bluuebunny/crossref_metadata_2025 huggingface dataset:
Composite electrode with gate-tunable work function for optoelectronic devices
Authors: Li Huaping , Liu Jiang , Zhao Fangchao , Luan Xinning , Zhou Lili
Published: September 2017

The work function (WF) of Al:LiF composite electrode is first reported to be tunable by electrostatic field effect via the polarization of LiF on Al atom layer. This observation was demonstrated in Kelvin probe force microscope measurement. The optimized Al:LiF composite electrode was employed as organic light emitting diode (OLED) cathode to show the electroluminescent brightness increased from 0 cd m−2 to >8000 cd m−2 and sub second temporal response in an electrolyte gated OLEDs, superior to LiF/Al and Al electrodes. These results are plausibly ascribed to the augmented electron injection with the concurrence of the upward shift of cathode WF induced by gating potential, leading to the improved electron/hole injection balance for efficient electroluminescence.
Ion acceleration and heating by kinetic Alfvén waves associated with magnetic reconnection
Authors: Liang Ji , Lin Yu , Johnson Jay R. , Wang Zheng-Xiong , Wang Xueyi
Published: September 2017

Our previous study on the generation and signatures of kinetic Alfvén waves (KAWs) associated with magnetic reconnection in a current sheet revealed that KAWs are a common feature during reconnection [Liang et al. J. Geophys. Res.: Space Phys. 121, 6526 (2016)]. In this paper, ion acceleration and heating by the KAWs generated during magnetic reconnection are investigated with a three-dimensional (3-D) hybrid model. It is found that in the outflow region, a fraction of inflow ions are accelerated by the KAWs generated in the leading bulge region of reconnection, and their parallel velocities gradually increase up to slightly super-Alfvénic. As a result of wave-particle interactions, an accelerated ion beam forms in the direction of the anti-parallel magnetic field, in addition to the core ion population, leading to the development of non-Maxwellian velocity distributions, which include a trapped population with parallel velocities consistent with the wave speed. The ions are heated in both parallel and perpendicular directions. In the parallel direction, the heating results from nonlinear Landau resonance of trapped ions. In the perpendicular direction, however, evidence of stochastic heating by the KAWs is found during the acceleration stage, with an increase of magnetic moment μ. The coherence in the perpendicular ion temperature T⊥ and the perpendicular electric and magnetic fields of KAWs also provides evidence for perpendicular heating by KAWs. The parallel and perpendicular heating of the accelerated beam occur simultaneously, leading to the development of temperature anisotropy with T⊥>T∥. The heating rate agrees with the damping rate of the KAWs, and the heating is dominated by the accelerated ion beam. In the later stage, with the increase of the fraction of the accelerated ions, interaction between the accelerated beam and the core population also contributes to the ion heating, ultimately leading to overlap of the beams and an overall anisotropy with T∥>T⊥.
Experimental demonstration of Fabry-Perot open resonators in a surface-wave bandgap crystal
Authors: Gao Zhen , Gao Fei , Xu Hongyi , Zhang Youming , Zhang Baile
Published: September 2017

We report on the proposal and experimental realization of a type of retardation-based Fabry-Perot (FP) open resonator in a surface-wave bandgap crystal implemented on a single structured metal surface. This surface-wave FP open resonator is formed by introducing a finite line defect in the surface-wave bandgap crystal, whose resonance frequencies lie exactly within the forbidden bandgap of the surrounding crystal. Due to the complete surface-wave forbidden bandgap, a new FP plasmonic resonance mode exhibiting monopolar features which is missing in both traditional FP resonators and plasmonic resonators is emerged. Near-field response spectra and imaged mode profiles are presented to characterize the properties of these FP open resonators in the microwave regime.
Instability modes on a solid-body-rotation flow in a finite-length pipe
Authors: Feng Chunjuan , Liu Feng , Rusak Zvi , Wang Shixiao
Published: September 2017

Numerical solutions of the incompressible Navier-Stokes equations are obtained to study the time evolution of both axisymmetric and three-dimensional perturbations to a base solid-body-rotation flow in a finite-length pipe with non-periodic boundary conditions imposed at the pipe inlet and outlet. It is found that for a given Reynolds number there exists a critical swirl number beyond which the initial perturbations grow, in contrast to the solid-body rotation flow in an infinitely-long pipe or a finite-length pipe with periodic inlet and exit boundary conditions for which the classical Kelvin analysis and Rayleigh stability criterion affirm neutrally stable for all levels of swirl. This paper uncovers for the first time the detailed evolution of the perturbations in both the axisymmetric and three-dimensional situations. The computations reveal a linear growth stage of the perturbations with a constant growth rate after a brief initial period of decay of the imposed initial perturbations. The fastest growing axisymmetric and three-dimensional instability modes and the associated growth rates are identified numerically for the first time. The computations show that the critical swirl number increases and the growth rate of instability decreases at the same swirl number with decreasing Reynolds number. The growth rate of the axisymmetric mode at high Reynolds number agrees well with previous stability theory for inviscid flow. More importantly, three-dimensional simulations uncover that the most unstable mode is the spiral type m = 1 mode, which appears at a lower critical swirl number than that for the onset of the axisymmetric mode. This spiral mode grows faster than the unstable axisymmetric mode at the same swirl. Moreover, the computations reveal that after the linear growing stage of the perturbation the flow continues to evolve nonlinearly to a saturated axisymmetric vortex breakdown state.
Determination of yield stress of 2D (Yukawa) dusty plasma
Authors: Liu Bin , Goree J.
Published: September 2017

Elastic and plastic deformations of a two-dimensional (2D) dusty plasma crystal under shear stresses are investigated using a numerical simulation. Our simulation mimics experiments that start with a crystal that is then manipulated by a pair of laser beams separated by a gap. In a pair of rectangular regions, we apply two equal but oppositely directed forces, to induce a shear deformation in the gap between. These external forces are increased incrementally to examine the elastic behavior, plasticity, and liquid flows. In the low-force elastic limit, a measurement of the shear modulus is obtained, which agrees with a theoretical value based on a sound speed. For larger forces resulting in plastic deformation, we determine the yield stress, which is found to agree with a common theoretical model for the critical yield stress, after accounting for the dimensionality for 2D.
One bipolar transistor selector - One resistive random access memory device for cross bar memory array
Authors: Aluguri R. , Kumar D. , Simanjuntak F. M. , Tseng T.-Y.
Published: September 2017

A bipolar transistor selector was connected in series with a resistive switching memory device to study its memory characteristics for its application in cross bar array memory. The metal oxide based p-n-p bipolar transistor selector indicated good selectivity of about 104 with high retention and long endurance showing its usefulness in cross bar RRAM devices. Zener tunneling is found to be the main conduction phenomena for obtaining high selectivity. 1BT-1R device demonstrated good memory characteristics with non-linearity of 2 orders, selectivity of about 2 orders and long retention characteristics of more than 105 sec. One bit-line pull-up scheme shows that a 650 kb cross bar array made with this 1BT1R devices works well with more than 10 % read margin proving its ability in future memory technology application.
Application of argon atmospheric cold plasma for indium tin oxide (ITO) based diodes
Authors: Akbari Nia S. , Jalili Y. Seyed , Salar Elahi A.
Published: September 2017

Transparent Conductive Oxide (TCO) layers due to transparency, high conductivity and hole injection capability have attracted a lot of attention. One of these layers is Indium Tin Oxide (ITO). ITO due to low resistance, transparency in the visible spectrum and its proper work function is widely used in the manufacture of organic light emitting diodes and solar cells. One way for improving the ITO surface is plasma treatment. In this paper, changes in surface morphology, by applying argon atmospheric pressure cold plasma, was studied through Atomic Force Microscopic (AFM) image analysis and Fourier Transform Infrared Spectroscopy (FTIR) analysis. FTIR analysis showed functional groups were not added or removed, but chemical bond angle and bonds strength on the surface were changed and also AFM images showed that surface roughness was increased. These factors lead to the production of diodes with enhanced Ohmic contact and injection mechanism which are more appropriate in industrial applications.
Sensitivity of reentrant driver localization to electrophysiological parameter variability in image-based computational models of persistent atrial fibrillation sustained by a fibrotic substrate
Authors: Deng Dongdong , Murphy Michael J. , Hakim Joe B. , Franceschi William H. , Zahid Sohail , Pashakhanloo Farhad , Trayanova Natalia A. , Boyle Patrick M.
Published: September 2017

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, causing morbidity and mortality in millions worldwide. The atria of patients with persistent AF (PsAF) are characterized by the presence of extensive and distributed atrial fibrosis, which facilitates the formation of persistent reentrant drivers (RDs, i.e., spiral waves), which promote fibrillatory activity. Targeted catheter ablation of RD-harboring tissues has shown promise as a clinical treatment for PsAF, but the outcomes remain sub-par. Personalized computational modeling has been proposed as a means of non-invasively predicting optimal ablation targets in individual PsAF patients, but it remains unclear how RD localization dynamics are influenced by inter-patient variability in the spatial distribution of atrial fibrosis, action potential duration (APD), and conduction velocity (CV). Here, we conduct simulations in computational models of fibrotic atria derived from the clinical imaging of PsAF patients to characterize the sensitivity of RD locations to these three factors. We show that RDs consistently anchor to boundaries between fibrotic and non-fibrotic tissues, as delineated by late gadolinium-enhanced magnetic resonance imaging, but those changes in APD/CV can enhance or attenuate the likelihood that an RD will anchor to a specific site. These findings show that the level of uncertainty present in patient-specific atrial models reconstructed without any invasive measurements (i.e., incorporating each individual's unique distribution of fibrotic tissue from medical imaging alongside an average representation of AF-remodeled electrophysiology) is sufficiently high that a personalized ablation strategy based on targeting simulation-predicted RD trajectories alone may not produce the desired result.
Synthesis and optical properties of (GaAs)yGe5-2y alloys assembled from molecular building blocks
Authors: Sims P. E. , Wallace P. M. , Xu Chi , Poweleit C. D. , Claflin B. , Kouvetakis J. , Menéndez J.
Published: September 2017

Monocrystalline alloys of GaAs and Ge with compositions (GaAs)yGe5–2y have been synthesized following a chemical vapor deposition approach that promotes the incorporation of Ga and As atoms as isolated donor-acceptor pairs. The structural and optical properties show distinct behavior relative to (GaAs)1-xGe2x counterparts produced by conventional routes. Strong band gap photoluminescence is observed in the 0.5–0.6 eV range for samples whose compositions approach the GaAsGe3 limit for isolated Ga-As pairs. In such samples, the Ge-like Raman modes appear at higher frequencies and are considerably narrower than those observed in samples with higher Ge concentrations. These results suggest that the growth mechanism may favor the formation of ordered phases comprising Ga-As-Ge3 tetrahedra. In contrast with the diamond-to-zincblende ordering transition previously reported for III-V-IV alloys, ordered structures built from Ga-As-Ge3 tetrahedra feature III-III and V-V pairs as third-nearest neighbors, and therefore both the III- and V-components are equally present in each of two fcc sublattices of the average diamond-like structure. These bonding arrangements likely lead to the observed optical response, indicating potential applications of these materials in mid-IR technologies integrated on Si.
Artificial meat and the future of the meat industry
Authors: Bonny Sarah P. F. , Gardner Graham E. , Pethick David W. , Hocquette Jean-François
Published: September 2017

The global population is estimated to plateau at 9 billion by the year 2050; however, projected food-production estimates would supply for only 8 billion people, using the ‘business as usual’ approach. In particular, the meat industry would need to increase production by ~50–73%. In response, there are several different options that have the potential to satisfy demand and increase production. Some of these options require advanced technologies and many may be considered as ‘artificial’ by different consumer groups. Within the meat industry itself, available technologies include selective breeding, agroecology systems, animal cloning and genetic modification. Alternatively, meat proteins can be replaced or substituted with proteins from plants, fungi, algae or insects. Finally, meat products could be produced using in vitro culturing and three-dimensional printing techniques. The protein produced by these techniques can be considered in the following three categories: modified livestock systems, synthetic meat systems, and meat substitutes. In the future, it is likely that meat substitutes will increase market share through competition with low-grade cuts of meat, sausages, ground meat and processed meat. However, synthetic meat systems and meat substitutes have significant barriers to commercialisation and widespread adoption that will affect their presence at least in the high-end premium sector in the market. To meet growing demands for protein, and in the face of growing competition from other sectors, the conventional meat industry must adopt new technologies and farming systems. These must be tailored to the challenges facing the industry and must effectively respond to consumer demands and the changing market place.
Calcium and phosphorus metabolism and nutrition of poultry: are current diets formulated in excess?
Authors: Li X. , Zhang D. , Bryden W. L.
Published: September 2017

Calcium (Ca) and phosphorus (P) are important nutrients in poultry diet formulations. In the present review, we discuss recent advances in our understanding of the metabolism of Ca and P in poultry. Recent data are provided in support of the proposition that current poultry diets are formulated in excess for Ca and P. The quantities of Ca and P available for metabolism reflect rates of intestinal absorption, bone accretion and resorption, glomerular filtration, renal tubular reabsorption, and intestinal endogenous losses. Ca and P homeostasis is largely under endocrine control. Parathyroid hormone and the hormonal form of vitamin D3 are the two hormones credited with this role. However, a novel hormonal axis involving Fibroblast Growth Factor 23 and Klotho has been recently delineated, which, in conjunction with parathyroid hormone and vitamin D3, tightly regulates Ca and P homeostasis. Recent studies have suggested that current commercial diets for both broilers and layers contain excess Ca and P, the content of which could be reduced without affecting production or bird welfare. The challenge in reducing Ca and P concentrations in poultry diets is the uncertainty about what concentrations of Ca and P can be fed without compromising bird welfare. This is because there are limited data on the available P and Ca concentrations in poultry feedstuffs determined biologically. This is further complicated by the need for agreement on evaluation systems for evaluation of Ca and P bioavailability. We conclude that direct ileal or pre-caecal digestible Ca and P values are preferred.
Pollinarium size as a hybridisation barrier between sympatric inter-compatible orchids
Authors: Vieira B. C. , Pansarin L. M. , Martucci M. E. P. , Gobbo-Neto L. , Pansarin E. R.
Published: September 2017

Hybridisation has been recorded for many different organisms, including plants, and is crucial in the diversification of Epidendrum, a neotropical orchid genus with ~1500 species. Based on the evidence of frequent natural hybridisation in Epidendrum and the absence of pre-mating barriers among the species, our main hypothesis was that pollen transfer is occurring between two sympatric species, Epidendrum secundum Jacq. and Epidendrum denticulatum Barb. Rodr. The reproduction of the species was investigated based on morpho-anatomical and histochemical analyses and intra- and interspecific crosses. Also, the relationship between co-occurring species was verified by floral morphometry, principal component analysis and sequence divergence analyses. Results showed that E. secundum and E. denticulatum are rewardless, self- and inter-compatible, and need a biotic vector for pollen transfer. Although there is inter-compatibility among the species, and E. secundum and E. denticulatum share the pollinators, our data showed no intermediary forms in either morphology or molecular data. All data collected suggest that, at least nowadays, no gene flow is occurring, and that hybridisation has been avoided due to the incompatible pollinarium size between the sympatric E. secundum and E. denticulatum, which acts as a pre-mating barrier in the studied population. This new discovery increases the knowledge about the isolation mechanisms and pre-pollination barriers in plants.
Preparing for advocacy, resisting attack
Authors: Martin Brian
Published: September 2017

When scientists engage in public advocacy, or indeed in any public comment on controversial issues, there is a risk they will come under attack. To reduce the possibility of reprisals, it is worthwhile preparing, in several ways, including learning from the experience of others and making mild comments to see the reaction. If there is a serious risk, reducing expenditures and transferring assets can provide extra financial security. Building networks for personal support is crucially important, including family and friends, work colleagues and various others. When coming under attack, it is important to document actions, seek advice and behave sensibly. The most powerful counter to attacks is mobilisation of support. It is important to support scientists who come under attack, as this protects scientific freedom for all.
Asymmetric mechanosensitivity in a eukaryotic ion channel
Authors: Clausen Michael V. , Jarerattanachat Viwan , Carpenter Elisabeth P. , Sansom Mark S. P. , Tucker Stephen J.
Published: September 2017

Significance

One important way in which living organisms are able to detect and respond to their environment is via the conversion of mechanical forces into electrical signals. However, the molecular mechanisms that enable mammalian “mechanosensitive” ion channels to detect a wide profile of forces within the membrane remain unclear. By studying the functional activity of individual TREK-2 K2P channels inserted in different directions into a lipid bilayer, we are now able to describe how the asymmetric structure of this channel enables it to sense such a broad profile of forces. These results help us understand how eukaryotic ion channels respond to a rich variety of sensory stimuli.
Continuous track paths reveal additive evidence integration in multistep decision making
Authors: Buc Calderon Cristian , Dewulf Myrtille , Gevers Wim , Verguts Tom
Published: September 2017

Significance

Many daily-life decisions consist of multiple steps (e.g., go outside, go left, arrive at Italian restaurant). We distinguish four prominent models of such multistep decision making. We further propose a paradigm in two experiments to disentangle these models. Only the models implementing additive integration from second- to first-step choices were able to account for track path movements. Specifically, we find that first-step decisions are initially based on the sum/mean of second-step future rewards. As information regarding the optimal second-step choice increases, the decision gradually becomes based on the maximal future reward. Hence, we suggest that multistep decision making involves progressive unraveling of future outcomes during decision making.
Transparency and language contact in the nativization of relative clauses in New Englishes
Authors: Suárez-Gómez Cristina
Published: September 2017

The present paper explores structural nativization in relative clauses in three varieties of English (India, Hong Kong, and Singapore Englishes). All three of these emerged as the consequence of British colonization, developed as varieties through educational systems, and are now consolidating as independent, linguistically different (local) prestige varieties. An analysis of comparable samples from the spoken component of theInternational Corpus of English(ICE) is carried out; in addition to the varieties mentioned above, data from ICE-GB are included for comparison. The analysis shows that certain features and structures predominate in specific varieties, and also illustrates constructions which are specific to the Asian varieties under investigation. These nativized relative clauses can be explained as cross-linguistic tendencies that go beyond the influence of the local language(s), and hence they are further analyzed in light of cognitive determinants of learning, which favor isomorphism and aim at maximizing transparency.
The Proto-Germanic irregular weak verbs of class I
Authors: Rombouts Stefan
Published: September 2017

This paper attempts to explain the origin and development of a subgroup of the Proto-Germanic weak verbs of class I (Gothicbugjan,waurkjan,þugkjan,þagkjan,sokjanandbrukjan). The core of this group consists of Proto-Indo-European zero-grade primary *-i̯e/opresents, which all developed aj-present, ablauting preterit and *-tó- participle in Early Proto-Germanic. In so doing, they came to violate the requirement that each ablauting verb must possess distinct present and preterit stems. With the introduction of a new preterit plural vowel in the ablaut model of classes V and VI, this problem was solved for the primary *-i̯e/opresents belonging to these. Owing to the dominance of the present tense within the strong paradigm, a remodelling of the preterit was also the preferred solution for the remaining verbs, and this was eventually found in the innovation of new weak forms through an analogy involving their *-tó- participle.
Scandinavian umlaut and contrastive feature hierarchies
Authors: Schalin Johan
Published: September 2017

With the application of the Contrastive Hierarchy Theory, the contrastive features of preliterary Scandinavian vowels are here inferred from the interaction between targets and triggers for metaphonic fronting, rounding and breaking. One Proto-Scandinavian feature hierarchy is reconstructed for prominent syllables and another for non-prominent ones. The former hierarchy sustained contrasts that differed from the latter, including contrast for rounding and a preserved distinction between Pre-Germanic */i/ and */e/. A prominence system is reconstructed that predicts both the outcome of syncope and the distribution of the two vowel systems between syllables. The analysis neatly accounts for many notorious cruxes of umlaut and breaking that correlate with the prosodic position of the trigger, including the frequent absence ofi-umlaut in light syllables.
Accounting for water formation from hydrocarbon fuel combustion in life cycle analyses
Authors: Belmont E L , Davidson F T , Glazer Y R , Beagle E A , Webber M E
Published: September 2017

Hydrocarbon fuel production and utilization are considered water intensive processes due to the high volumes of water used in source development and fuel processing. At the same time, there is significant water formed during combustion. However, this water is not currently widely harvested at the site of production. Instead, it is added to the hydrologic cycle, often in a different location from the fuel production site. This study quantifies the water formed from combustion of these fuels and analyzes the magnitudes of formation in the context of other hydrologic sources and sinks in order to facilitate future assessments of water harvesting technology and/or atmospheric impacts of combustion. Annual water formation from stoichiometric combustion of hydrocarbon fuels, including natural gas, oil- and natural gas liquid-derived products, and coal, in the United States and worldwide are presented and compared with quantities of water sequestered, evaporated, and stored in the atmosphere. Water production factors in terms of mass and energy of fuel consumed, WPFm and WPFe, respectively, are defined for the comparison of fuels and incorporation into future life cycle analyses (LCAs). Results show that water formation from combustion has increased worldwide from 2005 to 2015, with the largest increase coming from growth in combustion of natural gas. Water formation from combustion of hydrocarbon fuels equals or exceeds water sequestered from the hydrologic cycle through deep well injection in the US annually. Overall, water formation is deemed significant enough to warrant consideration by LCAs of water intensity in fuel production and use, and should be included in future analyses.
Security warning method and system for worker safety during live-line working
Authors: Jiang Chilong , Zou Dehua , Long Chenhai , Yang Miao , Zhang Zhanlong , Mei Daojun
Published: September 2017

Live-line working is an essential part in the operations in an electric power system. Live-line workers are required to wear shielding clothing. Shielding clothing, however, acts as a closed environment for the human body. Working in a closed environment for a long time can change the physiological responses of the body and even endanger personal safety. According to the typical conditions of live-line working, this study synthesizes environmental factors related to shielding clothing and the physiological factors of the body to establish the heart rate variability index RMSSD and the comprehensive security warning index SWI. On the basis of both indices, this paper proposes a security warning method and system for the safety live-line workers. The system can monitor the real-time status of workers during live-line working to provide security warning and facilitate the effective safety supervision by the live operation center during actual live-line working.
QuASAR-MPRA: accurate allele-specific analysis for massively parallel reporter assays
Authors: Kalita Cynthia A , Moyerbrailean Gregory A , Brown Christopher , Wen Xiaoquan , Luca Francesca , Pique-Regi Roger
Published: September 2017

Motivation

The majority of the human genome is composed of non-coding regions containing regulatory elements such as enhancers, which are crucial for controlling gene expression. Many variants associated with complex traits are in these regions, and may disrupt gene regulatory sequences. Consequently, it is important to not only identify true enhancers but also to test if a variant within an enhancer affects gene regulation. Recently, allele-specific analysis in high-throughput reporter assays, such as massively parallel reporter assays (MPRAs), have been used to functionally validate non-coding variants. However, we are still missing high-quality and robust data analysis tools for these datasets.

Results

We have further developed our method for allele-specific analysis QuASAR (quantitative allele-specific analysis of reads) to analyze allele-specific signals in barcoded read counts data from MPRA. Using this approach, we can take into account the uncertainty on the original plasmid proportions, over-dispersion, and sequencing errors. The provided allelic skew estimate and its standard error also simplifies meta-analysis of replicate experiments. Additionally, we show that a beta-binomial distribution better models the variability present in the allelic imbalance of these synthetic reporters and results in a test that is statistically well calibrated under the null. Applying this approach to the MPRA data, we found 602 SNPs with significant (false discovery rate 10%) allele-specific regulatory function in LCLs. We also show that we can combine MPRA with QuASAR estimates to validate existing experimental and computational annotations of regulatory variants. Our study shows that with appropriate data analysis tools, we can improve the power to detect allelic effects in high-throughput reporter assays.

Availability and implementation

http://github.com/piquelab/QuASAR/tree/master/mpra

Supplementary information

Supplementary data are available online at Bioinformatics.
TROVE: a user-friendly tool for visualizing and analyzing cancer hallmarks in signaling networks
Authors: Chua Huey Eng , Bhowmick Sourav S , Zheng Jie
Published: September 2017

Cancer hallmarks, a concept that seeks to explain the complexity of cancer initiation and development, provide a new perspective of studying cancer signaling which could lead to a greater understanding of this complex disease. However, to the best of our knowledge, there is currently a lack of tools that support such hallmark-based study of the cancer signaling network, thereby impeding the gain of knowledge in this area. We present TROVE, an user-friendly software that facilitates hallmark annotation, visualization and analysis in cancer signaling networks. In particular, TROVE facilitates hallmark analysis specific to particular cancer types.

Availability and implementation

Available under the Eclipse Public License from: https://sites.google.com/site/cosbyntu/softwares/trove and https://github.com/trove2017/Trove.
Optical polarimetry of KIC 8462852 in 2017 May–August
Authors: Steele I A , Copperwheat C M , Jermak H E , Kennedy G M , Lamb G P
Published: September 2017

We present optical polarimetry in the period of 2017 May–August of the enigmatic ‘dipping’ star KIC 8462852. During that period, three ∼1 per cent photometric dips were reported by other observers. We measured the average absolute polarization of the source, and find no excess or unusual polarization compared to a nearby comparison star. We place tight upper limits on any change in the degree of polarization of the source between epochs in-dip and out-of-dip of <0.1 per cent (8500  Å) and <0.2 per cent (7050  Å and 5300  Å). How our limits are interpreted depends on the specific model being considered. If the whole stellar disc were covered by material with an optical depth of ∼0.01, then the fractional polarization introduced by this material must be less than 10–20 per cent. While our non-detection does not constrain the comet scenario, it predicts that even modest amounts of dust that have properties similar to Solar system comets may be detectable. We note that the sensitivity of our method scales with the depth of the dip. Should a future ∼20 per cent photometric dip be observed (as was previously detected by Kepler), our method would constrain any induced polarization associated with any occulting material to 0.5–1.0 per cent.
A New Community Health Center/Academic Medicine Partnership for Medicaid Cost Control, Powered by the Mega Teaching Health Center
Authors: Rieselbach Richard E. , Epperly Ted , Friedman Aaron , Keahey David , McConnell Eleanor , Nichols Karen , Nycz Greg , Roberts Jeanette , Schmader Kenneth , Shin Peter , Shtasel Derri
Published: September 2017

Community health centers (CHCs), a principal source of primary care for over 24 million patients, provide high-quality affordable care for medically underserved and lower-income populations in urban and rural communities. The authors propose that CHCs can assume an important role in the quest for health care reform by serving substantially more Medicaid patients. Major expansion of CHCs, powered by mega teaching health centers (THCs) in partnership with regional academic medical centers (AMCs) or teaching hospitals, could increase Medicaid beneficiaries’ access to cost-effective care. The authors propose that this CHC expansion could be instrumental in limiting the added cost of Medicaid expansion via the Affordable Care Act (ACA) or subsequent legislation. Nevertheless, expansion cannot succeed without developing this CHC-AMC partnership both (1) to fuel the currently deficient primary care provider workforce pipeline, which now greatly limits expansion of CHCs; and (2) to provide more CHC-affiliated community outreach sites to enhance access to care. The authors describe the current status of Medicaid and CHCs, plus the evolution and vulnerability of current THCs. They also explain multiple features of a mega THC demonstration project designed to test this new paradigm for Medicaid cost control. The authors contend that the demonstration’s potential for success in controlling costs could provide help to preserve the viability of current and future expanded state Medicaid programs, despite a potential ultimate decrease in federal funding over time. Thus, the authors believe that the new AMC-CHC partnership paradigm they propose could potentially facilitate bipartisan support for repairing the ACA.
Combined Gluteus and Pudendal Thigh Flap Reconstruction of Vaginal Defects following Robotic Abdominoperineal Resection
Authors: Dassoulas Kasandra R. , Hedrick Traci L. , Campbell Chris A.
Published: September 2017

Low-lying rectal cancers are being treated more frequently with robotic-assisted abdominoperineal resection, obviating the need for laparotomy and the ability to raise vertical rectus abdominis musculocutaneous flaps. For female patients, posterior vaginectomy often accompanies the resection. Combined pudendal thigh flaps as an extension of bilateral gluteus advancement flaps allow for posterior vaginal resurfacing with thin pliable fasciocutaneous flaps, which rest on the gluteal flap soft-tissue bulk that obliterates the pelvic dead space. For patients with advanced cancers who have had neoadjuvant chemoradiation, the pudendal skin paddle can be planned more laterally to bring in healthier medial thigh skin. The donor incisions lie within the gluteal cleft and crease and groin creases recapitulating normal perineal anatomy and aesthetics.
Rate of Macular Ganglion Cell-inner Plexiform Layer Thinning in Glaucomatous Eyes With Vascular Endothelial Growth Factor Inhibition
Authors: Lee Won June , Kim Young Kook , Kim Yong Woo , Jeoung Jin Wook , Kim Seok Hwan , Heo Jang Won , Yu Hyeong Gon , Park Ki Ho
Published: September 2017

Purpose:

To evaluate the rate of progressive macular ganglion cell-inner plexiform layer (GCIPL) thinning in patients with open-angle glaucoma (OAG) who had been treated with intravitreal antivascular endothelial growth factor (VEGF) injection for wet age-related macular degeneration (AMD).

Methods:

This study was a retrospective modified case control study with fellow eye comparison. We enrolled bilateral OAG patients who had been treated with repeated anti-VEGF injections for unilateral wet AMD and followed-up on for a minimum of 24 months by Cirrus high-definition optical coherence tomography. The rate of macular GCIPL thinning was determined by linear regression of serial optical coherence tomography GCIPL thickness measurements over time. We compared the rate of macular GCIPL thinning between anti-VEGF-treated eyes and fellow untreated dry AMD eyes.

Results:

This study involved 32 OAG eyes of 16 subjects. The total follow-up period was 58.4±25.5 (24 to 98) months, and the mean number of anti-VEGF injections was 10.6±10.4 (3 to 40). The eyes with repeated anti-VEGF treatment differed significantly from their fellow eyes in the rate of GCIPL thinning (−2.95±3.58 vs. −0.77±0.95 µm/y, P=0.015). Also, multivariable regression analyses showed that anti-VEGF injection was significantly associated with the rate of GCIPL thinning (P=0.025).

Conclusions:

In subjects with bilateral OAG, the rate of GCIPL thinning is significantly faster in eyes treated with anti-VEGF injection for wet AMD than in untreated dry AMD fellow eyes. This finding suggests that in glaucomatous eyes, VEGF inhibition could play a role, at least in part, in progressive change of inner retinal layers.
Effects of Localized Cold Therapy on Pain in Postoperative Spinal Fusion Patients
Authors: Quinlan Patricia , Davis Jack , Fields Kara , Madamba Pia , Colman Lisa , Tinca Daniela , Cannon Drake Regina
Published: September 2017

BACKGROUND:

Cold therapy used in the sports medicine settings has been found to be effective in reducing postoperative pain; however, there are limited studies that examine the effect of cold therapy on postoperative pain in patients with posterior lumbar spinal fusion.

PURPOSE:

The purpose of this study was to determine the effects of cold on postoperative spine pain and add to the body of knowledge specific to practical application of cold therapy in the spine surgery setting.

METHODS:

Researchers used a two-group randomized control design to evaluate the effects of local cold therapy on postoperative pain and analgesia use after lumbar spinal fusion surgery. The primary outcome was postoperative pain. Secondary outcomes included analgesia use and perceived benefit of cold therapy.

RESULTS:

The intervention (cold) group had a marginally greater reduction in mean Numerical Rating Scale score across all 12 pain checks (M ± SD = −1.1 ± 0.8 points reduction vs. −1.0 ± 0.8 points reduction, p = .589). On average, the intervention group used less morphine equivalents (M ± SD = 12.6 ± 31.5 vs. 23.7 ± 40.0) than the control group across pain checks seven to 12 (p = .042).

CONCLUSIONS:

This study provides additional evidence to support the use of cold therapy as an adjuvant pain management strategy to optimize pain control and reduce opioid consumption following spine fusion surgical procedures.
Barriers Impeding the Use of Non-pharmacological, Non-surgical Care in Hip and Knee Osteoarthritis
Authors: Selten Ellen M. H. , Vriezekolk Johanna E. , Nijhof Marc W. , Schers Henk J. , van der Meulen-Dilling Roelien G. , van der Laan Willemijn H. , Geenen Rinie , van den Ende Cornelia H. M.
Published: September 2017

Background

Non-pharmacological, non-surgical treatment modalities are underused in the management of knee and hip osteoarthritis (OA). One possible explanation for this could be healthcare providers’ opinions about these treatment modalities. The objective of this qualitative study was to identify healthcare providers’ views on non-pharmacological, non-surgical care for OA.

Methods

Semi-structured in-depth interviews with 24 healthcare providers (rheumatologists, orthopedic surgeons, physical therapists and general practitioners) were held. Interviews were transcribed verbatim and analyzed using a three-step thematic approach. Two independent researchers continuously reflected upon, compared, discussed, and adjusted the codings.

Results

Eight themes were identified reflecting three main barriers to the provision of non-pharmacological, non-surgical care: perceived lack of expertise of the healthcare provider (including a lack of knowledge and skills that are required to support patients), perceived lack of evidence-based treatment (regarding weight management, and the intensity and dosage of physical exercise), and suboptimal organization of care (including hampered dialogue between disciplines and lack of clarity about the roles and responsibilities of disciplines).

Conclusions

Healthcare providers report multiple barriers impeding non-pharmacological, non-surgical care for patients with knee and hip OA. To overcome these barriers, education focused on initiating and supporting lifestyle changes, promotion of interventions according to evidence-based recommendations, and improved organization of care are proposed.
The Effect of Lactoferrin and Pepsin-Treated Lactoferrin on IEC-6 Cell Damage Induced by Clostridium Difficile Toxin B
Authors: Otake Kosuke , Sato Norio , Kitaguchi Ayako , Irahara Takayuki , Murata Satoru , Shiraga Keiichiro , Ogawa Yuichi , Fujiwara Takahiro K. , Koike Kaoru , Yokota Hiroyuki
Published: September 2017

Clostridium difficile infections (CDI) have recently increased worldwide. Some CDI progress to fulminant and recurrent CDI and are associated with high mortality and morbidity. CD produces toxins A and B, which cause intestinal mucosal damage, although toxin B exhibits greater cytotoxicity. Pepsin-treated lactoferrin (PLF) is the decomposed product of lactoferrin (LF), a multifunctional glycoprotein with anti-inflammatory properties. Here, we investigate the effects of LF and PLF in toxin B-stimulated rat intestinal epithelial (IEC-6) cells. Different toxin B concentrations were added to IEC-6 cells with or without LF or PLF. Mitochondrial function and cell cytotoxicity were assessed by measuring WST-1 and LDH levels, respectively. WST-1 levels were higher in IEC-6 cells treated with toxin B and LF or PLF than in the toxin B-only control (P < 0.05). Compared with the toxin B-only control, LDH levels significantly decreased after toxin B and LF or PLF addition (P < 0.05). Wound restitution measurement using microscopy demonstrated significantly greater levels of wound restitution in cells treated with toxin B and LF or PLF than in those treated with toxin B alone after 12 h (P < 0.001). Furthermore, changes in IEC-6 cell tight junctions (TJs) were evaluated by immunofluorescence microscopy and zonula occludens-1 (ZO-1) protein expression. When LF or PLF were added to IEC-6 cells, TJ structures were maintained, and ZO-1 and occludin expression was upregulated. Taken together, these results demonstrate that LF and PLF prevent the cytotoxicity of toxin B and might have the potential to control CDI.
Neutrophil-to-Lymphocyte Ratio Predicts Death in Acute-on-Chronic Liver Failure Patients Admitted to the Intensive Care Unit: A Retrospective Cohort Study
Authors: Moreau Nicolas , Wittebole Xavier , Fleury Yvan , Forget Patrice , Laterre Pierre-François , Castanares-Zapatero Diego
Published: September 2017

The neutrophil-to-lymphocyte ratio (NLR) is an inflammation score recognized as associated with outcome. Although inflammation has been shown to correlate with the development of acute-on-chronic liver failure (ACLF), we sought to investigate the role of NLR in predicting 90-day mortality in cirrhotic patients experiencing ACLF. We performed a retrospective cohort study involving a total of 108 consecutive cirrhotic patients admitted in the intensive care unit (ICU). NLR, clinical and biological data were recorded. Of the total, 75 patients had ACLF. The 90-day mortality rate was 53%. ACLF patients displayed higher NLR values in comparison with cirrhotic patients without ACLF throughout the ICU stay. NLR proved more elevated in nonsurvivors ACLF patients, with mortality correlating with increasing quartiles of NLR. On multivariable Cox regression analysis, NLR was found to be a predictor of mortality along with the Sequential Organ Failure Assessment (SOFA) score and mechanical ventilation requirement. The model for end-stage liver disease (MELD) score was not predictive of 90-days mortality. Performance analysis revealed an area under curve of 0.71 [95% confidence interval: 0.59–0.82] regarding NLR capacity to predict 90-days mortality. When including NLR, SOFA score, and mechanical ventilation requirement into the final model, the area under curve was significantly higher (0.81 [95% confidence interval: 0.72–0.91]).

These findings suggest that NLR is associated with mortality in ACLF patients admitted to the ICU. Combining NLR, SOFA score, and the need for mechanical ventilation could be a useful prognostic tool to identify ACLF patients at a higher risk of mortality.
Mass loss and stellar superwinds
Authors: Vink Jorick S.
Published: September 2017

Mass loss bridges the gap between massive stars and supernovae (SNe) in two major ways: (i) theoretically, it is the amount of mass lost that determines the mass of the star prior to explosion and (ii) observations of the circumstellar material around SNe may teach us the type of progenitor that made the SN. Here, I present the latest models and observations of mass loss from massive stars, both for canonical massive O stars, as well as very massive stars that show Wolf–Rayet type features.

This article is part of the themed issue ‘Bridging the gap: from massive stars to supernovae’.
The mechanism(s) of core-collapse supernovae
Authors: Couch Sean M.
Published: September 2017

Core-collapse supernovae (CCSNe) are the explosions that attend the deaths of massive stars. Despite decades of research, several aspects of the mechanism that drives these explosions remain uncertain and the subjects of continued investigation. In this short review, I will give an overview of the CCSN mechanism and current research in the field. In particular, I will focus on recent results from three-dimensional simulations and the impact of turbulence and detailed non-spherical progenitor structure on CCSNe. This contribution is based on a talk given at the ‘Bridging the Gap’ workshop at Chicheley Hall on 2 June 2016.

This article is part of the themed issue ‘Bridging the gap: from massive stars to supernovae’.
The virome ofDrosophila suzukii, an invasive pest of soft fruit
Authors: Medd Nathan C. , Fellous Simon , Waldron Fergal M. , Xuéreb Anne , Nakai Madoka , Cross Jerry V. , Obbard Darren J.
Published: September 2017

Drosophila suzukii(Matsumura) is one of the most damaging and costly pests to invade temperate horticultural regions in recent history. Conventional control of this pest is challenging, and an environmentally benign microbial biopesticide is highly desirable. A thorough exploration of the pathogens infecting this pest is not only the first step on the road to the development of an effective biopesticide, but also provides a valuable comparative dataset for the study of viruses in the model familyDrosophilidae.Here we use a metatransciptomic approach to identify viruses infecting this fly in both its native (Japanese) and invasive (British and French) ranges. We describe 18 new RNA viruses, including members of the Picornavirales, Mononegavirales, Bunyavirales, Chuviruses,Nodaviridae, Tombusviridae, Reoviridae,and Nidovirales, and discuss their phylogenetic relationships with previously known viruses. We also detect 18 previously described viruses of otherDrosophilaspecies that appear to be associated withD. suzukiiin the wild.