Towards IASI-New Generation (IASI-NG): impact of improved spectral resolution and radiometric noise on the retrieval of thermodynamic, chemistry and climate variables

Besides their strong contribution to weather forecast improvement through data assimilation, thermal infrared sounders onboard polar-orbiting platforms are now playing a key role for monitoring atmospheric composition changes. The Infrared Atmospheric Sounding Interferometer (IASI) instrument developed by the French space agency (CNES) and launched by Eumetsat onboard the Metop satellite series is providing essential inputs for weather forecasting and pollution/climate monitoring owing to its smart combination of large horizontal swath, good spectral resolution and high radiometric performance. EUMETSAT is currently preparing the next polar-orbiting program (EPS-SG) with the Metop-SG satellite series that should be launched around 2020. In this framework, CNES is studying the concept of a new instrument, the IASI-New Generation (IASI-NG), characterized by an improvement of both spectral and radiometric characteristics as compared to IASI, with three objectives: (i) continuity of the IASI/Metop series; (ii) improvement of vertical resolution; (iii) improvement of the accuracy and detection threshold for atmospheric and surface components. In this paper, we show that an improvement of spectral resolution and radiometric noise fulfill these objectives by leading to (i) a better vertical coverage in the lower part of the troposphere, thanks to the increase in spectral resolution; (ii) an increase in the accuracy of the retrieval of several thermodynamic, climate and chemistry variables, thanks to the improved signal-to-noise ratio as well as less interferences between the signatures of the absorbing species in the measured radiances. The detection limit of several atmospheric species is also improved. We conclude that IASI-NG has the potential for strongly benefiting the numerical weather prediction, chemistry and climate communities now connected through the European GMES/Copernicus initiative

Repression of PLA2R1 by c-MYC and HIF-2alpha promotes cancer growth

Loss of secreted phospholipase A2 receptor (PLA2R1) has recently been found to render human primary cells more resistant to senescence whereas increased PLA2R1 expression is able to induce cell cycle arrest, cancer cell death or blockage of cancer cell transformation in vitro, suggesting that PLA2R1 displays tumor suppressive activities. Here we report that PLA2R1 expression strongly decreases in samples of human renal cell carcinoma (RCC). Knockdown of PLA2R1 increases renal cancer cell tumorigenicity supporting a role of PLA2R1 loss to promote in vivo RCC growth. Most RCC result from Von Hippel-Lindau (VHL) tumor suppressor loss-of-function and subsequent gain-of-function of the oncogenic HIF-2alpha/c-MYC pathway. Here, by genetically manipulating VHL, HIF-2alpha and c-MYC, we demonstrate that loss of VHL, stabilization of HIF-2alpha and subsequent increased c-MYC activity, binding and transcriptional repression, through induction of PLA2R1 DNA methylation closed to PLA2R1 transcriptional start site, results in decreased PLA2R1 transcription. Our results describe for the first time an oncogenic pathway leading to PLA2R1 transcriptional repression and the importance of this repression for tumor growth

Metabolic changes in concussed American football players during the acute and chronic post-injury phases

<p>Abstract</p> <p>Background</p> <p>Despite negative neuroimaging findings many athletes display neurophysiological alterations and post-concussion symptoms that may be attributable to neurometabolic alterations.</p> <p>Methods</p> <p>The present study investigated the effects of sports concussion on brain metabolism using ¹H-MR Spectroscopy by comparing a group of 10 non-concussed athletes with a group of 10 concussed athletes of the same age (mean: 22.5 years) and education (mean: 16 years) within both the acute and chronic post-injury phases. All athletes were scanned 1-6 days post-concussion and again 6-months later in a 3T Siemens MRI.</p> <p>Results</p> <p>Concussed athletes demonstrated neurometabolic impairment in prefrontal and motor (M1) cortices in the acute phase where NAA:Cr levels remained depressed relative to controls. There was some recovery observed in the chronic phase where Glu:Cr levels returned to those of control athletes; however, there was a pathological increase of m-I:Cr levels in M1 that was only present in the chronic phase.</p> <p>Conclusions</p> <p>These results confirm cortical neurometabolic changes in the acute post-concussion phase as well as recovery and continued metabolic abnormalities in the chronic phase. The results indicate that complex pathophysiological processes differ depending on the post-injury phase and the neurometabolite in question.</p

Variation in Structure and Process of Care in Traumatic Brain Injury: Provider Profiles of European Neurotrauma Centers Participating in the CENTER-TBI Study.

INTRODUCTION: The strength of evidence underpinning care and treatment recommendations in traumatic brain injury (TBI) is low. Comparative effectiveness research (CER) has been proposed as a framework to provide evidence for optimal care for TBI patients. The first step in CER is to map the existing variation. The aim of current study is to quantify variation in general structural and process characteristics among centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. METHODS: We designed a set of 11 provider profiling questionnaires with 321 questions about various aspects of TBI care, chosen based on literature and expert opinion. After pilot testing, questionnaires were disseminated to 71 centers from 20 countries participating in the CENTER-TBI study. Reliability of questionnaires was estimated by calculating a concordance rate among 5% duplicate questions. RESULTS: All 71 centers completed the questionnaires. Median concordance rate among duplicate questions was 0.85. The majority of centers were academic hospitals (n = 65, 92%), designated as a level I trauma center (n = 48, 68%) and situated in an urban location (n = 70, 99%). The availability of facilities for neuro-trauma care varied across centers; e.g. 40 (57%) had a dedicated neuro-intensive care unit (ICU), 36 (51%) had an in-hospital rehabilitation unit and the organization of the ICU was closed in 64% (n = 45) of the centers. In addition, we found wide variation in processes of care, such as the ICU admission policy and intracranial pressure monitoring policy among centers. CONCLUSION: Even among high-volume, specialized neurotrauma centers there is substantial variation in structures and processes of TBI care. This variation provides an opportunity to study effectiveness of specific aspects of TBI care and to identify best practices with CER approaches

Variation in neurosurgical management of traumatic brain injury

Background: Neurosurgical management of traumatic brain injury (TBI) is challenging, with only low-quality evidence. We aimed to explore differences in neurosurgical strategies for TBI across Europe. Methods: A survey was sent to 68 centers participating in the Collaborative European Neurotrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. The questionnaire contained 21 questions, including the decision when to operate (or not) on traumatic acute subdural hematoma (ASDH) and intracerebral hematoma (ICH), and when to perform a decompressive craniectomy (DC) in raised intracranial pressure (ICP). Results: The survey was completed by 68 centers (100%). On average, 10 neurosurgeons work in each trauma center. In all centers, a neurosurgeon was available within 30 min. Forty percent of responders reported a thickness or volume threshold for evacuation of an ASDH. Most responders (78%) decide on a primary DC in evacuating an ASDH during the operation, when swelling is present. For ICH, 3% would perform an evacuation directly to prevent secondary deterioration and 66% only in case of clinical deterioration. Most respondents (91%) reported to consider a DC for refractory high ICP. The reported cut-off ICP for DC in refractory high ICP, however, differed: 60% uses 25 mmHg, 18% 30 mmHg, and 17% 20 mmHg. Treatment strategies varied substantially between regions, specifically for the threshold for ASDH surgery and DC for refractory raised ICP. Also within center variation was present: 31% reported variation within the hospital for inserting an ICP monitor and 43% for evacuating mass lesions. Conclusion: Despite a homogeneous organization, considerable practice variation exists of neurosurgical strategies for TBI in Europe. These results provide an incentive for comparative effectiveness research to determine elements of effective neurosurgical care

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P &lt; 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Retrieval of methane with IASI and GOSAT : spectrocopic issues

International audienc

Constraint Programming for Technician Scheduling in Precision agriculture

The conference was launched and is supported by the European Federation for Information Technology in Agriculture, Food and the Environment (EFITA) with the collaboration of the World Congress on Computers in Agriculture (WCCA).International audiencePrecision agriculture generally requires collecting data through regular sampling or sensor maintenance in the field. Managing technicians who perform these tasks becomes very complex when the number of plots increases.This research was motivated by a real problem of technician scheduling. Fruition Sciences is an information technology company that provides data driven web applications to enable grapegrowers to optimize grape quality and yield. The data come from various sources, including connected sap flow sensors that measure the wine transpiration in order to compute a water deficit index. The company employs several technicians to deploy and maintain such sensors. The technicians also perform regular samplings, routine maintenance and troubleshooting over a typical working day. With the company’s growth over the years, technician scheduling is becoming more and more complex and can benefit from constrained optimization techniques.One of the main challenges of this project was to help the company to clearly identify the optimization problem to solve. Fruition Sciences proposes several kinds of sampling operations that depend on the needs of the enduser. The regularity of a sampling is essential and can have different frequencies (daily, weekly, monthly). One part of the samples must be brought to the laboratory for analyses. Depending on the season, different analyses are performed thanks to different sensors. Technicians have to install and maintain sensors in the vineyards during the period. Because sensors wrap the vine, technicians must regularly inspect sensors to respect the growth of the plant. Also, technicians must prevent and repair faulty sensors and solve troubleshooting. Of course, the planning of technicians must respect the working time constraints like working hours, holidays, weekend, predawn work, etc. Hence, the Technician Scheduling Problem consists in finding a planning of technicians that satisfies all constraints, optimizes the frequency of operations and minimizes the travel time of all technicians.The problem was originally identified as a scheduling problem but during the study it also appeared close to a Vehicle Routing Problem (VRP) (Cortès et al. 2014). First proposed by Dantzig and Ramsey in 1959, the VRP consists in seeking a number of customers with a fleet of vehicles. Several variants of VRP exist, like VRP with time-window, VRP with precedence constraint, or VRP with pickup delivery.We propose a preliminary approach to solve the issue of the scheduling problem. It is based on Constraint Programming (CP), which is a powerful technique to solve combinatorial problems (Rossi et al. 2006). Constraint Programming uses tree search algorithms and branching strategies to decide if a problem has feasible solutions or not.One benefit of constraint programming is its expressiveness that allows a high level of abstraction. In constraint programming, each problem is defined by a set of variables and constraints on these variables. Domains are associated to variables: each value in that domain represents a possible value for the variable. Constraints on two or more variables are stated in a natural way to formulate the given problem and restrict the combinations of values for these variables. A Constraint Optimization Problem (COP) is a problem where one has to find a value for each variable satisfying the set of constraints and to optimize an objective function. A constraint solver can be used to find an optimal solution of the problem. Thanks to the flexibility of CP models, we can consider the addition of extra user-constraints in a simple way.The second main advantage of constraint programming is due to the efficiency of Constraint solvers (Rossi et al. 2006). They are based on the notion of “constraint propagation”. Constraint propagation takes into account the current state of the search tree, that is, variables already instantiated to values, and deletes infeasible values according to the constraints. Constraint propagation can drastically reduce the search effort. For each kind of constraints, specialized and powerful algorithms have been developed to perform propagation efficiently.One of the major issues of the project was to formalize the business rules of the Technician Scheduling Problem. We build a mathematical model of the problem in order to clarify these rules. However, the problem is quite complex and requires validating the rules on real data. Hence, we developed a preliminary COP model using the java library Choco (Prud’homme et al. 2014). The complexity of the problem grows with the number of vineyards, the number of operations and the number of technicians. Our method has been tested on two real instances. A first set of instances located around Paso Robles, California with 15 plots, 4 operations and 2 technicians and a more complex set of instances with almost 200 plots, 5 operations and 4 technicians, in Napa valley, California. Preliminary results shown the technical and economic value of handling such problems with constraint programming. On first instances, optimal solutions are found in seconds. On complex instances, an optimal solution is not found before a cutoff of 5 hours. However, the Solver produces incrementally better-cost solutions, which satisfy all the constraints of the problem.Thanks to our preliminary COP implementation of the problem, Fruition Sciences will be able to clarify and adapt the scheduling rules. This is a necessary step before a relevant and efficient solver could be developed for this problem. A promising perspective would be to use a Large Neighborhood Search approach that gives good results on complex routing problems (Di Gasparo et al. 2016). It combines the efficiency of Local Search with the expressiveness of Constraint Programming