Age-specific fertility trajectories are fundamental to understanding population structure and the evolutionary ecology of diverse life histories. However, characterizing reproductive ageing has been difficult with cross-sectional data, where senescence especially late in life can be confounded by selective disappearance. Addressing such challenge requires longitudinal data tracking the reproductive life span of known individuals, but such data are rare, especially for very long-lived species such as primates. We analyse the entire life span trajectory of annual fertility, from reproductive maturity to death, for 673 free-ranging female rhesus macaques, Macaca mulatta, on Cayo Santiago, Puerto Rico. Using generalized linear mixed-effects models (GLMMs), we first tested if time to death explains the ageing pattern independently of and additionally to chronological age, and if so, whether there is interaction between them. While GLMM captures the patterns in the data well, it is not a generative model. For example, given the GLMM and an individual's reproductive trajectory up to a given age, we cannot directly predict the probability of reproduction or death in the next year. For this reason, we further fitted a hidden Markov chain model (HMM) which allows just such a prediction, and additionally helps infer the process underlying the observed trajectory. We show that, after accounting for individual differences in fertility, reproductive ageing exhibits both age-dependent decline and also an abrupt terminal decline independently of age at death. We infer from the HMM that the underlying process of reproductive trajectory is where individuals cycle between reproductive bouts until they enter an irreversible frail condition that constrains fertility. The findings provide valuable insights into the longitudinal progression of reproductive trajectories in primates, by revealing both age-dependent and age-independent patterns and processes of ageing, and contribute to a growing body of literature on reproductive ageing and senescence across animal taxa.
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http://dx.doi.org/10.1111/1365-2656.13590 | DOI Listing |
J Med Internet Res
December 2024
Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
Background: Mobile health (mHealth) interventions have gained popularity in augmenting psychiatric care for adults with psychosis. Interest has grown in leveraging mHealth to empower individuals living with severe mental illness and extend continuity of care beyond the hospital to the community. However, reported outcomes have been mixed, likely attributed in part to the intervention and adopted outcomes, which affected between-study comparisons.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Huazhong University of Science and Technology - Main Campus: Huazhong University of Science and Technology, Materials Science and Engineering, CHINA.
Sulfurized polyacrylonitrile (SPAN) presents an opportunity to replace elemental sulfur as a "shuttle-free" cathode for secondary Li-S batteries, which can be an ideal choice for stationary energy storage due to its abundance, low cost, and sustainability. The electrolyte options for the state-of-the-art SPAN batteries have been limited to the flammable carbonate and ether ones, which raises safety concerns. Here, we explored the use of a non-flammable acetonitrile (AN) electrolyte for SPAN battery for the first time and identified the irreversible cleavage of C-S bonds of SPAN as the main reason for the failure of SPAN in AN electrolyte.
View Article and Find Full Text PDFBreastmilk is known to provide optimal nutrition for infant growth and development. A cross-sectional analysis of nationally representative US data from 2016 to 2021 revealed that >90% of lactating mothers reported using breast pumps to express milk. We conducted a survey of = 1,049 lactating or recently lactating individuals from a US nationally representative population to explore breastmilk storage practices among this group.
View Article and Find Full Text PDFJ Dent (Shiraz)
December 2024
Dept. of Restorative Dentistry, Dental Research Center, School of Dentistry, Birjand University of Medical Sciences, Birjand, Iran.
Statement Of The Problem: One of the most important factors in the clinical longevity of composite resin restorations is proper adhesion, which is achieved using phosphoric acid. Different phosphoric acid products might affect the micro-shear bond strength of composite resin to enamel.
Purpose: The present study aimed to evaluate the micro-shear bond strength of composite resin to sound enamel using six different brands of acid-etch agents.
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