bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wake behind a three-dimensional dry transom stern. Part 1. Flow structure and large-scale air entrainment
Authors: Hendrickson Kelli , Weymouth Gabriel D. , Yu Xiangming , Yue Dick K.-P. 
Published: July 2019

We present high-resolution implicit large eddy simulation (iLES) of the turbulent air-entraining flow in the wake of three-dimensional rectangular dry transom sterns with varying speeds and half-beam-to-draft ratios $B/D$. We employ two-phase (air/water), time-dependent simulations utilizing conservative volume-of-fluid (cVOF) and boundary data immersion (BDIM) methods to obtain the flow structure and large-scale air entrainment in the wake. We confirm that the convergent-corner-wave region that forms immediately aft of the stern wake is ballistic, thus predictable only by the speed and (rectangular) geometry of the ship. We show that the flow structure in the air–water mixed region contains a shear layer with a streamwise jet and secondary vortex structures due to the presence of the quasi-steady, three-dimensional breaking waves. We apply a Lagrangian cavity identification technique to quantify the air entrainment in the wake and show that the strongest entrainment is where wave breaking occurs. We identify an inverse dependence of the maximum average void fraction and total volume entrained with $B/D$. We determine that the average surface entrainment rate initially peaks at a location that scales with draft Froude number and that the normalized average air cavity density spectrum has a consistent value providing there is active air entrainment. A small parametric study of the rectangular geometry and stern speed establishes and confirms the scaling of the interface characteristics with draft Froude number and geometry. In Part 2 (Hendrikson & Yue, J. Fluid Mech., vol. 875, 2019, pp. 884–913) we examine the incompressible highly variable density turbulence characteristics and turbulence closure modelling.
A Viscoelastic-Plastic Constitutive Model of Shape Memory Polymer
Authors: Zheng Xueyao , Zhou Bo , Xue Shifeng 
Published: July 2019

ABSTRACTIt is of practical significance to develop a constitutive model which is able to predict the thermomechanical behaviors of the shape memory effect occurring in a shape memory polymer (SMP) accurately. The mechanism of shape memory effect of SMP is explained based on the assumption that SMP is composed by two phases, reversible phase and stationary phase. Especially the different flow elements are respectively added to the reversible phase and stationary phase in order to express the plastic behavior of SMP. There are two springs in series, one dashpot and one flow element in the reversible phase. There are two springs in parallel, one dashpot and one flow element in the stationary phase. A constitutive equation is developed to express the thermo-mechanical behaviors of shape memory effect in the SMP based on viscous-elastic mechanics and plastic theory. An internal variable, frozen ratio, is defined to follow the shape memory process in SMP, and the material properties are described as the functions of frozen ratio based on phase transition theorem. The developed constitutive model, which includes above constitutive equation and material parameter functions, is used to numerically simulate the thermo-mechanical behaviors of SMP under various load cycles. Results show that the developed constitutive model can not only predict the shape memory process of SMP accurately, but also express the rate-dependent behaviors of SMP effectively.
La morphologie du conservatisme américain à l’ère Trump
Authors: Fournier Philippe 
Published: July 2019

RésuméCet article vise à identifier et analyser les idées qui ont accompagné l’émergence et la victoire de Donald Trump. Nous nous intéressons tout particulièrement au paléoconservatisme, un courant idéologique jusque-là méconnu, qui a néanmoins su articuler les frustrations et aspirations d'une partie importante de l’électorat américain. Critique des élites économiques et politiques associées aux deux grands partis, le paléoconservatisme prône un nationalisme identitaire qui menace de bouleverser l’équilibre déjà fragile entre les variantes libertarienne et socialement conservatrice qui dominent au Parti républicain depuis quelques décennies.
Pre-training with non-expert human demonstration for deep reinforcement learning
Authors: de la Cruz Gabriel V. , Du Yunshu , Taylor Matthew E. 
Published: July 2019

Abstract
Deep reinforcement learning (deep RL) has achieved superior performance in complex sequential tasks by using deep neural networks as function approximators to learn directly from raw input images. However, learning directly from raw images is data inefficient. The agent must learn feature representation of complex states in addition to learning a policy. As a result, deep RL typically suffers from slow learning speeds and often requires a prohibitively large amount of training time and data to reach reasonable performance, making it inapplicable to real-world settings where data are expensive. In this work, we improve data efficiency in deep RL by addressing one of the two learning goals, feature learning. We leverage supervised learning to pre-train on a small set of non-expert human demonstrations and empirically evaluate our approach using the asynchronous advantage actor-critic algorithms in the Atari domain. Our results show significant improvements in learning speed, even when the provided demonstration is noisy and of low quality.
Pathways to social-emotional functioning in the preschool period: The role of child temperament and maternal anxiety in boys and girls
Authors: Behrendt Hannah F. , Wade Mark , Bayet Laurie , Nelson Charles A. , Bosquet Enlow Michelle 
Published: July 2019

AbstractIndividual differences in social-emotional functioning emerge early and have long-term implications for developmental adaptation and competency. Research is needed that specifies multiple early risk factors and outcomes simultaneously to demonstrate specificity. Using multigroup longitudinal path analysis in a sample of typically developing children (N= 541), we examined child temperament dimensions (surgency, negative affectivity, and regulation/effortful control) and maternal anxiety in infancy and age 2 as predictors of child externalizing, internalizing, dysregulation, and competence behaviors at age 3. Four primary patterns emerged. First, there was stability in temperament dimensions and maternal anxiety from infancy to age 3. Second, negative affectivity was implicated in internalizing problems and surgency in externalizing problems. Third, effortful control at age 2 was a potent mediator of maternal anxiety in infancy on age 3 outcomes. Fourth, there was suggestive evidence for transactional effects between maternal anxiety and child effortful control. Most pathways operated similarly for boys and girls, with some differences, particularly for surgency. These findings expand our understanding of the roles of specific temperamental domains and postnatal maternal anxiety in a range of social-emotional outcomes in the preschool period, and have implications for efforts to enhance the development of young children's social-emotional functioning and reduce risk for later psychopathology.
Methods for overcoming barriers in palliative care for ethnic/racial minorities: a systematic review
Authors: Mayeda Donna P. , Ward Katherine T. 
Published: July 2019

AbstractObjectivesEthnic/racial minority groups are less likely to discuss issues involving end-of-life treatment preferences and utilize palliative care or hospice services. Some barriers may be differences in language, religion, lower levels of health literacy, or less access to healthcare services and information. The purpose of this article is to conduct a systematic review on interventional studies that investigated methods to overcome the barriers faced by ethnic/racial minorities when accessing end-of-life services, including completing advanced directives, accepting palliative care, and enrolling in hospice.MethodsLiterature searches using four standard scientific search engines were conducted to retrieve articles detailing original research in an interventional trial design. All studies were conducted in an outpatient setting, including primary care visits, home visits, and dialysis centers. Target populations were those identified from ethnic or racial minorities.ResultsNine articles were selected to be included in the final review. All were full-text English language articles, with target populations including African Americans, Hispanic or Latinos, and Asian or Pacific Islanders. Measured outcomes involved level of comfort in discussing and knowledge of palliative care services, desire for aggressive care at the end-of-life, completion of advance directives, and rate of enrollment in hospice.Significance of ResultsThree main avenues of interventions included methods to enhance patient education, increase access to healthcare, or improve communication to establish better rapport with target population. Studies indicate that traditional delivery of healthcare services may be insufficient to recruit patients from ethnic/racial minorities, and outcomes can be improved by implementing tailored interventions to overcome barriers.
From norms to normative configurations: a pragmatist and relational approach to theorizing normativity in IR
Authors: Pratt Simon Frankel 
Published: July 2019

AbstractNormativity matters in international politics, but IR scholarship will benefit from de-reifying ‘norms’ as units into a relational, configurational alternative. The alternative I propose here is the ‘normative configuration’: an arrangement of ongoing, interacting practices establishing action-specific regulation, value-orientation, and avenues of contestation. This responds to recent constructivist scholarship, particularly from relational sociology and practice theory, that implies the need for ontological and analytical alternatives to ‘norms’ as central concepts responsible for establishing rules, institutions, and values in social life. I offer a way of conceptualizing and analyzing normativity consistent with these alternative approaches. Namely, I have brought together a pragmatist theory of action with the social theories of a number of key relational social theorists and philosophers, oriented around a reading of what norms-talk actually does for social enquiry. I then outline a three stage process – de-reification, attributing agency, and tracing transactions – that allows scholars to study transformations in normative configurations. Finally, I discuss what this contributes to the recent turns toward practices and relations, as the latest direction in constructivist scholarship within the discipline.
A machine-compiled database of genome-wide association studies
Authors: Kuleshov Volodymyr , Ding Jialin , Vo Christopher , Hancock Braden , Ratner Alexander , Li Yang , Ré Christopher , Batzoglou Serafim , Snyder Michael 
Published: July 2019

AbstractTens of thousands of genotype-phenotype associations have been discovered to date, yet not all of them are easily accessible to scientists. Here, we describe GWASkb, a machine-compiled knowledge base of genetic associations collected from the scientific literature using automated information extraction algorithms. Our information extraction system helps curators by automatically collecting over 6,000 associations from open-access publications with an estimated recall of 60–80% and with an estimated precision of 78–94% (measured relative to existing manually curated knowledge bases). This system represents a fully automated GWAS curation effort and is made possible by a paradigm for constructing machine learning systems called data programming. Our work represents a step towards making the curation of scientific literature more efficient using automated systems.
Bacterial outer membrane proteins assemble via asymmetric interactions with the BamA β-barrel
Authors: Doyle Matthew T. , Bernstein Harris D. 
Published: July 2019

AbstractThe integration of β-barrel proteins into the bacterial outer membrane (OM) is catalysed by the β-barrel assembly machinery (BAM). The central BAM subunit (BamA) itself contains a β-barrel domain that is essential for OM protein biogenesis, but its mechanism of action is unknown. To elucidate its function, here we develop a method to trap a native Escherichia coli β-barrel protein bound stably to BamA at a late stage of assembly in vivo. Using disulfide-bond crosslinking, we find that the first β-strand of a laterally ‘open’ form of the BamA β-barrel forms a rigid interface with the C-terminal β-strand of the substrate. In contrast, the lipid-facing surface of the last two BamA β-strands forms weaker, conformationally heterogeneous interactions with the first β-strand of the substrate that likely represent intermediate assembly states. Based on our results, we propose that BamA promotes the membrane integration of partially folded β-barrels by a ‘swing’ mechanism.
Single cell analysis of human foetal liver captures the transcriptional profile of hepatobiliary hybrid progenitors
Authors: Segal Joe M. , Kent Deniz , Wesche Daniel J. , Ng Soon Seng , Serra Maria , Oulès Bénédicte , Kar Gozde , Emerton Guy , Blackford Samuel J. I. , Darmanis Spyros , Miquel Rosa , Luong Tu Vinh , Yamamoto Ryo , Bonham Andrew , Jassem Wayel , Heaton Nigel , Vigilante Alessandra , King Aileen , Sancho Rocio , Teichmann Sarah , Quake Stephen R. , Nakauchi Hiromitsu , Rashid S. Tamir 
Published: July 2019

AbstractThe liver parenchyma is composed of hepatocytes and bile duct epithelial cells (BECs). Controversy exists regarding the cellular origin of human liver parenchymal tissue generation during embryonic development, homeostasis or repair. Here we report the existence of a hepatobiliary hybrid progenitor (HHyP) population in human foetal liver using single-cell RNA sequencing. HHyPs are anatomically restricted to the ductal plate of foetal liver and maintain a transcriptional profile distinct from foetal hepatocytes, mature hepatocytes and mature BECs. In addition, molecular heterogeneity within the EpCAM+population of freshly isolated foetal and adult human liver identifies diverse gene expression signatures of hepatic and biliary lineage potential. Finally, we FACS isolate foetal HHyPs and confirm their hybrid progenitor phenotype in vivo. Our study suggests that hepatobiliary progenitor cells previously identified in mice also exist in humans, and can be distinguished from other parenchymal populations, including mature BECs, by distinct gene expression profiles.
Arabidopsis SWR1-associated protein methyl-CpG-binding domain 9 is required for histone H2A.Z deposition
Authors: Potok Magdalena E. , Wang Yafei , Xu Linhao , Zhong Zhenhui , Liu Wanlu , Feng Suhua , Naranbaatar Bilguudei , Rayatpisheh Shima , Wang Zonghua , Wohlschlegel James A. , Ausin Israel , Jacobsen Steven E. 
Published: July 2019

AbstractDeposition of the histone variant H2A.Z by the SWI2/SNF2-Related 1 chromatin remodeling complex (SWR1-C) is important for gene regulation in eukaryotes, but the composition of the Arabidopsis SWR1-C has not been thoroughly characterized. Here, we aim to identify interacting partners of a conserved Arabidopsis SWR1 subunit ACTIN-RELATED PROTEIN 6 (ARP6). We isolate nine predicted components and identify additional interactors implicated in histone acetylation and chromatin biology. One of the interacting partners, methyl-CpG-binding domain 9 (MBD9), also strongly interacts with the Imitation SWItch (ISWI) chromatin remodeling complex. MBD9 is required for deposition of H2A.Z at a distinct subset of ARP6-dependent loci. MBD9 is preferentially bound to nucleosome-depleted regions at the 5’ ends of genes containing high levels of activating histone marks. These data suggest that MBD9 is a SWR1-C interacting protein required for H2A.Z deposition at a subset of actively transcribing genes.
Computational and experimental demonstrations of one-pot tandem catalysis for electrochemical carbon dioxide reduction to methane
Authors: Zhang Haochen , Chang Xiaoxia , Chen Jingguang G. , Goddard William A. , Xu Bingjun , Cheng Mu-Jeng , Lu Qi 
Published: July 2019

AbstractElectroreduction of carbon dioxide to hydrocarbons and oxygenates on copper involves reduction to a carbon monoxide adsorbate followed by further transformation to hydrocarbons and oxygenates. Simultaneous improvement of these processes over a single reactive site is challenging due to the linear scaling relationship of the binding strength of key intermediates. Herein, we report improved electroreduction of carbon dioxide by exploiting a one-pot tandem catalysis mechanism based on computational and electrochemical investigations. By constructing a well-defined copper-modified silver surface, adsorbed carbon monoxide generated on the silver sites is proposed to migrate to surface copper sites for the subsequent reduction to methane, which is consistent with insights gained from operando attenuated total reflectance surface enhanced infrared absorption spectroscopic investigations. Our results provide a promising approach for designing carbon dioxide electroreduction catalysts to enable one-pot reduction of products beyond carbon monoxide and formate.
Strong plasmon-molecule coupling at the nanoscale revealed by first-principles modeling
Authors: Rossi Tuomas P. , Shegai Timur , Erhart Paul , Antosiewicz Tomasz J. 
Published: July 2019

AbstractStrong light-matter interactions in both the single-emitter and collective strong coupling regimes attract significant attention due to emerging applications in quantum and nonlinear optics as well as opportunities for modifying material-related properties. Exploration of these phenomena is theoretically demanding, as polaritons exist at the intersection between quantum optics, solid state physics, and quantum chemistry. Fortunately, nanoscale polaritons can be realized in small plasmon-molecule systems, enabling treatment with ab initio methods. Here, we show that time-dependent density-functional theory calculations access the physics of nanoscale plasmon-molecule hybrids and predict vacuum Rabi splitting. By considering a system comprising a few-hundred-atom aluminum nanoparticle interacting with benzene molecules, we show that cavity quantum electrodynamics holds down to resonators of a few cubic nanometers in size, yielding a single-molecule coupling strength exceeding 200 meV due to a massive vacuum field of 4.5 V · nm−1. In a broader perspective, ab initio methods enable parameter-free in-depth studies of polaritonic systems for emerging applications.
Recent trend reversal for declining European seagrass meadows
Authors: de los Santos Carmen B. , Krause-Jensen Dorte , Alcoverro Teresa , Marbà Núria , Duarte Carlos M. , van Katwijk Marieke M. , Pérez Marta , Romero Javier , Sánchez-Lizaso José L. , Roca Guillem , Jankowska Emilia , Pérez-Lloréns José Lucas , Fournier Jérôme , Montefalcone Monica , Pergent Gérard , Ruiz Juan M. , Cabaço Susana , Cook Kevan , Wilkes Robert J. , Moy Frithjof E. , Trayter Gregori Muñoz-Ramos , Arañó Xavier Seglar , de Jong Dick J. , Fernández-Torquemada Yolanda , Auby Isabelle , Vergara Juan J. , Santos Rui 
Published: July 2019

AbstractSeagrass meadows, key ecosystems supporting fisheries, carbon sequestration and coastal protection, are globally threatened. In Europe, loss and recovery of seagrasses are reported, but the changes in extent and density at the continental scale remain unclear. Here we collate assessments of changes from 1869 to 2016 and show that 1/3 of European seagrass area was lost due to disease, deteriorated water quality, and coastal development, with losses peaking in the 1970s and 1980s. Since then, loss rates slowed down for most of the species and fast-growing species recovered in some locations, making the net rate of change in seagrass area experience a reversal in the 2000s, while density metrics improved or remained stable in most sites. Our results demonstrate that decline is not the generalised state among seagrasses nowadays in Europe, in contrast with global assessments, and that deceleration and reversal of declining trends is possible, expectingly bringing back the services they provide.
Strong magnetophonon oscillations in extra-large graphene
Authors: Kumaravadivel P. , Greenaway M. T. , Perello D. , Berdyugin A. , Birkbeck J. , Wengraf J. , Liu S. , Edgar J. H. , Geim A. K. , Eaves L. , Krishna Kumar R. 
Published: July 2019

AbstractVan der Waals materials and their heterostructures offer a versatile platform for studying a variety of quantum transport phenomena due to their unique crystalline properties and the exceptional ability in tuning their electronic spectrum. However, most experiments are limited to devices that have lateral dimensions of only a few micrometres. Here, we perform magnetotransport measurements on graphene/hexagonal boron-nitride Hall bars and show that wider devices reveal additional quantum effects. In devices wider than ten micrometres we observe distinct magnetoresistance oscillations that are caused by resonant scattering of Landau-quantised Dirac electrons by acoustic phonons in graphene. The study allows us to accurately determine graphene’s low energy phonon dispersion curves and shows that transverse acoustic modes cause most of phonon scattering. Our work highlights the crucial importance of device width when probing quantum effects and also demonstrates a precise, spectroscopic method for studying electron-phonon interactions in van der Waals heterostructures.
High-throughput computation and evaluation of raman spectra
Authors: Liang Qiaohao , Dwaraknath Shyam , Persson Kristin A. 
Published: July 2019

AbstractRaman spectroscopy is used ubiquitously in the characterization of condensed materials, spanning from biomaterials, minerals to polymers, as it provides a unique fingerprint of local bonding and environment. In this work, we design and demonstrate a robust, automatic computational workflow for Raman spectra that employs first-principle calculations based on density functional perturbation theory. A set of computational results are compared to Raman spectra obtained from established experimental databases to estimate the accuracy of the calculated properties across chemical systems and structures. Details regarding the computational methodology and technical validation are presented along with the format of our publicly available data record.