bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mapping kindergartners’ quantitative competence
Authors: Van den Heuvel-Panhuizen Marja , Elia Iliada 
Published: February 2020

AbstractIn this study we investigated the structure of quantitative competence of kindergartners by testing a hypothesized four-factor model of quantitative competence consisting of the components counting, subitizing, additive reasoning and multiplicative reasoning. Data were collected from kindergartners in the Netherlands (n = 334) and in Cyprus (n = 304). A confirmatory factor analysis showed that the four-factor structure fitted the empirical data from the Netherlands. For the Cyprus data a one-factor structure was found to have a more adequate fit. Regarding the effect of country on performance, a comparison at item level showed that the kindergartners in the Netherlands outperformed those in Cyprus in the majority of quantitative competence items. Analyses of variance revealed for each country a significant effect of kindergarten year on performance, with children in K2 (second kindergarten year) outperforming those in K1 (first kindergarten year). A statistical implicative analysis at item level revealed that in both countries the relevant implicative chain, showing what successful solving of an item implies for correct solving of another item, reflects by and large the sequential steps mostly followed in teaching kindergartners early number. This sequence starts with counting and subitizing, then continues with additive reasoning and finally multiplicative reasoning. These implicative chains also clearly show that the development of early quantitative competence is not linear. There are many parallel processes and cross-connections between the components of quantitative competence.
Development of a novel model to predict HPAM viscosity with the effects of concentration, salinity and divalent content
Authors: Al-Hamairi Abdullah , AlAmeri Waleed 
Published: February 2020

AbstractPolymer flooding has been established as an effective enhanced oil recovery (EOR) technique and can be utilized in large-scale field expansions. With high success rates and efficiency, polymer flooding operates by increasing the viscosity of water, promoting greater sweep efficiency and resulting in higher oil recovery beyond conventional waterflooding. Predicting viscosity has been established by numerous researchers as an essential tool to study polymers behavior under varying conditions. Previous model has proven a link between polymer viscosity and zero shear rate viscosity, relaxation time, hardness, and many other factors. This research initially reviews different types of polymers that can be applied successfully in EOR, demonstrate conditions that can alter polymer viscosity in porous medium, and analyze models that predict polymer bulk and in situ viscosity. The research then discusses a novel modification of the power law model to predict HPAM (SAV10) viscosity in a wide range of shear rates based on polymer concentration, fluid salinity, and divalent content. A polymer rheology study was carried out on SAV10 at various concentrations (750–5000 ppm) and brine salinities (43–210 k ppm). Results show the effectiveness of the model and the ability to predict viscosity accurately in low to medium shear rates, while in high shear rate, a slight deviation was noticeable.
Mechanical and biocompatible properties of polymer-infiltrated-ceramic-network materials for dental restoration
Authors: Cui Bencang , Zhang Ranran , Sun Fengbo , Ding Qian , Lin Yuanhua , Zhang Lei , Nan Cewen 
Published: February 2020

AbstractDental restorative materials with high mechanical properties and biocompatible performances are promising. In this work, polymer-infiltrated-ceramic-network materials (PICNs) were fabricated via infiltrating polymerizable monomers into porous ceramic networks and incorporated with hydroxyapatite nano-powders. Our results revealed that the flexural strength can be enhanced up to 157.32 MPa, and elastic modulus and Vickers hardness can be achieved up to 19.4 and 1.31 GPa, respectively, which are comparable with the commercial computer-aided design and computer-aided manufacturing (CAD/CAM) blocks. Additionally, the adhesion and spreading of rat bone marrow mesenchymal stem cells (rBMSCs) on the surface of such materials can be improved by adding hydroxyapatite, which results in good biocompatibility. Such PICNs are potential applicants for their application in the dental restoration.
Red-emitting YAG: Ce, Mn transparent ceramics for warm WLEDs application
Authors: Ling Junrong , Zhou Youfu , Xu Wentao , Lin He , Lu Shuai , Wang Bin , Wang Kun 
Published: February 2020

AbstractA series of YAG:Ce,Mn transparent ceramics were prepared via a solid-state reaction-vacuum sintering method. The effects of various Mn2+–Si4+ pair doping levels on the structure, transmittance, and luminescence properties were systematically investigated. These transparent ceramics have average grain sizes of 10–16 μm, clean grain boundaries, and excellent transmittance up to 83.4% at 800 nm. Under the excitation of 460 nm, three obvious emission peaks appear at 533, 590, and 745 nm, which can be assigned to the transition 5d→4f of Ce 3+ and 4T1→6A1 of Mn2+. Thus, the Mn2+–Si4+ pairs can effectively modulate the emission spectrum by compensating broad orange-red and red spectrum component to yield high quality warm white light. After the optimized YAG:Ce,Mn transparent ceramic packaged with blue light-emitting diode (LED) chips, correlated color temperature (CCT) as low as 3723 K and luminous efficiency (LE) as high as 96.54 lm/W were achieved, implying a very promising candidate for application in white light-emitting diodes (WLEDs) industry.
Ubrogepant: First Approval
Authors: Scott Lesley J. 
Published: February 2020

AbstractUbrogepant (Ubrelvy™) is an orally administered, small molecule, highly-selective, calcitonin gene-related peptide (CGRP) antagonist that was developed by Allergan under license to Merck & Co. as an acute treatment for migraine. In December 2019, ubrogepant received its first global approval in the USA for the acute treatment of migraine (± aura) in adults. This article summarizes the milestones in the development of ubrogepant leading to its first global approval for the acute treatment of migraine (± aura) in adults.
Rural Finance, Capital Constrained Small Farms, and Financial Performance: Findings from a Primary Survey
Authors: Khanal Aditya R. , Omobitan Omobolaji 
Published: February 2020

AbstractCapital and credit constraints limit the small farm’s ability to adequately use resources for optimum performance. Farmers’ access to capital is constrained in multiple ways, including price factors, risk factors, and transaction factors, as well as access to and ease of rural agricultural financing. Using a primary survey data of small farms in Tennessee, we analyzed factors influencing credit constraint and its impact on farm performance. Farm operators’ gender, off-farm work, land acreage holdings, farm specialization, and the use of smart phone with Internet significantly influenced credit constraint. We found that the financial performance of credit constrained small farmers was significantly lower than that of unconstrained small farmers—an adverse impact of constrained capacity to credit could result in up to $51,000 lower in gross farm sales. Additionally, our reason-specific results within credit constraint suggested that around $32,000 to $39,000 lower performance in gross sales can be attributable to the constrained borrowing with deficit to obtain agricultural loans at required or desired level.
Using Telemedicine in Mass Casualty Disasters
Authors: Gregory Megan E. , Sonesh Shirley C. , Hughes Ashley M. , Marttos Antonio , Schulman Carl I. , Salas Eduardo 
Published: February 2020

ABSTRACTObjectives:The goal of this study is to test an implementation and examine users’ perceptions about the usefulness of telemedicine in mass casualty and disaster settings and to provide recommendations for using telemedicine in these settings.Methods:Ninety-two US Army Forward Surgical Team (FST) members participated in a high-fidelity mass casualty simulation at the Army Trauma Training Center (ATTC). Telemedicine was implemented into this simulation.Results:Only 10.9% of participants chose to use telemedicine. The most common users were surgeons and nurses. Participants believed it somewhat improved patient care, attainment of expert resources, decision-making, and adaptation, but not the timeliness of patient care. Participants reported several barriers to using telemedicine in the mass casualty setting, including (1) confusion around team roles, (2) time constraints, and (3) difficultly using in the mass casualty setting (eg, due to noise and other conditions).Conclusions:There appear to be barriers to the use and usefulness of telemedicine in mass casualty and disaster contexts. Recommendations include designating a member to lead the use of telemedicine, providing telemedical resources whose benefits outweigh the perceived cost in lost time, and ensuring telemedicine systems are designed for the conditions inherent to mass casualty and disaster settings.
Transmission of Coxiella burnetii by ingestion in mice
Authors: Miller H. K. , Priestley R. A. , Kersh G. J. 
Published: February 2020

Abstract
Coxiella burnetii, the causative agent of Q fever, is widely present in dairy products around the world. It has been isolated from unpasteurised milk and cheese and can survive for extended periods of time under typical storage conditions for these products. Although consumption of contaminated dairy products has been suggested as a potential route for transmission, it remains controversial. Given the high prevalence of C. burnetii in dairy products, we sought to examine the feasibility of transmitting the major sequence types (ST16, ST8 and ST20) of C. burnetii circulating in the United States. We delivered three strains of C. burnetii, comprising each sequence type, directly into the stomachs of immunocompetent BALB/c mice via oral gavage (OG) and assessed them for clinical symptoms, serological response and bacterial dissemination. We found that mice receiving C. burnetii by OG had notable splenomegaly only after infection with ST16. A robust immune response and persistence in the stomach and mesenteric lymph nodes were observed in mice receiving ST16 and ST20 by OG, and dissemination of C. burnetii to peripheral tissues was observed in all OG infected mice. These findings support the oral route as a mode of transmission for C. burnetii.
Q fever seroprevalence in Australia suggests one in twenty people have been exposed
Authors: Gidding H. F. , Peng C. Q. , Graves S. , Massey P. D. , Nguyen C. , Stenos J. , Quinn H. E. , McIntyre P. B. , Durrheim D. N. , Wood N. 
Published: February 2020

Abstract
Q fever (caused by Coxiella burnetii) is thought to have an almost world-wide distribution, but few countries have conducted national serosurveys. We measured Q fever seroprevalence using residual sera from diagnostic laboratories across Australia. Individuals aged 1–79 years in 2012–2013 were sampled to be proportional to the population distribution by region, distance from metropolitan areas and gender. A 1/50 serum dilution was tested for the Phase II IgG antibody against C. burnetii by indirect immunofluorescence. We calculated crude seroprevalence estimates by age group and gender, as well as age standardised national and metropolitan/non-metropolitan seroprevalence estimates. Of 2785 sera, 99 tested positive. Age standardised seroprevalence was 5.6% (95% confidence interval (CI 4.5%–6.8%), and similar in metropolitan (5.5%; 95% CI 4.1%–6.9%) and non-metropolitan regions (6.0%; 95%CI 4.0%–8.0%). More males were seropositive (6.9%; 95% CI 5.2%–8.6%) than females (4.2%; 95% CI 2.9%–5.5%) with peak seroprevalence at 50–59 years (9.2%; 95% CI 5.2%–13.3%). Q fever seroprevalence for Australia was higher than expected (especially in metropolitan regions) and higher than estimates from the Netherlands (2.4%; pre-outbreak) and US (3.1%), but lower than for Northern Ireland (12.8%). Robust country-specific seroprevalence estimates, with detailed exposure data, are required to better understand who is at risk and the need for preventive measures.
Intraoperative echocardiographic coronary artery imaging in congenital and acquired heart disease
Authors: Yim Deane , Mertens Luc , Honjo Osami , Nield Lynne E. 
Published: February 2020

AbstractTransoesophageal and epicardial echocardiography are indispensible intraoperative imaging modalities to guide paediatric heart disease surgeries and influence surgical decision-making. A less well-described role of intraoperative imaging is its utility in evaluating coronary artery patency and flow. Focused two-dimensional, colour, and spectral Doppler imaging of the coronary arteries should be performed during surgeries involving coronary manipulation or re-implantation, or in cases where there is unexpected ventricular dysfunction or electrographic signs concerning for ischaemia. Intraoperative imaging allows for any anatomical issues to be detected and addressed promptly in the operating room. Imaging of the coronary arteries should identify unobstructed coronary ostia and proximal course without kinking, angulation, narrowing, or significant calibre change to suggest stenosis or extrinsic compression from neighbouring structures. The aim of this review is to highlight the usefulness of transoesophageal and epicardial echocardiography in evaluating coronary artery patency and flow, provide a how-to guide for optimal imaging, and to introduce a practical guideline to achieve best clinical practice.
COMPUTATION OF ZEROS OF MONOTONE TYPE MAPPINGS: ON CHIDUME’S OPEN PROBLEM
Authors: DJITTE N. , MENDY J. T. , SOW T. M. M. 
Published: February 2020

For $p\geq 2$, let $E$ be a 2-uniformly smooth and $p$-uniformly convex real Banach space and let $A:E\rightarrow E^{\ast }$ be a Lipschitz and strongly monotone mapping such that $A^{-1}(0)\neq \emptyset$. For given $x_{1}\in E$, let $\{x_{n}\}$ be generated by the algorithm $x_{n+1}=J^{-1}(Jx_{n}-\unicode[STIX]{x1D706}Ax_{n})$, $n\geq 1$, where $J$ is the normalized duality mapping from $E$ into $E^{\ast }$ and $\unicode[STIX]{x1D706}$ is a positive real number in $(0,1)$ satisfying suitable conditions. Then it is proved that $\{x_{n}\}$ converges strongly to the unique point $x^{\ast }\in A^{-1}(0)$. Furthermore, our theorems provide an affirmative answer to the Chidume et al. open problem [‘Krasnoselskii-type algorithm for zeros of strongly monotone Lipschitz maps in classical Banach spaces’, SpringerPlus4 (2015), 297]. Finally, applications to convex minimization problems are given.
Monitoring Intraseasonal Oscillations in the Indian Ocean Using Satellite Observations
Authors: Roman‐Stork Heather L. , Subrahmanyam Bulusu , Trott Corinne B. 
Published: February 2020

AbstractIntraseasonal oscillations (ISOs) in the Indian Ocean play a significant role in determining the active (wet) and break (dry) cycles of the southwest monsoon rainfall. In this study, we use satellite‐derived precipitation, sea level anomalies (SLAs), sea surface salinity (SSS), sea surface temperature, and surface winds to monitor the 30‐90‐day, 10‐20‐day, and 3‐7‐day ISOs, and how they influence local dynamics. The main focus of this work, however, is showing the importance of using SLA and SSS to monitor ISOs. Mixed Rossby gravity waves were found to induce convection associated with the southern cell of the 10‐20‐day mode, with surface winds from the northern cell modulating coastal Kelvin waves in the Bay of Bengal. The 10‐20‐day SSS response is instead more closely related to wind‐induced upwelling in the central Bay of Bengal and river runoff in the northern Bay. The 3‐7‐day mode was found to have a weak oceanic signal, as the monsoon trough is mainly positioned over land, though SSS captured the structure of the signal most clearly. This study highlights the need for high spatial resolution SLA in order to adequately capture 3‐7‐day oscillations in the monsoon trough.
Seasonal Shift From Biogenic to Geogenic Fluvial Carbon Caused by Changing Water Sources in the Wet‐Dry Tropics
Authors: Duvert Clément , Hutley Lindsay B. , Birkel Christian , Rudge Mitchel , Munksgaard Niels C. , Wynn Jonathan G. , Setterfield Samantha A. , Cendón Dioni I. , Bird Michael I. 
Published: February 2020

AbstractThe riverine export of carbon is expected to be driven by changes in connectivity between source areas and streams. Yet we lack a thorough understanding of the relative contributions of different water sources to the dissolved carbon flux, and of the way these contributions vary with seasonal changes in flow connectivity. Here we assess the temporal variations in water and associated dissolved inorganic carbon (DIC) sources and fluxes in a wet‐dry tropical river of northern Australia over two years. We use linear mixing models integrated into a Bayesian framework to determine the relative contributions of rainfall, seasonal wetlands, shallow groundwater, and a deep carbonate aquifer to riverine DIC fluxes, which we relate to the age of water sources. Our results suggest extreme shifts in water and DIC sources between the wet and dry seasons. Under wet conditions, most DIC was of biogenic origin and transported by relatively young water sources originating from shallow groundwater and wetlands. As rainfall ceased, the wetlands either dried out or became disconnected from the stream network. From this stage, DIC switched to a geogenic origin, nearly entirely conveyed via older water sources from the carbonate formation. Our findings demonstrate the importance of changing patterns of connectivity when evaluating riverine DIC export from catchments. This work also illustrates the need to systematically partition DIC fluxes between biogenic and geogenic sources, if we are to quantify how the riverine export of carbon affects net carbon soil storage.
Subdaily‐Scale Chemical Variability in a Torreites Sanchezi Rudist Shell: Implications for Rudist Paleobiology and the Cretaceous Day‐Night Cycle
Authors: de Winter Niels J. , Goderis Steven , Van Malderen Stijn J.M. , Sinnesael Matthias , Vansteenberge Stef , Snoeck Christophe , Belza Joke , Vanhaecke Frank , Claeys Philippe 
Published: February 2020

AbstractThis study presents subdaily resolved chemical records through fossil mollusk shell calcite. Trace element profiles resolve periodic variability across ~40‐μm‐thin daily growth laminae in a Campanian Torreites sanchezi rudist bivalve. These high‐resolution records are combined with seasonally resolved stable isotope and trace element records that allow shell‐chemical variability to be discussed on both seasonal and daily scale. A combination of layer counting, spectral analysis of chemical cyclicity and chemical layer counting shows that the rudist precipitated 372 daily laminae per year, demonstrating that length of day has increased since the Late Cretaceous, as predicted by astronomical models. This new approach to determine the length of a solar day in geologic history through multiproxy chemical records at subdaily resolution yields considerably more control on the uncertainty of this estimate. Daily chemical variability exceeds seasonal variability in our records, and cannot be explained by diurnal temperature changes. Instead, we postulate that rudist shell chemistry is driven on a daily scale by changes in light intensity. These results together with those of stable isotope analyses provide strong evidence that Torreites rudists had photosymbionts. Bivalve shell calcite generally preserves well. Therefore, this study paves the way for daily‐scale reconstructions of paleoenvironment and sunlight intensity on geologic time scales from bivalve shells, potentially allowing researchers to bridge the gap between climate and weather reconstructions. Such reconstructions improve shell chronologies, document environmental change in warm ecosystems, and widen our understanding of the magnitude of short‐term changes during greenhouse climates.
Raw Signal Simulation of Synthetic Aperture Radar Altimeter Over Complex Terrain Surfaces
Authors: Zhu Zhanyu , Zhang Hai , Xu Feng 
Published: February 2020

AbstractIn comparison with the conventional radar altimeter, synthetic aperture radar altimeter (SRAL) is developed with better along‐track spatial resolution and height precision. When SRAL improves the performance of height measurement, it also complicates the radar system designing, signal processing, data analyzing, and system testing. The SRAL raw signal is the result of the interaction between the transmitted signal and the complex terrain surfaces. Generally, the SRAL is used in ocean applications since the PDF can be derived from different ocean surfaces. However, the actual acquired SRAL waveforms can be from complex and variable surface, which may include mountains, cities, forests, lakes, and other types of terrain surfaces. These waveforms contain information about the surfaces of the Earth although difficult to analyze. This paper focuses on the study of the raw signal simulation of SRAL for complex terrain surfaces including land surfaces. The principle of radar altimeter, the electromagnetic characteristics of land targets, and the SRAL signal processing are analyzed. The geometric models are extracted from digital elevation model, and the scattering characteristics of the terrain surface are established with three scattering models. Finally, three cases of terrain surfaces, namely, ice surface, mountain area, and urban area, are simulated and validated against actual SRAL signals measured by the Sentinel‐3 SRAL sensor.
An UAV Wireless Communication Noise Suppression Method Based on OFDM Modulation and Demodulation
Authors: Jia Yinsen , Tu Xinqi , Yan Wei 
Published: February 2020

AbstractIn view of the problem that the unmanned aerial vehicle (UAV) communication link is vulnerable to strong electromagnetic pulse generated by lightning or high‐voltage transmission lines in the complex electromagnetic environment, the influence of the electromagnetic pulse generated by the high‐voltage transmission line of the EFT electromagnetic pulse and the surge electromagnetic pulse on wireless communication link are analyzed in this paper. When those electromagnetic pulse's noise field strength is 500 V/m, the bit‐error‐rate of the communication link is increased to 45.39%, 45.39%, and 46.10%, respectively, indicating that surge pulse has the strongest influence on the communication link. Therefore, a UAV noise suppression method based on the principle of orthogonal frequency‐division multiplexing (OFDM) modulation and demodulation and dual antenna design has been proposed in this paper. This method is used to filter out electromagnetic impulse noise after wireless signal reception, and then demodulate to achieve the goal of noise suppression. Applying the method to a certain type of UAV based on OFDM modulation and demodulation, and theoretical analysis and simulation results show that the proposed method can effectively suppress the electromagnetic pulse generated by high‐voltage transmission lines, EFT electromagnetic pulse, surge electromagnetic pulse, the bit‐error‐rate dropped to 0.005597%, 0.004531%, 0.005597%, respectively.