Exploring a statistical test for modality

This thesis explores the possibility of testing the statistical significance of modality based on the smoothed bootstrap test for modality. There is little information available on the plausibility of Silverman's test, potentially due to the computational requirements essential to perform the required bootstrap testing. Using the statistical package R, and incorporating parallel processing to perform large bootstrap simulations, the goal is to determine if a statistical test to estimate modality based on significance may exist. Simulation studies reveal properties of critical bandwidth and show modifications to the smoothed bootstrap test for modality make it possible to perform a statistical test for modality

Comparative analysis of physical development and functional capacity of different sports athletes during competition period

The aim of this study was to compare physical fitness of high performance canoeists, rowers, Greek-Roman style wrestlers, basketball players and skiers during their competition period. Indices of physical development, muscle and fat mass and their ratios were obtained. Single muscular contraction power (SMCP) and anaerobic alactic muscular power (AAMP) were also measured. The anaerobic glycolytic power (AGP) was estimated by ergometer. The Bosco methodology was used to estimate the activity of fast twitch fibres (FTF). The psychomotor response time (PRT) and movement frequency (MF) per 10 s were estimated and Roufier index (RI) was applied to measure functional capacity of circulatory and respiratory systems. The examination of athletes specialising in five different sports allowed for identification of the peculiarities of sports specialisation. The distinctive height, highest body weight and static hand power values characterised rowers and basketball players; while canoeists had the highest muscle mass. Only canoeists achieved high SMCP during the competition period. The SMCP of rowers and skiers was optimal, whereas the basketball players and wrestlers demonstrated an insufficient single muscular contraction power. The highest anaerobic alactic muscle power was observed in basketball players and canoeists, whereas in the muscles the basketball players and wrestlers the activity of FTF was insufficient. Though its parameters were approximate to endurance-trained rowers, they considerably fell behind those of canoeists. The functional capacity of circulatory and respiratory system of skiers was highest. The research revealed that the majority of indices of skiers and wrestlers’ physical fitness were lowest among the other studied athletes. Such results reflect their limited potential to achieve high results in international competitions

Air Pollution and the Dynamic Association Between Depressive Symptoms and Memory in Oldest-Old Women

BACKGROUND/OBJECTIVES Exposure to air pollution may contribute to both increasing depressive symptoms and decreasing episodic memory in older adulthood, but few studies have examined this hypothesis in a longitudinal context. Accordingly, we examined the association between air pollution and changes in depressive symptoms (DS) and episodic memory (EM) and their interrelationship in oldest-old (aged 80 and older) women. DESIGN Prospective cohort data from the Women\u27s Health Initiative Memory Study-Epidemiology of Cognitive Health Outcomes. SETTING Geographically diverse community-dwelling population. PARTICIPANTS A total of 1,583 dementia-free women aged 80 and older. MEASUREMENTS Women completed up to six annual memory assessments (latent composite of East Boston Memory Test and Telephone Interview for Cognitive Status) and the 15-item Geriatric Depression Scale (GDS-15). We estimated 3-year average exposures to regional particulate matter with aerodynamic diameter below 2.5 μm (PM2.5) (interquartile range [IQR] = 3.35 μg/m3) and gaseous nitrogen dioxide (NO2) (IQR = 9.55 ppb) at baseline and during a remote period 10 years earlier, using regionalized national universal kriging. RESULTS Latent change structural equation models examined whether residing in areas with higher pollutant levels was associated with annual changes in standardized EM and DS while adjusting for potential confounders. Remote NO2 (β = .287 per IQR; P = .002) and PM2.5 (β = .170 per IQR; P = .019) exposure was significantly associated with larger increases in standardized DS, although the magnitude of the difference, less than 1 point on the GDS-15, is of questionable clinical significance. Higher DS were associated with accelerated EM declines (β = −.372; P = .001), with a significant indirect effect of remote NO2 and PM2.5 exposure on EM declines mediated by DS. There were no other significant indirect exposure effects. CONCLUSION These findings in oldest-old women point to potential adverse effects of late-life exposure to air pollution on subsequent interplay between DS and EM, highlighting air pollution as an environmental health risk factor for older women

Outdoor Air Pollution Exposure and Inter-relation of Global Cognitive Performance and Emotional Distress in Older Women

The interrelationships among long-term ambient air pollution exposure, emotional distress and cognitive decline in older adulthood remain unclear. Long-term exposure may impact cognitive performance and subsequently impact emotional health. Conversely, exposure may initially be associated with emotional distress followed by declines in cognitive performance. Here we tested the inter-relationship between global cognitive ability, emotional distress, and exposure to PM2.5 (particulate matter with aerodynamic diameter 2 (nitrogen dioxide) in 6118 older women (aged 70.6 ± 3.8 years) from the Women’s Health Initiative Memory Study. Annual exposure to PM2.5 (interquartile range [IQR] = 3.37 μg/m3) and NO2 (IQR = 9.00 ppb) was estimated at the participant’s residence using regionalized national universal kriging models and averaged over the 3-year period before the baseline assessment. Using structural equation mediation models, a latent factor capturing emotional distress was constructed using item-level data from the 6-item Center for Epidemiological Studies Depression Scale and the Short Form Health Survey Emotional Well-Being scale at baseline and one-year follow-up. Trajectories of global cognitive performance, assessed by the Modified-Mini Mental State Examination (3MS) annually up to 12 years, were estimated. All effects reported were adjusted for important confounders. Increases in PM2.5 (β = -0.144 per IQR; 95% CI = −0.261; −0.028) and NO2 (β = −0.157 per IQR; 95% CI = −0.291; −0.022) were associated with lower initial 3MS performance. Lower 3MS performance was associated with increased emotional distress (β = −0.008; 95% CI = −0.015; −0.002) over the subsequent year. Significant indirect effect of both exposures on increases in emotional distress mediated by exposure effects on worse global cognitive performance were present. No statistically significant indirect associations were found between exposures and 3MS trajectories putatively mediated by baseline emotional distress. Our study findings support cognitive aging processes as a mediator of the association between PM2.5 and NO2 exposure and emotional distress in later-life

Association of improved air quality with lower dementia risk in older women

Late-life ambient air pollution is a risk factor for brain aging, but it remains unknown if improved air quality (AQ) lowers dementia risk. We studied a geographically diverse cohort of older women dementia free at baseline in 2008 to 2012 (n = 2,239, aged 74 to 92). Incident dementia was centrally adjudicated annually. Yearly mean concentrations of fine particulate matter (PM2.5) and nitrogen dioxide (NO2) were estimated using regionalized national universal kriging models and averaged over the 3-y period before baseline (recent exposure) and 10 y earlier (remote exposure). Reduction from remote to recent exposures was used as the indicator of improved AQ. Cox proportional hazard ratios (HRs) for dementia risk associated with AQ measures were estimated, adjusting for sociodemographic, lifestyle, and clinical characteristics. We identified 398 dementia cases during follow up (median = 6.1 y). PM2.5 and NO2 reduced significantly over the 10 y before baseline. Larger AQ improvement was associated with reduced dementia risks (HRPM2.5 0.80 per 1.78 μg/m3, 95% CI 0.71–0.91; HRNO2 0.80 per 3.91 parts per billion, 95% CI 0.71–0.90), equivalent to the lower risk observed in women 2.4 y younger at baseline. Higher PM2.5 at baseline was associated with higher dementia risk (HRPM2.5 1.16 per 2.90 μg/m3, 95% CI 0.98–1.38), but the lower dementia risk associated with improved AQ remained after further adjusting for recent exposure. The observed associations did not substantially differ by age, education, geographic region, Apolipoprotein E e4 genotypes, or cardiovascular risk factors. Long-term AQ improvement in late life was associated with lower dementia risk in older women

Behavioural activation by mental health nurses for late-life depression in primary care: a randomized controlled trial

Background: Depressive symptoms are common in older adults. The effectiveness of pharmacological treatments and the availability of psychological treatments in primary care are limited. A behavioural approach to depression treatment might be beneficial to many older adults but such care is still largely unavailable. Behavioural Activation (BA) protocols are less complicated and more easy to train than other psychological therapies, making them very suitable for delivery by less specialised therapists. The recent introduction of the mental health nurse in primary care centres in the Netherlands has created major opportunities for improving the accessibility of psychological treatments for late-life depression in primary care. BA may thus address the needs of older patients while improving treatment outcome and lowering costs.The primary objective of this study is to compare the effectiveness and cost-effectiveness of BA in comparison with treatment as usual (TAU) for late-life depression in Dutch primary care. A secondary goal is to explore several potential mechanisms of change, as well as predictors and moderators of treatment outcome of BA for late-life depression. Methods/design: Cluster-randomised controlled multicentre trial with two parallel groups: a) behavioural activation, and b) treatment as usual, conducted in primary care centres with a follow-up of 52 weeks. The main inclusion criterion is a PHQ-9 score > 9. Patients are excluded from the trial in case of severe mental illness that requires specialized treatment, high suicide risk, drug and/or alcohol abuse, prior psychotherapy, change in dosage or type of prescribed antidepressants in the previous 12 weeks, or moderate to severe cognitive impairment. The intervention consists of 8 weekly 30-min BA sessions delivered by a trained mental health nurse. Discussion: We expect BA to be an effective and cost-effective treatment for late-life depression compared to TAU. BA delivered by mental health nurses could increase the availability and accessibility of non-pharmacological treatments for late-life depression in primary care. Trial registration: This study is retrospectively registered in the Dutch Clinical Trial Register NTR6013on August 25th 2016. © 2017 The Author(s)

CD56 is a pathogen recognition receptor on human natural killer cells

Aspergillus (A.) fumigatus is an opportunistic fungal mold inducing invasive aspergillosis (IA) in immunocompromised patients. Although antifungal activity of human natural killer (NK) cells was shown in previous studies, the underlying cellular mechanisms and pathogen recognition receptors (PRRs) are still unknown. Using flow cytometry we were able to show that the fluorescence positivity of the surface receptor CD56 significantly decreased upon fungal contact. To visualize the interaction site of NK cells and A. fumigatus we used SEM, CLSM and dSTORM techniques, which clearly demonstrated that NK cells directly interact with A. fumigatus via CD56 and that CD56 is re-organized and accumulated at this interaction site time-dependently. The inhibition of the cytoskeleton showed that the receptor re-organization was an active process dependent on actin re-arrangements. Furthermore, we could show that CD56 plays a role in the fungus mediated NK cell activation, since blocking of CD56 surface receptor reduced fungal mediated NK cell activation and reduced cytokine secretion. These results confirmed the direct interaction of NK cells and A. fumigatus, leading to the conclusion that CD56 is a pathogen recognition receptor. These findings give new insights into the functional role of CD56 in the pathogen recognition during the innate immune response

Cardiorespiratory Fitness Is Associated with Better Executive Function in Young Women

Purpose: A positive association between cardiorespiratory fitness (CRF) and cognitive function has been demonstrated mainly in children and older adults. Women attending college live in a cognitively demanding setting where optimal cognition matters but often experience declines in CRF. Our aim was to test whether CRF is associated with executive function in young adult women. Methods: Participants in this cross-sectional study included 120 healthy women age 18–35 yr in a university setting. Each woman completed a maximal treadmill-based exercise test to determine peak oxygen uptake (V˙O2peak), computerized tests of executive function, and questionnaires to assess motivation and other factors with potential to influence physical and cognitive performance. Results: Overall CRF was excellent, with a sample mean V˙O2peak of 44.6 mL·min–1·kg–1. After adjusting for covariates, higher V˙O2peak was associated with better performance on attention (P \u3c 0.01), learning/ shifting (P \u3c 0.01), working memory (P \u3c 0.01), and problem-solving (P \u3c 0.05) tasks. Likewise, when women were grouped according to the American College of Sports Medicine fitness classification, performance on executive function tasks was poorest in women with very poor or poor CRF. Women with superior CRF performed best on executive function tasks, and performance was intermediate in women with fair, good, or excellent CRF. Conclusion: The findings from this cross-sectional study suggest that optimal cognition is related to CRF in young adult women. Future studies are needed to test whether strategies to improve CRF are effective in improving cognitive function

Fluidized-Bed Process for the Production of Uranium Tetrafluoride (Green Salt) From Uranyl Nitrate. Interim Report

A proposed new processing technique for the production of uranium tetrafluoride from uranyl nitrate solution is described. This technique involves the application of the fluidized-bod principle for the contacting of gases with powdered solids. A new application of fluidization developed at this Laboratory and applied to the denitration of uranyl nitrate to produce uranium trioxide is also described. The purpose of this work is to develop a low-cost, continuous process for the denitration of uranyl nitrate hexahydrate, the reduction of uranium trioxide to uranium dioxide, and the hydrofluorination of uranium dioxide to uranium tetrafluoride. Uranium trioxide and uranium dioxide powders can be satisfactorily fluidized over a wide range of particle sizes. The product is a powder having a high bulk density and satisfactory physical and chemioal properties. Production rates of 100 Ib/hr/ft/sup 2/ of reactor cross section were demonstrated. Experimental work is continuing to obtain additional information of the effects of operating variables. Experimental work is now underway to determine the optimum hydrofluorination operating oonditions and to estimate the size and number of stages required for the production of specification-grade uranium tetrafluoride. (auth