31 research outputs found
Influence of Language on Colour Perception: A Simulationist Explanation
âHow can perception be altered by language?â is the fundamental question of this article. Indeed, various studies have pointed out the influence of colour-related knowledge on object and colour perception, evoked by linguistic stimuli. Here the relevance of the simulationist approach is assumed in order to explain this influence, where the understanding of colour-related words or sentences involves a process of colour simulation that is supported by a neuronal network partially similar to the network involved in colour perception. Consequently, colour-related knowledge and colour perception can interact through a process of pattern interference. In support of this idea, studies are discussed showing priming effects between colour simulation and colour perception, but two limitations are also raised. Firstly, these works all used between-category colour discrimination tasks that allow the intervention of lexical processes that can also explain priming. Secondly, these works control the congruency link between prime and target at the level of âcolour categoryâ, and no demonstration is made of an influence at the level of specific hues. Consequently, the simulationist view of language/perception interactions seems an interesting way to thinking but more experimens are needed in order to overcome some limitations
Biomimetic Apatite-Based Functional Nanoparticles as Promising Newcomers in Nanomedicine: Overview of 10 Years of Initiatory Research
Biomimetic calcium phosphate apatites, analogous to bone mineral, may now be produced synthetically. Their intrinsic biocompatibility and the nanometer dimensions of their constitutive crystals not only allow one to envision applications in bone tissue regeneration, but also in other medical fields such as nanomedicine, and in particular in view of cell diagnosis. In this mini-review, we look back at 10 years of our dedicated research, and summarize the main advances made in terms of preparation, physical-chemical characterizations and biological evaluations of colloidal formulations of biomimetic apatite-based nanoparticles, which we illustrate here with the angle of cancer diagnosis. The confirmed exceptional biocompatibility of these engineered nanoparticles, associated to the possibility to confer them luminescence properties by way of controlled lanthanide doping, and their capacity to be internalized by cells, including with cancer cell addressing abilities (shown here as a proof of concept), underline that biomimetic apatite-based colloidal nanoparticles are particularly promising for nanomedicine applications, for example related to diseased cells diagnosis. Multidisciplinary research on these functional nanoparticles, initiated as described here, has now generated emulation in the scientific community where the concept of apatite nanoparticles for nanomedicine is being, gratifyingly, appropriated
Terre & Univers - ExtrĂȘmes de chaleur et changement climatique : chaud devant !
International audienceEn septembre dernier, MĂ©tĂ©o-France annonçait lâĂ©tĂ© 2017 comme le deuxiĂšme Ă©tĂ© le plus chaud enregistrĂ© en France depuis le dĂ©but des observations mĂ©tĂ©orologiques (Ă Ă©galitĂ© avec celui de 2015). LâĂ©tĂ© 2003, quant Ă lui, demeure Ă ce jour lâĂ©tĂ© le plus chaud jamais observĂ© en France. Ces saisons anormalement chaudes sont-elles attribuables au rĂ©chauffement climatique global ? LâintensitĂ© et la frĂ©quence de ces Ă©vĂšnements peuvent-elles ĂȘtre prĂ©vues dans le futur ? ĂlĂ©ments de rĂ©ponse avec quelques mĂ©thodes dĂ©veloppĂ©es et utilisĂ©es en sciences du climat
Terre & Univers - ExtrĂȘmes de chaleur et changement climatique : chaud devant !
International audienceEn septembre dernier, MĂ©tĂ©o-France annonçait lâĂ©tĂ© 2017 comme le deuxiĂšme Ă©tĂ© le plus chaud enregistrĂ© en France depuis le dĂ©but des observations mĂ©tĂ©orologiques (Ă Ă©galitĂ© avec celui de 2015). LâĂ©tĂ© 2003, quant Ă lui, demeure Ă ce jour lâĂ©tĂ© le plus chaud jamais observĂ© en France. Ces saisons anormalement chaudes sont-elles attribuables au rĂ©chauffement climatique global ? LâintensitĂ© et la frĂ©quence de ces Ă©vĂšnements peuvent-elles ĂȘtre prĂ©vues dans le futur ? ĂlĂ©ments de rĂ©ponse avec quelques mĂ©thodes dĂ©veloppĂ©es et utilisĂ©es en sciences du climat
Ăvolution des extrĂȘmes de tempĂ©rature et de stress thermique au 21Ăšme siĂšcle : cooccurrence, vitesses relatives et implications sur la perception du rĂ©chauffement climatique.
According to climate models, observed global warming will intensify during the 21st century due to the increase of greenhouse gas concentrations. This warming will be more readily perceived by human populations if it occurs rapidly and if it induces a thermal heat stress on the human body. This thesis proposes to study global warming through different indicators allowing us to provide a first assessment of the possible human perception of climate change. We focus on extreme values, which are particularly felt by people compared to the mean climate. In the first part, we analyse the effect of relative humidity variations on the occurrence and future changes in heat stress extremes, since this effect is often overlooked due to the major role played by temperature in heat stress variations. The second part investigates which populations will perceive the fastest and/or the most severe intensification of extremes, by using a moving baseline approach to analyse the warming speed. A set of 12 CMIP5 general circulation models is used to analyse the evolution of extremes between 1959 and 2100.Under the highest greenhouse gas emissions scenario (RCP8.5), relative humidity is projected to decrease over land, particularly in Europe and Amazonia. This drying enhances the increase of temperature extremes, but dampens the intensification of heat stress extremes. In a theoretical future in which temperature would increase without any humidity changes, the heat stress intensification would be 20 to 100 % higher in Europe and Amazonia respectively. According to international health recommendations, this moderating effect strongly reduces risks for population in Europe, but does not prevent risks in Amazonia, where the highest danger thresholds are simulated and observed to be reached before 2020. Moreover, an examination of seasonal cycles shows that temperature and heat stress extremes annually co-occur in mid-latitudes, but are time-lagged within the tropics. This time-lag results from the important role played by the relative humidity, especially in regions where the future maximum heat stress intensification is projected, such as the Sahel, Arabia or Amazonia. This result suggests that temperature and heat stress should be considered as two consecutive and additional extremes when studying annual climate impacts on population within these regions.We define the speed of change for each year of the period as a difference between two successive 20-year periods, one immediately preceding the year in question and one immediately after it (i.e. with a moving baseline). According to CMIP5 models, the change of temperature and heat stress extremes will be twice as fast in the future compared to the current speed of change in the mid-latitudes, and by up to four times faster in regions such as Amazonia. A larger acceleration is thus shown within the tropics compared to the mid-latitudes, but this acceleration is similar for both temperature and heat stress changes. However, in tropical regions, by 2080 this speed is projected to be 2.3 times larger than the recently experienced year-to-year variability for heat stress extremes, but only 1.5 to 1.8 times larger for temperature. We thus show that 36% of the total world population will experience a rapid and severe increase of heat stress extremes in 2080, but only 15% of the population for temperature extremes. According to future projections, the accelerated warming of future heat extremes will be more felt by populations than current changes, and this perceived change will be more severe for heat stress than for temperature, particularly in the tropics.DâaprĂšs les modĂšles de climat, le rĂ©chauffement global observĂ© va sâintensifier au cours du 21Ăšme siĂšcle, en lien avec lâaugmentation des concentrations en gaz Ă effet de serre. Ce rĂ©chauffement pourra ĂȘtre plus ressenti par les populations sâil se produit rapidement et sâil affecte le corps humain en provoquant un stress thermique. Dans cette thĂšse, je propose dâĂ©tudier le rĂ©chauffement global Ă travers lâanalyse de diffĂ©rents indicateurs permettant de fournir une estimation de la possible perception humaine du changement climatique futur. Lâaccent est mis sur lâanalyse des valeurs extrĂȘmes, plus ressenties par les populations que le climat moyen. Dans un premier temps, jâĂ©tudie lâeffet des variations dâhumiditĂ© dans lâoccurrence et les changements futurs de stress thermique extrĂȘme, effet peu Ă©tudiĂ© du fait du rĂŽle dominant de la tempĂ©rature dans les variations du stress thermique. Dans un second temps, une approche en rĂ©fĂ©rence glissante est utilisĂ©e pour analyser la vitesse du rĂ©chauffement, et dĂ©terminer quelles populations percevront lâintensification des extrĂȘmes la plus rapide ou la plus sĂ©vĂšre. Un ensemble de simulations de 12 modĂšles CMIP5 est utilisĂ© et analysĂ© entre 1959 et 2100.Dans le scĂ©nario dâĂ©missions futures le plus haut (RCP8.5), une diminution significative de lâhumiditĂ© relative est simulĂ©e au-dessus des continents, principalement en Europe et en Amazonie. Cet assĂšchement amplifie lâaugmentation des extrĂȘmes de tempĂ©rature, mais freine lâintensification des extrĂȘmes de stress thermique. On montre que dans un futur thĂ©orique oĂč la tempĂ©rature augmenterait sans assĂšchement, lâintensification du stress thermique extrĂȘme serait plus importante de 20 Ă 100 % en Europe et en Amazonie respectivement. DâaprĂšs les valeurs recommandĂ©es par les normes internationales de santĂ©, cette attĂ©nuation rĂ©duit significativement le risque pour les populations en Europe, mais nâattĂ©nue pas les risques en Amazonie, oĂč les valeurs atteintes dĂ©passent les seuils dâalerte les plus hauts avant 2020. De plus, lâĂ©tude des cycles saisonniers montre une cooccurrence annuelle des extrĂȘmes de tempĂ©rature et de stress thermique dans les moyennes latitudes, mais prĂ©sente en revanche un dĂ©phasage dans les tropiques. Ce dĂ©phasage rĂ©sulte du rĂŽle important jouĂ© par lâhumiditĂ© dans les rĂ©gions oĂč les modĂšles projettent le maximum dâintensification du stress thermique extrĂȘme, telles que le Sahel, lâArabie ou lâAmazonie. Ce rĂ©sultat suggĂšre de considĂ©rer les extrĂȘmes annuels de tempĂ©rature et de stress thermique comme additifs dans les Ă©tudes dâimpact menĂ©es sur ces rĂ©gions.Pour Ă©tudier la rapiditĂ© dâĂ©volution des extrĂȘmes, la vitesse est dĂ©finie pour chaque annĂ©e comme une diffĂ©rence entre deux pĂ©riodes successives de 20 ans. DâaprĂšs les modĂšles CMIP5, cette vitesse glissante du rĂ©chauffement des extrĂȘmes de stress thermique et de tempĂ©rature est deux fois plus rapide dans le futur quâactuellement dans lâhĂ©misphĂšre nord, et jusquâĂ quatre fois plus rapide en Amazonie dâaprĂšs certains modĂšles. On montre ainsi une accĂ©lĂ©ration du changement des extrĂȘmes plus importante dans les tropiques, et quasi-identique entre les deux mĂ©triques pour chaque rĂ©gion. Cependant, dans les latitudes tropicales, la vitesse du stress thermique en 2080 est jusquâĂ 2.3 fois plus Ă©levĂ©e que la variabilitĂ© interannuelle tout juste vĂ©cue, contre seulement 1.5 Ă 1.8 fois plus Ă©levĂ©e en tempĂ©rature. On montre ainsi que 36 % de la population mondiale vivra une augmentation significative des extrĂȘmes de stress thermique en 2080, contre 15 % pour les extrĂȘmes de tempĂ©rature. Non seulement lâintensification future des extrĂȘmes sera davantage perçue par les populations que le changement actuel, mais cette perception sera aussi plus sĂ©vĂšre en stress thermique quâen tempĂ©rature, en particulier dans les tropiques
The evolution of temperature and heat stress extremes during the 21st century : co-occurrence, relative speeds and insights on human perception of global warming
DâaprĂšs les modĂšles de climat, le rĂ©chauffement global observĂ© va sâintensifier au cours du 21Ăšme siĂšcle, en lien avec lâaugmentation des concentrations en gaz Ă effet de serre. Ce rĂ©chauffement pourra ĂȘtre plus ressenti par les populations sâil se produit rapidement et sâil affecte le corps humain en provoquant un stress thermique. Dans cette thĂšse, je propose dâĂ©tudier le rĂ©chauffement global Ă travers lâanalyse de diffĂ©rents indicateurs permettant de fournir une estimation de la possible perception humaine du changement climatique futur. Lâaccent est mis sur lâanalyse des valeurs extrĂȘmes, plus ressenties par les populations que le climat moyen. Dans un premier temps, jâĂ©tudie lâeffet des variations dâhumiditĂ© dans lâoccurrence et les changements futurs de stress thermique extrĂȘme, effet peu Ă©tudiĂ© du fait du rĂŽle dominant de la tempĂ©rature dans les variations du stress thermique. Dans un second temps, une approche en rĂ©fĂ©rence glissante est utilisĂ©e pour analyser la vitesse du rĂ©chauffement, et dĂ©terminer quelles populations percevront lâintensification des extrĂȘmes la plus rapide ou la plus sĂ©vĂšre. Un ensemble de simulations de 12 modĂšles CMIP5 est utilisĂ© et analysĂ© entre 1959 et 2100.Dans le scĂ©nario dâĂ©missions futures le plus haut (RCP8.5), une diminution significative de lâhumiditĂ© relative est simulĂ©e au-dessus des continents, principalement en Europe et en Amazonie. Cet assĂšchement amplifie lâaugmentation des extrĂȘmes de tempĂ©rature, mais freine lâintensification des extrĂȘmes de stress thermique. On montre que dans un futur thĂ©orique oĂč la tempĂ©rature augmenterait sans assĂšchement, lâintensification du stress thermique extrĂȘme serait plus importante de 20 Ă 100 % en Europe et en Amazonie respectivement. DâaprĂšs les valeurs recommandĂ©es par les normes internationales de santĂ©, cette attĂ©nuation rĂ©duit significativement le risque pour les populations en Europe, mais nâattĂ©nue pas les risques en Amazonie, oĂč les valeurs atteintes dĂ©passent les seuils dâalerte les plus hauts avant 2020. De plus, lâĂ©tude des cycles saisonniers montre une cooccurrence annuelle des extrĂȘmes de tempĂ©rature et de stress thermique dans les moyennes latitudes, mais prĂ©sente en revanche un dĂ©phasage dans les tropiques. Ce dĂ©phasage rĂ©sulte du rĂŽle important jouĂ© par lâhumiditĂ© dans les rĂ©gions oĂč les modĂšles projettent le maximum dâintensification du stress thermique extrĂȘme, telles que le Sahel, lâArabie ou lâAmazonie. Ce rĂ©sultat suggĂšre de considĂ©rer les extrĂȘmes annuels de tempĂ©rature et de stress thermique comme additifs dans les Ă©tudes dâimpact menĂ©es sur ces rĂ©gions.Pour Ă©tudier la rapiditĂ© dâĂ©volution des extrĂȘmes, la vitesse est dĂ©finie pour chaque annĂ©e comme une diffĂ©rence entre deux pĂ©riodes successives de 20 ans. DâaprĂšs les modĂšles CMIP5, cette vitesse glissante du rĂ©chauffement des extrĂȘmes de stress thermique et de tempĂ©rature est deux fois plus rapide dans le futur quâactuellement dans lâhĂ©misphĂšre nord, et jusquâĂ quatre fois plus rapide en Amazonie dâaprĂšs certains modĂšles. On montre ainsi une accĂ©lĂ©ration du changement des extrĂȘmes plus importante dans les tropiques, et quasi-identique entre les deux mĂ©triques pour chaque rĂ©gion. Cependant, dans les latitudes tropicales, la vitesse du stress thermique en 2080 est jusquâĂ 2.3 fois plus Ă©levĂ©e que la variabilitĂ© interannuelle tout juste vĂ©cue, contre seulement 1.5 Ă 1.8 fois plus Ă©levĂ©e en tempĂ©rature. On montre ainsi que 36 % de la population mondiale vivra une augmentation significative des extrĂȘmes de stress thermique en 2080, contre 15 % pour les extrĂȘmes de tempĂ©rature. Non seulement lâintensification future des extrĂȘmes sera davantage perçue par les populations que le changement actuel, mais cette perception sera aussi plus sĂ©vĂšre en stress thermique quâen tempĂ©rature, en particulier dans les tropiques.According to climate models, observed global warming will intensify during the 21st century due to the increase of greenhouse gas concentrations. This warming will be more readily perceived by human populations if it occurs rapidly and if it induces a thermal heat stress on the human body. This thesis proposes to study global warming through different indicators allowing us to provide a first assessment of the possible human perception of climate change. We focus on extreme values, which are particularly felt by people compared to the mean climate. In the first part, we analyse the effect of relative humidity variations on the occurrence and future changes in heat stress extremes, since this effect is often overlooked due to the major role played by temperature in heat stress variations. The second part investigates which populations will perceive the fastest and/or the most severe intensification of extremes, by using a moving baseline approach to analyse the warming speed. A set of 12 CMIP5 general circulation models is used to analyse the evolution of extremes between 1959 and 2100.Under the highest greenhouse gas emissions scenario (RCP8.5), relative humidity is projected to decrease over land, particularly in Europe and Amazonia. This drying enhances the increase of temperature extremes, but dampens the intensification of heat stress extremes. In a theoretical future in which temperature would increase without any humidity changes, the heat stress intensification would be 20 to 100 % higher in Europe and Amazonia respectively. According to international health recommendations, this moderating effect strongly reduces risks for population in Europe, but does not prevent risks in Amazonia, where the highest danger thresholds are simulated and observed to be reached before 2020. Moreover, an examination of seasonal cycles shows that temperature and heat stress extremes annually co-occur in mid-latitudes, but are time-lagged within the tropics. This time-lag results from the important role played by the relative humidity, especially in regions where the future maximum heat stress intensification is projected, such as the Sahel, Arabia or Amazonia. This result suggests that temperature and heat stress should be considered as two consecutive and additional extremes when studying annual climate impacts on population within these regions.We define the speed of change for each year of the period as a difference between two successive 20-year periods, one immediately preceding the year in question and one immediately after it (i.e. with a moving baseline). According to CMIP5 models, the change of temperature and heat stress extremes will be twice as fast in the future compared to the current speed of change in the mid-latitudes, and by up to four times faster in regions such as Amazonia. A larger acceleration is thus shown within the tropics compared to the mid-latitudes, but this acceleration is similar for both temperature and heat stress changes. However, in tropical regions, by 2080 this speed is projected to be 2.3 times larger than the recently experienced year-to-year variability for heat stress extremes, but only 1.5 to 1.8 times larger for temperature. We thus show that 36% of the total world population will experience a rapid and severe increase of heat stress extremes in 2080, but only 15% of the population for temperature extremes. According to future projections, the accelerated warming of future heat extremes will be more felt by populations than current changes, and this perceived change will be more severe for heat stress than for temperature, particularly in the tropics
Terre & Univers - ExtrĂȘmes de chaleur et changement climatique : chaud devant !
International audienceEn septembre dernier, MĂ©tĂ©o-France annonçait lâĂ©tĂ© 2017 comme le deuxiĂšme Ă©tĂ© le plus chaud enregistrĂ© en France depuis le dĂ©but des observations mĂ©tĂ©orologiques (Ă Ă©galitĂ© avec celui de 2015). LâĂ©tĂ© 2003, quant Ă lui, demeure Ă ce jour lâĂ©tĂ© le plus chaud jamais observĂ© en France. Ces saisons anormalement chaudes sont-elles attribuables au rĂ©chauffement climatique global ? LâintensitĂ© et la frĂ©quence de ces Ă©vĂšnements peuvent-elles ĂȘtre prĂ©vues dans le futur ? ĂlĂ©ments de rĂ©ponse avec quelques mĂ©thodes dĂ©veloppĂ©es et utilisĂ©es en sciences du climat
Biases in evaluation of neutral words due to motor compatibility effect
International audienceThis study aims to demonstrate the effect of action fluency on emotional evaluation, specifically to show that neutral words can be evaluated positively or negatively depending on motor activity and evaluative setting. Right-handers naturally tend to associate positive (negative) valence to the right (left) part of space (Casasanto, 2009). We extend these associations to lateralized behaviors by studying the combined effect of motor fluency of lateral arm movements and the evaluative scale on the subjective evaluation of neutral words. Three experiments evidenced that, for right-handers, the realization of fluent rightward arm movements and the use of an evaluative scale congruent with their valence/laterality associations (left negative, right positive) led to a positive evaluation of neutral words, while non-fluent leftward movements and an incongruent scale led to a negative evaluation. This study demonstrates that emotionâaction associations are experience-based, and influenced by functional and situational constraints
Effect of an unrelated fluent action on word recognition: a case of motor discrepancy
International audienceIt is now well established that motor fluency affects cognitive processes, including memory. In two experiments participants learned a list of words and then performed a recognition task. The original feature of our procedure is that before judging the words they had to perform a fluent gesture (i.e., typing a letter dyad). The dyads comprised letters located on either the right or left side of the keyboard. Participants typed dyads with their right or left index finger; the required movement was either very small (dyad composed of adjacent letters, Experiment 1) or slightly larger (dyad composed of letters separated by one key, experiment 2). The results show that when the gesture was performed in the ipsilateral space the probability of recognizing a word increased (to a lesser extent it is the same with the dominant hand, experiment 2). Moreover, a binary regression logistic highlighted that the probability of recognizing a word was proportional to the speed by which the gesture was performed. These results are discussed in terms of a feeling of familiarity emerging from motor discrepancy
Bidirectional Influences of Emotion and Action in Evaluation of Emotionally-Connoted Words
The goal of this review is to present the embodied character of emotionally-connoted language through the study of the mutual influences of affective language and motor action. After a brief definition of the embodied approach of cognition, the activity of language understanding is presented as an off-line embodied process implying sensory-motor resonance. Then the bidirectional character of influences between language and action will be addressed in both behavioral and neuropsychological studies, illustrated by the specific case of emotionally-connoted language. These reciprocal effects are grounded on the motor correspondence between action and the motor dimension of language, emerging from a diversity of source such as adaptive motivation, past experiences, body specificities, or motor fluency