bluuebunny/crossref_metadata_2025_split huggingface dataset:
Secondary aluminium, iron and silica phases across a volcanic soil climosequence, Galápagos Islands
Authors: Taboada Teresa , Ferro‐Vázquez Cruz , Stoops Georges , Martínez‐Cortizas Antonio , Rodríguez‐Flores Ruth , Rodríguez‐Lado Luis 
Published: January 2019

We applied selective dissolution extractions (Na‐pyrophosphate, acid oxalate, cold NaOH and citrate‐dithionite) to study Al, Fe and Si fractionation in 38 volcanic pedons located on the windward slopes of Santa Cruz (Galápagos Islands) that form a climosequence. The aim was to evaluate the distribution of secondary Fe, Al and Si phases in relation to environmental variables. Two main trends were observed: a geographical pattern in relation to altitude and a vertical differentiation within soil profiles. Soils from the drier coastal area had the smallest amounts of secondary Al, Fe and Si, whereas values were larger in soils at higher altitude, under a more humid climate. Organo–metallic complexes dominate the organic‐rich topsoils in these wetter areas as a result of larger availability of free Al, more humified organic matter with a greater capacity for metal adsorption and larger organic matter contributions from vegetation. This has led to increased accumulation of organic carbon in soils at higher altitudes. At lower elevations, inorganic secondary materials are more frequent, with short‐range‐order minerals prevailing in topsoils, whereas crystalline minerals dominate subsoils. Crystalline minerals are also frequent in some soils at higher altitudes in relation to acid pH. Vertical differentiation within the soil profile is also responsive to altitude: differences between topsoils and subsoils are generally more marked in soils at higher locations, thus wetter areas. A greater degree of weathering seems to be the main factor controlling both altitudinal trends and horizonation through its effect on pH, organic matter content and humification, ultimately controlled by climatic variation.Highlights

We analysed soils developed on volcanic material along the windward slope of Santa Cruz Island.
Organo–metallic complexes are abundant in acidic, organic‐rich epipedons at higher elevation.
Short‐range‐order minerals are more abundant in non‐acidic subsoils and tend to increase with altitude
Crystalline minerals predominate at lower elevation and in acidic subsoils at higher altitude.
Experimental comparison of thermal and solute dispersion under one‐dimensional water flow in saturated soils
Authors: Lu X. R. , Zhao H. L. , Qin Y. , Sun Y. , Li X. J. , Chen G. S. , Mou X. J. 
Published: January 2019

Thermal dispersion, which is similar to solute dispersion, results mainly from microscopic differences in pore‐scale water velocities in porous media. In this study, heat and Cl− were used as tracers to perform a systematic and quantitative comparison of the characteristics of coupled heat and solute dispersion through three types of saturated packed media (a sand, silt loam and sandy clay loam soil). An inverse model was used to calculate the thermal dispersion coefficient (Dh) and solute dispersion coefficient (Ds) by fitting a heat and solute transport model to the measured temperature and solute breakthrough curves obtained using the thermo–time domain reflectometry (thermo–TDR) technique under the same experimental conditions. Results showed that Ds and Dh were both described by a power function of water flux. Most importantly, heat and solute dispersivities had the same dimensions of length
, the magnitudes of which were maintained almost unchanged with water flux densities and depended considerably on soil texture. Fine‐textured soil had a greater dispersivity than did coarse‐textured soil, and solute dispersivity was 220% greater than heat dispersivity in sandy clay loam, about 92% greater in silt loam soil and 36% greater in sand. We suggest that the magnitude and dimension of heat dispersion were essentially comparable to those of solute dispersion, which provides a better understanding of the relation between heat and solute dispersion. It has also been shown to be advantageous in practice for using heat dispersion to quantify easily solute dispersion approximately (or vice versa).Highlights
Thermal and solute dispersion coefficients were power functions of water fluxes.
Heat and solute dispersivities had the same length and order of magnitude.
Thermal dispersion was experimentally comparable to solute dispersion.
Solute dispersion may be predicted quantitatively by heat dispersion values (or vice versa).
Medial pterygoid myositis in a Thoroughbred gelding
Authors: Tannahill V. J. , Giavitto A. , Munroe G. A. 
Published: January 2019

SummaryThis case report describes the investigation and treatment of an adult horse with purulent, malodorous exudate originating from a large intermandibular mass. Microbial culture of fluid aspirated from a draining tract yielded Peptostreptococcus and Prevotella species which are usually considered to originate from the oral cavity. Computed tomography (CT) was used to aid in the diagnosis and to allow careful presurgical planning, and the horse underwent successful debridement of the abscess cavity under general anaesthesia. Post‐operatively, the horse developed trismus (reduced opening of the jaws) but repeat CT identified that the surgery site was healing appropriately. It was recommended to continue feeding the horse hay to act as physiotherapy and the masticatory action of the horse subsequently returned to normal.
Cause‐specific mortality of the world’s terrestrial vertebrates
Authors: Hill Jacob E. , DeVault Travis L. , Belant Jerrold L. 
Published: January 2019

AbstractAimVertebrates are declining worldwide, yet a comprehensive examination of the sources of mortality is lacking. We conducted a global synthesis of terrestrial vertebrate cause‐specific mortality to compare the sources of mortality across taxa and determine predictors of susceptibility to these sources of mortality.LocationWorldwide.Time period1970–2018.Major taxa studiedMammals, birds, reptiles and amphibians.MethodsWe searched for studies that used telemetry to determine the cause of death of terrestrial vertebrates. We determined whether each mortality was caused by anthropogenic or natural sources and further classified mortalities within these two categories (e.g. harvest, vehicle collision and predation). For each study, we determined the diet and average adult body mass of the species and whether the study site permitted hunting. Mortalities were separated into juvenile or adult age classes. We used linear mixed effects models to predict the percentage of mortality from each source and the overall magnitude of mortality based on these variables.ResultsWe documented 42,755 mortalities of known cause from 120,657 individuals representing 305 vertebrate species in 1,114 studies. Overall, 28% of mortalities were directly caused by humans and 72% from natural sources. Predation (55%) and legal harvest (17%) were the leading sources of mortality.Main conclusionsHumans were directly responsible for more than one‐quarter of global terrestrial vertebrate mortality. Larger birds and mammals were harvested more often and suffered increased anthropogenic mortality. Anthropogenic mortality of mammals and birds outside areas that prohibited hunting was higher than within areas where hunting was prohibited. Mammals experienced shifts from predominately natural to anthropogenic mortality as they matured. Humans are a major contributor to terrestrial vertebrate mortality, potentially impacting evolutionary processes and ecosystem functioning.
Investigation of ZnFe2O4 spinel ferrite nanocrystalline screen‐printed thick films for application in humidity sensing
Authors: Nikolic Maria V. , Vasiljevic Zorka Z. , Lukovic Miloljub D. , Pavlovic Vera P. , Krstic Jugoslav B. , Vujancevic Jelena , Tadic Nenad , Vlahovic Branislav , Pavlovic Vladimir B. 
Published: January 2019

AbstractZinc ferrite nanocrystalline powder was obtained by solid state synthesis of starting zinc oxide and hematite nanopowders. Field emission scanning electron microscopy and transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy and Raman spectroscopy confirmed the formation of nanocrystalline zinc‐ferrite powder with a mixed spinel structure with small amounts of remaining zinc oxide and hematite as impurities. Thick film paste was formed and screen printed on test interdigitated PdAg electrodes on alumina substrate. Formation of a porous nanocrystalline structure was confirmed by scanning electron microscopy and Hg porosimetry. Humidity sensing properties of zinc ferrite thick films were investigated by monitoring the change in impedance in the relative humidity interval 30%‐90% in the frequency range 42 Hz‐1 MHz at room temperature (25°C) and 50°C. At 42 Hz at both analyzed temperatures the impedance reduced ~46 times in the humidity range 30%‐90%. The dominant influence of grain boundaries was confirmed by analysis of complex impedance with an equivalent circuit.
Use of a three‐tiered clinical decision rule to quantify unnecessary radiological investigation of suspected pulmonary embolism
Authors: Lim Lauren H. , Hayes Annabelle G. , Toh Dylan J. 
Published: January 2019

AbstractBackgroundClinical decision rules for suspected pulmonary embolism are proposed to identify patients suitable for discharge without radiological investigation. Their use varies between institutions.AimsTo quantify unnecessary radiological investigations for suspected pulmonary embolism (PE) as defined by a newly proposed three‐tiered clinical decision rule incorporating the revised Geneva score, Pulmonary Embolism Rule‐Out Criteria and D‐dimer. To quantify missed diagnosis of PE if the proposed clinical decision rule were followed.MethodsA retrospective audit was conducted; applying the proposed clinical decision rule to 584 emergency department (ED)‐based encounters at the Royal Adelaide Hospital from May to November 2015. Encounters were confined to emergency presentations where suspected acute PE was investigated with computed tomography pulmonary angiography or ventilation‐perfusion scanning; inpatient and follow‐up studies were excluded. Sensitivity, specificity, positive predictive value and negative predictive value of the proposed clinical decision rule within the studied population were calculated.ResultsData were obtained for 584 patient encounters where suspected PE was investigated radiologically. Applied retrospectively, the proposed clinical decision rule had a negative predictive value of 97.7% and a sensitivity of 98.5% for radiologically proven PE; 9.2% of scans could have been avoided. One case of PE would have been missed; a false‐negative rate of 1.5%.ConclusionRetrospective application of the proposed clinical decision rule to the studied cohort indicates at least 9% of radiological investigations were unnecessary. A prospective study is needed to assess the safety and cost‐effectiveness of applying such a pathway to all patients presenting to ED with suspected PE.
Fabrication of high‐strength porous SiC‐based composites with unidirectional channels
Authors: Cao Jiwei , Lu Zhongliang , Miao Kai , Zhao Hongjiong , Xia Yuanlin , wang Fu , Lu Bingheng 
Published: January 2019

AbstractCarbon fiber reinforced SiC‐based composites with unidirectional channels were obtained by freeze‐casting and chemical vapor infiltration techniques, and their microstructure and fracture behavior were investigated. The results indicated that the sizes of the unidirectional channels could be controlled in the 15‐70 μm range. The significant pseudo plastic and ductility features of the porous SiC‐based composite were demonstrated during the fracture process. The strains of the composites reached 4 ± 1% and 50 ± 6% during bending and compressive experiments, respectively. The bending and compressive strengths, 123 ± 20 and 99 ± 15 MPa, respectively, were far superior to those of homogeneous ceramics presenting the same porosity. Combining the aforesaid method with 3D printing techniques, a SiC‐based composite part with controlled macro‐micro channels was fabricated, which indicated that this method could be useful for fabricating ceramic parts with complex structure and superior mechanical performance.
Radiation interaction parameters of commercial building glasses at energies of interest for potential nuclear accidents
Authors: Al‐Hadeethi Yas , Tijani Saheed A. 
Published: January 2019

AbstractElemental composition, mass attenuation coefficients (MACs), effective atomic numbers (EANs), and effective electron densities (EEDs) give information about the nuclear applications of materials (dosimetry, shielding, etc.). In this work, MAC of some commercial building glasses were determined using the WinXCom computer program and GATE Monte Carlo code; additionally,EAN and EED of these glasses were also determined using related formulas, after the elemental compositions of the samples were determined by energy dispersive X‐ray spectroscopy (EDS) technique. These properties were determined at 59.5 keV (Am‐241), 380 keV (Ir‐192), 662 keV (Cs‐237), 1173 keV (Co‐60), and 1332 keV (Co‐60). These energies are of interest for any potential nuclear accident. The elemental compositions show the presence of C, O, Na, Mg, Si, and Ca in various percentages; MAC values ranged from about 0.05 to 0.225 cm2/g; EAN also ranged from about 9 to 11and EED is almost constant at all energies considered except at 59.5 keV where higher values were shown. The radiation interaction properties of the investigated glasses showed that they could be used as a dosimeters during emergency radiation exposure situations.
Mechanism studies of hydrothermal cold sintering of zinc oxide at near room temperature
Authors: Kang Xiaoyu , Floyd Richard , Lowum Sarah , Cabral Matthew , Dickey Elizabeth , Maria Jon‐Paul 
Published: January 2019

AbstractZinc oxide densification mechanisms occurring during the cold sintering process (CSP) are examined by investigating specifically the effects of ion concentration in solution, temperature, pressure, and die sealing. The experiments suggest that mass transport through solution is a primary densification mechanism and that either a pre‐loaded solution or grain dissolution can supply migrating ions. Additionally, results indicate cold sintering zinc oxide requires a critical pressure value, above which densification is relatively pressure independent under the majority of process conditions. This critical pressure is related to thermal expansion of the liquid and determines the uniaxial pressure threshold for densification. The data supports a three‐stage interpretation of cold sintering, which includes quick compaction, grain rearrangement, and dissolution‐reprecipitation events. Further, it is observed that under the lowest temperature conditions a net decrease in particle size can occur during the cold sintering process.
Surface shear stress relaxation of silica glass
Authors: Aaldenberg Emily M. , Aaldenberg Jared S. , Blanchet Thierry A. , Tomozawa Minoru 
Published: January 2019

AbstractA constant angle of twist was applied to silica glass rods in order to produce a torsional shear strain and a reduction in torque representative of the stress state in the glass was measured as a function of time when rods were heat‐treated in air at temperatures, 550‐700°C, far below the glass transition temperature. The monotonic decrease of torque with time was explained by surface stress relaxation, which can be described by a relaxation of stress at the surface of glass which is promoted by water. The obtained surface stress relaxation diffusion coefficients were consistent with those obtained earlier from silica glass fiber bending under a similar water vapor pressure. The observed relaxation in torsion supports the mechanism of surface stress relaxation over the swelling‐based mechanism for applications including glass fiber strengthening.
Ethical climate and service behaviours in nurses: The moderating role of employment type
Authors: Zhang Na , Gong Zhen‐Xing , Xu Zhen , Gilal Faheem Gul 
Published: January 2019

AbstractAimTo explore the relationship between ethical climate (EC) and nurses' service behaviours (SB) and examine the moderating effect of nurses' employment type.BackgroundAs most public hospitals in China implement the “dual‐track system” of nurses' employment, the two different types of nurses, contract‐employed nurses and state‐employed nurses, receive the different pay for the same work, which results in they providing different SB. It has become critical for hospital administrators and nursing managers to understand better the state of two groups of nurses and to find an effective method to improve the service level of the nursing workforce.DesignStepwise multiple regression analyses of survey data collected in June and July 2017 from Chinese nurses employed in three tertiary hospitals.MethodsChinese nurses (298 of 350 [85.1%]) were interviewed using the Ethical Climate Scale and Nurses' Service Behaviour Scale. Data were analysed statistically using descriptive statistics, confirmatory factor analysis, correlation coefficients (Pearson), two‐tailed t‐test and stepwise multiple regression analyses were conducted to test the proposed hypotheses. Data were analysed using SPSS and AMOS.ResultsThere were statistically significant correlations between EC and nurses' extra‐role service behaviour (ERSB) and overall service behaviour and nurses' employment type moderated the proposed relationships.ConclusionHealthcare institutions should pay more attention to cultivate EC and implement new incentive mechanism to better stimulate nurses to provide ERSB.
Can reciprocated parent–child eye gaze and emotional engagement enhance treatment for children with conduct problems and callous‐unemotional traits: a proof‐of‐concept trial
Authors: Dadds Mark R. , English Therese , Wimalaweera Subodha , Schollar‐Root Olivia , Hawes David J. 
Published: January 2019

BackgroundHigh levels of callous‐unemotional (CU) traits are associated with reduced effectiveness of parenting programmes for children with conduct problems. This may be due to low levels of emotional engagement (EE) by these children with their parents. We evaluate a theoretically driven strategy for improving emotional engagement in high CU traits children undergoing a parenting intervention (parent management training; PMT) for child conduct problems.MethodsN = 40, 3‐ to 8‐year‐old children referred for conduct problems and showing stable, high levels of CU traits, were randomised to receive PMT+Emotional Engagement (EE), or the control condition PMT+Child Centred Play (CCP). A benchmarking sample of N = 70 children who received PMT only was also included. Observational coding of the parent–child interactions targeted by EE and CCP respectively was repeated throughout treatment and follow‐up.ResultsEmotional engagement produced unique improvements in parent–child emotional engagement (shared eye gaze); however, these reverted to baseline levels after treatment. CCP produced unique improvements in parents’ child centeredness and child positive play, but by post‐treatment, all children had improved on these factors. Both interventions produced similar improvements in general parental warmth. Reductions in severity of conduct problems at post‐treatment and follow‐up were large in size and did not differ between conditions or from the benchmarking group. Levels of CU traits reduced significantly but again did not differ between groups.ConclusionsThe putative mechanism of emotional engagement through reciprocated eye gaze proved to be impervious to sustained change, and thus failed to have a specific impact of conduct problems or levels of CU traits. The development of novel treatment approaches to children with high levels of CU is a challenging endeavour, and these results indicate that focussing on children with stable levels at pretreatment should be a priority.
The balance of type 1 and type 2 immune responses in the contexts of hepatitis B infection and hepatitis D infection
Authors: Townsend Elizabeth C , Zhang Grace Y , Ali Rabab , Firke Marian , Moon Mi Sun , Han Ma Ai Thanda , Fram Benjamin , Glenn Jeffrey S , Kleiner David E , Koh Christopher , Heller Theo 
Published: January 2019

AbstractBackground and AimHepatitis delta virus (HDV) infection is the most rapidly progressive chronic viral hepatitis. Little is understood about the immune responses to HDV. This study aims to characterize the systemic immune environments of hepatitis B virus (HBV) and HDV patients at various disease stages.MethodsA total of 129 subjects were evaluated: 53 HBV, 43 HDV, and 33 healthy controls. HBV and HDV subjects were categorized by aspartate aminotransferase to platelet ratio index (APRI) into mild (APRI < 0.5), moderate, and severe (APRI > 1.0). Serum cytokines and immune markers were assessed at a single treatment‐naïve time‐point.ResultsType 1 cytokines are elevated in both HBV and HDV. Both groups show higher tumor necrosis factor‐α (TNF‐α), interleukin (IL)‐12p40, and C–X–C motif chemokine ligand 9 when compared with controls (all P < 0.05). However, only HBV group displayed elevated γ‐interferon compared with controls. Type 2 cytokines are elevated in HBV. HBV group shows higher IL‐4, IL‐13, and C–C motif chemokine ligand (CCL) 26 compared with healthy controls and HDV. Chemokines CCL2 and CCL13 are lower in HDV. When assessing ratios, HDV displays higher γ‐interferon/IL‐4, TNF‐α/IL‐4, and TNF‐α/IL‐13 ratios than HBV and controls.ConclusionHepatitis B virus and HDV subjects show similarly elevated type 1 cytokines. HDV subjects display relatively lower type 2 cytokines. These differences in the systemic immune environments, particularly the predominance of type 1 responses, may contribute to the comparatively rapid progression of HDV disease. Characterization of the imbalance in type 1 and type 2 immunity unique HDV has the potential to provide immunological insights for designing therapeutic targets in HDV‐associated disease progression.