Statistical mechanics of addition polymerisation. Calculations of the expectation and variance of the average atmosphere in growing self avoiding walks

NASA Astrophysics Data System (ADS)

Taniya, Abraham; Deepthi, Murali; Padmanabhan, Alapat

2018-06-01

Recent calculations on the change in radial dimensions of reacting (growing) polyethylene in the gas phase experiencing Lennard Jones and Kihara type potentials revealed that a single reacting polyethylene molecule does not experience polymer collapse. This implies that a transition that is the converse of what happens when molten polyethylene crystallizes, i.e. it transforms from random coil like structure to folded rigid rod type structure, occurs. The predicted behaviour of growing polyethylene was explained by treating the head of the growing polymer chain as myopic whereas as the whole chain (i.e. when under equilibrium conditions) being treated as having normal vision, i.e. the growing chain does not see the attractive part of the LJ or Kihara Potentials. In this paper we provide further proof for this argument in two ways. Firstly we carry forward the exact enumeration calculations on growing self avoiding walks reported in that paper to larger values of number of steps by using Monte Carlo type calculations. We thereby assign physical significance to the connective constant of self avoiding walks, which until now was treated as a purely abstract mathematical entity. Secondly since a reacting polymer molecule that grows by addition polymerisation sees only one step ahead at a time, we extend this calculation by estimating the average atmosphere for molecules, with repulsive potential only (growing self avoiding walks in two dimensions), that look at two, three, four, five ...steps ahead. Our calculation shows that the arguments used in the previous work are correct.

The Relationship Between Walking Capacity, Biopsychosocial Factors, Self-Efficacy and Walking Activity in Individuals Post Stroke

PubMed Central

Danks, Kelly A.; Pohlig, Ryan T.; Roos, Margie; Wright, Tamara R.; Reisman, Darcy S.

2016-01-01

Background/Purpose Many factors appear to be related to physical activity after stroke, yet it is unclear how these factors interact and which ones might be the best predictors. Therefore, the purpose of this study was twofold: 1) to examine the relationship between walking capacity and walking activity, and 2) to investigate how biopsychosocial factors and self-efficacy relate to walking activity, above and beyond walking capacity impairment post-stroke. Methods Individuals greater than 3 months post-stroke (n=55) completed the Yesavage Geriatric Depression Scale (GDS), Fatigue Severity Scale (FSS), Modified Cumulative Illness Rating (MCIR) Scale, Walk 12, Activities Specific Balance Confidence (ABC) Scale, Functional Gait Assessment (FGA), and oxygen consumption testing. Walking activity data was collected via a StepWatch Activity Monitor (SAM). Predictors were grouped into 3 constructs: (1) Walking Capacity: oxygen consumption and FGA; (2) Biopsychosocial: GDS, FSS, and MCIR; (3) Self-Efficacy: Walk 12 and ABC. Moderated sequential regression models were used to examine what factors best predicted walking activity. Results Walking capacity explained 35.9% (p<0.001) of the variance in walking activity. Self-efficacy (ΔR2 = 0.15, p<0.001) and the interaction between the FGA*ABC (ΔR2 = 0.047, p<0.001) significantly increased the variability explained. FGA (β=0.37, p=0.01), MCIR (β=−0.26, p=0.01), and Walk 12 (β=−0.45, p=0.00) were each individually significantly associated with walking activity. Discussion/Conclusion While measures of walking capacity and self-efficacy significantly contributed to "real-world" walking activity, balance self-efficacy moderated the relationship between walking capacity and walking activity. Improving low balance self-efficacy may augment walking capacity and translate to improved walking activity post-stroke. PMID:27548750

An exact formulation of the time-ordered exponential using path-sums

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giscard, P.-L., E-mail: p.giscard1@physics.ox.ac.uk; Lui, K.; Thwaite, S. J.

2015-05-15

We present the path-sum formulation for the time-ordered exponential of a time-dependent matrix. The path-sum formulation gives the time-ordered exponential as a branched continued fraction of finite depth and breadth. The terms of the path-sum have an elementary interpretation as self-avoiding walks and self-avoiding polygons on a graph. Our result is based on a representation of the time-ordered exponential as the inverse of an operator, the mapping of this inverse to sums of walks on a graphs, and the algebraic structure of sets of walks. We give examples demonstrating our approach. We establish a super-exponential decay bound for the magnitudemore » of the entries of the time-ordered exponential of sparse matrices. We give explicit results for matrices with commonly encountered sparse structures.« less

Interactions between psychosocial and built environment factors in explaining older adults' physical activity.

PubMed

Carlson, Jordan A; Sallis, James F; Conway, Terry L; Saelens, Brian E; Frank, Lawrence D; Kerr, Jacqueline; Cain, Kelli L; King, Abby C

2012-01-01

To evaluate ecological model predictions of cross-level interactions among psychosocial and environmental correlates of physical activity in 719 community-dwelling older adults in the Baltimore, Maryland and Seattle, Washington areas during 2005-2008. Walkability, access to parks and recreation facilities and moderate-to-vigorous physical activity (MVPA) minutes per week (min/week) were measured objectively. Neighborhood aesthetics, walking facilities, social support, self-efficacy, barriers and transportation and leisure walking min/week were self-reported. Walkability interacted with social support in explaining total MVPA (B=13.71) and with social support (B=7.90), self-efficacy (B=7.66) and barriers (B=-8.26) in explaining walking for transportation. Aesthetics interacted with barriers in explaining total MVPA (B=-12.20) and walking facilities interacted with self-efficacy in explaining walking for leisure (B=-10.88; Ps<.05). Summarizing across the interactions, living in a supportive environment (vs. unsupportive) was related to 30-59 more min/week of physical activity for participants with more positive psychosocial attributes, but only 0-28 more min/week for participants with less positive psychosocial attributes. Results supported synergistic interactions between built environment and psychosocial factors in explaining physical activity among older adults. Findings suggest multilevel interventions may be most effective in increasing physical activity. Copyright © 2011 Elsevier Inc. All rights reserved.

Avoidance of Heights on the Visual Cliff in Newly Walking Infants

ERIC Educational Resources Information Center

Witherington, David C.; Campos, Joseph J.; Anderson, David I.; Lejeune, Laure; Seah, Eileen

2005-01-01

Work with infants on the "visual cliff" links avoidance of drop-offs to experience with self-produced locomotion. Adolph's (2002) research on infants' perception of slope and gap traversability suggests that learning to avoid falling down is highly specific to the postural context in which it occurs. Infants, for example, who have…

The Effects of Shoe Traction and Obstacle Height on Lower Extremity Coordination Dynamics during Walking

PubMed Central

Decker, Leslie; Houser, Jeremy J.; Noble, John M.; Karst, Gregory M.; Stergiou, Nicholas

2009-01-01

This study aims to investigate the effects of shoe traction and obstacle height on lower extremity relative phase dynamics (analysis of intralimb coordination) during walking to better understand the mechanisms employed to avoid slippage following obstacle clearance. Ten participants walked at a self-selected pace during eight conditions: four obstacle heights (0%, 10%, 20%, and 40% of limb length) while wearing two pairs of shoes (low and high traction). A coordination analysis was used and phasing relationships between lower extremity segments were examined. The results demonstrated that significant behavioral changes were elicited under varied obstacle heights and frictional conditions. Both decreasing shoe traction and increasing obstacle height resulted in a more in-phase relationship between the interacting lower limb segments. The higher the obstacle and the lower the shoe traction, the more unstable the system became. These changes in phasing relationship and variability are indicators of alterations in coordinative behavior, which if pushed further may have lead to falling. PMID:19187929

Search for Directed Networks by Different Random Walk Strategies

NASA Astrophysics Data System (ADS)

Zhu, Zi-Qi; Jin, Xiao-Ling; Huang, Zhi-Long

2012-03-01

A comparative study is carried out on the efficiency of five different random walk strategies searching on directed networks constructed based on several typical complex networks. Due to the difference in search efficiency of the strategies rooted in network clustering, the clustering coefficient in a random walker's eye on directed networks is defined and computed to be half of the corresponding undirected networks. The search processes are performed on the directed networks based on Erdös—Rényi model, Watts—Strogatz model, Barabási—Albert model and clustered scale-free network model. It is found that self-avoiding random walk strategy is the best search strategy for such directed networks. Compared to unrestricted random walk strategy, path-iteration-avoiding random walks can also make the search process much more efficient. However, no-triangle-loop and no-quadrangle-loop random walks do not improve the search efficiency as expected, which is different from those on undirected networks since the clustering coefficient of directed networks are smaller than that of undirected networks.

Coherent-Anomaly Method in Self-Avoiding Walk Problems

NASA Astrophysics Data System (ADS)

Hu, Xiao; Suzuki, Masuo

Self-avoiding walk (SAW), being a nonequilibrium cooperative phenomenon, is investigated with a finite-order-restricted-walk (finite-ORW or FORW) coherent-anomaly method (CAM). The coefficient β1r in the asymptotic form Cnr ≃ βlrλn1r for the total number Cnr of r-ORW's with respect to the step number n is investigated for the first time. An asymptotic form for SAW's is thus obtained from the series of FORW approximants, Cnr ≃ brgμ(1 + a/r)n, as the envelope curve Cn ≃ b(ae/g)gμnng. Numerical results are given by Cn ≃ 1.424n0.27884.1507n and Cn ≃ 1.179n0.158710.005n for the plane triangular lattice and f.c.c. lattice, respectively. A good coincidence of the total numbers estimated from the above simple formulae with exact enumerations for finite-step SAW's implies that the essential nature of SAW (non-Markov process) can be understood from FORW (Markov process) in the CAM framework.

Origin of translocation barriers for polyelectrolyte chains.

PubMed

Kumar, Rajeev; Muthukumar, M

2009-11-21

For single-file translocations of a charged macromolecule through a narrow pore, the crucial step of arrival of an end at the pore suffers from free energy barriers, arising from changes in intrachain electrostatic interaction, distribution of ionic clouds and solvent molecules, and conformational entropy of the chain. All contributing factors to the barrier in the initial stage of translocation are evaluated by using the self-consistent field theory for the polyelectrolyte and the coupled Poisson-Boltzmann description for ions without radial symmetry. The barrier is found to be essentially entropic due to conformational changes. For moderate and high salt concentrations, the barriers for the polyelectrolyte chain are quantitatively equivalent to that of uncharged self-avoiding walks. Electrostatic effects are shown to increase the free energy barriers, but only slightly. The degree of ionization, electrostatic interaction strength, decreasing salt concentration, and the solvent quality all result in increases in the barrier.

Counting in Lattices: Combinatorial Problems from Statistical Mechanics.

NASA Astrophysics Data System (ADS)

Randall, Dana Jill

In this thesis we consider two classical combinatorial problems arising in statistical mechanics: counting matchings and self-avoiding walks in lattice graphs. The first problem arises in the study of the thermodynamical properties of monomers and dimers (diatomic molecules) in crystals. Fisher, Kasteleyn and Temperley discovered an elegant technique to exactly count the number of perfect matchings in two dimensional lattices, but it is not applicable for matchings of arbitrary size, or in higher dimensional lattices. We present the first efficient approximation algorithm for computing the number of matchings of any size in any periodic lattice in arbitrary dimension. The algorithm is based on Monte Carlo simulation of a suitable Markov chain and has rigorously derived performance guarantees that do not rely on any assumptions. In addition, we show that these results generalize to counting matchings in any graph which is the Cayley graph of a finite group. The second problem is counting self-avoiding walks in lattices. This problem arises in the study of the thermodynamics of long polymer chains in dilute solution. While there are a number of Monte Carlo algorithms used to count self -avoiding walks in practice, these are heuristic and their correctness relies on unproven conjectures. In contrast, we present an efficient algorithm which relies on a single, widely-believed conjecture that is simpler than preceding assumptions and, more importantly, is one which the algorithm itself can test. Thus our algorithm is reliable, in the sense that it either outputs answers that are guaranteed, with high probability, to be correct, or finds a counterexample to the conjecture. In either case we know we can trust our results and the algorithm is guaranteed to run in polynomial time. This is the first algorithm for counting self-avoiding walks in which the error bounds are rigorously controlled. This work was supported in part by an AT&T graduate fellowship, a University of California dissertation year fellowship and Esprit working group "RAND". Part of this work was done while visiting ICSI and the University of Edinburgh.

Anomalous critical behavior in the polymer collapse transition of three-dimensional lattice trails.

PubMed

Bedini, Andrea; Owczarek, Aleksander L; Prellberg, Thomas

2012-07-01

Trails (bond-avoiding walks) provide an alternative lattice model of polymers to self-avoiding walks, and adding self-interaction at multiply visited sites gives a model of polymer collapse. Recently a two-dimensional model (triangular lattice) where doubly and triply visited sites are given different weights was shown to display a rich phase diagram with first- and second-order collapse separated by a multicritical point. A kinetic growth process of trails (KGTs) was conjectured to map precisely to this multicritical point. Two types of low-temperature phases, a globule phase and a maximally dense phase, were encountered. Here we investigate the collapse properties of a similar extended model of interacting lattice trails on the simple cubic lattice with separate weights for doubly and triply visited sites. Again we find first- and second-order collapse transitions dependent on the relative sizes of the doubly and triply visited energies. However, we find no evidence of a low-temperature maximally dense phase with only the globular phase in existence. Intriguingly, when the ratio of the energies is precisely that which separates the first-order from the second-order regions anomalous finite-size scaling appears. At the finite-size location of the rounded transition clear evidence exists for a first-order transition that persists in the thermodynamic limit. This location moves as the length increases, with its limit apparently at the point that maps to a KGT. However, if one fixes the temperature to sit at exactly this KGT point, then only a critical point can be deduced from the data. The resolution of this apparent contradiction lies in the breaking of crossover scaling and the difference in the shift and transition width (crossover) exponents.

Relevance of physical fitness levels and exercise-related beliefs for self-reported and experimental pain in fibromyalgia: an explorative study.

PubMed

de Bruijn, Saskia T; van Wijck, Albert J M; Geenen, Rinie; Snijders, Tom J; van der Meulen, Wout J T M; Jacobs, Johannes W G; Veldhuijzen, Dieuwke Swaantje

2011-09-01

It has been suggested that low physical fitness is a contributor to pain in fibromyalgia and that exercise-related beliefs play a role in the persistence of this association. Yet the association between physical fitness and pain is hardly explored in detail. The aim of this exploratory study in patients with fibromyalgia was to investigate the association of physical fitness levels with self-reported and experimental pain as well as with pain catastrophizing and activity-avoidance beliefs. Physical fitness of 18 patients with fibromyalgia was examined using maximal ergocycling and the 6-minute walking test (6MWT). Pain intensity was assessed using self-report scales and quantitative sensory testing. A reduced walking distance on the 6MWT was correlated with more severe self-reported pain on the Fibromyalgia Impact Questionnaire (r = -0.52, P < 0.05). Recovery of heart rate after ergocycling was correlated with cold pain thresholds (r = 0.70, P < 0.01), pressure pain thresholds (r = -0.70, P < 0.01), and heat wind-up (r = 0.66, P < 0.05). Activity-avoidance beliefs correlated with a lower peak VO2 on the cycle test (r = -0.52, P < 0.05), a shorter distance on the 6MWT (r = -0.56, P < 0.05), and more severe self-reported pain (r = 0.61, P < 0.05), reflecting that patients with activity-avoidance beliefs were less physically fit and experienced more severe pain. The results demonstrate some associations between physical fitness and pain in fibromyalgia and point to the importance of activity avoidance. Although the causal directionality of the associations needs substantiation in clinical research, the findings support the notion that low fitness and activity-avoidance beliefs should be targeted while treating pain in fibromyalgia.

The associations between objectively-determined and self-reported urban form characteristics and neighborhood-based walking in adults.

PubMed

Jack, Elizabeth; McCormack, Gavin R

2014-06-04

Self-reported and objectively-determined neighborhood built characteristics are associated with physical activity, yet little is known about their combined influence on walking. This study: 1) compared self-reported measures of the neighborhood built environment between objectively-determined low, medium, and high walkable neighborhoods; 2) estimated the relative associations between self-reported and objectively-determined neighborhood characteristics and walking and; 3) examined the extent to which the objectively-determined built environment moderates the association between self-reported measures of the neighborhood built environment and walking. A random cross-section of 1875 Canadian adults completed a telephone-interview and postal questionnaire capturing neighborhood walkability, neighborhood-based walking, socio-demographic characteristics, walking attitudes, and residential self-selection. Walkability of each respondent's neighborhood was objectively-determined (low [LW], medium [MW], and high walkable [HW]). Covariate-adjusted regression models estimated the associations between weekly participation and duration in transportation and recreational walking and self-reported and objectively-determined walkability. Compared with objectively-determined LW neighborhoods, respondents in HW neighborhoods positively perceived access to services, street connectivity, pedestrian infrastructure, and utilitarian and recreation destination mix, but negatively perceived motor vehicle traffic and crime related safety. Compared with residents of objectively-determined LW neighborhoods, residents of HW neighborhoods were more likely (p < .05) to participate in (odds ratio [OR] = 3.06), and spend more time, per week (193 min/wk) transportation walking. Perceived access to services, street connectivity, motor vehicle safety, and mix of recreational destinations were also significantly associated with transportation walking. With regard to interactions, HW x utilitarian destination mix was positively associated with participation, HW x physical barriers and MW x pedestrian infrastructure were positively associated with minutes, and HW x safety from crime was negatively associated with minutes, of transportation walking. Neither neighborhood type nor its interactions with perceived measures of walkability were associated with recreational walking, although perceived aesthetics was associated with participation (OR = 1.18, p < .05). Objectively-determined and self-reported built characteristics are associated with neighborhood-based transportation walking. The objectively-determined built environment might moderate associations between perceptions of walkability and neighborhood-based transportation walking. Interventions that target perceptions in addition to modifications to the neighborhood built environment could result in increases in physical activity among adults.

Coherent-anomaly method in self-avoiding walk problems

NASA Astrophysics Data System (ADS)

Hu, Xiao; Suzuki, Masuo

1988-06-01

Self-avoiding walk (SAW), being a nonequilibrium cooperative phenomenon, is investigated with a finite-order-restricted-walk (finite-ORW or FORW) coherent-anomaly method (CAM). The coefficient β 1 r in the asymptotic form C nr≅ β 1 r λ n1 r for the total number C nr of r- ORW's with respect to the step number n is investigated for the first time. An asymptotic form for SAW's is thus obtained form the series of FORW approximants, C nr≅ brgμ n(1 + a/r) n, as the envelope curve C n≅b(ae/g) gμ nn g. Numerical results are given by C n≅1.424 n0.27884.1507 n and C n≅1.179 n0.158710.005 n for the plane triangular lattice and f.c.c. lattice, respectively. A good coincidence of the total numbers estimated from the above simple formulae with exact enumerations for finite-step SAW's implies that the essential nature of SAW (non-Markov process) can be understood from FORW (Markov process) in the CAM framework.

Critical phenomena on k -booklets

NASA Astrophysics Data System (ADS)

Grassberger, Peter

2017-01-01

We define a "k -booklet" to be a set of k semi-infinite planes with -∞

Finite-size scaling analysis on the phase transition of a ferromagnetic polymer chain model

NASA Astrophysics Data System (ADS)

Luo, Meng-Bo

2006-01-01

The finite-size scaling analysis method is applied to study the phase transition of a self-avoiding walking polymer chain with spatial nearest-neighbor ferromagnetic Ising interaction on the simple cubic lattice. Assuming the scaling M2(T,n)=n-2β/ν[Φ0+Φ1n1/ν(T-Tc)+O(n2/ν(T-Tc)2)] with the square magnetization M2 as the order parameter and the chain length n as the size, we estimate the second-order phase-transition temperature Tc=1.784J/kB and critical exponents 2β/ν≈0.668 and ν ≈1.0. The self-diffusion constant and the chain dimensions ⟨R2⟩ and ⟨S2⟩ do not obey such a scaling law.

Adults' Daily Walking for Travel and Leisure: Interaction Between Attitude Toward Walking and the Neighborhood Environment.

PubMed

Yang, Yong; Diez-Roux, Ana V

2017-09-01

Studies on how the interaction of psychological and environmental characteristics influences walking are limited, and the results are inconsistent. Our aim is to examine how the attitude toward walking and neighborhood environments interacts to influence walking. Cross-sectional phone and mail survey. Participants randomly sampled from 6 study sites including Los Angeles, Chicago, Baltimore, Minneapolis, Manhattan, and Bronx Counties in New York City, and Forsyth and Davidson Counties in North Carolina. The final sample consisted of 2621 persons from 2011 to 2012. Total minutes of walking for travel or leisure, attitude toward walking, and perceptions of the neighborhood environments were self-reported. Street Smart (SS) Walk Score (a measure of walkability derived from a variety of geographic data) was obtained for each residential location. Linear regression models adjusting for age, gender, race/ethnicity, education, and income. Attitude toward walking was positively associated with walking for both purposes. Walking for travel was significantly associated with SS Walk Score, whereas walking for leisure was not. The SS Walk Score and selected perceived environment characteristics were associated with walking in people with a very positive attitude toward walking but were not associated with walking in people with a less positive attitude. Attitudes toward walking and neighborhood environments interact to affect walking behavior.

Self-avoiding walk on a square lattice with correlated vacancies

NASA Astrophysics Data System (ADS)

Cheraghalizadeh, J.; Najafi, M. N.; Mohammadzadeh, H.; Saber, A.

2018-04-01

The self-avoiding walk on the square site-diluted correlated percolation lattice is considered. The Ising model is employed to realize the spatial correlations of the metric space. As a well-accepted result, the (generalized) Flory's mean-field relation is tested to measure the effect of correlation. After exploring a perturbative Fokker-Planck-like equation, we apply an enriched Rosenbluth Monte Carlo method to study the problem. To be more precise, the winding angle analysis is also performed from which the diffusivity parameter of Schramm-Loewner evolution theory (κ ) is extracted. We find that at the critical Ising (host) system, the exponents are in agreement with Flory's approximation. For the off-critical Ising system, we find also a behavior for the fractal dimension of the walker trace in terms of the correlation length of the Ising system ξ (T ) , i.e., DFSAW(T ) -DFSAW(Tc) ˜1/√{ξ (T ) } .

The Feasibility of Adaptive Unstructured Computations On Petaflops Systems

NASA Technical Reports Server (NTRS)

Biswas, Rupak; Oliker, Leonid; Heber, Gerd; Gao, Guang; Saini, Subhash (Technical Monitor)

1999-01-01

This viewgraph presentation covers the advantages of mesh adaptation, unstructured grids, and dynamic load balancing. It illustrates parallel adaptive communications, and explains PLUM (Parallel dynamic load balancing for adaptive unstructured meshes), and PSAW (Proper Self Avoiding Walks).

Cross-sectional interactions between quality of the physical and social environment and self-reported physical activity in adults living in income-deprived communities.

PubMed

Sawyer, Alexia D M; Jones, Russell; Ucci, Marcella; Smith, Lee; Kearns, Ade; Fisher, Abi

2017-01-01

Understanding the environmental determinants of physical activity in populations at high risk of inactivity could contribute to the development of effective interventions. Socioecological models of activity propose that environmental factors have independent and interactive effects of physical activity but there is a lack of research into interactive effects. This study aimed to explore independent and interactive effects of social and physical environmental factors on self-reported physical activity in income-deprived communities. Participants were 5,923 adults in Glasgow, United Kingdom. Features of the social environment were self-reported. Quality of the physical environment was objectively-measured. Neighbourhood walking and participation in moderate physical activity [MPA] on ≥5 days/week was self-reported. Multilevel multivariate logistic regression models tested independent and interactive effects of environmental factors on activity. 'Social support' (walking: OR:1.22,95%CI = 1.06-1.41,p<0.01; MPA: OR:0.79,95%CI = 0.67-0.94,p<0.01), 'social interaction' (walking: OR:1.25,95%CI = 1.10-1.42,p<0.01; MPA: OR:6.16,95%CI = 5.14-7.37,p<0.001) and 'cohesion and safety' (walking: OR:1.78,95%CI = 1.56-2.03,p<0.001; MPA: OR:1.93,95%CI = 1.65-2.27,p<0.001), but not 'trust and empowerment', had independent effects on physical activity. 'Aesthetics of built form' (OR:1.47,95%CI = 1.22-1.77,p<0.001) and 'aesthetics and maintenance of open space' (OR:1.32, 95%CI = 1.13-1.54,p<0.01) were related to walking. 'Physical disorder' (OR:1.63,95%CI = 1.31-2.03,p<0.001) had an independent effect on MPA. Interactive effects of social and physical factors on walking and MPA were revealed. Findings suggest that intervening to create activity-supportive environments in deprived communities may be most effective when simultaneously targeting the social and physical neighbourhood environment.

Can walking motions improve visually induced rotational self-motion illusions in virtual reality?

PubMed

Riecke, Bernhard E; Freiberg, Jacob B; Grechkin, Timofey Y

2015-02-04

Illusions of self-motion (vection) can provide compelling sensations of moving through virtual environments without the need for complex motion simulators or large tracked physical walking spaces. Here we explore the interaction between biomechanical cues (stepping along a rotating circular treadmill) and visual cues (viewing simulated self-rotation) for providing stationary users a compelling sensation of rotational self-motion (circular vection). When tested individually, biomechanical and visual cues were similarly effective in eliciting self-motion illusions. However, in combination they yielded significantly more intense self-motion illusions. These findings provide the first compelling evidence that walking motions can be used to significantly enhance visually induced rotational self-motion perception in virtual environments (and vice versa) without having to provide for physical self-motion or motion platforms. This is noteworthy, as linear treadmills have been found to actually impair visually induced translational self-motion perception (Ash, Palmisano, Apthorp, & Allison, 2013). Given the predominant focus on linear walking interfaces for virtual-reality locomotion, our findings suggest that investigating circular and curvilinear walking interfaces offers a promising direction for future research and development and can help to enhance self-motion illusions, presence and immersion in virtual-reality systems. © 2015 ARVO.

Hierarchical Shared Control of Cane-Type Walking-Aid Robot

PubMed Central

Tao, Chunjing

2017-01-01

A hierarchical shared-control method of the walking-aid robot for both human motion intention recognition and the obstacle emergency-avoidance method based on artificial potential field (APF) is proposed in this paper. The human motion intention is obtained from the interaction force measurements of the sensory system composed of 4 force-sensing registers (FSR) and a torque sensor. Meanwhile, a laser-range finder (LRF) forward is applied to detect the obstacles and try to guide the operator based on the repulsion force calculated by artificial potential field. An obstacle emergency-avoidance method which comprises different control strategies is also assumed according to the different states of obstacles or emergency cases. To ensure the user's safety, the hierarchical shared-control method combines the intention recognition method with the obstacle emergency-avoidance method based on the distance between the walking-aid robot and the obstacles. At last, experiments validate the effectiveness of the proposed hierarchical shared-control method. PMID:29093805

Cross-sectional interactions between quality of the physical and social environment and self-reported physical activity in adults living in income-deprived communities

PubMed Central

2017-01-01

Background Understanding the environmental determinants of physical activity in populations at high risk of inactivity could contribute to the development of effective interventions. Socioecological models of activity propose that environmental factors have independent and interactive effects of physical activity but there is a lack of research into interactive effects. Objectives This study aimed to explore independent and interactive effects of social and physical environmental factors on self-reported physical activity in income-deprived communities. Methods Participants were 5,923 adults in Glasgow, United Kingdom. Features of the social environment were self-reported. Quality of the physical environment was objectively-measured. Neighbourhood walking and participation in moderate physical activity [MPA] on ≥5 days/week was self-reported. Multilevel multivariate logistic regression models tested independent and interactive effects of environmental factors on activity. Results ‘Social support’ (walking: OR:1.22,95%CI = 1.06–1.41,p<0.01; MPA: OR:0.79,95%CI = 0.67–0.94,p<0.01), ‘social interaction’ (walking: OR:1.25,95%CI = 1.10–1.42,p<0.01; MPA: OR:6.16,95%CI = 5.14–7.37,p<0.001) and ‘cohesion and safety’ (walking: OR:1.78,95%CI = 1.56–2.03,p<0.001; MPA: OR:1.93,95%CI = 1.65–2.27,p<0.001), but not ‘trust and empowerment’, had independent effects on physical activity. ‘Aesthetics of built form’ (OR:1.47,95%CI = 1.22–1.77,p<0.001) and ‘aesthetics and maintenance of open space’ (OR:1.32, 95%CI = 1.13–1.54,p<0.01) were related to walking. ‘Physical disorder’ (OR:1.63,95%CI = 1.31–2.03,p<0.001) had an independent effect on MPA. Interactive effects of social and physical factors on walking and MPA were revealed. Conclusions Findings suggest that intervening to create activity-supportive environments in deprived communities may be most effective when simultaneously targeting the social and physical neighbourhood environment. PMID:29240791

An integrative review: application of self-efficacy instruments for walking in populations with peripheral arterial disease.

PubMed

Caldieraro-Bentley, Angela J; Andrews, Jeannette O

2013-09-01

The study objective was to identify which self-efficacy measurement instruments are being used for walking in patients with peripheral arterial disease (PAD), the psychometrics of these instruments, and recommendations for use in research on patients with PAD. PAD is a common problem for individuals with similar risk factors as cardiovascular disease (CVD). Experts recommend a supervised walking program with incremental increases in speed and distance as an initial treatment for patients with intermittent claudication. Because patients may experience pain while walking, there is a tendency to be nonadherent with exercise therapy, and many limit or avoid walking all together, resulting in a sedentary lifestyle. Self-efficacy plays a role in determining a person's confidence in his or her ability to participate in an exercise program. Data sources for this study were PubMed, Cumulative Index of Nursing and Allied Health Literature, PsycINFO, and the Cochrane database. The integrative review method described by Wittemore and Knafl was used for this review (Wittemore R, Knafl K. The integrative review: updated methodology. J Adv Nurs 2005;52:546-53.). Publications were retrieved electronically and reviewed for inclusion on the basis of studies that measured self-efficacy for walking in populations with PAD, peripheral vascular disease, and CVD. The analysis consisted of 9 publications. Only 2 studies were specific to the population with PAD. The remaining studies addressed self-efficacy issues in CVD or congestive heart failure. The analysis identified 4 instruments based on Bandura's Social Cognitive Theory that were used to assess self-efficacy: (1) the Self-Efficacy Expectation Scale, (2) the Self-Efficacy for Managing Chronic Disease Scale, (3) the Performance-Based Efficacy Scale, and (4) the Barriers Self-Efficacy Scale. The Self-Efficacy Expectation Scale was most frequently used in these studies. The use of the Self-Efficacy Expectation Scale instruments for walking in patients with PAD is limited because reliability and validity have been demonstrated in an older, mostly white population with CVD and congestive heart failure. Instruments that encompass the key constructs of self-efficacy, including physical, personal, and environmental aspects, would allow full evaluation with identification of potential explanations for success or failure for the chosen outcome. This should be taken into consideration in future studies when using instruments of self-efficacy. Copyright © 2013 Society for Vascular Nursing, Inc. Published by Mosby, Inc. All rights reserved.

Self-interacting polymer chains terminally anchored to adsorbing surfaces of three-dimensional fractal lattices

NASA Astrophysics Data System (ADS)

Živić, I.; Elezović-Hadžić, S.; Milošević, S.

2018-01-01

We have studied the adsorption problem of self-attracting linear polymers, modeled by self-avoiding walks (SAWs), situated on three-dimensional fractal structures, exemplified by 3d Sierpinski gasket (SG) family of fractals as containers of a poor solvent. Members of SG family are enumerated by an integer b (b ≥ 2), and it is assumed that one side of each SG fractal is an impenetrable adsorbing surface. We calculate the critical exponents γ1 ,γ11, and γs, which are related to the numbers of all possible SAWs with one, both, and no ends anchored to the adsorbing boundary, respectively. By applying the exact renormalization group (RG) method (for the first three members of the SG fractal family, b = 2 , 3, and 4), we have obtained specific values of these exponents, for θ-chain and globular polymer phase. We discuss their mutual relations and relations with corresponding values pertinent to extended polymer chain phase.

Hierarchical random walks in trace fossils and the origin of optimal search behavior

PubMed Central

Sims, David W.; Reynolds, Andrew M.; Humphries, Nicolas E.; Southall, Emily J.; Wearmouth, Victoria J.; Metcalfe, Brett; Twitchett, Richard J.

2014-01-01

Efficient searching is crucial for timely location of food and other resources. Recent studies show that diverse living animals use a theoretically optimal scale-free random search for sparse resources known as a Lévy walk, but little is known of the origins and evolution of foraging behavior and the search strategies of extinct organisms. Here, using simulations of self-avoiding trace fossil trails, we show that randomly introduced strophotaxis (U-turns)—initiated by obstructions such as self-trail avoidance or innate cueing—leads to random looping patterns with clustering across increasing scales that is consistent with the presence of Lévy walks. This predicts that optimal Lévy searches may emerge from simple behaviors observed in fossil trails. We then analyzed fossilized trails of benthic marine organisms by using a novel path analysis technique and find the first evidence, to our knowledge, of Lévy-like search strategies in extinct animals. Our results show that simple search behaviors of extinct animals in heterogeneous environments give rise to hierarchically nested Brownian walk clusters that converge to optimal Lévy patterns. Primary productivity collapse and large-scale food scarcity characterizing mass extinctions evident in the fossil record may have triggered adaptation of optimal Lévy-like searches. The findings suggest that Lévy-like behavior has been used by foragers since at least the Eocene but may have a more ancient origin, which might explain recent widespread observations of such patterns among modern taxa. PMID:25024221

Why some walk and others don't: exploring interactions of perceived safety and social neighborhood factors with psychosocial cognitions.

PubMed

Beenackers, Mariëlle A; Kamphuis, Carlijn B M; Mackenbach, Johan P; Burdorf, Alex; van Lenthe, Frank J

2013-04-01

Although physical activity is often believed to be influenced by both environmental and individual factors, little is known about their interaction. This study explores interactions of perceived safety and social neighborhood factors with psychosocial cognitions for leisure-time walking. Cross-sectional data were obtained from residents (age 25-75 years) of 212 neighborhoods in the South-East of the Netherlands, who participated in the Dutch GLOBE study in 2004 (N = 4395, survey response 64.4%). Direct associations of, and interactions between perceived neighborhood safety, social neighborhood factors (social cohesion, social network and feeling at home) and psychosocial cognitions (attitude, self-efficacy, social influence and intention) on two outcomes of leisure-time walking [yes versus no (binary), and among walkers: minutes per week (continuous)] were analyzed in multilevel regression models. The association between attitude and participating in leisure-time walking was stronger in those who felt less at home in their neighborhood. Social influence and attitude were stronger associated with participation in leisure-time walking in those who sometimes felt unsafe in their neighborhood. A positive intention was associated with more minutes walked in those who perceived their neighborhood as unsafe among those who walked. Only limited support was found for interactions between neighborhood perceptions and psychosocial cognitions for leisure-time walking.

Urban form and psychosocial factors: do they interact for leisure-time walking?

PubMed

Beenackers, Mariëlle A; Kamphuis, Carlijn B M; Prins, Richard G; Mackenbach, Johan P; Burdorf, Alex; van Lenthe, Frank J

2014-02-01

This cross-sectional study uses an adaptation of a social-ecological model on the hierarchy of walking needs to explore direct associations and interactions of urban-form characteristics and individual psychosocial factors for leisure-time walking. Questionnaire data (n = 736) from adults (25-74 yr) and systematic field observations within 14 neighborhoods in Eindhoven (the Netherlands) were used. Multilevel logistic regression models were used to relate the urban-form characteristics (accessibility, safety, comfort, and pleasurability) and individual psychosocial factors (attitude, self-efficacy, social influence, and intention) to two definitions of leisure-time walking, that is, any leisure-time walking and sufficient leisure-time walking according to the Dutch physical activity norm and to explore their interactions. Leisure-time walking was associated with psychosocial factors but not with characteristics of the urban environment. For sufficient leisure-time walking, interactions between attitude and several urban-form characteristics were found, indicating that positive urban-form characteristics contributed toward leisure-time walking only in residents with a less positive attitude toward physical activity. In contrast, living in a neighborhood that was accessible for walking was stronger associated with leisure-time walking among residents who experienced a positive social influence to engage in physical activity compared with those who reported less social influence. This study showed some evidence for an interaction between the neighborhood environment and the individual psychosocial factors in explaining leisure-time walking. The specific mechanism of interaction may depend on the specific combination of psychosocial factor and environmental factor. The lack of association between urban form and leisure-time walking could be partly due to the little variation in urban-form characteristics between neighborhoods.

Self-efficacy, pain, and quadriceps capacity at baseline predict changes in mobility performance over 2 years in women with knee osteoarthritis.

PubMed

Brisson, Nicholas M; Gatti, Anthony A; Stratford, Paul W; Maly, Monica R

2018-02-01

This study examined the extent to which baseline measures of quadriceps strength, quadriceps power, knee pain and self-efficacy for functional tasks, and their interactions, predicted 2-year changes in mobility performance (walking, stair ascent, stair descent) in women with knee osteoarthritis. We hypothesized that lesser strength, power and self-efficacy, and higher pain at baseline would each be independently associated with reduced mobility over 2 years, and each of pain and self-efficacy would interact with strength and power in predicting 2-year change in stair-climbing performance. This was a longitudinal, observational study of women with clinical knee osteoarthritis. At baseline and follow-up, mobility was assessed with the Six-Minute Walk Test, and stair ascent and descent tasks. Quadriceps strength and power, knee pain, and self-efficacy for functional tasks were also collected at baseline. Multiple linear regression examined the extent to which 2-year changes in mobility performances were predicted by baseline strength, power, pain, and self-efficacy, after adjusting for covariates. Data were analyzed for 37 women with knee osteoarthritis over 2 years. Lower baseline self-efficacy predicted decreased walking (β = 1.783; p = 0.030) and stair ascent (β = -0.054; p < 0.001) performances over 2 years. Higher baseline pain intensity/frequency predicted decreased walking performance (β = 1.526; p = 0.002). Lower quadriceps strength (β = 0.051; p = 0.015) and power (β = 0.022; p = 0.022) interacted with lesser self-efficacy to predict worsening stair ascent performance. Strategies to sustain or improve mobility in women with knee osteoarthritis must focus on controlling pain and boosting self-efficacy. In those with worse self-efficacy, developing knee muscle capacity is an important target.

Assessing interactions among multiple physiological systems during walking outside a laboratory: An Android based gait monitor

PubMed Central

Sejdić, E.; Millecamps, A.; Teoli, J.; Rothfuss, M. A.; Franconi, N. G.; Perera, S.; Jones, A. K.; Brach, J. S.; Mickle, M. H.

2015-01-01

Gait function is traditionally assessed using well-lit, unobstructed walkways with minimal distractions. In patients with subclinical physiological abnormalities, these conditions may not provide enough stress on their ability to adapt to walking. The introduction of challenging walking conditions in gait can induce responses in physiological systems in addition to the locomotor system. There is a need for a device that is capable of monitoring multiple physiological systems in various walking conditions. To address this need, an Android-based gait-monitoring device was developed that enabled the recording of a patient's physiological systems during walking. The gait-monitoring device was tested during self-regulated overground walking sessions of fifteen healthy subjects that included 6 females and 9 males aged 18 to 35 years. The gait-monitoring device measures the patient's stride interval, acceleration, electrocardiogram, skin conductance and respiratory rate. The data is stored on an Android phone and is analyzed offline through the extraction of features in the time, frequency and time-frequency domains. The analysis of the data depicted multisystem physiological interactions during overground walking in healthy subjects. These interactions included locomotion-electrodermal, locomotion-respiratory and cardiolocomotion couplings. The current results depicting strong interactions between the locomotion system and the other considered systems (i.e., electrodermal, respiratory and cardivascular systems) warrant further investigation into multisystem interactions during walking, particularly in challenging walking conditions with older adults. PMID:26390946

A semiflexible alternating copolymer chain adsorption on a flat and a fluctuating surface.

PubMed

Mishra, Pramod Kumar

2010-04-21

A lattice model of a directed self-avoiding walk is used to investigate adsorption properties of a semiflexible alternating copolymer chain on an impenetrable flat and fluctuating surface in two (square, hexagonal and rectangular lattice) and three dimensions (cubic lattice). In the cubic lattice case the surface is two-dimensional impenetrable flat and in two dimensions the surface is a fluctuating impenetrable line (hexagonal lattice) and also flat impenetrable line (square and rectangular lattice). Walks of the copolymer chains are directed perpendicular to the plane of the surface and at a suitable value of monomer surface attraction, the copolymer chain gets adsorbed on the surface. To calculate the exact value of the monomer surface attraction, the directed walk model has been solved analytically using the generating function method to discuss results when one type of monomer of the copolymer chain has attractive, repulsive or no interaction with the surface. Results obtained in the flat surface case show that, for a stiffer copolymer chain, adsorption transition occurs at a smaller value of monomer surface attraction than a flexible copolymer chain while in the case of a fluctuating surface, the adsorption transition point is independent of bending energy of the copolymer chain. These features are similar to that of a semiflexible homopolymer chain adsorption.

Monte Carlo simulations of lattice models for single polymer systems

NASA Astrophysics Data System (ADS)

Hsu, Hsiao-Ping

2014-10-01

Single linear polymer chains in dilute solutions under good solvent conditions are studied by Monte Carlo simulations with the pruned-enriched Rosenbluth method up to the chain length N ˜ O(10^4). Based on the standard simple cubic lattice model (SCLM) with fixed bond length and the bond fluctuation model (BFM) with bond lengths in a range between 2 and sqrt{10}, we investigate the conformations of polymer chains described by self-avoiding walks on the simple cubic lattice, and by random walks and non-reversible random walks in the absence of excluded volume interactions. In addition to flexible chains, we also extend our study to semiflexible chains for different stiffness controlled by a bending potential. The persistence lengths of chains extracted from the orientational correlations are estimated for all cases. We show that chains based on the BFM are more flexible than those based on the SCLM for a fixed bending energy. The microscopic differences between these two lattice models are discussed and the theoretical predictions of scaling laws given in the literature are checked and verified. Our simulations clarify that a different mapping ratio between the coarse-grained models and the atomistically realistic description of polymers is required in a coarse-graining approach due to the different crossovers to the asymptotic behavior.

Crossover transition in flowing granular chains

NASA Astrophysics Data System (ADS)

Ulrich, Xialing; Fried, Eliot; Shen, Amy Q.

2009-09-01

We report on the dynamical and statistical behavior of flowing collections of granular chains confined two-dimensionally (2D) within a rotating tumbler. Experiments are conducted with systems of chains of fixed length, but various lengths are considered. The dynamics are punctuated by cascades of chains along a free-surface cascades, which drive the development of mixed porous/laminar packing arrangements in bulk. We investigate the conformation of the system, as characterized by the porosity of the flow region occupied by the chains and the mean-square end-to-end distance of the chains during flow. Both of these measures show crossover transitions from a 2D self-avoiding walk to a 2D random walk when the chain length becomes long enough to allow self-contact.

Neighborhood walkability, fear and risk of falling and response to walking promotion: The Easy Steps to Health 12-month randomized controlled trial.

PubMed

Merom, D; Gebel, K; Fahey, P; Astell-Burt, T; Voukelatos, A; Rissel, C; Sherrington, C

2015-01-01

In older adults the relationships between health, fall-related risk factors, perceived neighborhood walkability, walking behavior and intervention impacts are poorly understood. To determine whether: i) health and fall-related risk factors were associated with perceptions of neighborhood walkability; ii) perceived environmental attributes, and fall-related risk factors predicted change in walking behavior at 12 months; and iii) perceived environmental attributes and fall-related risk factors moderated the effect of a self-paced walking program on walking behavior. Randomized trial on walking and falls conducted between 2009 and 2012 involving 315 community-dwelling inactive adults ≥ 65 years living in Sydney, Australia. Measures were: mobility status, fall history, injurious fall and fear of falling (i.e., fall-related risk factors), health status, walking self-efficacy and 11 items from the neighborhood walkability scale and planned walking ≥ 150 min/week at 12 months. Participants with poorer mobility, fear of falling, and poor health perceived their surroundings as less walkable. Walking at 12 months was significantly greater in "less greenery" (AOR = 3.3, 95% CI: 1.11-9.98) and "high traffic" (AOR = 1.98, 95% CI: 1.00-3.91) neighborhoods. The intervention had greater effects in neighborhoods perceived to have poorer pedestrian infrastructure (p for interaction = 0.036). Low perceived walkability was shaped by health status and did not appear to be a barrier to walking behavior. There appears to be a greater impact of, and thus, need for, interventions to encourage walking in environments perceived not to have supportive walking infrastructure. Future studies on built environments and walking should gather information on fall-related risk factors to better understand how these characteristics interact.

The walking behaviour of pedestrian social groups and its impact on crowd dynamics.

PubMed

Moussaïd, Mehdi; Perozo, Niriaska; Garnier, Simon; Helbing, Dirk; Theraulaz, Guy

2010-04-07

Human crowd motion is mainly driven by self-organized processes based on local interactions among pedestrians. While most studies of crowd behaviour consider only interactions among isolated individuals, it turns out that up to 70% of people in a crowd are actually moving in groups, such as friends, couples, or families walking together. These groups constitute medium-scale aggregated structures and their impact on crowd dynamics is still largely unknown. In this work, we analyze the motion of approximately 1500 pedestrian groups under natural condition, and show that social interactions among group members generate typical group walking patterns that influence crowd dynamics. At low density, group members tend to walk side by side, forming a line perpendicular to the walking direction. As the density increases, however, the linear walking formation is bent forward, turning it into a V-like pattern. These spatial patterns can be well described by a model based on social communication between group members. We show that the V-like walking pattern facilitates social interactions within the group, but reduces the flow because of its "non-aerodynamic" shape. Therefore, when crowd density increases, the group organization results from a trade-off between walking faster and facilitating social exchange. These insights demonstrate that crowd dynamics is not only determined by physical constraints induced by other pedestrians and the environment, but also significantly by communicative, social interactions among individuals.

Mapping of the Bak, Tang, and Wiesenfeld sandpile model on a two-dimensional Ising-correlated percolation lattice to the two-dimensional self-avoiding random walk

NASA Astrophysics Data System (ADS)

Cheraghalizadeh, J.; Najafi, M. N.; Dashti-Naserabadi, H.; Mohammadzadeh, H.

2017-11-01

The self-organized criticality on the random fractal networks has many motivations, like the movement pattern of fluid in the porous media. In addition to the randomness, introducing correlation between the neighboring portions of the porous media has some nontrivial effects. In this paper, we consider the Ising-like interactions between the active sites as the simplest method to bring correlations in the porous media, and we investigate the statistics of the BTW model in it. These correlations are controlled by the artificial "temperature" T and the sign of the Ising coupling. Based on our numerical results, we propose that at the Ising critical temperature Tc the model is compatible with the universality class of two-dimensional (2D) self-avoiding walk (SAW). Especially the fractal dimension of the loops, which are defined as the external frontier of the avalanches, is very close to DfSAW=4/3 . Also, the corresponding open curves has conformal invariance with the root-mean-square distance Rrms˜t3 /4 (t being the parametrization of the curve) in accordance with the 2D SAW. In the finite-size study, we observe that at T =Tc the model has some aspects compatible with the 2D BTW model (e.g., the 1 /log(L ) -dependence of the exponents of the distribution functions) and some in accordance with the Ising model (e.g., the 1 /L -dependence of the fractal dimensions). The finite-size scaling theory is tested and shown to be fulfilled for all statistical observables in T =Tc . In the off-critical temperatures in the close vicinity of Tc the exponents show some additional power-law behaviors in terms of T -Tc with some exponents that are reported in the text. The spanning cluster probability at the critical temperature also scales with L1/2, which is different from the regular 2D BTW model.

Critical Two-Point Function for Long-Range O( n) Models Below the Upper Critical Dimension

NASA Astrophysics Data System (ADS)

Lohmann, Martin; Slade, Gordon; Wallace, Benjamin C.

2017-12-01

We consider the n-component |φ|^4 lattice spin model (n ≥ 1) and the weakly self-avoiding walk (n=0) on Z^d, in dimensions d=1,2,3. We study long-range models based on the fractional Laplacian, with spin-spin interactions or walk step probabilities decaying with distance r as r^{-(d+α )} with α \\in (0,2). The upper critical dimension is d_c=2α . For ɛ >0, and α = 1/2 (d+ɛ ), the dimension d=d_c-ɛ is below the upper critical dimension. For small ɛ , weak coupling, and all integers n ≥ 0, we prove that the two-point function at the critical point decays with distance as r^{-(d-α )}. This "sticking" of the critical exponent at its mean-field value was first predicted in the physics literature in 1972. Our proof is based on a rigorous renormalisation group method. The treatment of observables differs from that used in recent work on the nearest-neighbour 4-dimensional case, via our use of a cluster expansion.

Self-paced versus fixed speed walking and the effect of virtual reality in children with cerebral palsy.

PubMed

Sloot, Lizeth H; Harlaar, Jaap; van der Krogt, Marjolein M

2015-10-01

While feedback-controlled treadmills with a virtual reality could potentially offer advantages for clinical gait analysis and training, the effect of self-paced walking and the virtual environment on the gait pattern of children and different patient groups remains unknown. This study examined the effect of self-paced (SP) versus fixed speed (FS) walking and of walking with and without a virtual reality (VR) in 11 typically developing (TD) children and nine children with cerebral palsy (CP). We found that subjects walked in SP mode with twice as much between-stride walking speed variability (p<0.01), fluctuating over multiple strides. There was no main effect of SP on kinematics or kinetics, but small interaction effects between SP and group (TD versus CP) were found for five out of 33 parameters. This suggests that children with CP might need more time to familiarize to SP walking, however, these differences were generally too small to be clinically relevant. The VR environment did not affect the kinematic or kinetic parameters, but walking with VR was rated as more similar to overground walking by both groups (p=0.02). The results of this study indicate that both SP and FS walking, with and without VR, can be used interchangeably for treadmill-based clinical gait analysis in children with and without CP. Copyright © 2015 Elsevier B.V. All rights reserved.

Starfish Behavior as an Anticipatory System: Its Flexibility in Obstacle Avoidance

NASA Astrophysics Data System (ADS)

Migita, Masao

2006-06-01

As starfish do not have central nervous systems, their behaviors such as walking, righting, feeding, and so on, must be produced by some processes of self-organization of many motor organs. It has been noticed that self-organized behavioral patterns are not strictly determined by external stimuli, though such stimuli may elicit the very self-organization processes. In this sense, starfish are not only reactive like a conventional discourse of comparative psychology have presupposed. In this study, I will show diversity in self-organized behavior of a starfish exhibited under experiments on obstacle avoidance. The starfish may be considered as an anticipatory system, because it usually appeared to be free from serious deadlock at the obstacles. I will also discuss that to view the animal as an anticipatory system may have an interesting implication on the fields of behavioral biology and comparative psychology.

Adaptive, fast walking in a biped robot under neuronal control and learning.

PubMed

Manoonpong, Poramate; Geng, Tao; Kulvicius, Tomas; Porr, Bernd; Wörgötter, Florentin

2007-07-01

Human walking is a dynamic, partly self-stabilizing process relying on the interaction of the biomechanical design with its neuronal control. The coordination of this process is a very difficult problem, and it has been suggested that it involves a hierarchy of levels, where the lower ones, e.g., interactions between muscles and the spinal cord, are largely autonomous, and where higher level control (e.g., cortical) arises only pointwise, as needed. This requires an architecture of several nested, sensori-motor loops where the walking process provides feedback signals to the walker's sensory systems, which can be used to coordinate its movements. To complicate the situation, at a maximal walking speed of more than four leg-lengths per second, the cycle period available to coordinate all these loops is rather short. In this study we present a planar biped robot, which uses the design principle of nested loops to combine the self-stabilizing properties of its biomechanical design with several levels of neuronal control. Specifically, we show how to adapt control by including online learning mechanisms based on simulated synaptic plasticity. This robot can walk with a high speed (>3.0 leg length/s), self-adapting to minor disturbances, and reacting in a robust way to abruptly induced gait changes. At the same time, it can learn walking on different terrains, requiring only few learning experiences. This study shows that the tight coupling of physical with neuronal control, guided by sensory feedback from the walking pattern itself, combined with synaptic learning may be a way forward to better understand and solve coordination problems in other complex motor tasks.

Human-Robot Interaction: Does Robotic Guidance Force Affect Gait-Related Brain Dynamics during Robot-Assisted Treadmill Walking?

PubMed

Knaepen, Kristel; Mierau, Andreas; Swinnen, Eva; Fernandez Tellez, Helio; Michielsen, Marc; Kerckhofs, Eric; Lefeber, Dirk; Meeusen, Romain

2015-01-01

In order to determine optimal training parameters for robot-assisted treadmill walking, it is essential to understand how a robotic device interacts with its wearer, and thus, how parameter settings of the device affect locomotor control. The aim of this study was to assess the effect of different levels of guidance force during robot-assisted treadmill walking on cortical activity. Eighteen healthy subjects walked at 2 km.h-1 on a treadmill with and without assistance of the Lokomat robotic gait orthosis. Event-related spectral perturbations and changes in power spectral density were investigated during unassisted treadmill walking as well as during robot-assisted treadmill walking at 30%, 60% and 100% guidance force (with 0% body weight support). Clustering of independent components revealed three clusters of activity in the sensorimotor cortex during treadmill walking and robot-assisted treadmill walking in healthy subjects. These clusters demonstrated gait-related spectral modulations in the mu, beta and low gamma bands over the sensorimotor cortex related to specific phases of the gait cycle. Moreover, mu and beta rhythms were suppressed in the right primary sensory cortex during treadmill walking compared to robot-assisted treadmill walking with 100% guidance force, indicating significantly larger involvement of the sensorimotor area during treadmill walking compared to robot-assisted treadmill walking. Only marginal differences in the spectral power of the mu, beta and low gamma bands could be identified between robot-assisted treadmill walking with different levels of guidance force. From these results it can be concluded that a high level of guidance force (i.e., 100% guidance force) and thus a less active participation during locomotion should be avoided during robot-assisted treadmill walking. This will optimize the involvement of the sensorimotor cortex which is known to be crucial for motor learning.

Reference trajectory generation for rehabilitation robots: complementary limb motion estimation.

PubMed

Vallery, Heike; van Asseldonk, Edwin H F; Buss, Martin; van der Kooij, Herman

2009-02-01

For gait rehabilitation robots, an important question is how to ensure stable gait, while avoiding any interaction forces between robot and human in case the patient walks correctly. To achieve this, the definition of "correct" gait needs to adapted both to the individual patient and to the situation. Recently, we proposed a method for online trajectory generation that can be applied for hemiparetic subjects. Desired states for one (disabled) leg are generated online based on the movements of the other (sound) leg. An instantaneous mapping between legs is performed by exploiting physiological interjoint couplings. This way, the patient generates the reference motion for the affected leg autonomously. The approach, called Complementary Limb Motion Estimation (CLME), is implemented on the LOPES gait rehabilitation robot and evaluated with healthy subjects in two different experiments. In a previously described study, subjects walk only with one leg, while the robot's other leg acts as a fake prosthesis, to simulate complete loss of function in one leg. This study showed that CLME ensures stable gait. In a second study, to be presented in this paper, healthy subjects walk with both their own legs to assess the interference with self-determined walking. Evaluation criteria are: Power delivered to the joints by the robot, electromyography (EMG) distortions, and kinematic distortions, all compared to zero torque control, which is the baseline of minimum achievable interference. Results indicate that interference of the robot is lower with CLME than with a fixed reference trajectory, mainly in terms of lowered exchanged power and less alteration of EMG. This implies that subjects can walk more naturally with CLME, and they are assisted less by the robot when it is not needed. Future studies with patients are yet to show whether these properties of CLME transfer to the clinical domain.

The effect of facial expressions on peripersonal and interpersonal spaces.

PubMed

Ruggiero, Gennaro; Frassinetti, Francesca; Coello, Yann; Rapuano, Mariachiara; di Cola, Armando Schiano; Iachini, Tina

2017-11-01

Identifying individuals' intent through the emotional valence conveyed by their facial expression influences our capacity to approach-avoid these individuals during social interactions. Here, we explore if and how the emotional valence of others' facial expressiveness modulates peripersonal-action and interpersonal-social spaces. Through Immersive Virtual Reality, participants determined reachability-distance (for peripersonal space) and comfort-distance (for interpersonal space) from male/female virtual confederates exhibiting happy, angry and neutral facial expressions while being approached by (passive-approach) or walking toward (active-approach) them. Results showed an increase of distance when seeing angry rather than happy confederates in both approach conditions of comfort-distance. The effect also appeared in reachability-distance, but only in the passive-approach. Anger prompts avoidant behaviors, and thus an expansion of distance, particularly with a potential violation of near body space by an intruder. Overall, the findings suggest that peripersonal-action space, in comparison with interpersonal-social space, is similarly sensitive to the emotional valence of stimuli. We propose that this similarity could reflect a common adaptive mechanism shared by these spaces, presumably at different degrees, for ensuring self-protection functions.

Location of the adsorption transition for lattice polymers

NASA Astrophysics Data System (ADS)

Madras, Neal

2017-02-01

We consider various lattice models of polymers: lattice trees, lattice animals, and self-avoiding walks. The polymer interacts with a surface (hyperplane), receiving an energy reward of β for each site in the surface. It is known that there is an adsorption transition at a critical value of β. We present a new proof of the result of Hammersley et al (1982 J. Phys. A: Math. Gen. 15 539-71) that the transition occurs at a strictly positive value of β when the surface is impenetrable, i.e. when the polymer is restricted to a half-space. In contrast, for a penetrable surface, it is an open problem to prove that the transition occurs at β =0 . We reduce this problem to proving that the fraction of N-site polymers whose span is less than N/{{log}2}N is not too small.

Crowd of individuals walking in opposite directions. A toy model to study the segregation of the group into lanes of individuals moving in the same direction

NASA Astrophysics Data System (ADS)

Goldsztein, Guillermo H.

2017-08-01

Consider a corridor, street or bridge crowded with pedestrians walking in both directions. The individuals do not walk in a completely straight line. They adjust their path to avoid colliding with incoming pedestrians. As a result of these adjustments, the whole group sometimes end up split into lanes of individuals moving in the same direction. While this formation of lanes facilitates the flow and benefits the whole group, it is believed that results from the actions of the individuals acting only on their behalf, without considering others. This phenomenon is an example of self-organization. We analyze a simple model. We assume that individuals move around a two-lane circular track. All of them at the same speed. Half of them in one direction and the rest in the opposite direction. Each time two individuals collide, one of them moves to the other lane. The individual changing lanes is selected randomly. The system self-organizes. Eventually each lane is occupied with individuals moving in only one direction. We show that the time required for the system to self-organize is bounded by a linear function on the number of individuals. This toy model provides an example where global self-organization occurs even though each member of the group acts without considering the rest.

Mapping of the Bak, Tang, and Wiesenfeld sandpile model on a two-dimensional Ising-correlated percolation lattice to the two-dimensional self-avoiding random walk.

PubMed

Cheraghalizadeh, J; Najafi, M N; Dashti-Naserabadi, H; Mohammadzadeh, H

2017-11-01

The self-organized criticality on the random fractal networks has many motivations, like the movement pattern of fluid in the porous media. In addition to the randomness, introducing correlation between the neighboring portions of the porous media has some nontrivial effects. In this paper, we consider the Ising-like interactions between the active sites as the simplest method to bring correlations in the porous media, and we investigate the statistics of the BTW model in it. These correlations are controlled by the artificial "temperature" T and the sign of the Ising coupling. Based on our numerical results, we propose that at the Ising critical temperature T_{c} the model is compatible with the universality class of two-dimensional (2D) self-avoiding walk (SAW). Especially the fractal dimension of the loops, which are defined as the external frontier of the avalanches, is very close to D_{f}^{SAW}=4/3. Also, the corresponding open curves has conformal invariance with the root-mean-square distance R_{rms}∼t^{3/4} (t being the parametrization of the curve) in accordance with the 2D SAW. In the finite-size study, we observe that at T=T_{c} the model has some aspects compatible with the 2D BTW model (e.g., the 1/log(L)-dependence of the exponents of the distribution functions) and some in accordance with the Ising model (e.g., the 1/L-dependence of the fractal dimensions). The finite-size scaling theory is tested and shown to be fulfilled for all statistical observables in T=T_{c}. In the off-critical temperatures in the close vicinity of T_{c} the exponents show some additional power-law behaviors in terms of T-T_{c} with some exponents that are reported in the text. The spanning cluster probability at the critical temperature also scales with L^{1/2}, which is different from the regular 2D BTW model.

When is success not satisfying? Integrating regulatory focus and approach/avoidance motivation theories to explain the relation between core self-evaluation and job satisfaction.

PubMed

Ferris, D Lance; Johnson, Russell E; Rosen, Christopher C; Djurdjevic, Emilija; Chang, Chu-Hsiang Daisy; Tan, James A

2013-03-01

Integrating implications from regulatory focus and approach/avoidance motivation theories, we present a framework wherein motivational orientations toward positive (approach motivation orientation) or negative (avoidance motivation orientation) stimuli interact with workplace success to mediate the relation of core self-evaluation (CSE) with job satisfaction. Using data collected from supervisor-subordinate dyads (Sample 1) and time-lagged data (Sample 2), we found that the results from two studies indicated that the interaction of workplace success and avoidance motivation orientation mediated relations of CSE with job satisfaction. Although approach motivation orientation did not interact with workplace success, it did mediate the CSE-job satisfaction relation on its own. Implications for the CSE and approach/avoidance literatures are discussed.

Cross-sectional and longitudinal associations between parenting style and adolescent girls’ physical activity

PubMed Central

2012-01-01

Background Understanding the influences on physical activity is crucial, particularly among important target groups such as adolescent girls. This study describes cross-sectional and longitudinal associations between parenting style and girls’ participation in organized sport, walking/cycling trips and objectively assessed moderate to vigorous physical activity (MVPA). Methods Data were collected from adolescent girls (n=222) and their parents in 2004 and again in 2006. Parents self-reported their demographic characteristics and parenting style. Girls self-reported their organized sport participation and weekly walking/cycling trips, while MVPA was assessed using accelerometers. Linear regression and interaction analyses were performed. Interactions between socio-demographic factors and parenting style with organized sport, walking/cycling trips and MVPA are presented. Results There were cross-sectional associations between authoritative (B=−0.45, p=0.042) and indulgent (B=−0.56, p=0.002) parenting and the number of walking/cycling trips, and authoritarian (B=0.27, p=0.033) parenting and frequency of organized sport. Significant interactions included those between: family status, authoritative parenting and daily (p=0.048) and week day (p=0.013) MVPA; education, indulgent parenting and MVPA on weekend days (p=0.006); and, employment, authoritarian parenting and duration and frequency of organized sport (p=0.004), highlighting the complexity of these relationships. Longitudinal analyses revealed significant decreases in organized sport and MVPA, significant increases in walking/cycling trips and no significant associations between parenting and physical activity. Conclusion Parenting styles appear to influence walking and cycling trips among adolescent girls, though not physical activity within other domains. Socio-demographic characteristics interact with the relationships between parenting and physical activity. While these findings can inform the development of family-based interventions to improve child and adolescent health, the direction of the observed associations and the number of associations approaching significance suggest the need to further explore this area. PMID:23199218

Cross-sectional and longitudinal associations between parenting style and adolescent girls' physical activity.

PubMed

Saunders, Julie; Hume, Clare; Timperio, Anna; Salmon, Jo

2012-12-03

Understanding the influences on physical activity is crucial, particularly among important target groups such as adolescent girls. This study describes cross-sectional and longitudinal associations between parenting style and girls' participation in organized sport, walking/cycling trips and objectively assessed moderate to vigorous physical activity (MVPA). Data were collected from adolescent girls (n=222) and their parents in 2004 and again in 2006. Parents self-reported their demographic characteristics and parenting style. Girls self-reported their organized sport participation and weekly walking/cycling trips, while MVPA was assessed using accelerometers. Linear regression and interaction analyses were performed. Interactions between socio-demographic factors and parenting style with organized sport, walking/cycling trips and MVPA are presented. There were cross-sectional associations between authoritative (B=-0.45, p=0.042) and indulgent (B=-0.56, p=0.002) parenting and the number of walking/cycling trips, and authoritarian (B=0.27, p=0.033) parenting and frequency of organized sport. Significant interactions included those between: family status, authoritative parenting and daily (p=0.048) and week day (p=0.013) MVPA; education, indulgent parenting and MVPA on weekend days (p=0.006); and, employment, authoritarian parenting and duration and frequency of organized sport (p=0.004), highlighting the complexity of these relationships. Longitudinal analyses revealed significant decreases in organized sport and MVPA, significant increases in walking/cycling trips and no significant associations between parenting and physical activity. Parenting styles appear to influence walking and cycling trips among adolescent girls, though not physical activity within other domains. Socio-demographic characteristics interact with the relationships between parenting and physical activity. While these findings can inform the development of family-based interventions to improve child and adolescent health, the direction of the observed associations and the number of associations approaching significance suggest the need to further explore this area.

Human-Robot Interaction: Does Robotic Guidance Force Affect Gait-Related Brain Dynamics during Robot-Assisted Treadmill Walking?

PubMed Central

Knaepen, Kristel; Mierau, Andreas; Swinnen, Eva; Fernandez Tellez, Helio; Michielsen, Marc; Kerckhofs, Eric; Lefeber, Dirk; Meeusen, Romain

2015-01-01

In order to determine optimal training parameters for robot-assisted treadmill walking, it is essential to understand how a robotic device interacts with its wearer, and thus, how parameter settings of the device affect locomotor control. The aim of this study was to assess the effect of different levels of guidance force during robot-assisted treadmill walking on cortical activity. Eighteen healthy subjects walked at 2 km.h-1 on a treadmill with and without assistance of the Lokomat robotic gait orthosis. Event-related spectral perturbations and changes in power spectral density were investigated during unassisted treadmill walking as well as during robot-assisted treadmill walking at 30%, 60% and 100% guidance force (with 0% body weight support). Clustering of independent components revealed three clusters of activity in the sensorimotor cortex during treadmill walking and robot-assisted treadmill walking in healthy subjects. These clusters demonstrated gait-related spectral modulations in the mu, beta and low gamma bands over the sensorimotor cortex related to specific phases of the gait cycle. Moreover, mu and beta rhythms were suppressed in the right primary sensory cortex during treadmill walking compared to robot-assisted treadmill walking with 100% guidance force, indicating significantly larger involvement of the sensorimotor area during treadmill walking compared to robot-assisted treadmill walking. Only marginal differences in the spectral power of the mu, beta and low gamma bands could be identified between robot-assisted treadmill walking with different levels of guidance force. From these results it can be concluded that a high level of guidance force (i.e., 100% guidance force) and thus a less active participation during locomotion should be avoided during robot-assisted treadmill walking. This will optimize the involvement of the sensorimotor cortex which is known to be crucial for motor learning. PMID:26485148

Teaching Women with Intellectual Disabilities to Identify and Report Inappropriate Staff-to-Resident Interactions

ERIC Educational Resources Information Center

Bollman, Jessica R.; Davis, Paula K.

2009-01-01

This study examined the effectiveness of behavioral skills training in teaching 2 adult women with mild intellectual disabilities to report inappropriate staff-to-resident interactions. The reporting skill included making a self-advocacy response, walking away, and reporting the interaction. Participants' performance was measured during baseline,…

The fiber walk: a model of tip-driven growth with lateral expansion.

PubMed

Bucksch, Alexander; Turk, Greg; Weitz, Joshua S

2014-01-01

Tip-driven growth processes underlie the development of many plants. To date, tip-driven growth processes have been modeled as an elongating path or series of segments, without taking into account lateral expansion during elongation. Instead, models of growth often introduce an explicit thickness by expanding the area around the completed elongated path. Modeling expansion in this way can lead to contradictions in the physical plausibility of the resulting surface and to uncertainty about how the object reached certain regions of space. Here, we introduce fiber walks as a self-avoiding random walk model for tip-driven growth processes that includes lateral expansion. In 2D, the fiber walk takes place on a square lattice and the space occupied by the fiber is modeled as a lateral contraction of the lattice. This contraction influences the possible subsequent steps of the fiber walk. The boundary of the area consumed by the contraction is derived as the dual of the lattice faces adjacent to the fiber. We show that fiber walks generate fibers that have well-defined curvatures, and thus enable the identification of the process underlying the occupancy of physical space. Hence, fiber walks provide a base from which to model both the extension and expansion of physical biological objects with finite thickness.

The Fiber Walk: A Model of Tip-Driven Growth with Lateral Expansion

PubMed Central

Bucksch, Alexander; Turk, Greg; Weitz, Joshua S.

2014-01-01

Tip-driven growth processes underlie the development of many plants. To date, tip-driven growth processes have been modeled as an elongating path or series of segments, without taking into account lateral expansion during elongation. Instead, models of growth often introduce an explicit thickness by expanding the area around the completed elongated path. Modeling expansion in this way can lead to contradictions in the physical plausibility of the resulting surface and to uncertainty about how the object reached certain regions of space. Here, we introduce fiber walks as a self-avoiding random walk model for tip-driven growth processes that includes lateral expansion. In 2D, the fiber walk takes place on a square lattice and the space occupied by the fiber is modeled as a lateral contraction of the lattice. This contraction influences the possible subsequent steps of the fiber walk. The boundary of the area consumed by the contraction is derived as the dual of the lattice faces adjacent to the fiber. We show that fiber walks generate fibers that have well-defined curvatures, and thus enable the identification of the process underlying the occupancy of physical space. Hence, fiber walks provide a base from which to model both the extension and expansion of physical biological objects with finite thickness. PMID:24465607

Deviation between self-reported and measured occupational physical activity levels in office employees: effects of age and body composition.

PubMed

Wick, Katharina; Faude, Oliver; Schwager, Susanne; Zahner, Lukas; Donath, Lars

2016-05-01

Whether occupational physical activity (PA) will be assessed via questionnaires or accelerometry depends on available resources. Although self-reported data collection seems feasible and inexpensive, obtained information could be biased by demographic determinants. Thus, we aimed at comparing self-reported and objectively measured occupational sitting, standing, and walking times adjusted for socio-demographic variables. Thirty-eight office employees (eight males, 30 females, age 40.8 ± 11.4 years, BMI 23.9 ± 4.2 kg/m(2)) supplied with height-adjustable working desks were asked to report sitting, standing, and walking times using the Occupational Sitting and Physical Activity Questionnaire during one working week. The ActiGraph wGT3X-BT was used to objectively measure occupational PA during the same week. Subjectively and objectively measured data were compared computing the intra-class correlation coefficients, paired t tests and Bland-Altman plots. Furthermore, repeated-measurement ANOVAs for measurement (subjective vs. objective) and socio-demographic variables were calculated. Self-reported data yielded a significant underestimation of standing time (13.3 vs. 17.9%) and an overestimation of walking time (12.7 vs. 5.0%). Significant interaction effects of age and measurement of standing time (F = 6.0, p = .02, ηp(2) = .14) and BMI group and measurement of walking time were found (F = 3.7, p = .04, ηp(2) = .17). Older employees (>39 years) underestimated their standing time, while underweight workers (BMI < 20 kg/m(2)) overestimated their walking time. Self-reported PA data differ from objective data. Demographic variables (age, BMI) affect the amount of self-reported misjudging of PA. In order to improve the validity of self-reported data, a correction formula for the economic assessment of PA by subjective measures is needed, considering age and BMI.

Adsorption of flexible polymer chains on a surface: Effects of different solvent conditions

NASA Astrophysics Data System (ADS)

Martins, P. H. L.; Plascak, J. A.; Bachmann, M.

2018-05-01

Polymer chains undergoing a continuous adsorption-desorption transition are studied through extensive computer simulations. A three-dimensional self-avoiding walk lattice model of a polymer chain grafted onto a surface has been treated for different solvent conditions. We have used an advanced contact-density chain-growth algorithm, in which the density of contacts can be directly obtained. From this quantity, the order parameter and its fourth-order Binder cumulant are computed, as well as the corresponding critical exponents and the adsorption-desorption transition temperature. As the number of configurations with a given number of surface contacts and monomer-monomer contacts is independent of the temperature and solvent conditions, it can be easily applied to get results for different solvent parameter values without the need of any extra simulations. In analogy to continuous magnetic phase transitions, finite-size-scaling methods have been employed. Quite good results for the critical properties and phase diagram of very long single polymer chains have been obtained by properly taking into account the effects of corrections to scaling. The study covers all solvent effects, going from the limit of super-self-avoiding walks, characterized by effective monomer-monomer repulsion, to poor solvent conditions that enable the formation of compact polymer structures.

Individual Differences in Approach and Avoidance Inclinations Moderate the Effect of Self-Control Depletion on Ad-Lib Drinking

PubMed Central

Schlauch, Robert C.; Christensen, Rita L.; Derrick, Jaye L.; Crane, Cory A.; Collins, R. Lorraine

2015-01-01

Background The current study sought to examine how exerting self-control to inhibit stereotype use affects alcohol consumption. In addition, we sought to expand previous findings via examination of how individual differences in motivations to approach or avoid alcohol consumption interact with self-control depletion to determine the regulation of ad-lib drinking behavior. Methods Sixty-one social drinkers (31 female) were recruited to participate in a socially relevant self-control depletion task in which they were randomly assigned to one of two creative writing conditions: 1) the self-control depletion condition with explicit instructions to refrain from using stereotypes, or 2) the non-depletion condition in which no instructions were given regarding the use of stereotypes. Participants then completed an ad-lib drinking task and self-report questionnaires pertaining to their motivation to consume alcohol. Results As predicted, results indicated a significant three-way interaction between depletion condition, approach inclinations, and avoidance inclinations. Specifically, self-control depletion predicted greater drinking disinhibition (i.e., mean sip size, total alcohol consumption) only among participants high in both approach and avoidance. Conclusions Taken together, results from the current study highlight the importance of both approach and avoidance inclinations in the failure to regulate alcohol consumption following a routine, socially relevant form of self-control depletion. Our results also suggest that the high approach / high avoidance motivational profile may predict the greatest risk among those actively trying to regulate their drinking. PMID:26756800

Experimental identification of the behaviour of and lateral forces from freely-walking pedestrians on laterally oscillating structures in a virtual reality environment.

PubMed

Bocian, Mateusz; Macdonald, John H G; Burn, Jeremy F; Redmill, David

2015-12-15

Modelling pedestrian loading on lively structures such as bridges remains a challenge. This is because pedestrians have the capacity to interact with vibrating structures which can lead to amplification of the structural response. Current design guidelines are often inaccurate and limiting as they do not sufficiently acknowledge this effect. This originates in scarcity of data on pedestrian behaviour on vibrating ground and uncertainty as to the accuracy of results from previous experimental campaigns aiming to quantify pedestrian behaviour in this case. To this end, this paper presents a novel experimental setup developed to evaluate pedestrian actions on laterally oscillating ground in the laboratory environment while avoiding the implications of artificiality and allowing for unconstrained gait. A biologically-inspired approach was adopted in its development, relying on appreciation of operational complexities of biological systems, in particular their adaptability and control requirements. In determination of pedestrian forces to the structure consideration was given to signal processing issues which have been neglected in past studies. The results from tests conducted on the setup are related to results from previous experimental investigations and outputs of the inverted pendulum pedestrian model for walking on laterally oscillating ground, which is capable of generating self-excited forces.

The Combined Effects of Body Weight Support and Gait Speed on Gait Related Muscle Activity: A Comparison between Walking in the Lokomat Exoskeleton and Regular Treadmill Walking

PubMed Central

Van Kammen, Klaske; Boonstra, Annemarijke; Reinders-Messelink, Heleen; den Otter, Rob

2014-01-01

Background For the development of specialized training protocols for robot assisted gait training, it is important to understand how the use of exoskeletons alters locomotor task demands, and how the nature and magnitude of these changes depend on training parameters. Therefore, the present study assessed the combined effects of gait speed and body weight support (BWS) on muscle activity, and compared these between treadmill walking and walking in the Lokomat exoskeleton. Methods Ten healthy participants walked on a treadmill and in the Lokomat, with varying levels of BWS (0% and 50% of the participants’ body weight) and gait speed (0.8, 1.8, and 2.8 km/h), while temporal step characteristics and muscle activity from Erector Spinae, Gluteus Medius, Vastus Lateralis, Biceps Femoris, Gastrocnemius Medialis, and Tibialis Anterior muscles were recorded. Results The temporal structure of the stepping pattern was altered when participants walked in the Lokomat or when BWS was provided (i.e. the relative duration of the double support phase was reduced, and the single support phase prolonged), but these differences normalized as gait speed increased. Alternations in muscle activity were characterized by complex interactions between walking conditions and training parameters: Differences between treadmill walking and walking in the exoskeleton were most prominent at low gait speeds, and speed effects were attenuated when BWS was provided. Conclusion Walking in the Lokomat exoskeleton without movement guidance alters the temporal step regulation and the neuromuscular control of walking, although the nature and magnitude of these effects depend on complex interactions with gait speed and BWS. If normative neuromuscular control of gait is targeted during training, it is recommended that very low speeds and high levels of BWS should be avoided when possible. PMID:25226302

Walking economy during cued versus non-cued self-selected treadmill walking in persons with Parkinson's disease.

PubMed

Gallo, Paul M; McIsaac, Tara L; Garber, Carol Ewing

2014-01-01

Gait impairments related to Parkinson's disease (PD) include variable step length and decreased walking velocity, which may result in poorer walking economy. Auditory cueing is a common method used to improve gait mechanics in PD that has been shown to worsen walking economy at set treadmill walking speeds. It is unknown if auditory cueing has the same effects on walking economy at self-selected treadmill walking speeds. To determine if auditory cueing will affect walking economy at self-selected treadmill walking speeds and at speeds slightly faster and slower than self-selected. Twenty-two participants with moderate PD performed three, 6-minute bouts of treadmill walking at three speeds (self-selected and ± 0.22 m·sec-1). One session used cueing and the other without cueing. Energy expenditure was measured and walking economy was calculated (energy expenditure/power). Poorer walking economy and higher energy expenditure occurred during cued walking at a self-selected and a slightly faster walking speed, but there was no apparent difference at the slightly slower speed. These results suggest that potential gait benefits of auditory cueing may come at an energy cost and poorer walking economy for persons with PD at least at some treadmill walking speeds.

A New Approach to Parallel Dynamic Partitioning for Adaptive Unstructured Meshes

NASA Technical Reports Server (NTRS)

Heber, Gerd; Biswas, Rupak; Gao, Guang R.

1999-01-01

Classical mesh partitioning algorithms were designed for rather static situations, and their straightforward application in a dynamical framework may lead to unsatisfactory results, e.g., excessive data migration among processors. Furthermore, special attention should be paid to their amenability to parallelization. In this paper, a novel parallel method for the dynamic partitioning of adaptive unstructured meshes is described. It is based on a linear representation of the mesh using self-avoiding walks.

Strategies for obstacle avoidance during walking in the cat.

PubMed

Chu, Kevin M I; Seto, Sandy H; Beloozerova, Irina N; Marlinski, Vladimir

2017-08-01

Avoiding obstacles is essential for successful navigation through complex environments. This study aimed to clarify what strategies are used by a typical quadruped, the cat, to avoid obstacles during walking. Four cats walked along a corridor 2.5 m long and 25 or 15 cm wide. Obstacles, small round objects 2.5 cm in diameter and 1 cm in height, were placed on the floor in various locations. Movements of the paw were recorded with a motion capture and analysis system (Visualeyez, PTI). During walking in the wide corridor, cats' preferred strategy for avoiding a single obstacle was circumvention, during which the stride direction changed while stride duration and swing-to-stride duration ratio were preserved. Another strategy, stepping over the obstacle, was used during walking in the narrow corridor, when lateral deviations of walking trajectory were restricted. Stepping over the obstacle involved changes in two consecutive strides. The stride preceding the obstacle was shortened, and swing-to-stride ratio was reduced. The obstacle was negotiated in the next stride of increased height and normal duration and swing-to-stride ratio. During walking on a surface with multiple obstacles, both strategies were used. To avoid contact with the obstacle, cats placed the paw away from the object at a distance roughly equal to the diameter of the paw. During obstacle avoidance cats prefer to alter muscle activities without altering the locomotor rhythm. We hypothesize that a choice of the strategy for obstacle avoidance is determined by minimizing the complexity of neuro-motor processes required to achieve the behavioral goal. NEW & NOTEWORTHY In a study of feline locomotor behavior we found that the preferred strategy to avoid a small obstacle is circumvention. During circumvention, stride direction changes but length and temporal structure are preserved. Another strategy, stepping over the obstacle, is used in narrow walkways. During overstepping, two strides adjust. A stride preceding the obstacle decreases in length and duration. The following stride negotiating the obstacle increases in height while retaining normal temporal structure and nearly normal length. Copyright © 2017 the American Physiological Society.

A Contextual Approach to Experiential Avoidance and Social Anxiety: Evidence from an Experimental Interaction and Daily Interactions of People with Social Anxiety Disorder

PubMed Central

Kashdan, Todd B.; Goodman, Fallon R.; Machell, Kyla A.; Kleiman, Evan M.; Monfort, Samuel S.; Ciarrochi, Joseph; Nezlek, John B.

2014-01-01

Experiential avoidance, the tendency to avoid internal, unwanted thoughts and feelings, is hypothesized to be a risk factor for social anxiety. Existing studies of experiential avoidance rely on trait measures with minimal contextual consideration. In two studies, we examined the association between experiential avoidance and anxiety within real-world social interactions. In the first study, we examined the effect of experiential avoidance on social anxiety in everyday life. For two weeks, 37 participants with Social Anxiety Disorder [SAD] and 38 healthy controls provided reports of experiential avoidance and social anxiety symptoms during face-to-face social interactions. Results showed that momentary experiential avoidance was positively related to anxiety symptoms during social interactions and this effect was stronger among people with SAD. People low in EA showed greater sensitivity to the level of situational threat than high EA people. In the second study, we facilitated an initial encounter between strangers. Unlike Study 1, we experimentally created a social situation where there was either an opportunity for intimacy (self-disclosure conversation) or no such opportunity (small-talk conversation). Results showed that greater experiential avoidance during the self-disclosure conversation temporally preceded increases in social anxiety for the remainder of the interaction; no such effect was found in the small-talk conversation. Our findings provide insight into the association between experiential avoidance on social anxiety in laboratory and naturalistic settings, and demonstrate that the effect of EA depends upon level of social threat and opportunity. PMID:24749634

Emotional influences on locomotor behavior.

PubMed

Naugle, Kelly M; Joyner, Jessica; Hass, Chris J; Janelle, Christopher M

2010-12-01

Emotional responses to appetitive and aversive stimuli motivate approach and avoidance behaviors essential for survival. The purpose of the current study was to determine the impact of specific emotional stimuli on forward, approach-oriented locomotion. Steady state walking was assessed while participants walked toward pictures varying in emotional content (erotic, happy people, attack, mutilation, contamination, and neutral). Step length and step velocity were calculated for the first two steps following picture onset. Exposure to the mutilation and contamination pictures shortened the lengths of step one and step two compared to the erotic pictures. Additionally, step velocity was greater during exposure to the erotic pictures compared to (1) the contamination and mutilation pictures for step one and (2) all other picture categories for step two. These findings suggest that locomotion is facilitated when walking toward approach-oriented emotional stimuli but compromised when walking toward aversive emotional stimuli. The data extend our understanding of fundamental interactions among motivational orientations, emotional reactions, and resultant actions. Theoretical and practical implications are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Collaborative robotic biomechanical interactions and gait adjustments in young, non-impaired individuals.

PubMed

Dionisio, Valdeci C; Brown, David A

2016-06-16

Collaborative robots are used in rehabilitation and are designed to interact with the client so as to provide the ability to assist walking therapeutically. One such device is the KineAssist which was designed to interact, either in a self-driven mode (SDM) or in an assist mode (AM), with neurologically-impaired individuals while they are walking on a treadmill surface. To understand the level of transparency (i.e., interference with movement due to the mechanical interface) between human and robot, and to estimate and account for changes in the kinetics and kinematics of the gait pattern, we tested the KineAssist under conditions of self-drive and horizontal push assistance. The aims of this study were to compare the joint kinematics, forces and moments during walking at a fixed constant treadmill belt speed and constrained walking cadence, with and without the robotic device (OUT) and to compare the biomechanics of assistive and self-drive modes in the device. Twenty non-neurologically impaired adults participated in this study. We evaluated biomechanical parameters of walking at a fixed constant treadmill belt speed (1.0 m/s), with and without the robotic device in assistive mode. We also tested the self-drive condition, which enables the user to drive the speed and direction of a treadmill belt. Hip, knee and ankle angular displacements, ground reaction forces, hip, knee and ankle moments, and center of mass displacement were compared "in" vs "out" of the device. A repeated measures ANOVA test was applied with the three level factor of condition (OUT, AM, and SDM), and each participant was used as its own comparison. When comparing "in" and "out" of the device, we did not observe any interruptions and/or reversals of direction of the basic gait pattern trajectory, but there was increased ankle and hip angular excursions, vertical ground reaction force and hip moments and reduced center of mass displacement during the "in device" condition. Comparing assistive vs self-drive mode in device, participants had greater flexed posture and accentuated hip moments and propulsive force, but reduced braking force. Although the magnitudes and/or range of certain gait pattern components were altered by the device, we did not observe any interruption from the mechanical interface upon the advancement of the trajectories nor reversals in direction of movement which suggests that the KineAssist permits relative transparency (i.e.. lack of interference of movement by the device mechanism) to the individual's gait pattern. However, there are interactive forces to take into account, which appear to be overcome by kinematic and kinetic adjustments.

Self-regulation as a moderator of the relation between coping and symptomatology in children of divorce.

PubMed

Lengua, L J; Sandler, I N

1996-12-01

Investigated the effects of self-regulation as a moderator of the relations between coping efforts and psychological symptoms of children of divorce. The interactions of two dimensions of self-regulation (task orientation and approach-flexibility) and two dimensions of coping (active and avoidant) predicting children's postdivorce symptoms were tested using a sample of 199 divorced mothers and their children, ages 8 to 12. The approach-flexibility dimension moderated the relations of both active and avoidant coping with children's self-report of anxiety. At higher levels of approach-flexibility, active coping was negatively related to anxiety, while at lower levels of approach-flexibility, active coping was unrelated to anxiety. Avoidant coping was unrelated to anxiety at higher levels of approach-flexibility, whereas at lower levels of approach-flexibility, avoidant coping was positively related to anxiety. The task orientation dimension did not interact with coping, but had direct, independent effects on children's self-report of conduct problems, depression, and parent-report of internalizing and externalizing behavior problems. The implications for understanding children's coping with divorce and future directions for research are discussed.

Neighborhood environment and physical activity among older adults: do the relationships differ by driving status?

PubMed

Ding, Ding; Sallis, James F; Norman, Gregory J; Frank, Lawrence D; Saelens, Brian E; Kerr, Jacqueline; Conway, Terry L; Cain, Kelli; Hovell, Melbourne F; Hofstetter, C Richard; King, Abby C

2014-07-01

Some attributes of neighborhood environments are associated with physical activity among older adults. This study examined whether the associations were moderated by driving status. Older adults from neighborhoods differing in walkability and income completed written surveys and wore accelerometers (N = 880, mean age = 75 years, 56% women). Neighborhood environments were measured by geographic information systems and validated questionnaires. Driving status was defined on the basis of a driver's license, car ownership, and feeling comfortable to drive. Outcome variables included accelerometer-based physical activity and self-reported transport and leisure walking. Multilevel generalized linear regression was used. There was no significant Neighborhood Attribute × Driving Status interaction with objective physical activity or reported transport walking. For leisure walking, almost all environmental attributes were positive and significant among driving older adults but not among nondriving older adults (five significant interactions at p < .05). The findings suggest that driving status is likely to moderate the association between neighborhood environments and older adults' leisure walking.

Indicators of walking speed in rheumatoid arthritis: relative influence of articular, psychosocial, and body composition characteristics.

PubMed

Lusa, Amanda L; Amigues, Isabelle; Kramer, Henry R; Dam, Thuy-Tien; Giles, Jon T

2015-01-01

To explore the contributions from and interactions between articular swelling and damage, psychosocial factors, and body composition characteristics on walking speed in rheumatoid arthritis (RA). RA patients underwent the timed 400-meter long-corridor walk. Demographics, self-reported levels of depressive symptoms and fatigue, RA characteristics, and body composition (using whole-body dual X-ray absorptiometry, and abdominal and thigh computed tomography) were assessed and their associations with walking speed explored. A total of 132 RA patients had data for the 400-meter walk, among whom 107 (81%) completed the full 400 meters. Significant multivariable indicators of slower walking speed were older age, higher depression scores, higher reported pain and fatigue, higher swollen and replaced joint counts, higher cumulative prednisone exposure, nontreatment with disease-modifying antirheumatic drugs, and worse body composition. These features accounted for 60% of the modeled variability in walking speed. Among specific articular features, slower walking speed was primarily correlated with large/medium lower-extremity joint involvement. However, these articular features accounted for only 21% of the explainable variability in walking speed. Having any relevant articular characteristic was associated with a 20% lower walking speed among those with worse body composition (P < 0.001), compared with only a 6% lower speed among those with better body composition (P = 0.010 for interaction). Psychosocial factors and body composition are potentially reversible contributors to walking speed in RA. Relative to articular disease activity and damage, nonarticular indicators were collectively more potent indicators of an individual's mobility limitations. Copyright © 2015 by the American College of Rheumatology.

Universality of crossover scaling for the adsorption transition of lattice polymers

NASA Astrophysics Data System (ADS)

Bradly, C. J.; Owczarek, A. L.; Prellberg, T.

2018-02-01

Recently, it has been proposed that the adsorption transition for a single polymer in dilute solution, modeled by lattice walks in three dimensions, is not universal with respect to intermonomer interactions. Moreover, it has been conjectured that key critical exponents ϕ , measuring the growth of the contacts with the surface at the adsorption point, and 1 /δ , which measures the finite-size shift of the critical temperature, are not the same. However, applying standard scaling arguments the two key critical exponents should rather be identical, hence pointing to a potential breakdown of these standard scaling arguments. Both of these conjectures are in contrast to the well-studied situation in two dimensions, where there are exact results from conformal field theory: these exponents are both accepted to be 1 /2 and universal. We use the flatPERM algorithm to simulate self-avoiding walks and trails on the hexagonal, square, and simple cubic lattices up to length 1024 to investigate these claims. Walks can be seen as a repulsive limit of intermonomer interaction for trails, allowing us to probe the universality of adsorption. For each lattice model we analyze several thermodynamic properties to produce different methods of estimating the critical temperature and the key exponents. We test our methodology on the two-dimensional cases, and the resulting spread in values for ϕ and 1 /δ indicates that there is a systematic error which can far exceed the statistical error usually reported. We further suggest a methodology for consistent estimation of the key adsorption exponents which gives ϕ =1 /δ =0.484 (4 ) in three dimensions. Hence, we conclude that in three dimensions these critical exponents indeed differ from the mean-field value of 1 /2 , as had previously been calculated, but cannot find evidence that they differ from each other. Importantly, we also find no substantive evidence of any nonuniversality in the polymer adsorption transition.

Multilevel modelling of built environment characteristics related to neighbourhood walking activity in older adults

PubMed Central

Li, F.; Fisher, K; Brownson, R.; Bosworth, M.

2005-01-01

Objective: To examine the relation between built environment factors (representing several dimensions of urban form of neighbourhoods) and walking activity at both the neighbourhood level and the resident level, in an older adult sample. Design, setting, participants: A cross sectional, multilevel design with neighbourhoods as the primary sampling unit and senior residents as the secondary unit. Five hundred and seventy seven residents (mean age = 74 years, SD = 6.3 years) participated in the survey, which was conducted among 56 city defined neighbourhoods in Portland, Oregon, USA. Neighbourhood level variables were constructed using geographical information systems. Resident level variables consisted of a mix of self reports and geocoded data on the built environment. Main outcome measure: Self reported neighbourhood walking. Main results: A positive relation was found between built environment factors (density of places of employment, household density, green and open spaces for recreation, number of street intersections) and walking activity at the neighbourhood level. At the resident level, perceptions of safety for walking and number of nearby recreational facilities were positively related to high levels of walking activity. A significant interaction was observed between number of street intersections and perceptions of safety from traffic. Conclusions: Certain neighbourhood built environment characteristics related to urban form were positively associated with walking activity in the neighbourhoods of senior residents. Public health promotion of walking activity/urban mobility and the design of interventions need to consider the contribution of neighbourhood level built environment influences. PMID:15965138

Differences in Self-Reported Physical Activity and Body Mass Index Among Older Hispanic and Non-Hispanic White Men and Women: Findings from the 2009 California Health Interview Survey.

PubMed

Sorkin, Dara H; Biegler, Kelly A; Billimek, John

2015-10-01

Older Hispanic Americans are a rapidly growing minority group who are disproportionately affected by diabetes mellitus and obesity. Given the importance of physical activity, particularly leisure-time activity, in the management of diabetes mellitus and obesity, the current study examined ethnic and sex differences in walking for transportation, leisure-time walking, moderate activity (not including walking), and vigorous activity between Hispanic and non-Hispanic white (NHW) older adults (age 55 and older) using the 2009 California Health Interview Survey, a population-based survey representative of California's noninstitutionalized population. The total sample consisted of 21,702 participants (20,148 NHW (7,968 men, 12,180 women) and 1,554 Hispanic (609 men, 945 women)). Multivariable logistic and linear regression analyses were adjusted for sociodemographic characteristics. The findings revealed that Hispanic men and women were significantly less likely to engage in self-reported leisure-time walking and vigorous activity than NHW men (adjusted odds ratio (aOR) = 0.71, 95% confidence interval (CI) = 0.51-0.99) and women (aOR = 0.60, 95% CI = 0.42-0.87). Regardless of ethnic group, men were more likely than women to engage in self-reported walking for transportation (aOR = 0.71, 95% CI = 0.58-0.87), moderate activity (aOR = 0.68, 95% CI = 0.57-0.81), and vigorous activity (aOR = 0.58, 95% CI = 0.50-0.68). All types of self-reported physical activity were associated with lower body mass index (BMI; P < .001), although significant interactions between sex and leisure time walking (P < .001), moderate activity (P < .001), and vigorous activity (P < .001) indicated that women who engaged in these activities reported the lowest BMIs. The findings highlight the importance of emphasizing walking in efforts to increase moderate and vigorous activity, particularly for older women. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

Adsorption of a single polymer chain on a surface: Effects of the potential range

NASA Astrophysics Data System (ADS)

Klushin, Leonid I.; Polotsky, Alexey A.; Hsu, Hsiao-Ping; Markelov, Denis A.; Binder, Kurt; Skvortsov, Alexander M.

2013-02-01

We investigate the effects of the range of adsorption potential on the equilibrium behavior of a single polymer chain end-attached to a solid surface. The exact analytical theory for ideal lattice chains interacting with a planar surface via a box potential of depth U and width W is presented and compared to continuum model results and to Monte Carlo (MC) simulations using the pruned-enriched Rosenbluth method for self-avoiding chains on a simple cubic lattice. We show that the critical value Uc corresponding to the adsorption transition scales as W-1/ν, where the exponent ν=1/2 for ideal chains and ν≈3/5 for self-avoiding walks. Lattice corrections for finite W are incorporated in the analytical prediction of the ideal chain theory Uc≈((π2)/(24))(W+1/2)-2 and in the best-fit equation for the MC simulation data Uc=0.585(W+1/2)-5/3. Tail, loop, and train distributions at the critical point are evaluated by MC simulations for 1≤W≤10 and compared to analytical results for ideal chains and with scaling theory predictions. The behavior of a self-avoiding chain is remarkably close to that of an ideal chain in several aspects. We demonstrate that the bound fraction θ and the related properties of finite ideal and self-avoiding chains can be presented in a universal reduced form: θ(N,U,W)=θ(NUc,U/Uc). By utilizing precise estimations of the critical points we investigate the chain length dependence of the ratio of the normal and lateral components of the gyration radius. Contrary to common expectations this ratio attains a limiting universal value /=0.320±0.003 only at N˜5000. Finite-N corrections for this ratio turn out to be of the opposite sign for W=1 and for W≥2. We also study the N dependence of the apparent crossover exponent ϕeff(N). Strong corrections to scaling of order N-0.5 are observed, and the extrapolated value ϕ=0.483±0.003 is found for all values of W. The strong correction to scaling effects found here explain why for smaller values of N, as used in most previous work, misleadingly large values of ϕeff(N) were identified as the asymptotic value for the crossover exponent.

Giant narrowband twin-beam generation along the pump-energy propagation direction

NASA Astrophysics Data System (ADS)

Pérez, Angela M.; Spasibko, Kirill Yu; Sharapova, Polina R.; Tikhonova, Olga V.; Leuchs, Gerd; Chekhova, Maria V.

2015-07-01

Walk-off effects, originating from the difference between the group and phase velocities, limit the efficiency of nonlinear optical interactions. While transverse walk-off can be eliminated by proper medium engineering, longitudinal walk-off is harder to avoid. In particular, ultrafast twin-beam generation via pulsed parametric down-conversion and four-wave mixing is only possible in short crystals or fibres. Here we show that in high-gain parametric down-conversion, one can overcome the destructive role of both effects and even turn them into useful tools for shaping the emission. In our experiment, one of the twin beams is emitted along the pump Poynting vector or its group velocity matches that of the pump. The result is markedly enhanced generation of both twin beams, with the simultaneous narrowing of angular and frequency spectrum. The effect will enable efficient generation of ultrafast twin photons and beams in cavities, waveguides and whispering-gallery mode resonators.

Humans do not have direct access to retinal flow during walking

PubMed Central

Souman, Jan L.; Freeman, Tom C.A.; Eikmeier, Verena; Ernst, Marc O.

2013-01-01

Perceived visual speed has been reported to be reduced during walking. This reduction has been attributed to a partial subtraction of walking speed from visual speed (Durgin & Gigone, 2007; Durgin, Gigone, & Scott, 2005). We tested whether observers still have access to the retinal flow before subtraction takes place. Observers performed a 2IFC visual speed discrimination task while walking on a treadmill. In one condition, walking speed was identical in the two intervals, while in a second condition walking speed differed between intervals. If observers have access to the retinal flow before subtraction, any changes in walking speed across intervals should not affect their ability to discriminate retinal flow speed. Contrary to this “direct-access hypothesis”, we found that observers were worse at discrimination when walking speed differed between intervals. The results therefore suggest that observers do not have access to retinal flow before subtraction. We also found that the amount of subtraction depended on the visual speed presented, suggesting that the interaction between the processing of visual input and of self-motion is more complex than previously proposed. PMID:20884509

First Steps into Language? Examining the Specific Longitudinal Relations between Walking, Exploration and Linguistic Skills

PubMed Central

Oudgenoeg-Paz, Ora; Volman, M(Chiel). J. M.; Leseman, Paul P. M.

2016-01-01

Recent empirical evidence demonstrates relationships between motor and language development that are partially mediated by exploration. This is in line with the embodied cognition approach to development that views language as grounded in real-life sensorimotor interactions with the environment. This view implies that the relations between motor and linguistic skills should be specific. Moreover, as motor development initially changes the possibilities children have to explore the environment, initial relations between motor and linguistic skills should become weaker over time. Empirical evidence pertaining to the duration and specificity of these relations is still lacking. The current study investigated longitudinal relations between attainment of walking and the development of several linguistic skills, and tested whether exploration through self-locomotion mediated these relations. Linguistic skills were measured at age 43 months, which is later than the age used in previous studies. Three hypotheses were tested: (1) the relations between walking and language found at younger ages will decrease over time (2) exploration through self-locomotion will remain an important predictor of spatial language (3) no relation will be found between walking, exploration and the use of grammatical and lexical categories and between exploration and general vocabulary. Thirty-one Dutch children took part in a longitudinal study. Parents reported about age of attainment of walking. Exploration through self-locomotion was measured using observations of play with a standard set of toys at age 20 months. Receptive vocabulary, spatial language and use of grammatical and lexical categories were measured at age 43 months using (standard) tests. Results reveal that age of walking does not directly predict spatial language at age 43 months. Exploration through self-locomotion does significantly and completely mediate the indirect effect of age of walking on spatial language. Moreover, neither age of walking nor exploration predict general vocabulary and the use of grammatical and lexical categories. Results support the idea that the initial relations between motor development and linguistic skills decrease over time and that these relations are specific and intrinsically dependent on the information children pick up through the execution of specific motor activities. PMID:27729885

First Steps into Language? Examining the Specific Longitudinal Relations between Walking, Exploration and Linguistic Skills.

PubMed

Oudgenoeg-Paz, Ora; Volman, M Chiel J M; Leseman, Paul P M

2016-01-01

Recent empirical evidence demonstrates relationships between motor and language development that are partially mediated by exploration. This is in line with the embodied cognition approach to development that views language as grounded in real-life sensorimotor interactions with the environment. This view implies that the relations between motor and linguistic skills should be specific. Moreover, as motor development initially changes the possibilities children have to explore the environment, initial relations between motor and linguistic skills should become weaker over time. Empirical evidence pertaining to the duration and specificity of these relations is still lacking. The current study investigated longitudinal relations between attainment of walking and the development of several linguistic skills, and tested whether exploration through self-locomotion mediated these relations. Linguistic skills were measured at age 43 months, which is later than the age used in previous studies. Three hypotheses were tested: (1) the relations between walking and language found at younger ages will decrease over time (2) exploration through self-locomotion will remain an important predictor of spatial language (3) no relation will be found between walking, exploration and the use of grammatical and lexical categories and between exploration and general vocabulary. Thirty-one Dutch children took part in a longitudinal study. Parents reported about age of attainment of walking. Exploration through self-locomotion was measured using observations of play with a standard set of toys at age 20 months. Receptive vocabulary, spatial language and use of grammatical and lexical categories were measured at age 43 months using (standard) tests. Results reveal that age of walking does not directly predict spatial language at age 43 months. Exploration through self-locomotion does significantly and completely mediate the indirect effect of age of walking on spatial language. Moreover, neither age of walking nor exploration predict general vocabulary and the use of grammatical and lexical categories. Results support the idea that the initial relations between motor development and linguistic skills decrease over time and that these relations are specific and intrinsically dependent on the information children pick up through the execution of specific motor activities.

Neural decoding of treadmill walking from noninvasive electroencephalographic signals

PubMed Central

Presacco, Alessandro; Goodman, Ronald; Forrester, Larry

2011-01-01

Chronic recordings from ensembles of cortical neurons in primary motor and somatosensory areas in rhesus macaques provide accurate information about bipedal locomotion (Fitzsimmons NA, Lebedev MA, Peikon ID, Nicolelis MA. Front Integr Neurosci 3: 3, 2009). Here we show that the linear and angular kinematics of the ankle, knee, and hip joints during both normal and precision (attentive) human treadmill walking can be inferred from noninvasive scalp electroencephalography (EEG) with decoding accuracies comparable to those from neural decoders based on multiple single-unit activities (SUAs) recorded in nonhuman primates. Six healthy adults were recorded. Participants were asked to walk on a treadmill at their self-selected comfortable speed while receiving visual feedback of their lower limbs (i.e., precision walking), to repeatedly avoid stepping on a strip drawn on the treadmill belt. Angular and linear kinematics of the left and right hip, knee, and ankle joints and EEG were recorded, and neural decoders were designed and optimized with cross-validation procedures. Of note, the optimal set of electrodes of these decoders were also used to accurately infer gait trajectories in a normal walking task that did not require subjects to control and monitor their foot placement. Our results indicate a high involvement of a fronto-posterior cortical network in the control of both precision and normal walking and suggest that EEG signals can be used to study in real time the cortical dynamics of walking and to develop brain-machine interfaces aimed at restoring human gait function. PMID:21768121

Walking: How to Get Started and Stay Motivated

MedlinePlus

... for various types of weather. If you walk outdoors when it's dark, wear bright colors or reflective ... your course carefully. If you'll be walking outdoors, avoid paths with cracked sidewalks, potholes, low-hanging ...

Required friction during overground walking is lower among obese compared to non-obese older men, but does not differ with obesity among women.

PubMed

Arena, Sara L; Garman, Christina R; Nussbaum, Maury A; Madigan, Michael L

2017-07-01

Obesity and aging have been independently associated with altered required friction during walking, but it is unclear how these factors interact to influence the likelihood of slipping. Therefore, the purpose of this study was to determine whether there are differences related to obesity and aging on required friction during overground walking. Fourteen older non-obese, 11 older obese, 20 younger non-obese, and 20 younger obese adults completed walking trials at both a self-selected and hurried speed. When walking at a hurried speed, older obese men walked at a slower gait speed and exhibited lower frictional demands compared both to older non-obese men and to younger obese men. No differences in required friction were found between non-obese and obese younger adults. These results suggest that the increased rate of falls among obese or older adults is not likely due to a higher risk of slip initiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Limb contribution to increased self-selected walking speeds during body weight support in individuals poststroke.

PubMed

Hurt, Christopher P; Burgess, Jamie K; Brown, David A

2015-03-01

Individuals poststroke walk at faster self-selected speeds under some nominal level of body weight support (BWS) whereas nonimpaired individuals walk slower after adding BWS. The purpose of this study was to determine whether increases in self-selected overground walking speed under BWS conditions of individuals poststroke can be explained by changes in their paretic and nonparetic ground reaction forces (GRF). We hypothesize that increased self-selected walking speed, recorded at some nominal level of BWS, will relate to decreased braking GRFs by the paretic limb. We recruited 10 chronic (>12 months post-ictus, 57.5±9.6 y.o.) individuals poststroke and eleven nonimpaired participants (53.3±4.1 y.o.). Participants walked overground in a robotic device, the KineAssist Walking and Balance Training System that provided varying degrees of BWS (0-20% in 5% increments) while individuals self-selected their walking speed. Self-selected walking speed and braking and propulsive GRF impulses were quantified. Out of 10 poststroke individuals, 8 increased their walking speed 13% (p=0.004) under some level of BWS (5% n=2, 10% n=3, 20% n=3) whereas nonimpaired controls did not change speed (p=0.470). In individuals poststroke, changes to self-selected walking speed were correlated with changes in paretic propulsive impulses (r=0.68, p=0.003) and nonparetic braking impulses (r=-0.80, p=0.006), but were not correlated with decreased paretic braking impulses (r=0.50 p=0.14). This investigation demonstrates that when individuals poststroke are provided with BWS and allowed to self-select their overground walking speed, they are capable of achieving faster speeds by modulating braking impulses on the nonparetic limb and propulsive impulses of the paretic limb. Copyright © 2015 Elsevier B.V. All rights reserved.

How might we increase physical activity through dog walking?: A comprehensive review of dog walking correlates.

PubMed

Westgarth, Carri; Christley, Robert M; Christian, Hayley E

2014-08-20

Physical inactivity and sedentary behaviour are major threats to population health. A considerable proportion of people own dogs, and there is good evidence that dog ownership is associated with higher levels of physical activity. However not all owners walk their dogs regularly. This paper comprehensively reviews the evidence for correlates of dog walking so that effective interventions may be designed to increase the physical activity of dog owners. Published findings from 1990-2012 in both the human and veterinary literature were collated and reviewed for evidence of factors associated with objective and self-reported measures of dog walking behaviour, or reported perceptions about dog walking. Study designs included cross-sectional observational, trials and qualitative interviews. There is good evidence that the strength of the dog-owner relationship, through a sense of obligation to walk the dog, and the perceived support and motivation a dog provides for walking, is strongly associated with increased walking. The perceived exercise requirements of the dog may also be a modifiable point for intervention. In addition, access to suitable walking areas with dog supportive features that fulfil dog needs such as off-leash exercise, and that also encourage human social interaction, may be incentivising. Current evidence suggests that dog walking may be most effectively encouraged through targeting the dog-owner relationship and by providing dog-supportive physical environments. More research is required to investigate the influence of individual owner and dog factors on 'intention' to walk the dog as well as the influence of human social interaction whilst walking a dog. The effects of policy and cultural practices relating to dog ownership and walking should also be investigated. Future studies must be of a higher quality methodological design, including accounting for the effects of confounding between variables, and longitudinal designs and testing of interventions in a controlled design in order to infer causality.

Too dog tired to avoid danger: self-control depletion in canines increases behavioral approach toward an aggressive threat.

PubMed

Miller, Holly C; DeWall, C Nathan; Pattison, Kristina; Molet, Mikaël; Zentall, Thomas R

2012-06-01

This study investigated whether initial self-control exertion by dogs would affect behavioral approach toward an aggressive threat. Dogs were initially required to exert self-control (sit still for 10 min) or not (caged for 10 min) before they were walked into a room in which a barking, growling dog was caged. Subject dogs spent 4 min in this room but were free to choose where in the room they spent their time. Approaching the unfamiliar conspecific was the predisposed response, but it was also the riskier choice (Lindsay, 2005). We found that following the exertion of self-control (in comparison with the control condition), dogs spent greater time in proximity to the aggressor. This pattern of behavior suggests that initial self-control exertion results in riskier and more impulsive decision making by dogs.

Perception of Self-Motion and Regulation of Walking Speed in Young-Old Adults.

PubMed

Lalonde-Parsi, Marie-Jasmine; Lamontagne, Anouk

2015-07-01

Whether a reduced perception of self-motion contributes to poor walking speed adaptations in older adults is unknown. In this study, speed discrimination thresholds (perceptual task) and walking speed adaptations (walking task) were compared between young (19-27 years) and young-old individuals (63-74 years), and the relationship between the performance on the two tasks was examined. Participants were evaluated while viewing a virtual corridor in a helmet-mounted display. Speed discrimination thresholds were determined using a staircase procedure. Walking speed modulation was assessed on a self-paced treadmill while exposed to different self-motion speeds ranging from 0.25 to 2 times the participants' comfortable speed. For each speed, participants were instructed to match the self-motion speed described by the moving corridor. On the walking task, participants displayed smaller walking speed errors at comfortable walking speeds compared with slower of faster speeds. The young-old adults presented larger speed discrimination thresholds (perceptual experiment) and larger walking speed errors (walking experiment) compared with young adults. Larger walking speed errors were associated with higher discrimination thresholds. The enhanced performance on the walking task at comfortable speed suggests that intersensory calibration processes are influenced by experience, hence optimized for frequently encountered conditions. The altered performance of the young-old adults on the perceptual and walking tasks, as well as the relationship observed between the two tasks, suggest that a poor perception of visual motion information may contribute to the poor walking speed adaptations that arise with aging.

The relevance of security: A latent domain of attachment relationships.

PubMed

Mannarini, Stefania; Boffo, Marilisa

2014-02-01

In the present study an adult attachment dimension, latent to the constructs of security, anxiety, and avoidance, was hypothesized, wherein security was expected to occupy the most relevant position. Furthermore, the reciprocal functioning of attachment constructs and their interactions with self-esteem were explored. Four hundreds and thirty-four Italian university students responded to two adult attachment questionnaires (Attachment Style Questionnaire and Adult Attachment Questionnaire) and to the Rosenberg Self-esteem scale. A Many-Facet Rasch Measurement modeling approach was adopted. The main results can be summarized as follows: (a) security, anxiety, and avoidance are nested under one latent attachment dimension; (b) security occupies the most prominent position on the dimension; (c) security is positively associated with a moderate level of attachment anxiety and negatively related to avoidance; and (d) a positive interaction between self-esteem and security, and a negative relation between self-esteem and anxiety, were detected. Theoretical, clinical, and empirical implications of the results are further discussed. © 2013 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Self-Attractive Random Walks: The Case of Critical Drifts

NASA Astrophysics Data System (ADS)

Ioffe, Dmitry; Velenik, Yvan

2012-07-01

Self-attractive random walks (polymers) undergo a phase transition in terms of the applied drift (force): If the drift is strong enough, then the walk is ballistic, whereas in the case of small drifts self-attraction wins and the walk is sub-ballistic. We show that, in any dimension d ≥ 2, this transition is of first order. In fact, we prove that the walk is already ballistic at critical drifts, and establish the corresponding LLN and CLT.

Finite Memory Walk and Its Application to Small-World Network

NASA Astrophysics Data System (ADS)

Oshima, Hiraku; Odagaki, Takashi

2012-07-01

In order to investigate the effects of cycles on the dynamical process on both regular lattices and complex networks, we introduce a finite memory walk (FMW) as an extension of the simple random walk (SRW), in which a walker is prohibited from moving to sites visited during m steps just before the current position. This walk interpolates the simple random walk (SRW), which has no memory (m = 0), and the self-avoiding walk (SAW), which has an infinite memory (m = ∞). We investigate the FMW on regular lattices and clarify the fundamental characteristics of the walk. We find that (1) the mean-square displacement (MSD) of the FMW shows a crossover from the SAW at a short time step to the SRW at a long time step, and the crossover time is approximately equivalent to the number of steps remembered, and that the MSD can be rescaled in terms of the time step and the size of memory; (2) the mean first-return time (MFRT) of the FMW changes significantly at the number of remembered steps that corresponds to the size of the smallest cycle in the regular lattice, where ``smallest'' indicates that the size of the cycle is the smallest in the network; (3) the relaxation time of the first-return time distribution (FRTD) decreases as the number of cycles increases. We also investigate the FMW on the Watts--Strogatz networks that can generate small-world networks, and show that the clustering coefficient of the Watts--Strogatz network is strongly related to the MFRT of the FMW that can remember two steps.

SAWdoubler: A program for counting self-avoiding walks

NASA Astrophysics Data System (ADS)

Schram, Raoul D.; Barkema, Gerard T.; Bisseling, Rob H.

2013-03-01

This article presents SAWdoubler, a package for counting the total number ZN of self-avoiding walks (SAWs) on a regular lattice by the length-doubling method, of which the basic concept has been published previously by us. We discuss an algorithm for the creation of all SAWs of length N, efficient storage of these SAWs in a tree data structure, and an algorithm for the computation of correction terms to the count Z2N for SAWs of double length, removing all combinations of two intersecting single-length SAWs. We present an efficient numbering of the lattice sites that enables exploitation of symmetry and leads to a smaller tree data structure; this numbering is by increasing Euclidean distance from the origin of the lattice. Furthermore, we show how the computation can be parallelised by distributing the iterations of the main loop of the algorithm over the cores of a multicore architecture. Experimental results on the 3D cubic lattice demonstrate that Z28 can be computed on a dual-core PC in only 1 h and 40 min, with a speedup of 1.56 compared to the single-core computation and with a gain by using symmetry of a factor of 26. We present results for memory use and show how the computation is made to fit in 4 GB RAM. It is easy to extend the SAWdoubler software to other lattices; it is publicly available under the GNU LGPL license. Catalogue identifier: AEOB_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOB_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU Lesser General Public Licence No. of lines in distributed program, including test data, etc.: 2101 No. of bytes in distributed program, including test data, etc.: 19816 Distribution format: tar.gz Programming language: C. Computer: Any computer with a UNIX-like operating system and a C compiler. For large problems, use is made of specific 128-bit integer arithmetic provided by the gcc compiler. Operating system: Any UNIX-like system; developed under Linux and Mac OS 10. Has the code been vectorised or parallelised?: Yes. A parallel version of the code is available in the “Extras” directory of the distribution file. RAM: Problem dependent (2 GB for counting SAWs of length 28 on the 3D cubic lattice) Classification: 16.11. Nature of problem: Computing the number of self-avoiding walks of a given length on a given lattice. Solution method: Length-doubling. Restrictions: The length of the walk must be even. Lattice is 3D simple cubic. Additional comments: The lattice can be replaced by other lattices, such as BCC, FCC, or a 2D square lattice. Running time: Problem dependent (2.5 h using one processor core for length 28 on the 3D cubic lattice).

Social Interaction and Conditional Self-Discrimination under a Paradigm of Avoidance and Positive Reinforcement in Wistar Rats

ERIC Educational Resources Information Center

Penagos-Corzo, Julio C.; Pérez-Acosta, Andrés M.; Hernández, Ingrid

2015-01-01

The experiment reported here uses a conditional self-discrimination task to examine the influence of social interaction on the facilitation of self-discrimination in rats. The study is based on a previous report (Penagos- Corzo et al., 2011) showing positive evidence of such facilitation, but extending the exposition to social interaction…

Self-reported walking ability predicts functional mobility performance in frail older adults.

PubMed

Alexander, N B; Guire, K E; Thelen, D G; Ashton-Miller, J A; Schultz, A B; Grunawalt, J C; Giordani, B

2000-11-01

To determine how self-reported physical function relates to performance in each of three mobility domains: walking, stance maintenance, and rising from chairs. Cross-sectional analysis of older adults. University-based laboratory and community-based congregate housing facilities. Two hundred twenty-one older adults (mean age, 79.9 years; range, 60-102 years) without clinical evidence of dementia (mean Folstein Mini-Mental State score, 28; range, 24-30). We compared the responses of these older adults on a questionnaire battery used by the Established Populations for the Epidemiologic Study of the Elderly (EPESE) project, to performance on mobility tasks of graded difficulty. Responses to the EPESE battery included: (1) whether assistance was required to perform seven Katz activities of daily living (ADL) items, specifically with walking and transferring; (2) three Rosow-Breslau items, including the ability to walk up stairs and walk a half mile; and (3) five Nagi items, including difficulty stooping, reaching, and lifting objects. The performance measures included the ability to perform, and time taken to perform, tasks in three summary score domains: (1) walking ("Walking," seven tasks, including walking with an assistive device, turning, stair climbing, tandem walking); (2) stance maintenance ("Stance," six tasks, including unipedal, bipedal, tandem, and maximum lean); and (3) chair rise ("Chair Rise," six tasks, including rising from a variety of seat heights with and without the use of hands for assistance). A total score combines scores in each Walking, Stance, and Chair Rise domain. We also analyzed how cognitive/ behavioral factors such as depression and self-efficacy related to the residuals from the self-report and performance-based ANOVA models. Rosow-Breslau items have the strongest relationship with the three performance domains, Walking, Stance, and Chair Rise (eta-squared ranging from 0.21 to 0.44). These three performance domains are as strongly related to one Katz ADL item, walking (eta-squared ranging from 0.15 to 0.33) as all of the Katz ADL items combined (eta-squared ranging from 0.21 to 0.35). Tests of problem solving and psychomotor speed, the Trails A and Trails B tests, are significantly correlated with the residuals from the self-report and performance-based ANOVA models. Compared with the rest of the EPESE self-report items, self-report items related to walking (such as Katz walking and Rosow-Breslau items) are better predictors of functional mobility performance on tasks involving walking, stance maintenance, and rising from chairs. Compared with other self-report items, self-reported walking ability may be the best predictor of overall functional mobility.

The ABC (in any D) of logarithmic CFT

NASA Astrophysics Data System (ADS)

Hogervorst, Matthijs; Paulos, Miguel; Vichi, Alessandro

2017-10-01

Logarithmic conformal field theories have a vast range of applications, from critical percolation to systems with quenched disorder. In this paper we thoroughly examine the structure of these theories based on their symmetry properties. Our analysis is model-independent and holds for any spacetime dimension. Our results include a determination of the general form of correlation functions and conformal block decompositions, clearing the path for future bootstrap applications. Several examples are discussed in detail, including logarithmic generalized free fields, holographic models, self-avoiding random walks and critical percolation.

Physical Activity and Functional Limitations in Older Adults: The Influence of Self-Efficacy and Functional Performance

PubMed Central

Mullen, Sean P.; Satariano, William A.; Kealey, Melissa; Prohaska, Thomas R.

2012-01-01

Objectives. Data from the Healthy Aging Network (HAN) study (Prohaska, T., Eisenstein, A., Satariano, W., Hunter, R., Bayles, C., Kurtovich, E., … Ivey, S. [2009]. Walking and the preservation of cognitive function in older populations. The Gerontologist, 49[Suppl. 1], S86–S93; and Satariano, W., Ivey, S., Kurtovich, E., Kealey, M., Hubbard, A., Bayles, C., … Prohaska, T. [2010]. Lower-body function, neighborhoods, and walking in an older population. American Journal of Preventive Medicine, 38, 419–428.) were used to examine the relationships among physical activity, self-efficacy, functional performance, and limitations. Method. Interviews were conducted within homes and senior centers in 4 geographic regions across the United States. Participants were 884 older adults (M age = 74.8; 77% female; 35% minority status) who completed measures of walking behavior, way-finding self-efficacy, walking self-efficacy, functional performance, functional limitations, and demographic characteristics. Results. Path analysis within a covariance modeling framework revealed significant direct effects of walking on self-efficacy constructs, functional performance on functional limitations, and efficacy on limitations. Additionally, significant indirect effects were also found, including walking on limitations via walking self-efficacy and performance and walking self-efficacy on limitations via performance. Furthermore, we found support for invariance of the model across geographical grouping. Discussion. Our findings provide further validation for an efficacy-based model of functional limitations. Walking-related efficacy may help reduce or possibly delay the onset of functional limitations. PMID:22473023

Physical activity and functional limitations in older adults: the influence of self-efficacy and functional performance.

PubMed

Mullen, Sean P; McAuley, Edward; Satariano, William A; Kealey, Melissa; Prohaska, Thomas R

2012-05-01

Data from the Healthy Aging Network (HAN) study (Prohaska, T., Eisenstein, A., Satariano, W., Hunter, R., Bayles, C., Kurtovich, E., … Ivey, S. [2009]. Walking and the preservation of cognitive function in older populations. The Gerontologist, 49[Suppl. 1], S86-S93; and Satariano, W., Ivey, S., Kurtovich, E., Kealey, M., Hubbard, A., Bayles, C., … Prohaska, T. [2010]. Lower-body function, neighborhoods, and walking in an older population. American Journal of Preventive Medicine, 38, 419-428.) were used to examine the relationships among physical activity, self-efficacy, functional performance, and limitations. Interviews were conducted within homes and senior centers in 4 geographic regions across the United States. Participants were 884 older adults (M age = 74.8; 77% female; 35% minority status) who completed measures of walking behavior, way-finding self-efficacy, walking self-efficacy, functional performance, functional limitations, and demographic characteristics. Path analysis within a covariance modeling framework revealed significant direct effects of walking on self-efficacy constructs, functional performance on functional limitations, and efficacy on limitations. Additionally, significant indirect effects were also found, including walking on limitations via walking self-efficacy and performance and walking self-efficacy on limitations via performance. Furthermore, we found support for invariance of the model across geographical grouping. Our findings provide further validation for an efficacy-based model of functional limitations. Walking-related efficacy may help reduce or possibly delay the onset of functional limitations.

Using built environment characteristics to predict walking for exercise

PubMed Central

Lovasi, Gina S; Moudon, Anne V; Pearson, Amber L; Hurvitz, Philip M; Larson, Eric B; Siscovick, David S; Berke, Ethan M; Lumley, Thomas; Psaty, Bruce M

2008-01-01

Background Environments conducive to walking may help people avoid sedentary lifestyles and associated diseases. Recent studies developed walkability models combining several built environment characteristics to optimally predict walking. Developing and testing such models with the same data could lead to overestimating one's ability to predict walking in an independent sample of the population. More accurate estimates of model fit can be obtained by splitting a single study population into training and validation sets (holdout approach) or through developing and evaluating models in different populations. We used these two approaches to test whether built environment characteristics near the home predict walking for exercise. Study participants lived in western Washington State and were adult members of a health maintenance organization. The physical activity data used in this study were collected by telephone interview and were selected for their relevance to cardiovascular disease. In order to limit confounding by prior health conditions, the sample was restricted to participants in good self-reported health and without a documented history of cardiovascular disease. Results For 1,608 participants meeting the inclusion criteria, the mean age was 64 years, 90 percent were white, 37 percent had a college degree, and 62 percent of participants reported that they walked for exercise. Single built environment characteristics, such as residential density or connectivity, did not significantly predict walking for exercise. Regression models using multiple built environment characteristics to predict walking were not successful at predicting walking for exercise in an independent population sample. In the validation set, none of the logistic models had a C-statistic confidence interval excluding the null value of 0.5, and none of the linear models explained more than one percent of the variance in time spent walking for exercise. We did not detect significant differences in walking for exercise among census areas or postal codes, which were used as proxies for neighborhoods. Conclusion None of the built environment characteristics significantly predicted walking for exercise, nor did combinations of these characteristics predict walking for exercise when tested using a holdout approach. These results reflect a lack of neighborhood-level variation in walking for exercise for the population studied. PMID:18312660

Adsorption of a single polymer chain on a surface: effects of the potential range.

PubMed

Klushin, Leonid I; Polotsky, Alexey A; Hsu, Hsiao-Ping; Markelov, Denis A; Binder, Kurt; Skvortsov, Alexander M

2013-02-01

We investigate the effects of the range of adsorption potential on the equilibrium behavior of a single polymer chain end-attached to a solid surface. The exact analytical theory for ideal lattice chains interacting with a planar surface via a box potential of depth U and width W is presented and compared to continuum model results and to Monte Carlo (MC) simulations using the pruned-enriched Rosenbluth method for self-avoiding chains on a simple cubic lattice. We show that the critical value U(c) corresponding to the adsorption transition scales as W(-1/ν), where the exponent ν=1/2 for ideal chains and ν≈3/5 for self-avoiding walks. Lattice corrections for finite W are incorporated in the analytical prediction of the ideal chain theory U(c)≈(π(2)/24)(W+1/2)(-2) and in the best-fit equation for the MC simulation data U(c)=0.585(W+1/2)(-5/3). Tail, loop, and train distributions at the critical point are evaluated by MC simulations for 1≤W≤10 and compared to analytical results for ideal chains and with scaling theory predictions. The behavior of a self-avoiding chain is remarkably close to that of an ideal chain in several aspects. We demonstrate that the bound fraction θ and the related properties of finite ideal and self-avoiding chains can be presented in a universal reduced form: θ(N,U,W)=θ(NU(c),U/U(c)). By utilizing precise estimations of the critical points we investigate the chain length dependence of the ratio of the normal and lateral components of the gyration radius. Contrary to common expectations this ratio attains a limiting universal value /=0.320±0.003 only at N~5000. Finite-N corrections for this ratio turn out to be of the opposite sign for W=1 and for W≥2. We also study the N dependence of the apparent crossover exponent φ(eff)(N). Strong corrections to scaling of order N(-0.5) are observed, and the extrapolated value φ=0.483±0.003 is found for all values of W. The strong correction to scaling effects found here explain why for smaller values of N, as used in most previous work, misleadingly large values of φ(eff)(N) were identified as the asymptotic value for the crossover exponent.

Impact of stride-coupled gaze shifts of walking blowflies on the neuronal representation of visual targets

PubMed Central

Kress, Daniel; Egelhaaf, Martin

2014-01-01

During locomotion animals rely heavily on visual cues gained from the environment to guide their behavior. Examples are basic behaviors like collision avoidance or the approach to a goal. The saccadic gaze strategy of flying flies, which separates translational from rotational phases of locomotion, has been suggested to facilitate the extraction of environmental information, because only image flow evoked by translational self-motion contains relevant distance information about the surrounding world. In contrast to the translational phases of flight during which gaze direction is kept largely constant, walking flies experience continuous rotational image flow that is coupled to their stride-cycle. The consequences of these self-produced image shifts for the extraction of environmental information are still unclear. To assess the impact of stride-coupled image shifts on visual information processing, we performed electrophysiological recordings from the HSE cell, a motion sensitive wide-field neuron in the blowfly visual system. This cell has been concluded to play a key role in mediating optomotor behavior, self-motion estimation and spatial information processing. We used visual stimuli that were based on the visual input experienced by walking blowflies while approaching a black vertical bar. The response of HSE to these stimuli was dominated by periodic membrane potential fluctuations evoked by stride-coupled image shifts. Nevertheless, during the approach the cell’s response contained information about the bar and its background. The response components evoked by the bar were larger than the responses to its background, especially during the last phase of the approach. However, as revealed by targeted modifications of the visual input during walking, the extraction of distance information on the basis of HSE responses is much impaired by stride-coupled retinal image shifts. Possible mechanisms that may cope with these stride-coupled responses are discussed. PMID:25309362

Walk Score(TM), Perceived Neighborhood Walkability, and walking in the US.

PubMed

Tuckel, Peter; Milczarski, William

2015-03-01

To investigate both the Walk Score(TM) and a self-reported measure of neighborhood walkability ("Perceived Neighborhood Walkability") as estimators of transport and recreational walking among Americans. The study is based upon a survey of a nationally-representative sample of 1224 American adults. The survey gauged walking for both transport and recreation and included a self-reported measure of neighborhood walkability and each respondent's Walk Score(TM). Binary logistic and linear regression analyses were performed on the data. The Walk Score(TM) is associated with walking for transport, but not recreational walking nor total walking. Perceived Neighborhood Walkability is associated with transport, recreational and total walking. Perceived Neighborhood Walkability captures the experiential nature of walking more than the Walk Score(TM).

Intelligent agents: adaptation of autonomous bimodal microsystems

NASA Astrophysics Data System (ADS)

Smith, Patrice; Terry, Theodore B.

2014-03-01

Autonomous bimodal microsystems exhibiting survivability behaviors and characteristics are able to adapt dynamically in any given environment. Equipped with a background blending exoskeleton it will have the capability to stealthily detect and observe a self-chosen viewing area while exercising some measurable form of selfpreservation by either flying or crawling away from a potential adversary. The robotic agent in this capacity activates a walk-fly algorithm, which uses a built in multi-sensor processing and navigation subsystem or algorithm for visual guidance and best walk-fly path trajectory to evade capture or annihilation. The research detailed in this paper describes the theoretical walk-fly algorithm, which broadens the scope of spatial and temporal learning, locomotion, and navigational performances based on optical flow signals necessary for flight dynamics and walking stabilities. By observing a fly's travel and avoidance behaviors; and, understanding the reverse bioengineering research efforts of others, we were able to conceptualize an algorithm, which works in conjunction with decisionmaking functions, sensory processing, and sensorimotor integration. Our findings suggest that this highly complex decentralized algorithm promotes inflight or terrain travel mobile stability which is highly suitable for nonaggressive micro platforms supporting search and rescue (SAR), and chemical and explosive detection (CED) purposes; a necessity in turbulent, non-violent structured or unstructured environments.

The Association between Belgian Older Adults' Physical Functioning and Physical Activity: What Is the Moderating Role of the Physical Environment?

PubMed

Van Holle, Veerle; Van Cauwenberg, Jelle; Gheysen, Freja; Van Dyck, Delfien; Deforche, Benedicte; Van de Weghe, Nico; De Bourdeaudhuij, Ilse

2016-01-01

Better physical functioning in the elderly may be associated with higher physical activity levels. Since older adults spend a substantial part of the day in their residential neighborhood, the neighborhood physical environment may moderate associations between functioning and older adults' physical activity. The present study investigated the moderating role of the objective and perceived physical environment on associations between Belgian older adults' physical functioning and transport walking, recreational walking, and moderate-to-vigorous physical activity. Data from 438 older adults were included. Objective physical functioning was assessed using the Short Physical Performance Battery. Potential moderators included objective neighborhood walkability and perceptions of land use mix diversity, access to recreational facilities, access to services, street connectivity, physical barriers for walking, aesthetics, crime-related safety, traffic speeding-related safety, and walking infrastructure. Transport and recreational walking were self-reported, moderate-to-vigorous physical activity was assessed through accelerometers. Multi-level regression analyses were conducted using MLwiN to examine two-way interactions between functioning and the environment on both walking outcomes. Based on a previous study where environment x neighborhood income associations were found for Belgian older adults' moderate-to-vigorous physical activity, three-way functioning x environment x income interactions were examined for moderate-to-vigorous physical activity. Objectively-measured walkability moderated the association between functioning and transport walking; this positive association was only present in high-walkable neighborhoods. Moreover, a three-way interaction was observed for moderate-to-vigorous physical activity. Only in high-income, high-walkable neighborhoods, there was a positive association between functioning and moderate-to-vigorous physical activity. No functioning x walkability interactions were observed for recreational walking, and none of the perceived environmental variables moderated the positive association between physical functioning and the physical activity outcomes. For older adults with better physical functioning, living in a high-walkable neighborhood could be beneficial to engage in more transport walking. Living in high-income, high-walkable neighborhoods and having better functioning might also be beneficial for more engagement in moderate-to-vigorous physical activity. This might suggest a protective role of neighborhood walkability for preventing declining physical functioning and consequently decreasing physical activity levels in older adults. However, given the cross-sectional design of the present study, this suggestion needs to be confirmed through longitudinal assessment investigating over-time changes in the observed associations.

Achievement of exercise objectives and satisfaction with the walk with ease program-group and self-directed participants.

PubMed

Nyrop, Kirsten A; Cleveland, Rebecca; Callahan, Leigh F

2014-01-01

This study presents group (instructor-led) and self-directed (nongroup) participant achievement of exercise objectives and satisfaction with the Arthritis Foundation's Walk With Ease (WWE) program at 6 weeks postintervention and 1-year follow-up. Secondary data analysis. Rural and urban counties in North Carolina. Four hundred sixty-two adults with self-reported joint pain/stiffness or physician-diagnosed arthritis, age ≥18 years, no serious medical condition, no cognitive impairments, English speaking. Intervention. WWE is a 6-week community-based walking program offered in two formats-group and self-directed. Self-report measures collected at baseline, 6 weeks, and 1 year. Descriptive statistics, χ (2) and t-tests. Individuals self-selected either group (n = 192) or self-directed (n = 270) format. On average, participants were age 67, Caucasian (70%), and female (88%). Mean minutes per walk increased from 16.7 at baseline to 34.2 minutes at 1 year among group participants, and from 16.5 to 33.7 minutes among self-directed. At 1 year, 59.6% of group and 69.3% of self-directed participants reported continued walking (p = .06). Group participants were more likely than self-directed to do recommended stretching (p < .02) and warm-up/cool-down exercises (p < .01). Group and self-directed participants have similar self-reported walking outcomes but have some differences in their utilization of WWE recommendations.

Treadmill Adaptation and Verification of Self-Selected Walking Speed: A Protocol for Children

ERIC Educational Resources Information Center

Amorim, Paulo Roberto S.; Hills, Andrew; Byrne, Nuala

2009-01-01

Walking is a common activity of daily life and researchers have used the range 3-6 km.h[superscript -1] as reference for walking speeds habitually used for transportation. The term self-selected (i.e., individual or comfortable walking pace or speed) is commonly used in the literature and is identified as the most efficient walking speed, with…

Hip pain

MedlinePlus

... from a chair, walking, climbing stairs, and driving Hamstring strain Iliotibial band syndrome Hip flexor strain Hip ... and cool down afterward. Stretch your quadriceps and hamstrings. Avoid running straight down hills. Walk down instead. ...

Physical Activity and the Association With Self-Reported Impairments, Walking Limitations, Fear of Falling, and Incidence of Falls in Persons With Late Effects of Polio.

PubMed

Winberg, Cecilia; Brogårdh, Christina; Flansbjer, Ulla-Britt; Carlsson, Gunilla; Rimmer, James; Lexell, Jan

2015-07-01

The purpose of this study was to determine the association between physical activity and self-reported disability in ambulatory persons with mild to moderate late effects of polio (N = 81, mean age 67 years). The outcome measures were: Physical Activity and Disability Survey (PADS), a pedometer, Self-Reported Impairments in Persons with Late Effects of Polio Scale (SIPP), Walking Impact Scale (Walk-12), Falls Efficacy Scale-International (FES-I), and self-reported incidence of falls. The participants were physically active on average 158 min per day and walked 6,212 steps daily. Significant associations were found between PADS and Walk-12 (r = -.31, p < .001), and between the number of steps and SIPP, Walk-12, and FES-I (r = -.22 to -.32, p < .05). Walk-12 and age explained 14% of the variance in PADS and FES-I explained 9% of the variance in number of steps per day. Thus, physical activity was only weakly to moderately associated with self-reported disability.

Use of self-report to predict ability to walk 400 meters in mobility-limited older adults.

PubMed

Sayers, Stephen P; Brach, Jennifer S; Newman, Anne B; Heeren, Tim C; Guralnik, Jack M; Fielding, Roger A

2004-12-01

To determine whether the ability to walk 400 m could be predicted from self-reported walking habits and abilities in older adults and to develop an accurate self-report measure appropriate for observational trials of mobility when functional measures are impractical to collect. Cross-sectional. University-based human physiology laboratory. One hundred fifty community-dwelling older men and women (mean age+/-standard error= 79.8+/-0.3). An 18-item questionnaire assessing walking habits and ability was administered to each participant, followed by a 400-m walk test. Ninety-eight (65%) volunteers were able to complete the 400-m walk; 52 (35%) were unable. Logistic regression was performed using response items from a questionnaire as predictors and 400-m walk as the outcome. Three questions (Do you think you could walk one-quarter of a mile now without sitting down to rest. Because of a health or physical problem, do you have difficulty walking 1 mile? Could you walk up and down every aisle of a grocery store without sitting down to rest or leaning on a cart?) were predictive of 400-m walking ability and were included in the model. If participants answered all three questions compatible with the inability to walk 400 m, there was a 91% probability that they were unable to walk 400 m, with a sensitivity of 46% and a specificity of 97%. A three-item self-report developed in the study was able to accurately predict mobility disability. The utility of this instrument may be in evaluating self-reported mobility in large observational trials on mobility when functional mobility tasks are impractical to collect.

Slip avoidance strategies in children with bilateral spastic cerebral palsy and crouch gait.

PubMed

Kleiner, Ana Francisca Rozin; Pacifici, Ilaria; Condoluci, Claudia; Sforza, Chiarella; Galli, Manuela

2018-06-01

A slip occurs when the required friction (RCOF) to prevent slipping at the foot/floor interfaces exceeds the available friction. The RCOF is dependent upon the biomechanics features of individuals and their gait. On the other hand, the available friction depends on environmental features. Once individuals with crouch gait have their biomechanics of gait completely altered, how do they interact with a supporting surface? The aim was to quantify the RCOF in children with bilateral spastic cerebral palsy (BSCP) and crouch gait. 11 children with crouch gait and 11 healthy age-matched children were instructed to walk barefoot at self-selected speed over a force platform. The RCOF curve was obtained as the ratio between the tangential forces (FT), and the vertical ground reaction force (FZ). Three points were extracted by the RCOF, FT and FZ curves at the loading response, midstance and push-off phases. Children with BSCP presented higher values of RCOF in all support phase and lower gait velocity relative to the healthy controls. For BSCP group no correlation between FT and FZ were found, indicating that this group is not able to negotiate the forces during the support phase. Children with BSCP and crouch gait are not able to negotiate the forces applied on the ground in support phase, so to avoid the fall, their strategy is to reduce the gait velocity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of interventions on normalizing step width during self-paced dual-belt treadmill walking with virtual reality, a randomised controlled trial.

PubMed

Oude Lansink, I L B; van Kouwenhove, L; Dijkstra, P U; Postema, K; Hijmans, J M

2017-10-01

Step width is increased during dual-belt treadmill walking, in self-paced mode with virtual reality. Generally a familiarization period is thought to be necessary to normalize step width. The aim of this randomised study was to analyze the effects of two interventions on step width, to reduce the familiarization period. We used the GRAIL (Gait Real-time Analysis Interactive Lab), a dual-belt treadmill with virtual reality in the self-paced mode. Thirty healthy young adults were randomly allocated to three groups and asked to walk at their preferred speed for 5min. In the first session, the control-group received no intervention, the 'walk-on-the-line'-group was instructed to walk on a line, projected on the between-belt gap of the treadmill and the feedback-group received feedback about their current step width and were asked to reduce it. Interventions started after 1min and lasted 1min. During the second session, 7-10days later, no interventions were given. Linear mixed modeling showed that interventions did not have an effect on step width after the intervention period in session 1. Initial step width (second 30s) of session 1 was larger than initial step width of session 2. Step width normalized after 2min and variation in step width stabilized after 1min. Interventions do not reduce step width after intervention period. A 2-min familiarization period is sufficient to normalize and stabilize step width, in healthy young adults, regardless of interventions. A standardized intervention to normalize step width is not necessary. Copyright © 2017 Elsevier B.V. All rights reserved.

Nail Fungal Infections

MedlinePlus

... your toenails. If you often walk barefoot in locker rooms, you can pick up a fungus from ... Avoid walking barefoot in public areas, such as locker rooms. Questions Questions to Ask Your Doctor My ...

Neighborhood preference, walkability and walking in overweight/obese men.

PubMed

Norman, Gregory J; Carlson, Jordan A; O'Mara, Stephanie; Sallis, James F; Patrick, Kevin; Frank, Lawrence D; Godbole, Suneeta V

2013-03-01

To investigate whether self-selection moderated the effects of walkability on walking in overweight and obese men. 240 overweight and obese men completed measures on importance of walkability when choosing a neighborhood (selection) and preference for walkable features in general (preference). IPAQ measured walking. A walkbility index was derived from geographic information systems (GIS). Walkability was associated with walking for transportation (p = .027) and neighborhood selection was associated with walking for transportation (p = .002) and total walking (p = .001). Preference was associated with leisure walking (p = .045) and preference moderated the relationship between walkability and total walking (p = .059). Walkability and self-selection are both important to walking behavior.

Fluid limit of nonintegrable continuous-time random walks in terms of fractional differential equations.

PubMed

Sánchez, R; Carreras, B A; van Milligen, B Ph

2005-01-01

The fluid limit of a recently introduced family of nonintegrable (nonlinear) continuous-time random walks is derived in terms of fractional differential equations. In this limit, it is shown that the formalism allows for the modeling of the interaction between multiple transport mechanisms with not only disparate spatial scales but also different temporal scales. For this reason, the resulting fluid equations may find application in the study of a large number of nonlinear multiscale transport problems, ranging from the study of self-organized criticality to the modeling of turbulent transport in fluids and plasmas.

Coined quantum walks on weighted graphs

NASA Astrophysics Data System (ADS)

Wong, Thomas G.

2017-11-01

We define a discrete-time, coined quantum walk on weighted graphs that is inspired by Szegedy’s quantum walk. Using this, we prove that many lackadaisical quantum walks, where each vertex has l integer self-loops, can be generalized to a quantum walk where each vertex has a single self-loop of real-valued weight l. We apply this real-valued lackadaisical quantum walk to two problems. First, we analyze it on the line or one-dimensional lattice, showing that it is exactly equivalent to a continuous deformation of the three-state Grover walk with faster ballistic dispersion. Second, we generalize Grover’s algorithm, or search on the complete graph, to have a weighted self-loop at each vertex, yielding an improved success probability when l < 3 + 2\\sqrt{2} ≈ 5.828 .

Video interaction guidance inviting transcendence of postpartum depressed mothers' self-centered state and holding behavior.

PubMed

Vik, Kari; Braten, Stein

2009-05-01

By sometimes evoking self-absorbed and avoidance behaviors in new mothers, postnatal depression affects the quality of mother-infant interaction, which in turn may invoke distress and avoidance in the infant and cause even more lasting impairment in the child's development. Three depressed mothers, A, B, and C, are reported upon after having been offered counseling in accordance with the Marte Meo approach through jointly watching with the therapist video replays of themselves interacting with their newborns. Clinical vignettes are offered which indicate how empathic and positive support of a sensitive therapist can be helpful in inviting the mother's recognition of her importance to her infant and facilitating mutually gratifying interaction between mother and child. Protocol analyses of select sessions of video-related therapy reveal that two of the mothers sometimes complete the therapist's unfinished statements in an other-centered manner, thereby transcending their initial self-centered state. This is most dramatic in the case of Mother A, who starts out in the first session almost incapable of speech, merely nodding or shaking her head. In addition to other indications of improved mother-infant interaction, comparison of pre- and postguidance windows regarding the three mothers' holding behaviors reveals a shift from an avoidance or anxious stance to closer and more secure holding. Copyright © 2009 Michigan Association for Infant Mental Health.

Walking drawings and walking ability in children with cerebral palsy.

PubMed

Chong, Jimmy; Mackey, Anna H; Stott, N Susan; Broadbent, Elizabeth

2013-06-01

To investigate whether drawings of the self walking by children with cerebral palsy (CP) were associated with walking ability and illness perceptions. This was an exploratory study in 52 children with CP (M:F = 28:24), mean age 11.1 years (range 5-18), who were attending tertiary level outpatient clinics. Children were asked to draw a picture of themselves walking. Drawing size and content was used to investigate associations with clinical walk tests and children's own perceptions of their CP assessed using a CP version of the Brief Illness Perception Questionnaire. Larger drawings of the self were associated with less distance traveled, higher emotional responses to CP, and lower perceptions of pain or discomfort, independent of age. A larger self-to-overall drawing height ratio was related to walking less distance. Drawings of the self confined within buildings and the absence of other figures were also associated with reduced walking ability. Drawing size and content can reflect walking ability, as well as symptom perceptions and distress. Drawings may be useful for clinicians to use with children with cerebral palsy to aid discussion about their condition. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Let's Walk Outdoors! Self-Paced Walking Outdoors Improves Future Intention to Exercise in Women With Obesity.

PubMed

Krinski, Kleverton; Machado, Daniel G S; Lirani, Luciana S; DaSilva, Sergio G; Costa, Eduardo C; Hardcastle, Sarah J; Elsangedy, Hassan M

2017-04-01

In order to examine whether environmental settings influence psychological and physiological responses of women with obesity during self-paced walking, 38 women performed two exercise sessions (treadmill and outdoors) for 30 min, where oxygen uptake, heart rate, ratings of perceived exertion, affect, attentional focus, enjoyment, and future intentions to walk were analyzed. Physiological responses were similar during both sessions. However, during outdoor exercise, participants displayed higher externally focused attention, positive affect, and lower ratings of perceived exertion, followed by greater enjoyment and future intention to participate in outdoor walking. The more externally focused attention predicted greater future intentions to participate in walking. Therefore, women with obesity self-selected an appropriate exercise intensity to improve fitness and health in both environmental settings. Also, self-paced outdoor walking presented improved psychological responses. Health care professionals should consider promoting outdoor forms of exercise to maximize psychological benefits and promote long-term adherence to a physically active lifestyle.

Discrete-to-continuum simulation approach to polymer chain systems: Subdiffusion, segregation, and chain folding

NASA Astrophysics Data System (ADS)

Foo, Grace M.; Pandey, R. B.

1998-05-01

A discrete-to-continuum approach is introduced to study the static and dynamic properties of polymer chain systems with a bead-spring chain model in two dimensions. A finitely extensible nonlinear elastic potential is used for the bond between the consecutive beads with the Lennard-Jones (LJ) potential with smaller (Rc=21/6σ=0.95) and larger (Rc=2.5σ=2.1) values of the upper cutoff for the nonbonding interaction among the neighboring beads. We find that chains segregate at temperature T=1.0 with Rc=2.1 and remain desegregated with Rc=0.95. At low temperature (T=0.2), chains become folded, in a ribbonlike conformation, unlike random and self-avoiding walk conformations at T=1.0. The power-law dependence of the rms displacements of the center of mass (Rc.m.) of the chains and their center node (Rcn) with time are nonuniversal, with the range of exponents ν1~=0.45-0.25 and ν2~=0.30-0.10, respectively. Both radius of gyration (Rg) and average bond length () decrease on increasing the range of interaction (Rc), consistent with the extended state in good solvent to collapsed state in poor solvent description of the polymer chains. Analysis of the radial distribution function supports these observations.

Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability.

PubMed

Gustafson, Jonathan A; Gorman, Shannon; Fitzgerald, G Kelley; Farrokhi, Shawn

2016-01-01

Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (p<0.01) and greater knee flexion excursions (p<0.01) compared to their knee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted. Copyright © 2015 Elsevier B.V. All rights reserved.

Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability

PubMed Central

Gustafson, Jonathan A.; Gorman, Shannon; Fitzgerald, G. Kelley; Farrokhi, Shawn

2017-01-01

Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (p<0.01) and greater knee flexion excursions (p<0.01) compared to their knee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted. PMID:26481256

Concentrated Solutions of Single-Chain Nanoparticles: A Simple Model for Intrinsically Disordered Proteins under Crowding Conditions.

PubMed

Moreno, Angel J; Lo Verso, Federica; Arbe, Arantxa; Pomposo, José A; Colmenero, Juan

2016-03-03

By means of large-scale computer simulations and small-angle neutron scattering (SANS), we investigate solutions of single-chain nanoparticles (SCNPs), covering the whole concentration range from infinite dilution to melt density. The analysis of the conformational properties of the SCNPs reveals that these synthetic nano-objects share basic ingredients with intrinsically disordered proteins (IDPs), as topological polydispersity, generally sparse conformations, and locally compact domains. We investigate the role of the architecture of the SCNPs in their collapse behavior under macromolecular crowding. Unlike in the case of linear macromolecules, which experience the usual transition from self-avoiding to Gaussian random-walk conformations, crowding leads to collapsed conformations of SCNPs resembling those of crumpled globules. This behavior is already found at volume fractions (about 30%) that are characteristic of crowding in cellular environments. The simulation results are confirmed by the SANS experiments. Our results for SCNPs--a model system free of specific interactions--propose a general scenario for the effect of steric crowding on IDPs: collapse from sparse conformations at high dilution to crumpled globular conformations in cell environments.

Evaluation of the Dogs, Physical Activity, and Walking (Dogs PAW) Intervention: A Randomized Controlled Trial.

PubMed

Richards, Elizabeth A; Ogata, Niwako; Cheng, Ching-Wei

2016-01-01

To facilitate physical activity (PA) adoption and maintenance, promotion of innovative population-level strategies that focus on incorporating moderate-intensity lifestyle PAs are needed. The purpose of this randomized controlled trial was to evaluate the Dogs, Physical Activity, and Walking intervention, a 3-month, social cognitive theory (SCT), e-mail-based PA intervention. In a longitudinal, repeated-measures design, 49 dog owners were randomly assigned to a control (n = 25) or intervention group (n = 24). The intervention group received e-mail messages (twice weekly for 4 weeks and weekly for 8 weeks) designed to influence SCT constructs of self-efficacy, self-regulation, outcome expectations and expectancies, and social support. At baseline and every 3 months through 1 year, participants completed self-reported questionnaires of individual, interpersonal, and PA variables. Linear mixed models were used to assess for significant differences in weekly minutes of dog walking and theoretical constructs between groups (intervention and control) across time. To test self-efficacy as a mediator of social support for dog walking, tests for mediation were conducted using the bootstrapping technique. With the exception of Month 9, participants in the intervention group accumulated significantly more weekly minutes of dog walking than the control group. On average, the intervention group accumulated 58.4 more minutes (SD = 18.1) of weekly dog walking than the control group (p < .05). Self-efficacy partially mediated the effect of social support variables on dog walking. Results indicate that a simple SCT-based e-mail intervention is effective in increasing and maintaining an increase in dog walking among dog owners at 12-month follow-up. In light of these findings, it may be advantageous to design dog walking interventions that focus on increasing self-efficacy for dog walking by fostering social support.

The interaction between self-regulation and motivation prospectively predicting problem behavior in adolescence.

PubMed

Rhodes, Jessica D; Colder, Craig R; Trucco, Elisa M; Speidel, Carolyn; Hawk, Larry W; Lengua, Liliana J; Das Eiden, Rina; Wieczorek, William

2013-01-01

A large literature suggests associations between self-regulation and motivation and adolescent problem behavior; however, this research has mostly pitted these constructs against one another or tested them in isolation. Following recent neural-systems based theories (e.g., Ernst & Fudge, 2009 ), the present study investigated the interactions between self-regulation and approach and avoidance motivation prospectively predicting delinquency and depressive symptoms in early adolescence. The community sample included 387 adolescents aged 11 to 13 years old (55% female; 17% minority). Laboratory tasks were used to assess self-regulation and approach and avoidance motivation, and adolescent self-reports were used to measure depressive symptoms and delinquency. Analyses suggested that low levels of approach motivation were associated with high levels of depressive symptoms, but only at high levels of self-regulation (p = .01). High levels of approach were associated with high levels of rule breaking, but only at low levels of self-regulation (p < .05). These findings support contemporary neural-based systems theories that posit integration of motivational and self-regulatory individual differences via moderational models to understand adolescent problem behavior.

The Interaction Between Self-Regulation and Motivation Prospectively Predicting Problem Behavior in Adolescence

PubMed Central

Rhodes, Jessica D.; Colder, Craig R.; Trucco, Elisa M.; Speidel, Carolyn; Hawk, Larry W.; Lengua, Liliana J.; Eiden, Rina Das; Wiezcorek, William

2013-01-01

Objective A large literature suggests associations between self-regulation and motivation and adolescent problem behavior, however this research has mostly pitted these constructs against one another or tested them in isolation. Following recent neural-systems based theories (e.g., Ernst & Fudge, 2009), the present study investigated the interactions between self-regulation and approach and avoidance motivation prospectively predicting delinquency and depressive symptoms in early adolescence. Method The community sample included 387 adolescents aged 11–13 years old (55% female; 17% minority). Laboratory tasks were used to assess self-regulation and approach and avoidance motivation, and adolescent self-reports were used to measure depressive symptoms and delinquency. Results Analyses suggested that low levels of approach motivation were associated with high levels of depressive symptoms, but only at high levels of self-regulation (p = .01). High levels of approach were associated with high levels of rule breaking, but only at low levels of self-regulation (p < .05). Conclusions These findings support contemporary neural-based systems theories that posit integration of motivational and self-regulatory individual differences via moderational models to understand adolescent problem behavior. PMID:23477426

Neighborhood Preference, Walkability and Walking in Overweight/Obese Men

PubMed Central

Norman, Gregory J.; Carlson, Jordan A.; O’Mara, Stephanie; Sallis, James F.; Patrick, Kevin; Frank, Lawrence D.; Godbole, Suneeta V.

2015-01-01

Objectives To investigate whether self-selection moderated the effects of walkability on walking in overweight and obese men. Methods 240 overweight and obese men completed measures on importance of walkability when choosing a neighborhood (selection) and preference for walkable features in general (preference). IPAQ measured walking. A walkbility index was derived from geographic information systems (GIS). Results Walkability was associated with walking for transportation (p = .027) and neighborhood selection was associated with walking for transportation (p = .002) and total walking (p = .001). Preference was associated with leisure walking (p = .045) and preference moderated the relationship between walkability and total walking (p = .059). Conclusion Walkability and self-selection are both important to walking behavior. PMID:23026109

Expected distributions of root-mean-square positional deviations in proteins.

PubMed

Pitera, Jed W

2014-06-19

The atom positional root-mean-square deviation (RMSD) is a standard tool for comparing the similarity of two molecular structures. It is used to characterize the quality of biomolecular simulations, to cluster conformations, and as a reaction coordinate for conformational changes. This work presents an approximate analytic form for the expected distribution of RMSD values for a protein or polymer fluctuating about a stable native structure. The mean and maximum of the expected distribution are independent of chain length for long chains and linearly proportional to the average atom positional root-mean-square fluctuations (RMSF). To approximate the RMSD distribution for random-coil or unfolded ensembles, numerical distributions of RMSD were generated for ensembles of self-avoiding and non-self-avoiding random walks. In both cases, for all reference structures tested for chains more than three monomers long, the distributions have a maximum distant from the origin with a power-law dependence on chain length. The purely entropic nature of this result implies that care must be taken when interpreting stable high-RMSD regions of the free-energy landscape as "intermediates" or well-defined stable states.

Walking and cycling for commuting, leisure and errands: relations with individual characteristics and leisure-time physical activity in a cross-sectional survey (the ACTI-Cités project).

PubMed

Menai, Mehdi; Charreire, Hélène; Feuillet, Thierry; Salze, Paul; Weber, Christiane; Enaux, Christophe; Andreeva, Valentina A; Hercberg, Serge; Nazare, Julie-Anne; Perchoux, Camille; Simon, Chantal; Oppert, Jean-Michel

2015-12-09

Increasing active transport behavior (walking, cycling) throughout the life-course is a key element of physical activity promotion for health. There is, however, a need to better understand the correlates of specific domains of walking and cycling to identify more precisely at-risk populations for public health interventions. In addition, current knowledge of interactions between domains of walking and cycling remains limited. We assessed past-month self-reported time spent walking and cycling in three specific domains (commuting, leisure and errands) in 39,295 French adult participants (76.5% women) of the on-going NutriNet Santé web-cohort. Multivariate logistic regression models were used to investigate the associations with socio-demographic and physical activity correlates. Having a transit pass was strongly positively associated with walking for commuting and for errands but was unrelated to walking for leisure or to all domains of cycling. Having a parking space at work was strongly negatively associated with walking for commuting and cycling for commuting. BMI was negatively associated with both walking for leisure and errands, and with the three domains of cycling. Leisure-time physical activity was negatively associated with walking for commuting but was positively associated with the two other domains of walking and with cycling (three domains). Walking for commuting was positively associated with the other domains of walking; cycling for commuting was also positively associated with the other domains of cycling. Walking for commuting was not associated with cycling for commuting. In adults walking and cycling socio-demographic and physical activity correlates differ by domain (commuting, leisure and errands). Better knowledge of relationships between domains should help to develop interventions focusing not only the right population, but also the right behavior.

Stepping strategies for regulating gait adaptability and stability.

PubMed

Hak, Laura; Houdijk, Han; Steenbrink, Frans; Mert, Agali; van der Wurff, Peter; Beek, Peter J; van Dieën, Jaap H

2013-03-15

Besides a stable gait pattern, gait in daily life requires the capability to adapt this pattern in response to environmental conditions. The purpose of this study was to elucidate the anticipatory strategies used by able-bodied people to attain an adaptive gait pattern, and how these strategies interact with strategies used to maintain gait stability. Ten healthy subjects walked in a Computer Assisted Rehabilitation ENvironment (CAREN). To provoke an adaptive gait pattern, subjects had to hit virtual targets, with markers guided by their knees, while walking on a self-paced treadmill. The effects of walking with and without this task on walking speed, step length, step frequency, step width and the margins of stability (MoS) were assessed. Furthermore, these trials were performed with and without additional continuous ML platform translations. When an adaptive gait pattern was required, subjects decreased step length (p<0.01), tended to increase step width (p=0.074), and decreased walking speed while maintaining similar step frequency compared to unconstrained walking. These adaptations resulted in the preservation of equal MoS between trials, despite the disturbing influence of the gait adaptability task. When the gait adaptability task was combined with the balance perturbation subjects further decreased step length, as evidenced by a significant interaction between both manipulations (p=0.012). In conclusion, able-bodied people reduce step length and increase step width during walking conditions requiring a high level of both stability and adaptability. Although an increase in step frequency has previously been found to enhance stability, a faster movement, which would coincide with a higher step frequency, hampers accuracy and may consequently limit gait adaptability. Copyright © 2012 Elsevier Ltd. All rights reserved.

Positive affect predicts avoidance goals in social interaction anxiety: testing a hierarchical model of social goals.

PubMed

Trew, Jennifer L; Alden, Lynn E

2012-01-01

Models of self-regulation suggest that social goals may contribute to interpersonal and affective difficulties, yet little research has addressed this issue in the context of social anxiety. The present studies evaluated a hierarchical model of approach and avoidance in the context of social interaction anxiety, with affect as a mediating factor in the relationship between motivational tendencies and social goals. This model was refined in one undergraduate sample (N = 186) and cross-validated in a second sample (N = 195). The findings support hierarchical relationships between motivational tendencies, social interaction anxiety, affect, and social goals, with higher positive affect predicting fewer avoidance goals in both samples. Implications for the treatment of social interaction anxiety are discussed.

Development of Walking and Self-Sufficiency Ability Related to Nutrition among People with Down Syndrome

ERIC Educational Resources Information Center

Brantmüller, Éva; Gyuró, Monika; Karácsony, Ilona

2015-01-01

Development of the walking ability and self-care of patients with Down syndrome is affected by their body weight determining their lifestyle to a great extent. Objectives: The study aimed at the determination of body mass index for persons living in residential institutions and families, exploration its impact on walking and self-care as two,…

Heterosexual social competence, anxiety, avoidance and self-judged physical attractiveness.

PubMed

Mitchell, K R; Orr, F E

1976-10-01

The relationship between self-judged physical attractiveness and opposite-sex behavior was examined as part of a large survey on the interaction patterns of 963 college students. The findings suggest that a self-rated negative physical image is related to significantly high levels of heterosexual difficulties.

Attachment insecurities and women's sexual function and satisfaction: the mediating roles of sexual self-esteem, sexual anxiety, and sexual assertiveness.

PubMed

Brassard, Audrey; Dupuy, Emmanuelle; Bergeron, Sophie; Shaver, Phillip R

2015-01-01

We examined the potential role of three mediators--sexual self-esteem, sexual anxiety, and sexual assertiveness--of the association between romantic attachment insecurities (anxiety and avoidance) and two aspects of women's sexual functioning: sexual function and sexual satisfaction. A sample of 556 women aged 18 to 30 agreed to complete an online series of validated questionnaires assessing attachment insecurities and several aspects of sexual functioning. Lower sexual self-esteem and higher sexual anxiety mediated the associations between attachment anxiety and lower sexual function and satisfaction. Lower sexual self-esteem and higher sexual anxiety also partially mediated the links between attachment-related avoidance and the two sexual functioning variables. Sexual assertiveness, however, did not mediate these associations. A significant interaction between attachment anxiety and avoidance was also found to predict sexual satisfaction, with women high in avoidance and low in anxiety being the least satisfied. Results are discussed in terms of theoretical and clinical implications.

Interactive contributions of self-regulation deficits and social motivation to psychopathology: Unraveling divergent pathways to aggressive behavior and depressive symptoms

PubMed Central

RUDOLPH, KAREN D.; TROOP-GORDON, WENDY; LLEWELLYN, NICOLE

2015-01-01

Poor self-regulation has been implicated as a significant risk factor for the development of multiple forms of psychopathology. This research examined the proposition that self-regulation deficits differentially predict aggressive behavior and depressive symptoms, depending on children’s social approach versus avoidance motivation. A prospective, multiple-informant approach was used to test this hypothesis in 419 children (M age = 8.92, SD = 0.36). Parents rated children’s inhibitory control. Children completed measures of social approach–avoidance motivation and depressive symptoms. Teachers rated children’s aggressive behavior. As anticipated, poor inhibitory control predicted aggressive behavior in boys with high but not low approach motivation and low but not high avoidance motivation, whereas poor inhibitory control predicted depressive symptoms in girls with high but not low avoidance motivation. This research supports several complementary theoretical models of psychopathology and provides insight into the differential contributions of poor self-regulation to maladaptive developmental outcomes. The findings suggest the need for targeted intervention programs that consider heterogeneity among children with self-regulatory deficits. PMID:23627953

Self-Monitoring vs. Implementation Intentions: a Comparison of Behaviour Change Techniques to Improve Sleep Hygiene and Sleep Outcomes in Students.

PubMed

Mairs, Lucinda; Mullan, Barbara

2015-10-01

This study seeks to investigate and compare the efficacy of self-monitoring and implementation intentions-two post-intentional behaviour change techniques-for improving sleep hygiene behaviours and sleep outcomes in university students. Seventy-two undergraduate students completed baseline measures of four sleep hygiene behaviours (making the sleep environment restful, avoiding going to bed hungry/thirsty, avoiding stress/anxiety-provoking activities near bed time and avoiding caffeine in the evening), as well as the Pittsburgh sleep quality index (PSQI) and the insomnia severity index (ISI). Participants were randomly assigned to an active-control diary-keeping, self-monitoring condition or completed implementation intentions for each behaviour. Post-intervention measurement was completed 2 weeks after baseline. Repeated measures analyses of variance found significant main effects of time for improvements in making the sleep environment restful and avoiding going to bed hungry or thirsty, as well as PSQI and ISI scores. Non-significant interactions suggested no group differences on any variable, except for increasing avoidance of stress and anxiety-provoking activities before bed time, for which only implementation intentions were found to be effective. Attrition was higher amongst self-monitoring participants. Both self-monitoring and implementation intentions appear to be promising behaviour change techniques for improving sleep hygiene and sleep. Future research should examine the acceptability of the two behaviour change techniques and the relationship with differential attrition, as well as effect size variations according to behaviour and technique. Researchers should investigate potential additive or interactive effects of the techniques, as they could be utilised in a complementary manner to target different processes in effecting behaviour change.

Healthy young adults implement distinctive avoidance strategies while walking and circumventing virtual human vs. non-human obstacles in a virtual environment.

PubMed

Souza Silva, Wagner; Aravind, Gayatri; Sangani, Samir; Lamontagne, Anouk

2018-03-01

This study examines how three types of obstacles (cylinder, virtual human and virtual human with footstep sounds) affect circumvention strategies of healthy young adults. Sixteen participants aged 25.2 ± 2.5 years (mean ± 1SD) were tested while walking overground and viewing a virtual room through a helmet mounted display. As participants walked towards a stationary target in the far space, they avoided an obstacle (cylinder or virtual human) approaching either from the right (+40°), left (-40°) or head-on (0°). Obstacle avoidance strategies were characterized using the position and orientation of the head. Repeated mixed model analysis showed smaller minimal distances (p = 0.007) while avoiding virtual humans as compared to cylinders. Footstep sounds added to virtual humans did not modify (p = 0.2) minimal distances compared to when no sound was provided. Onset times of avoidance strategies were similar across conditions (p = 0.06). Results indicate that the nature of the obstacle (human-like vs. non-human object) matters and can modify avoidance strategies. Smaller obstacle clearances in response to virtual humans may reflect the use of a less conservative avoidance strategy, due to a resemblance of obstacles to pedestrians and a recall of strategies used in daily locomotion. The lack of influence of footstep sounds supports the fact that obstacle avoidance primarily relies on visual cues and the principle of 'inverse effectiveness' whereby multisensory neurons' response to multimodal stimuli becomes weaker when the unimodal sensory stimulus (vision) is strong. Present findings should be taken into consideration to optimize the ecological validity of VR-based obstacle avoidance paradigms used in research and rehabilitation. Copyright © 2018 Elsevier B.V. All rights reserved.

Hand tactile discrimination, social touch and frailty criteria in elderly people: A cross sectional observational study.

PubMed

Vieira, Ana Isabel; Nogueira, Dália; de Azevedo Reis, Elisabeth; da Lapa Rosado, Maria; Vânia Nunes, Maria; Castro-Caldas, Alexandre

2016-01-01

Frailty is a common syndrome among elderly and sensory decline may exacerbate functional decline. The hand function, the manual dexterity, the performance of the daily living skills and the social interactions are determined, in a large degree, by sensory integrity. However, hand tactile sensory deterioration has been little explored in frailty. We performed a cross sectional observational study with 181 of institutionalized elders. From the initial sample we selected 50 subjects (68-99 years) who met the inclusion/exclusion criteria. Our goals were (1) to analyse the relationship between tactile discrimination (TD) of the hand, avoidance behaviours and attitudes towards social touch (BATST) and phenotype frailty criteria (unintentional weight loss, self-perception of exhaustion, decrease grip strength - GS, slow walking speed, low level of physical activity), (2) to explore whether other variables can contribute to explain the differences between pre-frail and frail elders. The results showed that increasing age is related to decline of TD of the hand (p=0.021) and to decrease in GS (p=0.025); women have significantly lower level of GS (p=0.001); TD decrease is correlated with higher avoidance BATST (p=0.000) and with lower GS (p=0.000); Lower GS corresponds to more avoidance BATST (p=0.003). Hand TD also can differentiate frail and pre-frail elderly subjects in this sample (p=0.037). Decreased TD of the hand may have implications on the functionality and on interpersonal relationships. TD of the hand also explains frailty levels in this sample. Hand TD should be used in assessment and intervention protocols in pre-frail and frail elders. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Factors relating to stages of change in walking exercise behavior among older adults living in a hilly, mountainous area.

PubMed

Ota, Kiyomi; Ninomiya, Kazue; Sakano, Junko

2014-01-01

We sought to identify factors relating to stages of change in walking exercise behavior among older adults living in a hilly, mountainous area in search of effective interventions to aid transitions. An anonymous self-administered questionnaire survey was conducted with all older adults aged between 60 and 74 years (n=752) living in Takahashi City in the district of Kawakami, Okayama Prefecture. Questionnaires were distributed by local volunteer staff to 752 older adults, who completed and mailed the questionnaires to the principal investigator. Data on participants' demographic characteristics (gender, age, family structure, etc.), stages of change in walking exercise behavior, self-efficacy, perceived physical environment, and perceived social environment were collected through the survey. The participants were divided into non-walking, preparation, and walking subgroups. The χ(2), Kruskal-Wallis, Mann-Whitney U, and Bonferroni's multiple comparison tests were performed. Significance was set at 0.05. of 325 returned questionnaires (response rate, 43.2%), 164 completed questionnaires were analyzed. Females were significantly more likely to be physically active than were males. The preparation group had the largest number of participants (n=69, 42.1%), while the walking group had the smallest (n=43, 26.2%). The Kruskal-Wallis test revealed differences between stages of change in walking exercise behavior in terms of self-efficacy, perceived physical environment (landscape), and perceived social environment (all items). Multiple comparisons revealed that there were significant differences between the non-walking and preparation groups in self-efficacy, landscape, and advice/guidelines, while there were significant differences between the preparation and walking groups in self-efficacy and understanding/empathy. Moving through the stages of change in walking exercise behavior was associated with gender, self-efficacy, the physical environment (landscape), and all components of the social environment. These findings suggest that in order to help older adults transition successfully through these stages of change, it is necessary to implement individualized interventions with due regard to landscape preservation, social environment, and self-efficacy, as well as participants' current stage of change.

Inception of self-interacting dark matter with dark charge conjugation symmetry

DOE PAGES

Ma, Ernest

2017-07-04

A new understanding of the stability of self-interacting dark matter is pointed out, based on the simplest spontaneously broken Abelian gauge model with one complex scalar and one Dirac fermion. The key is the imposition of dark charge conjugation symmetry. It allows the possible existence of two stable particles: the Dirac fermion and the vector gauge boson which acts as a light mediator for the former's self-interaction. Since this light mediator does not decay, it avoids the strong cosmological constraints recently obtained for all such models where the light mediator decays into standard-model particles.

Cognitive function and walking velocity in people with dementia; a comparison of backward and forward walking.

PubMed

Johansson, Hanna; Lundin-Olsson, Lillemor; Littbrand, Håkan; Gustafson, Yngve; Rosendahl, Erik; Toots, Annika

2017-10-01

How forward and backward walking, both central to everyday life, relate to cognition are relatively unexplored in people with dementia. This study aimed to investigate if forward and backward walking velocity respectively, associated with global cognition and executive function in people with dementia, and whether the association differed according to walking aid use or dementia type. Using a cross-sectional design, 161 participants (77% women), a mean Mini-Mental State Examination (MMSE) score of 15, and mean age of 85.5years and living in nursing homes were included. Self-paced forward walking (FW) and backward walking (BW) velocity over 2.4m was measured. Global cognitive outcome measurements included MMSE and Alzheimer Disease Assessment Scale - Cognitive subscale (ADAS-Cog). Executive function was measured using Verbal Fluency (VF). In comprehensively adjusted multivariate linear regression analyses, FW was independently associated with VF (p=0.001), but not MMSE (p=0.126) or ADAS-Cog (p=0.818). BW was independently associated with VF (p=0.043) and MMSE (p=0.022), but not ADAS-Cog (p=0.519). Interaction analyses showed that the association between BW velocity and executive function were stronger in participants who walked without a walking aid. No associations differed according to dementia type. In conclusion, executive function appears important to walking velocity, both forward and backward, in people with dementia with mild to moderately severe cognitive impairment. Global cognitive function was associated with backward walking only, perhaps due to it being more challenging. The association between BW velocity and executive function differed according to use of walking aids, which appeared to attenuate the association. Copyright © 2017 Elsevier B.V. All rights reserved.

High-speed DNA-based rolling motors powered by RNase H

PubMed Central

Yehl, Kevin; Mugler, Andrew; Vivek, Skanda; Liu, Yang; Zhang, Yun; Fan, Mengzhen; Weeks, Eric R.

2016-01-01

DNA-based machines that walk by converting chemical energy into controlled motion could be of use in applications such as next generation sensors, drug delivery platforms, and biological computing. Despite their exquisite programmability, DNA-based walkers are, however, challenging to work with due to their low fidelity and slow rates (~1 nm/min). Here, we report DNA-based machines that roll rather than walk, and consequently have a maximum speed and processivity that is three-orders of magnitude greater than conventional DNA motors. The motors are made from DNA-coated spherical particles that hybridise to a surface modified with complementary RNA; motion is achieved through the addition of RNase H, which selectively hydrolyses hybridised RNA. Spherical motors move in a self-avoiding manner, whereas anisotropic particles, such as dimerised particles or rod-shaped particles travel linearly without a track or external force. Finally, we demonstrate detection of single nucleotide polymorphism by measuring particle displacement using a smartphone camera. PMID:26619152

Walking and talking: an investigation of cognitive-motor dual tasking in multiple sclerosis.

PubMed

Hamilton, F; Rochester, L; Paul, L; Rafferty, D; O'Leary, C P; Evans, J J

2009-10-01

Deficits in motor functioning, including walking, and in cognitive functions, including attention, are known to be prevalent in multiple sclerosis (MS), though little attention has been paid to how impairments in these areas of functioning interact. This study investigated the effects of performing a concurrent cognitive task when walking in people with MS. Level of task demand was manipulated to investigate whether this affected level of dual-task decrement. Eighteen participants with MS and 18 healthy controls took part. Participants completed walking and cognitive tasks under single- and dual-task conditions. Compared to healthy controls, MS participants showed greater decrements in performance under dual-task conditions in cognitive task performance, walking speed and swing time variability. In the MS group, the degree of decrement under dual-task conditions was related to levels of fatigue, a measure of general cognitive functioning and self-reported everyday cognitive errors, but not to measures of disease severity or duration. Difficulty with walking and talking in MS may be a result of a divided attention deficit or of overloading of the working memory system, and further investigation is needed. We suggest that difficulty with walking and talking in MS may lead to practical problems in everyday life, including potentially increasing the risk of falls. Clinical tools to assess cognitive-motor dual-tasking ability are needed.

Orbiting pairs of walking droplets: Dynamics and stability

NASA Astrophysics Data System (ADS)

Oza, Anand U.; Siéfert, Emmanuel; Harris, Daniel M.; Moláček, Jan; Bush, John W. M.

2017-05-01

A decade ago, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)], 10.1103/PhysRevLett.97.154101 discovered that a millimetric droplet sustained on the surface of a vibrating fluid bath may self-propel through a resonant interaction with its own wave field. We here present the results of a combined experimental and theoretical investigation of the interactions of such walking droplets. Specifically, we delimit experimentally the different regimes for an orbiting pair of identical walkers and extend the theoretical model of Oza et al. [J. Fluid Mech. 737, 552 (2013)], 10.1017/jfm.2013.581 in order to rationalize our observations. A quantitative comparison between experiment and theory highlights the importance of spatial damping of the wave field. Our results also indicate that walkers adapt their impact phase according to the local wave height, an effect that stabilizes orbiting bound states.

The building blocks of a 'Liveable Neighbourhood': Identifying the key performance indicators for walking of an operational planning policy in Perth, Western Australia.

PubMed

Hooper, Paula; Knuiman, Matthew; Foster, Sarah; Giles-Corti, Billie

2015-11-01

Planning policy makers are requesting clearer guidance on the key design features required to build neighbourhoods that promote active living. Using a backwards stepwise elimination procedure (logistic regression with generalised estimating equations adjusting for demographic characteristics, self-selection factors, stage of construction and scale of development) this study identified specific design features (n=16) from an operational planning policy ("Liveable Neighbourhoods") that showed the strongest associations with walking behaviours (measured using the Neighbourhood Physical Activity Questionnaire). The interacting effects of design features on walking behaviours were also investigated. The urban design features identified were grouped into the "building blocks of a Liveable Neighbourhood", reflecting the scale, importance and sequencing of the design and implementation phases required to create walkable, pedestrian friendly developments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Annealing cycles and the self-organization of functionalized colloids

NASA Astrophysics Data System (ADS)

Dias, Cristóvão S.; Araújo, Nuno A. M.; Telo da Gama, Margarida M.

2018-01-01

The self-assembly of functionalized (patchy) particles with directional interactions into target structures is still a challenge, despite the significant experimental advances in their synthesis. Self-assembly pathways are typically characterized by high energy barriers that hinder access to stable (equilibrium) structures. A possible strategy to tackle this challenge is to perform annealing cycles. By periodically switching on and off the inter-particle bonds, one expects to smooth-out the kinetic pathways and favor the assembly of targeted structures. Preliminary results have shown that the efficiency of annealing cycles depends strongly on their frequency. Here, we study numerically how this frequency-dependence scales with the strength of the directional interactions (size of the patch σ). We use analytical arguments to show that the scaling results from the statistics of a random walk in configurational space.

Visual control of foot placement when walking over complex terrain.

PubMed

Matthis, Jonathan S; Fajen, Brett R

2014-02-01

The aim of this study was to investigate the role of visual information in the control of walking over complex terrain with irregularly spaced obstacles. We developed an experimental paradigm to measure how far along the future path people need to see in order to maintain forward progress and avoid stepping on obstacles. Participants walked over an array of randomly distributed virtual obstacles that were projected onto the floor by an LCD projector while their movements were tracked by a full-body motion capture system. Walking behavior in a full-vision control condition was compared with behavior in a number of other visibility conditions in which obstacles did not appear until they fell within a window of visibility centered on the moving observer. Collisions with obstacles were more frequent and, for some participants, walking speed was slower when the visibility window constrained vision to less than two step lengths ahead. When window sizes were greater than two step lengths, the frequency of collisions and walking speed were weakly affected or unaffected. We conclude that visual information from at least two step lengths ahead is needed to guide foot placement when walking over complex terrain. When placed in the context of recent research on the biomechanics of walking, the findings suggest that two step lengths of visual information may be needed because it allows walkers to exploit the passive mechanical forces inherent to bipedal locomotion, thereby avoiding obstacles while maximizing energetic efficiency. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Imagined Self-Motion Differs from Perceived Self-Motion: Evidence from a Novel Continuous Pointing Method

PubMed Central

Campos, Jennifer L.; Siegle, Joshua H.; Mohler, Betty J.; Bülthoff, Heinrich H.; Loomis, Jack M.

2009-01-01

Background The extent to which actual movements and imagined movements maintain a shared internal representation has been a matter of much scientific debate. Of the studies examining such questions, few have directly compared actual full-body movements to imagined movements through space. Here we used a novel continuous pointing method to a) provide a more detailed characterization of self-motion perception during actual walking and b) compare the pattern of responding during actual walking to that which occurs during imagined walking. Methodology/Principal Findings This continuous pointing method requires participants to view a target and continuously point towards it as they walk, or imagine walking past it along a straight, forward trajectory. By measuring changes in the pointing direction of the arm, we were able to determine participants' perceived/imagined location at each moment during the trajectory and, hence, perceived/imagined self-velocity during the entire movement. The specific pattern of pointing behaviour that was revealed during sighted walking was also observed during blind walking. Specifically, a peak in arm azimuth velocity was observed upon target passage and a strong correlation was observed between arm azimuth velocity and pointing elevation. Importantly, this characteristic pattern of pointing was not consistently observed during imagined self-motion. Conclusions/Significance Overall, the spatial updating processes that occur during actual self-motion were not evidenced during imagined movement. Because of the rich description of self-motion perception afforded by continuous pointing, this method is expected to have significant implications for several research areas, including those related to motor imagery and spatial cognition and to applied fields for which mental practice techniques are common (e.g. rehabilitation and athletics). PMID:19907655

Effects of a brisk walk on blood pressure responses to the Stroop, a speech task and a smoking cue among temporarily abstinent smokers.

PubMed

Taylor, Adrian; Katomeri, Magdalena

2006-01-01

A review and meta-analysis by Hamer et al. (2006) showed that a single session of exercise can attenuate post-exercise blood pressure (BP) responses to stress, but no studies examined the effects among smokers or with brisk walking. Healthy volunteers (n=60), averaging 28 years of age and smoking 15 cigarettes daily, abstained from smoking for 2 h before being randomly assigned to a 15-min brisk semi-self-paced walk or passive control condition. Subject characteristics, typical smoking cue-elicited cravings and BP were assessed at baseline. After each condition, BP was assessed before and after three psycho-social stressors were carried out: (1) computerised Stroop word-colour interference task, (2) speech task and (3) only handling a lit cigarette. A two-way mixed ANCOVA (controlling for baseline) revealed a significant overall interaction effect for time by condition for both systolic blood pressure (SBP) and diastolic blood pressure (DBP). Univariate ANCOVAs (to compare between-groups post-stressor BP, controlling for pre-stressor BP) revealed that exercise attenuated systolic BP and diastolic BP responses to the Stroop and speech tasks and SBP to the lit cigarette equivalent to an attenuated SBP and DBP of up to 3.8 mmHg. Post-exercise attenuation effects were moderated by resting blood pressure and self-reported smoking cue-elicited craving. Effects were strongest among those with higher blood pressure and smokers who reported typically stronger cravings when faced with smoking cues. Blood pressure responses to the lit cigarette were not associated with responses to the Stroop and speech task. A self-paced 15-min walk can reduce smokers' SBP and DBP responses to stress, of a magnitude similar on average to non-smokers.

Exploration as a mediator of the relation between the attainment of motor milestones and the development of spatial cognition and spatial language.

PubMed

Oudgenoeg-Paz, Ora; Leseman, Paul P M; Volman, M Chiel J M

2015-09-01

The embodied-cognition approach views cognition and language as grounded in daily sensorimotor child-environment interactions. Therefore, the attainment of motor milestones is expected to play a role in cognitive-linguistic development. Early attainment of unsupported sitting and independent walking indeed predict better spatial cognition and language at later ages. However, evidence linking these milestones with the development of spatial language and evidence regarding factors that might mediate this relation are scarce. The current study examined whether exploration of spatial-relational object properties (e.g., the possibility of containing or stacking) and exploration of the space through self-locomotion mediate the effect of, respectively, age of sitting and age of walking on spatial cognition and spatial language. Thus, we hypothesized that an earlier age of sitting and walking predicts, respectively, higher levels of spatial-relational object exploration and exploration through self-locomotion, which in turn, predict better spatial cognition and spatial language at later ages. Fifty-nine Dutch children took part in a longitudinal study. A combination of tests, observations, and parental reports was used to measure motor development, exploratory behavior (age 20 months), spatial memory (age 24 months), spatial processing (age 32 months), and spatial language (age 36 months). Results show that attainment of sitting predicted spatial memory and spatial language, but spatial-relational object exploration did not mediate these effects. Attainment of independent walking predicted spatial processing and spatial language, and exploration through self-locomotion (partially) mediated these relations. These findings extend previous work and provide partial support for the hypotheses about the mediating role of exploration. (c) 2015 APA, all rights reserved).

The relationship of dynamical heterogeneity to the Adam-Gibbs and random first-order transition theories of glass formation.

PubMed

Starr, Francis W; Douglas, Jack F; Sastry, Srikanth

2013-03-28

We carefully examine common measures of dynamical heterogeneity for a model polymer melt and test how these scales compare with those hypothesized by the Adam and Gibbs (AG) and random first-order transition (RFOT) theories of relaxation in glass-forming liquids. To this end, we first analyze clusters of highly mobile particles, the string-like collective motion of these mobile particles, and clusters of relative low mobility. We show that the time scale of the high-mobility clusters and strings is associated with a diffusive time scale, while the low-mobility particles' time scale relates to a structural relaxation time. The difference of the characteristic times for the high- and low-mobility particles naturally explains the well-known decoupling of diffusion and structural relaxation time scales. Despite the inherent difference of dynamics between high- and low-mobility particles, we find a high degree of similarity in the geometrical structure of these particle clusters. In particular, we show that the fractal dimensions of these clusters are consistent with those of swollen branched polymers or branched polymers with screened excluded-volume interactions, corresponding to lattice animals and percolation clusters, respectively. In contrast, the fractal dimension of the strings crosses over from that of self-avoiding walks for small strings, to simple random walks for longer, more strongly interacting, strings, corresponding to flexible polymers with screened excluded-volume interactions. We examine the appropriateness of identifying the size scales of either mobile particle clusters or strings with the size of cooperatively rearranging regions (CRR) in the AG and RFOT theories. We find that the string size appears to be the most consistent measure of CRR for both the AG and RFOT models. Identifying strings or clusters with the "mosaic" length of the RFOT model relaxes the conventional assumption that the "entropic droplets" are compact. We also confirm the validity of the entropy formulation of the AG theory, constraining the exponent values of the RFOT theory. This constraint, together with the analysis of size scales, enables us to estimate the characteristic exponents of RFOT.

Polymers with nearest- and next nearest-neighbor interactions on the Husimi lattice

NASA Astrophysics Data System (ADS)

Oliveira, Tiago J.

2016-04-01

The exact grand-canonical solution of a generalized interacting self-avoid walk (ISAW) model, placed on a Husimi lattice built with squares, is presented. In this model, beyond the traditional interaction {ω }1={{{e}}}{ɛ 1/{k}BT} between (nonconsecutive) monomers on nearest-neighbor (NN) sites, an additional energy {ɛ }2 is associated to next-NN (NNN) monomers. Three definitions of NNN sites/interactions are considered, where each monomer can have, effectively, at most two, four, or six NNN monomers on the Husimi lattice. The phase diagrams found in all cases have (qualitatively) the same thermodynamic properties: a non-polymerized (NP) and a polymerized (P) phase separated by a critical and a coexistence surface that meet at a tricritical (θ-) line. This θ-line is found even when one of the interactions is repulsive, existing for {ω }1 in the range [0,∞ ), i.e., for {ɛ }1/{k}BT in the range [-∞ ,∞ ). Thus, counterintuitively, a θ-point exists even for an infinite repulsion between NN monomers ({ω }1=0), being associated to a coil-‘soft globule’ transition. In the limit of an infinite repulsive force between NNN monomers, however, the coil-globule transition disappears, and only NP-P continuous transition is observed. This particular case, with {ω }2=0, is also solved exactly on the square lattice, using a transfer matrix calculation where a discontinuous NP-P transition is found. For attractive and repulsive forces between NN and NNN monomers, respectively, the model becomes quite similar to the semiflexible-ISAW one, whose crystalline phase is not observed here, as a consequence of the frustration due to competing NN and NNN forces. The mapping of the phase diagrams in canonical ones is discussed and compared with recent results from Monte Carlo simulations on the square lattice.

In an idealized world: can discrepancies across self-reported parental care and high betrayal trauma during childhood predict infant attachment avoidance in the next generation?

PubMed

Bernstein, Rosemary E; Laurent, Heidemarie K; Musser, Erica D; Measelle, Jeffery R; Ablow, Jennifer C

2013-01-01

Adult caregivers' idealization of their parents as assessed by the Adult Attachment Interview is a risk factor for the intergenerational transmission of the insecure-avoidant attachment style. This study evaluated a briefer screening approach for identifying parental idealization, testing the utility of prenatal maternal self-report measures of recalled betrayal trauma and parental care in childhood to predict observationally assessed infant attachment avoidance with 58 mother-infant dyads 18 months postpartum. In a logistic regression that controlled for maternal demographics, prenatal psychopathology, and postnatal sensitivity, the interaction between women's self-reported childhood high betrayal trauma and the level of care provided to them by their parents was the only significant predictor of 18-month infant security versus avoidance. Results suggest that betrayal trauma and recalled parental care in childhood can provide a means of identifying caregivers whose infant children are at risk for avoidant attachment, potentially providing an efficient means for scientific studies and clinical intervention aimed at preventing the intergenerational transmission of attachment problems.

Can a motivational intervention overcome an unsupportive environment for walking--findings from the Step-by-Step Study.

PubMed

Merom, Dafna; Bauman, Adrian; Phongsavan, Philayrath; Cerin, Ester; Kassis, Mazen; Brown, Wendy; Smith, Ben J; Rissel, Chris

2009-10-01

Interventions to promote walking have rarely examined how their effects varied by the attributes of the physical environment. The purpose of this study is to examine whether perceptions of environmental walkability predicted change in walking behavior following an individual-based intervention to promote walking and whether the intervention buffered the effects of unsupportive environment for walking. Inactive adults (aged 30-65 years, 85% women) who completed a 3-month randomized control trial comparing the effect of a single mail-out of a theoretically based self-help walking program (WP, n = 102); the same program plus a pedometer (WPP, n = 105); and a "no-treatment" control group (C, n = 107). Measures included change in self-reported walking time for all purposes and in the proportion of people reporting regular walking (i.e., > or =150 min/week and > or =5 sessions/wk). Perceptions of environmental esthetics, safety from crime, proximity to destinations, access to walking facilities, traffic, streetlights, connectivity, and hilliness were assessed at baseline and dichotomized into "low" or "high" by the median score. Covariates were social support, self-efficacy, intention to change behavior, and sociodemographic characteristics. Adjusting for baseline walking, significant covariates, and study groups, walking time at follow-up was lower if streetlights or esthetics were perceived to be "low" (-24% and -22%, respectively) compared with "high" (p < 0.05). In "low" esthetic conditions, those in the WPP were significantly more likely than controls to increase total walking time (Exp (b) = 2.53, p < 0.01) and to undertake regular walking (OR = 5.85, 95% CI 2.60-12.2), whereas in esthetically pleasing environments, the between-group differences were nonsignificant. Walkability attributes can influence individual-based walking programs. Some environmental barriers for walking can be overcome by motivational aids.

Physics Bus: An Innovative Model for Public Engagement

NASA Astrophysics Data System (ADS)

Fox, Claire

The Physics Bus is about doing science for fun. It is an innovative model for science outreach whose mission is to awaken joy and excitement in physics for all ages and walks of life - especially those underserved by science enrichment. It is a mobile exhibition of upcycled appliances-reimagined by kids-that showcase captivating physics phenomena. Inside our spaceship-themed school bus, visitors will find: a microwave ionized-gas disco-party, fog rings that shoot from a wheelbarrow tire, a tv whose electron beam is controlled by a toy keyboard, and over 20 other themed exhibits. The Physics Bus serves a wide range of public in diverse locations from local neighborhoods, urban parks and rural schools, to cross-country destinations. Its approachable, friendly and relaxed environment allows for self-paced and self-directed interactions, providing a positive and engaging experience with science. We believe that this environment enriches lives and inspires people. In this presentation we will talk about the nuts and bolts that make this model work, how the project got started, and the resources that keep it going. We will talk about the advantages of being a grassroots and community-based organization, and how programs like this can best interface with universities. We will explain the benefits of focusing on direct interactions and why our model avoids ``teaching'' physics content with words. Situating our approach within a body of research on the value of informal science we will discuss our success in capturing and engaging our audience. By the end of this presentation we hope to broaden your perception of what makes a successful outreach program and encourage you to value and support alternative outreach models such as this one. In Collaboration with: Eva Luna, Cornell University; Erik Herman, Cornell University; Christopher Bell, Ithaca City School District.

Randomized controlled trial of physical activity, cognition, and walking in multiple sclerosis.

PubMed

Sandroff, Brian M; Klaren, Rachel E; Pilutti, Lara A; Dlugonski, Deirdre; Benedict, Ralph H B; Motl, Robert W

2014-02-01

The present study adopted a randomized controlled trial design and examined the effect of a physical activity behavioral intervention on cognitive and walking performance among persons with MS who have mild or moderate disability status. A total of 82 MS patients were randomly allocated into intervention or wait-list control conditions. The intervention condition received a theory-based program for increasing physical activity behavior that was delivered via the Internet, and one-on-one video chat sessions with a behavior-change coach. Participants completed self-report measures of physical activity and disability status, and underwent the oral Symbol Digit Modalities Test (SDMT) and 6-minute walk (6MW) test before and after the 6-month period. Analysis using mixed-model ANOVA indicated a significant time × condition × disability group interaction on SDMT scores (p = 0.02, partial-η (2) = 0.08), such that persons with mild disability in the intervention condition demonstrated a clinically meaningful improvement in SDMT scores (~6 point change). There was a further significant time × condition interaction on 6MW distance (p = 0.02, partial-η (2) = 0.07), such that those in the intervention condition demonstrated an increase in 6MW distance relative to those in the control group. The current study supports physical activity as a promising tool for managing cognitive impairment and impaired walking performance in persons with MS, and suggests that physical activity might have specific effects on cognition and non-specific effects on walking performance in this population.

Comparing the appropriate geographic region for assessing built environmental correlates with walking trips using different metrics and model approaches

PubMed Central

Tribby, Calvin P.; Miller, Harvey J.; Brown, Barbara B.; Smith, Ken R.; Werner, Carol M.

2017-01-01

There is growing international evidence that supportive built environments encourage active travel such as walking. An unsettled question is the role of geographic regions for analyzing the relationship between the built environment and active travel. This paper examines the geographic region question by assessing walking trip models that use two different regions: walking activity spaces and self-defined neighborhoods. We also use two types of built environment metrics, perceived and audit data, and two types of study design, cross-sectional and longitudinal, to assess these regions. We find that the built environment associations with walking are dependent on the type of metric and the type of model. Audit measures summarized within walking activity spaces better explain walking trips compared to audit measures within self-defined neighborhoods. Perceived measures summarized within self-defined neighborhoods have mixed results. Finally, results differ based on study design. This suggests that results may not be comparable among different regions, metrics and designs; researchers need to consider carefully these choices when assessing active travel correlates. PMID:28237743

Characteristics of residential areas and transportational walking among frail and non-frail Dutch elderly: does the size of the area matter?

PubMed

Etman, Astrid; Kamphuis, Carlijn B M; Prins, Richard G; Burdorf, Alex; Pierik, Frank H; van Lenthe, Frank J

2014-03-04

A residential area supportive for walking may facilitate elderly to live longer independently. However, current evidence on area characteristics potentially important for walking among older persons is mixed. This study hypothesized that the importance of area characteristics for transportational walking depends on the size of the area characteristics measured, and older person's frailty level. The study population consisted of 408 Dutch community-dwelling persons aged 65 years and older participating in the Elderly And their Neighborhood (ELANE) study in 2011-2012. Characteristics (aesthetics, functional features, safety, and destinations) of areas surrounding participants' residences ranging from a buffer of 400 meters up to 1600 meters (based on walking path networks) were linked with self-reported transportational walking using linear regression analyses. In addition, interaction effects between frailty level and area characteristics were tested. An increase in functional features (e.g. presence of sidewalks and benches) within a 400 meter buffer, in aesthetics (e.g. absence of litter and graffiti) within 800 and 1200 meter buffers, and an increase of one destination per buffer of 400 and 800 meters were associated with more transportational walking, up to 2.89 minutes per two weeks (CI 1.07-7.32; p < 0.05). No differences were found between frail and non-frail elderly. Better functional and aesthetic features, and more destinations in the residential area of community-dwelling older persons were associated with more transportational walking. The importance of area characteristics for transportational walking differs by area size, but not by frailty level. Neighbourhood improvements may increase transportational walking among older persons, thereby contributing to living longer independently.

Influence of Systematic Increases in Treadmill Walking Speed on Gait Kinematics After Stroke

PubMed Central

Tyrell, Christine M.; Roos, Margaret A.; Rudolph, Katherine S.

2011-01-01

Background Fast treadmill training improves walking speed to a greater extent than training at a self-selected speed after stroke. It is unclear whether fast treadmill walking facilitates a more normal gait pattern after stroke, as has been suggested for treadmill training at self-selected speeds. Given the massed stepping practice that occurs during treadmill training, it is important for therapists to understand how the treadmill speed selected influences the gait pattern that is practiced on the treadmill. Objective The purpose of this study was to characterize the effect of systematic increases in treadmill speed on common gait deviations observed after stroke. Design A repeated-measures design was used. Methods Twenty patients with stroke walked on a treadmill at their self-selected walking speed, their fastest speed, and 2 speeds in between. Using a motion capture system, spatiotemporal gait parameters and kinematic gait compensations were measured. Results Significant improvements in paretic- and nonparetic-limb step length and in single- and double-limb support were found. Asymmetry of these measures improved only for step length. Significant improvements in paretic hip extension, trailing limb position, and knee flexion during swing also were found as speed increased. No increases in circumduction or hip hiking were found with increasing speed. Limitations Caution should be used when generalizing these results to survivors of a stroke with a self-selected walking speed of less than 0.4 m/s. This study did not address changes with speed during overground walking. Conclusions Faster treadmill walking facilitates a more normal walking pattern after stroke, without concomitant increases in common gait compensations, such as circumduction. The improvements in gait deviations were observed with small increases in walking speed. PMID:21252308

The Impact of Personality, Goal Orientation and Self-Efficacy on Participation of High School Teachers in Learning Activities in the Workplace

ERIC Educational Resources Information Center

van Daal, Tine; Donche, Vincent; De Maeyer, Sven

2014-01-01

This study examines the influence of personality traits, goal orientation and self-efficacy on high school teachers' participation in learning activities in the workplace (i.e. experimentation, informal interaction with colleagues, self-regulation and avoidance behaviour). A convenience sample of 95 teachers from six high schools in Flanders…

Determinants of gait stability while walking on a treadmill: A machine learning approach.

PubMed

Reynard, Fabienne; Terrier, Philippe

2017-12-08

Dynamic balance in human locomotion can be assessed through the local dynamic stability (LDS) method. Whereas gait LDS has been used successfully in many settings and applications, little is known about its sensitivity to individual characteristics of healthy adults. Therefore, we reanalyzed a large dataset of accelerometric data measured for 100 healthy adults from 20 to 70 years of age performing 10 min treadmill walking. We sought to assess the extent to which the variations of age, body mass and height, sex, and preferred walking speed (PWS) could influence gait LDS. The random forest (RF) and multiple adaptive regression splines (MARS) algorithms were selected for their good bias-variance tradeoff and their capabilities to handle nonlinear associations. First, through variable importance measure (VIM), we used RF to evaluate which individual characteristics had the highest influence on gait LDS. Second, we used MARS to detect potential interactions among individual characteristics that may influence LDS. The VIM and MARS results indicated that PWS and age correlated with LDS, whereas no associations were found for sex, body height, and body mass. Further, the MARS model detected an age by PWS interaction: on one hand, at high PWS, gait stability is constant across age while, on the other hand, at low PWS, gait instability increases substantially with age. We conclude that it is advisable to consider the participants' age as well as their PWS to avoid potential biases in evaluating dynamic balance through LDS. Copyright © 2017 Elsevier Ltd. All rights reserved.

Changes in Function After a 6-Month Walking Intervention in Patients With Intermittent Claudication Who Are Obese or Nonobese.

PubMed

Addison, Odessa; Ryan, Alice S; Prior, Steven J; Katzel, Leslie I; Kundi, Rishi; Lal, Brajesh K; Gardner, Andrew W

Both obesity and peripheral artery disease (PAD) limit function and may work additively to reduce mobility. The purpose of this study was to compare the effects of a 6-month, center-based walking program on mobility function between adults who are weight-stable obese and nonobese with PAD. This is a secondary data analysis of 2 combined studies taken from previous work. Fifty-three adults with PAD and intermittent claudication participated in 6 months of treadmill training or standard of care. Patients were divided into 4 groups for analyses: exercise nonobese (Ex), exercise obese (ExO), standard-of-care nonobese (SC), and standard-of-care obese (SCO). Mobility was assessed by a standardized treadmill test to measure claudication onset time (COT) and peak walking time (PWT) as well as the distance walked during a 6-minute walk distance (6MWD) test. There was a significant (P < .001) interaction (intervention × obesity) effect on 6MWD, wherein both exercise groups improved (Ex = 7%, ExO = 16%; P < .02), the SC group did not change (0.9%; P > .05), and the SCO group tended to decline (-18%; P = .06). Both exercise intervention groups significantly improved COT (Ex = 92%, ExO = 102%; P < .01) and PWT (Ex = 54%, ExO = 103%; P < .001). There was no change (P > .05) in either standard-of-care group. Individuals who are obese and nonobese with PAD made similar improvements after a 6-month, center-based walking program. However, patients who are obese with PAD and do not exercise may be susceptible to greater declines in mobility. Exercise may be particularly important in patients who are obese with PAD to avoid declines in mobility.

Visual task performance using a monocular see-through head-mounted display (HMD) while walking.

PubMed

Mustonen, Terhi; Berg, Mikko; Kaistinen, Jyrki; Kawai, Takashi; Häkkinen, Jukka

2013-12-01

A monocular see-through head-mounted display (HMD) allows the user to view displayed information while simultaneously interacting with the surrounding environment. This configuration lets people use HMDs while they are moving, such as while walking. However, sharing attention between the display and environment can compromise a person's performance in any ongoing task, and controlling one's gait may add further challenges. In this study, the authors investigated how the requirements of HMD-administered visual tasks altered users' performance while they were walking. Twenty-four university students completed 3 cognitive tasks (high- and low-working memory load, visual vigilance) on an HMD while seated and while simultaneously performing a paced walking task in a controlled environment. The results show that paced walking worsened performance (d', reaction time) in all HMD-administered tasks, but visual vigilance deteriorated more than memory performance. The HMD-administered tasks also worsened walking performance (speed, path overruns) in a manner that varied according to the overall demands of the task. These results suggest that people's ability to process information displayed on an HMD may worsen while they are in motion. Furthermore, the use of an HMD can critically alter a person's natural performance, such as their ability to guide and control their gait. In particular, visual tasks that involve constant monitoring of the HMD should be avoided. These findings highlight the need for careful consideration of the type and difficulty of information that can be presented through HMDs while still letting the user achieve an acceptable overall level of performance in various contexts of use. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Coping strategies and self-esteem in the high-risk offspring of bipolar parents.

PubMed

Goodday, Sarah M; Bentall, Richard; Jones, Steven; Weir, Arielle; Duffy, Anne

2018-03-01

This study investigated whether there were differences in coping strategies and self-esteem between offspring of parents with bipolar disorder (high-risk) and offspring of unaffected parents (control), and whether these psychological factors predicted the onset and recurrence of mood episodes. High-risk and control offspring were followed longitudinally as part of the Flourish Canadian high-risk bipolar offspring cohort study. Offspring were clinically assessed annually by a psychiatrist using semi-structured interviews and completed a measure of coping strategies and self-esteem. In high-risk offspring, avoidant coping strategies significantly increased the hazard of a new onset Diagnostic and Statistical Manual of Mental Disorders, 4th Edition twice revised mood episode or recurrence (hazard ratio: 1.89, p = 0.04), while higher self-esteem significantly decreased this hazard (hazard ratio: 2.50, p < 0.01). Self-esteem and avoidant coping significantly interacted with one another ( p < 0.05), where the risk of a Diagnostic and Statistical Manual of Mental Disorders, 4th Edition twice revised new onset mood episode or recurrence was only significantly increased among high-risk offspring with both high avoidant coping and low self-esteem. A reduction of avoidant coping strategies in response to stress and improvement of self-esteem may be useful intervention targets for preventing the new onset or recurrence of a clinically significant mood disorder among individuals at high familial risk.

Parental attachment style: examination of links with parent secure base provision and adolescent secure base use.

PubMed

Jones, Jason D; Cassidy, Jude

2014-01-01

The secure base construct represents one of attachment theory's most important contributions to our understanding of parent-child relationships and child development. The present study represents the first examination of how parents' self-reported attachment styles relate to parental secure base provision and adolescent (mean age = 16.6 years, SE = .59) secure base use during an observed parent-adolescent interaction. Further, the present study is the first to examine how fathers', as well as mothers', attachment styles relate to observed behavior in a parent-child interaction. At the bivariate level, maternal avoidance, but not anxiety, was negatively associated with observed adolescent secure base use. In addition, path analysis revealed that maternal avoidance was indirectly related to less adolescent secure base use through mothers' self-reported hostile behavior toward their adolescents and through adolescents' less positive perceptions of their mothers. Further, paternal anxiety, but not avoidance, was indirectly related to less adolescent secure base use through fathers' self-reported hostile behavior toward their adolescents. No significant findings emerged in relation to parental secure base provision. We discuss these results in the context of attachment theory and suggest directions for future research.

The role of fluctuations and interactions in pedestrian dynamics

NASA Astrophysics Data System (ADS)

Corbetta, Alessandro; Meeusen, Jasper; Benzi, Roberto; Lee, Chung-Min; Toschi, Federico

Understanding quantitatively the statistical behaviour of pedestrians walking in crowds is a major scientific challenge of paramount societal relevance. Walking humans exhibit a rich (stochastic) dynamics whose small and large deviations are driven, among others, by own will as well as by environmental conditions. Via 24/7 automatic pedestrian tracking from multiple overhead Microsoft Kinect depth sensors, we collected large ensembles of pedestrian trajectories (in the order of tens of millions) in different real-life scenarios. These scenarios include both narrow corridors and large urban hallways, enabling us to cover and compare a wide spectrum of typical pedestrian dynamics. We investigate the pedestrian motion measuring the PDFs, e.g. those of position, velocity and acceleration, and at unprecedentedly high statistical resolution. We consider the dependence of PDFs on flow conditions, focusing on diluted dynamics and pair-wise interactions (''collisions'') for mutual avoidance. By means of Langevin-like models we provide models for the measured data, inclusive typical fluctuations and rare events. This work is part of the JSTP research programme ``Vision driven visitor behaviour analysis and crowd management'' with Project Number 341-10-001, which is financed by the Netherlands Organisation for Scientific Research (NWO).

Twelve-month effects of Canada on the Move: a population-wide campaign to promote pedometer use and walking.

PubMed

Craig, C L; Tudor-Locke, C; Bauman, A

2007-06-01

Canada on the Move is a national campaign to promote pedometer use and walking among adult Canadians. The purpose of this paper is to investigate the initiative's impact on sufficient walking, defined here as at least an hour daily in the week prior to the survey. Data were collected via the national Canadian Physical Activity Monitor's rolling monthly sample throughout 2004. Population prevalence rates of walking were compared using Bonferroni-adjusted confidence intervals. Correlates of sufficient walking were estimated using odds ratios adjusted for age, sex, income and education. Message recall and pedometer ownership were associated with increased odds of self-reported walking. There was evidence of a campaign effect on walking behavior independent of secular trends. The increased likelihood of sufficient walking suggests an ongoing role for nationally funded public awareness campaigns. The effectiveness of health promotion to increase walking may be enhanced by combining motivational health-related messages with the dissemination and adoption of an easy-to-use tool for self-monitoring purposes.

Backward-walking biological motion orients attention to moving away instead of moving toward.

PubMed

Ding, Xiaowei; Yin, Jun; Shui, Rende; Zhou, Jifan; Shen, Mowei

2017-04-01

Walking direction is an important attribute of biological motion because it carries key information, such as the specific intention of the walker. Although it is known that spatial attention is guided by walking direction, it remains unclear whether this attentional shift is reflexive (i.e., constantly shifts to the walking direction) or not. A richer interpretation of this effect is that attention is guided to seek the information that is necessary to understand the motion. To investigate this issue, we examined how backward-walking biological motion orients attention because the intention of walking backward is usually to avoid something that walking forward would encounter. The results showed that attention was oriented to the walking-away direction of biological motion instead of the walking-toward direction (Experiment 1), and this effect was not due to the gaze direction of biological motion (Experiment 2). Our findings suggest that the attentional shift triggered by walking direction is not reflexive, thus providing support for the rich interpretation of these attentional effects.

A commercialized dietary supplement alleviates joint pain in community adults: a double-blind, placebo-controlled community trial.

PubMed

Nieman, David C; Shanely, R Andrew; Luo, Beibei; Dew, Dustin; Meaney, Mary Pat; Sha, Wei

2013-11-25

The purpose of this study was to assess the effect of 8-weeks ingestion of a commercialized joint pain dietary supplement (Instaflex™ Joint Support, Direct Digital, Charlotte, NC) compared to placebo on joint pain, stiffness, and function in adults with self-reported joint pain. Instaflex™ is a joint pain supplement containing glucosamine sulfate, methylsufonlylmethane (MSM), white willow bark extract (15% salicin), ginger root concentrate, boswella serrata extract (65% boswellic acid), turmeric root extract, cayenne, and hyaluronic acid. Subjects included 100 men and women, ages 50-75 years, with a history (>3 months) of joint pain, and were randomized to Instaflex™ or placebo (3 colored gel capsules per day for 8 weeks, double-blind administration). Subjects agreed to avoid the use of non-steroidal anti-inflammatory drugs (NSAID) and all other medications and supplements targeted for joint pain. Primary outcome measures were obtained pre- and post-study and included joint pain severity, stiffness, and function (Western Ontario and McMaster Universities [WOMAC]), and secondary outcome measures included health-related quality of life (Short Form 36 or SF-36), systemic inflammation (serum C-reactive protein and 9 plasma cytokines), and physical function (6-minute walk test). Joint pain symptom severity was assessed bi-weekly using a 12-point Likert visual scale (12-VS). Joint pain severity was significantly reduced in Instaflex™ compared to placebo (8-week WOMAC, ↓37% versus ↓16%, respectively, interaction effect P = 0.025), with group differences using the 12-VS emerging by week 4 of the study (interaction effect, P = 0.0125). Improvements in ability to perform daily activities and stiffness scores in Instaflex™ compared to placebo were most evident for the 74% of subjects reporting knee pain (8-week WOMAC function score, ↓39% versus ↓14%, respectively, interaction effect P = 0.027; stiffness score, ↓30% versus ↓12%, respectively, interaction effect P = 0.081). Patterns of change in SF-36, systemic inflammation biomarkers, and the 6-minute walk test did not differ significantly between groups during the 8-week study Results from this randomized, double blind, placebo-controlled community trial support the use of the Instaflex™ dietary supplement in alleviating joint pain severity in middle-aged and older adults, with mitigation of difficulty performing daily activities most apparent in subjects with knee pain.

Human-Human Interaction Forces and Interlimb Coordination During Side-by-Side Walking With Hand Contact.

PubMed

Sylos-Labini, Francesca; d'Avella, Andrea; Lacquaniti, Francesco; Ivanenko, Yury

2018-01-01

Handholding can naturally occur between two walkers. When people walk side-by-side, either with or without hand contact, they often synchronize their steps. However, despite the importance of haptic interaction in general and the natural use of hand contact between humans during walking, few studies have investigated forces arising from physical interactions. Eight pairs of adult subjects participated in this study. They walked on side-by-side treadmills at 4 km/h independently and with hand contact. Only hand contact-related sensory information was available for unintentional synchronization, while visual and auditory communication was obstructed. Subjects walked at their natural cadences or following a metronome. Limb kinematics, hand contact 3D interaction forces and EMG activity of 12 upper limb muscles were recorded. Overall, unintentional step frequency locking was observed during about 40% of time in 88% of pairs walking with hand contact. On average, the amplitude of contact arm oscillations decreased while the contralateral (free) arm oscillated in the same way as during normal walking. Interestingly, EMG activity of the shoulder muscles of the contact arm did not decrease, and their synergistic pattern remained similar. The amplitude of interaction forces and of trunk oscillations was similar for synchronized and non-synchronized steps, though the synchronized steps were characterized by significantly more regular orientations of interaction forces. Our results further support the notion that gait synchronization during natural walking is common, and that it may occur through interaction forces. Conservation of the proximal muscle activity of the contact (not oscillating) arm is consistent with neural coupling between cervical and lumbosacral pattern generation circuitries ("quadrupedal" arm-leg coordination) during human gait. Overall, the findings suggest that individuals might integrate force interaction cues to communicate and coordinate steps during walking.

Human-Human Interaction Forces and Interlimb Coordination During Side-by-Side Walking With Hand Contact

PubMed Central

Sylos-Labini, Francesca; d'Avella, Andrea; Lacquaniti, Francesco; Ivanenko, Yury

2018-01-01

Handholding can naturally occur between two walkers. When people walk side-by-side, either with or without hand contact, they often synchronize their steps. However, despite the importance of haptic interaction in general and the natural use of hand contact between humans during walking, few studies have investigated forces arising from physical interactions. Eight pairs of adult subjects participated in this study. They walked on side-by-side treadmills at 4 km/h independently and with hand contact. Only hand contact-related sensory information was available for unintentional synchronization, while visual and auditory communication was obstructed. Subjects walked at their natural cadences or following a metronome. Limb kinematics, hand contact 3D interaction forces and EMG activity of 12 upper limb muscles were recorded. Overall, unintentional step frequency locking was observed during about 40% of time in 88% of pairs walking with hand contact. On average, the amplitude of contact arm oscillations decreased while the contralateral (free) arm oscillated in the same way as during normal walking. Interestingly, EMG activity of the shoulder muscles of the contact arm did not decrease, and their synergistic pattern remained similar. The amplitude of interaction forces and of trunk oscillations was similar for synchronized and non-synchronized steps, though the synchronized steps were characterized by significantly more regular orientations of interaction forces. Our results further support the notion that gait synchronization during natural walking is common, and that it may occur through interaction forces. Conservation of the proximal muscle activity of the contact (not oscillating) arm is consistent with neural coupling between cervical and lumbosacral pattern generation circuitries (“quadrupedal” arm-leg coordination) during human gait. Overall, the findings suggest that individuals might integrate force interaction cues to communicate and coordinate steps during walking. PMID:29563883

Surface exponents of trails in two dimensions at tricriticality: Computer simulation study

NASA Astrophysics Data System (ADS)

Meirovitch, H.; Chang, I. S.; Shapir, Y.

1989-09-01

Using the scanning simulation method, we study self-attracting trails (with energy ɛ per intersection) terminally attached to an im- penetrable linear boundary on a square lattice at their tricrital collapse transition. Our results for the exponents of the partition functions are γ1=0.634+/-0.025 (one end attached to the surface) and γ11=-0.44+/-0.02 (both ends attached). These values (with 95% significance limits) are within the error bars of the numerical estimates of Seno and Stella [Europhys. Lett. 7, 605 (1989)] for self-avoiding walks (SAW's) at the FTHETA-point on the same lattice. Our results, however, differ significantly from the exact values derived by Duplantier and Saleur for SAW's on a dilute hexagonal lattice at the FTHETA' point. The collapse temperature Tt and the tricritical growth parameter μ are very close to their analytic bounds -ɛ/kBTt=ln3 and μ=3.

Effects of adding a virtual reality environment to different modes of treadmill walking.

PubMed

Sloot, L H; van der Krogt, M M; Harlaar, J

2014-03-01

Differences in gait between overground and treadmill walking are suggested to result from imposed treadmill speed and lack of visual flow. To counteract this effect, feedback-controlled treadmills that allow the subject to control the belt speed along with an immersive virtual reality (VR) have recently been developed. We studied the effect of adding a VR during both fixed speed (FS) and self-paced (SP) treadmill walking. Nineteen subjects walked on a dual-belt instrumented treadmill with a simple endless road projected on a 180° circular screen. A main effect of VR was found for hip flexion offset, peak hip extension, peak knee extension moment, knee flexion moment gain and ankle power during push off. A consistent interaction effect between VR and treadmill mode was found for 12 out of 30 parameters, although the differences were small and did not exceed 50% of the within subject stride variance. At FS, the VR seemed to slightly improve the walking pattern towards overground walking, with for example a 6.5mm increase in stride length. At SP, gait became slightly more cautious by adding a VR, with a 9.1mm decrease in stride length. Irrespective of treadmill mode, subjects rated walking with the VR as more similar to overground walking. In the context of clinical gait analysis, the effects of VR are too small to be relevant and are outweighed by the gains of adding a VR, such as a more stimulating experience and possibility of augmenting it by real-time feedback. Copyright © 2013 Elsevier B.V. All rights reserved.

Distinguishing healthy adults from people with social anxiety disorder: evidence for the value of experiential avoidance and positive emotions in everyday social interactions.

PubMed

Kashdan, Todd B; Farmer, Antonina S; Adams, Leah M; Ferssizidis, Patty; McKnight, Patrick E; Nezlek, John B

2013-08-01

Despite the increased attention that researchers have paid to social anxiety disorder (SAD), compared with other anxiety and mood disorders, relatively little is known about the emotional and social factors that distinguish individuals who meet diagnostic criteria from those who do not. In this study, participants with and without a diagnosis of SAD (generalized subtype) described their daily face-to-face social interactions for 2 weeks using handheld computers. We hypothesized that, compared with healthy controls, individuals diagnosed with SAD would experience fewer positive emotions, rely more on experiential avoidance (of anxiety), and have greater self-control depletion (feeling mentally and physically exhausted after socializing), after accounting for social anxiety, negative emotions, and feelings of belonging during social interactions. We found that compared with healthy controls, individuals with SAD experienced weaker positive emotions and greater experiential avoidance, but there were no differences in self-control depletion between groups. Moreover, the differences we found could not be attributed to comorbid anxiety or depressive disorders. Our results suggest that negative emotions alone do not fully distinguish normal from pathological social anxiety, and that assessing social anxiety disorder should include impairments in positive emotional experiences and dysfunctional emotion regulation (in the form of experiential avoidance) in social situations. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Reproducibility and Validity of the 6-Minute Walk Test Using the Gait Real-Time Analysis Interactive Lab in Patients with COPD and Healthy Elderly

PubMed Central

Meijer, Kenneth; Delbressine, Jeannet M.; Willems, Paul J.; Franssen, Frits M. E.; Wouters, Emiel F. M.; Spruit, Martijn A.

2016-01-01

Background The 6-minute walk test (6MWT) in a regular hallway is commonly used to assess functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD). However, treadmill walking might provide additional advantages over overground walking, especially if virtual reality and self-paced treadmill walking are combined. Therefore, this study aimed to assess the reproducibility and validity of the 6MWT using the Gait Real-time Analysis Interactive Lab (GRAIL) in patients with COPD and healthy elderly. Methodology/Results Sixty-one patients with COPD and 48 healthy elderly performed two 6MWTs on the GRAIL. Patients performed two overground 6MWTs and healthy elderly performed one overground test. Differences between consecutive 6MWTs and the test conditions (GRAIL vs. overground) were analysed. Patients walked further in the second overground test (24.8 m, 95% CI 15.2–34.4 m, p<0.001) and in the second GRAIL test (26.8 m, 95% CI 13.9–39.6 m). Healthy elderly improved their second GRAIL test (49.6 m, 95% CI 37.0–62.3 m). The GRAIL 6MWT was reproducible (intra-class coefficients = 0.65–0.80). The best GRAIL 6-minute walk distance (6MWD) in patients was shorter than the best overground 6MWD (-27.3 ± 49.1 m, p<0.001). Healthy elderly walked further on the GRAIL than in the overground condition (23.6 ± 41.4 m, p<0.001). Validity of the GRAIL 6MWT was assessed and intra-class coefficient values ranging from 0.74–0.77 were found. Conclusion The GRAIL is a promising system to assess the 6MWD in patients with COPD and healthy elderly. The GRAIL 6MWD seems to be more comparable to the 6MWDs assessed overground than previous studies on treadmills have reported. Furthermore, good construct validity and reproducibility were established in assessing the 6MWD using the GRAIL in patients with COPD and healthy elderly. PMID:27607426

Public transit, obesity, and medical costs: assessing the magnitudes.

PubMed

Edwards, Ryan D

2008-01-01

This paper assesses the potential benefits of increased walking and reduced obesity associated with taking public transit in terms of dollars of medical costs saved and disability avoided. I conduct a new analysis of a nationally representative U.S. transportation survey to gauge the net increase in walking associated with public transit usage. I translate minutes spent walking into energy expenditures and reductions in obesity prevalence, estimating the present value of costs and disability that may be avoided. Taking public transit is associated with walking 8.3 more minutes per day on average, or an additional 25.7-39.0 kcal. Hill et al. [Hill, J.O., Wyatt, H.R., Reed, G.W., Peters, J.C., 2003. Obesity and the environment: Where do we go from here? Science 299 (5608), 853-855] estimate that an increase in net expenditure of 100 kcal/day can stop the increase in obesity in 90% of the population. Additional walking associated with public transit could save $5500 per person in present value by reducing obesity-related medical costs. Savings in quality-adjusted life years could be even higher. While no silver bullet, walking associated with public transit can have a substantial impact on obesity, costs, and well-being. Further research is warranted on the net impact of transit usage on all behaviors, including caloric intake and other types of exercise, and on whether policies can promote transit usage at acceptable cost.

Validation of the Social Exercise and Anxiety Measure (SEAM): Assessing fears, avoidance, and importance of social exercise

PubMed Central

Levinson, Cheri A.; Rodebaugh, Thomas L.; Menatti, Andrew R.; Weeks, Justin W.

2012-01-01

In two studies (N = 416; N = 118) examining responses from undergraduates, we developed the Social Exercise and Anxiety Measure (SEAM) and tested its factorial, convergent, and divergent validity. Our results demonstrate that the SEAM exhibits an excellent three factor structure consisting of the following subscales: Social Exercise Self-efficacy, Gym Avoidance, and Exercise Importance. In both studies, Social Exercise Self-efficacy correlated negatively and Gym Avoidance correlated positively with social interaction anxiety, fear of scrutiny, and fear of negative evaluation. Exercise Importance correlated positively with frequency of exercise and frequency of public exercise. Implications for the mental and physical health of individuals with high levels of social anxiety are discussed. PMID:24244069

Self-paced exercise program for office workers: impact on productivity and health outcomes.

PubMed

Low, David; Gramlich, Martha; Engram, Barbara Wright

2007-03-01

The impact of a self-paced exercise program on productivity and health outcomes of 32 adult workers in a large federal office complex was investigated during 3 months. Walking was the sole form of exercise. The first month, during which no walking occurred, was the control period. The second and third months were the experimental period. Participants were divided into three levels based on initial weight and self-determined walking distance goals. Productivity (using the Endicott Work Productivity Scale), walking distance (using a pedometer), and health outcomes (blood pressure, weight, pulse rate, and body fat percentage) were measured weekly. Results from this study, based on a paired t test analysis, suggest that although the self-paced exercise program had no impact on productivity, it lowered blood pressure and promoted weight loss. Further study using a larger sample and a controlled experimental design is recommended to provide conclusive evidence.

Who walks? Factors associated with walking behavior in disabled older women with and without self-reported walking difficulty.

PubMed

Simonsick, E M; Guralnik, J M; Fried, L P

1999-06-01

To determine how severity of walking difficulty and sociodemographic, psychosocial, and health-related factors influence walking behavior in disabled older women. Cross-sectional analyses of baseline data from the Women's Health and Aging Study (WHAS). An urban community encompassing 12 contiguous zip code areas in the eastern portion of Baltimore City and part of Baltimore County, Maryland. A total of 920 moderately to severely disabled community-resident women, aged 65 years and older, identified from an age-stratified random sample of Medicare beneficiaries. Walking behavior was defined as minutes walked for exercise and total blocks walked per week. Independent variables included self-reported walking difficulty, sociodemographic factors, psychological status (depression, mastery, anxiety, and cognition), and health-related factors (falls and fear of falling, fatigue, vision and balance problems, weight, smoking, and cane use). Walking at least 8 blocks per week was strongly negatively related to severity of walking difficulty. Independent of difficulty level, older age, black race, fatigue, obesity, and cane use were also negatively associated with walking; living alone and high mastery had a positive association with walking. Even among functionally limited women, sociocultural, psychological, and health-related factors were independently associated with walking behavior. Thus, programs aimed at improving walking ability need to address these factors in addition to walking difficulties to maximize participation and compliance.

The comparison of transfemoral amputees using mechanical and microprocessor- controlled prosthetic knee under different walking speeds: A randomized cross-over trial.

PubMed

Cao, Wujing; Yu, Hongliu; Zhao, Weiliang; Meng, Qiaoling; Chen, Wenming

2018-04-20

The microprocessor-controlled prosthetic knees have been introduced to transfemoral amputees due to advances in biomedical engineering. A body of scientific literature has shown that the microprocessor-controlled prosthetic knees improve the gait and functional abilities of persons with transfemoral amputation. The aim of this study was to propose a new microprocessor-controlled prosthetic knee (MPK) and compare it with non-microprocessor-controlled prosthetic knees (NMPKs) under different walking speeds. The microprocessor-controlled prosthetic knee (i-KNEE) with hydraulic damper was developed. The comfortable self-selected walking speeds of 12 subjects with i-KNEE and NMPK were obtained. The maximum swing flexion knee angle and gait symmetry were compared in i-KNEE and NMPK condition. The comfortable self-selected walking speeds of some subjects were higher with i-KNEE while some were not. There was no significant difference in comfortable self-selected walking speed between the i-KNEE and the NMPK condition (P= 0.138). The peak prosthetic knee flexion during swing in the i-KNEE condition was between sixty and seventy degree under any walking speed. In the NMPK condition, the maximum swing flexion knee angle changed significantly. And it increased with walking speed. There is no significant difference in knee kinematic symmetry when the subjects wear the i-KNEE or NMPK. The results of this study indicated that the new microprocessor-controlled prosthetic knee was suitable for transfemoral amputees. The maximum swing flexion knee angle under different walking speeds showed different properties in the NMPK and i-KNEE condition. The i-KNEE was more adaptive to speed changes. There was little difference of comfortable self-selected walking speed between i-KNEE and NMPK condition.

Isotropic quantum walks on lattices and the Weyl equation

NASA Astrophysics Data System (ADS)

D'Ariano, Giacomo Mauro; Erba, Marco; Perinotti, Paolo

2017-12-01

We present a thorough classification of the isotropic quantum walks on lattices of dimension d =1 ,2 ,3 with a coin system of dimension s =2 . For d =3 there exist two isotropic walks, namely, the Weyl quantum walks presented in the work of D'Ariano and Perinotti [G. M. D'Ariano and P. Perinotti, Phys. Rev. A 90, 062106 (2014), 10.1103/PhysRevA.90.062106], resulting in the derivation of the Weyl equation from informational principles. The present analysis, via a crucial use of isotropy, is significantly shorter and avoids a superfluous technical assumption, making the result completely general.

Ankle Plantarflexor Spasticity Does Not Restrict the Recovery of Ankle Plantarflexor Strength or Ankle Power Generation for Push-Off During Walking Following Traumatic Brain Injury.

PubMed

Williams, Gavin; Banky, Megan; Olver, John

2016-01-01

The main aim of this project was to determine the impact of plantarflexor spasticity on muscle performance for ambulant people with traumatic brain injury (TBI). A large metropolitan rehabilitation hospital. Seventy-two ambulant people with TBI who were attending physiotherapy for mobility limitations. Twenty-four participants returned for a 6-month follow-up reassessment. Cross-sectional cohort study. Self-selected walking speed, Tardieu scale, ankle plantarflexor strength, and ankle power generation (APG). Participants with ankle plantarflexor spasticity had significantly lower self-selected walking speed; however, there was no significant difference in ankle plantarflexor strength or APG. Participants with ankle plantarflexor spasticity were not restricted in the recovery of self-selected walking speed, ankle plantarflexor strength, or APG, indicating equivalent ability to improve their mobility over time despite the presence of spasticity. Following TBI, people with ankle plantarflexor spasticity have significantly greater mobility limitations than those without spasticity, yet retain the capacity for recovery of self-selected walking speed, ankle plantarflexor strength, and APG.

Computing approximate solutions of the protein structure determination problem using global constraints on discrete crystal lattices.

PubMed

Dal Palù, Alessandro; Dovier, Agostino; Pontelli, Enrico

2010-01-01

Crystal lattices are discrete models of the three-dimensional space that have been effectively employed to facilitate the task of determining proteins' natural conformation. This paper investigates alternative global constraints that can be introduced in a constraint solver over discrete crystal lattices. The objective is to enhance the efficiency of lattice solvers in dealing with the construction of approximate solutions of the protein structure determination problem. Some of them (e.g., self-avoiding-walk) have been explicitly or implicitly already used in previous approaches, while others (e.g., the density constraint) are new. The intrinsic complexities of all of them are studied and preliminary experimental results are discussed.

Polymer collapse, protein folding, and the percolation threshold.

PubMed

Meirovitch, Hagai

2002-01-15

We study the transition of polymers in the dilute regime from a swollen shape at high temperatures to their low-temperature structures. The polymers are modeled by a single self-avoiding walk (SAW) on a lattice for which l of the monomers (the H monomers) are self-attracting, i.e., if two nonbonded H monomers become nearest neighbors on the lattice they gain energy of interaction (epsilon = -/epsilon/); the second type of monomers, denoted P, are neutral. This HP model was suggested by Lau and Dill (Macromolecules 1989, 22, 3986-3997) to study protein folding, where H and P are the hydrophobic and polar amino acid residues, respectively. The model is simulated on the square and simple cubic (SC) lattices using the scanning method. We show that the ground state and the sharpness of the transition depend on the lattice, the fraction g of the H monomers, as well as on their arrangement along the chain. In particular, if the H monomers are distributed at random and g is larger than the site percolation threshold of the lattice, a collapsed transition is very likely to occur. This conclusion, drawn for the lattice models, is also applicable to proteins where an effective lattice with coordination number between that of the SC lattice and the body centered cubic lattice is defined. Thus, the average fraction of hydrophobic amino acid residues in globular proteins is found to be close to the percolation threshold of the effective lattice.

An anterior ankle-foot orthosis improves walking economy in Charcot-Marie-Tooth type 1A patients.

PubMed

Menotti, Federica; Laudani, Luca; Damiani, Antonello; Mignogna, Teresa; Macaluso, Andrea

2014-10-01

Ankle-foot orthoses are commonly prescribed in Charcot-Marie-Tooth type 1A disease to improve quality of walking and reduce the risk of falling due to the foot drop. This study aimed at assessing the effect of an anterior ankle-foot orthosis on walking economy in a group of Charcot-Marie-Tooth type 1A patients. Within-group comparisons. 7 Charcot-Marie-Tooth type 1A patients (four women and three men; 37 ± 11 years; age range = 22-53 years) were asked to walk on a circuit at their self-selected speeds ('slow', 'comfortable' and 'fast') in two walking conditions: (1) with shoes only and (2) with Taloelast(®) anterior elastic ankle-foot orthoses. Speed of walking and metabolic cost of walking energy cost per unit of distance were assessed at the three self-selected speeds of walking for both walking conditions. Speed of walking at the three self-selected speeds did not differ between shoes only and anterior elastic ankle-foot orthoses, whereas walking energy cost per unit of distance at comfortable speed was lower in patients using anterior elastic ankle-foot orthoses with respect to shoes only (2.39 ± 0.22 vs 2.70 ± 0.19 J kg(-1) m(-1); P < 0.05). In Charcot-Marie-Tooth type 1A patients, the use of anterior elastic ankle-foot orthoses improved walking economy by reducing the energy cost of walking per unit of distance, thus reflecting a lower level of metabolic effort and improved mechanical efficiency in comparison with shoes only. From a practical perspective, Charcot-Marie-Tooth type 1A patients with anterior elastic ankle-foot orthoses can walk for a longer duration with a lower level of physical effort. Improvements in walking economy due to ankle-foot orthoses are likely a consequence of the reduction in steppage gait. © The International Society for Prosthetics and Orthotics 2013.

Land Use, Residential Density, and Walking

PubMed Central

Rodríguez, Daniel A.; Evenson, Kelly R.; Diez Roux, Ana V.; Brines, Shannon J.

2009-01-01

Background The neighborhood environment may play a role in encouraging sedentary patterns, especially for middle-aged and older adults. Purpose Associations between walking and neighborhood population density, retail availability, and land use distribution were examined using data from a cohort of adults aged 45 to 84 years old. Methods Data from a multi-ethnic sample of 5529 adult residents of Baltimore MD, Chicago IL, Forsyth County NC, Los Angeles CA, New York NY, and St. Paul MN, enrolled in the Multi-Ethnic Study of Atherosclerosis in 2000–2002 were linked to secondary land use and population data. Participant reports of access to destinations and stores and objective measures of the percentage of land area in parcels devoted to retail land uses, the population divided by land area in parcels, and the mixture of uses for areas within 200m of each participant's residence were examined. Multinomial logistic regression was used to investigate associations of self-reported and objective neighborhood characteristics with walking. All analyses were conducted in 2008 and 2009. Results After adjustment for individual-level characteristics and neighborhood connectivity, higher density, greater land area devoted to retail uses, and self-reported measures of proximity of destinations and ease of walking to places were each related to walking. In models including all land use measures, population density was positively associated with walking to places and with walking for exercise for more than 90 min/wk both relative to no walking. Availability of retail was associated with walking to places relative to not walking, having a more proportional mix of land uses was associated with walking for exercise for more than 90 min/wk, while self-reported ease of access to places was related to higher levels of exercise walking both relative to not walking. Conclusions Residential density and the presence of retail uses are related to various walking behaviors. Efforts to increase walking may benefit from attention to the intensity and type of land development. PMID:19840694

Land use, residential density, and walking. The multi-ethnic study of atherosclerosis.

PubMed

Rodríguez, Daniel A; Evenson, Kelly R; Diez Roux, Ana V; Brines, Shannon J

2009-11-01

The neighborhood environment may play a role in encouraging sedentary patterns, especially for middle-aged and older adults. The aim of this study was to examine the associations between walking and neighborhood population density, retail availability, and land-use distribution using data from a cohort of adults aged 45 to 84 years. Data from a multi-ethnic sample of 5529 adult residents of Baltimore MD, Chicago IL, Forsyth County NC, Los Angeles CA, New York NY, and St. Paul MN enrolled in the Multi-Ethnic Study of Atherosclerosis in 2000-2002 were linked to secondary land-use and population data. Participant reports of access to destinations and stores and objective measures of the percentage of land area in parcels devoted to retail land uses, the population divided by land area in parcels, and the mixture of uses for areas within 200 m of each participant's residence were examined. Multinomial logistic regression was used to investigate associations of self-reported and objective neighborhood characteristics with walking. All analyses were conducted in 2008 and 2009. After adjustment for individual-level characteristics and neighborhood connectivity, it was found that higher density, greater land area devoted to retail uses, and self-reported proximity of destinations and ease of walking to places were each related to walking. In models including all land-use measures, population density was positively associated with walking to places and with walking for exercise for more than 90 minutes/week, both relative to no walking. Availability of retail was associated with walking to places relative to not walking, and having a more proportional mix of land uses was associated with walking for exercise for more than 90 minutes/week, while self-reported ease of access to places was related to higher levels of exercise walking, both relative to not walking. Residential density and the presence of retail uses are related to various walking behaviors. Efforts to increase walking may benefit from attention to the intensity and type of land development.

The Role of Interpersonal Personality Traits and Reassurance Seeking in Eating Disorder Symptoms and Depressive Symptoms among Women with Bulimia Nervosa

PubMed Central

Mason, Tyler B.; Lavender, Jason M.; Wonderlich, Stephen A.; Crosby, Ross D.; Joiner, Thomas E.; Mitchell, James E.; Crow, Scott J.; Klein, Marjorie H.; Le Grange, Daniel; Bardone-Cone, Anna M.; Peterson, Carol B.

2017-01-01

Introduction The role of interpersonal factors has been proposed in various models of eating disorder (ED) psychopathology and treatment. We examined the independent and interactive contributions of two interpersonal-focused personality traits (i.e., social avoidance and insecure attachment) and reassurance seeking in relation to global ED psychopathology and depressive symptoms among women with bulimia nervosa (BN). Method Participants were 204 adult women with full or subclinical BN who completed a battery of self-report questionnaires. Hierarchical multiple OLS regressions including main effects and interaction terms were used to analyze the data. Results Main effects were found for social avoidance and insecure attachment in association with global ED psychopathology and depressive symptoms. In addition, two-way interactions between social avoidance and reassurance seeking were observed for both global ED psychopathology and depressive symptoms. In general, reassurance seeking strengthened the association between social avoidance and global ED psychopathology and depressive symptoms. Conclusion These results demonstrate the importance of reassurance seeking in psychopathology among women with BN who display personality features characterized by social avoidance. PMID:27234198

The role of interpersonal personality traits and reassurance seeking in eating disorder symptoms and depressive symptoms among women with bulimia nervosa.

PubMed

Mason, Tyler B; Lavender, Jason M; Wonderlich, Stephen A; Crosby, Ross D; Joiner, Thomas E; Mitchell, James E; Crow, Scott J; Klein, Marjorie H; Le Grange, Daniel; Bardone-Cone, Anna M; Peterson, Carol B

2016-07-01

The role of interpersonal factors has been proposed in various models of eating disorder (ED) psychopathology and treatment. We examined the independent and interactive contributions of two interpersonal-focused personality traits (i.e., social avoidance and insecure attachment) and reassurance seeking in relation to global ED psychopathology and depressive symptoms among women with bulimia nervosa (BN). Participants were 204 adult women with full or subclinical BN who completed a battery of self-report questionnaires. Hierarchical multiple OLS regressions including main effects and interaction terms were used to analyze the data. Main effects were found for social avoidance and insecure attachment in association with global ED psychopathology and depressive symptoms. In addition, two-way interactions between social avoidance and reassurance seeking were observed for both global ED psychopathology and depressive symptoms. In general, reassurance seeking strengthened the association between social avoidance and global ED psychopathology and depressive symptoms. These results demonstrate the importance of reassurance seeking in psychopathology among women with BN who display personality features characterized by social avoidance. Copyright © 2016. Published by Elsevier Inc.

Towards social autonomous vehicles: Efficient collision avoidance scheme using Richardson's arms race model.

PubMed

Riaz, Faisal; Niazi, Muaz A

2017-01-01

This paper presents the concept of a social autonomous agent to conceptualize such Autonomous Vehicles (AVs), which interacts with other AVs using social manners similar to human behavior. The presented AVs also have the capability of predicting intentions, i.e. mentalizing and copying the actions of each other, i.e. mirroring. Exploratory Agent Based Modeling (EABM) level of the Cognitive Agent Based Computing (CABC) framework has been utilized to design the proposed social agent. Furthermore, to emulate the functionality of mentalizing and mirroring modules of proposed social agent, a tailored mathematical model of the Richardson's arms race model has also been presented. The performance of the proposed social agent has been validated at two levels-firstly it has been simulated using NetLogo, a standard agent-based modeling tool and also, at a practical level using a prototype AV. The simulation results have confirmed that the proposed social agent-based collision avoidance strategy is 78.52% more efficient than Random walk based collision avoidance strategy in congested flock-like topologies. Whereas practical results have confirmed that the proposed scheme can avoid rear end and lateral collisions with the efficiency of 99.876% as compared with the IEEE 802.11n-based existing state of the art mirroring neuron-based collision avoidance scheme.

Towards social autonomous vehicles: Efficient collision avoidance scheme using Richardson’s arms race model

PubMed Central

Niazi, Muaz A.

2017-01-01

This paper presents the concept of a social autonomous agent to conceptualize such Autonomous Vehicles (AVs), which interacts with other AVs using social manners similar to human behavior. The presented AVs also have the capability of predicting intentions, i.e. mentalizing and copying the actions of each other, i.e. mirroring. Exploratory Agent Based Modeling (EABM) level of the Cognitive Agent Based Computing (CABC) framework has been utilized to design the proposed social agent. Furthermore, to emulate the functionality of mentalizing and mirroring modules of proposed social agent, a tailored mathematical model of the Richardson’s arms race model has also been presented. The performance of the proposed social agent has been validated at two levels–firstly it has been simulated using NetLogo, a standard agent-based modeling tool and also, at a practical level using a prototype AV. The simulation results have confirmed that the proposed social agent-based collision avoidance strategy is 78.52% more efficient than Random walk based collision avoidance strategy in congested flock-like topologies. Whereas practical results have confirmed that the proposed scheme can avoid rear end and lateral collisions with the efficiency of 99.876% as compared with the IEEE 802.11n-based existing state of the art mirroring neuron-based collision avoidance scheme. PMID:29040294

Dog walking: its association with physical activity guideline adherence and its correlates.

PubMed

Hoerster, Katherine D; Mayer, Joni A; Sallis, James F; Pizzi, Nicole; Talley, Sandra; Pichon, Latrice C; Butler, Dalila A

2011-01-01

We examined the prevalence and correlates of dog walking among dog owners, and whether dog walking is associated with meeting the American College of Sports Medicine/American Heart Association physical activity guidelines. In March 2008, we mailed a survey to dog-owning clients from two San Diego County veterinary clinics. Useable data were obtained from 984 respondents, and 75 of these completed retest surveys. We assessed associations between potential correlates and dog walking (i.e., yes/no dog walking for at least 10 min in past week). Test-retest reliability of measures was generally high. Approximately one-third of the sample (31.5%) were not dog walkers. Proportions of dog walkers versus non-dog walkers meeting United States guidelines were 64.3% and 55.0%, respectively. Dog walking was independently associated with meeting guidelines in a multivariate model (odds ratio=1.59, p=0.004). Three variables were independently associated with dog walking in a multivariate model: dog encouragement of dog walking, dog-walking obligation, and dog-walking self-efficacy. Dog walking was associated with meeting physical activity guidelines, making it a viable method for promoting physical activity. Dog-walking obligation and self-efficacy may be important mediators of dog walking and may need to be targeted if interventions are to be successful. Published by Elsevier Inc.

Effect of Interpersonal Interaction on Festinating Gait Rehabilitation in Patients with Parkinson’s Disease

PubMed Central

Uchitomi, Hirotaka; Ogawa, Ken-ichiro; Orimo, Satoshi; Wada, Yoshiaki; Miyake, Yoshihiro

2016-01-01

Although human walking gait rhythms are generated by native individual gait dynamics, these gait dynamics change during interactions between humans. A typical phenomenon is synchronization of gait rhythms during cooperative walking. Our previous research revealed that fluctuation characteristics in stride interval of subjects with Parkinson’s disease changed from random to 1/f fluctuation as fractal characteristics during cooperative walking with the gait assist system Walk-Mate, which emulates a human interaction using interactive rhythmic cues. Moreover, gait dynamics were relearned through Walk-Mate gait training. However, the system’s clinical efficacy was unclear because the previous studies did not focus on specific gait rhythm disorder symptoms. Therefore, this study aimed to evaluate the effect of Walk-Mate on festinating gait among subjects with Parkinson’s disease. Three within-subject experimental conditions were used: (1) preinteraction condition, (2) interaction condition, and (3) postinteraction condition. The only difference between conditions was the interactive rhythmic cues generated by Walk-Mate. Because subjects with festinating gait gradually and involuntarily decreased their stride interval, the regression slope of stride interval as an index of severity of preinteraction festinating gait was elevated. The regression slope in the interaction condition was more gradual than during the preinteraction condition, indicating that the interactive rhythmic cues contributed to relieving festinating gait and stabilizing gait dynamics. Moreover, the gradual regression slope was carried over to the postinteraction condition, indicating that subjects with festinating gait have the potential to relearn stable gait dynamics. These results suggest that disordered gait dynamics are clinically restored through interactive rhythmic cues and that Walk-Mate may have the potential to assist therapists in more effective rehabilitation. Trial Registration: UMIN Clinical Trials Registry UMIN000012591 PMID:27253376

Effect of Interpersonal Interaction on Festinating Gait Rehabilitation in Patients with Parkinson's Disease.

PubMed

Uchitomi, Hirotaka; Ogawa, Ken-Ichiro; Orimo, Satoshi; Wada, Yoshiaki; Miyake, Yoshihiro

2016-01-01

Although human walking gait rhythms are generated by native individual gait dynamics, these gait dynamics change during interactions between humans. A typical phenomenon is synchronization of gait rhythms during cooperative walking. Our previous research revealed that fluctuation characteristics in stride interval of subjects with Parkinson's disease changed from random to 1/f fluctuation as fractal characteristics during cooperative walking with the gait assist system Walk-Mate, which emulates a human interaction using interactive rhythmic cues. Moreover, gait dynamics were relearned through Walk-Mate gait training. However, the system's clinical efficacy was unclear because the previous studies did not focus on specific gait rhythm disorder symptoms. Therefore, this study aimed to evaluate the effect of Walk-Mate on festinating gait among subjects with Parkinson's disease. Three within-subject experimental conditions were used: (1) preinteraction condition, (2) interaction condition, and (3) postinteraction condition. The only difference between conditions was the interactive rhythmic cues generated by Walk-Mate. Because subjects with festinating gait gradually and involuntarily decreased their stride interval, the regression slope of stride interval as an index of severity of preinteraction festinating gait was elevated. The regression slope in the interaction condition was more gradual than during the preinteraction condition, indicating that the interactive rhythmic cues contributed to relieving festinating gait and stabilizing gait dynamics. Moreover, the gradual regression slope was carried over to the postinteraction condition, indicating that subjects with festinating gait have the potential to relearn stable gait dynamics. These results suggest that disordered gait dynamics are clinically restored through interactive rhythmic cues and that Walk-Mate may have the potential to assist therapists in more effective rehabilitation. UMIN Clinical Trials Registry UMIN000012591.

Understanding the relationships between self-esteem, experiential avoidance, and paranoia: structural equation modelling and experience sampling studies.

PubMed

Udachina, Alisa; Thewissen, Viviane; Myin-Germeys, Inez; Fitzpatrick, Sam; O'kane, Aisling; Bentall, Richard P

2009-09-01

Hypothesized relationships between experiential avoidance (EA), self-esteem, and paranoia were tested using structural equation modeling in a sample of student participants (N = 427). EA in everyday life was also investigated using the Experience Sampling Method in a subsample of students scoring high (N = 17) and low (N = 15) on paranoia. Results showed that paranoid students had lower self-esteem and reported higher levels of EA than nonparanoid participants. The interactive influence of EA and stress predicted negative self-esteem: EA was particularly damaging at high levels of stress. Greater EA and higher social stress independently predicted lower positive self-esteem. Low positive self-esteem predicted engagement in EA. A direct association between EA and paranoia was also found. These results suggest that similar mechanisms may underlie EA and thought suppression. Although people may employ EA to regulate self-esteem, this strategy is maladaptive as it damages self-esteem, incurs cognitive costs, and fosters paranoid thinking.

Development and psychometric testing of the Dogs and WalkinG Survey (DAWGS).

PubMed

Richards, Elizabeth A; McDonough, Meghan H; Edwards, Nancy E; Lyle, Roseann M; Troped, Philip J

2013-12-01

Dog owners represent 40% of the population, a promising audience to increase population levels of physical activity. The purpose of this study was to develop and test the psychometric properties of a new instrument to assess social-cognitive theory constructs related to dog walking. Dog owners (N = 431) completed the Dogs and WalkinG Survey (DAWGS). Survey items assessed dog-walking behaviors and self-efficacy, social support, outcome expectations, and outcome expectancies for dog walking. Test-retest reliability was assessed among 252 (58%) survey respondents who completed the survey twice. Factorial validity and factorial invariance by age and walking level were tested using confirmatory factor analysis. DAWGS items demonstrated moderate test-retest reliability (p = .39-.79; k = .41-.89). Acceptable model fit was found for all subscales. All subscales were invariant by age and walking level, except self-efficacy, which showed mixed evidence of invariance. The DAWGS is a psychometrically sound instrument for examining individual and interpersonal correlates of dog walking.

Assessing user engagement in a health promotion website using social networking.

PubMed

Tague, Rhys; Maeder, Anthony J; Vandelanotte, Corneel; Kolt, Gregory S; Caperchione, Cristina M; Rosenkranz, Richard R; Savage, Trevor N; Van Itallie, Anetta

2014-01-01

Remote provision of supportive mechanisms for preventive health is a fast-growing area in eHealth. Web-based interventions have been suggested as an effective way to increase adoption and maintenance of healthy lifestyle behaviours. This paper describes results obtained in the "Walk 2.0" trial to promote physical activity through a self-managed walking programme, using a social networking website that provided an online collaborative environment. Engagement of participants with the website was assessed by monitoring usage of the individual social networking functions (e.g. status post). The results demonstrate that users generally preferred contributing non-interactive public posts of information concerned with their individual physical activity levels, and more occasionally communicating privately to friends. Further analysis of topics within posts was done by classifying word usage frequencies. Results indicated that the dominant topics are well aligned with the social environment within which physical activity takes place. Topics centred around four main areas: description of the activity, timing of the activity, affective response to the activity, and context within which the activity occurs. These findings suggest that strong levels of user awareness and communication occur in the social networking setting, indicative of beneficial self-image and self-actualisation effects.

Self-evaluation on Motion Adaptation for Service Robots

NASA Astrophysics Data System (ADS)

Funabora, Yuki; Yano, Yoshikazu; Doki, Shinji; Okuma, Shigeru

We suggest self motion evaluation method to adapt to environmental changes for service robots. Several motions such as walking, dancing, demonstration and so on are described with time series patterns. These motions are optimized with the architecture of the robot and under certain surrounding environment. Under unknown operating environment, robots cannot accomplish their tasks. We propose autonomous motion generation techniques based on heuristic search with histories of internal sensor values. New motion patterns are explored under unknown operating environment based on self-evaluation. Robot has some prepared motions which realize the tasks under the designed environment. Internal sensor values observed under the designed environment with prepared motions show the interaction results with the environment. Self-evaluation is composed of difference of internal sensor values between designed environment and unknown operating environment. Proposed method modifies the motions to synchronize the interaction results on both environment. New motion patterns are generated to maximize self-evaluation function without external information, such as run length, global position of robot, human observation and so on. Experimental results show that the possibility to adapt autonomously patterned motions to environmental changes.

The cognitive benefits of interacting with nature.

PubMed

Berman, Marc G; Jonides, John; Kaplan, Stephen

2008-12-01

We compare the restorative effects on cognitive functioning of interactions with natural versus urban environments. Attention restoration theory (ART) provides an analysis of the kinds of environments that lead to improvements in directed-attention abilities. Nature, which is filled with intriguing stimuli, modestly grabs attention in a bottom-up fashion, allowing top-down directed-attention abilities a chance to replenish. Unlike natural environments, urban environments are filled with stimulation that captures attention dramatically and additionally requires directed attention (e.g., to avoid being hit by a car), making them less restorative. We present two experiments that show that walking in nature or viewing pictures of nature can improve directed-attention abilities as measured with a backwards digit-span task and the Attention Network Task, thus validating attention restoration theory.

Quantum walks of interacting fermions on a cycle graph

PubMed Central

Melnikov, Alexey A.; Fedichkin, Leonid E.

2016-01-01

Quantum walks have been employed widely to develop new tools for quantum information processing recently. A natural quantum walk dynamics of interacting particles can be used to implement efficiently the universal quantum computation. In this work quantum walks of electrons on a graph are studied. The graph is composed of semiconductor quantum dots arranged in a circle. Electrons can tunnel between adjacent dots and interact via Coulomb repulsion, which leads to entanglement. Fermionic entanglement dynamics is obtained and evaluated. PMID:27681057

Effect of visuospatial neglect on spatial navigation and heading after stroke.

PubMed

Aravind, Gayatri; Lamontagne, Anouk

2017-06-09

Visuospatial neglect (VSN) impairs the control of locomotor heading in post-stroke individuals, which may affect their ability to safely avoid moving objects while walking. We aimed to compare VSN+ and VSN- stroke individuals in terms of changes in heading and head orientation in space while avoiding obstacles approaching from different directions and reorienting toward the final target. Stroke participants with VSN (VSN+) and without VSN (VSN-) walked in a virtual environment avoiding obstacles that approached contralesionally, head-on or ipsilesionally. Measures of obstacle avoidance (onset-of-heading change, maximum mediolateral deviation) and target alignment (heading and head-rotation errors with respect to target) were compared across groups and obstacle directions. In total, 26 participants with right-hemisphere stroke participated (13 VSN+ and 13 VSN-; 24 males; mean age 60.3 years, range 48 to 72 years). A larger proportion of VSN+ (75%) than VSN- (38%) participants collided with contralesional and head-on obstacles. For VSN- participants, deviating to the same side as the obstacle was a safe strategy to avoid diagonal obstacles and deviating to the opposite-side led to occasional collisions. VSN+ participants deviated ipsilesionally, displaying same-side and opposite-side strategies for ipsilesional and contralesional obstacles, respectively. Overall, VSN+ participants showed greater distances at onset-of-heading change, smaller maximum mediolateral deviation and larger errors in target alignment as compared with VSN- participants. The ipsilesional bias arising from VSN influences the modulation of heading in response to obstacles and, along with the adoption of the "riskier" strategies, contribute to the higher number colliders and poor goal-directed walking abilities in stroke survivors with VSN. Future research should focus on developing assessment and training tools for complex locomotor tasks such as obstacle avoidance in this population. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Does walking speed mediate the association between visual impairment and self-report of mobility disability? The Salisbury Eye Evaluation Study.

PubMed

Swenor, Bonnielin K; Bandeen-Roche, Karen; Muñoz, Beatriz; West, Sheila K

2014-08-01

To determine whether performance speeds mediate the association between visual impairment and self-reported mobility disability over an 8-year period. Longitudinal analysis. Salisbury, Maryland. Salisbury Eye Evaluation Study participants aged 65 and older (N=2,520). Visual impairment was defined as best-corrected visual acuity worse than 20/40 in the better-seeing eye or visual field less than 20°. Self-reported mobility disability on three tasks was assessed: walking up stairs, walking down stairs, and walking 150 feet. Performance speed on three similar tasks was measured: walking up steps (steps/s), walking down steps (steps/s), and walking 4 m (m/s). For each year of observation, the odds of reporting mobility disability was significantly greater for participants who were visually impaired (VI) than for those who were not (NVI) (odds ratio (OR) difficulty walking up steps=1.58, 95% confidence interval (CI)=1.32-1.89; OR difficulty walking down steps=1.90, 95% CI=1.59-2.28; OR difficulty walking 150 feet=2.11, 95% CI=1.77-2.51). Once performance speed on a similar mobility task was included in the models, VI participants were no longer more likely to report mobility disability than those who were NVI (OR difficulty walking up steps=0.84, 95% CI=0.65-1.11; OR difficulty walking down steps=0.96, 95% CI=0.74-1.24; OR difficulty walking 150 feet=1.22, 95% CI=0.98-1.50). Slower performance speed in VI individuals largely accounted for the difference in the odds of reporting mobility disability, suggesting that VI older adults walk slower and are therefore more likely to report mobility disability than those who are NVI. Improving mobility performance in older adults with visual impairment may minimize the perception of mobility disability. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

The Effects of Dinner-to-Bed Time and Post-Dinner Walk on Gastric Cancer Across Different Age Groups: A Multicenter Case-Control Study in Southeast China.

PubMed

Xu, Le; Zhang, Xi; Lu, Jun; Dai, Jia-Xi; Lin, Ren-Qin; Tian, Fang-Xi; Liang, Bing; Guo, Yi-Nan; Luo, Hui-Yu; Li, Ni; Fang, Dong-Ping; Zhao, Ruo-Hua; Huang, Chang-Ming

2016-04-01

Gastric cancer (GC) remains a major killer throughout the world. Despite the dramatic decrease in GC over the last century, its etiology has not yet been well characterized. This study investigated the possible independent and combined effects of the dinner-to-bed time and post-dinner walk on the risk for GC across different age groups. A population-based, case-control study was conducted in southeast China, including 452 patients with GC and 465 age-, race-, and gender-matched controls. A self-designed questionnaire was used to collect information on demographic characteristics, dinner-to-bed time, post-dinner walk, and other behavioral factors. Conditional logistic regression models were used to estimate the effects of the dinner-to-bed time and post-dinner walk as well as their joint effect on the risk for GC across different age groups. Individuals with dinner-to-bed time <3 hours were more prone to have GC (P < 0.001), and the shorter the dinner-to-bed time was, the higher was the risk for GC (Ptrend < 0.001). Post-dinner nonwalk was associated with a 2.9-fold increased risk for GC compared with post-dinner walk (adjusted odds ratio [AOR] = 2.942, 95% confidence intervals [95% CIs] = 2.072-4.179). The interaction effect of dinner-to-bed time and post-dinner walk on GC risk was detected (AOR = 1.862, 95% CIs = 1.584-3.885, synergy index [SI] = 2.654, 95% CIs = 2.27-3.912). Participants with dinner-to-bed time <3 hours who did not walk after dinner were 7.4 times likely to suffer from GC (AOR = 7.401, 95% CIs = 4.523-13.16) than those with dinner-to-bed time ≥4 hours who took such walk. The risk of GC due to dinner-to-bed time <3 hours, post-dinner nonwalk and their interaction was positively correlated with age. The strongest risk was observed among people ≥70 years old, but the effects were not significant for people ≤55 years old. Dinner-to-bed time <3 hours and post-dinner nonwalk are independent risk factors for GC; the synergistic interaction between the 2 factors was positively related to age, which might significantly increase the risk for GC among people >55 years old.

The Effects of Dinner-to-Bed Time and Post-Dinner Walk on Gastric Cancer Across Different Age Groups

PubMed Central

Xu, Le; Zhang, Xi; Lu, Jun; Dai, Jia-Xi; Lin, Ren-Qin; Tian, Fang-Xi; Liang, Bing; Guo, Yi-Nan; Luo, Hui-Yu; Li, Ni; Fang, Dong-Ping; Zhao, Ruo-Hua; Huang, Chang-Ming

2016-01-01

Abstract Gastric cancer (GC) remains a major killer throughout the world. Despite the dramatic decrease in GC over the last century, its etiology has not yet been well characterized. This study investigated the possible independent and combined effects of the dinner-to-bed time and post-dinner walk on the risk for GC across different age groups. A population-based, case–control study was conducted in southeast China, including 452 patients with GC and 465 age-, race-, and gender-matched controls. A self-designed questionnaire was used to collect information on demographic characteristics, dinner-to-bed time, post-dinner walk, and other behavioral factors. Conditional logistic regression models were used to estimate the effects of the dinner-to-bed time and post-dinner walk as well as their joint effect on the risk for GC across different age groups. Individuals with dinner-to-bed time <3 hours were more prone to have GC (P < 0.001), and the shorter the dinner-to-bed time was, the higher was the risk for GC (Ptrend < 0.001). Post-dinner nonwalk was associated with a 2.9-fold increased risk for GC compared with post-dinner walk (adjusted odds ratio [AOR] = 2.942, 95% confidence intervals [95% CIs] = 2.072–4.179). The interaction effect of dinner-to-bed time and post-dinner walk on GC risk was detected (AOR = 1.862, 95% CIs = 1.584–3.885, synergy index [SI] = 2.654, 95% CIs = 2.27–3.912). Participants with dinner-to-bed time <3 hours who did not walk after dinner were 7.4 times likely to suffer from GC (AOR = 7.401, 95% CIs = 4.523–13.16) than those with dinner-to-bed time ≥4 hours who took such walk. The risk of GC due to dinner-to-bed time <3 hours, post-dinner nonwalk and their interaction was positively correlated with age. The strongest risk was observed among people ≥70 years old, but the effects were not significant for people ≤55 years old. Dinner-to-bed time <3 hours and post-dinner nonwalk are independent risk factors for GC; the synergistic interaction between the 2 factors was positively related to age, which might significantly increase the risk for GC among people >55 years old. PMID:27100427

Frontal Joint Dynamics when Initiating Stair Ascent from a Walk versus a Stand

PubMed Central

Vallabhajosula, Srikant; Yentes, Jennifer M.; Stergiou, Nicholas

2011-01-01

Ascending stairs is a challenging activity of daily living for many populations. Frontal plane joint dynamics are critical to understand the mechanisms involved in stair ascension as they contribute to both propulsion and medio-lateral stability. However, previous research is limited to understanding these dynamics while initiating stair ascent from a stand. We investigated if initiating stair ascent from a walk with a comfortable self-selected speed could affect the frontal plane lower-extremity joint moments and powers as compared to initiating stair ascent from a stand and if this difference would exist at consecutive ipsilateral steps on the stairs. Kinematics data using a 3-D motion capture system and kinetics data using two force platforms on the first and third stair treads were recorded simultaneously as ten healthy young adults ascended a custom-built staircase. Data were collected from two starting conditions of stair ascent, from a walk (speed: 1.42±0.21m/s) and from a stand. Results showed that subjects generated greater peak knee abductor moment and greater peak hip abductor moment when initiating stair ascent from a walk. Greater peak joint moments and powers at all joints were also seen while ascending the second ipsilateral step. Particularly, greater peak hip abductor moment was needed to avoid contact of the contralateral limb with the intermediate step by counteracting the pelvic drop on the contralateral side. This could be important for therapists using stair climbing as a testing/training tool to evaluate hip strength in individuals with documented frontal plane abnormalities (i.e. knee and hip osteoarthritis, ACL injury). PMID:22172606

Evaluation of group and self-directed formats of the Arthritis Foundation's Walk With Ease Program.

PubMed

Callahan, Leigh F; Shreffler, Jack H; Altpeter, Mary; Schoster, Britta; Hootman, Jennifer; Houenou, Laura O; Martin, Kathryn R; Schwartz, Todd A

2011-08-01

To evaluate the effects of a revised 6-week walking program for adults with arthritis, Walk With Ease (WWE), delivered in 2 formats, instructor-led group or self-directed. In an observational pre-post study design, 462 individuals with self-reported arthritis selected either a group format (n = 192) or a self-directed (n = 270) format. Performance and self-reported outcomes were assessed at baseline and at 6 weeks. Self-reported outcomes were assessed at 1 year. Adjusted mean outcome values for group and self-directed participants were determined using regression models, adjusting for covariates. At 6 weeks, significant adjusted mean improvements (P < 0.05) were seen for nearly all self-report and performance measures in both formats. Modest to moderate effect sizes (ES) were seen for disability (ES 0.16-0.23), pain, fatigue, and stiffness (ES 0.21-0.40), and helplessness (ES 0.24-0.28). The Arthritis Self-Efficacy (ASE) pain and symptom scales had modest improvements (ES 0.09-0.21). The performance measures of strength (ES 0.29-0.35), balance (ES 0.12-0.36), and walking pace (ES 0.12-0.32) all showed modest to moderate improvements. No adverse events were reported for either format. At 1 year, both formats showed modest improvement in ASE pain, but there were 5 outcomes where self-directed participants showed significant improvement, while the group participants did not. The revised WWE program decreases disability and improves arthritis symptoms, self-efficacy, and perceived control, balance, strength, and walking pace in individuals with arthritis, regardless of whether they are taking a group class or doing the program as self-directed walkers. At 1 year, some benefits are maintained, particularly among the self-directed. This is a safe, easy, and inexpensive program to promote community-based physical activity. Copyright © 2011 by the American College of Rheumatology.

Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot.

PubMed

Grinke, Eduard; Tetzlaff, Christian; Wörgötter, Florentin; Manoonpong, Poramate

2015-01-01

Walking animals, like insects, with little neural computing can effectively perform complex behaviors. For example, they can walk around their environment, escape from corners/deadlocks, and avoid or climb over obstacles. While performing all these behaviors, they can also adapt their movements to deal with an unknown situation. As a consequence, they successfully navigate through their complex environment. The versatile and adaptive abilities are the result of an integration of several ingredients embedded in their sensorimotor loop. Biological studies reveal that the ingredients include neural dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a many degrees-of-freedom (DOFs) walking robot is a challenging task. Thus, in this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural mechanisms with plasticity, exteroceptive sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent neural network consisting of two fully connected neurons. Online correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors) in the network to generate different turning angles with short-term memory for a walking robot. The turning information is transmitted as descending steering signals to the neural locomotion control which translates the signals into motor actions. As a result, the robot can walk around and adapt its turning angle for avoiding obstacles in different situations. The adaptation also enables the robot to effectively escape from sharp corners or deadlocks. Using backbone joint control embedded in the the locomotion control allows the robot to climb over small obstacles. Consequently, it can successfully explore and navigate in complex environments. We firstly tested our approach on a physical simulation environment and then applied it to our real biomechanical walking robot AMOSII with 19 DOFs to adaptively avoid obstacles and navigate in the real world.

Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot

PubMed Central

Grinke, Eduard; Tetzlaff, Christian; Wörgötter, Florentin; Manoonpong, Poramate

2015-01-01

Walking animals, like insects, with little neural computing can effectively perform complex behaviors. For example, they can walk around their environment, escape from corners/deadlocks, and avoid or climb over obstacles. While performing all these behaviors, they can also adapt their movements to deal with an unknown situation. As a consequence, they successfully navigate through their complex environment. The versatile and adaptive abilities are the result of an integration of several ingredients embedded in their sensorimotor loop. Biological studies reveal that the ingredients include neural dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a many degrees-of-freedom (DOFs) walking robot is a challenging task. Thus, in this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural mechanisms with plasticity, exteroceptive sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent neural network consisting of two fully connected neurons. Online correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors) in the network to generate different turning angles with short-term memory for a walking robot. The turning information is transmitted as descending steering signals to the neural locomotion control which translates the signals into motor actions. As a result, the robot can walk around and adapt its turning angle for avoiding obstacles in different situations. The adaptation also enables the robot to effectively escape from sharp corners or deadlocks. Using backbone joint control embedded in the the locomotion control allows the robot to climb over small obstacles. Consequently, it can successfully explore and navigate in complex environments. We firstly tested our approach on a physical simulation environment and then applied it to our real biomechanical walking robot AMOSII with 19 DOFs to adaptively avoid obstacles and navigate in the real world. PMID:26528176

Attachment predicts cortisol response and closeness in dyadic social interaction.

PubMed

Ketay, Sarah; Beck, Lindsey A

2017-06-01

The present study examined how the interplay of partners' attachment styles influences cortisol response, actual closeness, and desired closeness during friendship initiation. Participants provided salivary cortisol samples at four timepoints throughout either a high or low closeness task that facilitated high or low levels of self-disclosure with a potential friend (i.e., another same-sex participant). Levels of actual closeness and desired closeness following the task were measured via inclusion of other in the self. Results from multi-level modeling indicated that the interaction of both participants' attachment avoidance predicted cortisol response patterns, with participants showing the highest cortisol response when there was a mismatch between their own and their partners' attachment avoidance. Further, the interaction between both participants' attachment anxiety predicted actual closeness and desired closeness, with participants both feeling and wanting the most closeness with partners when both they and their partners were low in attachment anxiety. Copyright © 2017 Elsevier Ltd. All rights reserved.

Parental Attachment Style: Examination of Links with Parent Secure Base Provision and Adolescent Secure Base Use

PubMed Central

Jones, Jason D.; Cassidy, Jude

2014-01-01

The secure base construct is a core aspect of attachment theory and, according to Bowlby (1988), represents one of attachment theory’s most important contributions to our understanding of parent-child relationships and child development. The present study represents the first examination of how parents’ self-reported attachment styles relate to parental secure base provision and adolescent (Mage = 16.6 years, SE = .59) secure base use during an observed parent-adolescent interaction. Further, the present study is the first to examine how fathers’, as well as mothers’, attachment styles relate to observed behavior in a parent-child interaction. At the bivariate level, maternal avoidance, but not anxiety, was negatively associated with observed adolescent secure base use. In addition, path analysis revealed that maternal avoidance was indirectly related to less adolescent secure base use through mothers’ self-reported hostile behavior toward their adolescents and through adolescents’ less positive perceptions of their mothers. Further, paternal anxiety, but not avoidance, was indirectly related to less adolescent secure base use through fathers’ self-reported hostile behavior toward their adolescents. No significant findings emerged in relation to parental secure base provision. We discuss these results in the context of attachment theory and suggest directions for future research. PMID:24897927

Fuzzy integral-based gaze control architecture incorporated with modified-univector field-based navigation for humanoid robots.

PubMed

Yoo, Jeong-Ki; Kim, Jong-Hwan

2012-02-01

When a humanoid robot moves in a dynamic environment, a simple process of planning and following a path may not guarantee competent performance for dynamic obstacle avoidance because the robot acquires limited information from the environment using a local vision sensor. Thus, it is essential to update its local map as frequently as possible to obtain more information through gaze control while walking. This paper proposes a fuzzy integral-based gaze control architecture incorporated with the modified-univector field-based navigation for humanoid robots. To determine the gaze direction, four criteria based on local map confidence, waypoint, self-localization, and obstacles, are defined along with their corresponding partial evaluation functions. Using the partial evaluation values and the degree of consideration for criteria, fuzzy integral is applied to each candidate gaze direction for global evaluation. For the effective dynamic obstacle avoidance, partial evaluation functions about self-localization error and surrounding obstacles are also used for generating virtual dynamic obstacle for the modified-univector field method which generates the path and velocity of robot toward the next waypoint. The proposed architecture is verified through the comparison with the conventional weighted sum-based approach with the simulations using a developed simulator for HanSaRam-IX (HSR-IX).

Properties of knotted ring polymers. I. Equilibrium dimensions.

PubMed

Mansfield, Marc L; Douglas, Jack F

2010-07-28

We report calculations on three classes of knotted ring polymers: (1) simple-cubic lattice self-avoiding rings (SARs), (2) "true" theta-state rings, i.e., SARs generated on the simple-cubic lattice with an attractive nearest-neighbor contact potential (theta-SARs), and (3) ideal, Gaussian rings. Extrapolations to large polymerization index N imply knot localization in all three classes of chains. Extrapolations of our data are also consistent with conjectures found in the literature which state that (1) R(g)-->AN(nu) asymptotically for ensembles of random knots restricted to any particular knot state, including the unknot; (2) A is universal across knot types for any given class of flexible chains; and (3) nu is equal to the standard self-avoiding walk (SAW) exponent (congruent with 0.588) for all three classes of chains (SARs, theta-SARs, and ideal rings). However, current computer technology is inadequate to directly sample the asymptotic domain, so that we remain in a crossover scaling regime for all accessible values of N. We also observe that R(g) approximately p(-0.27), where p is the "rope length" of the maximally inflated knot. This scaling relation holds in the crossover regime, but we argue that it is unlikely to extend into the asymptotic scaling regime where knots become localized.

Walking Perception by Walking Observers

ERIC Educational Resources Information Center

Jacobs, Alissa; Shiffrar, Maggie

2005-01-01

People frequently analyze the actions of other people for the purpose of action coordination. To understand whether such self-relative action perception differs from other-relative action perception, the authors had observers either compare their own walking speed with that of a point-light walker or compare the walking speeds of 2 point-light…

Simulated interactions of pedestrian crossings and motorized vehicles in residential areas

NASA Astrophysics Data System (ADS)

Wang, Yan; Peng, Zhongyi; Chen, Qun

2018-01-01

To evaluate whether motorized vehicles can travel through a residential area, this paper develops a cellular automata (CA) model to simulate the interactions between pedestrian crossings and motorized vehicles in a residential area. In this paper, pedestrians determine their crossing speed according to their judgments of the position and velocity of the upcoming vehicles. The pedestrians may walk slowly or quickly or even run, and the pedestrian crossing time influences the vehicle movement. In addition, the proposed model considers the safety margin time needed for pedestrians to cross, and pedestrian-vehicle conflict is considered using the vehicle collision avoidance rule. Through simulations of interactions of pedestrian crossings with motorized vehicles' movement on a typical road in a residential area, the average wait time for pedestrians to cross and the average vehicle velocity under different pedestrian crossing volumes, different vehicle flows and different maximum vehicle velocities are obtained. To avoid an excessive waiting time for pedestrians to cross, the vehicle flow should be less than 180 veh/h, which allows an average of less than 10 s of waiting time; if the vehicle flow rate is less than 36 veh/h, then the waiting time is approximately 1 s. Field observations are conducted to validate the simulation results.

Multimedia Exercise Training Program Improves Distance Walked, Heart Rate Recovery, and Self-efficacy in Cardiac Surgery Patients.

PubMed

Wang, Li-Wei; Ou, Shu-Hua; Tsai, Chien-Sung; Chang, Yue-Cune; Kao, Chi-Wen

2016-01-01

Patient education has been shown to be more effective when delivered using multimedia than written materials. However, the effects of using multimedia to assist patients in cardiac rehabilitation have not been investigated. The purpose of this study is to examine the effect of an inpatient multimedia exercise training program on distance walked in the 6-minute walking test (6MWT), heart rate recovery, and walking self-efficacy of patients who had undergone heart surgery. For this longitudinal quasi-experimental study, 60 consecutive patients were assigned to an experimental (n = 20; inpatient multimedia exercise training program) or control (n = 40; routine care) group. Data were collected at 3 times (before surgery, 1 to 2 days before hospital discharge, and 1 month after hospital discharge) and analyzed with the generalized estimating equation approach. Most subjects were men (66.7%), had a mean age of 61.32 ± 13.4 years and left ventricular ejection fraction of 56.96% ± 13.28%, and underwent coronary artery bypass graft surgery (n = 34, 56.7%). Subjects receiving the exercise training program showed significantly greater improvement than those in the control group in the 6MWT walking distance (P < .001), heart rate recovery (P = .04), and self-efficacy (P = .002) at hospital discharge. Furthermore, the intervention effects on 6MWT distance (P < .001) and self-efficacy (P < .001) were sustained at 1 month after hospital discharge. Our inpatient multimedia exercise training program safely improved distance walked in the 6MWT, heart rate recovery, and self-efficacy at hospital discharge in patients after heart surgery and maintained their improvement in 6MWT and self-efficacy 1 month later.

Stop & Look with Willy Whistle [and] Walking with Your Eyes. A Teacher's Guide for the Video.

ERIC Educational Resources Information Center

National Highway Traffic Safety Administration (DOT), Washington, DC.

These two teacher's guides accompany two videotape presentations on pedestrian safety for children, focusing particularly on avoiding the "dart-out" accident. "Stop and Look with Willy Whistle," which targets children from kindergarten through third grade, is an updated version of the film "Willy Whistle.""Walking with Your Eyes," which targets…

An Ambulatory System for Gait Monitoring Based on Wireless Sensorized Insoles.

PubMed

González, Iván; Fontecha, Jesús; Hervás, Ramón; Bravo, José

2015-07-09

A new gait phase detection system for continuous monitoring based on wireless sensorized insoles is presented. The system can be used in gait analysis mobile applications, and it is designed for real-time demarcation of gait phases. The system employs pressure sensors to assess the force exerted by each foot during walking. A fuzzy rule-based inference algorithm is implemented on a smartphone and used to detect each of the gait phases based on the sensor signals. Additionally, to provide a solution that is insensitive to perturbations caused by non-walking activities, a probabilistic classifier is employed to discriminate walking forward from other low-level activities, such as turning, walking backwards, lateral walking, etc. The combination of these two algorithms constitutes the first approach towards a continuous gait assessment system, by means of the avoidance of non-walking influences.

Walking Speed Influences the Effects of Implicit Visual Feedback Distortion on Modulation of Gait Symmetry

PubMed Central

Maestas, Gabrielle; Hu, Jiyao; Trevino, Jessica; Chunduru, Pranathi; Kim, Seung-Jae; Lee, Hyunglae

2018-01-01

The use of visual feedback in gait rehabilitation has been suggested to promote recovery of locomotor function by incorporating interactive visual components. Our prior work demonstrated that visual feedback distortion of changes in step length symmetry entails an implicit or unconscious adaptive process in the subjects’ spatial gait patterns. We investigated whether the effect of the implicit visual feedback distortion would persist at three different walking speeds (slow, self-preferred and fast speeds) and how different walking speeds would affect the amount of adaption. In the visual feedback distortion paradigm, visual vertical bars portraying subjects’ step lengths were distorted so that subjects perceived their step lengths to be asymmetric during testing. Measuring the adjustments in step length during the experiment showed that healthy subjects made spontaneous modulations away from actual symmetry in response to the implicit visual distortion, no matter the walking speed. In all walking scenarios, the effects of implicit distortion became more significant at higher distortion levels. In addition, the amount of adaptation induced by the visual distortion was significantly greater during walking at preferred or slow speed than at the fast speed. These findings indicate that although a link exists between supraspinal function through visual system and human locomotion, sensory feedback control for locomotion is speed-dependent. Ultimately, our results support the concept that implicit visual feedback can act as a dominant form of feedback in gait modulation, regardless of speed. PMID:29632481

Seniors' self-preservation by maintaining established self and defying deterioration - A grounded theory.

PubMed

Eriksson, Jeanette Källstrand; Hildingh, Cathrine; Buer, Nina; Thulesius, Hans

2016-01-01

The purpose of this classic grounded theory study was to understand how seniors who are living independently resolve issues influenced by visual impairment and high fall risk. We interviewed and observed 13 seniors with visual impairment in their homes. We also interviewed six visual instructors with experience from many hundreds of relevant incidents from the same group of seniors. We found that the seniors are resolving their main concern of "remaining themselves as who they used to be" by self-preservation. Within this category, the strategies maintaining the established self and defying deterioration emerged as the most prominent in our data. The theme maintaining the established self is mostly guided by change inertia and includes living the past (retaining past activities, reminiscing, and keeping the home intact) and facading (hiding impairment, leading to avoidance of becoming a burden and to risk juggling). Defying deterioration is a proactive scheme and involves moving (by exercising, adapting activities, using walking aids, driving), adapting (by finding new ways), and networking by sustaining old support networks or finding new networks. Self-preservation is generic human behavior and modifying this theory to other fields may therefore be worthwhile. In addition, health care providers may have use for the theory in fall preventive planning.

Seniors’ self-preservation by maintaining established self and defying deterioration – A grounded theory

PubMed Central

Eriksson, Jeanette Källstrand; Hildingh, Cathrine; Buer, Nina; Thulesius, Hans

2016-01-01

The purpose of this classic grounded theory study was to understand how seniors who are living independently resolve issues influenced by visual impairment and high fall risk. We interviewed and observed 13 seniors with visual impairment in their homes. We also interviewed six visual instructors with experience from many hundreds of relevant incidents from the same group of seniors. We found that the seniors are resolving their main concern of “remaining themselves as who they used to be” by self-preservation. Within this category, the strategies maintaining the established self and defying deterioration emerged as the most prominent in our data. The theme maintaining the established self is mostly guided by change inertia and includes living the past (retaining past activities, reminiscing, and keeping the home intact) and facading (hiding impairment, leading to avoidance of becoming a burden and to risk juggling). Defying deterioration is a proactive scheme and involves moving (by exercising, adapting activities, using walking aids, driving), adapting (by finding new ways), and networking by sustaining old support networks or finding new networks. Self-preservation is generic human behavior and modifying this theory to other fields may therefore be worthwhile. In addition, health care providers may have use for the theory in fall preventive planning. PMID:27172511

Improvement of walking speed and gait symmetry in older patients after hip arthroplasty: a prospective cohort study.

PubMed

Rapp, Walter; Brauner, Torsten; Weber, Linda; Grau, Stefan; Mündermann, Annegret; Horstmann, Thomas

2015-10-12

Retraining walking in patients after hip or knee arthroplasty is an important component of rehabilitation especially in older persons whose social interactions are influenced by their level of mobility. The objective of this study was to test the effect of an intensive inpatient rehabilitation program on walking speed and gait symmetry in patients after hip arthroplasty (THA) using inertial sensor technology. Twenty-nine patients undergoing a 4-week inpatient rehabilitation program following THA and 30 age-matched healthy subjects participated in this study. Walking speed and gait symmetry parameters were measured using inertial sensor device for standardized walking trials (2*20.3 m in a gym) at their self-selected normal and fast walking speeds on postoperative days 15, 21, and 27 in patients and in a single session in control subjects. Walking speed was measured using timing lights. Gait symmetry was determined using autocorrelation calculation of the cranio-caudal (CC) acceleration signals from an inertial sensor placed at the lower spine. Walking speed and gait symmetry improved from postoperative days 15-27 (speed, female: 3.2 and 4.5 m/s; male: 4.2 and 5.2 m/s; autocorrelation, female: 0.77 and 0.81; male: 0.70 and 0.79; P <0.001 for all). After the 4-week rehabilitation program, walking speed and gait symmetry were still lower than those in control subjects (speed, female 4.5 m/s vs. 5.7 m/s; male: 5.2 m/s vs. 5.3 m/s; autocorrelation, female: 0.81 vs. 0.88; male: 0.79 vs. 0.90; P <0.001 for all). While patients with THA improved their walking capacity during a 4-week inpatient rehabilitation program, subsequent intensive gait training is warranted for achieving normal gait symmetry. Inertial sensor technology may be a useful tool for evaluating the rehabilitation process during the post-inpatient period.

Dynamic clearance measure to evaluate locomotor and perceptuo-motor strategies used for obstacle circumvention in a virtual environment.

PubMed

Darekar, Anuja; Lamontagne, Anouk; Fung, Joyce

2015-04-01

Circumvention around an obstacle entails a dynamic interaction with the obstacle to maintain a safe clearance. We used a novel mathematical interpolation method based on the modified Shepard's method of Inverse Distance Weighting to compute dynamic clearance that reflected this interaction as well as minimal clearance. This proof-of-principle study included seven young healthy, four post-stroke and four healthy age-matched individuals. A virtual environment designed to assess obstacle circumvention was used to administer a locomotor (walking) and a perceptuo-motor (navigation with a joystick) task. In both tasks, participants were asked to navigate towards a target while avoiding collision with a moving obstacle that approached from either head-on, or 30° left or right. Among young individuals, dynamic clearance did not differ significantly between obstacle approach directions in both tasks. Post-stroke individuals maintained larger and smaller dynamic clearance during the locomotor and the perceptuo-motor task respectively as compared to age-matched controls. Dynamic clearance was larger than minimal distance from the obstacle irrespective of the group, task and obstacle approach direction. Also, in contrast to minimal distance, dynamic clearance can respond differently to different avoidance behaviors. Such a measure can be beneficial in contrasting obstacle avoidance behaviors in different populations with mobility problems. Copyright © 2015 Elsevier B.V. All rights reserved.

Perceived individual, social, and environmental factors for physical activity and walking.

PubMed

Granner, Michelle L; Sharpe, Patricia A; Hutto, Brent; Wilcox, Sara; Addy, Cheryl L

2007-07-01

Few studies have explored associations of individual, social, and environmental factors with physical activity and walking behavior. A random-digit-dial questionnaire, which included selected individual, social, and environmental variables, was administered to 2025 adults, age 18 y and older, in two adjacent counties in a southeastern state. Logistic regressions were conducted adjusting for age, race, sex, education, and employment. In multivariate models, somewhat different variables were associated with physical activity versus regular walking. Self-efficacy (OR = 19.19), having an exercise partner (OR = 1.47), recreation facilities (OR = 1.54), and safety of trails from crime (OR = 0.72) were associated with physical activity level; while self-efficacy (OR = 4.22), known walking routes (OR = 1.54), recreation facilities (OR = 1.57-1.59), and safety of trails from crime (OR = 0.69) were associated with regular walking behavior. Physical activity and walking behaviors were associated with similar variables in this study.

Effect of a 4-week Nordic walking training on the physical fitness and self-assessment of the quality of health of women of the perimenopausal age.

PubMed

Saulicz, Mariola; Saulicz, Edward; Myśliwiec, Andrzej; Wolny, Tomasz; Linek, Paweł; Knapik, Andrzej; Rottermund, Jerzy

2015-06-01

To determine the effect of a 4-week Nordic walking training on the physical fitness of women of the perimenopausal age and self-assessment of the quality of their health. Eighty-four women between 48 and 58 years of age were included in the study. Half of the group (42) was assigned to the control group and the other half was assigned to the experimental group. In both groups studied, physical fitness was evaluated using a modified Fullerton's test and a quality of life self-assessment SF-36 (Short Form of Health Status Questionnaire). Similar tests were repeated 4 weeks later. In the experimental group, a Nordic walking training was conducted between the two tests. During 4 weeks, 10 training sessions were performed, each session was 60 minutes long, and there was an interval of 2 days between the sessions. A 4-week Nordic walking training resulted in a significant improvement (p < 0.001) of physical fitness as demonstrated by an increased strength and flexibility of the upper and lower part of the body and the ability to walk a longer distance during a 6-minute walking test. Women participating in the training also showed a significant improvement in health in terms of both physical health (p < 0.001) and mental health (p < 0.001). A 4-week Nordic walking training has a positive effect on the physical fitness of the women in the perimenopausal age. Participation in training contributes also to a clearly higher self-assessment of the quality of health.

Daily Parenting Engagement among New Mothers and Fathers: The Role of Romantic Attachment in Dual-Earner Families

PubMed Central

Lang, Sarah N.; Schoppe-Sullivan, Sarah J.; Kotila, Letitia E.; Kamp Dush, Claire M.

2014-01-01

We investigated the association of prenatal assessments of mothers’ and fathers’ self-reported romantic attachment anxiety and avoidance with the time mothers and fathers reported in proximity-focused and exploration-focused engagement with their infants at nine months postpartum. Our sample of 136 dual-earner couples came from a larger longitudinal study of the transition to parenthood. Time in proximity-focused (interactions that emphasize physical or emotional connection) and exploration-focused (activities that stimulate and build knowledge of the world) engagement on work and nonworkdays were measured using time diaries. Using Actor-Partner Interdependence Models, we found significant across partner associations between romantic attachment and parental engagement. In particular, analyses revealed interesting interactions: fathers higher in avoidance spent more time in exploration-focused engagement on workdays when mothers were more anxious, whereas mothers higher in anxiety spent more time in proximity-focused engagement on nonworkdays when fathers were more avoidant. Moreover, fathers demonstrated a compensatory pattern of engagement in response to mother’s greater attachment anxiety or avoidance. Findings support the utility of studying romantic attachment within a family system and extend the literature on correlates of early parental engagement. Keywords: self-reported romantic attachment, parent engagement, time diaries, transition to parenthood, family systems PMID:24127790

Steps to Take with the Board to Avoid Walking the Plank.

ERIC Educational Resources Information Center

Papallo, William R.

1990-01-01

A veteran superintendent outlines an eight-step method for achieving success, including assessing the situation, avoiding board overload, coping with stress, deemphasizing egoism, learning to live in the gray zone between policy formation and administration, ensuring effective board decisions, identifying prospective board members, and knowing…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kajita, Shin, E-mail: kajita.shin@nagoya-u.jp; Hwangbo, Dogyun; Ohno, Noriyasu

In recent experiments, clear transitions in velocity and trail width of an arc spot initiated on nanostructured tungsten were observed on the boundary of the thick and thin nanostructured layer regions. The velocity of arc spot was significantly decreased on the thick nanostructured region. It was suggested that the grouping decreased the velocity of arc spot. In this study, we try to explain the phenomena using a simple random walk model that has properties of directionality and self-avoidance. And grouping feature was added by installing an attractive force between spot cells with dealing with multi-spots. It was revealed that anmore » entanglement of arc spot cells decreased the spot velocity, and spot cells tend to stamp at the same location many times.« less

[Effects and the associated factors of the 2016 China Motivational Healthy Walking Program among occupational population].

PubMed

Jiang, W; Zhao, Y F; Yang, X Z; Li, Y C; Li, Z X; Wang, L H

2018-05-06

Objective: To examine the effects and associated factors of the China Motivational Healthy Walking Program among occupational population. Methods: The 2016 China Motivational Healthy Walking Program recruited 29 224 participants from 139 demonstration areas for comprehensive prevention and control of chronic and non-communicable disease at national level and 70 at provincial level. Intervention on walking was carried out by adopting group and individual motivating measures. Walking steps were recorded by electronic pedometer. We used percent of days achieving 10 000 steps (P10 000), percent of days fulfilling continuous walking (PCW), and proportion of valid walking (PVW) steps to reflect walking quantity, pattern and quality of participants. Motivation intensity was measured by summing up scores of each motivating activity. Questionnaire-based online survey collected information about demographic characteristics, lifestyle risk factors and chronic diseases. This study finally included 12 368 individuals in the analysis. Multilevel logistic regression model was used to assess the effect of group and individual motivating measures on walking activity and corresponding associated factors. Results: Age of the study sample was (41.2±8.99) years, and 58.17% (7 194) of them were female. After 100-day intervention, the P10 000, PCW and PVW of all participants were 93.89%±14.42%,92.01%±15.97% and 81.00%±7.45%, respectively. The mean P10 000 and PCW increased with rising group-motivated scores, self-motivated scores and individual-activity scores ( P< 0.001 for all). The mean PVW decreased with both higher group-motivated scores and self-motivated scores (both P< 0.05), and varied little among groups with different level individual-activity scores ( P= 0.525). According to the results from the multilevel model, those who had greater group-motivated scores and self-motivated scores tended to have more likelihood of high-level of P10 000 and PCW. Age, sex, smoking status, education attainment and alcohol drinking were associated with P10 000 and PCW ( P< 0.05 for all). Conclusion: The Motivational Healthy Walking Program had positive effect on promoting healthy walking among occupational population. Group-motivated and self-motivated activities were associated with healthy walking.

Locomotor-respiratory coupling patterns and oxygen consumption during walking above and below preferred stride frequency.

PubMed

O'Halloran, Joseph; Hamill, Joseph; McDermott, William J; Remelius, Jebb G; Van Emmerik, Richard E A

2012-03-01

Locomotor respiratory coupling patterns in humans have been assessed on the basis of the interaction between different physiological and motor subsystems; these interactions have implications for movement economy. A complex and dynamical systems framework may provide more insight than entrainment into the variability and adaptability of these rhythms and their coupling. The purpose of this study was to investigate the relationship between steady state locomotor-respiratory coordination dynamics and oxygen consumption [Formula: see text] of the movement by varying walking stride frequency from preferred. Twelve male participants walked on a treadmill at a self-selected speed. Stride frequency was varied from -20 to +20% of preferred stride frequency (PSF) while respiratory airflow, gas exchange variables, and stride kinematics were recorded. Discrete relative phase and return map techniques were used to evaluate the strength, stability, and variability of both frequency and phase couplings. Analysis of [Formula: see text] during steady-state walking showed a U-shaped response (P = 0.002) with a minimum at PSF and PSF - 10%. Locomotor-respiratory frequency coupling strength was not greater (P = 0.375) at PSF than any other stride frequency condition. The dominant coupling across all conditions was 2:1 with greater occurrences at the lower stride frequencies. Variability in coupling was the greatest during PSF, indicating an exploration of coupling strategies to search for the coupling frequency strategy with the least oxygen consumption. Contrary to the belief that increased strength of frequency coupling would decrease oxygen consumption; these results conclude that it is the increased variability of frequency coupling that results in lower oxygen consumption.

Walking model with no energy cost.

PubMed

Gomes, Mario; Ruina, Andy

2011-03-01

We have numerically found periodic collisionless motions of a walking model consisting of linked rigid objects. Unlike previous designs, this model can walk on level ground at noninfinitesimal speed with zero energy input. The model avoids collisional losses by using an internal mode of oscillation: swaying of the upper body coupled to the legs by springs. Appropriate synchronized internal oscillations set the foot-strike collision to zero velocity. The concept might be of use for energy-efficient robots and may also help to explain aspects of human and animal locomotion efficiency.

Effects of Social Context on Social Interaction and Self-Injurious Behavior in Cornelia de Lange Syndrome

ERIC Educational Resources Information Center

Arron, Kate; Oliver, Chris; Hall, Scott; Sloneem, Jenny; Forman, Debbie; McClintock, Karen

2006-01-01

Cornelia de Lange syndrome is reported to be associated with self-injurious behavior (SIB) and social avoidance. We used analog methodology to examine the effect of manipulating adult social contact on social communicative behaviors and SIB in 16 children with this syndrome. For 9 participants engagement behavior was related to levels of adult…

Self-esteem and other-esteem in college students with borderline and avoidant personality disorder features: An experimental vignette study.

PubMed

Bowles, David P; Armitage, Chris J; Drabble, Jennifer; Meyer, Björn

2013-11-01

An experimental study investigated self-esteem and other-esteem responses to either fully supportive or less supportive interpersonal feedback in college students with avoidant and borderline personality disorder features (APD and BPD respectively). Disturbances in self-esteem and in evaluations of others are central to definitions of both APD and BPD, but the extent to which such interpersonal appraisals are responsive to contextual features, such as evaluative feedback from others, is not yet clear. In theory, we would expect that individuals with pronounced PD features would show more inflexible and more negative self-evaluations and others- evaluations than those without PD features. In this study with 169 undergraduates, APD but not BPD features were associated with other-contingent state self-esteem and other-esteem. A significant interaction indicated that highly avoidant respondents felt particularly negatively about themselves and their close others in situations that conveyed subtle criticism but not in situations signalling unequivocal support. This suggests that their self-esteem and other-esteem, rather than being rigidly negative, are instead highly contingent upon interpersonal feedback. Such context contingency has implications for the trait-like description of diagnostic characteristics within current taxonomies and is in line with contemporary dynamic models of personality structure and process. Copyright © 2013 John Wiley & Sons, Ltd.

Interactive locomotion: Investigation and modeling of physically-paired humans while walking

PubMed Central

Le Goff, Camille G.; Ijspeert, Auke Jan

2017-01-01

In spite of extensive studies on human walking, less research has been conducted on human walking gait adaptation during interaction with another human. In this paper, we study a particular case of interactive locomotion where two humans carry a rigid object together. Experimental data from two persons walking together, one in front of the other, while carrying a stretcher-like object is presented, and the adaptation of their walking gaits and coordination of the foot-fall patterns are analyzed. It is observed that in more than 70% of the experiments the subjects synchronize their walking gaits; it is shown that these walking gaits can be associated to quadrupedal gaits. Moreover, in order to understand the extent by which the passive dynamics can explain this synchronization behaviour, a simple 2D model, made of two-coupled spring-loaded inverted pendulums, is developed, and a comparison between the experiments and simulations with this model is presented, showing that with this simple model we are able to reproduce some aspects of human walking behaviour when paired with another human. PMID:28877161

An Ambulatory System for Gait Monitoring Based on Wireless Sensorized Insoles

PubMed Central

González, Iván; Fontecha, Jesús; Hervás, Ramón; Bravo, José

2015-01-01

A new gait phase detection system for continuous monitoring based on wireless sensorized insoles is presented. The system can be used in gait analysis mobile applications, and it is designed for real-time demarcation of gait phases. The system employs pressure sensors to assess the force exerted by each foot during walking. A fuzzy rule-based inference algorithm is implemented on a smartphone and used to detect each of the gait phases based on the sensor signals. Additionally, to provide a solution that is insensitive to perturbations caused by non-walking activities, a probabilistic classifier is employed to discriminate walking forward from other low-level activities, such as turning, walking backwards, lateral walking, etc. The combination of these two algorithms constitutes the first approach towards a continuous gait assessment system, by means of the avoidance of non-walking influences. PMID:26184199

Continuity and Evolution: General Donn A. Starry and Doctrinal Change in the U.S. Army, 1974-1982

DTIC Science & Technology

2012-05-17

input from the Army leaders in the field instead of relying on assessments from the Pentagon. The investigation exposed a relative cognitive dissonance ...failed to learn and adapt effectively from constant interaction with the enemy, leading to a self-imposed cognitive isolation from the battlefield.63...realized that the vast majority of his battalion commanders could not, to his satisfaction , articulate their fighting plans during the terrain walk

Human motion behavior while interacting with an industrial robot.

PubMed

Bortot, Dino; Ding, Hao; Antonopolous, Alexandros; Bengler, Klaus

2012-01-01

Human workers and industrial robots both have specific strengths within industrial production. Advantageously they complement each other perfectly, which leads to the development of human-robot interaction (HRI) applications. Bringing humans and robots together in the same workspace may lead to potential collisions. The avoidance of such is a central safety requirement. It can be realized with sundry sensor systems, all of them decelerating the robot when the distance to the human decreases alarmingly and applying the emergency stop, when the distance becomes too small. As a consequence, the efficiency of the overall systems suffers, because the robot has high idle times. Optimized path planning algorithms have to be developed to avoid that. The following study investigates human motion behavior in the proximity of an industrial robot. Three different kinds of encounters between the two entities under three robot speed levels are prompted. A motion tracking system is used to capture the motions. Results show, that humans keep an average distance of about 0,5m to the robot, when the encounter occurs. Approximation of the workbenches is influenced by the robot in ten of 15 cases. Furthermore, an increase of participants' walking velocity with higher robot velocities is observed.

Time trends in leisure time physical activity and physical fitness in the elderly: five-year follow-up of the Spanish National Health Survey (2006-2011).

PubMed

Casado-Pérez, Carmen; Hernández-Barrera, Valentín; Jiménez-García, Rodrigo; Fernández-de-las-Peñas, Cesar; Carrasco-Garrido, Pilar; López-de-Andrés, Ana; Jimenez-Trujillo, Ma Isabel; Palacios-Ceña, Domingo

2015-04-01

To estimate the trends in the practice of leisure time physical activity, walking up 10 steps, and walking for 1h, during the years 2006-2011, in elderly Spanish people. Observational study, retrospective analysis of Spanish National Health Surveys. We analysed data collected from the Spanish National Health Surveys conducted in 2006 (n=30,072) and 2011 (n=21,007), through self-reported information. The number of subjects aged ≥65 years included in the current study was n=5756 in 2006 (19.14%) and n=4617 in 2011 (21.97%). We included responses from adults aged 65 years and older. The main variables included leisure-time physical activity, walking up 10 steps, and walking for 1h. We analysed socio-demographic characteristics, individuals' self-rated health status, lifestyle habits, co-morbid conditions and disability using multivariable logistic regression models. The total number of subjects was 10,373 (6076 women, 4297 men). The probability of self-reported capacity was significantly higher in 2006 than in 2011 for leisure-time physical activity, walking up 10 steps, and walking for 1h for both sexes (women: OR 2.20, 95%IC 1.91-5.55; OR 2.50, 95%IC 1.99-3.14; OR 1.04, 95%IC 1.01-1.07; men: OR 2.20, 95%IC 1.91-2.55; OR 2.01, 95%IC 1.40-2.89; OR 1.05, 95%IC 1.0-1.1) respectively. Both sexes were associated with a significantly lower probability of performing leisure-time physical activity, walking up 10 steps, and walking for 1h. Additionally, those over 80 years of age, on average, showed a poor or very poor perception of their health and presented with some type of disability. A decrease in the proportion of respondents who self-reported undertaking leisure-time physical activity, walking up 10 steps, and walking for 1h was observed in the Spanish population of over 65 years between 2006 and 2011. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Why Adolescents Fight: A Qualitative Study of Youth Perspectives on Fighting and Its Prevention

PubMed Central

Shetgiri, Rashmi; Lee, Simon C.; Tillitski, John; Wilson, Connie; Flores, Glenn

2014-01-01

Objective Identify risk factors for fighting, factors that protect against fighting, and strategies to prevent fighting, among adolescents who fight and those uninvolved in fighting. Methods Focus groups were conducted with middle and high-school students, stratified by fighting (fighter/non-fighter) status, race/ethnicity, and gender. Groups were audiotaped, transcribed, and analyzed using margin coding and thematic content analysis. Themes were independently identified by three coders; disagreements were resolved by consensus. Results The 65 participants in the 12 focus groups were 13–17 years old. Reasons for fighting include self-defense, to gain/maintain respect, or due to anger; having goals for the future is protective. Non-fighters state that their parents condone fighting only when physically attacked, and teach adolescents strategies to avoid fighting. Fighters describe mixed messages from parents, and pro-fighting attitudes and modeling of aggressive behavior among some family members. Non-fighters avoid fighting by ignoring insults or walking away. Fighters feel unable to use nonviolent conflict-resolution methods effectively. Peers may instigate or encourage fights. Suggested prevention strategies include anger-management and conflict-resolution programs, relationships with caring adults, and physicians counseling youth about the consequences of fighting. Conclusions Non-fighters use various strategies to avoid fighting, whereas fighters are aware of few alternatives to fighting. Conflicting parental messages about fighting may enhance the likelihood of fighting. Physicians can counsel youth about the negative consequences of fighting. Interventions that teach anger management and conflict resolution, promote adolescent self-efficacy for using non-violent strategies, and address parental attitudes about fighting may be effective in preventing fighting. PMID:25528128

Predicting home and community walking activity in people with stroke.

PubMed

Fulk, George D; Reynolds, Chelsea; Mondal, Sumona; Deutsch, Judith E

2010-10-01

To determine the ability of the 6-minute walk test (6MWT) and other commonly used clinical outcome measures to predict home and community walking activity in high-functioning people with stroke. Cross-sectional. Outpatient physical therapy clinic. Participants (N=32) with chronic stroke (n=19; >6mo poststroke) with self-selected gait speed (GS) faster than .40m/s and age-matched healthy participants (n=13). Not applicable. 6MWT, self-selected GS, Berg Balance Scale (BBS), lower extremity motor section of the Fugl-Meyer Assessment, and Stroke Impact Scale. Dependent variable: average steps taken per day during a 7-day period, measured using an accelerometer. 6MWT, self-selected GS, and BBS were moderately related to home and community walking activity. The 6MWT was the only predictor of average steps taken per day; it explained 46% of the variance in steps per day. The 6MWT is a useful outcome measure in higher functioning people with stroke to guide intervention and assess community walking activity. Copyright © 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Effects of a self-managed home-based walking intervention on psychosocial health outcomes for breast cancer patients receiving chemotherapy: a randomised controlled trial.

PubMed

Gokal, Kajal; Wallis, Deborah; Ahmed, Samreen; Boiangiu, Ion; Kancherla, Kiran; Munir, Fehmidah

2016-03-01

This study evaluated the effectiveness of a self-managed home-based moderate intensity walking intervention on psychosocial health outcomes among breast cancer patients undergoing chemotherapy. The randomised controlled trial compared a self-managed, home-based walking intervention to usual care alone among breast cancer patients receiving chemotherapy. Outcome measures included changes in self-report measures of anxiety, depression, fatigue, self-esteem, mood and physical activity. Fifty participants were randomised to either the intervention group (n = 25), who received 12 weeks of moderate intensity walking, or the control group (n = 25) mid-way through chemotherapy. Participants in the intervention group were provided with a pedometer and were asked to set goals and keep weekly diaries outlining the duration, intensity and exertion of their walking. Levels of psychosocial functioning and physical activity were assessed pre- and post-intervention in both groups. The intervention had positive effects on fatigue (F = 5.77, p = 0.02), self-esteem (F = 8.93, p ≤ 0.001), mood (F = 4.73, p = 0.03) and levels of physical activity (x (2) = 17.15, p = 0.0011) but not anxiety (F = 0.90, p = 0.35) and depression (F = 0.26, p = 0.60) as assessed using the HADS. We found an 80% adherence rate to completing the 12-week intervention and recording weekly logs. This self-managed, home-based intervention was beneficial for improving psychosocial well-being and levels of physical activity among breast cancer patients treated with chemotherapy. Current Controlled Trials ISRCTN50709297.

It's how you get there: walking down a virtual alley activates premotor and parietal areas.

PubMed

Wagner, Johanna; Solis-Escalante, Teodoro; Scherer, Reinhold; Neuper, Christa; Müller-Putz, Gernot

2014-01-01

Voluntary drive is crucial for motor learning, therefore we are interested in the role that motor planning plays in gait movements. In this study we examined the impact of an interactive Virtual Environment (VE) feedback task on the EEG patterns during robot assisted walking. We compared walking in the VE modality to two control conditions: walking with a visual attention paradigm, in which visual stimuli were unrelated to the motor task; and walking with mirror feedback, in which participants observed their own movements. Eleven healthy participants were considered. Application of independent component analysis to the EEG revealed three independent component clusters in premotor and parietal areas showing increased activity during walking with the adaptive VE training paradigm compared to the control conditions. During the interactive VE walking task spectral power in frequency ranges 8-12, 15-20, and 23-40 Hz was significantly (p ≤ 0.05) decreased. This power decrease is interpreted as a correlate of an active cortical area. Furthermore activity in the premotor cortex revealed gait cycle related modulations significantly different (p ≤ 0.05) from baseline in the frequency range 23-40 Hz during walking. These modulations were significantly (p ≤ 0.05) reduced depending on gait cycle phases in the interactive VE walking task compared to the control conditions. We demonstrate that premotor and parietal areas show increased activity during walking with the adaptive VE training paradigm, when compared to walking with mirror- and movement unrelated feedback. Previous research has related a premotor-parietal network to motor planning and motor intention. We argue that movement related interactive feedback enhances motor planning and motor intention. We hypothesize that this might improve gait recovery during rehabilitation.

Obesity Moderates the Effects of Motivational Interviewing Treatment Outcomes in Fibromyalgia.

PubMed

Kaleth, Anthony S; Slaven, James E; Ang, Dennis C

2018-01-01

Obesity is a common comorbid condition among patients with fibromyalgia (FM). Our objective was to assess if obesity moderates the treatment benefits of exercise-based motivational interviewing (MI) for FM. This is a secondary data analysis of a completed clinical trial of 198 FM patients who were randomized to receive either MI or attention control (AC). Using body mass index (BMI) to divide participants into obese (BMI≥30 kg/m) and nonobese (BMI<30 kg m) groups, mixed linear models were used to determine interaction between treatment arms and obesity status with regards to the primary outcome of global FM symptom severity (Fibromyalgia Impact Questionnaire, FIQ). Secondary measures included pain intensity (Brief Pain Inventory), 6-Minute Walk Test, and self-reported physical activity (Community Health Activities Model Program for Seniors). Of the 198 participants, 91 (46%) were nonobese and 107 (54%) were obese. On global FM symptom severity (FIQ), the interaction between treatment arms and obesity status was significant (P=0.02). In the nonobese group, MI was associated with a greater improvement in FIQ than AC. In the obese group, MI participants reported less improvement in FIQ compared with AC. The interaction analysis was also significant for Brief Pain Inventory pain intensity (P=0.01), but not for the walk test and self-reported physical activity. This is the first study to show that obesity negatively affects the treatment efficacy of MI in patients with FM. Our findings suggest that exercise-based MI may be more effective if initiated after weight loss is achieved.

Physical activity in older adults in a combined functional circuit and walking program.

PubMed

Gallagher, Nancy Ambrose; Clarke, Philippa; Carr, Emily

Our study examined the impact of a 16-week functional circuit/walking program on physical activity (PA) in older adults in independent-living facilities. Exploratory goals included examination of associations among self-efficacy, neighborhood and mobility. Participants (N = 13) were female (M = 77.8, SD = 7.44, range = 65-85 years). One third were African-American; the remainder Caucasian; 1/3 used assistive devices. PA increased from 70 min/week (SD = 35.51) at baseline to 81.31 min/week (SD = 34.21) at 16 weeks. PA was associated with self-efficacy for overcoming neighborhood and facility barriers to walking at all measurement points (baseline r = .73, p < .05 and r = .68, p < .05, respectively). At eight weeks, PA was associated with self-efficacy for walking duration (r = .58, p < .05), self-efficacy for individual (r = .66, p < .05), facility (r = .58, p < .05) and neighborhood (r = .70, p < .05) barriers. At sixteen weeks, physical activity was associated with balance confidence (r = .72, p < .05), and self-efficacy for individual (r = .76, p < .05), facility (r = .71, p < .05), and neighborhood (r = .80, p < .01) barriers. Functional circuit/walking interventions can increase PA in older adults. Further examination of self-efficacy, mobility, neighborhoods and PA is needed. Copyright © 2016 Elsevier Inc. All rights reserved.

Frontal joint dynamics when initiating stair ascent from a walk versus a stand.

PubMed

Vallabhajosula, Srikant; Yentes, Jennifer M; Stergiou, Nicholas

2012-02-02

Ascending stairs is a challenging activity of daily living for many populations. Frontal plane joint dynamics are critical to understand the mechanisms involved in stair ascension as they contribute to both propulsion and medio-lateral stability. However, previous research is limited to understanding these dynamics while initiating stair ascent from a stand. We investigated if initiating stair ascent from a walk with a comfortable self-selected speed could affect the frontal plane lower-extremity joint moments and powers as compared to initiating stair ascent from a stand and if this difference would exist at consecutive ipsilateral steps on the stairs. Kinematics data using a 3-D motion capture system and kinetics data using two force platforms on the first and third stair treads were recorded simultaneously as ten healthy young adults ascended a custom-built staircase. Data were collected from two starting conditions of stair ascent, from a walk (speed: 1.42 ± 0.21 m/s) and from a stand. Results showed that subjects generated greater peak knee abductor moment and greater peak hip abductor moment when initiating stair ascent from a walk. Greater peak joint moments and powers at all joints were also seen while ascending the second ipsilateral step. Particularly, greater peak hip abductor moment was needed to avoid contact of the contralateral limb with the intermediate step by counteracting the pelvic drop on the contralateral side. This could be important for therapists using stair climbing as a testing/training tool to evaluate hip strength in individuals with documented frontal plane abnormalities (i.e. knee and hip osteoarthritis, ACL injury). Copyright © 2011 Elsevier Ltd. All rights reserved.

Self-compassion, pain, and breaking a social contract.

PubMed

Purdie, Fiona; Morley, Stephen

2015-11-01

Self-compassion is the ability to respond to one's failures, shortcomings, and difficulties with kindness and openness rather than criticism. This study, which might be regarded as a proof-of-concept study, aimed to establish whether self-compassion is associated with expected emotional responses and the likelihood of responding with problem solving, support seeking, distraction, avoidance, rumination, or catastrophizing to unpleasant self-relevant events occurring in 3 social contexts. Sixty chronic pain patients were presented with 6 vignettes describing scenes in which the principal actor transgressed a social contract with negative interpersonal consequences. Vignettes represented 2 dimensions: (1) whether pain or a nonpain factor interrupted the fulfillment of the contract and (2) variation in the social setting (work, peer, and family). The Self-Compassion Scale was the covariate in the analysis. Higher levels of self-compassion were associated with significantly lower negative affect and lower reported likelihood of avoidance, catastrophizing, and rumination. Self-compassion did not interact with pain vs nonpain factor. Work-related vignettes were rated as more emotional and more likely to be associated with avoidance, catastrophizing, and rumination and less likelihood of problem solving. The findings suggest that self-compassion warrants further investigation in the chronic pain population both regarding the extent of its influence as a trait and in terms of the potential to enhance chronic pain patients' ability to be self-compassionate, with a view to its therapeutic utility in enhancing psychological well-being and adjustment. Limitations regarding the possible criterion contamination and the generalizability of vignette studies are discussed.

A walking prescription for statically-stable walkers based on walker/terrain interaction

NASA Technical Reports Server (NTRS)

Nagy, Peter V.; Whittaker, William L.; Desa, Subhas

1992-01-01

The walker/terrain interaction phenomena for the control of a statically stable walking machine are described. The algorithms, measures, and knowledge of walker/terrain interaction phenomena are then combined to form a prescription for how to walk on general terrain. This prescription consists of two parts: nominal control and reactive control. The function of nominal control is the evaluation and execution of planned motions, based on predicted foot force redistributions, to achieve reliable locomotion. The function of reactive control is the monitoring of walker/terrain interaction in real-time to detect anomalous conditions and then respond with the appropriate reflexive actions. Simulations and experiments have been used to test and verify various aspects of the walking prescription.

Pedometer Ownership, Motivation, and Walking: Do People Walk the Talk?

ERIC Educational Resources Information Center

Berry, Tanya R.; Fraser, Shawn N.; Spence, John C.; Bengoechea, Enrique Garcia

2007-01-01

The purpose of this research was to examine whether pedometer ownership and source of pedometer (i.e., self-purchased, a gift, a promotion) was related to physical activity self-efficacy and outcome expectations in relation to physical activity. Further, the authors examined whether there was a relationship between pedometer ownership and…

Pedometer Readings and Self-Reported Walking Distances in a Rural Hutterite Population

ERIC Educational Resources Information Center

Samra, Haifa Abou; Beare, Tianna; Specker, Bonny

2008-01-01

Purpose: This study assessed the accuracy with which a rural population reported daily walking distances using a 7-day activity recall questionnaire obtained quarterly compared to pedometer readings. Methods: Study participants were 48 Hutterite men and women aged 11-66 years. Findings: Pedometer-miles quartiles were associated with self-reported…

Older People's Experiences of Mobility and Mood in an Urban Environment: A Mixed Methods Approach Using Electroencephalography (EEG) and Interviews.

PubMed

Tilley, Sara; Neale, Chris; Patuano, Agnès; Cinderby, Steve

2017-02-04

There are concerns about mental wellbeing in later life in older people as the global population becomes older and more urbanised. Mobility in the built environment has a role to play in improving quality of life and wellbeing, as it facilitates independence and social interaction. Recent studies using neuroimaging methods in environmental psychology research have shown that different types of urban environments may be associated with distinctive patterns of brain activity, suggesting that we interact differently with varying environments. This paper reports on research that explores older people's responses to urban places and their mobility in and around the built environment. The project aim was to understand how older people experience different urban environments using a mixed methods approach including electroencephalography (EEG), self-reported measures, and interview results. We found that older participants experience changing levels of "excitement", "engagement" and "frustration" (as interpreted by proprietary EEG software) whilst walking between a busy built urban environment and an urban green space environment. These changes were further reflected in the qualitative themes that emerged from transcribed interviews undertaken one week post-walk. There has been no research to date that has directly assessed neural responses to an urban environment combined with qualitative interview analysis. A synergy of methods offers a deeper understanding of the changing moods of older people across time whilst walking in city settings.

Computer simulation of trails on a square lattice. II. Finite temperatures and the collapse transition

NASA Astrophysics Data System (ADS)

Meirovitch, H.; Lim, H. A.

1989-04-01

We study by the scanning simulation method trails on a square lattice at finite temperatures. This method constitutes a very efficient tool since it enables one to obtain results at many temperatures from a single sample generated at any given temperature. The tricritical temperature at which the collapse transition occurs is -ɛ/kBTt=1.086+/-0.002. The tricritical exponents of the trail shape and its free energy are, respectively, νt=0.569+/-0.008 and γt=1.133+/-0.024 (95% confidence limits). They are equal within the error bars to the exact values of self-attracting self-avoiding walks (SAW's). However, the crossover exponent φt=0.807+/-0.005 is significantly larger than the exact value 0.423 of SAW's. We also carry out a detailed scaling analysis near Tt and demonstrate that the various properties scale as predicted by theory. At sufficiently low temperatures (T<=Tt) the persistence length appears to be ~1.

Increasing walking among older people: A test of behaviour change techniques using factorial randomised N-of-1 trials

PubMed Central

Nyman, Samuel R.; Goodwin, Kelly; Kwasnicka, Dominika; Callaway, Andrew

2016-01-01

Objective: Evaluations of techniques to promote physical activity usually adopt a randomised controlled trial (RCT). Such designs inform how a technique performs on average but cannot be used for treatment of individuals. Our objective was to conduct the first N-of-1 RCTs of behaviour change techniques with older people and test the effectiveness of the techniques for increasing walking within individuals. Design: Eight adults aged 60–87 were randomised to a 2 (goal-setting vs. active control) × 2 (self-monitoring vs. active control) factorial RCT over 62 days. The time series data were analysed for each single case using linear regressions. Main outcome measures: Walking was objectively measured using pedometers. Results: Compared to control days, goal-setting increased walking in 4 out of 8 individuals and self-monitoring increased walking in 7 out of 8 individuals. While the probability for self-monitoring to be effective in 7 out of 8 participants was beyond chance (p = .03), no intervention effect was significant for individual participants. Two participants had a significant but small linear decrease in walking over time. Conclusion: We demonstrate the utility of N-of-1 trials for advancing scientific enquiry of behaviour change and in practice for increasing older people’s physical activity. PMID:26387689

Change in physical mobility over 10 years in post-polio syndrome.

PubMed

Bickerstaffe, A; Beelen, A; Nollet, F

2015-03-01

Post-polio syndrome is characterised by progressive muscle weakness and other symptoms which can limit physical mobility. We assessed the rate of decline in mobility over 10 years in relation to strength decline; and investigated potential predictors for the rate of decline of walking capacity, a measure of mobility, in 48 patients with post-polio syndrome and proven quadriceps dysfunction at baseline. Average walking capacity and self-reported physical mobility declined over 10 years, by 6 and 14%, respectively. Concomitantly people lost an average of 15% of isometric quadriceps strength. Significantly more people used walking aids offering greater support at follow-up. Notably, there was much individual variation, with 18% of participants losing a substantial amount of walking capacity (27% decline) and concomitant self-reported physical mobility (38% decline). Loss of quadriceps strength only explained a small proportion of the variance of the decline in walking capacity (R = 11%) and the rate of decline could not be predicted from baseline values for strength, walking capacity, self-reported physical mobility or basic demographics. The individual variability, yet lack of predictive factors, underscores the need for personally tailored care based on actual functional decline in patients with post-polio syndrome. Copyright © 2014. Published by Elsevier B.V.

Testing self-regulation interventions to increase walking using factorial randomized N-of-1 trials.

PubMed

Sniehotta, Falko F; Presseau, Justin; Hobbs, Nicola; Araújo-Soares, Vera

2012-11-01

To investigate the suitability of N-of-1 randomized controlled trials (RCTs) as a means of testing the effectiveness of behavior change techniques based on self-regulation theory (goal setting and self-monitoring) for promoting walking in healthy adult volunteers. A series of N-of-1 RCTs in 10 normal and overweight adults ages 19-67 (M = 36.9 years). We randomly allocated 60 days within each individual to text message-prompted daily goal-setting and/or self-monitoring interventions in accordance with a 2 (step-count goal prompt vs. alternative goal prompt) × 2 (self-monitoring: open vs. blinded Omron-HJ-113-E pedometer) factorial design. Aggregated data were analyzed using random intercept multilevel models. Single cases were analyzed individually. The primary outcome was daily pedometer step counts over 60 days. Single-case analyses showed that 4 participants significantly increased walking: 2 on self-monitoring days and 2 on goal-setting days, compared with control days. Six participants did not benefit from the interventions. In aggregated analyses, mean step counts were higher on goal-setting days (8,499.9 vs. 7,956.3) and on self-monitoring days (8,630.3 vs. 7,825.9). Multilevel analyses showed a significant effect of the self-monitoring condition (p = .01), the goal-setting condition approached significance (p = .08), and there was a small linear increase in walking over time (p = .03). N-of-1 randomized trials are a suitable means to test behavioral interventions in individual participants.

Dark matter self-interactions from a general spin-0 mediator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Wild, Sebastian, E-mail: felix.kahlhoefer@desy.de, E-mail: kai.schmidt-hoberg@desy.de, E-mail: sebastian.wild@desy.de

2017-08-01

Dark matter particles interacting via the exchange of very light spin-0 mediators can have large self-interaction rates and obtain their relic abundance from thermal freeze-out. At the same time, these models face strong bounds from direct and indirect probes of dark matter as well as a number of constraints on the properties of the mediator. We investigate whether these constraints can be consistent with having observable effects from dark matter self-interactions in astrophysical systems. For the case of a mediator with purely scalar couplings we point out the highly relevant impact of low-threshold direct detection experiments like CRESST-II, which essentiallymore » rule out the simplest realization of this model. These constraints can be significantly relaxed if the mediator has CP-violating couplings, but then the model faces strong constraints from CMB measurements, which can only be avoided in special regions of parameter space.« less

Air Pollution Exposure in Relation to the Commute to School: A Bradford UK Case Study

PubMed Central

Dirks, Kim N.; Wang, Judith Y. T.; Khan, Amirul; Rushton, Christopher

2016-01-01

Walking School Buses (WSBs) provide a safe alternative to being driven to school. Children benefit from the contribution the exercise provides towards their daily exercise target, it gives children practical experience with respect to road safety and it helps to relieve traffic congestion around the entrance to their school. Walking routes are designed largely based in road safety considerations, catchment need and the availability of parent support. However, little attention is given to the air pollution exposure experienced by children during their journey to school, despite the commuting microenvironment being an important contributor to a child’s daily air pollution exposure. This study aims to quantify the air pollution exposure experienced by children walking to school and those being driven by car. A school was chosen in Bradford, UK. Three adult participants carried out the journey to and from school, each carrying a P-Trak ultrafine particle (UFP) count monitor. One participant travelled the journey to school by car while the other two walked, each on opposite sides of the road for the majority of the journey. Data collection was carried out over a period of two weeks, for a total of five journeys to school in the morning and five on the way home at the end of the school day. Results of the study suggest that car commuters experience lower levels of air pollution dose due to lower exposure and reduced commute times. The largest reductions in exposure for pedestrians can be achieved by avoiding close proximity to traffic queuing up at intersections, and, where possible, walking on the side of the road opposite the traffic, especially during the morning commuting period. Major intersections should also be avoided as they were associated with peak exposures. Steps to ensure that the phasing of lights is optimised to minimise pedestrian waiting time would also help reduce exposure. If possible, busy roads should be avoided altogether. By the careful design of WSB routes, taking into account air pollution, children will be able to experience the benefits that walking to school brings while minimizing their air pollution exposure during their commute to and from school. PMID:27801878

Air Pollution Exposure in Relation to the Commute to School: A Bradford UK Case Study.

PubMed

Dirks, Kim N; Wang, Judith Y T; Khan, Amirul; Rushton, Christopher

2016-10-29

Walking School Buses (WSBs) provide a safe alternative to being driven to school. Children benefit from the contribution the exercise provides towards their daily exercise target, it gives children practical experience with respect to road safety and it helps to relieve traffic congestion around the entrance to their school. Walking routes are designed largely based in road safety considerations, catchment need and the availability of parent support. However, little attention is given to the air pollution exposure experienced by children during their journey to school, despite the commuting microenvironment being an important contributor to a child's daily air pollution exposure. This study aims to quantify the air pollution exposure experienced by children walking to school and those being driven by car. A school was chosen in Bradford, UK. Three adult participants carried out the journey to and from school, each carrying a P-Trak ultrafine particle (UFP) count monitor. One participant travelled the journey to school by car while the other two walked, each on opposite sides of the road for the majority of the journey. Data collection was carried out over a period of two weeks, for a total of five journeys to school in the morning and five on the way home at the end of the school day. Results of the study suggest that car commuters experience lower levels of air pollution dose due to lower exposure and reduced commute times. The largest reductions in exposure for pedestrians can be achieved by avoiding close proximity to traffic queuing up at intersections, and, where possible, walking on the side of the road opposite the traffic, especially during the morning commuting period. Major intersections should also be avoided as they were associated with peak exposures. Steps to ensure that the phasing of lights is optimised to minimise pedestrian waiting time would also help reduce exposure. If possible, busy roads should be avoided altogether. By the careful design of WSB routes, taking into account air pollution, children will be able to experience the benefits that walking to school brings while minimizing their air pollution exposure during their commute to and from school.

You Can't See the Real Me: Attachment Avoidance, Self-Verification, and Self-Concept Clarity.

PubMed

Emery, Lydia F; Gardner, Wendi L; Carswell, Kathleen L; Finkel, Eli J

2018-03-01

Attachment shapes people's experiences in their close relationships and their self-views. Although attachment avoidance and anxiety both undermine relationships, past research has primarily emphasized detrimental effects of anxiety on the self-concept. However, as partners can help people maintain stable self-views, avoidant individuals' negative views of others might place them at risk for self-concept confusion. We hypothesized that avoidance would predict lower self-concept clarity and that less self-verification from partners would mediate this association. Attachment avoidance was associated with lower self-concept clarity (Studies 1-5), an effect that was mediated by low self-verification (Studies 2-3). The association between avoidance and self-verification was mediated by less self-disclosure and less trust in partner feedback (Study 4). Longitudinally, avoidance predicted changes in self-verification, which in turn predicted changes in self-concept clarity (Study 5). Thus, avoidant individuals' reluctance to trust or become too close to others may result in hidden costs to the self-concept.

Evaluation of measurements of propulsion used to reflect changes in walking speed in individuals poststroke.

PubMed

Hsiao, HaoYuan; Zabielski, Thomas M; Palmer, Jacqueline A; Higginson, Jill S; Binder-Macleod, Stuart A

2016-12-08

Recent rehabilitation approaches for individuals poststroke have focused on improving walking speed because it is a reliable measurement that is associated with quality of life. Previous studies have demonstrated that propulsion, the force used to propel the body forward, determines walking speed. However, there are several different ways of measuring propulsion and no studies have identified which measurement best reflects differences in walking speed. The primary purposes of this study were to determine for individuals poststroke, which measurement of propulsion (1) is most closely related to their self-selected walking speeds and (2) best reflects changes in walking speed within a session. Participants (N=43) with chronic poststroke hemiparesis walked at their self-selected and maximal walking speeds on a treadmill. Propulsive impulse, peak propulsive force, and mean propulsive value (propulsive impulse divided by duration) were analyzed. In addition, each participant׳s cadence was calculated. Pearson correlation coefficients were used to determine the relationships between different measurements of propulsion versus walking speed as well as changes in propulsion versus changes in walking speed. Stepwise linear regression was used to determine which measurement of propulsion best predicted walking speed and changes in walking speed. The results showed that all 3 measurements of propulsion were correlated to walking speed, with peak propulsive force showed the strongest correlation. Similarly, when participants increased their walking speeds, changes in peak propulsive forces showed the strongest correlation to changes in walking speed. In addition, multiplying each measurement by cadence improved the correlations. The present study suggests that measuring peak propulsive force and cadence may be most appropriate of the variables studied to characterize propulsion in individuals poststroke. Copyright © 2016 Elsevier Ltd. All rights reserved.

Perceived Neighborhood Environmental Attributes Associated with Walking and Cycling for Transport among Adult Residents of 17 Cities in 12 Countries: The IPEN Study

PubMed Central

Kerr, Jacqueline; Emond, Jennifer A.; Badland, Hannah; Reis, Rodrigo; Sarmiento, Olga; Carlson, Jordan; Sallis, James F.; Cerin, Ester; Cain, Kelli; Conway, Terry; Schofield, Grant; Macfarlane, Duncan J.; Christiansen, Lars B.; Van Dyck, Delfien; Davey, Rachel; Aguinaga-Ontoso, Ines; Salvo, Deborah; Sugiyama, Takemi; Owen, Neville; Mitáš, Josef; Natarajan, Loki

2015-01-01

Introduction Prevalence of walking and cycling for transport is low and varies greatly across countries. Few studies have examined neighborhood perceptions related to walking and cycling for transport in different countries. Therefore, it is challenging to prioritize appropriate built-environment interventions. Objectives The aim of this study was to examine the strength and shape of the relationship between adults’ neighborhood perceptions and walking and cycling for transport across diverse environments. Methods As part of the International Physical activity and Environment Network (IPEN) adult project, self-reported data were taken from 13,745 adults (18–65 years) living in physically and socially diverse neighborhoods in 17 cities across 12 countries. Neighborhood perceptions were measured using the Neighborhood Environment Walkability Scale, and walking and cycling for transport were measured using the International Physical Activity Questionnaire–Long Form. Generalized additive mixed models were used to model walking or cycling for transport during the last seven days with neighborhood perceptions. Interactions by city were explored. Results Walking-for-transport outcomes were significantly associated with perceived residential density, land use mix–access, street connectivity, aesthetics, and safety. Any cycling for transport was significantly related to perceived land use mix–access, street connectivity, infrastructure, aesthetics, safety, and perceived distance to destinations. Between-city differences existed for some attributes in relation to walking or cycling for transport. Conclusions Many perceived environmental attributes supported both cycling and walking; however, highly walkable environments may not support cycling for transport. People appear to walk for transport despite safety concerns. These findings can guide the implementation of global health strategies. Citation Kerr J, Emond JA, Badland H, Reis R, Sarmiento O, Carlson J, Sallis JF, Cerin E, Cain K, Conway T, Schofield G, Macfarlane DJ, Christiansen LB, Van Dyck D, Davey R, Aguinaga-Ontoso I, Salvo D, Sugiyama T, Owen N, Mitáš J, Natarajan L. 2016. Perceived neighborhood environmental attributes associated with walking and cycling for transport among adult residents of 17 cities in 12 countries: the IPEN study. Environ Health Perspect 124:290–298; http://dx.doi.org/10.1289/ehp.1409466 PMID:26186801

An intervention to promote physical activity and self-management in people with stable chronic heart failure The Home-Heart-Walk study: study protocol for a randomized controlled trial

PubMed Central

2011-01-01

Background Chronic heart failure (CHF) is a chronic debilitating condition with economic consequences, mostly because of frequent hospitalisations. Physical activity and adequate self-management capacity are important risk reduction strategies in the management of CHF. The Home-Heart-Walk is a self-monitoring intervention. This model of intervention has adapted the 6-minute walk test as a home-based activity that is self-administered and can be used for monitoring physical functional capacity in people with CHF. The aim of the Home-Heart-Walk program is to promote adherence to physical activity recommendations and improving self-management in people with CHF. Methods/Design A randomised controlled trial is being conducted in English speaking people with CHF in four hospitals in Sydney, Australia. Individuals diagnosed with CHF, in New York Heart Association Functional Class II or III, with a previous admission to hospital for CHF are eligible to participate. Based on a previous CHF study and a loss to follow-up of 10%, 166 participants are required to be able to detect a 12-point difference in the study primary endpoint (SF-36 physical function domain). All enrolled participant receive an information session with a cardiovascular nurse. This information session covers key self-management components of CHF: daily weight; diet (salt reduction); medication adherence; and physical activity. Participants are randomised to either intervention or control group through the study randomisation centre after baseline questionnaires and assessment are completed. For people in the intervention group, the research nurse also explains the weekly Home-Heart-Walk protocol. All participants receive monthly phone calls from a research coordinator for six months, and outcome measures are conducted at one, three and six months. The primary outcome of the trial is the physical functioning domain of quality of life, measured by the physical functioning subscale of the Medical Outcome Study Short Form -36. Secondary outcomes include physical functional capacity measured by the standard six minute walk test, self-management capacity, health related quality of life measured by Medical Outcome Study Short Form -36 and Minnesota Living With Heart Failure Questionnaire, self-efficacy and self-care behaviour. Discussion A self-monitoring intervention that can improve individual's exercise self-efficacy, self-management capacity could have potential significance in improving the management of people with chronic heart failure in community settings. Trial Registration Australian New Zealand Clinical Trial Registry 12609000437268 PMID:21366927

An intervention to promote physical activity and self-management in people with stable chronic heart failure The Home-Heart-Walk study: study protocol for a randomized controlled trial.

PubMed

Du, Hui Y; Newton, Phillip J; Zecchin, Robert; Denniss, Robert; Salamonson, Yenna; Everett, Bronwyn; Currow, David C; Macdonald, Peter S; Davidson, Patricia M

2011-03-02

Chronic heart failure (CHF) is a chronic debilitating condition with economic consequences, mostly because of frequent hospitalisations. Physical activity and adequate self-management capacity are important risk reduction strategies in the management of CHF. The Home-Heart-Walk is a self-monitoring intervention. This model of intervention has adapted the 6-minute walk test as a home-based activity that is self-administered and can be used for monitoring physical functional capacity in people with CHF. The aim of the Home-Heart-Walk program is to promote adherence to physical activity recommendations and improving self-management in people with CHF. A randomised controlled trial is being conducted in English speaking people with CHF in four hospitals in Sydney, Australia. Individuals diagnosed with CHF, in New York Heart Association Functional Class II or III, with a previous admission to hospital for CHF are eligible to participate. Based on a previous CHF study and a loss to follow-up of 10%, 166 participants are required to be able to detect a 12-point difference in the study primary endpoint (SF-36 physical function domain).All enrolled participant receive an information session with a cardiovascular nurse. This information session covers key self-management components of CHF: daily weight; diet (salt reduction); medication adherence; and physical activity. Participants are randomised to either intervention or control group through the study randomisation centre after baseline questionnaires and assessment are completed. For people in the intervention group, the research nurse also explains the weekly Home-Heart-Walk protocol. All participants receive monthly phone calls from a research coordinator for six months, and outcome measures are conducted at one, three and six months. The primary outcome of the trial is the physical functioning domain of quality of life, measured by the physical functioning subscale of the Medical Outcome Study Short Form -36. Secondary outcomes include physical functional capacity measured by the standard six minute walk test, self-management capacity, health related quality of life measured by Medical Outcome Study Short Form -36 and Minnesota Living With Heart Failure Questionnaire, self-efficacy and self-care behaviour. A self-monitoring intervention that can improve individual's exercise self-efficacy, self-management capacity could have potential significance in improving the management of people with chronic heart failure in community settings. Australian New Zealand Clinical Trial Registry 12609000437268.

Gender and autistic traits modulate implicit motor synchrony

PubMed Central

Cheng, Miao; Kato, Masaharu

2017-01-01

Interpersonal motor synchrony during walking or dancing is universally observed across cultures, and this joint movement was modulated by physical and social parameters. However, human interactions are greatly shaped by our unique traits, and self-related factors are surprisingly little studied in the context of interpersonal motor synchrony. In this study, we investigated two such factors known to be highly associated with motor coordination: gender and autistic traits. We employed a real-world task extending our understanding beyond laboratory tasks. Participants of the same gender were paired up to walk and chat in a natural environment. A cover story was introduced so that participants would not know their walking steps were being recorded and instead believed that their location was being tracked by a global positioning system (GPS), so they would ignore the motor recording. We found that the female pairs’ steps were more synchronized than those of the males, and higher autistic tendencies (measured by the autism-spectrum quotient) attenuated synchronous steps. Those who synchronized better had higher impression rating increase for their walking partners (measured by interpersonal judgement scale) than those who synchronized less well. Our results indicated that the participants’ joint movements were shaped by predisposed traits and might share similar mechanism with social functions such as empathy. PMID:28873419

High- compared to low-arched athletes exhibit smaller knee abduction moments in walking and running.

PubMed

Powell, Douglas W; Andrews, Samantha; Stickley, Cris; Williams, D S Blaise

2016-12-01

High- (HA) and low-arched athletes (LA) experience distinct injury patterns. These injuries are the result of the interaction of structure and biomechanics. A suggested mechanism of patellofemoral pain pertains to frontal plane knee moments which may be exaggerated in LA athletes. We hypothesize that LA athletes will exhibit greater peak knee abduction moments than high-arched athletes. Twenty healthy female recreational athletes (10HA and 10LA) performed five over-ground barefoot walking and five barefoot running trials at a self-selected velocity while three-dimensional kinematics and ground reaction forces were recorded. Peak knee abduction moments and time-to-peak knee abduction moments were calculated using Visual 3D. High-arched athletes had smaller peak knee abduction moments compared to low-arched athletes during walking (KAM1: p=0.019; KAM2: p=0.015) and running (p=0.010). No differences were observed in time-to-peak knee abduction moment during walking (KAM1: p=0.360; KAM2: p=0.085) or running (p=0.359). These findings demonstrate that foot type is associated with altered frontal plane knee kinetics which may contribute to patellofemoral pain. Future research should address the efficacy of clinical interventions including orthotics and rehabilitation programs in these athletes. Copyright © 2016 Elsevier B.V. All rights reserved.

Self-Efficacy, Health Literacy, and Nutrition and Exercise Behaviors in a Low-Income, Hispanic Population.

PubMed

Guntzviller, Lisa M; King, Andy J; Jensen, Jakob D; Davis, LaShara A

2017-04-01

Public health goals have emphasized healthy nutrition and exercise behaviors, especially in underserved populations. According to social cognitive theory (SCT), self-efficacy and capability (e.g., health literacy) may interact to predict preventative behaviors. We surveyed 100 low-income, native Spanish-speakers living in the United States who were low in English proficiency and predominantly of Mexican heritage. Participants reported their nutritional and exercise self-efficacy, Spanish health literacy, and nutrition and physical activity behaviors. Consistent with SCT, the interaction of self-efficacy and health literacy significantly predicted fruit and vegetable consumption and weekly exercise, and marginally predicted avoidance of high fat foods. For all three interactions, higher health literacy levels strengthened the positive relationship between self-efficacy and health behaviors. The results offer support for the tenets of SCT and suggest-for low-income, Spanish-speaking adults-that a combination of behavioral confidence and literacy capability are necessary to enact appropriate health behaviors.

Delivering health information about self-medication to older adults: use of touchscreen-equipped notebook computers.

PubMed

Neafsey, P J; Strickler, Z; Shellman, J; Padula, A T

2001-11-01

Preventing Drug Interactions in Active Older Adults is an educational intervention to prevent prescription and over-the-counter (OTC) drug and alcohol interactions in active, community-living older adults. The objectives of the program are to increase older adults' knowledge of potential interactions of prescription medications with OTC drugs and alcohol and to increase their confidence (self-efficacy) about how to avoid such interactions. An interactive multimedia computer software program (Personal Education Program or PEP) was designed for the learning styles and psychomotor skills of older adults. Focus groups of older adults evaluated PEP components in a formative manner during development. The program content dealing with antacids, calcium supplements, and acid reducers was pilot tested with 60 older adults recruited from local senior centers. Participants used the PEP on notebook computers equipped with infrared-sensitive touchscreens. Users of PEP had greater knowledge and self-efficacy scores than controls. Participants indicated a high degree of satisfaction with the PEP and reported their intent to make specific changes in self-medication behaviors.

A commercialized dietary supplement alleviates joint pain in community adults: a double-blind, placebo-controlled community trial

PubMed Central

2013-01-01

Background The purpose of this study was to assess the effect of 8-weeks ingestion of a commercialized joint pain dietary supplement (InstaflexTM Joint Support, Direct Digital, Charlotte, NC) compared to placebo on joint pain, stiffness, and function in adults with self-reported joint pain. InstaflexTM is a joint pain supplement containing glucosamine sulfate, methylsufonlylmethane (MSM), white willow bark extract (15% salicin), ginger root concentrate, boswella serrata extract (65% boswellic acid), turmeric root extract, cayenne, and hyaluronic acid. Methods Subjects included 100 men and women, ages 50-75 years, with a history (>3 months) of joint pain, and were randomized to Instaflex™ or placebo (3 colored gel capsules per day for 8 weeks, double-blind administration). Subjects agreed to avoid the use of non-steroidal anti-inflammatory drugs (NSAID) and all other medications and supplements targeted for joint pain. Primary outcome measures were obtained pre- and post-study and included joint pain severity, stiffness, and function (Western Ontario and McMaster Universities [WOMAC]), and secondary outcome measures included health-related quality of life (Short Form 36 or SF-36), systemic inflammation (serum C-reactive protein and 9 plasma cytokines), and physical function (6-minute walk test). Joint pain symptom severity was assessed bi-weekly using a 12-point Likert visual scale (12-VS). Results Joint pain severity was significantly reduced in Instaflex™ compared to placebo (8-week WOMAC, ↓37% versus ↓16%, respectively, interaction effect P = 0.025), with group differences using the 12-VS emerging by week 4 of the study (interaction effect, P = 0.0125). Improvements in ability to perform daily activities and stiffness scores in Instaflex™ compared to placebo were most evident for the 74% of subjects reporting knee pain (8-week WOMAC function score, ↓39% versus ↓14%, respectively, interaction effect P = 0.027; stiffness score, ↓30% versus ↓12%, respectively, interaction effect P = 0.081). Patterns of change in SF-36, systemic inflammation biomarkers, and the 6-minute walk test did not differ significantly between groups during the 8-week study Conclusions Results from this randomized, double blind, placebo-controlled community trial support the use of the Instaflex™ dietary supplement in alleviating joint pain severity in middle-aged and older adults, with mitigation of difficulty performing daily activities most apparent in subjects with knee pain. Trial registration ClinicalTrials.gov Identifier: NCT01956500 PMID:24274358

Relationship of service members' deployment trauma, PTSD symptoms, and experiential avoidance to postdeployment family reengagement.

PubMed

Brockman, Callie; Snyder, James; Gewirtz, Abigail; Gird, Suzanne R; Quattlebaum, Jamie; Schmidt, Nicole; Pauldine, Michael R; Elish, Katie; Schrepferman, Lynn; Hayes, Charles; Zettle, Robert; DeGarmo, David

2016-02-01

This research examined whether military service members' deployment-related trauma exposure, posttraumatic stress disorder (PTSD) symptoms, and experiential avoidance are associated with their observed levels of positive social engagement, social withdrawal, reactivity-coercion, and distress avoidance during postdeployment family interaction. Self reports of deployment related trauma, postdeployment PTSD symptoms, and experiential avoidance were collected from 184 men who were deployed to the Middle East conflicts, were partnered, and had a child between 4 and 13 years of age. Video samples of parent-child and partner problem solving and conversations about deployment issues were collected, and were rated by trained observers to assess service members' positive engagement, social withdrawal, reactivity-coercion, and distress avoidance, as well as spouse and child negative affect and behavior. Service members' experiential avoidance was reliably associated with less observed positive engagement and more observed withdrawal and distress avoidance after controlling for spouse and child negative affect and behavior during ongoing interaction. Service members' experiential avoidance also diminished significant associations between service members' PTSD symptoms and their observed behavior. The results are discussed in terms of how service members' psychological acceptance promotes family resilience and adaption to the multiple contextual challenges and role transitions associated with military deployment. Implications for parenting and marital interventions are described. (c) 2016 APA, all rights reserved).

Relationship of Service Members’ Deployment Trauma, PTSD Symptoms and Experiential Avoidance to Postdeployment Family Reengagement

PubMed Central

Brockman, Callie; Snyder, James; Gewirtz, Abigail; Gird, Suzanne R.; Quattlebaum, Jamie; Schmidt, Nicole; Pauldine, Michael R.; Elish, Katie; Schrepferman, Lynn; Hayes, Charles; Zettle, Robert; DeGarmo, David

2016-01-01

This research examined whether military service members’ deployment-related trauma exposure, PTSD symptoms and experiential avoidance are associated with their observed levels of positive social engagement, social withdrawal, reactivity-coercion, and distress avoidance during postdeployment family interaction. Self reports of deployment related trauma, postdeployment PTSD symptoms and experiential avoidance were collected from 184 men who were deployed to the Middle East conflicts, were partnered, and had a child between 4 and 13 years of age. Video samples of parent-child and partner problem solving and conversations about deployment issues were collected, and were rated by trained observers to assess service members’ positive engagement, social withdrawal, reactivity-coercion, and distress avoidance, as well as spouse and child negative affect and behavior. Service members’ experiential avoidance was reliably associated with less of observed positive engagement and more observed withdrawal and distress avoidance after controlling for spouse and child negative affect and behavior during ongoing interaction. Service members’ experiential avoidance also diminished significant associations between service members’ PTSD symptoms and their observed behavior. The results are discussed in terms of how service members’ psychological acceptance promotes family resilience and adaption to the multiple contextual challenges and role transitions associated with military deployment. Implications for parenting and marital interventions are described. PMID:26437144

The Back 2 Activity Trial: education and advice versus education and advice plus a structured walking programme for chronic low back pain

PubMed Central

2010-01-01

Background Current evidence supports the use of exercise-based treatment for chronic low back pain that encourages the patient to assume an active role in their recovery. Walking has been shown it to be an acceptable type of exercise with a low risk of injury. However, it is not known whether structured physical activity programmes are any more effective than giving advice to remain active. Methods/Design The proposed study will test the feasibility of using a pedometer-driven walking programme, as an adjunct to a standard education and advice session in participants with chronic low back pain. Fifty adult participants will be recruited via a number of different sources. Baseline outcome measures including self reported function; objective physical activity levels; fear-avoidance beliefs and health-related quality of life will be recorded. Eligible participants will be randomly allocated under strict, double blind conditions to one of two treatments groups. Participants in group A will receive a single education and advice session with a physiotherapist based on the content of the 'Back Book'. Participants in group B will receive the same education and advice session. In addition, they will also receive a graded pedometer-driven walking programme prescribed by the physiotherapist. Follow up outcomes will be recorded by the same researcher, who will remain blinded to group allocation, at eight weeks and six months post randomisation. A qualitative exploration of participants' perception of walking will also be examined by use of focus groups at the end of the intervention. As a feasibility study, treatment effects will be represented by point estimates and confidence intervals. The assessment of participant satisfaction will be tabulated, as will adherence levels and any recorded difficulties or adverse events experienced by the participants or therapists. This information will be used to modify the planned interventions to be used in a larger randomised controlled trial. Discussion This paper describes the rationale and design of a study which will test the feasibility of using a structured, pedometer-driven walking programme in participants with chronic low back pain. Trial Registration [ISRCTN67030896] PMID:20633256

Does self-threat promote social connection? The role of self-esteem and contingencies of self-worth.

PubMed

Park, Lora E; Maner, Jon K

2009-01-01

Six studies examined the social motivations of people with high self-esteem (HSE) and low self-esteem (LSE) following a threat to a domain of contingent self-worth. Whether people desired social contact following self-threat depended on an interaction between an individual's trait self-esteem and contingencies of self-worth. HSE participants who strongly based self-worth on appearance sought to connect with close others following a threat to their physical attractiveness. LSE participants who staked self-worth on appearance wanted to avoid social contact and, instead, preferred a less interpersonally risky way of coping with self-threat (wanting to enhance their physical attractiveness). Implications for theories of self-esteem, motivation, and interpersonal processes are discussed.

Self-Disclosure Avoidance: Why I Am Afraid to Tell You Who I Am.

ERIC Educational Resources Information Center

Rosenfeld, Lawrence B.

1979-01-01

Reports on research to determine relationships between self-disclosure and self-disclosure avoidance. Generally, males avoid self-disclosure in order to maintain control over their relationships; females avoid self-disclosure in order to avoid personal hurt and problems with their interpersonal relationships. (JMF)

Promoting the avoidance of high-calorie snacks. The role of temporal message framing and eating self-efficacy.

PubMed

Churchill, Susan; Good, Anna; Pavey, Louisa

2014-09-01

Message framing outcomes of healthy behaviours as occurring 'every day' vs. 'every year' can influence the temporal proximity and perceived likelihood of these outcomes. However, it is not known how pre-existing beliefs such as confidence in one's ability to perform health-related behaviour interact with such messages. The purpose of this research was to investigate whether eating self-efficacy moderates the effect of temporal framing (day-frame vs. year-frame) on snacking behaviour. Participants (N = 95) completed the short form of the Weight Efficacy Lifestyle Questionnaire (WEL-SF) and read either a day-framed or year-framed message about the health benefits associated with avoiding snacking. Consumption of snacks was reported 7 days later. For those with low levels of eating self-efficacy (WEL-SF score < 4.3 on a 7-point response scale), the year-framed message was associated with lower levels of snacking than the day-framed message. The current research identifies a key role for eating self-efficacy in shaping recipients' responses to temporally framed messages about the health benefits associated with the avoidance of snacking. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ability to walk 1/4 mile predicts subsequent disability, mortality, and health care costs.

PubMed

Hardy, Susan E; Kang, Yihuang; Studenski, Stephanie A; Degenholtz, Howard B

2011-02-01

Mobility, such as walking 1/4 mile, is a valuable but underutilized health indicator among older adults. For mobility to be successfully integrated into clinical practice and health policy, an easily assessed marker that predicts subsequent health outcomes is required. To determine the association between mobility, defined as self-reported ability to walk 1/4 mile, and mortality, functional decline, and health care utilization and costs during the subsequent year. Analysis of longitudinal data from the 2003-2004 Medicare Current Beneficiary Survey, a nationally representative sample of Medicare beneficiaries. Participants comprised 5895 community-dwelling adults aged 65 years or older enrolled in Medicare. Mobility (self-reported ability to walk 1/4 mile), mortality, incident difficulty with activities of daily living (ADLs), total annual health care costs, and hospitalization rates. Among older adults, 28% reported difficulty and 17% inability to walk 1/4 mile at baseline. Compared to those without difficulty and adjusting for demographics, socioeconomic status, chronic conditions, and health behaviors, mortality was greater in those with difficulty [AOR (95% CI): 1.57 (1.10-2.24)] and inability [AOR (CI): 2.73 (1.79-4.15)]. New functional disability also occurred more frequently as self-reported ability to walk 1/4 mile declined (subsequent incident disability among those with no difficulty, difficulty, or inability to walk 1/4 mile at baseline was 11%, 29%, and 47% for instrumental ADLs, and 4%, 14%, and 23% for basic ADLs). Total annual health care costs were $2773 higher (95% CI $1443-4102) in persons with difficulty and $3919 higher (CI $1948-5890) in those who were unable. For each 100 persons, older adults reporting difficulty walking 1/4 mile at baseline experienced an additional 14 hospitalizations (95% CI 8-20), and those who were unable experienced an additional 22 hospitalizations (CI 14-30) during the follow-up period, compared to persons without walking difficulty. Mobility disability, a simple self-report measure, is a powerful predictor of future health, function, and utilization independent of usual health and demographic indicators. Mobility disability may be used to target high-risk patients for care management and preventive interventions.

Is perception of self-motion speed a necessary condition for intercepting a moving target while walking?

PubMed

Morice, Antoine H P; Wallet, Grégory; Montagne, Gilles

2014-04-30

While it has been shown that the Global Optic Flow Rate (GOFR) is used in the control of self-motion speed, this study examined its relevance in the control of interceptive actions while walking. We asked participants to intercept approaching targets by adjusting their walking speed in a virtual environment, and predicted that the influence of the GOFR depended on their interception strategy. Indeed, unlike the Constant Bearing Angle (CBA), the Modified Required Velocity (MRV) strategy relies on the perception of self-displacement speed. On the other hand, the CBA strategy involves specific speed adjustments depending on the curvature of the target's trajectory, whereas the MRV does not. We hypothesized that one strategy is selected among the two depending on the informational content of the environment. We thus manipulated the curvature and display of the target's trajectory, and the relationship between physical walking speed and the GOFR (through eye height manipulations). Our results showed that when the target trajectory was not displayed, walking speed profiles were affected by curvature manipulations. Otherwise, walking speed profiles were less affected by curvature manipulations and were affected by the GOFR manipulations. Taken together, these results show that the use of the GOFR for intercepting a moving target while walking depends on the informational content of the environment. Finally we discuss the complementary roles of these two perceptual-motor strategies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Energy Expenditure in Vinyasa Yoga Versus Walking.

PubMed

Sherman, Sally A; Rogers, Renee J; Davis, Kelliann K; Minster, Ryan L; Creasy, Seth A; Mullarkey, Nicole C; O'Dell, Matthew; Donahue, Patrick; Jakicic, John M

2017-08-01

Whether the energy cost of vinyasa yoga meets the criteria for moderate-to-vigorous physical activity has not been established. To compare energy expenditure during acute bouts of vinyasa yoga and 2 walking protocols. Participants (20 males, 18 females) performed 60-minute sessions of vinyasa yoga (YOGA), treadmill walking at a self-selected brisk pace (SELF), and treadmill walking at a pace that matched the heart rate of the YOGA session (HR-Match). Energy expenditure was assessed via indirect calorimetry. Energy expenditure was significantly lower in YOGA compared with HR-Match (difference = 79.5 ± 44.3 kcal; P < .001) and SELF (difference = 51.7 ± 62.6 kcal; P < .001), but not in SELF compared with HR-Match (difference = 27.8 ± 72.6 kcal; P = .054). A similar pattern was observed for metabolic equivalents (HR-Match = 4.7 ± 0.8, SELF = 4.4 ± 0.7, YOGA = 3.6 ± 0.6; P < .001). Analyses using only the initial 45 minutes from each of the sessions, which excluded the restorative component of YOGA, showed energy expenditure was significantly lower in YOGA compared with HR-Match (difference = 68.0 ± 40.1 kcal; P < .001) but not compared with SELF (difference = 15.1 ± 48.7 kcal; P = .189). YOGA meets the criteria for moderate-intensity physical activity. Thus, YOGA may be a viable form of physical activity to achieve public health guidelines and to elicit health benefits.

Greater avoidance behavior in individuals with posttraumatic stress disorder symptoms

PubMed Central

Sheynin, Jony; Shind, Christine; Radell, Milen; Ebanks-Williams, Yasheca; Gilbertson, Mark W.; Beck, Kevin D.; Myers, Catherine E.

2017-01-01

While avoidance is a core symptom of PTSD, little is known about whether individuals with PTSD show a general cognitive bias to acquire and express avoidance, in situations not related to trauma or fear. Here, we used a computer-based task to examine operant acquisition and extinction of avoidance in participants with and without severe self -reported PTSD symptoms. A total of 119 participants (77 male, 42 female; 74 veteran, 45 civilian) with symptoms (PTSS; n=63) or with few/no symptoms (noPTSS; n=56) performed a task, in which they controlled a spaceship and could shoot a target to gain points or hide in “safe areas” to escape or avoid on-screen aversive events. Results show that participants with PTSS exhibited more avoidance across trials than no PTSS participants, particularly due to more avoidance behavior in PTSS females compared to noPTSS females. Avoidance behavior decreased across extinction trials but interactions with PTSS and gender fell short of significance. Overall, PTSD symptoms were associated with propensity to acquire and express avoidance behavior, in both civilians and veterans, and even in a cognitive task that does not explicitly involve trauma or fear. This effect was more pronounced in females, highlighting the role of gender differences in PTSD symptomatology. Importantly, this study also demonstrates the potential of an objective assessment of avoidance behavior, which could be used to supplement the common but limited self-report tools. PMID:28322068

Greater avoidance behavior in individuals with posttraumatic stress disorder symptoms.

PubMed

Sheynin, Jony; Shind, Christine; Radell, Milen; Ebanks-Williams, Yasheca; Gilbertson, Mark W; Beck, Kevin D; Myers, Catherine E

2017-05-01

While avoidance is a core symptom of PTSD, little is known about whether individuals with PTSD show a general cognitive bias to acquire and express avoidance, in situations not related to trauma or fear. Here, we used a computer-based task to examine operant acquisition and extinction of avoidance in participants with and without severe self-reported PTSD symptoms. A total of 119 participants (77 male, 42 female; 74 veteran, 45 civilian) with symptoms (PTSS; n = 63) or with few/no symptoms (noPTSS; n = 56) performed a task, in which they controlled a spaceship and could shoot a target to gain points or hide in "safe areas" to escape or avoid on-screen aversive events. Results show that participants with PTSS exhibited more avoidance across trials than noPTSS participants, particularly due to more avoidance behavior in PTSS females compared to noPTSS females. Avoidance behavior decreased across extinction trials but interactions with PTSS and gender fell short of significance. Overall, PTSD symptoms were associated with propensity to acquire and express avoidance behavior, in both civilians and veterans, and even in a cognitive task that does not explicitly involve trauma or fear. This effect was more pronounced in females, highlighting the role of gender differences in PTSD symptomatology. Importantly, this study also demonstrates the potential of an objective assessment of avoidance behavior, which could be used to supplement the common but limited self-report tools.

Memory matters: influence from a cognitive map on animal space use.

PubMed

Gautestad, Arild O

2011-10-21

A vertebrate individual's cognitive map provides a capacity for site fidelity and long-distance returns to favorable patches. Fractal-geometrical analysis of individual space use based on collection of telemetry fixes makes it possible to verify the influence of a cognitive map on the spatial scatter of habitat use and also to what extent space use has been of a scale-specific versus a scale-free kind. This approach rests on a statistical mechanical level of system abstraction, where micro-scale details of behavioral interactions are coarse-grained to macro-scale observables like the fractal dimension of space use. In this manner, the magnitude of the fractal dimension becomes a proxy variable for distinguishing between main classes of habitat exploration and site fidelity, like memory-less (Markovian) Brownian motion and Levy walk and memory-enhanced space use like Multi-scaled Random Walk (MRW). In this paper previous analyses are extended by exploring MRW simulations under three scenarios: (1) central place foraging, (2) behavioral adaptation to resource depletion (avoidance of latest visited locations) and (3) transition from MRW towards Levy walk by narrowing memory capacity to a trailing time window. A generalized statistical-mechanical theory with the power to model cognitive map influence on individual space use will be important for statistical analyses of animal habitat preferences and the mechanics behind site fidelity and home ranges. Copyright © 2011 Elsevier Ltd. All rights reserved.

Walking like an ant: a quantitative and experimental approach to understanding locomotor mimicry in the jumping spider Myrmarachne formicaria

PubMed Central

Hoy, Ron R.; Cohen, Itai; Beatus, Tsevi

2017-01-01

Protective mimicry, in which a palatable species avoids predation by being mistaken for an unpalatable model, is a remarkable example of adaptive evolution. These complex interactions between mimics, models and predators can explain similarities between organisms beyond the often-mechanistic constraints typically invoked in studies of convergent evolution. However, quantitative studies of protective mimicry typically focus on static traits (e.g. colour and shape) rather than on dynamic traits like locomotion. Here, we use high-speed cameras and behavioural experiments to investigate the role of locomotor behaviour in mimicry by the ant-mimicking jumping spider Myrmarachne formicaria, comparing its movement to that of ants and non-mimicking spiders. Contrary to previous suggestions, we find mimics walk using all eight legs, raising their forelegs like ant antennae only when stationary. Mimics exhibited winding trajectories (typical wavelength = 5–10 body lengths), which resemble the winding patterns of ants specifically engaged in pheromone-trail following, although mimics walked on chemically inert surfaces. Mimics also make characteristically short (approx. 100 ms) pauses. Our analysis suggests that this makes mimics appear ant-like to observers with slow visual systems. Finally, behavioural experiments with predatory spiders yield results consistent with the protective mimicry hypothesis. These findings highlight the importance of dynamic behaviours and observer perception in mimicry. PMID:28701553

The Animadora Project: Identifying factors related to the promotion of physical activity among Mexican Americans with diabetes

PubMed Central

Ingram, Maia; Ruis, Maricruz; Mayorga, Maria Theresa; Rosales, Cecilia

2015-01-01

Purpose There is a dearth of information about factors related to physical activity among Mexican Americans with diabetes. Self efficacy and social support are associated with physical activity, however little is known about their role within different cultural groups. Design Focus groups were used to identify factors that motivate walking. Setting Two Mexican American communities located in Tucson, Arizona. Subjects Individuals who attended diabetes education. Intervention A community-based provider organized walking groups with people who previously attended diabetes classes. Walkers participated in focus groups exploring themes related to their experience. Measures Self efficacy, social support, and collective efficacy. Grounded theory was used to analyze focus group results using two rounds of analysis; the first identifying references to self efficacy and social support and the second adding collective efficacy as a theoretical basis for walking. Results Among 43 eligible participants, 20 participated in focus groups. Social support was expressed as commitment and companionship. Walkers demonstrated a high level of self efficacy for walking. Development of group identity/social cohesion was also a motivator to walk. Collective efficacy emerged as an applicable theoretical model encompassing these themes and their interrelationship. Conclusion Collective efficacy, or the belief that the group can improve their lives through collective effort, is a viable theoretical construct in the development of physical activity interventions targeting Mexican Americans with diabetes. PMID:19601479

Mechanical energy assessment of adult with Down syndrome during walking with obstacle avoidance.

PubMed

Salami, Firooz; Vimercati, Sara Laura; Rigoldi, Chiara; Taebi, Amirtaha; Albertini, Giorgio; Galli, Manuela

2014-08-01

The aim of this study is analyzing the differences between plane walking and stepping over an obstacle for two groups of healthy people and people with Down syndrome and then, evaluating the movement efficiency between the groups by comprising of their mechanical energy exchanges. 39 adults including two groups of 21 people with Down syndrome (age: 21.6 ± 7 years) and 18 healthy people (age: 25.1 ± 2.4 years) participated in this research. The test has been done in two conditions, first in plane walking and second in walking with an obstacle (10% of the subject's height). The gait data were acquired using quantitative movement analysis, composed of an optoelectronic system (Elite2002, BTS) with eight infrared cameras. Mechanical energy exchanges are computed by dedicated software and finally the data including spatiotemporal parameters, mechanical energy parameters and energy recovery of gait cycle are analyzed by statistical software to find significant differences. Regards to spatiotemporal parameters velocity and step length are lower in people with Down syndrome. Mechanical energy parameters particularly energy recovery does not change from healthy people to people with Down syndrome. However, there are some differences in inter-group through plane walking to obstacle avoidance and it means people with Down syndrome probably use their residual abilities in the most efficient way to achieve the main goal of an efficient energy recovery. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of intensive diet and exercise on self-efficacy in overweight and obese adults with knee osteoarthritis: The IDEA randomized clinical trial.

PubMed

Mihalko, Shannon L; Cox, Phillip; Beavers, Daniel P; Miller, Gary D; Nicklas, Barbara J; Lyles, Mary; Hunter, David J; Eckstein, Felix; Guermazi, Ali; Loeser, Richard F; DeVita, Paul; Messier, Stephen P

2018-04-04

Physical activity decreases the risk of osteoarthritis (OA)-related disability; however, pain and lack of confidence represent barriers for older adults with knee OA. The purpose of this study was to examine (a) the baseline associations among self-efficacy and physical activity, function, and pain; (b) longitudinal changes in self-efficacy; and (c) whether self-efficacy mediates treatment effects on clinical outcomes. The Intensive Diet and Exercise for Arthritis (IDEA) trial was a single-blind, randomized controlled 18-month study including 454 overweight/obese older adults (M age = 66 years) with knee OA. Participants were randomized to one of three interventions: exercise (E), diet-induced weight loss (D), or both (D+E). Self-efficacy for gait, balance, and walking duration were assessed at baseline, 6 months, and 18 months. Baseline associations were tested using Pearson correlations, and group least squares means were compared using mixed linear models at follow-up. Participants with higher self-efficacy reported significantly better physical function and less knee pain at baseline, walked farther (6-min walk), and were more physically active (all |r| > 0.12, all p < .01). Significant differences between groups were detected for all self-efficacy measures at 18 months; the D+E group reported significantly (all p < .005) higher self-efficacy for gait, walking duration, and balance compared with the D- or E-only groups. Self-efficacy significantly (p < .05) mediated treatment effects on physical function and pain at 18 months. A combined intervention of diet-induced weight loss and exercise is the treatment of choice to maximize self-efficacy, improve physical function, and reduce pain in overweight/obese adults with knee OA.

76 FR 80875 - Los Padres National Forest: California; Environmental Impact Statement for the Removal of the...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-27

... minimize trampling of arroyo toads and vegetation. Applicators would avoid walking or stepping in water, to... red-legged frog found within the treatment sites shall be carefully moved outside the immediate work... within access routes may be moved to appropriate habitat if their avoidance is not practicable. If...

Lunar Landing Walking Simulator

NASA Image and Video Library

1965-09-03

Lunar Landing Walking Simulator: Researchers at Langley study the ability of astronauts to walk, run and perform other tasks required during lunar exploration. The Reduced Gravity Simulator gave researchers the opportunity to look at the effects of one-sixth normal gravity on self-locomotion. Several Apollo astronauts practiced lunar waling at the facility.

Any way you look at it, successful obstacle negotiation needs visually guided on-line foot placement regulation during the approach phase.

PubMed

Patla, Aftab E; Greig, Michael

In the two experiments discussed in this paper we quantified obstacle avoidance performance characteristics carried out open loop (without vision) but with different initial visual sampling conditions and compared it to the full vision condition. The initial visual sampling conditions included: static vision (SV), vision during forward walking for three steps and stopping (FW), vision during forward walking for three steps and not stopping (FW-NS), and vision during backward walking for three steps and stopping (BW). In experiment 1, we compared performance during SV, FW and BW with full vision condition, while in the second experiment we compared performance during FW and FW-NS conditions. The questions we wanted to address are: Is ecologically valid dynamic visual sampling of the environment superior to static visual sampling for open loop obstacle avoidance task? What are the reasons for failure in performing open loop obstacle avoidance task? The results showed that irrespective of the initial visual sampling condition when open loop control is initiated from a standing posture, the success rate was only approximately 50%. The main reason for the high failure rates was not inappropriate limb elevation, but incorrect foot placement before the obstacle. The second experiment showed that it is not the nature of visual sampling per se that influences success rate, but the fact that the open loop obstacle avoidance task is initiated from a standing posture. The results of these two experiments clearly demonstrate the importance of on-line visual information for adaptive human locomotion.

The Relationship Between Approach to Activity Engagement, Specific Aspects of Physical Function, and Pain Duration in Chronic Pain.

PubMed

Andrews, Nicole E; Strong, Jenny; Meredith, Pamela J

2016-01-01

To examine: (1) the relationships between habitual approach to activity engagement and specific aspects of physical functioning in chronic pain; and (2) whether or not these relationships differ according to pain duration. Outpatients (N=169) with generalized chronic pain completed a set of written questionnaires. Categories of "approach to activity engagement" were created using the confronting and avoidance subscales of the Pain and Activity Relations Questionnaire. An interaction term between "approach to activity engagement" categories and pain duration was entered into analysis with age, sex, pain intensity, the categorical "approach to activity engagement" variable, and pain duration, in 9 ordinal regression models investigating functioning in a variety of daily activities. The "approach to activity engagement" category predicted the personal care, lifting, sleeping, social life, and traveling aspects of physical functioning but, interestingly, not the performance skills used during these activities, that is, walking, sitting, and standing. The interaction term was significant in 2 models; however, the effect of pain duration on associations was the inverse of that theorized, with the relationship between variables becoming less pronounced with increasing duration of pain. The results of this study do not support the commonly held notion that avoidance and/or overactivity behavior leads to deconditioning and reduced physical capacity over time. Findings do, however, suggest that a relationship exists between avoidance and/or overactivity behavior and reduced participation in activities. Implications for the clinical management of chronic pain and directions for further research are discussed.

Improved methods of estimating critical indices via fractional calculus

NASA Astrophysics Data System (ADS)

Bandyopadhyay, S. K.; Bhattacharyya, K.

2002-05-01

Efficiencies of certain methods for the determination of critical indices from power-series expansions are shown to be considerably improved by a suitable implementation of fractional differentiation. In the context of the ratio method (RM), kinship of the modified strategy with the ad hoc `shifted' RM is established and the advantages are demonstrated. Further, in the course of the estimation of critical points, significant betterment of convergence properties of diagonal Padé approximants is observed on several occasions by invoking this concept. Test calculations are performed on (i) various Ising spin-1/2 lattice models for susceptibility series attended with a ferromagnetic phase transition, (ii) complex model situations involving confluent and antiferromagnetic singularities and (iii) the chain-generating functions for self-avoiding walks on triangular, square and simple cubic lattices.

A "Sit Less, Walk More" Workplace Intervention for Office Workers: Long-Term Efficacy of a Quasi-Experimental Study.

PubMed

Lin, Yun-Ping; Hong, OiSaeng; Lin, Chiu-Chu; Lu, Shu-Hua; Chen, Meei-Maan; Lee, Kwo-Chen

2018-06-01

This study tested the maintenance outcomes of a 3-month Sit Less, Walk More (SLWM) workplace intervention for office workers compared with usual care at 12 months from the baseline. A quasi-experimental study was conducted in two workplaces. The intervention group (n = 51) received multi-component intervention and the comparison group (n = 50) received newsletters only. The outcomes of the study (self-reported psychosocial, physical activity, sitting, and lost productivity; objectively measured cardiometabolic biomarkers) were compared at baseline, 3, and 12 months. Generalized estimating equations analyses found that the intervention group had significant improvements in self-regulation for sitting less and moving more (P = 0.017), walking (P = 0.003), weight (P = 0.013), waist circumference (P = 0.002), and insulin (P = 0.000) at 12 months compared with the comparison group. The SLWM intervention was effective in improving self-regulation, walking, and some cardiometabolic biomarkers in office workers.

Race walking gait and its influence on race walking economy in world-class race walkers.

PubMed

Gomez-Ezeiza, Josu; Torres-Unda, Jon; Tam, Nicholas; Irazusta, Jon; Granados, Cristina; Santos-Concejero, Jordan

2018-03-06

The aim of this study was to determine the relationships between biomechanical parameters of the gait cycle and race walking economy in world-class Olympic race walkers. Twenty-One world-class race walkers possessing the Olympic qualifying standard participated in this study. Participants completed an incremental race walking test starting at 10 km·h -1 , where race walking economy (ml·kg -1 ·km -1 ) and spatiotemporal gait variables were analysed at different speeds. 20-km race walking performance was related to race walking economy, being the fastest race walkers those displaying reduced oxygen cost at a given speed (R = 0.760, p < 0.001). Longer ground contact times, shorter flight times, longer midstance sub-phase and shorter propulsive sub-phase during stance were related to a better race walking economy (moderate effect, p < 0.05). According to the results of this study, the fastest race walkers were more economi cal than the lesser performers. Similarly, shorter flight times are associated with a more efficient race walking economy. Coaches and race walkers should avoid modifying their race walking style by increasing flight times, as it may not only impair economy, but also lead to disqualification.

Obstacle crossing with dual tasking is a danger for individuals with Alzheimer's disease and for healthy older people.

PubMed

Simieli, Lucas; Barbieri, Fabio Augusto; Orcioli-Silva, Diego; Lirani-Silva, Ellen; Stella, Florindo; Gobbi, Lilian Teresa Bucken

2015-01-01

The aim of this study was to analyze the effects of dual tasking on obstacle crossing during walking by individuals with Alzheimer's disease (AD) and by healthy older people. Thirty four elderly individuals (16 healthy subjects and 18 individuals with AD) were recruited to participate in this study. Three AD individuals and one control participant were excluded due to exclusion criteria. The participants were instructed to walk barefoot at their own speed along an 8 m long pathway. Each participant performed five trials for each condition (unobstructed walking, unobstructed walking with dual tasking, and obstacle crossing during walking with dual tasking). The trials were completely randomized for each participant. The mid-pathway stride was measured in the unobstructed walking trials and the stride that occurred during the obstacle avoidance was measured in the trials that involved obstacle crossing. The behavior of the healthy elderly subjects and individuals with AD was similar for obstacle crossing during walking with dual tasking. Both groups used the "posture first" strategy to prioritize stability and showed decreased attention to executive tasking while walking. Additionally, AD had a strong influence on the modifications that are made by the elderly while walking under different walking conditions.

Evolution of Inbreeding Avoidance and Inbreeding Preference through Mate Choice among Interacting Relatives.

PubMed

Duthie, A Bradley; Reid, Jane M

2016-12-01

While extensive population genetic theory predicts conditions favoring evolution of self-fertilization versus outcrossing, there is no analogous theory that predicts conditions favoring evolution of inbreeding avoidance or inbreeding preference enacted through mate choice given obligate biparental reproduction. Multiple interacting processes complicate the dynamics of alleles underlying such inbreeding strategies, including sexual conflict, distributions of kinship, genetic drift, purging of mutation load, direct costs, and restricted kin discrimination. We incorporated these processes into an individual-based model to predict conditions where selection should increase or decrease frequencies of alleles causing inbreeding avoidance or inbreeding preference when females or males controlled mating. Selection for inbreeding avoidance occurred given strong inbreeding depression when either sex chose mates, while selection for inbreeding preference occurred given very weak inbreeding depression when females chose but never occurred when males chose. Selection for both strategies was constrained by direct costs and restricted kin discrimination. Purging was negligible, but allele frequencies were strongly affected by drift in small populations, while selection for inbreeding avoidance was weak in larger populations because inbreeding risk decreased. Therefore, while selection sometimes favored alleles underlying inbreeding avoidance or preference, evolution of such strategies may be much more restricted and stochastic than is commonly presumed.

[Validity and reliability of a scale to assess self-efficacy for physical activity in elderly].

PubMed

Borges, Rossana Arruda; Rech, Cassiano Ricardo; Meurer, Simone Teresinha; Benedetti, Tânia Rosane Bertoldo

2015-04-01

This study aimed to analyze the confirmatory factor validity and reliability of a self-efficacy scale for physical activity in a sample of 118 elderly (78% women) from 60 to 90 years of age. Mplus 6.1 was used to evaluate the confirmatory factor analysis. Reliability was tested by internal consistency and temporal stability. The original scale consisted of five items with dichotomous answers (yes/no), independently for walking and moderate and vigorous physical activity. The analysis excluded the item related to confidence in performing physical activities when on vacation. Two constructs were identified, called "self-efficacy for walking" and "self-efficacy for moderate and vigorous physical activity", with a factor load ≥ 0.50. Internal consistency was adequate both for walking (> 0.70) and moderate and vigorous physical activity (> 0.80), and temporal stability was adequate for all the items. In conclusion, the self-efficacy scale for physical activity showed adequate validity, reliability, and internal consistency for evaluating this construct in elderly Brazilians.

Continuous time random walk with local particle-particle interaction

NASA Astrophysics Data System (ADS)

Xu, Jianping; Jiang, Guancheng

2018-05-01

The continuous time random walk (CTRW) is often applied to the study of particle motion in disordered media. Yet most such applications do not allow for particle-particle (walker-walker) interaction. In this paper, we consider a CTRW with particle-particle interaction; however, for simplicity, we restrain the interaction to be local. The generalized Chapman-Kolmogorov equation is modified by introducing a perturbation function that fluctuates around 1, which models the effect of interaction. Subsequently, a time-fractional nonlinear advection-diffusion equation is derived from this walking system. Under the initial condition of condensed particles at the origin and the free-boundary condition, we numerically solve this equation with both attractive and repulsive particle-particle interactions. Moreover, a Monte Carlo simulation is devised to verify the results of the above numerical work. The equation and the simulation unanimously predict that this walking system converges to the conventional one in the long-time limit. However, for systems where the free-boundary condition and long-time limit are not simultaneously satisfied, this convergence does not hold.

The Sense of 1PP-Location Contributes to Shaping the Perceived Self-location Together with the Sense of Body-Location

PubMed Central

Huang, Hsu-Chia; Lee, Yen-Tung; Chen, Wen-Yeo; Liang, Caleb

2017-01-01

Self-location—the sense of where I am in space—provides an experiential anchor for one's interaction with the environment. In the studies of full-body illusions, many researchers have defined self-location solely in terms of body-location—the subjective feeling of where my body is. Although this view is useful, there is an issue regarding whether it can fully accommodate the role of 1PP-location—the sense of where my first-person perspective is located in space. In this study, we investigate self-location by comparing body-location and 1PP-location: using a head-mounted display (HMD) and a stereo camera, the subjects watched their own body standing in front of them and received tactile stimulations. We manipulated their senses of body-location and 1PP-location in three different conditions: the participants standing still (Basic condition), asking them to move forward (Walking condition), and swiftly moving the stereo camera away from their body (Visual condition). In the Walking condition, the participants watched their body moving away from their 1PP. In the Visual condition, the scene seen via the HMD was systematically receding. Our data show that, under different manipulations of movement, the spatial unity between 1PP-location and body-location can be temporarily interrupted. Interestingly, we also observed a “double-body effect.” We further suggest that it is better to consider body-location and 1PP-location as interrelated but distinct factors that jointly support the sense of self-location. PMID:28352241

The Sense of 1PP-Location Contributes to Shaping the Perceived Self-location Together with the Sense of Body-Location.

PubMed

Huang, Hsu-Chia; Lee, Yen-Tung; Chen, Wen-Yeo; Liang, Caleb

2017-01-01

Self-location -the sense of where I am in space-provides an experiential anchor for one's interaction with the environment. In the studies of full-body illusions, many researchers have defined self-location solely in terms of body-location -the subjective feeling of where my body is. Although this view is useful, there is an issue regarding whether it can fully accommodate the role of 1PP-location -the sense of where my first-person perspective is located in space. In this study, we investigate self-location by comparing body-location and 1PP-location: using a head-mounted display (HMD) and a stereo camera, the subjects watched their own body standing in front of them and received tactile stimulations. We manipulated their senses of body-location and 1PP-location in three different conditions: the participants standing still (Basic condition), asking them to move forward (Walking condition), and swiftly moving the stereo camera away from their body (Visual condition). In the Walking condition, the participants watched their body moving away from their 1PP. In the Visual condition, the scene seen via the HMD was systematically receding. Our data show that, under different manipulations of movement, the spatial unity between 1PP-location and body-location can be temporarily interrupted. Interestingly, we also observed a "double-body effect." We further suggest that it is better to consider body-location and 1PP-location as interrelated but distinct factors that jointly support the sense of self-location.

Random walk study of electron motion in helium in crossed electromagnetic fields

NASA Technical Reports Server (NTRS)

Englert, G. W.

1972-01-01

Random walk theory, previously adapted to electron motion in the presence of an electric field, is extended to include a transverse magnetic field. In principle, the random walk approach avoids mathematical complexity and concomitant simplifying assumptions and permits determination of energy distributions and transport coefficients within the accuracy of available collisional cross section data. Application is made to a weakly ionized helium gas. Time of relaxation of electron energy distribution, determined by the random walk, is described by simple expressions based on energy exchange between the electron and an effective electric field. The restrictive effect of the magnetic field on electron motion, which increases the required number of collisions per walk to reach a terminal steady state condition, as well as the effect of the magnetic field on electron transport coefficients and mean energy can be quite adequately described by expressions involving only the Hall parameter.

The energy expenditure of using a "walk-and-work" desk for office workers with obesity.

PubMed

Levine, James A; Miller, Jennifer M

2007-09-01

For many people, most of the working day is spent sitting in front of a computer screen. Approaches for obesity treatment and prevention are being sought to increase workplace physical activity because low levels of physical activity are associated with obesity. Our hypothesis was that a vertical workstation that allows an obese individual to work while walking would be associated with significant and substantial increases in energy expenditure over seated work. The vertical workstation is a workstation that allows an office worker to use a standard personal computer while walking on a treadmill at a self-selected velocity. 15 sedentary individuals with obesity (14 women, one man; 43 (7.5) years, 86 (9.6) kg; body mass index 32 (2.6) kg/m(2)) underwent measurements of energy expenditure at rest, seated working in an office chair, standing and while walking at a self-selected speed using the vertical workstation. Body composition was measured using dual x ray absorptiometry. The mean (SD) energy expenditure while seated at work in an office chair was 72 (10) kcal/h, whereas the energy expenditure while walking and working at a self-selected velocity of 1.1 (0.4) mph was 191 (29) kcal/h. The mean (SD) increase in energy expenditure for walking-and-working over sitting was 119 (25) kcal/h. If sitting computer-time were replaced by walking-and-working, energy expenditure could increase by 100 kcal/h. Thus, if obese individuals were to replace time spent sitting at the computer with walking computer time by 2-3 h/day, and if other components of energy balance were constant, a weight loss of 20-30 kg/year could occur.

Reliability and relative weighting of visual and nonvisual information for perceiving direction of self-motion during walking

PubMed Central

Saunders, Jeffrey A.

2014-01-01

Direction of self-motion during walking is indicated by multiple cues, including optic flow, nonvisual sensory cues, and motor prediction. I measured the reliability of perceived heading from visual and nonvisual cues during walking, and whether cues are weighted in an optimal manner. I used a heading alignment task to measure perceived heading during walking. Observers walked toward a target in a virtual environment with and without global optic flow. The target was simulated to be infinitely far away, so that it did not provide direct feedback about direction of self-motion. Variability in heading direction was low even without optic flow, with average RMS error of 2.4°. Global optic flow reduced variability to 1.9°–2.1°, depending on the structure of the environment. The small amount of variance reduction was consistent with optimal use of visual information. The relative contribution of visual and nonvisual information was also measured using cue conflict conditions. Optic flow specified a conflicting heading direction (±5°), and bias in walking direction was used to infer relative weighting. Visual feedback influenced heading direction by 16%–34% depending on scene structure, with more effect with dense motion parallax. The weighting of visual feedback was close to the predictions of an optimal integration model given the observed variability measures. PMID:24648194

Changes in walking associated with perceived neighborhood safety and police-recorded crime: The multi-ethnic study of atherosclerosis.

PubMed

Kerr, Zachary; Evenson, Kelly R; Moore, Kari; Block, Richard; Diez Roux, Ana V

2015-04-01

To explore the association of changes in perceived safety and police-recorded crime with changes in transport and leisure walking using longitudinal data from Chicago residents participating in the Multi-Ethnic Study of Atherosclerosis (2000-2012). Main exposures included perceived safety (self-reported as feeling safe walking in the neighborhood and reporting violence to be a problem in the neighborhood), and one-year counts of police-recorded crime occurring within a one-mile buffer of participants' residences. Main outcomes included transport and leisure walking (self-reported and calculated as total minutes/week across four study visits). Fixed effects models assessed the association of change in perceived safety and police-recorded crime with changes in transport and leisure walking over a 10-year period for 796 adults. No associations were found between changes in perceived safety and either changes in transport or leisure walking. Residing in areas with increases in murder was associated with decreases in transport walking. However, no other associations were found with police-recorded crime. There continues to be a need to explore the benefits of cultivating safe neighborhoods that enhance resident health and well-being. Research should continue examining how community initiatives may build safe environments and community identity that promote walking. Copyright © 2015 Elsevier Inc. All rights reserved.

Exploring the Relationship between Experiential Avoidance, Coping Functions and the Recency and Frequency of Self-Harm

PubMed Central

Sayal, Kapil; Townsend, Ellen

2016-01-01

This study investigated the relationship between experiential avoidance, coping and the recency and frequency of self-harm, in a community sample (N = 1332, aged 16–69 years). Participants completed online, self-report measures assessing self-harm, momentary affect, experiential avoidance and coping in response to a recent stressor. Participants who had self-harmed reported significantly higher levels of experiential avoidance and avoidance coping, as well as lower levels of approach, reappraisal and emotional regulation coping, than those with no self-harm history. Moreover, more recent self-harm was associated with lower endorsement of approach, reappraisal and emotion regulation coping, and also higher levels of both avoidance coping and experiential avoidance. Higher experiential avoidance and avoidance coping also predicted increased lifetime frequency of self-harm. Conversely, increased approach and reappraisal coping were associated with a decreased likelihood of high frequency self-harm. Although some of the effects were small, particularly in relation to lifetime frequency of self-harm, overall our results suggest that experiential avoidance tendency may be an important psychological factor underpinning self-harm, regardless of suicidal intent (e.g. including mixed intent, suicidal intent, ambivalence), which is not accounted for in existing models of self-harm. PMID:27442036

How Many Objects are You Worth? Quantification of the Self-Motion Load on Multiple Object Tracking

PubMed Central

Thomas, Laura E.; Seiffert, Adriane E.

2011-01-01

Perhaps walking and chewing gum is effortless, but walking and tracking moving objects is not. Multiple object tracking is impaired by walking from one location to another, suggesting that updating location of the self puts demands on object tracking processes. Here, we quantified the cost of self-motion in terms of the tracking load. Participants in a virtual environment tracked a variable number of targets (1–5) among distractors while either staying in one place or moving along a path that was similar to the objects’ motion. At the end of each trial, participants decided whether a probed dot was a target or distractor. As in our previous work, self-motion significantly impaired performance in tracking multiple targets. Quantifying tracking capacity for each individual under move versus stay conditions further revealed that self-motion during tracking produced a cost to capacity of about 0.8 (±0.2) objects. Tracking your own motion is worth about one object, suggesting that updating the location of the self is similar, but perhaps slightly easier, than updating locations of objects. PMID:21991259

Near or far? It depends on my impression: moral information and spatial behavior in virtual interactions.

PubMed

Iachini, Tina; Pagliaro, Stefano; Ruggiero, Gennaro

2015-10-01

Near body distance is a key component of action and social interaction. Recent research has shown that peripersonal space (reachability-distance for acting with objects) and interpersonal space (comfort-distance for interacting with people) share common mechanisms and reflect the social valence of stimuli. The social psychological literature has demonstrated that information about morality is crucial because it affects impression formation and the intention to approach-avoid others. Here we explore whether peripersonal/interpersonal spaces are modulated by moral information. Thirty-six participants interacted with male/female virtual confederates described by moral/immoral/neutral sentences. The modulation of body space was measured by reachability-distance and comfort-distance while participants stood still or walked toward virtual confederates. Results showed that distance expanded with immorally described confederates and contracted with morally described confederates. This pattern was present in both spaces, although it was stronger in comfort-distance. Consistent with an embodied cognition approach, the findings suggest that high-level socio-cognitive processes are linked to sensorimotor-spatial processes. Copyright © 2015. Published by Elsevier B.V.

Agenesis of the Corpus Callosum

MedlinePlus

... such as walking, talking, or reading; challenges with social interactions; clumsiness and poor motor coordination, particularly on skills ... such as walking, talking, or reading; challenges with social interactions; clumsiness and poor motor coordination, particularly on skills ...

ACE polymorphisms and the acute response of blood pressure to a walk in medicated hypertensive patients.

PubMed

Goessler, Karla F; Cornelissen, Véronique A; de Oliveira, Edilamar M; de F Mota, Glória; Polito, Marcos D

2015-12-01

Polymorphisms of the angiotensin converting enzyme (ACE) gene can interfere with exercise-induced acute blood pressure (BP) reduction. This cross-over study investigated the acute effect of a single walk on BP and tested whether polymorphisms of the ACE gene might explain the variation in BP responses. Thirty-four healthy medicated individuals were randomized to one control and one walking session at 60-75% of heart rate reserve. Subjects left the laboratory wearing an ambulatory BP monitor until waking the next morning. Overall, systolic BP was somewhat lower following the walking session (p=.06), which could be attributed to a consistently lower systolic BP for 5 h after exercise (p-interaction<.04) compared with control rest. Similarly, II/ID individuals had a lower systolic BP (p-interaction=.02) and diastolic BP (p-interaction<.01) for 5 h after walking compared with control rest. Among DD individuals, a single walk did not induce a reduction in BP (p-interaction>.05). Our results showed that postexercise hypotension can occur after a walk at moderate intensity in carriers of the I allele; we were not able to demonstrate this in DD individuals. Our results suggest that genetic variation in the ACE gene might affect the BP response to exercise, although more research is needed to confirm these findings. © The Author(s) 2015.

Identification of walking human model using agent-based modelling

NASA Astrophysics Data System (ADS)

Shahabpoor, Erfan; Pavic, Aleksandar; Racic, Vitomir

2018-03-01

The interaction of walking people with large vibrating structures, such as footbridges and floors, in the vertical direction is an important yet challenging phenomenon to describe mathematically. Several different models have been proposed in the literature to simulate interaction of stationary people with vibrating structures. However, the research on moving (walking) human models, explicitly identified for vibration serviceability assessment of civil structures, is still sparse. In this study, the results of a comprehensive set of FRF-based modal tests were used, in which, over a hundred test subjects walked in different group sizes and walking patterns on a test structure. An agent-based model was used to simulate discrete traffic-structure interactions. The occupied structure modal parameters found in tests were used to identify the parameters of the walking individual's single-degree-of-freedom (SDOF) mass-spring-damper model using 'reverse engineering' methodology. The analysis of the results suggested that the normal distribution with the average of μ = 2.85Hz and standard deviation of σ = 0.34Hz can describe human SDOF model natural frequency. Similarly, the normal distribution with μ = 0.295 and σ = 0.047 can describe the human model damping ratio. Compared to the previous studies, the agent-based modelling methodology proposed in this paper offers significant flexibility in simulating multi-pedestrian walking traffics, external forces and simulating different mechanisms of human-structure and human-environment interaction at the same time.

Unmanned Aircraft Systems Human-in-the-Loop Controller and Pilot Acceptability Study: Collision Avoidance, Self-Separation, and Alerting Times (CASSAT)

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; Ghatas, Rania W.; Vincent, Michael J.; Consiglio, Maria C.; Munoz, Cesar; Chamberlain, James P.; Volk, Paul; Arthur, Keith E.

2016-01-01

The Federal Aviation Administration (FAA) has been mandated by the Congressional funding bill of 2012 to open the National Airspace System (NAS) to Unmanned Aircraft Systems (UAS). With the growing use of unmanned systems, NASA has established a multi-center "UAS Integration in the NAS" Project, in collaboration with the FAA and industry, and is guiding its research efforts to look at and examine crucial safety concerns regarding the integration of UAS into the NAS. Key research efforts are addressing requirements for detect-and-avoid (DAA), self-separation (SS), and collision avoidance (CA) technologies. In one of a series of human-in-the-loop experiments, NASA Langley Research Center set up a study known as Collision Avoidance, Self-Separation, and Alerting Times (CASSAT). The first phase assessed active air traffic controller interactions with DAA systems and the second phase examined reactions to the DAA system and displays by UAS Pilots at a simulated ground control station (GCS). Analyses of the test results from Phase I and Phase II are presented in this paper. Results from the CASSAT study and previous human-in-the-loop experiments will play a crucial role in the FAA's establishment of rules, regulations, and procedures to safely, efficiently, and effectively integrate UAS into the NAS.

Dizziness

MedlinePlus

... help walking when you have a loss of balance during a vertigo attack. Avoid bright lights, TV, ... include: Blood pressure reading Electrocardiogram ( ECG ) Hearing tests Balance testing ( ENG ) Magnetic Resonance Imaging (MRI) Your provider ...

Persistent-random-walk approach to anomalous transport of self-propelled particles

NASA Astrophysics Data System (ADS)

Sadjadi, Zeinab; Shaebani, M. Reza; Rieger, Heiko; Santen, Ludger

2015-06-01

The motion of self-propelled particles is modeled as a persistent random walk. An analytical framework is developed that allows the derivation of exact expressions for the time evolution of arbitrary moments of the persistent walk's displacement. It is shown that the interplay of step length and turning angle distributions and self-propulsion produces various signs of anomalous diffusion at short time scales and asymptotically a normal diffusion behavior with a broad range of diffusion coefficients. The crossover from the anomalous short-time behavior to the asymptotic diffusion regime is studied and the parameter dependencies of the crossover time are discussed. Higher moments of the displacement distribution are calculated and analytical expressions for the time evolution of the skewness and the kurtosis of the distribution are presented.

"Step by Step". A feasibility study of a lunchtime walking intervention designed to increase walking, improve mental well-being and work performance in sedentary employees: Rationale and study design.

PubMed

Thøgersen-Ntoumani, Cecilie; Loughren, Elizabeth A; Duda, Joan L; Fox, Kenneth R; Kinnafick, Florence-Emilie

2010-09-27

Following an extensive recruitment campaign, a 16-week lunchtime intervention to increase walking was implemented with insufficiently physically active University employees to examine programme feasibility and the effects of the programme in increasing walking behaviour, and in improving well-being and work performance. A feasibility study in which participants were randomised to an immediate treatment or a delayed treatment control (to start at 10 weeks) group. For the first ten weeks of the intervention, participants took part in three facilitator-led group walks per week each of thirty minutes duration and were challenged to accumulate another sixty minutes of walking during the weekends. In the second phase of the intervention, the organised group walks ceased to be offered and participants were encouraged to self-organise their walks. Motivational principles were employed using contemporary motivational theory. Outcome measures (including self-reported walking, step counts, cardiovascular fitness, general and work-related well-being and work performance) were assessed at baseline, at the end of the 16-week intervention and (for some) four months after the end of the intervention. Process and outcome assessments were also taken throughout, and following, the intervention. The results of the intervention will determine the feasibility of implementing a lunchtime walking programme to increase walking behaviour, well-being and performance in sedentary employees. If successful, there is scope to implement definitive trials across a range of worksites with the aim of improving both employee and organisational health. Current Controlled Trials ISRCTN81504663.

Hearing acuity as a predictor of walking difficulties in older women.

PubMed

Viljanen, Anne; Kaprio, Jaakko; Pyykkö, Ilmari; Sorri, Martti; Koskenvuo, Markku; Rantanen, Taina

2009-12-01

To examine whether hearing acuity correlates with walking ability and whether impaired hearing at baseline predicts new self-reported walking difficulties after 3 years. Prospective follow-up. Research laboratory and community. Four hundred thirty-four women aged 63 to 76. Hearing was measured using clinical audiometry. A person was defined as having a hearing impairment if a pure-tone average of thresholds at 0.5 to 4 kHz in the better ear was 21 dB or greater. Maximal walking speed was measured over 10 m (m/s), walking endurance as the distance (m), covered in 6 minutes and difficulties in walking 2 km according to self-report. At baseline, women with hearing impairment (n=179) had slower maximal walking speed (1.7 +/- 0.3 m/s vs 1.8 +/- 0.3 m/s, P=.007), lower walking endurance (520 +/- 75 m vs 536 +/- 75 m, P=.08), and more selfreported major difficulties in walking 2 km (12.8% vs 5.5%, P=.02) than those without hearing impairment. During follow-up, major walking difficulties developed for 33 participants. Women with hearing impairment at baseline had a twice the age-adjusted risk for new walking difficulties as those without hearing impairment (odds ratio=2.04, 95% confidence interval=0.96-4.33). Hearing acuity correlated with mobility, which may be explained by the association between impaired hearing and poor balance and greater risk for falls, both of which underlie decline in mobility. Prevention of hearing loss is not only important for the ability to communicate, but may also have more wide-ranging influences on functional ability.

Energy cost of walking: solving the paradox of steady state in the presence of variable walking speed.

PubMed

Plasschaert, Frank; Jones, Kim; Forward, Malcolm

2009-02-01

Measurement of the energy cost of walking in children with cerebral palsy is used for baseline and outcome assessment. However, such testing relies on the establishment of steady state that is deemed present when oxygen consumption is stable. This is often assumed when walking speed is constant but in practice, speed can and does vary naturally. Whilst constant speed is achievable on a treadmill, this is often impractical clinically, thus rendering an energy cost test to an element of subjectivity. This paper attempts to address this issue by presenting a new method for calculating energy cost of walking that automatically applies a mathematically defined threshold for steady state within a (non-treadmill) walking trial and then strips out all of the non-steady state events within that trial. The method is compared with a generic approach that does not remove non-steady state data but rather uses an average value over a complete walking trial as is often used in the clinical environment. Both methods were applied to the calculation of several energy cost of walking parameters of self-selected walking speed in a cohort of unimpaired subjects and children with cerebral palsy. The results revealed that both methods were strongly correlated for each parameter but showed systematic significant differences. It is suggested that these differences are introduced by the rejection of non-steady state data that would otherwise have incorrectly been incorporated into the calculation of the energy cost of walking indices during self-selected walking with its inherent speed variation.

Measuring self-aligned quadruple patterning pitch walking with scatterometry-based metrology utilizing virtual reference

NASA Astrophysics Data System (ADS)

Kagalwala, Taher; Vaid, Alok; Mahendrakar, Sridhar; Lenahan, Michael; Fang, Fang; Isbester, Paul; Shifrin, Michael; Etzioni, Yoav; Cepler, Aron; Yellai, Naren; Dasari, Prasad; Bozdog, Cornel

2016-10-01

Advanced technology nodes, 10 nm and beyond, employing multipatterning techniques for pitch reduction pose new process and metrology challenges in maintaining consistent positioning of structural features. A self-aligned quadruple patterning (SAQP) process is used to create the fins in FinFET devices with pitch values well below optical lithography limits. The SAQP process bears the compounding effects from successive reactive ion etch and spacer depositions. These processes induce a shift in the pitch value from one fin compared to another neighboring fin. This is known as pitch walking. Pitch walking affects device performance as well as later processes, which work on an assumption that there is consistent spacing between fins. In SAQP, there are three pitch walking parameters of interest, each linked to specific process steps in the flow. These pitch walking parameters are difficult to discriminate at a specific process step by singular evaluation technique or even with reference metrology, such as transmission electron microscopy. We will utilize a virtual reference to generate a scatterometry model to measure pitch walk for SAQP process flow.

[Psychometric properties of a self-efficacy scale for physical activity in Brazilian adults].

PubMed

Rech, Cassiano Ricardo; Sarabia, Tais Taiana; Fermino, Rogério César; Hallal, Pedro Curi; Reis, Rodrigo Siqueira

2011-04-01

To test the validity and reliability of a self-efficacy scale for physical activity (PA) in Brazilian adults. A self-efficacy scale was applied jointly with a multidimensional questionnaire through face-to-face interviews with 1,418 individuals (63.4% women) aged ≥ 18 years. The scale was submitted to validity (factorial and construct) and reliability analysis (internal consistency and temporal stability). A test-retest procedure was conducted with 74 individuals to evaluate temporal stability. Exploratory factor analyses revealed two independent factors: self-efficacy for walking and self-efficacy for moderate and vigorous PA (MVPA). Together, these two factors explained 65.4% of the total variance of the scale (20.9% and 44.5% for walking and MVPA, respectively). Cronbach's alpha values were 0.83 for walking and 0.90 for MVPA, indicating high internal consistency. Both factors were significantly and positively correlated (rho ≥ 0.17, P < 0.001) with quality of life indicators (health perception, self-satisfaction, and energy for daily activities), indicating an adequate construct validity. The scale's validity, internal consistency, and reliability were adequate to evaluate self-efficacy for PA in Brazilian adults.

Negative mood regulation expectancies moderate the relationship between psychological abuse and avoidant coping.

PubMed

Shepherd-McMullen, Cassandra; Mearns, Jack; Stokes, Julie E; Mechanic, Mindy B

2015-05-01

This study explored the relationships among psychological abuse, attitudes about intimate partner violence (IPV), negative mood regulation expectancies (NMRE), and coping. Participants were 126 female college students in dating, cohabitating, or married relationships within the previous year. In one single session, they completed self-report scales measuring IPV, NMRE, and coping. Results indicated that women reporting higher levels of psychological abuse reported less negative attitudes toward IPV, engaged in less-active coping responses, and had lower NMRE. Psychological abuse was a significant predictor of avoidant coping, while NMRE significantly predicted both active and avoidant coping. In addition, the interaction of NMRE × Psychological abuse added incremental prediction of avoidant coping. Implications for research and practice are discussed. © The Author(s) 2014.

Scaling analysis and SE simulation of the tilted cylinder-interface capillary interaction

NASA Astrophysics Data System (ADS)

Gao, S. Q.; Zhang, X. Y.; Zhou, Y. H.

2018-06-01

The capillary interaction induced by a tilted cylinder and interface is the basic configuration of many complex systems, such as micro-pillar arrays clustering, super-hydrophobicity of hairy surface, water-walking insects, and fiber aggregation. We systematically analyzed the scaling laws of tilt angle, contact angle, and cylinder radius on the contact line shape by SE simulation and experiment. The following in-depth analysis of the characteristic parameters (shift, stretch and distortion) of the deformed contact lines reveals the self-similar shape of contact line. Then a general capillary force scaling law is proposed to incredibly grasp all the simulated and experimental data by a quite straightforward ellipse approximation approach.

Environmental, psychological, and social influences on physical activity among Japanese adults: structural equation modeling analysis.

PubMed

Ishii, Kaori; Shibata, Ai; Oka, Koichiro

2010-08-05

An understanding of the contributing factors to be considered when examining how individuals engage in physical activity is important for promoting population-based physical activity. The environment influences long-term effects on population-based health behaviors. Personal variables, such as self-efficacy and social support, can act as mediators of the predictive relationship between the environment and physical activity. The present study examines the direct and indirect effects of environmental, psychological, and social factors on walking, moderate-intensity activity excluding walking, and vigorous-intensity activity among Japanese adults. The participants included 1,928 Japanese adults aged 20-79 years. Seven sociodemographic attributes (e.g., gender, age, education level, employment status), psychological variables (self-efficacy, pros, and cons), social variables (social support), environmental variables (home fitness equipment, access to facilities, neighborhood safety, aesthetic sensibilities, and frequency of observing others exercising), and the International Physical Activity Questionnaire were assessed via an Internet-based survey. Structural equation modeling was conducted to determine associations between environmental, psychological, and social factors with physical activity. Environmental factors could be seen to have indirect effects on physical activity through their influence on psychological and social variables such as self-efficacy, pros and cons, and social support. The strongest indirect effects could be observed by examining the consequences of environmental factors on physical activity through cons to self-efficacy. The total effects of environmental factors on physical activity were 0.02 on walking, 0.02 on moderate-intensity activity excluding walking, and 0.05 on vigorous-intensity activity. The present study indicates that environmental factors had indirect effects on walking, moderate-intensity activity excluding walking and vigorous-intensity activity among Japanese adults, especially through the effects on these factors of self-efficacy, social support, and pros and cons. The findings of the present study imply that intervention strategies to promote more engagement in physical activity for population-based health promotion may be necessary.

Environmental, psychological, and social influences on physical activity among Japanese adults: structural equation modeling analysis

PubMed Central

2010-01-01

Background An understanding of the contributing factors to be considered when examining how individuals engage in physical activity is important for promoting population-based physical activity. The environment influences long-term effects on population-based health behaviors. Personal variables, such as self-efficacy and social support, can act as mediators of the predictive relationship between the environment and physical activity. The present study examines the direct and indirect effects of environmental, psychological, and social factors on walking, moderate-intensity activity excluding walking, and vigorous-intensity activity among Japanese adults. Methods The participants included 1,928 Japanese adults aged 20-79 years. Seven sociodemographic attributes (e.g., gender, age, education level, employment status), psychological variables (self-efficacy, pros, and cons), social variables (social support), environmental variables (home fitness equipment, access to facilities, neighborhood safety, aesthetic sensibilities, and frequency of observing others exercising), and the International Physical Activity Questionnaire were assessed via an Internet-based survey. Structural equation modeling was conducted to determine associations between environmental, psychological, and social factors with physical activity. Results Environmental factors could be seen to have indirect effects on physical activity through their influence on psychological and social variables such as self-efficacy, pros and cons, and social support. The strongest indirect effects could be observed by examining the consequences of environmental factors on physical activity through cons to self-efficacy. The total effects of environmental factors on physical activity were 0.02 on walking, 0.02 on moderate-intensity activity excluding walking, and 0.05 on vigorous-intensity activity. Conclusions The present study indicates that environmental factors had indirect effects on walking, moderate-intensity activity excluding walking and vigorous-intensity activity among Japanese adults, especially through the effects on these factors of self-efficacy, social support, and pros and cons. The findings of the present study imply that intervention strategies to promote more engagement in physical activity for population-based health promotion may be necessary. PMID:20684794

Allostatic Load and Health in the Older Population of England: A Crossed-Lagged Analysis

PubMed Central

Read, Sanna; Grundy, Emily

2014-01-01

Objective Allostatic load, a composite measure of accumulated physical wear and tear, has been proposed as an early sign of physiological dysregulation predictive of health problems, functional limitation, and disability. However, much previous research has been cross sectional and few studies consider repeated measures. We investigate the directionality of associations between allostatic load, self-rated health, and a measure of physical function (walking speed). Methods The sample included men and women 60 and older who participated in Wave 2 (2004) and Wave 4 (2008) of the English Longitudinal Study of Ageing (n = 6132 in Wave 2). Allostatic load was measured with nine biomarkers using a multisystem summary approach. Self-rated health was measured using a global 5 point summary indicator. Time to walk 8 ft was used as a measure of function. We fitted and tested autoregressive cross-lagged models between the allostatic load measure, self-rated health, and walking speed in Waves 2 and 4. Models were adjusted for age, sex, educational level, and smoking status at Wave 2 and for time-varying indicators of marital status, wealth, physical activity, and social support. Results Allostatic load predicted slower walking speed (standardized estimate = −0.08, 95% confidence interval [CI] = −0.10 to −0.05). Better self-rated health predicted faster walking speed (standardized estimate = 0.11, 95% CI = 0.08-0.13) as well as lower allostatic load (standardized estimate = −0.15, 95% CI = −0.22 to −0.09), whereas paths from allostatic load and walking speed to self-rated health were weaker (standardized estimates = −0.05 [95% CI = −0.07 to −0.02] and 0.06 [95% CI = 0.04–0.08]). Conclusions Allostatic load can be a useful risk indicator of subsequent poor health or function. PMID:25153937

Personality trait interactions in parents of patients with borderline personality disorder: a controlled study using the Temperament and Character Inventory.

PubMed

Fassino, Secondo; Amianto, Federico; Gastaldi, Filippo; Abbate-Daga, Giovanni; Brambilla, Francesca; Leombruni, Paolo

2009-01-30

Family environment is a pathogenic factor of borderline personality disorder (BPD). However, the personality traits of patients with BPD and their parents have never been assessed using the same instrument and then examined for relationships. In the present study, we explored the temperament and character traits of BPD patients and their parents to investigate possible interactions. In total, 56 patients with BPD and their parents were evaluated with the Temperament and Character Inventory (TCI) and compared with 53 control families. Discriminant and correlation analyses indicated that subjects with BPD displayed higher levels of novelty seeking, harm avoidance, and self-transcendence and lower levels of self-directedness than control subjects. Their fathers displayed higher levels of novelty seeking and lower levels of persistence and self-directedness, and their mothers displayed lower levels of self-directedness compared with levels in control parents. In BPD families, temperament and character traits displayed high levels of discriminatory power. Novelty seeking in offspring with borderline personality disorder was significantly correlated with their mothers' novelty seeking and their fathers' self-transcendence. Self-directedness in borderline offspring was significantly correlated with both their mothers' and fathers' novelty seeking, and their self-transcendence was significantly correlated with their mothers' novelty seeking and harm avoidance. The different correlational pattern for borderline and control families is discussed. Characteristic personality patterns were found in BPD offspring and in both parents. The relationship between personality traits of borderline offspring and those of their parents may be related to both genetic transmission and family dynamics. Ramifications for treatment are discussed.

Elastic coupling of limb joints enables faster bipedal walking

PubMed Central

Dean, J.C.; Kuo, A.D.

2008-01-01

The passive dynamics of bipedal limbs alone are sufficient to produce a walking motion, without need for control. Humans augment these dynamics with muscles, actively coordinated to produce stable and economical walking. Present robots using passive dynamics walk much slower, perhaps because they lack elastic muscles that couple the joints. Elastic properties are well known to enhance running gaits, but their effect on walking has yet to be explored. Here we use a computational model of dynamic walking to show that elastic joint coupling can help to coordinate faster walking. In walking powered by trailing leg push-off, the model's speed is normally limited by a swing leg that moves too slowly to avoid stumbling. A uni-articular spring about the knee allows faster but uneconomical walking. A combination of uni-articular hip and knee springs can speed the legs for improved speed and economy, but not without the swing foot scuffing the ground. Bi-articular springs coupling the hips and knees can yield high economy and good ground clearance similar to humans. An important parameter is the knee-to-hip moment arm that greatly affects the existence and stability of gaits, and when selected appropriately can allow for a wide range of speeds. Elastic joint coupling may contribute to the economy and stability of human gait. PMID:18957360

Repelling, binding, and oscillating of two-particle discrete-time quantum walks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Qinghao; Li, Zhi-Jian, E-mail: zjli@sxu.edu.cn

In this paper, we investigate the effects of particle–particle interaction and static force on the propagation of probability distribution in two-particle discrete-time quantum walk, where the interaction and static force are expressed as a collision phase and a linear position-dependent phase, respectively. It is found that the interaction can lead to boson repelling and fermion binding. The static force also induces Bloch oscillation and results in a continuous transition from boson bunching to fermion anti-bunching. The interplays of particle–particle interaction, quantum interference, and Bloch oscillation provide a versatile framework to study and simulate many-particle physics via quantum walks.

Effect of walking speed on lower extremity joint loading in graded ramp walking.

PubMed

Schwameder, Hermann; Lindenhofer, Elke; Müller, Erich

2005-07-01

Lower extremity joint loading during walking is strongly affected by the steepness of the slope and might cause pain and injuries in lower extremity joint structures. One feasible measure to reduce joint loading is the reduction of walking speed. Positive effects have been shown for level walking, but not for graded walking or hiking conditions. The aim of the study was to quantify the effect of walking speed (separated into the two components, step length and cadence) on the joint power of the hip, knee and ankle and to determine the knee joint forces in uphill and downhill walking. Ten participants walked up and down a ramp with step lengths of 0.46, 0.575 and 0.69 m and cadences of 80, 100 and 120 steps per minute. The ramp was equipped with a force platform and the locomotion was filmed with a 60 Hz video camera. Loading of the lower extremity joints was determined using inverse dynamics. A two-dimensional knee model was used to calculate forces in the knee structures during the stance phase. Walking speed affected lower extremity joint loading substantially and significantly. Change of step length caused much greater loading changes for all joints compared with change of cadence; the effects were more distinct in downhill than in uphill walking. The results indicate that lower extremity joint loading can be effectively controlled by varying step length and cadence during graded uphill and downhill walking. Hikers can avoid or reduce pain and injuries by reducing walking speed, particularly in downhill walking.

Learning to Walk: Changing Your Self, Your Perspectives, and Your Assumptions

ERIC Educational Resources Information Center

Sullivan, Debra R.

2011-01-01

Watching babies learn to walk can teach one a lot about himself/herself and one's ability to change. Changing one's self, perspectives, or assumptions requires: (1) the determination and perseverance to persist; (2) the openness to believe that if one can't change now, maybe he/she can later; (3) the ability to take a stand, even if one knows it…

Older People’s Experiences of Mobility and Mood in an Urban Environment: A Mixed Methods Approach Using Electroencephalography (EEG) and Interviews

PubMed Central

Tilley, Sara; Neale, Chris; Patuano, Agnès; Cinderby, Steve

2017-01-01

There are concerns about mental wellbeing in later life in older people as the global population becomes older and more urbanised. Mobility in the built environment has a role to play in improving quality of life and wellbeing, as it facilitates independence and social interaction. Recent studies using neuroimaging methods in environmental psychology research have shown that different types of urban environments may be associated with distinctive patterns of brain activity, suggesting that we interact differently with varying environments. This paper reports on research that explores older people’s responses to urban places and their mobility in and around the built environment. The project aim was to understand how older people experience different urban environments using a mixed methods approach including electroencephalography (EEG), self-reported measures, and interview results. We found that older participants experience changing levels of “excitement”, “engagement” and “frustration” (as interpreted by proprietary EEG software) whilst walking between a busy built urban environment and an urban green space environment. These changes were further reflected in the qualitative themes that emerged from transcribed interviews undertaken one week post-walk. There has been no research to date that has directly assessed neural responses to an urban environment combined with qualitative interview analysis. A synergy of methods offers a deeper understanding of the changing moods of older people across time whilst walking in city settings. PMID:28165409

Children's GPS-determined versus self-reported transport in leisure time and associations with parental perceptions of the neighborhood environment.

PubMed

Vanwolleghem, Griet; Schipperijn, Jasper; Gheysen, Freja; Cardon, Greet; De Bourdeaudhuij, Ilse; Van Dyck, Delfien

2016-05-05

This study aimed to examine both GPS-determined and self-reported walking, cycling and passive transport in leisure time during week- and weekend-days among 10 to 12-year old children. Comparisons between GPS-determined and self-reported transport in leisure time were investigated. Second, associations between parental perceptions of the neighborhood environment and GPS-determined walking, cycling and passive transport in leisure time were studied. Children (10 to 12-years old; n = 126) wore a GPS device and an accelerometer for 7 consecutive days to assess objectively measured transport in leisure time and filled out a diary to assess self-reported transport in leisure time. Parents completed a questionnaire to assess parental perceptions of the neighborhood environment. Pearson correlations and t-tests were used to test for concurrent validity and differences between GPS-determined and self-reported transport in leisure time. Generalized linear models were used to determine the associations between the parental perceptions of the neighborhood environment and GPS-determined transport in leisure time. Overall, children under-reported their walking and cycling in leisure time, compared to GPS-determined measures (all p values <0.001). However, children reported their passive transport in leisure time during weekend days quite accurate. GPS-determined measures revealed that children walked most during weekdays (M = 3.96 trips/day; 26.10 min/day) and used passive transport more frequently during weekend days (M = 2.12 trips/day; 31.39 min/day). Only a few parental perceived environmental attributes of the neighborhood (i.e. residential density, land use mix access, quality and availability of walking and cycling facilities, and aesthetics) were significantly associated with children's GPS-determined walking, cycling or passive transport in leisure time. To accurately assess children's active transport in leisure time, GPS measures are recommended over self-reports. More research using GPS with a focus on children's transport in leisure time and investigating the associations with parental perceptions of the neighborhood environment is needed to confirm the results of the present study.

Pedometer accuracy in slow walking older adults.

PubMed

Martin, Jessica B; Krč, Katarina M; Mitchell, Emily A; Eng, Janice J; Noble, Jeremy W

2012-07-03

The purpose of this study was to determine pedometer accuracy during slow overground walking in older adults (Mean age = 63.6 years). A total of 18 participants (6 males, 12 females) wore 5 different brands of pedometers over 3 pre-set cadences that elicited walking speeds between 0.3 and 0.9 m/s and one self-selected cadence over 80 meters of indoor track. Pedometer accuracy decreased with slower walking speeds with mean percent errors across all devices combined of 56%, 40%, 19% and 9% at cadences of 50, 66, and 80 steps/min, and self selected cadence, respectively. Percent error ranged from 45.3% for Omron HJ105 to 66.9% for Yamax Digiwalker 200. Due to the high level of error across the slowest cadences of all 5 devices, the use of pedometers to monitor step counts in healthy older adults with slower gait speeds is problematic. Further research is required to develop pedometer mechanisms that accurately measure steps at slower walking speeds.

Pedometer accuracy in slow walking older adults

PubMed Central

Martin, Jessica B.; Krč, Katarina M.; Mitchell, Emily A.; Eng, Janice J.; Noble, Jeremy W.

2013-01-01

The purpose of this study was to determine pedometer accuracy during slow overground walking in older adults (Mean age = 63.6 years). A total of 18 participants (6 males, 12 females) wore 5 different brands of pedometers over 3 pre-set cadences that elicited walking speeds between 0.3 and 0.9 m/s and one self-selected cadence over 80 meters of indoor track. Pedometer accuracy decreased with slower walking speeds with mean percent errors across all devices combined of 56%, 40%, 19% and 9% at cadences of 50, 66, and 80 steps/min, and self selected cadence, respectively. Percent error ranged from 45.3% for Omron HJ105 to 66.9% for Yamax Digiwalker 200. Due to the high level of error across the slowest cadences of all 5 devices, the use of pedometers to monitor step counts in healthy older adults with slower gait speeds is problematic. Further research is required to develop pedometer mechanisms that accurately measure steps at slower walking speeds. PMID:24795762

Self-consistent perturbation theory for two dimensional twisted bilayers

NASA Astrophysics Data System (ADS)

Shirodkar, Sharmila N.; Tritsaris, Georgios A.; Kaxiras, Efthimios

Theoretical modeling and ab-initio simulations of two dimensional heterostructures with arbitrary angles of rotation between layers involve unrealistically large and expensive calculations. To overcome this shortcoming, we develop a methodology for weakly interacting heterostructures that treats the effect of one layer on the other as perturbation, and restricts the calculations to their primitive cells. Thus, avoiding computationally expensive supercells. We start by approximating the interaction potential between the twisted bilayers to that of a hypothetical configuration (viz. ideally stacked untwisted layers), which produces band structures in reasonable agreement with full-scale ab-initio calculations for commensurate and twisted bilayers of graphene (Gr) and Gr/hexagonal boron nitride (h-BN) heterostructures. We then self-consistently calculate the charge density and hence, interaction potential of the heterostructures. In this work, we test our model for bilayers of various combinations of Gr, h-BN and transition metal dichalcogenides, and discuss the advantages and shortcomings of the self-consistently calculated interaction potential. Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.

Ability to Walk 1/4 Mile Predicts Subsequent Disability, Mortality, and Health Care Costs

PubMed Central

Kang, Yihuang; Studenski, Stephanie A.; Degenholtz, Howard B.

2010-01-01

ABSTRACT Background Mobility, such as walking 1/4 mile, is a valuable but underutilized health indicator among older adults. For mobility to be successfully integrated into clinical practice and health policy, an easily assessed marker that predicts subsequent health outcomes is required. Objective To determine the association between mobility, defined as self-reported ability to walk 1/4 mile, and mortality, functional decline, and health care utilization and costs during the subsequent year. Design Analysis of longitudinal data from the 2003–2004 Medicare Current Beneficiary Survey, a nationally representative sample of Medicare beneficiaries. Participants Participants comprised 5895 community-dwelling adults aged 65 years or older enrolled in Medicare. Main Measures Mobility (self-reported ability to walk 1/4 mile), mortality, incident difficulty with activities of daily living (ADLs), total annual health care costs, and hospitalization rates. Key Results Among older adults, 28% reported difficulty and 17% inability to walk 1/4 mile at baseline. Compared to those without difficulty and adjusting for demographics, socioeconomic status, chronic conditions, and health behaviors, mortality was greater in those with difficulty [AOR (95% CI): 1.57 (1.10-2.24)] and inability [AOR (CI): 2.73 (1.79-4.15)]. New functional disability also occurred more frequently as self-reported ability to walk 1/4 mile declined (subsequent incident disability among those with no difficulty, difficulty, or inability to walk 1/4 mile at baseline was 11%, 29%, and 47% for instrumental ADLs, and 4%, 14%, and 23% for basic ADLs). Total annual health care costs were $2773 higher (95% CI $1443-4102) in persons with difficulty and $3919 higher (CI $1948-5890) in those who were unable. For each 100 persons, older adults reporting difficulty walking 1/4 mile at baseline experienced an additional 14 hospitalizations (95% CI 8-20), and those who were unable experienced an additional 22 hospitalizations (CI 14-30) during the follow-up period, compared to persons without walking difficulty. Conclusions Mobility disability, a simple self-report measure, is a powerful predictor of future health, function, and utilization independent of usual health and demographic indicators. Mobility disability may be used to target high-risk patients for care management and preventive interventions. PMID:20972641

Reliability and Validity of the International Physical Activity Questionnaire for Assessing Walking

ERIC Educational Resources Information Center

van der Ploeg, Hidde P.; Tudor-Locke, Catrine; Marshall, Alison L.; Craig, Cora; Hagstromer, Maria; Sjostrom, Michael; Bauman, Adrian

2010-01-01

The single most commonly reported physical activity in public health surveys is walking. As evidence accumulates that walking is important for preventing weight gain and reducing the risk of diabetes, there is increased need to capture this behavior in a valid and reliable manner. Although the disadvantages of a self-report methodology are well…

Interactive video dance games for healthy older adults.

PubMed

Studenski, S; Perera, S; Hile, E; Keller, V; Spadola-Bogard, J; Garcia, J

2010-12-01

Physical activity promotes health in older adults but participation rates are low. Interactive video dance games can increase activity in young persons but have not been designed for use with older adults. The purpose of this research was to evaluate healthy older adults' interest and participation in a dance game adapted for an older user. Healthy older adults were recruited from 3 senior living settings and offered three months of training and supervision using a video dance game designed for older people. Before and after the program, data was collected on vital signs, physical function and self reported quality of life. Feedback was obtained during and after training. Of 36 persons who entered (mean age 80.1 + 5.4 years, 83 % female), 25 completed the study. Completers were healthier than noncompleters. Completers showed gains in narrow walk time, self-reported balance confidence and mental health. While there were no serious adverse events, 4 of 11 noncompleters withdrew due to musculoskeletal complaints. Adapted Interactive video dance is feasible for some healthy older adults and may help achieve physical activity goals.

Multidirectional walk test in individuals with Parkinson's disease: a validity study.

PubMed

Bryant, Mon S; Workman, Craig D; Jackson, George R

2015-03-01

Gait parameters of forward, backward, and sideways walk were studied when the participants walked overground in four directions at their self-selected speed and were compared with walking in the four directions on an instrumented GAITRite walkway. Intraclass correlation coefficients between the overground walk test measures and the instrumented walkway measures of gait speed, cadence, and stride length for the forward walk were 0.85, 0.88, and 0.87, respectively. For the backward walk, the coefficients were 0.91 for gait speed, 0.75 for cadence, and 0.93 for stride length. For the sideways walk, the coefficients were 0.92 for gait speed, 0.93 for cadence, and 0.94 for stride length. Gait parameters of forward, backward, and sideways walk obtained by the overground walk test had excellent agreement with those obtained by the instrumented walkway. The quick timed test provided quantitative data for gait evaluation and was valid for clinical use.

Walking for Transportation or Leisure Among U.S. Women and Men - National Health Interview Survey, 2005-2015.

PubMed

Ussery, Emily N; Carlson, Susan A; Whitfield, Geoffrey P; Watson, Kathleen B; Berrigan, David; Fulton, Janet E

2017-06-30

Physical activity confers considerable health benefits, but only half of U.S. adults report participating in levels of aerobic physical activity consistent with guidelines (1,2). Step It Up! The Surgeon General's Call to Action to Promote Walking and Walkable Communities identified walking as an important public health strategy to increase physical activity levels (3). A previous report showed that the self-reported prevalence of walking for transportation or leisure increased by 6 percentage points from 2005 to 2010 (4), but it is unknown whether this increase has been sustained. CDC analyzed National Health Interview Survey (NHIS) data from 2005 (26,551 respondents), 2010 (23,313), and 2015 (28,877) to evaluate trends in the age-adjusted prevalence of self-reported walking among adults aged ≥18 years. The prevalence of walking increased steadily among women, from 57.3% in 2005, to 62.5% in 2010, and to 65.1% in 2015 (significant linear trend). Among men, a significant linear increase in reported walking was observed, from 54.3% in 2005, to 61.8% in 2010, and to 62.8% in 2015, although the increase stalled between 2010 and 2015 (significant linear and quadratic trends). Community design policies and practices that encourage pedestrian activity and programs tailored to the needs of specific population subgroups remain important strategies for promoting walking (3).

Temporal relationships of emotional avoidance in a patient with anorexia nervosa--a time series analysis.

PubMed

Stroe-Kunold, Esther; Wesche, Daniela; Friederich, Hans-Christoph; Herzog, Wolfgang; Zastrow, Arne; Wild, Beate

2012-01-01

Anorexia nervosa (AN) is a serious eating disorder marked by self-induced underweight. In patients with AN, the avoidance of emotions appears to be a central feature that is reinforced during the acute state of the disorder. This single case study investigated the role of emotional avoidance of a 25-year-old patient with AN during her inpatient treatment. Throughout the course of 96 days, the patient answered questions daily about her emotional avoidance, pro-anorectic beliefs, perfectionism, and further variables on an electronic diary. The patient's daily self-assessment of emotional avoidance was described in terms of mean value, range, and variability for the various treatment phases. Temporal relationships between emotional avoidance and further variables were determined using a time series approach (vector autoregressive (VAR) modelling). Diary data reflect that the patient's ability to tolerate unpleasant emotions appeared to undergo a process of change during inpatient treatment. Results of the time series analysis indicate that the more the patient was able to deal with negative emotions on any one day (t-1), the less she would be socially avoidant, cognitively confined to food and eating, as well as feeling less secure with her AN, and less depressive on the following day (t). The findings show that for this patient emotional avoidance plays a central role in the interacting system of various psychosocial variables. Replication of these results in other patients with AN would support the recommendation to focus more on emotional regulation in the treatment of AN.

Feasibility of a Virtual Exercise Coach to Promote Walking in Community-Dwelling Persons with Parkinson Disease

PubMed Central

Ellis, Terry; Latham, Nancy K.; DeAngelis, Tamara R.; Thomas, Cathi A.; Saint-Hilaire, Marie; Bickmore, Timothy W.

2013-01-01

Objective The short-term benefits of exercise for persons with Parkinson Disease (PD) are well-established, but long-term adherence is limited. The aim of this study was to explore the feasibility, acceptability and preliminary evidence of effectiveness of a virtual exercise coach to promote daily walking in community dwelling persons with PD. Design Twenty subjects with PD participated in this Phase I single group, non-randomized clinical trial. Subjects were instructed to interact with the virtual exercise coach for 5 minutes, wear a pedometer and walk daily for one month. Retention rate, satisfaction and interaction history were assessed at 1-month. Six-minute walk and gait speed were assessed at baseline and post intervention. Results Participants were 55% female, mean age 65.6. At study completion, there was a 100% retention rate. Subjects had an average satisfaction score of 5.6/7 (with seven indicating maximal satisfaction) with the virtual exercise coach. Interaction history revealed that participants logged-in an average of 25.4 days (SD 7) out of the recommended 30 days. Mean adherence to daily walking was 85%. Both gait speed and the 6-minute walk test significantly improved (p<0.05). No adverse events were reported. Conclusions Sedentary persons with PD successfully used a computer and interacted with a virtual exercise coach. Retention, satisfaction and adherence to daily walking were high over one-month and significant improvements were seen in mobility. PMID:23552335

Biopsychosocial Characteristics of Community-dwelling Older Adults with Limited Ability to Walk ¼ Mile

PubMed Central

Hardy, Susan E.; McGurl, David J.; Studenski, Stephanie A.; Degenholtz, Howard B.

2010-01-01

Objectives To establish nationally representative estimates of the prevalence of self-reported difficulty and inability to walk ¼ mile among older adults and to identify the characteristics independently associated with difficulty or inability to walk ¼ mile. Design Cross-sectional analysis of data from the 2003 Cost and Use Medicare Current Beneficiary Survey. Setting Community. Participants 9563 community-dwelling Medicare beneficiaries aged 65 years or older, representing an estimated total population of 34.2 million older adults. Measurements Self-reported ability to walk ¼ mile, sociodemographics, chronic conditions, body mass index, smoking, and functional status. Results In 2003, an estimated 9.5 million aged Medicare beneficiaries had difficulty walking ¼ mile and 5.9 million were unable. Among the 20.2 million older adults with no difficulty in basic or instrumental activities of daily living (ADL), an estimated 4.3 million (21%) had limited ability to walk ¼ mile. Having difficulty or being unable to walk ¼ mile was independently associated with older age, female sex, non-Hispanic ethnicity, lower educational level, Medicaid entitlement, most chronic medical conditions, current smoking, and being overweight or obese. Conclusion Almost half of older adults, and 20% of those reporting no ADL limitations, report limited ability to walk ¼ mile. Among functionally independent older adults, reported ability to walk ¼ mile can identify vulnerable older adults with greater medical problems and fewer resources, and may be a valuable clinical marker in planning their care. Future work is needed to determine the association between ¼ mile walk ability and subsequent functional decline and healthcare utilization. PMID:20210817

Warming up and cooling down (image)

MedlinePlus

... for 5 to 10 minutes, one may avoid injury and build endurance over time. Cooling down after exercise by walking slowly, then stretching muscles, may also prevent strains and blood pressure fluctuation.

Color in context: psychological context moderates the influence of red on approach- and avoidance-motivated behavior.

PubMed

Meier, Brian P; D'Agostino, Paul R; Elliot, Andrew J; Maier, Markus A; Wilkowski, Benjamin M

2012-01-01

A basic premise of the recently proffered color-in-context model is that the influence of color on psychological functioning varies as a function of the psychological context in which color is perceived. Some research has examined the appetitive and aversive implications of viewing the color red in romance- and achievement-relevant contexts, respectively, but in all existing empirical work approach and avoidance behavior has been studied in separate tasks and separate experiments. Research is needed to directly test whether red influences the same behavior differently depending entirely on psychological context. The present experiment was designed to put this premise to direct test in romance- and achievement-relevant contexts within the same experimental paradigm involving walking behavior. Our results revealed that exposure to red (but not blue) indeed has differential implications for walking behavior as a function of the context in which the color is perceived. Red increased the speed with which participants walked to an ostensible interview about dating (a romance-relevant context), but decreased the speed with which they walked to an ostensible interview about intelligence (an achievement-relevant context). These results are the first direct evidence that the influence of red on psychological functioning in humans varies by psychological context. Our findings contribute to both the literature on color psychology and the broader, emerging literature on the influence of context on basic psychological processes.

Biopsychosocial characteristics of community-dwelling older adults with limited ability to walk one-quarter of a mile.

PubMed

Hardy, Susan E; McGurl, David J; Studenski, Stephanie A; Degenholtz, Howard B

2010-03-01

To establish nationally representative estimates of the prevalence of self-reported difficulty and inability of older adults to walk one-quarter of a mile and to identify the characteristics independently associated with difficulty or inability to walk one-quarter of a mile. Cross-sectional analysis of data from the 2003 Cost and Use Medicare Current Beneficiary Survey. Community. Nine thousand five hundred sixty-three community-dwelling Medicare beneficiaries aged 65 and older, representing an estimated total population of 34.2 million older adults. Self-reported ability to walk one-quarter of a mile, sociodemographics, chronic conditions, body mass index, smoking, functional status. In 2003, an estimated 9.5 million older Medicare beneficiaries had difficulty walking one-quarter of a mile, and 5.9 million were unable to do so. Of the 20.2 million older adults with no difficulty in activities of daily living (ADLs) or instrumental activities of daily living (IADLs), an estimated 4.3 million (21%) had limited ability to walk one-quarter of a mile. Having difficulty or being unable to walk one-quarter of a mile was independently associated with older age, female sex, non-Hispanic ethnicity, lower educational level, Medicaid entitlement, most chronic medical conditions, current smoking, and being overweight or obese. Almost half of older adults and 20% of those reporting no ADL or IADL limitations report limited ability to walk one-quarter of a mile. For functionally independent older adults, reported ability to walk one-quarter of a mile can identify vulnerable older adults with greater medical problems and fewer resources and may be a valuable clinical marker in planning their care. Future work is needed to determine the association between ability to walk one-quarter of a mile walk and subsequent functional decline and healthcare use.

Reductions in knee joint forces with weight loss are attenuated by gait adaptations in class III obesity.

PubMed

DeVita, Paul; Rider, Patrick; Hortobágyi, Tibor

2016-03-01

A consensus exists that high knee joint forces are a precursor to knee osteoarthritis and weight loss reduces these forces. Because large weight loss also leads to increased step length and walking velocity, knee contact forces may be reduced less than predicted by the magnitude of weight loss. The purpose was to determine the effects of weight loss on knee muscle and joint loads during walking in Class III obese adults. We determined through motion capture, force platform measures and biomechanical modeling the effects of weight loss produced by gastric bypass surgery over one year on knee muscle and joint loads during walking at a standard, controlled velocity and at self-selected walking velocities. Weight loss equaling 412 N or 34% of initial body weight reduced maximum knee compressive force by 824 N or 67% of initial body weight when walking at the controlled velocity. These changes represent a 2:1 reduction in knee force relative to weight loss when walking velocity is constrained to the baseline value. However, behavioral adaptations including increased stride length and walking velocity in the self-selected velocity condition attenuated this effect by ∼50% leading to a 392 N or 32% initial body weight reduction in compressive force in the knee joint. Thus, unconstrained walking elicited approximately 1:1 ratio of reduction in knee force relative to weight loss and is more indicative of walking behavior than the standard velocity condition. In conclusion, massive weight loss produces dramatic reductions in knee forces during walking but when patients stride out and walk faster, these favorable reductions become substantially attenuated. Copyright © 2016 Elsevier B.V. All rights reserved.

The impact of a home-based walking programme on falls in older people: the Easy Steps randomised controlled trial.

PubMed

Voukelatos, Alexander; Merom, Dafna; Sherrington, Catherine; Rissel, Chris; Cumming, Robert G; Lord, Stephen R

2015-05-01

walking is the most popular form of exercise in older people but the impact of walking on falls is unclear. This study investigated the impact of a 48-week walking programme on falls in older people. three hundred and eighty-six physically inactive people aged 65+ years living in the community were randomised into an intervention or control group. The intervention group received a self-paced, 48-week walking programme that involved three mailed printed manuals and telephone coaching. Coinciding with the walking programme manual control group participants received health information unrelated to falls. Monthly falls calendars were used to monitor falls (primary outcome) over 48 weeks. Secondary outcomes were self-reported quality of life, falls efficacy, exercise and walking levels. Mobility, leg strength and choice stepping reaction time were measured in a sub-sample (n = 178) of participants. there was no difference in fall rates between the intervention and control groups in the follow-up period (IRR = 0.88, 95% CI: 0.60-1.29). By the end of the study, intervention group participants spent significantly more time exercising in general, and specifically walking for exercise (median 1.69 versus 0.75 h/week, P < 0.001). our finding that a walking programme is ineffective in preventing falls supports previous research and questions the suitability of recommending walking as a fall prevention strategy for older people. Walking, however, increases physical activity levels in previously inactive older people. © The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Plantarflexor weakness negatively impacts walking in persons with multiple sclerosis more than plantarflexor spasticity

PubMed Central

Wagner, Joanne M.; Kremer, Theodore R.; Van Dillen, Linda R.; Naismith, Robert T.

2014-01-01

Objective To determine if plantarflexor (PF) spasticity or ankle strength best predicts variance in walking capacity or self-perceived limitations in walking in persons with multiple sclerosis (pwMS), and if pwMS with PF spasticity are weaker and have greater walking dysfunction than pwMS without PF spasticity. Design Cross-sectional study. Setting University research laboratory. Participants Forty-two pwMS (age: 42.9 ± 10.1 years; Expanded Disability Status Scale (EDSS): median = 3.0, range = 0–6) and 14 adults without disability (WD) (age: 41.9 ± 10.1 years). Intervention Not applicable. Main Outcome Measures PF spasticity and dorsiflexion (DF) and PF maximum voluntary isometric torque (MVIT) were assessed using the Modified Ashworth Scale (MAS) and a computerized dynamometer, respectively. The Timed 25-Foot Walk Test (T25FWT) was the primary outcome measure of walking capacity. Secondary measures included the Six Minute Walk Test (6MWT) and 12-item Multiple Sclerosis Walking Scale (MSWS-12). Results PF strength was the most consistent predictor of the variance in walking capacity (T25FWT: R2 change = 0.23 to 0.29, p ≤ 0.001; 6MWT: R2 change = 0.12 to 0.29, p ≤ 0.012), and self-perceived limitations of walking (MSWS-12: R2 change = 0.04 to 0.14, p < 0.18). There were no significant differences (p > 0.05) between the pwMS with PF spasticity and pwMS without PF spasticity for any of the outcome measures. Conclusions Our study suggests a unique contribution of PF weakness to walking dysfunction in pwMS, and highlights the importance of evaluating PF strength in this clinical population. PMID:24582617

Maximum walking speeds obtained using treadmill and overground robot system in persons with post-stroke hemiplegia

PubMed Central

2012-01-01

Background Previous studies demonstrated that stroke survivors have a limited capacity to increase their walking speeds beyond their self-selected maximum walking speed (SMWS). The purpose of this study was to determine the capacity of stroke survivors to reach faster speeds than their SMWS while walking on a treadmill belt or while being pushed by a robotic system (i.e. “push mode”). Methods Eighteen chronic stroke survivors with hemiplegia were involved in the study. We calculated their self-selected comfortable walking speed (SCWS) and SMWS overground using a 5-meter walk test (5-MWT). Then, they were exposed to walking at increased speeds, on a treadmill and while in “push mode” in an overground robotic device, the KineAssist, until they were tested at a speed that they could not sustain without losing balance. We recorded the time and number of steps during each trial and calculated gait speed, average cadence and average step length. Results Maximum walking speed in the “push mode” was 13% higher than the maximum walking speed on the treadmill and both were higher (“push mode”: 61%; treadmill: 40%) than the maximum walking speed overground. Subjects achieved these faster speeds by initially increasing both step length and cadence and, once individuals stopped increasing their step length, by only increasing cadence. Conclusions With post-stroke hemiplegia, individuals are able to walk at faster speeds than their SMWS overground, when provided with a safe environment that provides external forces that requires them to attempt dynamic stability maintenance at higher gait speeds. Therefore, this study suggests the possibility that, given the appropriate conditions, people post-stroke can be trained at higher speeds than previously attempted. PMID:23057500

Trajectories of Children's Social Interactions with their Infant Sibling in the First Year: A Multi-Dimensional Approach

PubMed Central

Oh, Wonjung; Volling, Brenda L.; Gonzalez, Richard

2015-01-01

Individual differences in longitudinal trajectories of children's social behaviors toward their infant sibling were examined simultaneously across multiple social dimensions: Positive engagement (moving toward), Antagonism (moving against), and Avoidance (moving away). Three distinct social patterns were identified: (C1) Positively-Engaged (n=107, 50%); (C2) Escalating-Antagonism (n=90, 42%); and (C3) Early-Onset Antagonism (n=16, 8%). Children in the positively-engaged class had high levels of positive engagement with their infant siblings, coupled with low levels of antagonism and avoidance. The escalating-antagonism class was positively engaged in sibling interaction with a steep escalation in antagonistic behavior and avoidance from 4 to 12 months. Children in the early-onset antagonism class displayed the highest level of antagonistic behavior starting as early as 4 months, and became increasingly avoidant over time. A path model, guided by a process × person × context × time model, revealed that low parental self-efficacy heightened by parenting stress and children's dysregulated temperament was directly related to the escalating-antagonism pattern. Punitive parenting in response to children's antagonistic behavior increased the likelihood of being in the early-onset antagonism class. Together, the results highlighted heterogeneity in the earliest emergence of sibling interaction patterns and the interplay of child and parent factors in predicting distinct sibling interaction trajectory patterns. PMID:25664367

Accelerometry in persons with multiple sclerosis: measurement of physical activity or walking mobility?

PubMed

Weikert, Madeline; Motl, Robert W; Suh, Yoojin; McAuley, Edward; Wynn, Daniel

2010-03-15

Motion sensors such as accelerometers have been recognized as an ideal measure of physical activity in persons with MS. This study examined the hypothesis that accelerometer movement counts represent a measure of both physical activity and walking mobility in individuals with MS. The sample included 269 individuals with a definite diagnosis of relapsing-remitting MS who completed the Godin Leisure-Time Exercise Questionnaire (GLTEQ), International Physical Activity Questionnaire (IPAQ), Multiple Sclerosis Walking Scale-12 (MSWS-12), Patient Determined Disease Steps (PDDS), and then wore an ActiGraph accelerometer for 7days. The data were analyzed using bivariate correlation and confirmatory factor analysis. The results indicated that (a) the GLTEQ and IPAQ scores were strongly correlated and loaded significantly on a physical activity latent variable, (b) the MSWS-12 and PDDS scores strongly correlated and loaded significantly on a walking mobility latent variable, and (c) the accelerometer movement counts correlated similarly with the scores from the four self-report questionnaires and cross-loaded on both physical activity and walking mobility latent variables. Our data suggest that accelerometers are measuring both physical activity and walking mobility in persons with MS, whereas self-report instruments are measuring either physical activity or walking mobility in this population.

A community-based Falls Management Exercise Programme (FaME) improves balance, walking speed and reduced fear of falling.

PubMed

Yeung, Pui Yee; Chan, Wayne; Woo, Jean

2015-04-01

Although effective community falls prevention programmes for the older persons have been described, challenges remain in translating proven interventions into daily practice. To evaluate the efficacy, feasibility and acceptability of a falls prevention programme that can be integrated into daily activities in a group of community-dwelling older adults with risk of falling. A cohort study with intervention and comparison groups was designed to evaluate a 36-week group-based falls prevention exercise programme (FaME) in the community setting. Participants were aged 60 years or older, had fallen in the past 12 months, had fear of falling with avoidance of activities or had deficits in balance control. Primary outcome measures included assessment of balance control and mobility; secondary outcome measures included level of physical activity, assessment of fear of falling and health-related quality of life. There were 48 and 51 participants in the intervention and comparison groups, respectively. There were improvements in measurements of balance, walking speed and self-efficacy. The drop out rate was low (14.6% and 3.9% from the intervention and comparison groups, respectively). Overall compliance in the intervention group was 79%. Factors that motivated continued participation include the regular and long-term nature of the programme helping to reinforce their exercise habits, the simplicity of movements and friendliness of the group. The FaME programme improves balance, walking speed and reduces fear of falling. It could be widely promoted and integrated into regular health and social activities in community settings.

Improving chronic lung disease management in rural and remote Australia: the Breathe Easy Walk Easy programme.

PubMed

Johnston, Catherine L; Maxwell, Lyndal J; Boyle, Eileen; Maguire, Graeme P; Alison, Jennifer A

2013-01-01

To evaluate the impact of a chronic lung disease management training programme, Breathe Easy Walk Easy (BEWE), for rural and remote health-care practitioners. Quasi-experimental, before and after repeated measures design. Health-care practitioners (n = 33) from various professional backgrounds who attended the BEWE training workshop were eligible to participate. Breathe Easy Walk Easy, an interactive educational programme, consisted of a training workshop, access to online resources, provision of community awareness-raising materials and ongoing telephone/email support. Participant confidence, knowledge and attitudes were assessed via anonymous questionnaire before, immediately after and at 3 and 12 months following the BEWE workshop. At 12 months, local provision of pulmonary rehabilitation services and patient outcome data (6-min walk test results before and after pulmonary rehabilitation) were also recorded. Measured knowledge (score out of 19) improved significantly after the workshop (mean difference 7.6 correct answers, 95% confidence interval: 5.8-9.3). Participants' self-rated confidence and knowledge also increased. At 12-month follow up, three locally run pulmonary rehabilitation programmes had been established. For completing patients, there was a significant increase in 6-min walk distance following rehabilitation of 48 m (95% confidence interval: 18-70 m). The BEWE programme increased rural and remote health-care practitioner knowledge and confidence in delivering management for people living with chronic lung disease and facilitated the establishment of effective pulmonary rehabilitation programmes in regional and remote Australian settings where access to such programmes is limited. © 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.

Large-cell Monte Carlo renormalization of irreversible growth processes

NASA Technical Reports Server (NTRS)

Nakanishi, H.; Family, F.

1985-01-01

Monte Carlo sampling is applied to a recently formulated direct-cell renormalization method for irreversible, disorderly growth processes. Large-cell Monte Carlo renormalization is carried out for various nonequilibrium problems based on the formulation dealing with relative probabilities. Specifically, the method is demonstrated by application to the 'true' self-avoiding walk and the Eden model of growing animals for d = 2, 3, and 4 and to the invasion percolation problem for d = 2 and 3. The results are asymptotically in agreement with expectations; however, unexpected complications arise, suggesting the possibility of crossovers, and in any case, demonstrating the danger of using small cells alone, because of the very slow convergence as the cell size b is extrapolated to infinity. The difficulty of applying the present method to the diffusion-limited-aggregation model, is commented on.

Compaction of quasi-one-dimensional elastoplastic materials.

PubMed

Shaebani, M Reza; Najafi, Javad; Farnudi, Ali; Bonn, Daniel; Habibi, Mehdi

2017-06-06

Insight into crumpling or compaction of one-dimensional objects is important for understanding biopolymer packaging and designing innovative technological devices. By compacting various types of wires in rigid confinements and characterizing the morphology of the resulting crumpled structures, here, we report how friction, plasticity and torsion enhance disorder, leading to a transition from coiled to folded morphologies. In the latter case, where folding dominates the crumpling process, we find that reducing the relative wire thickness counter-intuitively causes the maximum packing density to decrease. The segment size distribution gradually becomes more asymmetric during compaction, reflecting an increase of spatial correlations. We introduce a self-avoiding random walk model and verify that the cumulative injected wire length follows a universal dependence on segment size, allowing for the prediction of the efficiency of compaction as a function of material properties, container size and injection force.

A new time domain random walk method for solute transport in 1-D heterogeneous media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banton, O.; Delay, F.; Porel, G.

A new method to simulate solute transport in 1-D heterogeneous media is presented. This time domain random walk method (TDRW), similar in concept to the classical random walk method, calculates the arrival time of a particle cloud at a given location (directly providing the solute breakthrough curve). The main advantage of the method is that the restrictions on the space increments and the time steps which exist with the finite differences and random walk methods are avoided. In a homogeneous zone, the breakthrough curve (BTC) can be calculated directly at a given distance using a few hundred particles or directlymore » at the boundary of the zone. Comparisons with analytical solutions and with the classical random walk method show the reliability of this method. The velocity and dispersivity calculated from the simulated results agree within two percent with the values used as input in the model. For contrasted heterogeneous media, the random walk can generate high numerical dispersion, while the time domain approach does not.« less

The facilitative nature of avoidance coping within sports injury rehabilitation.

PubMed

Carson, F; Polman, R C J

2010-04-01

Avoidance coping has commonly been reported within literature to be a debilitative process. However, in situations where goal attainment is reduced or eradicated avoidance coping strategies appear to have some benefit. The aim of this study was to identify the role of avoidance coping within the sports injury rehabilitation setting. A mixed methodological approach was utilized with four professional male rugby union players, concurrent with their rehabilitation from anterior cruciate ligament (ACL) surgery. Twice monthly interviews were conducted with each player, along with a self-report diary and the Coping with Health, Injuries and Problems (CHIP; Endler & Parker, 2000) inventory. Content analysis showed six higher-order themes split into two general dimensions: (a) behavioral avoidance coping (physical distraction, social interaction, maladaptive behaviors), and (b) cognitive avoidance coping (denial, thought stopping, cognitive distraction). Results suggest avoidance coping strategies facilitate control of short-term emotional states, as well has appearing to have long-term benefits for injured players. Particular benefits were associated with undertaking alternate work within the sports organization.

Direct detection signatures of self-interacting dark matter with a light mediator

DOE PAGES

Nobile, Eugenio Del; Kaplinghat, Manoj; Yu, Hai-Bo

2015-10-27

Self-interacting dark matter (SIDM) is a simple and well-motivated scenario that could explain long-standing puzzles in structure formation on small scales. If the required self-interaction arises through a light mediator (with mass ~ 10 MeV) in the dark sector, this new particle must be unstable to avoid overclosing the universe. The decay of the light mediator could happen due to a weak coupling of the hidden and visible sectors, providing new signatures for direct detection experiments. The SIDM nuclear recoil spectrum is more peaked towards low energies compared to the usual case of contact interactions, because the mediator mass ismore » comparable to the momentum transfer of nuclear recoils. We show that the SIDM signal could be distinguished from that of DM particles with contact interactions by considering the time-average energy spectrum in experiments employing different target materials, or the average and modulated spectra in a single experiment. Using current limits from LUX and SuperCDMS, we also derive strong bounds on the mixing parameter between hidden and visible sector.« less

Vigilance-avoidance and disengagement are differentially associated with fear and avoidant behaviors in social anxiety.

PubMed

Evans, Travis C; Walukevich, Katherine A; Britton, Jennifer C

2016-07-15

Individuals with Social Anxiety Disorder (SAD) often exhibit preferential attention for social threat, demonstrating abnormal orientation to threat (i.e., vigilance-avoidance) and/or difficulty disengaging from threat. However, no research has compared the relationship between attention indices (i.e., vigilance-avoidance, difficulty disengaging from threat) and characteristic features of the disorder such as fear during social situations (social fear) and avoidant behaviors (social avoidance). To address this issue, seventy adults (19.29±1.47 years, 33 females) were separated into low (n=37) or high (n=33) socially anxious groups using clinical cutoff scores on the Social Interaction Anxiety Scale (SIAS). Participants in both groups completed a dot-probe task with congruent, incongruent, and neutral trials to obtain measures of vigilance-avoidance and difficulty disengaging. Using linear regression, we examined the associations each attention index shared with self-reported social fear and social avoidance. Exclusively in the high anxious group, greater vigilance towards threat was associated with higher self-reported social fear, but not with social avoidance. However, difficulty disengaging was not associated with either social measure. In the low anxiety group, no relationships between attention indices and either social measure emerged. Future research with clinical samples is necessary to replicate and extend these findings. The small sample size studied may have limited our ability to detect other smaller effects. Indices of attention bias may contribute differently to the etiology and maintenance of SAD, which offers important implications for novel treatments that target attention. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of 1-Mile Walk Tests to Estimate Aerobic Fitness in Children

ERIC Educational Resources Information Center

Sung, Hoyong; Collier, David N.; DuBose, Katrina D.; Kemble, C. David; Mahar, Matthew T.

2018-01-01

To examine the reliability and validity of 1-mile walk tests for estimation of aerobic fitness (VO[subscript 2max]) in 10- to 13-year-old children and to cross-validate previously published equations. Participants (n = 61) walked 1-mile on two different days. Self-reported physical activity, demographic variables, and aerobic fitness were used in…

Random walks of colloidal probes in viscoelastic materials

NASA Astrophysics Data System (ADS)

Khan, Manas; Mason, Thomas G.

2014-04-01

To overcome limitations of using a single fixed time step in random walk simulations, such as those that rely on the classic Wiener approach, we have developed an algorithm for exploring random walks based on random temporal steps that are uniformly distributed in logarithmic time. This improvement enables us to generate random-walk trajectories of probe particles that span a highly extended dynamic range in time, thereby facilitating the exploration of probe motion in soft viscoelastic materials. By combining this faster approach with a Maxwell-Voigt model (MVM) of linear viscoelasticity, based on a slowly diffusing harmonically bound Brownian particle, we rapidly create trajectories of spherical probes in soft viscoelastic materials over more than 12 orders of magnitude in time. Appropriate windowing of these trajectories over different time intervals demonstrates that random walk for the MVM is neither self-similar nor self-affine, even if the viscoelastic material is isotropic. We extend this approach to spatially anisotropic viscoelastic materials, using binning to calculate the anisotropic mean square displacements and creep compliances along different orthogonal directions. The elimination of a fixed time step in simulations of random processes, including random walks, opens up interesting possibilities for modeling dynamics and response over a highly extended temporal dynamic range.

Walking smoothness is associated with self-reported function after accounting for gait speed.

PubMed

Lowry, Kristin A; Vanswearingen, Jessie M; Perera, Subashan; Studenski, Stephanie A; Brach, Jennifer S

2013-10-01

Gait speed has shown to be an indicator of functional status in older adults; however, there may be aspects of physical function not represented by speed but by the quality of movement. The purpose of this study was to determine the relations between walking smoothness, an indicator of the quality of movement based on trunk accelerations, and physical function. Thirty older adults (mean age, 77.7±5.1 years) participated. Usual gait speed was measured using an instrumented walkway. Walking smoothness was quantified by harmonic ratios derived from anteroposterior, vertical, and mediolateral trunk accelerations recorded during overground walking. Self-reported physical function was recorded using the function subscales of the Late-Life Function and Disability Instrument. Anteroposterior smoothness was positively associated with all function components of the Late-Life Function and Disability Instrument, whereas mediolateral smoothness exhibited negative associations. Adjusting for gait speed, anteroposterior smoothness remained associated with the overall and lower extremity function subscales, whereas mediolateral smoothness remained associated with only the advanced lower extremity subscale. These findings indicate that walking smoothness, particularly the smoothness of forward progression, represents aspects of the motor control of walking important for physical function not represented by gait speed alone.

I Walk My Dog Because It Makes Me Happy: A Qualitative Study to Understand Why Dogs Motivate Walking and Improved Health

PubMed Central

Marvin, Garry; Perkins, Elizabeth

2017-01-01

Dog walking is a popular everyday physical activity. Dog owners are generally more active than non-owners, but some rarely walk with their dog. The strength of the dog–owner relationship is known to be correlated with dog walking, and this qualitative study investigates why. Twenty-six interviews were combined with autoethnography of dog walking experiences. Dog walking was constructed as “for the dog”, however, owners represented their dog’s needs in a way which aligned with their own. Central to the construction of need was perceptions of dog personality and behaviour. Owners reported deriving positive outcomes from dog walking, most notably, feelings of “happiness”, but these were “contingent” on the perception that their dogs were enjoying the experience. Owner physical activity and social interaction were secondary bonuses but rarely motivating. Perceptions and beliefs of owners about dog walking were continually negotiated, depending on how the needs of the owner and dog were constructed at that time. Complex social interactions with the “significant other” of a pet can strongly motivate human health behaviour. Potential interventions to promote dog walking need to account for this complexity and the effect of the dog-owner relationship on owner mental wellbeing. PMID:28825614

I Walk My Dog Because It Makes Me Happy: A Qualitative Study to Understand Why Dogs Motivate Walking and Improved Health.

PubMed

Westgarth, Carri; Christley, Robert M; Marvin, Garry; Perkins, Elizabeth

2017-08-19

Dog walking is a popular everyday physical activity. Dog owners are generally more active than non-owners, but some rarely walk with their dog. The strength of the dog-owner relationship is known to be correlated with dog walking, and this qualitative study investigates why. Twenty-six interviews were combined with autoethnography of dog walking experiences. Dog walking was constructed as "for the dog", however, owners represented their dog's needs in a way which aligned with their own. Central to the construction of need was perceptions of dog personality and behaviour. Owners reported deriving positive outcomes from dog walking, most notably, feelings of "happiness", but these were "contingent" on the perception that their dogs were enjoying the experience. Owner physical activity and social interaction were secondary bonuses but rarely motivating. Perceptions and beliefs of owners about dog walking were continually negotiated, depending on how the needs of the owner and dog were constructed at that time. Complex social interactions with the "significant other" of a pet can strongly motivate human health behaviour. Potential interventions to promote dog walking need to account for this complexity and the effect of the dog-owner relationship on owner mental wellbeing.

Lévy walks

NASA Astrophysics Data System (ADS)

Zaburdaev, V.; Denisov, S.; Klafter, J.

2015-04-01

Random walk is a fundamental concept with applications ranging from quantum physics to econometrics. Remarkably, one specific model of random walks appears to be ubiquitous across many fields as a tool to analyze transport phenomena in which the dispersal process is faster than dictated by Brownian diffusion. The Lévy-walk model combines two key features, the ability to generate anomalously fast diffusion and a finite velocity of a random walker. Recent results in optics, Hamiltonian chaos, cold atom dynamics, biophysics, and behavioral science demonstrate that this particular type of random walk provides significant insight into complex transport phenomena. This review gives a self-consistent introduction to Lévy walks, surveys their existing applications, including latest advances, and outlines further perspectives.

Trunk motion visual feedback during walking improves dynamic balance in older adults: Assessor blinded randomized controlled trial.

PubMed

Anson, Eric; Ma, Lei; Meetam, Tippawan; Thompson, Elizabeth; Rathore, Roshita; Dean, Victoria; Jeka, John

2018-05-01

Virtual reality and augmented feedback have become more prevalent as training methods to improve balance. Few reports exist on the benefits of providing trunk motion visual feedback (VFB) during treadmill walking, and most of those reports only describe within session changes. To determine whether trunk motion VFB treadmill walking would improve over-ground balance for older adults with self-reported balance problems. 40 adults (75.8 years (SD 6.5)) with self-reported balance difficulties or a history of falling were randomized to a control or experimental group. Everyone walked on a treadmill at a comfortable speed 3×/week for 4 weeks in 2 min bouts separated by a seated rest. The control group was instructed to look at a stationary bulls-eye target while the experimental group also saw a moving cursor superimposed on the stationary bulls-eye that represented VFB of their walking trunk motion. The experimental group was instructed to keep the cursor in the center of the bulls-eye. Somatosensory (monofilaments and joint position testing) and vestibular function (canal specific clinical head impulses) was evaluated prior to intervention. Balance and mobility were tested before and after the intervention using Berg Balance Test, BESTest, mini-BESTest, and Six Minute Walk. There were no significant differences between groups before the intervention. The experimental group significantly improved on the BESTest (p = 0.031) and the mini-BEST (p = 0.019). The control group did not improve significantly on any measure. Individuals with more profound sensory impairments had a larger improvement on dynamic balance subtests of the BESTest. Older adults with self-reported balance problems improve their dynamic balance after training using trunk motion VFB treadmill walking. Individuals with worse sensory function may benefit more from trunk motion VFB during walking than individuals with intact sensory function. Copyright © 2018 Elsevier B.V. All rights reserved.

Relationship between neighborhood walkability and older adults' physical activity: results from the Belgian Environmental Physical Activity Study in Seniors (BEPAS Seniors).

PubMed

Van Holle, Veerle; Van Cauwenberg, Jelle; Van Dyck, Delfien; Deforche, Benedicte; Van de Weghe, Nico; De Bourdeaudhuij, Ilse

2014-08-23

Adequate knowledge on environmental correlates of physical activity (PA) in older adults is needed to develop effective health promotion initiatives. However, research in this age group is scarce and most existing studies were conducted in North America. The present study aimed to examine relationships between GIS-based neighborhood walkability and objective and self-reported PA in community-dwelling Belgian older adults. Furthermore, moderating effects of neighborhood income levels were investigated. The Belgian Environmental Physical Activity Study (BEPAS) for Seniors is a cross-sectional study in older adults (≥65 yrs) and was conducted between October 2010 and September 2012. Data from 438 older adults living in 20 neighborhoods across Ghent (Belgium) were analyzed. Stratification of selected neighborhoods was based upon objective walkability and neighborhood income. Participants wore an accelerometer during seven consecutive days to obtain objective levels of moderate-to-vigorous physical activity (MVPA). Self-reported levels of transportation walking/cycling and recreational walking/cycling were assessed using the International Physical Activity Questionnaire (long, last 7 days version) adapted for the elderly. Multi-level regression analyses were conducted. Findings showed a positive relationship between neighborhood walkability and weekly minutes of older adults' self-reported walking for transportation (B = 4.63 ± 1.05;p < 0.001) and a negative relationship between walkability and accelerometer-derived low-light PA (B = -1.38 ± 0.62;p = 0.025). Walkability was not related to any measure of recreational PA. A walkability x income interaction was found for accelerometer-derived MVPA (B = -1.826 ± 1.03;p = 0.075), showing only a positive association between walkability and MVPA in low-income neighborhood residents. This was the first European study to examine walkability-PA relationships in older adults. These Belgian findings suggest that a high neighborhood walkability relates to higher levels of older adults' transport-related walking. As transport-related walking is an accessible activity for older adults and easy to integrate in their daily routine, policy makers and health promoters are advised to provide sufficient destinations and pedestrian-friendly facilities in the close vicinity of older adults' residences, so short trips can be made by foot. Neighborhood income moderated the relationship between walkability and objectively-measured MVPA. Increasing total MVPA levels in older adults should be a key topic in development of promotion initiatives and special attention should be paid to low-income neighborhood residents.

The Effect of Priming with Photographs of Environmental Settings on Walking Speed in an Outdoor Environment.

PubMed

Franěk, Marek; Režný, Lukáš

2017-01-01

This study examined the effect of priming with photographs of various environmental settings on the speed of a subsequent outdoor walk in an urban environment. Either photographs of urban greenery, conifer forests, or shopping malls were presented or no prime was employed. Three experiments were conducted ( N = 126, N = 88, and N = 121). After being exposed to the priming or no-priming conditions, the participants were asked to walk along an urban route 1.9 km long with vegetation and mature trees (Experiment 1, Experiment 3) or along a route in a modern suburb (Experiment 2). In accord with the concept of approach-avoidance behavior, it was expected that priming with photographs congruent with the environmental setting of the walking route would result in slower walking speed. Conversely, priming with photographs incongruent with the environmental setting should result in faster walking speed. The results showed that priming with the photographs with vegetation caused a decrease in overall walking speed on the route relative to other experimental conditions. However, priming with incongruent primes did not lead to a significant increase in walking speed. In all experimental conditions, the slowest walking speed was found in sections with the highest natural character. The results are explained in terms of congruency between the prime and the environment, as well as by the positive psychological effects of viewing nature.

The Effect of Priming with Photographs of Environmental Settings on Walking Speed in an Outdoor Environment

PubMed Central

Franěk, Marek; Režný, Lukáš

2017-01-01

This study examined the effect of priming with photographs of various environmental settings on the speed of a subsequent outdoor walk in an urban environment. Either photographs of urban greenery, conifer forests, or shopping malls were presented or no prime was employed. Three experiments were conducted (N = 126, N = 88, and N = 121). After being exposed to the priming or no-priming conditions, the participants were asked to walk along an urban route 1.9 km long with vegetation and mature trees (Experiment 1, Experiment 3) or along a route in a modern suburb (Experiment 2). In accord with the concept of approach-avoidance behavior, it was expected that priming with photographs congruent with the environmental setting of the walking route would result in slower walking speed. Conversely, priming with photographs incongruent with the environmental setting should result in faster walking speed. The results showed that priming with the photographs with vegetation caused a decrease in overall walking speed on the route relative to other experimental conditions. However, priming with incongruent primes did not lead to a significant increase in walking speed. In all experimental conditions, the slowest walking speed was found in sections with the highest natural character. The results are explained in terms of congruency between the prime and the environment, as well as by the positive psychological effects of viewing nature. PMID:28184208

Studies on Metabolism of 1,4-Dioxane

DTIC Science & Technology

2010-03-01

altered strength, and stereotypes or bizarre behavior (e.g., self mutilation, walking backwards). f. Study conduct. The study described will be...from dioxane in drinking water that is the foundation of the EPA drinking water risk assessment. V.3.3 Laboratory Animals: V.3.3.1 Genus and Species...stimuli, altered strength, and stereotypes or bizarre behavior (e.g., self mutilation, walking backwards). V.4.1.2.3 Paralytics: N/A V.4.1.3 Literature

Approximate scaling properties of RNA free energy landscapes

NASA Technical Reports Server (NTRS)

Baskaran, S.; Stadler, P. F.; Schuster, P.

1996-01-01

RNA free energy landscapes are analysed by means of "time-series" that are obtained from random walks restricted to excursion sets. The power spectra, the scaling of the jump size distribution, and the scaling of the curve length measured with different yard stick lengths are used to describe the structure of these "time series". Although they are stationary by construction, we find that their local behavior is consistent with both AR(1) and self-affine processes. Random walks confined to excursion sets (i.e., with the restriction that the fitness value exceeds a certain threshold at each step) exhibit essentially the same statistics as free random walks. We find that an AR(1) time series is in general approximately self-affine on timescales up to approximately the correlation length. We present an empirical relation between the correlation parameter rho of the AR(1) model and the exponents characterizing self-affinity.

Modelling vertical human walking forces using self-sustained oscillator

NASA Astrophysics Data System (ADS)

Kumar, Prakash; Kumar, Anil; Racic, Vitomir; Erlicher, Silvano

2018-01-01

This paper proposes a model of a self-sustained oscillator which can generate reliably the vertical contact force between the feet of a healthy pedestrian and the supporting flat rigid surface. The model is motivated by the self-sustained nature of the walking process, i.e. a pedestrian generates the required inner energy to sustain its repetitive body motion. The derived model is a fusion of the well-known Rayleigh, Van der Pol and Duffing oscillators. Some additional nonlinear terms are added to produce both the odd and even harmonics observed in the experimentally measured force data. The model parameters were derived from force records due to twelve pedestrians walking on an instrumented treadmill at ten speeds using a linear least square technique. The stability analysis was performed using the energy balance method and perturbation method. The results obtained from the model show a good agreement with the experimental results.

Walking performance and muscle strength in the later stage poststroke: a nonlinear relationship.

PubMed

Carvalho, Cristiane; Sunnerhagen, Katharina S; Willén, Carin

2013-05-01

To evaluate the relation between muscle strength in the lower extremities and walking performance (speed and distance) in subjects in the later stage poststroke and to compare this with normative data. A cross-sectional observational study. University hospital department. Subjects poststroke (n=41; 31 men, 10 women) with a mean age of 59±5.8 years and a time from stroke onset of 52±36 months were evaluated. An urban sample (n=144) of 40- to 79-year-olds (69 men, 75 women) formed the healthy reference group. Not applicable. Muscle strength in the lower extremities was measured with an isokinetic dynamometer and combined into a strength index. Values for the 30-meter walk test for self-selected and maximum speed and the 6-minute walk test were measured. A nonlinear regression model was used. The average strength index was 730±309 in the subjects after stroke compared with 1112±362 in the healthy group. A nonlinear relation between walking performance and muscle strength was evident. The model explained 37% of the variance in self-selected speed in the stroke group and 20% in the healthy group, and 63% and 38%, respectively, in the maximum walking speed. For the 6-minute walk test, the model explained 44% of the variance in the stroke group. Subjects in the later stage poststroke were weaker than the healthy reference group, and their weakness was associated with walking performance. At the same strength index, subjects walked at lower speeds and shorter distances after stroke, indicating that there are multiple impairments that affect walking ability. Treatments focused on increasing muscle strength thus continue to hold promise. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Does walking explain associations between access to greenspace and lower mortality?

PubMed Central

Lachowycz, Kate; Jones, Andy P.

2014-01-01

Despite emerging evidence that access to greenspace is associated with longer life expectancy, little is understood about what causal mechanisms may explain this relationship. Based on social-ecological theories of health, greenspace has multifaceted potential to influence mortality but the potential alternative mediating pathways have not been empirically tested. This study evaluates relationships between access to greenspace, walking and mortality. Firstly, we test for an association between access to greenspace and self-reported levels of walking using a survey of 165,424 adults across England collected during 2007 and 2008. Negative binomial regression multilevel models were used to examine associations between greenspace access and self reported number of days walked in the last month, in total and for recreational and health purposes, after controlling for relevant confounders. Secondly we use an area level analysis of 6781 middle super output areas across England to examine if recreational walking mediates relationships between greenspace access and reduced premature mortality from circulatory disease. Results show clear evidence of better greenspace access being associated with higher reported recreational walking. There were between 13% and 18% more days of recreational walking in the greenest quintile compared with the least green after adjustment for confounders. Tests for mediation found no evidence that recreational walking explain the associations between greenspace and mortality. Futhermore, whilst the relationship between greenspace access and walking was observed for all areas, the relationship between greenspace access and reduced mortality was only apparent in the most deprived areas. These findings indicate that the association between greenspace and mortality, if causal, may be explained by mediators other than walking, such as psychosocial factors. Future research should concentrate on understanding the causal mechanisms underlying observed associations. PMID:24602966

Fractal fluctuations in spatiotemporal variables when walking on a self-paced treadmill.

PubMed

Choi, Jin-Seung; Kang, Dong-Won; Seo, Jeong-Woo; Tack, Gye-Rae

2017-12-08

This study investigated the fractal dynamic properties of stride time (ST), stride length (SL) and stride speed (SS) during walking on a self-paced treadmill (STM) in which the belt speed is automatically controlled by the walking speed. Twelve healthy young subjects participated in the study. The subjects walked at their preferred walking speed under four conditions: STM, STM with a metronome (STM+met), fixed-speed (conventional) treadmill (FTM), and FTM with a metronome (FTM+met). To compare the fractal dynamics between conditions, the mean, variability, and fractal dynamics of ST, SL, and SS were compared. Moreover, the relationship among the variables was examined under each walking condition using three types of surrogates. The mean values of all variables did not differ between the two treadmills, and the variability of all variables was generally larger for STM than for FTM. The use of a metronome resulted in a decrease in variability in ST and SS for all conditions. The fractal dynamic characteristics of SS were maintained with STM, in contrast to FTM, and only the fractal dynamic characteristics of ST disappeared when using a metronome. In addition, the fractal dynamic patterns of the cross-correlated surrogate results were identical to those of all variables for the two treadmills. In terms of the fractal dynamic properties, STM walking was generally closer to overground walking than FTM walking. Although further research is needed, the present results will be useful in research on gait fractal dynamics and rehabilitation. Copyright © 2017 Elsevier Ltd. All rights reserved.

A walk through the planned CS building. M.S. Thesis

NASA Technical Reports Server (NTRS)

Khorramabadi, Delnaz

1991-01-01

Using the architectural plan views of our future computer science building as test objects, we have completed the first stage of a Building walkthrough system. The inputs to our system are AutoCAD files. An AutoCAD converter translates the geometrical information in these files into a format suitable for 3D rendering. Major model errors, such as incorrect polygon intersections and random face orientations, are detected and fixed automatically. Interactive viewing and editing tools are provided to view the results, to modify and clean the model and to change surface attributes. Our display system provides a simple-to-use user interface for interactive exploration of buildings. Using only the mouse buttons, the user can move inside and outside the building and change floors. Several viewing and rendering options are provided, such as restricting the viewing frustum, avoiding wall collisions, and selecting different rendering algorithms. A plan view of the current floor, with the position of the eye point and viewing direction on it, is displayed at all times. The scene illumination can be manipulated, by interactively controlling intensity values for 5 light sources.

Spectacular Batesian mimicry in ants

NASA Astrophysics Data System (ADS)

Ito, Fuminori; Hashim, Rosli; Huei, Yek Sze; Kaufmann, Eva; Akino, Toshiharu; Billen, Johan

2004-10-01

The mechanism by which palatable species take advantage of their similarity in appearance to those that are unpalatable, in order to avoid predation, is called Batesian mimicry. Several arthropods are thought to be Batesian mimics of social insects; however, social insects that are Batesian mimics among themselves are rare. In Malaysia we found a possible Batesian mimic in an arboreal ant species, Camponotus sp., which was exclusively observed on foraging trails of the myrmicine ant Crematogaster inflata. The bright yellow and black colouring pattern, as well as the walking behaviour, were very similar in both species. We observed general interactions between the two species, and tested their palatability and the significance of the remarkably similar visual colour patterns for predator avoidance. Prey offered to C. inflata was also eaten by Camponotus workers in spite of their being attacked by C. inflata, indicating that Camponotus sp. is a commensal of C. inflata. An experiment with chicks as potential predators suggests that Camponotus sp. is palatable whereas C. inflata is unpalatable. After tasting C. inflata, the chicks no longer attacked Camponotus sp., indicating that Camponotus sp. is a Batesian mimic of Crematogaster inflata.

When sex is more than just sex: attachment orientations, sexual experience, and relationship quality.

PubMed

Birnbaum, Gurit E; Reis, Harry T; Mikulincer, Mario; Gillath, Omri; Orpaz, Ayala

2006-11-01

The authors explored the contribution of individual differences in attachment orientations to the experience of sexual intercourse and its association with relationship quality. In Study 1, 500 participants completed self-report scales of attachment orientations and sexual experience. The findings indicated that whereas attachment anxiety was associated with an ambivalent construal of sexual experience, attachment avoidance was associated with more aversive sexual feelings and cognitions. In Study 2, 41 couples reported on their attachment orientations and provided daily diary measures of sexual experiences and relationship interactions for a period of 42 days. Results showed that attachment anxiety amplified the effects of positive and negative sexual experiences on relationship interactions. In contrast, attachment avoidance inhibited the positive relational effect of having sex and the detrimental relational effects of negative sexual interactions. The authors discuss the possibility that attachment orientations are associated with different sex-related strategies and goals within romantic relationships.

Access to commercial destinations within the neighbourhood and walking among Australian older adults.

PubMed

Nathan, Andrea; Pereira, Gavin; Foster, Sarah; Hooper, Paula; Saarloos, Dick; Giles-Corti, Billie

2012-11-20

Physical activity, particularly walking, is greatly beneficial to health; yet a sizeable proportion of older adults are insufficiently active. The importance of built environment attributes for walking is known, but few studies of older adults have examined neighbourhood destinations and none have investigated access to specific, objectively-measured commercial destinations and walking. We undertook a secondary analysis of data from the Western Australian state government's health surveillance survey for those aged 65-84 years and living in the Perth metropolitan region from 2003-2009 (n = 2,918). Individual-level road network service areas were generated at 400 m and 800 m distances, and the presence or absence of six commercial destination types within the neighbourhood service areas identified (food retail, general retail, medical care services, financial services, general services, and social infrastructure). Adjusted logistic regression models examined access to and mix of commercial destination types within neighbourhoods for associations with self-reported walking behaviour. On average, the sample was aged 72.9 years (SD = 5.4), and was predominantly female (55.9%) and married (62.0%). Overall, 66.2% reported some weekly walking and 30.8% reported sufficient walking (≥150 min/week). Older adults with access to general services within 400 m (OR = 1.33, 95% CI = 1.07-1.66) and 800 m (OR = 1.20, 95% CI = 1.02-1.42), and social infrastructure within 800 m (OR = 1.19, 95% CI = 1.01-1.40) were more likely to engage in some weekly walking. Access to medical care services within 400 m (OR = 0.77, 95% CI = 0.63-0.93) and 800 m (OR = 0.83, 95% CI = 0.70-0.99) reduced the odds of sufficient walking. Access to food retail, general retail, financial services, and the mix of commercial destination types within the neighbourhood were all unrelated to walking. The types of neighbourhood commercial destinations that encourage older adults to walk appear to differ slightly from those reported for adult samples. Destinations that facilitate more social interaction, for example eating at a restaurant or church involvement, or provide opportunities for some incidental social contact, for example visiting the pharmacy or hairdresser, were the strongest predictors for walking among seniors in this study. This underscores the importance of planning neighbourhoods with proximate access to social infrastructure, and highlights the need to create residential environments that support activity across the life course.

Why Some Walk and Others Don't: Exploring Interactions of Perceived Safety and Social Neighborhood Factors with Psychosocial Cognitions

ERIC Educational Resources Information Center

Beenackers, Marielle A.; Kamphuis, Carlijn B. M.; Mackenbach, Johan P.; Burdorf, Alex; van Lenthe, Frank J.

2013-01-01

Although physical activity is often believed to be influenced by both environmental and individual factors, little is known about their interaction. This study explores interactions of perceived safety and social neighborhood factors with psychosocial cognitions for leisure-time walking. Cross-sectional data were obtained from residents (age 25-75…

Spatial awareness in immersive virtual environments revealed in open-loop walking

NASA Astrophysics Data System (ADS)

Turano, Kathleen A.; Chaudhury, Sidhartha

2005-03-01

People are able to walk without vision to previously viewed targets in the real world. This ability to update one"s position in space has been attributed to a path integration system that uses internally generated self-motion signals together with the perceived object-to-self distance of the target. In a previous study using an immersive virtual environment (VE), we found that many subjects were unable to walk without vision to a previously viewed target located 4 m away. Their walking paths were influenced by the room structure that varied trial to trial. In this study we investigated whether the phenomenon is specific to a VE by testing subjects in a real world and a VE. The real world was viewed with field restricting goggles and via cameras using the same head-mounted display as in the VE. The results showed that only in the VE were walking paths influenced by the room structure. Women were more affected than men, and the effect decreased over trials and after subjects performed the task in the real world. The results also showed that a brief (<0.5 s) exposure to the visual scene during self-motion was sufficient to reduce the influence of the room structure on walking paths. The results are consistent with the idea that without visual experience within the VE, the path integration system is unable to effectively update one"s spatial position. As a result, people rely on other cues to define their position in space. Women, unlike men, choose to use visual cues about environmental structure to reorient.

Engineering online and in-person social networks to sustain physical activity: application of a conceptual model.

PubMed

Rovniak, Liza S; Sallis, James F; Kraschnewski, Jennifer L; Sciamanna, Christopher N; Kiser, Elizabeth J; Ray, Chester A; Chinchilli, Vernon M; Ding, Ding; Matthews, Stephen A; Bopp, Melissa; George, Daniel R; Hovell, Melbourne F

2013-08-14

High rates of physical inactivity compromise the health status of populations globally. Social networks have been shown to influence physical activity (PA), but little is known about how best to engineer social networks to sustain PA. To improve procedures for building networks that shape PA as a normative behavior, there is a need for more specific hypotheses about how social variables influence PA. There is also a need to integrate concepts from network science with ecological concepts that often guide the design of in-person and electronically-mediated interventions. Therefore, this paper: (1) proposes a conceptual model that integrates principles from network science and ecology across in-person and electronically-mediated intervention modes; and (2) illustrates the application of this model to the design and evaluation of a social network intervention for PA. A conceptual model for engineering social networks was developed based on a scoping literature review of modifiable social influences on PA. The model guided the design of a cluster randomized controlled trial in which 308 sedentary adults were randomly assigned to three groups: WalkLink+: prompted and provided feedback on participants' online and in-person social-network interactions to expand networks for PA, plus provided evidence-based online walking program and weekly walking tips; WalkLink: evidence-based online walking program and weekly tips only; Minimal Treatment Control: weekly tips only. The effects of these treatment conditions were assessed at baseline, post-program, and 6-month follow-up. The primary outcome was accelerometer-measured PA. Secondary outcomes included objectively-measured aerobic fitness, body mass index, waist circumference, blood pressure, and neighborhood walkability; and self-reported measures of the physical environment, social network environment, and social network interactions. The differential effects of the three treatment conditions on primary and secondary outcomes will be analyzed using general linear modeling (GLM), or generalized linear modeling if the assumptions for GLM cannot be met. Results will contribute to greater understanding of how to conceptualize and implement social networks to support long-term PA. Establishing social networks for PA across multiple life settings could contribute to cultural norms that sustain active living. ClinicalTrials.gov NCT01142804.

Walking and cognition, but not symptoms, correlate with dual task cost of walking in multiple sclerosis.

PubMed

Motl, Robert W; Sosnoff, Jacob J; Dlugonski, Deirdre; Pilutti, Lara A; Klaren, Rachel; Sandroff, Brian M

2014-03-01

Performing a cognitive task while walking results in a reduction of walking performance among persons with MS. To date, very little is known about correlates of this dual task cost (DTC) of walking in MS. We examined walking performance, cognitive processing speed, and symptoms of fatigue, depression, anxiety, and pain as correlates of DTC of walking in MS. 82 persons with MS undertook a 6-min walk test (6MWT) and completed the Symbol Digit Modalities Test (SDMT), Fatigue Severity Scale (FSS), Short-form of the McGill Pain Questionnaire (SF-MPQ), Hospital Anxiety and Depression Scale (HADS), and self-reported Expanded Disability Status Scale (SR-EDSS). The participants completed 4 trials of walking at a self-selected pace on an electronic walkway that recorded spatiotemporal parameters of gait. The first 2 trials were performed without a cognitive task, whereas the second 2 trials were completed while performing a modified Word List Generation task. There were significant and large declines in gait performance with the addition of a cognitive task for velocity (p<.001, η2=.52), cadence (p<.001, η2=.49), and step length (p<.001, η2=.23). 6MWT and SDMT scores correlated with DTC for velocity (r=-.41, p<.001 and r=-.32, p<.001, respectively) and step length (r=-.45, p<.001 and r=-.37, p<.001, respectively); there were no significant associations between FSS, SF-MPQ, and HADS scores with the DTC of walking. Regression analyses indicated that 6MW, but not SDMT, explained variance in DTC for velocity (ΔR2=.11, p<.001) and step length (ΔR2=.13, p<.001), after controlling for SR-EDSS scores. Walking performance might be a target of interventions for reducing the DTC of walking in MS. Copyright © 2013 Elsevier B.V. All rights reserved.

[Valences of self-evaluation and approach-avoidance tendencies: research based on regulatory focus theory].

PubMed

Ozaki, Yuka; Karasawa, Kaori

2011-12-01

Four studies were conducted to investigate the relationship between valences of self-evaluation and approach-avoidance tendencies. Based on regulatory focus theory (Higgins, 1997, 1998), we predicted that positivity of self-evaluation is related to the tendency to approach gains, while negativity of self-evaluation is related to the tendency to avoid losses. In Study 1, a self-report measure of behavioral tendencies for approaching gains and avoiding losses was developed. In Studies 2 to 4, correlations between these approach/avoidance tendencies and various kinds of self-evaluations were examined. Overall, the authors' predictions were supported. The results suggest that the self-evaluation system and the self-regulation system work in close cooperation with each other in controlling human behavior.

Avoidant decision making in social anxiety: the interaction of angry faces and emotional responses

PubMed Central

Pittig, Andre; Pawlikowski, Mirko; Craske, Michelle G.; Alpers, Georg W.

2014-01-01

Recent research indicates that angry facial expressions are preferentially processed and may facilitate automatic avoidance response, especially in socially anxious individuals. However, few studies have examined whether this bias also expresses itself in more complex cognitive processes and behavior such as decision making. We recently introduced a variation of the Iowa Gambling Task which allowed us to document the influence of task-irrelevant emotional cues on rational decision making. The present study used a modified gambling task to investigate the impact of angry facial expressions on decision making in 38 individuals with a wide range of social anxiety. Participants were to find out which choices were (dis-) advantageous to maximize overall gain. To create a decision conflict between approach of reward and avoidance of fear-relevant angry faces, advantageous choices were associated with angry facial expressions, whereas disadvantageous choices were associated with happy facial expressions. Results indicated that higher social avoidance predicted less advantageous decisions in the beginning of the task, i.e., when contingencies were still uncertain. Interactions with specific skin conductance responses further clarified that this initial avoidance only occurred in combination with elevated responses before choosing an angry facial expressions. In addition, an interaction between high trait anxiety and elevated responses to early losses predicted faster learning of an advantageous strategy. These effects were independent of intelligence, general risky decision-making, self-reported state anxiety, and depression. Thus, socially avoidant individuals who respond emotionally to angry facial expressions are more likely to show avoidance of these faces under uncertainty. This novel laboratory paradigm may be an appropriate analog for central features of social anxiety. PMID:25324792

Avoidant decision making in social anxiety: the interaction of angry faces and emotional responses.

PubMed

Pittig, Andre; Pawlikowski, Mirko; Craske, Michelle G; Alpers, Georg W

2014-01-01

Recent research indicates that angry facial expressions are preferentially processed and may facilitate automatic avoidance response, especially in socially anxious individuals. However, few studies have examined whether this bias also expresses itself in more complex cognitive processes and behavior such as decision making. We recently introduced a variation of the Iowa Gambling Task which allowed us to document the influence of task-irrelevant emotional cues on rational decision making. The present study used a modified gambling task to investigate the impact of angry facial expressions on decision making in 38 individuals with a wide range of social anxiety. Participants were to find out which choices were (dis-) advantageous to maximize overall gain. To create a decision conflict between approach of reward and avoidance of fear-relevant angry faces, advantageous choices were associated with angry facial expressions, whereas disadvantageous choices were associated with happy facial expressions. Results indicated that higher social avoidance predicted less advantageous decisions in the beginning of the task, i.e., when contingencies were still uncertain. Interactions with specific skin conductance responses further clarified that this initial avoidance only occurred in combination with elevated responses before choosing an angry facial expressions. In addition, an interaction between high trait anxiety and elevated responses to early losses predicted faster learning of an advantageous strategy. These effects were independent of intelligence, general risky decision-making, self-reported state anxiety, and depression. Thus, socially avoidant individuals who respond emotionally to angry facial expressions are more likely to show avoidance of these faces under uncertainty. This novel laboratory paradigm may be an appropriate analog for central features of social anxiety.

Effect of multilayer high-compression bandaging on ankle range of motion and oxygen cost of walking

PubMed Central

Roaldsen, K S; Elfving, B; Stanghelle, J K; Mattsson, E

2012-01-01

Objective To evaluate the effects of multilayer high-compression bandaging on ankle range of motion, oxygen consumption and subjective walking ability in healthy subjects. Method A volunteer sample of 22 healthy subjects (10 women and 12 men; aged 67 [63–83] years) were studied. The intervention included treadmill-walking at self-selected speed with and without multilayer high-compression bandaging (Proforeº), randomly selected. The primary outcome variables were ankle range of motion, oxygen consumption and subjective walking ability. Results Total ankle range of motion decreased 4% with compression. No change in oxygen cost of walking was observed. Less than half the subjects reported that walking-shoe comfort or walking distance was negatively affected. Conclusion Ankle range of motion decreased with compression but could probably be counteracted with a regular exercise programme. There were no indications that walking with compression was more exhausting than walking without. Appropriate walking shoes could seem important to secure gait efficiency when using compression garments. PMID:21810941

Psychotherapy and Moralising Rhetoric in Galen’s Newly Discovered Avoiding Distress (Peri Alypias)

PubMed Central

Xenophontos, Sophia

2014-01-01

In this article, I examine Galen’s credentials as an ethical philosopher on the basis of his recently discovered essay Avoiding Distress (Peri alypias). As compensation for the scholarly neglect from which Galen’s ethics suffers, I argue that his moral agenda is an essential part of his philosophical discourse, one that situates him firmly within the tradition of practical ethics of the Roman period. Galen’s engagement with Stoic psychotherapy and the Platonic-Aristotelian educational model affirms his ethical authority; on the other hand, his distinctive moralising features such as the autobiographical perspective of his narrative and the intimacy between author and addressee render his Avoiding Distress exceptional among other essays, Greek or Latin, treating anxiety. Additionally, I show that Galen’s self-projection as a therapist of the emotions corresponds to his role as a practising physician, especially as regards the construction of authority, the efficacy of his therapy and the importance of personal experience as attested in his medical accounts. Finally, the diligence with which Galen retextures his moral advice in his On the Affections and Errors of the Soul – a work of different nature and intent in relation to Avoiding Distress – is a testimony to the dynamics of his ethics and more widely to his philosophical medicine. The philosopher’s lecture room is a ‘hospital’: you ought not to walk out of it in a state of pleasure, but in pain; for you are not in good condition when you arrive. Epictetus, Discourses 3.23.30 PMID:25284896

Optimism, Symptom Distress, Illness Appraisal, and Coping in Patients With Advanced-Stage Cancer Diagnoses Undergoing Chemotherapy Treatment.

PubMed

Sumpio, Catherine; Jeon, Sangchoon; Northouse, Laurel L; Knobf, M Tish

2017-05-01

To explore the relationships between optimism, self-efficacy, symptom distress, treatment complexity, illness appraisal, coping, and mood disturbance in patients with advanced-stage cancer.
. Cross-sectional study.
. Smilow Cancer Hospital at Yale New Haven in Connecticut, an outpatient comprehensive cancer center.
. A convenience sample of 121 adult patients with stages III-IV cancer undergoing active chemotherapy.
. Participants completed common self-report questionnaires to measure variables. Treatment hours and visits were calculated from data retrieved from medical record review. Mediation and path analysis were conducted to identify direct and indirect pathways from the significant antecedent variables to mood disturbance.
. Dispositional optimism, self-efficacy, social support, treatment complexity, symptom distress, illness appraisal, coping, and mood disturbance.
. Greater optimism and self-efficacy were associated with less negative illness appraisal, less avoidant coping, and decreased mood disturbance. Conversely, greater symptom distress was associated with greater negative illness appraisal, greater avoidant coping, and greater mood disturbance. In the final model, optimism and symptom distress had direct and indirect effects on mood disturbance. Indirect effects were partially mediated by illness appraisal.
. Mood disturbance resulted from an interaction of disease stressors, personal resources, and cognitive appraisal of illness. Avoidant coping was associated with greater disturbed mood, but neither avoidant nor active coping had a significant effect on mood in the multivariate model. 
. Illness appraisal, coping style, and symptom distress are important targets for intervention. Optimism is a beneficial trait and should be included, along with coping style, in comprehensive nursing assessments of patients with cancer.

A new urban planning code's impact on walking: the residential environments project.

PubMed

Christian, Hayley; Knuiman, Matthew; Bull, Fiona; Timperio, Anna; Foster, Sarah; Divitini, Mark; Middleton, Nicholas; Giles-Corti, Billie

2013-07-01

We examined whether people moving into a housing development designed according to a state government livable neighborhoods subdivision code engage in more walking than do people who move to other types of developments. In a natural experiment of 1813 people building homes in 73 new housing developments in Perth, Western Australia, we surveyed participants before and then 12 and 36 months after moving. We measured self-reported walking using the Neighborhood Physical Activity Questionnaire and collected perceptions of the environment and self-selection factors. We calculated objective measures of the built environment using a Geographic Information System. After relocation, participants in livable versus conventional developments had greater street connectivity, residential density, land use mix, and access to destinations and more positive perceptions of their neighborhood (all P < .05). However, there were no significant differences in walking over time by type of development (P > .05). Implementation of the Livable Neighborhoods Guidelines produced more supportive environments; however, the level of intervention was insufficient to encourage more walking. Evaluations of new urban planning policies need to incorporate longer term follow-up to allow time for new neighborhoods to develop.

Spontaneous Velocity Effect of Musical Expression on Self-Paced Walking.

PubMed

Buhmann, Jeska; Desmet, Frank; Moens, Bart; Van Dyck, Edith; Leman, Marc

2016-01-01

The expressive features of music can influence the velocity of walking. So far, studies used instructed (and intended) synchronization. But is this velocity effect still present with non-instructed (spontaneous) synchronization? To figure that out, participants were instructed to walk in their own comfort tempo on an indoor track, first in silence and then with tempo-matched music. We compared velocities of silence and music conditions. The results show that some music has an activating influence, increasing velocity and motivation, while other music has a relaxing influence, decreasing velocity and motivation. The influence of musical expression on the velocity of self-paced walking can be predicted with a regression model using only three sonic features explaining 56% of the variance. Phase-coherence between footfall and beat did not contribute to the velocity effect, due to its implied fixed pacing. The findings suggest that the velocity effect depends on vigor entrainment that influences both stride length and pacing. Our findings are relevant for preventing injuries, for gait improvement in walking rehabilitation, and for improving performance in sports activities.

Spontaneous Velocity Effect of Musical Expression on Self-Paced Walking

PubMed Central

Buhmann, Jeska; Desmet, Frank; Moens, Bart; Van Dyck, Edith; Leman, Marc

2016-01-01

The expressive features of music can influence the velocity of walking. So far, studies used instructed (and intended) synchronization. But is this velocity effect still present with non-instructed (spontaneous) synchronization? To figure that out, participants were instructed to walk in their own comfort tempo on an indoor track, first in silence and then with tempo-matched music. We compared velocities of silence and music conditions. The results show that some music has an activating influence, increasing velocity and motivation, while other music has a relaxing influence, decreasing velocity and motivation. The influence of musical expression on the velocity of self-paced walking can be predicted with a regression model using only three sonic features explaining 56% of the variance. Phase-coherence between footfall and beat did not contribute to the velocity effect, due to its implied fixed pacing. The findings suggest that the velocity effect depends on vigor entrainment that influences both stride length and pacing. Our findings are relevant for preventing injuries, for gait improvement in walking rehabilitation, and for improving performance in sports activities. PMID:27167064

Impacts of Encouraging Dog Walking on Returns of Newly Adopted Dogs to a Shelter.

PubMed

Gunter, Lisa; Protopopova, Alexandra; Hooker, Steven P; Der Ananian, Cheryl; Wynne, Clive D L

2017-01-01

This study involved examining the ability of a postadoption intervention to reduce returns of newly adopted dogs to shelters by encouraging physical activity between adopters and their dogs. Guardians in the intervention group received emails with dog behavior and human activity advice as well as invitations to join weekly dog walks. Both the intervention and control groups completed surveys regarding outdoor activity with their dogs, their dog-walking habits, and perceptions of their dogs' behaviors. Adopter-dog pairs in the intervention group were not significantly more active than those in the control group, nor did they show a reduced incidence of returning their dogs. Guardians in both groups who reported higher obligation and self-efficacy in their dog walking were more active regardless of experimental condition; however, obligation, dog-walking self-efficacy, and perceptions about their dogs' on-leash behaviors did not predict rates of return to the shelter. These findings add to the understanding of shelter dog re-relinquishment and the effective utilization of resources postadoption, and they indicate further research is needed to address the complexities of this newly forming human-dog relationship.

Prey Foraging Under Sublethal Lambda-Cyhalothrin Exposure on Pyrethroid-Susceptible and -Resistant Lady Beetles (Eriopis connexa (Coleoptera: Coccinelidae)).

PubMed

D'Ávila, V A; Reis, L C; Barbosa, W F; Cutler, G C; Torres, J B; Guedes, R N C

2018-05-28

Sublethal insecticide exposure may affect foraging of insects, including natural enemies, although the subject is usually neglected. The lady beetle Eriopis connexa (Germar, 1824) (Coleoptera: Coccinelidae) is an important predator of aphids with existing pyrethroid-resistant populations that are undergoing scrutiny for potential use in pest management systems characterized by frequent insecticide use. However, the potential effect of sublethal pyrethroid exposure on this predator's foraging activity has not yet been assessed and may compromise its use in biological control. Therefore, our objective was to assess the effect of sublethal lambda-cyhalothrin exposure on three components of the prey foraging activity (i.e., walking, and prey searching and handling), in both pyrethroid-susceptible and -resistant adults of E. connexa. Both lady beetle populations exhibited similar walking patterns without insecticide exposure in noncontaminated arenas, but in partially contaminated arenas walking differed between strains, such that the resistant insects exhibited greater walking activity. Behavioral avoidance expressed as repellence to lambda-cyhalothrin was not observed for either the susceptible or resistant populations of E. connexa, but the insecticide caused avoidance by means of inducing irritability in 40% of the individuals, irrespective of the strain. Insects remained in the insecticide-contaminated portion of the arena for extended periods resulting in greater exposure. Although lambda-cyhalothrin exposure did not affect prey searching by susceptible lady beetles, prey searching was extended for exposed resistant predators. In contrast, prey handling was not affected by population or by lambda-cyhalothrin exposure. Thus, sublethal exposure to the insecticide in conjunction with the insect resistance profile can affect prey foraging with pyrethroid-exposed resistant predators exhibiting longer prey searching time associated with higher walking activity reducing its predatory performance.

Relationships between Psychological Wellbeing of Thai College Students, Goal Orientations, and Gender

ERIC Educational Resources Information Center

Sosik, John J.; Chun, Jae Uk; Koul, Ravinder

2017-01-01

This paper examined the direct and interaction effects of students' learning and performance-avoidance goal orientations on their psychological wellbeing and a moderating role of students' gender in these relationships. Using 564 self-reports of freshman college students in a Thai university, we found students' psychological wellbeing to be…

Entropy driven key-lock assembly.

PubMed

Odriozola, G; Jiménez-Angeles, F; Lozada-Cassou, M

2008-09-21

The effective interaction between a sphere with an open cavity (lock) and a spherical macroparticle (key), both immersed in a hard sphere fluid, is studied by means of Monte Carlo simulations. As a result, a two-dimensional map of the key-lock effective interaction potential is constructed, which leads to the proposal of a self-assembling mechanism: There exists trajectories through which the key-lock pair could assemble avoiding trespassing potential barriers. Hence, solely the entropic contribution can induce their self-assembling even in the absence of attractive forces. This study points out the solvent contribution within the underlying mechanisms of substrate-protein assemblydisassembly processes, which are important steps of the enzyme catalysis and protein mediated transport.

Entropy driven key-lock assembly

NASA Astrophysics Data System (ADS)

Odriozola, G.; Jiménez-Ángeles, F.; Lozada-Cassou, M.

2008-09-01

The effective interaction between a sphere with an open cavity (lock) and a spherical macroparticle (key), both immersed in a hard sphere fluid, is studied by means of Monte Carlo simulations. As a result, a two-dimensional map of the key-lock effective interaction potential is constructed, which leads to the proposal of a self-assembling mechanism: There exists trajectories through which the key-lock pair could assemble avoiding trespassing potential barriers. Hence, solely the entropic contribution can induce their self-assembling even in the absence of attractive forces. This study points out the solvent contribution within the underlying mechanisms of substrate-protein assembly/disassembly processes, which are important steps of the enzyme catalysis and protein mediated transport.

Improving the efficiency of quantum hash function by dense coding of coin operators in discrete-time quantum walk

NASA Astrophysics Data System (ADS)

Yang, YuGuang; Zhang, YuChen; Xu, Gang; Chen, XiuBo; Zhou, Yi-Hua; Shi, WeiMin

2018-03-01

Li et al. first proposed a quantum hash function (QHF) in a quantum-walk architecture. In their scheme, two two-particle interactions, i.e., I interaction and π-phase interaction are introduced and the choice of I or π-phase interactions at each iteration depends on a message bit. In this paper, we propose an efficient QHF by dense coding of coin operators in discrete-time quantum walk. Compared with existing QHFs, our protocol has the following advantages: the efficiency of the QHF can be doubled and even more; only one particle is enough and two-particle interactions are unnecessary so that quantum resources are saved. It is a clue to apply the dense coding technique to quantum cryptographic protocols, especially to the applications with restricted quantum resources.

Acute Inhalation Toxicity and Blood Absorption of 3-Nitro-1,2,4-Triazol-5-One (NTO) in Rats

DTIC Science & Technology

2013-09-16

strength, and stereotypes or bizarre behavior (e.g., self mutilation, walking backwards). In addition, rats exposed via the inhalation route of...species due to an historical and extensive database. V.3.3. Laboratory animals V.3.3.1 . Genus and Species: Rattus norvegicus V.3.3.2. Strain/Stock...or sensory stimuli, altered strength , and stereotypes or bizarre behavior (e.g., self mutilation, walking backwards). Observation and body weight

Negotiating identity and self-image: perceptions of falls in ambulatory individuals with spinal cord injury - a qualitative study.

PubMed

Jørgensen, Vivien; Roaldsen, Kirsti Skavberg

2017-04-01

Explore and describe experiences and perceptions of falls, risk of falling, and fall-related consequences in individuals with incomplete spinal cord injury (SCI) who are still walking. A qualitative interview study applying interpretive content analysis with an inductive approach. Specialized rehabilitation hospital. A purposeful sample of 15 individuals (10 men), 23 to 78 years old, 2-34 years post injury with chronic incomplete traumatic SCI, and walking ⩾75% of time for mobility needs. Individual, semi-structured face-to-face interviews were recorded, condensed, and coded to find themes and subthemes. One overarching theme was revealed: "Falling challenges identity and self-image as normal" which comprised two main themes "Walking with incomplete SCI involves minimizing fall risk and fall-related concerns without compromising identity as normal" and "Walking with incomplete SCI implies willingness to increase fall risk in order to maintain identity as normal". Informants were aware of their increased fall risk and took precautions, but willingly exposed themselves to risky situations when important to self-identity. All informants expressed some conditional fall-related concerns, and a few experienced concerns limiting activity and participation. Ambulatory individuals with incomplete SCI considered falls to be a part of life. However, falls interfered with the informants' identities and self-images as normal, healthy, and well-functioning. A few expressed dysfunctional concerns about falling, and interventions should target these.

Gender differences in asymmetrical limb support patterns between subjects with and without recurrent low back pain.

PubMed

Sung, Paul S; Zipple, J Tim; Danial, Pamela

2017-04-01

New insight regarding limb-dominance effects on temporal-spatial gait parameters is needed to further investigate subjects with recurrent low back pain (LBP). Although an asymmetrical gait pattern was found to reflect natural functional differences, there is a lack of information regarding gender differences on dominant limb support patterns in subjects with LBP. The purpose of this study was to investigate temporal-spatial gait parameters based on limb dominance and gender between subjects with and without LBP. One hundred and ten right limb dominant older adults (51 subjects with LBP and 59 control subjects) participated in the study. A three-dimensional motion capture system was utilized to measure temporal-spatial gait parameters, including initial double, single, and terminal double limb support times and walking speed. The gender differences between subjects with and without LBP were analyzed based on dominance for those parameters. Overall, limb dominance demonstrated significant differences on single and terminal double limb support times as well as walking speed. Limb dominance also demonstrated interactions on group x gender for single limb support time and walking speed. The male subjects with LBP demonstrated significantly increased single limb support times on the non-dominant limb. The significant gender and group interactions based on limb dominance account for a possible pain avoidance, asymmetrical limb support pattern. The causal pathway in dominance dependency gait by unweighted ambulation might be considered as an intervention for correcting these gait deviations in subjects with LBP. The specific modification recovery profiles of the subjects with LBP could shed light on variability of current LBP experiences of the subjects and reasons for gait deviations. Clinicians need to consider the mechanism of dominant limb dependency, which requires postural control strategies in male subjects with recurrent LBP. Copyright © 2017 Elsevier B.V. All rights reserved.

Walking for Transportation and Leisure Among U.S. Adults--National Health Interview Survey 2010.

PubMed

Paul, Prabasaj; Carlson, Susan A; Carroll, Dianna D; Berrigan, David; Fulton, Janet E

2015-06-16

Walking, the most commonly reported physical activity among U.S. adults, is undertaken in various domains, including transportation and leisure. This study examined prevalence, bout length, and mean amount of walking in the last week for transportation and leisure, by selected characteristics. Self-reported data from the 2010 National Health Interview Survey (N = 24,017) were analyzed. Prevalence of transportation walking was 29.4% (95% CI: 28.6%-30.3%) and of leisure walking was 50.0% (95% CI: 49.1%-51.0%). Prevalence of transportation walking was higher among men; prevalence of leisure walking was higher among women. Most (52.4%) transportation walking bouts were 10 to 15 minutes; leisure walking bouts were distributed more evenly (28.0%, 10-15 minutes; 17.1%, 41-60 minutes). Mean time spent in transportation walking was higher among men, decreased with increasing BMI, and varied by race/ethnicity and region of residence. Mean time spent leisure walking increased with increasing age and with decreasing BMI. Demographic correlates and patterns of walking differ by domain. Interventions focusing on either leisure or transportation walking should consider correlates for the specific walking domain. Assessing prevalence, bout length, and mean time of walking for transportation and leisure separately allows for more comprehensive surveillance of walking.

Color in Context: Psychological Context Moderates the Influence of Red on Approach- and Avoidance-Motivated Behavior

PubMed Central

Meier, Brian P.; D’Agostino, Paul R.; Elliot, Andrew J.; Maier, Markus A.; Wilkowski, Benjamin M.

2012-01-01

Background A basic premise of the recently proffered color-in-context model is that the influence of color on psychological functioning varies as a function of the psychological context in which color is perceived. Some research has examined the appetitive and aversive implications of viewing the color red in romance- and achievement-relevant contexts, respectively, but in all existing empirical work approach and avoidance behavior has been studied in separate tasks and separate experiments. Research is needed to directly test whether red influences the same behavior differently depending entirely on psychological context. Methodology/Principal Findings The present experiment was designed to put this premise to direct test in romance- and achievement-relevant contexts within the same experimental paradigm involving walking behavior. Our results revealed that exposure to red (but not blue) indeed has differential implications for walking behavior as a function of the context in which the color is perceived. Red increased the speed with which participants walked to an ostensible interview about dating (a romance-relevant context), but decreased the speed with which they walked to an ostensible interview about intelligence (an achievement-relevant context). Conclusions/Significance These results are the first direct evidence that the influence of red on psychological functioning in humans varies by psychological context. Our findings contribute to both the literature on color psychology and the broader, emerging literature on the influence of context on basic psychological processes. PMID:22808136

Dual tasking negatively impacts obstacle avoidance abilities in post-stroke individuals with visuospatial neglect: Task complexity matters!

PubMed

Aravind, Gayatri; Lamontagne, Anouk

2017-01-01

Persons with perceptual-attentional deficits due to visuospatial neglect (VSN) after a stroke are at a risk of collisions while walking in the presence of moving obstacles. The attentional burden of performing a dual-task may further compromise their obstacle avoidance performance, putting them at a greater risk of collisions. The objective of this study was to compare the ability of persons with (VSN+) and without VSN (VSN-) to dual task while negotiating moving obstacles. Twenty-six stroke survivors (13 VSN+, 13 VSN-) were assessed on their ability to (a) negotiate moving obstacles while walking (locomotor single task); (b) perform a pitch-discrimination task (cognitive single task) and (c) simultaneously perform the walking and cognitive tasks (dual task). We compared the groups on locomotor (collision rates, minimum distance from obstacle and onset of strategies) and cognitive (error rates) outcomes. For both single and dual task walking, VSN+ individuals showed higher collision rates compared to VSN- individuals. Dual tasking caused deterioration of locomotor (more collisions, delayed onset and smaller minimum distances) and cognitive performances (higher error rate) in VSN+ individuals. Contrastingly, VSN- individuals maintained collision rates, increased minimum distance, but showed more cognitive errors, prioritizing their locomotor performance. Individuals with VSN demonstrate cognitive-locomotor interference under dual task conditions, which could severely compromise safety when ambulating in community environments and may explain the poor recovery of independent community ambulation in these individuals.

Multi-scale analysis of collective behavior in 2D self-propelled particle models of swarms: An Advection-Diffusion with Memory Approach

NASA Astrophysics Data System (ADS)

Raghib, Michael; Levin, Simon; Kevrekidis, Ioannis

2010-05-01

Self-propelled particle models (SPP's) are a class of agent-based simulations that have been successfully used to explore questions related to various flavors of collective motion, including flocking, swarming, and milling. These models typically consist of particle configurations, where each particle moves with constant speed, but changes its orientation in response to local averages of the positions and orientations of its neighbors found within some interaction region. These local averages are based on `social interactions', which include avoidance of collisions, attraction, and polarization, that are designed to generate configurations that move as a single object. Errors made by the individuals in the estimates of the state of the local configuration are modeled as a random rotation of the updated orientation resulting from the social rules. More recently, SPP's have been introduced in the context of collective decision-making, where the main innovation consists of dividing the population into naïve and `informed' individuals. Whereas naïve individuals follow the classical collective motion rules, members of the informed sub-population update their orientations according to a weighted average of the social rules and a fixed `preferred' direction, shared by all the informed individuals. Collective decision-making is then understood in terms of the ability of the informed sub-population to steer the whole group along the preferred direction. Summary statistics of collective decision-making are defined in terms of the stochastic properties of the random walk followed by the centroid of the configuration as the particles move about, in particular the scaling behavior of the mean squared displacement (msd). For the region of parameters where the group remains coherent , we note that there are two characteristic time scales, first there is an anomalous transient shared by both purely naïve and informed configurations, i.e. the scaling exponent lies between 1 and 2. The long-time behavior of the msd of the centroid walk scales linearly with time for naïve groups (diffusion), but shows a sharp transition to quadratic scaling (advection) for informed ones. These observations suggest that the mesoscopic variables of interest are the magnitude of the drift, the diffusion coefficient and the time-scales at which the anomalous and the asymptotic behavior respectively dominate transport, the latter being linked to the time scale at which the group reaches a decision. In order to estimate these summary statistics from the msd, we assumed that the configuration centroid follows an uncoupled Continuous Time Random Walk (CTRW) with smooth jump and waiting time pdf's. The mesoscopic transport equation for this type of random walk corresponds to an Advection-Diffusion Equation with Memory (ADEM). The introduction of the memory, and thus non-Markovian effects, is necessary in order to correctly account for the two time scales present. Although we were not able to calculate the memory directly from the individual-level rules, we show that it can estimated from a single, relatively short, simulation run using a Mittag-Leffler function as template. With this function it is possible to predict accurately the behavior of the msd, as well as the full pdf for the position of the centroid. The resulting ADEM is self-consistent in the sense that transport parameters estimated from the memory via a Kubo relationship coincide with those estimated from the moments of the jump size pdf of the associated CTRW for a large number of group sizes, proportions of informed individuals, and degrees of bias along the preferred direction. We also discuss the phase diagrams for the transport coefficients estimated from this method, where we notice velocity-precision trade-offs, where precision is a measure of the deviation of realized group orientations with respect to the informed direction. We also note that the time scale to collective decision is invariant with respect to group size, and depends only on the proportion of informed individuals and the strength of the coupling along the informed direction.

The Prevalence and Use of Walking Loops in Neighborhood Parks: A National Study.

PubMed

Cohen, Deborah A; Han, Bing; Evenson, Kelly R; Nagel, Catherine; McKenzie, Thomas L; Marsh, Terry; Williamson, Stephanie; Harnik, Peter

2017-02-01

Previous studies indicate that the design of streets and sidewalks can influence physical activity among residents. Park features also influence park use and park-based physical activity. Although individuals can walk on streets and sidewalks, walking loops in parks offer a setting to walk in nature and to avoid interruptions from traffic. Here we describe the use of walking loops in parks and compare the number of park users and their physical activity in urban neighborhood parks with and without walking loops. We analyzed data from the National Study of Neighborhood Parks in which a representative sample of neighborhood parks (n = 174) from 25 U.S. cities with > 100,000 population were observed systematically to document facilities and park users by age group and sex. We compared the number of people and their physical activity in parks with and without walking loops, controlling for multiple factors, including park size, facilities, and population density. Overall, compared with parks without walking loops, on average during an hourly observation, parks with walking loops had 80% more users (95% CI: 42, 139%), and levels of moderate-to-vigorous physical activity were 90% higher (95% CI: 49, 145%). The additional park use and park-based physical activity occurred not only on the walking loops but throughout the park. Walking loops may be a promising means of increasing population level physical activity. Further studies are needed to confirm a causal relationship. Citation: Cohen DA, Han B, Evenson KR, Nagel C, McKenzie TL, Marsh T, Williamson S, Harnik P. 2017. The prevalence and use of walking loops in neighborhood parks: a national study. Environ Health Perspect 125:170-174; http://dx.doi.org/10.1289/EHP293.

The Prevalence and Use of Walking Loops in Neighborhood Parks: A National Study

PubMed Central

Cohen, Deborah A.; Han, Bing; Evenson, Kelly R.; Nagel, Catherine; McKenzie, Thomas L.; Marsh, Terry; Williamson, Stephanie; Harnik, Peter

2016-01-01

Background: Previous studies indicate that the design of streets and sidewalks can influence physical activity among residents. Park features also influence park use and park-based physical activity. Although individuals can walk on streets and sidewalks, walking loops in parks offer a setting to walk in nature and to avoid interruptions from traffic. Objectives: Here we describe the use of walking loops in parks and compare the number of park users and their physical activity in urban neighborhood parks with and without walking loops. Methods: We analyzed data from the National Study of Neighborhood Parks in which a representative sample of neighborhood parks (n = 174) from 25 U.S. cities with > 100,000 population were observed systematically to document facilities and park users by age group and sex. We compared the number of people and their physical activity in parks with and without walking loops, controlling for multiple factors, including park size, facilities, and population density. Results: Overall, compared with parks without walking loops, on average during an hourly observation, parks with walking loops had 80% more users (95% CI: 42, 139%), and levels of moderate-to-vigorous physical activity were 90% higher (95% CI: 49, 145%). The additional park use and park-based physical activity occurred not only on the walking loops but throughout the park. Conclusions: Walking loops may be a promising means of increasing population level physical activity. Further studies are needed to confirm a causal relationship. Citation: Cohen DA, Han B, Evenson KR, Nagel C, McKenzie TL, Marsh T, Williamson S, Harnik P. 2017. The prevalence and use of walking loops in neighborhood parks: a national study. Environ Health Perspect 125:170–174; http://dx.doi.org/10.1289/EHP293 PMID:27517530

That Pain in Your Back Could be Linked to Your Feet

MedlinePlus

... hurts, so you change your gait to avoid bending the joint when you walk. Changing your gait ... ps.position.alert.message}} Getting your location, one moment... Please enter a 5-digit zip code. Please ...

Breathing difficulties - first aid

MedlinePlus

... walk around every few hours to avoid forming blood clots in your legs. While seated, do ankle circles ... lower your heels, toes, and knees to increase blood flow in your legs. Clots can break off and lodge in your lungs. ...

An intelligent rollator for mobility impaired persons, especially stroke patients.

PubMed

Hellström, Thomas; Lindahl, Olof; Bäcklund, Tomas; Karlsson, Marcus; Hohnloser, Peter; Bråndal, Anna; Hu, Xiaolei; Wester, Per

2016-07-01

An intelligent rollator (IRO) was developed that aims at obstacle detection and guidance to avoid collisions and accidental falls. The IRO is a retrofit four-wheeled rollator with an embedded computer, two solenoid brakes, rotation sensors on the wheels and IR-distance sensors. The value reported by each distance sensor was compared in the computer to a nominal distance. Deviations indicated a present obstacle and caused activation of one of the brakes in order to influence the direction of motion to avoid the obstacle. The IRO was tested by seven healthy subjects with simulated restricted and blurred sight and five stroke subjects on a standardised indoor track with obstacles. All tested subjects walked faster with intelligence deactivated. Three out of five stroke patients experienced more detected obstacles with intelligence activated. This suggests enhanced safety during walking with IRO. Further studies are required to explore the full value of the IRO.

Associations among self-concept, verbal behaviors, and group climate early in the group counseling process.

PubMed

Jen Der Pan, Peter; Fan, Ai Chun; Bhat, Christine Suniti; Chang, Shona Shih Hua

2012-12-01

In this study, relations among group members' self-concept, verbal behaviors, and group climate early in the group counseling process were assessed for college students who were randomly assigned to four counseling groups. Based on measures from the hill interaction matrix, it was observed that family, social, and action self-concepts, as well as engagement, avoidance, and conflict group climate, were correlated with several verbal behaviors. Silence and quadrant 4 (Q4), which consists of speculative and confrontative verbal behaviors at personal and relationship levels, significantly predicted and explained 43% of the variance in engagement group climate. Silence and Q3, comprised of conventional and assertive verbal behaviors at personal and relationship levels, and Q1, conventional and assertive verbal behaviors at topic and group levels, explained 66% of variance in avoidance climate. Q4 and Silence explained 33% of conflict climate variance early in the group sessions. Implications for research and counseling practice are suggested.

Effectiveness of two Arthritis Foundation programs: Walk With Ease, and YOU Can Break the Pain Cycle

PubMed Central

Bruno, Michelle; Cummins, Susan; Gaudiano, Lisha; Stoos, Johanna; Blanpied, Peter

2006-01-01

Objective: To evaluate the effectiveness of two Arthritis Foundation programs: Walk With Ease (WWE) and YOU Can Break The Pain Cycle (PC). Design: Quasi-experimental, repeated measures design. Retested at six weeks and four months. Setting: Community based intervention. Participants: Volunteer sample of 163 adults with arthritis recruited through mailings, newspapers, and flyers. Interventions: Subjects participated in a 90 minute seminar (PC, Group A), a six-week walking program (WWE, Group B), or both programs (Group C). Main outcome measures: Survey assessment of arthritis knowledge, general health, self-management activities, confidence, physical abilities, depression, health distress, and how arthritis affects their life. A Squat Test, a Six Minute Walk test, and a Timed Functional Walk Test were also administered. Results: Subjects in Group B were more confident, less depressed, had less health distress, and less pain than subjects in Group A. Scores of Group C were between Group A and B scores. Differences in groups over time indicated that the WWE resulted in increased confidence, physical abilities, time spent in self-management activities and decreased pain and fatigue. All groups increased in walking endurance at six weeks, and increased in health distress at four months. Conclusion: Subjects in different programs differed on impact of arthritis. These programs provide effective arthritis management opportunities. PMID:18046884

An aerobic walking programme versus muscle strengthening programme for chronic low back pain: a randomized controlled trial.

PubMed

Shnayderman, Ilana; Katz-Leurer, Michal

2013-03-01

To assess the effect of aerobic walking training as compared to active training, which includes muscle strengthening, on functional abilities among patients with chronic low back pain. Randomized controlled clinical trial with blind assessors. Outpatient clinic. Fifty-two sedentary patients, aged 18-65 years with chronic low back pain. Patients who were post surgery, post trauma, with cardiovascular problems, and with oncological disease were excluded. Experimental 'walking' group: moderate intense treadmill walking; control 'exercise' group: specific low back exercise; both, twice a week for six weeks. Six-minute walking test, Fear-Avoidance Belief Questionnaire, back and abdomen muscle endurance tests, Oswestry Disability Questionnaire, Low Back Pain Functional Scale (LBPFS). Significant improvements were noted in all outcome measures in both groups with non-significant difference between groups. The mean distance in metres covered during 6 minutes increased by 70.7 (95% confidence interval (CI) 12.3-127.7) in the 'walking' group and by 43.8 (95% CI 19.6-68.0) in the 'exercise' group. The trunk flexor endurance test showed significant improvement in both groups, increasing by 0.6 (95% CI 0.0-1.1) in the 'walking' group and by 1.1 (95% CI 0.3-1.8) in the 'exercise' group. A six-week walk training programme was as effective as six weeks of specific strengthening exercises programme for the low back.

Interacting with Nature Improves Cognition and Affect for Individuals with Depression

PubMed Central

Berman, Marc G.; Kross, Ethan; Krpan, Katherine M.; Askren, Mary K.; Burson, Aleah; Deldin, Patricia J.; Kaplan, Stephen; Sherdell, Lindsey; Gotlib, Ian H.; Jonides, John

2012-01-01

Background This study aimed to explore whether walking in nature may be beneficial for individuals with major depressive disorder (MDD). Healthy adults demonstrate significant cognitive gains after nature walks, but it was unclear whether those same benefits would be achieved in a depressed sample as walking alone in nature might induce rumination, thereby worsening memory and mood. Methods Twenty individuals diagnosed with MDD participated in this study. At baseline, mood and short term memory span were assessed using the PANAS and the backwards digit span (BDS) task, respectively. Participants were then asked to think about an unresolved negative autobiographical event to prime rumination, prior to taking a 50 minute walk in either a natural or urban setting. After the walk, mood and short-term memory span were reassessed. The following week, participants returned to the lab and repeated the entire procedure, but walked in the location not visited in the first session (i.e., a counterbalanced within-subjects design). Results Participants exhibited significant increases in memory span after the nature walk relative to the urban walk, p < .001, ηp2= .53 (a large effect-size). Participants also showed increases in mood, but the mood effects did not correlate with the memory effects, suggesting separable mechanisms and replicating previous work. Limitations Sample size and participants’ motivation. Conclusions These findings extend earlier work demonstrating the cognitive and affective benefits of interacting with nature to individuals with MDD. Therefore, interacting with nature may be useful clinically as a supplement to existing treatments for MDD. PMID:22464936

Interacting with nature improves cognition and affect for individuals with depression.

PubMed

Berman, Marc G; Kross, Ethan; Krpan, Katherine M; Askren, Mary K; Burson, Aleah; Deldin, Patricia J; Kaplan, Stephen; Sherdell, Lindsey; Gotlib, Ian H; Jonides, John

2012-11-01

This study aimed to explore whether walking in nature may be beneficial for individuals with major depressive disorder (MDD). Healthy adults demonstrate significant cognitive gains after nature walks, but it was unclear whether those same benefits would be achieved in a depressed sample as walking alone in nature might induce rumination, thereby worsening memory and mood. Twenty individuals diagnosed with MDD participated in this study. At baseline, mood and short term memory span were assessed using the PANAS and the backwards digit span (BDS) task, respectively. Participants were then asked to think about an unresolved negative autobiographical event to prime rumination, prior to taking a 50-min walk in either a natural or urban setting. After the walk, mood and short-term memory span were reassessed. The following week, participants returned to the lab and repeated the entire procedure, but walked in the location not visited in the first session (i.e., a counterbalanced within-subjects design). Participants exhibited significant increases in memory span after the nature walk relative to the urban walk, p<.001, η(p)(2)=.53 (a large effect-size). Participants also showed increases in mood, but the mood effects did not correlate with the memory effects, suggesting separable mechanisms and replicating previous work. Sample size and participants' motivation. These findings extend earlier work demonstrating the cognitive and affective benefits of interacting with nature to individuals with MDD. Therefore, interacting with nature may be useful clinically as a supplement to existing treatments for MDD. Copyright © 2012 Elsevier B.V. All rights reserved.

Neighborhood walkability, physical activity, and walking for transportation: A cross-sectional study of older adults living on low income.

PubMed

Chudyk, Anna M; McKay, Heather A; Winters, Meghan; Sims-Gould, Joanie; Ashe, Maureen C

2017-04-10

Walking, and in particular, outdoor walking, is the most common form of physical activity for older adults. To date, no study investigated the association between the neighborhood built environment and physical activity habits of older adults of low SES. Thus, our overarching aim was to examine the association between the neighborhood built environment and the spectrum of physical activity and walking for transportation in older adults of low socioeconomic status. Cross-sectional data were from the Walk the Talk Study, collected in 2012. Participants (n = 161, mean age = 74 years) were in receipt of a rental subsidy for low income individuals and resided in neighbourhoods across Metro Vancouver, Canada. We used the Street Smart Walk Score to objectively characterize the built environment main effect (walkability), accelerometry for objective physical activity, and the Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire to measure walking for transportation. We used regression analyses to examine associations of objectively measured physical activity [total volume, light intensity and moderate intensity physical activity (MVPA)] and self-reported walking for transportation (any, frequency, duration) with walkability. We adjusted analyses for person- and environment-level factors associated with older adult physical activity. Neighbourhood walkability was not associated with physical activity volume or intensity and self-reported walking for transportation, with one exception. Each 10-point increase in Street Smart Walk Score was associated with a 45% greater odds of any walking for transportation (compared with none; OR = 1.45, 95% confidence interval = 1.18, 1.78). Sociodemographic, physical function and attitudinal factors were significant predictors of physical activity across our models. The lack of associations between most of the explored outcomes may be due to the complexity of the relation between the person and environment. Given that this is the first study to explore these associations specifically in older adults living on low income, this study should be replicated in other settings.

How to Sync to the Beat of a Persistent Fractal Metronome without Falling Off the Treadmill?

PubMed Central

Roerdink, Melvyn; Daffertshofer, Andreas; Marmelat, Vivien; Beek, Peter J.

2015-01-01

In rehabilitation, rhythmic acoustic cues are often used to improve gait. However, stride-time fluctuations become anti-persistent with such pacing, thereby deviating from the characteristic persistent long-range correlations in stride times of self-paced walking healthy adults. Recent studies therefore experimented with metronomes with persistence in interbeat intervals and successfully evoked persistent stride-time fluctuations. The objective of this study was to examine how participants couple their gait to a persistent metronome, evoking persistently longer or shorter stride times over multiple consecutive strides, without wandering off the treadmill. Twelve healthy participants walked on a treadmill in self-paced, isochronously paced and non-isochronously paced conditions, the latter with anti-persistent, uncorrelated and persistent correlations in interbeat intervals. Stride-to-stride fluctuations of stride times, stride lengths and stride speeds were assessed with detrended fluctuation analysis, in conjunction with an examination of the coupling between stride times and stride lengths. Stride-speed fluctuations were anti-persistent for all conditions. Stride-time and stride-length fluctuations were persistent for self-paced walking and anti-persistent for isochronous pacing. Both stride times and stride lengths changed from anti-persistence to persistence over the four non-isochronous metronome conditions, accompanied by an increasingly stronger coupling between these gait parameters, with peak values for the persistent metronomes. These results revealed that participants were able to follow the beat of a persistent metronome without falling off the treadmill by strongly coupling stride-length fluctuations to the stride-time fluctuations elicited by persistent metronomes, so as to prevent large positional displacements along the treadmill. For self-paced walking, in contrast, this coupling was very weak. In combination, these results challenge the premise that persistent metronomes in gait rehabilitation would evoke stride-to-stride dynamics reminiscent of self-paced walking healthy adults. Future studies are recommended to include an analysis of the interrelation between stride times and stride lengths in addition to the correlational structure of either one in isolation. PMID:26230254

How to Sync to the Beat of a Persistent Fractal Metronome without Falling Off the Treadmill?

PubMed

Roerdink, Melvyn; Daffertshofer, Andreas; Marmelat, Vivien; Beek, Peter J

2015-01-01

In rehabilitation, rhythmic acoustic cues are often used to improve gait. However, stride-time fluctuations become anti-persistent with such pacing, thereby deviating from the characteristic persistent long-range correlations in stride times of self-paced walking healthy adults. Recent studies therefore experimented with metronomes with persistence in interbeat intervals and successfully evoked persistent stride-time fluctuations. The objective of this study was to examine how participants couple their gait to a persistent metronome, evoking persistently longer or shorter stride times over multiple consecutive strides, without wandering off the treadmill. Twelve healthy participants walked on a treadmill in self-paced, isochronously paced and non-isochronously paced conditions, the latter with anti-persistent, uncorrelated and persistent correlations in interbeat intervals. Stride-to-stride fluctuations of stride times, stride lengths and stride speeds were assessed with detrended fluctuation analysis, in conjunction with an examination of the coupling between stride times and stride lengths. Stride-speed fluctuations were anti-persistent for all conditions. Stride-time and stride-length fluctuations were persistent for self-paced walking and anti-persistent for isochronous pacing. Both stride times and stride lengths changed from anti-persistence to persistence over the four non-isochronous metronome conditions, accompanied by an increasingly stronger coupling between these gait parameters, with peak values for the persistent metronomes. These results revealed that participants were able to follow the beat of a persistent metronome without falling off the treadmill by strongly coupling stride-length fluctuations to the stride-time fluctuations elicited by persistent metronomes, so as to prevent large positional displacements along the treadmill. For self-paced walking, in contrast, this coupling was very weak. In combination, these results challenge the premise that persistent metronomes in gait rehabilitation would evoke stride-to-stride dynamics reminiscent of self-paced walking healthy adults. Future studies are recommended to include an analysis of the interrelation between stride times and stride lengths in addition to the correlational structure of either one in isolation.

Modeling spatial segregation and travel cost influences on utilitarian walking: Towards policy intervention

PubMed Central

Yang, Yong; Auchincloss, Amy H.; Rodriguez, Daniel A.; Brown, Daniel G.; Riolo, Rick; Diez-Roux, Ana V.

2015-01-01

We develop an agent-based model of utilitarian walking and use the model to explore spatial and socioeconomic factors affecting adult utilitarian walking and how travel costs as well as various educational interventions aimed at changing attitudes can alter the prevalence of walking and income differentials in walking. The model is validated against US national data. We contrast realistic and extreme parameter values in our model and test effects of changing these parameters across various segregation and pricing scenarios while allowing for interactions between travel choice and place and for behavioral feedbacks. Results suggest that in addition to income differences in the perceived cost of time, the concentration of mixed land use (differential density of residences and businesses) are important determinants of income differences in walking (high income walk less), whereas safety from crime and income segregation on their own do not have large influences on income differences in walking. We also show the difficulty in altering walking behaviors for higher income groups who are insensitive to price and how adding to the cost of driving could increase the income differential in walking particularly in the context of segregation by income and land use. We show that strategies to decrease positive attitudes towards driving can interact synergistically with shifting cost structures to favor walking in increasing the percent of walking trips. Agent-based models, with their ability to capture dynamic processes and incorporate empirical data, are powerful tools to explore the influence on health behavior from multiple factors and test policy interventions. PMID:25733776

The immediate and long-term effects of a walking-skill program compared to usual physiotherapy care in patients who have undergone total knee arthroplasty (TKA): a randomized controlled trial.

PubMed

Bruun-Olsen, Vigdis; Heiberg, Kristi Elisabeth; Wahl, Astrid Klopstad; Mengshoel, Anne Marit

2013-01-01

To examine the immediate and long-term effects of a walking-skill program compared with usual physiotherapy on physical function, pain and perceived self-efficacy in patients after total knee arthroplasty (TKA). A single blind randomized controlled trial design was applied. Fifty-seven patients with primary TKA, mean age of 69 years (SD ± 9), were randomly assigned to a walking-skill program emphasizing weight-bearing exercises or usual physiotherapy. Outcomes were assessed before the interventions started at 6 weeks postoperatively (T1), directly after the interventions at 12-14 weeks (T2) and 9 months after the interventions (T3). Walking was the primary outcome, assessed by the 6 min walk test (6MWT). The secondary outcomes were timed stair climbing, timed stands, Figure-of-eight test, Index of muscle function, active knee range of motion, Knee Injury and Osteoarthritis Outcome Score and self-efficacy score. From T1 to T2, a better 6MWT score was found in favor of the walking-skill program of 39 m (2-76), p = 0.04. The difference between the groups in 6MWT persisted at T3, 44 m (8-80), p = 0.02. No differences in other outcome measures were found. The walking-skill program had better effect on walking than usual physiotherapy. Weight bearing was tolerated. Implications for Rehabilitation Weight-bearing exercises are tolerated by the patients in the early stage after TKA. Physiotherapy that focuses on learning different ways of walking through practice may be a plausible way to train patients after TKA.

The effect of uphill and downhill walking on gait parameters: A self-paced treadmill study.

PubMed

Kimel-Naor, Shani; Gottlieb, Amihai; Plotnik, Meir

2017-07-26

It has been shown that gait parameters vary systematically with the slope of the surface when walking uphill (UH) or downhill (DH) (Andriacchi et al., 1977; Crowe et al., 1996; Kawamura et al., 1991; Kirtley et al., 1985; McIntosh et al., 2006; Sun et al., 1996). However, gait trials performed on inclined surfaces have been subject to certain technical limitations including using fixed speed treadmills (TMs) or, alternatively, sampling only a few gait cycles on inclined ramps. Further, prior work has not analyzed upper body kinematics. This study aims to investigate effects of slope on gait parameters using a self-paced TM (SPTM) which facilitates more natural walking, including measuring upper body kinematics and gait coordination parameters. Gait of 11 young healthy participants was sampled during walking in steady state speed. Measurements were made at slopes of +10°, 0° and -10°. Force plates and a motion capture system were used to reconstruct twenty spatiotemporal gait parameters. For validation, previously described parameters were compared with the literature, and novel parameters measuring upper body kinematics and bilateral gait coordination were also analyzed. Results showed that most lower and upper body gait parameters were affected by walking slope angle. Specifically, UH walking had a higher impact on gait kinematics than DH walking. However, gait coordination parameters were not affected by walking slope, suggesting that gait asymmetry, left-right coordination and gait variability are robust characteristics of walking. The findings of the study are discussed in reference to a potential combined effect of slope and gait speed. Follow-up studies are needed to explore the relative effects of each of these factors. Copyright © 2017. Published by Elsevier Ltd.

Onychomycosis: diagnosis and systemic treatment.

PubMed

Milles, C L; Riley, P A; Kessenich, C R

1998-12-01

Onychomycosis, a persistent fungal infection affecting the toenails and fingernails, can interfere with standing, walking, and exercising. Associated physical impairments can result in paresthesia, pain, discomfort, and loss of manual dexterity. Patients may also suffer from loss of self-esteem and social interaction. A definitive diagnosis is crucial for effective treatment, because many other skin and nail disorders mimic onychomycosis. Diagnosis involves microscopic potassium hydroxide preparation, cultures, nail biopsy, and histologic analysis. Treatment can include topical and systemic antifungal therapies as well as nonpharmaceutical methods. This paper discusses pathophysiology, diagnosis, and treatment options for this common nail dystrophy, including the newer antifungal medications now available.

Electron avalanche structure determined by random walk theory

NASA Technical Reports Server (NTRS)

Englert, G. W.

1973-01-01

A self-consistent avalanche solution which accounts for collective long range Coulomb interactions as well as short range elastic and inelastic collisions between electrons and background atoms is made possible by a random walk technique. Results show that the electric field patterns in the early formation stages of avalanches in helium are close to those obtained from theory based on constant transport coefficients. Regions of maximum and minimum induced electrostatic potential phi are located on the axis of symmetry and within the volume covered by the electron swarm. As formation time continues, however, the region of minimum phi moves to slightly higher radii and the electric field between the extrema becomes somewhat erratic. In the intermediate formation periods the avalanche growth is slightly retarded by the high concentration of ions in the tail which oppose the external electric field. Eventually the formation of ions and electrons in the localized regions of high field strength more than offset this effect causing a very abrupt increase in avalanche growth.

Predicting RNA pseudoknot folding thermodynamics

PubMed Central

Cao, Song; Chen, Shi-Jie

2006-01-01

Based on the experimentally determined atomic coordinates for RNA helices and the self-avoiding walks of the P (phosphate) and C4 (carbon) atoms in the diamond lattice for the polynucleotide loop conformations, we derive a set of conformational entropy parameters for RNA pseudoknots. Based on the entropy parameters, we develop a folding thermodynamics model that enables us to compute the sequence-specific RNA pseudoknot folding free energy landscape and thermodynamics. The model is validated through extensive experimental tests both for the native structures and for the folding thermodynamics. The model predicts strong sequence-dependent helix-loop competitions in the pseudoknot stability and the resultant conformational switches between different hairpin and pseudoknot structures. For instance, for the pseudoknot domain of human telomerase RNA, a native-like and a misfolded hairpin intermediates are found to coexist on the (equilibrium) folding pathways, and the interplay between the stabilities of these intermediates causes the conformational switch that may underlie a human telomerase disease. PMID:16709732

Compaction of quasi-one-dimensional elastoplastic materials

PubMed Central

Shaebani, M. Reza; Najafi, Javad; Farnudi, Ali; Bonn, Daniel; Habibi, Mehdi

2017-01-01

Insight into crumpling or compaction of one-dimensional objects is important for understanding biopolymer packaging and designing innovative technological devices. By compacting various types of wires in rigid confinements and characterizing the morphology of the resulting crumpled structures, here, we report how friction, plasticity and torsion enhance disorder, leading to a transition from coiled to folded morphologies. In the latter case, where folding dominates the crumpling process, we find that reducing the relative wire thickness counter-intuitively causes the maximum packing density to decrease. The segment size distribution gradually becomes more asymmetric during compaction, reflecting an increase of spatial correlations. We introduce a self-avoiding random walk model and verify that the cumulative injected wire length follows a universal dependence on segment size, allowing for the prediction of the efficiency of compaction as a function of material properties, container size and injection force. PMID:28585550

Critical points of the O(n) loop model on the martini and the 3-12 lattices

NASA Astrophysics Data System (ADS)

Ding, Chengxiang; Fu, Zhe; Guo, Wenan

2012-06-01

We derive the critical line of the O(n) loop model on the martini lattice as a function of the loop weight n basing on the critical points on the honeycomb lattice conjectured by Nienhuis [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.49.1062 49, 1062 (1982)]. In the limit n→0 we prove the connective constant μ=1.7505645579⋯ of self-avoiding walks on the martini lattice. A finite-size scaling analysis based on transfer matrix calculations is also performed. The numerical results coincide with the theoretical predictions with a very high accuracy. Using similar numerical methods, we also study the O(n) loop model on the 3-12 lattice. We obtain similarly precise agreement with the critical points given by Batchelor [J. Stat. Phys.JSTPBS0022-471510.1023/A:1023065215233 92, 1203 (1998)].

Association of knee confidence with pain, knee instability, muscle strength, and dynamic varus-valgus joint motion in knee osteoarthritis.

PubMed

Skou, Søren T; Wrigley, Tim V; Metcalf, Ben R; Hinman, Rana S; Bennell, Kim L

2014-05-01

To investigate associations between self-reported knee confidence and pain, self-reported knee instability, muscle strength, and dynamic varus-valgus joint motion during walking. We performed a cross-sectional analysis of baseline data from 100 participants with symptomatic and radiographic medial tibiofemoral compartment osteoarthritis (OA) and varus malalignment recruited for a randomized controlled trial. The extent of knee confidence, assessed using a 5-point Likert scale item from the Knee Injury and Osteoarthritis Outcome Score, was set as the dependent variable in univariable and multivariable ordinal regression, with pain during walking, self-reported knee instability, quadriceps strength, and dynamic varus-valgus joint motion during walking as independent variables. One percent of the participants were not troubled with lack of knee confidence, 17% were mildly troubled, 50% were moderately troubled, 26% were severely troubled, and 6% were extremely troubled. Significant associations were found between worse knee confidence and higher pain intensity, worse self-reported knee instability, lower quadriceps strength, and greater dynamic varus-valgus joint motion. The multivariable model consisting of the same variables significantly accounted for 24% of the variance in knee confidence (P < 0.001). Worse knee confidence is associated with higher pain, worse self-reported knee instability, lower quadriceps muscle strength, and greater dynamic varus-valgus joint motion during walking. Since previous research has shown that worse knee confidence is predictive of functional decline in knee OA, addressing lack of knee confidence by treating these modifiable impairments could represent a new therapeutic target. Copyright © 2014 by the American College of Rheumatology.

Do walking strategies to increase physical activity reduce reported sitting in workplaces: a randomized control trial

PubMed Central

Gilson, Nicholas D; Puig-Ribera, Anna; McKenna, Jim; Brown, Wendy J; Burton, Nicola W; Cooke, Carlton B

2009-01-01

Background Interventions designed to increase workplace physical activity may not automatically reduce high volumes of sitting, a behaviour independently linked to chronic diseases such as obesity and type II diabetes. This study compared the impact two different walking strategies had on step counts and reported sitting times. Methods Participants were white-collar university employees (n = 179; age 41.3 ± 10.1 years; 141 women), who volunteered and undertook a standardised ten-week intervention at three sites. Pre-intervention step counts (Yamax SW-200) and self-reported sitting times were measured over five consecutive workdays. Using pre-intervention step counts, employees at each site were randomly allocated to a control group (n = 60; maintain normal behaviour), a route-based walking group (n = 60; at least 10 minutes sustained walking each workday) or an incidental walking group (n = 59; walking in workday tasks). Workday step counts and reported sitting times were re-assessed at the beginning, mid- and endpoint of intervention and group mean± SD steps/day and reported sitting times for pre-intervention and intervention measurement points compared using a mixed factorial ANOVA; paired sample-t-tests were used for follow-up, simple effect analyses. Results A significant interactive effect (F = 3.5; p < 0.003) was found between group and step counts. Daily steps for controls decreased over the intervention period (-391 steps/day) and increased for route (968 steps/day; t = 3.9, p < 0.000) and incidental (699 steps/day; t = 2.5, p < 0.014) groups. There were no significant changes for reported sitting times, but average values did decrease relative to the control (routes group = 7 minutes/day; incidental group = 15 minutes/day). Reductions were most evident for the incidental group in the first week of intervention, where reported sitting decreased by an average of 21 minutes/day (t = 1.9; p < 0.057). Conclusion Compared to controls, both route and incidental walking increased physical activity in white-collar employees. Our data suggests that workplace walking, particularly through incidental movement, also has the potential to decrease employee sitting times, but there is a need for on-going research using concurrent and objective measures of sitting, standing and walking. PMID:19619295

Psychometric properties of the modified RESIDE physical activity questionnaire among low-income overweight women.

PubMed

Jones, Sydney A; Evenson, Kelly R; Johnston, Larry F; Trost, Stewart G; Samuel-Hodge, Carmen; Jewell, David A; Kraschnewski, Jennifer L; Keyserling, Thomas C

2015-01-01

This study explored the criterion-related validity and test-retest reliability of the modified RESIDential Environment physical activity questionnaire and whether the instrument's validity varied by body mass index, education, race/ethnicity, or employment status. Validation study using baseline data collected for randomized trial of a weight loss intervention. Participants recruited from health departments wore an ActiGraph accelerometer and self-reported non-occupational walking, moderate and vigorous physical activity on the modified RESIDential Environment questionnaire. We assessed validity (n=152) using Spearman correlation coefficients, and reliability (n=57) using intraclass correlation coefficients. When compared to steps, moderate physical activity, and bouts of moderate/vigorous physical activity measured by accelerometer, these questionnaire measures showed fair evidence for validity: recreational walking (Spearman correlation coefficients 0.23-0.36), total walking (Spearman correlation coefficients 0.24-0.37), and total moderate physical activity (Spearman correlation coefficients 0.18-0.36). Correlations for self-reported walking and moderate physical activity were higher among unemployed participants and women with lower body mass indices. Generally no other variability in the validity of the instrument was found. Evidence for reliability of RESIDential Environment measures of recreational walking, total walking, and total moderate physical activity was substantial (intraclass correlation coefficients 0.56-0.68). Evidence for questionnaire validity and reliability varied by activity domain and was strongest for walking measures. The questionnaire may capture physical activity less accurately among women with higher body mass indices and employed participants. Capturing occupational activity, specifically walking at work, may improve questionnaire validity. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Changes in Objectively-Determined Walkability and Physical Activity in Adults: A Quasi-Longitudinal Residential Relocation Study

PubMed Central

McCormack, Gavin R.; McLaren, Lindsay; Salvo, Grazia; Blackstaffe, Anita

2017-01-01

Causal evidence for the built environment’s role in supporting physical activity is needed to inform land use and transportation policies. This quasi-longitudinal residential relocation study compared within-person changes in self-reported transportation walking, transportation cycling, and overall physical activity during the past 12 months among adults who did and did not move to a different neighbourhood. In 2014, a random sample of adults from 12 neighbourhoods (Calgary, AB, Canada) with varying urban form and socioeconomic status provided complete self-administered questionnaire data (n = 915). Participants, some of whom moved neighbourhood during the past 12 months (n = 95), reported their perceived change in transportation walking and cycling, and overall physical activity during that period. The questionnaire also captured residential self-selection, and sociodemographic and health characteristics. Walk Scores® were linked to each participant’s current and previous neighbourhood and three groups identified: walkability “improvers” (n = 48); “decliners” (n = 47), and; “maintainers” (n = 820). Perceived change in physical activity was compared between the three groups using propensity score covariate-adjusted Firth logistic regression (odds ratios: OR). Compared with walkability maintainers, walkability decliners (OR 4.37) and improvers (OR 4.14) were more likely (p < 0.05) to report an increase in their transportation walking since moving neighbourhood, while walkability decliners were also more likely (OR 3.17) to report decreasing their transportation walking since moving. Walkability improvers were more likely than maintainers to increase their transportation cycling since moving neighbourhood (OR 4.22). Temporal changes in neighbourhood walkability resulting from residential relocation appear to be associated with reported temporal changes in transportation walking and cycling in adults. PMID:28531149

Changes in Objectively-Determined Walkability and Physical Activity in Adults: A Quasi-Longitudinal Residential Relocation Study.

PubMed

McCormack, Gavin R; McLaren, Lindsay; Salvo, Grazia; Blackstaffe, Anita

2017-05-22

Causal evidence for the built environment's role in supporting physical activity is needed to inform land use and transportation policies. This quasi-longitudinal residential relocation study compared within-person changes in self-reported transportation walking, transportation cycling, and overall physical activity during the past 12 months among adults who did and did not move to a different neighbourhood. In 2014, a random sample of adults from 12 neighbourhoods (Calgary, AB, Canada) with varying urban form and socioeconomic status provided complete self-administered questionnaire data ( n = 915). Participants, some of whom moved neighbourhood during the past 12 months ( n = 95), reported their perceived change in transportation walking and cycling, and overall physical activity during that period. The questionnaire also captured residential self-selection, and sociodemographic and health characteristics. Walk Scores ® were linked to each participant's current and previous neighbourhood and three groups identified: walkability "improvers" ( n = 48); "decliners" ( n = 47), and; "maintainers" ( n = 820). Perceived change in physical activity was compared between the three groups using propensity score covariate-adjusted Firth logistic regression (odds ratios: OR). Compared with walkability maintainers, walkability decliners (OR 4.37) and improvers (OR 4.14) were more likely ( p < 0.05) to report an increase in their transportation walking since moving neighbourhood, while walkability decliners were also more likely (OR 3.17) to report decreasing their transportation walking since moving. Walkability improvers were more likely than maintainers to increase their transportation cycling since moving neighbourhood (OR 4.22). Temporal changes in neighbourhood walkability resulting from residential relocation appear to be associated with reported temporal changes in transportation walking and cycling in adults.

"You've got to walk before you run": positive evaluations of a walking program as part of a gender-sensitized, weight-management program delivered to men through professional football clubs.

PubMed

Hunt, Kate; McCann, Claire; Gray, Cindy M; Mutrie, Nanette; Wyke, Sally

2013-01-01

To explore men's views of a pedometer-based walking program, part of a weight-management intervention delivered through Scottish Premier League football clubs, and the congruence or challenge this poses to masculine identities. Semistructured telephone interviews with a sample of participants in a gender-sensitized, group weight-management program. Interviewing continued until data saturation was reached (n = 29). All men were positive about the context, style of delivery, and content of the broader intervention. These things encouraged men to increase their physical activity (and adopt other behavioral changes) that they may not otherwise have found appealing. The success and acceptability of the walking program resided in three interrelated factors: (a) the utility of pedometers as a technology for motivation, self-monitoring and surveillance, and target setting; (b) the speed with which fitness was regained and weight reduced (enabling men to begin to do more desired forms of physical activity, and so regain visceral, experiential, and pragmatic masculine capital); and (c) bolstering their masculine identities through the receipt of the program in a valued, masculinised context. These data suggest that men will enthusiastically embrace a graduated walking program when the presentation is gender sensitive in context, content, and delivery. Pedometers were viewed as a valuable, reliable technological aid which motivated men and empowered them in self-monitoring of progress toward self-defined goals. Many men experienced the walking program as a means of regaining fitness, thereby enabling them to also regain valued masculine identities and activities, and a step toward regaining a more acceptable masculine body. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Multitasking in older adults with type 2 diabetes: A cross-sectional analysis

PubMed Central

McDowd, Joan M.; Mahnken, Jonathan D.; Burns, Jeffrey M.; Sabus, Carla H.; Britton-Carpenter, Amanda J.; Utech, Nora B.; Kluding, Patricia M.

2017-01-01

Background and purpose Deficits in the ability to multitask contribute to gait abnormalities and falls in many at-risk populations. However, it is unclear whether older adults with type 2 diabetes mellitus (DM) also demonstrate impairments in multitasking. The purpose of this study was to compare multitasking performance in cognitively intact older adults with and without DM and explore its relationship to measures of gait and functional ability. Methods We performed a cross-sectional analysis of 40 individuals aged 60 and older with type 2 DM and a matched group of 40 cognitively intact older adults without DM. Multitasking was examined via the ambulatory Walking and Remembering Test (WART) and seated Pursuit Rotor Test (PRT). Self-selected normal and fast walking speed and stride length variability were quantitatively measured, and self-reported functional ability was assessed via the Late Life Function and Disability Index (LLFDI). Results Participants with DM walked slower and took more steps off path when multitasking during the WART. No between-group differences in multitasking performance were observed on the PRT. Multitasking performance demonstrated little correlation with gait and functional ability in either group. Discussion and conclusions Older adults with DM appear to perform poorly on an ambulatory measure of multitasking. However, we analyzed a relatively small, homogenous sample of older adults with and without type 2 DM and factors such as peripheral neuropathy and the use of multiple comparisons complicate interpretation of the data. Future research should explore the interactions between multitasking and safety, fall risk, and function in this vulnerable population. Clinicians should recognize that an array of factors may contribute to gait and physical dysfunction in older adults with type 2 diabetes, and be prepared to assess and intervene appropriately. PMID:29045492

Multitasking in older adults with type 2 diabetes: A cross-sectional analysis.

PubMed

Rucker, Jason L; McDowd, Joan M; Mahnken, Jonathan D; Burns, Jeffrey M; Sabus, Carla H; Britton-Carpenter, Amanda J; Utech, Nora B; Kluding, Patricia M

2017-01-01

Deficits in the ability to multitask contribute to gait abnormalities and falls in many at-risk populations. However, it is unclear whether older adults with type 2 diabetes mellitus (DM) also demonstrate impairments in multitasking. The purpose of this study was to compare multitasking performance in cognitively intact older adults with and without DM and explore its relationship to measures of gait and functional ability. We performed a cross-sectional analysis of 40 individuals aged 60 and older with type 2 DM and a matched group of 40 cognitively intact older adults without DM. Multitasking was examined via the ambulatory Walking and Remembering Test (WART) and seated Pursuit Rotor Test (PRT). Self-selected normal and fast walking speed and stride length variability were quantitatively measured, and self-reported functional ability was assessed via the Late Life Function and Disability Index (LLFDI). Participants with DM walked slower and took more steps off path when multitasking during the WART. No between-group differences in multitasking performance were observed on the PRT. Multitasking performance demonstrated little correlation with gait and functional ability in either group. Older adults with DM appear to perform poorly on an ambulatory measure of multitasking. However, we analyzed a relatively small, homogenous sample of older adults with and without type 2 DM and factors such as peripheral neuropathy and the use of multiple comparisons complicate interpretation of the data. Future research should explore the interactions between multitasking and safety, fall risk, and function in this vulnerable population. Clinicians should recognize that an array of factors may contribute to gait and physical dysfunction in older adults with type 2 diabetes, and be prepared to assess and intervene appropriately.

Relationship Between Types of Exercise and Quality of Life in a Korean Metabolic Syndrome Population: A Cross-Sectional Study.

PubMed

Oh, Sang Ho; Son, Sun Han; Kang, Si Hyun; Kim, Don-Kyu; Seo, Kyung Mook; Lee, Sang Yoon

2017-05-01

Metabolic syndrome (MetS) significantly correlates with exercise. MetS also has an independent and inverse correlation to quality of life (QoL). However, few studies have examined the association between exercise and QoL in people with MetS. The aim of this study was to ascertain the relationship between exercise and QoL in a MetS population. This was a cross-sectional study using public data from the Sixth Korean National Health and Nutrition Examination Survey in 2014 (n = 7550). MetS was defined on the basis of the revised National Cholesterol Education Program criteria. Demographic factors, three types of exercise (resistance, flexibility, walking), five subsets of EuroQoL (mobility, self-care, usual activities, pain/discomfort, anxiety/depression), and QoL scores (EQ-VAS), were investigated. Independent associations of each exercise on five subsets of QoL were determined using odds ratios (OR) adjusted for four demographic factors (age group, sex, weight change, and area of residence) using multivariate logistic regression analysis. Prevalence of MetS was 26.4% and the ratio of subjects performing resistance, flexibility, or walking exercise was 17.7%, 45.8%, and 71.5% among this population, respectively. EQ-VAS of exercisers was significantly higher than that of non-exercisers in resistance, flexibility, and walking exercise. Although resistance and flexibility exercise did not correlate with any subsets of QoL, mobility and self-care were significantly associated with walking exercise (OR = 0.635, 95% CI = 0.439-0.919 and OR = 0.577, 95% CI = 0.348-0.958, respectively). All exercisers showed higher QoL scores than non-exercisers. Among QoL subsets, mobility and self-care were independently associated with walking exercise in the MetS population. Regular walking exercise was important to higher QoL in those with MetS. This is the first clinical report to indicate that QoL could be independently influenced by walking exercise.

Hysterectomy - Series (image)

MedlinePlus

... hysterectomy. If the bladder was involved, then a catheter may remain in place for 3 to 4 days to help the bladder pass urine. Moving about as soon as possible helps to avoid blood clots in the legs and other problems. Walking to ...

Self-Tuning Threshold Method for Real-Time Gait Phase Detection Based on Ground Contact Forces Using FSRs.

PubMed

Tang, Jing; Zheng, Jianbin; Wang, Yang; Yu, Lie; Zhan, Enqi; Song, Qiuzhi

2018-02-06

This paper presents a novel methodology for detecting the gait phase of human walking on level ground. The previous threshold method (TM) sets a threshold to divide the ground contact forces (GCFs) into on-ground and off-ground states. However, the previous methods for gait phase detection demonstrate no adaptability to different people and different walking speeds. Therefore, this paper presents a self-tuning triple threshold algorithm (STTTA) that calculates adjustable thresholds to adapt to human walking. Two force sensitive resistors (FSRs) were placed on the ball and heel to measure GCFs. Three thresholds (i.e., high-threshold, middle-threshold andlow-threshold) were used to search out the maximum and minimum GCFs for the self-adjustments of thresholds. The high-threshold was the main threshold used to divide the GCFs into on-ground and off-ground statuses. Then, the gait phases were obtained through the gait phase detection algorithm (GPDA), which provides the rules that determine calculations for STTTA. Finally, the STTTA reliability is determined by comparing the results between STTTA and Mariani method referenced as the timing analysis module (TAM) and Lopez-Meyer methods. Experimental results show that the proposed method can be used to detect gait phases in real time and obtain high reliability when compared with the previous methods in the literature. In addition, the proposed method exhibits strong adaptability to different wearers walking at different walking speeds.

Understanding How Families Use Magnifiers during Nature Center Walks

ERIC Educational Resources Information Center

Zimmerman, Heather Toomey; McClain, Lucy Richardson; Crowl, Michele

2013-01-01

This analysis uses a sociocultural learning theory and parent-child interaction framework to understand families' interactions with one type of scientific tool, the magnifier, during nature walks offered by a nature center. Families were video recorded to observe how they organized their activities where they used magnifiers to explore in the…

Interactive Effects of Generalized and Situational Expectancies on the Arousal of Cognitive and Emotional Components of Social Anxiety.

ERIC Educational Resources Information Center

Morris, Larry W.; And Others

1981-01-01

Examined the arousal of social anxiety in an interview setting as a function of anticipated self-disclosure. During the interview, both components of anxeity (worry and emotionality) were affected by expectancy conditions, and emotionality was higher for high- than for low-social-avoidance-and-distress subjects. (Author)

Random Walk Quantum Clustering Algorithm Based on Space

NASA Astrophysics Data System (ADS)

Xiao, Shufen; Dong, Yumin; Ma, Hongyang

2018-01-01

In the random quantum walk, which is a quantum simulation of the classical walk, data points interacted when selecting the appropriate walk strategy by taking advantage of quantum-entanglement features; thus, the results obtained when the quantum walk is used are different from those when the classical walk is adopted. A new quantum walk clustering algorithm based on space is proposed by applying the quantum walk to clustering analysis. In this algorithm, data points are viewed as walking participants, and similar data points are clustered using the walk function in the pay-off matrix according to a certain rule. The walk process is simplified by implementing a space-combining rule. The proposed algorithm is validated by a simulation test and is proved superior to existing clustering algorithms, namely, Kmeans, PCA + Kmeans, and LDA-Km. The effects of some of the parameters in the proposed algorithm on its performance are also analyzed and discussed. Specific suggestions are provided.

Why not walk faster?

PubMed Central

Usherwood, James Richard

2005-01-01

Bipedal walking following inverted pendulum mechanics is constrained by two requirements: sufficient kinetic energy for the vault over midstance and sufficient gravity to provide the centripetal acceleration required for the arc of the body about the stance foot. While the acceleration condition identifies a maximum walking speed at a Froude number of 1, empirical observation indicates favoured walk–run transition speeds at a Froude number around 0.5 for birds, humans and humans under manipulated gravity conditions. In this study, I demonstrate that the risk of ‘take-off’ is greatest at the extremes of stance. This is because before and after kinetic energy is converted to potential, velocities (and so required centripetal accelerations) are highest, while concurrently the component of gravity acting in line with the leg is least. Limitations to the range of walking velocity and stride angle are explored. At walking speeds approaching a Froude number of 1, take-off is only avoidable with very small steps. With realistic limitations on swing-leg frequency, a novel explanation for the walk–run transition at a Froude number of 0.5 is shown. PMID:17148201

The Use of the 6-Min Walk Test as a Proxy for the Assessment of Energy Expenditure during Gait in Individuals with Lower-Limb Amputation

ERIC Educational Resources Information Center

Kark, Laurena; McIntosh, Andrew S.B; Simmons, Annea

2011-01-01

The objective of this study was to determine, and compare, the utility of the 6-min walk test (6 MWT) and self-selected walking speed over 15 m as proxies for the assessment of energy expenditure during gait in individuals with lower-limb amputation. Patients with unilateral, transfemoral amputation (n = 6) and patients with unilateral,…

Participatory Learning Walks: Reflective Practice for the Conductor-Music Educator

ERIC Educational Resources Information Center

Baker, William J.; King, Heidi

2013-01-01

Learning walks can be defined as ongoing, structured classroom visits by senior teachers and other colleagues intended to gather data about teaching and learning through observation and interaction with students. Used in areas such as classroom teaching, learning walks are designed to support professional learning for educators and encourage…

Kinematic and muscle demand similarities between motor-assisted elliptical training and walking: Implications for pediatric gait rehabilitation.

PubMed

Burnfield, Judith M; Cesar, Guilherme M; Buster, Thad W; Irons, Sonya L; Nelson, Carl A

2017-01-01

Many children with physical disabilities and special health care needs experience barriers to accessing effective therapeutic technologies to improve walking and fitness in healthcare and community environments. The expense of many robotic and exoskeleton technologies hinders widespread use in most clinics, school settings, and fitness facilities. A motor-assisted elliptical trainer that is being used to address walking and fitness deficits in adults was modified to enable children as young as three years of age to access the technology (Pedi-ICARE). We compared children's kinematic and muscle activation patterns during walking and training on the Pedi-ICARE. Eighteen children walked (self-selected comfortable speed), Pedi-ICARE trained with motor-assistance at self-selected comfortable speed (AAC), and trained while over-riding motor-assistance (AAC+). Coefficient of multiple correlations (CMCs) compared lower extremity kinematic profiles during AAC and AAC+ to gait. Repeated measures ANOVAs identified muscle demand differences across conditions. CMCs revealed strong similarities at the hip and knee between each motor-assisted elliptical condition and gait. Ankle CMCs were only moderate. Muscle demands were generally lowest during AAC. Over-riding the motor increased hip and knee muscle demands. The similarity of motion patterns between Pedi-ICARE conditions and walking suggest the device could be used to promote task-specific training to improve walking. The capacity to manipulate muscle demands using different motor-assistance conditions highlights Pedi-ICARE's versatility in addressing a wide range of children's abilities. Copyright © 2016 Elsevier B.V. All rights reserved.

Walking for Transportation and Leisure Among U.S. Adults—National Health Interview Survey 2010

PubMed Central

Paul, Prabasaj; Carlson, Susan A.; Carroll, Dianna D.; Berrigan, David; Fulton, Janet E.

2015-01-01

Background Walking, the most commonly reported physical activity among U.S. adults, is undertaken in various domains, including transportation and leisure. Methods This study examined prevalence, bout length, and mean amount of walking in the last week for transportation and leisure, by selected characteristics. Self-reported data from the 2010 National Health Interview Survey (N = 24,017) were analyzed. Results Prevalence of transportation walking was 29.4% (95% CI: 28.6%–30.3%) and of leisure walking was 50.0% (95% CI: 49.1%–51.0%). Prevalence of transportation walking was higher among men; prevalence of leisure walking was higher among women. Most (52.4%) transportation walking bouts were 10 to 15 minutes; leisure walking bouts were distributed more evenly (28.0%, 10–15 minutes; 17.1%, 41–60 minutes). Mean time spent in transportation walking was higher among men, decreased with increasing BMI, and varied by race/ethnicity and region of residence. Mean time spent leisure walking increased with increasing age and with decreasing BMI. Conclusion Demographic correlates and patterns of walking differ by domain. Interventions focusing on either leisure or transportation walking should consider correlates for the specific walking domain. Assessing prevalence, bout length, and mean time of walking for transportation and leisure separately allows for more comprehensive surveillance of walking. PMID:25133651

The time course of location-avoidance learning in fear of spiders.

PubMed

Rinck, Mike; Koene, Marieke; Telli, Sibel; Moerman-van den Brink, Wiltine; Verhoeven, Barbara; Becker, Eni S

2016-01-01

Two experiments were designed to study the time course of avoidance learning in spider fearfuls (SFs) under controlled experimental conditions. To achieve this, we employed an immersive virtual environment (IVE): While walking freely through a virtual art museum to search for specific paintings, the participants were exposed to virtual spiders. Unbeknown to the participants, only two of four museum rooms contained spiders, allowing for avoidance learning. Indeed, the more SF the participants were, the faster they learned to avoid the rooms that contained spiders (Experiment. 1), and within the first six trials, high fearfuls already developed a preference for starting their search task in rooms without spiders (Experiment 2). These results illustrate the time course of avoidance learning in SFs, and they speak to the usefulness of IVEs in fundamental anxiety research.

"Pokémon Go!" May Promote Walking, Discourage Sedentary Behavior in College Students.

PubMed

Barkley, Jacob E; Lepp, Andrew; Glickman, Ellen L

2017-06-01

To assess self-reported walking and sedentary behavior in young adults before and after downloading "Pokémon Go!". In September 2016, a sample of 358 (19.8 ± 2.1 years old, n = 187 females) college students who had downloaded "Pokémon Go!" on their cellular telephones (i.e., cell phones) were surveyed for weekly walking and sedentary behavior via the International Physical Activity Questionnaire. A single interview was administered to participants who estimated their walking and sedentary behavior at three time points: the week immediately preceding their download of "Pokémon Go!" (Baseline), the first week after downloading the game (Time 1), and the week the survey was completed (Time 2). Differences in self-reported physical activity and sedentary behavior across the three time points and across the two genders were compared via analyses of variance. There was a significant main effect of time (F ≥ 49.3, P ≤ 0.001) for walking and sedentary behavior. Participants reported greater (t ≥ 9.5, P < 0.001) daily walking during Time 1 (218.6 ± 156.3 minutes) and Time 2 (182.7 ± 172.1 minutes) versus the baseline (108.5 ± 110.8 minutes). Walking behavior was also significantly greater (t = 4.1, P < 0.001) at Time 1 versus Time 2. Participants reported greater (t ≥ 6.5, P < 0.001) daily sedentary behavior during baseline (346.6 ± 201.3 minutes) versus both Time 1 (261.7 ± 172.4 minutes) and Time 2 (284.3 ± 175.4 minutes). Sedentary behavior was also significantly greater (t = 2.6, P = 0.03) at Time 2 versus Time 1. There were no effects of gender (F ≤ 1.8, P ≥ 0.17). Playing "Pokémon Go!" was associated with increased self-reported walking and decreased sedentary behavior. Such games hold promise as technology that may promote physical activity and discourage sedentary behavior.

Walking the Tightrope: Colloidal surfers mimicking molecular motors

NASA Astrophysics Data System (ADS)

Horowitz, Viva R.; Driscoll, Michelle; Ferrari, Melissa; Youssef, Mena; Sacanna, Stefano; Chaikin, Paul; Manoharan, Vinothan N.

We aim to understand cellular processes, particularly intracellular transport, at a physical level by building simple, well-\\x90controlled systems that mimic the functions of a cell. We are inspired by molecular motors such as kinesin and myosin, which create a dynamic environment that is likely necessary for the biochemical reactions that take place in a eukaryotic cell. One approach we have taken is to investigate the superdiffusive environment created by platinum Janus swimmers encapsulated in artificial cells. Now we are investigating the motion of light-activated colloidal surfers. When they are activated, these particles are attracted to each other and to surfaces, and they are self-propelled, moving via self-diffusiophoresis. On a flat surface, these properties cause the particles to form active crystal structures. When we introduce a wire to the geometry, the particles walk along a wire, reminiscent of the motion of molecular motors such as kinesin walking on a microtubule. When the wire is suspended in the center of a fluid chamber, the particles walk the tightrope. This bio-inspired research may lead to systems of particles walking networks of wires and carrying cargo through an artificial cell.

Considering Attachment and Partner Perceptions in the Prediction of Physical and Emotional Sexual Satisfaction.

PubMed

Øverup, Camilla S; Smith, C Veronica

2017-01-01

Attachment theory provides a framework for understanding sexual satisfaction; in general, research suggests that attachment anxiety and avoidance are associated with decreased sexual satisfaction. Given their different working models of self and other, perceptions of the partner's level of satisfaction might differentially influence people's own perceptions of satisfaction based on their attachment avoidance and anxiety. To examine the predictive value of attachment anxiety and avoidance and perceptions of partner satisfaction in predicting physical and emotional satisfaction after sexual interactions in two studies. Participants (study 1, n = 52; study 2, n = 144) completed a one-time survey containing a measurement of attachment and then reported on their physical and emotional sexual satisfaction after each sexual interaction over the course of 2 to 3 weeks. The Experiences in Close Relationships Scale-Revised was completed during the one-time survey, and ratings of personal physical and emotional sexual satisfaction (studies 1 and 2) and perceptions of partner's physical and emotional satisfaction were completed after sexual interactions (study 2). Greater attachment avoidance was associated with lesser physical and emotional satisfaction. Moreover, when perceiving the partner to be emotionally satisfied, people with more attachment avoidance reported less emotional satisfaction for themselves. For greater attachment anxiety, greater perceived partner satisfaction (physical and emotional) predicted greater personal satisfaction of the two types. The findings support attachment theory as a valuable lens through which to study sexual satisfaction. Moreover, the results suggest that it is important to consider perceptions of partner sexual satisfaction in understanding the sexual satisfaction of people who demonstrate attachment anxiety and avoidance. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

A Renormalisation Group Method. V. A Single Renormalisation Group Step

NASA Astrophysics Data System (ADS)

Brydges, David C.; Slade, Gordon

2015-05-01

This paper is the fifth in a series devoted to the development of a rigorous renormalisation group method applicable to lattice field theories containing boson and/or fermion fields, and comprises the core of the method. In the renormalisation group method, increasingly large scales are studied in a progressive manner, with an interaction parametrised by a field polynomial which evolves with the scale under the renormalisation group map. In our context, the progressive analysis is performed via a finite-range covariance decomposition. Perturbative calculations are used to track the flow of the coupling constants of the evolving polynomial, but on their own perturbative calculations are insufficient to control error terms and to obtain mathematically rigorous results. In this paper, we define an additional non-perturbative coordinate, which together with the flow of coupling constants defines the complete evolution of the renormalisation group map. We specify conditions under which the non-perturbative coordinate is contractive under a single renormalisation group step. Our framework is essentially combinatorial, but its implementation relies on analytic results developed earlier in the series of papers. The results of this paper are applied elsewhere to analyse the critical behaviour of the 4-dimensional continuous-time weakly self-avoiding walk and of the 4-dimensional -component model. In particular, the existence of a logarithmic correction to mean-field scaling for the susceptibility can be proved for both models, together with other facts about critical exponents and critical behaviour.

Trichotomous goals of elementary school students learning English as a foreign language: a structural equation model.

PubMed

He, Tung-Hsien; Chang, Shan-Mao; Chen, Shu-Hui Eileen; Gou, Wen Johnny

2012-02-01

This study applied structural equation modeling (SEM) techniques to define the relations among trichotomous goals (mastery goals, performance-approach goals, and performance-avoidance goals), self-efficacy, use of metacognitive self-regulation strategies, positive belief in seeking help, and help-avoidance behavior. Elementary school students (N = 105), who were learning English as a foreign language, were surveyed using five self-report scales. The structural equation model showed that self-efficacy led to the adoption of mastery goals but discouraged the adoption of performance-approach goals and performance-avoidance goals. Furthermore, mastery goals increased the use of metacognitive self-regulation strategies, whereas performance-approach goals and performance-avoidance goals reduced their use. Mastery goals encouraged positive belief in help-seeking, but performance-avoidance goals decreased such belief. Finally, performance-avoidance goals directly led to help-avoidance behavior, whereas positive belief assumed a critical role in reducing help-avoidance. The established structural equation model illuminated the potential causal relations among these variables for the young learners in this study.

Negotiating identity and self-image: perceptions of falls in ambulatory individuals with spinal cord injury – a qualitative study

PubMed Central

Jørgensen, Vivien; Roaldsen, Kirsti Skavberg

2016-01-01

Objective: Explore and describe experiences and perceptions of falls, risk of falling, and fall-related consequences in individuals with incomplete spinal cord injury (SCI) who are still walking. Design: A qualitative interview study applying interpretive content analysis with an inductive approach. Setting: Specialized rehabilitation hospital. Subjects: A purposeful sample of 15 individuals (10 men), 23 to 78 years old, 2-34 years post injury with chronic incomplete traumatic SCI, and walking ⩾75% of time for mobility needs. Methods: Individual, semi-structured face-to-face interviews were recorded, condensed, and coded to find themes and subthemes. Results: One overarching theme was revealed: “Falling challenges identity and self-image as normal” which comprised two main themes “Walking with incomplete SCI involves minimizing fall risk and fall-related concerns without compromising identity as normal” and “Walking with incomplete SCI implies willingness to increase fall risk in order to maintain identity as normal”. Informants were aware of their increased fall risk and took precautions, but willingly exposed themselves to risky situations when important to self-identity. All informants expressed some conditional fall-related concerns, and a few experienced concerns limiting activity and participation. Conclusion: Ambulatory individuals with incomplete SCI considered falls to be a part of life. However, falls interfered with the informants’ identities and self-images as normal, healthy, and well-functioning. A few expressed dysfunctional concerns about falling, and interventions should target these. PMID:27170274

Preliminary evidence of altered biomechanics in adolescents with Juvenile Fibromyalgia

PubMed Central

Sil, Soumitri; Thomas, Staci; DiCesare, Christopher; Strotman, Daniel; Ting, Tracy V; Myer, Gregory; Kashikar-Zuck, Susmita

2014-01-01

Objective Juvenile Fibromyalgia (JFM) is characterized by chronic musculoskeletal pain and marked reduction in physical activity. Despite recommendations for exercise to manage JFM pain, exercise adherence is poor. Due to pain and activity avoidance, adolescents with JFM are at risk for altered joint mechanics that may make them susceptible to increased pain and reduced tolerance for exercise. The primary aim of this study was to assess functional deficits in patients with JFM compared to healthy controls using objective biomechanical assessment. Methods Female adolescent patients with JFM (n=17) and healthy controls (n=14) completed biomechanical assessments including gait analysis and tests of lower extremity strength (isokinetic knee extension/flexion, hip abduction) and functional performance (Drop Vertical Jump) along with self-report measures of disability (Functional Disability Inventory), pain intensity, depressive symptoms (Children’s Depression Inventory), and fear of movement (Tampa Scale of Kinesiophobia). Results Patients with JFM demonstrated mild deficiencies in walking gait and functional performance (p’s <. 05), significantly lower left knee extension and flexion strength (19–26% deficit) and bilateral hip abduction strength (33–37%) compared to healthy controls (p’s < .008). Patients with JFM reported significantly higher functional disability, pain intensity, depressive symptoms, and fear of movement relative to controls (p’s < 0.01). Conclusions This study showed that adolescents with JFM exhibited objective alterations in biomechanics, and self-reported fear of movement which may reinforce their activity avoidance. Interventions for JFM should include a focus on correcting functional deficits and instilling greater confidence in adolescents with JFM to engage in exercise to improve functional outcomes. PMID:25156509

Self-Supervised Dynamical Systems

NASA Technical Reports Server (NTRS)

Zak, Michail

2003-01-01

Some progress has been made in a continuing effort to develop mathematical models of the behaviors of multi-agent systems known in biology, economics, and sociology (e.g., systems ranging from single or a few biomolecules to many interacting higher organisms). Living systems can be characterized by nonlinear evolution of probability distributions over different possible choices of the next steps in their motions. One of the main challenges in mathematical modeling of living systems is to distinguish between random walks of purely physical origin (for instance, Brownian motions) and those of biological origin. Following a line of reasoning from prior research, it has been assumed, in the present development, that a biological random walk can be represented by a nonlinear mathematical model that represents coupled mental and motor dynamics incorporating the psychological concept of reflection or self-image. The nonlinear dynamics impart the lifelike ability to behave in ways and to exhibit patterns that depart from thermodynamic equilibrium. Reflection or self-image has traditionally been recognized as a basic element of intelligence. The nonlinear mathematical models of the present development are denoted self-supervised dynamical systems. They include (1) equations of classical dynamics, including random components caused by uncertainties in initial conditions and by Langevin forces, coupled with (2) the corresponding Liouville or Fokker-Planck equations that describe the evolutions of probability densities that represent the uncertainties. The coupling is effected by fictitious information-based forces, denoted supervising forces, composed of probability densities and functionals thereof. The equations of classical mechanics represent motor dynamics that is, dynamics in the traditional sense, signifying Newton s equations of motion. The evolution of the probability densities represents mental dynamics or self-image. Then the interaction between the physical and metal aspects of a monad is implemented by feedback from mental to motor dynamics, as represented by the aforementioned fictitious forces. This feedback is what makes the evolution of probability densities nonlinear. The deviation from linear evolution can be characterized, in a sense, as an expression of free will. It has been demonstrated that probability densities can approach prescribed attractors while exhibiting such patterns as shock waves, solitons, and chaos in probability space. The concept of self-supervised dynamical systems has been considered for application to diverse phenomena, including information-based neural networks, cooperation, competition, deception, games, and control of chaos. In addition, a formal similarity between the mathematical structures of self-supervised dynamical systems and of quantum-mechanical systems has been investigated.

What's keeping people after stroke from walking outdoors to become physically active? A qualitative study, using an integrated biomedical and behavioral theory of functioning and disability.

PubMed

Outermans, Jacqueline; Pool, Jan; van de Port, Ingrid; Bakers, Japie; Wittink, Harriet

2016-08-15

In general people after stroke do not meet the recommendations for physical activity to conduct a healthy lifestyle. Programs to stimulate walking activity to increase physical activity are based on the available insights into barriers and facilitators to physical activity after stroke. However, these programs are not entirely successful. The purpose of this study was to comprehensively explore perceived barriers and facilitators to outdoor walking using a model of integrated biomedical and behavioral theory, the Physical Activity for people with a Disability model (PAD). Included were community dwelling respondents after stroke, classified ≥ 3 at the Functional Ambulation Categories (FAC), purposively sampled regarding the use of healthcare. The data was collected triangulating in a multi-methods approach, i.e. semi-structured, structured and focus-group interviews. A primarily deductive thematic content analysis using the PAD-model in a framework-analysis' approach was conducted after verbatim transcription. 36 respondents (FAC 3-5) participated in 16 semi-structured interviews, eight structured interviews and two focus-group interviews. The data from the interviews covered all domains of the PAD model. Intention, ability and opportunity determined outdoor walking activity. Personal factors determined the intention to walk outdoors, e.g. negative social influence, resulting from restrictive caregivers in the social environment, low self-efficacy influenced by physical environment, and also negative attitude towards physical activity. Walking ability was influenced by loss of balance and reduced walking distance and by impairments of motor control, cognition and aerobic capacity as well as fatigue. Opportunities arising from household responsibilities and lively social constructs facilitated outdoor walking. To stimulate outdoor walking activity, it seems important to influence the intention by addressing social influence, self-efficacy and attitude towards physical activity in the development of efficient interventions. At the same time, improvement of walking ability and creation of opportunity should be considered.

Predictive value of health-related fitness tests for self-reported mobility difficulties among high-functioning elderly men and women.

PubMed

Hämäläinen, H Pauliina; Suni, Jaana H; Pasanen, Matti E; Malmberg, Jarmo J; Miilunpalo, Seppo I

2006-06-01

The functional independence of elderly populations deteriorates with age. Several tests of physical performance have been developed for screening elderly persons who are at risk of losing their functional independence. The purpose of the present study was to investigate whether several components of health-related fitness (HRF) are valid in predicting the occurrence of self-reported mobility difficulties (MD) among high-functioning older adults. Subjects were community-dwelling men and women, born 1917-1941, who participated in the assessment of HRF [6.1-m (20-ft) walk, one-leg stand, backwards walk, trunk side-bending, dynamic back extension, one-leg squat, 1-km walk] and who were free of MD in 1996 (no difficulties in walking 2- km, n=788; no difficulties in climbing stairs, n=647). Postal questionnaires were used to assess the prevalence of MD in 1996 and the occurrence of new MD in 2002. Logistic regression analysis was used as the statistical method. Both inability to perform the backwards walk and a poorer result in it were associated with risk of walking difficulties in the logistic model, with all the statistically significant single test items included. Results of 1-km walk time and one-leg squat strength test were also associated with risk, although the squat was statistically significant only in two older birth cohorts. Regarding stair-climbing difficulties, poorer results in the 1-km walk, dynamic back extension and one-leg squat tests were associated with increased risk of MD. The backwards walk, one-leg squat, dynamic back extension and 1-km walk tests were the best predictors of MD. These tests are recommended for use in screening high-functioning older people at risk of MD, as well as to target physical activity counseling to those components of HRF that are important for functional independence.

Self-Esteem, Achievement Goals, and Self-Handicapping in College Physical Education.

PubMed

Chen, Zuosong; Sun, Kaihong; Wang, Kun

2017-01-01

This study aims to investigate the relationships among self-esteem, achievement goals, and self-handicapping and the potential mediating role of achievement goals in the relationship between self-esteem and self-handicapping in college physical education. The participants were 320 Chinese college students. Three validated scales were employed to assess participants' self-esteem, achievement goals, and self-handicapping in college physical education. Results showed that self-esteem had a negative effect on self-handicapping. Self-esteem had a positive effect on mastery goals, but had a negative effect on performance-avoidance goals. Mastery goals had a negative effect and performance-avoidance goals had a positive effect on self-handicapping. Moreover, mastery goals and performance-avoidance goals partially mediated the relationship between self-esteem and self-handicapping, and self-esteem had both direct and indirect effects on self-handicapping in college physical education. The findings indicate that improving individual's self-esteem and promoting mastery goals while reducing performance-avoidance goals may be relevant strategies to reduce self-handicapping in college physical education.

Gestational diabetes - self-care

MedlinePlus

... will create a diet just for you. Your health care provider may ask you to keep track of what you eat. Exercise will help keep your blood sugar under control. A low-impact activity such as walking is a safe and effective type of exercise. Try walking 1 to 2 ...

Activity Monitors Step Count Accuracy in Community-Dwelling Older Adults.

PubMed

Johnson, Marquell

2015-01-01

Objective: To examine the step count accuracy of activity monitors in community-dwelling older adults. Method : Twenty-nine participants aged 67.70 ± 6.07 participated. Three pedometers and the Actical accelerometer step count functions were compared with actual steps taken during a 200-m walk around an indoor track and during treadmill walking at three different speeds. Results : There was no statistical difference between activity monitors step counts and actual steps during self-selected pace walking. During treadmill walking at 0.67 m∙s -1 , all activity monitors step counts were significantly different from actual steps. During treadmill walking at 0.894m∙s -1 , the Omron HJ-112 pedometer step counts were not significantly different from actual steps. During treadmill walking at 1.12 m∙s -1 , the Yamax SW-200 pedometer steps were significantly different from actual steps. Discussion : Activity monitor selection should be deliberate when examining the walking behaviors of community-dwelling older adults, especially for those who walk at a slower pace.

Activity Monitors Step Count Accuracy in Community-Dwelling Older Adults

PubMed Central

2015-01-01

Objective: To examine the step count accuracy of activity monitors in community-dwelling older adults. Method: Twenty-nine participants aged 67.70 ± 6.07 participated. Three pedometers and the Actical accelerometer step count functions were compared with actual steps taken during a 200-m walk around an indoor track and during treadmill walking at three different speeds. Results: There was no statistical difference between activity monitors step counts and actual steps during self-selected pace walking. During treadmill walking at 0.67 m∙s−1, all activity monitors step counts were significantly different from actual steps. During treadmill walking at 0.894m∙s−1, the Omron HJ-112 pedometer step counts were not significantly different from actual steps. During treadmill walking at 1.12 m∙s−1, the Yamax SW-200 pedometer steps were significantly different from actual steps. Discussion: Activity monitor selection should be deliberate when examining the walking behaviors of community-dwelling older adults, especially for those who walk at a slower pace. PMID:28138464

Achilles Tendon Rupture

MedlinePlus

... also help the muscle and tendon absorb more force and prevent injury. Vary your exercises. Alternate high-impact sports, such as running, with low-impact sports, such as walking, biking or swimming. Avoid activities that place excessive stress on your Achilles tendons, such as hill ...

Semiflexible macromolecules in quasi-one-dimensional confinement: Discrete versus continuous bond angles.

PubMed

Huang, Aiqun; Hsu, Hsiao-Ping; Bhattacharya, Aniket; Binder, Kurt

2015-12-28

The conformations of semiflexible polymers in two dimensions confined in a strip of width D are studied by computer simulations, investigating two different models for the mechanism by which chain stiffness is realized. One model (studied by molecular dynamics) is a bead-spring model in the continuum, where stiffness is controlled by a bond angle potential allowing for arbitrary bond angles. The other model (studied by Monte Carlo) is a self-avoiding walk chain on the square lattice, where only discrete bond angles (0° and ±90°) are possible, and the bond angle potential then controls the density of kinks along the chain contour. The first model is a crude description of DNA-like biopolymers, while the second model (roughly) describes synthetic polymers like alkane chains. It is first demonstrated that in the bulk the crossover from rods to self-avoiding walks for both models is very similar, when one studies average chain linear dimensions, transverse fluctuations, etc., despite their differences in local conformations. However, in quasi-one-dimensional confinement two significant differences between both models occur: (i) The persistence length (extracted from the average cosine of the bond angle) gets renormalized for the lattice model when D gets less than the bulk persistence length, while in the continuum model it stays unchanged. (ii) The monomer density near the repulsive walls for semiflexible polymers is compatible with a power law predicted for the Kratky-Porod model in the case of the bead-spring model, while for the lattice case it tends to a nonzero constant across the strip. However, for the density of chain ends, such a constant behavior seems to occur for both models, unlike the power law observed for flexible polymers. In the regime where the bulk persistence length ℓp is comparable to D, hairpin conformations are detected, and the chain linear dimensions are discussed in terms of a crossover from the Daoud/De Gennes "string of blobs"-picture to the flexible rod picture when D decreases and/or the chain stiffness increases. Introducing a suitable further coarse-graining of the chain contours of the continuum model, direct estimates for the deflection length and its distribution could be obtained.

Entangled spin chain

NASA Astrophysics Data System (ADS)

Salberger, Olof; Korepin, Vladimir

We introduce a new model of interacting spin 1/2. It describes interactions of three nearest neighbors. The Hamiltonian can be expressed in terms of Fredkin gates. The Fredkin gate (also known as the controlled swap gate) is a computational circuit suitable for reversible computing. Our construction generalizes the model presented by Peter Shor and Ramis Movassagh to half-integer spins. Our model can be solved by means of Catalan combinatorics in the form of random walks on the upper half plane of a square lattice (Dyck walks). Each Dyck path can be mapped on a wave function of spins. The ground state is an equally weighted superposition of Dyck walks (instead of Motzkin walks). We can also express it as a matrix product state. We further construct a model of interacting spins 3/2 and greater half-integer spins. The models with higher spins require coloring of Dyck walks. We construct a SU(k) symmetric model (where k is the number of colors). The leading term of the entanglement entropy is then proportional to the square root of the length of the lattice (like in the Shor-Movassagh model). The gap closes as a high power of the length of the lattice [5, 11].

Experiential avoidance, self-compassion, self-judgment and coping styles in infertility.

PubMed

Cunha, Marina; Galhardo, Ana; Pinto-Gouveia, José

2016-12-01

This study sought out to explore the existence of differences regarding emotion regulation processes (psychological inflexibility/experiential avoidance, self-judgment and self-compassion) and coping styles (emotional/detached, avoidant and rational) in three different groups of couples: 120 fertile couples (FG), 147 couples with an infertility diagnosis who were pursuing medical treatment for their fertility problem(s) (IG), and 59 couples with infertility applying for adoption (AG). Cross-sectional survey, using the couple as unit of analysis. Participants filled in paper-pencil questionnaires assessing coping styles, psychological inflexibility/experiential avoidance, self-judgment and self-compassion. IG couples, and particularly women, tend to use more experiential avoidance and self-judgment mechanisms and less emotional/detached coping style. When compared to FG couples, IG and AG couples tend to apply more avoidant coping strategies. AG couples showed higher self-compassion. Findings suggest that emotion regulation processes may be an important target in psychological interventions for patients dealing with infertility and with the demands of medical treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

Walking the Talk: Fostering Self-Regulated Learning in the Classroom.

ERIC Educational Resources Information Center

Ridley, D. Scott; And Others

1994-01-01

Describes how teachers can transform self-regulated learning theory and research into classroom practice. Defines the concept and discusses the costs of encouraging student dependency, the benefits of nurturing student self-regulation, and implementation recommendations. Teachers should model self-regulatory attitudes and behaviors, incorporate…

Walk Score® and Transit Score® and Walking in the Multi-Ethnic Study of Atherosclerosis

PubMed Central

Hirsch, Jana A.; Moore, Kari A.; Evenson, Kelly R.; Rodriguez, Daniel A; Diez Roux, Ana V.

2013-01-01

Background Walk Score® and Transit Score® are open-source measures of the neighborhood built environment to support walking (“walkability”) and access to transportation. Purpose To investigate associations of Street Smart Walk Score and Transit Score with self-reported transport and leisure walking using data from a large multi-city and diverse population-based sample of adults. Methods Data from a sample of 4552 residents of Baltimore MD; Chicago IL; Forsyth County NC; Los Angeles CA; New York NY; and St. Paul MN from the Multi-Ethnic Study of Atherosclerosis (2010–2012) were linked to Walk Score and Transit Score (collected in 2012). Logistic and linear regression models estimated ORs of not walking and mean differences in minutes walked, respectively, associated with continuous and categoric Walk Score and Transit Score. All analyses were conducted in 2012. Results After adjustment for site, key sociodemographic, and health variables, a higher Walk Score was associated with lower odds of not walking for transport and more minutes/week of transport walking. Compared to those in a “walker’s paradise,” lower categories of Walk Score were associated with a linear increase in odds of not transport walking and a decline in minutes of leisure walking. An increase in Transit Score was associated with lower odds of not transport walking or leisure walking, and additional minutes/week of leisure walking. Conclusions Walk Score and Transit Score appear to be useful as measures of walkability in analyses of neighborhood effects. PMID:23867022

Exploring the interaction of patient activation and message design variables: message frame and presentation mode influence on the walking behavior of patients with type 2 diabetes.

PubMed

Ledford, Christy J W

2012-10-01

Examining interpersonal (physician-patient) communication strategies for promoting walking exercise to patients with type 2 diabetes assigned to primary care clinics, the study evaluated two message design variables--frame and presentation mode--as influencers of communication and adoption success. The single-site, four-week, prospective intervention study followed a 2×3 factorial, non-equivalent comparison group quasi-experimental design. Results showed frame was significantly related to steps walked; however, when including patient activation as an interaction, frame was non-significant. The model including patient activation interactions, however, detected significant mode effects on behavior. Results provide evidence that statistics are most effectively used with activated patients.

Making your skin crawl: The role of tactile sensitivity in disease avoidance.

PubMed

Hunt, David Francis; Cannell, Grace; Davenhill, Nicholas A; Horsford, Stephanie A; Fleischman, Diana S; Park, Justin H

2017-07-01

Mounting evidence indicates that animals, including humans, have evolved a behavioral disease-avoidance system designed to facilitate the detection and avoidance of sources of pathogens, and that this system interacts with physiological defenses. The skin acts as an important anatomical barrier, yet little research has investigated the role of tactile sensitivity in disease avoidance. Increased tactile sensitivity in the presence of potential sources of pathogens may facilitate prophylactic behaviors such as self-grooming. Across multiple studies, we tested the hypothesis that the induction of disgust-the key emotion underlying disease avoidance-may lead to greater tactile sensitivity compared to control conditions. A nonsignificant trend was found in a pilot study, which was replicated (and found to be significant) in Studies 1 and 2. To our knowledge, these results are the first to demonstrate disgust-induced changes in tactile sensitivity, and they contribute to the growing literature on the integrated evolved defenses against infectious disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Walking deficits and centrophobism in an α-synuclein fly model of Parkinson's disease1

PubMed Central

Chen, A Y; Wilburn, P; Hao, X; Tully, T

2014-01-01

Parkinson's disease (PD) is a movement neurodegenerative disorder, characterized by bradykinesia, rigidity and tremor, constituting difficulties in walking and abnormal gait. Previous research shows that Drosophila expressing human α-synuclein A30P (A30P) develop deficits in geotaxis climbing; however, geotaxis climbing is a different movement modality from walking. Whether A30P flies would exhibit abnormal walking in a horizontal plane, a measure more relevant to PD, is not known. In this study, we characterized A30P fly walking using a high-speed camera and an automatic behavior tracking system. We found that old but not young A30P flies exhibited walking abnormalities, specifically decreased total moving distance, distance per movement, velocity, angular velocity and others, compared with old control flies. Those features match the definition of bradykinesia. Multivariate analysis further suggested a synergistic effect of aging and A30P, resulting in a distinct pattern of walking deficits, as seen in aged A30P flies. Psychiatric problems are common in PD patients with anxiety affecting 40–69% of patients. Central avoidance is one assessment of anxiety in various animal models. We found old but not young A30P flies exhibited increased centrophobism, suggesting possible elevated anxiety. Here, we report the first quantitative measures of walking qualities in a PD fly model and propose an alternative behavior paradigm for evaluating motor functions apart from climbing assay. PMID:25113870

Safe RESIDential Environments? A longitudinal analysis of the influence of crime-related safety on walking.

PubMed

Foster, Sarah; Hooper, Paula; Knuiman, Matthew; Christian, Hayley; Bull, Fiona; Giles-Corti, Billie

2016-02-16

Numerous cross-sectional studies have investigated the premise that the perception of crime will cause residents to constrain their walking; however the findings to date are inconclusive. In contrast, few longitudinal or prospective studies have examined the impact of crime-related safety on residents walking behaviours. This study used longitudinal data to test whether there is a causal relationship between crime-related safety and walking in the local neighbourhood. Participants in the RESIDential Environments Project (RESIDE) in Perth, Australia, completed a questionnaire before moving to their new neighbourhood (n = 1813) and again approximately one (n = 1467), three (n = 1230) and seven years (n = 531) after relocating. Self-report measures included neighbourhood perceptions (modified NEWS items) and walking inside the neighbourhood (min/week). Objective built environmental measures were generated for each participant's 1600 m neighbourhood at each time-point, and the count of crimes reported to police were generated at the suburb-level for the first three time-points only. The impact of crime-related safety on walking was examined in SAS using the Proc Mixed procedure (marginal repeated measures model with unrestricted variance pattern). Initial models controlled for demographics, time and self-selection, and subsequent models progressively adjusted for other built and social environment factors based on a social ecological model. For every increase of one level on a five-point Likert scale in perceived safety from crime, total walking within the local neighbourhood increased by 18.0 min/week (p = 0.000). This relationship attenuated to an increase of 10.5 min/week after accounting for other built and social environment factors, but remained significant (p = 0.008). Further analyses examined transport and recreational walking separately. In the fully adjusted models, each increase in safety from crime was associated with a 7.0 min/week increase in recreational walking (p = 0.009), however findings for transport walking were non-significant. All associations between suburb-level crime and walking were non-significant. This study provides longitudinal evidence of a potential causal relationship between residents' perceptions of safety from crime and recreational walking. Safety perceptions appeared to influence recreational walking, rather than transport-related walking. Given the popularity of recreational walking and the need to increase levels of physical activity, community social and physical environmental interventions that foster residents' feelings of safety are likely to increase recreational walking and produce public health gains.

A Walking Education Program for Patients with Osteoarthritis of the Knee: Theory and Intervention Strategies.

ERIC Educational Resources Information Center

Allegrante, John P.; And Others

1993-01-01

A walking program for osteoarthritis patients promoted adoption by guided practice, reinforcement, and stimulus control; facilitated compliance by behavioral contracting; maintained behavior change through generalization and self-control strategies; and prevented relapse by realignment of normative beliefs and planned relapse techniques. (SK)

An Innovative Framework for Delivering Psychotherapy to Patients With Treatment-Resistant Posttraumatic Stress Disorder: Rationale for Interactive Motion-Assisted Therapy.

PubMed

van Gelderen, Marieke J; Nijdam, Mirjam J; Vermetten, Eric

2018-01-01

Despite an array of evidence-based psychological treatments for patients with a posttraumatic stress disorder (PTSD), a majority of patients do not fully benefit from the potential of these therapies. In veterans with PTSD, up to two-thirds retain their diagnosis after psychotherapy and often their disorder is treatment-resistant, which calls for improvement of therapeutic approaches for this population. One of the factors hypothesized to underlie low response in PTSD treatment is high behavioral and cognitive avoidance to traumatic reminders. In the current paper we explore if a combination of personalized virtual reality, multi-sensory input, and walking during exposure can enhance treatment engagement, overcome avoidance, and thereby optimize treatment effectiveness. Virtual reality holds potential to increase presence and in-session attention and to facilitate memory retrieval. Multi-sensory input such as pictures and music can personalize this experience. Evidence for the positive effect of physical activity on fear extinction and associative thinking, as well as embodied cognition theories, provide a rationale for decreased avoidance by literally approaching cues of the traumatic memories. A dual-attention task further facilitates new learning and reconsolidation. These strategies have been combined in an innovative framework for trauma-focused psychotherapy, named Multi-modular Motion-assisted Memory Desensitization and Reconsolidation (3MDR). In this innovative treatment the therapeutic setting is changed from the face-to-face sedentary position to a side-by-side activating context in which patients walk toward trauma-related images in a virtual environment. The framework of 3MDR has been designed as a boost for patients with treatment-resistant PTSD, which is illustrated by three case examples. The intervention is discussed in context of other advancements in treatment for treatment-resistant PTSD. Novel elements of this approach are activation, personalization and empowerment. While developed for veterans with PTSD who do not optimally respond to standardized treatments, this innovative framework holds potential to also be used for other patient populations and earlier stages of treatment for patients with PTSD.

An Innovative Framework for Delivering Psychotherapy to Patients With Treatment-Resistant Posttraumatic Stress Disorder: Rationale for Interactive Motion-Assisted Therapy

PubMed Central

van Gelderen, Marieke J.; Nijdam, Mirjam J.; Vermetten, Eric

2018-01-01

Despite an array of evidence-based psychological treatments for patients with a posttraumatic stress disorder (PTSD), a majority of patients do not fully benefit from the potential of these therapies. In veterans with PTSD, up to two-thirds retain their diagnosis after psychotherapy and often their disorder is treatment-resistant, which calls for improvement of therapeutic approaches for this population. One of the factors hypothesized to underlie low response in PTSD treatment is high behavioral and cognitive avoidance to traumatic reminders. In the current paper we explore if a combination of personalized virtual reality, multi-sensory input, and walking during exposure can enhance treatment engagement, overcome avoidance, and thereby optimize treatment effectiveness. Virtual reality holds potential to increase presence and in-session attention and to facilitate memory retrieval. Multi-sensory input such as pictures and music can personalize this experience. Evidence for the positive effect of physical activity on fear extinction and associative thinking, as well as embodied cognition theories, provide a rationale for decreased avoidance by literally approaching cues of the traumatic memories. A dual-attention task further facilitates new learning and reconsolidation. These strategies have been combined in an innovative framework for trauma-focused psychotherapy, named Multi-modular Motion-assisted Memory Desensitization and Reconsolidation (3MDR). In this innovative treatment the therapeutic setting is changed from the face-to-face sedentary position to a side-by-side activating context in which patients walk toward trauma-related images in a virtual environment. The framework of 3MDR has been designed as a boost for patients with treatment-resistant PTSD, which is illustrated by three case examples. The intervention is discussed in context of other advancements in treatment for treatment-resistant PTSD. Novel elements of this approach are activation, personalization and empowerment. While developed for veterans with PTSD who do not optimally respond to standardized treatments, this innovative framework holds potential to also be used for other patient populations and earlier stages of treatment for patients with PTSD. PMID:29780334

Functional Coping Dynamics and Experiential Avoidance in a Community Sample with No Self-Injury vs. Non-Suicidal Self-Injury Only vs. Those with Both Non-Suicidal Self-Injury and Suicidal Behaviour

PubMed Central

Nielsen, Emma; Sayal, Kapil; Townsend, Ellen

2017-01-01

Although emotional avoidance may be a critical factor in the pathway from psychological distress to self-injury and/or suicidality, little is known about the relative importance of differing functional coping dynamics and experiential avoidance between people with self-injury histories of differing intent (e.g., Non-Suicidal Self-Injury only vs. Non-Suicidal Self-Injury plus Suicidal Behaviour; NSSI vs. NSSI + SB). A community-based survey (N = 313; female, 81%; ages 16–49 years, M = 19.78, SD = 3.48) explored self-reported experiential avoidance and functional coping dynamics in individuals with (i) no self-injury history (controls); (ii) a history of NSSI only; and (iii) a history of NSSI + SB. Jonckheere-Terpstra trend tests indicated that avoidance coping was higher in the NSSI and NSSI + SB groups than in controls. Emotion regulation was higher in controls than those with a history of self-injury (NSSI and NSSI + SB). Approach and reappraisal coping demonstrated significant ordered effects such that control participants were higher in these coping dynamics than those with a history of NSSI only, who, in turn, were higher than those with a history of NSSI + SB (Control > NSSI > NSSI + SB). Endorsement of the reappraisal/denial facet of experiential avoidance was most pronounced in those with a history of NSSI + SB (Control < NSSI < NSSI + SB). No significant ordered effects were observed for other dimensions of experiential avoidance. Understanding how the endorsement of functional coping dynamics and which components of experiential avoidance vary between groups with differing self-injury intent histories has important implications for treatment planning. PMID:28555056

Functional Coping Dynamics and Experiential Avoidance in a Community Sample with No Self-Injury vs. Non-Suicidal Self-Injury Only vs. Those with Both Non-Suicidal Self-Injury and Suicidal Behaviour.

PubMed

Nielsen, Emma; Sayal, Kapil; Townsend, Ellen

2017-05-29

Although emotional avoidance may be a critical factor in the pathway from psychological distress to self-injury and/or suicidality, little is known about the relative importance of differing functional coping dynamics and experiential avoidance between people with self-injury histories of differing intent (e.g., Non-Suicidal Self-Injury only vs. Non-Suicidal Self-Injury plus Suicidal Behaviour; NSSI vs. NSSI + SB). A community-based survey (N = 313; female, 81%; ages 16-49 years, M = 19.78, SD = 3.48) explored self-reported experiential avoidance and functional coping dynamics in individuals with (i) no self-injury history (controls); (ii) a history of NSSI only; and (iii) a history of NSSI + SB. Jonckheere-Terpstra trend tests indicated that avoidance coping was higher in the NSSI and NSSI + SB groups than in controls. Emotion regulation was higher in controls than those with a history of self-injury (NSSI and NSSI + SB). Approach and reappraisal coping demonstrated significant ordered effects such that control participants were higher in these coping dynamics than those with a history of NSSI only, who, in turn, were higher than those with a history of NSSI + SB (Control > NSSI > NSSI + SB). Endorsement of the reappraisal/denial facet of experiential avoidance was most pronounced in those with a history of NSSI + SB (Control < NSSI < NSSI + SB). No significant ordered effects were observed for other dimensions of experiential avoidance. Understanding how the endorsement of functional coping dynamics and which components of experiential avoidance vary between groups with differing self-injury intent histories has important implications for treatment planning.

Lévy meets poisson: a statistical artifact may lead to erroneous recategorization of Lévy walk as Brownian motion.

PubMed

Gautestad, Arild O

2013-03-01

The flow of GPS data on animal space is challenging old paradigms, such as the issue of the scale-free Lévy walk versus scale-specific Brownian motion. Since these movement classes often require different protocols with respect to ecological analyses, further theoretical development in this field is important. I describe central concepts such as scale-specific versus scale-free movement and the difference between mechanistic and statistical-mechanical levels of analysis. Next, I report how a specific sampling scheme may have produced much confusion: a Lévy walk may be wrongly categorized as Brownian motion if the duration of a move, or bout, is used as a proxy for step length and a move is subjectively defined. Hence, the categorization and recategorization of movement class compliance surrounding the Lévy walk controversy may have been based on a statistical artifact. This issue may be avoided by collecting relocations at a fixed rate at a temporal scale that minimizes over- and undersampling.

Development of a Wearable Assist Robot for Walk Rehabilitation After Knee Arthroplasty Surgery

NASA Astrophysics Data System (ADS)

Terada, H.; Zhu, Y.; Horiguchi, K.; Nakamura, M.; Takahashi, R.

In Japan, it is popular that the disease knee joints will be replaced to artificial joints by surgery. And we have to assist so many patients for walk rehabilitation. So, the wearable assist robot has been developed. This robot includes the knee motion assist mechanism and the hip joint support mechanism. Especially, the knee motion assist mechanism consists of a non-circular gear and grooved cams. This mechanism rotates and slides simultaneously, which has two degree-of-freedom. Also, the hip joint support mechanism consists of a hip brace and a ball-joint. This mechanism can avoid motion constraints which are the internal or external rotation and the adduction or abduction. Then, the control algorithm, which considers an assisting timing for the walk rehabilitation, has been proposed. A sensing system of a walk state for this control system uses a heel contacts sensor and knee and hip joint rotation angle sensors. Also, the prototype robot has been tested. And it is confirmed that the assisting system is useful.

Failure-Avoidance: Parenting, the Achievement Environment of the Home and Strategies for Reduction

ERIC Educational Resources Information Center

Thompson, Ted

2004-01-01

This paper draws together the as yet nascent literature on the development of failure-avoidant patterns of behaviour. These are behaviours intended to minimise risk to self-worth in the event of failure, thereby avoiding the negative impact of poor performance in terms of damage to self-worth. Self-worth protection, self-handicapping, impostor…

Origami-inspired active graphene-based paper for programmable instant self-folding walking devices.

PubMed

Mu, Jiuke; Hou, Chengyi; Wang, Hongzhi; Li, Yaogang; Zhang, Qinghong; Zhu, Meifang

2015-11-01

Origami-inspired active graphene-based paper with programmed gradients in vertical and lateral directions is developed to address many of the limitations of polymer active materials including slow response and violent operation methods. Specifically, we used function-designed graphene oxide as nanoscale building blocks to fabricate an all-graphene self-folding paper that has a single-component gradient structure. A functional device composed of this graphene paper can (i) adopt predesigned shapes, (ii) walk, and (iii) turn a corner. These processes can be remote-controlled by gentle light or heating. We believe that this self-folding material holds potential for a wide range of applications such as sensing, artificial muscles, and robotics.

When avoidance leads to approach: how ear preference interacts with neuroticism to predict disinhibited approach.

PubMed

Jackson, Chris J

2008-07-01

A series of eight studies focuses on how the avoidance system represented by neuroticism can lead to disinhibited approach tendencies. Based on research which argues that hemispheric preferences predispose the left hemisphere to fast action goal formation, and contralateral pathways between ear and brain, it is proposed that (a) people with a right ear preference will engage in fast action goal formation and (b) disinhibited approach results from neurotic people who reduce anxiety by means of fast action goal formation. Study 1 provides evidence from telesales operators of a link between self-rated ear preference and objective ear preference and provides evidence that disinhibited approach is predicted by a neuroticismxear preference interaction. Studies 2, 3, and 4 provide evidence that ear preference is related to other measures of objective aural preference and action goal formation. Studies 5, 6, 7, and 8 provide evidence that the neuroticismxear preference interaction predicts a variety of different disinhibited approach tendencies.

The psychological costs and benefits of being highly persistent: personality profiles distinguish mood disorders from anxiety disorders.

PubMed

Cloninger, C Robert; Zohar, Ada H; Hirschmann, Schmuel; Dahan, Dana

2012-02-01

The personality trait of Persistence is highly valued by conscientious overachievers, but it has both psychological costs and benefits. The interactions among multiple personality factors influencing the development of mood and anxiety disorders have been confounded in prior clinical samples, but can be disentangled in terms of their underlying brain circuitry and influence on perception of emotional stimuli. 285 individuals who represented the full range of personality variation in a large sample of adult volunteers from the general community of Israel were selected for follow-up by psychiatric interviews, cognitive testing, and medical examinations. The Temperament and Character Inventory (TCI) measured profiles of traits that distinguished individuals with diagnoses of mood and/or anxiety disorders using linear discriminant analysis and non-linear profile analysis. High Harm Avoidance and low Self-directedness strongly distinguished people with mood and/or anxiety disorders from those with neither. High Persistence distinguished people with only anxiety disorders from those with mood disorders. High Persistence was associated with greater health and happiness overall, but also led to more negative emotions than in people with low Persistence unless they were both unusually tolerant of frustration (i.e., low in Harm Avoidance) and self-accepting of personal limitations (i.e. high in Self-directedness). Subjects were volunteers over 40 years of age at assessment. People who are highly persistent (i.e., persevering, ambitious, perfectionistic) are more likely to have anxiety disorders than mood disorders, even when they have other traits increasing risk for both (i.e., high Harm Avoidance and low Self-directedness). High Persistence increases both positive and negative emotions in most people. However, high Persistence reduces negative emotions and increases positive emotions if a person is easy-going (i.e., "happy-go-lucky" when low in both Harm Avoidance and Self-directedness). Copyright © 2011 Elsevier B.V. All rights reserved.

Low back pain functional disability in athletes; conceptualization and initial development of a questionnaire.

PubMed

Zamani, Elham; Kordi, Ramin; Nourian, Ruhollah; Noorian, Negin; Memari, Amir Hossein; Shariati, Mohammad

2014-12-01

Low Back Pain (LBP) is one of the most prevalent causes of disability not only in the general population but also in athletes. Despite a large number of self-reported back specific disability questionnaires, there is no specific, well documented, outcome measure for athletes suffering from back pain. This study aimed to identify the main descriptive themes representing functional disability in athletes due to LBP. We conducted a qualitative study using in-depth interviews to characterize the experiences of athletes with LBP. Twenty athletes with LBP were recruited and the main descriptive elements of their LBP related disability were extracted. Then a preliminary questionnaire using these themes was proposed. The main disability indicators were pain intensity; stretching exercises, strengthening exercises, sport specific skills, back range of motion (ROM), sitting, walking, sleep patterns, self-care, and recreational activities, fear of pain and avoidance behavior, and changes in sexual activity. The findings of this study suggest that apart from non-sports items, some sport related items should be included in the assessment of LBP disability levels in athletes. Our results have also been organized as a preliminary LBP disability questionnaire for athletes.

Low Back Pain Functional Disability in Athletes; Conceptualization and Initial Development of a Questionnaire

PubMed Central

Zamani, Elham; Kordi, Ramin; Nourian, Ruhollah; Noorian, Negin; Memari, Amir Hossein; Shariati, Mohammad

2014-01-01

Background: Low Back Pain (LBP) is one of the most prevalent causes of disability not only in the general population but also in athletes. Despite a large number of self-reported back specific disability questionnaires, there is no specific, well documented, outcome measure for athletes suffering from back pain. Objectives: This study aimed to identify the main descriptive themes representing functional disability in athletes due to LBP. Patients and Methods: We conducted a qualitative study using in-depth interviews to characterize the experiences of athletes with LBP. Twenty athletes with LBP were recruited and the main descriptive elements of their LBP related disability were extracted. Then a preliminary questionnaire using these themes was proposed. Results: The main disability indicators were pain intensity; stretching exercises, strengthening exercises, sport specific skills, back range of motion (ROM), sitting, walking, sleep patterns, self-care, and recreational activities, fear of pain and avoidance behavior, and changes in sexual activity. Conclusions: The findings of this study suggest that apart from non-sports items, some sport related items should be included in the assessment of LBP disability levels in athletes. Our results have also been organized as a preliminary LBP disability questionnaire for athletes. PMID:25741417

DAIDALUS: Detect and Avoid Alerting Logic for Unmanned Systems

NASA Technical Reports Server (NTRS)

Munoz, Cesar; Narkawicz, Anthony; Hagen, George; Upchurch, Jason; Dutle, Aaron; Consiglio, Maria; Chamberlain, James

2015-01-01

This paper presents DAIDALUS (Detect and Avoid Alerting Logic for Unmanned Systems), a reference implementation of a detect and avoid concept intended to support the integration of Unmanned Aircraft Systems into civil airspace. DAIDALUS consists of self-separation and alerting algorithms that provide situational awareness to UAS remote pilots. These algorithms have been formally specified in a mathematical notation and verified for correctness in an interactive theorem prover. The software implementation has been verified against the formal models and validated against multiple stressing cases jointly developed by the US Air Force Research Laboratory, MIT Lincoln Laboratory, and NASA. The DAIDALUS reference implementation is currently under consideration for inclusion in the appendices to the Minimum Operational Performance Standards for Unmanned Aircraft Systems presently being developed by RTCA Special Committee 228.

Hip or knee replacement - in the hospital after

MedlinePlus

Hip replacement surgery - after - self-care; Knee replacement surgery - after - self-care ... taking walks in the hallways with help. After knee replacement, some surgeons recommend using a continuous passive ...

Gait and functionality of individuals with visual impairment who participate in sports.

PubMed

da Silva, Edson Soares; Fischer, Gabriela; da Rosa, Rodrigo Gomes; Schons, Pedro; Teixeira, Luísa Beatriz Trevisan; Hoogkamer, Wouter; Peyré-Tartaruga, Leonardo Alexandre

2018-05-01

Individuals with visual impairment (VI) have often been observed to walk slower than individuals with unimpaired vision. These observations might be confounded by typical low levels of physical activity and greater sedentary behavior in individuals with VI than the overall population. Here, we compared gait and balance measures between individuals with VI who participate in disability sports, and activity level matched sighted individuals. We assessed static balance, anthropometry, self-selected walking speed, locomotion rehabilitation index, and lower limb muscular endurance; and applied physical activity level and fear of falling questionnaires. Individuals with VI who participate in disability sports, self-selected a similar walking speed (1.29 ± 0.26 m/s) as active sighted individuals (1.39 ± 0.21 m/s). Locomotor rehabilitation index and muscular endurance of lower limbs were also similar between groups. Individuals with VI presented lower static balance (42.0 ± 17.0s) than the sighted control group (45.0 ± 0s) when the controls were tested with their eyes open. However, no difference was found when the controls were tested with their eyes closed (30.3 ± 17.0s). Furthermore, individuals with VI showed a greater fear of falling. In conclusion, individuals with VI who participate in disability sports, as goalball and football, walk with similar self-selected walking speeds as active sighted individuals, but have slightly worse static balance and fear of falling. Copyright © 2018 Elsevier B.V. All rights reserved.

Association between exercise type and quality of life in a community-dwelling older people: A cross-sectional study

PubMed Central

Oh, Sang-Ho; Kim, Don-Kyu; Lee, Shi-Uk; Jung, Se Hee

2017-01-01

Objectives This study aimed to investigate the effects of three major representative exercises (resistance, flexibility, and walking) on quality of life (QoL) in a population of community-dwelling older adults. Materials and methods This cross-sectional study used public data from the Sixth Korean National Health and Nutrition Examination Survey in 2014 (n = 1,586 older people). Demographic factors, three types of exercise, five EuroQoL subsets (mobility, self-care, usual activities, pain/discomfort, anxiety/depression), and QoL scores (EQ-VAS) were investigated. The independent associations between each exercise and the five QoL subsets were determined using odds ratios (OR) adjusted for three demographic factors (age group, sex, and area of residence), using multivariate logistic regression analysis. Results The EQ-VAS scores of the exercisers was significantly higher than those of the non-exercisers for all exercise types. Subjects with problems in mobility dimension performed less exercise of all types of than those with normal mobility (resistance: OR, 0.687; flexibility: OR, 0.733, and walking: OR, 0.489). The self-care dimension was independently correlated with flexibility (OR, 0.558) and walking (OR, 0.485). Conclusion All types of exercisers showed higher QoL scores than non-exercisers. Among the QoL dimensions, mobility and self-care were independently associated with flexibility and walking exercise in this older people, suggesting that engaging in regular flexibility and walking exercise is important for achieving higher QoL in the older people. PMID:29216283

Social anxiety and disinhibition: An analysis of curiosity and social rank appraisals, approach-avoidance conflicts, and disruptive risk-taking behavior

PubMed Central

Kashdan, Todd B.; Elhai, Jon D.; Breen, William E.

2008-01-01

We examined how social anxiety is related to appraisals for various disinhibited behaviors and sought to identify potential subgroups of socially anxious people. College students completed trait measures and appraised disinhibited behaviors on their potential for threat, opportunity to satisfy curiosity, and ability to enhance social status. Three months later, participants were asked to report on their frequency of disinhibited behaviors since the initial assessment. People with greater social anxiety demonstrated frequent approach-avoidance conflicts - co-existing recognition of threats and rewards - about social interactions and disinhibited behaviors. Even when asked about the activity most likely to be avoided, participants with greater social anxiety evaluated these as having potential to satisfy curiosity and advance their social status. Three qualitatively different groups of people were identified based on social anxiety tendencies and approach-avoidance appraisal patterns. Groups differed on the degree of approach-avoidance conflicts, measures of psychological and social well-being, and frequency of social interactions and disinhibited behaviors. Moderately socially anxious people who were approach oriented reported the most difficulties. Results suggest that social anxiety is associated with tension between competing desires to avoid anxiety and explore. However, there appears to be important variability in the regulatory orientation, behavior, and well-being of socially anxious people. Conclusions about the nature of social anxiety may be compromised by not attending to existing differences in self-regulatory orientation and strategies. PMID:17981434

Social anxiety and disinhibition: an analysis of curiosity and social rank appraisals, approach-avoidance conflicts, and disruptive risk-taking behavior.

PubMed

Kashdan, Todd B; Elhai, Jon D; Breen, William E

2008-08-01

We examined how social anxiety is related to appraisals for various disinhibited behaviors and sought to identify potential subgroups of socially anxious people. College students completed trait measures and appraised disinhibited behaviors on their potential for threat, opportunity to satisfy curiosity, and ability to enhance social status. Three months later, participants were asked to report on their frequency of disinhibited behaviors since the initial assessment. People with greater social anxiety demonstrated frequent approach-avoidance conflicts - co-existing recognition of threats and rewards - about social interactions and disinhibited behaviors. Even when asked about the activity most likely to be avoided, participants with greater social anxiety evaluated these as having potential to satisfy curiosity and advance their social status. Three qualitatively different groups of people were identified based on social anxiety tendencies and approach-avoidance appraisal patterns. Groups differed on the degree of approach-avoidance conflicts, measures of psychological and social well-being, and frequency of social interactions and disinhibited behaviors. Moderately socially anxious people who were approach oriented reported the most difficulties. Results suggest that social anxiety is associated with tension between competing desires to avoid anxiety and explore. However, there appears to be important variability in the regulatory orientation, behavior, and well-being of socially anxious people. Conclusions about the nature of social anxiety may be compromised by not attending to existing differences in self-regulatory orientation and strategies.

The effect of hospital unit layout on nurse walking behavior.

PubMed

Yi, Lu; Seo, Hyun-Bo

2012-01-01

To confirm a new method for the research question, "How do different hospital unit layouts affect nurses' walking behavior and distance?" Concern is renewed regarding nurses' long walking distances because of the trend toward larger patient rooms with family areas inside, resulting in a larger overall unit size. Studies have found unit design characteristics that support nurses' efficient walking, but few have done it in units designed for patient- and family-centered care. To examine the effect of unit design on nurses' walking behavior, the authors propose a new method of observing a specific task. The authors observed nurses during the task of medication administration. Contrary to their hypotheses, results showed: (1) Experienced nurses had more unnecessary stops and longer walking distances than new nurses because of interactions; and (2) nurses in the smaller wing of the unit walked more than those in the larger wing of the same unit. The authors posit that the closeness between the nurses' path to the medication supply room and the central nurses' station affected the frequency of interactions and prompted a deviation from the shortest and most efficient path during medication administration. Observing a specific task to identify the effect of unit layout was effective, determining that overall unit shape or unit layout type might not be a good predictor of nurses' walking behavior; instead the characteristics of the path that connects functional spaces such as patient room and medication area might better predict nurses' walking behavior.

Environmental factors influencing older adults' walking for transportation: a study using walk-along interviews.

PubMed

Van Cauwenberg, Jelle; Van Holle, Veerle; Simons, Dorien; Deridder, Riet; Clarys, Peter; Goubert, Liesbet; Nasar, Jack; Salmon, Jo; De Bourdeaudhuij, Ilse; Deforche, Benedicte

2012-07-10

Current knowledge on the relationship between the physical environment and walking for transportation among older adults (≥ 65 years) is limited. Qualitative research can provide valuable information and inform further research. However, qualitative studies are scarce and fail to include neighborhood outings necessary to study participants' experiences and perceptions while interacting with and interpreting the local social and physical environment. The current study sought to uncover the perceived environmental influences on Flemish older adults' walking for transportation. To get detailed and context-sensitive environmental information, it used walk-along interviews. Purposeful convenience sampling was used to recruit 57 older adults residing in urban or semi-urban areas. Walk-along interviews to and from a destination (e.g. a shop) located within a 15 minutes' walk from the participants' home were conducted. Content analysis was performed using NVivo 9 software (QSR International). An inductive approach was used to derive categories and subcategories from the data. Data were categorized in the following categories and subcategories: access to facilities (shops & services, public transit, connectivity), walking facilities (sidewalk quality, crossings, legibility, benches), traffic safety (busy traffic, behavior of other road users), familiarity, safety from crime (physical factors, other persons), social contacts, aesthetics (buildings, natural elements, noise & smell, openness, decay) and weather. The findings indicate that to promote walking for transportation a neighborhood should provide good access to shops and services, well-maintained walking facilities, aesthetically appealing places, streets with little traffic and places for social interaction. In addition, the neighborhood environment should evoke feelings of familiarity and safety from crime. Future quantitative studies should investigate if (changes in) these environmental factors relate to (changes in) older adults' walking for transportation.

Environmental factors influencing older adults’ walking for transportation: a study using walk-along interviews

PubMed Central

2012-01-01

Background Current knowledge on the relationship between the physical environment and walking for transportation among older adults (≥ 65 years) is limited. Qualitative research can provide valuable information and inform further research. However, qualitative studies are scarce and fail to include neighborhood outings necessary to study participants’ experiences and perceptions while interacting with and interpreting the local social and physical environment. The current study sought to uncover the perceived environmental influences on Flemish older adults’ walking for transportation. To get detailed and context-sensitive environmental information, it used walk-along interviews. Methods Purposeful convenience sampling was used to recruit 57 older adults residing in urban or semi-urban areas. Walk-along interviews to and from a destination (e.g. a shop) located within a 15 minutes’ walk from the participants’ home were conducted. Content analysis was performed using NVivo 9 software (QSR International). An inductive approach was used to derive categories and subcategories from the data. Results Data were categorized in the following categories and subcategories: access to facilities (shops & services, public transit, connectivity), walking facilities (sidewalk quality, crossings, legibility, benches), traffic safety (busy traffic, behavior of other road users), familiarity, safety from crime (physical factors, other persons), social contacts, aesthetics (buildings, natural elements, noise & smell, openness, decay) and weather. Conclusions The findings indicate that to promote walking for transportation a neighborhood should provide good access to shops and services, well-maintained walking facilities, aesthetically appealing places, streets with little traffic and places for social interaction. In addition, the neighborhood environment should evoke feelings of familiarity and safety from crime. Future quantitative studies should investigate if (changes in) these environmental factors relate to (changes in) older adults’ walking for transportation. PMID:22780948

A self-aligning knee joint for walking assistance devices.

PubMed

Byungjune Choi; Younbaek Lee; Jeonghun Kim; Minhyung Lee; Jongwon Lee; Se-Gon Roh; Hyundo Choi; Yong-Jae Kim; Jung-Yun Choi

2016-08-01

This paper presents a novel self-aligning knee mechanism for walking assistance devices for the elderly to provide physical gait assistance. Self-aligning knee joints can assist in flexion/extension motions of the knee joint and compensate the knee's transitional movements in the sagittal plane. In order to compensate the center of rotation, which moves with the flexion/extension motion of the human knee joint, a self-aligning knee joint is proposed that adds redundant degrees of freedom (i.e., 2-DoF) to the 1-DoF revolute joint. The key idea of the proposed mechanism is to decouple joint rotations and translations for use in lower-extremity wearable devices. This paper describes the mechanical design of this self-aligning knee mechanism and its implementation on a wearable robot and in preliminary experiments. The performance of the proposed mechanism is verified by simulations and experiments.

Self-efficacy mediates the effects of topiramate and GRIK1 genotype on drinking.

PubMed

Kranzler, Henry R; Armeli, Stephen; Wetherill, Reagan; Feinn, Richard; Tennen, Howard; Gelernter, Joel; Covault, Jonathan; Pond, Timothy

2016-03-01

Previous studies indicate that topiramate reduces alcohol use among problem drinkers, with one study showing that the effect was moderated by a polymorphism (rs2832407) in GRIK1, the gene encoding the GluK1 kainate subunit. We examined whether the interactive effect of medication and genotype (1) altered the association between daily self-efficacy and later-day drinking; and (2) had an indirect effect on drinking via self-efficacy. In a 12-week, placebo-controlled trial of topiramate, we used daily interactive voice response technology to measure self-efficacy (i.e. confidence in avoiding heavy drinking later in the day) and drinking behavior in 122 European-American heavy drinkers. Topiramate's effects on both self-efficacy and drinking level were moderated by rs2832407. C-allele homozygotes treated with topiramate showed higher levels of self-efficacy and lower levels of nighttime drinking across the 12-week trial. Further, the interactive effect of topiramate and genotype on mean nighttime drinking levels was mediated by mean levels of self-efficacy. By modeling topiramate's effects on nighttime drinking across multiple levels of analysis, we found that self-efficacy, a key psychologic construct, mediated the effect of topiramate, which was moderated by rs2832407 genotype. Thus, it may be possible to use an individualized assessment (i.e. genotype) to select treatment to optimize the reduction in heavy drinking and thereby provide a personalized treatment approach. © 2014 Society for the Study of Addiction.