Church leaders' barriers and facilitators before and after implementing a physical activity and nutrition intervention.

Faith-based health promotion programs have been effective in increasing healthy eating (HE) and physical activity (PA). Very few reports exist regarding church leaders' anticipated and experienced barriers and facilitators to program implementation. Pastors (n = 38, 70%) and program coordinators (n = 54, 100%) from churches (N = 54) who attended a program training answered open-ended questions about anticipated barriers and facilitators to implementing the HE and PA parts of the Faith, Activity, and Nutrition (FAN) program. Twelve months later, pastors (n = 49, 92%) and coordinators (n = 53, 98%) answered analogous questions about their experienced barriers and facilitators to implementing the HE and PA parts of the FAN program. Responses were coded using thematic analysis. Similar themes appeared at baseline and follow-up for anticipated and experienced barriers and facilitators. The most common barriers were no anticipated barriers, resistance to change, church characteristics, and lack of participation/motivation. The most common facilitators were internal support, leadership, and communication. Few differences were found between anticipated and experienced barriers and facilitators. Understanding these perspectives, particularly overcoming resistance to change and church characteristics through strong leadership and internal support from church leaders, will improve future program development, resources, and technical assistance in faith-based and non-faith-based communities alike.

Clinically meaningful changes in functional performance resulting from self-directed interventions in individuals with arthritis.

OBJECTIVES: To examine the clinical meaningfulness of changes observed in functional performance from two self-directed interventions targeting adults with arthritis. STUDY DESIGN: Randomized controlled trial. METHODS: Participants (n = 312) were randomized to a 12-week self-directed exercise or nutrition intervention. Objective measures of functional performance (6-minute walk, seated reach, grip strength, 30-second chair stand, gait speed, balance) were obtained at baseline, 12 weeks, and nine months. Minimally (≥0.20 standard deviation) and substantially (≥0.50) meaningful changes in functional performance were examined. Changes in the percent 'impaired' and at risk for losing independence using established standards, and associations between physical activity and impairment/risk status were also examined. Group × Time interactions were not significant; therefore groups were combined in all analyses. RESULTS: Minimally (31-71%) and substantially (13-54%) meaningful changes in function were shown. There was a significant decrease in the percentage of participants 'impaired' on the 30-second chair stand (both time points) and gait speed (nine months). The percentage of participants at risk for losing independence significantly decreased for the 30-second chair stand (both time points) and the 6-minute walk (nine months). Those engaging in ≥2 h of leisure-time physical activity were significantly less likely to be impaired on the 6-minute walk, 30-second chair stand, and gait speed at 12 weeks, and the 6-minute walk at nine months. CONCLUSIONS: Interventions that can slow functional declines, and ideally result in clinically meaningful improvements in functional performance among adults with arthritis are needed. Meaningful improvements in various indicators of functional performance can result from self-directed exercise and nutrition programs. These types of programs have the potential for wide-spread dissemination, and thus broad reach.

Physical activity mediates the relationship between program participation and improved mental health in older adults.

OBJECTIVES: There is an implicit assumption that increased physical activity (PA) levels are responsible for the mental health benefits resulting from participation in PA programs. Other factors associated with participation may in fact be responsible. The purpose of this study was to examine whether changes in PA mediated the effects of two PA programs (Active Choices [AC] and Active Living Every Day [ALED]) on mental health outcomes. STUDY DESIGN: Secondary data analyses of quasi-experimental study. METHODS: A sub-sample of older adults who participated in AC (n = 744) and ALED (n = 853) were included in the current analyses. MacKinnon's product of coefficients was used to test change in PA as a mediator of the relationship between program dose and change in mental health outcomes (depressive symptoms, stress, and number of days with poor mental health). RESULTS: Change in PA explained 19% (AC) and 13% (ALED) of the absolute effects of program dose on depressive symptoms, 18% (AC) and 14% (ALED) of the effects on stress, and 37% (ALED) of the effects on days with poor mental health. CONCLUSIONS: Mounting evidence from both epidemiological studies and controlled trials suggests that PA can improve mental health. This study adds that increasing PA levels may improve mental health in older adults in 'real-world' settings.

Influence of blood flow occlusion on the development of peripheral and central fatigue during small muscle mass handgrip exercise.

Critical power represents an important threshold for neuromuscular fatigue development and may, therefore, dictate intensities for which exercise tolerance is determined by the magnitude of fatigue accrued. Peripheral fatigue appears to be constant across O2 delivery conditions for large muscle mass exercise, but this consistency is equivocal for smaller muscle mass exercise. We sought to determine the influence of blood flow occlusion during handgrip exercise on neuromuscular fatigue development and to examine the relationship between neuromuscular fatigue development and W '. Blood flow occlusion influenced the development of both peripheral and central fatigue, thus providing further evidence that the magnitude of peripheral fatigue is not constant across O2 delivery conditions for small muscle mass exercise. W ' appears to be related to the magnitude of fatigue accrued during exercise, which may explain the reported consistency of intramuscular metabolic perturbations and work performed for severe-intensity exercise. The influence of the muscle metabolic milieu on peripheral and central fatigue is currently unclear. Moreover, the relationships between peripheral and central fatigue and the curvature constant (W ') have not been investigated. Six men (age: 25 ± 4 years, body mass: 82 ± 10 kg, height: 179 ± 4 cm) completed four constant power handgrip tests to exhaustion under conditions of control exercise (Con), blood flow occlusion exercise (Occ), Con with 5 min post-exercise blood flow occlusion (Con + Occ), and Occ with 5 min post-exercise blood flow occlusion (Occ + Occ). Neuromuscular fatigue measurements and W ' were obtained for each subject. Each trial resulted in significant peripheral and central fatigue. Significantly greater peripheral (79.7 ± 5.1% vs. 22.7 ± 6.0%) and central (42.6 ± 3.9% vs. 4.9 ± 2.0%) fatigue occurred for Occ than for Con. In addition, significantly greater peripheral (83.0 ± 4.2% vs. 69.0 ± 6.2%) and central (65.5 ± 14.6% vs. 18.6 ± 4.1%) fatigue occurred for Occ + Occ than for Con + Occ. W ' was significantly related to the magnitude of global (r = 0.91) and peripheral (r = 0.83) fatigue. The current findings demonstrate that blood flow occlusion exacerbated the development of both peripheral and central fatigue and that post-exercise blood flow occlusion prevented the recovery of both peripheral and central fatigue. Moreover, the current findings suggest that W ' may be determined by the magnitude of fatigue accrued during exercise.

Anatomical changes within the medullary dorsal horn in chronic temporomandibular disorder pain.

Accumulated evidence from experimental animal models suggests that neuroplastic changes at the dorsal horn are critical for the maintenance of various chronic musculoskeletal pain conditions. However, to date, no study has specifically investigated whether neuroplastic changes also occur at this level in humans. Using brain imaging techniques, we sought to determine whether anatomical changes were present in the medullary dorsal horn (spinal trigeminal nucleus caudalis) in subjects with the chronic musculoskeletal pain. In twenty-two subjects with painful temporomandibular disorders (TMDs) and forty pain-free controls voxel based morphometry of T1-weighted anatomical images and diffusion tensor images were used to assess regional grey matter volume and microstructural changes within the brainstem and, in addition, the integrity of ascending pain pathways. Voxel based morphometry revealed significant regional grey matter volume decreases in the medullary dorsal horn, in conjunction with alterations in diffusivity properties, namely an increase in mean diffusivity, in TMD subjects. Volumetric and mean diffusivity changes also occurred in TMD subjects in regions of the descending pain modulation system, including the midbrain periaqueductal grey matter and nucleus raphe magnus. Finally, tractography revealed altered diffusivity properties, namely decreased fractional anisotropy, in the root entry zone of the trigeminal nerve, the spinal trigeminal tract and the ventral trigeminothalamic tracts of TMD subjects. These data reveal that chronic musculoskeletal pain in humans is associated with discrete alterations in the anatomy of the medullary dorsal horn, as well as its afferent and efferent projections. These neural changes may be critical for the maintenance of pathological pain.

Influence of blood flow occlusion on muscle oxygenation characteristics and the parameters of the power-duration relationship.

It was previously (Monod H, Scherrer J. Ergonomics 8: 329-338, 1965) postulated that blood flow occlusion during exercise would reduce critical power (CP) to 0 Watts (W), while not altering the curvature constant (W'). We empirically assessed the influence of blood flow occlusion on CP, W', and muscle oxygenation characteristics. Ten healthy men (age: 24.8 ± 2.6 yr; height: 180 ± 5 cm; weight: 84.6 ± 10.1 kg) completed four constant-power handgrip exercise tests during both control blood flow (control) and blood flow occlusion (occlusion) for the determination of the power-duration relationship. Occlusion CP (-0.7 ± 0.4 W) was significantly (P < 0.001) lower than control CP (4.1 ± 0.7 W) and significantly (P < 0.001) lower than 0 W. Occlusion W' (808 ± 155 J) was significantly (P < 0.001) different from control W' (558 ± 129 J), and all 10 subjects demonstrated an increased occlusion W' with a mean increase of ∼49%. The present findings support the aerobic nature of CP. The findings also demonstrate that the amount of work that can be performed above CP is constant for a given condition, but can vary across conditions. Moreover, this amount of work that can be performed above CP does not appear to be the determinant of W', but rather a consequence of the depletion of intramuscular energy stores and/or the accumulation of fatigue-inducing metabolites, which limit exercise tolerance and determine W'.

The relationship between critical speed and the respiratory compensation point: Coincidence or equivalence.

It has previously been suggested that the respiratory compensation point (RCP) and critical speed (CS) parameters are equivalent and, therefore, like CS, RCP demarcates the boundary between the heavy- and severe-intensity domains. However, these findings are equivocal and therefore must be interpreted cautiously. Thus, we examined the relationship between CS and RCP across a wide range of subject fitness levels, in an attempt to determine if CS and RCP are equivalent. Forty men and 30 women (age: 23.2 ± 2.5 year, height: 174 ± 10 cm, body mass: 74.1 ± 15.7 kg) completed an incremental and four constant-speed protocols on a treadmill. RCP was determined as the point at which the minute ventilation increased disproportionately to CO2 production and the end-tidal CO2 partial pressure began to decrease. CS was determined from the constant-speed protocols using the linearized 1·time(-1) model. CS and RCP, expressed as speed or metabolic rate, were not significantly different (11.7 ± 2.3 km·h(-1) vs. 11.5 ± 2.3 km·h(-1), p = 0.208; 2.88 ± 0.80 l·min(-1) vs. 2.83 ± 0.72 l·min(-1), p = 0.293) and were significantly correlated (r(2) = 0.52, p < 0.0001; r(2) = 0.74, p < 0.0001, respectively). However, there was a high degree of variability between the parameters. The findings of the current study indicate that, while on average CS and RCP were not different, the high degree of variability between these parameters does not permit accurate estimation of one from the other variable and suggests that these parameters may not be physiologically equivalent.

A brief introduction to the military workplace culture.

BACKGROUND: Military culture and workplace are areas of interest for researchers across disciplines. However, few publications on military culture exist. OBJECTIVE: The purpose of this article is to introduce general concepts regarding the structure and culture of the United States Military and discuss how this creates challenges for reintegrating into the civilian world. METHOD: Topics that will be covered in this article include an overview of the Department of Defense (DoD) and Department of Veterans Affairs (VA), socialization to military culture, the unique features of the military as a workplace, the cultural experiences of military personnel reintegrating back into the community, and the challenges faced by military members and their spouses. RESULTS: The provided information on military culture will expand military cultural competency so that civilian employers can enhance their ability to create supportive workplaces for veterans and military spouses during times of transition and reintegration. DISCUSSION: The unique characteristics of the military culture should be understood by those who work with or plan to work with military populations.

Baseline predictors of physical activity in a sample of adults with arthritis participating in a self-directed exercise program.

OBJECTIVES: To examine baseline predictors of moderate-to-vigorous intensity physical activity (MVPA) at the 12-week follow-up in a sample of adults with arthritis participating in a self-directed, multicomponent exercise program. STUDY DESIGN: Pretest-posttest. Analyses were limited to those randomized to the exercise intervention. METHODS: Participants (n = 152) completed a survey assessing demographic, health-related, and arthritis-related factors, and completed anthropometric and functional measurements at baseline. Self-reported MVPA was assessed at baseline and 12 weeks. Participants were classified as engaging in ≥2.5 or <2.5 h/week of MVPA at the 12-week follow-up. Baseline demographic, health-related, arthritis-related, and functional factors were examined as predictors of engaging in ≥2.5 h of MVPA. RESULTS: At the 12-week follow-up, 66.5% (n = 101) of participants engaged in ≥2.5 h/week of MVPA. Those with a higher body mass index, more days with poor physical health, a greater number of health conditions, self-reported hypertension, self-reported high cholesterol, and greater pain and stiffness were less likely to engage in ≥2.5 h of MVPA at the 12-week follow-up; those with greater arthritis self-efficacy and better performance on the 6 minute walk test were more likely. None of the other factors examined were associated with MVPA. CONCLUSIONS: This study uncovered health-related, arthritis-related, and functional factors associated with MVPA that may help guide intervention strategies. Participants with less severe symptoms, better functional performance and fewer comorbidities at baseline were more likely to achieve the recommended MVPA level at 12 weeks; therefore self-directed PA interventions may be best suited for those with relatively good health status despite arthritis, while those with worse symptoms and health status may benefit more from other intervention delivery modalities such as structured, individualized programs where additional support for managing arthritis symptoms and comorbidity can be addressed.

Relationship between simulated extravehicular activity tasks and measurements of physical performance.

The purpose was to evaluate the relationships between tests of fitness and two activities that simulate components of Lunar- and Martian-based extravehicular activities (EVA). Seventy-one subjects completed two field tests: a physical abilities test and a 10km Walkback test. The relationships between test times and the following parameters were determined: running V˙O2max, gas exchange threshold (GET), speed at V˙O2max (s-V˙O2max), highest sustainable rate of aerobic metabolism [critical speed (CS)], and the finite distance that could be covered above CS (D'): arm cranking V˙O2peak, GET, critical power (CP), and the finite work that can be performed above CP (W'). CS, running V˙O2max, s-V˙O2max, and arm cranking V˙O2peak had the highest correlations with the physical abilities field test (r=0.66-0.82, P<0.001). For the 10km Walkback, CS, s-V˙O2max, and running V˙O2max were significant predictors (r=0.64-0.85, P<0.001). CS and to a lesser extent V˙O2max are most strongly associated with tasks that simulate aspects of EVA performance, highlighting CS as a method for evaluating astronaut physical capacity.

Thalamic activity and biochemical changes in individuals with neuropathic pain after spinal cord injury.

There is increasing evidence relating thalamic changes to the generation and/or maintenance of neuropathic pain. We have recently reported that neuropathic orofacial pain is associated with altered thalamic anatomy, biochemistry, and activity, which may result in disturbed thalamocortical oscillatory circuits. Despite this evidence, it is possible that these thalamic changes are not responsible for the presence of pain per se, but result as a consequence of the injury. To clarify this subject, we compared brain activity and biochemistry in 12 people with below-level neuropathic pain after complete thoracic spinal cord injury with 11 people with similar injuries and no neuropathic pain and 21 age- and gender-matched healthy control subjects. Quantitative arterial spinal labelling was used to measure thalamic activity, and magnetic resonance spectroscopy was used to determine changes in neuronal variability quantifying N-acetylaspartate and alterations in inhibitory function quantifying gamma amino butyric acid. This study revealed that the presence of neuropathic pain is associated with significant changes in thalamic biochemistry and neuronal activity. More specifically, the presence of neuropathic pain after spinal cord injury is associated with significant reductions in thalamic N-acetylaspartate, gamma amino butyric acid content, and blood flow in the region of the thalamic reticular nucleus. Spinal cord injury on its own did not account for these changes. These findings support the hypothesis that neuropathic pain is associated with altered thalamic structure and function, which may disturb central processing and play a key role in the experience of neuropathic pain.

Influence of duty cycle on the power-duration relationship: observations and potential mechanisms.

The highest sustainable rate of aerobic metabolism [critical power (CP)] and the finite amount of work that can be performed above CP (W' [curvature constant]) were determined under two muscle contraction duty cycles. Eight men completed at least three constant-power handgrip tests to exhaustion to determine CP and W' for 50% and 20% duty cycles, while brachial artery blood flow (Q̇BA) and deoxygenated-[hemoglobin + myoglobin] (deoxy-[Hb+Mb]) were measured. CP was lower for the 50% duty cycle (3.9 ± 0.9 W) than the 20% duty cycle (5.1 ± 0.8 W; p < 0.001), while W' was not significantly different (50% duty cycle: 452 ± 141 J vs. 20% duty cycle: 432 ± 130 J; p > 0.05). At the same power output, Q̇BA and deoxy-[Hb + Mb] achieved higher end-exercise values for the 20% duty cycle (9.87 ± 1.73 ml·s(-1); 51.7 ± 4.7 µM) than the 50% duty cycle (7.37 ± 1.76 ml·s(-1), p < 0.001; 44.3 ± 2.4 µM, p < 0.03). These findings indicate that blood flow influences CP, but not W'.

Development and validation of a portable platform for deploying decision-support algorithms in prehospital settings.

BACKGROUND: Advanced decision-support capabilities for prehospital trauma care may prove effective at improving patient care. Such functionality would be possible if an analysis platform were connected to a transport vital-signs monitor. In practice, there are technical challenges to implementing such a system. Not only must each individual component be reliable, but, in addition, the connectivity between components must be reliable. OBJECTIVE: We describe the development, validation, and deployment of the Automated Processing of Physiologic Registry for Assessment of Injury Severity (APPRAISE) platform, intended to serve as a test bed to help evaluate the performance of decision-support algorithms in a prehospital environment. METHODS: We describe the hardware selected and the software implemented, and the procedures used for laboratory and field testing. RESULTS: The APPRAISE platform met performance goals in both laboratory testing (using a vital-sign data simulator) and initial field testing. After its field testing, the platform has been in use on Boston MedFlight air ambulances since February of 2010. CONCLUSION: These experiences may prove informative to other technology developers and to healthcare stakeholders seeking to invest in connected electronic systems for prehospital as well as in-hospital use. Our experiences illustrate two sets of important questions: are the individual components reliable (e.g., physical integrity, power, core functionality, and end-user interaction) and is the connectivity between components reliable (e.g., communication protocols and the metadata necessary for data interpretation)? While all potential operational issues cannot be fully anticipated and eliminated during development, thoughtful design and phased testing steps can reduce, if not eliminate, technical surprises.

Gene expression levels as endophenotypes in genome-wide association studies of Alzheimer disease.

BACKGROUND: Late-onset Alzheimer disease (LOAD) is a common disorder with a substantial genetic component. We postulate that many disease susceptibility variants act by altering gene expression levels. METHODS: We measured messenger RNA (mRNA) expression levels of 12 LOAD candidate genes in the cerebella of 200 subjects with LOAD. Using the genotypes from our LOAD genome-wide association study for the cis-single nucleotide polymorphisms (SNPs) (n = 619) of these 12 LOAD candidate genes, we tested for associations with expression levels as endophenotypes. The strongest expression cis-SNP was tested for AD association in 7 independent case-control series (2,280 AD and 2,396 controls). RESULTS: We identified 3 SNPs that associated significantly with IDE (insulin degrading enzyme) expression levels. A single copy of the minor allele for each significant SNP was associated with approximately twofold higher IDE expression levels. The most significant SNP, rs7910977, is 4.2 kb beyond the 3' end of IDE. The association observed with this SNP was significant even at the genome-wide level (p = 2.7 x 10(-8)). Furthermore, the minor allele of rs7910977 associated significantly (p = 0.0046) with reduced LOAD risk (OR = 0.81 with a 95% CI of 0.70-0.94), as expected biologically from its association with elevated IDE expression. CONCLUSIONS: These results provide strong evidence that IDE is a late-onset Alzheimer disease (LOAD) gene with variants that modify risk of LOAD by influencing IDE expression. They also suggest that the use of expression levels as endophenotypes in genome-wide association studies may provide a powerful approach for the identification of disease susceptibility alleles.

Computer simulation to aid the risk assessment of wheelchair and special seating systems used in transport.

The crashworthiness of occupied proprietary wheelchairs, which are transported in motor vehicles, is currently assessed by physical crash testing in accordance with ISO 7176-19. If such wheelchairs are modified to meet the needs of the occupant, e.g. the addition of special seating, environmental control systems or life support equipment, then those making the modifications take on the manufacturer's responsibilities, one of these being the assessment of the modified wheelchair's ability to withstand vehicle crash forces. Destructively testing bespoke wheelchair designs is not practical so, currently, the transport-related risk is assessed using best engineering judgement. To improve this process virtual crash testing of the wheelchair and occupant was used. A modified crash criteria from ISO 7176-19 is proposed to enable assessment of the wheelchair's crashworthiness and provide the clinical engineer with an informed judgement of how both wheelchair alone and occupant and wheelchair together will behave in a crash.

High risk infusions--accuracy compromised by changes in patient venous pressure.

Intensive care often requires the simultaneous administration of high potency short half-life intravenous drugs. Numerous reported instances of unwanted transient flow characteristics such as bolus flow, slow start-up at set rate and fluid reflux-where fluid is found to flow away from the infusion site-have indicated a need for better understanding of the system dynamic. This article introduces a simple mathematical model of an infusion pump system, highlighting system mechanical compliance as a major contributory factor for flow error. The model is verified as correctly predicting flow variation caused by pump height change and is offered as an aid in the development of more accurate infusion devices. The accurate delivery of low flow rates requires small volume rigid components. This study also suggests that the current design of syringe infusion devices makes them susceptible to flow error caused by change in patient venous pressure.

Modeling of defect modes in photonic crystals using the fictitious source superposition method.

We present an exact theory for modeling defect modes in two-dimensional photonic crystals having an infinite cladding. The method is based on three key concepts, namely, the use of fictitious sources to modify response fields that allow defects to be introduced, the representation of the defect mode field as a superposition of solutions of quasiperiodic field problems, and the simplification of the two-dimensional superposition to a more efficient, one-dimensional average using Bloch mode methods. We demonstrate the accuracy and efficiency of the method, comparing results obtained using alternative techniques, and then concentrate on its strengths, particularly in handling difficult problems, such as where a mode is highly extended near cutoff, that cannot be dealt with in other ways.

Long wavelength behavior of the fundamental mode in microstructured optical fibers.

Using a novel computational method, the fundamental mode in index-guided microstructured optical fibers with genuinely infinite cladding is studied. It is shown that this mode has no cut-off, although its area grows rapidly when the wavelength crosses a transition region. The results are compared with those for w-fibers, for which qualitatively similar results are obtained.

Disruption of a novel member of a sodium/hydrogen exchanger family and DOCK3 is associated with an attention deficit hyperactivity disorder-like phenotype.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a complex condition with high heritability. However, both biochemical investigations and association and linkage studies have failed to define fully the underlying genetic factors associated with ADHD. We have identified a family co-segregating an early onset behavioural/developmental condition, with features of ADHD and intellectual disability, with a pericentric inversion of chromosome 3, 46N inv(3)(p14:q21). METHODS: We hypothesised that the inversion breakpoints affect a gene or genes that cause the observed phenotype. Large genomic clones (P1 derived/yeast/bacterial artificial chromosomes) were assembled into contigs across the two inversion breakpoints using molecular and bioinformatic technologies. Restriction fragments crossing the junctions were identified by Southern analysis and these fragments were amplified using inverse PCR. RESULTS: The amplification products were subsequently sequenced to reveal that the breakpoints lay within an intron of the dedicator of cytokinesis 3 (DOCK3) gene at the p arm breakpoint, and an intron of a novel member of the solute carrier family 9 (sodium/hydrogen exchanger) isoform 9 (SLC9A9) at the q arm. Both genes are expressed in the brain, but neither of the genes has previously been implicated in developmental or behavioural disorders. CONCLUSION: These two disrupted genes are candidates for involvement in the pathway leading to the neuropsychological condition in this family.