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PubMed1997

Identification of a large motility operon in Borrelia burgdorferi by semi-random PCR chromosome walking.

Motility has been implicated in the invasive process of Borrelia burgdorferi (Bb), the etiologic agent of Lyme disease. To identify Bb motility related genes, we used a method termed 'semi-random PCR chromosome walking' (SRPCW) to walk through a large motility gene cluster. The major advantage of this approach over other PCR walking methods is that it employs a secondary PCR amplification of cloned fragments which can be readily sequenced and analyzed. Starting with a primer specific to flgE, we identified and sequenced 14 open reading frames (ORFs) spanning 11 kb downstream of the flgE gene. The genes identified include flbD, motA, motB, fliL, fliM, fliN, fliZ, fliP, fliQ, fliR, flhB, flhA, flhF and flbE. Twelve of the deduced proteins shared extensive homology with flagellar proteins from other bacteria. The gene products and order of genes within this cluster are most similar to those of Treponema pallidum (Tp) and Bacillus subtilis (Bs). One of the unique genes identified, flbD, demonstrated homology to an ORF from the same operon of Tp. Another ORF, flbE, showed similarity to genes from both Tp and Bs. RT-PCR and primer extension analysis revealed that this gene cluster is transcribed as a single unit indicating that it is part of a large motility operon spanning more than 21 kb. Antisera to Escherichia coli and Salmonella typhimurium FliN, FliM, FlhB and FlhA reacted with proteins of the predicted molecular weights in cell lysates of Bb. The results suggest that the flagellar system is highly conserved in evolution and thus underscore the importance of motility in bacterial survival and pathogenesis.

Bacterial Proteins↗
PubMed2026

Clinical efficacy and brain mechanism characteristics of guide chi and regulate spirit tuina therapy in the treatment of post-stroke walking dysfunction: A randomized controlled trial based on fNIRS.

BACKGROUND: This study aims to preliminarily evaluate the role of Guide Chi and Regulate Spirit(GCRS) Tuina in enhancing walking function in post-stroke patients with walking dysfunction; secondly, by using functional near-infrared spectroscopy (fNIRS), it investigates the effect of GCRS Tuina on the restoration of brain function in this patient population. METHODS: Participants in the control group received 4-week rehabilitation treatment, while those in the Combined Tuina Group (CTG) additionally received GCRS Tuina therapy for another 4 weeks on this basis. Functional Ambulation Category (FAC), Fugl - Meyer Assessment Scale for Lower Extremity Motor Function (FMA - LE), and Modified Barthel Index (MBI) were evaluated at the baseline and after 4 treatment weeks. A gait and motion analysis system was used to measure step length, stride, walking speed, and step frequency. FNIRS was used to measure the resting-state functional connectivity(FC) strength, as well as the &#x3b2; - value and HbO2 concentration mean during the walking task. RESULTS: A total of 60 participants completed the randomized, and 53 completed the trial and entered the statistical analysis. Compared with the Single Rehabilitation Group(SRG), the CTG group had higher FAC, FMA-LE, and MBI scores after 4 weeks. After the treatment course, the standardized step length, stride, walking speed, and step frequency of the CTG were higher than SRG. At the Region of Interest(ROI) level, the CTG exhibited 13 inter-ROI FC strengths that were higher than SRG, and the differences could survive the FDR correction (PFDR<0.05). Under the walking task, the CTG group had higher &#x3b2; values in 18 channels and higher Oxyhemoglobin(HbO2) concentrations in 19 channels than the SRG (PFDR <0.05). CONCLUSION: GCRS Tuina therapy can significantly improve patients' walking function, enhance lower limb motor ability and daily living ability. It can improve walking efficiency. Tuina can significantly increase the FC and enhance the activation levels and HbO2 concentrations. The stimulation of Tuina may help reconstruct the brain's motor control network, restore impaired motor function, promote the occurrence of neural plasticity, strengthen the neural circuits in the cognitive-motor-sensory cortex to improve walking function. TRIAL REGISTRATION: This study has been registered with the International Traditional Medicine Clinical Trial Registry (ITMCTR2024000654).

Humans↗
PubMedDate not supplied

A randomized trial of walking versus physical methods for chronic pain management.

We conducted a pilot study to evaluate a practical exercise program for elderly people with chronic musculo-skeletal pain. Thirty-three subjects (mean age, 73 years; 69% back pain; 24% knee pain; 9% hip pain) were randomly assigned to one of three groups. Group 1 received 6-week supervised program of walking. Group 2 received a pain education program that included instruction and demonstration of use of heat, cold, massage, relaxation and distraction. Group 3 received usual care. Outcomes including pain, self-reported health and functional status, and performance-based measures of functional status were evaluated at baseline, at two weeks and at eight weeks (end of study). Attendance was 100% for the education sessions and 93% for walking sessions. No injuries were sustained. Both intervention groups demonstrated significant improvements in pain (p < 0.05) and performance-based measures of functional status (p < 0.05), while the control group had no changes. These data suggest that patient education and fitness walking can improve overall pain management and related functional limitations among elderly people with chronic musculo-skeletal pain.

Aged↗
PubMed2003

Towards deterministic equations for Lévy walks: the fractional material derivative.

Lévy walks are random processes with an underlying spatiotemporal coupling. This coupling penalizes long jumps, and therefore Lévy walks give a proper stochastic description for a particle's motion with broad jump length distribution. We derive a generalized dynamical formulation for Lévy walks, in which the fractional equivalent of the material derivative occurs. Our approach is expected to be useful for the dynamical formulation of Lévy walks in an external force field or in phase space, for which the description in terms of the continuous time random walk or its corresponding generalized master equation are less well suited.

Journal Article↗
PubMed2005

Long range correlations in the stride interval of running.

Fluctuations in the stride interval time series of unconstrained walking are not random but exhibit long range correlations that decay as a power law [Hausdorff JM, Peng CK, Ladin Z, Wei JY, Goldberger AL. Is walking a random walk? Evidence for long range correlations in stride interval of human gait. J Appl Physiol 1995;78:349-58]. Here, we examine whether the long range correlations are present in the stride interval time series of running. Recreational female runners ran 8min trials at their preferred running speed as well as 10% and 20% slower and faster than their preferred speed. Both the average time and the amount of variability of the stride interval decreased with increasing speed. Detrended fluctuation analysis (DFA) showed that there were long range correlations present in the stride interval time series and these correlations followed a quasi U-shaped function, with the minimum at the preferred running speed. These results are consistent with the hypothesis that the preferred running speed, falling as it does between the upper and lower limits of possible running speeds, is the speed at which the most dynamical degrees of freedom are available for adaptive control of locomotion.

Adult↗
PubMed2004

The effect of an ankle-foot orthosis on walking ability in chronic stroke patients: a randomized controlled trial.

OBJECTIVE: Regaining walking ability is a major goal during the rehabilitation of stroke patients. To support this process an ankle-foot orthosis (AFO) is often prescribed. The aim of this study is to investigate the effect of an AFO on walking ability in chronic stroke patients. DESIGN: Cross-over design with randomization for the interventions. METHODS: Twenty chronic stroke patients, wearing an AFO for at least six months, were included. Walking ability was operationalized as comfortable walking speed, scores on the timed up and go (TUG) test and stairs test. Patients were measured with and without their AFO, the sequence of which was randomized. Additionally, subjective impressions of self-confidence and difficulty of the tasks were scored. Clinically relevant differences based on literature were defined for walking speed (20 cm/s), the TUG test (10 s). Gathered data were statistically analysed using a paired t-test. RESULTS: The mean difference in favour of the AFO in walking speed was 4.8 cm/s (95% CI 0.85-8.7), in the TUG test 3.6 s (95% CI 2.4-4.8) and in the stairs test 8.6 s (95% CI 3.1-14.1). Sixty-five per cent of the patients experienced less difficulty and 70% of the patients felt more self-confident while wearing the AFO. CONCLUSIONS: The effect of an AFO on walking ability is statistically significant, but compared with the a priori defined differences it is too small to be clinically relevant. The effect on self-confidence suggests that other factors might play an important role in the motivation to use an AFO.

Adult↗
PubMed1993

Metabolic response to graded downhill walking.

Compared with level walking or running, progressive downhill walking or running requires a decreasing energy cost to some minimum where the cost again increases with further decrements in grade. Margaria estimated this minimum occurs at a -9% grade. In this study an attempt was made to more precisely track the energy cost curve in progressive downhill treadmill walking. Ten men, mean age 22.0 +/- 2.5 yr, volunteered as subjects. After VO2max determinations the subjects attended two downhill walking sessions. Each subject performed 14 randomly ordered walking bouts of 6 min in duration, at speeds of 90 and 105 m.min-1. The grades used were 0, -3, -6, -9, -12, -15, and -18%. Gas exchange measurements were obtained by open circuit spirometry during each work bout. Heart rate was monitored continuously and the stride frequency was counted by direct observation during each walking bout. Net VO2 values decreased with decrements in grade to -9, -12% for the respective speeds of 90 and 105 m.min-1. The group mean net VO2 minimums at -9 and -12%, however, were not significantly different (P > 0.05) from the group mean values at -6 and -15% at 90 m.min-1, or between -9 and -15% grades at 105 m.min-1, Group mean net VO2 values at 0, -3, and -18% were significantly different (P < 0.05) from net VO2 values for the other grades at 90 m.min-1 walking. At 105 m.min-1, mean net VO2 values at 0, -3, -6, and -18% were significantly different (P < 0.05) from net VO2 values at the other grades.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2003

Musical motor feedback (MMF) in walking hemiparetic stroke patients: randomized trials of gait improvement.

OBJECTIVE: To demonstrate the effect of rhythmical auditory stimulation in a musical context for gait therapy in hemiparetic stroke patients, when the stimulation is played back measure by measure initiated by the patient's heel-strikes (musical motor feedback). Does this type of musical feedback improve walking more than a less specific gait therapy? DESIGN: The randomized controlled trial considered 23 registered stroke patients. Two groups were created by randomization: the control group received 15 sessions of conventional gait therapy and the test group received 15 therapy sessions with musical motor feedback. SETTING: Inpatient rehabilitation hospital. SUBJECTS: Median post-stroke interval was 44 days and the patients were able to walk without technical aids with a speed of approximately 0.71 m/s. MAIN OUTCOME MEASURES: Gait velocity, step duration, gait symmetry, stride length and foot rollover path length (heel-on-toe-off distance). RESULT: The test group showed more mean improvement than the control group: stride length increased by 18% versus 0%, symmetry deviation decreased by 58% versus 20%, walking speed increased by 27% versus 4% and rollover path length increased by 28% versus 11%. CONCLUSION: Musical motor feedback improves the stroke patient's walk in selected parameters more than conventional gait therapy. A fixed memory in the patient's mind about the song and its timing may stimulate the improvement of gait even without the presence of an external pacemaker.

Feedback↗
PubMed2004

Aerobic treadmill plus Bobath walking training improves walking in subacute stroke: a randomized controlled trial.

OBJECTIVE: To evaluate the immediate and long-term effects of aerobic treadmill plus Bobath walking training in subacute stroke survivors compared with Bobath walking training alone. DESIGN: Randomized controlled trial. SETTING: Rehabilitation unit. SUBJECTS: Fifty patients, first-time supratentorial stroke, stroke interval less than six weeks, Barthel Index (0-100) from 50 to 80, able to walk a minimum distance of 12 m with either intermittent help or stand-by while walking, cardiovascular stable, minimum 50 W in the bicycle ergometry, randomly allocated to two groups, A and B. INTERVENTIONS: Group A 30 min of treadmill training, harness secured and minimally supported according to patients' needs, and 30 min of physiotherapy, every workday for six weeks, speed and inclination of the treadmill were adjusted to achieve a heart rate of HR: (Hrmax-HRrest)*0.6+HRrest; in group B 60 min of daily physiotherapy for six weeks. MAIN OUTCOME MEASURES: Primary outcome variables were the absolute improvement of walking velocity (m/s) and capacity (m), secondary were gross motor function including walking ability (score out of 13) and walking quality (score out of 41), blindly assessed before and after the intervention, and at follow-up three months later. RESULTS: Patients tolerated the aerobic training well with no side-effects, significantly greater improvement of walking velocity and capacity both at study end (p =0.001 versus p =0.002) and at follow-up (p <0.001 versus p <0.001) in the experimental group. Between weeks 0 and 6, the experimental group improved walking speed and capacity by a mean of.31 m/s and 91 m, the control group by a mean of 0.16 m/s and 56 m. Between weeks 0 and 18, the experimental group improved walking speed and capacity by a mean of 0.36 m/s and 111 m, the control group by a mean of 0.15 m/s and 57 m. Gross motor function and walking quality did not differ at any time. CONCLUSIONS: Aerobic treadmill plus Bobath walking training in moderately affected stroke patients was better than Bobath walking training alone with respect to the improvement of walking velocity and capacity. The treatment approach is recommended in patients meeting the inclusion criteria. A multicentre trial should follow to strengthen the evidence.

Aged↗
PubMed2002

Analytic expression for the mean time to absorption for a random walker on the Sierpinski gasket.

The exact analytic expression for the mean time to absorption (or mean walk length) for a particle performing a random walk on a finite Sierpinski gasket with a trap at one vertex is found to be T((n))=[3(n)5(n+1)+4(5(n))-3(n)]/(3(n+1)+1) where n denotes the generation index of the gasket, and the mean is over a set of starting points of the walk distributed uniformly over all the other sites of the gasket. In terms of the number N(n) of sites on the gasket and the spectral dimension d of the gasket, the precise asymptotic behavior for large N(n) is T((n))-->1/3(2N(n))(2/d)-N1.464. This serves as a partial check on our result, as it is (a) intermediate between the known results T-N2 (d=1) and T-N ln N (d=2) for random walks on d-dimensional Euclidean lattices and (b) consistent with the known result for the asymptotic behavior of the mean number of distinct sites visited in a random walk on a fractal lattice.

Journal Article↗
PubMed1999

The energy cost of horizontal walking and running in adolescents.

PURPOSE: This study developed and cross-validated generalized equations for predicting VO2 (mL x kg(-1) x min(-1)) and caloric expenditure (kcal x kg(-1) x min(-1)) during horizontal walking and running in adolescents. METHODS: Subjects were 47 male and 35 female adolescent volunteers, ages 12-18. Each subject underwent a submaximal treadmill exercise test to determine VO2 at randomly selected walking and jogging speeds (67-215 m x min(-1)). Caloric expenditure was estimated from VO2 and RER. Multiple regression was used to develop prediction equations for estimating VO2 and caloric expenditure from a derivation sample of 77 random observations, both walking and running. RESULTS: The group relationship between running speed and energy cost in the derivation sample was linear, whereas the relationship between walking speed and energy cost was quadratic. Gender, age, and height each failed to account for significant additional variation in energy cost after speed and mode were considered. Skinfolds accounted for a small yet significant amount of additional variation in energy cost. The derived equations were cross-validated on a sample of 76 separate random observations. The cross-validation statistics are: for VO2, R = 0.95, error = 3.58 mL x kg(-1) x min(-1), and for caloric expenditure, R = 0.94, error = 0.019 kcal x kg(-1) x min(-1). Most selected adult equations consistently underestimated both VO2 and caloric expenditure in the cross-validation sample. CONCLUSIONS: These results suggest that in adolescents, within the range of speeds tested, the relationship between speed of movement and energy cost for running is linear, but for walking is curvilinear. Also, adult models for estimating VO2 or caloric expenditure do not account for the higher relative energy cost of walking and running in adolescents.

Adolescent↗
PubMed1985

Significance of nucleotide sequence alignments: a method for random sequence permutation that preserves dinucleotide and codon usage.

The similarity of two nucleotide sequences is often expressed in terms of evolutionary distance, a measure of the amount of change needed to transform one sequence into the other. Given two sequences with a small distance between them, can their similarity be explained by their base composition alone? The nucleotide order of these sequences contributes to their similarity if the distance is much smaller than their average permutation distance, which is obtained by calculating the distances for many random permutations of these sequences. To determine whether their similarity can be explained by their dinucleotide and codon usage, random sequences must be chosen from the set of permuted sequences that preserve dinucleotide and codon usage. The problem of choosing random dinucleotide and codon-preserving permutations can be expressed in the language of graph theory as the problem of generating random Eulerian walks on a directed multigraph. An efficient algorithm for generating such walks is described. This algorithm can be used to choose random sequence permutations that preserve (1) dinucleotide usage, (2) dinucleotide and trinucleotide usage, or (3) dinucleotide and codon usage. For example, the similarity of two 60-nucleotide DNA segments from the human beta-1 interferon gene (nucleotides 196-255 and 499-558) is not just the result of their nonrandom dinucleotide and codon usage.

Base Sequence↗
PubMed2005

Adaptive walk on complex networks.

We investigate the properties of adaptive walks on an uncorrelated fitness landscape which is established in sequence spaces of complex structure. In particular, we perform numerical simulations of adaptive walks on random graphs and scale-free networks. For the former, we also derive some analytical approximations for the density of local optima of the fitness landscape and the mean length walk. We compare our results with those obtained for regular lattices. We obtain that the density of local optima decreases as 1/z, where z is the mean connectivity, for all networks we have investigated. In random graphs, the mean length walk L reaches the asymptotic value e - 1 for large z, which corresponds to the result for regular networks. Although we could not find an exact estimate, we derive an underestimated value for L. Unlike random graphs, scale-free networks show an upper asymptotic value of L.

Adaptation, Physiological↗
PubMed2003

Winding angle variance of Fortuin-Kasteleyn contours.

The variance in the winding number of various random fractal curves, including the self-avoiding walk, the loop-erased random walk, contours of Fortuin-Kastelyn clusters, and stochastic Loewner evolution, has been studied by numerous researchers. Usually the focus has been on the winding at the end points. We measure the variance in winding number at typical points along the curve. More generally, we study the winding at points where k strands come together, and some adjacent strands may be conditioned not to hit each other. The measured values are consistent with an interesting conjecture.

Journal Article↗
PubMed2005

Gait outcomes after additional backward walking training in patients with stroke: a randomized controlled trial.

OBJECTIVE: To examine the effectiveness of additional backward walking training on gait outcome of patients post stroke. DESIGN: Randomized controlled trial. SETTING: Medical centre. SUBJECTS: Twenty-five subjects with stroke, who were lower extremity Brunnstrom motor recovery stage at 3 or 4 and were able to walk 11 m with or without a walking aid or orthosis, randomly allocated to two groups, control (n = 12) and experimental (n = 13). INTERVENTIONS: Subjects in both groups participated in 40 min of conventional training programme three times a week for three weeks. Subjects in experimental group received additional 30 min of backward walking training for three weeks at a frequency of three times per week. MAIN MEASURES: Gait was measured using the Stride Analyzer. Gait parameters of interest were walking speed, cadence, stride length, gait cycle and symmetry index. Measures were made at baseline before commencement of training (pre-training) and at the end of the three-week training period (post-training). RESULTS: After a three-week training period, subjects in experimental group showed more improvement than those in control group for walking speed (change score: 8.60 +/- 6.95 versus 3.65 +/- 2.92, p-value = 0.032), stride length (change score: 0.090 +/- 0.076 versus -0.0064 +/- 0.078, p-value = 0.006), and symmetry index (change score: 44.07 +/- 53.29 versus 5.30 +/- 13.91, p-value = 0.018). CONCLUSIONS: This study demonstrated that asymmetric gait pattern in patients post stroke could be improved from receiving additional backward walking therapy.

Female↗