98%
921
2 minutes
20
Optimality theories of ageing predict that the balance between reproductive effort and somatic maintenance determines the rate of ageing. Laboratory studies find that increased reproductive effort shortens lifespan, but through increased short-term mortality rather than ageing. In contrast, high fecundity in early life is associated with accelerated senescence in free-living vertebrates, but these studies are non-experimental. We performed lifelong brood size manipulation in free-living jackdaws. Actuarial senescence--the increase in mortality rate with age--was threefold higher in birds rearing enlarged- compared to reduced broods, confirming a key prediction of the optimality theory of ageing. Our findings contrast with the results of single-year brood size manipulation studies carried out in many species, in which there was no overall discernible manipulation effect on mortality. We suggest that our and previous findings are in agreement with predictions based on the reliability theory of ageing and propose further tests of this proposition.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/ele.12263 | DOI Listing |
PLoS One
September 2025
Department of Community Ecology, Helmholtz Centre for Environmental Research - UFZ, Halle (Saale), Germany.
Pollination is essential for maintaining biodiversity and ensuring food security, and in Europe it is primarily mediated by four insect orders (Coleoptera, Diptera, Hymenoptera, Lepidoptera). However, traditional monitoring methods are costly and time consuming. Although recent automation efforts have focused on butterflies and bees, flies, a diverse and ecologically important group of pollinators, have received comparatively little attention, likely due to the challenges posed by their subtle morphological differences.
View Article and Find Full Text PDFFront Psychol
August 2025
Department of Work and Social Psychology, Fontys University of Applied Sciences, Eindhoven, Netherlands.
Background: Psychosocial disability (PSD) refers to the limitations experienced by persons with mental illness (PWMI) in interacting with their social environment. Persons with psychosocial disabilities (PPSD) face significant barriers to accessing sexual and reproductive health (SRH) services due to structural and institutional barriers. Despite commitments under the Convention on the Rights of Persons with Disabilities (CRPD), there are persistent rights violations and denial of PPSD to exercise their rights and access services related to SRH care.
View Article and Find Full Text PDFHum Reprod
September 2025
Institut National de la Santé et de la Recherche Médicale, Ecole des Hautes Etudes en Santé Publique, Institut de recherche en santé, environnement et travail, Université de Rennes-UMR_S1085, Rennes, France.
Study Question: What is the direct effect of mumps virus (MuV) replication within the human testis on the tissue innate immune responses and testicular cell functions?
Summary Answer: MuV induces an early pro-inflammatory response in the human testis ex vivo and infects both Leydig cells and Sertoli cells, which drastically alters testosterone and inhibin B production.
What Is Known Already: Despite widespread vaccination efforts, orchitis remains a significant complication of MuV infection, especially in young men, which potentially results in infertility in up to 87% of patients with bilateral orchitis. Our understanding of MuV pathogenesis in the human testis has been limited by the lack of relevant animal models, impairing the development of effective treatments.
One in five adolescents (10-19) live in sub-Saharan Africa. Despite the availability of policies targeted at this age group, policy formulation, implementation, and gains in adolescent health continue to be underwhelming. Actors or stakeholders are architects of policy, bringing their ideological values, interests, power, and positions to policy formulation and implementation and thus influencing the policy process.
View Article and Find Full Text PDFDev Cell
September 2025
Department of Pharmacology, University of Cambridge, Cambridge, UK; Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK. Electronic address:
Single-cell studies on breast tissue have contributed to a change in our understanding of breast epithelial diversity that has, in turn, precipitated a lack of consensus on breast cell types. The confusion surrounding this issue highlights a possible challenge for advancing breast atlas efforts. In this perspective, we present our consensus on the identities, properties, and naming conventions for breast epithelial cell types and propose goals for future atlas endeavors.
View Article and Find Full Text PDF