bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient parallel reconstruction for high resolution multishot spiral diffusion data with low rank constraint
Authors: Liao Congyu , Chen Ying , Cao Xiaozhi , Chen Song , He Hongjian , Mani Merry , Jacob Mathews , Magnotta Vincent , Zhong Jianhui
Published: March 2016

Purpose

To propose a novel reconstruction method using parallel imaging with low rank constraint to accelerate high resolution multishot spiral diffusion imaging.

Theory and Methods

The undersampled high resolution diffusion data were reconstructed based on a low rank (LR) constraint using similarities between the data of different interleaves from a multishot spiral acquisition. The self‐navigated phase compensation using the low resolution phase data in the center of k‐space was applied to correct shot‐to‐shot phase variations induced by motion artifacts. The low rank reconstruction was combined with sensitivity encoding (SENSE) for further acceleration. The efficiency of the proposed joint reconstruction framework, dubbed LR‐SENSE, was evaluated through error quantifications and compared with
regularized compressed sensing method and conventional iterative SENSE method using the same datasets.

Results

It was shown that with a same acceleration factor, the proposed LR‐SENSE method had the smallest normalized sum‐of‐squares errors among all the compared methods in all diffusion weighted images and DTI‐derived index maps, when evaluated with different acceleration factors (R = 2, 3, 4) and for all the acquired diffusion directions.

Conclusion

Robust high resolution diffusion weighted image can be efficiently reconstructed from highly undersampled multishot spiral data with the proposed LR‐SENSE method. Magn Reson Med 77:1359–1366, 2017. © 2016 International Society for Magnetic Resonance in Medicine
Enhancing Multiple Routing Configurations through systematic analysis of topological characteristics
Authors: Cevher Selcuk , Ulutas Mustafa , Hokelek Ibrahim
Published: March 2016

Previous studies show that topological characteristics in IP networks significantly influence the performance of networking algorithms, which therefore should be systematically analyzed using diverse topologies prior to their deployments. In this paper, we present an elaborate topological dependency analysis of a multi‐topology routing‐based IP fast re‐route technology, namely, Multiple Routing Configurations (MRC), using a large topology pool with diverse properties. Through an extensive analysis using our automated topological analysis tool, we discover a significant correlation between the performance of MRC and topological characteristics. MRC needs to construct a higher number of virtual topologies to provide full alternate path coverage if a network topology tends to have more hub nodes, whose degree is much higher than the rest of the network. Inspired by our topological analysis results, we propose a new heuristic algorithm enhancing MRC. Numerical experiments demonstrate that our heuristic significantly improves the performance of MRC confirming the effectiveness of the systematic analysis of topological characteristics. Copyright © 2016 John Wiley & Sons, Ltd.
Repeated Blood Cultures in Pediatric Febrile Neutropenia: Would Following the Guidelines Alter the Outcome?
Authors: Petty Lindsay A. , Sokol Elizabeth A. , Bartlett Allison H. , McNeer Jennifer L. , Alexander Kenneth A. , Pisano Jennifer
Published: March 2016

Background

The Infectious Diseases Society of America (IDSA) guidelines recommend collecting blood cultures for the first 3 days of febrile neutropenia (FN) in the clinically stable oncology patient with persistent fevers. Nonetheless, many physicians send daily blood cultures beyond 3 days, and the impact of that practice is uncertain.

Procedure

We reviewed pediatric FN episodes from July 2009 to May 2014 at University of Chicago Comer Children's Hospital. For each positive culture, we determined if it was a pathogen or a contaminant. We reviewed episode and patient demographics to identify risk factors for subsequent positive blood cultures in the setting of an initially negative culture.

Results

We identified 381 episodes of FN in 162 patients. Of those, 87 had a positive blood culture on day 1 (21.0% incidence of bacteremia). Of 294 episodes with a negative blood culture on day 1, six (2.04%, 95% confidence interval [CI] 0.42–3.67) had a positive culture after day 3. Of those, three were pathogens (1.02%, 95%CI –0.14 to 2.18), and only one was found in a hemodynamically stable patient (0.34%, 95%CI –0.33 to 1.01) with new mucositis. In the other two patients, Escherichia coli was isolated from blood cultures after day 10 in the setting of significant hemodynamic changes. Risk factor analysis performed in stable patients yielded nonsignificant results.

Conclusions

Of 294 FN episodes with an initial negative blood culture, only one episode of bacteremia occurred without hemodynamic changes past day 3, supporting the IDSA guidelines to discontinue blood cultures in stable FN patients after day 3.
A Diagnostic Dilemma: Similarity of Neuroradiological Findings in Central Nervous System Hemophagocytic Lymphohistiocytosis and Aspergillosis
Authors: Foley Jessica M. , Borders Heather , Kurt Beth A.
Published: March 2016

Central nervous system (CNS) involvement in the context of hemophagocytic lymphohistiocytosis (HLH) is not uncommon. Given the immunosuppressive nature of HLH therapy, infectious complications are also seen. We describe a 9‐year‐old male who developed acute neurological decline secondary to aspergillosis while undergoing HLH therapy. The significant overlap observed in CNS neuroimaging of HLH and aspergillosis and the subtleties that may help differentiate the two are discussed. The importance of obtaining tissue for definitive diagnosis is underscored.
Plasma‐enhanced modification of multiwalled carbon nanotube with conducting polymers for dye sensitized solar cells
Authors: Cogal Sadik , Ela Sule Erten , Cogal Gamze Celik , Micusik Matej , Omastova Maria , Oksuz Aysegul Uygun
Published: March 2016

This study presents the modification of multi‐walled carbon nanotube (MWCNT) with poly(3‐hexylthiophene) (P3HT) and polypyrrole (PPy) through the fast, versatile, and environmentally friendly process of radiofrequency (RF)‐rotating plasma polymerization. Morphological characterization of composites was performed using scanning electron microscopy (SEM) and showed that the P3HT and PPy conducting polymers coated the MWCNT surface. The surface properties of the MWCNT composites were determined using Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and SEM analysis. MWCNT composites were used as cathodes in dye‐sensitized solar cells (DSSCs). The short circuit current densities of P3HT/MWCNT‐ and PPy/MWCNT‐based DSSCs were found to be 5.61 and 4.19 mA/cm2, respectively. POLYM. COMPOS., 39:668–674, 2018. © 2016 Society of Plastics Engineers
The influence of semiconductive binary systems on electrical conductivity, mechanical, and thermal properties of epoxy composites
Authors: Soydal Ulku , Ahmetli Gulnare
Published: March 2016

The purpose of this study is to develop epoxy composites with improved mechanical, thermal, and electrical properties. Semiconducting glass (SG) binary systems such as As2S3‐TlS and As2Se3‐TlS were synthesized in various mole ratios (1:1 and 1:3). Electrically conductive DGEBA‐type epoxy‐SG‐filled composites were developed containing 1–15 wt% of fillers and characterized by X‐ray diffraction and scanning electron microscopy techniques. As a result, the effects of the type and amount of semiconductive filler on the mechanical, thermal, and electrical properties of commercial epoxy resins (ERs) were examined. It was found that I2 doping of the filler significantly increased the electrical conductivity of the composites up to 10−3 S cm−1. Percolation concentrations were found to be 7 wt% for all composites studied. The maximum tensile strength changed in the range of 86–114 MPa was obtained with 5–10 wt% of SG particles. In addition, the thermal behavior and stability of the epoxy composites were studied using thermogravimetric analysis. The incorporation of SG particles increased the 10% decomposition temperature of neat epoxy by 5°C–35°C. ER/SG coatings showed the best adhesion results and perfect resistance to 3% NaCl, 3% HCl, and 5% NaOH solutions. POLYM. COMPOS., 39:681–690, 2018. © 2016 Society of Plastics Engineers
On the abrasiveness and reinforcement of fillers in PTFE/epoxy composites
Authors: Shen J.T. , Van Rijn F. , Pei Y.T. , De Hosson J.T.M.
Published: March 2016

This article addresses the question what the influence is of size and shape of glass both particles and fibers, as well as carbon fibers on the abrasiveness of polytetrafluoroethylene (PTFE)/epoxy composites sliding against steel balls. A size‐dependence appears, i.e. large size glass particles (∼80 µm, L) are more abrasive than medium‐size (∼50 µm, M) and small‐size (∼27 µm, S) glass particles. Longer glass fibers (submilimeter) are more abrasive. Nevertheless, longer glass fibers still enhance the intrinsic mechanical properties of the composites. Also, carbon fibers reinforced composites yield much better mechanical properties than the glass fibers reinforced composites, but much more abrasive wear on the steel ball due to less surface‐adhered polymer layers on fibers. Mechanical properties are enhanced by an increasing amount of glass fillers and by adding a small concentration of nanofillers. POLYM. COMPOS., 39:698–707, 2018. © 2016 Society of Plastics Engineers
Chitosan composites with nanohydroxyapatite prepared by wet chemical reaction along with microwave irradiation: permeability and swelling aspects
Authors: Thomas Selvin P. , Alghamdi Mohammed N.
Published: March 2016

This paper reports the properties of chitosan (CS) reinforced with varying weight percentage of hydroxyapatite (HA) particles with respect to physical and chemical properties. Coprecipitation process of calcium nitrate tetrahydrate and phosphoric acid followed by microwave irradiation was used to synthesize nanosize rod‐shaped HA. The prepared powder was characterized using various chemical and physical methods. HA filled CS composites in different weight percentages were prepared by solvent casting method. The mechanical, thermal, and degradation studies of the composites showed improvement in properties indicating good filler‐matrix interaction in the composites. The highlights are the improvement in the thermal stability of the composites, significant reduction of gas permeability through the membranes, increase in the hydrophilicity of the composites and reduction in water swelling rate with respect to the filler content. POLYM. COMPOS., 39:718–729, 2018. © 2016 Society of Plastics Engineers
Are Perfectionism Dimensions Vulnerability Factors for Depressive Symptoms after Controlling for Neuroticism? A Meta–analysis of 10 Longitudinal Studies
Authors: Smith Martin M. , Sherry Simon B. , Rnic Katerina , Saklofske Donald H. , Enns Murray , Gralnick Tara
Published: March 2016

Extensive evidence suggests neuroticism is a higher–order personality trait that overlaps substantially with perfectionism dimensions and depressive symptoms. Such evidence raises an important question: Which perfectionism dimensions are vulnerability factors for depressive symptoms after controlling for neuroticism? To address this, a meta–analysis of research testing whether socially prescribed perfectionism, concern over mistakes, doubts about actions, personal standards, perfectionistic attitudes, self–criticism and self–oriented perfectionism predict change in depressive symptoms, after controlling for baseline depression and neuroticism, was conducted. A literature search yielded 10 relevant studies (N = 1,758). Meta–analysis using random–effects models revealed that all seven perfectionism dimensions had small positive relationships with follow–up depressive symptoms beyond baseline depression and neuroticism. Perfectionism dimensions appear neither redundant with nor captured by neuroticism. Results lend credence and coherence to theoretical accounts and empirical studies suggesting perfectionism dimensions are part of the premorbid personality of people vulnerable to depressive symptoms. Copyright © 2016 European Association of Personality Psychology
Shotgun proteomic analysis of soybean embryonic axes during germination under salt stress
Authors: Fercha Azzedine , Capriotti Anna Laura , Caruso Giuseppe , Cavaliere Chiara , Stampachiacchiere Serena , Zenezini Chiozzi Riccardo , Laganà Aldo
Published: March 2016

Seed imbibition and radicle emergence are generally less affected by salinity in soybean than in other crop plants. In order to unveil the mechanisms underlying this remarkable salt tolerance of soybean at seed germination, a comparative label‐free shotgun proteomic analysis of embryonic axes exposed to salinity during germination sensu stricto (GSS) was conducted. The results revealed that the application of 100 and 200 mmol/L NaCl stress was accompanied by significant changes (>2‐fold, P<0.05) of 97 and 75 proteins, respectively. Most of these salt‐responsive proteins (70%) were classified into three major functional categories: disease/defense response, protein destination and storage and primary metabolism. The involvement of these proteins in salt tolerance of soybean was discussed, and some of them were suggested to be potential salt‐tolerant proteins. Furthermore, our results suggest that the cross‐protection against aldehydes, oxidative as well as osmotic stress, is the major adaptive response to salinity in soybean.
Mechanistic study of the anti‐cancer effect of Gynostemma pentaphyllum saponins in the ApcMin/+ mouse model
Authors: Tai William Chi‐Shing , Wong Wing‐Yan , Lee Magnolia Muk‐Lan , Chan Brandon Dow , Lu Cheng , Hsiao Wen‐Luan Wendy
Published: March 2016

Gynostemma pentaphyllum saponins (GpS) have been shown to have anti‐cancer activity. However, the underlying mechanisms remain unclear. In this study, we used the ApcMin/+ colorectal cancer (CRC) mouse model to investigate the anti‐cancer effect of GpS and we demonstrated that GpS treatment could significantly reduce the number and size of intestinal polyps in ApcMin/+ mice. In order to identify the potential targets and mechanisms involved, a comparative proteomics analysis was performed and 40 differentially expressed proteins after GpS treatment were identified. Bioinformatics analyses suggested a majority of these proteins were involved in processes related to cellular redox homeostasis, and predicted Raf‐1 as a potential target of GpS. The upregulation of two proteins known to be involved in redox homeostasis, peroxiredoxin‐1 (Prdx1) and peroxiredoxin‐2 (Prdx2), and the downregulation of Raf‐1 were validated using Western blot analysis. After further investigation of the associated signaling networks, we postulated that the anti‐cancer effect of GpS was mediated through the upregulation of Prdx1 and Prdx2, suppression of Ras, RAF/MEK/ERK/STAT, PI3K/AKT/mTOR signaling and modulation of JNK/p38 MAPK signaling. We also examined the potential combinatorial effect of GpS with the chemotherapeutic 5‐fluorouracil (5‐FU) and found that GpS could enhance the anti‐cancer efficacy of 5‐FU, further suppressing the number of polyps in ApcMin/+ mice. Our findings highlight the potential of GpS as an anti‐cancer agent, the potential mechanisms of its anti‐cancer activities, and its effect as an adjuvant of 5‐FU in the chemotherapy of CRC.
Distinct metabolic changes between wheat embryo and endosperm during grain development revealed by 2D‐DIGE‐based integrative proteome analysis
Authors: Cao Hui , He Miao , Zhu Chong , Yuan Linlin , Dong Liwei , Bian Yanwei , Zhang Wenying , Yan Yueming
Published: March 2016

Two Chinese bread wheat cultivars, Jinghua 9 and Zhongmai 175, distinct in grain weight and dough quality, were used to study proteome changes in the embryo and endosperm during grain development using a two‐dimensional difference gel electrophoresis (2D‐DIGE)‐based proteomics approach. In total, 138 and 127 differentially expressed protein (DEP) spots representing 116 and 113 unique DEPs were identified in the embryo and endosperm, respectively. Among them, 54 (31%) DEPs were commonly present in both organs while 62 (35%) and 59 (34%) DEPs occurred only in the embryo and endosperm, respectively. Embryonic DEPs are primarily stress‐related proteins and involved in carbohydrate and lipid metabolism, while those from the endosperm are related primarily to carbohydrate metabolism and storage. Principal component analysis (PCA) indicated that the proteome differences in the endosperm caused by different cultivars were greater than those by development stages, while the differences in the embryo showed the opposite pattern. Protein‐protein interaction (PPI) analysis revealed a complex network centered primarily on enzymes involved in carbohydrate and protein metabolism. The transcriptional levels of fourteen important DEPs encoding genes showed high similarity between organs and cultivars. In particular, some key DEPs of the endosperm, such as phosphoglucomutase, ADP‐glucose pyrophosphorylase (AGPase), and sucrose synthase (SUS), showed significantly upregulated expression, indicating their key roles in starch biosynthesis and grain yield. Moreover, upregulated expression of some storage proteins in the endosperm could improve wheat bread‐making quality.
Protein biomarkers on tissue as imaged via MALDI mass spectrometry: A systematic approach to study the limits of detection
Authors: van de Ven Stephanie M. W. Y. , Bemis Kyle D. , Lau Kenneth , Adusumilli Ravali , Kota Uma , Stolowitz Mark , Vitek Olga , Mallick Parag , Gambhir Sanjiv S.
Published: March 2016

MALDI mass spectrometry imaging (MSI) is emerging as a tool for protein and peptide imaging across tissue sections. Despite extensive study, there does not yet exist a baseline study evaluating the potential capabilities for this technique to detect diverse proteins in tissue sections. In this study, we developed a systematic approach for characterizing MALDI‐MSI workflows in terms of limits of detection, coefficients of variation, spatial resolution, and the identification of endogenous tissue proteins. Our goal was to quantify these figures of merit for a number of different proteins and peptides, in order to gain more insight in the feasibility of protein biomarker discovery efforts using this technique. Control proteins and peptides were deposited in serial dilutions on thinly sectioned mouse xenograft tissue. Using our experimental setup, coefficients of variation were <30% on tissue sections and spatial resolution was 200 μm (or greater). Limits of detection for proteins and peptides on tissue were in the micromolar to millimolar range. Protein identification was only possible for proteins present in high abundance in the tissue. These results provide a baseline for the application of MALDI‐MSI towards the discovery of new candidate biomarkers and a new benchmarking strategy that can be used for comparing diverse MALDI‐MSI workflows.
Association of BNP, NTproBNP, and early postnatal pulmonary hypertension in very preterm infants
Authors: König Kai , Guy Katelyn J. , Walsh Geraldine , Drew Sandra M. , Barfield Charles P.
Published: March 2016

Objective

B‐type natriuretic peptide (BNP) has been shown to correlate with pulmonary hypertension (PH) in term neonates with persistent pulmonary hypertension of the newborn or congenital diaphragmatic hernia, and in very preterm infants with bronchopulmonary dysplasia. This study investigated the potential association of BNP and N‐terminal‐pro‐BNP (NTproBNP) and PH within the first 72 hr of life in very preterm infants.

Methods

Preterm infants <32 weeks gestational age who received an echocardiogram within the first 72 hr of life were eligible. BNP and NTproBNP were sampled at the time of the echocardiogram. Right ventricular systolic pressure (RVSP) was calculated as a surrogate marker of PH. Simple and multiple linear regression analysis was performed to examine associations and potential confounding factors.

Results

Sixty‐one infants were included with a median (IQR) birth weight of 983 g (826–1,167) and a median (IQR) gestational age of 272 weeks (262–286). There was no difference between BNP or NTproBNP levels for infants with or without measurable RVSP. There was no significant correlation of BNP and RVSP in multiple linear regression analysis (regression coefficient −0.0035 (95%CI: −0.020 to 0.013), P = 0.67). Also, NTproBNP and RVSP were not significantly correlated in multiple linear regression analysis (regression coefficient 0.0071 (95%CI: −0.019 to 0.033), P = 0.58).

Conclusion

B‐type natriuretic peptides did not correlate with RVSP in the early postnatal period of very preterm infants. Pediatr Pulmonol. 2016;51:820–824. © 2016 Wiley Periodicals, Inc.
Thermal conductivity of bulk boron nitride nanotube sheets and their epoxy‐impregnated composites
Authors: Jakubinek Michael B. , Niven John F. , Johnson Michel B. , Ashrafi Behnam , Kim Keun Su , Simard Benoit , White Mary Anne
Published: March 2016

The thermal conductivity of bulk, self‐supporting boron nitride nanotube (BNNT) sheets composed of nominally 100% BNNTs oriented randomly in‐plane was measured by a steady‐state, parallel thermal conductance method. The sheets were either collected directly during synthesis or produced by dispersion and filtration. Differences between the effective thermal conductivities of filtration‐produced BNNT buckypaper (∼1.5 W m−1 K−1) and lower‐density as‐synthesized sheets (∼0.75 W m−1 K−1), which are both porous materials, were primarily due to their density. The measured results indicate similar thermal conductivity, in the range of 7–12 W m−1 K−1, for the BNNT network in these sheets. High BNNT‐content composites (∼30 wt.% BNNTs) produced by epoxy impregnation of the porous BNNT network gave 2–3 W m−1 K−1, more than 10× the baseline epoxy. The combination of manufacturability, thermal conductivity, and electrical insulation offers exciting potential for electrically insulating, thermally conductive coatings and packaging.

Thermal conductivity of free‐standing BNNT buckypaper, buckypaper composites, and related materials at room temperature.
Magnetically controlled space charge capacitance at La1−xSrxMnO3/SrxLa1−xTiO3 interfaces
Authors: Schmidt Rainer , García‐Barriocanal Javier , Varela María , García‐Hernández Mar , León Carlos , Santamaría Jacobo
Published: March 2016

This work reports on magnetocapacitance (MC) effects in epitaxial heterostructures of nominally 15 unit cells (u.c.) LaMnO3 (LMO) and 2 u.c. SrTiO3 (STO) with an alternating layer‐repetition rate of 8: (LMO15/STO2)8. Epitaxial multilayer growth at high temperatures (900 °C) activates a selective inter‐diffusion of La3+ and Sr2+ cations across the interfaces, which gives rise to Sr p‐doping of the LMO and La n‐doping of the STO layers. MC effects at the buried La1–xSrxMnO3/SrxLa1–xTiO3 (LSMO/SLTO) interfaces are probed by frequency, temperature and magnetic field dependent AC impedance spectroscopy. The technique is shown to be appropriate to account for the separate analysis of different resistance and capacitance contributions at the buried interfaces. As a result of the La/Sr inter‐diffusion process, Schottky barriers are formed at the LSMO/SLTO interfaces, which give rise to massive MC of up to ≈ −200% in the out‐of‐plane film direction. The capacitance of the manganite‐titanate LSMO/SLTO interfaces may be coupled indirectly to the resistance of the LSMO layers, because the Schottky space‐charge layers and their capacitance can be modulated by varying the concentration of highly mobile charge carriers in the LSMO with a magnetic field.
Cubic‐structured tin selenide thin film as a novel solar cell absorber
Authors: Nair P. K. , Barrios‐Salgado E. , Nair M. T. S.
Published: March 2016

Tin selenide thin film with a simple cubic crystalline structure (SnSe‐CUB) of unit cell dimension a = 11.9632 Å is obtained via chemical deposition on a tin sulfide (SnS‐CUB) thin film base layer of simple cubic structure of a = 11.5873 Å. The SnSe‐CUB films obtained this way are thermally stable while heating to 300 °C. Its optical band gap is 1.4 eV. A thin film of 200 nm in thickness of this material in a solar cell may lead to a light generated current density of 23 mA cm−2 and a maximum of 29 mA cm−2. Thin film of SnSe‐CUB possesses p‐type electrical conductivity of 5 × 10−5 Ω−1 cm−1, which is three orders of magnitude lower than that of SnSe films of orthorhombic crystalline structure. Overall, these characteristics make SnSe‐CUB thin film a novel solar cell absorber material.
The effectiveness of electron blocking layer in InGaN‐based laser diodes with different indium content
Authors: Li X. , Zhao D. G. , Jiang D. S. , Chen P. , Liu Z. S. , Zhu J. J. , Yang J. , Liu W. , He X. G. , Li X. J. , Liang F. , Zhang L. Q. , Liu J. P. , Yang H.
Published: March 2016

The effects of Al composition in p‐type AlGaN electron blocking layer (EBL) on electron leakage and device performance in InGaN‐based quantum well (QW) laser diodes (LDs) are numerically investigated in connection with the depth of QWs. It is found that the effectiveness of EBL in blocking electron leakage depends much on Al content in EBL and In content in InGaN QWs. It is effective for low‐In‐content InGaN QW LDs to add moderate Al in AlGaN EBL, while it is hardly helpful and even harmful for high‐In‐content InGaN QW LDs to increase Al content. In addition, it is found that too much Al in EBL is unfavorable for all LDs due to the downward conduction band‐bending in the last quantum barrier (LQB) layer.
A win ratio approach to comparing continuous non‐normal outcomes in clinical trials
Authors: Wang Duolao , Pocock Stuart
Published: March 2016

Clinical trials are often designed to compare continuous non‐normal outcomes. The conventional statistical method for such a comparison is a non‐parametric Mann–Whitney test, which provides a P‐value for testing the hypothesis that the distributions of both treatment groups are identical, but does not provide a simple and straightforward estimate of treatment effect. For that, Hodges and Lehmann proposed estimating the shift parameter between two populations and its confidence interval (CI). However, such a shift parameter does not have a straightforward interpretation, and its CI contains zero in some cases when Mann–Whitney test produces a significant result. To overcome the aforementioned problems, we introduce the use of the win ratio for analysing such data. Patients in the new and control treatment are formed into all possible pairs. For each pair, the new treatment patient is labelled a ‘winner’ or a ‘loser’ if it is known who had the more favourable outcome. The win ratio is the total number of winners divided by the total numbers of losers. A 95% CI for the win ratio can be obtained using the bootstrap method. Statistical properties of the win ratio statistic are investigated using two real trial data sets and six simulation studies. Results show that the win ratio method has about the same power as the Mann–Whitney method. We recommend the use of the win ratio method for estimating the treatment effect (and CI) and the Mann–Whitney method for calculating the P‐value for comparing continuous non‐Normal outcomes when the amount of tied pairs is small. Copyright © 2016 John Wiley & Sons, Ltd.
Systematic reviews of research in education: aims, myths and multiple methods
Authors: Gough David , Thomas James
Published: March 2016

Systematic reviews are still a controversial topic in some quarters, with the arguments for and against their use being well‐rehearsed. In an attempt to advance a more nuanced approach to thinking about systematic reviewing, this paper illustrates the wide range of theoretical perspectives, methodologies and purposes that underpin the vast range of systematic review approaches now available; and in the light of this picture, re‐examines some of the perennial arguments against reviews, arguing that they are often poorly targeted, based on a misreading of what systematic reviews aim to do, or simply incommensurable with the tenets that underpin academic enquiry.
Searchable symmetric encryption capable of searching for an arbitrary string
Authors: Uchide Yoshinao , Kunihiro Noboru
Published: March 2016

A booming cloud service has made it possible to consider a third‐party server as private storage. When storage is used as a document archive, it is useful to provide functionality that allows users to find documents containing a specified string as a substring. The current method for providing such functionality while keeping the contents of the documents secret, either has linear complexity in the total size of the documents or needs to extract keywords when the documents are stored. Therefore, no method exists for efficiently searching for an arbitrary string that has not been extracted as a keyword. We propose the first encryption scheme that enables efficient searching for an arbitrary string. Although our scheme leaks some information for the sake of efficiency, all information leaked is derived from the precise leakage profile we have defined. © 2016 The Authors Security and Communication Networks Published by John Wiley & Sons Ltd
A secure chaotic maps‐based privacy‐protection scheme for multi‐server environments
Authors: Li Chun‐Ta
Published: March 2016

A multi‐server environment helps the users to register at the registration center once and can gain numerous network services and resources provided by remote application servers. In order to protect sensitive data from unauthorized disclosure, to authenticate the identities of network participants, and to preserve user anonymity, many chaotic maps‐based multi‐server authenticated key agreement schemes with user anonymity were proposed. Recently, Zhu proposed a provable privacy‐protection system towards multi‐server architecture, and the main contributions of their proposed system are achieving mutual authentication between network participants and ensuring the anonymity or hiding identities for the login users. However, we analyze the security of Zhu's scheme and show that it is vulnerable to privileged‐insider attack and does not protect user anonymity. We also demonstrate that Zhu's scheme fails to provide mutual authentication between login user and application server and has a design flaw in anonymous authentication. To withstand these security drawbacks, we further design an improved chaotic maps‐based privacy‐protection scheme for multi‐server environments. In comparison with the existing chaotic maps‐based privacy‐protection schemes, our proposed scheme is more secure with acceptable computation costs for multi‐server environments. Copyright © 2016 John Wiley & Sons, Ltd.
Density functional study of H2 molecule and H atom adsorption on α‐U(001) surface
Authors: Huang Shanqisong , Zeng Xiu‐Lin , Zhao Feng‐Qi , Ju Xue‐Hai
Published: March 2016

Density functional theory method has been employed to investigate the adsorption of H2 molecule and H atom on α‐U(001) surface. There exist four initial sites [top (A), triangle‐center (B), long‐bridge (C), and short‐bridge (D)] for H2 and H atom adsorptions on α‐U(001) surface. The Eads (adsorption energy) values on the top sites of H2‐U(001) configurations are around −0.666 eV, and H2 molecule has been elongated but not broken into H atoms. For the other three sites, the Eads values are around −1.521 eV. The long‐bridge site is the most reactive site for H2 decomposing. For the H‐U(001) configurations, the Eads are around −2.904 eV. Top site and short‐bridge site are the most reactive sites for the H atom react on the α‐U(001) surface. Our work reveals that the different reactive sites play discrepant effects on hydrogenation process. Geometric deformations, diffusion paths, and partial density of states of H2‐U(001) and H‐U(001) configurations have also been analyzed. Copyright © 2016 John Wiley & Sons, Ltd.
Corrosion resistance of direct metal laser sintering AlSiMg alloy
Authors: Cabrini M. , Lorenzi S. , Pastore T. , Pellegrini S. , Pavese M. , Fino P. , Ambrosio E. P. , Calignano F. , Manfredi D.
Published: March 2016

The paper investigates the corrosion behavior of AlSi10Mg alloy produced by direct metal laser sintering (DMLS). Potentiodynamic tests were performed in aerated diluted Harrison solution, on specimens with different orientation with respect to the building plane. Different surface finishing were analyzed, covering rough surfaces as produced by DMLS and after polishing by means of emery papers and alumina slurry or chemical polishing with phosphoric and nitric acid bright dipping (BD). A conversion treatment by short immersion in Ce(III) salt solution was evaluated in order to improve corrosion resistance of both as‐produced surface and polished surface.

Selective attack of α‐Al phase occurs at the border of the melting pools, typical of DMLS process, and slightly reduces on transversal planes, perpendicular to the building plane. Acid pickling slightly improves the corrosion resistance of as‐produced surface, but no positive effects were noticed on polished one.

The Ce(III) conversion treatment does not inhibit corrosion on as‐produced specimens. Its effectiveness is higher on polished and pickled specimens. On polished surface, the effectiveness of conversion treatment mainly depends on plane orientation. Copyright © 2016 John Wiley & Sons, Ltd.
Adhesion of PDMS substrates assisted by Plasma Graft Polymerization
Authors: Jung Kwang‐Ho , Kim Dae Gon , Jung Seung‐Boo
Published: March 2016

Transparent polymers have great potential when applied toward flexible devices as encapsulation or substrate materials in the fields of electronics, optics, biology, and so on because of their low costs and lightweight. The use of polymeric materials in bonding technology is indispensable due to the practicality of these materials. In general, polymer bonding can be achieved through the use of interlayer‐like adhesives or through direct bonds such as ultrasonic or thermocompression bonding. Polydimethylsiloxane (PDMS) joints were achieved by surface modification via oxygen‐argon plasma. Plasma treatment at various plasma power levels (150, 200, 250, and 300 W) was conducted on the PDMS surface with the modified surfaces being analyzed via contact angle measurement and X‐ray photoelectron spectroscopy. Plasma‐activated PDMS films were bonded without adhesives at 160 °C, which did not lead to deformation. The bond strength of the plasma‐activated PDMS was measured using a T‐peel test prior to and after bending cycles, and the optical transmittance of the specimens was also measured. The fractured surface was investigated via optical microscopy and scanning electron microscopy following adhesion testing. The experimental results revealed that the bond strength of PDMS was proportional to the employed plasma power level. The bond strength of PDMS decreased by approximately 10.8% after 100 000 bending cycles, indicating that plasma polymerization‐assisted direct bonding could function as a versatile bonding method for polymeric materials. Copyright © 2016 John Wiley & Sons, Ltd.
Micropore formation mechanism in iridium coating after high‐temperature treatment
Authors: Wu Wang‐ping , Chen Zhao‐feng
Published: March 2016

Noble metal iridium is of great interest for high‐temperature applications and extreme environments. A high (110)‐oriented iridium coating was prepared by a double glow plasma process on the surface of niobium substrate. The morphology and composition of the coating were determined by scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy, respectively. The phase of the coating was identified by X‐ray diffraction analysis. The misorientation angle distributions of grains on the surface and cross section of the coating were characterized by electron backscatter diffraction system. The uniform and pure iridium coating consisted of the submicrometer‐sized columnar grains with high‐angle boundary. The mean misorientation angles on the surface and cross section of the coating were 38.6° and 45.6°, respectively. After high‐temperature treatment, the coating was composed of equiaxed grains with distinct grain boundaries. Micropores appeared on the fracture surface of the coating. The micropore formation mechanism in Ir coating after high‐temperature treatment was investigated. Copyright © 2016 John Wiley & Sons, Ltd.
Empirical extensions of the lasso penalty to reduce the false discovery rate in high‐dimensional Cox regression models
Authors: Ternès Nils , Rotolo Federico , Michiels Stefan
Published: March 2016

Correct selection of prognostic biomarkers among multiple candidates is becoming increasingly challenging as the dimensionality of biological data becomes higher. Therefore, minimizing the false discovery rate (FDR) is of primary importance, while a low false negative rate (FNR) is a complementary measure. The lasso is a popular selection method in Cox regression, but its results depend heavily on the penalty parameter λ. Usually, λ is chosen using maximum cross‐validated log‐likelihood (max‐cvl). However, this method has often a very high FDR. We review methods for a more conservative choice of λ. We propose an empirical extension of thecvlby adding a penalization term, which trades off between the goodness‐of‐fit and the parsimony of the model, leading to the selection of fewer biomarkers and, as we show, to the reduction of the FDR without large increase in FNR. We conducted a simulation study considering null and moderately sparse alternative scenarios and compared our approach with the standard lasso and 10 other competitors: Akaike information criterion (AIC), corrected AIC, Bayesian information criterion (BIC), extended BIC, Hannan and Quinn information criterion (HQIC), risk information criterion (RIC), one‐standard‐error rule, adaptive lasso, stability selection, and percentile lasso. Our extension achieved the best compromise across all the scenarios between a reduction of the FDR and a limited raise of the FNR, followed by the AIC, the RIC, and the adaptive lasso, which performed well in some settings. We illustrate the methods using gene expression data of 523 breast cancer patients. In conclusion, we propose to apply our extension to the lasso whenever a stringent FDR with a limited FNR is targeted. Copyright © 2016 John Wiley & Sons, Ltd.
Limitations of empirical calibration of p‐values using observational data
Authors: Gruber Susan , Tchetgen Tchetgen Eric
Published: March 2016

Controversy over non‐reproducible published research reporting a statistically significant result has produced substantial discussion in the literature. p‐value calibration is a recently proposed procedure for adjusting p‐values to account for both random and systematic errors that address one aspect of this problem. The method's validity rests on the key assumption that bias in an effect estimate is drawn from a normal distribution whose mean and variance can be correctly estimated. We investigated the method's control of type I and type II error rates using simulated and real‐world data. Under mild violations of underlying assumptions, control of the type I error rate can be conservative, while under more extreme departures, it can be anti‐conservative. The extent to which the assumption is violated in real‐world data analyses is unknown. Barriers to testing the plausibility of the assumption using historical data are discussed. Our studies of the type II error rate using simulated and real‐world electronic health care data demonstrated that calibrating p‐values can substantially increase the type II error rate. The use of calibrated p‐values may reduce the number of false‐positive results, but there will be a commensurate drop in the ability to detect a true safety or efficacy signal. While p‐value calibration can sometimes offer advantages in controlling the type I error rate, its adoption for routine use in studies of real‐world health care datasets is premature. Separate characterizations of random and systematic errors provide a richer context for evaluating uncertainty surrounding effect estimates. Copyright © 2016 John Wiley & Sons, Ltd.
Structure and emulsification properties of octenyl succinic anhydride starch using acid‐hydrolyzed method
Authors: Hong Yan , Li Zhengsong , Gu Zhengbiao , Wang Yan , Pang Yansheng
Published: March 2016

The structure and emulsification properties of octenyl succinic anhydride (OSA) starch hydrolyzed with hydrochloric acid (HCl) were studied by varying the HCl concentration through the range of 0.5–2.0 mol/L. The degree of substitution (DS), viscosity, thermal properties, and molecular weight (Mw) were obtained. A comparison between hydrolyzed OSA starches and the native OSA starches exhibited a reduction in both viscosity and retrogradation. The same trend was observed in DS values, enthalpy values, and Mw values. The results of confocal laser scanning microscopy (CLSM) and droplet size distribution (DSD) analysis showed that the emulsification properties of acid‐hydrolyzed OSA starch were much stronger than those of unhydrolyzed OSA starch.
Prospective first‐trimester screening for trisomies by cell‐free DNA testing of maternal blood in twin pregnancy
Authors: Sarno L. , Revello R. , Hanson E. , Akolekar R. , Nicolaides K. H.
Published: March 2016

Objectives

First, to examine in twin pregnancies the performance of first‐trimester screening for fetal trisomies 21, 18 and 13 by cell‐free (cf) DNA testing of maternal blood and, second, to compare twin and singleton pregnancies regarding the distribution of fetal fraction of cfDNA and rate of failure to obtain a result.

Methods

This was a prospective study in 438 twin and 10 698 singleton pregnancies undergoing screening for fetal trisomies by cfDNA testing at 10 + 0 to 13 + 6 weeks' gestation. Chromosome‐selective sequencing of cfDNA was used and, in twin pregnancies, an algorithm was applied that relies on the lower fetal fraction contributed by the two fetuses. Multivariate regression analysis was used to determine significant predictors of fetal fraction and a failed result.

Results

In twin pregnancies, the median fetal fraction was lower (8.0% (interquartile range (IQR), 6.0–10.4%) vs 11.0% (IQR, 8.3–14.4%); P < 0.0001) and failure rate after first sampling was higher (9.4% vs 2.9%; P < 0.0001) compared to in singletons. Multivariate logistic regression analysis demonstrated that the risk of test failure increased with increasing maternal age and body mass index and decreased with fetal crown–rump length. The risk was increased in women of South Asian racial origin and in pregnancies conceived by in‐vitro fertilization (IVF). The main contributor to the higher rate of failure in twins was conception by IVF which was observed in 9.5% of singletons and 56.2% of twins. In the 417 twin pregnancies with a cfDNA result after first or second sampling, the detection rate was 100% (8/8) for trisomy 21 and 60% (3/5) for trisomies 18 or 13, at a false‐positive rate (FPR) of 0.25% (1/404). In the 10 530 singleton pregnancies with a cfDNA result after first or second sampling, the detection rate was 98.7% (156/158) for trisomy 21 and 80.3% (49/61) for trisomies 18 or 13, at a FPR of 0.22% (23/10 311).

Conclusions

In twin pregnancies undergoing first‐trimester screening for trisomies by cfDNA testing, the fetal fraction is lower and failure rate higher compared to in singletons. The number of trisomic twin pregnancies examined was too small for an accurate assessment of performance of screening, but it may be similar to that in singleton pregnancies. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
Awareness of rabies and response to dog bites in a Bangladesh community
Authors: Ghosh Sumon , Chowdhury Sukanta , Haider Najmul , Bhowmik Rajub K. , Rana Md. S. , Prue Marma Aung S. , Hossain Muhammad B. , Debnath Nitish C. , Ahmed Be‐Nazir
Published: March 2016

Community awareness regarding rabies and treatment seeking behaviours are critical both for the prevention and control of the disease in human and animals. We conducted a study to explore people's awareness about rabies, their attitudes towards dogs and practices associated with treating dog bites in Satkhira Sadar, a south‐western sub‐district of Bangladesh. Of the total 3200 households (HHs) surveyed, the majority of the respondents have heard about rabies (73%) and there was a high level of awareness that dog bite is the main cause of rabies (86%), and that rabies can be prevented by vaccination (85%). However, 59% of the dog bite victims first seek treatment from traditional healers instead of visiting the hospitals, 29% received the rabies vaccine, 2% practiced proper wound washing with soap and water, while 4.8% have not taken any measures. None of the victims have received rabies immunoglobulin (RIG). Of the respondents, 5.2% reported a history of dog bite in at least one family member, and 11.8% reported a history of dog bite in domestic animals during the previous year. The HHs having a higher number of family members (OR: 1.13, 95% CI: 1.07–1.2), having a pet dog (OR: 2.1, 95% CI: 1.4–3.2) and caring or feeding a community dog (OR: 2.1, 95% CI: 1.4–2.9) showed an increased risk of getting a dog bite. Among the bite victims, 3.6% (n = 6) humans and 15.8% (n = 60) animals died. As a measure for dog population management (DPM), 56% preferred sterilization while the rest preferred killing of dogs. The current treatment seeking behaviours of the respondents should be improved through additional education and awareness programme and better availability for the provision of post‐exposure prophylaxis in Bangladesh. We recommend scaling up national mass dog vaccination and DPM to reduce the burden of rabies cases and dog bites in Bangladesh.
Climate, history, society over the last millennium in southeast Africa
Authors: Hannaford Matthew J. , Nash David J.
Published: March 2016

Climate variability has been causally linked to the transformation of society in pre‐industrial southeast Africa. A growing critique, however, challenges the simplicity of ideas that identify climate as an agent of past societal change; arguing instead that the value of historical climate–society research lies in understanding human vulnerability and resilience, as well as how past societies framed, responded and adapted to climatic phenomena. We work across this divide to present the first critical analysis of climate–society relationships in southeast Africa over the last millennium. To achieve this, we review the now considerable body of scholarship on the role of climate in regional societal transformation, and bring forward new perspectives on climate–society interactions across three areas and periods using the theoretical frameworks of vulnerability and resilience. We find that recent advances in paleoclimatology and archaeology give weight to the suggestion that responses to climate variability played an important part in early state formation in the Limpopo valley (1000–1300), though evidence remains insufficient to clarify similar debates concerning Great Zimbabwe (1300–1450/1520). Written and oral evidence from the Zambezi‐Save (1500–1830) andKwaZulu‐Natal areas (1760–1828) nevertheless reveals a plurality of past responses to climate variability. These were underpinned by the organization of food systems, the role of climate‐related ritual and political power, social networks, and livelihood assets and capabilities, as well as the nature of climate variability itself. To conclude, we identify new lines of research on climate, history and society, and discuss how these can more directly inform contemporary African climate adaptation challenges.WIREs Clim Change2016, 7:370–392. doi: 10.1002/wcc.389

This article is categorized under:

Climate, History, Society, Culture > World Historical Perspectives