HAL Portal UPPA (University of Pau and the Pays de l'Adour)
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Drastic Changes in Macrofaunal Communities of Intertidal Boulder Fields’ Habitat During the Last Decade in the South of the Bay of Biscay
No full textInternational audienceThe cumulative effects of environmental and anthropogenic pressures on marine environments are endangering the biocenoses that inhabit them. Identifying and understanding the impacts of global changes are key challenges for maintaining habitats in a good ecological state and require the use of standardized monitoring and reliable ecological indicators.During last decade, as part of various research programs, macrofaunal communities were inventoried in the boulder fields in the Southeastern Bay of Biscay, in an area devoid of fishing pressure. During two time periods, 2015-2016 and 2021-2022, mobile and sessile macrofauna of the upper and lower mediolittoral zones were sampled annually between April and June following a stratified random sampling design. The results reveal significant spatio-temporal changes over the study period, with a transitional year in 2020, that may be associated with the annual appearance of toxic blooms of the microalga Ostreopsis. Shifts in biodiversity, functional structure and the status of indicator species of the habitat were observed, with a marked decline or even local disappearance of several species. From a functional perspective, the decline in grazer abundance was striking particularly in the upper zone. While other guilds in the upper zone showed limited and non-significant changes, the lower zone revealed a broader and significant decline across multiple trophic groups, reflecting a more generalized functional reorganization and supporting the shift toward a new ecosystem state. This ecological shift appears to coincide with long-term changes in environmental parameters (e.g. water temperature, salinity) and may signal a transition toward a novel community state.These results underscored the importance of ongoing monitoring for the management and conservation of coastal rocky habitats in the Southeastern Bay of Biscay. The findings highlight the capacity of this monitoring method to detect early signs of ecosystem change and reveal emerging stressors. The effect of the change and the transition to a new state on ecosystem functioning are discussed
Simultaneous reconstruction of an obstacle and its wavenumber for the Helmholtz equation: a robust optimization approach
No full textIn this paper, we propose a method to recover simultaneously the shape and wavenumber of an object from noisy radar or sonar measurements. The physical problem is modeled in a bounded domain with the Helmholtz equation and appropriate transmission conditions. The approach relies on a Kohn-Vogelius formulation of the inverse problem and uses Nesterov's accelerated gradient descent combined with shape optimization techniques. To address the robustness of the method with respect to measurement noise, we are looking to minimize a convex combination of the expected value and variance, which we achieve by using a Karhunen-Loève expansion. The effectiveness of the approach is demonstrated through twodimensional numerical experiments.</div
La philosophie et les défis du contemporain : l' expérience de la Société congolaise de philosophie (Sophia)
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Spatial Distribution of European Grayling Reflects Longitudinal Temperature Patterns in a Swiss River
No full textInternational audienceMost salmonid populations are declining across their entire habitat range, partly because of large‐scale loss of crucial physical habitats. Alterations in river flow and temperature resulting from climate change are likely to further degrade habitat quality, particularly summer thermal conditions experienced by temperature‐sensitive fish species. Understanding how summer thermal conditions control the spatial distribution of ectotherms is thus central to helping project the consequences of climate change and develop management solutions. This study uses snorkelling fish surveys collected over 10 years and airborne thermal infrared (TIR) mapping of surface temperature acquired in 2022 to assess the relationship between European grayling distribution and thermal habitats along a 9‐km long reach of the Allondon River, Switzerland. Results show that all 3 grayling life stages (adults, sub‐adults and juveniles) respond negatively to elevated summer temperature, with distribution patterns highlighting thermal structuring effects on fish populations. The presence of two cooler reaches appears critical to the survival of the Allondon's declining grayling population, while the warmest reach that separates these habitats potentially acts as a thermal barrier during critical summer conditions. These results were used to guide local stakeholders towards short‐term and longer‐term actions to be taken on the river, which include: concerted trans‐national management to protect key upstream tributaries, tree planting to limit summer peak temperature and strategic protection of cold‐water patches that may act as thermal refuges during critical periods
Does treating customers badly increase employee social loafing? The role of disidentification, collective guilt, and moral attentiveness
No full textInternational audiencePurpose Drawing on the theories of social identity and affective events, this research aims to explore the effect of corporate social responsibility (CSR) towards customers on employees’ social loafing. In addition, the authors consider that moral attentiveness moderates the relationship of CSR towards customers with employee disidentification and collective guilt. Design/methodology/approach Time-lagged data (N = 152) were collected at three time points (T1, T2 and T3) through the data collection platform Amazon Mechanical Turk from the full-time employees working in the USA. Findings The results suggest that both disidentification and collective guilt significantly mediate the relationship between customer CSR and social loafing. Moreover, moral attentiveness significantly moderates both customer CSR–disidentification and customer CSR–collective guilt relationships. Originality/value This study provides novel insights into the process underlying the relationship between CSR towards customers and social loafing by revealing the mediating role of disidentification and collective guilt, as well as the moderating role of moral attentiveness. The authors discuss the theoretical and practical implications of these findings and offer directions for future research on CSR towards customers and social loafing
La discipline pénitentiaire à l'épreuve de la surpopulation carcérale dans les pays de la zone CEMAC : cas du Cameroun, du Congo et du Gabon
No full textThe current concern is based on the question of whether prisons would be lawless zones where people could be piled up endlessly. Obviously not, asserts Adeline HAZAN. The prison institution cannot simply be equated with a receptacle for an inexhaustible flow of inmates, confined within a very limited prison space. Although these flows are legally regulated, it seems that the primary worry about overcrowding of inmates remains more relevant than ever. In this case, it concerns prison overcrowding. Overcrowding in detention facilities inevitably leads to a reduction in the living space of prisoners. Defined as the space necessary for every man's survival, living space can be physical or psychological. Yesterday, as today, and if caution is not exercised, tomorrow as well, overcrowding would remain a recurring challenge for the prison administration. Indeed, for more than two centuries, prisons have faced a long-standing problem in the management of inmates, both quantitative and qualitative: prison overcrowding; the need to separate incarcerated individuals based on their legal status, gender, age, and often, their level of dangerousness. This is why prison overcrowding constitutes a detriment to prison discipline.L'inquiétude actuelle est basée sur la question de savoir si les prisons seraient une zone de non droit où l'on pourrait entasser les gens à l'infini. Non évidemment, affirme Adeline HAZAN. L'institution carcérale ne saurait être simplement assimilée à un réceptacle de flux de détenus intarissable, affecté dans un espace carcéral bien réduit. Bien que ces flux soient juridiquement régis, il semble que l'inquiétude première d'un entassement de détenus paraisse plus que jamais d'actualité . Il s'agit en l'espèce de la surpopulation carcérale. Le surpeuplement des lieux de détention se traduit forcément par la diminution de l'espace vital des prisonniers. Défini comme l'espace nécessaire à la survie de tout homme, l'espace vital peut être physique ou psychologique. Hier, comme aujourd'hui, et si l'on n'y prend pas garde, demain aussi, la surpopulation demeurerait un serpent de mer pour l'administration pénitentiaire. En effet, depuis plus de deux siècles, la prison est confrontée à un problème de gestion aussi bien quantitative que qualitative des détenus : la surpopulation carcérale ; la nécessité de séparer les personnes emprisonnées en fonction de leur statut pénal, leurs sexes, leurs âges et, bien souvent, en fonction de leur dangerosité. Raison pour laquelle la surpopulation carcérale constitue un malus à la discipline pénitentiaire
