bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pore‐scale simulation of carbonate dissolution in micro‐CT images
Authors: Pereira Nunes J. P. , Blunt M. J. , Bijeljic B. 
Published: January 2016

AbstractWe present a particle‐based method to simulate carbonate dissolution at the pore scale directly on the voxels of three‐dimensional micro‐CT images. The flow field is computed on the images by solving the incompressible Navier‐Stokes equations. Rock‐fluid interaction is modeled using a three‐step approach: solute advection, diffusion, and reaction. Advection is simulated with a semianalytical pore‐scale streamline tracing algorithm, diffusion by random walk is superimposed, while the reaction rate is defined by the flux of particles through the pore‐solid interface. We derive a relationship between the local particle flux and the independently measured batch calcite dissolution rate. We validate our method against a dynamic imaging experiment where a Ketton oolite is imaged during CO2‐saturated brine injection at reservoir conditions. The image‐calculated increases in porosity and permeability are predicted accurately, and the spatial distribution of the dissolution front is correctly replicated. The experiments and simulations are performed at a high flow rate, in the uniform dissolution regime – Pe ≫ 1 and PeDa ≪ 1—thus extending the reaction throughout the sample. Transport is advection dominated, and dissolution is limited to regions with significant inflow of solute. We show that the sample‐averaged reaction rate is 1 order of magnitude lower than that measured in batch reactors. This decrease is the result of restrictions imposed on the flux of solute to the solid surface by the heterogeneous flow field, at the millimeter scale.
Observations of grain size sensitive power law creep of olivine aggregates over a large range of lattice‐preferred orientation strength
Authors: Tielke Jacob A. , Hansen Lars N. , Tasaka Miki , Meyers Cameron , Zimmerman Mark E. , Kohlstedt David L. 
Published: January 2016

AbstractGrain size sensitive (GSS) power law creep of San Carlos olivine aggregates was investigated by comparing strain rates measured in laboratory deformation experiments to strain rates determined from a micromechanical model of intragranular dislocation processes. The plastic flow behavior of olivine aggregates due solely to intragranular slip was determined using flow laws for olivine single crystals in combination with grain orientations measured by electron backscatter diffraction. Measured strain rates were compared to results from the micromechanical model for samples deformed in compression to an axial strain of <0.2 and in torsion to a shear strain of up to 7.4. Olivine aggregates deform up to a factor of 4.6 times faster than the maximum possible rates determined from the micromechanical model of intragranular slip. Comparison of our data to published flow laws indicates that diffusion creep cannot account for this difference. The ratio of experimentally determined strain rates to those from the micromechanical model is strongly dependent upon grain size but is independent of stress and strength of lattice‐preferred orientation. These observations indicate that GSS power law creep, consistent with dislocation‐accommodated grain boundary sliding, occurs in both weakly and strongly textured olivine aggregates at the studied conditions.
Memorable Tourist Experiences and Place Attachment When Consuming Local Food
Authors: Tsai Chen‐Tsang (Simon) 
Published: January 2016

AbstractThe purpose of the study was to model the memorable travel experiences, place attachment and behavioral intentions for consuming local food. Data were collected by self‐administered surveys of 378 tourists visiting Tainan, Taiwan. The survey results show that the experiences of consuming local cuisines enable tourists to create positive and unforgettable memories, and such positive memories further enhance their identification with or strong attachment to local attractions and behavioral intention. Place identity under place attachment also revealed mediating effects between memorable travel experiences and behavioral intention. Copyright © 2016 John Wiley & Sons, Ltd.
A case of Human Bone Chalcolithic Technology from the Perdigões site (Alentejo, Portugal)
Authors: Cunha C. , Almeida N. J. , Santander B. , Tomé T. , Saladié P. , Valera A. , Cabaço N. , Silva A. M. 
Published: January 2016

AbstractA human femur diaphysis in the form of a burin was excavated from a secondary burial context containing osteological remains and industry in the Archaeological Complex of Perdigões (Portugal). The majority of these evidences are thermo‐altered and highly fragmented. Radiocarbon dates for this context place it in the middle 3rd millennium BC. Typological analyses indicate that the human femur fragment is a burin, and use‐wear comparisons suggest that it was used to drill hide. Copyright © 2016 John Wiley & Sons, Ltd.
Can stochastic discount factor models explain the cross‐section of equity returns?
Authors: Abhakorn Pongrapeeporn , Smith Peter N. , Wickens Michael R. 
Published: January 2016

AbstractWe propose a multivariate test of the capital asset pricing model (C‐CAPM) of the cross‐sectional variation in equity returns in which we compare cross‐sectional variation in equity returns to the cross‐sectional variation in their conditional covariance with stochastic discount factors. We use a multivariate generalized heteroskedasticity in mean model to estimate 25 portfolios that are formed on size and the book‐to‐market ratio. Each portfolio is allowed to have its own no‐arbitrage condition. We find that although the conditional covariances of returns with consumption exhibit negative variation across size, they do not vary across the book‐to‐market ratio. Thus, C‐CAPM can capture the size effect, but not the value effect. The fit is, however, improved by allowing the coefficients on the consumption covariances to be different. The value effect appears to be associated with the book‐to‐market ratio as well as size. On its own the book‐to‐market ratio does not generate additional information about average returns to C‐CAPM. A possible explanation for these findings is that both small and low book‐to‐market ratio firms are expected to have higher rates of growth.
The regularity and stability of solutions to semilinear fourth-order elliptic problems with negative exponents
Authors: Lai Baishun 
Published: January 2016

We examine the regularity of the extremal solution of the nonlinear eigenvalue problemon a general bounded domainΩin ℝN, with Navier boundary conditionu= Δuon ∂Ω. Firstly, we prove the extremal solution is smooth for anyp> 1 andN⩽ 4, which improves the result of Guo and Wei (Discrete Contin. Dynam. Syst.A34(2014), 2561–2580). Secondly, ifp= 3,N= 3, we prove that any radial weak solution of this nonlinear eigenvalue problem is smooth in the caseΩ= 𝔹, which completes the result of Dávilaet al. (Math. Annalen348(2009), 143–193). Finally, we also consider the stability of the entire solution of Δ2u= –l/upin ℝNwithu> 0.
Arsenic exposure and the seroprevalence of total hepatitis A antibodies in the US population: NHANES, 2003–2012
Authors: CARDENAS A. , SMIT E. , BETHEL J. W. , HOUSEMAN E. A. , KILE M. L. 
Published: January 2016

SUMMARYWe evaluated the association between urinary arsenic and the seroprevalence of total hepatitis A antibodies (total anti-HAV: IgG and IgM) in 11 092 participants aged ⩾6 years using information collected in the US National Health and Nutrition Examination Survey (2003–2012). Multivariate logistic regression models evaluated associations between total anti-HAV and total urinary arsenic defined as the sum of arsenite, arsenate, monomethylarsonate and dimethylarsinate (TUA1). Effect modification by self-reported HAV immunization status was evaluated. Total anti-HAV seroprevalence was 35·1% [95% confidence interval (CI) 33·3–36·9]. Seropositive status was associated with higher arsenic levels and this association was modified by immunization status (P= 0·03). For participants that received ⩾2 vaccine doses or did not know if they had received any doses, a positive dose-response association was observed between increasing TUA1 and odds of total anti-HAV [odds ratio (OR) 1·42, 95% CI 1·11–1·81; and OR 1·75, 95% CI 1·22–2·52], respectively. A positive but not statistically significant association was observed in those who received <2 doses (OR 1·46, 95% CI 0·83–2·59) or no dose (OR 1·12, 95% CI 0·98–1·30). Our analysis indicates that prevalent arsenic exposure was associated with positive total anti-HAV seroprevalence. Further studies are needed to determine if arsenic increases the risk for incident hepatitis A infection or HAV seroconversion.
Genomic architecture of inflammatory bowel disease in five families with multiple affected individuals
Authors: Stittrich Anna B , Ashworth Justin , Shi Mude , Robinson Max , Mauldin Denise , Brunkow Mary E , Biswas Shameek , Kim Jin-Man , Kwon Ki-Sun , Jung Jae U , Galas David , Serikawa Kyle , Duerr Richard H , Guthery Stephen L , Peschon Jacques , Hood Leroy , Roach Jared C , Glusman Gustavo 
Published: January 2016

AbstractCurrently, the best clinical predictor for inflammatory bowel disease (IBD) is family history. Over 163 sequence variants have been associated with IBD in genome-wide association studies, but they have weak effects and explain only a fraction of the observed heritability. It is expected that additional variants contribute to the genomic architecture of IBD, possibly including rare variants with effect sizes larger than the identified common variants. Here we applied a family study design and sequenced 38 individuals from five families, under the hypothesis that families with multiple IBD-affected individuals harbor one or more risk variants that (i) are shared among affected family members, (ii) are rare and (iii) have substantial effect on disease development. Our analysis revealed not only novel candidate risk variants but also high polygenic risk scores for common known risk variants in four out of the five families. Functional analysis of our top novel variant in the remaining family, a rare missense mutation in the ubiquitin ligase TRIM11, suggests that it leads to increased nuclear factor of kappa light chain enhancer in B-cells (NF-κB) signaling. We conclude that an accumulation of common weak-effect variants accounts for the high incidence of IBD in most, but not all families we analyzed and that a family study design can identify novel rare variants conferring risk for IBD with potentially large effect size, such as the TRIM11 p.H414Y mutation.
Molar tooth carbonates and benthic methane fluxes in Proterozoic oceans
Authors: Shen Bing , Dong Lin , Xiao Shuhai , Lang Xianguo , Huang Kangjun , Peng Yongbo , Zhou Chuanming , Ke Shan , Liu Pengju 
Published: January 2016

AbstractMolar tooth structures are ptygmatically folded and microspar-filled structures common in early- and mid-Proterozoic (∼2,500–750 million years ago, Ma) subtidal successions, but extremely rare in rocks <750 Ma. Here, on the basis of Mg and S isotopes, we show that molar tooth structures may have formed within sediments where microbial sulphate reduction and methanogenesis converged. The convergence was driven by the abundant production of methyl sulphides (dimethyl sulphide and methanethiol) in euxinic or H2S-rich seawaters that were widespread in Proterozoic continental margins. In this convergence zone, methyl sulphides served as a non-competitive substrate supporting methane generation and methanethiol inhibited anaerobic oxidation of methane, resulting in the buildup of CH4, formation of degassing cracks in sediments and an increase in the benthic methane flux from sediments. Precipitation of crack-filling microspar was driven by methanogenesis-related alkalinity accumulation. Deep ocean ventilation and oxygenation around 750 Ma brought molar tooth structures to an end.
Computational multiqubit tunnelling in programmable quantum annealers
Authors: Boixo Sergio , Smelyanskiy Vadim N. , Shabani Alireza , Isakov Sergei V. , Dykman Mark , Denchev Vasil S. , Amin Mohammad H. , Smirnov Anatoly Yu , Mohseni Masoud , Neven Hartmut 
Published: January 2016

AbstractQuantum tunnelling is a phenomenon in which a quantum state traverses energy barriers higher than the energy of the state itself. Quantum tunnelling has been hypothesized as an advantageous physical resource for optimization in quantum annealing. However, computational multiqubit tunnelling has not yet been observed, and a theory of co-tunnelling under high- and low-frequency noises is lacking. Here we show that 8-qubit tunnelling plays a computational role in a currently available programmable quantum annealer. We devise a probe for tunnelling, a computational primitive where classical paths are trapped in a false minimum. In support of the design of quantum annealers we develop a nonperturbative theory of open quantum dynamics under realistic noise characteristics. This theory accurately predicts the rate of many-body dissipative quantum tunnelling subject to the polaron effect. Furthermore, we experimentally demonstrate that quantum tunnelling outperforms thermal hopping along classical paths for problems with up to 200 qubits containing the computational primitive.
Lessons learnt from a primary care asthma improvement project
Authors: Lenney Warren , Clayton Sadie , Gilchrist Francis J , Price David , Small Iain , Smith Judy , Sutton Emma J 
Published: January 2016

AbstractAsthma is a very common disease that can occur at any age. In the UK and in many other countries it is mainly managed in primary care. The published evidence suggests that the key to improving diagnosis and management lies in better training and education rather than in the discovery of new medications. An asthma improvement project managed through the British Lung Foundation is attempting to do this. The project has three pilot sites: two in England supported by the Department of Health and one in Scotland supported by the Scottish Government. If the project is successful it will be rolled out to other health areas within the UK. The results of this project are not yet available. This article highlights the challenges encountered in setting up the project and may well be applicable to other areas in the UK and to other countries where similar healthcare systems exist. The encountered challenges reflect the complex nature of healthcare systems and electronic data capture in primary care. We discuss the differences between general practices in their ability and willingness to support the project, the training and education of their staff on asthma management, governance issues in relation to information technology systems, and the quality of data capture. Virtually all the challenges have now been overcome, but discussing them should ensure that others become aware of them at an early stage should they wish to undertake similar projects in the future.
Elderly male smokers with right lung tumors are viable candidates for KRAS mutation screening
Authors: Yang Yang , Shi Chun , Sun Hui , Yin Wei , Zhou Xiao , Zhang Lei , Jiang Gening 
Published: January 2016

AbstractGenetic aberrations in tumor driver genes provide specific molecular targets for therapeutic intervention, which can greatly improve therapeutic outcomes. Here, we analyzed the mutational frequency of EGFR and KRAS gene, as well as EML4-ALK rearrangement and summarized the clinicopathological characters of Chinese lung cancer patients. We detected the mutation spectrum of 1033 primary lung cancer patients. The analyzed clinicopathological parameters included gender, age at diagnosis, smoking status, pathological TNM stage, tumor morphology and location, visceral pleural invasion and histological type. A total of 618 patients had mutations in EGFR or KRAS gene as well as rearrangement of EML4-ALK. Exon 19 deletions and L858R in the EGFR gene were the most frequent mutations. Left-side lung cancer was more common in female patients carrying the KRAS mutation. Rearrangement of EML4-ALK was more common in non-tobacco-using male patients, who also exhibited a higher likelihood of visceral pleura invasion. Elderly females who never smoked and possessed 1–20 mm stage I adenocarcinomas in the right side exhibited a higher frequency of EGFR mutations. Elderly male smokers with right lung tumors were viable candidates for KRAS mutation screening.
Synthesis and DFT investigation of new bismuth-containing MAX phases
Authors: Horlait Denis , Middleburgh Simon C. , Chroneos Alexander , Lee William E. 
Published: January 2016

AbstractThe Mn + 1AXn phases (M = early transition metal; A = group A element and X = C and N) are materials exhibiting many important metallic and ceramic properties. In the present study powder processing experiments and density functional theory calculations are employed in parallel to examine formation of Zr2(Al1−xBix)C (0 ≤ x ≤ 1). Here we show that Zr2(Al1−xBix)C and particularly with x ≈ 0.58, can be formed from powders even though the end members Zr2BiC and Zr2AlC seemingly cannot. This represents a significant extension of the MAX phase family, as this is the first report of a bismuth-based MAX phase.
Water Dynamics in Shewanella oneidensis at Ambient and High Pressure using Quasi-Elastic Neutron Scattering
Authors: Foglia Fabrizia , Hazael Rachael , Simeoni Giovanna G. , Appavou Marie-Sousai , Moulin Martine , Haertlein Michael , Trevor Forsyth V. , Seydel Tilo , Daniel Isabelle , Meersman Filip , McMillan Paul F. 
Published: January 2016

AbstractQuasielastic neutron scattering (QENS) is an ideal technique for studying water transport and relaxation dynamics at pico- to nanosecond timescales and at length scales relevant to cellular dimensions. Studies of high pressure dynamic effects in live organisms are needed to understand Earth’s deep biosphere and biotechnology applications. Here we applied QENS to study water transport inShewanella oneidensisat ambient (0.1 MPa) and high (200 MPa) pressure using H/D isotopic contrast experiments for normal and perdeuterated bacteria and buffer solutions to distinguish intracellular and transmembrane processes. The results indicate that intracellular water dynamics are comparable with bulk diffusion rates in aqueous fluids at ambient conditions but a significant reduction occurs in high pressure mobility. We interpret this as due to enhanced interactions with macromolecules in the nanoconfined environment. Overall diffusion rates across the cell envelope also occur at similar rates but unexpected narrowing of the QENS signal appears between momentum transfer valuesQ = 0.7–1.1 Å−1corresponding to real space dimensions of 6–9 Å. The relaxation time increase can be explained by correlated dynamics of molecules passing through Aquaporin water transport complexes located within the inner or outer membrane structures.
Compact Nonlinear Yagi-Uda Nanoantennas
Authors: Xiong Xiaoyan Y. Z. , Jiang Li Jun , Sha Wei E. I. , Lo Yat Hei , Chew Weng Cho 
Published: January 2016

AbstractNanoantennas have demonstrated unprecedented capabilities for manipulating the intensity and direction of light emission over a broad frequency range. The directional beam steering offered by nanoantennas has important applications in areas including microscopy, spectroscopy, quantum computing and on-chip optical communication. Although both the physical principles and experimental realizations of directional linear nanoantennas has become increasingly mature, angular control of nonlinear radiation using nanoantennas has not been explored yet. Here we propose a novel concept of nonlinear Yagi-Uda nanoantenna to direct second harmonic radiation from a metallic nanosphere. By carefully tuning the spacing and dimensions of two lossless dielectric elements, which function respectively as a compact director and reflector, the second harmonic radiation is deflected 90 degrees with reference to the incident light (pump) direction. This abnormal light-bending phenomenon is due to the constructive and destructive interference between the second harmonic radiation governed by a special selection rule and the induced electric dipolar and magnetic quadrupolar radiation from the two dielectric antenna elements. Simultaneous spectral and spatial isolation of scattered second harmonic waves from incident fundamental waves pave a new way towards nonlinear signal detection and sensing.
Change Point Detection in Correlation Networks
Authors: Barnett Ian , Onnela Jukka-Pekka 
Published: January 2016

AbstractMany systems of interacting elements can be conceptualized as networks, where network nodes represent the elements and network ties represent interactions between the elements. In systems where the underlying network evolves, it is useful to determine the points in time where the network structure changes significantly as these may correspond to functional change points. We propose a method for detecting change points in correlation networks that, unlike previous change point detection methods designed for time series data, requires minimal distributional assumptions. We investigate the difficulty of change point detection near the boundaries of the time series in correlation networks and study the power of our method and competing methods through simulation. We also show the generalizable nature of the method by applying it to stock price data as well as fMRI data.
Experimental demonstration of plasmon enhanced energy transfer rate in NaYF4:Yb3+,Er3+ upconversion nanoparticles
Authors: Lu Dawei , Mao Chenchen , Cho Suehyun K. , Ahn Sungmo , Park Wounjhang 
Published: January 2016

AbstractEnergy transfer upconversion (ETU) is known to be the most efficient frequency upconversion mechanism. Surface plasmon can further enhance the upconversion process, opening doors to many applications. However, ETU is a complex process involving competing transitions between multiple energy levels and it has been difficult to precisely determine the enhancement mechanisms. In this paper, we report a systematic study on the dynamics of the ETU process in NaYF4:Yb3+,Er3+ nanoparticles deposited on plasmonic nanograting structure. From the transient near-infrared photoluminescence under various excitation power densities, we observed faster energy transfer rates under stronger excitation conditions until it reached saturation where the highest internal upconversion efficiency was achieved. The experimental data were analyzed using the complete set of rate equations. The internal upconversion efficiency was found to be 56% and 36%, respectively, with and without the plasmonic nanograting. We also analyzed the transient green emission and found that it is determined by the infrared transition rate. To our knowledge, this is the first report of experimentally measured internal upconversion efficiency in plasmon enhanced upconversion material. Our work decouples the internal upconversion efficiency from the overall upconverted luminescence efficiency, allowing more targeted engineering for efficiency improvement.
Unique Static Magnetic and Dynamic Electromagnetic Behaviors in Titanium Nitride/Carbon Composites Driven by Defect Engineering
Authors: Gong Chunhong , Meng Hongjie , Zhao Xiaowei , Zhang Xuefeng , Yu Laigui , Zhang Jingwei , Zhang Zhijun 
Published: January 2016

AbstractRecently, the defect-induced static magnetic behaviours of nanomaterials have been a cutting-edge issue in diluted magnetic semiconductor materials. However, the dynamic magnetic properties of nanomaterials are commonly ignored if their bulk counterparts are non-magnetic. In the present research, titanium nitride-carbon (TiN/C) nanocomposites were found to exhibit both static and dynamic magnetic properties that vary in the opposite trend. Moreover, novel unconventional electromagnetic resonance behaviour was demonstrated in TiN/C systems and their permeability and permittivity show similar trend. This is challenging for the traditional understanding of electromagnetism and makes it possible to achieve an appropriate balance between the permeability and permittivity simultaneously in a simple system. Hopefully, the results could provide some valuable clues to revealing the magnetism and electromagnetism of nanostructures.