bluuebunny/crossref_metadata_2025_split huggingface dataset:
Existence and decay of solution to coupled system of viscoelastic wave equations with strong damping in Rn
Authors: Bouhali Keltoum , Ellaggoune Fateh 
Published: October 2020

In this paper, we establish a general decay rate properties of solutions for a coupled system of viscoelastic wave equations in IRn under some assumptions on g1; g2 and linear forcing terms. We exploit a density function to introduce weighted spaces for solutions and using an appropriate perturbed energy method. The questions of global existence in the nonlinear cases is also proved in Sobolev spaces using the well known Galerkin method.
Ethnic Music and Identity: Surveying Polka DJs and IJs
Authors: Jackson David J. , Liggett Lori 
Published: October 2020

AbstractThis article explores how radio disc jockeys (DJs) and internet disc jockeys (IJs) who play polka music derived from Central and Eastern European music traditions are involved in the process of promoting and preserving ethnic identity in the United States.1 We surveyed DJs and IJs and found that they believe they are keeping an important tradition alive, promoting their ethnic culture, and sometimes teaching their audiences about the Polish, Czech, Slovenian, and German languages. These cultural gatekeepers believe the future of polka music is very challenging, in that there are diminishing numbers of people attending polka events in many of the regions where polka used to be popular. There is also a decline in the number of polka bands, and some DJs and IJs perceive a decline in the quality of both musicianship and singing in the European languages. There are, however, cultural conditions that make it possible for polka music to have an evolving and relevant future.
Social cognition and social functioning in people with borderline personality disorder and their first-degree relatives
Authors: Ortega-Díaz Esther , García-Campos Jonatan , Rico-Gomis José María , Cuesta-Moreno Carlos , Palazón-Bru Antonio , Estañ-Cerezo Gabriel , Piqueras-Rodríguez José Antonio , Rodríguez-Marín Jesús 
Published: October 2020

Background
A few papers studying healthy, first-degree relatives of people with borderline personality disorder (BPD) have found that this group presents attention and memory problems. However, current research has not analyzed their social cognition.

Materials and Methods
We designed an age-, gender- and education-level matched case-control study involving 57 people with BPD, 32 of their first-degree relatives, and 57 healthy controls in Spain in 2018–2019. All were assessed for social cognition and functioning using the Movie for Assessment of Social Cognition and the Social Functioning Scale; other potential confounders were also collected (marital status, occupation and household variables).

Results
There were differences in the social cognition domain of overmentalizing errors, with the BPD group scoring significantly higher than controls; however, there was no significant difference with relatives; in the social functioning domain of family relationships, with the controls showing the highest scores. Social engagement/withdrawal, interpersonal behavior, independence-competence, prosocial activities, full scale and categorization domains showed the same pattern: the BPD group had lower scores than their relatives and the controls. Relatives were significantly different from BPD patients in family relationships, social engagement/withdrawal and interpersonal behavior, as well as on the full Social Functioning Scale (both as a linear and categorical variable). However, only controls showed differences with relatives in family relationships.

Conclusions
All in all, relatives show similar levels of social cognition and functioning compared with controls, and people with BPD show some alterations in different domains of both social cognition and functioning.
On local scouring downstream small water structures
Authors: Kiraga Marta , Popek Zbigniew 
Published: October 2020

Background
In order to regulate water flow, hydraulic structures such as weirs or checks, frequently equipped with gates, are used. Water can flow below or over the gate or, simultaneously, over and below the gate. Both diversifications of hydraulic gradient, being an effect of damming up a river by the structure and shear stresses at the bed, which exceeds the critical shear stress value, invoke the local scouring downstream the structure. This phenomenon has been studied in laboratory and field conditions for many years, however Researchers do not agree on the parameters that affect the size of the local scour and the intensity of its formation. There are no universal methods for estimating its magnitude However, solutions are sought in the form of calculation formulas typical for the method of flow through the structure, taking into account the parameters that characterize a given structure. These formulas are based on factors that affect the size of the local scours, that is, their dimensions and location. Examples of such formulas are those contained in this article: Franke (1960), Straube (1963), Tarajmovič (1966), Rossinski & Kuzmin (1969) equations. The need to study this phenomenon results from the prevalence of hydrotechnical structures equipped with gates (from small gated checks to large weirs) and from potential damage that may be associated with excessive development of local erosion downstream, including washing of foundations and, consequently, loss of stability of the structure.

Methods
This study verifies empirical formulas applied to estimate the geometry parameters of a scour hole on a laboratory model of a structure where water is conducted downstream the gate with bottom reinforcements of various roughness. A specially designed remote-controlled measuring device, equipped with laser scanner, was applied to determine the shape of the sandy bottom. Then the formula optimization is conducted, using Monte Carlo sampling method, followed by verification of field conditions.

Results
The suitability of a specially designed device, equipped with laser scanner for measuring the bottom shape in laboratory conditions was demonstrated. Simple formula describing local scour geometry in laboratory conditions was derived basing on the Straube formula. The optimized formula was verified in field conditions giving very good comparative results. Therefore, it can be applied in engineering and designing practices.
Suction Stress in Unsaturated Soils Considering Hydraulic Hysteresis
Authors: Jiménez J. Ramírez , Rangel J. M. Horta , Rea M. L. Pérez , González E. Rojas , Lara T. Lopez , Zaragoza J. B. Hernandez 
Published: October 2020

Aims: To develop a flow-moisture model that allows determining the variation of suction over time, as well as the suction stresses, using the finite element method in a two-dimensional model of unsaturated soil through an analogy with a transient thermal problem.
Study Design: The variables used in this study were soil suction, hydraulic conductivity, diffusivity and degree of saturation which was represented as the parameter of the Bishop’s effective stress equation.
Place and Duration of Study: Graduate Engineering Department, Universidad Autónoma de Querétaro, between November 2019 and August 2020.
Methodology: To establish the model, experimental Soil-Water Retention Curve was taken from Galaviz (2016). With this information, the curves of hydraulic conductivity and diffusivity were calculated with the methods of Fredlund et al. (2012) and Li (1996). In ANSYS 19.2, an analogous transient thermal analysis was run to determine suction changes over time in a 12 x 2.4 meters two-dimensional medium with an impermeable membrane at the center of its surface which was 4.8 meters long. Through these suction changes, the hydraulic hysteresis algorithm presented by Zhou et al. (2012) was used to calculate the respective degrees of saturation, which were considered as the parameter to obtain the suction stresses.
Results: The changes in soil suction, degree of saturation and suction stress were properly modeled.
Conclusion: When considering the hydraulic hysteresis cycles, both spatial and temporal variations behaved in a similar way in the parameters as well as in the suction stresses. Such stresses depended on the analysis period, increasing in the dry season, according to the precipitation-evapotranspiration model, and decreasing in the wetting season. A time lag was observed between the maximum and minimum stresses as greater depths were studied. Along the horizontal axis, considering the same depth, the stresses varied more in the areas adjacent to the impermeable membrane, while at the center this variation was practically null.
Habitual sleep disturbances and migraine: a Mendelian randomization study
Authors: Daghlas Iyas , Vgontzas Angeliki , Guo Yanjun , Chasman Daniel I. ,   International Headache Genetics Consortium, Saxena Richa 
Published: October 2020

AbstractObjectiveSleep disturbances are associated with increased risk of migraine, however the extent of shared underlying biology and the direction of causal relationships between these traits is unclear. Delineating causality between sleep patterns and migraine may offer new pathophysiologic insights and inform subsequent intervention studies. Here, we used genetic approaches to test for shared genetic influences between sleep patterns and migraine, and to test whether habitual sleep patterns may be causal risk factors for migraine and vice versa.MethodsTo quantify genetic overlap, we performed genome‐wide genetic correlation analyses using genome‐wide association studies of nine sleep traits in the UK Biobank (n ≥ 237,627), and migraine from the International Headache Genetics Consortium (59,674 cases and 316,078 controls). We then tested for potential causal effects between sleep traits and migraine using bidirectional, two‐sample Mendelian randomization.ResultsSeven sleep traits demonstrated genetic overlap with migraine, including insomnia symptoms (rg = 0.29, P < 10−31) and difficulty awakening (rg = 0.11, P < 10−4). Mendelian randomization analyses provided evidence for potential causal effects of difficulty awakening on risk of migraine (OR [95% CI] = 1.37 [1.12–1.68], P = 0.002), and nominal evidence that liability to insomnia symptoms increased the risk of migraine (1.09 [1.02–1.16], P = 0.02). In contrast, there was minimal evidence for an effect of migraine liability on sleep patterns or disturbances.InterpretationThese data support a shared genetic basis between several sleep traits and migraine, and support potential causal effects of difficulty awakening and insomnia symptoms on migraine risk. Treatment of sleep disturbances may therefore be a promising clinical intervention in the management of migraine.
Effects of Oxygen and Glucose on Bone Marrow Mesenchymal Stem Cell Culture
Authors: Lau Fiona , Dalisson Benjamin , Zhang Yu Ling , Zhao Jing , Eliopoulos Nicoletta , Barralet Jake E. 
Published: October 2020

AbstractThis study determines whether the viability of mesenchymal stem cell (MSC) in vitro is most sensitive to oxygen supply, energetic substrate supply, or accumulation of lactate. Mouse unmodified (wild type (WT)) and erythropoietin (EPO) gene‐modified MSC is cultured for 7 days in normoxic (21%) and anoxic conditions. WT‐MSC is cultured in anoxia for 45 days in high and regular glucose media and both have similar viability when compared to their normoxic controls at 7 days. Protein production of EPO‐MSC is unaffected by the absence of oxygen. MSC doubling time and post‐anoxic exposure is increased (WT: 32.3–73.3 h; EPO: 27.2–115 h). High glucose leads to a 37% increase in cell viability at 13 days and 17% at 30 days, indicating that MSC anoxic survival is affected by supply of metabolic substrate. However, after 30 days, little difference in viability is found, and at 45 days, complete cell death occurs in both the conditions. This death cannot be attributed to lack of glucose or lactate levels. MSC stemness is retained for both osteogenic and adipogenic differentiations. The absence of oxygen increases the doubling time of MSC but does not affect their viability, protein production, or differentiation capacity.
Effective Strategies for Droplet Transport on Solid Surfaces
Authors: Lin Shiji , Li Bin , Xu Yi , Mehrizi Abbasali Abouei , Chen Longquan 
Published: October 2020

AbstractDroplet manipulation on solid surfaces is a key technique involved in a variety of applications ranging from self‐cleaning coatings to micro total analysis systems, and thus has been extensively investigated over the recent years. Here, an attempt is made to provide an overview of the latest developed strategies for controlling droplet dynamics, which include droplet motion mediated by surface wettability gradient or external actuation sources, and liquid transport at high‐temperature surfaces or high‐energy surfaces. More specifically, the working mechanism of diverse strategies is introduced, and their advantages and disadvantages are compared, based on which, an outlook of the future development of their applications is provided.
The Potential of Combining Thermal Scanning Probes and Phase‐Change Materials for Tunable Metasurfaces
Authors: Michel Ann‐Katrin U. , Meyer Sebastian , Essing Nicolas , Lassaline Nolan , Lightner Carin R. , Bisig Samuel , Norris David J. , Chigrin Dmitry N. 
Published: October 2020

AbstractMetasurfaces allow for the spatiotemporal variation of amplitude, phase, and polarization of optical wavefronts. Implementation of active tunability of metasurfaces promises compact flat optics capable of reconfigurable wavefront shaping. Phase‐change materials (PCMs) are a prominent material class enabling reconfigurable metasurfaces due to their large refractive index change upon structural transition. However, commonly employed laser‐induced switching of PCMs limits the achievable feature sizes and restricts device miniaturization. Thermal scanning‐probe‐induced local switching of the PCM germanium telluride is proposed to realize near‐infrared metasurfaces with feature sizes far below what is achievable with diffraction‐limited optical switching. The design is based on a planar multilayer and does not require fabrication of protruding resonators as commonly applied in the literature. Instead, it is numerically demonstrated that a broad‐band tuning of perfect absorption can be realized by the localized tip‐induced crystallization of the PCM. The spectral response of the metasurface is explained using resonance mode analysis and numerical simulations. To facilitate experimental realization, a theoretical description of the tip‐induced crystallization employing multiphysics simulations is provided to demonstrate the great potential for fabricating compact reconfigurable metasurfaces. The concept can be applied not only for plasmonic sensing and spatial frequency filtering, but also be transferred to all‐dielectric metasurfaces.
Psychological and Structural Barriers to Immigrant Community Participation: The Experience of Peruvians in Santiago de Chile
Authors: Martinez Damia S. , Marzana D. , Alfieri S. , Pozzi M. , Marta E. , Martinez M.L. 
Published: October 2020

AbstractCommunity participation can be considered a pillar for the promotion of social justice and well‐being for immigrants in new countries. Participation may be influenced by different forms of oppression which decrease opportunities for immigrants to be engaged. The present study explores the difficulties that Peruvian immigrants encountered and still encountering to participate in Santiago de Chile through in‐depth qualitative interviews. Eighteen semi‐structured interviews were conducted with Peruvian leaders of Ethnic Community Based Organizations (ECBOs) in Santiago de Chile. Interviews focused on the community engagement of Peruvians highlighting the difficulties they encountered when deciding whether to engage and throughout the process of carrying out their commitment, along with their perceptions when trying to engage their compatriots. The present study contributes to the literature in three aspects. First, it focused on the phenomenon of South–South migration. Secondly, it delved into the psychological and structural barriers that immigrants’ experience, considering their disadvantaged conditions. Thirdly, it used Situational Analysis, along with the constructionist drift of Grounded Theory, which is widely used in critical, qualitative research, and is sensitive to producing situated knowledge. Coding and mapping analysis identified experiences related to historical trauma, transnational bonds, and dominant master narratives in both countries as well as challenges due to balancing time and priorities, surviving institutional deterrents, and inter‐organizations competitiveness. Finally, transnational commitments, mechanisms of social disconnection, and under valuated rights that Peruvians may live in Chile were pointed out. These results intend to have practical implications for immigrants and for community psychologists.
Chemical Amination/Imination of Carbonothiolated Nucleosides During RNA Hydrolysis
Authors: Jora Manasses , Borland Kayla , Abernathy Scott , Zhao Ruoxia , Kelley Melissa , Kellner Stefanie , Addepalli Balasubrahmanyam , Limbach Patrick A. 
Published: October 2020

AbstractLiquid chromatography‐tandem mass spectrometry (LC‐MS/MS) has become the gold‐standard technique to study RNA and its various modifications. While most research on RNA nucleosides has been focused on their biological roles, discovery of new modifications remains of interest. With state‐of‐the‐art technology, the presence of artifacts can confound the identification of new modifications. Here, we report the characterization of a non‐natural mcm5isoC ribonucleoside in S. cerevisiae total tRNA hydrolysate by higher‐energy collisional dissociation (HCD)‐based fingerprints and isotope labeling of RNA. Its discovery revealed a class of amino/imino ribonucleoside artifacts that are generated during RNA hydrolysis under ammonium‐buffered mild basic conditions. We then identified digestion conditions that can reduce or eliminate their formation. These finding and method enhancements will improve the accurate detection of new RNA modifications.
Stereospecific Ring‐Opening Metathesis Polymerization of Norbornene Catalyzed by Iron Complexes
Authors: Belov Dmitry S. , Mathivathanan Logesh , Beazley Melanie J. , Martin William Blake , Bukhryakov Konstantin V. 
Published: October 2020

AbstractDeveloping well‐defined iron‐based catalysts for olefin metathesis would be a breakthrough achievement in the field not only to replace existing catalysts by inexpensive metals but also to attain a new reactivity taking advantage of the unique electronic structure of the base metals. Here, we present a two‐coordinate homoleptic iron complex, Fe(HMTO)2 [HMTO=O‐2,6‐(2,4,6‐Me3C6H2)2C6H3], that is capable of performing ring‐opening metathesis polymerization of norbornene to produce highly stereoregular polynorbornene (99 % cis, syndiotactic). The use of heteroleptic Fe(HMTO)(RO) [RO=(CH3)2CF3CO, CH3(CF3)2CO, or Ph(CF3)2CO] prepared in situ significantly increases the polymerization rate while preserving selectivity. The resulting polymers were characterized by 1H and 13C NMR spectroscopy and gel‐permeation chromatography.
Reversibly Photo‐Modulating Mechanical Stiffness and Toughness of Bioengineered Protein Fibers
Authors: Sun Jing , Ma Chao , Maity Sourav , Wang Fan , Zhou Yu , Portale Giuseppe , Göstl Robert , Roos Wouter H. , Zhang Hongjie , Liu Kai , Herrmann Andreas 
Published: October 2020

AbstractLight‐responsive materials have been extensively studied due to the attractive possibility of manipulating their properties with high spatiotemporal control in a non‐invasive fashion. This stimulated the development of a series of photo‐deformable smart devices. However, it remained a challenge to reversibly modulate the stiffness and toughness of bulk materials. Here, we present bioengineered protein fibers and their optomechanical manipulation by employing electrostatic interactions between supercharged polypeptides (SUPs) and an azobenzene (Azo)‐based surfactant. Photo‐isomerization of the Azo moiety from the E‐ to Z‐form reversibly triggered the modulation of tensile strength, stiffness, and toughness of the bulk protein fiber. Specifically, the photo‐induced rearrangement into the Z‐form of Azo possibly strengthened cation–π interactions within the fiber material, resulting in an around twofold increase in the fiber's mechanical performance. The outstanding mechanical and responsive properties open a path towards the development of SUP‐Azo fibers as smart stimuli‐responsive mechano‐biomaterials.
Octakis(phenyl)‐T8‐silsesquioxane‐filled silicone elastomers with enhanced electromechanical capability
Authors: Dascalu Mihaela , Iacob Mihail , Tugui Codrin , Bele Adrian , Stiubianu George‐Theodor , Racles Carmen , Cazacu Maria 
Published: October 2020

AbstractThe first dielectric elastomer actuators based on electroactive nanocomposites with octakis(phenyl)‐T8‐silsesquioxane (phenyl‐T8), obtained ex‐situ, used as voltage stabilizer filler for silicone elastomers are reported. The incorporation and homogeneous dispersion of crystalline phenyl‐T8 in percentages of 2.5, 3.5, 5, and 10 into the amorphous matrix consisting in a polydimethylsiloxane‐α,ω‐diol with Mn = 240,000 g/mol was successfully achieved by solution mixing and crosslinking. For the sample with the best actuation performance (that containing 3.5 wt.% filler), an optimized filled elastomer was obtained by dispersing 3.6 wt. % phenyl‐T8 in the matrix using a suitable surfactant (Pluronic L81), thus gaining an increased electrical breakdown of 30% compared with the pristine sample. Beside dielectric strength, the matured films were characterized in terms of morphology, mechanical, dielectric and actuation tests. In spite of structural incompatibility between the filler and the matrix, the obtained materials are soft elastomers showing high strain (~800%) and low Young's modulus of 50–100 kPa. The use of phenyl‐T8 in a silicone matrix lead to electroactive films with slightly increased lateral actuation strain and electric breakdown strength.
Development of hydroxyapatite nanoparticles reinforced chlorinated acrylonitrile butadiene rubber/chlorinated ethylene propylene diene monomer rubber blends
Authors: Nihmath Alasseri , Ramesan Manammel Thankappan 
Published: October 2020

AbstractHydroxyapatite nanoparticles (HA) reinforced polymer blend based on chlorinated nitrile rubber (Cl‐NBR) and chlorinated ethylene propylene diene monomer rubber (Cl‐EPDM) were prepared. Resulting blend composites were analyzed with regard to their rheometric processing, crystallinity, glass transition temperature (Tg), mechanical properties, oil resistance, AC conductivity, and transport behavior. The decrease in optimum cure time with the addition of HA is more advantageous for the development of products from these blend nanocomposites. The XRD, FTIR, and SEM confirmed the attachment and uniform dispersion of HA nanoparticles in the Cl‐NBR/Cl‐EPDM blend. The good compatibility between polymer blend and nanoparticles was also deduced by the formation of spherically shaped HA particles in the blend matrix determined by TEM analysis. DSC analysis showed an increase in Tg of the blend with the filler loading. The addition of HA particles to the blend produced a remarkable increase in tensile and tear strength, hardness, AC conductivity, abrasion, and oil resistance. The diffusion of blend composites was decreased with an increase in penetrant size. The diffusion mechanism was found to follow an anomalous trend. Among the blend composites, the sample with 7 phr of HA not only showed good oil and solvent resistance but also a remarkable increase in AC conductivity and mechanical properties.