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Journal of Thoracic Disease Oct 2017
PubMed: 29268316
DOI: 10.21037/jtd.2017.08.155 -
BMJ Medicine 2022
PubMed: 36936585
DOI: 10.1136/bmjmed-2022-000194 -
The British Journal of General Practice... Jun 2017
Topics: Anesthetics, Inhalation; Demyelinating Diseases; Humans; Nitrous Oxide; Substance-Related Disorders; Vitamin B 12 Deficiency
PubMed: 28546398
DOI: 10.3399/bjgp17X691049 -
Theory in Biosciences = Theorie in Den... Nov 2021Collective behavior is widely regarded as a hallmark property of living and intelligent systems. Yet, many examples are known of simple physical systems that are not... (Review)
Review
Collective behavior is widely regarded as a hallmark property of living and intelligent systems. Yet, many examples are known of simple physical systems that are not alive, which nonetheless display collective behavior too, prompting simple physical models to often be adopted to explain living collective behaviors. To understand collective behavior as it occurs in living examples, it is important to determine whether or not there exist fundamental differences in how non-living and living systems act collectively, as well as the limits of the intuition that can be built from simpler, physical examples in explaining biological phenomenon. Here, we propose a framework for comparing non-living and living collectives as a continuum based on their information architecture: that is, how information is stored and processed across different degrees of freedom. We review diverse examples of collective phenomena, characterized from an information-theoretic perspective, and offer views on future directions for quantifying living collective behaviors based on their informational structure.
Topics: Group Processes; Mass Gatherings
PubMed: 33532895
DOI: 10.1007/s12064-020-00331-5 -
PM & R : the Journal of Injury,... Nov 2022The 4-wheeled walker is intended to enhance balance and gait for older adults. Yet, some research suggests that walking aids increase falls risk. An understanding of the...
INTRODUCTION
The 4-wheeled walker is intended to enhance balance and gait for older adults. Yet, some research suggests that walking aids increase falls risk. An understanding of the influence of age with walker use on gait performance is required.
OBJECTIVE
To examine the effect of initial 4-wheeled walker use on spatiotemporal gait parameters between younger and older adults.
DESIGN
Cross-sectional, repeated-measures.
SETTING
Community-dwelling.
PARTICIPANTS
Twenty-five younger (age: 26.5 ± 4.1 years) and 24 older (age: 68.5 ± 10.5 years) adults participated. Younger adults were aged 18 to 35 years, whereas older adults were 50 years or older. Included were people not requiring the use of a walking aid, and those able to converse in English.
INTERVENTIONS
Not applicable.
MAIN OUTCOME MEASURE(S)
Gait velocity and stride time variability were recorded using accelerometers. Gait was examined under three conditions: unassisted walking; walking with a 4-wheeled walker; and walking with a 4-wheeled walker while completing a secondary task. Conditions were performed across two walking paths: straight and figure-of-8 Walk Test. Separate mixed-methods analyses of variance (ANOVAs; within-subject: condition/path; between-subject: group) were used for statistical analyses.
RESULTS
Velocity was lower when walking using a walker while completing a cognitive task (p < .001), in the figure-of-8 Walk Test (p < .001), and in older adults (p = .001). Stride time variability increased with walking path and condition difficulty (p < .001) for the straight path versus the figure-of-8 Walk Test.
CONCLUSIONS
Using a 4-wheeled walker resulted in a slower and more inconsistent gait pattern across both age groups. Walking more complex configurations resulted in the prioritization of gait over the cognitive task while performing the dual-task conditions. No evidence of an age-related difference in the effect of initial walker use on gait was observed. Nonetheless, walkers are cognitively demanding and their introduction should warrant a clinical follow-up.
Topics: Humans; Aged; Young Adult; Adult; Middle Aged; Cross-Sectional Studies; Gait; Walkers; Walking; Accidental Falls
PubMed: 34464511
DOI: 10.1002/pmrj.12700 -
Journal of Athletic Training Mar 2021
PubMed: 33751114
DOI: 10.4085/1062-6050-0176-20 -
PLoS Computational Biology Feb 2022We examine the structure of the visual motion projected on the retina during natural locomotion in real world environments. Bipedal gait generates a complex, rhythmic...
We examine the structure of the visual motion projected on the retina during natural locomotion in real world environments. Bipedal gait generates a complex, rhythmic pattern of head translation and rotation in space, so without gaze stabilization mechanisms such as the vestibular-ocular-reflex (VOR) a walker's visually specified heading would vary dramatically throughout the gait cycle. The act of fixation on stable points in the environment nulls image motion at the fovea, resulting in stable patterns of outflow on the retinae centered on the point of fixation. These outflowing patterns retain a higher order structure that is informative about the stabilized trajectory of the eye through space. We measure this structure by applying the curl and divergence operations on the retinal flow velocity vector fields and found features that may be valuable for the control of locomotion. In particular, the sign and magnitude of foveal curl in retinal flow specifies the body's trajectory relative to the gaze point, while the point of maximum divergence in the retinal flow field specifies the walker's instantaneous overground velocity/momentum vector in retinotopic coordinates. Assuming that walkers can determine the body position relative to gaze direction, these time-varying retinotopic cues for the body's momentum could provide a visual control signal for locomotion over complex terrain. In contrast, the temporal variation of the eye-movement-free, head-centered flow fields is large enough to be problematic for use in steering towards a goal. Consideration of optic flow in the context of real-world locomotion therefore suggests a re-evaluation of the role of optic flow in the control of action during natural behavior.
Topics: Eye Movements; Locomotion; Optic Flow; Reflex, Vestibulo-Ocular; Retina
PubMed: 35192614
DOI: 10.1371/journal.pcbi.1009575 -
BMJ (Clinical Research Ed.) Dec 2002
Review
Topics: Decision Making; Female; Food Hypersensitivity; Humans; Immunoglobulin E; Professional Practice; Referral and Consultation
PubMed: 12468484
DOI: 10.1136/bmj.325.7376.1337 -
BMJ (Clinical Research Ed.) Aug 1988
Topics: Accidents, Home; Humans; Infant; Infant Care; Orthopedic Equipment; Walkers
PubMed: 3408989
DOI: No ID Found -
BMJ (Clinical Research Ed.) Jul 1988
Topics: Accidents, Home; Equipment Safety; Humans; Infant; Orthopedic Equipment; Walkers
PubMed: 3408967
DOI: 10.1136/bmj.297.6642.202-c