bluuebunny/crossref_metadata_2025 huggingface dataset:
The intrinsic atomic-level surface roughness mobility limit of 4H-SiC
Authors: Darmody C. , Goldsman N.
Published: September 2018

Presently, models to describe surface roughness scattering combine intrinsic and extrinsic effects, where extrinsic effects include process-induced interactions and intrinsic effects are due to inherent atomic structure. In this work, we present a general method for extracting the intrinsic surface roughness scattering rate of a material interface from the atomic structure, using Density Functional Theory and Fermi's Golden Rule. We find for the case of the 4H-SiC/SiO2 interface, intrinsic surface roughness mobility is several orders of magnitude greater than the extrinsic mobility which depends on process induced nonidealities. This result suggests that a path forward for higher mobility SiC devices may be the reduction of extrinsic miscut roughness.
Invited Article: Nano-kirigami metasurfaces by focused-ion-beam induced close-loop transformation
Authors: Liu Zhiguang , Du Huifeng , Li Zhi-Yuan , Fang Nicholas X. , Li Jiafang
Published: September 2018

Reducing fabrication difficulties while maintaining structural complexities and functionalities is one of the key challenges faced by the applications of nanophotonic devices. Here we demonstrate an exotic metasurface by using a simple close-loop nano-kirigami method. Based on the focused-ion-beam induced continuous shape transformation of a suspended ultra-thin gold film, pinwheel-like metasurfaces with uniaxial broadband polarization conversion and handedness-sensitive phase properties are readily fabricated. By deliberately patterning the metasurfaces periodically with opposite handedness, high-contrast cross-polarized diffractions are successfully observed in both linear and radial configurations. The demonstrated new types of metasurfaces, together with their suspended features for reconfiguration potentials, can open up new possibilities for the exploration of functional and reconfigurable micro-/nano-photonic and electronic devices.
Dielectric breakdown at sub-critical fields
Authors: Zuo Zhou , Dissado L. A. , Chalashkanov N. M. , Dodd S. J. , Yao Chenguo
Published: September 2018

We present a quantitative physical model based on experimentally determined parameter values for the description of the way that dielectric breakdown occurs after a period of stressing at fields below the critical values required for deterministic theories. It is found that for most of the material lifetime isolated regions of deterioration occur and that breakdown only ensues when the field in one such region reaches a critical value that produces a runaway extension. Only at low fields, do the deteriorated regions link up to form a conducting short-circuit. The generic form used means that the theory can be adapted for different physical mechanisms, and its concepts can be applied to the electrical reliability of many different types of dielectrics in a wide range of applications.
Impact of intrinsic amorphous silicon bilayers in silicon heterojunction solar cells
Authors: Sai Hitoshi , Chen Po-Wei , Hsu Hung-Jung , Matsui Takuya , Nunomura Shota , Matsubara Koji
Published: September 2018

The impact of intrinsic amorphous silicon bilayers in amorphous silicon/crystalline silicon (a-Si:H/c-Si) heterojunction solar cells is investigated. The microstructure factor R* of the interfacial a-Si:H layer, which is related to the Si-H bond microstructure and determined by infrared absorption spectroscopy, is controlled in a wide range by varying the growth pressure and the power density in plasma-enhanced chemical vapor deposition process. Surface passivation at the a-Si:H/c-Si interface is significantly improved by using an intrinsic a-Si:H bilayer, i.e., a stack of an interfacial layer with a large R* and an additional dense layer, particularly after the deposition of an overlying p-type a-Si:H layer. Consequently, the conversion efficiency of a-Si:H/c-Si heterojunction solar cells is markedly increased. However, it is also revealed that such an interfacial layer causes some negative effects including the increase in the series resistance and the current loss at the front side, depending on the growth condition. This result indicates that the interfacial layer has a significant impact on both the majority and the minority carrier transport. Thus, R* of the interfacial layer is an important parameter for obtaining good surface passivation at the a-Si/c-Si interface, but not the sole parameter determining the conversion efficiency of a-Si:H/c-Si heterojunction solar cells.
Investigation of a multi-element focused air-coupled transducer
Authors: Wang Xiaoyu , Wu Haodong , Zhang Xiaodong , Zhang De , Gong Xun , Zhang Dong
Published: September 2018

This paper presents the results of a numerical simulation and experimental test of a multi-element focused air-coupled transducer. The experimental structure of each transducer element comprises 1-3 connectivity piezo-composite stacking with two matching layers to overcome the enormous impedance mismatch between the piezo-composite disc and air. The numerical simulation is carried out using the circular-piston radiation model, and the experimental results for the acoustic field agree well with the simulation results. Furthermore, surface microcracks are detected successfully using a C-scan system involving the designed multi-element focused air-coupled transducer. The results show that the designed multi-element focused air-coupled transducer offers excellent focusing ability and is beneficial for detecting surface microcracks.
Strained SixGe1−x-Ge-Si core-double-shell nanowire heterostructures for simultaneous hole and electron mobility enhancement
Authors: Wen Feng , Tutuc Emanuel
Published: September 2018

We report the growth, structural, and electrical characterization of epitaxial, strained SixGe1−x-Ge-Si core-double-shell nanowire heterostructures designed to provide quantum confinement of holes and electrons in the compressively strained Ge and tensile-strained Si shells, respectively. The growth utilizes the vapor-liquid-solid growth mechanism for the SixGe1−x core, followed by a sequence of in-situ ultra-high-vacuum chemical vapor deposition for the epitaxial Ge and Si shell growth. Using a combination of micro-Raman spectroscopy on individual nanowires and lattice dynamic theory, we determine a large compressive (tensile) hydrostatic strain of up to −0.9% (0.67%) in the Ge (Si) shell. We demonstrate p- and n-type metal-oxide-semiconductor field-effect transistors using SixGe1−x-Ge-Si core-double-shell nanowires as channel and observe a 500% (20%) enhancement of the average hole (electron) mobility compared to control devices using Si nanowires, due to an increased hole (electron) mobility in the compressively strained Ge (tensile strained Si) shell. An analysis of the hole transport provides the valence band offset in the core-double-shell nanowire heterostructures.
Deformation of a ferrofluid droplet in simple shear flows under uniform magnetic fields
Authors: Hassan Md Rifat , Zhang Jie , Wang Cheng
Published: September 2018

We numerically investigate the deformation and orientation of a ferrofluid droplet in a simple shear flow under a uniform magnetic field. The numerical simulation is based on the finite element method and couples the magnetic and flow fields. A level set method is used to model the dynamic motion of the droplet interface. Systematic numerical simulations are used to assess the effects of the direction and the strength of the magnetic field. Focusing on low Reynolds number flows (Re ≲ 0.02), the numerical results indicate that at a small capillary number (Ca ≈ 0.02), the magnetic field dominates over the shear flow above a certain magnetic bond number (Bom ≈ 3). The orientation of the droplet is aligned with the direction of the magnetic field, while the deformation of the droplet varies slightly when the direction of the magnetic field is varied. On the other hand, for large capillary numbers (Ca ≈ 0.23), the deformation and orientation of the droplet is influenced by both the shear flow and the magnetic field, except for a small magnetic bond number (Bom ≲ 0.2). In both the small and large capillary number cases, the droplet deformation is found to be maximum at α = 45° (the direction of magnetic field) and minimum at α = 135°. In addition, the effect of the magnetic field on the flow field inside and outside the droplet at different conditions is examined. We demonstrate active control of lateral migration of ferrofluid droplets in wall-bounded simple shear flows. The direction of the lateral migration depends on the orientation of the deformed droplets due to uniform magnetic fields at different directions.
Improving solvation energy predictions using the SMD solvation method and semiempirical electronic structure methods
Authors: Kromann Jimmy C. , Steinmann Casper , Jensen Jan H.
Published: September 2018

The PM6 implementation in the GAMESS program is extended to elements requiring d-integrals and interfaced with the conducter-like polarized continuum model of solvation, including gradients. The accuracy of aqueous solvation energies computed using AM1, PM3, PM6, and DFT tight binding (DFTB) and the Solvation Model Density (SMD) continuum solvation model is tested using the Minnesota Solvation Database data set. The errors in SMD solvation energies predicted using Neglect of Diatomic Differential Overlap (NDDO)-based methods are considerably larger than when using density functional theory (DFT) and HF, with root mean square error (RMSE) values of 3.4-5.9 (neutrals) and 6-15 kcal/mol (ions) compared to 2.4 and ∼5 kcal/mol for HF/6-31G(d). For the NDDO-based methods, the errors are especially large for cations and considerably higher than the corresponding conductor-like screening model results, which suggests that the NDDO/SMD results can be improved by re-parameterizing the SMD parameters focusing on ions. We found that the best results are obtained by changing only the radii for hydrogen, carbon, oxygen, nitrogen, and sulfur, and this leads to RMSE values for PM3 (neutrals: 2.8/ions: ∼5 kcal/mol), PM6 (4.7/∼5 kcal/mol), and DFTB (3.9/∼5 kcal/mol) that are more comparable to HF/6-31G(d) (2.4/∼5 kcal/mol). Although the radii are optimized to reproduce aqueous solvation energies, they also lead more accurate predictions for other polar solvents such as dimethyl sulfoxide, acetonitrile, and methanol, while the improvements for non-polar solvents are negligible.
Letter: The effects of streamwise system rotation on pressure fluctuations in a turbulent channel flow
Authors: Yang Zixuan , Deng Bing-Qing , Wang Bing-Chen , Shen Lian
Published: September 2018

In this letter, we report the modulating effects of streamwise system rotation on both the amplitude and the wavenumber of pressure fluctuations in a plane channel flow. The analysis of the pressure field is conducted based on a set of comprehensive direct numerical simulation data of six rotation numbers. It is observed that high pressure fluctuation regions collocate with the Taylor–Görtler-like (TGL) vortex cores. By decomposing the pressure field into rotation-induced and convection-induced parts, it is observed that the rotation-induced part dominates the total pressure fluctuations and facilitates the growth of TGL vortices. Furthermore, through a spectral analysis, it is discovered that the system rotation acts as a “linear amplifier,” which converts high-wavenumber low-amplitude streamwise vorticity fluctuations into low-wavenumber high-amplitude pressure fluctuations.
Highly parallelisable simulations of time-dependent viscoplastic fluid flow with structured adaptive mesh refinement
Authors: Sverdrup Knut , Nikiforakis Nikolaos , Almgren Ann
Published: September 2018

We present the extension of an efficient and highly parallelisable framework for incompressible fluid flow simulations to viscoplastic fluids. The system is governed by incompressible conservation of mass, the Cauchy momentum equation, and a generalised Newtonian constitutive law. In order to simulate a wide range of viscoplastic fluids, we employ the Herschel-Bulkley model for yield-stress fluids with nonlinear stress-strain dependency above the yield limit. We utilise Papanastasiou regularisation in our algorithm to deal with the singularity in apparent viscosity. The resulting system of partial differential equations is solved using the IAMR (Incompressible Adaptive Mesh Refinement) code, which uses second-order Godunov methodology for the advective terms and semi-implicit diffusion in the context of an approximate projection method to solve adaptively refined meshes. By augmenting the IAMR code with the ability to simulate regularised Herschel-Bulkley fluids, we obtain efficient numerical software for time-dependent viscoplastic flow in three dimensions, which can be used to investigate systems not considered previously due to computational expense. We validate results from simulations using this new capability against previously published data for Bingham plastics and power-law fluids in the two-dimensional lid-driven cavity. In doing so, we expand the range of Bingham and Reynolds numbers which have been considered in the benchmark tests. Moreover, extensions to time-dependent flow of Herschel-Bulkley fluids and three spatial dimensions offer new insights into the flow of viscoplastic fluids in this test case, and we provide missing benchmark results for these extensions.
Dissociative electron attachment studies with hyperthermal Rydberg atoms
Authors: Buathong S. , Dunning F. B.
Published: September 2018

Earlier studies of the velocity distributions of heavy-Rydberg ion-pair states formed in collisions between potassium Rydberg atoms with low-to-intermediate values of n, 10 ≲ n ≲ 15, and targets that attach free low-energy electrons have shown that such measurements can provide a window into the dynamics of dissociative electron capture. Here we propose that the reaction dynamics can be explored in much greater detail through studies using hyperthermal Rydberg atoms. This is demonstrated using, as an example, helium Rydberg atoms and a semi-classical Monte Carlo collision code developed specifically to model the dynamics of Rydberg electron transfer in collisions between Rydberg atoms and attaching targets. The simulations show that the outcome of collisions is sensitive not only to the lifetime and decay energetics of the excited intermediate negative ion formed upon initial Rydberg electron capture but also to the radial electron probability density distribution in the Rydberg atom itself, i.e., to its ℓ value.
Detection of hydrogen by the extraordinary Hall effect in CoPd alloys
Authors: Das S. S. , Kopnov G. , Gerber A.
Published: September 2018

The effect of hydrogen adsorption on the extraordinary Hall phenomenon (EHE) in ferromagnetic CoPd films is studied as a function of composition, thickness, substrate, and hydrogen concentration in the atmosphere. Adsorption of hydrogen adds a positive term in the extraordinary Hall effect coefficient and modifies the perpendicular magnetic anisotropy with the respective changes in coercivity and remanence of hysteresis loops. Hydrogen sensitive compositions are within the Co concentration range of 20% ≤ x ≤ 50% with the strongest response near the EHE polarity reversal point x0∼ 38%. Depending on the film composition and field of operation, the EHE response of CoPd to low concentration hydrogen can reach hundreds of percent, which makes the method and the material attractive for hydrogen sensing.
High-quality indium gallium nitride baskets revealed by their differential indium content
Authors: DeJarnette Drew
Published: September 2018

Clusters of lattice dislocations cause relative changes in the indium content in defect-free regions of gallium indium nitride needed in high-quality devices for high-temperature electronics.
Language switching decomposed through MEG and evidence from bimodal bilinguals
Authors: Blanco-Elorrieta Esti , Emmorey Karen , Pylkkänen Liina
Published: September 2018

Significance

Bilingual individuals have the ability to switch between two languages, which requires engaging cognitive control processes to simultaneously “turn off” (disengage) one language and “turn on” (engage) their other language. The unique ability of American Sign Language (ASL)–English bilinguals to simultaneously produce a word and a sign (a code-blend) allows us to unpack these two processes (e.g., switching into a code-blend involves only turning on a language). Magnetoencephalography (MEG) evidence indicates that activating a new language does not recruit brain regions involved in cognitive control, but having to disengage from the previous language does. Additionally, this study reveals that, without motor constraints, simultaneously retrieving two words in different languages is less cognitively effortful than having to inhibit the production of the dominant language.
Linalool odor stimulation improves heat stress tolerance and decreases fat accumulation in nematodes
Authors: Hirano Naoko , Sakamoto Kazuichi
Published: September 2018

Aromatherapy uses plant essential oils and fragrant ingredients for relaxation, sleep assistance, and improvement of restlessness related to dementia. Certain aromatic substances increase the life span and stress tolerance of nematodes. We investigated effects of exposure to linalool, a linear chain monoterpenic alcohol that is present in the essential oils of many plants, and its optical isomer, l-linalool, in Caenorhabditis elegans. Nematodes were repelled by the odor of both linalool and l-linalool; however, linalool odor stimulation decreased fat accumulation and increased motility after thermal stress. Analysis of a gene-deficient mutant revealed that the DAF-16 insulin-signaling pathway, which is involved in heat stress tolerance, was enhanced by linalool treatment. Linalool stimulation increased the expression of downstream genes such as sod-3 and hsp-12.6 via DAF-16. We conclude that linalool odor induces a repelling behavior in nematodes, improves heat stress tolerance through the DAF-16 signaling pathway, and affects fat accumulation.
N-Acylhomoserine lactone-mediated quorum sensing regulates biofilm structure in Methylobacterium populi P-1M, an isolate from a pink-pigmented household biofilm
Authors: Morohoshi Tomohiro , Xie Xiaonan , Ikeda Tsukasa
Published: September 2018

Numerous gram-negative bacteria have quorum-sensing systems and produce AHL as a quorum-sensing signal molecule. In this study, we demonstrated that Methylobacterium populi P-1M, an isolate from a pink-pigmented household biofilm, produced two AHLs, C14:1-HSL as a predominant product and 3OHC14-HSL as a minor product. The complete genome sequence of M. populi P-1M revealed the presence of genes that are predicted to encode an AHL synthase (mpoI) and AHL receptor (mpoR). M. populi P-1M formed a pellicle-like biofilm, which had a flat surface and was easily removable. In contrast, biofilms formed by mpoI and/or mpoR deletion mutants had a wavy surface structure and strongly adhered to the glass tube. When C14:1-HSL was added to the mpoI mutant culture, the biofilm structure resembled that of the wild-type strain. These results demonstrated that the structure and adhesion strength of M. populi P-1M biofilms are determined in part by AHL-mediated quorum sensing.

Abbreviations: AHL: N-acyl-l-homoserine lactone; C14:1-HSL: N-tetradecenoyl-l-homoserine lactone; 3OHC14-HSL: N-(3-hydroxytetradecanoyl)-l-homoserine lactone; SAM: S-adenosyl-l-methionine; ACP: acyl-acyl carrier protein; EPS: extracellular polysaccharide; DMSO: dimethyl sulfoxide
Dynamics in the Eremenko-Lyubich class
Authors: Sixsmith David
Published: September 2018

The study of the dynamics of polynomials is now a major field of research, with many important and elegant results. The study of entire functions that are not polynomials – in other words transcendental entire functions – is somewhat less advanced, in part due to certain technical differences compared to polynomial or rational dynamics.

In this paper we survey the dynamics of functions in the Eremenko-Lyubich class,B\mathcal {B}. Among transcendental entire functions, those in this class have properties that make their dynamics most “similar” to the dynamics of a polynomial, and so particularly accessible to detailed study. Many authors have worked in this field, and the dynamics of classB\mathcal {B}functions is now particularly well-understood and well-developed. There are many striking and unexpected results. Several powerful tools and techniques have been developed to help progress this work. There is also an increasing expectation that learning new results in transcendental dynamics will lead to a better understanding of the polynomial and rational cases.

We consider the fundamentals of this field, review some of the most important results, techniques and ideas, and give stepping-stones to deeper inquiry.
Model selection and parameter estimation for dynamic epidemic models via iterated filtering: application to rotavirus in Germany
Authors: Stocks Theresa , Britton Tom , Höhle Michael
Published: September 2018

Despite the wide application of dynamic models in infectious disease epidemiology, the particular modeling of variability in the different model components is often subjective rather than the result of a thorough model selection process. This is in part because inference for a stochastic transmission model can be difficult since the likelihood is often intractable due to partial observability. In this work, we address the question of adequate inclusion of variability by demonstrating a systematic approach for model selection and parameter inference for dynamic epidemic models. For this, we perform inference for six partially observed Markov process models, which assume the same underlying transmission dynamics, but differ with respect to the amount of variability they allow for. The inference framework for the stochastic transmission models is provided by iterated filtering methods, which are readily implemented in the R package pomp by King and others (2016, Statistical inference for partially observed Markov processes via the R package pomp. Journal of Statistical Software69, 1–43). We illustrate our approach on German rotavirus surveillance data from 2001 to 2008, discuss practical difficulties of the methods used and calculate a model based estimate for the basic reproduction number $R_0$ using these data.
Nuclear localization and phosphorylation modulate pathological effects of alpha-synuclein
Authors: Pinho Raquel , Paiva Isabel , Jerčić Kristina Gotovac , Fonseca-Ornelas Luis , Gerhardt Ellen , Fahlbusch Christiane , Garcia-Esparcia Paula , Kerimoglu Cemil , Pavlou Maria A S , Villar-Piqué Anna , Szegő Éva , Lopes da Fonseca Tomás , Odoardi Francesca , Soeroes Szabolcs , Rego Ana Cristina , Fischle Wolfgang , Schwamborn Jens C , Meyer Thomas , Kügler Sebastian , Ferrer Isidre , Attems Johannes , Fischer André , Becker Stefan , Zweckstetter Markus , Borovecki Fran , Outeiro Tiago F
Published: September 2018

Alpha-synuclein (aSyn) is a central player in Parkinson’s disease (PD) but the precise molecular mechanisms underlying its pathogenicity remain unclear. It has recently been suggested that nuclear aSyn may modulate gene expression, possibly via interactions with DNA. However, the biological behavior of aSyn in the nucleus and the factors affecting its transcriptional role are not known. Here, we investigated the mechanisms underlying aSyn-mediated transcription deregulation by assessing its effects in the nucleus and the impact of phosphorylation in these dynamics. We found that aSyn induced severe transcriptional deregulation, including the downregulation of important cell cycle-related genes. Importantly, transcriptional deregulation was concomitant with reduced binding of aSyn to DNA. By forcing the nuclear presence of aSyn in the nucleus (aSyn-NLS), we found the accumulation of high molecular weight aSyn species altered gene expression and reduced toxicity when compared with the wild-type or exclusively cytosolic protein. Interestingly, nuclear localization of aSyn, and the effect on gene expression and cytotoxicity, was also modulated by phosphorylation on serine 129. Thus, we hypothesize that the role of aSyn on gene expression and, ultimately, toxicity, may be modulated by the phosphorylation status and nuclear presence of different aSyn species. Our findings shed new light onto the subcellular dynamics of aSyn and unveil an intricate interplay between subcellular location, phosphorylation and toxicity, opening novel avenues for the design of future strategies for therapeutic intervention in PD and other synucleinopathies.
A brief history of lumpfishing, assessment, and management across the North Atlantic
Authors: Kennedy James , Durif Caroline M F , Florin Ann-Britt , Fréchet Alain , Gauthier Johanne , Hüssy Karin , Jónsson Sigurður Þór , Ólafsson Halldór Gunnar , Post Søren , Hedeholm Rasmus B
Published: September 2018

This report documents the fishery, assessment, and management of lumpfish (Cyclopterus lumpus) across its distribution range. Targeting lumpfish for their roe on a large scale began in the 1950s in Iceland and Norway and then in Canada in the 1970s and Greenland in the 1990s. When the fishery began, there were few regulations, but limits on vessel size, mesh size, number of nets, and length of the fishing season were gradually implemented over time. Worldwide landings have varied from ca. 2000 to 8000 tonnes of roe between 1977 and 2016. Iceland and Canada accounted for >80% of the landings until 2000. After 2013, Greenland and Iceland accounted for >94%. All countries except Iceland show a decreasing trend in the number of boats participating in the fishery, which is related to several factors: the monetary value of the roe, changes in the abundance of lumpfish, and increasing age of artisanal fishers. Each country has a different combination of data available for assessment from basic landings and fishing effort data to more detailed fishery independent survey indices of abundance. The management of total catch also differs, with an effort-controlled fishery in Iceland and Canada, a total allowable catch (TAC) per boat in Norway, and TAC per area in Greenland. Population abundance is above management targets in Iceland and Norway, but the status is less clear in Greenland and around Denmark/Sweden and appears to be depleted around Canada. Certification by the Marine Stewardship Council was instrumental in the adoption of a management plan in Greenland; however, benefits to the fishers remain unclear. Aspects surrounding the biology of lumpfish, which is poorly understood and requires investigation, include growth rate, natural mortality, and population differentiation. In addition, there is concern about the potential impacts that the recent escalation in production of lumpfish for use as cleaner fish in the aquaculture industry could have on the wild population.
Failed cooperation in times of natural disasters: explaining the rejection of humanitarian aid
Authors: Dany Charlotte
Published: September 2018

This article asks why economically strong democracies reject humanitarian aid after severe natural disasters, focusing on the Kobe earthquake in Japan (1995), India’s response to the Indian Ocean tsunami (2004), and Hurricane Katrina in the United States (2005). It explains these rejections of humanitarian aid by analyzing the decision-makers’ ‘self-perceptions’ through the factors of manageability, national role perceptions, and domestic political impact, as well as ’other-perceptions’ through their relations to donors and the nature of the aid offers. It finds that even in those disaster-prepared and economically strong democracies, state leaders rejected humanitarian aid not simply because they had sufficient disaster management capabilities. Rather, bureaucratic hurdles and administrative failure impeded aid acceptance. Moreover, conceptions of those countries’ roles as established or emerging donors, as well as domestic political factors influenced their decisions. Ultimately, the dominant explanations focusing on wealth and capabilities are thus too shortsighted. Not only giving but also rejecting humanitarian aid follows political considerations.
Detecting moderate or complex congenital heart defects in adults from an electronic health records system
Authors: Diallo Alpha Oumar , Krishnaswamy Asha , Shapira Stuart K , Oster Matthew E , George Mary G , Adams Jenna C , Walker Elizabeth R , Weiss Paul , Ali Mohammed K , Book Wendy
Published: September 2018

Background

The prevalence of moderate or complex (moderate-complex) congenital heart defects (CHDs) among adults is increasing due to improved survival, but many patients experience lapses in specialty care or their CHDs are undocumented in the medical system. There is, to date, no efficient approach to identify this population.

Objective

To develop and assess the performance of a risk score to identify adults aged 20-60 years with undocumented specific moderate-complex CHDs from electronic health records (EHR).

Methods

We used a case-control study (596 adults with specific moderate-complex CHDs and 2384 controls). We extracted age, race/ethnicity, electrocardiogram (EKG), and blood tests from routine outpatient visits (1/2009 through 12/2012). We used multivariable logistic regression models and a split-sample (4: 1 ratio) approach to develop and internally validate the risk score, respectively. We generated receiver operating characteristic (ROC) c-statistics and Brier scores to assess the ability of models to predict the presence of specific moderate-complex CHDs.

Results

Out of six models, the non-blood biomarker model that included age, sex, and EKG parameters offered a high ROC c-statistic of 0.96 [95% confidence interval: 0.95, 0.97] and low Brier score (0.05) relative to the other models. The adult moderate-complex congenital heart defect risk score demonstrated good accuracy with 96.4% sensitivity and 80.0% specificity at a threshold score of 10.

Conclusions

A simple risk score based on age, sex, and EKG parameters offers early proof of concept and may help accurately identify adults with specific moderate-complex CHDs from routine EHR systems who may benefit from specialty care.
Free-form modelling of galaxy clusters: a Bayesian and data-driven approach
Authors: Olamaie Malak , Hobson Michael P , Feroz Farhan , Grainge Keith J B , Lasenby Anthony , Perrott Yvette C , Rumsey Clare , Saunders Richard D E
Published: September 2018

A new method is presented for modelling the physical properties of galaxy clusters. Our technique moves away from the traditional approach of assuming specific parameterized functional forms for the variation of physical quantities within the cluster, and instead allows for a ‘free-form’ reconstruction, but one for which the level of complexity is determined automatically by the observational data and may depend on position within the cluster. This is achieved by representing each independent cluster property as some interpolating or approximating function that is specified by a set of control points, or ‘nodes’, for which the number of nodes, together with their positions and amplitudes, are allowed to vary and are inferred in a Bayesian manner from the data. We illustrate our nodal approach in the case of a spherical cluster by modelling the electron pressure profile Pe(r) in analyses both of simulated Sunyaev–Zel’dovich (SZ) data from the Arcminute MicroKelvin Imager (AMI) and of real AMI observations of the cluster MACS J0744+3927 in the CLASH sample. We demonstrate that one may indeed determine the complexity supported by the data in the reconstructed Pe(r), and that one may constrain two very important quantities in such an analysis: the cluster total volume integrated Comptonization parameter (Ytot) and the extent of the gas distribution in the cluster (rmax). The approach is also well-suited to detecting clusters in blind SZ surveys, in the case where the population of radio sources is known in advance.
SURVEY OF KEY RADIATION SAFETY PRACTICES IN INTERVENTIONAL RADIOLOGY: AN IRISH AND ENGLISH STUDY
Authors: O’Hora L , Ryan M L , Rainford L
Published: September 2018

Interventional radiology is a rapidly evolving speciality with potential to deliver high patient radiation doses, as a result high standards of radiation safety practice are imperative. IR radiation safety practice must be considered before during and after procedures through appropriate patient consent, dose monitoring and patient follow-up. This questionnaire-based study surveyed fixed IR departments across Ireland and England to establish clinical practice in relation to radiation safety. Pre-procedure IR patient consent includes all radiation effects in 11% of cases. The patient skin dose surrogate parameter of Kerma to air at a reference point (Kar) is under-reported. Only 39% of respondents use a substantial radiation dose level and inform patients after these have been reached. Poor compliance with unambiguous, readily available best practice guidance was observed throughout highlighting patient communication, patient dose quantification and subsequent patient dose management concerns.
PERFORMANCE OF THE INSTADOSETM DOSEMETER FOR INTERVENTIONAL RADIOLOGY AND CARDIOLOGY APPLICATION
Authors: Garzón W J , Khoury H , Ovalle S A M , Medeiros R B
Published: September 2018

The aim of this article was to verify the performance of the Mirion InstadoseTM dosemeter under clinical conditions and to compare its response in typical X-ray fields used during interventional and cardiology procedures with the TLD-100, usually used for radiation dosimetry. It was also objective of this study to verify the feasibility of using the InstadoseTM dosemeter response at the chest level for estimation of occupational eye lens dose in cardiology and interventional radiology. Initially the response of the dosemeter was tested using continuous X-ray beams and the results showed that the Instadose dosemeter present a satisfactory behavior of the most important dosimetric properties based on the tests as described in the IEC 62387 standard. The measurements performed in clinical conditions showed that the InstadoseTM dosemeter response was comparable to that of TL dosemeters used in interventional radiology and cardiology procedures and there is a correlation between the eye lens doses and the chest doses measured with the InstadoseTM. Based on the results obtained, we recommend the use of the InstadoseTM dosemeter for purposes of occupational whole-body monitoring of medical staff in interventional radiology and cardiology procedures.
Pruning Wound Protection Strategies for Simultaneous Control of Eutypa and Botryosphaeria Dieback in New Zealand
Authors: Sosnowski Mark R. , Mundy Dion C.
Published: September 2018

The grapevine trunk diseases Eutypa and Botryosphaeria dieback threaten the sustainability of vineyards worldwide. This study aimed to develop practical and efficient wound protection strategies, which will lead to widespread adoption of preventative control for these diseases and increased longevity of vineyards. Five fungicides (tebuconazole, carbendazim, fluazinam, mancozeb, and flusilazole) were evaluated for efficacy against Eutypa lata and Neofusicoccum luteum infection on pruning wounds of ‘Sauvignon blanc’ in a New Zealand vineyard. All five fungicides controlled infection by both pathogens to varying degrees, with mean percent disease control of 70 to 90% for E. lata and 33 to 93% for N. luteum. This has led to the first known registration of a fungicide, fluazinam (Gem), for simultaneous control of both Eutypa and Botryosphaeria dieback. Furthermore, application of carbendazim with tractor-driven sprayers provided similar control of E. lata and N. luteum to that when applied by hand with a paintbrush. This constitutes the first report of Botryosphaeria dieback control with fungicides applied with tractor-driven sprayers.
Overwintering of Wheat Stripe Rust Under Field Conditions in the Northwestern Regions of China
Authors: Xu Xiangming , Ma Lijie , Hu Xiaoping
Published: September 2018

Stripe rust, caused by Puccinia striiformis f. sp. tritici Erikss., is an important disease of wheat worldwide. Identification of pathogen survival hot spots is important for predicting disease onset and subsequent spread to other regions, and such understanding is essential for developing integrated management strategies. We conducted field studies to determine the relationship of P. striiformis f. sp. tritici overwintering potential to winter temperatures in 10 sites in the northwest of China in three growing seasons (2011–12, 2012–13, and 2013–14). The fungus survived better in wheat cultivars with stronger winter hardiness than in those with weaker winter hardiness. Windowpane analysis suggested that P. striiformis f. sp. tritici winter survival is related to temperatures in the coldest period from mid-December to late January. β Regression showed that P. striiformis f. sp. tritici winter survival was negatively related to the number of days with daily average temperature <−2°C for cultivars with weak winter hardiness and <−4°C for cultivars with both moderate and strong winter hardiness. Models developed under constant temperature experiments greatly underestimate the P. striiformis f. sp. tritici overwinter potential under field conditions. This underestimation probably results from the possibility that P. striiformis f. sp. tritici in wheat tissues may have increased tolerance to low temperatures because of acclimation to gradual temperature changes under field conditions. The present models can be used to predict quantitative risks of P. striiformis f. sp. tritici overwintering in winter-wheat-growing regions for timely implementation of regional disease management strategies.
Fatal strongyloidiasis after corticosteroid therapy for presumed chronic obstructive pulmonary disease
Authors: Khadka Priyatam , Khadka Pratap , Thapaliya Januka , Karkee Dhana Bikram
Published: September 2018

Introduction. Strongyloidiasis is a neglected tropical disease with global prevalence. Under some cases of immune suppression (especially with corticosteroid administration), the nematode involved disseminates, leading to an amplified, possibly lethal hyper-infection syndrome.

Case presentation. A 56-year-old Nepalese man presenting with chief complaints of nausea, vomiting, joint pain and abdominal cramps was admitted to Sumeru Hospital. His past history revealed: chronic obstructive pulmonary disease (COPD), systemic hypertension and previously treated pulmonary tuberculosis. The patient had been treated with oral prednisolone (60 mg gl−1) for 8 days due to a presumed exacerbation of his COPD. Sequentially, he developed haemoptysis, chest tightness, frequent wheezing and worsening cough. Bronchoscopy showed severe diffuse alveolar haemorrhage; microbiological examination of broncho-alveolar lavage (BAL) was recommended. Examination of an acid fast bacilli stain preparation of BAL revealed filariform larvae of Strongyloides. Stool specimen examination revealed larvae of Strongyloides. The physical condition of the patient began to deteriorate; a few days after admission, vancomycin-sensitive Enterococcus faecium was isolated from a blood sample. He was treated with ivermectin and albendazole for strongyloides and linezolid plus vancomycin for E. faecium. However, the patient failed to recover from the illness and died.

Conclusion. The findings of our study suggest that corticosteroid administration in strongyloidiasis can lead to the development of fatal strongyloides hyper-infection syndrome. Hence our experience suggests the need for early diagnosis of strongyloidiasis to avoid such an outcome. A deterioration of the patient's condition after the initiation of corticosteroid therapy in endemic areas should raise the possibility of strongyloidiasis.
Context triggers the retrieval of long-term memories into working memory to guide attention
Authors: Itthipuripat Sirawaj , Woodman Geoffrey F
Published: September 2018

How do we know what we are looking for in familiar scenes and surroundings? Here we tested a novel hypothesis derived from theories of human memory that working memory (WM) buffers mnemonic contents retrieved from long-term memory (LTM) to control attention. To test this hypothesis, we measured the electrical fields recorded noninvasively from human subjects’ as they searched for specific sets of objects in learned contexts. We found that the subjects’ WM-indexing brain activity tracked the number of real-world objects people learned to search for in each context. Moreover, the level of this WM activity predicted the inter-subject variability in behavioral performance. Together, our results demonstrate that familiar contexts can trigger the transfer of information from LTM to WM to provide top-down attentional control.
Interpretation of ‘Omics dynamics in a single subject using local estimates of dispersion between two transcriptomes
Authors: Li Qike , Zaim Samir Rachid , Aberasturi Dillon , Berghout Joanne , Li Haiquan , Vitali Francesca , Kenost Colleen , Zhang Helen Hao , Lussier Yves A.
Published: September 2018

Calculating Differentially Expressed Genes (DEGs) from RNA-sequencing requires replicates to estimate gene-wise variability, infeasible in clinics. By imposing restrictive transcriptome-wide assumptions limiting inferential opportunities of conventional methods (edgeR, NOISeq-sim, DESeq, DEGseq), comparing two conditions without replicates (TCWR) has been proposed, but not evaluated. Under TCWR conditions (e.g., unaffected tissue vs. tumor), differences of transformed expression of the proposed individualized DEG (iDEG) method follow a distribution calculated across a local partition of related transcripts at baseline expression; thereafter the probability of each DEG is estimated by empirical Bayes with local false discovery rate control using a two-group mixture model. In extensive simulation studies of TCWR methods, iDEG and NOISeq are more accurate at 5%<DEGs<20% (precision>90%, recall>75%, false_positive_rate<1%) and 30%<DEGs<40% (precision=recall∼90%), respectively.

The proposed iDEG method borrows localized distribution information from the same individual, a strategy that improves accuracy to compare transcriptomes in absence of replicates at low DEGs conditions. http://www.lussiergroup.org/publications/iDEG
Truncated power-law distribution of group sizes in antelope
Authors: Minasandra Pranav , Isvaran Kavita
Published: September 2018

Group size distributions are instrumental in understanding group behaviour in animal populations. We analysed group size data of the blackbuck,Antilope cervicapra,from six different field sites to estimate the group size distribution of this antelope. We show that an exponentially truncated power law (called the polylog distribution in this paper) is the best fitting distribution, against the simple power law and lognormal distributions as other contenders, and the exponential distribution as a control. To show this, we use two likelihood based methods (AICs and likelihood ratios). Finally, we show that polylog distribution parameters can be used to better understand group dynamics, by using them to explore how habitat openness affects group behaviour.
Genetic and neuroanatomical support for functional brain network dynamics in epilepsy
Authors: Reddy Pranav G. , Betzel Richard F. , Khambhati Ankit N. , Shah Preya , Kini Lohith , Litt Brian , Lucas Timothy H. , Davis Kathryn A. , Bassett Danielle S.
Published: September 2018

Focal epilepsy is a devastating neurological disorder that affects an overwhelming number of patients world-wide, many of whom prove resistant to medication. The efficacy of current innovative technologies for the treatment of these patients has been stalled by the lack of accurate and effective methods to fuse multimodal neuroimaging data to map anatomical targets driving seizure dynamics. Here we propose a parsimonious model that explains how large-scale anatomical networks and shared genetic constraints shape inter-regional communication in focal epilepsy. In extensive ECoG recordings acquired from a group of patients with medically refractory focal-onset epilepsy, we find that ictal and preictal functional brain network dynamics can be accurately predicted from features of brain anatomy and geometry, patterns of white matter connectivity, and constraints complicit in patterns of gene coexpression, all of which are conserved across healthy adult populations. Moreover, we uncover evidence that markers of non-conserved architecture, potentially driven by idiosyncratic pathology of single subjects, are most prevalent in high frequency ictal dynamics and low frequency preictal dynamics. Finally, we find that ictal dynamics are better predicted by white matter features and more poorly predicted by geometry and genetic constraints than preictal dynamics, suggesting that the functional brain network dynamics manifest in seizures rely on – and may directly propagate along – underlying white matter structure that is largely conserved across humans. Broadly, our work offers insights into the generic architectural principles of the human brain that impact seizure dynamics, and could be extended to further our understanding, models, and predictions of subject-level pathology and response to intervention.
Mechanical Coupling Coordinates the Co-elongation of Axial and Paraxial Tissues in Avian Embryos
Authors: Xiong Fengzhu , Ma Wenzhe , Bénazéraf Bertrand , Mahadevan L. , Pourquié Olivier
Published: September 2018

Tissues undergoing morphogenesis impose mechanical effects on one another. How developmental programs adapt to or take advantage of these effects remains poorly explored. Here, using a combination of live imaging, modeling, and microsurgical perturbations, we show that the axial and paraxial tissues in the forming avian embryonic body coordinate their rates of elongation through mechanical interactions. First, a cell motility gradient drives paraxial presomitic mesoderm (PSM) expansion, resulting in compression of the axial neural tube and notochord; second, elongation of axial tissues driven by PSM compression and polarized cell intercalation pushes the caudal progenitor domain posteriorly; finally, the axial push drives progenitors to emigrate into the PSM to maintain tissue growth and cell motility. These interactions form an engine-like positive feedback loop, which ensures the tissue-coupling and self-sustaining characteristics of body elongation. Our results suggest a general role of inter-tissue forces in the coordination of complex morphogenesis involving distinct tissues.
Manipulation of microbiota reveals altered myelination and white matter plasticity in a model of Huntington disease
Authors: Radulescu Carola I. , Garcia-Miralles Marta , Sidik Harwin , Bardile Costanza Ferrari , Mohammad Yusof Nur Amirah Binte , Lee Hae Ung , Pei Ho Eliza Xin , Chu Collins Wenhan , Layton Emma , Low Donovan , De Sessions Paola Florez , Pettersson Sven , Ginhoux Florent , Pouladi Mahmoud A.
Published: September 2018

Structural and molecular myelination deficits represent early pathological features of Huntington disease (HD). Recent evidence from germ-free (GF) animals suggests a role for microbiota-gut-brain bidirectional communication in the regulation of myelination. In this study, we aimed to investigate the impact of microbiota on myelin plasticity and oligodendroglial population dynamics in the mixed-sex BACHD mouse model of HD. Ultrastructural analysis of myelin in the corpus callosum revealed alterations of myelin thickness in BACHD GF compared to specific-pathogen free (SPF) mice, whereas no differences were observed between wild-type (WT) groups. In contrast, myelin compaction was altered in all groups when compared to WT SPF animals. Levels of myelin-related proteins were generally reduced, and the number of mature oligodendrocytes was decreased in the prefrontal cortex under GF compared to SPF conditions, regardless of genotype. Minor differences in commensal bacteria at the family and genera levels were found in the gut microbiota of BACHD and WT animals housed in standard living conditions. Our findings indicate complex effects of a germ-free status on myelin-related characteristics, and highlight the adaptive properties of myelination as a result of environmental manipulation.