bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of imperfect channel estimation and antenna correlation on quantised massive multiple‐input multiple‐output systems
Authors: Temiz Murat , Alsusa Emad , Danoon Laith
Published: February 2019

This study examines the uplink performance of large‐constellation multi‐user massive multiple‐input multiple‐output systems with low‐resolution analogue‐to‐digital converters (ADCs) in the presence of channel correlation and imperfect channel state information (CSI). The base station (BS) employs a large number of antennas for multiplexing and demultiplexing co‐channel users with each antenna element having a dedicated radio frequency chain and two low‐resolution ADCs. While such ADCs cause data loss due to coarse quantisation, the large number of antennas can be exploited not only to alleviate such a problem but also to make it possible to utilise large‐constellation modulation schemes. The results provide an insight into the trade‐off between various performance metrics and the number of quantisation bits under a wide range of realistic conditions. It will be shown that 1‐bit quantisation provides sufficient resolution with 100 BS antennas to communicate with ten user equipments using quadrature phase shift keying, but the number of quantisation bits must be increased for larger constellations particularly to overcome CSI mismatch and channel correlation. The results also consider the trade‐off between average mutual information and power consumption of the low‐resolution ADCs. It will be shown that 16‐quantum amplitude modulation with 2‐bit quantisation may provide a good compromise between energy efficiency and average mutual information.
Data‐driven tuning of feedforward controller structured with infinite impulse response filter via iterative learning control
Authors: Zhang Xinxin , Li Min , Ding Huafeng , Yao Xiangyu
Published: February 2019

Iterative learning control (ILC) is an effective approach for tracking control system that performs repeating tasks. However, the performance of ILC is significantly deteriorated when the reference is changed. To obtain high tracking performance for both repeating and varying tasks, a novel data‐driven tuning method of feedforward controller structured with infinite impulse response (IIR) filter via ILC is developed in this study. Global optimal parameters of the feedforward controller are obtained by linear least‐squares method based on the optimal feedforward control force obtained by ILC, while model information is not required. Additionally, to deal with the possible instability problem of the feedforward controller structured with IIR filter, a stable approximation approach on the basis of zero‐phase‐error tracking algorithm is presented. The stable approximation approach can convert the approximation problem to a convex optimisation problem. Finally, the proposed approach is compared with the standard ILC and a data‐driven feedforward control structured with finite impulse response filter by two simulation studies. Simulation results demonstrate that the proposed data‐driven feedforward tuning method can achieve high tracking performance and is insensitive to reference variations.
Generalising Laplacian controllability of paths
Authors: Hsu Shun‐Pin , Yang Ping‐Yen
Published: February 2019

It is well known that if a network topology is a path or line and the states of vertices or nodes evolve according to the consensus policy, then the network is Laplacian controllable by an input connected to its terminal vertex. In this work, a path is regarded as the resulting graph after interconnecting a finite number of two‐vertex antiregular graphs and then possibly connecting one more vertex. It is shown that the single‐input Laplacian controllability of a path can be extended to the case of interconnecting a finite number of k ‐vertex antiregular graphs with or without one more vertex appended, for any positive integer k. The methods to interconnect these antiregular graphs and to select the vertex for connecting the single input that renders the network Laplacian controllable are presented as well.
Localisation‐based autonomous vehicle rear‐end collision avoidance by emergency steering
Authors: Chen Maolin , Zhan Xingqun , Zhang Xin , Pan Weichuan
Published: February 2019

Rear end collision is one hazard accident for an autonomous vehicle. Emergency braking has already been deeply researched and applied into some new model vehicles to avoid rear‐end collision or mitigate its impacts. Emergency steering is another promising method to enhance vehicle safety; this kind of collision avoidance approach remains to be carefully studied. To fill this gap, this work proposes an emergency steering based rear‐end collision avoidance approach concerning required safe distance as safety index. Vehicle dynamics, Tire Slip Angle and Segal lateral force model, are concerned to obtain the vehicle states. Monte Carlo simulation is executed to determine the value of required safe distance when encountering with a stationary and a suddenly decelerating target vehicle at different velocities. Safe Distance Margin and quantised influence two indexes are proposed to assess the influence of measurement uncertainty. Simulation and road test experiment results demonstrate that the proposed method is effective to avoid rear‐end collision by emergency steering manoeuvre. Moreover, some aspects, like vehicle lateral stability, emergency manoeuvre selection and simultaneously emergency manoeuvres are discussed as well in this work in order to apply this collision avoidance method into practical application.
Analysis and design of modular open‐loop LED driver with multi‐channel output currents
Authors: He Qingqing , Luo Quanming , Huang Jian , Cao Chi , Sun Pengju
Published: February 2019

In view of some applications for red green blue (RGB) light‐emitting diodes (LEDs), a modular multi‐channel constant‐current LED driver is getting more important to obtain desirable colour and brightness. A multi‐channel constant‐current LED driver is proposed according to the constant‐current characteristics of the passive LCL‐T resonant network, which is composed of one high‐frequency half‐bridge inverter and as many passive LCL‐T resonant rectifiers as the number of output channels. Only one passive resonant rectifier is added to increase a constant‐current output channel, thus, it is easy to achieve multi‐channel constant‐current output as needed. In practical applications, the control can be simplified and the reliability can be improved in the open‐loop mode. However, any change of input and output voltage would cause a certain fluctuation in the output current considering the high‐order harmonic components in the open‐loop mode. To this end, the precise solution of the actual output current is obtained in the paper. The quantitative parameter design has been completed according to the desirable current to meet the output constant‐current accuracy within the given input and output. Finally, a 120‐W prototype with three different constant‐current outputs is built to verify the correctness of theoretical analysis.
Genetic algorithm and least square method‐based calibration of measurement apparatus
Authors: Hacizade Ulviye
Published: February 2019

The calibration process is one of the methods for decreasing the measurement apparatus uncertainties. In this study, the sensor calibration is performed using the values reproduced by stan­dard setting devices. Generally, the calibration characteristics of measurement apparatus are taken in a polynomial form. In this study, a genetic algorithm (GA) is used for the measurement apparatus calibration purpose. As an example, GA‐based calibration of a differential pressure gauge using standard pressure setting devices is examined. The calibration results, founded using the proposed GA, are compared with the results obtained via the classical least square method. As a result, the recommendations on how to get better calibration characteristics for the differential pressure gauge are given.
Synthesis and characterisation of TiO2 nanoparticles/Fe2O3 waste chips composite
Authors: Koohestani Hassan
Published: February 2019

Water contamination along with the environmental issues resulted by industrial wastewaters have caused a trend in applying semiconducting photocatalysts, among which TiO2 composites have been particularly focused on to overcome the drawbacks of titanium(IV) oxide also known as titania. In the current investigation, waste chips of a structural steel bar with the chemical composition of Fe2O3 were utilised to obtain the TiO2–Fe2O3 composite. X‐ray diffraction (XRD), field‐emission scanning electron microscopy, energy dispersive spectroscopy, diffusive reflectance spectra, and Brunauer–Emmett–Teller analyses were made to evaluate the composition and structure of the samples. Furthermore, the photocatalytic performance of the samples was studied by methyl orange (MeO) degradation. XRD spectra proved the presence of anatase and Fe2O3 phases in the sample of 10%wt. Fe2O3. The results indicate that as the Fe2O3 content rises, the bandgap narrows. However, the specific surface area enlarges as this amount goes up to a certain limit (10%wt.), from which any further increase leads to a reduction in the specific surface area. The obtained results of MeO decolourisation presented the Fe2O3 of 10%wt. and bandgap of 2.72 eV, and the specific surface area of 63 m2/g to be of the highest efficiency (96%).
Biotemplate preparation of Bi2O3 nanosheet for enhanced photodegradation of methylene blue
Authors: Yang Jing , Wang Meiyan , Zhao Susu , Liu Yangyang , Zhang Wei , Wu Bowen , Liu Qing
Published: February 2019

Bi2O3 nanosheet was synthesised using China rose petal as a biotemplate for the photodegradation of methylene blue under xenon lamp irradiation. The samples were characterised by thermogravimetric analysis–differential scanning calorimetric analysis, Fourier‐transform infrared spectroscopy, nitrogen adsorption, X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and ultraviolet–visible diffuse reflectance spectroscopy. The results revealed that the Bi2O3 nanosheet with pure monoclinic phase was successfully synthesised by replication of the petal template with a thickness of about 100 nm, and showed the absorption thresholds wavelength of 480 nm. Moreover, the Bi2O3 nanosheet exhibited 94.84% degradation efficiency of photodegradation of methylene blue in 180 min, which was much more active than that of the commercial α‐Bi2O3 due to its high specific surface area of 45.7 m2 g−1 and wide band gap of 3.10 eV.
Investigation of photocatalytic performance of natural zeolite/TiO2 composites
Authors: Koohestani Hassan , Hassanabadi Mohammad , Mansouri Hamed , Pirmoradian Abbas
Published: February 2019

The growing increase of industrial wastewater, environmental contaminations, and the necessity of clean water has stressed the importance of removing pollutants. One of the effective means of removing pollutants from water and wastewater is by utilising zeolite. Zeolite, despite possessing unique photophysical properties (such as numerous fine cavities, the high capability to adsorb, and chemical–thermal stability), represents some limitations when being used. Depositing photocatalysts on zeolite particles to improve its removal potential is of much interest. In this work, therefore, TiO2 nanoparticles were deposited on fine particles of zeolite. Zeolite/TiO2 composites were evaluated by X‐ray diffractometer, scanning electron microscope, Brunauer–Emmett–Teller, diffuse reflectance spectroscopy analyses. The results indicate that the presence of TiO2 nanoparticles reduces the specific surface area. However, it causes the ability to absorb UV light. Increasing the amount of TiO2 any further will bring about a redshift in absorption edge. Photocatalytic properties of the composites were assessed by methyl orange and cyanide ion removal examination. The 10%TiO2 composite with the specific surface area of 34 m2/g and bandgap energy of 3.3 eV showed to be the most efficient. The superior photocatalytic performance of 10%TiO2 sample was confirmed by the examination of producing hydrogen from water/methanol.
GALEX colours of quasars and intergalactic medium opacity at low redshift
Authors: Deharveng J.-M. , Milliard B. , Péroux C. , Small T.
Published: February 2019

Aims. The distribution of neutral hydrogen in the intergalactic medium (IGM) is currently explored at low redshift by means of UV spectroscopy of quasars. We propose here an alternative approach based on UV colours of quasars as observed from GALEX surveys. We built a NUV-selected sample of 9033 quasars with (FUV−NUV) colours. The imprint of HI absorption in the observed colours is suggested qualitatively by their distribution as a function of quasar redshift.

Methods. Because broad band fluxes lack spectral resolution and are sensitive to a large range of HI column densities a Monte Carlo simulation of IGM opacity is required for quantitative analysis. It was performed with absorbers randomly distributed along redshift and column density distributions. The column density distribution was assumed to be a broken power law with index β1 (1015 cm−2 <  NHI <  1017.2 cm−2) and β2 (1017.2 cm−2 <  NHI <  1019 cm−2). For convenience the redshift distribution is taken proportional to the redshift evolution law of the number density of Lyman limit systems (LLS) per unit redshift as determined by existing spectroscopic surveys. The simulation is run with different assumptions on the spectral index αν of the quasar ionising flux.

Results. The fits between the simulated and observed distribution of colours require an LLS redshift density larger than that derived from spectroscopic counting. This result is robust in spite of difficulties in determining the colour dispersion other than that due to neutral hydrogen absorption. This difference decreases with decreasing αν (softer ionising quasar spectrum) and would vanish only with values of αν which are not supported by existing observations.

Conclusions. We provide arguments to retain αν = −2, a value already extreme with respect to those measured with HST/COS. Further fitting of power law index β1 and β2 leads to a higher density by a factor of 1.7 (β1 = −1.7, β2 = −1.5), possibly 1.5 (β1 = −1.7, β2 = −1.7). Beyond the result in terms of density the analysis of UV colours of quasars reveals a tension between the current description of IGM opacity at low z and the published average ionising spectrum of quasars.
Quality of endoscopy reporting at index colonoscopy significantly impacts outcome of subsequent EMR in patients with > 20 mm colon polyps
Authors: Raju Gottumukkala , Lum Phillip , Ross William , Thirumurthi Selvi , Miller Ethan , Lynch Patrick , Lee Jeffrey , Bhutani Manoop , Shafi Mehnaz , Weston Brian , Blechacz Boris , Chang George , Hagan Katherine , Rashid Asif , Davila Marta , Stroehlein John
Published: February 2019

Background and study aims Endoscopic mucosal resection (EMR) is safe and cost-effective in management of patients with colon polyps. However, very little is known about the actions of the referring endoscopist following identification of these lesions at index colonoscopy, and the impact of those actions on the outcome of subsequent referral for EMR. The aim of this study was to identify practices at index colonoscopy that lead to failure of subsequent EMR.

Patients and methods Two hundred and eighty-nine consecutive patients with biopsy-proven non-malignant colon polyps (> 20 mm) referred for EMR were analyzed to identify practices that could be improved from the time of identifying the lesion at index colonoscopy until completion of therapy.

Results EMR was abandoned at colonoscopy at the EMR center in 71 of 289 patients (24.6 %). Reasons for abandoning EMR included diagnosis of invasive carcinoma (n = 9; 12.7 %), tethered lesions (n = 21; 29.6 %) from prior endoscopic interventions, and overly large (n = 22; 31 %) and inaccessible lesions (n = 17; 24 %) for complete and safe resection whose details were not recorded in the referring endoscopy report, or polyposis syndromes (n = 2; 2.8 %) that were not recognized.

Conclusions In our practice, one in four EMR attempts were abandoned as a result of inadequate diagnosis or management by the referring endoscopist, which could be improved by education on optical diagnosis of polyps, comprehensive documentation of the procedure and avoidance of interventions that preclude resection.
Clinicopathological features and endoscopic characteristics of inverted sessile serrated adenomas/polyps
Authors: Takashima Kenji , Oono Yasuhiro , Kojima Motohiro , Ikematsu Hiroaki , Akimoto Tetsuo , Yano Tomonori
Published: February 2019

Background and study aims This study was designed to clarify clinicopathological, endoscopic, and genetic characteristics of inverted sessile serrated adenomas/polyps.

Patients and methods In this retrospective study, we reviewed the pathology reports of patients treated in our hospital between January 2010 and June 2015 and identified sessile serrated adenomas/polyps that were diagnosed with endoscopic resected specimens. Clinicopathological, endoscopic, and genetic features were compared between the inverted and ordinary types.

Results Among the 104 sessile serrated adenomas/polyps, 37 lesions were inverted (35.6 %). The inverted types had two patterns of invasion: expansive and infiltrating growth. Expansive growth was observed in 15 cases (40.5 %) and infiltrating in 22 (59.5 %). Regarding the clinicopathological findings and endoscopic characteristics of the inverted types, presence of adherent mucous, location in the right-side colon, an expanded type-II pit pattern, irregularly dilated vessels, and a depression were demonstrated in 89 % (33/37), 73 % (27/37), 54 % (20/37), 75 % (28/37), and 35 % (13/37), respectively. Contrastingly, these were demonstrated in 86 % (58/67), 84 % (56/67), 55 % (37/67), 58 % (39/67), and 0 % (0/67), respectively, in the ordinary type. In the univariate analysis, male sex and a depression in the adenoma/polyp were significantly associated with inverted types (P < 0.001). BRAF mutation at codon 600 was found in six of seven ordinary types and in 11 of 11 of the inverted types. KRAS, NRAS, and PIK3CA mutations were not found in the ordinary and inverted types.

Conclusion More than 30 % of sessile serrated adenomas/polyps were pathologically diagnosed as inverted, and approximately 40 % of them were of the expansive growth type and easily diagnosed with endoscopy.
EUS-guided coil placement for acute gastric variceal bleeding induced by non-EUS-guided variceal glue injection (with video)
Authors: Mazzawi Tarek , Markhus Carl , Havre Roald , Do-Cong Pham Khanh
Published: February 2019

Background and study aims Endoscopic ultrasound (EUS)-guided coil placement is a new emerging technique for management of gastric varices. In this video case report, we describe an EUS-guided coil placement for managing acute bleeding of gastric varices, following an unsuccessful glue injection to achieve hemostasis.
Synthesis of a Variety of Activated Pyrrolo[3,2,1-ij]quinolines
Authors: Jumina Jumina , Wenholz Daniel , Kumar Naresh , Black David
Published: February 2019

A range of 7,9-dimethoxypyrrolo[3,2.1-ij]quinolines have been prepared by the cyclisation of 7-formyl-1-diethylcarbethoxyindoles. The functionality at C5 has been varied by the conversion of the carbethoxy group into carboxy, azidocarbonyl and isocyanate groups. The hydroboration of a previously reported pyrroloquinolone gave a related 5-hydroxypyrrolo[3,2,1-ij]quinolone, and the hydroxyl group was sequentially converted into tosylate, azido and amino groups.
Lithopedion Causing Intestinal Obstruction in a 71-Year-Old Woman: A Case Report
Authors: de Oliveira Francisco Eliomar Gomes , Santos Sandra Regina Alves dos , Duarte Bruno Gomes , Sisnando Alexandre Sabino
Published: February 2019

Ectopic pregnancy is the leading cause of pregnancy-related death during the first trimester, and it occurs in 1 to 2% of pregnancies. Over 90% of ectopic pregnancies are located in the fallopian tube. Abdominal pregnancy refers to an ectopic pregnancy that has implanted in the peritoneal cavity, external to the uterine cavity and fallopian tubes. The estimated incidence is 1 per 10,000 births and 1.4% of ectopic pregnancies. Lithopedion is a rare type of ectopic pregnancy, and it occurs when the fetus from an unrecognized abdominal pregnancy may die and calcify. The resulting “stone baby” may not be detected for decades and may cause a variety of complications. Lithopedion is a very rare event that occurs in 0.0054% of all gestations. About 1.5 to 1.8% of the abdominal babies develop into lithopedion. There are only ∼ 330 known cases of lithopedion in the world. We describe a lithopedion that complicated as intestinal obstruction in a 71-year-old woman.
Patient Satisfaction and Quality of Life with Enhanced Recovery Protocols
Authors: Li Debbie , Jensen Christine
Published: February 2019

While studies have demonstrated the benefits of Enhanced Recovery after Surgery (ERAS) programs in reducing length of stay and costs without increasing complications, fewer studies have evaluated patient satisfaction and quality of life (QOL) with enhanced recovery protocols. The aim of this project was to summarize the literature comparing satisfaction and quality of life after colorectal surgery following treatment within an ERAS protocol to standard postoperative care. The available evidence suggests patients suffer no detriment to satisfaction or quality of life with use of ERAS protocols, and may suffer less fatigue and return to activities sooner. Most publications reported no adverse effects on postoperative pain. However, a limited number of studies suggest patients may experience increased early postoperative pain with ERAS pathways, particularly following open colorectal procedures. Future research should focus on potential improvements in ERAS protocols to better manage postoperative pain. Overall, the evidence supports more widespread implementation of ERAS pathways in colorectal surgery.
Reduction and Association of the Lunotriquetral Ligament for Reverse Perilunate Dislocation
Authors: Huang Hui-Kuang , Tsai Tung-Yeh , Wang Jung-Pan
Published: February 2019

Background Reverse perilunate injuries are rare. Contrary to perilunate injuries, the violent force would start from the lunotriquetral ligament, go reversely toward the radial side, and cause the reverse or ulnar-sided perilunate dislocation.

Case Description We describe a 31-year-old man with a reverse perilunate dislocation, who presented to our institution 3 weeks after a motorcycle accident. The patient was successfully treated with the reduction and association of the lunate and triquetrum (RALT) procedure by using closed maneuver and percutaneous headless compression screw fixation. The patient can obtain a good radiographic result and satisfactory function at the 30-month follow-up.

Literature Review Many case series were reported concerning the perilunate injuries. However, few cases of reverse perilunate dislocation have been reported in the literature. No cases of reverse perilunate dislocation treated 3 weeks after the injury with the RALT procedure have been reported.

Clinical Relevance In this case, we found that the dislocation could still be reduced with the closed maneuver. With the RALT procedure, the carpal alignment can be maintained and the stability can be regained. Also, the functional outcomes are good.
Developing a Core Outcome Set for Cesarean Delivery Maternal Infectious Morbidity Outcomes
Authors: Briscoe Kristin E. , Haas David M.
Published: February 2019

Objective This study aimed to develop a core outcome set of primary outcomes for studies involving cesarean deliveries with infectious morbidity outcomes.

Study Design Authors reported primary outcomes from 11 Cochrane systematic reviews (SRs), 12 other SRs, and 327 randomized controlled trials (RCTs). These outcomes were condensed into 20 primary outcome groups. Next, a modified Delphi technique was used to gain consensus on key outcomes. Authors from included SRs were sent a questionnaire consisting of a free response and multiple-choice questions. These data were used to propose a set of core outcomes.

Results The most frequent outcomes in RCTs were composite “infectious outcomes” (24%) with the second most common being endometritis (12%). The most common reported SR outcomes were wound infection (21%) and endometritis (16%). For the Delphi survey free response portion, wound infection (88%) and endometritis (79%) were the most commonly endorsed outcomes. Chosen list outcomes were maternal mortality (83%), wound infection (83%), wound complications (86%), and postpartum endometritis (80%). The proposed final core outcome set for cesarean trials was endometritis (primary outcome), maternal mortality, wound infection, wound complications, febrile morbidity, and neonatal morbidity.

Conclusion Utilizing defined core outcomes in all studies of cesarean section can harmonize trial reports and allow data synthesis for meta-analyses.
Time-resolved simulation of the negative capacitance stage emerging at the ferroelectric/semiconductor hetero-junction
Authors: Takada K. , Yoshimura T. , Fujimura N.
Published: February 2019

Recently, a number of papers have demonstrated sub-60 mV/decade switching by using the negative capacitance (NC) effect in ferroelectric-gate FETs. However, the physical picture is not yet understood. In this paper, an alternative physical picture for emerging NC is proposed and the development of the NC stage at the ferroelectric/semiconductor hetero-junction is described. Proposed physical picture is based on two factors, 1. “decrease in an additional voltage originated from the depolarization field by surface potential of semiconductor” and 2. “Change in the distribution ratio of gate voltage (VG) to voltage applied to the ferroelectric layer (VF) and surface potential of the semiconductor (ψS) due to the capacitance change of semiconductor.” With considering these two essential phenomena, time-resolved simulations of the NC stage emerging at the ferroelectric/semiconductor hetero-junction were carried out. This NC phenomena expressed by the negative differential of the DF for the VF, i.e. (∂DF/∂VF<0), emerging in the MFS (metal/ferroelectric/semiconductor) capacitor without inserting dielectric layer, are dynamically simulated to discuss the proposed NC process. The simulation results clearly reveal that the NC stage is originated from the existence of additional voltage caused by the depolarization field by surface potential of semiconductor originated from the existence of remanent polarization of ferroelectric layer, and change in the capacitance of the semiconductor during polarization switching. The different physical picture from steady-state NC and transient NC can be clearly shown.
Mode broadening induced by rotation rate in an atom assisted microresonator
Authors: Zhang Hao , Li Wenxiu , Han Peng , Chang Xiaoyang , Liu Jiaming , Huang Anping , Xiao Zhisong
Published: February 2019

Nonreciprocity of the counterpropagating waves in a ring resonator induced by the rotation rate results in a measurable frequency shift. A self-reference measurement using mode broadening induced by backscattering is proposed to detect the rotation rate in a whispering gallery mode resonator with a cavity-made slot filled with atomic vapor. Through detuning an optical pump rate and a strong driving field coupled to a three-level atomic vapor, the backscattering generated by the cavity-made slot becomes sensitive to the rotation. Degenerate clockwise and counterclockwise modes couple to each other and create two new eigenmodes via manipulating the backscattering of the cavity-made slot. Detecting the mode broadening induced by the rotation rate enables the gyroscope’s sensitivity to be enhanced at least four orders of magnitude in a low Q factor microresonator.
Selective control of magnetism in FeAl/PIN-PMN-PT using an electric field
Authors: Wei Yanping , Yang Guoqiang , Yang Hongbing , Xi Shibo
Published: February 2019

Mediating nonvolatile magnetism by purely electrical methods is a crucial challenge for the development of high-density and low energy consumption information storage. Research into most material systems, including ferromagnetic /ferroelectric heterostructures and, especially, magnetostriction/lead magnesium niobate-lead titanate (PMN-PT), has focused mainly on the nonvolatile strain-mediated converse magnetoelectric (ME) effect. The recent discovery of a type of FeAl/lead indium niobate (PIN)-PMN-PT heterostructure has provided an approach for electrical control of magnetism at room temperature. We demonstrate selective control of nonvolatile magnetism in (001)- and (111)-oriented FeAl/PIN-PMN-PT. In order to illustrate the behavior of electric field control of magnetism in (111)-oriented PIN-PMN-PT, a converse ME coupling mechanism is presented via polarization switching models. This mechanism indicates that the magnetization process is related to both the direction of polarization switching and the strain-mediated effect. By controlling the piezoresponse force microscopy (PFM) scan direction and analyzing the color contrast of the PFM images, we confirm the validity of the proposed models of polarization switching and demonstrate the validity of the mechanism. The results of this study may offer a method for the selective control of magnetism in nonvolatile multilevel data storage.
Direct observation of proximity-induced magnetism and spin reorientation in topological insulator on a ferrimagnetic oxide
Authors: Yang Chao-Yao , Lee Yen-Hsun , Ou Yang Kui-Hon , Chiu Kuan-Chia , Tang Chi , Liu Yawen , Zhao Yi-Fan , Chang Cui-Zu , Chang Fan-Hsiu , Lin Hong-Ji , Shi Jing , Lin Minn-Tsong
Published: February 2019

The quantum anomalous Hall effect (QAHE) in a magnetic topological insulator system without the need of an external magnetic field becomes of great interest because of its dissipationless spin currents. The proximity effect via a magnetic adlayer is a promising strategy to bring magnetism into a topological insulator (TI) due to its boosted Curie temperature for a realistic application. In this work, a proximity-induced magnetism above 90 K in a TI, (Bi0.25Sb0.75)2Te3, on a ferrimagnetic adlayer with perpendicular magnetic anisotropy, thulium-iron-garnet (TIG), was evidenced directly by using magnetic circular dichroism. A competition between exchange couplings with different sublattice-sites was further revealed element-specifically in a temperature-driven spin-reorientation of TI, bringing an issue on magnetic inhomogeneity at the interface, which might cause difficulties in obtaining QAHE in such a TI/TIG bilayer system. Our results prove directly the robust magnetism of TI above liquid nitrogen temperatures and also give a deep insight into the mechanism of interfacial coupling in the proximity effect for the bilayer of TI and magnetic oxide, which could be essential for the design of a system with QAHE.
Anomalous behavior of electrically active defects near EC−0.5 eV in MOCVD, as-grown GaN
Authors: Boturchuk Ievgen , Scheffler Leopold , Larsen Arne Nylandsted , Julsgaard Brian
Published: February 2019

The present work reports on a distinct and very reproducible bistable-like behavior of two defects at around EC − 0.5 eV in MOCVD-grown GaN. The kinetics of the thermally activated transformation between the two states are analyzed in an Arrhenius model, yielding an energy barrier of 0.4 ± 0.1 eV, and a frequency factor of 106±1 s−1. Depth profiles suggest that the charge state of the defects determines the observed amplitude variation. Relevant models for the observed behavior, and their shortcomings are discussed: (i) passivating properties of hydrogen, and (ii) bistable defect component(s). A proper explanation of the experimental observations represents, however, a further challenge.
Effect of different emitter types on the production of nanofibrous tubular structures: Thickness uniformity and productivity
Authors: Kotzianova Adela , Klemes Jan , Zidek Ondrej , Mlynar Zdenek , Pokorny Marek , Velebny Vladimir
Published: February 2019

This contribution focuses on the effects of electrospinning process on the homogeneity of nanofibrous tubular structures caused by different emitters. Six types of emitters were used for the production of nanofibrous tubes. For all, the electric potential and the electric field were simulated. The quality of the produced tubes was verified by scanning electron microscopy, contact measurement of thickness and by a new digital image processing method based on transillumination. The analysis of the spun samples proved that the quality and therefore the parameters of the prepared tubes are significantly influenced by the choice of an emitter and its configuration. The use of the five-needle and needleless emitters resulted in a tenfold increase in production, however, image analysis revealed major thickness inhomogeneities. The highest thickness homogeneity and a high repeatability of the spinning process were achieved by using a moving double-needle emitter. The results will find use especially in the research of small-diameter vascular replacements and other applications in the field of tissue engineering requiring highly uniform tubular grafts.
Knee deep in trouble: rusa deer use an aquatic escape behaviour to delay attack by Komodo dragons
Authors: Ariefiandy Achmad , Purwandana Deni , Benu Yunias Jackson , Letnic Mike , Jessop Tim S.
Published: February 2019

We document six observations of an aquatic behaviour used by rusa deer (Rusa timorensis) to delay an imminent attack from Komodo dragons (Varanus komodoensis). This unusual behaviour arose after rusa deer fled into the nearby seawater following an attack from a solitary Komodo dragon. Once in the sea, rusa deer remained relatively stationary by standing in shallow water (<1 m deep) for up to 4 h. This behaviour generally allowed rusa deer to avoid an in-water attack from Komodo dragons. However, if rusa did not die from injuries, they moved back onto land and were subsequently killed by Komodo dragons. The aquatic behaviour delays subsequent attacks on rusa deer by Komodo dragons, but this appears only to postpone, rather than prevent, the deer’s death.
Enhancing joint reconstruction and segmentation with non-convex Bregman iteration
Authors: Corona Veronica , Benning Martin , Ehrhardt Matthias J , Gladden Lynn F , Mair Richard , Reci Andi , Sederman Andrew J , Reichelt Stefanie , Schönlieb Carola-Bibiane
Published: February 2019

All imaging modalities such as computed tomography, emission tomography and magnetic resonance imaging require a reconstruction approach to produce an image. A common image processing task for applications that utilise those modalities is image segmentation, typically performed posterior to the reconstruction. Recently, the idea of tackling both problems jointly has been proposed. We explore a new approach that combines reconstruction and segmentation in a unified framework. We derive a variational model that consists of a total variation regularised reconstruction from undersampled measurements and a Chan–Vese-based segmentation. We extend the variational regularisation scheme to a Bregman iteration framework to improve the reconstruction and therefore the segmentation. We develop a novel alternating minimisation scheme that solves the non-convex optimisation problem with provable convergence guarantees. Our results for synthetic and real data show that both reconstruction and segmentation are improved compared to the classical sequential approach.
Life is sweet: the cell biology of glycoconjugates
Authors: Broussard Alex C. , Boyce Michael
Published: February 2019

Cells are dazzling in their diversity, both within and across organisms. And yet, throughout this variety runs at least one common thread: sugars. All cells on Earth, in all domains of life, are literally covered in glycans, a term referring to the carbohydrate portion of glycoproteins and glycolipids. In spite of (or, perhaps, because of) their tremendous structural and functional complexity, glycans have historically been underexplored compared with other areas of cell biology. Recently, however, advances in experimental systems and analytical methods have ushered in a renaissance in glycobiology, the study of the biosynthesis, structures, interactions, functions, and evolution of glycans. Today, glycobiology is poised to make major new contributions to cell biology and become more fully integrated into our understanding of cell and organismal physiology.
Are Many Patients Diagnosed With Healthcare-associated Clostridioides difficile Infections Colonized With the Infecting Strain on Admission?
Authors: Gonzalez-Orta Melany , Saldana Carlos , Ng-Wong Yilen , Cadnum Jennifer , Jencson Annette , Jinadatha Chetan , Donskey Curtis J
Published: February 2019

In a cohort of 480 patients admitted to an acute care hospital, 68 (14%) had positive perirectal cultures for toxigenic Clostridioides difficile on admission. Of the 11 patients (2%) diagnosed with healthcare-associated C. difficile infections, 3 (27%) had genetically related admission and infection isolates, based on whole-genome sequencing.
Stand-level windthrow patterns and long-term dynamics of surviving trees in natural secondary stands after a stand-replacing windthrow event
Authors: Shibuya Masato , Ishibashi Satoshi
Published: February 2019

We examined typhoon windthrow patterns in stand-scale permanent plots within three natural forests and the long-term dynamics of surviving trees in two of these plots. The aim was to verify whether pre-disturbance composition and structure affected windthrow damage and stand recovery. The stands, which were in Hokkaido, the northernmost main island of Japan, differed in pre-disturbance composition (coniferous, mixed and broadleaved stands) and structure, and the basal area losses by the windthrow event were 81–93 per cent. Tree mortality was significantly related to tree size (diameter at breast height) and species. The windthrow patterns differed among the three stands; and, windthrow severity was affected by the pre-disturbance composition and structure. The mortality of trees that survived the windthrow event was ~60 per cent in the two plots. The surviving trees comprised a majority of the canopy layer in the secondary stands. The relative basal area of surviving trees decreased rapidly with increasing tree density in the stand initiation stage but differed between plots. Consequently, the pre-disturbance composition and structure influenced windthrow severity, stand recovery and secondary succession in the recovered stands.
Evidence of Bidirectional Associations Between Depressive Symptoms and Body Mass Among Older Adults
Authors: Emery Charles F , Finkel Deborah , Gatz Margaret , Dahl Aslan Anna K
Published: February 2019

Objectives

Body fat, measured with body mass index (BMI), and obesity are associated with depressive symptoms. Among younger adults there is stronger evidence of obesity leading to depressive symptoms than of depressive symptoms leading to obesity, but the temporal relationship is unknown among older adults. This study utilized dual-change-score models (DCSMs) to determine the directional relationship between body mass and depressive symptoms among older adults.

Method

Participants (n = 1,743) from the Swedish Twin Registry (baseline age range 50–96 years) completed at least one assessment of BMI (nurse measurement of height and weight) and the Center for Epidemiologic Studies-Depression scale (CESD). More than half the sample completed 3 or more assessments, scheduled at intervals of 2–4 years. DCSMs modeled the relationship of BMI and CESD across age, both independently and as part of bivariate relationships.

Results

Depressive symptoms contributed to subsequent changes in BMI after age 70, while BMI contributed to subsequent changes in depressive symptoms after age 82. Thus, there is a reciprocal relationship that may change with age. The effect was more pronounced for women.

Discussion

The association of BMI and depressive symptoms is bidirectional among older adults, and it appears to be affected by both age and sex.
Generating approximate halo catalogues for blind challenges in precision cosmology
Authors: Garrison Lehman H , Eisenstein Daniel J
Published: February 2019

We present a method for generating suites of dark matter halo catalogues with only a few N-body simulations, focusing on making small changes to the underlying cosmology of a simulation with high precision. In the context of blind challenges, this allows us to re-use a simulation by giving it a new cosmology after the original cosmology is revealed. Starting with full N-body realizations of an original cosmology and a target cosmology, we fit a transfer function that displaces haloes in the original so that the galaxy/HOD power spectrum matches that of the target cosmology. This measured transfer function can then be applied to a new realization of the original cosmology to create a new realization of the target cosmology. For a 1 per cent change in σ8, we achieve 0.1 per cent accuracy to $k = 1\, h\, \mathrm{Mpc}^{-1}$ in the real-space power spectrum; this degrades to 0.3 per cent when the transfer function is applied to a new realization. We achieve similar accuracy in the redshift-space monopole and quadrupole. In all cases, the result is better than the sample variance of our $1.1\, h^{-1}\, \mathrm{Gpc}$ simulation boxes.
Secondary Overtriage in Patients with Complicated Mild Traumatic Brain Injury: An Observational Study and Socioeconomic Analysis of 1447 Hospitalizations
Authors: Dengler Bradley A , Plaza-Wüthrich Sonia , Chick Robert C , Muir Mark T , Bartanusz Viktor
Published: February 2019

BACKGROUND

Secondary overtriage is a problematic phenomenon because it creates unnecessary expense and potentially results in the mismanagement of healthcare resources. The rates of secondary overtriage among patients with complicated mild traumatic brain injury (cmTBI) are unknown.

OBJECTIVE

To determine the rate of secondary overtriage among patients with cmTBI using the institutional trauma registry.

METHODS

An observational study using retrospective analysis of 1447 hospitalizations including all consecutive patients with cmTBI between 2004 and 2013. Data on age, sex, race/ethnicity, insurance status, GCS, Injury Severity Score (ISS), Trauma Injury Severity Score, transfer mode, overall length of stay (LOS), LOS within intensive care unit, and total charges were collected and analyzed.

RESULTS

Overall, the rate of secondary overtriage among patients with cmTBI was 17.2%. These patients tended to be younger (median: 41 vs 60.5 yr; P < .001), have a lower ISS (9 vs 16; P < .001), and were more likely to be discharged home or leave against medical advice.

CONCLUSION

Our findings provide evidence to the growing body of literature suggesting that not all patients with cmTBI need to be transferred to a tertiary care center. In our study, these transfers ultimately incurred a total cost of $13 294 ($1337 transfer cost) per patient.
Incentive Pay and Systemic Risk
Authors: Albuquerque Rui , Cabral Luís , Guedes José
Published: February 2019

We show that, in the presence of correlated investment opportunities across firms, risk sharing between firm shareholders and firm managers leads to compensation contracts that include relative performance evaluation. These contracts bias investment choices toward correlated investment opportunities, and thus create systemic risk. Furthermore, we show that leverage amplifies all such effects. In the context of the banking industry, we analyze recent policy recommendations for firm managerial pay and show how shareholders optimally undo the policies’ intended effects.

Received October 31, 2017; editorial decision August 21, 2018 by Editor Wei Jiang. Authors have furnished an Internet Appendix, which is available on the Oxford University Press Web site next to the link to the final published paper online.
Interhospital variation in mortality among patients with systemic lupus erythematosus and sepsis in the USA
Authors: Tektonidou Maria G , Dasgupta Abhijit , Ward Michael M
Published: February 2019

Objective

To determine whether the risk of mortality in patients with SLE hospitalized with sepsis varies among hospitals in the USA.

Methods

We used the National Inpatient Sample (2002–2011) to obtain national population-based data on outcomes for adults with SLE admitted with sepsis, and compared it with that for patients without SLE admitted with sepsis at the same hospital. We computed expected mortality based on patient demographic characteristics, comorbidities and major organ dysfunction, and calculated observed/expected (O/E) mortality ratios separately for patients with SLE and without SLE for each hospital. We then computed the ratio of these O/E ratios within hospitals to assess relative SLE mortality. We considered hospitals with a risk ratio (RR) of ⩾2.0 as having high relative SLE mortality.

Results

Among 424 hospitals that treated a total of 4024 patients with SLE and sepsis, the risk of in-hospital mortality varied from 0% to 60% (median 11.1%). The RR ranged from 0 to 9.75, with a median of 0.84, indicating that O/E mortality was similar in patients with and without SLE at the average hospital. Sixty-one hospitals (14.4%) had a RR of ⩾2.0, indicating higher mortality among patients with SLE. Hospitals that on average treated ⩾3.9 patients with SLE and sepsis annually were less likely to have a RR of ⩾2.0 than hospitals that treated fewer patients (10% vs 17%; P = 0.004).

Conclusion

Mortality among patients with SLE and sepsis varied widely between hospitals, and was lower at hospitals that treated more of these patients.
Paget disease of the vulva
Authors: Johnson Jennifer , O'Laughlin Danielle
Published: February 2019

Vulvar Paget disease (VPD) is an unusual and rare adenocarcinoma that can be challenging to diagnose. Although the condition has a high treatment success rate, it can be associated with underlying malignancy, recurrence rates can be high, and patients often need regular and frequent follow-up. The article describes a woman whose nonresolving, pruritic vulvar lesion was found to be VPD on biopsy.
Mr. Blue and His Six Cats
Authors: Rader Mariya
Published: February 2019

A nurse learns what it means to trust her gut.
Why We Needn’t Fear the Machines: Opportunities for Medicine in a Machine Learning World
Authors: Li David , Kulasegaram Kulamakan , Hodges Brian D.
Published: February 2019

Recently in medicine, the accuracy of machine learning models in predictive tasks has started to meet or exceed that of board-certified specialists. The ability to automate cognitive tasks using software has raised new questions about the future role of human physicians in health care. Emerging technologies can displace people from their jobs, forcing them to learn new skills, so it is clear that this looming challenge needs to be addressed by the medical education system. While current medical education seeks to prepare the next generation of physicians for a rapidly evolving health care landscape to meet the needs of the communities they serve, strategic decisions about disruptive technologies should be informed by a deeper investigation of how machine learning will function in the context of medicine. Understanding the purpose and strengths of machine learning elucidates its implications for the practice of medicine. An economic lens is used to analyze the interaction between physicians and machine learning. According to economic theory, competencies that are complementary to machine prediction will become more valuable in the future, while competencies that are substitutes for machine prediction will become less valuable. Applications of machine learning to highly specific cognitive tasks will increase the performance and value of health professionals, not replace them. To train physicians who are resilient in the face of potential labor market disruptions caused by emerging technologies, medical education must teach and nurture unique human abilities that give physicians a comparative advantage over computers.