bluuebunny/crossref_metadata_2025 huggingface dataset:
An automated system for performing continuous viscosity versus temperature measurements of fluids using an Ostwald viscometer
Authors: Beaulieu L. Y. , Logan E. R. , Gering K. L. , Dahn J. R.
Published: October 2017

An automated system was developed to measure the viscosity of fluids as a function of temperature using image analysis tracking software. An Ostwald viscometer was placed in a three-wall dewar in which ethylene glycol was circulated using a thermal bath. The system collected continuous measurements during both heating and cooling cycles exhibiting no hysteresis. The use of video tracking analysis software greatly reduced the measurement errors associated with measuring the time required for the meniscus to pass through the markings on the viscometer. The stability of the system was assessed by performing 38 consecutive measurements of water at 42.50 ± 0.05 °C giving an average flow time of 87.7 ± 0.3 s. A device was also implemented to repeatedly deliver a constant volume of liquid of 11.00 ± 0.03 ml leading to an average error in the viscosity of 0.04%. As an application, the system was used to measure the viscosity of two Li-ion battery electrolyte solvents from approximately 10 to 40 °C with results showing excellent agreement with viscosity values calculated using Gering’s Advanced Electrolyte Model (AEM).
Premelting, solid-fluid equilibria, and thermodynamic properties in the high density region based on the Lennard-Jones potential
Authors: Köster Andreas , Mausbach Peter , Vrabec Jadran
Published: October 2017

The Lennard-Jones potential is used to study the high density fluid and face centered cubic solid state region, including solid-fluid equilibria. Numerous thermodynamic properties are considered, elucidating the behavior of matter in this poorly studied region. The present molecular simulation results are extensively compared to the latest and most accurate equation of state models for fluid and solid phases. It is shown that current models do not cover the thermodynamics of the system adequately near the solid-fluid phase transition. Furthermore, thermodynamic stability is analyzed, indicating that published solid-fluid coexistence data may not be correct at high temperatures. Particular attention is paid to the premelting zone, a range of states close to the melting line, which is characterized by strong variations of several thermodynamic properties. Because the underlying microscopic mechanisms are not yet fully understood, it is hoped that these data may contribute to the development of a theoretical framework for describing premelting effects.
Driving range estimation for electric vehicles based on driving condition identification and forecast
Authors: Pan Chaofeng , Dai Wei , Chen Liao , Chen Long , Wang Limei
Published: October 2017

With the impact of serious environmental pollution in our cities combined with the ongoing depletion of oil resources, electric vehicles are becoming highly favored as means of transport. Not only for the advantage of low noise, but for their high energy efficiency and zero pollution. The Power battery is used as the energy source of electric vehicles. However, it does currently still have a few shortcomings, noticeably the low energy density, with high costs and short cycle life results in limited mileage compared with conventional passenger vehicles. There is great difference in vehicle energy consumption rate under different environment and driving conditions. Estimation error of current driving range is relatively large due to without considering the effects of environmental temperature and driving conditions. The development of a driving range estimation method will have a great impact on the electric vehicles. A new driving range estimation model based on the combination of driving cycle identification and prediction is proposed and investigated. This model can effectively eliminate mileage errors and has good convergence with added robustness. Initially the identification of the driving cycle is based on Kernel Principal Component feature parameters and fuzzy C referring to clustering algorithm. Secondly, a fuzzy rule between the characteristic parameters and energy consumption is established under MATLAB/Simulink environment. Furthermore the Markov algorithm and BP(Back Propagation) neural network method is utilized to predict the future driving conditions to improve the accuracy of the remaining range estimation. Finally, driving range estimation method is carried out under the ECE 15 condition by using the rotary drum test bench, and the experimental results are compared with the estimation results. Results now show that the proposed driving range estimation method can not only estimate the remaining mileage, but also eliminate the fluctuation of the residual range under different driving conditions.
A perforated microhole-based microfluidic device for improving sprouting angiogenesis in vitro
Authors: Chen Sijia , Zhang Liguang , Zhao Yi , Ke Ming , Li Bo , Chen Longcong , Cai Shaoxi
Published: October 2017

Microfluidic technology is an important research tool for investigating angiogenesis in vitro. Here, we fabricated a polydimethylsiloxane (PDMS) microfluidic device with five cross-shaped chambers using a coverslip molding method. Then, the perforated PDMS microhole arrays prepared by soft lithography were assembled in the device as barriers; a single microhole had a diameter of 100 μm. After injecting type I collagen into the middle gel chamber, we added a culture medium containing a vascular endothelial growth factor (VEGF) into the middle chamber. It would generate a linear concentration gradient of VEGF across the gel region from the middle chamber to the four peripheral chambers. Human umbilical vein endothelial cells (HUVECs) were then seeded on the microhole barrier. With VEGF stimulation, cells migrated along the inner walls of the microholes, formed annularly distributed cell clusters at the gel-barrier interface, and then three-dimensionally (3D) sprouted into the collagen scaffold. After 4 days of culture, we quantitatively analyzed the sprouting morphogenesis. HUVECs cultured on the microhole barrier had longer sprouts than HUVECs cultured without the barrier (controls). Furthermore, the initial distribution of sprouts was more regular and more connections of tube-like structures were generated when the microhole barrier was used. This study introduces a novel microfluidic device containing both microtopographic structures and 3D collagen. HUVECs cultured with the microhole barrier could form well-interconnected tube-like structures and are thus an ideal in vitro angiogenesis model.
Alternative generation of well-aligned uniform lying helix texture in a cholesteric liquid crystal cell
Authors: Yu Chia-Hua , Wu Po-Chang , Lee Wei
Published: October 2017

This work demonstrates a simple approach for obtaining a well-aligned uniform lying helix (ULH) texture and a tri-bistable feature at ambient temperature in a typical 90°-twisted cell filled with a short-pitch cholesteric liquid crystal. This ULH texture is obtained at room temperature from initially field-induced helix-free homeotropic state by gradually decreasing the applied voltage. Depending on the way and rate of reducing the voltage, three stable states (i.e., Grandjean planar, focal conic, and ULH) are generated and switching between any two of them is realized. Moreover, the electrical operation of the cell in the ULH state enables the tunability in phase retardation via the deformation of the ULH. The observations made in this work may be useful for applications such as tunable phase modulators and energy-efficient photonic devices.
Optical and electrical properties of capacitive coupled radio frequency Ar-H2 mixture discharge at the low pressure
Authors: Tanışlı Murat , Şahin Neslihan , Younus Maria , Rehman Najeeb Ur , Demir Süleyman
Published: October 2017

In this study, the electrical and optical properties and plasma's parameters of capacitive radio frequency (RF) discharge for the argon and hydrogen mixture at low pressure are investigated using optical emission spectroscopy (OES) and a Langmuir probe. The wavelengths of spectral lines obtained from OES are between 400 and 950 nm. By using the spectral lines and probe data, the electron temperature for every different RF power, mixture rate and flow rate are determined by the modified Boltzmann curve method. The Langmuir probe gives the electron temperature and other plasma properties for the same discharge parameters.
A DFT study of intrinsic point defects in monolayer MoSe2
Authors: Shafqat Alina , Iqbal Tahir , Majid Abdul
Published: October 2017

This study is a computational investigation of the electronic structure of the eight most-frequently observed intrinsic point-defect configurations in monolayer Molybdenum diselenide (m-MoSe2); analyzed using the Amsterdam Density Functional (ADF) BAND package. Pristine m-MoSe2 is an intrinsic semiconductor with a direct band gap of 1.44 eV. MoSe2 is defect-sensitive due to the similar orbital character of the Valence Band Maximum (VBM) and Conduction Band Minimum (CBM), with deep states induced in the structure by the defects. These states can be attributed solely to the metal d and chalcogen p states, which spring enhanced photoluminescence, making MoSe2 a potential candidate for optoelectronic applications. Band-gap narrowing is proportional to the number of chalcogen vacancies. All defect configurations cause shifting of the Fermi-level, with metal vacancies shifting the semiconducting character of pristine m-MoSe2 to metallic. Only the antisite defect configuration of MoSe2 and Mo-vacancies at a large distance could introduce spin in the structure, with spin attributed to the metal d and chalcogen p states. These findings suggest the possible application of m-MoSe2 for fabricating DMS by defect engineering.
Propagation characteristics of audible noise generated by single corona source under positive DC voltage
Authors: Li Xuebao , Cui Xiang , Lu Tiebing , Wang Donglai
Published: October 2017

The directivity and lateral profile of corona-generated audible noise (AN) from a single corona source are measured through experiments carried out in the semi-anechoic laboratory. The experimental results show that the waveform of corona-generated AN consists of a series of random sound pressure pulses whose pulse amplitudes decrease with the increase of measurement distance. A single corona source can be regarded as a non-directional AN source, and the A-weighted SPL (sound pressure level) decreases 6 dB(A) as doubling the measurement distance. Then, qualitative explanations for the rationality of treating the single corona source as a point source are given on the basis of the Ingard’s theory for sound generation in corona discharge. Furthermore, we take into consideration of the ground reflection and the air attenuation to reconstruct the propagation features of AN from the single corona source. The calculated results agree with the measurement well, which validates the propagation model. Finally, the influence of the ground reflection on the SPL is presented in the paper.
Wavenumber-frequency analysis of single-layer shallow-water beta-plane quasi-geostrophic turbulence
Authors: Morten A. J. , Arbic B. K. , Flierl G. R.
Published: October 2017

We numerically investigate single-layer shallow-water beta-plane quasi-geostrophic turbulence in a doubly periodic domain with emphasis on wavenumber-frequency spectra. We conduct a broad parameter sweep, varying the deformation radius (Ld), the narrow-band forcing wavenumber (kf), and the meridional gradient of the Coriolis parameter (β). Out of 54 simulations we present ten in detail spanning slowly propagating vortices to strong jets. We define a nondimensional parameter γβ in terms of β, Ld, and the energy injection rate. The moderately low γβ case is characterized by westward propagating coherent vortices and zonal wavenumber-frequency spectra dominated by a nondispersive line (NDL) corresponding to uniform propagation at or near the long-wave Rossby speed. The moderately high γβ case is characterized by jets, and the NDL persists even when there are no coherent vortices. The jets have large meridional excursions (meanders) that propagate westward nearly uniformly at a speed slower than the long-wave Rossby speed. Also at moderately high γβ, a second dispersion relation appears, roughly corresponding to linear waves on a zonal potential vorticity (PV) staircase. At very high γβ, during the slow evolution to a PV staircase, the structure of the linear waves is altered by the small perturbations to a constant potential vorticity gradient. A simple model treating the small perturbation as a sinusoid accurately predicts the meridional wavenumber-frequency spectra in the very high γβ simulations.
Studying the field induced breakup of acoustically levitated drops
Authors: Warschat C. , Riedel J.
Published: October 2017

Coulomb fission of charged droplets (The terms drop and droplet are often used synonymous. Throughout this manuscript, to avoid confusion, the terms drop and droplet will be used for liquid spheres with radii in the millimeter range and the micrometer range, respectively. In our experiments, the first correspond to the parent drop while the latter describes the ejected progeny droplets.) is a well-studied natural phenomenon. Controlled droplet fission is already successfully employed in several technological applications. Still, since the occurring surface rupture relies on the exact understanding and description of the liquid gas boundary, some details are still under debate. Most empirical systematic studies observe falling micrometer droplets passing through the electric field inside a plate capacitor. This approach, although easily applicable and reliable, limits the experimental degrees of freedom regarding the observable time and the maximum size of the drops and can only be performed in consecutive individual observations of different subsequent drops. Here we present a novel setup to study the field induced breakup of acoustically levitated drops. The design does not bear any restrictions towards the temporal window of observation, and allows handling of drops of a tunable radius ranging from 10 μm to several millimeters and a real-time monitoring of one single drop. Our comprehensive study includes a time resolved visual inspection, laser shadowgraphy, laser induced fluorescence imaging, and ambient mass spectrometric interrogation of the nascent Taylor cone. The results shown for a millimeter sized drop, previously inaccessible for Coulomb fission experiments, are mostly comparable with previous results for smaller drops. The major difference is the time scale and the threshold potential of the drop rupture. Both values, however, resemble theoretically extrapolations to the larger radius. The technique allows for a systematic study of breakup behavior of drops of different charge, material, and size.
Absence of periodic orbits in digital memcomputing machines with solutions
Authors: Di Ventra Massimiliano , Traversa Fabio L.
Published: October 2017

In Traversa and Di Ventra [Chaos 27, 023107 (2017)] we argued, without proof, that if the non-linear dynamical systems with memory describing the class of digital memcomputing machines (DMMs) have equilibrium points, then no periodic orbits can emerge. In fact, the proof of such a statement is a simple corollary of a theorem already demonstrated in Traversa and Di Ventra [Chaos 27, 023107 (2017)]. Here, we point out how to derive such a conclusion. Incidentally, the same demonstration implies absence of chaos, a result we have already demonstrated in Di Ventra and Traversa [Phys. Lett. A 381, 3255 (2017)] using topology. These results, together with those in Traversa and Di Ventra [Chaos 27, 023107 (2017)], guarantee that if the Boolean problem the DMMs are designed to solve has a solution, the system will always find it, irrespective of the initial conditions.
Triboelectric effect: A new perspective on electron transfer process
Authors: Pan Shuaihang , Zhang Zhinan
Published: October 2017

As interest in the triboelectric effect increases in line with the development of tribo-electrification related devices, the mechanisms involved in this phenomenon require more systematic review from the dual perspectives of developed classical insights and emerging quantum understanding. In this paper, the clear energy changing and transferring process of electrons have been proposed from the quantum point of view as the trigger for the charging initiation process in the triboelectric effect, and the phonon modes on the friction surfaces are believed to hold great importance as one of the main driving forces. Compatible with Maxwell Displacement Current theory, the complete consideration for charging steady state, i.e., the competition mechanisms between the breakdown process and the continuously charging process, and the balance mechanisms of phonon-electron interaction, built voltage, and induced polarization, are illustrated. In brief, the proposed theory emphasizes the fundamental role of electron transferring in tribo-electrical fields. By comparing certain experimental results from the previous studies, the theory is justified.
Pseudo-spatial coherence resonance in an excitable laser with long delayed feedback
Authors: Marino Francesco , Giacomelli Giovanni
Published: October 2017

The effect of noise in an excitable semiconductor laser with feedback is studied in the framework of the spatio-temporal representation of long delayed systems. Propagation, noise-induced creation, and destruction of excitable pulses in the pseudo time are observed. The addition of a variable quantity of noise leads to the occurrence of a phenomenon that we term “pseudo-spatial coherence resonance.” A phenomenological model well describes the system and allows for a comparison with the experimental observations. A simple Monte Carlo approach is also introduced and permits to explain the features observed in terms of the key dynamical ingredients of the physical system.
Analytic non-Maxwellian electron velocity distribution function in a Hall discharge plasma
Authors: Shagayda Andrey , Tarasov Alexey
Published: October 2017

The electron velocity distribution function in the low-pressure discharges with the crossed electric and magnetic fields, which occur in magnetrons, plasma accelerators, and Hall thrusters with a closed electron drift, is not Maxwellian. A deviation from equilibrium is caused by a large electron mean free path relative to the Larmor radius and the size of the discharge channel. In this study, we derived in the relaxation approximation the analytical expression of the electron velocity distribution function in a weakly ionized Lorentz plasma with the crossed electric and magnetic fields in the presence of the electron density and temperature gradients in the direction of the electric field. The solution was obtained in the stationary approximation far from boundary surfaces, when diffusion and mobility are determined by the classical effective collision frequency of electrons with ions and atoms. The moments of the distribution function including the average velocity, the stress tensor, and the heat flux were calculated and compared with the classical hydrodynamic expressions. It was shown that a kinetic correction to the drift velocity stems from a contribution of the off-diagonal component of the stress tensor. This correction becomes essential if the drift velocity in the crossed electric and magnetic fields would be comparable to the thermal velocity of electrons. The electron temperature has three different components at a nonzero effective collision frequency and two different components in the limit when the collision frequency tends to zero. It is shown that, in the presence of ionization collisions, the components of the heat flux have additives that are not related to the temperature gradient, and arise because of the electron drift.
Co-inoculation of maize with Azospirillum brasilense and Rhizobium tropici as a strategy to mitigate salinity stress
Authors: Fukami Josiane , de la Osa Clara , Ollero Francisco Javier , Megías Manuel , Hungria Mariangela
Published: October 2017

Plants are highly affected by salinity, but some plant growth-promoting bacteria (PGPB) may trigger induced systemic tolerance (IST), conferring protection against abiotic stresses. We investigated plant mechanisms under saline stress (170 mM NaCl) when maize was singly or co-inoculated with Azospirillum brasilense strains Ab-V5 and Ab-V6 and Rhizobium tropici strain CIAT 899. Under greenhouse conditions, plants responded positively to inoculation and co-inoculation, but with differences between strains. Inoculation affected antioxidant enzymes that detoxify reactive oxygen species (ROS) – ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD) – mainly in leaves. Proline contents in leaves and roots and malondialdehyde (MDA) in leaves – plant-stress-marker molecules – were significantly reduced due to the inoculation, indicating reduced need for the synthesis of these molecules. Significant differences were attributed to inoculation in the expression of genes related to antioxidant activity, in general with upregulation of APX1, CAT1, SOD2 and SOD4 in leaves, and APX2 in roots. Pathogenesis-related genes PR1, prp2, prp4 and heat-shock protein hsp70 were downregulated in leaves and roots, indicating that inoculation with PGPB might reduce the need for this protection. Together the results indicate that inoculation with PGPB might provide protection from the negative effects of saline stress. However, differences were observed between strains, as A. brasilense Ab-V5 did not show salt tolerance, while the best inoculation treatments to mitigate saline stress were with Ab-V6 and co-inoculation with Ab-V6+CIAT 899. Inoculation with these strains may represent an effective strategy to mitigate salinity stress.
Molecular basis for unique specificity of human TRAF4 for platelets GPIbβ and GPVI
Authors: Kim Chang Min , Son Young-Jin , Kim Sunghwan , Kim Seo Yun , Park Hyun Ho
Published: October 2017

Significance

TRAF4 is a signaling molecule involved in cancer by direct interaction with the TGF-β receptor and in ROS production in platelets that initiates thrombosis. Previous studies indicated that disruptions of the TRAF4 interaction with platelet receptors and the TGF-β receptor are a potential target for therapeutic intervention by antithrombotic drugs and anticancer drugs, respectively. In this study, we report a crystal structure of TRAF4 in complex with a peptide from the GPIbβ receptor. The structure revealed a TRAF4-binding motif of Arg–Leu–X–Ala. We also found that the TGF-β receptor contains the TRAF4-binding motif and showed a direct interaction between TRAF4 and the receptor. The current structure will provide a template for furthering our understanding of the receptor-binding specificity of TRAF4, TRAF4-mediated signaling, and related diseases.
Production of diverse PET probes with limited resources: 24
18
F-labeled compounds prepared with a single radiosynthesizer
Authors: Collins Jeffrey , Waldmann Christopher M. , Drake Christopher , Slavik Roger , Ha Noel S. , Sergeev Maxim , Lazari Mark , Shen Bin , Chin Frederick T. , Moore Melissa , Sadeghi Saman , Phelps Michael E. , Murphy Jennifer M. , van Dam R. Michael
Published: October 2017

Significance

Molecular imaging with PET can provide a dynamic, whole-body picture of the rate of biological processes or distribution of biological targets by tracking the distribution of radiolabeled molecules or particles in the body over time. Continual efforts to develop new PET probes are expanding the variety of processes and targets that can be visualized, facilitating basic research, drug development, and patient care. However, access to these probes at all stages of their development is hindered by high costs arising, in large part, from the significant resources that are typically dedicated to production of a single probe. Emerging technologies with increased synthesis flexibility are allowing increased probe diversity with fewer resources and could significantly increase access to new molecular imaging agents.
Universal photonic quantum computation via time-delayed feedback
Authors: Pichler Hannes , Choi Soonwon , Zoller Peter , Lukin Mikhail D.
Published: October 2017

Significance

Creating large entangled states with photons as quantum information carriers is a central challenge for quantum information processing. Since photons do not interact directly, entangling them requires a nonlinear element. One approach is to sequentially generate photons using a quantum emitter that can induce quantum correlations between photons. Here we show that delayed quantum feedback dramatically expands the class of achievable photonic quantum states. In particular, we show that in state-of-the-art experiments with single atom-like quantum emitters, the most basic form of delayed quantum feedback already allows for creation of states that are universal resources for quantum computation. This opens avenues for quantum information processing with photons using minimal experimental resources.
Categorial flexibility as an emergent phenomenon
Authors: Kihm Alain
Published: October 2017

The present paper takes the view that categorial flexibility (CF, also called polycategoriality), i.e. having the “same” items function both as nouns and verbs, is not a possible substantial property of lexemes. Given the semantic quirks that often characterize such alternative uses (e.g. a tree vs. to tree), assuming CF leads one to posit roots endowed with general and vague meanings, the grammatical and cognitive reality of which appears highly dubious. Lexemes ought therefore to be viewed as rigidly categorized with precise meanings. CF is an emergent phenomenon that results when nouns and verbs share more or less loose semantic networks with the language-particular morphological property that they do not or minimally differ in their forms.
Polycategoriality and hybridity across Mayan languages
Authors: Lois Ximena , Vapnarsky Valentina , Becquey Cédric , Monod Becquelin Aurore
Published: October 2017

This article presents a comparative study of Mayan languages belonging to three different branches (Cholan, Tseltalan and Yucatecan), with respect to polycategoriality. Mayan languages appear to be particularly interesting for exploring polycategoriality for several structural reasons, as well as for the way relevant properties vary across the Mayan family. We analyze levels and processes of categorial determination and their relationship with other facts, in particular the ergative splits (aspectual and agentive). We study morphophonological, morphosyntactic and semantic properties for evaluating polycategoriality at the root or stem level. At the structure level, we put forth the hypothesis of a hybrid nature based on simultaneous nominal and verbal properties. For some cases, a reanalysis from nominal to verbal stems is proposed.
The ontology of roots and the emergence of nouns and verbs in Kuikuro
Authors: Franchetto Bruna , Santos Mara
Published: October 2017

Kuikuro, a dialect of the Upper Xingu Carib Language (Southern Amazonia, Brazil), cannot be defined as polycategorial. Instead, we argue that it is a highly agglutinative language in which the postulates of Distributed Morphology are extremely effective for their descriptive and explanatory power: roots are acategorized lexical items from which families of words can be generated in syntax, and not before, through pairing with functional morphemes. Inflection, both nominal and verbal, is the phonological expression of syntactic identities and functions, e.g., Nouns and Verbs as arguments and their heads. A first excursion into the speech production of Kuikuro children aged 14 to 36 months brings new evidence in favor of the hypothesis that Nouns and Verbs emerge step by step in the development of syntactic functional projections, from an early phase of multi-functional and uninflected baby-words – a phenomenon at the heart of the ethnotheory of language acquisition.
Flexibles and polyvalence in Ku Waru
Authors: Merlan Francesca , Rumsey Alan
Published: October 2017

This chapter concerns the nature and universality of word classes and their relation to syntagmatic types. Having thought through these issues on the basis of material from a Papuan language, Ku Waru, of the Western Highlands of Papua New Guinea, in this paper we make use of child language acquisition data from that language to examine the acquisition of word classes and clause-level syntactic structures. In particular, we examine the frequency and development in children’s acquisition of two distinct multi-word verbal constructions: the adjunct+verb construction and the serial verb construction. The paper considers these structures and the processes of their acquisition from two points of view: that of the adult target language towards which children’s proficiency is developing; and that of children’s speech at various points in development, from 17 to about 36 months, considered as emergent and evolving systems in their own right.
Noun and Verb categories in acquisition
Authors: Veneziano Edy
Published: October 2017

Our analyses suggest that early fillers are premorphological. They help children realize phonoprosodic features, and reflect the distributional regularities of child-directed speech, but are not used to differentiate nouns from verbs, a differentiation that starts to show up a few months after their appearance. The analysis of verbal inflectional morphology confirms these results, showing that, at first, verbs are not treated differently from nouns. The results of a comprehension task administered longitudinally to one of the children are also reported. In this task the child has to attribute an action or object meaning to homophonous or nonce words on the sole basis of the grammatical context in which they occur. The more mature understanding of the distinction between noun and verb frames required by the comprehension task sheds further light on the early psychological reality of Nouns and Verbs for young children.
Semantic discrimination of Noun/Verb categories in French children aged 1;6 to 2;11
Authors: Parisse Christophe , Rossi Caroline
Published: October 2017

This study assesses the part played by semantics in the emergence of grammatical categories in child language. Based on basic, real-world properties, we analyze each of the first nouns and verbs used by three French-speaking children, and code them along six semantic dimensions – animacy, concreteness, determination, distance, motion and number. We use multiple correspondence analyses and hierarchical clustering to model the categories of child language that emerge based on the above semantic dimensions. We then compare them with adult noun and verb categories. Our results show that a gradual organization of meaning takes place during language development, with a degree of variation from one child to the other, especially in the early steps.
The acquisition of action nouns in Yucatec Maya
Authors: Pfeiler Barbara
Published: October 2017

The fact that ergative-absolutive inflectional morphology applies to nouns as well as to verbs in Yucatec Maya obscures the boundary between nouns and verbs, and makes it difficult for children to acquire the distinction between them. Acquisition is particularly difficult for the category of action nouns which can be used as either nouns or verbs in Yucatec. The analysis of the spontaneous speech of two Yucatec monolingual children from 1;9 to 2;3 shows that the most frequent action noun ‘play, toy’ is used as both a noun and a verb in the children’s corpus. The children preferred the nominal use of other action nouns when referring to concrete objects. The frequency of action noun use in the adult speech, the discourse context and rephrasing affected the children’s use of action nouns to different degrees. Research on the acquisition of language-specific lexical categories is essential to understanding how children acquire language.
Machine learning accelerates MD-based binding pose prediction between ligands and proteins
Authors: Terayama Kei , Iwata Hiroaki , Araki Mitsugu , Okuno Yasushi , Tsuda Koji
Published: October 2017

Motivation

Fast and accurate prediction of protein–ligand binding structures is indispensable for structure-based drug design and accurate estimation of binding free energy of drug candidate molecules in drug discovery. Recently, accurate pose prediction methods based on short Molecular Dynamics (MD) simulations, such as MM-PBSA and MM-GBSA, among generated docking poses have been used. Since molecular structures obtained from MD simulation depend on the initial condition, taking the average over different initial conditions leads to better accuracy. Prediction accuracy of protein–ligand binding poses can be improved with multiple runs at different initial velocity.

Results

This paper shows that a machine learning method, called Best Arm Identification, can optimally control the number of MD runs for each binding pose. It allows us to identify a correct binding pose with a minimum number of total runs. Our experiment using three proteins and eight inhibitors showed that the computational cost can be reduced substantially without sacrificing accuracy. This method can be applied for controlling all kinds of molecular simulations to obtain best results under restricted computational resources.

Availability and implementation

Code and data are available on GitHub at https://github.com/tsudalab/bpbi.

Supplementary information

Supplementary data are available at Bioinformatics online.
Beyond similarity assessment: selecting the optimal model for sequence alignment via the Factorized Asymptotic Bayesian algorithm
Authors: Takeda Taikai , Hamada Michiaki
Published: October 2017

Motivation

Pair Hidden Markov Models (PHMMs) are probabilistic models used for pairwise sequence alignment, a quintessential problem in bioinformatics. PHMMs include three types of hidden states: match, insertion and deletion. Most previous studies have used one or two hidden states for each PHMM state type. However, few studies have examined the number of states suitable for representing sequence data or improving alignment accuracy.

Results

We developed a novel method to select superior models (including the number of hidden states) for PHMM. Our method selects models with the highest posterior probability using Factorized Information Criterion, which is widely utilized in model selection for probabilistic models with hidden variables. Our simulations indicated that this method has excellent model selection capabilities with slightly improved alignment accuracy. We applied our method to DNA datasets from 5 and 28 species, ultimately selecting more complex models than those used in previous studies.

Availability and implementation

The software is available at https://github.com/bigsea-t/fab-phmm.

Supplementary information

Supplementary data are available at Bioinformatics online.
AEGS: identifying aberrantly expressed gene sets for differential variability analysis
Authors: Guan Jinting , Chen Moliang , Ye Congting , Cai James J , Ji Guoli
Published: October 2017

Motivation

In gene expression studies, differential expression (DE) analysis has been widely used to identify genes with shifted expression mean between groups. Recently, differential variability (DV) analysis has been increasingly applied as analyzing changed expression variability (e.g. the changes in expression variance) between groups may reveal underlying genetic heterogeneity and undetected interactions, which has great implications in many fields of biology. An easy-to-use tool for DV analysis is needed.

Results

We develop AEGS for DV analysis, to identify aberrantly expressed gene sets in diseased cases but not in controls. AEGS can rank individual genes in an aberrantly expressed gene set by each gene’s relative contribution to the total degree of aberrant expression, prioritizing top genes. AEGS can be used for discovering gene sets with disease-specific expression variability changes.

Availability and implementation

AEGS web server is accessible at http://bmi.xmu.edu.cn:8003/AEGS, where a stand-alone AEGS application can also be downloaded.
Characterizing Cefepime Neurotoxicity: A Systematic Review
Authors: Appa Ayesha A , Jain Rupali , Rakita Robert M , Hakimian Shahin , Pottinger Paul S
Published: October 2017

Neurotoxicity due to cefepime has not been well characterized. We performed a systematic review of the literature and included 5 additional cases from our center. Of the 198 cases found, the mean age was 67 years and 87% of patients had renal dysfunction. The most common clinical features were diminished level of consciousness (80%), disorientation/agitation (47%), and myoclonus (40%). It is worth noting that nonconvulsive status epilepticus was relatively common with 31% of cases, whereas only 11% had convulsive seizures. Single-center estimate of incidence was 1 in 480 courses of cefepime. Cefepime neurotoxicity should be considered in older patients with renal dysfunction and new onset encephalopathy, especially if concurrent myoclonus is present. More work is needed to prospectively assess incidence and outcomes related to cefepime neurotoxicity.
The Return to Literature—Making Doctors Matter in the New Era of Medicine
Authors: Marchalik Daniel
Published: October 2017

The rapid explosion of medical knowledge of the 19th and 20th centuries required a transformation in medical education, which, to that point, had been marked by low educational standards. To combat the lack of regulation, the 1910 Flexner Report recommended sweeping reforms. By 1930, students hoping to enroll in a medical school would need to complete courses in chemistry, physics, and biology, leaving little room for the liberal arts.

Medicine is once again changing. The impact of artificial intelligence is being felt across all medical fields, and the nature of physicians’ jobs in the new landscape of intelligent machines will inevitably also have to change. What will the role of new physicians be? And how should medical education be amended to meet those needs?

In 2017, the Georgetown University School of Medicine graduated the first group of students from its Literature and Medicine Track—the first U.S. medical school track dedicated to the study of literature. This Invited Commentary explores the work done in, and the scholarship resulting from, this novel educational program and suggests ways in which literature could be used to prepare future doctors for the evolving demands of the medical field.
Mapping the Landscape, Journeying Together: The Gold Foundation’s Model for Research-Based Advocacy in Humanism in Medicine
Authors: Gaufberg Elizabeth
Published: October 2017

Mapping the Landscape, Journeying Together (MTL) is an initiative of the Arnold P. Gold Foundation Research Institute. The MTL initiative awards teams with a grant to complete a rigorous review of the literature on a topic related to humanism in health care. Teams may then seek a discovery or advocacy grant to fill in gaps in knowledge or to make or advocate for change. In this Commentary, the author reveals the MTL journey through the metaphor of cartography. She describes the initial development of a road map, as well as the MTL community’s experience of navigation, discovery, and exploration. MTL participants are not only incrementally adding to a complex body of knowledge but also actively cultivating a robust community of practice.
Do Changes in Sensory Processing Precede Low Back Pain Development in Healthy Individuals?
Authors: Hwang Ching-Ting , Van Dillen Linda R. , Haroutounian Simon
Published: October 2017

Objectives:

Low back pain (LBP) is the most commonly reported chronic pain condition. In this study, a clinically relevant, induced-LBP paradigm was used to study sensory processing as a risk factor and predictor for LBP development in healthy people. Our aim was to examine sensory processing in those who do develop LBP and those who do not develop LBP with the paradigm, and to examine the relationships between scores on psychosocial questionnaires and sensory processing measures in these healthy people.

Methods:

A total of 71 participants completed the Pain Catastrophizing Scale (PCS) and Hospital Anxiety and Depression Scale (HADS) and then took part in quantitative sensory testing. An induced-LBP paradigm, where participants stand for 2 hours and rate their low back symptoms over time, was used to classify participants as those who did develop LBP and those who did not develop LBP.

Results:

No differences in sensory processing were identified between those who did develop LBP and those who did not develop LBP (Ps>0.05). Scores for the PCS and HADS were similar between the groups (Ps>0.05). Small significant relationships between PCS scores and cold detection and cold pain thresholds were found (rs=0.23 to 0.31; Ps<0.05) and between the pressure pain thresholds at the thenar eminence and paraspinals (r=0.53; P<0.01).

Discussion:

These results provide evidence that altered sensory processing was not present in healthy people and thus is not a risk factor for development of LBP in standing.
Expanding Prenatal Care to Unauthorized Immigrant Women and the Effects on Infant Health
Authors: Swartz Jonas J. , Hainmueller Jens , Lawrence Duncan , Rodriguez Maria I.
Published: October 2017

OBJECTIVE:

To measure the effect of access to prenatal care on unauthorized and low-income, new legal permanent resident immigrant women and their offspring.

METHODS:

We used a difference-in-differences design that leverages the staggered rollout of Emergency Medicaid Plus by county from 2008 to 2013 as a natural experiment to estimate the effect on health service utilization for women and health outcomes for their infants. Regular Medicaid pregnancies were used as an additional control in a triple difference design.

RESULTS:

Our sample included pregnancies covered by Emergency Medicaid (35,182), Emergency Medicaid Plus (12,510), and Medicaid (166,054). After expansion of access to prenatal care, there was an increase in prenatal visits (7.2 more visits, 95% CI 6.45–7.96), receipt of adequate prenatal care (28% increased rate, CI 26–31), rates of diabetes screening (61% increased rate, CI 56–66), and fetal ultrasonograms (74% increased rate, CI 72–76). Maternal access to prenatal care was also associated with an increased number of well child visits (0.24 more visits, CI 0.07–0.41), increased rates of recommended screenings and vaccines (0.04 increased probability, CI 0.002–0.074), and reduced infant mortality (−1.01/1,000, CI −1.42 to −0.60) and rates of extremely low birth weight (less than 1,000 g) (−1.33/1,000, CI −2.44 to −0.21).

CONCLUSION:

Our results provide evidence of increased utilization and improved health outcomes for unauthorized immigrants and their children who are U.S. citizens after introduction of prenatal care expansion in Oregon. This study contributes to the debate around reauthorization of the Children's Health Insurance Program in 2017.
First-Trimester Serum Fatty Acid-Binding Protein 4 and Subsequent Gestational Diabetes Mellitus
Authors: Tu Wen-Jun , Guo Min , Shi Xiao-Dong , Cai Yan , Liu Qiang , Fu Chen-Wei
Published: October 2017

OBJECTIVE:

To examine whether plasma fatty acid-binding protein 4 concentrations, measured in the first trimester, are associated with gestational diabetes mellitus (GDM).

METHODS:

This prospective, multicenter cohort study was conducted at three maternity centers in two cities (Harbin and Beijing) in China from July 2015 to June 2016. Data for fasting plasma glucose and fatty acid-binding protein 4 concentrations in the first trimester and one-step GDM screening with a 75-g oral glucose tolerance test performed between 24 and 28 weeks of gestation were collected and analyzed.

RESULTS:

Plasma from women in the first trimester was available for 1,150 women, of whom 135 (11.7%) developed GDM. The GDM distribution across the fatty acid-binding protein 4 quartiles ranged from 3.8% (first quartile) to 21.6% (fourth quartile). In multivariate models comparing the second (quartile 2), third, and fourth quartiles against the first quartile of fatty acid-binding protein 4, concentrations of fatty acid-binding protein 4 in quartile 2, quartile 3, and quartile 4 were associated with the development of GDM with respective associated adjusted odds ratios (95% CIs) of 1.76 (1.21–2.58), 2.36 (1.55–4.29), and 3.57 (1.99–6.11). A significant difference in the area under receiver operating characteristic curve between established risk factors alone and the addition of fatty acid-binding protein 4 concentrations was observed (difference 0.042 [95% CI 0.028–0.055]; P=.03).

CONCLUSIONS:

Higher fatty acid-binding protein 4 concentrations in the first trimester visit were associated with increased risk of GDM and might be useful in identifying women at risk for GDM for early prevention strategies.
Performance Measures for Contraceptive Care
Authors: Moniz Michelle H. , Gavin Loretta E. , Dalton Vanessa K.
Published: October 2017

Contraception is an essential health service for reducing unintended pregnancy rates, improving health outcomes, and reducing health care costs. However, contraceptive services may not consistently provide access to the full method mix and to patient-centered care. Improving the quality of contraceptive care is a critical strategy to improve contraceptive use, health outcomes, and the patient experience of care. We here describe the three National Quality Forum–endorsed performance measures for contraceptive care, which are intended to monitor 1) provision of most and moderately effective methods, 2) access to long-acting reversible contraception, and 3) provision of most and moderately effective methods and access to long-acting reversible contraception after childbirth. These contraceptive care measures are designed to ensure that contraceptive care is accessible and offers the full spectrum of methods. Payers, health care systems, public agencies, and researchers could all monitor these performance measures for different populations. We describe the crucial role of clinicians in disseminating and using the contraceptive care performance measures for quality improvement. We describe ongoing efforts to improve contraceptive care quality, including the development of measures to monitor other dimensions of quality such as the safety and patient-centeredness of care. Thirty-eight million women at risk of unintended pregnancy are counting on us to improve the quality of family planning care in the United States and ensure that all women have the resources and tools to make free, informed choices about whether and when to become pregnant.
A Gartner Duct Cyst Masquerading as Anterior Vaginal Prolapse
Authors: Davidson Emily R. W. , Barber Matthew D.
Published: October 2017

BACKGROUND:

Gartner duct cysts are embryologic remnants of the mesonephric ducts that may present as a vaginal mass or cyst.

CASE:

A patient was referred for surgical management of prolapse whose bulging anterior vagina was actually a Gartner duct cyst that required excision as a result of symptoms. Preoperative magnetic resonance imaging helped confirm the diagnosis.

CONCLUSION:

A Gartner duct cyst may present as a vaginal cyst that, if large, may mimic pelvic organ prolapse. The diagnosis should be considered when a patient's individual prolapse compartments are inconsistent or when physical examination is suggestive of another process.