bluuebunny/crossref_metadata_2025 huggingface dataset:
Double challenges: How working from home affects dual‐earner couples’ work‐family experiences
Authors: Hu Jia (Jasmine) , Chiang Jack Ting‐Ju , Liu Yihao , Wang Zheng , Gao Yating
Published: December 2022

Against the backdrop of COVID‐19 pandemic, we draw on family systems theory to elucidate how daily work‐from‐home status (WFH) affects both members in dual‐earner couples. We propose that the WFH exerts intra‐individual and inter‐individual influences on employees’ and their partners’ work task and family task completion and their subsequent reactions to their work and family experiences. We examined the hypothesized relationships with two daily survey studies on dual‐earner couples conducted during the pandemic (i.e., 1,559 daily responses of 165 dual‐earner couples from China in Study 1, and 773 daily responses of 57 dual‐earner couples from South Korea in Study 2). The two studies provide converging results that working from home (vs. office) increased employees’ family task completion for both husbands and wives and that wives working from home (vs. office) decreased husbands’ family task completion. Further, in both studies, daily work task completion increased felt guilt toward family (for wives only) through increased work‐family conflict, and daily family task completion increased psychological withdrawal from work through increased family‐work conflict for both husbands and wives. Moreover, we found in Study 2 that on days when husbands had flexible work schedule, wives completed more work tasks when working from home (vs. office) and that on days when wives had inflexible work arrangement, husbands completed more family tasks when working from home (vs. office). Across the two studies, there were no clear gender‐difference patterns in husbands’ and wives’ work and family experiences.
Product‐line pricing with dual objective of profit and consumer surplus
Authors: Huh Woonghee T. , Li Hongmin
Published: December 2022

In many settings, consumer surplus directly impacts a firm or organization's objective, and the profit‐only objective becomes inadequate. Our paper is the first to consider the dual objective of profit and consumer surplus in multi‐product pricing under the multinomial logit demand, where the prices are continuously set. We define a firm's marginal consumer surplus as its marginal contribution to the expected customer utility transformed into monetary unit. Although the profit is concave in the choice probability space, the marginal consumer surplus is convex, complicating the analysis. We identify the optimal monopoly pricing solution and develop solution approaches for the equilibrium solutions of both price‐competition and quantity‐competition oligopolies. In the monopolistic setting, we solve the optimal solution in a near‐closed‐form expression, and show that the firm's markup and profit decline as its emphasis for marginal consumer surplus increases and eventually drops to zero when the firm turns into a social welfare maximizer. Therefore, social welfare is maximized only when the monopolist is willing to endure zero profit. In competitive settings, if one firm's emphasis on marginal consumer surplus increases, then the improvement in marginal consumer surplus can magnify through competitive forces, reflected in reduced equilibrium prices for all firms. Moreover, we find that, while the overall marginal consumer surplus always increases with any firm's weight on marginal consumer surplus in its objective (referred to as the CS weight), a firm's marginal consumer surplus increases in its own CS weight but decreases in other firms' CS weight. Finally, we prove that, all else equal, a firm with a higher CS weight can earn a higher profit than its profit‐maximizing competitors, which is counterintuitive. In the quantity competition, a firm may even increase its absolute profit level by increasing its CS weight.
Sustainability outcomes of aquaculture eco‐certification: Challenges and opportunities
Authors: Rector Megan E. , Filgueira Ramon , Bailey Megan , Walker Tony R. , Grant Jon
Published: December 2022

Both the aquaculture industry and eco‐certification of aquaculture have grown significantly over the past 20 years, but the extent to which aquaculture eco‐certification is effective in creating positive environmental and societal outcomes is uncertain. Therefore, a scoping review of research on the effectiveness of eco‐certification in improving aquaculture sustainability outcomes, based on systematic search and inclusion criteria, was conducted. Challenges in producing sustainability outcomes through eco‐certification were identified, including (1) choosing which components of sustainability to reflect in eco‐certification criteria, (2) the risk of limiting improvements in sustainability by labelling a product ‘sustainable’, (3) accounting for different spatial scales of aquaculture effects, and (4) designing and applying sustainability criteria that work across different local environments. Potential approaches to these challenges include applying an ecosystem services framework to the identification of issues that could be addressed by eco‐certification criteria, supporting continuous improvement of industry best practices, incorporating criteria related to the far‐field effects of aquaculture, and recognising and accounting for the impact of local conditions on farming and eco‐certification. Although alternate governance approaches may be better suited to ensuring improved sustainability outcomes, potential improvements to eco‐certification criteria and processes are presented as opportunities to match the effectiveness of eco‐certification in creating positive sustainability outcomes to its success in creating a market for eco‐certified farmed seafood. However, some of these improvements may require the addition of criteria or complexity within the eco‐certification process, and their impact on market outcomes, particularly the participation of producers, should be considered.
Red Schools, Blue Schools? Republican and Democratic Student Groups at U.S. Colleges and Universities1
Authors: Coley Jonathan S. , McElroy Jericho R. , Schachle Jessica L.
Published: December 2022

How prevalent are Republican and Democratic student groups, and why are some schools home to Republican and Democratic student groups while other schools are not? Some commentators and scholars suggest that Republican student groups may be less prevalent than Democratic student groups and, when present, will likely be found at “red schools” (rather than “blue schools”) in Republican‐leaning areas of the country. However, other scholars argue that both Republican and Democratic student groups should be similar in their overall prevalence and located at a similar set of “engaged schools” (as opposed to “unengaged schools”). Analyzing our original database of Republican and Democratic student organizations across 1,953 four‐year, not‐for‐profit U.S. colleges and universities, we first show that Republican student groups are nearly as common as Democratic student groups: Republican student groups can be found at 39% of campuses, while Democratic student groups are present on 40% of campuses. Employing binary and multinomial logistic regression analyses, we then show that Republican and Democratic student groups tend to be located at the same types of schools, that is, larger, wealthier, public schools that offer political science majors. Our article holds significant implications for theorizing on student organization presence more generally.
BRXL4‐LAZY1 interaction at the plasma membrane controls Arabidopsis branch angle and gravitropism
Authors: Che Ximing , Splitt Bessie L. , Eckholm Magnus T. , Miller Nathan D. , Spalding Edgar P.
Published: December 2022

Gravitropism guides growth to shape plant architecture above and below ground. Mutations in LAZY1 impair stem gravitropism and cause less upright inflorescence branches (wider angles). The LAZY1 protein resides at the plasma membrane and in the nucleus. The plasma membrane pool is necessary and sufficient for setting branch angles. To investigate the molecular mechanism of LAZY1 function, we screened for LAZY1‐interacting proteins in yeast. We identified BRXL4, a shoot‐specific protein related to BREVIS RADIX. The BRXL4‐LAZY1 interaction occurred at the plasma membrane in plant cells, and not detectably in the nucleus. Mutations in the C‐terminus of LAZY1, but not other conserved regions, prevented the interaction. Opposite to lazy1, brxl4 mutants displayed faster gravitropism and more upright branches. Overexpressing BRXL4 produced strong lazy1 phenotypes. The apparent negative regulation of LAZY1 function is consistent with BRXL4 reducing LAZY1 expression or the amount of LAZY1 at the plasma membrane. Measurements indicated that both are true. LAZY1 mRNA was three‐fold more abundant in brxl4 mutants and almost undetectable in BRXL4 overexpressors. Plasma membrane LAZY1 was higher and nuclear LAZY1 lower in brxl4 mutants compared with the wild type. To explain these results, we suggest that BRXL4 reduces the amount of LAZY1 at the plasma membrane where it functions in gravity signaling and promotes LAZY1 accumulation in the nucleus where it reduces LAZY1 expression, possibly by suppressing its own transcription. This explanation of how BRXL4 negatively regulates LAZY1 suggests ways to modify shoot system architecture for practical purposes.
Animal research, ethical boundary‐work, and the geographies of veterinary expertise
Authors: Anderson Alistair , Hobson‐West Pru
Published: December 2022

The veterinary profession has been relatively understudied in social science, though recent work has highlighted the geographic dimensions of veterinary expertise. This paper draws on in‐depth qualitative interviews with Named Veterinary Surgeons (NVSs) working in UK animal research to demonstrate how and why they distinguish between ethical aspects of veterinary work in the spaces of the laboratory and general clinical practice. The paper mobilises the sociological concept of ethical boundary‐work to help understand how animal research – often assumed to represent a contentious ethical space – is constructed positively as a space for veterinary work. Findings suggest first, that NVSs differentiate between laboratory veterinary‐work and clinical work based on the scale at which veterinary expertise functions in the provision of healthcare to animals. Second, NVSs highlight a geography of veterinary authority in which veterinary expertise is felt to be more successfully applied in the laboratory compared with the clinic, where professional expertise competes with other sources of information and clients' finances and behaviours. Third, NVSs articulate a geography of consistency in which veterinary care in the laboratory is claimed to be more consistent between animals, as opposed to in the clinic, where animal experience may be influenced by individual owner characteristics. Overall, we show how through engaging in this kind of ethical boundary‐work NVSs are not only presenting a form of scientific practice as ‘ethical’, they are also constructing a professional topology of veterinary practice and expertise. Finally, the paper argues for greater attentiveness to veterinary geographies beyond the more routine spaces of veterinary practice.
The Application of Section 8 of Cybercrimes Act 19 of 2020 in Civil Procedure in South Africa is a Hailing Snow: A Comparative Studies between South Africa and United Kingdom
Authors: Queen Mabeka Nombulelo
Published: December 2022

In South Africa the legislature passed a statute that regulates cyber fraud that is called Cybercrimes Act 19 of 2020 in an attempt to combat cybercrimes, which include cyber fraud. The commission of cyber fraud in Civil Procedure constitutes a cause of action that enables the victim to claim for damages. It is not clear in terms of Cybercrimes Act whether the victim may institute proceedings whilst the matter is pending before the court in criminal proceedings or after the perpetrator is convicted. This raises a question on the application of the two common law principles that the defendant may raise as a special plea. Thus, res judicata and lis pendens may be raised as a special plea to prevent the victim of cyber fraud from receiving compensation for damages suffered. This prejudices the victims because some of the consequences that result from cyber fraud are dire to the victim. For example, the victim may loose money, property and may psychologically be affected as a result of cyber fraud. This article follows a qualitative research methodology that is based on an analysis in jurisprudence. Thus, the article looks at section 8 of the Cybercrimes Act, judicial precedent, as well as scholarly views shared by various authors to determine the gap. The author provides a solution, as well as recommendations that will ensure that the victims have a recourse in Civil Procedure. Moreover, there is evidence that proves that cyber fraud does exist in jurisdictions such as the United Kingdom. The article examines the legal position of cyber fraud in the United Kingdom and does a comparative studies between South Africa and the United Kingdom.
On Kitaoka's conjecture and lifting problem for universal quadratic forms
Authors: Kala Vítězslav , Yatsyna Pavlo
Published: December 2022

For a totally positive definite quadratic form over the ring of integers of a totally real number field , we show that there are only finitely many totally real field extensions of of a fixed degree over which the form is universal (namely, those that have a short basis in a suitable sense). Along the way we give a general construction of a universal form of rank bounded by , where is the degree of over and is its discriminant. Furthermore, for any fixed degree we prove (weak) Kitaoka's conjecture that there are only finitely many totally real number fields with a universal ternary quadratic form.
Decoupling Uniaxial Tensile Prestress and Waveguide Effects From Estimates of the Complex Shear Modulus in a Cylindrical Structure Using Transverse-Polarized Dynamic Elastography
Authors: Salehabadi Melika , Crutison Joseph , Klatt Dieter , Royston Thomas J.
Published: December 2022

Dynamic elastography, whether based on magnetic resonance, ultrasound, or optical modalities, attempts to reconstruct quantitative maps of the viscoelastic properties of biological tissue, properties altered by disease and injury, by noninvasively measuring mechanical wave motion in the tissue. Most reconstruction strategies that have been developed neglect boundary conditions, including quasi-static tensile or compressive loading resulting in a nonzero prestress. Significant prestress is inherent to the functional role of some biological tissues currently being studied using elastography, such as skeletal and cardiac muscle, arterial walls, and the cornea. In the present article a configuration, inspired by muscle elastography but generalizable to other applications, is analytically and experimentally studied. A hyperelastic polymer phantom cylinder is statically elongated in the axial direction while its response to transverse-polarized vibratory excitation is measured. We examine the interplay between uniaxial prestress and waveguide effects in this muscle-like tissue phantom using computational finite element simulations and magnetic resonance elastography measurements. Finite deformations caused by prestress coupled with waveguide effects lead to results that are predicted by a coordinate transformation approach that has been previously used to simplify reconstruction of anisotropic properties using elastography. Here, the approach estimates material viscoelastic properties that are independent of the nonhomogeneous prestress conditions without requiring advanced knowledge of those stress conditions.
Computational Fluid Dynamics Modeling of Gaseous Cavitation in Lubricating Vane Pumps: On Metering Grooves for Pressure Ripple Optimization
Authors: Stuppioni Umberto , Blum Alessandro , Suman Alessio , Pinelli Michele
Published: December 2022

This paper addresses the topic of balanced vane pump simulations for pressure ripple optimization by means of metering grooves at the leading edge of delivery ports. It presents a computational fluid dynamics case study based on a transient three-dimensional model developed using an up-to-date commercial software tool. Special attention is dedicated to gaseous cavitation and the impact of the related modeling choices on predictions. The effect of groove dimensions and interaction with the precompression features of the cam ring of the pump are addressed. Experimental data obtained using a dedicated test rig are presented for comparison with numerical results in terms of delivery pressure ripple and volumetric flowrate. A validation strategy based on tuning of the dynamic cavitation model adopted for simulations is proposed. The results demonstrate the critical importance of gas release modeling for the simulation of porting details in the case of significant aeration effects.
Large Eddy Simulation of Gasoline Sprays in a Lagrangian–Eulerian Framework Using the High-Order Spectral Element Method
Authors: Colmenares F. Juan D. , Ameen Muhsin M. , Patel Saumil S.
Published: December 2022

Predicting the spray evolution using simulations requires accurate modeling of the turbulent gas-phase flow field. In this study, the high-order spectral-element method (SEM), implemented in the code Nek5000, was used to provide highly resolved solutions to the turbulent flow field. Spray modeling capabilities were implemented into the Nek5000 code. The spray is modeled in a Lagrangian–Eulerian (LE) framework, where the liquid is represented by discrete parcels of droplets. The method for coupling liquid and gas in the context of SEM is described, which allows for very fine meshes to be used without affecting the stability of the solution. Large-eddy simulations (LES) of the eight-hole ECN Spray G gasoline injector were conducted. Numerical results are compared against experimental data for liquid penetration, droplet size and gas velocity. The morphology of the multiplume spray is compared against experimental data. The effect of different spray injection inputs is analyzed. It was found that using a plume direction of 33 deg and an injection cone angle of 30 deg produced the best results overall. This work shows the applicability of SEM for spray modeling applications, where use of a high-order flow solver can help us understand the multiplume spray aerodynamics and how it leads to plume collapse under certain conditions. Results also highlight the need for tuning spray input parameters in the LE framework, even when high-fidelity gas flow solutions are possible.
Machine Learning and Simulation Based Temperature Prediction on High-Performance Processors
Authors: Knox Carlton , Yuan Zihao , Coskun Ayse K.
Published: December 2022

Emerging thermal management policies for high-power processors often rely on the temperature readings from on-chip digital thermal sensors. However, thermal sensors may not accurately measure the maximum temperature on chip. This is because thermal hot spots are typically located near important CPU components, limiting the power and physical space available for thermal sensors. As a result, sensors usually need to be placed some distance away from the hot spots. Additionally, on-chip thermal sensors also operate within an error margin, which could under/over-estimate the temperature readings. Prior methods introduced machine learning algorithms for predicting chip temperatures trained with Infrared (IR) camera measurements of the physical chip to construct accurate on-chip thermal profiles. While such methods produce an accurate model, the thermal imaging setup is expensive, and it can be time-consuming to collect and process the temperature data for a physical chip. This paper proposes a simulation-based method of using a machine learning regression model to predict a chip’s full temperature map based solely on the current power usage, core utilization, and measured sensor temperatures. The proposed model is trained and evaluated based on data generated from performance, power, and thermal simulations for the Intel i7 6950× Extreme Edition processor. When running a set of realistic benchmarks, this model is able to accurately predict temperatures within a root mean squared error (RMSE) of less than 0.25°C. The proposed model’s accuracy is not affected by the placement of the thermal sensors, and the maximum error resulting from the placement of thermal sensors is less than 0.12° C. For a real-world application, the proposed model can be trained based on realistic simulation or measured temperature data, then be applied to predict a chip’s temperature map in real-time. Using actual temperature data measured from an IR camera is more accurate, but the IR camera setup itself is expensive. Using simulation data to train the machine learning model is low-cost and more practical than temperature prediction based on an expensive IR camera.
Multiphysics Co-Optimization Design and Analysis of a Double-Side-Cooled Silicon Carbide-Based Power Module
Authors: Feng Xuhui , Moreno Gilberto , Narumanchi Sreekant , Paret Paul
Published: December 2022

With the rapid growth of electric vehicles and hybrid electric vehicles, rigorous design targets in terms of cost, efficiency, and power density have been set for automotive power electronics. Novel power module and inverter technologies based on wide-bandgap semiconductors have been developed to meet these design targets. Compared with conventional cooling techniques, which are normally applied only on one side of the power module, a double-sided cooling approach enables higher power density and lower thermal resistance.

In this work, we develop a three-phase power module that is double-side cooled using dielectric fluid jet impingement. In each phase, four silicon carbide power semiconductors are bonded to copper busbars without electrical insulation layers. A finite element analysis (FEA) model is created for thermal and thermomechanical analysis. Based on the modeling results, we develop a design space to correlate input and output parameters to generate response surfaces. We then use a multi-objective genetic algorithm-based optimization method to minimize the maximum junction temperature and thermal stresses within the power module. The multiphysics co-optimization approach enables an efficient design process of power modules with greatly reduced computational cost, as compared to conventional processes that rely on exhaustive numerical simulations and iterations.
Predictive Cohesive Zone Modeling for Delamination at PCB-Potting Material Interfaces Under Four-Point Bend Loading With Sustained High-Temperature Exposure
Authors: Lall Pradeep , Pandurangan Aathi Raja Ram , Blecker Ken
Published: December 2022

Potting is one of the most effective techniques for safeguarding electronics assembly in challenging harsh conditions, including shock and vibration. Interconnect failures are often preceded by delamination at the PCB and epoxy interface. PCB-Epoxy interfaces have not been extensively researched for interfacial fracture resistance under high thermo-mechanical loading. In this study, bi-material PCB-epoxy samples are made and exposed to long-term high-temperature aging followed by monotonic four-point bend loading. The evolution of the interfacial integrity under sustained high-temperature exposure has been quantified. The study looks at five distinct types of potting materials with varying properties. The specimens are exposed to a high temperature of 100°C and 150°C for 30 days, 60 days, 90 days, 120 days, 180 days, 240 days, and 360 days. Steady-state strain energy release rate, mode-I (KI), and mode-II (KII) stress intensity factors are determined for the PCB-Epoxy interface. Cohesive zone parameters for each of the PCB-Epoxy interfaces have been determined and implemented into a predictive cohesive zone model (CZM). The PCB-Epoxy bi-material specimen has been modeled in ABAQUS with a cohesive zone at the interface and subjected to mode-I four-point bend loading. Damage is considered to occur at the interface where the cohesive zone has been modeled. For both pristine and aged tests, the damage accumulation is predicted using the interfacial fracture parameters from the experiment.
High Strain Rate Properties and Evolution of Plastic-Work for Doped Solder SAC-Q for Isothermal Aging Up to 240-Days at 100°C
Authors: Lall Pradeep , Mehta Vishal , Suhling Jeff , Blecker Ken
Published: December 2022

In automotive, aerospace, and defense applications – electronic parts can often be exposed to high strain loads during shocks, vibrations and drop-impact conditions. Electronic parts can often face extreme low and high temperatures ranging from −65°C to 200°C. Additionally, these electronic devices can be subjected to strain rates of 1 to 100 per second in a critical environment. Numerous doped solder alloys have emerged to mitigate the effects of sustained high-temperature operation. The mechanical properties of SAC-Q solder alloy, isothermally aged for prolonged durations and tested at extremely low to high operating temperatures, are not available. In this work, SAC-Q doped solder material is tested and studied for this study at a range of operating temperatures of −65°C to 200°C and at a strain rate up to 75 per second for up to 240 days (i.e. 8 months) of isothermal aging with a storage temperature of 100°C. For the extensive range of strain rates and surrounding test temperatures, stress-strain curves are established for the solder. The measured experimental results and data were fitted to the Anand viscoplasticity model. The Anand constants were calculated by estimating the stress-strain behavior measured for operating temperatures −65°C to 200°C for SAC-Q solder. FE analysis for drop/shock events for BGA package assembly with PCB has been carried out. Hysteresis stress-strain curves and plastic work density curves are generated for various aging conditions for SAC-Q solder ball joints.
Feasibility Demonstration of Server Chip Package With Direct-to-Chip Optical Transceivers
Authors: Li Shidong , Parikh Bakul , Savoy Chelsea , Kuchta Daniel , Jutras Guillaume , Bagheri Harry , Toy Hilton , Ross Joe , Akasofu Ken-Ichi , Kapfhammer Mark , Schultz Mark , Ostrander Steven , Wassick Thomas
Published: December 2022

Fiber optic interconnect provides unique advantage over to copper signaling including: 1) Optical links are more capable of transmitting high speed signals over a longer distance than copper cable. The latter usually requires high power for distant transmission. 2) Low power optic interface enables to lower the overall system power. 3) Higher input/output density can be achieved through optical fibers than copper wires.

Optical transceivers are typically designed for integration at printed circuit boards (PCB) level. However, driving signal from packaged processor chip, through processor interconnect and across PCB causes significant signal integrity challenges. Co-packaging solution with the optical transceiver integrated on processor module and with direct-to-substrate cabling enables high-speed signals by avoiding the PCB altogether. The challenge lies in adapting the optical transceiver for compatibility with the processor module structure, as well as the environmental exposures of both the processor module bond and assembly process and system application condition.

This paper focuses on the assembly, characterization, and reliability stress results of an array of optical transceivers co-packaged within single chip processor module. The co-package studied is a 76.5mm × 68.5mm flip chip packaging with 4 or 5 optical transceivers assembled on the chip carrier substrate. A chip package interaction (CPI) test chip was mounted on laminate along with the connectors using traditional bond and assembly (BA) processes and fixtures. This was followed by lidding with a Thermal Interface Material (TIM) between the test chip and copper heat spreader, and a separate TIM between optical transceivers and heat spreader, and an elastomer structural bond between the laminate and the heat spreader.

The co-packaged module was then tested, land grid array (LGA) socketed to a thermal card for power and signal connection. Examination of the thermal performance and structural integrity after 1000 cycles of deep thermal cycling (DTC), Shock and Vibration (S&V), Temperature and Humidity testing, and High Temperature Storage (HTS) will be discussed. Characterization and construction analysis of the package, and model and data comparison with traditional packages will be presented.
A thermodynamically consistent constitutive equation describing polymer disentanglement under flow
Authors: Dolata Benjamin E. , Olmsted Peter D.
Published: December 2022

We derive a thermodynamically consistent framework for incorporating entanglement dynamics into constitutive equations for flowing polymer melts. We use this to combine the convected constraint release (CCR) dynamics of Ianniruberto–Marriccui into a finitely extensible version of the Rolie–Poly model, and also include an anisotropic mobility as in the Giesekus model. The reversible dynamics are obtained from a free energy that describes both a finitely extensible conformation tensor and an ideal gas of entanglements along the chain. The dissipative dynamics give rise to coupled kinetic equations for the conformation tensor and entanglements, whose coupling terms describe shear-induced disentanglement. The relaxation dynamics of the conformation tensor follow the GLaMM and Rolie–Poly models, and account for reptation, retraction, and CCR. We propose that the relaxation time τν for entanglement recovery is proportional to the Rouse time τR which governs polymer stretch within the tube. This matches recent molecular dynamics simulations and corresponds to relaxing the entanglement number before the entire polymer anisotropy has relaxed on the longer reptation time τd. Our model suggests that claimed signatures of slow re-entanglement on the reptation time in step-strain experiments may be interpreted as arising from anisotropies in reptation dynamics.
Phosphate Loading Does not Improve 30-km Cycling Time-Trial Performance in Trained Cyclists
Authors: Pope Harry , Davis Max , Delgado-Charro M. Begona , Peacock Oliver J. , Gonzalez Javier , Betts James A.
Published: December 2022

Phosphate is integral to numerous metabolic processes, several of which strongly predict exercise performance (i.e., cardiac function, oxygen transport, and oxidative metabolism). Evidence regarding phosphate loading is limited and equivocal, at least partly because studies have examined sodium phosphate supplements of varied molar mass (e.g., mono/di/tribasic, dodecahydrate), thus delivering highly variable absolute quantities of phosphate. Within a randomized cross-over design and in a single-blind manner, 16 well-trained cyclists (age 38 ± 16 years, mass 74.3 ± 10.8 kg, training 340 ± 171 min/week; mean ± SD) ingested either 3.5 g/day of dibasic sodium phosphate (Na2HPO4: 24.7 mmol/day phosphate; 49.4 mmol/day sodium) or a sodium chloride placebo (NaCl: 49.4 mmol/day sodium and chloride) for 4 days prior to each of two 30-km time trials, separated by a washout interval of 14 days. There was no evidence of any ergogenic benefit associated with phosphate loading. Time to complete the 30-km time trial did not differ following ingestion of sodium phosphate and sodium chloride (3,059 ± 531 s vs. 2,995 ± 467 s). Accordingly, neither absolute mean power output (221 ± 48 W vs. 226 ± 48 W) nor relative mean power output (3.02 ± 0.78 W/kg vs. 3.08 ± 0.71 W/kg) differed meaningfully between the respective intervention and placebo conditions. Measures of cardiovascular strain and ratings of perceived exertion were very closely matched between treatments (i.e., average heart rate 161 ± 11 beats per minute vs. 159 ± 12 beats per minute; Δ2 beats per minute; and ratings of perceived exertion 18 [14–20] units vs. 17 [14–20] units). In conclusion, supplementing with relatively high absolute doses of phosphate (i.e., >10 mmol daily for 4 days) exerted no ergogenic effects on trained cyclists completing 30-km time trials.
A Cloth Facemask Causes No Major Respiratory or Cardiovascular Perturbations During Moderate to Heavy Exercise
Authors: Guardieiro Natália Mendes , Barreto Gabriel , Marticorena Felipe Miguel , Nunes Oliveira Tamires , de Oliveira Luana Farias , Pinto Ana Lucia de Sá , Prado Danilo Marcelo Leite do , Saunders Bryan , Gualano Bruno
Published: December 2022

Purpose: Investigate whether a cloth facemask could affect physiological and perceptual responses to exercise at distinct exercise intensities in untrained individuals. Methods: Healthy participants (n = 35; 17 men, age 30 [4] y, and 18 women, age 28 [5] y) underwent a progressive square wave test at 4 intensities: (1) 80% of ventilatory anaerobic threshold; (2) ventilatory anaerobic threshold; (3) respiratory compensation point; and (4) exercise peak (Peak) to exhaustion, 5-minute stages, with or without a triple-layered cloth facemask (Mask or No-Mask). Several physiological and perceptual measures were analyzed. Results: Mask reduced inspiratory capacity at all exercise intensities (P < .0001). Mask reduced respiratory frequency (P = .001) at Peak (−8.3 breaths·min−1; 95% confidence interval [CI], −5.8 to −10.8), respiratory compensation point (−6.9 breaths·min−1; 95% CI, −4.6 to −9.2), and ventilatory anaerobic threshold (−6.5 breaths·min−1; 95% CI, −4.1 to −8.8), but not at Baseline or 80% of ventilatory anaerobic threshold. Mask reduced tidal volume (P < .0001) only at respiratory compensation point (−0.5 L; 95% CI, −0.3 to −0.6) and Peak (−0.8 L; 95% CI, −0.6 to −0.9). Shallow breathing index was increased with Mask only at Peak (11.3; 95% CI, 7.5 to 15.1). Mask did not change HR, lactate, ratings of perceived exertion, blood pressure, or oxygen saturation. Conclusions: A cloth facemask reduced time to exhaustion but had no major impact on cardiorespiratory parameters and had a slight but clinically meaningless impact on respiratory variables at higher intensities. Moderate to heavy activity is safe and tolerable for healthy individuals while wearing a cloth facemask. ClinicalTrials.gov: NCT04887714.
Prospective Association Patterns for the Physical Activity Intensity Spectrum With Body Mass Index and Lower Body Muscle Strength in Norwegian Children Aged 3–9 Years
Authors: Aadland Eivind , Ylvisåker Einar , Johannessen Kjersti , Nilsen Ada Kristine Ofrim
Published: December 2022

Background: Limited evidence exists regarding prospective associations for physical activity (PA) and sedentary time (SED) with body mass index (BMI) and muscle strength in young children. We aimed to determine prospective associations for PA and SED with change in BMI and standing long jump over 2 and 4 years in children aged 3–5 years at baseline. Methods: A sample of 262 Norwegian children (50% girls) was followed from 2015 to 2017 and/or 2019. PA and SED (hip-worn ActiGraph GT3X+) were measured at baseline and BMI and standing long jump at baseline and at follow-ups. Multivariate pattern analysis was used to determine prospective associations between the triaxial PA intensity spectrum (0–99 to ≥15,000 counts per minute) and the change in outcomes. Results: We found significant prospective associations between the PA intensity spectrum and standing long jump at 2- (explained variance = 5.8%–7.7%) and 4-year (explained variance = 4.8%–5.6%) follow-ups. Associations were negative for SED and positive for all PA intensities. We found no associations between PA/SED and BMI. Conclusions: Our findings suggest that PA and SED can predict future lower body muscle strength but not BMI in early childhood.
Advocating for Implementation of the Global Action Plan on Physical Activity: Challenges and Support Requirements
Authors: Murphy Joey , Milton Karen , Mclaughlin Matthew , Shilton Trevor , McLoughlin Gabriella M. , Reece Lindsey J. , Mair Jacqueline L. , Direito Artur , Kariippanon Katharina E. , Mackenzie Kelly J. , Mavilidi Myrto F. , Shellington Erin M. , Kamada Masamitsu , Heron Leonie , Jauregui Edtna , Abdeta Chalchisa , Pina Ilaria , Pinto Ryan , Sutherland Rachel
Published: December 2022

Background: There is limited understanding of the challenges experienced and supports required to aid effective advocacy of the Global Action Plan on Physical Activity (GAPPA). The purpose of this study was to assess the challenges experienced and supports needed to advocate for the GAPPA across countries of different income levels. Methods: Stakeholders working in an area related to the promotion of physical activity were invited to complete an online survey. The survey assessed current awareness and engagement with the GAPPA, factors related to advocacy, and the perceived challenges and supports related to advocacy for implementation of the GAPPA. Closed questions were analyzed in SPSS, with a Pearson’s chi-square test used to assess differences between country income level. Open questions were analyzed using inductive thematic analysis. Results: Participants (n = 518) from 81 countries completed the survey. Significant differences were observed between country income level for awareness of the GAPPA and perceived country engagement with the GAPPA. Challenges related to advocacy included a lack of support and engagement, resources, priority, awareness, advocacy education and training, accessibility, and local application. Supports needed for future advocacy included guidance and support, cooperation and alliance, advocacy education and training, and advocacy resources. Conclusions: Although stakeholders from different country income levels experience similar advocacy challenges and required supports, how countries experience these can be distinct. This research has highlighted some specific ways in which those involved in the promotion of physical activity can be supported to scale up advocacy for the GAPPA. When implementing such supports, consideration of regional, geographic, and cultural barriers and opportunities is important to ensure they are effective and equitable.
Ableism in Kinesiology in Higher Education: A Conversation Starter
Authors: Arroyo-Rojas Fabián , Simpson A. Chloe , Laxton Paige , Leake Marie , Linker Jamie , Haegele Justin A.
Published: December 2022

In this expository paper, we reflect upon our understanding of how disabled people are discussed and treated in kinesiology and adapted physical activity in higher education and explore potential areas of unintentional harm that may be present in our everyday practice. There are three particular aspects of kinesiology in higher education that we discuss: access, language, and assessment. We discuss the challenges of access of disabled people in positions in higher education, language in higher education which serves as centers for knowledge creation, and the problematic nature of assessments based on societal norms, and for us, it is important to shine a spotlight on the many systemic limitations and barriers that disabled persons experience, in hope to amplify the importance of these issues.
Growth mechanism of carbon nanotubes from Co-W-C alloy catalyst revealed by atmospheric environmental transmission electron microscopy
Authors: Wang Yang , Qiu Lu , Zhang Lili , Tang Dai-Ming , Ma Ruixue , Ren Cui-Lan , Ding Feng , Liu Chang , Cheng Hui-Ming
Published: December 2022

High–melting point alloy catalysts have been reported to be effective for the structure-controlled growth of single-wall carbon nanotubes (SWCNTs). However, some fundamental issues remain unclear because of the complex catalytic growth environment. Here, we directly investigated the active catalytic phase of Co-W-C alloy catalyst, the growth kinetics of CNTs, and their interfacial dynamics using closed-cell environmental transmission electron microscopy at atmospheric pressure. The alloy catalyst was precisely identified as a cubic η-carbide phase that remained unchanged during the whole CNT growth process. Rotations of the catalyst nanoparticles during CNT growth were observed, implying a weak interfacial interaction and undefined orientation dependence for the solid catalyst. Theoretical calculations suggested that the growth kinetics are determined by the diffusion of carbon atoms on the surface of the η-carbide catalyst and through the interface of the catalyst-CNT wall.
Autonomous self-healing optical sensors for damage intelligent soft-bodied systems
Authors: Bai Hedan , Kim Young Seong , Shepherd Robert F.
Published: December 2022

We introduce damage intelligent soft-bodied systems via a network of self-healing light guides for dynamic sensing (SHeaLDS). Exploiting the intrinsic damage resilience of light propagation in an optical waveguide, in combination with a tough, transparent, and autonomously self-healing polyurethane urea elastomer, SHeaLDS enables damage resilient and intelligent robots by self-healing cuts as well as detecting this damage and controlling the robot’s actions accordingly. With optimized material and structural design for hyperelastic deformation of the robot and autonomous self-healing capacity, SHeaLDS provides reliable dynamic sensing at large strains (ε = 140%) with no drift or hysteresis, is resistant to punctures, and self-heals from cuts at room temperature with no external intervention. As a demonstration of utility, a soft quadruped protected by SHeaLDS detects and self-heals from extreme damage (e.g., six cuts on one leg) in 1 min and monitors and adapts its gait based on the damage condition autonomously through feedback control.
Indigenous fire management and cross-scale fire-climate relationships in the Southwest United States from 1500 to 1900 CE
Authors: Roos Christopher I. , Guiterman Christopher H. , Margolis Ellis Q. , Swetnam Thomas W. , Laluk Nicholas C. , Thompson Kerry F. , Toya Chris , Farris Calvin A. , Fulé Peter Z. , Iniguez Jose M. , Kaib J. Mark , O’Connor Christopher D. , Whitehair Lionel
Published: December 2022

Prior research suggests that Indigenous fire management buffers climate influences on wildfires, but it is unclear whether these benefits accrue across geographic scales. We use a network of 4824 fire-scarred trees in Southwest United States dry forests to analyze up to 400 years of fire-climate relationships at local, landscape, and regional scales for traditional territories of three different Indigenous cultures. Comparison of fire-year and prior climate conditions for periods of intensive cultural use and less-intensive use indicates that Indigenous fire management weakened fire-climate relationships at local and landscape scales. This effect did not scale up across the entire region because land use was spatially and temporally heterogeneous at that scale. Restoring or emulating Indigenous fire practices could buffer climate impacts at local scales but would need to be repeatedly implemented at broad scales for broader regional benefits.
Symbioses are restructured by repeated mass coral bleaching
Authors: Quigley Kate M. , Ramsby Blake , Laffy Patrick , Harris Jessica , Mocellin Veronique J. L. , Bay Line K.
Published: December 2022

Survival of symbiotic reef-building corals under global warming requires rapid acclimation or adaptation. The impact of accumulated heat stress was compared across 1643 symbiont communities before and after the 2016 mass bleaching in three coral species and free-living in the environment across ~900 kilometers of the Great Barrier Reef. Resilient reefs (less aerial bleaching than predicted from high satellite sea temperatures) showed low variation in symbioses. Before 2016, heat-tolerant environmental symbionts were common in ~98% of samples and moderately abundant (9 to 40% in samples). In corals, heat-tolerant symbionts were at low abundances (0 to 7.3%) but only in a minority (13 to 27%) of colonies. Following bleaching, environmental diversity doubled (including heat-tolerant symbionts) and increased in one coral species. Communities were dynamic (
Acropora millepora
) and conserved (
Acropora hyacinthus
and
Acropora tenuis
), including symbiont community turnover and redistribution. Symbiotic restructuring after bleaching occurs but is a taxon-specific ecological opportunity.
Indoor photovoltaics awaken the world’s first solar cells
Authors: Yan Bin , Liu Xinsheng , Lu Wenbo , Feng Mingjie , Yan Hui-Juan , Li Zongbao , Liu Shunchang , Wang Cong , Hu Jin-Song , Xue Ding-Jiang
Published: December 2022

Selenium (Se) solar cells were the world’s first solid-state photovoltaics reported in 1883, opening the modern photovoltaics. However, its wide bandgap (~1.9 eV) limits sunlight harvesting. Here, we revisit the world’s oldest but long-ignored photovoltaic material with the emergence of indoor photovoltaics (IPVs); the absorption spectrum of Se perfectly matches the emission spectra of commonly used indoor light sources in the 400 to 700 nm range. We find that the widely used Te adhesion layer also passivates defects at the nonbonded Se/TiO
2
interface. By optimizing the Te coverage from 6.9 to 70.4%, the resulting Se cells exhibit an efficiency of 15.1% under 1000 lux indoor illumination and show no efficiency loss after 1000 hours of continuous indoor illumination without encapsulation, outperforming the present IPV industry standard of amorphous silicon cells in both efficiency and stability. We further fabricate Se modules (6.75 cm
2
) that produce 232.6 μW output power under indoor illumination, powering a radio-frequency identification–based localization tag.
Confinement, chaotic transport, and trapping of active swimmers in time-periodic flows
Authors: Qin Boyang , Arratia Paulo E.
Published: December 2022

Microorganisms encounter complex unsteady flows, including algal blooms in marine settings, microbial infections in airways, and bioreactors for vaccine and biofuel production. Here, we study the transport of active swimmers in two-dimensional time-periodic flows using Langevin simulations and experiments with swimming bacteria. We find that long-term swimmer transport is controlled by two parameters, the pathlength of the unsteady flow and the normalized swimmer speed. The pathlength nonmonotonically controls swimmer dispersion dynamics, giving rise to three distinct dispersion regimes. Weak flows hinder swimmer transport by confining cells toward flow manifolds. As pathlength increases, chaotic transport along flow manifolds initiates, maximizing the number of unique flow cells traveled. Last, strong flows trap swimmers at the vortex core, suppressing dispersal. Experiments with
Vibrio cholerae
showed qualitative agreement with model dispersion patterns. Our results reveal that nontrivial chaotic transport can arise in simple unsteady flows and suggest a potentially optimal dispersal strategy for microswimmers in nature.
Nonproductive Hepatitis B Virus Covalently Closed Circular DNA Generates HBx-Related Transcripts from the HBx/Enhancer I Region and Acquires Reactivation by Superinfection in Single Cells
Authors: Peng Bo , Jing Zhiyi , Zhou Zhongmin , Sun Yinyan , Guo Guilan , Tan Zexi , Diao Yan , Yao Qiyan , Ping Yi , Li Xuelei , Ren Tengfei , Li Bin , Li Wenhui
Published: December 2022

Hepatitis B virus (HBV) infection can be effectively suppressed but rarely cured by available drugs. Chronic HBV infection is based on persistence of covalently closed circular DNA (cccDNA) and continuous infection and reinfection with HBV in the liver.
Defining the Benefits of Antibiotic Resistance in Commensals and the Scope for Resistance Optimization
Authors: Wollein Waldetoft Kristofer , Sundius Sarah , Kuske Rachel , Brown Sam P.
Published: December 2022

Antibiotic resistance is commonly viewed as universally costly, regardless of which bacterial cells express resistance. Here, we derive an opposing logic, where resistance in commensal bacteria can lead to reductions in pathogen density and improved outcomes on both the patient and public health scales.