Two-Segment Foot Model for the Biomechanical Analysis of Squat

Squat exercise is acquiring interest in many fields, due to its benefits in improving health and its biomechanical similarities to a wide range of sport motions and the recruitment of many body segments in a single maneuver. Several researches had examined considerable biomechanical aspects of lower limbs during squat, but not without limitations. The main goal of this study focuses on the analysis of the foot contribution during a partial body weight squat, using a two-segment foot model that considers separately the forefoot and the hindfoot. The forefoot and hindfoot are articulated by the midtarsal joint. Five subjects performed a series of three trials, and results were averaged. Joint kinematics and dynamics were obtained using motion capture system, two force plates closed together, and inverse dynamics techniques. The midtarsal joint reached a dorsiflexion peak of 4°. Different strategies between subjects revealed 4° supination and 2.5° pronation of the forefoot. Vertical GRF showed 20% of body weight concentrated on the forefoot and 30% on the hindfoot. The percentages varied during motion, with a peak of 40% on the hindfoot and correspondently 10% on the forefoot, while the traditional model depicted the unique constant 50% value. Ankle peak of plantarflexion moment, power absorption, and power generation was consistent with values estimated by the one-segment model, without statistical significance.

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Biomechanical analysis of the figth by frontal head preasure on the chest of the opponent i sumo

Pedagogical Almanac ◽

10.54664/zzww8736 ◽

2019 ◽

Vol 27 (2) ◽

Author(s):

Hristo Hristov ◽

Keyword(s):

Sagittal Plane ◽

Lower Limbs ◽

Biomechanical Analysis ◽

Upper Body ◽

Acceleration Phase ◽

Motor Action ◽

Wide Range ◽

Head Pressure ◽

Functional Features ◽

The One

The Sumo sport discipline is characterized by incomparable by the nature and character force interactions. The briefness of the fight requires the sumo wrestlers to possess a wide range of sports and technical almost automated skills to manage their motor action depending on the opponent qualification. The aim of the present study is to establish the phase structure, functional features and mechanical principles of the sport-technical skills of the fight by frontal head pressure on the chest of the opponent in sumo. Methodology. For the purposes of the analysis, the fight is divided into separate phases, using a video computer system for determining the kinematic and energetic parameters of the movements. Results. Taking into account the fact that the mass of the defeating athlete is 23.5% lower and he is 5 cm shorter than the opponent, the results show three basic mechanical conditions that contribute to his victory during the fight: generating a powerful power rotation moment from the lower limbs to raise and guide the upper body through the initial acceleration phase; creating and increasing the detour force arm in order to disturb the balance of the opponent in the sagittal plane and use its inertia of movement. Discussion. The results of the study, on the one hand, justify the use of this sport technique against opponents with higher stature and mass. On the other hand, the resulting quantitative values of the parameters can serve to improve the training process, providing guidance on the qualities required for the competitors to use this technique,and also for defensive actions.

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General Trend of Negative Transference Number in Li Salt/Ionic Liquid Mixtures

10.26434/chemrxiv.7728545 ◽

2019 ◽

Cited By ~ 1

Author(s):

Nicola Molinari ◽

Jonathan P. Mailoa ◽

Boris Kozinsky

Keyword(s):

Ionic Liquid ◽

Transference Number ◽

Liquid Mixtures ◽

Single Linkage ◽

Self Diffusion ◽

Wide Range ◽

Single Linkage Cluster ◽

Concentrated Solution ◽

The One ◽

Dynamics Simulations

We show that strong cation-anion interactions in a wide range of lithium-salt/ionic liquid mixtures result in a negative lithium transference number, using molecular dynamics simulations and rigorous concentrated solution theory. This behavior fundamentally deviates from the one obtained using self-diffusion coefficient analysis and agrees well with experimental electrophoretic NMR measurements, which accounts for ion correlations. We extend these findings to several ionic liquid compositions. We investigate the degree of spatial ionic coordination employing single-linkage cluster analysis, unveiling asymmetrical anion-cation clusters. Additionally, we formulate a way to compute the effective lithium charge that corresponds to and agrees well with electrophoretic measurements and show that lithium effectively carries a negative charge in a remarkably wide range of chemistries and concentrations. The generality of our observation has significant implications for the energy storage community, emphasizing the need to reconsider the potential of these systems as next generation battery electrolytes.

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Modes of Interaction in Naturally Occurring Medical Encounters With General Practitioners: The “One in a Million” Study

Qualitative Health Research ◽

10.1177/1049732321993790 ◽

2021 ◽

pp. 104973232199379

Author(s):

Olaug S. Lian ◽

Sarah Nettleton ◽

Åge Wifstad ◽

Christopher Dowrick

Keyword(s):

General Practitioners ◽

Narrative Analysis ◽

Mode Competition ◽

General Applicability ◽

Naturally Occurring ◽

Wide Range ◽

The One ◽

Narrative Mode ◽

Modes Of Interaction

In this article, we qualitatively explore the manner and style in which medical encounters between patients and general practitioners (GPs) are mutually conducted, as exhibited in situ in 10 consultations sourced from the One in a Million: Primary Care Consultations Archive in England. Our main objectives are to identify interactional modes, to develop a classification of these modes, and to uncover how modes emerge and shift both within and between consultations. Deploying an interactional perspective and a thematic and narrative analysis of consultation transcripts, we identified five distinctive interactional modes: question and answer (Q&A) mode, lecture mode, probabilistic mode, competition mode, and narrative mode. Most modes are GP-led. Mode shifts within consultations generally map on to the chronology of the medical encounter. Patient-led narrative modes are initiated by patients themselves, which demonstrates agency. Our classification of modes derives from complete naturally occurring consultations, covering a wide range of symptoms, and may have general applicability.

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COVID-19 and Its Symptoms’ Panoply: A Case-Control Study of 919 Suspected Cases in Locked-Down Ovar, Portugal

Portuguese Journal of Public Health ◽

10.1159/000514925 ◽

2021 ◽

pp. 1-8

Author(s):

Regina Sá ◽

Tiago Pinho-Bandeira ◽

Guilherme Queiroz ◽

Joana Matos ◽

João Duarte Ferreira ◽

...

Keyword(s):

Large Scale ◽

Case Control Study ◽

Statistical Significance ◽

Case Control ◽

Case Definition ◽

Suspected Case ◽

Risk Characteristics ◽

Increased Risk ◽

Wide Range ◽

Control Study

Background: Ovar was the first Portuguese municipality to declare active community transmission of SARS-CoV-2, with total lockdown decreed on March 17, 2020. This context provided conditions for a large-scale testing strategy, allowing a referral system considering other symptoms besides the ones that were part of the case definition (fever, cough, and dyspnea). This study aims to identify other symptoms associated with COVID-19 since it may clarify the pre-test probability of the occurrence of the disease. Methods: This case-control study uses primary care registers between March 29 and May 10, 2020 in Ovar municipality. Pre-test clinical and exposure-risk characteristics, reported by physicians, were collected through a form, and linked with their laboratory result. Results: The study population included a total of 919 patients, of whom 226 (24.6%) were COVID-19 cases and 693 were negative for SARS-CoV-2. Only 27.1% of the patients reporting contact with a confirmed or suspected case tested positive. In the multivariate analysis, statistical significance was obtained for headaches (OR 0.558), odynophagia (OR 0.273), anosmia (OR 2.360), and other symptoms (OR 2.157). The interaction of anosmia and odynophagia appeared as possibly relevant with a borderline statistically significant OR of 3.375. Conclusion: COVID-19 has a wide range of symptoms. Of the myriad described, the present study highlights anosmia itself and calls for additional studies on the interaction between anosmia and odynophagia. Headaches and odynophagia by themselves are not associated with an increased risk for the disease. These findings may help clinicians in deciding when to test, especially when other diseases with similar symptoms are more prevalent, namely in winter.

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Entangling Lattice-Trapped Bosons with a Free Impurity: Impact on Stationary and Dynamical Properties

Entropy ◽

10.3390/e23030290 ◽

2021 ◽

Vol 23 (3) ◽

pp. 290

Author(s):

Maxim Pyzh ◽

Kevin Keiler ◽

Simeon I. Mistakidis ◽

Peter Schmelcher

Keyword(s):

Structural Changes ◽

Many Body ◽

Wide Range ◽

Entropy Measures ◽

Particle Level ◽

The Many ◽

The One ◽

Tunneling Dynamics ◽

The Individual ◽

Trapped Bosons

We address the interplay of few lattice trapped bosons interacting with an impurity atom in a box potential. For the ground state, a classification is performed based on the fidelity allowing to quantify the susceptibility of the composite system to structural changes due to the intercomponent coupling. We analyze the overall response at the many-body level and contrast it to the single-particle level. By inspecting different entropy measures we capture the degree of entanglement and intraspecies correlations for a wide range of intra- and intercomponent interactions and lattice depths. We also spatially resolve the imprint of the entanglement on the one- and two-body density distributions showcasing that it accelerates the phase separation process or acts against spatial localization for repulsive and attractive intercomponent interactions, respectively. The many-body effects on the tunneling dynamics of the individual components, resulting from their counterflow, are also discussed. The tunneling period of the impurity is very sensitive to the value of the impurity-medium coupling due to its effective dressing by the few-body medium. Our work provides implications for engineering localized structures in correlated impurity settings using species selective optical potentials.

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Bio-Inspired Modality Fusion for Active Speaker Detection

Applied Sciences ◽

10.3390/app11083397 ◽

2021 ◽

Vol 11 (8) ◽

pp. 3397

Author(s):

Gustavo Assunção ◽

Nuno Gonçalves ◽

Paulo Menezes

Keyword(s):

Superior Colliculus ◽

Visual Information ◽

Human Beings ◽

Validation Process ◽

Detection Approach ◽

Wide Range ◽

Speaker Detection ◽

The One ◽

The Brain ◽

Fusion Ability

Human beings have developed fantastic abilities to integrate information from various sensory sources exploring their inherent complementarity. Perceptual capabilities are therefore heightened, enabling, for instance, the well-known "cocktail party" and McGurk effects, i.e., speech disambiguation from a panoply of sound signals. This fusion ability is also key in refining the perception of sound source location, as in distinguishing whose voice is being heard in a group conversation. Furthermore, neuroscience has successfully identified the superior colliculus region in the brain as the one responsible for this modality fusion, with a handful of biological models having been proposed to approach its underlying neurophysiological process. Deriving inspiration from one of these models, this paper presents a methodology for effectively fusing correlated auditory and visual information for active speaker detection. Such an ability can have a wide range of applications, from teleconferencing systems to social robotics. The detection approach initially routes auditory and visual information through two specialized neural network structures. The resulting embeddings are fused via a novel layer based on the superior colliculus, whose topological structure emulates spatial neuron cross-mapping of unimodal perceptual fields. The validation process employed two publicly available datasets, with achieved results confirming and greatly surpassing initial expectations.

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Impact of Diagnosed and Undiagnosed Respiratory Pseudomonas on VAP and VAE During Long-Term Acute Care

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2020.823 ◽

2020 ◽

Vol 41 (S1) ◽

pp. s258-s259

Author(s):

James Harrigan ◽

Ebbing Lautenbach ◽

Emily Reesey ◽

Magda Wernovsky ◽

Pam Tolomeo ◽

...

Keyword(s):

Bacterial Community ◽

Acute Care ◽

Statistical Significance ◽

Rrna Gene ◽

Care Hospital ◽

16S Sequencing ◽

Increased Risk ◽

Wide Range ◽

The Impact

Background: Clinically diagnosed ventilator-associated pneumonia (VAP) is common in the long-term acute-care hospital (LTACH) setting and may contribute to adverse ventilator-associated events (VAEs). Pseudomonas aeruginosa is a common causative organism of VAP. We evaluated the impact of respiratory P. aeruginosa colonization and bacterial community dominance, both diagnosed and undiagnosed, on subsequent P. aeruginosa VAP and VAE events during long-term acute care. Methods: We enrolled 83 patients on LTACH admission for ventilator weaning, performed longitudinal sampling of endotracheal aspirates followed by 16S rRNA gene sequencing (Illumina HiSeq), and bacterial community profiling (QIIME2). Statistical analysis was performed with R and Stan; mixed-effects models were fit to relate the abundance of respiratory Psa on admission to clinically diagnosed VAP and VAE events. Results: Of the 83 patients included, 12 were diagnosed with P. aeruginosa pneumonia during the 14 days prior to LTACH admission (known P. aeruginosa), and 22 additional patients received anti–P. aeruginosa antibiotics within 48 hours of admission (suspected P. aeruginosa); 49 patients had no known or suspected P. aeruginosa (unknown P. aeruginosa). Among the known P. aeruginosa group, all 12 patients had P. aeruginosa detectable by 16S sequencing, with elevated admission P. aeruginosa proportional abundance (median, 0.97; IQR, 0.33–1). Among the suspected P. aeruginosa group, all 22 patients had P. aeruginosa detectable by 16S sequencing, with a wide range of admission P. aeruginosa proportional abundance (median, 0.0088; IQR, 0.00012–0.31). Of the 49 patients in the unknown group, 47 also had detectable respiratory Psa, and many had high P. aeruginosa proportional abundance at admission (median, 0.014; IQR, 0.00025–0.52). Incident P. aeruginosa VAP was observed within 30 days in 4 of the known P. aeruginosa patients (33.3%), 5 of the suspected P. aeruginosa patients (22.7%), and 8 of the unknown P. aeruginosa patients (16.3%). VAE was observed within 30 days in 1 of the known P. aeruginosa patients (8.3%), 2 of the suspected P. aeruginosa patients (9.1%), and 1 of the unknown P. aeruginosa patients (2%). Admission P. aeruginosa abundance was positively associated with VAP and VAE risk in all groups, but the association only achieved statistical significance in the unknown group (type S error <0.002 for 30-day VAP and <0.011 for 30-day VAE). Conclusions: We identified a high prevalence of unrecognized respiratory P. aeruginosa colonization among patients admitted to LTACH for weaning from mechanical ventilation. The admission P. aeruginosa proportional abundance was strongly associated with increased risk of incident P. aeruginosa VAP among these patients.Funding: NoneDisclosures: None

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1174. Phase 2 STRIVE Clinical Trial of Rezafungin for Treatment of Candidemia and/or Invasive Candidiasis Demonstrates Consistent Trough Concentrations Across Diverse Patient Populations

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.1360 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S612-S613

Author(s):

Shawn Flanagan ◽

Christopher M Rubino ◽

Taylor Sandison

Keyword(s):

Body Weight ◽

Invasive Candidiasis ◽

Fungal Infections ◽

Standard Of Care ◽

Geographic Region ◽

Continuous Variables ◽

Phase 2 ◽

Double Blind ◽

Wide Range ◽

Diverse Patient Populations

Abstract Background Rezafungin is a novel echinocandin antifungal in development for treatment as well as prevention (prophylaxis) of invasive fungal infections. STRIVE (NCT02734862) is a global, randomized, double-blind, placebo-controlled, Phase 2 trial evaluating safety and efficacy of IV rezafungin once weekly (QWk) for treatment of candidemia and/or invasive candidiasis compared with standard-of-care (IV caspofungin once daily with optional oral stepdown). Here we report pharmacokinetic (PK) data from the completed STRIVE trial analyzed by patient demographics at baseline. Methods Rezafungin Day 8 trough (Cmin) concentrations from patients treated with rezafungin were summarized categorically by race (black or white), sex (male or female), and geographic region (North America [NA], or Europe [EU]), or plotted versus continuous variables of age, body weight, body mass index (BMI), and body surface area (BSA). As the first dose of rezafungin was 400 mg for all rezafungin-treated patients, data from both dose groups (Group 1: 400 mg QWk; Group 2: 400 mg in Week 1 followed by 200 mg QWk) were combined in this analysis. Results Rezafungin mean Cmin (SD) values were 1.8 (0.7) and 2.3 (1.2) in black and white patients, 1.9 (1.0) and 2.6 (1.2) in males and females, and 1.9 (0.6) and 2.4 (1.3) in patients from NA and EU. There were small differences in point estimates between the groups, but there was a great deal of overlap and the differences are not expected to be clinically meaningful (Figure). Similarly, no trends in Cmin values were observed across a range of ages (20-80 years), weights (~40-155 kg), BMI (~15-65 kg/m2), and BSA (~1.4-2.4 m2). Figure Conclusion No meaningful differences in rezafungin Cmin values were observed in patients grouped by sex, race, or geographic region, or across a wide range of patient factors, including age and body weight and size. These findings indicate that a single rezafungin dose regimen can be expected to provide consistent PK across diverse patient populations. Disclosures Shawn Flanagan, PhD, Cidara Therapeutics, Inc. (Employee, Shareholder) Christopher M. Rubino, PharMD, Institute for Clinical Pharmacodynamics, Inc. (Employee)Spero Therapeutics (Grant/Research Support) Taylor Sandison, MD, MPH, Cidara Therapeutics, Inc. (Employee, Shareholder)

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Biomechanical analysis of an unpowered hip flexion orthosis on individuals with and without multiple sclerosis

Journal of NeuroEngineering and Rehabilitation ◽

10.1186/s12984-021-00891-7 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Ross M. Neuman ◽

Staci M. Shearin ◽

Karen J. McCain ◽

Nicholas P. Fey

Keyword(s):

Multiple Sclerosis ◽

Muscle Activity ◽

Healthy Subjects ◽

Muscle Activation ◽

Assistive Technologies ◽

Lower Limbs ◽

Biomechanical Analysis ◽

Foot Drop ◽

Plantar Flexors ◽

Hip Flexion

Abstract Background Gait impairment is a common complication of multiple sclerosis (MS). Gait limitations such as limited hip flexion, foot drop, and knee hyperextension often require external devices like crutches, canes, and orthoses. The effects of mobility-assistive technologies (MATs) prescribed to people with MS are not well understood, and current devices do not cater to the specific needs of these individuals. To address this, a passive unilateral hip flexion-assisting orthosis (HFO) was developed that uses resistance bands spanning the hip joint to redirect energy in the gait cycle. The purpose of this study was to investigate the short-term effects of the HFO on gait mechanics and muscle activation for people with and without MS. We hypothesized that (1) hip flexion would increase in the limb wearing the device, and (2) that muscle activity would increase in hip extensors, and decrease in hip flexors and plantar flexors. Methods Five healthy subjects and five subjects with MS walked for minute-long sessions with the device using three different levels of band stiffness. We analyzed peak hip flexion and extension angles, lower limb joint work, and muscle activity in eight muscles on the lower limbs and trunk. Single-subjects analysis was used due to inter-subject variability. Results For subjects with MS, the HFO caused an increase in peak hip flexion angle and a decrease in peak hip extension angle, confirming our first hypothesis. Healthy subjects showed less pronounced kinematic changes when using the device. Power generated at the hip was increased in most subjects while using the HFO. The second hypothesis was not confirmed, as muscle activity showed inconsistent results, however several subjects demonstrated increased hip extensor and trunk muscle activity with the HFO. Conclusions This exploratory study showed that the HFO was well-tolerated by healthy subjects and subjects with MS, and that it promoted more normative kinematics at the hip for those with MS. Future studies with longer exposure to the HFO and personalized assistance parameters are needed to understand the efficacy of the HFO for mobility assistance and rehabilitation for people with MS.

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Numerical investigation of the propagation of shock waves in rigid porous materials: development of the computer code and comparison with experimental results

Journal of Fluid Mechanics ◽

10.1017/s0022112096007872 ◽

1996 ◽

Vol 324 ◽

pp. 163-179 ◽

Cited By ~ 21

Author(s):

A. Levy ◽

G. Ben-Dor ◽

S. Sorek

Keyword(s):

Porous Materials ◽

Initial Conditions ◽

Computer Code ◽

Experimental Results ◽

Numerical Code ◽

Materials Development ◽

Numerical Predictions ◽

Wide Range ◽

Dimensional Version ◽

The One

The governing equations of the flow field which is obtained when a thermoelastic rigid porous medium is struck head-one by a shock wave are developed using the multiphase approach. The one-dimensional version of these equations is solved numerically using a TVD-based numerical code. The numerical predictions are compared to experimental results and good to excellent agreements are obtained for different porous materials and a wide range of initial conditions.

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