Limb articulation of biological motion can induce illusory motion perception during self-motion.

When one walks toward a crowd of pedestrians, dealing with their biological motion while controlling one's own self-motion is a difficult perceptual task. Limb articulation of a walker is naturally coupled to the walker's translation through the scene and allows the separation of optic flow generated by self-motion from the biological motion of other pedestrians. Recent research has shown that if limb articulation and translation mismatch, such as for walking in place, self-motion perception becomes biased. This bias may reflect an illusory motion attributed to the pedestrian crowd from the articulation of their limbs. To investigate this hypothesis, we presented observers with a simulation of forward self-motion toward a laterally moving crowd of point-light walkers and asked them to report the perceived lateral speed of the crowd. To investigate the dependence of the crowd speed percept on biological motion, we also included conditions in which the points of the walker were spatially scrambled to destroy body form and limb articulation. We observed illusory crowd speed percepts that were related to the articulation rate of the biological motion. Scrambled walkers also produced illusory motion but it was not related to articulation rate. We conclude that limb articulation induces percepts of crowd motion that can be used for interpreting self-motion toward crowds.

Parents' Knowledge, Attitudes, and Practices Regarding Baby Walkers, Baby Car Seats, Oral Health, and Child Screen Time in Saudi Arabia: A Cross-Sectional Study.

Background Awareness of age-appropriate milestones and developmental stages is crucial for parents to identify any potential delays or concerns early on and seek appropriate interventions. This study aimed to assess the knowledge, attitudes, and practices of caregivers in Saudi Arabia regarding baby walkers, baby car seats, early dental visits, and screen time for young children. Methods A cross-sectional survey was conducted among parents in Saudi Arabia using a structured questionnaire. A convenience and snowball sampling method was employed to recruit participants from various regions of the country. The questionnaire aimed to assess parents' knowledge regarding the recommended use of baby walkers and baby car seats, their awareness of the importance of early dental visits, and their understanding of appropriate screen time guidelines. Additionally, the survey explored parents' practices toward these recommendations. Descriptive statistics were used to analyze the data, and associations between variables were examined using the chi-squared test. Results A total of 1318 participants were included. The analysis revealed that the majority of the participants (n=1066,81.3%) use a baby walker, while only (n=292,22.3%) consider that they should never be used. Overall, (n=388,29.6%) of the participants never used a car seat for their infants or children. In terms of early childhood dental visits, approximately (n=518,39.5%) of the participants reported actually taking their child to the dentist within the recommended timeframe. Regarding screen time for children, (n=148,11.3%) of the participants reported that their children spend >5 hours daily in front of the screen.  Conclusions Raising parents' awareness about recent childcare recommendations and safe practices is crucial for promoting optimal child development, preventing health problems, facilitating evidence-based decision-making, reducing risks, enhancing parental confidence and empowerment, and nurturing positive parent-child relationships.

Exonuclease-catalyzed recycling and annular four-footed DNA walking amplification-assisted "on-off-super on" signal transitions for photoelectrochemical biosensing of kanamycin.

Photoelectrochemical (PEC) biosensors have exhibited a promising potential for assays of a large variety of analytes; however, how to realize their low background-based "super on" signal output is still a great challenge. Herein, we report a novel multiple nucleic acid amplification-assisted "on-off-super on" signal transition mechanism for the PEC biosensing of kanamycin antibiotics. The biosensing platform was constructed on a perylene-3,4,9,10-tetracarboxylic dianhydride-based photoelectrode, and its strong photocurrent could be well inhibited by an anchored ferrocene (Fc)-labeled hairpin DNA to produce a low background signal. Two target biorecognition-triggered exonuclease III-catalytic reactions were adopted to produce an annular four-footed DNA walker (AFW) and a methylene blue (MB)-labeled DNA strand. By using their synergistic effect to release Fc quenchers and simultaneously capture MB sensitizers, a "super on" signal output was realized. As a result, a very wide linear range from 10 fg mL-1 to 10 ng mL-1 and an ultra-low detection limit of 7.8 fg mL-1 were obtained. Meanwhile, the aptamer recognition-based homogeneous reaction and AFW-based multiple nucleic acid amplification effectively simplified the assay manipulation and well ensured the repeatability of the method. The satisfactory sample experiment results indicated its good reliability and accuracy for the antibiotic residue analysis application.

Think positive! Resolving human motion ambiguity in the presence of disease threat.

Recently, approach-avoidance tendencies and visual perception biases have been increasingly studied using bistable point-light walkers (PLWs). Prior studies have found a facing-the-viewer bias when one is primed with general threat stimuli (e.g. angry faces), explained by the "error management theory", as failing to detect a threat as approaching is riskier than the opposite. Importantly, no study has explored how disease threat - linked to the behavioural immune system - might affect this bias. This study aimed to explore whether disease-signalling cues can alter how we perceive the motion direction of ambiguous PLWs. Throughout 3 experiments, participants indicated the motion direction of a bistable PLW previously primed with a control or disease-signalling stimuli - that is, face with a surgical mask (Experiment 1), sickness sound (Experiment 2), or face with a disease cue (Experiment 3). Results showed that sickness cues do not significantly modulate the perception of approach-avoidance behaviours. However, a pattern emerged in Experiments 2 and 3, suggesting that sickness stimuli led to more facing away percepts. Unlike other types of threat, this implies that disease-related threat stimuli might trigger a distinct perceptual bias, indicating a preference to avoid a possible infection source. Nonetheless, this finding warrants future investigations.

Dynamic Phosphorus: Thiolate Exchange Cascades with Higher Phosphorothioates.

In this study, we introduce phosphorus, a pnictogen, as an exchange center for dynamic covalent chemistry. Cascade exchange of neutral phosphorotri- and -tetrathioates with thiolates is demonstrated in organic solvents, aqueous micellar systems, and in living cells. Exchange rates increase with the pH value, electrophilicity of the exchange center, and nucleophilicity of the exchangers. Molecular walking of the dynamic phosphorus center along Hammett gradients is simulated by the sequential addition of thiolate exchangers. Compared to phosphorotrithioates, tetrathioates are better electrophiles with higher exchange rates. Dynamic phosphorotri- and -tetrathioates are non-toxic to HeLa Kyoto cells and participate in the dynamic networks that account for thiol-mediated uptake into living cells.

Effects of gait training with weight support feedback walker on walker dependence, lower limb muscle activation, and gait ability in patients with incomplete spinal cord injury: A pilot randomized controlled trial.

BACKGROUND: Spinal cord injury (SCI) is a devastating condition affecting an individual's life, particularly through lower extremity paralysis, which limits walking and daily activities. OBJECTIVES: This study investigated the effects of weight support feedback walker (WSFW) gait training on walker dependence, lower limb muscle activation, and gait ability in patients with incomplete SCI (ISCI). METHODS: Eleven subjects capable of walking > 20 m with and without a walker were randomly assigned to WSFW gait training (n = 6) or conventional walker (CW) gait training groups (n = 5). All subjects underwent standard physical therapy for 4 weeks. Additionally, the WSFW group participated in WSFW gait training, whereas the CW group participated in CW gait training conducted for 30 min per day, thrice per week, for 4 weeks. Walker dependence (the average force pressing WSFW with the user's arm during walker gait), lower extremity muscle activity (rectus femoris, biceps femoris, and medial gastrocnemius), and gait ability (gait elements: velocity, cadence, step length, and step length asymmetry) were measured to investigate the effects of training. RESULTS: The WSFW group showed significant decrease in walker dependence compared to the CW group (P < 0.05). Some lower extremity muscle activation (left side biceps femoris) and velocity of the gait elements were increased in the WSFW group compared with those in the CW group (P < 0.05). CONCLUSION: WSFW gait training could help patients with ISCI transfer their body weight to the paralyzed lower extremity. However, a randomized controlled trial with several subjects is essential to verify the effects of WSFW training.

Evaluating Gait Stability and Muscle Activation in Different Hand Holding Conditions Using the Robotic Walker-mTPAD.

While walkers are used as mobility aids for different gait impairments, little is known about the factors that affect the performance of such aids. Therefore, we investigated the impact of arm-holding conditions on gait stability and muscle activation. We used surface electromyography (sEMG) sensors on specific arm and leg muscles while the users took laps with a robotic walker, the mobile Tethered Pelvic Assist Device (mTPAD), on an instrumented mat. Eleven participants without gait disorders walked with and without a 10% body weight (BW) force applied on the pelvis in the following three configurations: (i) while gripping the walker's frame, (ii) while using an armrest with their arms at a 90∘ angle, and (iii) while using an armrest with their arms at a 130∘ angle for 5 min each. Our results showed that when applying a force, the users changed their gait to increase stability. We also discovered differences in muscle activation based on the user's specific arm conditions. Specifically, the 130∘ condition required the least muscle activation, while gripping the walker's frame increased specific muscle activation compared to 90∘ and 130∘. This study is the first to evaluate how arm-holding and external loading conditions alter gait and muscle activations using the mTPAD.

Frequently asked questions about mobility devices among older adults.

PURPOSE: To assess frequently asked questions (FAQs) about mobility devices among older adults. MATERIALS AND METHODS: We searched multiple terms on Google to find FAQs. Rothwell's classification, JAMA benchmark criteria, and Brief DISCERN were used to categorize and assess each entry. RESULTS: Our search yielded 224 unique combinations of questions and linked answer sources. Viewing questions alone resulted in 214 unique FAQs, with the majority seeking factual information (130/214, 60.7%). Viewing website sources alone resulted in 175 unique answer sources, most of which were retail commercial sites (68/175, 38.9%) followed by non-retail commercial sites (65/175, 37.1%). Statistical analysis showed a significant difference between the JAMA benchmark scores by source type (p < 0.00010) and Brief DISCERN scores by source type (p = 0.0001). DISCUSSION: Our findings suggest government, academic, and possibly non-retail commercial sources may provide better quality information about the use of mobility devices. We recommend medical providers be prepared to promote and provide quality resources on the risks, benefits, and proper techniques for using mobility devices.

A qualitative exploration of adherence to wearing removable cast walkers in patients with diabetic foot ulcers.

OBJECTIVE: To explore adherence to wearing removable cast walkers (RCWs) among patients with diabetic foot ulcers (DFUs). METHOD: A qualitative study was conducted by interviewing patients with active DFUs and using knee-high RCWs as their offloading treatment. The interviews were undertaken at two diabetic foot clinics in Jordan, using a semi-structured guide. Data were analysed through content analysis by developing main themes and categories. RESULTS: Following interviews with 10 patients, two main key themes with a total of six categories were identified: theme 1-reporting of adherence levels was inconsistent, included two categories: i) a belief in achieving optimal adherence, and ii) non-adherence was often reported indoors; and theme 2-adherence was a consequence of multiple psychosocial, physiological and environmental factors, which included four categories: i) specific offloading knowledge or beliefs influenced adherence; ii) severity of foot disease influenced adherence; iii) social support benefitted adherence; and iv) physical features of RCWs (the usability of the offloading device) impacted adherence. CONCLUSION: Patients with active DFUs reported inconsistent levels of adherence to wearing RCWs which, after deeper investigation, seemed to be due to participants' misperceptions of the optimal adherence. Adherence to wearing RCWs also seemed to be impacted by multiple psychosocial, physiological and environmental factors.

Dual cascade DNA walking-induced "super on" photocurrent response for constructing a novel antibiotic biosensing method.

The construction of effective methods for the convenient testing of antibiotic residues in real samples has attracted considerable interest. Herein, we designed a dual cascade DNA walking amplification strategy and combined it with the controllable photocurrent regulation of a photoelectrode to develop a novel photoelectrochemical (PEC) biosensing method for antibiotic detection. The photoelectrode was prepared through the surface modification of a glassy carbon electrode with the TiO2/CdS QDs nanocomposite synthesized by an in situ hydrothermal deposition method. The strong anodic PEC response of the nanocomposite could be well inhibited by the introduction of a silver nanoclusters (Ag NCs)-labeled DNA hairpin onto its surface. Upon the target biorecognition reaction, an Mg2+-dependent DNAzyme (MNAzyme)-driven DNA walking was triggered to release another MNAzyme strand-linked streptavidin (SA) complex. As this SA complex could serve as a four-legged DNA walker, its cascade walking on the electrode surface not only released Ag NCs but also caused the linking of Rhodamine 123 with the electrode to realize the "super on" photocurrent output. By using kanamycin as the model analyte, this method showed a very wide linear range from 10 fg mL-1 to 1 ng mL-1 and a very low detection limit of 0.53 fg mL-1. Meanwhile, the simple photoelectrode preparation and the aptamer recognition-based autonomous DNA walking resulted in the convenient manipulation and excellent repeatability. These unique performances determine the great potential of the proposed method for practical applications.

Engineering Biomimetic Biosensor Using Dual-Targeting Multivalent Aptamer Regulated 3D DNA Walker Enables High-Performance Detection of Heterogeneous Circulating Tumor Cells.

The phenotypic heterogeneity of circulating tumor cells (CTCs) and the nonspecific adsorption of background cells impede the effective and sensitive detection of rare CTCs. Although leukocyte membrane coating approach has a good antileukocyte adhesion ability and holds great promise for addressing the challenge of capture purity, its limited specificity and sensitivity prevent its use in the detection of heterogeneous CTCs. To overcome these obstacles, a biomimetic biosensor that integrated dual-targeting multivalent aptamer/walker duplex functionalized biomimetic magnetic beads and an enzyme-powered DNA walker signal amplification strategy is designed. As compared to conventional leukocyte membrane coating, the biomimetic biosensor achieves efficient and high purity enrichment of heterogeneous CTCs with different epithelial cell adhesion molecule (EpCAM) expression while minimizing the interference of leukocytes. Meanwhile, the capture of target cells can trigger the release of walker strands to activate an enzyme-powered DNA walker, resulting in cascade signal amplification and the ultrasensitive and accurate detection of rare heterogeneous CTCs. Importantly, the captured CTCs remained viable and can be recultured in vitro with success. Overall, this work provides a new perspective for the efficient detection of heterogeneous CTCs by biomimetic membrane coating and paves the way for early cancer diagnosis.

A randomized, cross-over trial comparing the effect of innovative robotic gait training and functional clinical therapy in children with cerebral palsy; a protocol to test feasibility.

PURPOSE: Robotic gait training is relatively new in the world of pediatric rehabilitation. Preliminary feasibility studies and case reports include stationary robot-assisted treadmill training. Mobile robotic gait trainers hold greater promise for intensive practice-based therapy within hospitals, schools, rehabilitation centers, and at-home therapy as they enable participation and social integration while practicing high-quality gait patterns. MATERIALS AND METHODS: This paper (clinical trials registry number: NCT05378243) provides a detailed description of a mixed-method cross-over trial design with a broad set of outcome measures. Ultimately the goal is to establish the feasibility of this design which includes the collection of qualitative data regarding patient, family, and therapist experience and quantitative data regarding gait efficiency and quality, impact on tone, individualized goal achievement and bone strength.

Perception of biological motion. No sensitivity differences between patients with Parkinson's disease and healthy observers.

The use of biological motion (BM) stimuli (point-light walkers PLW) may be a novel alternative to improve the clinical impact of Action Observation treatments in Parkinson's Disease, by directing the patient's attentional focus on gait kinematics. However, the recognition of biological motion in Parkinson's patients has thus far been controversial. To evaluate the clinical feasibility of using BM stimuli in Action Observation treatments, we aimed at investigating whether Parkinson's patients in the ON-state condition can identify and use gender-specific cues conveyed by the body structure and by the kinematics of gait of a PLW. 30 Parkinson's patients and 30 healthy elderly observers were tested in a gender identification task with PLW. Parkinson's patients were able to correctly identify the gender of PLW; no differences were found between the two groups of observers. While for both groups, the gender identification task was easier when it required a judgment on a healthy PLW. Lastly, we found that females were more sensitive than males in our identification task. Our study shows that Parkinson's patients in the ON-state condition are able to extract subtle structural and kinematic characteristics from biological motion stimuli, which is favorable to the use of BM in Action Observation treatments.

Universal DNAzyme walkers-triggered CRISPR-Cas12a/Cas13a bioassay for the synchronous detection of two exosomal proteins and its application in intelligent diagnosis of cancer.

Exosomal proteins are considered to be promising indicators of cancer. Herein, a novel DNAzyme walkers-triggered CRISPR-Cas12a/Cas13a strategy was proposed for the synchronous determination of exosomal proteins: serum amyloid A-1 protein (SAA1) and coagulation factor V (FV). In this design, the paired antibodies were used to recognize targets, thereby ensuring the specificity. DNAzyme walkers were employed to convert the contents of SAA1 and FV into activators (P1 and P2), and one target can produce abundant activators, thus achieving an initial amplification of signal. Furthermore, the P1 and P2 can activate CRISPR-Cas12a/Cas13a system, which in turn trans-cleaves the reporters, enabling a second amplification and generating two fluorescent signals. The assay is highly sensitive (limits of detection as low as 30.00 pg/mL for SAA1 and 200.00 pg/mL for FV), highly specific and ideally accurate. More importantly, it is universal and can be used to detect both non-membrane and membrane proteins in exosome. Besides, the method can be successfully applied to detect SAA1 and FV in plasma exosomes to differentiate between lung cancer patients and healthy individuals. To explore the application of the developed method in tumor diagnosis, a deep learning model based on the expressions of SAA1 and FV was developed. The accuracy of this model can achieve 86.96%, which proves that it has a promising practical application capacity. Thus, this study does not only provide a new tool for the detection of exosomal proteins and cancer diagnosis, but also propose a new strategy to detect non-nucleic acid analytes for CRISPR-Cas system.

Assistive Devices for Personal Mobility in Parkinson's Disease: A Systematic Review of the Literature.

Background: Gait abnormalities are a hallmark of Parkinson's disease and contribute to falling risk. As disease symptoms progress, assistive devices are often prescribed. However, there are no guidelines for choosing appropriate ambulatory devices for gait impairment. Objective: To review the scientific evidence on assistive devices for gait impairment in Parkinson's disease. Methods: We performed a systematic literature review for articles relating to parkinsonian gait impairment and assistive devices. We assessed the studies' methodological quality and risk of bias using the PEDro scale. Results: Seventeen articles were reviewed. Four articles (23.53%) showed that canes and standard and two-wheeled walkers without visual cues decreased gait speed and stride length, with no significant effects on freezing of gait or falls. Instead, improvements were observed with the use of visual [seven articles (41.18%)] and auditory cues [three articles (17.65%)], including decreased number of freezing episodes and increased stride length. Conclusions: Although assistive devices seem to improve confidence, there is still limited information about the efficacy of assistive devices on gait parameters and functional disability in Parkinson's disease. Further, longitudinal, multicenter, randomized, blinded, and controlled studies using assistive devices in a free-living context are required to provide the best scientific evidence.

Perspectives of children with physical disabilities, parents and physiotherapists on use of walkers and their potential to increase physical activity. A qualitative exploration.

Children with physical disabilities are less physically active than children with typical development. How children's experiences of using walkers relates to their physical activity has not been studied previously. This study aimed to explore perspectives of walker use and their potential to increase physical activity. Four focus groups were conducted with children aged 7-10 (n = 3; 12.5%), aged 9-12 (n = 4; 16.7%), parents (n = 7; 29.2%) and paediatric physiotherapists (n = 10; 41.7%). Groups were audio recorded and transcribed. Data were analysed using framework analysis. An overarching concept of walkers needing flexibility to accommodate individual, interpersonal and environmental variability was underpinned by three themes: (a) contrasting drivers for use/non-use of walkers, (b) trade-offs, (c) acceptance of technology within walkers to increase physical activity. Participants were motivated by differing drivers: social for children, emotional for parents and professional for physiotherapists. These contrasting drivers create trade-offs, for example between quality of movement and independence. To maximise physical activity, walker prescribers and designers should prioritise drivers that motivate children and parents, ensuring goal setting is family-centred and participation orientated. Involving families in co-designing walkers is therefore important. Individual clinical assessment allows for identification of children's specific needs and how a child's, parent's and physiotherapist's goals may differ.

Who, if anyone, may benefit from a total hip arthroplasty after a displaced femoral neck fracture?: a post hoc subgroup analysis of the HEALTH trial.

AIMS: The aim of this study was to explore the functional results in a fitter subgroup of participants in the Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemiarthroplasty (HEALTH) trial to determine whether there was an advantage of total hip arthroplasty (THA) versus hemiarthroplasty (HA) in this population. METHODS: We performed a post hoc exploratory analysis of a fitter cohort of patients from the HEALTH trial. Participants were aged over 50 years and had sustained a low-energy displaced femoral neck fracture (FNF). The fittest participant cohort was defined as participants aged 70 years or younger, classified as American Society of Anesthesiologists grade I or II, independent walkers prior to fracture, and living at home prior to fracture. Multilevel models were used to estimate the effect of THA versus HA on functional outcomes. In addition, a sensitivity analysis of the definition of the fittest participant cohort was performed. RESULTS: There were 143 patients included in the fittest cohort. Mean age was 66 years (SD 4.5) and 103 were female (72%). No clinically relevant differences were found between the treatment groups in the primary and sensitivity analyses. CONCLUSION: This analysis found no differences in functional outcomes between HA and THA within two years of displaced low-energy FNF in a subgroup analysis of the fittest HEALTH patients. These findings suggest that very few patients above 50 years of age benefit in a clinically meaningful way from a THA versus a HA early after injury.Cite this article: Bone Jt Open 2022;3(8):611-617.

The Effects on Gait of 4-Wheeled Walker Use in People with Alzheimer's Disease Dementia and Gait Impairment: A Pilot Study.

In people with dementia, provision of mobility aids is standard treatment for those with impaired gait. However, mobility aid use is independently associated with increased falls risk. In this short communication, gait velocity and stride time variability were recorded in eleven adults with Alzheimer's disease dementia. Three conditions were tested: single-task (no aid), walking with a walker, and dual-task (walker use and counting backwards) under both a straight path and Figure-of-8 walking configuration. Gait velocity increased when using a walker compared to no aid in the Figure-of-8 walking configuration. Walker use improved gait in simple walking, but benefits diminished upon dual-task.

An Intervention of 12 Weeks of Nordic Walking and Recreational Walking to Improve Cardiorespiratory Capacity and Fitness in Older Adult Women.

(1) Background: The main aim of this study was to examine the effect of an intervention of 12 weeks in three groups on anthropometric measurement and heart rate (HR) variables, fitness index, and maximal oxygen consumption (VO2max) in older women. (2) Methods: In total, 166 Serbian adult women, aged 50 to 69 years old, participated in this study, comprising a control group (60 participants, µage = 57.8 + 6.6), Nordic-walking (NW) group (53 participants, µage = 57.5 + 6.8), and recreational-walking (RW) group (53 participants, µage = 57.8 + 6.6) in a physical fitness programme for 12 weeks. (3) Results: Anthropometric measurement variables were measured using a stadiometer and an electronic scale. The data showed differences in walking heart rate (bt/min) (p < 0.001; η2 = 0.088) between control, NW, and RW groups in the pretest analysis. Moreover, there were significant differences in walking heart rate (bt/min) (η2 = 0.155), heart rate at the end of the test (bt/min) (η2 = 0.093), total time of fitness index test (min) (η2 = 0.097), fitness index (η2 = 0.130), and VO2max (η2 = 0.111) (all, p < 0.001) between control, NW, and RW groups in the posttest analysis. (4) Conclusions: NW group training resulted in slightly greater benefits than RW group training. The present study demonstrated that both groups could act as modalities to improve the functionality and quality of life of people during the ageing process, reflected mainly in HR variables; UKK test measurements, and VO2max. It also contributes to the extant research on older women during exercise and opens interesting avenues for future research.

Three Months-Old' Preferences for Biological Motion Configuration and Its Subsequent Decline.

To perceive, identify and understand the action of others, it is essential to perceptually organize individual and local moving body parts (such as limbs) into the whole configuration of a human body in action. Configural processing-processing the relations among features or parts of a stimulus-is a fundamental ability in the perception of several important social stimuli, such as faces or biological motion. Despite this, we know very little about how human infants develop the ability to perceive and prefer configural relations in biological motion. We present two preferential looking experiments (one cross-sectional and one longitudinal) measuring infants' preferential attention between a coherent motion configuration of a person walking vs. a scrambled point-light walker (i.e., a stimulus in which all configural relations were removed, thus, in which the perception of a person is impossible). We found that three-month-old infants prefer a coherent point-light walker in relation to a scrambled display, but both five- and seven-month-old infants do not show any preference. We discuss our findings in terms of the different perceptual, attentional, motor, and brain processes available at each age group, and how they dynamically interact with selective attention toward the coherent and socially relevant motion of a person walking during our first year of life.