bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discerning excellence from mediocrity in swimming: New insights using Bayesian quantile regression
Authors: Myers Tony D. , Negra Yassine , Sammoud Senda , Chaabene Helmi , Nevill Alan M. 
Published: August 2020

AbstractPurpose: Previous research has captured point estimates for population means of somatic variables associated with swimming speed across strokes, but have not determined if predictors of swimming speed operate the same at the upper tails of the distribution (τ = 0.9) as they do at the median levels (τ = 0.5) and lower levels (τ = 0.1). Method: Three hundred sixty‐three competitive‐level swimmers (male [n = 202]; female [n = 161]) participated in the study. To identify key somatic variables associated with 100‐m swimming across and between strokes controlling for age, we used a Bayesian allometric quantile regression model, refined using Bayes Factors and Leave‐one‐out cross validation. Results: High probabilities (>99%) were found for arm‐span, seated‐height and shoulder‐breadth being the strongest somatic predictors across strokes. For individual strokes, Bayesian quantile regression demonstrated that the relative importance of predictors differs across quantiles. For swimmers in the 0.9 quartile, shoulder‐breadth is a more important than height for front‐crawl, wide shoulders are important for breaststroke swimmers but can be detrimental when combined with narrow hips, seated‐height and hip‐width are important for backstroke swimming speed, and calf girth for butterfly. Conclusion: These results highlight the importance of considering key somatic variables for talent identification in swimming and ensure young swimmers focus on strokes compatible with their somatic structure. The most important new insight is that predictors differ for the best swimmers compared to average or poorer swimmers. This has implications beyond swimming, pointing to the importance of considering the upper tails of distributions in performance and talent identification contexts.
NiTi shape memory alloy cellular meshes: manufacturing by investment casting and characterization
Authors: Montenegro E O S , Grassi E N D , Simões J B , Sales da Silva P C , de Araújo C J 
Published: August 2020

Abstract
Recent studies have shown that conventional meshes comprising pure titanium and its alloys can be used to assist the recovery of bone fractures in various parts of the human body, such as the face, jaw, skull and knee. In anticipation of an improved efficiency for these applications and other applications, this work analyses the thermomechanical behaviour of a type of metallic mesh that is fabricated with NiTi shape memory alloys (SMAs), which are smart metals that exhibit functional properties, such as the shape memory effect (SME) and superelasticity (SE). The development of NiTi SMA meshes with different cell designs, good mechanical strength and recoverable deformation to replace titanium meshes and enhance biomedical applications (as well as applications in other fields) can be considered a current technological challenge. In this framework, this study aims to perform the fabrication and mechanical characterization of NiTi SMA meshes produced by investment casting with three different cell geometries (circular, hexagonal and square) in two states (as cast and heat treated). The obtained results show that the manufactured meshes present functional properties even in the as-cast state, as thermoelastic phase transformation and deformation recovery on the order of 6% is demonstrated. The results show that between the heat treatment and mesh cell geometry, the latter factor is the most influential factor in the mechanical behaviour of the meshes. A brief numerical simulation of the tensile behaviour of the meshes is used to deepen the analysis of the influence of cell geometry on their mechanical behaviour. Overall, as-cast meshes with circular and square cells present a high stiffness under tension and bending. The produced meshes show enough thermomechanical features to enhance biomedical applications. These results support the replacement of conventional titanium alloys, which do not possess functional properties, with NiTi SMAs.
A low-power, jamming, magnetorheological valve using electropermanent magnets suitable for distributed control in soft robots
Authors: Leps T , Glick P E , Ruffatto III D , Parness A , Tolley M T , Hartzell C 
Published: August 2020

Abstract
Magnetorheological (MR) valves are an attractive way to make reliable valves with no moving parts. MR fluid valves operate by powering an electromagnet positioned near a constriction through which MR fluid is flowing. However, these valves are high-power devices, consuming on the order of watts of power while closed, and the electromagnets and flow paths are relatively bulky. Due to their power draw and size, they are unsuitable for many miniaturized and portable applications which would otherwise benefit from a solid state valve. In this paper, we introduce a low power, jamming MR valve that makes use of an electropermanent magnet, which can provide either a strong magnetic field or no field, with no continuous power draw and no moving parts. The resulting valve has overall dimensions of 4× 4×6mm, a mass of 0.476g, material costs of $7.32 per valve USD at quantity 100, holds over 415 kPa of pressure, and leaks only 0.02g of fluid over a 24h period when held at 105 kPa. These valves are well suited for use in soft robots, e.g. robots composed of stretchable elastomers and may allow for increased degrees of freedom in soft robotic designs. We discuss the design considerations for making MR valves, study the effect of different fluids and valve sizes, develop a numerical framework for simulation and further valve design, and demonstrate the use of a MR valve to control the actuation of a soft robotic appendage.
Trade-off between filtering and symmetry breaking mean-field coupling in inducing macroscopic dynamical states
Authors: Singh Uday , Sathiyadevi K , Chandrasekar V K , Zou W , Kurths J , Senthilkumar D V 
Published: August 2020

Abstract
We study the manifestation of the competing interaction between the mean-field intensity and the symmetry breaking coupling on the phenomenon of aging transition in an ensemble of limit-cycle oscillators comprising of active and inactive oscillators. Further, we also introduce filtering in both the intrinsic and extrinsic variables of the mean-field diffusive coupling to investigate the counter-intuitive effect of both filterings. We find that large values of the mean-field intensity near unity favor the oscillatory nature of the ensemble, whereas low values favor the onset of the aging transition and heterogeneous dynamical states such as cluster oscillation death and chimera death states even at low values of the symmetry breaking coupling strength. Heterogeneous dynamical states predominates at large values of the coupling strength in all available parameter spaces. We also uncover that even a weak intrinsic filtering favors the aging transition and heterogeneous dynamical states, while a feeble extrinsic filtering favors the oscillatory state. Chimera death state is observed among the active oscillators for the first time in the aging literature. Our results can lead to engineering the dynamical states as desired by an appropriate choice of the control parameters. Further, the transition from the oscillatory to the aging state occurs via an inverse Hopf bifurcation, while the transition from the aging state to the cluster oscillation death states emerges through a supercritical pitch-fork bifurcation. The deduced analytical bifurcation curves are in good agreement with the numerical boundaries of the observed dynamical states.
Resolidification-controlled melt dynamics under fast transient tokamak plasma loads
Authors: Ratynskaia S. , Thorén E. , Tolias P. , Pitts R. A. , Krieger K. , Vignitchouk L. , Iglesias D. 
Published: August 2020

Abstract
Studies of macroscopic melt motion induced by fast transient power loads and the ensuing damage to plasma-facing components are critical for ITER. Based on state-of-the-art experiments, heat transfer is argued to be strongly entangled with fluid dynamics. The physics model of the MEMOS-U code is introduced. Simulations are reported of recent tokamak experiments concerning deliberate transient melting of beryllium main chamber tiles (JET) and tungsten divertor components (ASDEX Upgrade, JET). MEMOS-U is demonstrated to capture the main physics responsible for melt dynamics and to reproduce the observed surface deformation. The intricate role of resolidification is elucidated.
Future climate impacts on global agricultural yields over the 21st century
Authors: Waldhoff Stephanie T , Wing Ian Sue , Edmonds James , Leng Guoyong , Zhang Xuesong 
Published: August 2020

Abstract
Analyses of the future impacts of changing crop yields on agricultural production, prices, food security, and GDP growth using Integrated Assessment models require country-level yield shocks due to changing weather conditions, for a wide range of crops and warming scenarios. We characterize impacts of different climate futures on crop yields for individual countries and years. We use historical crop yield and weather data to empirically estimate annual crop yield responses to temperature and precipitation, constructing reduced-form statistical models that are then coupled with earth system model outputs for the same variables to project future yields. Our main result is a panel of annual shocks to yields of 12 crops (cassava, cotton, maize, potatoes, rice, sorghum, soybean, sugar beet, sugarcane, sunflower, and winter and spring wheat) for 58–136 countries, depending on the crop, through 2099, under moderate and vigorous warming scenarios. We find that global yield impacts by century’s end (2086–2095) are − 2%, − 19%, − 14%, and − 1%, without the CO2 fertilization effect (CFE), for maize, rice, soybean, and wheat, respectively, with similar global values with CFE. However, the global and decadal averages mask regional and year-to-year differences that may have large economic consequences, which IAMs could more fully address by representing agricultural yield impacts through the parameters supplied by our study.
Molten pool structure, temperature and velocity flow in selective laser melting AlCu5MnCdVA alloy
Authors: Lu Pan , Cheng-Lin Zhang , Liang Wang , Tong Liu , Jiang-lin Liu 
Published: August 2020

Abstract
Selective Laser Melting (SLM) has become one of the most promising technologies in Metal Additive Manufacturing (MAM), which is a complex dynamic non-equilibrium process involving heat transfer, melting, phase transition, vaporization and mass transfer. The characteristics of the molten pool (structure, temperature flow and velocity flow) have a decisive influence on the final forming quality of SLM. In this study, both numerical simulation and experiments were employed to study molten pool structure, temperature flow and velocity field in Selective Laser Melting AlCu5MnCdVA alloy. The results showed the structure of molten pool showed different forms (deep-concave structure, double-concave structure, plane structure, protruding structure and ideal planar structure), and the size of the molten pool was approximately 132 μm × 107 μm × 50 μm: in the early stage, molten pool was in a state of deep-concave shape with a depth of 15 μm due to multiple driving forces, while a protruding shape with a height of 10 μm duo to tension gradient in the later stages of forming. The metal flow inside the molten pool was mainly driven by laser impact force, metal liquid gravity, surface tension and recoil pressure. For AlCu5MnCdVA alloy, metal liquid solidification speed was extremely fast (3.5 × 10−4 S), the heating rate and cooling rate reached 6.5 × 107 K S−1 and 1.6 × 106 K S−1, respectively. Choosing surface roughness as a visual standard, low-laser energy AlCu5MnCdVA alloy optimum process parameters window was obtained by numerical simulation: laser power 250 W, hatching space 0.11 mm, layer thickness 0.03 mm, laser scanning velocity 1.5 m s−1. In addition, compared with experimental printing and numerical simulation, the width of the molten pool was about 205 um and about 210 um, respectively, and overlapping between two adjacent molten tracks was all about 65 um. The results showed that the numerical simulation results were basically consistent with the experimental print results, which proved the correctness of the numerical simulation model.
Measuring Precarious Employment: Type of Contract Can Lead to Serious Misclassification Error
Authors: Vives Alejandra , Gonzalez Lopez Francisca , Benach Joan 
Published: August 2020

Abstract
This study aims to assess the accuracy of temporary employment as indicator or proxy measure of precarious employment. Using sensitivity and specificity analysis, we compared type of contract (temporary versus permanent) with the Chilean version of the multidimensional Employment Precariousness Scale. Temporary employment exhibited very low sensitivity (&lt;30%) (specificity &gt;90%), resulting in roughly 38% of false negative results. Different EPRES-Ch cut-off scores produced similar results. The main implication of these findings is that the public health relevance of precarious employment is being underestimated both in terms of prevalence and of its association with health, making it critical that valid multidimensional measures of precarious employment be implemented.
Peripheral action of kisspeptin at reproductive tissues—role in ovarian function and embryo implantation and relevance to assisted reproductive technology in livestock: a review
Authors: D’Occhio Michael J , Campanile Giuseppe , Baruselli Pietro S 
Published: August 2020

AbstractKisspeptin (KISS1) is encoded by the KISS1 gene and was initially found to be a repressor of metastasis. Natural mutations in the KISS1 receptor gene (KISS1R) were subsequently shown to be associated with idiopathic hypothalamic hypogonadism and impaired puberty. This led to interest in the role of KISS1 in reproduction. It was established that KISS1 had a fundamental role in the control of gonadotropin releasing hormone (GnRH) secretion. KISS1 neurons have receptors for leptin and estrogen receptor α (ERα), which places KISS1 at the gateway of metabolic (leptin) and gonadal (ERα) regulation of GnRH secretion. More recently, KISS1 has been shown to act at peripheral reproductive tissues. KISS1 and KISS1R genes are expressed in follicles (granulosa, theca, oocyte), trophoblast, and uterus. KISS1 and KISS1R proteins are found in the same tissues. KISS1 appears to have autocrine and paracrine actions in follicle and oocyte maturation, trophoblast development, and implantation and placentation. In some studies, KISS1 was beneficial to in vitro oocyte maturation and blastocyst development. The next phase of KISS1 research will explore potential benefits on embryo survival and pregnancy. This will likely involve longer-term KISS1 treatments during proestrus, early embryo development, trophoblast attachment, and implantation and pregnancy. A deeper understanding of the direct action of KISS1 at reproductive tissues could help to achieve the next step change in embryo survival and improvement in the efficiency of assisted reproductive technology.
Powassan Virus Encephalitis Following Brief Attachment of Connecticut Deer Ticks
Authors: Feder Henry M , Telford Sam , Goethert Heidi K , Wormser Gary P 
Published: August 2020

AbstractBackgroundPowassan virus (POWV) is a tick-transmitted pathogen that may cause severe encephalitis; experimentally, it can be transmitted within just 15 minutes following a tick bite. The deer tick virus subtype of POWV (DTV) is transmitted by the deer tick and is the likely cause of the increase in the number of POWV cases reported in the United States. However, DTV has only been definitively documented in 6 patients by molecular analysis of the virus.MethodsTwo patients from Connecticut with encephalitis, who had a recent deer tick bite, were evaluated by the relevant serologic tests to determine if they had been infected with POWV. Evaluation also included molecular testing of an adult deer tick that had been removed from one of the patients.ResultsWe documented neuroinvasive POWV infection in 2 children from Connecticut. Based on the results of testing the tick removed from case 2, this patient was infected by DTV, representing the 7th reported case and the first documented case of DTV infection in a child. Of note, the duration of the tick bites in both cases was very short.ConclusionsWe provide the first clinical and epidemiologic evidence that POWV/DTV can be rapidly transmitted to a human host, that is, within hours of tick attachment, which is distinctive when compared to other deer tick-transmitted infections such as Lyme disease.
Significantly Lower Case-fatality Ratio of Coronavirus Disease 2019 (COVID-19) than Severe Acute Respiratory Syndrome (SARS) in Hong Kong—A Territory-Wide Cohort Study
Authors: Lui Grace Chung-Yan , Yip Terry Cheuk-Fung , Wong Vincent Wai-Sun , Chow Viola Chi-Ying , Ho Tracy Hang-Yee , Li Timothy Chun-Man , Tse Yee-Kit , Chan Henry Lik-Yuen , Hui David Shu-Cheong , Wong Grace Lai-Hung 
Published: August 2020

Abstract

Background
The case-fatality ratios (CFR) of coronavirus disease 2019 (COVID-19) and severe acute respiratory syndrome (SARS) appeared to differ substantially. We aimed to compare the CFR and its predictors of COVID-19 and SARS patients using a territory-wide cohort in Hong Kong.

Methods
This was a territory-wide retrospective cohort study using data captured from all public hospitals in Hong Kong. Laboratory-confirmed COVID-19 and SARS patients were identified. The primary endpoint was a composite endpoint of intensive care unit admission, use of mechanical ventilation, and/or death.

Results
We identified 1013 COVID-19 patients (mean age, 38.4 years; 53.9% male) diagnosed from 23 January to 14 April 2020 and 1670 SARS patients (mean age, 44.4 years; 44.0% male) from March to June 2003. Fifty-five (5.4%) COVID-19 patients and 432 (25.9%) SARS patients had reached the primary endpoint in 30 days. By 30 June 2003, 286 SARS patients had died (CFR, 17.1%). By 7 June 2020, 4 COVID-19 patients had died (CFR, 0.4%). After adjusting for demographic and clinical parameters, COVID-19 was associated with a 71% lower risk of primary endpoint compared with SARS (adjusted hazard ratio, 0.29; 95% confidence interval, .21–.40; P &lt; .0001). Age, diabetes mellitus, and laboratory parameters (high lactate dehydrogenase, high C-reactive protein, and low platelet count) were independent predictors of the primary endpoint in COVID-19 patients, whereas use of antiviral treatments was not associated with primary endpoint.

Conclusions
The CFR of COVID-19 was 0.4%. Age and diabetes were associated with worse outcomes, whereas antiviral treatments were not.
Fake News is Not a Virus: On Platforms and Their Effects
Authors: Anderson C W 
Published: August 2020

Abstract
This article attempts to uncover the intellectual, economic, and methodological structures that have led to the recent emergence of a particular notion of digital communication on social media platforms, one that emphasizes the power of (false) media messages to cause irrational political behavior and combines individual level understanding of media effects with a networked notion of society and information diffusion. After pointing out some of the real political-economic forces at work in setting the contours of this intellectual turn, I discuss how spaces between mutually constructed but overlapping paradigmatic understandings of media behavior lead to theories that serve as boundary objects, linking (and misunderstanding) older fields in order to advance new agendas. I then turn to the consequences of particular methodological choices, drawing on key works in Science and Technology Studies (STS) to make the point that these methodological choices not only establish scientific fields, they construct certain types of human subjects as well. The article concludes with a call for a more humanistic and interpretive approach to the understanding of political behavior and communication.
Evaluating and engineering Saccharomyces cerevisiae promoters for increased amylase expression and bioethanol production from raw starch
Authors: Myburgh Marthinus W , Rose Shaunita H , Viljoen-Bloom Marinda 
Published: August 2020

ABSTRACT
Bioethanol production from starchy biomass via consolidated bioprocessing (CBP) will benefit from amylolytic Saccharomyces cerevisiae strains that produce high levels of recombinant amylases. This could be achieved by using strong promoters and modification thereof to improve gene expression under industrial conditions. This study evaluated eight endogenous S. cerevisiae promoters for the expression of a starch-hydrolysing α-amylase gene. A total of six of the native promoters were modified to contain a promoter-proximal intron directly downstream of the full-length promoter. Varying results were obtained; four native promoters outperformed the ENO1P benchmark under aerobic conditions and two promoters showed better expression under simulated CBP conditions. The addition of the RPS25A intron significantly improved the expression from most promoters, displaying increased transcript levels, protein concentrations and amylase activities. Raw starch-utilising strains were constructed through co-expression of selected α-amylase cassettes and a glucoamylase gene. The amylolytic strains displayed improved fermentation vigour on raw corn starch and broken rice, reaching 97% of the theoretical ethanol yield and converting 100% of the available carbon to products within 120 h in small-scale CBP fermentations on broken rice. This study showed that enhanced amylolytic strains for the conversion of raw starch to ethanol can be achieved through turnkey promoter selection and/or engineering.
Making effective referrals happen: a theory-informed policy analysis
Authors: Kane Sumit , Jiang Hong , Tian Yuan , Mukhopadhyay Maitrayee , Qian Xu 
Published: August 2020

Abstract
Effective referral is a critical element of a well-functioning health system. While having a good referral policy in place is important, equally important is its effective implementation. Using the implementation of a policy on referral of obstetric emergencies in Shanghai as a case, we illustrate the application of the ‘Inhabited Institutions’ analytical approach for studying policy implementation. In doing so, our study highlights how ‘referral’ is a quintessential systems process embedded in institutional, social and historical contexts. We show that multiple institutional logics, in the form of explicit and tacit organizing principles and assumptions, intersect to influence and shape actors’ actions, sometimes with good outcomes and sometimes with poor outcomes. We reveal the embedded agency of frontline healthcare managers and providers across different levels of care. We show how frontline managers and providers, operating under conditions of uncertainties and ambiguities in organizational processes, actively draw upon their experience and network capital to creatively adapt to get referrals done in a timely manner to save lives of critically ill pregnant women. From our findings, two sets of linked implications emerge for strengthening referral systems. Given that referral often involves ill and complicated cases, getting referrals right depends on the exercise of discretion and judgement by those at the frontline to arrive at timely and workable solutions—health systems need to recognize this. We also conclude that to get referrals right, while one needs clearly defined policies and implementation processes that are locally appropriate, well understood by all concerned and easy to follow, this is not enough. In addition, explicit measures that enable the exercise of discretion and judgement at the frontline need to be locally identified and adopted.