bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of Nonlinear Wave–Ice Interaction Using Parameter Study and Numerical Simulation
Authors: Hartmann Moritz C. N. , von Bock und Polach Franz , Ehlers Sören , Hoffmann Norbert , Onorato Miguel , Klein Marco
Published: December 2019

This paper investigates the question of the existence of nonlinear wave–ice interaction with the focus on nonlinear wave propagation and dispersion of waves. The scope of this investigation is to provide a better understanding of ice and wave conditions required to observe nonlinear wave effects under level ice. Direct numerical simulations of nonlinear waves in solid ice are performed within the weakly nonlinear Schrödinger equation (NLSE) framework, using the theoretical findings from Liu and Mollo-Christensen’s 1988 paper. Systematic variations of wave and ice parameters address the impact of the mechanical ice properties and ice thickness on traveling waves of certain wave lengths. The impacts of parameter characteristics on nonlinear focusing and wave dynamics, as well as possible constraints regarding physical consistency, are discussed. It is presented that nonlinear focusing in level ice occurs theoretically. Hereby, distinctive areas of validity with respect to nonlinear wave focusing are identified within the parameter study, which strongly depends on the material properties of the level ice. The results obtained in the parameter study are subsequently used to investigate wave focusing under level ice. Therefore, an exact solution of the NLSE, the Peregrine breather, is utilized. The analytical solution for level ice is compared to the open water solution and accompanied by direct numerical simulations. These investigations show that nonlinear wave focusing can be predicted under level ice for certain parameters. In addition, the agreement of the direct simulations and the analytic solution verifies the numerical approach for nonlinear waves in solid ice.
Analysis of Spiral-Grooved Gas Journal Bearings by the Narrow-Groove Theory and the Finite Element Method At Large Eccentricities
Authors: Iseli Elia , Guenat Eliott , Tresch Roger , Schiffmann Jürg
Published: December 2019

A finite groove approach (FGA), based on the finite element method (FEM), is used for analyzing the static and dynamic behavior of spiral-grooved aerodynamic journal bearings at different eccentricities, number of grooves, and compressibility numbers. The results of the FGA are compared with the narrow-groove theory (NGT) solutions. For the rotating-groove case, a novel time-periodic solution method is presented for computing the quasi-steady-state and dynamic pressure profiles. The new method offers the advantage of avoiding time-consuming transient integration, while resolving a finite number of grooves. The static and dynamic solutions of the NGT and FGA approach are compared, and they show good agreement, even at large eccentricities (ε=0.8) and high compressibility numbers (Λ = 40). Stability maps at different eccentricities are presented. At certain operation points, a stability decrease toward larger eccentricities is observed. The largest stability deviations of the NGT from the FGA solutions occur at large groove angle, low number of grooves, and large compressibility numbers.
Association of Social Networks and Physical Activity in South Asians: The Mediators of Atherosclerosis in South Asians Living in America Cohort Study
Authors: Thanawala Mitali S. , Siddique Juned , Schneider John A. , Kanaya Alka M. , Cooper Andrew J. , Dave Swapna S. , Lancki Nicola , Kandula Namratha R.
Published: December 2019

Background: Eliminating racial/ethnic disparities in physical activity remains a challenge in the United States. South Asian immigrants in the United States have particularly low physical activity levels, and evidence suggests that social context may be important. This study examined associations between personal social networks and moderate to vigorous leisure-time physical activity (MVPA) among South Asians in the United States. Methods: We used cross-sectional data (2014–2017) from 689 South Asians (aged 43–85 y) who participated in the Mediators of Atherosclerosis in South Asians Living in America study. Self-reported physical activity and egocentric network data were collected from participants about their network members. Regression models were used to determine associations between social network characteristics and participants’ MVPA. Results: Participants were on average 59 years old (SD = 9) and reported 1335 metabolic equivalent minutes per week of MVPA (interquartile range = 735, 2212). Having network members who exercised or who were exercise partners associated with increased MVPA in men (β coefficient = 241 MET min/wk [95% confidence interval, 63 to 419] and β = 520 MET min/wk [95% confidence interval, 322 to 718], respectively). For women, the association was only significant if the exercise partner was a spouse. Conclusion: Physical activity interventions utilizing network members as exercise partners may have potential in South Asians but must consider gender differences.
Effects of College Athlete Life Stressors on Baseline Concussion Measures
Authors: DeFreese J.D. , Baum Michael J. , Schmidt Julianne D. , Goerger Benjamin M. , Barczak Nikki , Guskiewicz Kevin M. , Mihalik Jason P.
Published: December 2019

Context:Concussion baseline testing helps injury evaluation by allowing postinjury comparisons to preinjury measures. To facilitate best practice, common neurocognitive, balance, and symptom report metrics used in concussion baseline testing merit examination relative to participant life stressors.Objective:The purpose of this study was to determine if life stressors are associated with college athlete neurocognitive function, postural control, and symptom scores at preseason baseline assessment.Design:All study variables were collected in a single laboratory session where athletes completed valid and reliable psychometrics as well as a computerized neurocognitive and balance assessments.Setting:Sports medicine research center on an American university campus.Participants:A convenience sample of 123 college student-athletes: 47 females (age = 18.9 [4.3] y) and 76 males (age = 19.4 [1.6] y).Main Outcome Measures:Participants were categorized into low, moderate, or high life stressors groups using scores from the Social Readjustment Rating Scale-Revised. Dependent variables included outcomes from the CNS Vitals Signs test, the Sensory Organization Test, and the graded symptom checklist indexing neurocognition, balance, and symptom severity, respectfully.Results:One-way analysis of variance revealed that the moderate life stressors group performed significantly worse than the low life stressors group on the baseline verbal memory domain of the CNS Vital Signs (F2,119 = 3.28;P = .04) only.Conclusion:In the current college athlete sample, few baseline concussion assessment variables were found to be significantly associated with life stressors. Considering the clinical significance of these variables, psychological life stressors may not be a confounding factor in concussion evaluation.
Effects of the Functional Heel Drop Exercise on the Muscle Architecture of the Gastrocnemius
Authors: Alonso-Fernandez Diego , Taboada-Iglesias Yaiza , García-Remeseiro Tania , Gutiérrez-Sánchez Águeda
Published: December 2019

Context: The architectural characteristics of a muscle determine its function. Objective: To determine the architectural adaptations of the lateral gastrocnemius (LG) and medial gastrocnemius (MG) muscles after a functional eccentric strength training protocol consisting of heel drop exercises, followed by a subsequent detraining period. Design: Pretest and posttest. Setting: Training rooms and laboratory. Participants: The participants (N = 45) who were randomly divided into an experimental group (EG, n = 25) and a control group (CG, n = 20). Interventions: The 13-week intervention included participants (N = 45) who were randomly divided into an EG (n = 25) and a CG (n = 20). The EG performed a week of control and training, 8 weeks of eccentric training, and 4 weeks of detraining. The CG did not perform any type of muscular training. The architectural characteristics of the LG and MG muscles were evaluated at rest in both groups using 2-D ultrasound before (pretest–week 1) and after (posttest–week 9) the training, and at the end of the detraining period (retest–week 13). Main Outcome Measures: One-way repeated measures analysis of variance was used to determine training-induced changes in each of the variables of the muscle architecture. Results: After the training period, the members of the EG experienced a significant increase in the fascicle length of LG (t = −9.85, d = 2.78, P < .001) and MG (t = −8.98, d = 2.54, P < .001), muscle thickness (t = −6.71, d = 2.86, P < .001) and (t = −7.85, d = 2.22, P < .001), and the pennation angle (t = −10.21, d = 1.88, P < .05) and (t = −1.87, d = 0.53, P < .05), respectively. After the detraining period, fascicle length, muscle thickness, and pennation angle showed a significant decrease. In the CG, no significant changes were observed in any of the variables. Conclusions: The heel drop exercise seems to generate adaptations in the architectural conditions of LG and MG, which are also reversible after a detraining period. These results may have practical implications for injury prevention and rehabilitation programs.
Magma reservoir failure and the onset of caldera collapse at Kīlauea Volcano in 2018
Authors: Anderson Kyle R. , Johanson Ingrid A. , Patrick Matthew R. , Gu Mengyang , Segall Paul , Poland Michael P. , Montgomery-Brown Emily K. , Miklius Asta
Published: December 2019

Caldera collapse and flank eruption

Real-time monitoring of volcanic eruptions involving caldera-forming events are rare (see the Perspective by Sigmundsson). Anderson
et al.
used several types of geophysical observations to track the caldera-forming collapse at the top of Kīlauea Volcano, Hawai'i, during the 2018 eruption. Gansecki
et al.
used near–real-time lava composition analysis to determine when magma shifted from highly viscous, slow-moving lava to low-viscosity, fast-moving lava. Patrick
et al.
used a range of geophysical tools to connect processes at the summit to lava rates coming out of far-away fissures. Together, the three studies improve caldera-collapse models and may help improve real-time hazard responses.

Science
, this issue p.
eaaz0147
, p.
eaay9070
; p.
eaaz1822
; see also p.
1200
Ceftazidime-Avibactam To Treat Life-Threatening Infections by Carbapenem-Resistant Pathogens in Critically Ill Mechanically Ventilated Patients
Authors: Tsolaki Vasiliki , Mantzarlis Konstantinos , Mpakalis Athanasios , Malli Ergina , Tsimpoukas Fotios , Tsirogianni Athanasia , Papagiannitsis Constantinos , Zygoulis Paris , Papadonta Maria-Eirini , Petinaki Efthimia , Makris Demosthenes , Zakynthinos Epaminondas
Published: December 2019

Data on the effectiveness of ceftazidime-avibactam (CAZ-AVI) in critically ill, mechanically ventilated patients are limited. The present retrospective observational cohort study, which was conducted in two general intensive care units (ICUs) in central Greece, compared critically ill, mechanically ventilated patients suffering from carbapenem-resistant
Enterobacteriaceae
(CRE) infections receiving CAZ-AVI to patients who received appropriate available antibiotic therapy.
The Locus of Heat Resistance Confers Resistance to Chlorine and Other Oxidizing Chemicals in Escherichia coli
Authors: Wang Zhiying , Fang Yuan , Zhi Shuai , Simpson David J. , Gill Alexander , McMullen Lynn M. , Neumann Norman F. , Gänzle Michael G.
Published: December 2019

Chlorine treatments are used in water and wastewater sanitation; the resistance of
Escherichia coli
to chlorine is thus of concern to public health. We show that a genetic island termed the locus of heat resistance (LHR) protects
E. coli
not only against heat but also against chlorine and other oxidizing chemicals, adding to our knowledge of the tools used by
E. coli
to resist stress. Specific detection of the oxidation of different cellular targets in combination with the cloning of fragments of the LHR provided insight into mechanisms of protection and demonstrated that different fragments of the LHR protect different cellular targets. In
E. coli
, the presence of the LHR virtually always excluded other virulence factors. It is tempting to speculate that the LHR is maintained by strains of
E. coli
with an environmental lifestyle but is excluded by pathogenic strains that adapted to interact with vertebrate hosts.
MhpA Is a Hydroxylase Catalyzing the Initial Reaction of 3-(3-Hydroxyphenyl)Propionate Catabolism in
Escherichia coli
K-12
Authors: Xu Ying , Zhou Ning-Yi
Published: December 2019

Phenylpropionate and its hydroxylated derivatives resulted from lignin degradation ubiquitously exist on the Earth. A number of bacterial strains have the ability to grow on 3HPP, one of the above derivatives. The hydroxylation was thought to be the initial and vital step for its aerobic catabolism via the
meta
pathway. The significance of our research is the functional identification and characterization of the purified 3HPP 2-hydroxylase MhpA from
Escherichia coli
K-12 at biochemical and genetic levels, since this enzyme has not previously been expressed from its encoding gene, purified, and characterized in any bacteria. It will not only fill a gap in our understanding of 3HPP 2-hydroxylase and its corresponding gene for the critical step in microbial 3HPP catabolism but also provide another example of the diversity of microbial degradation of plant-derived phenylpropionate and its hydroxylated derivatives.
Ischaemic stroke and pre-eclampsia in the third trimester of pregnancy: a diagnostic and therapeutic challenge
Authors: Grammatis Alexandros Loukas , Catton Hannah Louise , Hilton Derek
Published: December 2019

A 23-year-old low-risk primiparous patient, who was 35 weeks pregnant, presented in the emergency department after collapsing at home. Her observations showed severe hypertension with proteinuria. On examination, she had left hemiparesis and was aphasic. Fetal monitoring was reassuring. Initial CT did not reveal any evidence of intracranial pathology. She was stabilised and delivered via emergency caesarean section. Subsequent MRI and CT showed an acute right-sided infarct involving the right middle cerebral artery territory, frontal and parietal regions, and increased mass effect. She was transferred to the nearest neurosurgical centre where she was conservatively managed and discharged home 3 weeks later for continuing rehabilitation. She achieved a good recovery.
Wandering spleen: a rare complication of sleeve gastrectomy
Authors: Camarillo Gerardo , Kopelman Yael , Daskal Yaakov , Sheffer Daniel
Published: December 2019

The spleen is an intraperitoneal organ typically located in the left upper quadrant. Ectopic (‘wandering’) spleen refers to the displacement of the spleen from its normal anatomical location to another region in the abdominal cavity or pelvis. It’s a relatively rare condition with no clear aetiology. We present, here, a case of a wandering spleen following sleeve gastrectomy in a 23-year-old female patient, whose spleen, prior to this event, was demonstrated by imaging in a normal anatomical position. A splenectomy was performed, and after an uneventful postoperative period, the patient was discharged. No similar case description was found in the relevant medical literature. Possible causes and decision-making process are discussed. We conclude that the wandering spleen phenomenon should be considered in the differential diagnosis of patients presenting with abdominal pain and new abdominal mass following sleeve gastrectomy.
Early intervention services for non-psychotic mental health disorders: a scoping review protocol
Authors: Richards Katie , Austin Amelia , Allen Karina , Schmidt Ulrike
Published: December 2019

Introduction

Worldwide mental health disorders are associated with a considerable amount of human suffering, disability and mortality. Yet, the provision of rapid evidence-based care to mitigate the human and economic costs of these disorders is limited. The greatest progress in developing and delivering early intervention services has occurred within psychosis. There is now growing support for and calls to extend such approaches to other diagnostic groups. The aim of this scoping review is to systematically map the emerging literature on early intervention services for non-psychotic mental health disorders, with a focus on outlining how services are structured, implemented and scaled.

Methods and analysis

The protocol was developed using the guidance for scoping reviews in the Joanna Briggs Institute manual and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews checklist. A systematic search for published and unpublished literature will be conducted using the following databases: (1) MEDLINE, (2) PsycINFO, (3) HMIC, (4) EMBASE and (5) ProQuest. To be included, documents must describe and/or evaluate an early intervention service for adolescents or adults with a non-psychotic mental health disorder. There will be no restrictions on publication type, study design and date. Title and abstract, and full-text screening will be completed by one reviewer, with a proportion of articles screened in duplicate. Data analysis will primarily involve a qualitatively summary of the early intervention literature, the characteristics of early intervention services and key findings relating to their evaluation and implementation.

Ethics and dissemination

The synthesis of published and unpublished articles will not require ethical approval. The results of this scoping review will be published in a peer-reviewed journal and disseminated via social media, conference presentations and other knowledge translation activities.
Maximum elongation growth promoted as a shade-avoidance response by blue light is related to deactivated phytochrome: a comparison with red light in four microgreen species
Authors: Kong Yun , Schiestel Katherine , Zheng Youbin
Published: December 2019

To clarify detailed patterns of responses to blue light associated with decreasing phytochrome activity, the growth and morphology traits of arugula, cabbage, mustard, and kale microgreens were compared under the treatments: (1) R, pure red light; (2) B, pure blue light; (3) BRF0, (4) BRF2, (5) BRF4, and (6) BRF6: unpure blue lights created by mixing B with low-level (6%) R, and further adding 0, 2, 4, and 6 μmol m−2 s−1 of far-red light, respectively. The calculated phytochrome photostationary state (PPS) value, indicating phytochrome activity, gradually decreased in the order of R (0.89), BRF0 (0.69), BRF2 (0.65), BRF4 (0.63), BRF6 (0.60), and B (0.50). Generally, the elongation growth (including stem extension rate, hypocotyl length, or petiole length) under blue lights increased with the decreasing PPS values, showing the highest and lowest sensitivity for arugula and mustard, respectively. However, the elongation promoted by blue lights gradually became saturated once the PPS values decreased below 0.60, a level which deactivates phytochrome. Other plant traits, such as biomass allocation and plant color, varied with increasing shade-avoidance responses to blue lights with decreasing PPS values relative to R, and these traits reached saturation at a similar PPS value as elongation. The response sensitivity was highest in elongation growth for arugula and cabbage, and highest in plant color for kale and mustard. This suggests that deactivated phytochrome contributes to the maximum elongation promotion as a shade-avoidance response induced by blue light, although the response sensitivity varies with plant traits and species.
New algorithms to obtain analytical solutions of Einstein’s equations in isotropic coordinates
Authors: Las Heras Camilo , León Pablo
Published: December 2019

The main objective of this work, is to show two inequivalent methods to obtain new spherical symmetric solutions of Einstein’s Equations with anisotropy in the pressures in isotropic coordinates. This was done inspired by the MGD method, which is known to be valid for line elements in Schwarzschild coordinates. As example, we obtained four analytical solutions using Gold III as seed solution. Two solutions, out of four, (one for each algorithm), satisfy the physical acceptability conditions.
Mass and angular momentum of charged rotating Gödel black holes in five-dimensional minimal supergravity
Authors: Peng Jun-Jin
Published: December 2019

In this paper, for the sake of providing a concrete comparison between the usual Abbott–Deser–Tekin (ADT) formalism and its off-shell extension, as well as comparing the latter with the Barnich–Brandt–Compere (BBC) approach, we carry out these methods to compute the mass and angular momentum of the rotating charged Gödel black holes in five-dimensional minimal supergravity. We first present the off-shell ADT potential of the supergravity theories in arbitrary odd dimensions, which is consistent with the superpotential via the BBC approach. Then the off-shell generalized ADT method is applied to evaluate the mass and angular momentum of the Gödel-type black holes by including the contribution from the gauge field. Finally, we strictly obey the rules of the original ADT formalism to incorporate the contribution from the gauge field within the potential. With the help of the modified potential, we try to seek for appropriate reference backgrounds to produce the mass and angular momentum. It is observed that the ADT formalism has to incorporate the contribution from the matter fields to yield physical charges for the Gödel-type black holes.
Darboux transformation approach for two new coupled nonlinear evolution equations
Authors: Zhao Dan , Zhaqilao
Published: December 2019

A new coupled Burgers equation and a new coupled KdV equation which are associated with [Formula: see text] matrix spectial problem are investigated for complete integrability and covariant property. For integrability, Lax pair and conservation laws of the two new coupled equations with four potentials are established. For covariant property, Darboux transformation (DT) is used to construct explicit solutions of the two new coupled equations.
Transverse nonlinear vibration modeling and response of eccentric rotor in a switched reluctance motor
Authors: Wang Feng , Wu Zhiqiang , Li Yajie , Wang Yuancen
Published: December 2019

In order to investigate the transverse vibration of eccentric rotor in a 12/8 switched reluctance motor (SRM), a whole nonlinear coupled vibration equation of eccentric rotor is built with finite element method (FEM). Based on single tooth radial force and the key parameters variation with rotor position, an analytical formula of magnetic resultant taking into account of the rotor’s vibration displacement is deduced in detail, which is applied onto the intermediate node of eccentric rotor in form of concentrated force. Once the windings currents obtained either by experiments or numerical simulations is input, the vibration response can be solved numerically by Newmark-[Formula: see text] method. Six phase windings currents under angle position control (APC) strategy are chosen as an example and the vibration response are discussed to reflect intrinsic vibration characteristics. From radical resultant vector and its amplitude spectrum, it is proved that the magnetic resultant vector presents multi-petals star shape. The frequency components in magnetic resultant are [Formula: see text], [Formula: see text], and [Formula: see text], [Formula: see text], related to rotational speed, current waveform and minimum common multiple of stator and rotor teeth. However, from displacement locus and its amplitude spectrum, the frequency component of the rotor vibration displacement is also related to the critical whirl speed of the rotor. Transverse superharmonic resonance of eccentric rotor appears at some particular rotational speed and result in a larger rotor vibration. If the rotor runs at the superharmonic speed of 1/19 of first-order critical whirl speed, the maximum vibration displacement radius of the eccentric rotor reaches almost four times that of the rated speed. The vibration locus at these particular speed show rich diversity.
Electronic and optical properties of GaN/AlN core–shell nanowires
Authors: Zheng Jiangshan , Li Enling , Yan Jie , Cui Zhen , Ma Deming
Published: December 2019

The electronic and optical properties of GaN/AlN core–shell nanowires (NWs) with different core–shell ratios are studied by means of density functional theory (DFT). The results show that as the GaN core structure increases (the AlN shell remains unchanged), the band gap of NWs decreases. In contrast, with the increase of AlN shell (GaN nucleus remains unchanged), the band gap almost remains unchanged. That is to say the adjustment capability of core–shell ratio for the band gap of GaN/AlN core–shell NWs with the same diameter of GaN core degenerates, and the band gap of which are mainly controlled by GaN core. Ga–N bond and Al–N bond show a strong ionic property because of the electronegativity of N is strong over Ga and Al. In addition, the calculated results of the real part [Formula: see text] and the imaginary parts [Formula: see text] with photon energy indicate that the storage capability and loss of the NWs to electric field energy are different with the content of AlN. The four structured NWs reflect electromagnetic waves as conductor in a high frequency ultraviolet range. The results are valuable for the design of GaN/AlN core–shell NWs optoelectronic nanodevices and the research of other core–shell NWs heterostructures.
A channel-potential-based surface potential model and a turn-on DC channel-potential-based drain current model for fully-depleted poly-Si thin film transistors including tail and deep acceptor-like trap states in bulk
Authors: Zhu Zhen , Chu Junhao
Published: December 2019

For fully-depleted polycrystalline silicon thin film transistors including both tail and deep acceptor-like trap states in the bulk and interface charges, a channel-potential-based surface potential model (including front and back surface potential) and a turn-on DC channel-potential-based drain current model are proposed with the effect of the back surface potential considered. Firstly, a channel-potential-based surface potential model is obtained by introducing a channel-potential-based front and back surface potential equation and a channel-potential-based equation describing the coupling effect of the front and back surface potential. Contributions of active acceptors, electrons and trapped charges are all taken into account in this coupling effect. Moreover, by integrating the electron concentration, vertically to the front poly-Si/oxide interface, in the inversion layer, using the average electric field concept and considering the effect of channel potential in the potential of the inversion layer’s ending point, the areal density of the inversion charge is deduced. Furthermore, a channel-potential-based drain current model, avoiding the double numerical integration, is developed with the merit of relative simplification in calculation. By using recursive Simpson rules, this drain current model is calculated by numerical integration with the examining condition. And the above proposed models are verified by 2D-device simulation from MEDICI.
Density profile diagrams of harmonically trapped two-component Bose–Einstein condensates
Authors: Ji Liang , Wen Wen
Published: December 2019

We present an analytical study for density profiles of two-component Bose–Einstein condensates (BECs) in an isotropic trap within the miscible regime. The analytical equations for the density profiles and the conditions for three different density configurations are presented, which allow us to explore the density profile diagrams of general two-component BECs depending on broad ranges of experimental parameters. Furthermore, we show that the obtained explicit expressions of the density profiles can also be applied to study the collective modes of the two-component BECs, and the frequencies of the two-component BECs clearly characterize the density configurations.
Technology Adoption in Emerging Regions: Case of the Smartphone in Saudi Arabia
Authors: Aldhaban Fahad , Daim Tugrul , Harmon Robert , Basoglu Nuri
Published: December 2019

This paper examines the adoption of Smartphones in Saudi Arabia. A theoretical research model is developed based on the unified theory of acceptance and use of technology. A web-based survey has been used to gather data from randomly selected Smartphone users in Saudi Arabia. For data analysis, SEM approach was followed, SPSS and AMOS were utilized for analyzing data. The results indicate that performance expectancy, effort expectancy, brand influence, perceived enjoyment, and design constructs have a positive and significant relationship with users’ behavioral intention to adopt and use Smartphones in Saudi Arabia.
A NEW PROCEDURE FOR TESTING THE EXPORT-LED GROWTH HYPOTHESIS: A RESEARCH NOTE
Authors: FURUOKA FUMITAKA
Published: December 2019

This study proposes a novel statistical procedure to test the export-led growth hypothesis. The procedure integrates a Fisher-type causality method in the statistical analysis. In order to demonstrate the application of this procedure, this study examined the exports–growth nexus in low-income and lower middle-income countries in Africa. The findings obtained from the newly-proposed integrated statistical procedure were more conclusive compared to the results obtained from the individual causality tests; the findings also highlighted a complex nature of the exports–growth nexus in Africa.
"Mothers as Candy Wrappers": Critical Infrastructure Supporting the Transition into Motherhood
Authors: Britton Lauren , Barkhuus Louise , Semaan Bryan
Published: December 2019

The transition into motherhood is a complicated and often unsupported major life disruption. To alleviate mental health issues and to support identity re-negotiation, mothers are increasingly turning to online mothers' groups, particularly private and secret Facebook groups; these can provide a complex system of social, emotional, and practical support for new mothers. In this paper we present findings from an exploratory interview study of how new mothers create, find, use, and participate in ICTs, specifically online mothers' groups, to combat the lack of formal support systems by developing substitute networks. Utilizing a framework of critical infrastructures, we found that these online substitute networks were created by women, for women, in an effort to fill much needed social, political, and medical gaps that fail to see 'woman and mother' as a whole being, rather than simply as a 'discarded candy wrapper'. Our study contributes to the growing literature on ICT use by mothers for supporting and negotiating new identities, by illustrating how these infrastructures can be re-designed and appropriated in use, for critical utilization.
Effects of Anonymity, Ephemerality, and System Routing on Cost in Social Question Asking
Authors: Ma Haiwei , Cheng Hao-Fei , Yu Bowen , Zhu Haiyi
Published: December 2019

Online platforms provide new channels for people in need to seek help from friends and strangers. However, individuals often encounter psychological barriers that deter them from asking for help. For example, people might have different concerns about asking for help, including acknowledging incompetence, bothering others, and accruing social debt. These perceived social costs limit the potential benefits of help solicitations. In this study, we attempt to investigate whether anonymity (posting a question anonymously), ephemerality (allowing questions to be visible for only a short period), and system routing (having the system handle the question routing) could reduce social costs in a typical online help-seeking behavior-question asking. We built a platform to support these three features and conducted a controlled within-subjects experiment to test their effects on the social costs of posting questions. Results suggest that the presence of anonymity, ephemerality, and system routing reduce social costs. Further, we find that employing anonymity and system routing features did not lower the quality and quantity of answers to the questions in our system.
Altruism and Wellbeing as Care Work in a Craft-based Maker Culture
Authors: Vyas Dhaval
Published: December 2019

This paper aims to examine motivations of participants for being involved in a crafts-based, women-only maker organization. Over a period of three months, we observed and interviewed ten women aged 42 - 78 to explore how they experienced being involved in knitting, sewing, crocheting, card making and other similar craft forms. Using the ethos of care as a lens to interpret our data, we found that our participants perceived making as an 'outlet' for them to perform activities that support their physical and mental wellbeing. Moreover, they perceived making as a tool to support others in need and help the larger community rather than a self-serving achievement. We also observed how the use of technology was inherent into their craft making activities that supported not only the making processes but also sharing these with others. Our findings highlight the 'care work' that goes into making in such a social setting that generally goes unnoticed when the focus is purely on instrumental and objective aspects of making. We believe that these findings will inform CSCW researchers to think about the not-so-visible qualities of making that elevate care (for self and for others), and to support these via the design of innovative technologies.?
Creativity, Copyright, and Close-Knit Communities
Authors: Fiesler Casey , Bruckman Amy S.
Published: December 2019

Social norms as a regulatory mechanism often carry more weight than formal law--particularly in contexts when legal rules are gray. In online creative communities that focus on remix, community members must navigate copyright complexities regarding how they are permitted to re-use existing content. This paper focuses on one such community--transformative fandom--where strong social norms regulate behavior beyond copyright law. We conducted interviews with fan creators about their "unwritten rules" surrounding copying and remix and identified highly consistent social norms that have been remarkably effective in policing this community. In examining how these norms have formed over time, and how they are enforced, we conclude that the effectiveness of norms in encouraging cooperative behavior is due in part to a strong sense of social identity within the community. Furthermore, our findings suggest the benefits of creating formal rules within a community that support existing norms, rather than imposing rules from external sources.
Assembling the Case
Authors: Holten Møller Naja L. , Fitzpatrick Geraldine , Le Dantec Christopher A.
Published: December 2019

This study examines caseworkers' and citizens' interactions when assembling resource development applications for citizens with serious health and personal issues. As with other types of welfare schemes, the application serves as a mechanism of both support and control. From our study, we illustrate how an increased reliance on data is transforming the citizen-caseworker interaction in social welfare. We characterize this transformation as 'dataRication': a phenomenon where the increased reliance on data for decision-support across contexts of data production makes it challenging for individual citizens to contest or correct data-born accounts of their situation. Our contribution is two-fold: Rirst, we empirically characterize the citizen-caseworker interaction in the application process. Second, we discuss how citizens' private resourcing complements the formal application process and provides them with strategies to give authority to their case and exercise personal autonomy. The private resourcing practices we observed show how integrating supplementary accounts from citizens into the systems that caseworkers rely on could make citizens' experiences and social context legible. This in turn has policy and technology design implications as public services increasingly introduce data-driven modes of case management.
Part-Time Ride-Sharing
Authors: Ma Ning F. , Hanrahan Benjamin V.
Published: December 2019

Ride-sharing companies have been reshaping the structure and practice of ride-hailing work. At the same time, studies have been showing mixed driver experiences on the platform while many of the drivers are working part-time. In this research, we seek to understand why drivers on this platform are working part-time, how this impacts their view of the platform, and what this means for more accurately evaluating the design of these platforms. To investigate this question, we focused on situating ride-sharing in the lives and constellation of gigs that drivers maintain. We collected 53 survey responses and conducted 10 semi-structured interviews with drivers to probe these questions. We found that the extent that drivers categorize themselves as part-time is less about the number of hours worked and more about how dependent they are on ride-sharing income. The level of this dependency seemed to heavily influence how they interacted with the platform and their attitudes towards difficulties faced. It seemed to us that in some ways that the design or functioning of the platform almost pushed users towards working part-time. We discuss the importance of taking these different types of workers and their situations into consideration when evaluating the design and usability of these platforms.
Mortar
Authors: Fierro Gabe , Pritoni Marco , Abdelbaky Moustafa , Lengyel Daniel , Leyden John , Prakash Anand , Gupta Pranav , Raftery Paul , Peffer Therese , Thomson Greg , Culler David E.
Published: December 2019

Access to large amounts of real-world data has long been a barrier to the development and evaluation of analytics applications for the built environment. Open datasets exist, but they are limited in their span (how much data is available) and context (what kind of data is available and how it is described). Evaluation of such analytics is also limited by how the analytics themselves are implemented, often using hard-coded names of building components, points and locations, or unique input data formats.

To advance the methodology for how such analytics are implemented and evaluated, we present Mortar: an open testbed for portable building analytics, currently spanning 90 buildings and containing over 9.1 billion data points. All buildings in the testbed are described using Brick, a recently developed metadata schema, providing rich functional descriptions of building assets and subsystems. We also propose a simple architecture for writing portable analytics applications that are robust to the diversity of buildings and can configure themselves based on context. We demonstrate the utility of Mortar by implementing 11 applications from the literature.
The Actin Cytoskeleton as an Active Adaptive Material
Authors: Banerjee Shiladitya , Gardel Margaret L. , Schwarz Ulrich S.
Published: December 2019

Actin is the main protein used by biological cells to adapt their structure and mechanics to their needs. Cellular adaptation is made possible by molecular processes that strongly depend on mechanics. The actin cytoskeleton is also an active material that continuously consumes energy. This allows for dynamical processes that are possible only out of equilibrium and opens up the possibility for multiple layers of control that have evolved around this single protein. Here we discuss the actin cytoskeleton from the viewpoint of physics as an active adaptive material that can build structures superior to man-made soft matter systems. Not only can actin be used to build different network architectures on demand and in an adaptive manner, but it also exhibits the dynamical properties of feedback systems, like excitability, bistability, or oscillations. Therefore, it is a prime example of how biology couples physical structure and information flow and a role model for biology-inspired metamaterials.
Recent Advances in Robot Learning from Demonstration
Authors: Ravichandar Harish , Polydoros Athanasios S. , Chernova Sonia , Billard Aude
Published: December 2019

In the context of robotics and automation, learning from demonstration (LfD) is the paradigm in which robots acquire new skills by learning to imitate an expert. The choice of LfD over other robot learning methods is compelling when ideal behavior can be neither easily scripted (as is done in traditional robot programming) nor easily defined as an optimization problem, but can be demonstrated. While there have been multiple surveys of this field in the past, there is a need for a new one given the considerable growth in the number of publications in recent years. This review aims to provide an overview of the collection of machine-learning methods used to enable a robot to learn from and imitate a teacher. We focus on recent advancements in the field and present an updated taxonomy and characterization of existing methods. We also discuss mature and emerging application areas for LfD and highlight the significant challenges that remain to be overcome both in theory and in practice.
Multiagent System for Mutual Collaboration Classification for Cancer Detection
Authors: Qasem Mais Haj , Hudaib Amjad , Obeid Nadim
Published: December 2019

A multiagent system (MAS) is a mechanism for creating goal‐oriented autonomous agents in shared environments with communication and coordination facilities. Distributed data mining benefits from this goal‐oriented mechanism by implementing various distributed clustering, classification, and prediction techniques. Hence, this study developed a novel multiagent model for distributed classification tasks in cancer detection with the collaboration of several hospitals worldwide using different classifier algorithms. A hospital agent requests help from other agents for instances that are difficult to classify locally. The agents communicate their beliefs (calculated classification), and others decide on the benefit of using such beliefs in classifying instances and adjusting their prior assumptions on each class of data. A MAS model state and behavior and communication are then developed to facilitate information sharing among agents. Regarding accuracy, implementing the proposed approach in comparison with typically different noncommunicated distributed classifications shows that sharable information considerably increases the classification task accuracy by 25.77%.
Transcriptome Sequencing to Detect the Potential Role of Long Noncoding RNAs in Salt-Sensitive Hypertensive Rats
Authors: Wu Hao , Zhu Sibo , Yuan Rui , Yi Yang , Wang Hanqing , Gu Bo , Zhen Timing , Xing Kaichen , Ma Jun
Published: December 2019

Backgrounds. Long noncoding RNAs (lncRNAs) play an important role in various biological processes. However, their functions in salt-sensitive hypertension are largely unknown. In this study, the lncRNA-seq technique was employed to compare the expression profiles of lncRNAs and mRNAs in salt-sensitive hypertensive rats. Methods. Blood pressure, serum sodium, and urinary creatinine were texted in salt-sensitive and salt-insensitive rats fed with different salt concentrations. High-throughput sequencing was used to detect the expression of lncRNAs and mRNA in the renal medulla of the two groups. Results. Blood pressure and urinary sodium/creatinine of high-salt diets of the sensitive group were significantly higher than that in the control group. Serum sodium has no significant difference between the two groups in high-salt diets. NONRATG007131.2 and NONRATG012674.2 were the most different lncRNAs in the high salt-sensitive group. Correlation analysis reveals that Matn1, Serpinb12, Anxa8, and Hspa5 may play an important role in salt-sensitive hypertension. Conclusion. This study analyzed the difference in lncRNA and mRNA between salt-sensitive and salt-insensitive rats with different salt diets by high-throughput sequencing. Salt sensitivity and salt concentration were two key factors for the induction of hypertension. We found some potential genes that play an important role in salt-sensitive hypertension.
Platelet-Rich Fibrin as a Bone Graft Material in Oral and Maxillofacial Bone Regeneration: Classification and Summary for Better Application
Authors: Liu Yiping , Sun Xiaolin , Yu Jize , Wang Jia , Zhai Peisong , Chen Siyu , Liu Manxuan , Zhou Yanmin
Published: December 2019

Platelet-rich fibrin (PRF) is an autologous platelet concentrate that consists of cytokines, platelets, leukocytes, and circulating stem cells. It has been considered to be effective in bone regeneration and is mainly used for oral and maxillofacial bone. Although currently the use of PRF is thought to support alveolar ridge preservation, there is a lack of evidence regarding the application of PRF in osteogenesis. In this paper, we will provide examples of PRF application, and we will also summarize different measures to improve the properties of PRF for achieving better osteogenesis. The effect of PRF as a bone graft material on osteogenesis based on laboratory investigations, animal tests, and clinical evaluations is first reviewed here. In vitro, PRF was able to stimulate cell proliferation, differentiation, migration, mineralization, and osteogenesis-related gene expression. Preclinical and clinical trials suggested that PRF alone may have a limited effect. To enlighten researchers, modified PRF graft materials are further reviewed, including PRF combined with other bone graft materials, PRF combined with drugs, and a new-type PRF. Finally, we will summarize the common shortcomings in the application of PRF that probably lead to application failure. Future scientists should avoid or solve these problems to achieve better regeneration.
Identification of Key Genes and Pathways Associated with Sex Differences in Osteoarthritis Based on Bioinformatics Analysis
Authors: Wang Shiying , Wang Huanmei , Liu Wei , Wei Biaofang
Published: December 2019

Sex differences have been suggested to play critical roles in the pathophysiology of osteoarthritis (OA), resulting in sex-specific prevalence and incidence. However, their roles in the development of OA remain largely unknown. The aim of this study was to screen out key genes and pathways mediating biological differences between OA females after menopause and OA males. First, the gene expression data of GSE36700 and GSE55457 were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between sexes were identified using R software, respectively. The overlapping DEGs were obtained. Then, protein-protein interactive (PPI) network was constructed to further analyze interactions between the overlapping DEGs. Finally, enrichment analyses were separately performed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes tools. In our results, a total of 278 overlapping DEGs were identified between OA females after menopause and OA males, including 219 upregulated and 59 downregulated genes. In the PPI network, seven hub genes were identified, including EGF, ERBB2, CDC42, PIK3R2, LCK, CBL, and STAT1. Functional enrichment analysis revealed that these genes were mainly enriched in PI3K-Akt signaling pathway, osteoclast differentiation, and focal adhesion. In conclusion, the results in the current study suggest that pathways of PI3K-Akt, osteoclast differentiation, and focal adhesion may play important roles in the development of OA females after menopause. EGFR, ERBB2, CDC42, and STAT1 may be key genes related to OA progression in postmenopausal women and may be promising therapeutic targets for OA.