29 research outputs found
The INRIA-LIM-VocR and AXES submissions to Trecvid 2014 Multimedia Event Detection
-This paper describes our participation to the 2014 edition of the TrecVid Multimedia Event Detection task. Our system is based on a collection of local visual and audio descriptors, which are aggregated to global descriptors, one for each type of low-level descriptor, using Fisher vectors. Besides these features, we use two features based on convolutional networks: one for the visual channel, and one for the audio channel. Additional high-level featuresare extracted using ASR and OCR features. Finally, we used mid-level attribute features based on object and action detectors trained on external datasets. Our two submissions (INRIA-LIM-VocR and AXES) are identical interms of all the components, except for the ASR system that is used. We present an overview of the features andthe classification techniques, and experimentally evaluate our system on TrecVid MED 2011 data
Dominant-negative mutations in human IL6ST underlie hyper-IgE syndrome
Autosomal dominant hyper-IgE syndrome (AD-HIES) is typically caused by dominant-negative (DN) STAT3 mutations. Patients suffer from cold staphylococcal lesions and mucocutaneous candidiasis, severe allergy, and skeletal abnormalities. We report 12 patients from 8 unrelated kindreds with AD-HIES due to DN IL6ST mutations. We identified seven different truncating mutations, one of which was recurrent. The mutant alleles encode GP130 receptors bearing the transmembrane domain but lacking both the recycling motif and all four STAT3-recruiting tyrosine residues. Upon overexpression, the mutant proteins accumulate at the cell surface and are loss of function and DN for cellular responses to IL-6, IL-11, LIF, and OSM. Moreover, the patientsâ heterozygous leukocytes and fibroblasts respond poorly to IL-6 and IL-11. Consistently, patients with STAT3 and IL6ST mutations display infectious and allergic manifestations of IL-6R deficiency, and some of the skeletal abnormalities of IL-11R deficiency. DN STAT3 and IL6ST mutations thus appear to underlie clinical phenocopies through impairment of the IL-6 and IL-11 response pathways
Les CBNPC de stades avancés hors addiction oncogénique: les traitements systémiques de deuxiÚme ligne
International audienceThe emergence of immunotherapy as the cornerstone of first line therapy in advanced stage non-small cell lung cancer, without oncogenic driver, has led to change the treatment algorithm of second line, which was previously and mainly based on anti-PD(L)-1 given as a single agent. Second-line treatment is currently based on chemotherapy, with a platinum-based doublet for patients treated in first line by pembrolizumab alone, and standard second-line chemotherapy options for patients treated by chemotherapy-immunotherapy combinations, i.e. docétaxel regardless of histology or pemetrexed for non-squamous cell carcinoma when not used in first line. Addition of an antiangiogenic agent to docétaxel only achieved a modest improvement of overall survival but neither nintedanib, nor docétaxel is available in France. The future of second line treatment would require a better knowledge and understanding of resistance mechanisms to anti-PD(L)-1, and randomized phase III clinical trials, in order to optimize therapeutic options, including or not a rechallenge to an immunotherapy, targeting to restore anti-tumour immune response
Assessment of hydraulic conductivity from the hydrographic network in shallow crystalline aquifers
International audienceHydrological predictions for ungauged basins at catchment and regional scales still faces the challenge of lack of available data. To meet this challenge, we propose a new method relying on the structure of the stream network. Under the assumption that the perennial stream network is mostly fed by groundwaters, its structure derives from the underlying aquifer properties. It is especially the case for shallow crystalline aquifers under temperate climates where the surface and subsurface hydrological systems are directly connected. The groundwater table remains close to the topography and the spatial extent of the stream network is then controlled by the magnitude of the subsurface hydraulic conductivity (K) with respect to the actual recharge rates (R). Using a parsimonious 3D groundwater flow model, we propose a novel performance criterion to assess the similarity between the modelled seepage areas and the observed stream network. We investigate the sensitivity of our methodology to different digital elevation models (DEM) and stream network products from different databases that may impact the estimates through their different spatial resolutions. We use this method to determine the equivalent hydraulic conductivity for 25 crystalline catchments in western France. The results show that our methodology allows predicting the spatial patterns of the stream network with a high sensitivity to the hydraulic conductivity. We found that estimated hydraulic conductivities vary over two orders of magnitude [10-5 to 10-4 m/s] across the 25 investigated catchments and are well correlated to the lithology. While the DEM resolution has no major effect on the results, we found that the proportion of described low-order streams significantly controls the estimations. The proposed approach constitutes a paradigm shift in current methodologies designed to assess catchment-scale hydraulic properties with great perspectives regarding the emergence of remote sensing techniques for the mapping of wetlands and soil moisture. Our method might bring up new opportunities to provide predictions for ungauged basins such as the hydrographic network dynamics in a changing climate
Can stream architecture inform on subsurface properties to characterize intermittence ?
International audienceGroundwater (GW) and streams are intimately linked. Transient groundwater storage is the main driver for streamflow during extended periods of droughts. The connection between GW and streams is more resilient when the drainage timescale is longer, i.e. with slower GW flows and low hydraulic conductivity. Eventually, a gaining stream can be transformed into a losing one when the GW table level drops below the streambed elevation, in which case surface and subsurface bodies become disconnected. Identifying the processes controlling fluxes of GW into stream boundaries has been identified as one of the main challenges by the hydrological community (Blöschl et al., 2019). The emergence of new surface observations of stream network dynamics, provides new opportunities to address this challenge. In this work, we explore the information content of surface stream mapping (perennial and intermittent rivers) to characterize subsurface hydraulic properties. To this end, we set up a process-based parsimonious model to relate the recharge assessed independently by climate models and the subsurface hydraulic properties to the structure of the stream network and its evolutions. The model uses the water balance of the SURFEX regional land surface model as an input of a 3D groundwater flow model. The river networks directly result from the interception of the GW table with the topography. We investigate about thirty watersheds in Brittany and Normandy covering a variety of climatic, geomorphological and geological conditions by calibrating observed perennial stream referenced in the national river database (BD Topage). Results are twofold: First, the perennial stream network is highly sensitive to the ratio of hydraulic conductivity to recharge. For each lithology, estimated permeabilities are found consistent with previous estimates reported in similar context. Secondly, hydraulic conductivities defined in the previous steady-state approach are used to simulate observed transient stream discharge and expansion/contraction dynamics of the stream network (Onde database). This surface-based information on the seasonal expansion and contraction of intermittent stream network contributes to constrain the aquifer storage capacity. The use of surface observations on stream to characterize near subsurface properties might bring up new opportunities to provide predictions for ungauged basins with absence of stream discharge data. Applied with other remote sensing products, this method could contribute to identify the spatial distribution and dynamic reorganization of intermittent rivers. It would be especially useful in a context of climate change, as reduced recharge would changes the organization, fragmentation and hierarchy of groundwater flow systems
Can stream observations inform subsurfaceproperties to characterize intermittence?
International audienc
Can stream observations inform subsurfaceproperties to characterize intermittence?
International audienc
Assessment of hydraulic conductivity from the hydrographic network in shallow crystalline aquifers
International audienceHydrological predictions for ungauged basins at catchment and regional scales still faces the challenge of lack of available data. To meet this challenge, we propose a new method relying on the structure of the stream network. Under the assumption that the perennial stream network is mostly fed by groundwaters, its structure derives from the underlying aquifer properties. It is especially the case for shallow crystalline aquifers under temperate climates where the surface and subsurface hydrological systems are directly connected. The groundwater table remains close to the topography and the spatial extent of the stream network is then controlled by the magnitude of the subsurface hydraulic conductivity (K) with respect to the actual recharge rates (R). Using a parsimonious 3D groundwater flow model, we propose a novel performance criterion to assess the similarity between the modelled seepage areas and the observed stream network. We investigate the sensitivity of our methodology to different digital elevation models (DEM) and stream network products from different databases that may impact the estimates through their different spatial resolutions. We use this method to determine the equivalent hydraulic conductivity for 25 crystalline catchments in western France. The results show that our methodology allows predicting the spatial patterns of the stream network with a high sensitivity to the hydraulic conductivity. We found that estimated hydraulic conductivities vary over two orders of magnitude [10-5 to 10-4 m/s] across the 25 investigated catchments and are well correlated to the lithology. While the DEM resolution has no major effect on the results, we found that the proportion of described low-order streams significantly controls the estimations. The proposed approach constitutes a paradigm shift in current methodologies designed to assess catchment-scale hydraulic properties with great perspectives regarding the emergence of remote sensing techniques for the mapping of wetlands and soil moisture. Our method might bring up new opportunities to provide predictions for ungauged basins such as the hydrographic network dynamics in a changing climate
Calibration of groundwater seepage against the spatial distribution of the stream network to assess catchment-scale hydraulic properties
The assessment of effective hydraulic properties at the catchment scale, i.e., hydraulic conductivity (K) and transmissivity (T), is particularly challenging due to the sparse availability of hydrological monitoring systems through stream gauges and boreholes. To overcome this challenge, we propose a calibration methodology which only considers information from a digital elevation model (DEM) and the spatial distribution of the stream network. The methodology is built on the assumption that the groundwater system is the main driver controlling the stream density and extension, where the perennial stream network reflects the intersection of the groundwater table with the topography. Indeed, the groundwater seepage at the surface is primarily controlled by the topography, the aquifer thickness and the dimensionless parameter K/R, where R is the average recharge rate. Here, we use a process-based and parsimonious 3D groundwater flow model to calibrate K/R by minimizing the relative distances between the observed and the simulated stream network generated from groundwater seepage zones. By deploying the methodology in 24 selected headwater catchments located in northwestern France, we demonstrate that the method successfully predicts the stream network extent for 80â% of the cases. Results show a high sensitivity of K/R to the extension of the low-order streams and limited impacts of the DEM resolution as long the DEM remains consistent with the stream network observations. By assuming an average recharge rate, we found that effective K values vary between 1.0Ă10-5 and 1.1Ă10-4âmâsâ1, in agreement with local estimates derived from hydraulic tests and independent calibrated groundwater model. With the emergence of global remote-sensing databases compiling information on high-resolution DEM and stream networks, this approach provides new opportunities to assess hydraulic properties of unconfined aquifers in ungauged basins
Geomorphological controls on groundwater transit times:a synthetic analysis at the hillslope scale
International audienceWe investigated how geomorphological structures shape Transit Time Distributions (TTDs) in shallow aquifers. Extensive 3D simulations were performed to determine the TTDs for synthetic convergent, straight and divergent hillslopes with a constant slope. The uniform recharge applied on top of the aquifer is transferred to the receiving stream through steady-state groundwater flows, return flows and saturation excess overland flows. Without seepage, TTDs evolve from uniform- to power law-like- distributions depending on the average distance of the groundwater volume to the river (barycenter). Remarkably, the coefficient of variation (ratio of the standard deviation to the mean) of the TTDs scales linearly with the barycenter in agreement with a theoretical prediction based on three analytical approximations derived for specific cases. With seepage, the TTD has three separate modes corresponding to rapid saturation excess overland flows, to the intermediate flow paths ending in seepage area and to the slower flow paths going all the way to a discharge in the river. The coefficient of variation additionally depends on the extent of the seepage area. For a natural hillslope in the crystalline basement of Normandy (France), the same synthetic analysis demonstrates that the coefficient of variation is not only determined by the extent of the seepage zone but also by its structure in relation to the local and global geomorphological organization. The results suggest the possibility to assess the variability of transit times by combining geomorphological analysis, surface soil saturation observations and environmental tracers