Ageing, depression, anxiety, social support and the diurnal rhythm and awakening response of salivary cortisol

The present study compared the cortisol awakening response and diurnal rhythm in 24 young healthy students and 48 community-dwelling older adults. The associations with diurnal cortisol and depression, anxiety and social support were also examined in relation to age. Salivary cortisol was measured over the course of one day: immediately upon awakening, 30 min later, and then 3 h, 6 h, 9 h and 12 h post-awakening. Participants completed a questionnaire measuring symptoms of anxiety and depression and social support was assessed. Older adults exhibited a significantly reduced awakening response, overall cortisol levels, area under the curve (AUC) and diurnal slopes than younger adults, resulting in a flatter diurnal rhythm. Younger adults with higher depression scores had significantly higher overall cortisol and higher levels upon awakening and 30 min post-awakening. In the younger adults, anxiety and depression correlated positively with AUC and the cortisol awakening response (CAR). Older adults with lower social support had a reduced AUC where younger adults with lower social support displayed a larger AUC. These findings suggest that the diurnal rhythm and awakening response of salivary cortisol are significantly reduced in older adults and the associations between anxiety, depression and social support and diurnal cortisol vary with age.\ud \u

Individual Differences in Comparison Question Anxiety

"The comparison question polygraph test (CQT) is a well-known technique for the detection of deception in legal and criminal settings (Raskin et al., 1989). According to Raskin and colleagues, the CQT was developed to address the limitations of the relevant-irrelevant (R-I) test, which uses only two types of questions, relevant and neutral. In the R-I test, neutral questions do not have any salience (i.e. are not relevant) for the innocent examinee. In this sense, they function as a ttcontrol" condition."(...

Experimental chronic noise is related to elevated fecal corticosteroid metabolites in lekking male greater Sage-Grouse (Centrocercus urophasianus).

There is increasing evidence that individuals in many species avoid areas exposed to chronic anthropogenic noise, but the impact of noise on those who remain in these habitats is unclear. One potential impact is chronic physiological stress, which can affect disease resistance, survival and reproductive success. Previous studies have found evidence of elevated stress-related hormones (glucocorticoids) in wildlife exposed to human activities, but the impacts of noise alone are difficult to separate from confounding factors. Here we used an experimental playback study to isolate the impacts of noise from industrial activity (natural gas drilling and road noise) on glucocorticoid levels in greater sage-grouse (Centrocercus urophasianus), a species of conservation concern. We non-invasively measured immunoreactive corticosterone metabolites from fecal samples (FCMs) of males on both noise-treated and control leks (display grounds) in two breeding seasons. We found strong support for an impact of noise playback on stress levels, with 16.7% higher mean FCM levels in samples from noise leks compared with samples from paired control leks. Taken together with results from a previous study finding declines in male lek attendance in response to noise playbacks, these results suggest that chronic noise pollution can cause greater sage-grouse to avoid otherwise suitable habitat, and can cause elevated stress levels in the birds who remain in noisy areas

The utility of saliva for the assessment of anti-pneumococcal antibodies: investigation of saliva as a marker of antibody status in serum

Context: Salivary antibodies may act as non-invasive marker of systemic immunity enabling assessment of vaccination and protection against bacterial infections. Objective: To assess if levels of anti-pneumococcal (Pn) antibodies in saliva reflect concentrations in serum and determine whether saliva can accurately identify protective concentrations in serum. Methods: IgG, IgA and IgM antibody levels in paired saliva and serum samples were measured against 12 Pn polysaccharide antigens in 72 healthy adults. Results: Antibody levels in saliva correlated positively with serum across immunoglobulin classes, most strongly for IgA. Individuals who had protective antibody levels in serum demonstrated significantly higher IgG and IgA salivary antibody concentrations/secretion rates. Salivary IgG and IgA Pn antibodies were able to distinguish between those with/without protective levels in serum for the majority of serotypes. Salivary IgM antibodies were not able to differentiate protective status. Median IgG and IgA Pn salivary parameters were able to identify individuals who had protective levels in serum on ≥8/12 serotypes with moderate accuracy: median IgA secretion rates provided the best sensitivity (73%) and specificity (71%). Conclusions: These findings suggest that IgG and IgA Pn specific antibodies in saliva may be useful surrogate markers of antibody status in serum

Serum free light chains are reduced in endurance trained older adults: Evidence that exercise training may reduce basal inflammation in older adults

Traditionally, free light chains (FLCs) are used as key serum biomarkers in the diagnosis and monitoring of plasma cell malignancies, but polyclonal FLCs can also be used as an accurate real-time indicator of immune-activation and inflammation. The primary aim of the present study was to assess the effects of exercise training status on serum FLCs in older adults, and secondly, to examine if training status moderated serum FLC responses to acute exercise. Kappa and lambda serum FLC levels were measured in 45 healthy older adults (aged ≥ 60 years) who were either sedentary, physically active or endurance trained. FLCs were measured at baseline and in response to an acute bout of submaximal exercise. The endurance trained group had significantly lower levels of kappa and lambda serum FLCs compared with physically active or sedentary elderly adults; these effects were independent of age, BMI and renal function. There was no significant difference in whole immunoglobulins between groups. Exercise training status had no effect on serum FLC responses to acute exercise, which were marginal. In conclusion, endurance training was associated with lower FLC levels compared with less physically active individuals. These findings suggest that long-term endurance training may be beneficial in reducing basal inflammation in older adults as well as elevated FLCs present in inflammatory and autoimmune conditions, often associated with ageing. FLCs may serve as a useful biomarker for monitoring the efficacy of exercise intervention studies in healthy and clinical populations

Acaricidal efficacy of various agents in the treatment of naturally occurring Ornithonyssus sylviarum (Acari: Macronyssidae) infestations of chickens

The northern fowl mite (NFM), Ornithonyssus sylviarum, is a commonly occurring external parasite of chickens. Primarily, caged layers have the greatest incidence of this mite, with bird unrest, unthriftiness and lowered production as some of the adverse effects of the infestation. In the current study, birds with natural NFM infestations were randomized into five treatment groups, placed in individual cages in treatment-specific batteries (all in one room), and evaluated for 28 d for infestation quantification by way of index scoring and feather digest. No treatments were 100% effective in eliminating all life stages of the mite. Tetrachlorvinphos in combination with dichlorvos (RAVAP E.C.® Boehringer Ingelheim) was the most effective with consistently negative post-treatment index scores and the greatest decrease in mite life stages (eggs, larvae, and nymphs/adults). Malathion dust (Hi-Yield® Voluntary Purchasing Groups, Inc.) and 10% garlic oil were next in level of effectiveness, with significant (P \u3c 0.05) post-treatment reductions in both index scores and mite life-stage populations. Permethrin (Permectrin II® Boehringer Ingelheim) provided the least control of the infestations, with no significant reductions in index scores and only slight reduction in the abundance of life stages after treatment

An example of enhanced tephra deposition driven by topographically-induced atmospheric turbulence

Spatial variations in the thickness and grain-size characteristics of tephra fall deposits imply that tephra depositional processes cannot be fully captured by models of single-particle sedimentation from the base of the eruption plume. Here, we document a secondary thickness maximum in a ∼9.75 ka tephra fall deposit from Chaitén volcano, Chile (Cha1 eruption). This secondary thickness maximum is notably coarser-grained than documented historical examples, being dominated by medium-grained ash, and an origin via particle aggregation is therefore unlikely. In the region of secondary thickening, we propose that high levels of atmospheric turbulence accelerated particles held within the mid- to lower-troposphere (0 to ∼6 km) towards the ground surface. We suggest that this enhancement in vertical atmospheric mixing was driven by the breaking of lee waves, generated by winds passing over elevated topography beneath the eruption plume. Lower atmospheric circulation patterns may exert a significant control on the dispersal and deposition of tephra from eruption plumes across all spatial scales, particularly in areas of complex topography

AEGIS: Enhancement of Dust-enshrouded Star Formation in Close Galaxy Pairs and Merging Galaxies up to z ~ 1

Using data from the DEEP2 Galaxy Redshift Survey and HST/ACS imaging in the Extended Groth Strip, we select nearly 100 interacting galaxy systems including kinematic close pairs and morphologically identified merging galaxies. Spitzer MIPS 24 micron fluxes of these systems reflect the current dusty star formation activity, and at a fixed stellar mass (M_{*}) the median infrared luminosity (L_{IR}) among merging galaxies and close pairs of blue galaxies is twice (1.9 +/- 0.4) that of control pairs drawn from isolated blue galaxies. Enhancement declines with galaxy separation, being strongest in close pairs and mergers and weaker in wide pairs compared to the control sample. At z ~ 0.9, 7.1% +/- 4.3% of massive interacting galaxies (M_{*} > 2*10^{10} M_{solar}) are found to be ULIRGs, compared to 2.6% +/- 0.7% in the control sample. The large spread of IR luminosity to stellar mass ratio among interacting galaxies suggests that this enhancement may depend on the merger stage as well as other as yet unidentified factors (e.g., galaxy structure, mass ratio, orbital characteristics, presence of AGN or bar). The contribution of interacting systems to the total IR luminosity density is moderate (<= 36 %).Comment: 12 pages, 2 figures, 1 table, minor changes to match the proof version, accepted for publication in the ApJL AEGIS Special Issu

Disordered eating behaviour is associated with blunted cortisol and cardiovascular reactions to acute psychological stress

Research suggests a potential dysregulation of the stress response in individuals with bulimia nervosa. This study measured both cardiovascular and cortisol reactions to a standardised laboratory stress task in individuals identified as showing disordered eating behaviour to determine whether dysregulation of the stress response is characteristic of the two branches of the stress response system. Female students (N = 455) were screened using two validated eating disorder questionnaires. Twelve women with disordered eating, including self-induced vomiting, and 12 healthy controls were selected for laboratory stress testing. Salivary cortisol and cardiovascular activity, via Doppler imaging and semi-automatic blood pressure monitoring, were measured at resting baseline and during and after exposure to a 10-min mental arithmetic stress task. Compared to controls the disordered eating group showed blunted cortisol, cardiac output, heart rate, and stroke volume reactions to the acute stress, as well as an attenuated vasodilatory reaction. These effects could not be accounted for in terms of group differences in stress task performance, subjective task impact/engagement, age, BMI, neuroticism, cardiorespiratory fitness, or co-morbid exercise dependence. Our findings suggest that disordered eating is characterised by a dysregulation of the autonomic stress-response system. As such, they add further weight to the general contention that blunted stress reactivity is characteristic of a number of maladaptive behaviours and states

Physical Activity, Life Events Stress, Cortisol, and DHEA: Preliminary Findings That Physical Activity May Buffer Against the Negative Effects of Stress

The present study examined the relationship between habitual physical activity, life events stress, the diurnal rhythms of cortisol and DHEA, and the cortisol:dehydroepiandrosterone (DHEA) ratio in older adults. Thirty-six participants aged ≥ 65 reported their habitual physical activity, and indicated if a particular event happened to them in the past year (stress incidence) and how stressful they perceived the event to be (stress severity). Older adults with higher stress severity demonstrated a significantly higher cortisol:DHEA ratio. Individuals with higher stress incidence scores and who did not participate in aerobic exercise had a significantly higher cortisol:DHEA ratio and flatter DHEA diurnal rhythm compared with those who regularly participated in aerobic exercise. In conclusion, life events stress may have a negative impact on the cortisol:DHEA ratio in older adults. Under conditions of high stress exposure, exercise may protect older adults from an increased cortisol:DHEA ratio and flatter DHEA diurnal rhythm