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We focus on obtaining Block–Savits type characterizations for different ageing classes as well as some important renewal classes by using the Laplace transform. We also introduce a novel approach, based on the equilibrium distribution, to handle situations where the techniques of Block and Savits (1980) either fail or involve tedious calculations. Our approach in conjunction with the theory of total positivity yields Vinogradov’s (1973) result for the increasing failure rate class when the distribution function is continuous. We also present simple but elegant proofs for Block and Savits’ results for the decreasing mean residual life, new better than used in expectation, and harmonic new better than used in expectation classes as applications of our approach. We address several other related issues that are germane to our problem. Finally, we conclude with a short discussion on the issue of convolutions.
This study explores retirement processes. State pension age is gradually increasing in many countries, including the Netherlands. The traditional retirement pathway where individuals have a cliff-edge transition from a full-time job with a permanent contract to full retirement appears to be applicable to an ever-smaller group of employees. Hence, more recently, ‘retirement’ is viewed not as a single transition out of the labour force but rather as a process determined by several intertwined contractual and financial aspects of the labour market. Research has hardly ever combined labour market aspects such as employment security (type of employment contract), financial security (income), work-time arrangements (hours worked) and social protection (receipt of pension and other benefits). This study aims to address this knowledge gap using register data from Statistics Netherlands and treating the status of individuals before and immediately after retirement as a latent variable (late employment quality [LEQ]) measured by several indicators: contract type, contractual working hours, self-employment, income and different types of benefits including pension. We follow older workers between 2008 and 2019 for at least four years before and two years after state pension age and derive trajectories of LEQ using a mixture hidden Markov model. The results indicate several avenues: ‘retirement with medium/high pension’, ‘from non-employment to low pension’, ‘eventually partial retirement’, ‘steps from employment to low pension’ and ‘alternating work and non-work’. It seems to be the case that most older workers in the Netherlands cannot simply be categorised as having either cliff-edge transitions or atypical retirement.
Japan is shrinking. Current projections indicate a population decrease of around one quarter by mid-century. Depopulation is potentially good news, providing opportunities for reconfiguring living conditions and alleviating human-environmental pressures. Nevertheless, ageing and depopulation have outcomes that require adjustment. One of these is spatial inequalities, which have been accelerating since the 1990s. Japan is the Asia-Pacific’s pioneer ageing and shrinking society. In East Asia both China and South Korea are ageing and expected to begin shrinking soon. Even high immigration Anglophone countries such as New Zealand are experiencing post-growth demographic processes at subnational level. Japan’s significance is in how adaptive responses there inform prospects for others as they experience their own post-growth pathways. This article presents case studies of Sado Island in Japan and New Zealand’s South Island in a comparative qualitative analysis of rural agency under population decline. Overall, I contend there is potential for benefitting from demographic shrinkage - what I term a ‘depopulation dividend’ - and for rural regions in the Asia-Pacific to progress towards a sustainable post-growth economy and society.
The rising incidence of neurodegenerative diseases in an ageing global population has shifted research focus towards modifiable risk factors, such as diet. Despite potential links between dietary patterns and brain health, inconsistencies in neuroimaging outcomes underscore a gap in understanding how diet impacts brain ageing. This study explores the relationship between three dietary patterns – Mediterranean, Dietary Approaches to Stop Hypertension (DASH) and Mediterranean-DASH Intervention for Neurodegenerative Delay – and cognitive outcomes as well as brain connectivity. The study aimed to assess the association of these diets with brain structure and cognitive function, involving a middle-aged healthy group and an older cohort with subjective cognitive decline. The study included cognitive assessments and diffusion-weighted MRI data to analyse white matter microstructural integrity. Participants comprised fifty-five older individuals with subjective cognitive decline (54·5 % female, mean age = 64) and fifty-two healthy middle-aged individuals (48·1 % female, mean age = 53). Age inversely correlated with certain cognitive functions and global brain metrics, across both cohorts. Adherence to the Mediterranean, DASH and Mediterranean-DASH Intervention for Neurodegenerative Delay diets showed no significant cognitive or global brain metric improvements after adjusting for covariates (age, education, BMI). Network-based statistics analysis revealed differences in brain subnetworks based on DASH diet adherence levels in the subjective cognitive decline cohort. In the healthy cohort, lower white matter connectivity was associated with reduced adherence to Mediterranean-DASH Intervention for Neurodegenerative Delay and DASH diets. Ultimately, the study found no strong evidence connecting dietary patterns to cognitive or brain connectivity outcomes. Future research should focus on longitudinal studies and refine dietary assessments.
Accelerated ageing indexed by telomere attrition is suggested in schizophrenia spectrum- (SCZ) and bipolar disorders (BD). While inflammation may promote telomere shortening, few studies have investigated the association between telomere length (TL) and markers of immune activation and inflammation in severe mental disorders.
Methods:
Leucocyte TL defined as telomere template/amount of single-copy gene template (T/S ratio), was determined in participants with SCZ (N = 301) or BD (N = 211) and a healthy control group (HC, N = 378). TL was analysed with linear regressions for associations with levels of 12 immune markers linked to SCZ or BD. Adjustments were made for a broad range of potential confounding variables. TL was measured by quantitative polymerase chain reaction (qPCR) and the immune markers were measured by enzyme immunoassays.
Results:
A positive association between levels of soluble tumour necrosis factor receptor 1A (sTNF-R1) and TL in SCZ (β = 0.191, p = 0.012) was observed. Plasma levels of the other immune markers were not significantly associated with TL in the BD, SCZ or HC groups.
Conclusion:
There was limited evidence of association between immune markers and TL in SCZ and BD. The results provide little support for involvement of immune dysregulation, as reflected by current systemic markers, in telomere attrition-related accelerated ageing in severe mental disorders.
Discourses and how they construct policy ‘problems’ delimit ‘solutions’, including the scale, shape and structure of services. This article discusses how the adult social care sector in England is presented as a policy problem, with the greater use of technology the associated ‘common-sense’ solution – both to the ‘crisis of care’ in a society with an ageing population and as a means to stimulate the national economy. It draws upon critical discourse analysis to examine English policy documents and other government texts published between 2020 and 2022. In doing so, it de-objectivises and de-universalises semiotic claims around care and technology and explores omitted alternatives. In discourse, ageing and care are framed as both problems to be solved and opportunities for entrepreneurship. Technologies are bound together with efficiency, with limited exploration of how use of the former necessarily entails the latter. Technology is, in addition, presented as agentic, inevitable and unassailable, closing off debates as to whether other, less seemingly ‘innovative’ options for reform and change could entail more favourable outcomes. Discourse thus limits the role of the state to stimulating the environment required for technological advancement.
This chapter examines ageing and chronic illness among LGBTIQ people. First, this chapter discusses the relative visibility/invisibility of LGBTIQ ageing, alongside introducing and critiquing the prevalent neoliberal concept of successful ageing. Following this, the chapter engages with cohort effects (e.g., generational differences) in LGBTIQ populations and their impacts on ageing experiences. The chapter also reviews research on chronic illness in LGBTIQ populations, with specific reference to dementia. LGBTIQ people’s experiences of dying and bereavement are also discussed, with specific reference to AIDS-related bereavement (in the 1980s) and ‘bereavement overload’ and partner loss, including the possibility of ‘disenfranchised grief’.
Seed genebanks must maintain collections of healthy seeds and regenerate accessions before seed viability declines. Seed shelf life is often characterized at the species level; however, large, unexplained variation among genetic lines within a species can and does occur. This variation contributes to unreliable predictions of seed quality decline with storage time. To assess variation of seed longevity and aid in timing regeneration, ten varieties of pea (Pisum sativum L.), chickpea (Cicer arietinum L.) and lentil (Lens culinaris Medikus subsp. culinaris) from the Australian Grains Genebank were stored at moderate temperature (20°C) and moisture (7–11% water, relative humidity [RH] ~30%) and deterioration was assessed by yearly germination tests for 20 years. Decline in germination was fit to a sigmoidal model and the time corresponding to 50% germination (P50) was used to express seed longevity for each genetic line. The feasibility of using RNA fragmentation to assess changed seed health was measured using RNA integrity number (RIN) from RNA extracted from seeds that were stored for 13 and 20 years. Seed lots of legume grains that maintained high survival throughout the 20 years (i.e. they aged slower than other lines) had higher RIN than samples that degraded faster. RIN was lower in embryonic axes compared with cotyledons in the more deteriorated samples, perhaps indicating that axes exhibit symptoms of ageing sooner than cotyledons. Overall, RIN appears to be associated with longevity indicators of germination for these legumes and indicating that RIN decline can be used to assess ageing rate, which is needed to optimize viability monitoring.
We investigated associations between ‘healthy dietary pattern’ scores, at ages 36, 43, 53 and 60–64 years, and body composition at age 60–64 years among participants from the MRC National Survey of Health and Development (NSHD). Principal component analyses of dietary data (food diaries) at age 60–64 years were used to calculate diet scores (healthy dietary pattern scores) at each age. Higher scores indicated healthier diets (higher consumption of fruit, vegetables and wholegrain bread). Linear regression was used to investigate associations between diet scores at each age and height-adjusted dual-energy X-ray absorptiometry-measured fat and lean mass measures at age 60–64 years. Analyses, adjusting for sex and other potential confounders (age, smoking history, physical activity and occupational class), were implemented among 692 men and women. At age 43, 53 and 60–64 years, higher diet scores were associated with lower fat mass index (FMI) and android:gynoid fat mass ratio; for example, in fully adjusted analyses, a standard deviation (sd) increase in diet score at age 60–64 years was associated with an SD difference in mean FMI of −0·18 (95 % CI: −0·25, −0·10). In conditional analyses, higher diet scores at ages 43, 53 and 60–64 years (than expected from diet scores at younger ages) were associated with lower FMI and android:gynoid fat mass ratio in fully adjusted analyses. Diet scores at age 36 years had weaker associations with the outcomes considered. No associations regarding appendicular lean mass index were robust after full adjustment. This suggests that improvements in diet through adulthood are linked to beneficial effects on adiposity in older age.
Civic engagement is increasingly relevant for healthy and active ageing and addressing social exclusion among older people. Current research focuses primarily on formal volunteering, overlooking other ways older people contribute to their families and communities. This study addresses these gaps by recognising civic engagement as multi-dimensional – including associational engagement, informal care-giving, formal volunteering, digital engagement and formal/informal political engagement – and exploring activity combinations among older individuals. Using data from the 2016 European Quality of Life Survey (33 European countries), it examines the civic engagement of 9,031 individuals aged 65+. Descriptive analysis maps their multi-dimensional civic engagement, while latent class analysis identifies distinct engagement profiles and explores which activities are combined. It also investigates the socio-structural and social capital resources associated with each profile. Findings reveal that 32 per cent of older individuals are not engaged in civic activities. Among the civically engaged, five profiles emerge, illustrating varied engagement across multiple activities. Many older people (35.8 per cent) combine several civic activities, albeit in different combinations. Informal care-giving can be found in all profiles; and for a large part of the population, it is their only civic activity, while another profile displays older Europeans engaged in several activities simultaneously. Higher levels of socio-structural resources are associated with greater diversity in civic engagement in later life. Interventions and policies therefore must consider the diverse circumstances and preferences of older people and valorise and include all forms of multi-dimensional civic engagement, including informal care-giving, in policy making.
Ageing is an inevitable biological process accompanied by various physiological changes, and researchers have long sought interventions to promote healthy ageing. This article explores the effects of four natural compounds – omega-3 fatty acids, coenzyme Q10, gingerol and curcumin – on the ageing process. We delve into the scientific literature to examine the potential benefits and mechanisms behind these substances in mitigating age-related conditions. Omega-3’s anti-inflammatory properties, coenzyme Q10’s cellular energy support, gingerol’s antioxidant effects and curcumin’s anti-ageing properties are discussed. By shedding light on the impact of these compounds, this review aims to contribute to a better understanding of how natural substances may play a role in promoting longevity and enhancing the quality of life during the ageing journey.
Humans age. Domestic animals age. But is that true for all species? Is ageing a necessary consequence of evolution? Yes - for a long time, this was the undisputed answer of classic evolutionary theories of ageing. This chapter tells the story about how this paradigm of inevitable ageing has been challenged and refuted. Thanks to decades of monitoring individual survival and death across species in captivity and in the wild, researchers have been able to study patterns of the ageing process’s ultimate consequence - age trajectories of mortality. Though ageing is a complex, multiscale process, increasing mortality with age is, overall, indicative of a loss of functioning with age - senescence. Constant or declining mortality with adult age is indicative of maintained or improved functioning - negligible or negative senescence. Evidence supports that ageing patterns across the tree of life are diverse. Whether current evidence for negligible or negative senescence truly reflects an absence of senescence or just an absence of evidence is an open challenge. Similarly, why certain types of species show certain types of senescence patterns is an open research question. Future evolutionary theories of ageing will have to include trade-offs justified by structural arguments - genetic structure, physiological structure, social structure, ecological structure - to explain types of ageing patterns across types of species.
Our study aims to contribute to the existing body of research on age-related changes in decision-making by investigating susceptibility to the attraction effect across adulthood. Prior studies have produced inconsistent conclusions regarding the decision-making abilities of older individuals, with some portraying them as easily manipulated and risk-averse, while others suggest the opposite. To address this issue, we conducted two experiments using a novel paradigm of the roulette task: (1) in an online environment with 357 participants and (2) in a laboratory setting with 173 participants. The results were consistent and demonstrated the robustness of the attraction effect. However, no age differences in susceptibility to the attraction effect as a common decision bias were found. As predicted, older adults were more likely to commit simple decision-making mistakes, especially in the preliminary trials, which could have serious financial or societal consequences. Additionally, older adults exhibited more risk-seeking behaviours. Furthermore, we observed that the dynamics of decision competence (as indicated by a decrease in the selection of erroneous decoy options and an increase in decision fluency) were similar for both younger and older adults, suggesting preservation of the ability to optimise decision-making while becoming familiar with new tasks. These findings provide insight into the cognitive functioning of older adults and indicate that decision-making abilities in late adulthood may be more complex than commonly assumed.
Negative relationships between the parental age and offspring life history traits have been widely observed across diverse animal taxa. However, there is a lack of studies examining the influence of parental age on offspring performance using mites, particularly phytoseiid predators as subjects. This study explored the influence of maternal age on offspring life history traits in Amblyseius herbicolus (Chant) (Acari: Mesostigmata), a phytoseiid predatory mite reproducing through thelytokous parthenogenesis. We hypothesised that increased maternal age negatively impacts offspring traits, including developmental duration, body size, fecundity and lifespan. Amblyseius herbicolus was reared under controlled laboratory conditions, and the life history traits of offspring from mothers of varying ages were analysed using linear mixed-effect models. Our results showed that the increase in maternal age significantly reduced individual egg volume, but did not significantly affect offspring developmental duration, body size, fecundity or lifespan. These findings indicate that while older A. herbicolus females produced smaller eggs, the subsequent performance (i.e. body size, fecundity and lifespan) of offspring remained largely unaffected, suggesting possible compensatory mechanisms in the offspring or alternative maternal provisioning strategies. The results of this study offer useful insights into the reproductive strategies of phytoseiid predators and asexually reproducing species, enhancing our understanding of how maternal age affects offspring fitness. Further studies can examine how offspring of A. herbicolus from mothers of different ages perform under adverse environmental conditions.
Skeletal muscle is of great importance for human activity and quality of life, as its loss contributes greatly to immobilisation, especially for aged individuals. An increased dietary intake of antioxidant vitamins may be beneficial for muscle loss because of ageing. However, the quantitative relationship between total antioxidant capacity (TAC) of antioxidant vitamins and muscle mass is undetermined. Totally, 4009 participants from the National Health and Nutrition Examination Survey (NHANES) were included. Multivariate linear regression analysis was performed with demographic, lifestyle and dietary intake adjustment factors. The dose saturation effect was also determined by a saturation effect analysis. Subgroup analysis was performed for age and sex. In the fully adjusted model, per unit increase of dietary TAC was associated with an increase of 0·018 g/kg appendicular lean mass (95 % CI 0·007, 0·029), 0·014 g/kg trunk lean mass (95 % CI 0·004, 0·024) and 0·035 g/kg total lean mass (95 % CI 0·014, 0·055). TAC was associated with a decrease of 0·004 kg/kg total percent fat (95 % CI −0·006, −0·002), 0·005 kg/kg trunk percent fat (95 % CI −0·007, −0·002) and 0·003 kg/m2 BMI (95 % CI −0·006, −0·001) at the same time. Subgroup analysis indicated that women and adults < 50 years may experience the most significant association between TAC and skeletal muscle mass. We revealed a positive correlation between TAC and lean body mass and a negative association between TAC and body fat and BMI. Saturation values were found among people aged 40–59 years. Age and sex mediate these associations.
Musculoskeletal disorders and age-related musculoskeletal decline are major contributors to the burden of ill health seen in older subjects. Despite this increased burden, these chronic disorders of old age receive a relatively small proportion of national research funds. Much has been learned about fundamental processes involved in ageing from basic science research and this is leading to identification of key pathways that mediate ageing which may help the search for interventions to reduce age-related musculoskeletal decline. This short review will focus on the role of reactive oxygen species in age-related skeletal muscle decline and on the implications of this work for potential nutritional interventions in sarcopenia. The key physiological role of reactive oxygen species is now known to be in mediating redox signalling in muscle and other tissues and ageing leads to disruption of such pathways. In muscle, this is reflected in an age-related attenuation of specific adaptations and responses to contractile activity that impacts the ability of skeletal muscle from ageing individuals to respond to exercise. These pathways provides potential targets for identification of logical interventions that may help maintain muscle mass and function during ageing.
The relationship between nutrition and ageing is complex. The metabolism and synthesis of micronutrients within the gut microbiome can influence human health but is challenging to study. Furthermore, studying ageing in humans is time-consuming and difficult to control for environmental factors. Studies in model organisms can guide research efforts in this area. This review describes how the nematode Caenorhabditis elegans can be used to study how bacteria and diet influence ageing and inform follow-on studies in humans. It is known that certain bacteria accelerate ageing in C. elegans. This age-accelerating effect is prevented by inhibiting folate synthesis within the bacteria, and we propose that in the human microbiome, certain bacteria also accelerate ageing in a way that can be modulated by interfering with bacterial folate synthesis. Bacterial-derived folates do not promote ageing themselves; rather, ageing is accelerated by bacteria in some way, either through secondary metabolites or other bacterial activity, which is dependent on bacterial folate synthesis. In humans, it may be possible to inhibit bacterial folate synthesis in the human gut while maintaining healthy folate status in the body via food and supplementation. The supplement form of folic acid has a common breakdown product that can be used by bacteria to increase folate synthesis. Thus, supplementation with folic acid may not be good for health in certain circumstances such as in older people or those with an excess of proteobacteria in their microbiome. For these groups, alternative supplement strategies may be a safer way to ensure adequate folate levels.
Loss of skeletal muscle strength and mass (sarcopenia) is common in older adults and associated with an increased risk of disability, frailty and premature death. Finding cost-effective prevention and treatment strategies for sarcopenia for the growing ageing population is therefore of great public health interest. Although nutrition is considered an important factor in the aetiology of sarcopenia, its potential for sarcopenia prevention and/or treatment is still being evaluated. Nutrition research for sarcopenia utilises three main approaches to understand muscle-nutrition relationships, evaluating: single nutrients, whole foods and whole diet effects – both alone or combined with exercise. Applying these approaches, we summarise recent evidence from qualitative and quantitative syntheses of findings from observational and intervention studies of healthy older adults, and those with sarcopenia. We consider protein supplements, whole foods (fruits and vegetables) and the Mediterranean diet as exemplars. There is some evidence of beneficial effects of protein supplementation ≥ 0·8 g/kg body weight/d on muscle mass when combined with exercise training in intervention studies of healthy and sarcopenic older adults. In contrast, evidence for effects on muscle function (strength and physical performance) is inconclusive. There is reasonably consistent epidemiological evidence suggesting benefits of higher fruits and vegetables consumption for better physical performance. Similarly, higher adherence to the Mediterranean diet is associated with beneficial effects on muscle function in observational studies. However, intervention studies are lacking. This review discusses how current evidence may inform the development of preventive and intervention strategies for optimal muscle ageing and nutritional public policy aimed at combatting sarcopenia.
Deficiency of vitamin B12 (B12 or cobalamin), an essential water-soluble vitamin, leads to neurological damage, which can be irreversible and anaemia, and is sometimes associated with chronic disorders such as osteoporosis and cardiovascular diseases. Clinical tests to detect B12 deficiency lack specificity and sensitivity. Delays in detecting B12 deficiency pose a major threat because the progressive decline in organ functions may go unnoticed until the damage is advanced or irreversible. Here, using targeted unbiased metabolomic profiling in the sera of subjects with low B12 levels v control individuals, we set out to identify biomarker(s) of B12 insufficiency. Metabolomic profiling identified seventy-seven metabolites, and partial least squares discriminant analysis and hierarchical clustering analysis showed a differential abundance of taurine, xanthine, hypoxanthine, chenodeoxycholic acid, neopterin and glycocholic acid in subjects with low B12 levels. Random forest multivariate analysis identified a taurine/chenodeoxycholic acid ratio, with an AUC score of 1, to be the best biomarker to predict low B12 levels. Mechanistic studies using a mouse model of B12 deficiency showed that B12 deficiency reshaped the transcriptomic and metabolomic landscape of the cell, identifying a downregulation of methionine, taurine, urea cycle and nucleotide metabolism and an upregulation of Krebs cycle. Thus, we propose taurine/chenodeoxycholic acid ratio in serum as a potential biomarker of low B12 levels in humans and elucidate using a mouse model of cellular metabolic pathways regulated by B12 deficiency.