Increased Bilateral Interactions in Middle-Aged Subjects

A hallmark of the age-related neural reorganization is that old versus young adults execute typical motor tasks by a more diffuse neural activation pattern including stronger ipsilateral activation during unilateral tasks. Whether such changes in neural activation are present already at middle age and affect bimanual interactions is unknown. We compared the amount of associated activity, i.e., muscle activity and force produced by the non-task hand and motor evoked potentials (MEPs) produced by magnetic brain stimulation between young (mean 24 years, n = 10) and middle-aged (mean 50 years, n = 10) subjects during brief unilateral (seven levels of % maximal voluntary contractions, MVCs) and bilateral contractions (4 × 7 levels of % MVC combinations), and during a 120-s-long MVC of sustained unilateral index finger abduction. During the force production, the excitability of the ipsilateral (iM1) or contralateral primary motor cortex (cM1) was assessed. The associated activity in the “resting” hand was ~2-fold higher in middle-aged (28% of MVC) versus young adults (11% of MVC) during brief unilateral MVCs. After controlling for the background muscle activity, MEPs in iM1 were similar in the two groups during brief unilateral contractions. Only at low (bilateral) forces, MEPs evoked in cM1 were 30% higher in the middle-aged versus young adults. At the start of the sustained contraction, the associated activity was higher in the middle-aged versus young subjects and increased progressively in both groups (30 versus 15% MVC at 120 s, respectively). MEPs were greater at the start of the sustained contraction in middle-aged subjects but increased further during the contraction only in young adults. Under these experimental conditions, the data provide evidence for the reorganization of neural control of unilateral force production as early as age 50. Future studies will determine if the altered neural control of such inter-manual interactions are of functional significance

XMM observations of three middle-aged pulsars

X-ray observations of middle-aged pulsars allow one to study nonthermal radiation from pulsar magnetospheres and thermal radiation from neutron star (NS) surfaces. In particular, from the analysis of thermal radiation one can infer the surface temperatures and radii of NSs, which is important for investigating evolution of these objects and constraining the equation of state of the superdense matter in the NS interiors. Here we present results of XMM observations of three middle-aged pulsars, J0538+2817, B0656+14 and J0633+1746 (Geminga), and briefly discuss mechanisms of their X-ray emission.Comment: 6 pages, 8 figures; to be published in Memorie della Societa' Astronomica Italiana, the Proceedings of the EPIC Consortium (held on Oct 14-16, 2003 in Palermo

Syphilis among middle-aged female sex workers in China: a three-site cross-sectional study.

ObjectivesThis study addresses the lack of empirical studies about the epidemic of syphilis among middle-aged female sex workers (FSWs). The objectives of this study were to investigate prevalence of syphilis, and its potential risk factors among middle-aged FSWs in China.DesignA cross-sectional study with respondent-driven sampling (RDS).SettingA multisite study conducted at three Chinese cites (Nanning, Hefei, and Qingdao) with different levels of sexually transmitted diseases in 2014.Participants1245 middle-aged female sex workers who were over 35 years old (about 400 per study site).Main outcome measuresUnprotected commercial sex, and syphilis and HIV infection were biologically tested and measured.ResultsThe RDS-adjusted prevalence of active syphilis was 17.3% in Hefei, 9.9% in Qingdao, and 5.4% in Nanning. The RDS-adjusted prevalence of prevalent syphilis was between 6.8% and 33.6% in the three cities. The proportion of unprotected sex in the past 48 h verified by the prostate-specific antigen test (PSA) was between 27.8% and 42.4%. Multiple log-binomial regression analyses indicate that middle-aged FSWs who had 5 or more clients in the past week prior to interviews and engaged in unprotected sex were more likely to be active syphilitic cases. Middle-aged FSWs who had rural residency were less likely to be active syphilitic cases.ConclusionsIn contrast with previous studies that reported low prevalence of syphilis and high prevalence of protected sex among FSWs in China, both the prevalence of syphilis and unprotected sex were high among middle-aged FSWs. Evidence-based intervention programmes should be developed and evaluated among this vulnerable population in China and other countries with similar settings

Whole body vibration training and its application to age-related performance decrements:an exploratory analysis

Middle age is associated with a pronounced decline in power and flexibility. Whilst whole body vibration training (WBVT) improves performance in a range of populations, whether WBVT can improve muscle power and flexibility in a middle-aged population is not known. The present study aimed to determine the influence of 5 weeks progressive WBVT in middle-aged (45-55 yrs.) and younger (20-30 yrs.) recreationally active females. Participants in each age group were randomly allocated to an intervention (WBVT) or control group. The WBVT groups trained for five weeks on a vibration platform, while the control groups performed identical exercises, with no vibration. Prior to, and after, the five-week study vertical countermovement jump (VCMJ) and range of motion (ROM) performance were measured. WBVT significantly (P = 0.001) improved VCMJ performance when compared to the control groups. This improvement was significantly (P = 0.001) greater in the middle-aged compared with the younger WBVT group. WBVT significantly (P = 0.001) improved ROM irrespective of age. Taken together, these results suggest that WBVT can off-set age related performance decrements, which has therapeutic implications for musculoskeletal aging. Therefore, WBVT could be undertaken to minimise age-related performance deterioration in middle-aged female populations

The Retirement Expectations of Middle-Aged Individuals

We use the first three waves of the Household Income and Labour Dynamics in Australia (HILDA) Survey to examine the retirement plans of middle-aged workers (aged 45-55). Our results indicate that approximately two-thirds of men and more then half of women appear to be making standard retirement plans. At the same time, more than one in five individuals seem to have delayed their retirement planning and approximately one in ten either do not know when they expect to retire or expect to never retire. Retirement plans are closely related to current labor market position. Specifically, forming expectations about the age at which one will leave the labor market appears to be easier for workers in jobs with well defined pension benefits and standard retirement ages. Moreover, those who report that they do not know when they expect to retire do in fact appear to face greater uncertainty in their retirement planning. Those who anticipate working forever seem to do so out of concerns about the adequacy of their retirement incomes rather than out of increased job satisfaction or a heightened desire to remain employed. Finally, men alter their retirement plans in response to labor market shocks, while women are more sensitive to their own and their partners’ health changes.retirement, expectations, middle-aged workers