Effect of age and refractive error on the melanopsin mediated Post-Illumination Pupil Response (PIPR)

Melanopsin containing intrinsically photosensitive Retinal Ganglion cells (ipRGCs) mediate the pupil light reflex (PLR) during light onset and at light offset (the post-illumination pupil response, PIPR). Recent evidence shows that the PLR and PIPR can provide non-invasive, objective markers of age-related retinal and optic nerve disease, however there is no consensus on the effects of healthy ageing or refractive error on the ipRGC mediated pupil function. Here we isolated melanopsin contributions to the pupil control pathway in 59 human participants with no ocular pathology across a range of ages and refractive errors. We show that there is no effect of age or refractive error on ipRGC inputs to the human pupil control pathway. The stability of the ipRGC mediated pupil response across the human lifespan provides a functional correlate of their robustness observed during ageing in rodent models.

Modelling growth rate of Penaeus monodon Fabricius in intensively managed ponds: effects of temperature, pond age and stocking density

Records of shrimp growth and water quality made during 12 crops from each of 48 ponds, over a period of 6.5 years, were provided by a Queensland, Australia, commercial shrimp farm, These data were analysed with a new growth model derived from the Gompertz model. The results indicate that water temperature, mortality and pond age significantly affect growth rates. After 180 days, shrimp reach 34 g at constant 30 degrees C, but only 15 g after the same amount of time at 20 degrees C. Mortality, through thinning the density of shrimp in the ponds, increased the growth rate, but the effect is small. With continual production, growth rates at first remained steady, then appeared to decrease for the sixth and seventh crop, after which they have increased steadily with each crop. It appears that conservative pond management, together with a gradual improvement in husbandry techniques, particularly feed management, brought about this change. This has encouraging implications for the long-term sustainability of the farming methods used. The growth model can be used to predict productivity, and hence, profitability, of new aquaculture locations or new production strategies.

Organisational age cultures: The interplay of chief executive officers age and attitudes toward younger and older employees

This article investigates the interactive effects of chief executive officer (CEO) age and CEO attitudes toward younger and older employees on organisational age cultures. Data was collected from 66 CEOs of small and medium-sized businesses and 274 employees. Results were consistent with expectations based on organisational culture and upper echelons theories. The relationship between CEO age and organisational age culture for younger employees was negative for CEOs with a less positive attitude toward younger employees and positive for those with a more positive attitude toward younger employees. The relationship between CEO age and organisational age culture for older employees was positive for CEOs with a more positive attitude toward older employees and non-significant for those with a less positive attitude toward older employees. The findings provide initial support for the existence of organisational age cultures, suggesting that these cultures can be predicted by the interplay of CEO age and age-related attitudes.

Older job seekers' job search intensity: The interplay of proactive personality, age and occupational future time perspective

Long-term unemployment of older people can have severe consequences for individuals, communities and ultimately economies, and is therefore a serious concern in countries with an ageing population. However, the interplay of chronological age and other individual difference characteristics in predicting older job seekers' job search is so far not well understood. This study investigated relationships among age, proactive personality, occupational future time perspective (FTP) and job search intensity of 182 job seekers between 43 and 77 years in Australia. Results were mostly consistent with expectations based on a combination of socio-emotional selectivity theory and the notion of compensatory psychological resources. Proactive personality was positively related to job search intensity and age was negatively related to job search intensity. Age moderated the relationship between proactive personality and job search intensity, such that the relationship was stronger at higher compared to lower ages. One dimension of occupational FTP (perceived remaining time left in the occupational context) mediated this moderating effect, but not the overall relationship between age and job search intensity. Implications for future research, including the interplay of occupational FTP and proactive personality, and some tentative practical implications are discussed.

Stepping into my shoes: Generativity as a mediator of the relationship between business owners' age and family succession

The authors investigated generativity – the concern in establishing and guiding the next generation – as a mediator of the relationship between family business owners' age and succession in family businesses. Data came from 155 family business owners in Germany from different industries between the ages of 26 and 83 years. Results showed that age was positively related to generativity, and that generativity, in turn, positively influenced an objective measure of family succession. Generativity fully mediated the positive relationship between age and family succession. The findings suggest that generativity is an important psycho-social construct for understanding ageing, careers and succession in family business settings.

Professor age and research assistant ratings of passive-avoidant and proactive leadership: The role of age-related work concerns and age stereotypes

Recent research has shown that, in general, older professors are rated to have more passive-avoidant leadership styles than younger professors by their research assistants. The current study investigated professors' age-related work concerns and research assistants' favorable age stereotypes as possible explanations for this finding. Data came from 128 university professors paired to one research assistant each. Results show that professors' age-related work concerns (decreased enthusiasm for research, growing humanism, development of exiting consciousness and increased follower empowerment) did not explain the relationships between professor age and research assistant ratings of passive-avoidant and proactive leadership. However, research assistants' favorable age stereotypes influenced the relationships between professor age and research assistant ratings of leadership, such that older professors were rated as more passive-avoidant and less proactive than younger professors by research assistants with less favorable age stereotypes, but not by research assistants with more favorable age stereotypes.

Focus on opportunities as a mediator of the relationship between business owners' age and venture growth

Combining upper echelons and lifespan theories, we investigated the mediating effect of focus on opportunities on the negative relationship between business owners' age and venture growth. We also expected that mental health moderates the negative relationship between business owners' age and focus on opportunities. Path analytic findings based on data from 84 business owners (mean age = 44, range 24-74) supported these hypotheses. Findings suggest that focus on opportunities is a psychological mechanism that links business owners' age with venture growth. Our findings also indicate that mental health helps maintain a high level of focus on opportunities with increasing age.

Age and leadership: The moderating role of legacy beliefs

Age and age-related motivations have been neglected in leadership research. This study examined the moderating influence of legacy beliefs on the relationships between age and transformational, transactional, and passive-avoidant leadership behaviors. Legacy beliefs involve individuals' convictions about whether they and their actions will be remembered, have an enduring influence, and leave something behind after death. It was expected that at higher ages, low legacy beliefs impede transformational and transactional leadership behaviors and boost passive-avoidant leadership behaviors. One hundred and six university professors, between 30 and 70 years old, provided ratings of their legacy beliefs; each professor's leadership behaviors were evaluated by one of his or her employees. Results confirmed the assumptions for overall transformational leadership and its charisma subdimension as well as for overall transactional leadership and its active management-by-exception subdimension but not for passive-avoidant leadership.

Physical activity in mid-age and older women: Lessons from the Australian longitudinal study on women’s health

The Australian Longitudinal Study on Women’s Health (ALSWH) commenced in Australia in 1996 when researchers recruited approximately 40,000 women in three birth cohorts: 1973–1978, 1946–1951, and 1921–1926. Since then participants have completed surveys on a wide range of health issues, at approximately three-year intervals. This overview describes changes in physical activity (PA) over time in the mid-age and older ALSWH cohorts, and summarizes the findings of studies published to date on the determinants of PA, and its associated health outcomes in Australian women. The ALSWH data show a significant increase in PA during mid-age, and a rapid decline in activity levels when women are in their 80s. The study has demonstrated the importance of life stages and key life events as determinants of activity, the additional benefits of vigorous activity for mid-age women, and the health benefits of ‘only walking’ for older women. ALSWH researchers have also drawn attention to the benefits of activity in terms of a wide range of physical and mental health outcomes, as well as overall vitality and well-being. The data indicate that maintaining a high level of PA throughout mid and older age will not only reduce the risk of premature death, but also significantly extend the number of years of healthy life.

Intergenerational Perceptions and Conflicts in Multi-Age and Multigenerational Work Environments

One underappreciated consequence of the aging population phenomenon is that we are now experiencing what is arguably the most age-diverse workforce in modern history (Hanks & Icenogle, 2001; Newton, 2006; Toossi, 2004). As our workforce continues to age, shifts in the age demographic composition (i.e., the age diversity) of organizations and their subunits will become more apparent (Roth, Wegge, & Schmidt, 2007). Several factors have influenced and will continue to drive this trend. For example, in Western countries, younger people entering the workforce are more educated than ever before (Hussar & Bailey, 2013; Ryan & Siebens, 2012; Stoops, 2003) and could feasibly rise to positions of power in organizations more quickly than others have in the past (e.g., promotion rates vary as a function of age) (Rosenbaum, 1979; see also Clemens, 2012 conceptualization of the "fast track effect"). Furthermore, older workers are increasingly delaying retirement beyond the normative retirement age (Baltes & Rudolph, 2012; Burtless, 2012; Flynn, 2010), and already retired individuals are seeking re-employment in bridge employment roles in higher numbers than before (e.g., Adams & Rau, 2004; Kim & Feldman, 2000; Weckerle & Shultz, 1999).

Physical activity and health in mid age and older Australian women

The US Surgeon General's report was a landmark publication in the field of physical activity and health, but was constrained by a lack of evidence relating to women. This report examines the links between physical activity and health in mid-age and older women. It includes four parts (i)recent evidence relating physical activity to the national public health priorities and reproductive health (ii)consideration of the amount of physical activity required to obtain health benefits (iii)new data from the Australian Longitudinal Study on Women's Health on activity patterns, including relationships between changes in physical activity and life events, sociodemographic characteristics and health behaviours in mid-age and older Australian women (iv)new data from the Australian Longitudinal Study on Women's Health on the relationships between physical activity and menopausal symptoms, stiff or painful joints and arthritis, anxiety and depression, memory problems, falls and fractures, general physical and psychological well-being, and healthcare costs in mid-age and older Australian women

How small business managers’ age and focus on opportunities affect business growth: A mediated moderation growth model

Research on business growth has been criticized for methodological weaknesses. We present a mediated moderation growth model as a new methodological approach. We hypothesized that small business managers' age negatively affects business growth through focus on opportunities. We sampled 201 small business managers and obtained firm performance data over 5 years, resulting in 836 observations. Growth modeling showed systematic differences in firm performance trajectories. These differences could be explained by modeling focus on opportunities as a mediator of the relationship between small business managers' age and business growth. The study illustrates how mediation models can be tested using growth modeling.

Advanced paternal age is associated with impaired neurocognitive outcomes during infancy and childhood

Background Advanced paternal age (APA) is associated with an increased risk of neurodevelopmental disorders such as autism and schizophrenia, as well as with dyslexia and reduced intelligence. The aim of this study was to examine the relationship between paternal age and performance on neurocognitive measures during infancy and childhood. Methods and Findings A sample of singleton children (n = 33,437) was drawn from the US Collaborative Perinatal Project. The outcome measures were assessed at 8 mo, 4 y, and 7 y (Bayley scales, Stanford Binet Intelligence Scale, Graham-Ernhart Block Sort Test, Wechsler Intelligence Scale for Children, Wide Range Achievement Test). The main analyses examined the relationship between neurocognitive measures and paternal or maternal age when adjusted for potential confounding factors. Advanced paternal age showed significant associations with poorer scores on all of the neurocognitive measures apart from the Bayley Motor score. The findings were broadly consistent in direction and effect size at all three ages. In contrast, advanced maternal age was generally associated with better scores on these same measures. Conclusions The offspring of older fathers show subtle impairments on tests of neurocognitive ability during infancy and childhood. In light of secular trends related to delayed fatherhood, the clinical implications and the mechanisms underlying these findings warrant closer scrutiny.

Serum polybrominated diphenyl ethers (PBDE) in pooled serum are higher in children (2-5 years of age) than in infants and adults

Background: Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in many products and have been detected in human samples worldwide. Limited data show that concentrations are elevated in young children. Objectives: We investigated the association between PBDEs and age with an emphasis on young children from Australia in 2006–2007. Methods: We collected human blood serum samples (n = 2,420), which we stratified by age and sex and pooled for analysis of PBDEs. Results: The sum of BDE-47, -99, -100, and -153 concentrations (Σ4PBDE) increased from 0–0.5 years (mean ± SD, 14 ± 3.4 ng/g lipid) to peak at 2.6–3 years (51 ± 36 ng/g lipid; p < 0.001) and then decreased until 31–45 years (9.9 ± 1.6 ng/g lipid). We observed no further significant decrease among ages 31–45, 45–60 (p = 0.964), or > 60 years (p = 0.894). The mean Σ4PBDE concentration in cord blood (24 ± 14 ng/g lipid) did not differ significantly from that in adult serum at ages 15–30 (p = 0.198) or 31–45 years (p = 0.140). We found no temporal trend when we compared the present results with Australian PBDE data from 2002–2005. PBDE concentrations were higher in males than in females; however, this difference reached statistical significance only for BDE-153 (p = 0.05). Conclusions: The observed peak concentration at 2.6–3 years of age is later than the period when breast-feeding is typically ceased. This suggests that in addition to the exposure via human milk, young children have higher exposure to these chemicals and/or a lower capacity to eliminate them. Key words: Australia, children, cord blood, human blood serum, PBDEs, polybrominated diphenyl ethers. Environ Health Perspect 117:1461–1465 (2009). doi:10.1289/ehp.0900596

Is the association between temperature and mortality modified by age, gender and socio-economic status?

Background: A number of studies have examined the relationship between high ambient temperature and mortality. Recently, concern has arisen about whether this relationship is modified by socio-demographic factors. However, data for this type of study is relatively scarce in subtropical/tropical regions where people are well accustomed to warm temperatures. Objective: To investigate whether the relationship between daily mean temperature and daily all-cause mortality is modified by age, gender and socio-economic status (SES) in Brisbane, Australia. Methods: We obtained daily mean temperature and all-cause mortality data for Brisbane, Australia during 1996–2004. A generalised additive model was fitted to assess the percentage increase in all deaths with every one degree increment above the threshold temperature. Different age, gender and SES groups were included in the model as categorical variables and their modification effects were estimated separately. Results: A total of 53,316 non-external deaths were included during the study period. There was a clear increasing trend in the harmful effect of high temperature on mortality with age. The effect estimate among women was more than 20 times that among men. We did not find an SES effect on the percent increase associated with temperature. Conclusions: The effects of high temperature on all deaths were modified by age and gender but not by SES in Brisbane, Australia.