This paper presents results of an iterative sequence of tests and improvements of a coupled rockfall and forest dynamics model with focus on the rockfall module. As evaluation data a real-size rockfall experiment in the French Alps and two 2-D rockfall trajectories from Austria and Switzerland were used. Modification of the rebound algorithm and the inclusion of an algorithm accounting for the sudden halt of falling rocks due to surface roughness greatly improved the correspondence between simulated and observed key rockfall variables like run-out distances, rebound heights and jump lengths for the real-size rockfall experiment. Moreover, the observed jump lengths and run-out distances of the 2-D trajectories were well within the stochastic range of variation yielded by the simulations. Based on evaluation results it is concluded that the rockfall model can be employed to assess the protective effect of forest vegetation.

Only a few rockfall simulation models take into account the mitigating effect of existing forest cover. The objective of our study was to improve the generic rockfall simulation model RockyFor, which does take the effect of forest stands into account, thereby developing a clear method for quantifying and modelling slope surface characteristics based on quantitative field data. To obtain these data we carried out 218 real-size rockfall experiments on forested and non-forested sites on a mountain slope in the French Alps. On the basis of a polygon map representing different diameter classes of the material covering the slope, we determine the mean obstacle height (MOH) for each homogeneous unit at the experimental sites. We proposed an algorithm for calculating the tangential coefficient of restitution using the MOH. Comparing the simulated and observed data from the real-size rockfall experiments showed that the 3-D combined deterministic-probabilistic rockfall simulation model RockyFor accurately predicted rockfall events on a non-forested (Root Mean Square Error = 17%) and a forested site (Root Mean Square Error = 12%). We conclude that for further improvement of rockfall-forest simulation on different slope types more quantitative data is required on (1) the energy dissipative capacity of shrubs and bushes (e.g. in coppice stands), (2) the effect of the slope material, (3) the rock shape as well as the rock size, and (4) the tangential and normal coefficient of restitution. Based on the presented results we can state that the RockyFor model could contribute to better taking into account the mitigating effect of the existing forest cover when planning protective measures.

To date, most studies of multigenic expression patterns by long DNA array have used DNA fragments as probes. These probes are usually obtained as PCR products, and this represents a time-consuming and error-prone approach, requiring strict quality control. The present study examines the use of 40- and 70-mer synthetic oligonucleotides as probes for DNA array analysis with radioactive labeled targets. Design, spotting onto nylon filters, and hybridization conditions were determined and optimized. In this approach, the sensitivity and the specificity of the hybridization appear comparable to the conventional long DNA probes assay, permitting the analysis of small samples of approximately 1 μg total RNA. The long oligonucleotide array thus provides a very convenient method for the analysis of gene expression patterns in biological specimens and in clinical research.

We have developed a convenient and sensitive method for the quantification of RNA in samples from microbiopsies. This procedure is especially suitable for quantitating very small amounts of RNA in largescale biological samples. This method, using a microarray-spotting facility for the study of multigenic expression, entails the hybridization of a DNA probe with RNA spotted at high density on nylon membrane. Furthermore, with this procedure, the reproducibility, sensitivity, and accuracy of the assay are notably improved as compared to current methods.

Mountain forests are multifunctional forests that play a key role in both biodiversity conservation and rockfall protection. Most of these forests are in the process of secondary succession, where several stages with well differentiated diametric structures can be distinguished. These diametric structures strongly influence the two functions, i.e. biodiversity conservation and rockfall protection. The advanced stages of succession, representing mature forest, are the most important stages for conservation. The first, the ageing stage where the stand is still dominated by the initial cohort, has numerous, very large dominant trees. The two following stages, the renewal and irregular stages, are very heterogeneous in terms of tree dimensions. The most effective stages for rockfall protection are the densest stages, i.e. the first stage of the succession, the initial stage, and the irregular stage. In certain mountain-forest contexts, the irregular stage which optimises the two functions is difficult for forest managers to maintain. Consequently, when the protection function is the priority, it is recommended to precipitate the renewal of the stands by creating openings large enough to launch a new succession (from 0.1 to 0.5 ha). Forest management then organises the spatial and temporal distribution of these openings on a forested slope and aims to create a perennial mosaic of small groups of trees at initial, intermediate (self-thinning) and ageing stages. The latest stages of the succession, the best in terms of biodiversity, are often under-represented in this forest mosaic. The installation of small islands of carefully located old-growth stands makes it possible to compensate for this under-representation.

Les caractéristiques structurales de la forêt de montagne changent en fonction de son stade d'évolution. Ces changements impactent fortement deux fonctions-clé : la conservation de la biodiversité et la protection contre les risques naturels. Quels sont les stades les plus favorables à l'une ou l'autre de ces fonctions ? Est-il possible d'optimiser la réalisation de ces deux fonctions dans l'espace et dans le temps ? Cette étude apporte des éléments de réponse.

Il n'y a actuellement pas de règles claires et précises pour évaluer la fonction de protection des forêts vis-à-vis des chutes de pierres, en tenant compte des paramètres dendrométriques, des caractéristiques topographiques du site, ainsi que de la taille et de l'énergie maximale des projectiles rocheux. Afin de fournir un outil qui réponde à ces exigences et qui permette de donner, à l'échelle d'un versant, une évaluation quantitative de la capacité de protection d'une forêt, nous avons développé l'utilitaire Rockfor.NET (en accès libre sur le site internet www.rockfor.net). Cet article présente les principes sous-jacents de cet utilitaire, les méthodes de calcul ainsi que les études de cas utilisées pour sa validation.

Cet article présente la façon dont l'ingénierie écologique pour le contrôle de l'érosion dans les bassins versants torrentiels est abordée au Cemagref de Grenoble. Il expose en quoi la prise en compte des problématiques de protection des territoires de montagne contre l'érosion amène à orienter les recherches vers une meilleure compréhension des interactions entre la végétation et l'érosion, une meilleure connaissance de l'efficacité des actions de restauration écologique et une meilleure connaissance de l'écologie des milieux restaurés. Des études sont notamment menées sur l'efficacité des barrières végétales naturelles pour le piégeage des sédiments, sur les moyens de les installer par le biais d'ouvrages de génie biologique, ainsi que sur la dynamique végétale naturelle s'instaurant après leur installation. Des stratégies économes d'utilisation du génie biologique pour une rétention durable des sédiments dans les bassins versants, devant mener à une réduction de la charge solide des cours d'eau, sont alors proposées. Ces différentes étapes sont abordées à travers l'exemple de la problématique des dépôts de sédiments à l'aval du bassin versant de la Durance, dans les Alpes du Sud.

Les forêts peuvent jouer un important rôle de protection contre les aléas naturels en milieu de montagne, en particulier contre l'érosion et les chutes de pierres. Cet article présente dans un premier temps les connaissances concernant la capacité des forêts dans la maîtrise des aléas naturels. Ensuite, des principes de zonage sont présentés ; basés sur l'utilisation d'un SIG, ils permettent de déterminer des zones d'interventions forestières prioritaires, dans une optique de « gestion minimale » des écosystèmes forestiers de montagne. Enfin, il est expliqué comment les résultats des recherches sont utilisés pour la gestion des écosystèmes de montagne.

La végétation forestière peut jouer un rôle de protection " passive " contre certains aléas naturels, c'est-à-dire qu'elle peut permettre de réduire l'impact d'un aléa après que celui-ci se soit déclenché. Ce type d'action de la végétation peut être observé avec l'érosion et les chutes de pierres. Il apparaît alors intéressant de chercher à quantifier ce rôle de protection. Deux programmes de recherche ont ainsi été initiés sur ces deux types d'aléas. Dans les deux cas, des expériences grandeur nature ont été réalisées et permettent de montrer, qualitativement et quantitativement, l'impact de barrières végétales sur les mouvements de matériaux allant du sédiment au bloc. Les premiers résultats montrent qu'il sera possible de déterminer des règles de gestion des problèmes liés à l'érosion et aux chutes de pierres par la voie de l'ingénierie écologique.

La méthodologie de classification des forêts en fonction de leur rôle de protection vis-à-vis des risques naturels mise au point par le Cemagref est paramétrée et opérationnelle pour les peuplements forestiers nord-alpins. Cette méthodologie est transposable à d'autres massifs montagnards à condition d'adapter, aux nouvelles conditions géographiques, les grilles de classifications utilisées dans la méthodologie nord-alpine. Les objectifs principaux de cette étude sont de réaliser un transfert de connaissance et de compétence auprès des services gestionnaires (RTM et ONF).

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Esophageal involvement is a common situation found in 50 to 80% of patients with scleroderma, but Boerhaave's syndrome is rare in this context. The authors report the first case of spontaneous esophageal rupture occurring in a chronic renal failure patient treated by continuous ambulatory peritoneal dialysis. In this observation, sclerodermal esophageal dyskinesia, chronic renal failure which is a classical cause of vomiting and the peritoneal dialysis which play an increasing role in the intraabdominal pressure are potential contributing factors to Boerhave's syndrome. In such patients presenting risk factors, even if they are asymptomatic, it seems reasonable to propose esophageal explorations with manometry or/and endoscopy looking for dyskinesia or other complications of gastro-esophageal reflux.