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Bridging Macroecology and Temporal Dynamics to Better Attribute Global Change Impacts on Biodiversity: Short title : Dynamic Macroecology for diversity changes
No full textInternational audienceContext. The ongoing biodiversity crisis presents a complex challenge for ecological science. Despite a consensus on general biodiversity decline, identifying clear trends remains difficult due to variability in data, methodologies, and scales of analysis. Ideas. To enhance our understanding of ongoing biodiversity changes and address discrepancies in biodiversity trend detection, we propose integrating macroecological theory with temporal and trait-based perspectives. First, analyzing temporal changes in diversity scaling relationships, such as species accumulation curves or distance decay, can reconcile and synthesize conflicting observations of biodiversity change, enabling quantification of diversity shifts from local to regional spatial scales. Second, diversity patterns across scales are linked to three proximate components: abundance, evenness, and spatial aggregation of species. Investigating temporal changes in these components provides deeper insights into how human activities directly influence biodiversity trends. Third, incorporating species traits into the analysis of these macroecological patterns improves our understanding of human impacts on biodiversity by elucidating the links between species characteristics and their responses to environmental changes.Case study. We illustrate this integration in forest and farmland birds in France, highlighting how studying diversity changes across scales, and decomposing temporal change in different components can help to elucidate the mechanisms driving diversity change.Conclusions. We discuss the limitations and challenges of this integrative approach and highlight how it offers a comprehensive framework for understanding the drivers of biodiversity change across scales. This framework facilitates a more nuanced understanding of how human activities impact biodiversity, ultimately paving the way for more informed actions to mitigate biodiversity loss across spatial and temporal scales
Selective serotonin reuptake inhibitors enhance cancer immunosurveillance by pleiotropic mechanisms
No full textInternational audienceIn a recent paper published in Cell, Li et al. suggest that selective serotonin reuptake inhibitors (SSRIs) antidepressants act on serotonin transporters on CD8 + T cells to enhance antitumor immunity. Beyond this mechanism, SSRIs can act on malignant cells, as well as on other immune cells, to improve cancer immunosurveillance
Marine predator super-habitats: Channels used for foraging, resting, mating, and parturition in sharks
No full textConservation measures for marine animals include protecting habitats that are important for foraging, reproduction, and refuging. This can be particularly challenging for mobile marine animals such as sharks that may use a wide range of habitats across life stages and for important ecological events. Channels connecting coastal ocean habitats with lagoons or estuaries are well known for their high abundance of predators and other fishes. Using a combination of biologging and diving observations, we show that a single channel in Fakarava, French Polynesia, is used for foraging, refuging, mating, and parturition by the grey reef shark, Carcharhinus amblyrhinchos. Despite over 500 sharks using and being residential to this channel, grey reef sharks can complete most of their life stages in a single restricted habitat. We classify this channel as a ‘super-habitat’ and propose that channels may be even more important to marine predators than previously thought and should be incorporated into conservation planning
De Sigebert à Vincent, en passant par Hélinand : stratégies pour écrire l’histoire du monde
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Optimisation de l'activation des promédicaments par clivage enzymatique du cycle β-lactame des carbapénèmes
No full textInternational audienceβ‐lactam antibiotics remain the best treatment to fight bacterial infections. Among various antibiotics used today, β‐lactams belonging to the carbapenem class are last resort drugs active against many multiresistant Gram‐negative bacteria. Carbapenem antibiotics are prone to hydrolysis by certain β‐lactamases, leading to the opening of the β‐lactam ring and drug inactivation. This mechanism can be repurposed for targeted molecular fragmentation. Here, we report the synthesis of model prodrugs consisting of two carbapenems connected by original self‐immolative linkers. A mass spectrometry assay was developed to simultaneously monitor acylation of a β‐lactam target by the prodrugs and by their sacrificial and warhead moieties. The linker connecting the two carbapenems was optimized with respect to prodrug stability and effective release of the activated warhead upon carbapenem ring opening
Universal Prime Editing Therapeutic Strategy for RyR1-Related Myopathies: A Protective Mutation Rescues Leaky RyR1 Channel
No full textInternational audienceRyR1-related myopathies (RyR1-RMs) include a wide range of genetic disorders that result from mutations in the RYR1 gene. Pathogenic variants lead to defective intracellular calcium homeostasis and muscle dysfunction. Fixing intracellular calcium leaks by stabilizing the RyR1 calcium channel has been identified as a promising therapeutic target. Gene therapy via prime editing also holds great promise as it can cure diseases by correcting genetic mutations. However, as more than 700 variants have been identified in the RYR1 gene, a universal treatment would be a more suitable solution for patients. Our investigation into the RyR1-S2843A mutation has yielded promising results. Using a calcium leak assay, we determined that the S2843A mutation was protective when combined with pathogenic mutations and significantly reduced the Ca2+ leak of the RyR1 channel. Our study demonstrated that prime editing can efficiently introduce the protective S2843A mutation. In vitro experiments using the RNA electroporation of the prime editing components in human myoblasts achieved a 31% introduction of this mutation. This article lays the foundation for a new therapeutic approach for RyR1-RM, where a unique once-in-a-lifetime prime editing treatment could potentially be universally applied to all patients with a leaky RyR1 channel
Chercher la vie à la frontière: Les commerçantes migrantes face à la masculinité hégémonique à Kasumbalesa (Zambie/RDC)
No full textInternational audienceIn Kasumbalesa, a small town straddling the border between Zambia and the Democratic Republic of the Congo (DRC), small-scale cross-border trade is predominantly sustained by migrant women who are routinely subjected to sexual harassment by border officials. Based on long-term ethnographic fieldwork, this article documents the gendered constraints experienced by these female traders originating from the adjacent Kasai Region, as well as the strategies they employ to continue “seeking a living” in a hostile environment. The analysis highlights practices known as “sponsorship” (“parrainage”), referring to transactional relationships with male agents, which allow these women to reduce systemic harassment, obtain favours, protection, or easier border passage. Sponsorship appears here as a specific form of clientelism. Drawing on the concept of agency, the analysis shows how these women develop situated, ambiguous, and often constrained—but nonetheless active—forms of action within a context marked by hegemonic masculinity. The paper calls for moving beyond moralizing interpretations of these practices to better understand the adaptive logics, negotiations, and differentiated power relations at play.À Kasumbalesa, petite ville située de part et d’autre de la frontière entre la Zambie et le Congo (RDC), le petit commerce transfrontalier est en grande partie animé par des femmes migrantes qui sont confrontées à des formes routinières de harcèlement sexuel de la part des agents des services frontaliers. Cet article s’appuie sur une enquête ethnographique qui documente les contraintes de genre qui pèsent sur ces commerçantes provenant de la région voisine du Kasaï. L’enquête étudie aussi les stratégies que ces femmes mobilisent pour continuer à « chercher la vie » dans un environnement hostile. L’analyse met en lumière des pratiques dites de « parrainage », désignant une relation transactionnelle économico-sexuelle avec un agent frontalier, permettant aux commerçantes de réduire le harcèlement massif, de bénéficier de faveurs, de protection ou d’un passage facilité à la frontière. Le parrainage apparaît ainsi comme une forme spécifique de clientélisme. En s’appuyant sur la notion d’agentivité, l’analyse montre comment ces commerçantes développent des formes d’action situées, ambiguës, souvent contraintes, mais actives, dans un cadre marqué par une masculinité hégémonique. L’article invite à dépasser une lecture moralisante de ces pratiques pour mieux saisir les logiques d’adaptation, de négociation et les formes différenciées de pouvoir qui s’y exercent
Cardiovascular responses to mental fatigue in a sequential task paradigm
No full textInternational audienceThis study investigated mental fatigue within a sequential task paradigm using cardiovascular measures and predictions derived from Motivational Intensity Theory. Forty-two undergraduate students were assigned to either a fatigue group (n = 21) or a control group (n = 21). The fatigue group completed a difficult task, while the control group watched a documentary, before both groups performed the same difficult subsequent task. Subjective fatigue, performance, and cardiovascular responses were assessed. Participants in the fatigue group reported significantly higher levels of subjective fatigue and lower effort intensity during the subsequent task compared to the control group, as evidenced by reduced PEP and HR reactivity. Despite these differences, performance on the subsequent task did not differ between groups. These findings suggest that a prior difficult task can increase the perceived difficulty of subsequent tasks. When the subsequent task is also difficult, the effort required may be viewed as no longer worthwhile, leading to reduced effort investment. Cardiovascular measures and theory-driven approaches, such as Motivational Intensity Theory, provide valuable insights for understanding mental fatigue and should be employed rather than relying exclusively on performance-based data.</div
