bluuebunny/crossref_metadata_2025 huggingface dataset:
Fuel Consumption Reduction of Off-Road Vehicles by Improving the Efficiency of the Hydromechanical Variable Transmission’s Lubrication and Actuation Systems
Authors: Milani Massimo , Montorsi Luca , Terzi Stefano , Mario Gelmini , Panizzolo Fabrizio , Profumo Giovanni
Published: February 2021

The paper investigates the efficiency of a hydro-mechanical variable transmission combining experimental and numerical approaches in order to develop operating strategies for power transmission losses reduction due to hydraulic circuits design. Two operating regions, characterized by high working time, have been detected analyzing the telescopic boom handler load spectral map of a real off-road vehicle transmission; the first one characterized by high output speed and the second one by low speed and torque transmission.

The efficiency of the former region has been increased by improving the fluid dynamic behavior of the lubrication system, which is greatly affected by the high flow rate generated by the fixed displacement pump operating at high speed, while the latter has been improved regulating the flow pressure of the actuation system with a controlled relief valve. The power losses of the system are experimentally determined testing an instrumented transmission on an ad-hoc test rig.

CFD dynamic models are adopted for the lubrication circuit optimization, addressing its real geometrical features as well as the actual operating conditions. Furthermore, the influence of the hydrodynamic resistance of the reverse and first wet clutches on the transmission power losses is investigated regulating the lubrication flow through an on/off valve. Tests demonstrated that up to 6.5 kW can be saved at high transmission ratios.

Finally, the effect of the two regulating strategies have been estimated in terms of energy saving and C02 emission reduction on the total vehicle life. Results proved that 5600 kWh and 7250 kWh saved energy can be achieved for the two strategies corresponding to 3.7 tons and 4.6 tons of avoided CO2 respectively.
Risk Analysis of Live Fire Shoot House Containment Systems Against Multiple Projectile Impacts
Authors: Andreen Steven D. , Davis Brad G.
Published: February 2021

Many analytical and numerical models exist that can describe the effect of single projectile impacts on steel targets. These models are not adequate for the evaluation of live fire shoot house containment systems, which are subjected to repeated impact loading from small caliber projectiles over the lifetime of the structure. Models assuming perfectly rigid projectiles over-predict penetration depths. Models assuming rigid targets cannot predict any penetration, and hydrodynamic models are best suited to high velocity impacts well above the ranges of conventional ordinance. Development of sufficient analytical or numerical tools using traditional techniques would be either intractable, empirically based and unique to a given scenario, require unique material properties that are not commonly available, or require significant computational effort. Due to the limited amount of empirical data on multiple impact failure, classical reliability methods are not suitable for assessing the probability of containment system perforation. Using existing experimental results of .223 caliber ammunition against AR500 steel panels with 2-inch ballistic rubber, a commonly found protective system in these facilities, the cumulative effects of multiple projectiles were quantified to estimate the number of impacts required to perforate the target material. Impacts were simulated from normal distributions of the x and y coordinates describing the impact point using a cartesian coordinate plane. The impact resistance of the steel was also simulated from a triangular distribution to account for the variability of the experimental results. Monte Carlo Simulation was then used to estimate the expected number of impacts to cause failure at a single point on the target. Using this collective model, it was possible to determine that the distribution of the number of rounds to cause target failure approached a normal distribution. The results indicated that the mean impacts at failure was 11800 with a standard deviation of 800 impacts. Finally, targeting the allowable risk level for structural failure from the JCSS probabilistic model code from the simulated normal distribution, it was determined that the safe number of impacts was approximately 7996. Decision makers can utilize the safe number of impacts to inform training guidance for the future use of facilities and to develop effective inspection requirements. This model can also be adapted to evaluate similar training facilities and to assess how other small caliber projectile impacts would affect live fire shoot house containment systems, providing a useful tool for the design and analysis of future and the assessment of existing facilities for use with ammunition that did not exist during its design.
Study on Model-Based Systems Engineering Method for Modeling of Thermal Power System
Authors: Chen Jinwei , Li Yuanfu , Hu Zhenchao , Zhang Huisheng
Published: February 2021

Thermal power systems, particularly with large capacity and high operating parameters, are more and more complicated nowadays, which include machinery, electronics, electrical, hydraulic, thermal, control, and process-oriented subsystems. The traditional development method based on documents has the problems of difficulty to reuse the designed elements, weak traceability of requirements, and lack of top-level logic verification. Moreover, there is a large gap because different models, tools and terminology are used during design process. The gap results in inefficiencies and quality issues that can be very expensive. In this paper, a model-based systems engineering (MBSE) approach is introduced for the top-down design flow of thermal power systems. The MBSE method can perfected the requirement definition, complete the mapping of the requirements to the system elements, realize the function logic verification, and support requirements verification at all stages. A GOPPRR (graph, object, point, property, role, relationship) meta-modeling method is proposed to support the MBSE formalisms. An Architecture Analysis and Design Integrated Approach (Arcadia) framework is adopted to capture the complex architecture, which is a standardized modeling method including requirement analysis, function analysis, logic analysis, and architecture design. Based on the architecture-driven algorithm and code generation, the standardized modeling process can establish a traceable relationship at each design stage and can verify the availability of initial requirements. Moreover, the designed elements of previous work can be reused in other relative design processes. The proposed MBSE method in this paper is applied to establish a gas turbine performance simulation model. The entire modeling process is enhanced by managing the relative design information consistently. The performance of the design process with MBSE method is analyzed and compared from different aspects. The results show that the performance simulation model of the power system established by the MBSE method can effectively describe the requirements, functions, logic, and architecture during design process. Based on the MBSE method, the requirements of the system are refined, traced and verified.
Development of a Low-Cost Sensor Network for Community-Made Measurements of Air Pollution
Authors: Sandoval Campos Sebastian , Ballesteros Higuera Fabián A. , Roa Prada Sebastián , Cáceres Becerra Claudia I. , Díaz Claro Alfredo A.
Published: February 2021

The levels of pollution present in the air have been dramatically increasing over the years due to the continuous emission of greenhouse gases such as CO2, CO, NOx and H2S, among others. The main source of these emissions is from burning fossil fuels for electricity, heat, and transportation. This represents a tremendous risk to the populations located near the emission sources where people get exposed to dangerous concentrations of such gases on a daily basis. The lack of open real-time monitoring tools makes people unaware of the damage these pollutants cause to their health.

This research proposes the development and implementation of a low-cost independent solution to keep the members of a community informed about concentration levels of air pollution due to local emissions. This tool must be easily accessible to the users so that the data about the number of particulates per million of a specific gas within a zone of interest can be viewed at any time. The proposed solution consists of a sensor network, covering the widest possible area, with respect to the point of interest. The collected data is sent to a cloud server, which operates as storage center and in which the data can be latter accessed for subsequent analysis. The measurements are sent to the server by means of a wireless communication protocol, carried out by a General Packet Radio Service, GPRS, communication module connected to each station. In this way, the coverage of the network is not limited by issues such as the use of local area networks which at the same time facilitates the transportation and installation of the stations at any desired measurement site.

Since each station can collect large amounts of data during a given period of time, it was necessary to implement techniques such as Big Data in order to extract important information and to identify patterns from the data such as the areas having the highest concentration of gases and possible correlations with other variables such as local weather conditions. This information could be used to support the making of decisions that benefit the communities impacted by air pollution, for example the early triggering of bad air quality alarms or the development of policies to regulate industry operation that can potentially impact the health of neighboring communities. A pilot case study was implemented in the city of Floridablanca, Colombia, to demonstrate the monitoring of the emissions of hydrogen sulfide of a big wastewater processing plant.
Innovative Thermal Management and Control to Surmount Challenges of Exploring Ocean Worlds on Europa and Enceladus
Authors: Hendricks Terry J. , Mueller Juergen , Furst Ben I. , Brandt Margarita N. , Hockman Benjamin J. , Berisford Daniel , Tarau Calin , Lee Kuan-Lin
Published: February 2021

Probes to penetrate the thick ice shells of our solar system’s Ocean Worlds have been studied for nearly 20 years, since scientific evidence strongly suggested a subsurface ocean on the Jupiter moon called Europa. There is keen scientific interest in exploring four significant themes on such proposed missions: 1) Geodynamics, 2) Geochemistry, 3) Habitability, and 4) Life Detection. The ice shells of Ocean Worlds are predicted to be up to 40 km thick; they exhibit extreme thermal environments, with ice temperatures from 100 K to 270 K, and extreme pressure environments from vacuum to 53 MPa. Jet Propulsion Laboratory has conducted a broad-look investigation of proposed mission concepts to Europa to identify the significant technology and operational challenges of Europa icepenetration. The thermal-mechanical system (TMS) of an ice penetration probe (IPP) mission concept designed to access the ocean of an icy moon using radioisotope thermoelectric generators for heat and power faces technological hurdles exacerbated by severe thermal and volume constraints. This study identified thermal management and control (TMC) challenges that are strongly linked to: ice penetration start-up, mobility and navigation in the ice, communications while in the ice sheet, and detecting and avoiding in-ice hazards. The major objectives of the TMC system are: 1) Absorb internal thermal energy from the IPP radioisotope power source, 2) Maintain liquid water conditions around the IPP at all times, 3) Manage and control thermal flows from probe nose to tail, and 4) Provide pressure containment for all internal probe components. This work discusses the baseline TMC system architecture and design developed to accomplish these objectives, and survive and transit the extreme ice thicknesses in pursuit of Icy/Ocean Worlds science goals. The proposed TMC system consisting of an internal pumped two-phase fluid loop “thermal bus” for thermal energy capture, variable conductance heat pipe system for passively adaptive thermal energy transport around the probe, and water jetting system for ice cutting is described and discussed. Critical testing performed to date is described.
Microstructural Enhancement and Performance of Additive Manufactured Titanium Alloy Grade 5 Composite Coatings
Authors: Fatoba O. S. , Akinlabi S. A. , Akinlabi E. T. , Naidoo L. C. , Adediran A. A. , Odebiyi O. S.
Published: February 2021

The surface integrity of Titanium alloy may be improved by surface modification, to expand its availability for more diverse industrial applications. Additive manufacturing is a commercially competitive manufacturing technique with the possibility of altering the entire perception of design and fabrication. The study experimentally investigates the effects that Ytterbium Laser System process parameters, such as laser power, powder feed rate and traverse speed, has on the resultant microstructure of Ti-6Al-4V grade 5 alloy. The deposition process was conducted employing a 3kW (CW) Ytterbium Laser System (YLS-2000-TR) machine, coaxial to the reinforcement powder. The laser scanning speed and power were varied between the intervals of 1–1.2 m/min and 900–1000 W. All other parameters kept constant were the rate of gas flow, the spot diameter, and the rate of powder flow. The microstructure was characterized by grain size and morphology by using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM). During the DLMD process, the thermal histories induced in the process led to the promotion of the transformed α+β microstructure from the initial primary a microstructure; the growth and evolution of the distinct grain morphologies and stability of the alpha and beta structures upon increased and reduced structures. It was ascertained that by increasing the traverse speeds, the cooling rates increased, which resulted in the decrease in the width of the columnar grains.
Stiffness Degradation of Digital Polypropylene Under Fatigue Loading: Investigations via 3-Dimensional Polyjet Printed Coupons
Authors: Tomar Ravi Pratap Singh , Ulu Furkan I. , Kelkar Ajit , Mohan Ram V.
Published: February 2021

The utilization of additively manufactured parts is gaining popularity in functional applications. Polymer-based additive manufacturing (AM) parts are utilized in a variety of engineering applications for automotive, aerospace, and energy. AM printed parts are however newer class of materials, and structural performance of these materials is not fully understood completely, and very limited exists currently on precisely performance of Polyjet printed parts and associated digital materials under fatigue loading.

This paper investigates the stiffness degradation under tension-tension fatigue loading of digital polypropylene using homogenous 3-Dimensional test coupons formed using PolyJet printing. Homogeneous 3-Dimensional test configuration employed in the present study eliminates the process-induced limitations of traditional ASTM D638 2D fatigue test coupons for AM processed materials.

Fatigue data is analyzed to present an empirical model of effective elastic modulus and an analytical model of the accumulated damage state, as defined on the basis of stiffness degradation during cyclic loading. Further, the actual damage accumulation due to cyclic loading with the predicted model is compared. Modeling of the S-N diagram provides a better estimation of fatigue life and fatigue life modeling of AM printed test coupons and is obtained via linear regression analysis of experimental data with high correlation coefficient R2 (0.9971). The analytical model of the accumulated damage state is based on the stiffness degradation and is derived from the regression analysis of experimental data of stiffness degradation at different loading percentages assuming a polynomial of degree 4. Present study provides insight into the fatigue damage state and cyclic performance of digital polypropylene from Polyjet printing.
Experimental Optimization of Polymer Jetting Additive Manufacturing Process Using Taguchi Design
Authors: Weese Nathan A. , Rankin Chantz M. , Zhao Daguan , Hart Christoph , Quinlan Patrick , Day James B. , Salary Roozbeh (Ross)
Published: February 2021

Polymer jet printing (PJP) is a direct-write additive manufacturing process, emerging as a rapid high-resolution method particularly in the medical field for the fabrication of a wide spectrum of products, e.g., anatomical models, tissue scaffolds, implants, and prosthetics. PJP allows for non-contact multi-material deposition of functional polymer inks. The PJP process centers on simultaneous deposition of build and support photopolymer materials on a free surface, which are immediately cured in situ using a UV light source, allowing for solid-freeform fabrication. The PJP process is inherently complex, governed by a multitude of parameters as well as material-machine-process interactions, which collectively affect the functional properties of a fabricated structure. Consequently, physics-based characterization and optimization of the PJP process would be inevitable.

In this study, a new test standard was forwarded for the characterization of the mechanical properties of PJP-fabricated bone structures; the standard was designed on the basis of an X-ray p-CT scan of a femur bone in addition to the ASTM D638-14 standard. Furthermore, the Taguchi L8 orthogonal array design was utilized to investigate the effects of influential PJP process parameters on the mechanical properties of the bone structures, including Young’s modulus of elasticity, tensile strength, breaking strength, and ductility. The selected process parameters (each at two levels) were: (i) print direction, (ii) resolution factor, (iii) UV light intensity, and (iv) deposition head temperature. The mechanical properties of the femur bone structures were measured using a tensile testing machine.

The UV light intensity appeared as the most significant factor, influencing all the aforementioned mechanical properties, while the resolution factor was identified as an inconsequential factor. In addition, it was observed that the print direction and the head temperature significantly affected the breaking strength and the ductility, respectively. Overall, the results of this study pave the way for further investigation of the effects of the PJP parameters toward optimal fabrication of complex bone tissue scaffolds and implants with long-lasting functional characteristics.
Measurement of Thermal Conductivities of Bi2Te3 and Sb2Te3 Nano-Powders at Extreme Temperature and Strain
Authors: Xu Chenxin , Wang Brandon , Sneddon Emily , Marcovecchio Gianna , Ota Greg , Hunstein Karina , Zhang Xian
Published: February 2021

The Raman optothermal technique has been the most successful method for measurement of thermal conductivity of two dimensional (2D) materials, and was used to measure the thin films for the first time in this work. In this technique, a laser is focused at the center of a thin film and used to measure the peak position of a Raman-active mode. As the laser power is increased, the sample is heated which enables red-shift Raman mode due to thermal softening. Another comparison experiment is conducted by placing the samples on a heating platform and monitor the change of Raman-active mode peak position shift. Combining these two sections of experiments provide us the thermal modeling can then be used to extract the thermal conductivity from the measured shift rate. We have used a refined version of the optothermal Raman technique to study thermal conductivity of thin films of Bi2Te3 and Sb2Te3, at extreme temperatures and mechanical strains. It is the first thermal measurement on these two materials by Raman optothermal technique. This work also addresses several important issues in the measurement of thermal conductivity of thin films using Raman spectroscopy.
Microwave Induced Thermoacoustic Imaging With Multi-Pulse in Geological Application
Authors: Mao Xu , Liu Chang , Wang Chang , Heredia-Juesas Juan , Martinez-Lorenzo Jose Angel
Published: February 2021

The accurate and real-time monitoring of fluid flow in porous media can boost the prediction of mass transport and chemical reactions, which profoundly impacts the subsurface exploration and hydrocarbon extractions. Our preliminary effort has shown the efficacy of employing a thermoacoustic (TA) technology for imaging an immobile rock sample. The results support the applicability of making this methodology to move forward for imaging a dynamical process. But the real-time monitoring of fluid flow requires the target under test to excite TA signals with a higher signal-to-noise ratio (SNR), which will promise a sufficient image resolution with fewer necessary measurements or less averaged times, and then lead to a faster scan. It is proved that the excitation pulse is directly proportional to the microwave absorption rate, and thus determines the observability of the corresponding TA signals. Unfortunately, due to the thermal and stress confinements, a microsecond-width pulse envelope is greatly limited and is not sufficient for achieving a high SNR. Although a recently proposed Frequency Modulation Continuous Wave (FMCW) showed an improvement on SNR, it signifies a deficiency of the long-time irradiation and additional electronic disturbance especially at a high peak power. To address this issue, we propose a new excitation envelope with multi-pulses, to favor the coherent frequency-domain signaling method for optimizing the image reconstruction while shortening the total envelope duration than that of the FMCW. In the present paper, the TA sensing of a dry sandstone sample is presented, which efficiently enhances the SNR of TA signals and the image resolution, thus validating the appropriateness of the proposed multi-pulse envelope. The current study also promises a future possibility towards its application for dynamically exploring the underground flow transport.
Efficient pancreatic cancer detection through personalized protein corona of gold nanoparticles
Authors: Digiacomo Luca , Caputo Damiano , Coppola Roberto , Cascone Chiara , Giulimondi Francesca , Palchetti Sara , Pozzi Daniela , Caracciolo Giulio
Published: February 2021

Characterization of the personalized protein corona (PC) that forms around nanomaterials upon exposure to human plasma is emerging as powerful technology for early cancer detection. However, low material stability and interbatch variability have limited its clinical application so far. Here, we present a nanoparticle-enabled blood (NEB) test that uses 120 nm gold nanoparticles (NPs) as the accumulator of blood plasma proteins. In the test, the personalized PC of gold NPs is characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis. As a paradigmatic case study, pancreatic ductal adenocarcinoma (PDAC) was chosen due to the lack of effective detection strategies that lead to poor survival rate after diagnosis (<1 year) and extremely low 5-years survival rate (15–20%). Densitometric analysis of 75 protein patterns (28 from healthy subjects and 47 from PDAC patients) allowed us to distinguish nononcological and PDAC patients with good sensitivity (78.6%) and specificity (85.3%). The gold NEB test is completely aligned to affordable, sensitive, specific, user-friendly, rapid and robust, equipment-free, and deliverable to end users criteria stated by the World Health Organization for cancer screening and detection. Thus, it could be very useful in clinical practice at the first level of investigation to decide whether to carry out more invasive analyses or not.
Challenges and solutions for fabrication of three-dimensional cocultures of neural cell-loaded biomimetic constructs
Authors: Aregueta Robles Ulises A. , Martens Penny J. , Poole-Warren Laura A.
Published: February 2021

Fabrication of three-dimensional (3D) constructs to model body tissues and organs can contribute to research into tissue development and models for studying disease, as well as supporting preclinical drug screening in vitro. Furthermore, 3D constructs can also be used for diagnosis and therapy of disease conditions via lab on a chip and microarrays for diagnosis and engineered products for tissue repair, replacement, and regeneration. While cell culture approaches for studying tissue development and disease in two dimensions are long-established, the translation of this knowledge into 3D environments remains a fertile field of research. In this Tutorial, we specifically focus on the application of biosynthetic hydrogels for neural cell encapsulation. The Tutorial briefly covers background on using biosynthetic hydrogels for cell encapsulation, as well as common fabrication techniques. The Methods section focuses on the hydrogel design and characterization, highlighting key elements and tips for more effective approaches. Coencapsulation of different cell types, and the challenges associated with different growth and maintenance requirements, is the main focus of this Tutorial. Much care is needed to blend different cell types, and this Tutorial provides tips and insights that have proven successful for 3D coculture in biosynthetic hydrogels.
Time−Motion Characteristics and Physiological Responses of Para-Footballers With Cerebral Palsy in Two Small-Sided Games and a Simulated Game
Authors: Henríquez Matías , Iturricastillo Aitor , González-Olguín Arturo , Herrera Felipe , Riquelme Sonny , Reina Raul
Published: February 2021

This study compared physical performance in a group of international cerebral palsy football players during two formats of small-sided games (SSGs) and performance in a simulated game (SG) according to players’ sport classes (FT1, FT2, and FT3). Internal load (heart rate and rating of perceived exertion) and external load (total distance, distance covered at different velocities, maximum speed reached, acceleration, and deceleration) were obtained with global positioning system devices during two formats of SSGs (2-a-side/SSG2 and 4-a-side/SSG4) and an SG (7-a-side). SSG2 demands faster actions compared with SSG4/SG, and significant differences and large effect sizes were found in the distance covered in Speed Zones 5 (16.0−17.9 km/hr) and 6 (>18.0 km/hr; p < .05; , large). Lower moderate accelerations and decelerations per minute in SSG4/SG compared with SSG2 were also found (p < .01; , large). In the SSG2 task, the FT3 players reached maximum speeds, covered more distance at the highest intensities, and performed more moderate/high accelerations/decelerations and more sprints compared with FT1 and FT2 players (p < .05; −0.85 < dg < −4.64, large). The SSG2 task could be the best option for discriminating physical demands in important variables for cerebral palsy football performance between classes FT3 versus FT1/FT2.
Short-Term Psychological and Hormonal Effects of Virtual Reality Training on Chronic Low Back Pain in Soccer Players
Authors: Nambi Gopal , Abdelbasset Walid Kamal , Alsubaie Saud F. , Saleh Ayman K. , Verma Anju , Abdelaziz Mohamed A. , Alkathiry Abdulaziz A.
Published: February 2021

Objective: To find the short-term psychological and hormonal effects of virtual reality training on chronic low back pain in American soccer players. Design, Setting, Participants: The 3-block random sampling method was used on 54 university American soccer players with chronic low back pain, and they were allocated into 3 groups: virtual reality training (VRT; n = 18), combined physical rehabilitation (n = 18), and control (n = 18) groups at University Hospital. They underwent different balance training exercises for 4 weeks. The participants and the therapist who is assessing the outcomes were blinded. Psychological (pain intensity and kinesiophobia) and hormonal (glucose, insulin, Homeostatic Model Assessment of Insulin Resistance, growth hormone, prolactin, adrenocorticotropic hormone, and cortisol) values were measured at baseline, after 4 weeks, and after 6 months. Results: The baseline demographic, psychological, and hormonal data between the VRT, combined physical rehabilitation, and control groups show no statistical difference (P ≥ .05). Four weeks following training, the VRT group shows more significant changes in pain intensity and kinesiophobia than the combined physical rehabilitation and control groups (P < .001), and the improvement was noted in the 6-month follow-up. All the hormonal variables (glucose, insulin, growth hormone, prolactin, adrenocorticotropic hormone, and cortisol) show significant changes at 4-week training (P < .001), except for the Homeostatic Model Assessment of Insulin Resistance (P = .075) between the 3 groups. At 6-month follow-up glucose, prolactin, adrenocorticotropic hormone, and cortisol show more significant difference in the VRT group than the other 2 groups (P < .001). At the same time, insulin (P = .694), Homeostatic Model Assessment of Insulin Resistance (P = .272), and growth hormone (P = .145) failed to show significant changes between the groups. Conclusion: Training through virtual reality is an effective treatment program when compared with conventional exercise training programs from a psychological and hormonal analysis perspective in American soccer players with chronic low back pain.
The Effect of Diacutaneous Fibrolysis on Local and Widespread Hyperalgesia and Muscle Length in Patients With Patellofemoral Pain Syndrome: Secondary Analysis of a Pretest–Posttest Clinical Trial
Authors: Fanlo-Mazas Pablo , Bueno-Gracia Elena , Ruiz de Escudero-Zapico Alazne , López-de-Celis Carlos , Hidalgo-García César , Rodríguez-Sanz Jacobo , Lucha-López María Orosia
Published: February 2021

Context: Localized and widespread hyperalgesia has been observed in patients with patellofemoral pain. Diacutaneous fibrolysis (DF) has shown to be effective in reducing pain in several musculoskeletal conditions including patellofemoral pain syndrome, but no studies have evaluated the effects of this technique in reducing localized and widespread hyperalgesia. Objective: To assess the effect of DF on the pressure pain threshold and muscle length tests in patients with patellofemoral pain syndrome. Design: A single-group, pretest–posttest clinical trial. Setting: University of Zaragoza. Participants: Forty-six subjects with patellofemoral pain (20 males and 26 females: age 27.8 [6.9] y). Intervention: Three sessions of DF. Main Outcome Measures: Pressure pain threshold using a handheld pressure algometer (4 sites around the knee, on tibialis anterior muscle, and one remote site on the upper contralateral limb); muscle length test of the iliotibial band, rectus femoris, and hamstring muscles; and patient-perceived treatment effect score. Results: The application of 3 sessions of DF significantly increased the pressure pain threshold in all sites at posttreatment evaluation (P < .001) and at a 1-week follow-up (P < .001). A significant increase in muscle length was also observed at the posttreatment evaluation (P < .001) and 1-week follow-up (P < .001). Ninety-seven percent of the patients reported subjective improvement at posttreatment and at 1-week follow-up. Conclusion: This study found that local and widespread hyperalgesia was significantly reduced after 3 sessions of diacutaneous fibrolysis and at the 1-week follow-up. A significant improvement on muscle length tests was also observed, with high clinical satisfaction among patients.
Biomechanics Differ for Individuals With Similar Self-Reported Characteristics of Patellofemoral Pain During a High-Demand Multiplanar Movement Task
Authors: Seeley Matthew K. , Son Seong Jun , Kim Hyunsoo , Ty Hopkins J.
Published: February 2021

Context: Patellofemoral pain (PFP) is often categorized by researchers and clinicians using subjective self-reported PFP characteristics; however, this practice might mask important differences in movement biomechanics between PFP patients. Objective: To determine whether biomechanical differences exist during a high-demand multiplanar movement task for PFP patients with similar self-reported PFP characteristics but different quadriceps activation levels. Design: Cross-sectional design. Setting: Biomechanics laboratory. Participants: A total of 15 quadriceps deficient and 15 quadriceps functional (QF) PFP patients with similar self-reported PFP characteristics. Intervention: In total, 5 trials of a high-demand multiplanar land, cut, and jump movement task were performed. Main Outcome Measures: Biomechanics were compared at each percentile of the ground contact phase of the movement task (α = .05) between the quadriceps deficient and QF groups. Biomechanical variables included (1) whole-body center of mass, trunk, hip, knee, and ankle kinematics; (2) hip, knee, and ankle kinetics; and (3) ground reaction forces. Results: The QF patients exhibited increased ground reaction force, joint torque, and movement, relative to the quadriceps deficient patients. The QF patients exhibited: (1) up to 90, 60, and 35 N more vertical, posterior, and medial ground reaction force at various times of the ground contact phase; (2) up to 4° more knee flexion during ground contact and up to 4° more plantarflexion and hip extension during the latter parts of ground contact; and (3) up to 26, 21, and 48 N·m more plantarflexion, knee extension, and hip extension torque, respectively, at various times of ground contact. Conclusions: PFP patients with similar self-reported PFP characteristics exhibit different movement biomechanics, and these differences depend upon quadriceps activation levels. These differences are important because movement biomechanics affect injury risk and athletic performance. In addition, these biomechanical differences indicate that different therapeutic interventions may be needed for PFP patients with similar self-reported PFP characteristics.
Concurrent Continuous Versus Bandwidth Visual Feedback With Varying Body Representation for the 2-Legged Squat Exercise
Authors: Sanford Sean , Liu Mingxiao , Nataraj Raviraj
Published: February 2021

Context: Continuous visual feedback (VF) can improve abilities to achieve desired movements and maximize rehabilitation outcomes by displaying actual versus target body positions in real time. Bandwidth VF reduces the reliance on feedback by displaying movement cues only when performance errors exceed specified thresholds. As such, bandwidth VF may better train independent movement abilities through greater development of intrinsic body control. In this study, continuous and bandwidth VF were investigated across modes of display (abstract and representative) that differed in body-discernibility. Objective: To compare the performance of the 2-legged squat during training with concurrent feedback (real-time VF) and short-term retention (immediately after training, VF removed). Design: Cross-sectional. Setting: University research laboratory. Participants: Eighteen healthy individuals. Methods: Marker-based motion capture displayed real-time position. Main Outcome Measures: Four VF cases (continuous–abstract, bandwidth–abstract, continuous–representative, and bandwidth–representative) were evaluated for accuracy and consistency to a target trajectory and target depth. Results: During training, both continuous VF cases showed significantly (P < .05) higher accuracy and consistency to the target trajectory compared with both bandwidth VF cases. Bandwidth VF resulted in greater potential learning (retention performance relative to a training baseline) compared with continuous–abstract. Conclusions: Continuous–representative may offer unique performance benefits in both training and retention of multisegment movement tasks. Bandwidth VF showed greater potential for learning. For long-term learning, an optimal VF paradigm should consider continuous–representative with bandwidth features.
Perspectives of Nigerian Athletes About Physiotherapy Services in Sports Injury Management: Implications for Rehabilitation
Authors: Odole Adesola C. , Agbomeji Olawale T. , Onyeso Ogochukwu K.K. , Ojo Joshua O. , Odunaiya Nse A.
Published: February 2021

Background: Athletes’ perceptions toward physiotherapy services have an impact on their general attitude toward these services and their willingness to work together with physiotherapists for rehabilitation. The study investigated athletes’ perspectives of physiotherapy services in sports injury management. Methods: A mixed-study design of a cross-sectional survey that involved 178 conveniently sampled athletes and an explanatory qualitative study (8 purposively-selected athletes) was used. The authors assessed the participants’ knowledge and perception of physiotherapy services using the modified versions of the Athletes’ Level of Knowledge Questionnaire, Matsuno Athletes Perception Scale, and focus group discussion. The data were analyzed using chi-square, Spearman correlation at P ≤ .05, and deductive reasoning thematic analysis. Results: The age of the participants for the cross-sectional survey (131 men and 47 women) was 22.50 (7.51) years. Our results showed that the majority (91.6%) of them had adequate knowledge and (78.7%) positive perception about the role physiotherapists play in sports injury management. The participants’ knowledge of physiotherapy services had a significantly positive correlation with age (ρ = .12; P = .01), sporting years (ρ = .17; P = .02), and duration in sports council (ρ = .19; P = .01), while their perception showed a negative correlation with age (ρ = −.15; P = .05), sporting years (ρ = −.16; P = .03), and duration in sports council (ρ = −.08; P = .02). However, no significant correlation existed between the participants’ knowledge; perception and level of education; level of competition; type of sport; and type, nature, and severity of sport injury. Seven themes were generated from the focus group discussion. Conclusion: The participants reported adequate knowledge and a positive perception of physiotherapy services. The correlates of participants’ knowledge and perception of physiotherapy services are age, sporting years, and duration in the sports council. From the qualitative component of the study, the authors identified the need to provide more physiotherapy services to athletes and more facilities for physiotherapy services.
Altered Central Pain Processing in Patients With Chronic Plantar Heel Pain: A Critically Appraised Topic
Authors: Jayaseelan Dhinu J. , Fernandez-de-las-Penas Cesar , Blattenberger Taylor , Bonneau Dean
Published: February 2021

Clinical Scenario: Plantar heel pain is a common condition frequently associated with persistent symptoms and functional limitations affecting both the athletic and nonathletic populations. Common interventions target impairments at the foot and ankle and local drivers of symptoms. If symptoms are predominantly perpetuated by alterations in central pain processing, addressing peripheral impairments alone may not be sufficient. Clinical Question: Do individuals with chronic plantar heel pain demonstrate signs potentially associated with altered central pain processing? Summary of Key Findings: After searching 6 electronic databases (PubMed, CINAHL, Scopus, SportDiscus, Cochrane, and PEDro) and filtering titles based on predetermined inclusion and exclusion criteria, 4 case-control studies were included. All studies scored highly on the Newcastle-Ottawa Scale for quality assessment. Using pressure pain thresholds, each study found decreased pressure pain hypersensitivity locally and at a remote site compared to control groups, suggesting the presence, to some extent, of altered nociceptive pain processing. Clinical Bottom Line: In the studies reviewed, reported results suggest a possible presence of centrally mediated symptoms in persons with plantar heel pain. However, despite findings from these studies, limitations in appropriate matching based on body mass index and measures used suggest additional investigation is warranted. Strength of Recommendation: According to the Oxford Centre for Evidence-Based Medicine, there is evidence level C to suggest chronic plantar heel pain is associated with alterations in central pain processing.
U.S. Physical Education Teacher Education Faculty Members’ Workplace Perceptions Across Gender and Institution Type
Authors: Richards K. Andrew R. , Graber Kim C. , Woods Amelia Mays , Ison Shelby E. , Killian Chad M.
Published: February 2021

Purpose: To examine the workplace experience of physical education teacher educators while accounting for gender and institution type. Method: Participants included 286 U.S. faculty members (151 females and 135 males). Data were collected using an online survey that included measures of negative (i.e., marginalization, isolation, role stress, emotional exhaustion) and positive (i.e., perceived mattering, perceived organizational support) workplace experiences. Primary analyses began with a multivariate analysis of covariance followed up by univariate analyses of covariance to examine the differences in study variables based on gender and institution type. Results: Doctoral institution faculty members reported higher marginalization and lower perceived mattering and organizational support. Female faculty members reported higher role overload and emotional exhaustion. Discussion: Results highlight differences in the faculty experience across institution types as well as gender disparities. Recommendations are provided for improving the faculty experience as well as for future research in the area.
Relaxed initiation pausing of ribosomes drives oncogenic translation
Authors: Dong Leiming , Mao Yuanhui , Zhou Aidong , Liu Xiao-Min , Zhou Jun , Wan Ji , Qian Shu-Bing
Published: February 2021

Ribosome pausing at start codons limits translational output, which is controlled by altered mRNA methylation in cancer cells.
Submilligram-scale separation of near-zigzag single-chirality carbon nanotubes by temperature controlling a binary surfactant system
Authors: Yang Dehua , Li Linhai , Wei Xiaojun , Wang Yanchun , Zhou Weiya , Kataura Hiromichi , Xie Sishen , Liu Huaping
Published: February 2021

Submilligram-scale separation of near-zigzag single-chirality carbon nanotubes has been achieved by gel chromatography.
Floquet maser
Authors: Jiang Min , Su Haowen , Wu Ze , Peng Xinhua , Budker Dmitry
Published: February 2021

We report on a (Floquet) maser that delivers promising performance for applications in applied and fundamental science.
3D microscopy and deep learning reveal the heterogeneity of crown-like structure microenvironments in intact adipose tissue
Authors: Geng Junlong , Zhang Xiaohui , Prabhu Suma , Shahoei Sayyed Hamed , Nelson Erik R. , Swanson Kelly S. , Anastasio Mark A. , Smith Andrew M.
Published: February 2021

3D microscopy and deep learning classify adipose tissue immune microenvironments associated with obesity comorbidities.
The chromatin remodeler ISWI acts during
Drosophila
development to regulate adult sleep
Authors: Gong Naihua N. , Dilley Leela Chakravarti , Williams Charlette E. , Moscato Emilia H. , Szuperak Milan , Wang Qin , Jensen Matthew , Girirajan Santhosh , Tan Tiong Yang , Deardorff Matthew A. , Li Dong , Song Yuanquan , Kayser Matthew S.
Published: February 2021

A neurodevelopmental disorder-associated gene, ISWI/SMARCA5, acts during development to coordinate sleep later in life.
Genomic profiling of native R loops with a DNA-RNA hybrid recognition sensor
Authors: Wang Kang , Wang Honghong , Li Conghui , Yin Zhinang , Xiao Ruijing , Li Qiuzi , Xiang Ying , Wang Wen , Huang Jian , Chen Liang , Fang Pingping , Liang Kaiwei
Published: February 2021

A DNA-RNA hybrid recognition sensor protein profiles native R loop structures in the genome.
The racial burden of voter list maintenance errors: Evidence from Wisconsin’s supplemental movers poll books
Authors: Huber Gregory A. , Meredith Marc , Morse Michael , Steele Katie
Published: February 2021

Removing individuals thought to have moved from voter rolls is more likely to yield errors for minority than white registrants.
Clinical Relevance of Topical Antibiotic Use in Coselecting for Multidrug-Resistant Staphylococcus aureus: Insights from
In Vitro
and
Ex Vivo
Models
Authors: Nong Yi , Taiaroa George , Pasricha Shivani , Guérillot Romain , Monk Ian R. , Baines Sarah L. , Carter Glen P. , Howden Benjamin P. , Williamson Deborah A.
Published: February 2021

Topical antibiotic preparations, such as fusidic acid (FA) or mupirocin, are used in the prevention and treatment of superficial skin infections caused by staphylococci. Previous genomic epidemiology work has suggested an association between the widespread use of topical antibiotics and the emergence of methicillin-resistant
Staphylococcus aureus
in some settings.
Draft Genome Sequences of Pelagimyophage Mosig EXVC030M and Pelagipodophage Lederberg EXVC029P, Isolated from Devil’s Hole, Bermuda
Authors: Buchholz Holger H. , Michelsen Michelle , Parsons Rachel J. , Bates Nicholas R. , Temperton Ben
Published: February 2021

We present the genomes of two isolated bacteriophages infecting
Pelagibacter ubique
HTCC1062.
Pelagibacter
phage Mosig EXVC030M (
Myoviridae
) and
Pelagibacter
phage Lederberg EXVC029P (
Podoviridae
) were isolated by dilution-to-extinction culturing from the oxygen minimum zone at Devil’s Hole (Harrington Sound, Bermuda).
Draft Genome Sequences of 113 Escherichia coli Strains Isolated from Intramammary Infections in Dairy Cattle
Authors: Jung Dongyun , Park Soyoun , Ruffini Janina , Dufour Simon , Ronholm Jennifer
Published: February 2021

Escherichia coli
is one of the most common etiological agents responsible for clinical bovine mastitis. Here, we report the draft genome sequences and annotations of 113
E. coli
strains that were isolated from Holstein cows with intramammary infections in Canada.
Supplemental Material: Calcium isotope composition of Morozovella over the late Paleocene–early Eocene
Authors: Kitch Gabriella , al. et
Published: February 2021

Extended methods including age model and statistical analysis details, and Figures S1–S10.
Prematurity and postnatal alterations in intermittent hypoxaemia
Authors: Di Fiore Juliann M , Shah Vidhi , Patwardhan Abhijit , Sattar Abdus , Wang Shengxuan , Raffay Thomas , Martin Richard J , Abu Jawdeh Elie G
Published: February 2021

Intermittent hypoxaemia (IH) events are well described in extremely preterm infants, but the occurrence of IH patterns in more mature preterm infants remains unclear. The objective of this study was to characterise the effect of gestational age on early postnatal patterns of IH in extremely (<28 weeks), very (28–<32 weeks) and moderately (32–<34 weeks) preterm infants. As expected, extremely preterm infants had a significantly higher frequency of IH events of longer durations and greater time with hypoxaemia versus very and moderately preterm infants. In addition, the postnatal decrease in IH duration was comparable in the very and moderately preterm infants. This progression of IH events should assist clinicians and families in managing expectations for resolution of IH events during early postnatal life.