bluuebunny/crossref_metadata_2025_split huggingface dataset:
An analytical model for describing sequential initiation and simultaneous propagation of multiple fractures in hydraulic fracturing shale oil/gas formations
Authors: Xiao Dong , Guo Boyun , Zhang Xiaohui 
Published: August 2019

AbstractFrac‐driven interactions (FDI) cause sharp declines in gas and oil production rates followed by slow recovery or no recovery. How to minimize the FDI is an open problem for researchers and engineers to solve in the energy industry. An analytical model is presented in this paper for simulating simultaneous propagations of multiple fractures to identify factors affecting FDI. Result of sensitivity analyses with the model indicates that increasing fluid injection rate can depress the growth of long fractures and thus reduce FDI intensity. Using dilatant fracturing fluids can slow down the growth of long fractures and thus reduce the chance of FDI. In order to better apply the model to solving the FDI problem, future research should include determination of the critical fracture width in different types of shale gas/oil formations.
The externalities of credit default swaps on stock return synchronicity
Authors: Zhao Ran , Zhu Lu 
Published: August 2019

AbstractWe examine the externality effect of customer firms’ credit default swap (CDS) trading on the stock price informativeness of supplier firms. Our empirical results show that firms with a high proportion of sales to CDS referenced customers tend to have more firm‐specific embedded information in their stock prices and thus higher stock price informativeness, which is associated with a lower level of stock return synchronicity. We provide new evidence of CDS trading externality on equity market information environments along the supply chain.
The time‐to‐maturity pattern of futures price sensitivity to news
Authors: Phan Hoang‐Long , Zurbruegg Ralf 
Published: August 2019

AbstractThis paper examines the effect time‐to‐maturity has on how sensitive futures prices are to news flows. Unscheduled daily news flows that relate to the underlying asset of a futures contract are related to the daily realized volatility of futures to calculate a price‐news sensitivity ratio. The observed pattern follows an inverted U‐shape relationship and has a bearing on whether the maturity effect will be noticeable in a futures contract. This paper also shows that by examining the peak‐to‐maturity of the price sensitivity to news pattern, it is possible to better identify which contracts are more likely to yield higher volatility.
Driver glance behaviors and scanning patterns: Applying static and dynamic glance measures to the analysis of curve driving with secondary tasks
Authors: Jeong Heejin , Kang Ziho , Liu Yili 
Published: August 2019

AbstractPerforming secondary tasks (or non‐driving‐related tasks) while driving on curved roads may be risky and unsafe. The purpose of this study was to explore whether driving safety in situations involving curved roads and secondary tasks can be evaluated using multiple measures of eye movement. We adopted Markov‐based transition algorithms (i.e., transition/stationary probabilities, entropy) to quantify drivers’ dynamic eye movement patterns, in addition to typical static visual measures, such as frequency and duration of glances. The algorithms were evaluated with data from an experiment (Jeong & Liu, 2019) involving multiple road curvatures and stimulus‐response secondary task types. Drivers were more likely to scan only a few areas of interest with a long duration in sharper curves. Total head‐down glance time was longer in less sharp curves in the experiment, but the probability of head‐down glances was higher in sharper curves over the long run. The number of reliable transitions between areas of interest varied with the secondary task type. The visual scanning patterns for visually undemanding tasks were as random as those for visually demanding tasks. Markov‐based measures of dynamic eye movements provided insights to better understand drivers’ underlying mental processes and scanning strategies, compared with typical static measures. The presented methods and results can be useful for in‐vehicle systems design and for further analysis of visual scanning patterns in the transportation domain.
Effect of ionizing radiation on mechanical properties and translucency of monolithic zirconia
Authors: Alshamrani Abdullah A. , De Souza Grace M. 
Published: August 2019

AbstractThis study aimed to evaluate the effect of radiation therapy (RT) on mechanical properties and translucency of monolithic zirconia. Yttria‐ stabilized zirconia (Y‐PSZ) materials (14 × 4.0 × 1.5 mm) were divided in four experimental groups (n = 30): High‐translucency/control (HT/C), high‐translucency/irradiated (HT/I), low‐translucency/control (LT/C), low‐translucency/irradiated (LT/I). Irradiated specimens were submitted to a single dose irradiation of 70 Gray. Flexural strength (n = 10) (FS—3‐point bending test), fatigue limits (n = 15) at 100,000 cycles (FLs—staircase approach), and translucency (n = 5) (TP—dental spectrometer) were analyzed. X‐ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the materials. FS and TP data were analyzed by one‐way Analysis of Variance (ANOVA) and Tukey HSD. FLs were analyzed using Dixon and Mood method, and Kaplan–Meier survival analysis. RT affected FS of LT zirconia (p = .032) but not of HT zirconia (p = .86). FLs and TP of both materials were not affected by RT (p > .05). Higher cubic content after RT was observed. In conclusion, RT may affect flexural strength and crystalline content of zirconia‐based materials, but this effect was not observed under fatigue. Translucency of Y‐PSZ restorations is also not affected by RT.
Histopathological patterns seen around failed metal‐on‐metal hip replacements: Cluster and latent class analysis of patterns of failure
Authors: Reito Aleksi , Lehtovirta Lari , Parkkinen Jyrki , Eskelinen Antti 
Published: August 2019

AbstractWe aimed to establish latent subtypes of histopathological patterns in failed metal‐on‐metal hip replacements. Tissue samples of the synovia from the neocapsule were retrieved from 284 revised ASR (Articular Surface Replacement) hip replacements and analyzed histologically. Hierarchical cluster analysis and polytomous latent class analysis were performed to establish the underlying structure and relationships of the histological observations and to find similar cohorts of cases. Clustering analyses suggested four distinct subtypes that could be readily and reasonably labeled and mapped against a recent consensus statement. The first two subtypes showed synovial necrosis, lymphocyte sheets, and abundant or thin histiocyte sheets. In addition, the first subtype showed abundant germinal centers and no metal particles either extracellularly or intracellularly. Metal particles were, however, seen in the second subtype. Hence, the first subtype was labeled “immunologic Type IV neosynovitis” and the second subtype “abrasion‐induced inflammatory lymphocytic Type I neosynovitis.” The third and fourth subtypes showed no perivascular and diffuse lymphocytes, but a higher number of metal particles intracellularly and extracellularly. The third subtype had synovial necrosis along with granulomas and was labeled “abrasion‐induced necrotic Type I neosynovitis,” whereas the fourth subtype had readily intact synovial lining, and this subtype was labeled “abrasion‐induced foreign body Type I neosynovitis.” Histopathological findings in failed MoM hips are not just one wide entity. These hips evince four different histological patterns that also differ at the macroscopic level. Moreover, the often stated “ALVAL‐type reaction” seems to be dualistic in nature, which is a novel finding.
Proliferation and Activation of Osterix‐Lineage Cells Contribute to Loading‐Induced Periosteal Bone Formation in Mice
Authors: Zannit Heather M , Silva Matthew J 
Published: August 2019

ABSTRACTMechanical loading stimulates bone formation. Bone‐lining‐cell activation and cell proliferation have been implicated in this process. However, the origin of osteoblasts that form bone following mechanical stimulation remains unknown. Our objective was to identity the contributions of activation, differentiation, and proliferation of osteoblast lineage cells to loading‐induced periosteal bone formation. Tamoxifen‐inducible Osx‐Cre‐ERT2;Ai9/TdTomato reporter mice (male and female) were aged to young adult (5 months) and middle age (12 months), and were administered tamoxifen for 5 consecutive days to label osterix‐lineage cells. Following a 3‐week clearance period, mice were subjected to five consecutive bouts of unilateral axial tibial compression. We first confirmed this protocol stimulated an increase in periosteal bone formation that was primarily lamellar apposition. Next, mice received 5‐bromo‐2′‐deoxyuridine (BrdU) in their drinking water daily to label proliferating cells; calcein was given to label active mineralizing surfaces. Tibias were harvested after the fifth loading day and processed for frozen undecalcified histology. The middiaphyseal periosteal surface in the region of peak bone formation was analyzed. Histology revealed both nonloaded and loaded tibias were covered in osterix positive (Osx+) cells on the periosteal surface of both 5‐ and 12‐month‐old animals. There was a significant increase in the mineralizing surface (calcein+) covered with Osx+ cells in loaded versus control limbs. Furthermore, nearly all of the mineralizing surfaces (>95%) were lined with Osx+ cells. We also observed approximately 30% of Osx+ cells were also BrdU+, indicating they arose via proliferation. These results show that following mechanical loading, pre‐existing cells of the Osx lineage cover the vast majority of surfaces where there is active loading‐induced bone formation, and a portion of these cells proliferated in the 5‐day loading period. We conclude the initial anabolic response after mechanical loading is based on the activation and proliferation of Osx lineage cells, not the differentiation of progenitor cells. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
Morphogenetic and constructional differences of the carapace of aquatic and terrestrial turtles and their evolutionary significance
Authors: Cherepanov Gennady 
Published: August 2019

AbstractThe postembryonic development of the turtle carapace was studied in the aquatic Еmys orbicularis and the terrestrial Тestudo graeca. Differences in the structure of the bony shell in aquatic and terrestrial turtles were shown to be associated with varying degrees of development of epidermal derivatives, namely, the thickness of the scutes and the depth of horny furrows. Sinking of the horny furrows into the dermis causes local changes in the structure of the collagen matrix, which might precondition the acceleration of the ossification. Aquatic turtles possess a relatively thin horny cover, whose derivatives are either weakly developed or altogether absent and thus make no noticeable impact on the growth dynamics of bony plates. Carapace plates of these turtles outgrow more or less evenly around the periphery, which results in uniform costals, relatively narrow and partly reduced neurals, and broad peripherals extending beyond the marginal scutes. In terrestrial turtles (Testudinidae), horny structures are much more developed and exert a considerable impact on the growth of bony elements. As a result, bony plates outgrow unevenly in the dermis, expanding fast in the zones under the horny furrows and slowly outside these zones. This determines the basic features of the testudinid carapace: alternately cuneate shape of costals, an alternation of broad octagonal and narrow tetragonal neurals, and the limitation of the growth of peripherals by pleuro‐marginal furrows. The evolutionary significance of morphogenetic and constructional differences in the turtle carapace, and the association of these differences with the turtle habitats are discussed.
Pancreatic perfusion modulation following glucose stimulation assessed by noninvasive arterial spin labeling (ASL) MRI
Authors: Taso Manuel , Papadopoulou Fotini , Smith Martin P. , Tsai Leo L. , Mortele Koenraad J. , Alsop David C. 
Published: August 2019

BackgroundMore than 100 million adults in the US suffer from prediabetes or type‐2 diabetes. Noninvasive imaging of pancreas endocrine function might provide a surrogate marker of β‐cell functional integrity loss linked to this disease.PurposeTo noninvasively assess pancreatic blood‐flow modulation following a glucose challenge using arterial spin labeling (ASL) MRI.Study Type: Prospective.SubjectsFourteen adults (30 ± 7 years old, 3M/11F, body mass index [BMI] = 24 ± 3 kg.m‐2).Field Strength/Sequence3T MRI / background‐suppressed pseudocontinuous PCASL preparation with single‐shot fast‐spin‐echo (FSE) readout before and after an oral glucose challenge using either fruit juice (n = 7) or over‐the‐counter glucose gel (n = 7).AssessmentSubjects were fasting prior to initiation of oral stimulation, then dynamic perfusion measurements were performed every 2 minutes for 30 minutes. We quantified absolute blood flow at each timepoint.Statistical TestsRepeated‐measures analysis of variance (ANOVA) followed by paired t‐tests to assess for a significant effect of glucose challenge on measured perfusion.ResultsMeasured basal blood flow was 187 ± 53 mL/100g/min. A significant blood flow increase of +38 ± 26% was observed 10 minutes poststimulation (P < 0.05) and continuing until the end of the experiment. The gel stimulation provided the most consistent results, with an early rise followed by an additional later increase consistent with the known pancreatic insulin response to elevated blood glucose. Across‐subject variations in blood flow increase were partially attributable to basal flow, with a negative correlation of r = –0.84 between basal and maximal relative flow increase in the gel group.Data ConclusionASL can be used to measure pancreatic flow in response to a glucose challenge, which could be linked to insulin release and secretion. This paradigm might be useful to characterize disorders of glucose regulation.Level of Evidence: 1Technical Efficacy: Stage 3J. Magn. Reson. Imaging 2020;51:854–860.
ESI‐MS/MS analysis of protonated N‐methyl amino acids and their immonium ions
Authors: Pallerla Pavankumar , Bhumireddy Sudarshana Reddy , Lingampally Sai Sachin , Ragi Nagarjuna Chary , Sripadi Prabhakar 
Published: August 2019

AbstractMethylation is one of the important posttranslational modifications of biological systems. At the metabolite level, the methylation process is expected to convert bioactive compounds such as amino acids, fatty acids, lipids, sugars, and other organic acids into their methylated forms. A few of the methylated amino acids are identified and have been proved as potential biomarkers for several metabolic disorders by using mass spectrometry–based metabolomics workstation. As it is possible to encounter all the N‐methyl forms of the proteinogenic amino acids in plant/biological systems, it is essential to have analytical data of all N‐methyl amino acids for their detection and identification. In earlier studies, we have reported the ESI‐MS/MS data of all methylated proteinogenic amino acids, except that of mono‐N‐methyl amino acids. In this study, the N‐methyl amino acids of all the amino acids (1‐21; including one isomeric pair) were synthesized and characterized by ESI‐MS/MS, LC/MS/MS, and HRMS. These data could be useful for detection and identification of N‐methyl amino acids in biological systems for future metabolomics studies. The MS/MS spectra of [M + H]+ ions of most N‐methyl amino acids showed respective immonium ions by the loss of (H2O, CO). The other most common product ions detected were [MH‐(NH2CH3]+, [MH‐(RH)]+ (where R = side chain group) ions, and the selective structure indicative product ions due to side chain and N‐methyl group. The isomeric/isobaric N‐methyl amino acids could easily be differentiated by their distinct MS/MS spectra. Further, the MS/MS of immonium ions inferred side chain structure and methyl group on α‐nitrogen of the N‐methyl amino acids.
Silver spray deposition for AgLDI imaging MS of cholesterol and other olefins on thin tissue sections
Authors: Yang Ethan , Fournelle Frédéric , Chaurand Pierre 
Published: August 2019

AbstractOlefins such as cholesterol and unsaturated fatty acids play important biological roles. Silver‐assisted laser desorption ionization (AgLDI) takes advantage of the strong affinity of silver to conjugate with double bonds to selectively ionize these molecules for imaging mass spectrometry (IMS) experiments. For IMS studies, two main approaches for silver deposition have been described in the literature: fine coating by silver sputtering and spray deposition of silver nanoparticles. While these approaches allow for extremely high resolution IMS experiments to be conducted, they are not readily available to all laboratories. Herein, we present a silver nitrate spray deposition approach as an alternative to silver sputtering and nanoparticle deposition for routine IMS analysis. The silver nitrate spray has the same level of specificity and sensitivity for olefins, particularly cholesterol, and has shown to be capable of IMS experiments down to 10‐μm spatial resolution. Minimal sample preparation and the affordability of silver nitrate make this a convenient and accessible technique worth considering.
Large‐scale atmospheric circulation control of summer extreme hot events over China
Authors: Li Muyuan , Luo Dehai , Yao Yao , Zhong Linhao 
Published: August 2019

AbstractA large‐scale high air temperature event in China during July 2017 is examined using observational reanalysis data. Based on this case study, summer extreme hot events (EHEs) over China are classified into five types using the self‐organizing map (SOM) method. The five EHE types include those over northeast China (NEC type), northwest China (NWC type), north China (NC type), mid‐eastern China (MEC type) and south China (SC type). All types are associated with sustainable anticyclones (EHE anticyclones). Composite analysis shows that the EHE anticyclone in northern China (corresponding to the NEC, NWC and NC types) is primarily formed by downstream wave train propagation from upstream blocking, while EHE anticyclone formation in southern China (corresponding to the MEC and SC types) is driven by the joint action of downstream wave train propagation and westward movement of the western Pacific subtropical high. Moreover, the upstream blocking and downstream EHE anticyclone embedded in the wave train play important roles in maintaining the wave train. The upstream blocking acts as an energy source for downstream EHE anticyclone intensification and leads to EHE formation, with the intensified zonal wind at certain latitudes affecting the wave train propagation direction. This finding indicates that the upstream blocking with intensified zonal wind at certain latitudes may serve as an indicator for the prediction of EHE anticyclones over China. As a consequence of the persistent EHE anticyclone, the land surface is primarily warmed by enhanced shortwave radiation through reduced regional cloud cover. For the NWC and NC types, heating of the lower atmosphere takes place via the sensible heat flux; whereas, for the NEC, MEC and SC types, the main heating terms are the latent heat flux, sensible heat flux and upward longwave radiation.
Precursor in Arctic oscillation for the East Asian January temperature and its relationship with stationary planetary waves: Results from CMIP5 models
Authors: Li Shuo , He Shengping , Li Fei , Wang Huijun 
Published: August 2019

AbstractThe emerging precursor in December Arctic oscillation (AO) for the following January temperature over East Asia (TEA) has been noticed by recent researches. This study evaluates the precursor in December AO for the following January TEA using 35 climate models from the Coupled Model Intercomparison Project Phase 5. Results indicate that, 24 (multi‐model ensemble mean; MME‐GOOD) out of total 35 models reproduce the statistically significant positive correlation between the December AO and the January TEA identified in the observation, but the remaining 11 models (MME‐BAD) fail. Further, the investigation focuses on these models' simulations for the December AO‐associated atmospheric circulation in January. Eighteen (MME‐GOOD‐18) out of the above 24 models reproduce the persistence of December AO‐related atmospheric circulation, including the seesaw structure of the sea level pressure anomalies, the sweeping southerly 850‐hPa wind anomalies over the East Asia–Northwest Pacific region, the weakening of the East Asian trough, and the weakened meridional shear of the East Asian jet stream in January following an enhanced December AO. It is found that the propagation of stationary planetary waves plays a crucial role in connecting the December AO and the January TEA. Therefore, the models' ability to simulate the stratosphere–troposphere interaction is essential for the successful simulations on the persistence of December AO. Additionally, the future projections indicate that the precursor in December AO for the following January TEA is still robust during the 21st century.
Illustration of Multilevel Explanatory IRT Model DIF Testing with the Creative Thinking Scale
Authors: Qian Meihua , Wang Xianyong 
Published: August 2019

ABSTRACTCreativity has been well studied in the past several decades, and numerous measures have been developed to assess creativity. However, validity evidence associated with each measure is often mixed. In particular, the social consequence aspect of validity has received little attention. This is partly due to the difficulty of testing for differential item functioning (DIF) within the traditional classical test theory framework, which still remains the most popular approach to assessing creativity. Hence, this study provides an example of examining differential item functioning using multilevel explanatory item response theory models. The Creative Thinking Scale was tested for DIF in a sample of 1043 10th–12th graders. Results revealed significant uniform and non‐uniform DIF for some items. Differentially functioning items are able to produce measurement bias and should be either deleted or modeled. The detailed implications for researchers and practitioners are discussed.