bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Applied Detachment Force, Fibronectin Adsorption, and Surface Reaction Stage on Initial Cell Adhesion to Bioactive Glass
Authors: García Andrés J. , Ducheyne Paul , Boettiger David
Published: July 2023

Bone bioactive materials, react with physiological fluids, enhance osseous tissue formation, and bond to bone. Cell adhesion to bioactive materials is one of the events involved in bone bioactivity. The effects of applied detachment force, fibronectin adsorption, and surface reaction treatment on the initial attachment of osteogenic cells to bioactive glass were examined using a spinning disk device. This apparatus applies a range of surface shear stresses while maintaining a uniform surface chemical environment. The number of adherent cells decreased sigmoidally with applied force. The adhesion strength varied linearly with fibronectin surface density. Surface reaction treatment of bioactive glass enhanced fibronectin-mediated cell adhesion but did not affect the amount of adsorbed fibronectin, suggesting changes in the conformation of the adsorbed fibronectin.
Simulation of Turbulent Pulsatile Flow Past a Mechanical Heart Valve
Authors: Bluestein Danny , Schoephoerster Richard T.
Published: July 2023

The thrombogenicity of all mechanical heart valves is primarily due to an activation of platelets. As a blood platelet passes through a mechanical heart valve it is exposed to varying degrees of shear, elongational and turbulent stresses. Numerical simulation of turbulent pulsatile flow through a 2D model of a St. Jude bileaflet valve in the aortic position was obtained, to allow the quantitative examination of the cumulative effects of elevated stresses on the blood platelets. The simulation was used to indicate the potential for stress-induced platelet activation due to anomalous flow patterns produced by the valve, a problem shared by all mechanical heart valves designs in use today.
Characterization of Drug Delivery by a Novel Local Infusion Device
Authors: Lutostansky Elizabeth M. , Ku David N. , Markou Christos , Hanson Stephen
Published: July 2023

The most widely used synthetic vascular graft is made of expanded polytetrafluoroethylene (ePTFE). In the early post operative period, ePTFE grafts are susceptible to thrombosis. Pharmacological agents, such as heparin, can be used to inhibit platelet aggregation and adhesion. Long-term, systemic heparin is associated with complications such as hemorrhage. However, heparin may be infused locally for extended periods of time without the complications associated with systemic heparin. In addition, the smaller volume of anti-coagulants required for local infusion dramatically reduces costs.
Stability of Human Spine in Prolonged Neutral Postures
Authors: Kiefer A. , Shirazi-Adl A. , Parnianpour M.
Published: July 2023

The normal axial shortening of the thoracolumbar spine, TLS, under the body weight during the diurnal cycle ranges from 0.5 to 2% of the total body height and is fully recuperated during the night in the absence of the vertical load [1]. Workplace automation has led to an increased number of occupations requiring to sustain prolonged seated or standing postures. Epidemiological studies have identified these prolonged static postures as a risk factor in low back disorders [2]. Although, the creep response of the individual spinal motion segments and diurnal variation of the body height have been the subject of numerous studies, the stability requirements of the spinal column in prolonged postures have not been yet fully determined. The objectives of our study are:

(i) to develop a computationally efficient finite element, FE, model describing the overall creep behaviour of the TLS.

(ii) to investigate spinal response in prologued neutral postures

(iii) to determine the effect of spinal creep on the stabilizing muscle forces

(iv) to examine the effect of changes in the lordosis and pelvic rotation on the spinal stability in prolonged neutral postures
Quantification of Moment Arms and Isometric Strength of Neck Muscles in Neutral Head Position
Authors: Li Siping , Vasavada Anita N. , Delp Scott L.
Published: July 2023

The maintenance of head stability is essential during activities of daily living. Yet the head is part of an unstable biomechanical system composed of a heavy mass on top of a flexible cervical column. The stability of the system is achieved through the interplay of a passive subsystem including the ligamentous cervical spine, and an active subsystem including the neck musculature (Panjabi, 1992). Many biomechanical studies have focused on defining kinematics and the strength of ligamentous cervical spine. However, the passive cervical spine does not provide enough support to stabilize the head in the neutral position; neck muscles must generate forces and moments to maintain head stability. Quantification of the moment-generating capacity of the neck muscles will provide insight into the contributions of the neck muscles to head stabilization. The objective of this study was to quantify the moment arms and maximal isometric force-generating capacity of neck muscles in flexion-extension, lateral bending, and axial rotation.
The Effect of Glenohumeral Joint Conformity in the Total Shoulder Arthroplasty
Authors: Salehi Abraham , Cooper Michael
Published: July 2023

A finite element (FE) analysis was performed to study the local sensitivity of the stress components in the polyethylene (poly) glenoid insert to the change in its material stiffness, thickness and the size of the humeral head. The FE results indicated that the magnitudes of the critical stress components in the poly insert increased by increasing its stiffness, decreasing its thickness, and decreasing the size of the humeral head while maintaining a constant spherical radius for the poly insert. Based on this parametric study, the Cofield™ (Smith & Nephew Richards) shoulder was designed to have 2 mm radial mismatch between the glenoid and the humeral head surfaces. This mismatch allows a more normal anatomical motion and induces a low stress level in the glenoid polyethylene insert.
In Vitro Simulation of Knee Joint Mechanics for the Validation of Biomechanical Models
Authors: Wilson David R. , MacWilliams Bruce A. , DesJardins John D. , Chao Edmund Y. S.
Published: July 2023

Mathematical models that predict such variables as joint contact force and stress, muscle force, ligament force and joint kinematics are vital tools in biomechanical analysis. One of the most exciting applications of biomechanical models is in preoperative planning. One example of such an application is the OASIS system, which has been developed to plan knee osteotomies. A knee osteotomy is performed to correct an abnormal distribution of forces in the tibiofemoral joint. The OASIS model predicts the force distribution in the tibiofemoral joint for a particular site and size of bone wedge. By considering many options, the system predicts the optimal site and size of osteotomy. Preoperative planning for this and other procedures is quickly becoming a viable and cost-effective means of improving surgical procedures. Steady advances in joint imaging, bringing about more accurate geometric representations of joint structures, have allowed the development of models that are increasingly complex. A major drawback of models, particularly those used in preoperative planning, is that the accuracy of their predictions has seldom been confirmed. In this paper, the application of a joint simulator for the validation of knee biomechanical models is discussed.
Effects of Vessel Wall Compliance on Flow and Stress Patterns in Arterial Bends and Bifurcations
Authors: Perktold Karl , Rappitsch Gerhard , Hofer Michael , Karner Gerhard , Andlinger Kurt
Published: July 2023

The influence of vessel wall distensibility on arterial flow and stress patters is analysed using computer simulation. The considered models are a curved tube model simulating an artery bend and an anatomically correct human carotid artery bifurcation, where the computational geometric model is generated from an optically digitized cast (Perktold et al., 1995). The description of the fluid dynamics uses the time-dependent 3D Navier-Stokes equations. The vessel wall mechanics is modelled applying geometrically non-linear shell structure. The effect of wall compliance with respect to transient flow separation is quantified using the oscillating shear index (OSI) defined by Ku et al., 1985.
Effects of Time-Varying Curvature due to Myocardial Contraction on Flow in the Coronary Arteries
Authors: Santamarina Aland , Siegel John M. , Moore James E.
Published: July 2023

Atherosclerosis, the cause of most mortality in western countries is a localized disease. This fact has led to the hypothesis that mechanical factors may be involved in the disease development process. In the coronary arteries, an important site of atherosclerosis, the solid and fluid mechanic stresses on the artery wall may be strongly influenced by the large scale movement and deformation that occur due to myocardial contraction.
Geometrical and Mechanical Adaptation of Arteries to Induced Hypertension
Authors: Stergiopulos N. , Rachev A. , Meister J.-J.
Published: July 2023

The aim of the present study was to develop a phenomenological model for the mechanical and geometrical adaptation of arteries in response to a sudden increase in pressure. Evolution equations for the geometrical parameters describing the zero stress state, the intimal shear stress and the constants of the strain energy function are postulated. Stimuli for the remodeling process are instantaneous differences from control values of the circumferential stress, intimal shear and Peterson modulus. The integration of the evolution equations yields the time course (dynamics) of the geometrical and elastic properties of the artery. Results are in good agreement with published experimental data.
The Effects of Tibial Tuberosity Transfer on the Patellofemoral Joint: A 3-D Simulation
Authors: Cohen Zohara A. , Kwak S. Daniel , Ateshian Gerard A. , Blankevoort Leendert , Henry Jack H. , Grelsamer Ronald P. , Mow Van C.
Published: July 2023

Anterior transfer of the tibial tuberosity has been shown in some clinical studies to relieve anterior knee pain. Maquet (1976) used 2-D analysis of the knee to show that a 2 cm advancement of the tuberosity would cause a 50% reduction in patellofemoral contact force. Fulkerson and colleagues (1990) evaluated the effects of anteromedial tibial tuberosity transfer on cadaver knees using pressure sensitive film and found anteromedialization to be successful at balancing the stresses between medial and lateral facets of the patella and at reducing the overall stress. Other experimental studies, however, have shown tibial tuberosity transfer to be unsuccessful at relieving patella cartilage stresses (Hayes, 1990).
Transition to Turbulence in Physiologically Intermittent Flow in an Aortic Arch Model
Authors: Sato Yoshihide , Koshiba Jun , Oka Kotaro , Tanishita Kazuo
Published: July 2023

Turbulence occurred in the major arteries affects in the development of a variety of pathphysiological process. The purpose of this study is to characterize the transition process in order to understand the nature of turbulence in the aorta. The axial and secondary velocity of intermittent flow in an aortic arch model were measured by Laser Doppler Velocimeter. As a result, for η = 1/2, during the deceleration, at the lower stations of 60 degrees, prominent fluctuations in the axial and secondary flow appear near the inner wall, and the turbulence propagated toward the outer wall in the diastolic period. The turbulence with shorter stationary period appears at earlier phase and nearer to the the entrance.
Incremental-Loading, Plane-Strain Prediction of Dilation Rupture of Atherosclerotic Plaque Within the Coronary Arterial Wall
Authors: Pao Y. C. , Srivatsa S. S. , Ritman E. L.
Published: July 2023

The true cross-sectional shape and dimensions of a coronary arterial wall with an atherosclerotic plaque obtained at postmortem, Fig. 1, is utilized for dilation rupture study related to the balloon angioplasty process. Plane-strain, finite-element analysis [1,2] of the shape changes and stress distributions of the cross section are performed by an incremental loading approach. The location of rupture is predicted by a dilation study ranging from 10 kPa to 120 kPa (about 1.2-fold of atmospheric pressure).
A Novel Registration Method for Robot-Assisted Surgery
Authors: Abdel-Malek K. , McGowan D. P. , Goel V. K. , Kowalski D.
Published: July 2023

A generally applicable registration method for orthopaedic internal fixation in conjunction with robotic-assisted intervention is presented. The method uses partial impression material of the bone surface to obtain partial molds. Computed Tomography (CT) scans of the bone surface are obtained. Computed Tomography scans of the mold is also obtained. Both CT scans are digitized and entered into a computer-aided engineering system. Meshing of the two models is accomplished using a computational surface matching algorithm. The matching yields the identification of bone surface coordinates with respect to the partial mold. The identification of the mold with respect to the robot base coordinate system is accomplished by manipulating the robot arm to be inserted into a fixture secured to the partial mold. The joint coordinates are then used to compute the direct kinematics of the manipulator therefore, identifying a coordinate system associated with the fixture.
The Effects of Strength on Simulation of the Trunk Motion
Authors: Parnianpour M. , Shirazi-Adl A. , Wang J. L. , Khayatian B. , Lafferriere G.
Published: July 2023

A computational method is proposed for simulation of the trunk movement. The present study emphasizes the importance of including realistic constraints on the maximum performance of the neuro-muscular system. The application areas of this study are: 1) providing optimized trajectories for biofeedback to patients during the rehabilitation process; and 2) aiding the engineering evaluation in terms of ergonomics and workplace interventions needed to accommodate individuals with prior disability.
Predictions of Knee Torque Based on Measured Torque at the Ski Binding/Boot Interface
Authors: Greenwald Richard M. , Hendee Shonn P. , Kaplan Ben J.
Published: July 2023

Injuries to the knee, in particular to the anterior cruciate ligament (ACL), continue to be the predominant injury in Alpine skiing, accounting for as many as 42% of all injuries[1]. Conversely, injuries to the tibia and ankle have decreased over the past two decades and now represent a very small fraction of the total injuries in skiing[2]. Ski equipment has been implicated as a possible factor in the significant rise of knee injuries. While standardized testing of Alpine ski bindings is used to determine the functionality of the binding under a variety of applied loading conditions, the models currently used in binding standards are based on protecting the tibia rather than the knee. An understanding of the relationship between forces and moments measured at the ski binding and forces and moments generated at the knee might be useful in determining if there is a role for ski bindings in protecting the knee and reducing the incidence of knee injuries in skiing.
How Many Gait Cycles Are Needed to Obtain Reliable Data?
Authors: Kaufman K. R. , Chambers H. G. , Sutherland D. H.
Published: July 2023

Human gait demonstrates stride-to-stride variability. This study quantifies the minimum number of cycles which are required to obtain a precise representation of a subject’s gait during a testing session. Ninety-two clinical studies from 72 subjects were evaluated. Two levels of error were considered. At least seven gait cycles are needed to obtain temporal-distance data which is low in precision, whereas at least 22 gait cycles are needed to obtain more precise data.
Dynamics of Marching With Varying Backpack Loading
Authors: Quesada Peter M. , Mengelkoch Larry J. , Hale Robert C. , Simon Sheldon R.
Published: July 2023

The investigation reported here was undertaken to obtain an improved understanding of kinematic, kinetic, and physiologic effects of marching with varying backpack loading. In addition to addressing the effects of load magnitude, we attempted to consider also biomechanical and phyisiologic changes from the beginning to the latter portion of a march. Such knowledge could be of potential value in development of training protocols that may reduce overuse injury risk, while still fostering desired conditioning.

We obtained kinematic and kinetic data for twelve young, healthy adult males walking with the military’s ACLICE backpack system loaded to 0%, 15%, and 30% of body weight. For each backpack load, biomechanical data were obtained before and after treadmill simulated marches. In addition, various physiological variables were measured during each treadmill march.
The Influence of Loading During Gait on Bone Loss in Preoperative Patients for Total Hip Replacement
Authors: Hurwitz D. E. , Hulet C. H. , Sumner R. D. , Andriacchi T. P. , Galante J. O. , Rosenberg A. G.
Published: July 2023

Extensive periprosthetic bone loss in total hip replacement (THR) has been attributed primarily to stress shielding. However, it is well known that decreased loading can result in bone loss (1). There is also evidence that subjects with a THR walk in an asymmetric manner that reduces the loads on the affected side (2). Decreased loading during daily activities may contribute to periprosthetic bone loss in addition to that due to stress-shielding. This study tested the hypothesis that asymmetries during gait were related to asymmetries in femoral bone mineral density (BMD).
Optimal Description of Anatomical Joint Motion
Authors: Kirstukas Steven J. , Lewis Jack L.
Published: July 2023

Anatomical joint motion is usually expressed as the motion of the distal boney segment relative to the more proximal boney segment of the two bones that articulate at the joint. Typically, right-handed Cartesian coordinate frames are assigned to each boney segment that is involved at the joint and the reported motion is that which occurs between the two coordinate frames. The quantitative description of motion is dependent upon two primary choices: (i) assignment of coordinate frames in the distal and proximal boney segments, (ii) and selection of the method used to locate the ‘movable’ distal frame relative to the ‘stationary’ proximal frame.
Temperature Measurement by Thermoreflectance at Near Grazing Angles
Authors: Lee Anthony S. , Hostetler John L. , Norris Pamela M.
Published: July 2023

An ellipsometric method has been developed that utilizes a thermoreflectance technique to measure the differential reflectance from a polarization modulated laser beam at near grazing probe angles. The technique is investigated here as a potential method for monitoring small changes in temperature about a control point on closely stacked silicon wafers in a heated furnace during batch processing. The technique is demonstrated on both polished and unpolished wafers with a temperature resolution of ∼0.5°C. Temperature measurement and sensitivity is investigated for furnace temperatures ranging from 20°C to 1000°C.
Thermal Lagging in Amorphous Materials
Authors: Tzou Da Yu , Xu Yunsheng
Published: July 2023

Thermal lagging in amorphous materials is studied in this work. Anomalous diffusion resulting from fracton vibrations on the fractal network are described in terms of the delayed response in time due to the percolating structure in such materials. In correspondence with the effects of fracton and fractal dimensions in percolating structures, slowing down of heat transport is found to be characterized by the ratio of two phase lags. The dual-phase-lag model fully describes the intrinsic transition from the stage of “close-to” diffusion at extremely short times, anomalous diffusion at intermediate times, and exact diffusion at relatively long times.
An Integrated Silicon Based Wall Pressure-Shear Stress Sensor for Measurements in Turbulent Flows
Authors: Löfdahl L. , Kälvesten E. , Hadzianagnostakis T. , Stemme G.
Published: July 2023

An integrated silicon pressure-shear stress sensor has been designed, fabricated and tested in a turbulent wall-boundary layer . The piezoresistive pressure sensor is based on polysilicon diaphragm technology and the thermal shear stress sensor on the gas cooling of a polyimide insulated heated chip. The pressure sensor diaphragm area is 100 × 100 μm, the top-area of the shear stress sensor hot chip is 300 × 60 μm and the edge-to-edge distance between the two areas is 100 μm. The measured steady-state power dissipation of the shear stress sensor in a turbulent wall-boundary layer at an over-temperature of 100°C was P = 42 + 1.1τ00.50 mW where τ0 is the time-average wall shear stress. The new integrated sensor has been applied for the simultaneous measurement of fluctuating pressure and shear stress in a flat plate boundary layer at a Reynolds number range of 4.9 × 103 < Reθ < 1.0 × 104. Pressure-shear stress correlation coefficients were found between 0.40 and 0.50 for the parallel, and between 0.20 and 0.25 for the perpendicular configuration to the mean flow.
Coupled Fluids and Mechanics Simulations Using Finite Element Analysis
Authors: van Kuijk Joost , Neagu Cristina , Gilbert John R.
Published: July 2023

We have developed a simulation tool which combines finite element calculations in both the fluid domain and the mechanical domain. In the fluid domain, the Navier-Stokes equations are solved for steady state incompressible fluids with constant density and viscosity. In the mechanical domain, non-linear finite elements are used. The coupled problem itself is solved by a simple relaxation method. Both normal and shear fluid stresses are taken into account; at low Reynolds number the viscous forces become important. The program has been used to simulate a micro mechanically fabricated eye pressure regulator developed by Neagu (1996) and a collapsible membrane in a flow channel as reported in literature Luo (1995). We show that these coupled calculations are a necessity when modelling and simulating these devices. Membrane deflections in the coupled calculations differ more than 10 % from the non-coupled calculations even when geometrical non-linear mechanical analysis is used.
A Technique for Determining the Poisson’s Ratio of Thin Films
Authors: Krulevitch Peter
Published: July 2023

The theory and experimental approach for a new technique used to determine the Poisson’s ratio of thin films are presented. The method involves taking the ratio of curvatures of cantilever beams and plates micromachined out of the film of interest. Curvature is induced by a through-thickness variation in residual stress, or by depositing a thin film under residual stress onto the beams and plates. This approach is made practical by the fact that the two curvatures are the only required experimental parameters, and small calibration errors cancel when their ratio is taken. The uncertainly in this method is due primarily to variation in the measured curvatures, and should range from ±0.02 to 0.04 with proper measurement technique.
Development of a Tangential Tactor Using a LIGA/MEMS Linear Microactuator Technology
Authors: Ghodssi R. , Beebe D. J. , White V. , Denton D. D.
Published: July 2023

Tactile transducers can provide information via stimulating the skin of individuals who either have sensory disability or experience overload in other sensory modalities. Advances in Microelectromechanical Systems (MEMS) technologies have initiated research in the field of tactile communication on a microscale that were not previously attainable. We are investigating the development of a tangential tactor using a LIGA (a German acronym for Lithography-Electroplating-Injection Molding) based linear microactuator technology. These LIGA based tactor devices will be used to stimulate the mechanoreceptors in the skin tangentially. The linear microactuator devices are designed to produce a linear motion of 30–200 μm in a direction tangential to the skin surface with a minimum driving force of 1 mN. Results of the design and LIGA/MEMS microfabrication process are reported.
Dynamic Characteristics of the Corrugated and the Flat p+ Diaphragms Actuated Electrostatically Under Residual Stress
Authors: Yang E. H. , Yang S. S. , Park E. J. , Yoo S. H.
Published: July 2023

This paper presents the dynamic characteristics of a corrugated p+ diaphragm and a flat one actuated electrostatically under residual stress. The numerical calculations of the dynamic characteristics of the diaphragms under the residual stress and damping have been performed using the general purpose finite element simulation program, ABAQUS. The velocity responses of the center of the diaphragms actuated electrostatically have been measured using a laser vibrometer. The test results are compared with the calculation results under tensile residual stress. For the corrugated diaphragm, the measured deflection coincides with the calculation result under the tensile residual stress of 100 MPa and the damping coefficient of 5, and for the flat one, under the tensile residual stress of 40 MPa and the damping coefficient of 500.
Calculation of Mode Mixity for Delamination Cracks in Composite Laminates Under In-Plane Loading
Authors: Qian W. , Sun C. T.
Published: July 2023

For material in monoclinic media such as composite laminates, the near-tip field can be expressed explicitly in terms of components of Barnett and Lothe tensors. Due to the oscillatory characteristics of stresses and displacements near the crack tip, individual strain energy release rates no longer exist. Strain energy release rates for finite crack extension Δa are introduced. The explicit quadratic relations between stress intensity factors and these finite extension strain energy release rates is established. Very accurate stress intensity factors can be obtained by calculating these finite extension strain energy release rates in the finite element analysis through these quadratic relations. An alternative and efficient method based on near-tip crack surface displacement ratios is also introduced to obtain these stress intensity factors. An edge-delaminated angle-ply composite laminate under uniform in-plane loading is investigated as an example for its mode mixity.
Stress Singularities Applied to Crack Initiation by Damage of Multimaterial Joints
Authors: Desmorat Rodrigue , Lemaitre Jean
Published: July 2023

We consider a multimaterial consisting of dissimilar layers submitted to plane deformations. The elastic stress field at any corner of this kind of joint often exhibits a stress singularity expressed as a function of the r-θ polar coordinates by σ_=hrδ−1F_(θ) where h is the intensity factor and δ the singuarity exponent. The resolution of the local singularity problem leads to the closed-form expression of F when δ is obtained as a root of a 2 × 2 determinant.

The exponent δ, always larger than 0 and smaller than 1, leads to a finite strain energy which is used as an input in a damage law. The damage rate D˙, where D represents the surface density of microcracks or microvoids, is a function of the strain energy density release rate Y. Some examples of crack initiation conditions are pointed out for brittle or quasi-brittle materials for joints loaded in monotonic loading or in fatigue.
Effect of Cell Morphology on the Properties of Microcellular Foamed PVC/Wood-Fiber Composites
Authors: Matuana Laurent M. , Park Chul B. , Balatinecz John J.
Published: July 2023

Wood-fiber composites make use of cellulose fibers as a reinforcing filler in the polymer matrix and are known to have a lower material cost and a higher stiffness compared to neat polymers. However, the lower material cost and enhanced stiffness of wood-fiber composites are achieved at the expense of other properties such as the ductility and the impact strength. Since microcellular plastics exhibit a higher relative impact strength, higher relative toughness, and increased relative fatigue life compared to unfoamed plastics, microcellular foaming of wood-fiber composites will improve the mechanical properties of the composites and therefore increase the usefulness of the materials. In this paper, microcellular foamed PVC/wood-fiber composites with unique cell morphology and material composition are characterized. Microcellular structures are produced in PVC/wood-fiber composites by first saturating the composite samples with CO2 under high pressure followed by rapidly decreasing the solubility of gas in the samples. The void fraction of the microcellular foamed PVC/wood-fiber composites is controlled by tailoring the composition of materials and the foaming process parameters. The results indicate that tensile and impact properties of microcellular foamed PVC/wood-fiber composites are most sensitive to changes in the cell morphology and the surface modification of fibers.
Online Learning in a High-Performance Sport Environment—A Mixed-Method Study
Authors: Fyall Glenn , Bennett Blake , Cowan Jackie
Published: July 2023

This study investigated a high-performance rugby academy program in New Zealand during the COVID-19 lockdown period in 2020. Unsurprisingly, this challenged academy staff who were abruptly charged with conceptualizing and implementing the program in innovative ways including a move to online learning and the adoption of online learning tools. A mixed-method sequential exploratory design was employed to explore the managers, coaches, and learners’ experiences. Phase 1 explored three coaches and two academy managers conceptualization and subsequent experiences of the online program. Phase 2 explored 44 academy players’ experiences of the online learning program. Our findings reveal that an explicit focus on player well-being and connection online appeared to increase a “sense of community” within and across both cohorts through enhanced communication, participation, and interaction. The challenges encountered included: accessibility, the amount, flow, and direction of information, “app fatigue,” and online technologies that were not fit-for-purpose. Our discussion reinforces that purposeful design and constant reflection is requisite to the successful and sustainable implementation of online coaching environments. We conclude with five fundamental lessons learned from COVID-19 that are worthy of consideration in the purposeful design of future online high-performance sporting programmes.
Is Binge Drinking Associated With Specific Types of Exercise and Free Time Sports? A Pooled Analysis With 718,147 Adults
Authors: da Silva Michael Pereira , Guimarães Roseane de Fátima , Bozza Rodrigo , Matias Thiago , Piola Thiago Silva , Corrêa Leandro Quadro , Ramires Virgílio , Alexandrino Eduardo , Dumith Samuel de Carvalho
Published: July 2023

Objective: To verify the association between exercise and free time sport types and binge drinking in a large sample of adults. Methods: Data of 718,147 adults from the “Surveillance of Risk and Protection Factors for Chronic Diseases by Telephone Survey” were used. We described the demographic and behavioral variables, and negative binomial regression analyzed the association between exercise and free time sport types and binge drinking adjusted by demographics variables, body mass index status, and television time. Results: Outdoor walking/running was the most common exercise reported (20.0%, 95% confidence interval [CI], 19.8%–20.2%), followed by team sports (8.1%; 95% CI, 8.0%–8.2%) and strengthening (8.0%; 95% CI, 7.9%–8.1%). The prevalence of binge drinking for each exercise and free time sport type ranged from 6.9% (water aerobics) to 31.9% (team sports). Participants engaging in strengthening (prevalence ratio = 1.12; 95% CI, 1.04–1.21, P = .002) and team sports (prevalence ratio = 1.11; 95% CI, 1.07–1.17, P < .001) were more likely to binge drink more frequently in the past 30 days than inactive participants. Conclusions: It appears that the participants’ profile plays an important role in the underlying social context of this association. Participants with more frequent strengthening and less frequent team sports practice, who were primarily younger and single, were more likely to binge drink frequently.
TRIM11 protects against tauopathies and is down-regulated in Alzheimer’s disease
Authors: Zhang Zi-Yang , Harischandra Dilshan S. , Wang Ruifang , Ghaisas Shivani , Zhao Janet Y. , McMonagle Thomas P. , Zhu Guixin , Lacuarta Kenzo D. , Song Jianing , Trojanowski John Q. , Xu Hong , Lee Virginia M.-Y. , Yang Xiaolu
Published: July 2023

Aggregation of tau into filamentous inclusions underlies Alzheimer’s disease (AD) and numerous other neurodegenerative tauopathies. The pathogenesis of tauopathies remains unclear, which impedes the development of disease-modifying treatments. Here, by systematically analyzing human tripartite motif (TRIM) proteins, we identified a few TRIMs that could potently inhibit tau aggregation. Among them, TRIM11 was markedly down-regulated in AD brains. TRIM11 promoted the proteasomal degradation of mutant tau as well as superfluous normal tau. It also enhanced tau solubility by acting as both a molecular chaperone to prevent tau misfolding and a disaggregase to dissolve preformed tau fibrils. TRIM11 maintained the connectivity and viability of neurons. Intracranial delivery of TRIM11 through adeno-associated viruses ameliorated pathology, neuroinflammation, and cognitive impairments in multiple animal models of tauopathies. These results suggest that TRIM11 down-regulation contributes to the pathogenesis of tauopathies and that restoring TRIM11 expression may represent an effective therapeutic strategy.
In vivo hematopoietic stem cell modification by mRNA delivery
Authors: Breda Laura , Papp Tyler E. , Triebwasser Michael P. , Yadegari Amir , Fedorky Megan T. , Tanaka Naoto , Abdulmalik Osheiza , Pavani Giulia , Wang Yongping , Grupp Stephan A. , Chou Stella T. , Ni Houping , Mui Barbara L. , Tam Ying K. , Weissman Drew , Rivella Stefano , Parhiz Hamideh
Published: July 2023

Hematopoietic stem cells (HSCs) are the source of all blood cells over an individual’s lifetime. Diseased HSCs can be replaced with gene-engineered or healthy HSCs through HSC transplantation (HSCT). However, current protocols carry major side effects and have limited access. We developed CD117/LNP–messenger RNA (mRNA), a lipid nanoparticle (LNP) that encapsulates mRNA and is targeted to the stem cell factor receptor (CD117) on HSCs. Delivery of the anti–human CD117/LNP–based editing system yielded near-complete correction of hematopoietic sickle cells. Furthermore, in vivo delivery of pro-apoptotic PUMA (p53 up-regulated modulator of apoptosis) mRNA with CD117/LNP affected HSC function and permitted nongenotoxic conditioning for HSCT. The ability to target HSCs in vivo offers a nongenotoxic conditioning regimen for HSCT, and this platform could be the basis of in vivo genome editing to cure genetic disorders, which would abrogate the need for HSCT.
Asymmetric ideological segregation in exposure to political news on Facebook
Authors: González-Bailón Sandra , Lazer David , Barberá Pablo , Zhang Meiqing , Allcott Hunt , Brown Taylor , Crespo-Tenorio Adriana , Freelon Deen , Gentzkow Matthew , Guess Andrew M. , Iyengar Shanto , Kim Young Mie , Malhotra Neil , Moehler Devra , Nyhan Brendan , Pan Jennifer , Rivera Carlos Velasco , Settle Jaime , Thorson Emily , Tromble Rebekah , Wilkins Arjun , Wojcieszak Magdalena , de Jonge Chad Kiewiet , Franco Annie , Mason Winter , Stroud Natalie Jomini , Tucker Joshua A.
Published: July 2023

Does Facebook enable ideological segregation in political news consumption? We analyzed exposure to news during the US 2020 election using aggregated data for 208 million US Facebook users. We compared the inventory of all political news that users could have seen in their feeds with the information that they saw (after algorithmic curation) and the information with which they engaged. We show that (i) ideological segregation is high and increases as we shift from potential exposure to actual exposure to engagement; (ii) there is an asymmetry between conservative and liberal audiences, with a substantial corner of the news ecosystem consumed exclusively by conservatives; and (iii) most misinformation, as identified by Meta’s Third-Party Fact-Checking Program, exists within this homogeneously conservative corner, which has no equivalent on the liberal side. Sources favored by conservative audiences were more prevalent on Facebook’s news ecosystem than those favored by liberals.
Independence by permission
Authors: Wagner Michael W.
Published: July 2023

Industry–academy collaboration explores the 2020 US election
Trimming away tau in neurodegeneration
Authors: Noble Wendy , Hanger Diane P.
Published: July 2023

Tau quality control by tripartite motif 11 (TRIM11) protects neurons in mice
Gut microbiota and inflammation patterns for specialized athletes: a multi-cohort study across different types of sports
Authors: Li Yuxue , Cheng Mingyue , Zha Yuguo , Yang Kun , Tong Yigang , Wang Song , Lu Qunwei , Ning Kang
Published: July 2023

Regular high-intensity exercise can cause changes in athletes’ gut microbiota, and the extent and nature of these changes may be affected by the athletes’ exercise patterns. However, it is still unclear to what extent different types of athletes have distinct gut microbiome profiles and whether we can effectively monitor an athlete’s inflammatory risk based on their microbiota. To address these questions, we conducted a multi-cohort study of 543 fecal samples from athletes in three different sports: aerobics (
n
= 316), wrestling (
n
= 53), and rowing (
n
= 174). We sought to investigate how athletes’ gut microbiota was specialized for different types of sports, and its associations with inflammation, diet, anthropometrics, and anaerobic measurements. We established a microbiota catalog of multi-cohort athletes and found that athletes have specialized gut microbiota specific to the type of sport they engaged in. Using latent Dirichlet allocation, we identified 10 microbial subgroups of athletes’ gut microbiota, each of which had specific correlations with inflammation, diet, and anaerobic performance in different types of athletes. Notably, most inflammation indicators were associated with
Prevotella
-driven subgroup 7. Finally, we found that the effects of sport types and exercise intensity on the gut microbiota were sex-dependent. These findings shed light on the complex associations between physical factors, gut microbiota, and inflammation in athletes of different sports types and could have significant implications for monitoring potential inflammation risk and developing personalized exercise programs.

IMPORTANCE

This study is the first multi-cohort investigation of athletes across a range of sports, including aerobics, wrestling, and rowing, with the goal of establishing a multi-sport microbiota catalog. Our findings highlight that athletes’ gut microbiota is sport-specific, indicating that exercise patterns may play a significant role in shaping the microbiome. Additionally, we observed distinct associations between gut microbiota and markers of inflammation, diet, and anaerobic performance in athletes of different sports. Moreover, we expanded our analysis to include a non-athlete cohort and found that exercise intensity had varying effects on the gut microbiota of participants, depending on sex.
Evaluating the impact of skill development for drowning prevention: a relationship-building approach to community engagement
Authors: Kamstra Peter , Cook Brian R , Brander Robert , Lawes Jasmin C , Calverley Hannah , Strugnell Grace , Kiss Beata , Bond James , Daw Shane
Published: July 2023

Objective

Evaluate the impact of a broadened theoretical and empirical model of community engagement aimed at coastal drowning prevention via relationship building between lifeguards and beachgoers through the delivery of skill development sessions on the beach.

Setting

A lifeguard-patrolled beach in Lorne, Victoria, Australia, during the 2023 peak summer holiday season.

Methods

In total, 12 skill development sessions were delivered by teams of lifeguards and risk researchers to beachgoers. Sessions were codesigned by the research team and shared with lifeguards beforehand to review and include lifeguards’ interpretations of localised risk during delivery. In total, 85 survey interviews were conducted with self-selecting beachgoers post participation.

Results

In total, 79 participants (93%) enjoyed participating in the session(s) and 77 participants (91%) reported learning something new. Learning how to identify rip current (n=59) and escape a rip current (n=40) were the two most commonly learnt skills. Participants’ intended changes in future beachgoing behaviours (n=46) include asking lifeguards at patrolled beaches how to identify site-specific (rip current) risk (n=11) and attempting to identify a rip current before entering the water (n=10). The spillover effects of participation include sharing what participants had learnt with family and friends.

Conclusions

Creating a dialogic model of collaboration via participatory community engagements between lifeguards and researchers with the beachgoing public can successfully prompt learning drowning prevention skills. These skills are required when navigating dynamic coastal hazards at unpatrolled beaches. Supporting lifeguards and life-savers to provide skill development expands the ways that life-saving services can engage the public, including measurement of lifeguards’ contributions to coastal drowning prevention.
Transvenous balloon-assisted approach to anterior fossa dural arteriovenous fistula using retrograde pressure cooker technique
Authors: Devarajan Alex , Rossitto Christina P , Al-Kawaz Mais , Giovanni Brian , Vasan Vikram , Shigematsu Tomoyoshi , Berenstein Alejandro , Fifi Johanna T
Published: July 2023

Endovascular embolization is the first-line therapy for dural arteriovenous fistulas (dAVFs). Transarterial embolization (TAE) may be limited by poor anatomical access. Transvenous embolization avoids this, but carries a risk of hemorrhage, venous redirection, and neurologic deterioration. Dual-lumen balloon microcatheters like the Scepter Mini (Microvention, Aliso Viejo, CA, USA) provide flow arrest and prevent reflux during TAE with liquid embolic agents (LEAs), but use in the distensible veins may be challenging. In this video, we use a Scepter Mini in a transvenous approach to a Cognard type IV anterior ethmoidal dAVF as a safe alternative to surgery, transvenous pressure cooker, and trans-ophthalmic TAE (video 1). The Scepter Mini was navigated transvenously to the anterior superior sagittal sinus. LEA was injected with excellent penetration to the venous pouch and further penetration into the network of tortuous feeders. No neurologic complications were experienced, and follow-up angiogram 9 months later demonstrated cure of the dAVF. Video 2 describes procedural considerations in transvenous approaches, steps of the procedure, and includes references1–10 which are relevant to this topic.

Video 1

 

Video 2
Possible combinations of early and late time cosmologies through BAO scales
Authors: Kalita Sanjeev , Rabha Chayanika
Published: July 2023

The theoretical scenarios of early universe and late time accelerated expansion constitute an open problem in cosmology. Relative Baryon Acoustic Oscillation (BAO) scales measured by 6dFGS, $$\mathrm SDSS+2dFGRS$$

S
D
S
S
+
2
d
F
G
R
S

, BOSS DR11 Ly$$\alpha $$
α
and BOSS DR11 QSO Ly$$\alpha $$
α
are used to investigate the parameter spaces of combinations of pre-recombination physics and late time cosmology. For pre-recombination physics we fix $$\mathrm N_{eff}=3$$

N

eff

=
3

and 4 and incorporate an Early Dark Energy (EDE) component. For late time cosmologies we consider curved $$\Lambda $$
Λ
CDM model, Dynamical Dark Energy (DDE) model with CPL parameterisation ($$\omega _0,\omega _1$$

ω
0

,

ω
1

) of equation of state, Coupled Dark Energy (CDE) model with constant coupling and curved DGP brane-world scenario. Combination of a curved $$\Lambda $$
Λ
CDM ($$\Omega _{\textrm{k}}\Lambda $$

Ω
k

Λ

CDM) model with $$\mathrm N_{eff}$$

N

eff

-EDE cosmology is found to be possible. For DDE, the relative BAO scales are achievable through $$\omega _1$$

ω
1

preferring the region $$\omega _1< 0$$

ω
1

<
0

. For $$\mathrm N_{eff}$$

N

eff

-EDE-CDE, the BAO scales are generated for both dark energy-dark matter and dark matter-dark energy conversion, however with exceptionally large value of dark energy density parameter and constant equation of state with $$\omega _0 > -1$$

ω
0

>
-
1

. Curved DGP cosmology ($$\Omega _\textrm{k}$$

Ω
k

DGP) is found to join with $$N_{\textrm{eff}}$$

N
eff

-EDE cosmology through curvature parameter $$\Omega _{\mathrm{k(0)}}\in [-0.002, -0.1]$$

Ω

k
(
0
)

∈

[
-
0.002
,
-
0.1
]

and cross-over parameter $$\Omega _{\mathrm{r_c}} \in [0.08, 0.45]$$

Ω

r
c

∈

[
0.08
,
0.45
]

. Cosmic ages are calculated for the derived parameters of $$\Omega _{\textrm{k}}\Lambda $$

Ω
k

Λ

CDM, flat DDE and $$\Omega _{\textrm{k}}$$

Ω
k

DGP models and compared with the ages of few globular clusters available in literature. Curved cosmologies are found to be promising.
Unsteady non-axisymmetric MHD Homann stagnation point flow of CNTs-suspended nanofluid over convective surface with radiation using Yamada–Ota model
Authors: Hamid Ganie Abdul , Mahmood Zafar , M. AlBaidani Mashael , Alharthi N. S. , Khan Umar
Published: July 2023

The increasing number of ways in which carbon nanotubes (CNTs) may be used in business and technology has led to an explosion of interest in these tiny tubes. As a result, the Yamada–Ota model is used to investigate the unsteady, non-axisymmetric MHD Homann stagnation point of carbon nanotubes passing over a convective surface with nonlinear radiation. Consisting of single-walled and multi-walled carbon nanotubes that are suspended in water (H2O). The length of the nanomaterial is between [Formula: see text] nanometers, while its radius is between [Formula: see text]. The method of similarity transformation is altered so that it may be used to get the dimensionless system of differential equations from the mathematical model that is envisioned for PDEs. After that, approximate solutions are obtained using MATHEMATICA and the Shooting with RK-IV technique. In this paper, we provide a graphical discussion and a physical interpretation of the results of measures of practical significance as a function of key factors. The results indicated that an increase in the volume fraction led to a corresponding rise in the heat transfer rate. However, it is reduced by the magnetic energy that is supplied to it. Carbon nanoliquids with a single wall have a greater melting point than nanoliquids with multiple walls. Industrial and technological uses of the issue under examination span several fields, including aviation and health. The results of the interface velocity and heat transfer rate at the surface, as well as the solution of each profile, are shown graphically, along with an analysis of the effects of MHD on the flow and heat transfer characteristics of the fluid under the influence of radiation.
Structure and Mössbauer study of La1−xCaxFeO3−δ perovskite
Authors: Zhou Kexuan , Cao Huanhuan , Gao Kaiyang , Shen Jiyu , Lu Zeyi , Wu Zhongjin , Liu Min
Published: July 2023

In this paper, La[Formula: see text]CaxFeO3 ([Formula: see text], 0.1, 0.2, 0.3, 0.4, 0.5) perovskite samples were synthesized by sol–gel method. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Mössbauer were used for measuring. XRD measurement shows that the unit cell volume of LaFeO3 gradually decreases with increasing Ca content. The morphology of the sample was observed by TEM, and there were significant changes in volume and size of the samples with different calcium contents. Mössbauer spectrum study found that with the gradual increase of Ca content, Fe[Formula: see text] and Fe[Formula: see text] were formed in the sample. The study in this paper will provide a reference for future research on the effect of different calcium contents on the electronic structure of lanthanide ferrite.