Histoires fausse

La numérisation des images, aussi laborieux que soit l'exercice, est tout de même l’endroit de pensées plaisantes. Ainsi, travaillant au numéro 4 de la revue Étant donné Marcel Duchamp, je peste contre le photographe qui nous a livré une aussi mauvaise reproduction d'une caricature de Duchamp jouant aux échecs, le fou nonchalamment tenu au-dessus d'un échiquier dont on voit peu de choses (le caricaturiste n'était pas joueur d'échecs, cela se voit du premier coup d'œil, il aurait autrement pri..

Risk assessment in the Caribbean: modeling a GIS-based Flood risk Tool for Jamaica

The Caribbean is known to be one of the most hazard-prone regions in the world. Although the growing intensity of these disasters increases the concern of decision makers, researchers have not yet succeeded in developing an accurate multi-hazard risk assessment tool to locate the high-risk areas. Many single-hazard risk analyses adequately estimate the risk of one hazard, but the complexity of the relation between the different types of hazards causes difficulties in developing one risk analysis to assess all hazards. This research aims to develop such a model for the Caribbean. In a first step, a flood risk tool was developed for Jamaica. After optimizing this tool, the methods will be used for other hazard types. In a final step, all single-hazard tools will be combined into one multi-hazard risk assessment. To generate the flood risk tool, a new methodology based on minimizing risks rather than building water defences, was used. In the Flemish Region in Belgium, this method is already used in a tool called LATIS, and has proven that using a risk-based methodology helps tremendously in finding the most cost-efficient measures to reduce risk. For Jamaica, the lack of data was and is a big concern. Since there was only minimal rainfall data available, flood hazard maps could not be generated. Therefore, a risk map could not yet be computed, only a vulnerability map and a damage map could. Furthermore, the available damage functions did not cover all elements at risk. Before regenerating the damage map, these functions will have to be reassessed. However, the vulnerability map that was produced shows promising results in indicating the high-risk areas, which are the most important factor in the decision making process. Further research will focus on the flood hazard maps and the damage functions, before applying this method to other natural hazards

The Gaia satellite: a tool for Emission Line Stars and Hot Stars

The Gaia satellite will be launched at the end of 2011. It will observe at least 1 billion stars, and among them several million emission line stars and hot stars. Gaia will provide parallaxes for each star and spectra for stars till V magnitude equal to 17. After a general description of Gaia, we present the codes and methods, which are currently developed by our team. They will provide automatically the astrophysical parameters and spectral classification for the hot and emission line stars in the Milky Way and other close Local Group galaxies such as the Magellanic Clouds.Comment: SF2A2008, session GAIA, invited tal

A GIS-based flood risk tool for Jamaica: the first step towards a multi-hazard risk assessment in the Carribean

The Caribbean is known to be one of the most hazard-prone regions in the world. Hurricanes, flooding, storm surges, earthquakes and landslides lead to extensive material, human and economic losses in the region. The growing intensity of these hazards, combined with the consequences of climate change, rapidly increases the concern among decision makers. Although many researchers have succeeded in developing a single-hazard risk assessment that accurately estimates the risk of one type of hazard, the complexity of the relation between the different types of hazards is causing difficulties in the development of a multi-hazard risk analysis. This research aims to develop such a model. In a first step, the consequences of each type of hazard will be assessed individually, starting with riverine flooding. In the next step, the methodology used in this tool will be assessed and modified to fit other types of hazards. Finally, all single-hazard tools will be combined into a generic multi-hazard risk assessment tool for the region. In Jamaica, local governments use a flood risk methodology that is based on building water defence structures to evacuate the water as quickly as possible. This methodology, however, causes bigger damages downstream. Another method, based on minimizing the consequences of the overall flood, is already in use in many countries. In the Flemish region of Belgium, it is implemented in a tool called LATIS and has already proven to decrease losses after a flood event. Therefore, this risk-based methodology is used as the base for developing the Jamaican flood risk tool. The biggest concern during this research is the lack of data in the region. The methodology used, is based on the Flemish flood risk tool and the acquired data is thus very elaborate. During the implementation of the methods for the Caribbean, especially the lack of sufficient rainfall data and adequate damage functions has proven to result in less accurate damage and vulnerability maps

A GIS-based tool for flood damage assessment and delineation of a methodology for future risk assessment : case study for Annotto Bay, Jamaica

Flood risk assessments and damage estimations form integral parts of the disaster risk management in Jamaica, owing its vulnerability to hydrometeorological hazards. Although island wide damage and risk assessments have been carried out for major flood events in Jamaica, few studies have been conducted for the creation of damage and risk maps for vulnerable areas. In this study, a risk-based tool was developed by transferring a proven methodology for flood risk assessment in Flanders, called LATIS, to areas with limited data resources. The town of Annotto Bay was chosen as case study due to its vulnerability to coastal and riverine flooding. The model uses input parameters such as flood data, land use, and socioeconomic data and rainfall values to estimate the damage. The flooding of 2001, caused by tropical storm Michelle, as well as a storm surge with a 100-year return period, was input for the model in order to estimate damage from fresh and saltwater for Annotto Bay. The produced maps show the spatial variation of the damage costs, which correlates with the flood depths. The total calculated damage cost from the freshwater flood of 2001 in the study area was estimated just over USD 7 million. Saltwater damages were calculated at USD 30 million. Although validation of the exact damage costs was not possible, the damage spread and number of affected elements were accurate. The model output also shows the potential number of people who would be killed as a result of the event, which was calculated at only 2 casualties for freshwater. Since in reality no one died, this low estimate can be considered accurate. The casualties caused by the saltwater flooding with a return period of 100 years were estimated at 150 people killed. The results of this approach can be extended to other vulnerable areas of the island having topographical and geographical similarities and being affected by similar hydrometeorological events. Hence, the method allows damage assessment for data-sparse regions, aiding in planning and mitigation measures for flood-prone communities

Cardiac autonomic response to hyperventilation and risk of SUDEP

34th International Epilepsy Congress, ELECTR NETWORK, AUG 28-SEP 01, 2021International audienc

Cardiac Autonomic Dysfunction and Risk of Sudden Unexpected Death in Epilepsy

International audienceOBJECTIVE: We aimed to test whether patients who died from sudden unexpected death in epilepsy (SUDEP) had an abnormal cardiac autonomic response to sympathetic stimulation by hyperventilation. METHODS: We conducted a retrospective, observational, case-control study of a group of patients who died from SUDEP and controls who were matched with the patients for epilepsy type, drug resistance, sex, age at electroencephalogram recording, age at onset of epilepsy, and duration of epilepsy. We analyzed the heart rate (HR) and heart rate variability (HRV) at rest, during and after hyperventilation performed during the patient’s last electroencephalogram recording before SUDEP. In each group, changes over time in HRV indexes were analyzed using linear mixed models. RESULTS: Twenty patients were included in each group. In the control group, the HR increased and the RMSSD decreased during the hyperventilation and then returned to the baseline values. In the SUDEP group, however, the HR and RMSSD did not change significantly during or after hyperventilation. A difference in HR between the end of the hyperventilation and 4 min after its end discriminated well between SUDEP patients and control patients (AUC: 0.870; sensitivity: 85%; specificity: 75%). CONCLUSION: Most of patients with subsequent SUDEP have an abnormal cardiac autonomic response to sympathetic stimulation through hyperventilation. An index reflecting the change in heart rate upon hyperventilation (dHRh) might be predictive of the risk of SUDEP and could be used to select patients at risk of SUDEP for inclusion in trials assessing protective measures

Cardiac autonomic response to hyperventilation and risk of SUDEP

34th International Epilepsy Congress, ELECTR NETWORK, AUG 28-SEP 01, 2021International audienc