bluuebunny/crossref_metadata_2025_split huggingface dataset:
Game of protocols: Is QUIC ready for prime time streaming?
Authors: Arisu Sevket , Yildiz Ertan , Begen Ali C. 
Published: February 2019

SummaryQuick User Datagram Protocol (UDP) Internet Connections (QUIC) is an experimental and low‐latency transport protocol proposed by Google, which is still being improved and specified in the Internet Engineering Task Force (IETF). The viewer's quality of experience (QoE) in HTTP adaptive streaming (HAS) applications may be improved with the help of QUIC's low‐latency, improved congestion control, and multiplexing features. We measured the streaming performance of QUIC on wireless and cellular networks in order to understand whether the problems that occur when running HTTP over TCP can be reduced by using HTTP over QUIC. The performance of QUIC was tested in the presence of network interface changes caused by the mobility of the viewer. We observed that QUIC resulted in quicker start of media streams, better streaming, and seeking experience, especially during the higher levels of congestion in the network and had a better performance than TCP when the viewer was mobile and switched between the wireless networks. Furthermore, we measured QUIC's performance in an emulated network that had a various amount of losses and delays to evaluate how QUIC's multiplexing feature would be beneficial for HAS applications. We compared the performance of HAS applications using multiplexing video streams with HTTP/1.1 over multiple TCP connections to HTTP/2 over one TCP connection and to QUIC over one UDP connection. To that effect, we observed that QUIC provided better performance than TCP on a network that had large delays. However, QUIC did not provide a significant improvement when the loss rate was large. Finally, we analyzed the performance of the congestion control mechanisms implemented by QUIC and TCP, and tested their ability to provide fairness among streaming clients. We found that QUIC always provided fairness among QUIC flows, but was not always fair to TCP.
First‐principles studies of lithium adsorption and diffusion on silicene with grain boundaries
Authors: Wang Xiao , Liu Huazhong , Huttula Marko , Luo Youhua , Zhang Meng , Cao Wei 
Published: February 2019

AbstractAs a close relative to graphene, silicene is advanced in high lithium capacity, yet attracting various manipulation strategies to promote its role in energy storage. Following grain boundary (GB) engineering route as widely used in graphene studies, in this work, first‐principles calculations were performed to investigate adsorption and diffusion behaviors of lithium on silicene with GBs of 4|8 or 5|5|8 defects. In both GB forms, donation of the Li 2s electron to the GBs significantly increases the Li adsorption energy, whereas small energy barriers facilitate the Li migration on the silicene surface. Furthermore, the large hole of GB(4‐8) also permits easy penetration of the Li ions through the defective silicene sieve. These important features demonstrate GBs are beneficial for enhancing capacity and charge speed of the Li batteries. Thus, superior anodes made of silicene with GBs are expected to serve a key solution for future energy storages.
Localization of malonyl and acetyl on substituted saikosaponins according to the full‐scan mass spectra and the fragmentation of sodium‐adduct ions in the positive mode
Authors: Liu Guoqiang , Zhang Zunjian , Lv Xiaoqing , Zhan Shuyu , Ding Baoue , Yang Xinji , Zhu Qifeng 
Published: February 2019

RationaleDiscriminating between aglycone‐substituted and saccharide‐substituted saikosaponins by liquid chromatography/tandem mass spectrometry (LC/MSn) is a long‐standing issue that is still to be resolved. It is necessary to characterize the two types of substituted saikosaponins taking into consideration the potential significant difference in their bioactivity.MethodsTaking the substituents malonyl and acetyl as examples, we developed a MS strategy to discriminate between the aglycone‐substituted and saccharide‐substituted saikosaponins through comparing their Y0 − nH2O (n = 1–2) ions from the protonated molecules in the full‐scan mass spectra and their B ions in the MS2 spectra of sodium‐adduct molecules in the positive mode.ResultsThe deprotonated molecules of the aglycone‐substituted saikosaponins presented similar fragmentation patterns to those of saccharide‐substituted ones in the negative mode, which could not discriminate whether the substitutes were located on the aglycone or the saccharide. In contrast, the Y0 − nH2O (n = 1–2) ions containing or no substituent were observed respectively in the mass fragmentation of the protonated molecules of aglycone‐substituted or saccharide‐substituted saikosaponins in the positive mode. In addition, the B ions containing or no substituent were observed respectively in the mass fragmentation of the sodium‐adduct molecules of the saccharide‐substituted or aglycone‐substituted saikosaponins in the positive mode. Two aglycone‐malonylated saikosaponins were reported for the first time.ConclusionsWhether the substituents were located on the aglycone or the saccharide could be determined according to the Y0 − nH2O (n = 1–2) ions from the protonated molecules in the full‐scan mass spectra and the B ions in the MS2 spectra of sodium‐adduct molecules in the positive mode. Our results have updated the mass fragmentation patterns of substituted saikosaponins, which is helpful for the quality control of pharmaceutical preparations containing saikosaponins. More importantly, this MS strategy should be able to be extended to characterize other substituted saponins of bioactive significance in future studies.
Gendered genetics: How reading about the genetic basis of sex differences in biology textbooks could affect beliefs associated with science gender disparities
Authors: Donovan Brian M. , Stuhlsatz Molly A. M. , Edelson Daniel C. , Buck Bracey Zoë E. 
Published: February 2019

AbstractThe belief that men and women differ in science ability because of genetics contributes to gender disparities in science, technology, engineering, and math (STEM) in complex ways. In this field experiment, we explored how the content of the genetics curriculum affected beliefs about science ability through its impact on a social–cognitive bias known as neurogenetic essentialism. Students (n = 460, 8th–10th grade) were randomized to read a genetics text that (a) explained plant sex differences, (b) explained human sex differences, or (c) refuted neurogenetic essentialism. After reading, students in the two genetics of sex conditions had significantly greater belief in neurogenetic essentialism and the innate basis of science ability compared with students who read the text that refuted neurogenetic essentialism. Structural equation modeling (SEM) of the experimental data demonstrated that the effect of the readings on the belief that science ability is innate was mediated by neurogenetic essentialism and this indirect effect was significant for girls but not boys. In turn, the belief that science ability is innate predicted lower future interest in STEM for girls, but not for boys. These findings suggest that learning about human genetic difference is not a socially neutral endeavor. Implications for mitigating gender disparities in STEM are discussed.
Urban freshwaters, biodiversity, and human health and well‐being: Setting an interdisciplinary research agenda
Authors: Higgins Sahran L. , Thomas Felicity , Goldsmith Ben , Brooks Stephen J. , Hassall Christopher , Harlow Julian , Stone Dave , Völker Sebastian , White Piran 
Published: February 2019

The findings of a national workshop that explored the social and environmental impacts, challenges, and research opportunities associated with the role of urban freshwaters for improved public health are discussed. Bringing together the collective expertise of academics, practitioners, policy, and user‐groups from urban aquatic ecology and human health backgrounds, this commentary develops a progressive agenda for future research by synthesizing current understandings and knowledge of urban aquatic biodiversity relative to health‐related ecosystem service outcomes, from a cross‐sectoral and cross‐disciplinary perspective. Key areas include (a) a need for greater interaction between sectors to maximize opportunities for collaboration and to promote the cobenefits (both environmental and health) associated with urban freshwater ecosystems; and (b) the need for a unified understanding and operationalization of the definition of aquatic biodiversity across sectors and disciplines, to improve our understanding of whether actual freshwater biodiversity or the perception of biodiversity is important for maximizing gains in health. Methods of valuation relating to ecosystem services and resource allocation and investment in urban freshwaters are critical in ensuring that research addresses the pathways and contexts within which health and environmental benefits from blue space can be maximized.This article is categorized under:
Human Water > Value of Water
Surface and Subsurface Investigations for the Detection and Mapping of Underground Karst Cavities in MChentel Area, Cheria Basin, Northeast of Algeria
Authors: Saddek Bouhlassa , Chemseddine Fehdi , Djamel Boubaya , Nabil Bougherira 
Published: February 2019

Abstract
A combined approach using the surface geophysical method (microgravimetric survey) and sub-surface investigations (speleology) was undertaken at an experimental karst site located in the MChentel area near Cheria town (Northeast of Algeria). The gravimetric survey, carried out by a gravimeter GNU-KC 444 during March-April 2016, allowed the procurement of 614 gravimetric measurements distributed on the whole of the zone of study.
The gravimetric data shows a reduction in the values of the Bouguer anomaly between two collapses. This trend probably implies an effect of karstification that would explain the reduction in the values of the Bouguer anomaly while moving towards the centre of the zone of study. The results provided in this work of underground exploration by the team of speleologists from Polytechnic Nice-Sophia in 2013 and 2014 are particularly well illustrated by the topography of the cavities upstream and the real photographs, the micromorphology and the microstructures of the walls of the cavities explored.
The joint application of the microgravimetry and speleology make it possible to evaluate the advantages and effectiveness of the microgravimetry for the detection of underground cavities. This improves knowledge of the karstic system structure of Eocene carbonates in the studied area.
Granular surface flow on an asymmetric conical heap
Authors: Mandal Sandip , Khakhar D. V. 
Published: February 2019

We carry out an experimental study of the granular surface flow of nearly monodisperse glass beads on a conical heap formed on a rough circular disc by a narrow stream of the particles from a hopper, with the pouring point displaced from the centre of the disc. During the growth phase, an axisymmetric heap is formed, which grows either by periodic avalanches or by non-periodic avalanches that occur randomly over the azimuthal location of the heap, depending on the operating conditions and system properties. The dynamics of heap growth is characterized by the variation of the heap height, angle of repose and the angular velocity of the periodic avalanche with time, for different mass flow rates from the hopper. When the base of the heap reaches the edge of the disc closest to the pouring point, the heap stops growing and a steady surface flow of particles is developed on the heap surface, with particles flowing over the edge of the disc into a collection tray. The geometry is a unique example of a granular flow on an erodible bed without any bounding side walls. The corresponding steady state geometry of the asymmetric heap is characterized by means of surface contours and angles of repose. The streamwise and transverse surface velocities are measured using high-speed video photography and image analysis for different mass flow rates. The flowing layer thickness is measured by immersing a coated needle in the flow at different positions on the mid-line of the flow. The surface angle of the flowing layer is found to be significantly smaller than the angle of repose and to be independent of the mass flow rate. The velocity profiles at different streamwise positions for different mass flow rates are found to be geometrically similar and are well described by Gaussian functions. The flowing layer thickness is calculated from a model using the measured surface velocities. The predicted values match the measured values quite well.
The evolution of public policy attitudes: comparing the mechanisms of policy support across the stages of a policy cycle
Authors: Jagers Sverker C. , Matti Simon , Nordblom Katarina 
Published: February 2019

AbstractWe analyse the importance of legitimacy on public policy support by comparing how drivers of public policy attitudes evolve across the policy process consisting of the input (the processes forgoing acquisition of power and the procedures permeating political decisionmaking), throughput (the inclusion of and interactions between actors in a governance system) and output (the substantive consequences of those decisions) stages. Using unique panel data through three phases of the implementation of a congestion tax in the Swedish city of Gothenburg, we find that legitimacy is indeed important in explaining policy support. Moreover, we find a lingering effect where support in one phase depends on legitimacy both in the present and in previous phases. Hence, our study takes us one step further on the road to understand the complicated dynamic mechanisms behind the interactions between policymaking, policy support, and the legitimacy and approval of politicians and political processes.
A MAGNETIC DOUBLE INTEGRAL
Authors: BROADHURST DAVID , ZUDILIN WADIM 
Published: February 2019

In a recent study of how the output voltage of a Hall plate is affected by the shape of the plate and the size of its contacts, U. Ausserlechner has come up with a remarkable double integral that can be viewed as a generalisation of the classical elliptic ‘arithmetic–geometric mean (AGM)’ integral. Here we discuss transformation properties of the integral, which were experimentally observed by Ausserlechner, as well as its analytical and arithmetic features including connections with modular forms.
Seasonal Variability of Deuterium in the Upper Atmosphere of Mars
Authors: Mayyasi Majd , Clarke J. , Bhattacharyya D. , Chaufray J. Y. , Benna M. , Mahaffy P. , Stone S. , Yelle R. , Thiemann E. , Chaffin M. , Deighan J. , Jain S. , Schneider N. , Jakosky B. 
Published: February 2019

AbstractMeasurements by multiple Mars Atmosphere and Volatile Evolution mission instruments, obtained between November 2014 and November 2017, are analyzed to produce deuterium properties in the upper atmosphere of Mars. We show here, for the first time, the seasonal distribution and variability of D densities, temperatures, and estimated Jeans escape rates at the exobase (200 km). Within the data constraints, it is found that the variations in D properties are similar for the northern and southern hemispheres, and peak near southern summer solstice. Trends in the D Lyman‐α brightness, temperature, density, and escape rate are increasing during the beginning of the dust storm season, peak near southern summer solstice, and decrease toward the end of the dust storm season. This suggests that seasonal drivers at Mars cause deuterium in the upper atmosphere to become globally enhanced when Mars is closest to the Sun and during the Martian dust season when water is provided to the upper atmosphere by subsurface, hydrological, and dust storm dynamics.
Large‐Scale Characteristics of Flux Transfer Events on the Dayside Magnetopause
Authors: Sun T. R. , Tang B. B. , Wang C. , Guo X. C. , Wang Y. 
Published: February 2019

AbstractBy using global MHD simulation, we present the large‐scale characteristics of flux transfer events (FTEs) on the dayside magnetopause during periods of generic southward interplanetary magnetic field. It is revealed that FTEs can be generated both at lower and higher latitudes, and also at almost all local times. The occurrence rate of FTEs has an apparent longitudinal/latitudinal dependence, with a higher occurrence rate near noon/at lower latitudes. It is further shown that even under constant solar wind conditions, the azimuthal lengths of FTEs can have large variability, changing from as short as <1RE to as long as >10RE for different FTEs. Moreover, FTEs generated closer to the subsolar point tend to have longer extensions along their axes. These new knowledge of large‐scale properties of FTEs will improve our understanding of the solar wind‐magnetosphere interaction.
Nucleation and Arrest of Dynamic Rupture Induced by Reservoir Depletion
Authors: Buijze L. , van den Bogert P. A. J. , Wassing B. B. T. , Orlic B. 
Published: February 2019

AbstractSeismic events induced by the depletion of hydrocarbon reservoirs can cause damage to housing and cause societal and economic unrest. However, the factors controlling the nucleation and size of production‐induced seismic events are not well understood. Here we used geomechanical modeling of production‐induced stresses and dynamic rupture modeling to assess the conditions controlling down‐dip rupture size. A generic model of (offset) depleting reservoir compartments separated by a fault was modeled in 2‐D using the Finite Element package DIANA FEA. Linear slip‐weakening was used to control fault friction behavior. Fault reactivation was computed in a quasi‐static analysis simulating stresses during reservoir depletion, followed by a fully dynamic analysis simulating seismic rupture. The sensitivity of reactivation and rupture size to in situ stress, dynamic friction, critical slip distance, and reservoir offset was evaluated. After reactivation, a critical fault length was required to slip before seismic instability could occur. In a subsequent fully dynamic analysis the propagation and arrest of dynamic rupture was simulated. Rupture remained mostly confined to the reservoir interval but could also propagate into the overburden and underburden or sometimes transition into a run‐away rupture. Propagation outside the reservoir interval was promoted by a critical in situ stress, a large stress drop, a small fracture energy, and no or little reservoir offset. With increasing offset (up to the reservoir thickness), reactivation was promoted but dynamic rupture size decreased.
Toward Improving Short‐Term Predictions of Fine Particulate Matter Over the United States Via Assimilation of Satellite Aerosol Optical Depth Retrievals
Authors: Kumar Rajesh , Delle Monache Luca , Bresch Jamie , Saide Pablo E. , Tang Youhua , Liu Zhiquan , da Silva Arlindo M. , Alessandrini Stefano , Pfister Gabriele , Edwards David , Lee Pius , Djalalova Irina 
Published: February 2019

AbstractThis study develops a new approach to improve simulations of the particulate matter of aerodynamic diameter smaller than 2.5 μm (PM2.5) in the Community Multiscale Air Quality (CMAQ) model via assimilation of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) retrievals using the Gridpoint Statistical Interpolation (GSI) system. In contrast to previous studies that only consider errors due to transport, our computation of the background error covariance matrix incorporates uncertainties in anthropogenic emissions. To understand the impact of this approach, three experiments (one background and two assimilations) are performed over the contiguous United States (CONUS) from 15 July to 14 August 2014. The background CMAQ experiment significantly underestimates both the MODIS AOD and surface PM2.5 levels. MODIS AOD assimilation pushes both the CMAQ AOD and surface PM2.5 distributions toward the observed distributions, but CMAQ still underestimates the observations. Averaged over CONUS, the two assimilation experiments with and without including the anthropogenic emission uncertainties improve the correlation coefficient between the model and independent observations of PM2.5 by ~67% and ~48%, respectively, and reduces the mean bias by ~38% and ~10%, respectively. The assimilation improves the model performance everywhere over CONUS, except the New York and Wisconsin, where CMAQ overestimates the observed PM2.5 during nighttime after assimilation likely because of overcorrection of aerosol mass concentrations by the AOD assimilation. Future work should incorporate uncertainties in other processes (biomass burning and biogenic emissions, deposition, chemistry, transport, and boundary conditions) to further enhance the value of assimilating spaceborne AOD retrievals.
Variability in Contrail Ice Nucleation and Its Dependence on Soot Number Emissions
Authors: Bier A. , Burkhardt U. 
Published: February 2019

AbstractContrail ice nucleation is mainly controlled by aircraft emissions and the atmospheric state. The nucleation rate can have a strong impact on microphysical processes, optical properties, lifetime, and, therefore, on the climate impact of contrail cirrus. We study contrail ice crystal formation offline for specified atmospheric conditions and its spatial variability in a global climate model. Assuming the standard atmosphere, above around 270 hPa (10 km) contrail ice nucleation is mainly controlled by aircraft soot number emissions and below additionally by atmospheric temperature. Parameterizing contrail ice nucleation in a global climate model, we find that in the northern extratropics contrails form frequently far away from their formation threshold. For current soot number emissions and in case of contrail formation, 90% of emitted soot particles form on average ice crystals around the cruise level and more than 70% between cruise altitudes and 300 hPa. The number of nucleated ice crystals in the extratropics decreases nearly at the same rate as soot number emissions. In contrast, in the tropics around cruise altitudes approximately 60% of contrails develop close to their formation threshold so that on average only about 50% of emitted soot particles can form ice crystals. Below, contrail formation occurs rarely and ice nucleation is reduced more strongly. Of the main air traffic areas, contrail ice nucleation is significantly limited by the atmospheric state over eastern Asia and over the southeastern United States. This limitation is enhanced during the summer months.