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Multi-proxy documentation of past storm events in a mid-latitude coastal environment
No full textInternational audienceAs extreme events are expected to become more frequent, the combination of different environmental approaches is essential to apprehend the evolution of their occurrences. This requires a substantial time depth with a robust record of such events. This work presents a combined approach crossing historical, dendrochronological and meteorological indicators to document storm occurrences from a primary maritime pine (Pinus pinaster) tree-ring dataset extracted at Pointe d’Arcay coastal environment (western France), covering the period 1964 to 2019. From the analyses of tree-ring patterns, we identified fourteen years during which the growth of trees was strongly disturbed by significant storm winds, including those associated with Lothar and Martin (1999), Xynthia (2010), Joachim (2012), Klaus and Quinten (2009) storm systems. The analysis of wind parameters (intensity, direction, and persistence) based on ERA5 reanalysis showed a ∼85 % fit between historical archives, dendrochronology, and meteorological data. As trees were sampled through the main tilting axis, tree rings revealed the impacts of windstorms originating from only one direction. The wind intensity appears to be an important factor to produce tree-ring eccentric growth; however, it does not explain all eccentric growth cases. Thus, we analyzed wind persistence as a potential parameter influencing dendrochronological signals recorded during years without storms. We demonstrate that dendrochronology, with the support of meteorological, historical and reanalysis wind data, accurately documents storm winds in a mid-latitude coastal environment. Tree-ring archives are effective to estimate windy phases of extratropical storms and can be used to understand past storm activity with trees older than the available meteorological records
Plasmonic Behaviour of Poly(2-ethyl-2-oxazoline)-Coated Gold Nanoparticles for Sensing and Temperature-Controlled Applications
No full textInternational audienceGold nanoparticles, functionalized with xanthate-poly(2-ethyl-2-oxazoline) (PEtOx-AuNPs) exhibit tunable thermoresponsive optical properties. PEtOx-AuNPs show prominent changes in surface plasmon resonance and enhanced Raman scattering signals upon lower critical solution temperature of..
Tuning the Metal-Free Room Temperature Phosphorescence of Fluorene-Based Chromophores through Side-Group Molecular Engineering
No full textInternational audienceA series of bromofluorene-based metal-free dyes (BrFX) exhibiting room-temperature phosphorescence (RTP) were synthesized via a scalable two-step process in high yields from the linkage of 2-bromofluorene (BrF) through a ketone with different side group (X). Structural analysis of BrFX revealed that the ketone group was well conjugated with the fluorene group but less conjugated with the X side group. The nature of the X side group played a crucial role in fine-tuning emission maxima of BrFX. Moreover, incorporating aromatic side groups having low triplet energy effectively red-shifted RTP and increased its lifetime. Theoretical calculations using density functional theory revealed that the highest occupied molecular orbital was localized on the fluorene core, supporting these experimental observations. BrFX showed strong phosphorescence in diverse amorphous semiconducting hosts with quantum yields up to 65%, enabling their application in light-emitting electrochemical cells. These findings underscore the success of converting BrFH into its ketone analogs, BrFX, as an effective strategy to enhance both phosphorescence and electroluminescence, representing a notable advancement in RTP molecule design
L’impact des niveaux de revendication territoriale régionale sur l’intention d’achat de produits alimentaires : Le rôle médiateur de la valeur perçue
No full textInternational audienceThis research focuses on consumer perceptions of the territorial claims made by a region brand on food product packaging. The aim is to study the impact of territorial claims–weak (simple mention of the place) and strong (label set up by the region to meet demanding specifications)–on purchase intention via perceived value. An experiment involving 186 respondents and manipulating the level of territorial claim (absence vs. weak vs. strong) shows that emotional perceived value mediates the impact of the presence of a territorial claim on purchase intention. However, this positive impact is no greater when the claim is strong. Thus, a weak territorial claim improves levels of perceived value (emotional dimension) and purchase intention just as much as a claim that justifies an accreditation process. However, a strong claim generates higher levels of price and social value than a weak claim.Cette recherche s’intéresse aux perceptions des consommateurs vis-à-vis des revendications territoriales proposées par une marque région sur les packagings de produits alimentaires. Il s’agit d’étudier l’impact des revendications territoriales – faible (simple mention du territoire) et forte (label mis en place par la région répondant à un cahier des charges exigeant) – sur l’intention d’achat via la valeur perçue. Une expérimentation auprès de 186 répondants et manipulant le niveau de revendication territoriale (absence vs. faible vs. forte) montre que la valeur perçue émotionnelle médiatise l’impact de la présence d’une revendication territoriale sur l’intention d’achat. En revanche, cet impact positif n’est pas plus important lorsque la revendication territoriale est forte. Ainsi, une revendication territoriale faible améliore tout autant les niveaux de valeur perçue (dimension émotionnelle) et d’intention d’achat qu’une revendication justifiant d’une démarche d’accréditation. Une revendication forte amène cependant des niveaux de valeur prix et sociale plus importants qu’une revendication faible
Introduction : Des parcours sous influences territoriales
No full textNumber: 169 Publisher: La documentation françaiseInternational audienceLe thème de ce dossier, « Des parcours sous influences territoriales » interroge les rapports entre société et espace en mobilisant la géographie dans un contexte interdisciplinaire. Ce questionnement, amorcé lors des 28es journées du longitudinal à Caen, appelle des analyses croisées, où la géographie interagit avec la sociologie, l’économie, la démographie, les sciences de gestion, les sciences de l’éducation et les sciences politiques. En effet, « le mot-clé de territoire est devenu incont..
Les grands enjeux du dépistage - Dépistage radiologique et gestion des données :les grands enjeux de demain !
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Toward accessible MRI: SDR4MR, a simple RF pulse monitoring technique using an inexpensive software-defined radio
No full textInternational audienceObjective: This study evaluated the applicability and performance of the SDR4MR method at 1.5 T and 3 T across different acquisition scenarios in a clinical environment.Materials and methods: The SDR4MR hardware consists of a broadband receiver coil connected to a software-defined radio (SDR) via optional RF attenuators. The SDR stick is plugged into the computer's USB port, which runs the SDR software and a Mathematica script to decode the RF pulse sequence. Several MRI pulse sequences were recorded: (i) a multi-echo multi-slice spin echo sequence to check the SDR4MR configuration on a well-known simple sequence; (ii) 2D and 3D sequences for which detailed information is not available in the user interface.Results: The measured RF pulse sequences have been drawn in the style of illustrations found in MRI textbooks. Sequence times and amplitudes were estimated, and sequence details not described in the MRI user interface were retrieved.Conclusion: The present study demonstrated the implementation of SDR4MR on clinical scanners. This easy-to-use configuration enables precise monitoring of RF pulse sequences. This method could be further improved by taking advantage of advances in SDR hardware and software
Paleo-Scours Within the Layered Sulfate-Bearing Unit at Gale Crater, Mars: Evidence for Intense Wind Erosion
No full textInternational audienceThe surface of modern Mars is largely shaped by wind, but the influence of past wind activity is less well constrained. Sedimentary rocks exposed in the lower foothills of Aeolis Mons, the central mound within Gale crater, record a transition from predominantly lacustrine deposition in the Murray formation to aeolian deposition in the Mirador formation. Here, we report a series of enigmatic decameter-wide, concave-up scour-and-fill structures within the Mirador formation and discuss their formation mechanisms. Using panoramic images of stratigraphy exposed in cliff faces acquired by the Curiosity rover, we map the extent, distribution and orientation of the scour-and-fill structures and document the sedimentary facies within and surrounding these structures. The scours are grouped into two classes: (A) scours with a simple, symmetric morphology and light-toned, draping infill; and (B) scours with lateral pinching and dark-toned infill. We find that the scour-enclosing environment is composed of planar, even-in-thickness laminations with a pin-stripe pattern which we interpret as wind-ripple strata formed within an aeolian sandsheet environment. Class B contains cm-scale cross-bedding and a wing-shaped feature making this scour-and-fill structure consistent with fluvial processes. We interpret scour fill of class A as an aeolian infill due to similarities with the surrounding sandsheet strata. The broad morphologies and distribution of class A are also consistent with the geometry of blowout structures formed by localized, enhanced wind deflation. These paleo-blowout structures occur clustered within the same stratigraphic interval, which may imply that they record an interval of intensified wind activity at Gale crater
From Failure to Salvation: The Unexpected Redemption of Philip Roth’s Schlemiels
No full textInternational audienceAbstract: The definition of the schlemiel indicates that he is unable to achieve success in his endeavors and is characterized by his failures and narrative stagnation. Philip Roth, however, depicts his schlemiels within the context of a new era of progressive secularization, thereby transforming his Jewish schlemiels into archetypal American Everymen. This development is illustrated across his canon by Neil Klugman, Alex Portnoy, and the unnamed protagonist of Everyman . The new universality of Roth’s schlemiels facilitates reader engagement with the characters’ predicaments and allows for interpretations that do not reduce the schlemiels to their failures. This essay argues that by presenting his characters’ moral questions with humor and immersive narrative devices—in a general postmodern secular Talmud—Roth enables his schlemiels to achieve redemption
The mediating effect of psychosocial work factors in the prospective associations between organisational changes and self-rated health: Results from the national French working conditions survey
No full textInternational audienceObjectives: Organisational changes have been found to be associated with health outcomes but the underlying mechanisms remain understudied. The study aimed at exploring the prospective associations of organisational changes with self-rated health and the mediating effect of psychosocial work factors in these associations.Study design: The study had a prospective design.Methods: The study was based on a nationally representative sample of 14,989 employees surveyed in 2013, 2016, and 2019 (national French working conditions survey). The associations between seven organisational changes, a large set of psychosocial work factors, and the incidence of poor self-rated health were studied using weighted robust Poisson regression models and the Karlson, Holm and Breen (KHB) method. Covariates included gender, age, marital status, stressful life events, social support outside work, occupation, and economic activity of the company.Results: The exposure to any organisational change predicted the incidence of poor self-rated health (covariate-adjusted incidence rate ratio: 1.30, 95 % CI: 1.16-1.46). All types of organisational changes were predictors of the incidence of poor self-rated health. There was a linear trend between the number of changes and the incidence of poor self-rated health. Mismanagement of changes increased the incidence still further. Psychosocial work factors had a mediating effect of 18.4-51.8 % in the associations between organisational changes and the incidence of poor self-rated health. The most contributing factors were those related to quantitative demands, role stressors, job insecurity, and internal violence.Conclusions: Prevention oriented towards organisational changes may be useful to improve psychosocial working conditions and health among working populations