Detection of "Flavescence dorée" Grapevine Disease Using Unmanned Aerial Vehicle (UAV) Multispectral Imagery

Flavescence dorée is a grapevine disease affecting European vineyards which has severe economic consequences and containing its spread is therefore considered as a major challenge for viticulture. Flavescence dorée is subject to mandatory pest control including removal of the infected vines and, in this context, automatic detection of Flavescence dorée symptomatic vines by unmanned aerial vehicle (UAV) remote sensing could constitute a key diagnosis instrument for growers. The objective of this paper is to evaluate the feasibility of discriminating the Flavescence dorée symptoms in red and white cultivars from healthy vine vegetation using UAV multispectral imagery. Exhaustive ground truth data and UAV multispectral imagery (visible and near-infrared domain) have been acquired in September 2015 over four selected vineyards in Southwest France. Spectral signatures of healthy and symptomatic plants were studied with a set of 20 variables computed from the UAV images (spectral bands, vegetation indices and biophysical parameters) using univariate and multivariate classification approaches. Best results were achieved with red cultivars (both using univariate and multivariate approaches). For white cultivars, results were not satisfactory either for the univariate or the multivariate. Nevertheless, external accuracy assessment show that despite problems of Flavescence dorée and healthy pixel misclassification, an operational Flavescence dorée mapping technique using UAV-based imagery can still be proposed

CarDen: A software for fast measurement of wood density on increment cores by CT scanning

Increment cores are often used in wood science for measuring wood density of trees non destructively and at large scale, for instance with the objective to assess the available biomass in a forest resource. This paper presents a software allowing to measure by X-ray computed tomography (CT) the wood density of thousands increment cores. The software is able to process 3000 cores per hour semi-automatically. Manual intervention may be required to control and eventually adjust the positioning of the cores. The software was tested on 30 trees from 13 temperate species. Two increment cores were taken from each tree: one 5 mm diameter core and one 4 mm diameter core. The obtained CT density of the cores was compared to reference data obtained by volume and mass measurement on the 5 mm cores. The reference data were used for tuning the software settings by leave-one-out cross validation method. The obtained root mean square error was below 10 kg/m3 (1.7%) for the 5 mm cores. For the 4 mm cores, the root mean square difference with the reference density of the 5 mm cores was 25 kg/m(3) (4.2%)

Simulations of Hydro-Elastic Impacts Using a Parallel SPH Model

International audienceThe work presented in this paper started with a PhD Thesis (GTT/ECN) (Deuff, 2007) dedicated to the development of a Smoothed Particle Hydrodynamics (SPH) solver able to simulate hydro-elastic impacts with strong fluid/structure coupling. Further developments have been made to integrate the fluid/structure SPH solver in an industrial SPH platform named SPHF low. These developments have mainly focused on the parallelisation of the fluid/structure solver and the implementation of solutions to avoid the so-called Tensile Instability. They enable the simulation of liquid impacts on complex structures such as MarkIII or NO96 containment systems. The paper first describes the theoretical core of the SPH fluid/structure solver. Various academic test cases are presented for validation of the recently implemented SPH structural model, such as the free vibration of a beam and wave propagation through a heterogeneous material. Recent developments on the parallelisation and solutions implemented to avoid Tensile Instability are described. The final validation case allows a comparison of the results of the fluid/structure SPH solver with analytical model results on a deformable beam wedge impacting the free surface at very high velocity

Potentiality of uav multispectral imagery to detect flavescence doree and grapevine trunk diseases

International audienc

Long‐term psycho‐traumatic consequences of the COVID‐19 health crisis among emergency department healthcare workers

International audienceAbstract Assess the changes in post‐traumatic stress disorder (PTSD), burnout, anxiety, depression, jobstrain, and isostrain levels over time among healthcare workers in emergency departments (EDs) after successive outbreaks of COVID‐19. A prospective, multicenter study was conducted in 3 EDs and an emergency medical service. Healthcare workers who participated in our previous study were invited to participate in a follow‐up 16 and 18 months and completed the questionnaires to assess symptoms of PTSD, burnout, anxiety, depression, jobstrain, and isostrain. Among the 485 healthcare workers asked to participate, 211 (43.5%) completed the survey at inclusion (122 were followed up at 3 months) and 59 participate to the follow‐up study. At 16 months, 10.9% of healthcare workers had symptoms of PTSD and 17.4% at 18 months. At inclusion, 33.5% and 11.7% of healthcare workers had symptoms of anxiety and depression, respectively. A decrease in anxiety between inclusion and 16 months ( p = 0.02) and an increase between 16 and 18 months ( p = 0.009) was observed. At inclusion, 40.8% of all healthcare workers had symptoms of burnout. There was an increase in symptoms of burnout between inclusion and 18 months ( p = 0.006). At inclusion, 43.2% and 29.5% of healthcare workers were exposed to jobstrain and isostrain, respectively. Jobstrain were higher among paramedics and administrative staff compared to physicians ( p = 0.001 and p = 0.026, respectively). Successive outbreaks of COVID‐19 led to long‐term mental health consequences among ED healthcare workers that differed according to occupation. This must be taken into account to rethink the management of teams

Récit et connaissance

Après un long déclin consécutif aux bouleversements idéologiques des xviie et xviiie siècles, le récit redevient, sous des formes nouvelles, vecteur et facteur de connaissance. Les contributions de vingt-cinq chercheurs américains et européens travaillant dans des disciplines aussi diverses que l'anthropologie, la sociologie, les études littéraires, la linguistique, le journalisme, examinent comment la réémergence du récit est susceptible d'entraîner la redéfinition et la valorisation d'une connaissance qui ne serait plus contrainte par les normes de la rationalité et de l'objectivité qui ont soutenu l'idéologie scientifique

Docetaxel, Cisplatin, and 5-fluorouracil (DCF) chemotherapy in the treatment of metastatic or unresectable locally recurrent anal squamous cell carcinoma: a phase II study of French interdisciplinary GERCOR and FFCD groups (Epitopes-HPV02 study)

Abstract Background The squamous cell carcinoma of the anus (SCCA) is a rare disease, but its incidence is markedly increasing. About 15% of patients are diagnosed at metastatic stage, and more than 20% with a localized disease treated by chemoradiotherapy (CRT) will recur. In advanced SCCA, cisplatin and 5-fluorouracil (CF) combination is the standard option but complete response is a rare event and the prognosis remains poor with most disease progression occurring within the first 12 months. We have previously published the potential role of the addition of docetaxel (D). Among 8 consecutive patients with advanced recurrent SCCA after CRT, the DCF regimen induced a complete response in 4 patients, including 3 pathological complete responses. Then, the Epitopes-HPV02 study was designed to confirm the interest of DCF regimen in SCCA patients. Methods This multicentre phase II trial assesses the DCF regimen in advanced SCCA patients. Main eligibility criteria are: histologically proven SCCA, unresectable locally advanced recurrent or metastatic disease, Eastern Cooperative Oncology Group-performance status (ECOG-PS) vs. ≤ 75 years-old) and ECOG-PS (0 vs. 1). The trial was set up based on a Simon’s optimal two-stage design for phase II trials, allowing an early futility interim analysis. The primary endpoint is the observed progression-free survival (PFS) rate at 12 months from the first DCF cycle. A PFS rate below 10% is considered uninteresting, while a PFS rate above 25% is expected. With a unilateral alpha error of 5% and a statistical power of 90%, 66 evaluable patients should be included. Main secondary endpoints are overall survival, PFS, response rate, safety, health-related quality of life, and the correlation of biomarkers with treatment efficacy. Discussion Since the recommended CF regimen is based in a small retrospective analysis and generates a low rate of complete responses, the Epitopes-HPV02 study will establish a new standard in case of a positive result. Associated biomarker studies will contribute to understand the underlying mechanism of resistance and the role of immunity in SCCA. Trial registration NCT02402842 , EudraCT: 2014–001789-81