Search results for " longevity"
showing 10 items of 86 documents
Sex-allocation conflict and sexual selection throughout the lifespan of eusocial colonies.
2018
AbstractModels of sex allocation conflict are central to evolutionary biology but have mostly assumed static decisions, where resource allocation strategies are constant over colony lifespan. Here, we develop a model to study how the evolution of dynamic resource allocation strategies is affected by the queen-worker conflict in annual eusocial insects. We demonstrate that the time of dispersal of sexuals affects the sex allocation ratio through sexual selection on males. Furthermore, our model provides three predictions that depart from established results of classic static allocation models. First, we find that the queen wins the sex allocation conflict, while the workers determine the max…
Biology and Behaviour of Cirrospilus diallus and Cirrospilus pictus, Parasitoids of Phyllocnistis citrella
2005
International audience; Studies were carried out on some biological and behavioral aspects of Cirrospilus diallus Walker and Cirrospilus pictus (Nees) (Hymenoptera: Eulophidae) in relation to their host, the citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae). Adults of both species fed with sugar lived on average 4.45 +/- 0.19 days, whereas adults provided with honey survived on average 40.62 +/- 1.97 days. Rates of host mortality due to parasitoid stings without oviposition were as high as 31.25 and 37.73% for C. pictus and C. diallus, respectively. Both species showed arrhenotokous parthenogenesis. Sex ratios of parasitoids emerging from the 2nd and 3rd …
Telomere Length, SIRT1, and Insulin in Male Master Athletes: The Path to Healthy Longevity?
2021
AbstractLower SIRT1 and insulin resistance are associated with accelerated telomere shortening. This study investigated whether the lifestyle of master athletes can attenuate these age-related changes and thereby slow aging. We compared insulin, SIRT1, and telomere length in highly trained male master athletes (n=52; aged 49.9±7.2 yrs) and age-matched non-athletes (n=19; aged 47.3±8.9 yrs). This is a cross-sectional study, in which all data were collected in one visit. Overnight fasted SIRT1 and insulin levels in whole blood were assessed using commercial kits. Relative telomere length was determined in leukocytes through qPCR analyses. Master athletes had higher SIRT1, lower insulin, and l…
Longevity: Lesson from model organisms
2019
Research on longevity and healthy aging promises to increase our lifespan and decrease the burden of degenerative diseases with important social and economic effects. Many aging theories have been proposed, and important aging pathways have been discovered. Model organisms have had a crucial role in this process because of their short lifespan, cheap maintenance, and manipulation possibilities. Yeasts, worms, fruit flies, or mammalian models such as mice, monkeys, and recently, dogs, have helped shed light on aging processes. Genes and molecular mechanisms that were found to be critical in simple eukaryotic cells and species have been confirmed in humans mainly by the functional analysis of…
Oxidative stress and exceptional human longevity: Systematic review.
2020
Oxidative stress (OS) has been previously linked to the aging process, as have some diseases and geriatric syndromes as frailty and sarcopenia. The aim of the present study was to perform a systematic review on oxidative stress activity and extreme longevity in humans.We conducted a systematic literature review following the PRISMA guidelines. Observational studies assessing OS-biomarkers and/or antioxidants in long-lived individuals (97 years old or over) comparing them to those of one or more age groups, (at least one of which from comprising elderly subjects) were considered for inclusion. A narrative synthesis was planned. Quality of selected studies was assessed using the Newcastle-Ott…
Nutrigerontology: A key for achieving successful ageing and longevity
2016
During the last two centuries the average lifespan has increased at a rate of approximately 3 months/year in both sexes, hence oldest old people are becoming the population with the fastest growth in Western World. Although the average life expectancy is increasing dramatically, the healthy lifespan is not going at the same pace. This underscores the importance of studies on the prevention of age-related diseases, in order to satisfactorily decrease the medical, economic and social problems associated to advancing age, related to an increased number of individuals not autonomous and affected by invalidating pathologies. In particular, data from experimental studies in model organisms have c…
A Stress-Resistant Lipidomic Signature Confers Extreme Longevity to Humans.
2015
Plasma lipidomic profile is species specific and an optimized feature associated with animal longevity. In the present work, the use of mass spectrometry technologies allowed us to determine the plasma lipidomic profile and the fatty acid pattern of healthy humans with exceptional longevity. Here, we show that it is possible to define a lipidomic signature only using 20 lipid species to discriminate adult, aged and centenarian subjects obtaining an almost perfect accuracy (90%-100%). Furthermore, we propose specific lipid species belonging to ceramides, widely involved in cell-stress response, as biomarkers of extreme human longevity. In addition, we also show that extreme longevity present…
Gut microbiota and aging-A focus on centenarians.
2020
Gut microbiota (GM) is a dynamic organ throughout the lifespan. Aging is a complex process that comprises a plethora of mechanisms such as senescence, immunosenescence and inflammaging, representing important pathways of age-related diseases. GM structure could both influence and be influenced by aging occurring changes within the host. A unique category of long living individuals exists, namely centenarians that have the outstanding capacity to adapt to various challenges. Longevity seems to be associated with certain GM which, among other factors, might render individuals more resistant to age-related diseases and subsequently to long living. Diet, prebiotics, probiotics and synbiotics ma…
Association of immunoglobulin GM allotypes with longevity in long-living individuals from Southern Italy
2018
Abstract Background The aim of this study was to analyse the role of GM allotypes, i.e. the hereditary antigenic determinants expressed on immunoglobulin polypeptide chains, in the attainment of longevity. The role played by immunoglobulin allotypes in the control of immune responses is well known as well as the role of an efficient immune response in longevity achievement. So, it is conceivable that particular GM allotypes may contribute to the generation of an efficient immune response that supports successful ageing, hence longevity. Methods In order to show if GM allotypes play a role in the achievement of longevity, we typed the DNA of 95 Long-living individuals (LLIs) and 96 young con…
Taste receptors, innate immunity and longevity: the case of TAS2R16 gene
2019
Abstract Background Innate immunity utilizes components of sensory signal transduction such as bitter and sweet taste receptors. In fact, empirical evidence has shown bitter and sweet taste receptors to be an integral component of antimicrobial immune response in upper respiratory tract infections. Since an efficient immune response plays a key role in the attainment of longevity, it is not surprising that the rs978739 polymorphism of the bitter taste receptor TAS2R16 gene has been shown to be associated with longevity in a population of 941 individuals ranging in age from 20 to 106 years from Calabria (Italy). There are many possible candidate genes for human longevity, however of the many…