Postural change, gait, and physical function in older adults.

Unlabelled: In a more clinical setting, abrupt posture change may be used to determine the presence of orthostatic hypotension, a hemodynamic response with relationships to physical function. Certain gait features and physical function performance are also associated with risk of falling in older adults. However, the extent to which posture change is associated with subsequent gait and physical function has received little attention in the literature.

Impact of cardiovascular risk factors on the relationships of physical activity with mood and cognitive function in a diverse sample.

Physical activity has well-known benefits for older adults' mood and cognitive functioning; however, it is not clear whether risk factors for cardiovascular disease (CVD) affect the relationships of physical activity with these health outcomes among diverse older adults. This study investigated the impact of CVD risk burden on the relationships among self-reported physical activity, mood, and cognitive functioning in a diverse sample of 62 adults age 45 and older. We found that higher physical activity was associated with better attention and verbal working memory at lower CVD risk, but with worse attention and verbal working memory at higher CVD risk levels.

Classification of older adults with/without a fall history using machine learning methods.

Falling is a serious problem in an aged society such that assessment of the risk of falls for individuals is imperative for the research and practice of falls prevention. This paper introduces an application of several machine learning methods for training a classifier which is capable of classifying individual older adults into a high risk group and a low risk group (distinguished by whether or not the members of the group have a recent history of falls). Using a 3D motion capture system, significant gait features related to falls risk are extracted.

Social engagement and health in younger, older, and oldest-old adults in the Louisiana Healthy Aging Study.

Social support has been shown to influence health outcomes in later life. In this study, we focus on social engagement as an umbrella construct that covers select social behaviors in a life span sample that included oldest-old adults, a segment of the adult population for whom very little data currently exist. We examined relationships among social engagement, positive health behaviors, and physical health to provide new evidence that addresses gaps in the extant literature concerning social engagement and healthy aging in very old adults.

Comparison of the validity of four fall-related psychological measures in a community-based falls risk screening.

We examined the measurement properties offall-related psychological instruments with a sample of 133 older adults (M age = 74.4 years, SD = 9.4).

Falls risk factors and a compendium of falls risk screening instruments.

Clinical Problem: Falls are the leading cause of nonfatal injuries and injurious death among older adults; the aftermath of a fall stresses the health care system and places financial and psychological burdens on the patient and family. Because of this, fall prevention/risk reduction is a primary focus of numerous health care agendas. Over the last 2 decades, clinical research has provided clinicians with a variety of screening tools to quantify risk factors for falls.

Communication: Combining non-Boltzmann sampling with free energy perturbation to calculate free energies of hydration of quantum models from a simulation of an approximate model.

This paper proposes combining non-Boltzmann sampling with free energy perturbation to allow calculations of the free energy of hydration of a solute with both solute-water and water-water interactions with the nearest waters calculated by high-level quantum models. The method involves simulation of an approximate model of all interactions and uses both free energy perturbation and non-Boltzmann sampling to calculate the difference in energy between the approximate and quantum models.

Problems with Some Current Water Models for Close Pair Interactions That Are Not Near the Minimum Energy.

The ability of an empirical, polarizable model of water to predict a thermal ensemble of molecular configurations at ambient conditions was examined using first-principle quantum mechanics. The empirical model of water selected for this evaluation was the TTM2-F model. The quantum mechanical methodology selected was the second-order Møller-Plesset model (MP2).

Predictors of ADL Disability in Culturally Diverse Older Adults.

The purpose of this study was to utilize the disablement pathway model to examine the contribution of physical function, dyspnea, and pain to disability in activities-of-daily-living (ADL) in culturally diverse older adults. Participants were 51 older adults (age = 69.0 years ± 9.

Structure of an accurate ab initio model of the aqueous Na+ ion at high temperatures.

The structure of an accurate ab initio model of aqueous sodium ion was calculated at two high temperature state points (573 K, 0.72 g/cm(3) and 723 K, 0.0098 g/cm(3)) by a two-step procedure.

The association between flow-mediated dilation and physical function in older men.

Unlabelled: The probability that an individual is able to live independently decreases sharply below the threshold score of 57 units on the physical functional performance (PFP-10) test.

Purpose: To examine the relation between brachial artery flow-mediated dilation (BAFMD) on individual and total scores on the PFP-10. We hypothesized that lower scores on the PFP-10 test would be associated with lower BAFMD.

Sodium chloride in supercritical water as a function of density: potentials of mean force and an equation for the dissociation constant from 723 to 1073 K and from 0 to 0.9 g/cm(3).

The potential of mean force (PMF) of sodium chloride in water has been calculated by using the ab initio classical free-energy perturbation method at five state points: at 973 K with densities of 0.2796, 0.0935, and 0.

Construct validation of physical activity surveys in culturally diverse older adults: a comparison of four commonly used questionnaires.

The purpose of this study was to establish validity evidence of four physical activity (PA) questionnaires in culturally diverse older adults by comparing self-report PA with performance-based physical function. Participants were 54 older adults who completed the Continuous Scale Physical Functional Performance 10-item Test (CS-PFP10), Physical Activity Scale for the Elderly (PASE), HAMPS Physical Activity Questionnaire for Older Adults, Yale Physical Activity Survey (YPAS), and modified Baecke questionnaire. The total PASE score, three outcome scores for the CHAMPS, and three summary indices for the YPAS were significantly correlated with total CS-PFP10 score.

Physical activity level and physical functionality in nonagenarians compared to individuals aged 60-74 years.

Background: Functional dependence and the risks of disability increase with age. The loss of independence is thought to be partially due to a decrease in physical activity. However, in populations, accurate measurement of physical activity is challenging and may not provide information on functional impairment.

Age-related deterioration in flexibility is associated with health-related quality of life in nonagenarians.

Background And Purpose: Studies indicate that age is associated with deterioration in physical function and a concomitant decrease in health-related quality of life (HRQL). The contribution of physical function to HRQL in nonagenarians (ages 90-99) is unknown. The purposes of this study were to examine age-related changes in physical function and HRQL among community-dwelling nonagenarians and to determine the relationship between their physical function and HRQL.

Conductance study of association in aqueous CaCl2, Ca(CH3COO)2, and Ca(CH3COO)2.nCH3COOH from 348 to 523 K at 10 MPa.

The conductances of aqueous CaCl2, Ca(CH3COO)2, and Ca(CH3COO)2.nCH3COOH were measured from 348 to 523 K at pressures near 10 MPa using a flow conductometric technique. The first association constant for calcium chloride and the first and second association constants for calcium acetate in water, were derived from a least-squares fit of the measurements to a conductance model in which activity coefficients were calculated using the mean spherical approximation (MSA) and the conductance was modeled by the Turq, Blum, Bernard, and Kunz (TBBK) equation, plus a mixture model.

Electrical conductances of aqueous Na2SO4, H2SO4, and their mixtures: limiting equivalent ion conductances, dissociation constants, and speciation to 673 K and 28 MPa.

The electrical conductivities of aqueous solutions of Na(2)SO(4), H(2)SO(4), and their mixtures have been measured at 373-673 K at 12-28 MPa in dilute solutions for molalities up to 10(-2) mol kg(-1). These conductivities have been fit to the conductance equation of Turq et al.(1) with a consensus mixing rule and mean spherical approximation activity coefficients.

Biphasic responses of the brachial artery diameter following forearm occlusion: a blunted response in the elderly.

Background: The purpose was to examine the temporal response of the brachial artery diameter following 5 minutes of forearm occlusion in young men. A secondary objective was to compare the main features of the temporal pattern between young and old.

Methods: Sixteen young (28 +/- 8 yrs) and fifteen older (85 +/- 8 yrs) men underwent high-resolution ultrasonography of the brachial artery before and after five minutes of forearm occlusion.

Heart rate variability and the exercise pressor reflex during dynamic handgrip exercise and postexercise arterial occlusion.

Background: The exercise pressor reflex is thought to be an important cardiovascular control mechanism that may be compromised in disease states such as congestive heart failure and other metabolic syndromes. The purpose was to describe the exercise pressor reflex by observing heart rate variability and blood pressure responses to handgrip-exercise and postexercise arterial occlusion.

Methods: Continuous electrocardiography, arterial blood pressure, and pneumotachogram data were collected on 38 participants (age, 20 +/- 1 year) during spontaneous breathing, venous-occluded exercise (60% maximal voluntary contraction, 0.

Free energy perturbation study of water dimer dissociation kinetics.

An efficient approach is described for using accurate ab initio calculations to determine the rates of elementary condensation and evaporation processes that lead to nucleation of aqueous aerosols. The feasibility of the method is demonstrated in an application to evaporation rates of water dimer at 230 K. The method, known as ABC-FEP (ab initio/classical free energy perturbation), begins with a calculation of the potential of mean force for the dissociation (evaporation) of small water clusters using a molecular dynamics (MD) simulation with a model potential.

Measurements of vascular function using strain-gauge plethysmography: technical considerations, standardization, and physiological findings.

The main purpose of the present study was to examine the relationships between measures of fitness [estimated peak oxygen consumption (V(O2) peak) and handgrip strength] and forearm vascular function in 55 young (22.6 +/- 3.5 yr) adults.

Evidence of an association among age-related changes in physical, psychomotor and autonomic function.

Background: autonomic modulation of the heart, as measured by heart rate variability, is directly associated with cardiorespiratory fitness and inversely associated with all-cause mortality. The extent to which cardiorespiratory fitness and heart rate variability are related in older adults is difficult to ascertain due to difficulties in assessing physical fitness among older age groups.

Objective: to examine heart rate variability and measures of physical function, thereby allowing for the inclusion of a greater cross-section of older adults than can be tested using traditional fitness tests.

Influence of short-term endurance exercise training on heart rate variability.

Purpose: To examine the influence of 2 wk (eight sessions) of endurance training on cardiac autonomic modulation, as measured by heart rate variability (HRV).

Methods: Twenty-four males (mean age: 23.1 yr) were randomized to an exercise (EX; N = 12) or control group (CT; N = 12).