Can Sophie's Choice Be Adequately Captured by Cold Computation of Minimizing Losses? An fMRI Study of Vital Loss Decisions

The vast majority of decision-making research is performed under the assumption of the value maximizing principle. This principle implies that when making decisions, individuals try to optimize outcomes on the basis of cold mathematical equations. However, decisions are emotion-laden rather than cool and analytic when they tap into life-threatening considerations. Using functional magnetic resonance imaging (fMRI), this study investigated the neural mechanisms underlying vital loss decisions. Participants were asked to make a forced choice between two losses across three conditions: both losses are trivial (trivial-trivial), both losses are vital (vital-vital), or one loss is trivial and the other is vital (vital-trivial). Our results revealed that the amygdala was more active and correlated positively with self-reported negative emotion associated with choice during vital-vital loss decisions, when compared to trivial-trivial loss decisions. The rostral anterior cingulate cortex was also more active and correlated positively with self-reported difficulty of choice during vital-vital loss decisions. Compared to the activity observed during trivial-trivial loss decisions, the orbitofrontal cortex and ventral striatum were more active and correlated positively with self-reported positive emotion of choice during vital-trivial loss decisions. Our findings suggest that vital loss decisions involve emotions and cannot be adequately captured by cold computation of minimizing losses. This research will shed light on how people make vital loss decisions

Estimation of evapotranspiration using SVAT models and IR brightness temperature

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USE OF THERMAL INFRARED REMOTE SENSING FOR WATER BUDGET STUDIES

International audienceWe have developed in our group an interface model which simulates the thermal and hydraulic exchanges between the soil, the vegetation and the atmosphere and estimates the energy fluxes at the surface. This model has been shown to be able to assimilate thermal infrared and microwave data for calibration of some surface parameters. It has been used over different regions and different periods of the year. Recentresults will be presented. A first study in the frame of the HAPEX-MOBILHY experiment,(1985-1986) has shown that satellite thermal infrared and visible data may be used to calibrate the soil and the vegetation functional parameters of the model and estimate during the year either the soil moisture in the surface layer or the water available in the root zone at a scale compatible with the grid of an hydrological model. The second study is the application of this method over a Finnish watershed continuously over the month of July 1988. The total evapoiranspiration has been estimated and compared to the estimate given by a water balance method

Estimation of heat and mass fluxes from IR brightness temperature

International audienceSoil-vegetation-atmosphere transfer models have been developed to simulate mass and energy exchanges between vegetation canopies, the soil, and the atmosphere. They may be used in conjunction with remote sensing data through inversion procedures. In this study, the inversions of two soil-vegetation-atmosphere transfer models are compared on the same data set. Hourly evolutions of stomatal conductance and evapotranspiration are retrieved from the midday measurement of thermal infrared brightness temperature. Seasonal evolution of evapotranspiration and midday stomatal conductance are monitored with a good accuracy with both models. However, the simpler model underestimates evapotranspiration because it does not include a realistic description of hourly evolution of stomatal conductance, and then underestimates morning and afternoon evapotranspiration. The other model gives a better description of hourly evolutions of stomatal conductance and evapotranspiration. This model gives also better estimates of hourly canopy photosynthesis. However, it requires more parameters and computer time than the simpler model, two unfavorable factors for inversion

Estimation of evapotranspiration using SVAT models and IR brightness temperature

National audienc

Elasticidad de la demanda francesa de carne de cordero de origen espanol

En este trabajo se aborda el estudio de las exporaciones espanolas de carne de ovino y caprino hacia la UE y, en particular, hacia Francia, principal destino de las mismas. El metodo utilizado se basa en la estimacion de un sistema de demanda de importaciones en el que se ha prestado especial atencion a las propiedades estadisticas de las series incluidas. La existencia de precios no estacionarios ha determinado la realizacion de un analisis previo de los mismos con el fin de determinar si estaban cointegrados y si cumplian la resticcion de homogeneidad. la aceptacion de dicha hipotesis ha permitido la especificacion de un sistema con precios relativos. Los ersultados obtenidos indican un incremento de la competitividad via precios de las exportaciones espanolas y una potencial ganancia en cuota de mercado siempre que el mercado de importanciones frances continue en expansion como ha sucedido en llos ultimos anos... The aim of the paper is to analyse the Spanish lamb exports to the EU and, particularly, to France, which is their main destination. The method used is based on the estimation of an imports demand system. The novelty of the paper relies on the explicit consideration of the stochastic characteristics of series included in the system. As prices are no stationary, cointegration among them has been tested. Results indicate that they are cointegrated and homogeneity holds. As a result, relative prices are included in the imports demand system. Results indicate an increasing price competitiveness of Spanish exports and a potential gain in market share if the French lamb imports go on growing as they have done in recent years

Seasonal estimation of evaporation and stomatal conductance over a soybean field using surface IR temperatures

International audienc

A grammar of Papuan Malay

International audienc

A study of the slope stability in unsaturated swelling marly clay

The analysis of the some experimental field data on the unsaturated unstable slope constituted with a marly clay soil showed that the swelling and collapse phenomena were the origin of the landslide problem. In the studied case, field investigation data and laboratory tests based on the water retention curve determination were analysed. The recorded pore-water pressure field helped us to identify the hydrological conditions. In fact, the wetting and drying cycles involve the total suction and the degree of saturation changes. To predict the shallow slope failure, a constitutive model taking into account the suction effect as well as their dependence on degree of saturation is proposed. It is especially remarkable that the collapse phenomenon is well reproduced when the model incorporates suction changes and saturated preconsolidation stress. The analysis of the slope failure, basing on the field data and the theoretical study, shows the hydraulic and mechanical effects

Estimation of stomatal resistance and canopy evaporation during the HAPEX-MOBILHY experiment

International audienceSurface energy fluxes can be evaluated from remotely sensed data using models describing the transfers of energy, mass and radiation between soil, vegetation and atmosphere. To be applied over partial canopies where the soil evaporation is comparable with that from foliage, these models need three key soil parameters: thermal inertia P, hydraulic diffusivity D(w), and limit evaporation E(lim), which depend on the soil type and on its moisture and three key, vegetation parameters: height of vegetation h, leaf area index L, and minimum leaf resistance to transpiration r(s,min) which depend on the type and on the physiology of the vegetation. In this paper, we propose a methodology to estimate these parameters. The soil parameters are fitted during a period of bare soil. The vegetation parameters, h and L may be estimated using remote sensing in the optical bands and mean biophysical relationships. The single parameter which remains to be estimated is r(s,min). Assuming that r(s,min) is constant during the growing period, it is adjusted during a period of dense canopy where the contribution of soil to the total evaporation is negligible. This method is tested using the Special Observing Period (SOP) (7 May-15 July 1986) of the international HAPEX-MOBILHY experiment where the sites ranged from bare soils to dense covered areas. It is shown that the model is able to reproduce the surface energy flux components over both dense and partial canopies. and that the partition between soil evaporation and foliage transpiration can be made, leading to the monitoring of global vegetation stomatal resistance through the growing season