bluuebunny/crossref_metadata_2025 huggingface dataset:
Discovery of a jet-like structure with overionized plasma in the SNR IC 443
Authors: Greco Emanuele , Miceli Marco , Orlando Salvatore , Peres Giovanni , Troja Eleonora , Bocchino Fabrizio
Published: April 2018

Context. IC 443 is a supernova remnant (SNR) located in a quite complex environment since it interacts with nearby clouds. Indications for the presence of overionized plasma have been found though the possible physical causes of overionization are still debated. Moreover, because of its peculiar position and proper motion, it is not clear if the pulsar wind nebula (PWN) within the remnant is the relic of the IC 443 progenitor star or just a rambling one seen in projection on the remnant.

Aims. Here we address the study of IC 443 plasma in order to clarify the relationship PWN-remnant, the presence of overionization and the origin of the latter.

Methods. We analyzed two XMM-Newton observations producing background-subtracted, vignetting-corrected and mosaicked images in two different energy bands and we performed a spatially resolved spectral analysis of the X-ray emission.

Results. We identified an elongated (jet-like) structure with Mg-rich plasma in overionization. The head of the jet is interacting with a molecular cloud and the jet is aligned with the position of the PWN at the instant of the supernova explosion. Interestingly, the direction of the jet of ejecta is somehow consistent with the direction of the PWN jet.

Conclusions. Our discovery of a jet of ejecta in IC 443 enlarge the sample of core-collapse SNRs with collimated ejecta structures. IC 443’s jet is the first one which shows overionized plasma, possibly associated with the adiabatic expansion of ejecta. The match between the jet’s direction and the original position of the PWN strongly supports the association between the neutron star and IC 443.
Spino-pelvic radiological parameters in normal Indian population
Authors: Singh Roop , Yadav Sushil Kumar , Sood Sushma , Yadav Rohtas Kumar , Rohilla Ravi
Published: April 2018

Introduction: There is increasing emphasis on the sagittal spino-pelvic alignment and its interpretation is of critical importance in the management of spinal disorders. A cross-sectional study of several spino-pelvic radiographic parameters was conducted to determine the physiological values of these parameters, to calculate the variations of these parameters according to epidemiological data, and to study the relationships among these parameters.

Material and method: Fifty normal healthy volunteers (29 males and 21 females) with no history of back pain were selected and were subjected to standing sagittal spino-pelvic radiographs. All the measurements of various radiographic parameters were performed with use of a software program. A statistical analysis was done to study the relationships among them.

Results: The mean values of pelvic incidence (PI) and lumbar Lordosis Angle (LLA) were 48.52 ± 8.99 and 58.78 ± 9.51, respectively. There was statistical difference between male and female parameters in LLA, lumbo-sacral angle (LSA), sacral horizontal angle (SHA), sacral inclination angle (SIA), sacropelvic angle (PRS1), pelvisacral angle (PSA), and PI. A majority of parameters had higher values for female subjects when compared to male subjects. PI was positively correlated with LLA, pelvic angle (PA), pelvic overhang (PO), pelvic tilt (PT), sacrofemoral distance (SFD), SHA, and sacropelvic translation (SPT), which were highly significant, whereas LLA was positively correlated with SHA and SIA only. PI and LLA were both negatively correlated with PSA, pelvic thickness (PTH), and PRS1.

Conclusions: This study presents the various spino-pelvic radiographic parameter values of a sample of the normal asymptomatic Indian population. There was significant difference in radiographic parameters between males and females in about half of the parameters studied in the sample. The values obtained are comparable with the values presented as normal in the literature. A comparison of the study results with data published about other populations revealed no differences in any of the pelvic parameters between the Indian, Brazilian, and Korean populations.
Arterial Stiffness Response to Regular Aerobic Training in Hypercholesterolemia Patients
Authors: Liu Guanghui , Zhao Jiasheng , Cao Yang
Published: April 2018

Physical exercise increase is confirmed as a fundamental treatment for hypercholesterolemia patients, but the effect on the arterial stiffness and oxidative stress is still unclear. 74 hypercholesterolemia patients were divided into 2 groups. The exercise group received dietary recommendations and a 3-month exercise program, prescribed according to their first cardiopulmonary exercise tests(CPET), while the control group only received dietary recommendations. All patients underwent blood tests, CPET and brachial-ankle pulse wave velocity (baPWV) studies at enrollment and at 3 months’ follow-up. At the end of 3 months, there was no change in total cholesterol (TC) level in either group. However, in the exercise group, we found maximal exercise parameters increased and baPWV values declined. Meanwhile, there were significant changes in the level of malondialdehyde, 8-isoprostane-F2α and superoxide dismutase. Moreover, the change of baPWV was positively correlated with the change of 8-isoprostane-F2α (r=0.36, P<0.01). In the control group, no change in baPWV or oxidative biomarker was observed. Our findings suggested that regular aerobic exercise could lessen arterial stiffness in hypercholesterolemia patients, even in the context of no obvious TC decrease. During this process, favorable adjustment in oxidative stress might be an important pathway, which remains to be further explored.
Modification of FN tunneling provoking gate-leakage current in ZTO (zinc-tin oxide) TFT by regulating the ZTO/SiO2 area ratio
Authors: Li Jeng-Ting , Tsai Ho-Lin , Lai Wei-Yao , Hwang Weng-Sing , Chen In-Gann , Chen Jen-Sue
Published: April 2018

This study addresses the variation in gate-leakage current due to the Fowler-Nordheim (FN) tunneling of electrons through a SiO2 dielectric layer in zinc-tin oxide (ZTO) thin film transistors. It is shown that the gate-leakage current is not related to the absolute area of the ZTO active layer, but it is reduced by reducing the ZTO/SiO2 area ratio. The ZTO/SiO2 area ratio modulates the ZTO-SiO2 interface dipole strength as well as the ZTO-SiO2 conduction band offset and subsequently affects the FN tunneling current through the SiO2 layer, which provides a route that modifies the gate-leakage current.
Deuterium results at the negative ion source test facility ELISE
Authors: Kraus W. , Wünderlich D. , Fantz U. , Heinemann B. , Bonomo F. , Riedl R.
Published: April 2018

The ITER neutral beam system will be equipped with large radio frequency (RF) driven negative ion sources, with a cross section of 0.9 m × 1.9 m, which have to deliver extracted D− ion beams of 57 A at 1 MeV for 1 h. On the extraction from a large ion source experiment test facility, a source of half of this size is being operational since 2013. The goal of this experiment is to demonstrate a high operational reliability and to achieve the extracted current densities and beam properties required for ITER. Technical improvements of the source design and the RF system were necessary to provide reliable operation in steady state with an RF power of up to 300 kW. While in short pulses the required D− current density has almost been reached, the performance in long pulses is determined in particular in Deuterium by inhomogeneous and unstable currents of co-extracted electrons. By application of refined caesium evaporation and distribution procedures, and reduction and symmetrization of the electron currents, considerable progress has been made and up to 190 A/m2 D−, corresponding to 66% of the value required for ITER, have been extracted for 45 min.
Confinement-induced InAs/GaSb heterojunction electron–hole bilayer tunneling field-effect transistor
Authors: Padilla J. L. , Medina-Bailon C. , Alper C. , Gamiz F. , Ionescu A. M.
Published: April 2018

Electron–Hole Bilayer Tunneling Field-Effect Transistors are typically based on band-to-band tunneling processes between two layers of opposite charge carriers where tunneling directions and gate-induced electric fields are mostly aligned (so-called line tunneling). However, the presence of intense electric fields associated with the band bending required to trigger interband tunneling, along with strong confinement effects, has made these types of devices to be regarded as theoretically appealing but technologically impracticable. In this work, we propose an InAs/GaSb heterostructure configuration that, although challenging in terms of process flow design and fabrication, could be envisaged for alleviating the electric fields inside the channel, whereas, at the same time, making quantum confinement become the mechanism that closes the broken gap allowing the device to switch between OFF and ON states. The utilization of induced doping prevents the harmful effect of band tails on the device performance. Simulation results lead to extremely steep slope characteristics endorsing its potential interest for ultralow power applications.
Terahertz orbital angular momentum modes with flexible twisted hollow core antiresonant fiber
Authors: Stefani Alessio , Fleming Simon C. , Kuhlmey Boris T.
Published: April 2018

THz radiation is a more commonplace in research laboratories as well as in everyday life, with applications ranging from body scanners at airport security to short range wireless communications. In the optical domain, waveguides and other devices to manipulate radiation are well established. This is not yet the case in the THz regime because of the strong interaction of THz radiation with matter, leading to absorption, and the millimeter size of the wavelength and therefore of the required waveguides. We propose the use of a new material, polyurethane, for waveguides that allows high flexibility, overcoming the problem that large sizes otherwise result in rigid structures. With this material, we realize antiresonant hollow-core waveguides and we use the flexibility of the material to mechanically twist the waveguide in a tunable and reversible manner, with twist periods as short as tens of wavelengths. Twisting the waveguide, we demonstrate the generation of modes carrying orbital angular momentum. We use THz time domain spectroscopy to measure and clearly visualize the vortex nature of the mode, which is difficult in the optical domain. The proposed waveguide is a new platform offering new perspectives for THz guidance and particularly mode manipulation. The demonstrated ability to generate modes with an orbital angular momentum within a waveguide, in a controllable manner, will be beneficial to both fundamental, e.g., matter-radiation interaction, and applied, e.g., THz telecommunications, advances of THz research and technology. Moreover, this platform is not limited to the THz domain and could be scaled for other electromagnetic wavelengths.
Method for reducing measurement errors of a Langmuir probe with a protective RF shield
Authors: Riaby V. , Masherov P. , Savinov V. , Yakunin V.
Published: April 2018

Probe measurements were conducted in the middle cross-section of an inductive, low-pressure xenon plasma using a straight cylindrical Langmuir probe with a bare metal shield that protected the probe from radio frequency interference. As a result, reliable radial distributions of the plasma parameters were obtained. Subsequent analyses of these measurements revealed that the electron energy distribution function (EEDF) deviated substantially from the Maxwellian functions and that this deviation depended on the length of the probe shield. To evaluate the shield's influence on the measurement results, in addition to the probe (which was moved radially as its shield length varied in the range of lsh1 = lmax–0), an additional L-shaped probe was inserted at a different location. This probe was moved differently from the first probe and provided confirmational measurements in the common special position where lsh1 = 0 and lsh2 ≠ 0. In this position, the second shield decreased all the plasma parameters. A comparison of the probe datasets identified the principles of the relationships between measurement errors and EEDF distortions caused by the bare probe shields. This dependence was used to correct the measurements performed using the first probe by eliminating the influence of its shield. Physical analyses based on earlier studies showed that these peculiarities are caused by a short-circuited double-probe effect that occurs in bare metal probe protective shields.
Refining Markov state models for conformational dynamics using ensemble-averaged data and time-series trajectories
Authors: Matsunaga Y. , Sugita Y.
Published: April 2018

A data-driven modeling scheme is proposed for conformational dynamics of biomolecules based on molecular dynamics (MD) simulations and experimental measurements. In this scheme, an initial Markov State Model (MSM) is constructed from MD simulation trajectories, and then, the MSM parameters are refined using experimental measurements through machine learning techniques. The second step can reduce the bias of MD simulation results due to inaccurate force-field parameters. Either time-series trajectories or ensemble-averaged data are available as a training data set in the scheme. Using a coarse-grained model of a dye-labeled polyproline-20, we compare the performance of machine learning estimations from the two types of training data sets. Machine learning from time-series data could provide the equilibrium populations of conformational states as well as their transition probabilities. It estimates hidden conformational states in more robust ways compared to that from ensemble-averaged data although there are limitations in estimating the transition probabilities between minor states. We discuss how to use the machine learning scheme for various experimental measurements including single-molecule time-series trajectories.
Split-gate device for indirect excitons
Authors: Dorow C. J. , Leonard J. R. , Fogler M. M. , Butov L. V. , West K. W. , Pfeiffer L. N.
Published: April 2018

We present a concept and experimental proof of principle for split-gate devices for indirect excitons (IXs). The split-gate forms a narrow channel, a point contact, for IX current. Control of IX flow through the split-gate with both gate voltage and excitation power is demonstrated.
Reaction fronts of the autocatalytic hydrogenase reaction
Authors: Gyevi-Nagy László , Lantos Emese , Gehér-Herczegh Tünde , Tóth Ágota , Bagyinka Csaba , Horváth Dezső
Published: April 2018

We have built a model to describe the hydrogenase catalyzed, autocatalytic, reversible hydrogen oxidation reaction where one of the enzyme forms is the autocatalyst. The model not only reproduces the experimentally observed front properties, but also explains the found hydrogen ion dependence. Furthermore, by linear stability analysis, two different front types are found in good agreement with the experiments.
Temperature dependence of water-water and ion-water correlations in bulk water and electrolyte solutions probed by femtosecond elastic second harmonic scattering
Authors: Chen Yixing , Dupertuis Nathan , Okur Halil I. , Roke Sylvie
Published: April 2018

The temperature dependence of the femtosecond elastic second harmonic scattering (fs-ESHS) response of bulk light and heavy water and their electrolyte solutions is presented. We observe clear temperature dependent changes in the hydrogen (H)-bond network of water that show a decrease in the orientational order of water with increasing temperature. Although D2O has a more structured H-bond network (giving rise to more fs-ESHS intensity), the relative temperature dependence is larger in H2O. The changes are interpreted in terms of the symmetry of H-bonds and are indicators of nuclear quantum effects. Increasing the temperature in electrolyte solutions decreases the influence of the total electrostatic field from ions on the water-water correlations, as expected from Debye-Hückel theory, since the Debye length becomes longer. The effects are, however, 1.9 times (6.3 times) larger than those predicted for H2O (D2O). Since fs-ESHS responses can be computed from known molecular coordinates, our observations provide a unique opportunity to refine quantum mechanical models of water.
Modeling and design of a two-axis elliptical notch flexure hinge
Authors: Wu Jianwei , Zhang Yin , Lu Yunfeng , Wen Zhongpu , Bin Deer , Tan Jiubin
Published: April 2018

As an important part of the joule balance system, the two-axis elliptical notch flexure hinge (TENFH) which typically consists of two single-axis elliptical notch flexure hinges was studied. First, a 6 degrees of freedom (6-DOF) compliance model was established based on the coordinate transformation method. In addition, the maximum stress of the TENFH was derived. The compliance and maximum stress model was verified using finite element analysis simulation. To decouple the attitude of the suspended coil system and reduce the offset between the centroid of the suspended coil mechanism and the mass comparator in the joule balance system, a new mechanical structure of TENFH was designed based on the compliance model and stress model proposed in this paper. The maximum rotation range is up to 10°, and the axial load is more than 5 kg, which meets the requirements of the system. The compliance model was also verified by deformation experimentation with the designed TENFH.
Electronic structures and chemical states of methylammonium lead triiodide thin films and the impact of annealing and moisture exposure
Authors: Yamanaka Soichiro , Hayakawa Kei , Cojocaru Ludmila , Tsuruta Ryohei , Sato Tomoya , Mase Kazuhiko , Uchida Satoshi , Nakayama Yasuo
Published: April 2018

Methylammonium lead triiodide (CH3NH3PbI3) is the fundamental material used in perovskite solar cells, and its electronic properties have, therefore, attracted a great deal of attention as a potential key to highly efficient solar cell performance. However, the deterioration of perovskite solar cells when exposed to high temperature and humidity remains a serious obstacle to the material's use, and the clarification of the degradation mechanisms has been keenly anticipated. In this study, the valence electronic structures and depth-dependence of the chemical states of CH3NH3PbI3 thin films are investigated using ultraviolet photoelectron spectroscopy and excitation energy dependent X-ray photoelectron spectroscopy. Additionally, the effects of high temperature and a moisture rich atmosphere on the CH3NH3PbI3 thin films are examined. It is confirmed that the high temperature and moist atmosphere facilitate the oxidation of CH3NH3PbI3, whereas the Pb:I stoichiometry of the CH3NH3PbI3 thin films is found to be preserved at its original ratio (1:3) after thermal annealing and exposure to a moist atmosphere.
Bifurcations in the theory of current transfer to cathodes of DC discharges and observations of transitions between different modes
Authors: Bieniek M. S. , Santos D. F. N. , Almeida P. G. C. , Benilov M. S.
Published: April 2018

General scenarios of transitions between different spot patterns on electrodes of DC gas discharges and their relation to bifurcations of steady-state solutions are analyzed. In the case of cathodes of arc discharges, it is shown that any transition between different modes of current transfer is related to a bifurcation of steady-state solutions. In particular, transitions between diffuse and spot modes on axially symmetric cathodes, frequently observed in the experiment, represent an indication of the presence of pitchfork or fold bifurcations of steady-state solutions. Experimental observations of transitions on cathodes of DC glow microdischarges are analyzed and those potentially related to bifurcations of steady-state solutions are identified. The relevant bifurcations are investigated numerically and the computed patterns are found to conform to those observed in the course of the corresponding transitions in the experiment.
Direct dynamics simulations of the unimolecular dissociation of dioxetane: Probing the non-RRKM dynamics
Authors: Malpathak Shreyas , Ma Xinyou , Hase William L.
Published: April 2018

In a previous UB3LYP/6-31G* direct dynamics simulation, non-Rice–Ramsperger–Kassel–Marcus (RRKM) unimolecular dynamics was found for vibrationally excited 1,2-dioxetane (DO); [R. Sun et al., J. Chem. Phys. 137, 044305 (2012)]. In the work reported here, these dynamics are studied in more detail using the same direct dynamics method. Vibrational modes of DO were divided into 4 groups, based on their characteristic motions, and each group excited with the same energy. To compare with the dynamics of these groups, an additional group of trajectories comprising a microcanonical ensemble was also simulated. The results of these simulations are consistent with the previous study. The dissociation probability, N(t)/N(0), for these excitation groups were all different. Groups A, B, and C, without initial excitation in the O–O stretch reaction coordinate, had a time lag to of 0.25–1.0 ps for the first dissociation to occur. Somewhat surprisingly, the C–H stretch Group A and out-of-plane motion Group C excitations had exponential dissociation probabilities after to, with a rate constant ∼2 times smaller than the anharmonic RRKM value. Groups B and D, with excitation of the H–C–H bend and wag, and ring bend and stretch modes, respectively, had bi-exponential dissociation probabilities. For Group D, with excitation localized in the reaction coordinate, the initial rate constant is ∼7 times larger than the anharmonic RRKM value, substantial apparent non-RRKM dynamics. N(t)/N(0) for the random excitation trajectories was non-exponential, indicating intrinsic non-RRKM dynamics. For the trajectory integration time of 13.5 ps, 9% of these trajectories did not dissociate in comparison to the RRKM prediction of 0.3%. Classical power spectra for these trajectories indicate they have regular intramolecular dynamics. The N(t)/N(0) for the excitation groups are well described by a two-state coupled phase space model. From the intercept of N(t)/N(0) with random excitation, the anharmonic correction to the RRKM rate constant is approximately a factor of 1.5.
On the anisotropic velocity distribution of fast ions in NBI-heated toroidal plasmas
Authors: Nishimura Shin
Published: April 2018

A method to calculate the flux-surface-averaged anisotropy (the second Legendre order) in the slowing down velocity distribution of the fast ions generated by tangentially injected neutral beams is shown. This component is required for (1) perpendicular and parallel currents in MHD equilibrium calculations including the fast ions' pressure, (2) the anisotropic heating analyses on the thermalized target plasma species, and (3) the classical and the Pfirsch-Schlüter radial transport of both the thermalized target plasma species and the fast ions themselves. For including the parallel guiding center motion effect in non-symmetric toroidal configurations such as stellarators and heliotrons, the adjoint equation and the eigenfunctions are applied. In contrast to the previously investigated configuration dependence of the first Legendre order as the momentum input to the target plasma species, a quite different dependence of the second Legendre order on the magnetic field strength modulation B(θ,ζ) on the magnetic flux-surfaces is found. Even in a low energy range of the slowing down velocity distribution, the deviation (reduction) of the anisotropy from a result neglecting the orbit effect is proportional to 1−〈B〉/Bmax.
Optical spatial differentiator based on subwavelength high-contrast gratings
Authors: Dong Zhewei , Si Jiangnan , Yu Xuanyi , Deng Xiaoxu
Published: April 2018

An optical spatial differentiator based on subwavelength high-contrast gratings (HCGs) is proposed experimentally. The spatial differentiation property of the subwavelength HCG is analyzed by calculating its spatial spectral transfer function based on the periodic waveguide theory. By employing the FDTD solutions, the performance of the subwavelength HCG spatial differentiator was investigated numerically. The subwavelength HCG differentiator with the thickness at the nanoscale was fabricated on the quartz substrate by electron beam lithography and Bosch deep silicon etching. Observed under an optical microscope with a CCD camera, the spatial differentiation of the incident field profile was obtained by the subwavelength HCG differentiator in transmission without Fourier lens. By projecting the images of slits, letter “X,” and a cross on the subwavelength HCG differentiator, edge detections of images were obtained in transmission. With the nanoscale HCG structure and simple optical implementation, the proposed optical spatial differentiator provides the prospects for applications in optical computing systems and parallel data processing.
Sequencing of semiflexible polymers of varying bending rigidity using patterned pores
Authors: Kumar Rajneesh , Chaudhuri Abhishek , Kapri Rajeev
Published: April 2018

We study the translocation of a semiflexible polymer through extended pores with patterned stickiness, using Langevin dynamics simulations. We find that the consequence of pore patterning on the translocation time dynamics is dramatic and depends strongly on the interplay of polymer stiffness and pore-polymer interactions. For heterogeneous polymers with periodically varying stiffness along their lengths, we find that variation of the block size of the sequences and the orientation results in large variations in the translocation time distributions. We show how this fact may be utilized to develop an effective sequencing strategy. This strategy involving multiple pores with patterned surface energetics can predict heteropolymer sequences having different bending rigidity to a high degree of accuracy.
Revealing the specificity of regulatory T cells in murine autoimmune diabetes
Authors: Spence Allyson , Purtha Whitney , Tam Janice , Dong Shen , Kim Youmin , Ju Chia-Hsin , Sterling Teague , Nakayama Maki , Robinson William H. , Bluestone Jeffrey A. , Anderson Mark S. , Tang Qizhi
Published: April 2018

Significance

Tissue antigen-specific Tregs are critical for the prevention of organ-specific autoimmune diseases, yet very little is known about their specificity in a natural repertoire. Here, we show an accumulation of antigen-experienced Tregs in the inflamed islets using a mouse model of autoimmune diabetes. MHC tetramer staining and single-cell T cell receptor (TCR) analyses of islet Tregs reveal their specificity for insulin and other islet-derived antigens. Tregs from inflamed islets prevent diabetes when transferred to diabetes-susceptible recipients. The identification of functional islet antigen-specific Tregs with distinct TCR usage paves the way for future investigations of their development and homeostasis to better understand pathogenesis and treatment of autoimmune diabetes.
Habitat degradation negatively affects auditory settlement behavior of coral reef fishes
Authors: Gordon Timothy A. C. , Harding Harry R. , Wong Kathryn E. , Merchant Nathan D. , Meekan Mark G. , McCormick Mark I. , Radford Andrew N. , Simpson Stephen D.
Published: April 2018

Significance

Climate change is causing widespread damage to the world’s tropical coral reefs, via increases in cyclones and mass bleaching. Healthy populations of reef fishes facilitate recovery from such events, and recruitment of juvenile fish is influenced by acoustic cues that guide larval orientation, habitat selection, and settlement to reefs. Our matched recordings of Australia’s Great Barrier Reef before and after recent severe degradation demonstrate major changes to natural reef sound. In field experiments using these recordings, we show the potential impact of such acoustic changes. Postdegradation reef sounds were less attractive to young fishes than their predegradation equivalents. Reductions in fish settlement, caused by acoustic changes, may threaten the recovery potential of degraded coral reefs.
Earth’s magnetic field is probably not reversing
Authors: Brown Maxwell , Korte Monika , Holme Richard , Wardinski Ingo , Gunnarson Sydney
Published: April 2018

Significance

Earth’s magnetic field is generated in Earth’s convecting liquid iron outer core and protects Earth’s surface from harmful solar radiation. The field has varied on different timescales throughout geological history, and these variations reflect changes deep within the Earth. Two of the field’s most extreme variations are reversals and excursions. During such events, the strength of the field decreases and the magnetic poles rapidly flip polarity, with reversals characterized by the pole retaining an opposite polarity, while excursions are marked by a return to the original polarity. Field strength over the past centuries has also been decreasing strongly; however, through analyzing previous excursions, we infer that Earth’s magnetic field is not in an early stage of a reversal or excursion.
Catalytic amino acid production from biomass-derived intermediates
Authors: Deng Weiping , Wang Yunzhu , Zhang Sui , Gupta Krishna M. , Hülsey Max J. , Asakura Hiroyuki , Liu Lingmei , Han Yu , Karp Eric M. , Beckham Gregg T. , Dyson Paul J. , Jiang Jianwen , Tanaka Tsunehiro , Wang Ye , Yan Ning
Published: April 2018

Significance

Today, amino acids are primarily manufactured via microbial cultivation processes, which are costly, are time consuming, and require extensive separations processes. As an alternative, chemocatalytic approaches to produce amino acids from renewable feedstocks such as bio-based sugars could offer a rapid and potentially more efficient means of amino acid synthesis, but efforts to date have been limited by the development of facile chemistry and associated catalyst materials to selectively produce α-amino acids. In this work, various α-amino acids, including alanine, leucine, aspartic acid, and phenylalanine, were obtained from both biomass-derived α-hydroxyl acids and glucose. The route bridges plant-based biomass and proteinogenic α-amino acids, offering a chemical approach that is potentially superior to microbial cultivation processes.
Ribosome protection by antibiotic resistance ATP-binding cassette protein
Authors: Su Weixin , Kumar Veerendra , Ding Yichen , Ero Rya , Serra Aida , Lee Benjamin Sian Teck , Wong Andrew See Weng , Shi Jian , Sze Siu Kwan , Yang Liang , Gao Yong-Gui
Published: April 2018

Significance

ARE ABC-F genes have been found in numerous pathogen genomes and multi-drug resistance conferring plasmids. Further transmission will challenge the clinical use of many antibiotics. The development of improved ribosome-targeting therapeutics relies on the elucidation of the resistance mechanisms. Characterization of MsrE protein bound to the bacterial ribosome is first of its kind for ARE ABC-F members. Together with biochemical data, it sheds light on the ribosome protection mechanism by domain linker-mediated conformational change and displacement leading to drug release, suggesting a mechanism shared by other ARE ABC-F proteins. These proteins present an intriguing example of structure-function relationship and a medically relevant target of study as they collectively mediate resistance to the majority of antibiotic classes targeting the peptidyl-transferase center region.
MYB30 links ROS signaling, root cell elongation, and plant immune responses
Authors: Mabuchi Kaho , Maki Hiromasa , Itaya Tomotaka , Suzuki Takamasa , Nomoto Mika , Sakaoka Satomi , Morikami Atsushi , Higashiyama Tetsuya , Tada Yasuomi , Busch Wolfgang , Tsukagoshi Hironaka
Published: April 2018

Significance

Plant roots tune their growth to the environment. An important class of molecules involved in environmental responses as well as in root growth regulation is composed of reactive oxygen species (ROS). By making use of a comprehensive transcriptome atlas capturing ROS responses in different developmental zones of the root, we uncovered a regulatory network that is involved in root-growth regulation and responses to biotic stress. This network is composed of the ROS-responsive transcription factor MYB30, which regulates multiple genes involved in the transport of very-long-chain fatty acids (VLCFAs). Overall, our findings show that
Arabidopsis
uses the same
MYB30
-dependent regulatory network for root-growth and immunity responses, processes that were considered largely independent of each other.
La servante au grand cœur…(poème C desFleurs du Mal)
Authors: Dominicy Marc
Published: April 2018

A linguistic and genetic study ofLa servante au grand cœur…(inLes Fleurs du Mal) shows that Baudelaire endeavoured to attribute a complex network of emotive and/or hallucinatory mental states to the poetic self by resorting to a rich inventory of formal and expressive devices: syntax and its interface with meter; the deontic and evidential readings of the modal verbdevoir; pragmatic connectives (pourtant,certes); evaluative items (the verbtrouver, the adverbbien, the prepositionàintroducing an infinitival clause); the intertextual dimension of the poetic lexicon; contrasts between elevated and everyday language. The analysis provided paves the way to an integrated interpretation of the poem and definitely refutes Valéry’s and Benjamin’s comments on its first two verses.
A Bayesian hidden Potts mixture model for analyzing lung cancer pathology images
Authors: Li Qiwei , Wang Xinlei , Liang Faming , Yi Faliu , Xie Yang , Gazdar Adi , Xiao Guanghua
Published: April 2018

Digital pathology imaging of tumor tissues, which captures histological details in high resolution, is fast becoming a routine clinical procedure. Recent developments in deep-learning methods have enabled the identification, characterization, and classification of individual cells from pathology images analysis at a large scale. This creates new opportunities to study the spatial patterns of and interactions among different types of cells. Reliable statistical approaches to modeling such spatial patterns and interactions can provide insight into tumor progression and shed light on the biological mechanisms of cancer. In this article, we consider the problem of modeling a pathology image with irregular locations of three different types of cells: lymphocyte, stromal, and tumor cells. We propose a novel Bayesian hierarchical model, which incorporates a hidden Potts model to project the irregularly distributed cells to a square lattice and a Markov random field prior model to identify regions in a heterogeneous pathology image. The model allows us to quantify the interactions between different types of cells, some of which are clinically meaningful. We use Markov chain Monte Carlo sampling techniques, combined with a double Metropolis–Hastings algorithm, in order to simulate samples approximately from a distribution with an intractable normalizing constant. The proposed model was applied to the pathology images of $205$ lung cancer patients from the National Lung Screening trial, and the results show that the interaction strength between tumor and stromal cells predicts patient prognosis (P = $0.005$). This statistical methodology provides a new perspective for understanding the role of cell–cell interactions in cancer progression.
Death of a Polemicist: Honour and Calumny in Early Modern European Religious Debate
Authors: Cohen Paul
Published: April 2018

This article proposes a novel interpretation of printed religious polemic in the context of European religious struggle in the Age of Reformations. While recent scholarship has underscored the virulence with which controversialists waged their doctrinal debates, I argue that such work has not yet acknowledged the structuring, autonomous role played by honour in religious polemic. To this end, I consider the case of Guillaume de Reboul, a Protestant-turned-Catholic polemicist who left France to take up service in the Roman Curia, before his arrest and execution under mysterious circumstances. First, I argue that the vocabularies of honour and calumny with which polemicists such as Reboul fashioned their texts played a role at least as important as that of theology, providing the motors which drove debates forward and many of the rules of the polemical game. Secondly, I consider Reboul’s writings as tactical moves in a broader strategy of personal, professional and confessional advancement. As Reboul’s case illustrates, writing was only one weapon among many in the polemical arsenal, and such debates represented forms of social struggle that could entail considerably more dangerous forms of conflict. Thirdly, I reconstruct the ecclesiastical, political and geopolitical landscapes which made a career like Reboul’s possible—and which made it possible to put authors like him to death when expedient. Fourthly, I consider how Reboul and his opponents’ printed appeals conjured into being a reading public. I argue that the culture of honour represented a defining feature of the early modern public sphere.
Simple, direct and efficient multi-way spectral clustering
Authors: Damle Anil , Minden Victor , Ying Lexing
Published: April 2018

We present a new algorithm for spectral clustering based on a column-pivoted QR factorization that may be directly used for cluster assignment or to provide an initial guess for k-means. Our algorithm is simple to implement, direct and requires no initial guess. Furthermore, it scales linearly in the number of nodes of the graph and a randomized variant provides significant computational gains. Provided the subspace spanned by the eigenvectors used for clustering contains a basis that resembles the set of indicator vectors on the clusters, we prove that both our deterministic and randomized algorithms recover a basis close to the indicators in Frobenius norm. We also experimentally demonstrate that the performance of our algorithm tracks recent information theoretic bounds for exact recovery in the stochastic block model. Finally, we explore the performance of our algorithm when applied to a real-world graph.
Drawing Cone Spherical Metrics via Strebel Differentials
Authors: Song Jijian , Cheng Yiran , Li Bo , Xu Bin
Published: April 2018

Cone spherical metrics are conformal metrics with constant curvature one and finitely many conical singularities on compact Riemann surfaces. By using Strebel differentials as a bridge, we construct a new class of cone spherical metrics on compact Riemann surfaces by drawing on the surfaces some class of connected metric ribbon graphs.
The Current Understanding of the Endocrine Effects From Immune Checkpoint Inhibitors and Recommendations for Management
Authors: Girotra Monica , Hansen Aaron , Farooki Azeez , Byun David J , Min Le , Creelan Ben C , Callahan Margaret K , Atkins Michael B , Sharon Elad , Antonia Scott J , West Pamela , Gravell Amy E ,   Investigational Drug Steering Committee (IDSC) Immunotherapy Task Force collaboration
Published: April 2018

Clinical trials in the past decade have established the antitumor effects of immune checkpoint inhibition as a revolutionary treatment for cancer. Namely, blocking antibodies to cytotoxic T-lymphocyte antigen 4 and programmed death 1 or its ligand have reached routine clinical use. Manipulation of the immune system is not without side effects, and autoimmune toxicities often known as immune-related adverse events (IRAEs) are observed. Endocrine IRAEs, such as hypophysitis, thyroid dysfunction, and insulin-dependent diabetes mellitus, can present with unique profiles that are not seen with the use of traditional chemotherapeutics. In this Review, we discuss the current hypotheses regarding the mechanism of these endocrinopathies and their clinical presentations. Further, we suggest guidelines and algorithms for patient management and future clinical trials to optimize the detection and treatment of immune checkpoint–related endocrinopathies.
Vascular access management after percutaneous transluminal angioplasty using a calcium alginate sheet: a randomized controlled trial
Authors: Matsubara Makoto , Banshodani Masataka , Takahashi Akira , Kawai Yusuke , Saiki Tomoki , Yamashita Masahiro , Shiraki Nobuaki , Shintaku Sadanori , Moriishi Misaki , Masaki Takao , Kawanishi Hideki
Published: April 2018

Background

Management of vascular access (VA) is essential in hemodialysis (HD) patients. However, VA often fails and percutaneous transluminal angioplasty (PTA) is required. Conventional hemostasis at the puncture site is associated with complications. This study aimed to analyze the efficacy and safety of a hemostatic wound dressing made of calcium alginate at the puncture site of VA after PTA and evaluate other factors affecting hemostasis.

Methods

After PTA for VA, 200 HD patients were randomized to a calcium alginate sheet (CA) group (n = 100) or a no drug-eluting sheet (control) group (n = 100). We recorded time to hemostasis at the puncture site every 5 min, noting any complications.

Results

In the CA group, rates of hemostatic achievement at 5, 10, 15 and >15 min were 57, 25, 8 and 10%, respectively. In the control group, the rates were 39, 28, 14 and 19%, respectively. Rates of hemostatic achievement at 5 min were significantly higher in the CA group (P = 0.01). In logistic regression analysis, factors affecting hemostasis within 5 min were use of the CA sheet [odds ratio (OR) 2.33; 95% confidence interval (CI) 1.26–4.37], platelet count ≤100 000/μL (OR 0.19; 95% CI 0.04–0.69), number of antithrombotic tablets used per day ≥1 tablet (OR 0.50; 95% CI 0.26–0.94) and upper arm VA (OR 0.16; 95% CI 0.03–0.55).

Conclusions

A CA sheet can safely reduce time to hemostasis at the puncture site after PTA, and should be considered for treating patients with a bleeding tendency.
Morphological Variables Associated With Ruptured Middle Cerebral Artery Aneurysms
Authors: Zhang Jian , Can Anil , Mukundan Srinivasan , Steigner Michael , Castro Victor M , Dligach Dmitriy , Finan Sean , Yu Sheng , Gainer Vivian , Shadick Nancy A , Savova Guergana , Murphy Shawn , Cai Tianxi , Wang Zhong , Weiss Scott T , Du Rose
Published: April 2018

BACKGROUND

Geometric factors of intracranial aneurysms and surrounding vasculature could affect the risk of aneurysm rupture. However, large-scale assessments of morphological parameters correlated with intracranial aneurysm rupture in a location-specific manner are scarce.

OBJECTIVE

To investigate the morphological characteristics associated with ruptured middle cerebral artery (MCA) aneurysms.

METHODS

Five hundred sixty-one patients with 638 MCA aneurysms diagnosed between 1990 and 2016 who had available computed tomography angiography (CTA) were included in this study. CTAs were evaluated using the Vitrea Advanced Visualization software for 3-dimensional (3D) reconstruction. Morphological parameters examined in each model included aneurysm projection, wall irregularity, presence of a daughter dome, presence of hypoplastic or aplastic A1 arteries and hypoplastic or fetal posterior communicating arteries (PCoA), aneurysm height and width, neck diameter, bottleneck factor, aspect and size ratio, height/width ratio, and diameters and angles of surrounding parent and daughter vessels. Univariable and multivariable statistical analyses were performed to determine the association of morphological characteristics with rupture of MCA aneurysms. Logistic regression was used to build a predictive MCA score.

RESULTS

Greater bottleneck and size ratio, and irregular, multilobed, temporally projecting MCA aneurysms are associated with higher rupture risk, whereas higher M1/M2 ratio, larger width, and the presence of an ipsilateral or bilateral hypoplastic PCoA were inversely associated with rupture. The MCA score had good predictive capacity with area under the receiver operating curve = 0.88.

CONCLUSION

These practical morphological parameters specific to MCA aneurysms are easy to assess when examining 3D reconstructions of unruptured aneurysms and could aid in risk evaluation in these patients.
Indian Forest Rights Legislation: Significance of Recognizing the Legal Pluralism for Indigenous Peoples Rights
Authors: Prasad M Deva , Menon C Suchithra
Published: April 2018

Indigenous people’s traditional customary claim over the forest land was not accepted by the formal legal mechanism in India for a long period of time. The underlying rationale for the claim is livelihood, religious, and cultural reasons. The indigenous people’s claims remained as informal norm, which were not accepted by the formal state legal system in India. Discriminating legal centralism was existing in the area of forest governance and policy till the Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act was enacted in 2006. The Forest Rights Act, 2006 has brought a paradigm shift in the entire approach of law towards the indigenous people and acknowledged the rights of the indigenous people. This article makes an attempt to understand the significance of recognition of legal pluralistic norms through legislation.
Transmission of climate risks across sectors and borders
Authors: Challinor Andy J. , Adger W. Neil , Benton Tim G. , Conway Declan , Joshi Manoj , Frame Dave
Published: April 2018

Systemic climate risks, which result from the potential for cascading impacts through inter-related systems, pose particular challenges to risk assessment, especially when risks are transmitted across sectors and international boundaries. Most impacts of climate variability and change affect regions and jurisdictions in complex ways, and techniques for assessing this transmission of risk are still somewhat limited. Here, we begin to define new approaches to risk assessment that can account for transboundary and trans-sector risk transmission, by presenting: (i) a typology of risk transmission that distinguishes clearly the role of climate versus the role of the social and economic systems that distribute resources; (ii) a review of existing modelling, qualitative and systems-based methods of assessing risk and risk transmission; and (iii) case studies that examine risk transmission in human displacement, food, water and energy security. The case studies show that policies and institutions can attenuate risks significantly through cooperation that can be mutually beneficial to all parties. We conclude with some suggestions for assessment of complex risk transmission mechanisms: use of expert judgement; interactive scenario building; global systems science and big data; innovative use of climate and integrated assessment models; and methods to understand societal responses to climate risk. These approaches aim to inform both research and national-level risk assessment.