bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Dependence of Water Permeability in Quartz Sand on Gas Hydrate Saturation in the Pore Space
Authors: Kossel E. , Deusner C. , Bigalke N. , Haeckel M. 
Published: February 2018

AbstractTransport of fluids in gas hydrate bearing sediments is largely defined by the reduction of the permeability due to gas hydrate crystals in the pore space. Although the exact knowledge of the permeability behavior as a function of gas hydrate saturation is of crucial importance, state‐of‐the‐art simulation codes for gas production scenarios use theoretically derived permeability equations that are hardly backed by experimental data. The reason for the insufficient validation of the model equations is the difficulty to create gas hydrate bearing sediments that have undergone formation mechanisms equivalent to the natural process and that have well‐defined gas hydrate saturations. We formed methane hydrates in quartz sand from a methane‐saturated aqueous solution and used magnetic resonance imaging to obtain time‐resolved, three‐dimensional maps of the gas hydrate saturation distribution. These maps were fed into 3‐D finite element method simulations of the water flow. In our simulations, we tested the five most well‐known permeability equations. All of the suitable permeability equations include the term (1‐SH)n, where SH is the gas hydrate saturation and n is a parameter that needs to be constrained. The most basic equation describing the permeability behavior of water flow through gas hydrate bearing sand is k = k0 (1‐SH)n. In our experiments, n was determined to be 11.4 (±0.3). Results from this study can be directly applied to bulk flow analysis under the assumption of homogeneous gas hydrate saturation and can be further used to derive effective permeability models for heterogeneous gas hydrate distributions at different scales.
Comprehensive Assessment of Global Surface Net Radiation Products and Uncertainty Analysis
Authors: Jia Aolin , Liang Shunlin , Jiang Bo , Zhang Xiaotong , Wang Guoxin 
Published: February 2018

AbstractEarth surface net radiation (Rn) characterizes the surface radiation budget and plays a critical role in ecological, biogeochemical, and hydrological processes. The Rn products from remote sensing and reanalysis have not been validated comprehensively. In this study, four Rn products (Clouds and the Earth's Radiant Energy System [CERES], ERA‐Interim, Modern‐Era Retrospective analysis for Research and Applications version 2, and Japanese 55‐year Reanalysis) were validated using global ground measurements on monthly (255 sites) and annual (172 sites) timescales. These products have similar accuracies, with average root‐mean‐square error (RMSE) ranges of 5.35 W m−2 (monthly) and 2.30 W m−2 (annually). However, varying accuracies and systemic biases exist across different climatic zones. The annual land Rn intercomparison illustrates that large uncertainty exists over polar regions and deserts. A significantly negative annual anomaly in the CERES product for the 2001–2008 period is identified when examining annual Rn anomalies over the global land surface. Detailed uncertainty analysis indicates that the global CERES Rn anomaly is mainly due to different versions of input data such as aerosol optical thickness and atmospheric profiles (in 2006 and 2008) and cloud properties (in 2002). This work demonstrates that temporal analysis provides powerful quality control for global time series satellite products when the validation using ground measurements fails to capture potential issues.
Chemistry of Volatile Organic Compounds in the Los Angeles Basin: Formation of Oxygenated Compounds and Determination of Emission Ratios
Authors: de Gouw J. A. , Gilman J. B. , Kim S.‐W. , Alvarez S. L. , Dusanter S. , Graus M. , Griffith S. M. , Isaacman‐VanWertz G. , Kuster W. C. , Lefer B. L. , Lerner B. M. , McDonald B. C. , Rappenglück B. , Roberts J. M. , Stevens P. S. , Stutz J. , Thalman R. , Veres P. R. , Volkamer R. , Warneke C. , Washenfelder R. A. , Young C. J. 
Published: February 2018

AbstractWe analyze an expanded data set of oxygenated volatile organic compounds (OVOCs) in air measured by several instruments at a surface site in Pasadena near Los Angeles during the National Oceanic and Atmospheric Administration California Nexus study in 2010. The contributions of emissions, chemical formation, and removal are quantified for each OVOC using CO as a tracer of emissions and the OH exposure of the sampled air masses calculated from hydrocarbon ratios. The method for separating emissions from chemical formation is evaluated using output for Pasadena from the Weather Research and Forecasting‐Chemistry model. The model is analyzed by the same method as the measurement data, and the emission ratios versus CO calculated from the model output agree for ketones with the inventory used in the model but overestimate aldehydes by ~70%. In contrast with the measurements, nighttime formation of OVOCs is significant in the model and is attributed to overestimated precursor emissions and overestimated rate coefficients for the reactions of the precursors with ozone and NO3. Most measured aldehydes correlated strongly with CO at night, suggesting a contribution from motor vehicle emissions. However, the emission ratios of most aldehydes versus CO are higher than those reported in motor vehicle emissions and the aldehyde sources remain unclear. Formation of several OVOCs is investigated in terms of the removal of specific precursors. Direct emissions of alcohols and aldehydes contribute significantly to OH reactivity throughout the day, and these emissions should be accurately represented in models describing ozone formation.
High Spectral Resolution Spectroscopy of Sprites: A Natural Probe of the Mesosphere
Authors: Gordillo‐Vázquez F. J. , Passas M. , Luque A. , Sánchez J. , van der Velde O. A. , Montanyá J. 
Published: February 2018

AbstractWe present the first high spectral resolution (0.24 nm) spectra of sprites. These spectra were recorded in Europe in the summers and falls of 2015 and 2016 and during January 2017. The use of high spectral resolution has allowed us to resolve for the first time the internal (vibrorotational) structure of the sprite molecular N2 first positive system and to quantify the local gas (rotational) temperature of the mesosphere under the influence of sprites revealing that there is no measurable heating of the atmosphere associated to sprites at the altitudes explored. The temperatures of the explored region of the mesosphere range between 149 K ± 10 K and 226 K ± 20 K. The recorded spectroscopic data also provide valuable quantitative information on the concentrations of some of the vibrational levels of molecular nitrogen involved in transient red‐near‐infrared optical emissions from sprites. The regions of the transient luminous events recorded with our spectrograph (equipped with a horizontally oriented slit) correspond to altitudes in the 66 km to 74 km ± 5 km range.
Anisotropy of Observed and Simulated Turbulence in Marine Stratocumulus
Authors: Pedersen J. G. , Ma Y.‐F. , Grabowski W. W. , Malinowski S. P. 
Published: February 2018

AbstractAnisotropy of turbulence near the top of the stratocumulus‐topped boundary layer (STBL) is studied using large‐eddy simulation (LES) and measurements from the POST and DYCOMS‐II field campaigns. Focusing on turbulence
m below the cloud top, we see remarkable similarity between daytime and nocturnal flight data covering different inversion strengths and free‐tropospheric conditions. With λ denoting wavelength and
cloud‐top height, we find that turbulence at
is weakly dominated by horizontal fluctuations, while turbulence at
becomes strongly dominated by horizontal fluctuations. Between are scales at which vertical fluctuations dominate. Typical‐resolution LES of the STBL (based on POST flight 13 and DYCOMS‐II flight 1) captures observed characteristics of below‐cloud‐top turbulence reasonably well. However, using a fixed vertical grid spacing of 5 m, decreasing the horizontal grid spacing and increasing the subgrid‐scale mixing length leads to increased dominance of vertical fluctuations, increased entrainment velocity, and decreased liquid water path. Our analysis supports the notion that entrainment parameterizations (e.g., in climate models) could potentially be improved by accounting more accurately for anisotropic deformation of turbulence in the cloud‐top region. While LES has the potential to facilitate improved understanding of anisotropic cloud‐top turbulence, sensitivity to grid spacing, grid‐box aspect ratio, and subgrid‐scale model needs to be addressed.
BAYSPLINE: A New Calibration for the Alkenone Paleothermometer
Authors: Tierney Jessica E. , Tingley Martin P. 
Published: February 2018

AbstractThe alkenone‐based U
proxy is a cornerstone of paleoclimatology, providing insight into the temperature history of the Earth's surface ocean. Although the relationship between U
and sea surface temperatures (SSTs) is robust and well supported by experimental data, there remain outstanding issues regarding the seasonality of production of alkenones and the response of U
at very warm and cold SSTs. Using a data set of over 1,300 core‐top U
measurements, we find compelling evidence of seasonal production in the North Atlantic, North Pacific, and Mediterranean Oceans. We also find significant attenuation of the U
response to SST at warm temperatures (>24°C), with the slope reduced by nearly 50% as U
approaches unity. To account for these observations in a calibration, we develop a new Bayesian B‐spline regression model, BAYSPLINE, for the U
paleothermometer. BAYSPLINE produces similar estimates as previous calibrations below ∼24°, but above this point it predicts larger SST changes, in accordance with the attenuation of the U
response. Example applications of BAYSPLINE demonstrate that its treatment of seasonality and slope attenuation improves paleoclimatic interpretations, with important consequences for the inference of SSTs in the tropical oceans. BAYSPLINE facilitates a probabilistic approach to paleoclimate, building upon growing efforts to develop more formalized statistical frameworks for paleoceanographic reconstruction.
Measuring Disease Damage and Its Severity in Childhood‐Onset Systemic Lupus Erythematosus
Authors: Holland Michael J. , Beresford Michael W. , Feldman Brian M. , Huggins Jennifer , Norambuena Ximena , Silva Clovis A. , Susic Gordana , Sztajnbok Flavio , Uziel Yosef , Appenzeller Simone , Ardoin Stacy P. , Avcin Tadej , Flores Francisco , Goilav Beatrice , Khubchandani Raju , Klein‐Gitelman Marissa , Levy Deborah , Ravelli Angelo , Wenderfer Scott E. , Ying Jun , Ruperto Nicolino , Brunner Hermine I. ,   the PRINTO and PRCSG Investigators
Published: February 2018

ObjectiveTo describe the frequency and types of disease damage occurring with childhood‐onset systemic lupus erythematosus (SLE) as measured by the 41‐item Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI), and to assess the SDI's ability to reflect damage severity.MethodsInformation for the SDI was prospectively collected from 1,048 childhood‐onset SLE patients. For a subset of 559 patients, physician‐rated damage severity measured by visual analog scale (MD VAS damage) was also available. Frequency of SDI items and the association between SDI summary scores and MD VAS damage were estimated. Finally, an international consensus conference, using nominal group technique, considered the SDI's capture of childhood‐onset SLE–associated damage and its severity.ResultsAfter a mean disease duration of 3.8 years, 44.2% of patients (463 of 1,048) already had an SDI summary score >0 (maximum 14). The most common SDI items scored were proteinuria, scarring alopecia, and cognitive impairment. Although there was a moderately strong association between SDI summary scores and MD VAS damage (Spearman's r = 0.49, P < 0.0001) in patients with damage (SDI summary score >0), mixed‐effects analysis showed that only 4 SDI items, each occurring in <2% of patients overall, were significantly associated with MD VAS damage. There was consensus among childhood‐onset SLE experts that the SDI in its current form is inadequate for estimating the severity of childhood‐onset SLE–associated damage.ConclusionDisease damage as measured by the SDI is common in childhood‐onset SLE, even with relatively short disease durations. Given the shortcomings of the SDI, there is a need to develop new tools to estimate the impact of childhood‐onset SLE–associated damage.
Minimal Disease Activity Among Active Psoriatic Arthritis Patients Treated With Secukinumab: 2‐Year Results From a Multicenter, Randomized, Double‐Blind, Parallel‐Group, Placebo‐Controlled Phase III Study
Authors: Coates Laura C. , Mease Philip J. , Gossec Laure , Kirkham Bruce , Sherif Bintu , Gaillez Corine , Mpofu Shephard , Jugl Steffen M. , Karyekar Chetan , Gandhi Kunal K. 
Published: February 2018

ObjectiveTo evaluate minimal disease activity (MDA) among psoriatic arthritis (PsA) patients receiving secukinumab through 2 years in the FUTURE 2 study.MethodsPatients with active PsA were randomized to receive subcutaneous secukinumab 300, 150, or 75 mg or placebo. MDA was assessed in the overall population (anti–tumor necrosis factor [anti‐TNF]–naive and inadequate responders [anti–TNF‐IR]) and in patients stratified by prior anti‐TNF exposure and by time since diagnosis at weeks 16, 24, 52, and 104. Function and patient‐reported outcomes (PROs), including health‐related quality of life (QoL) and work productivity, were assessed in MDA responders versus nonresponders.ResultsOverall, 28% of patients (27 of 98) and 23% (23 of 100) achieved MDA at week 16 with secukinumab 300 and 150 mg, respectively, versus 10% (9 of 94) with placebo. In the anti–TNF‐naive cohort, a higher proportion of patients achieved MDA at week 16 with secukinumab 300 and 150 mg (34% and 32%, respectively) versus placebo (13%). The corresponding value in the anti–TNF‐IR cohort was 15% and 8% with secukinumab 300 and 150 mg, respectively, versus with placebo (3%). At week 16, 27.1% of MDA responders (16 of 59) achieved a very low disease activity (VLDA) response, with the percentage being numerically greater with secukinumab 300 and 150 mg (30% [8 of 27] and 26% [6 of 23], respectively) versus placebo (22% [2 of 9]). The MDA and VLDA responses with secukinumab 300 and 150 mg were sustained through 2 years. MDA responders showed greater improvements in QoL outcomes compared to nonresponders through 2 years.ConclusionA greater proportion of patients achieved MDA with secukinumab versus placebo at week 16, with response rates sustained through 2 years. MDA was associated with improved PROs, including QoL, through 2 years.
Learning Analytics in Medical Education Assessment: The Past, the Present, and the Future
Authors: Chan Teresa , Sebok‐Syer Stefanie , Thoma Brent , Wise Alyssa , Sherbino Jonathan , Pusic Martin 
Published: February 2018

AbstractWith the implementation of competency‐based medical education (CBME) in emergency medicine, residency programs will amass substantial amounts of qualitative and quantitative data about trainees’ performances. This increased volume of data will challenge traditional processes for assessing trainees and remediating training deficiencies. At the intersection of trainee performance data and statistical modeling lies the field of medical learning analytics. At a local training program level, learning analytics has the potential to assist program directors and competency committees with interpreting assessment data to inform decision making. On a broader level, learning analytics can be used to explore system questions and identify problems that may impact our educational programs. Scholars outside of health professions education have been exploring the use of learning analytics for years and their theories and applications have the potential to inform our implementation of CBME. The purpose of this review is to characterize the methodologies of learning analytics and explore their potential to guide new forms of assessment within medical education.
N‐methyl‐D‐aspartate receptor antibody production from germinal center reactions: Therapeutic implications
Authors: Makuch Mateusz , Wilson Robert , Al‐Diwani Adam , Varley James , Kienzler Anne‐Kathrin , Taylor Jennifer , Berretta Antonio , Fowler Darren , Lennox Belinda , Leite M. Isabel , Waters Patrick , Irani Sarosh R 
Published: February 2018

IntroductionN‐methyl‐D‐aspartate receptor (NMDAR) antibody encephalitis is mediated by immunoglobulin G (IgG) autoantibodies directed against the NR1 subunit of the NMDAR. Around 20% of patients have an underlying ovarian teratoma, and the condition responds to early immunotherapies and ovarian teratoma removal. However, despite clear therapeutic relevance, mechanisms of NR1‐IgG production and the contribution of germinal center B cells to NR1‐IgG levels are unknown.MethodsClinical data and longitudinal paired serum NR1‐reactive IgM and IgG levels from 10 patients with NMDAR‐antibody encephalitis were determined. Peripheral blood mononuclear cells from these 10 patients, and two available ovarian teratomas, were stimulated with combinations of immune factors and tested for secretion of total IgG and NR1‐specific antibodies.ResultsIn addition to disease‐defining NR1‐IgG, serum NR1‐IgM was found in 6 of 10 patients. NR1‐IgM levels were typically highest around disease onset and detected for several months into the disease course. Moreover, circulating patient B cells were differentiated into CD19+CD27++CD38++ antibody‐secreting cells in vitro and, from 90% of patients, secreted NR1‐IgM and NR1‐IgG. Secreted levels of NR1‐IgG correlated with serum NR1‐IgG (p < 0.0001), and this was observed across the varying disease durations, suggestive of an ongoing process. Furthermore, ovarian teratoma tissue contained infiltrating lymphocytes which produced NR1‐IgG in culture.InterpretationSerum NR1‐IgM and NR1‐IgG, alongside the consistent production of NR1‐IgG from circulating B cells and from ovarian teratomas suggest that ongoing germinal center reactions may account for the peripheral cell populations which secrete NR1‐IgG. Cells participating in germinal center reactions might be a therapeutic target for the treatment of NMDAR‐antibody encephalitis. Ann Neurol 2018;83:553–561
Discovery and Enumeration of Organic‐Chemical and Biomimetic Reaction Cycles within the Network of Chemistry
Authors: Bajczyk Michał D. , Dittwald Piotr , Wołos Agnieszka , Szymkuć Sara , Grzybowski Bartosz A. 
Published: February 2018

AbstractAnalysis of the chemical‐organic knowledge represented as a giant network reveals that it contains millions of reaction sequences closing into cycles. Without realizing it, independent chemists working at different times have jointly created examples of cyclic sequences that allow for the recovery of useful reagents and for the autoamplification of synthetically important molecules, those that mimic biological cycles, and those that can be operated one‐pot.
Highly flame‐retardant polyurethane foam based on reactive phosphorus polyol and limonene‐based polyol
Authors: Bhoyate Sanket , Ionescu M. , Kahol P. K. , Chen J. , Mishra S. R. , Gupta Ram K. 
Published: February 2018

ABSTRACTPolyurethane foams are in general flammable and their flammability can be controlled by adding flame‐retardant (FR) materials. Reactive FR have the advantage of making strong bond within the polyurethane chains to provide excellent FR over time without compromising physico‐mechanical properties. Here, phenyl phosphonic acid and propylene oxide‐based reactive FR polyol was synthesized and used along with limonene based polyol for preparation of FR polyurethanes. All the obtained foams showed higher closed cell content (above 96%). By the addition of FR–polyol, the compressive strength of the foams showed 160% increment which could be due to reactive nature of FR–polyol. Moreover, 1.5 wt % of phosphorus (P) content reduced the self‐extinguishing time of the foam from 81 (28% weight loss) to 11.2 s (weight loss of 9.8%). Cone test showed 68.6% reduction in peak heat release rate along with 23.4% reduction in thermal heat release. The change in char structure of carbon after burning was analyzed using Raman spectra which, suggests increment in the graphitic phase of the carbon over increased concentration of phosphorus. It can be concluded from this study that phosphorous based polyol could be blended with bio‐based polyols to prepare highly FR and superior physico‐mechanical rigid polyurethane foams. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46224.
Second‐generation bio‐based plastics are becoming a reality – Non‐renewable energy and greenhouse gas (GHG) balance of succinic acid‐based plastic end products made from lignocellulosic biomass
Authors: Patel Martin K. , Bechu Aude , Villegas Juan David , Bergez‐Lacoste Manon , Yeung Kenny , Murphy Richard , Woods Jeremy , Mwabonje Onesmus N. , Ni Yuanzhi , Patel Akshay D. , Gallagher Joe , Bryant David 
Published: February 2018

AbstractBio‐based and bio‐degradable plastics such as polybutylene succinate (PBS) have the potential to become sustainable alternatives to petrochemical‐based plastics. Polybutylene succinate can be produced from bio‐based succinic acid and 1,4‐butanediol using first‐generation (1G) or second‐generation (2G) sugars. A cradle‐to‐grave environmental assessment was performed for PBS products in Europe to investigate the non‐renewable energy use (NREU) and greenhouse gas (GHG) impacts. The products investigated are single‐use trays and agricultural film, with incineration, industrial composting and degradation on agricultural land as end‐of‐life scenarios. Both end products manufactured from fully bio‐based PBS and from partly bio‐based PBS (made from bio‐based succinic acid and fossil fuel‐based 1,4 butanediol) were analysed. We examine corn (1G) as well as corn stover, wheat straw, miscanthus and hardwood as 2G feedstocks. For the cradle‐to‐grave system, 1G fully bio‐based PBS plastic products were found to have environmental impacts comparable with their petrochemical incumbents, while 2G fully bio‐based PBS plastic products allow to reduce NREU and GHG by around one third under the condition of avoidance of concentration of sugars and energy integration of the pretreatment process with monomer production. Without energy integration and with concentration of sugars (i.e., separate production), the impacts of 2G fully bio‐based PBS products are approximately 15–20% lower than those of 1G fully bio‐based PBS products. The environmental analysis of PBS products supports the value proposition related to PBS products while also pointing out areas requiring further research and development. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd
Planung und Ausführung von Fugen und Fugenabdichtungssystemen für WU‐Konstruktionen
Authors: Hohmann Rainer 
Published: February 2018

AbstractWasserundurchlässige Bauwerke aus Beton, sogenannte „Weiße Wannen”, müssen im Regelfall das Eindringen oder das Austreten von Wasser verhindern oder beides. Hierzu müssen alle Arbeitsfugen, Dehnfugen, Sollrissquerschnitte und Durchdringungen planmäßig dauerhaft wasserdicht abgedichtet werden. Die Ausbildung der Fugen und deren Abdichtung erfordern die besondere Beachtung von Planern und Ausführenden. Dies setzt vertiefte Kenntnisse über Fugen, die unterschiedlichen Fugenabdichtungssysteme und deren fachgerechter Anwendung voraus. Der Beitrag bietet einen Überblick über die Fugenabdichtungssysteme und gibt Hinweise für die Auswahl, Planung und Bauausführung der unterschiedlichen Fugenabdichtungssysteme.