bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation of Choline/Creatine and Apparent Diffusion Coefficient values with the prognostic parameters of Head and Neck Squamous Cell Carcinoma
Authors: Razek Ahmed Abdel Khalek Abdel , Nada Nadia
Published: February 2016

The aim of this study was to measure choline/creatine (Ch/Cr) levels through 1H‐MRS and apparent diffusion coefficient (ADC) values through diffusion‐weighted MRI, and to correlate these values with the prognostic parameters of head and neck squamous cell carcinoma (HNSCC). The institutional review board approved this study and informed written consent was obtained from all study participants. A prospective study of 43 patients (31 men and 12 women; mean age, 65 years) with HNSCC was conducted. Single‐voxel 1H‐MRS was performed at the tumor or metastatic cervical lymph node with point‐resolved spectroscopy (PRESS) at TE = 135 ms. Diffusion‐weighted MR images with b values of 0, 500 and 1000 s/mm2 and contrast MRI of the head and neck were performed. The Ch/Cr levels and ADC values of HNSCC were calculated. The gross tumor volume (GTV) was also calculated. The degree of tumor differentiation was determined through pathological examination. The HNSCC Ch/Cr level was negatively correlated with the ADC value (r = −0.662, p = 0.001). There was a significant difference in the Ch/Cr and ADC values at different degrees of tumor differentiation (p = 0.003 and p = 0.001) and with different GTVs (p = 0.122 and p = 0.001). The following prognostic parameter categories were used: (i) poorly differentiated and undifferentiated versus well differentiated to moderately differentiated; and (ii) HNSCC with GTV < 30 cm3 versus GTV > 30 cm3. The cut‐off values for Cho/Cr and ADC for each category were 1.83, 0.95 and 1.94, 0.99, respectively, and the areas under the curve were 0.771, 0.967 and 0.726, 0.795, respectively, for each category. We conclude that the Ch/Cr levels determined using 1H‐MRS and the ADC values are well correlated with several prognostic parameters of HNSCC. Copyright © 2016 John Wiley & Sons, Ltd.
Birth Prevalence of Sickle Cell Trait and Sickle Cell Disease in Shelby County, TN
Authors: Smeltzer Matthew P. , Nolan Vikki G. , Yu Xinhua , Nottage Kerri A. , Davis Bertha A. , Yang Yong , Wang Winfred C. , Gurney James G. , Hankins Jane S.
Published: February 2016

Background

Accurate quantification of the regional burden of sickle cell disease (SCD) is vital to allocating health‐related resources. Shelby County, TN, which includes the city of Memphis and the regional pediatric SCD treatment center at St. Jude Children's Research Hospital, is home to a large population of African Americans.

Procedure

We postulated that the regional birth prevalence of SCD in Shelby County, TN, would differ from national rates. Using data from 2002 to 2012, we estimated the birth prevalence of SCD and sickle cell trait (SCT) in Shelby County and evaluated the distribution of SCD cases by ZIP code of residence with geographic information systems (GIS).

Results

The prevalence of SCD in African Americans was 1/287 (95% confidence interval [CI]: 1/323, 1/256) live births, significantly higher than the nationally reported 1/350 –1/500. The prevalence of SCT in African Americans was 1/14.7 (95% CI: 1/15.0, 1/14.3) live births, significantly lower than the nationally reported 1/12. We found that 48% of the SCD cases resided in only six of the 37 residential ZIP codes, and using GIS mapping there were two clusters composed of two and four adjacent urban ZIP codes. SCT cases were also centered predominantly in the same two clusters, but slightly more dispersed.

Conclusions

Recent Shelby County birth prevalence estimates differ substantially from national estimates with higher SCD and lower SCT than expected. Preliminary evidence suggests substantial clustering in two small geographic urban areas within Shelby County that may provide target areas for educational and outreach services.
Guidewire Catheter Exchange in Pediatric Oncology: Indications, Postoperative Complications, and Outcomes
Authors: Fernandez‐Pineda I. , Ortega‐Laureano L. , Wu H. , Wu J. , Sandoval J. A. , Rao B. N. , Shochat S. J. , Davidoff A. M.
Published: February 2016

Background

Maintaining long‐term central venous catheters (CVCs) in children undergoing chemotherapy can be challenging. Guidewire catheter exchange (GCE) replaces a CVC without repeat venipuncture. This study evaluated the indications, success rate, and complications of GCE in a large cohort of pediatric cancer patients.

Procedure

Medical records of pediatric cancer patients who underwent GCE at our institution between 2003 and 2013 were retrospectively reviewed. Variables analyzed included gender, age at GCE, primary cancer diagnosis, indication for GCE, absolute neutrophil count (ANC) at GCE, vein used, success rate, and postoperative complications (<30 days after exchange).

Results

A total of 435 GCEs performed in 407 patients (230 males and 177 females) were reviewed. Median age at GCE was 8 years (range, 0.2–24). Acute lymphoblastic leukemia was the most common diagnosis (50.6%). The primary indication for GCE was the desire to have an alternative type of CVC (71%). Other indications included catheter displacement (17%), catheter malfunction (11%), and catheter infection (1%). Median ANC at GCE was 2,581/mm3 (range, 0–43,400). Left subclavian vein was more commonly used (57.7%). The success rate of GCE was 93.4% (406 of 435 procedures, 95% confidence interval: 91.0–97.5%). A total of 33 (7.5%) postoperative complications occurred including central line associated bloodstream infection (CLABSI) (n = 20, 4.5%), catheter dislodgement (n = 6, 1.4%), and catheter malfunction (n = 7, 1.6%).

Conclusions

We conclude that GCE in pediatric cancer patients is associated with a high success rate and a low risk of complications. The most common postoperative complication, CLABSI, occurred at a rate significantly lower than following de novo CVC placement.
Quantitative proteomics suggests metabolic reprogramming during ETHE1 deficiency
Authors: Sahebekhtiari Navid , Thomsen Michelle M. , Sloth Jens J. , Stenbroen Vibeke , Zeviani Massimo , Gregersen Niels , Viscomi Carlo , Palmfeldt Johan
Published: February 2016

Deficiency of mitochondrial sulfur dioxygenase (ETHE1) causes the severe metabolic disorder ethylmalonic encephalopathy, which is characterized by early‐onset encephalopathy and defective cytochrome C oxidase because of hydrogen sulfide accumulation. Although the severe systemic consequences of the disorder are becoming clear, the molecular effects are not well defined. Therefore, for further elucidating the effects of ETHE1‐deficiency, we performed a large scale quantitative proteomics study on liver tissue from ETHE1‐deficient mice. Our results demonstrated a clear link between ETHE1‐deficiency and redox active proteins, as reflected by downregulation of several proteins related to oxidation‐reduction, such as different dehydrogenases and cytochrome P450 (CYP450) members. Furthermore, the protein data indicated impact of the ETHE1‐deficiency on metabolic reprogramming through upregulation of glycolytic enzymes and by altering several heterogeneous ribonucleoproteins, indicating novel link between ETHE1 and gene expression regulation. We also found increase in total protein acetylation level, pointing out the link between ETHE1 and acetylation, which is likely controlled by both redox state and cellular metabolites. These findings are relevant for understanding the complexity of the disease and may shed light on important functions influenced by ETHE1 deficiency and by the concomitant increase in the gaseous mediator hydrogen sulfide. All MS data have been deposited in the ProteomeXchange with the dataset identifiers PXD002741 (http://proteomecentral.proteomexchange.org/dataset/PXD002741) and PXD002742 (http://proteomecentral.proteomexchange.org/dataset/PXD002741).
Poly(N‐vinyl pyrrolidone)‐block‐Poly(N‐vinyl carbazole)‐block‐poly(N‐vinyl pyrrolidone) triblock copolymers: Synthesis via RAFT/MADIX process, self‐assembly behavior, and photophysical properties
Authors: Xiang Yixin , Cong Houluo , Li Lei , Zheng Sixun
Published: February 2016

Poly(N‐vinyl pyrrolidone)‐block‐poly(N‐vinyl carbazole)‐block‐poly(N‐vinyl pyrrolidone) (PVP‐b‐PVK‐b‐PVP) triblock copolymers were synthesized via sequential reversible addition‐fragmentation chain transfer/macromolecular design via the interchange of xanthate (RAFT/MADIX) process. First, 1,4‐phenylenebis(methylene)bis(ethyl xanthate) was used as a chain transfer agent to mediate the radical polymerization of N‐vinyl carbazole (NVK). It was found that the polymerization was in a controlled and living manner. Second, one of α,ω‐dixanthate‐terminated PVKs was used as the macromolecular chain transfer agent to mediate the radical polymerization of N‐vinyl pyrrolidone (NVP) to obtain the triblock copolymers with various lengths of PVP blocks. Transmission electron microscopy (TEM) showed that the triblock copolymers in bulks were microphase‐separated and that PVK blocks were self‐organized into cylindrical microdomains, depending on the lengths of PVP blocks. In aqueous solutions, all these triblock copolymers can self‐assemble into the spherical micelles. The critical micelle concentrations of the triblock copolymers were determined without external adding fluorescence probe. By analyzing the change in fluorescence intensity as functions of the concentration, it was judged that the onset of micellization occurred at the concentration while the FL intensity began negatively to deviate from the initial linear increase with the concentration. Fluorescence spectroscopy indicates that the self‐assembled nanoobjects of the PVP‐b‐PVK‐b‐PVP triblock copolymers in water were capable of emitting blue/or purple fluorescence under the irradiation of ultraviolet light. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1852–1863
Unraveling the mechanism of proton translocation in the extracellular half‐channel of bacteriorhodopsin
Authors: Ge Xiaoxia , Gunner M. R.
Published: February 2016

Bacteriorhodopsin, a light activated protein that creates a proton gradient in halobacteria, has long served as a simple model of proton pumps. Within bacteriorhodopsin, several key sites undergo protonation changes during the photocycle, moving protons from the higher pH cytoplasm to the lower pH extracellular side. The mechanism underlying the long‐range proton translocation between the central (the retinal Schiff base SB216, D85, and D212) and exit clusters (E194 and E204) remains elusive. To obtain a dynamic view of the key factors controlling proton translocation, a systematic study using molecular dynamics simulation was performed for eight bacteriorhodopsin models varying in retinal isomer and protonation states of the SB216, D85, D212, and E204. The side‐chain orientation of R82 is determined primarily by the protonation states of the residues in the EC. The side‐chain reorientation of R82 modulates the hydrogen‐bond network and consequently possible pathways of proton transfer. Quantum mechanical intrinsic reaction coordinate calculations of proton‐transfer in the methyl guanidinium‐hydronium‐hydroxide model system show that proton transfer via a guanidinium group requires an initial geometry permitting proton donation and acceptance by the same amine. In all the bacteriorhodopsin models, R82 can form proton wires with both the CC and the EC connected by the same amine. Alternatively, rare proton wires for proton transfer from the CC to the EC without involving R82 were found in an O′ state where the proton on D85 is transferred to D212. Proteins 2016; 84:639–654. © 2016 Wiley Periodicals, Inc.
Mott lecture: How bonding concepts can help understand amorphous semiconductor behavior
Authors: Robertson John
Published: February 2016

The article discusses how bonding concepts have allowed the development of amorphous semiconductors, in particular the 8−N rule of bonding, the doping mechanism in a‐Si:H, the weak effect of disorder on s states in amorphous oxide semiconductors, the strong effect of disorder on p states in amorphous carbon, and the effect of the change from resonant bonding to simple molecular covalent bonding in chalcogenide phase change materials.
In situ graphene doping as a route toward efficient perovskite tandem solar cells
Authors: Lang Felix , Gluba Marc A. , Albrecht Steve , Shargaieva Oleksandra , Rappich Jörg , Korte Lars , Rech Bernd , Nickel Norbert H.
Published: February 2016

Tandem solar cells consisting of perovskite and silicon absorbers have the potential to outperform respective state‐of‐the‐art single junction efficiencies. However, their development requires the gentle deposition of a transparent electrode onto the hybrid perovskite and its organic layers. Implementation of large area graphene obtained by chemical vapor deposition seems to be an excellent solution. In this paper, we present the impact of graphene on perovskite solar cells and their organic layers. Direct application of graphene on CH3NH3PbI3 is limited by a highly defective interface but insertion of spiro‐OMeTAD enables a defect free implementation. Solar cells containing transparent graphene contacts approach identical electrical performance compared to devices with standard Au contacts. Hall‐effect measurements of graphene on various organic thin‐films, revealed the importance of field‐effect doping. Gained knowledge enabled the development of a strategy to increase the charge carrier density in graphene by 60%, while lowering graphene sheet resistance by 24%. This combined route of spiro‐OMeTAD and stabilized adsorbent doping is an important step toward the targeted application in high performance monolithic perovskite/silicon tandem solar cells.
The effect of bottom LaB6 electrode and La2O3 interlayer on resistance switching in devices based on Li‐doped ZnO films
Authors: Kafadaryan Y. , Igityan A. , Aghamalyan N. , Petrosyan S.
Published: February 2016

Resistance switching (RS) characteristics of Al/ZnO:Li/LaB6 and Al/ZnO:Li/La2O3/LaB6 devices in which LaB6 and lithium‐doped ZnO (ZnO:Li) films are regarded as shallow work function metal and p‐type semiconductor, respectively, are studied. The alternation from bistable unipolar memory switching (URS) to monostable threshold switching (MTS) in the Al/ZnO:Li/LaB6 device is observed. These two switching behaviors can be activated separately depending on the polarity of applied dc voltage: with a positive polarity the URS behavior is measured, while the MTS behavior is observed with a negative polarity. With increase in the number of switching cycles, the MTS and URS behaviors irreversibly transform to bipolar resistance switching (BRS) behavior. The Al/ZnO:Li/La2O3/LaB6 device shows only the BRS behavior, but after certain number of cycles device serves as a rectifying diode. On the basis of the I–V and C–V characteristics, it is concluded that RS properties depend on the barrier height and reactivity between LaB6 metal and ZnO:Li oxide.
On the Multihead Weigher Machine Setup Problem
Authors: Beretta Alessia , Semeraro Quirico , Castillo Enrique del
Published: February 2016

A multihead weigher machine (MWM) is a computer‐controlled machine used to fill a package with small products or parts with a given target weight. MWMs are widespread in the food and non‐food industries because of their high performance in terms of variety of products to be packed, high throughput and quality of the packaged items. Despite the popularity of these machines, no studies to date have addressed how to set up the operating parameters of these machines. In industrial practice, operators currently use ad hoc rules to setup an MWM, but the initial settings can have a dramatic effect on the machine performance. The aim of this paper is to formalize the setup problem and its main variables. Then an optimization technique is proposed to solve the problem. Copyright © 2016 John Wiley & Sons, Ltd.
Differentiating samples and experimental protocols by direct comparison of tandem mass spectra
Authors: Plas‐Duivesteijn Suzanne J. van der , Wulff Tune , Klychnikov Oleg , Ohana Dana , Dalebout Hans , van Veelen Peter A. , de Keijzer Jeroen , Nessen Merel A. , van der Burgt Yuri E. M. , Deelder André M. , Palmblad Magnus
Published: February 2016

Rationale

Peptide tandem mass spectra can be analyzed by a number of means. They can be compared against predicted spectra of peptides derived from genome sequences, compared against previously acquired and identified spectra, or – sometimes – sequenced de novo. We recently introduced another method which compares spectra between liquid chromatography/tandem mass spectrometry (LC/MS/MS) datasets to determine the shared spectral content, and demonstrated how this can be applied in a molecular phylogenetic study using sera from human and non‐human primates. We will here explore if such a method have other, serendipitous uses.

Methods

We used the existing compareMS2 algorithm without modification on a diverse set of experiments.

Results

First we conducted a small phylogenetic study, using (mammalian) bone samples to study old material, and human pathogens aiming to distinguish clinically important strains. Although not as straightforward as primate sera analysis, the method shows significant promise for all these applications. We also used the algorithm to compare 24 different protocols for extraction of proteins from muscle tissue. The results provided useful information in comparing protocols. Finally, we applied compareMS2 aiming for quality control of two traceable protein reference standards (troponin) used in clinical chemistry assays, by analysing the effect of storage conditions.

Conclusions

The results illustrate a broad applicability of the metric based on shared tandem mass spectra between LC/MS/MS datasets for analysing protein digests in different types of experiments. There is no reason to assume that our instance of this method is optimal in any of these situations, as it makes limited or no use of accurate mass and chromatographic retention time. We propose that with further improvement and refinement, this type of analysis can be applied as a simple but informative first step in many pipelines for bottom‐up tandem mass spectrometry data analysis in proteomics and other fields, comparing or analysing large numbers of samples or datasets. Copyright © 2016 John Wiley & Sons, Ltd.
Do some schools narrow the gap? Differential school effectiveness revisited
Authors: Strand Steve
Published: February 2016

Relatively little research has explored whether schools differ in their effectiveness for different group of pupils (e.g. by ethnicity, poverty or gender), for different curriculum subjects (e.g. English, mathematics or science) or over time (different cohorts). This paper uses multilevel modelling to analyse the national test results at age 7 and age 11 of over 6000 pupils attending 57 mainstream primary schools over three successive years in a socially and ethnically diverse inner London borough. The pupil groups with the poorest progress were White British pupils on Free School Meals (FSM) and Black Caribbean pupils, both those entitled and those not entitled to FSM. Differences between schools in average pupil progress were large, but there was no evidence of differential school effectiveness in relation to FSM, ethnicity or gender, all pupil groupings benefitted from attending the more effective schools and to a broadly similar extent. More effective schools ‘raised the bar’ but did not ‘close the gap’ suggesting that differences between schools in ‘quality’ plays little role in equity gaps. While school residuals for different pupil groups were extremely highly correlated, school residuals were only moderately correlated across subjects (English, mathematics and science) and over time, with particularly poor stability for English.
Context and Implications Document for: Feedback effectiveness in professional learning contexts
Authors: Johnson Martin
Published: February 2016

This guide accompanies the following article: Martin Johnson. Feedback effectiveness in professional learning contexts. Review of Education, DOI:10.1002/rev3.3061
Visualizing statistical models: Removing the blindfold
Authors: Wickham Hadley , Cook Dianne , Hofmann Heike
Published: February 2016

Visualization can help in model building, diagnosis, and in developing an understanding about how a model summarizes data. This paper proposes three strategies for visualizing statistical models: (i) display the model in the data space, (ii) look at all members of a collection, and (iii) explore the process of model fitting, not just the end result. Each strategy is accompanied by examples, includingmanova, classification algorithms, hierarchical clustering, ensembles of linear models, projection pursuit, self‐organizing maps, and neural networks.
On the estimability of the PV single‐diode model parameters
Authors: Zaharatos Brian R. , Campanelli Mark , Tenorio Luis
Published: February 2016

The single‐diode model is a widely used representation of the electrical performance of a photovoltaic (PV) device. This model relates the PV device's terminal current and voltage at a given irradiance and temperature. In order to obtain reasonable estimates of single‐diode model parameters given noisy data, one ought to be able to characterize the estimability of the model parameters. Here, we look to an established method called data cloning to check for evidence of inestimability.
The potential of learning from erroneous models: comparing three types of model instruction
Authors: Wijnen Frances M. , Mulder Yvonne G. , Alessi Stephen M. , Bollen Lars
Published: February 2016

Learning from computer models is a promising approach to learning. This study investigated how three types of learning from computer models can be applied to teach high‐school students (aged 14–17) about the process of glucose–insulin regulation. Two traditional forms of learning from models (i.e. simulating a predefined model and constructing a model) were compared to learning from an erroneous model. In this innovative form of learning from computer models, students are provided with a model that contained errors to be corrected. As such, students do not have to engage in the difficult task of constructing a model. Rather, they are challenged to work with and correct the model in order for the simulation to generate correct output. As predicted, learning from erroneous models enhances learning of domain‐specific knowledge better than running a simulation or constructing a model. Copyright © 2016 System Dynamics Society
A privacy‐preserving group authentication protocol for machine‐type communication in LTE/LTE‐A networks
Authors: Fu Anmin , Song Jianye , Li Shuai , Zhang Gongxuan , Zhang Yuqing
Published: February 2016

Machine‐type communication (MTC) is a very important application of the Internet of things. It has a vast market and application scenarios. However, supporting a large number of low‐power devices transmission is an important issue in long‐term evolution/long‐term evolution advanced (LTE/LTE‐A) networks. Specifically, when a large number of machine‐type communication devices (MTCDs) with low‐power consumption requirements simultaneously request access to the LTE/LTE‐A networks, each MTCD needs an independent complete access authentication process with core network, which may cause a serious signaling congestion in the core network. To solve this problem, in this paper, we propose a novel group authentication protocol with privacy‐preserving for MTC in the LTE/LTE‐A networks. The proposed protocol cannot only simultaneously authenticate a group of MTCDs and minimize the signaling overhead but also provide robust privacy‐preserving for each MTCD (including anonymity, unlinkability, and traceability). In particular, our scheme can avoid denial of service attack by filtering some illegal devices in the first four procedures of the mutual authentication. Moreover, our scheme fulfills all the security requirements of the MTC in LTE/LTE‐A networks. In addition, the formal verification by the ProVerif tool shows that the proposed scheme is secure against various malicious attacks, and the performance evaluation indicates that it achieves outstanding results in terms of signaling and computation overhead. Copyright © 2016 John Wiley & Sons, Ltd.
1D/2D Carbon Nanomaterial‐Polymer Dielectric Composites with High Permittivity for Power Energy Storage Applications
Authors: Dang Zhi‐Min , Zheng Ming‐Sheng , Zha Jun‐Wei
Published: February 2016

With the development of flexible electronic devices and large‐scale energy storage technologies, functional polymer‐matrix nanocomposites with high permittivity (high‐k) are attracting more attention due to their ease of processing, flexibility, and low cost. The percolation effect is often used to explain the high‐k characteristic of polymer composites when the conducting functional fillers are dispersed into polymers, which gives the polymer composite excellent flexibility due to the very low loading of fillers. Carbon nanotubes (CNTs) and graphene nanosheets (GNs), as one‐dimensional (1D) and two‐dimensional (2D) carbon nanomaterials respectively, have great potential for realizing flexible high‐k dielectric nanocomposites. They are becoming more attractive for many fields, owing to their unique and excellent advantages. The progress in dielectric fields by using 1D/2D carbon nanomaterials as functional fillers in polymer composites is introduced, and the methods and mechanisms for improving dielectric properties, breakdown strength and energy storage density of their dielectric nanocomposites are examined. Achieving a uniform dispersion state of carbon nanomaterials and preventing the development of conductive networks in their polymer composites are the two main issues that still need to be solved in dielectric fields for power energy storage. Recent findings, current problems, and future perspectives are summarized.
Middle Devonian jawed polychaete fauna from the type Eifel area, western Germany, and its biogeographical and evolutionary affinities
Authors: Tonarová Petra , Hints Olle , Königshof Peter , Suttner Thomas J. , Kido Erika , Da Silva Anne‐Christine , Pas Damien
Published: February 2016

A rich assemblage of Middle Devonian (late Eifelian) polychaete jaws (scolecodonts) from the Blankenheimerdorf section in the type Eifel area, western Germany, is described. The top part of the section also reflects the onset of the global Kačák Event. The sediments of the section were deposited in a shallow to deep subtidal environment on the southern Avalonian margin. The habitat was obviously favourable for jaw‐bearing polychaetes, which are represented by 18 species belonging to 9 genera. The assemblage is dominated by polychaetaspids, followed by mochtyellids, paulinitids and kielanoprionids. Notably, this study documents one of the oldest records of kielanoprionids, a polychaete family common since the Middle Devonian and closely related to the extant Hartmaniellidae. This may indicate that a prominent change in jawed polychaete evolution occurred during the Early–Middle Devonian transition. Moreover, we present new information on polychaete palaeobiogeography, which when compared with previously described Devonian scolecodonts shows that very similar polychaete faunas with many species in common were widespread in today's Europe and North America.
Stem Cells Antigen-1 Enriches for a Cancer Stem Cell-Like Subpopulation in Mouse Gastric Cancer
Authors: Park Jun Won , Park Jung Min , Park Dong Min , Kim Dae-Yong , Kim Hark Kyun
Published: February 2016

There is a strong need to identify markers to enrich gastric cancer stem cells (CSCs). However, CSC enrichment markers for mouse gastric cancers have not yet been determined. In our previous study, we generated primary mouse gastric cancer cell line NCC-S1 (S1) established from a Villin-cre;Smad4F/F;Trp53F/F;Cdh1F/wt mouse and its metastatic variant cell line NCC-S1M (S1M). Interestingly, S1M cells exhibited CSC-like features, such as increased tumorigenic potential and chemoresistance. By comparing gene expression profiles between S1 and S1M cells, we identified Stem Cells Antigen-1 (Sca-1) as a cell surface marker, which was mostly upregulated in S1M. Sca-1 was upregulated in tumorspheres from S1 cells or after cisplatin treatment in S1 cells. Immunofluorescence (IF) analysis showed that approximately 7% of cancer cells exhibited positivity for Sca-1 in primary mouse gastric cancer tissues. An in vivo-limiting dilution assay showed that Sca-1high mouse gastric cancer cells demonstrated increased tumorigenicity compared with Sca-1negative cells. The Sca-1 expression was downregulated by TGF-β pathway activation and Wnt pathway inhibition in mouse gastric cancer cells. Sca-1high cells showed relatively low TGF-β reporter activity and high TCF/LEF1 reporter activity compared with Sca-1negative cells. A chromatin immunoprecipitation analysis demonstrated that Sca-1 was a β-catenin/LEF1 target gene. Sca-1high allografts were more resistant to cisplatin/fluorouracil chemotherapy than Sca-1negative allografts, and overexpressed Bcl-xL. Eighty-five mouse genes overexpressed in Sca-1high S1 cells compared with Sca-1negative cells clustered 123 pretreatment gastric cancer patient samples according to survival following chemotherapy. Taken together, Sca-1 is a novel CSC enrichment marker that mediates TGF-β and Wnt/β-catenin signaling in mouse gastric cancer.
Dendrimers with 1, 3, 5‐Trisilacyclohexane as Core Unit
Authors: Weisheim Eugen , Neumann Beate , Stammler Hans‐Georg , Mitzel Norbert W.
Published: February 2016

1, 1, 3, 3, 5, 5‐Hexavinyl‐1, 3, 5‐trisilacylohexane [Si(CH=CH2)2CH2]3 was synthesized and hydrosilylated with trichlorosilane to afford the first generation of a dendrimer. Conversion of this molecule with 18 Si–Cl functions on its surface with an excess of vinylmagnesium bromide yielded the 18‐fold vinylated dendrimer. The new compounds were identified by elemental analyses, multi‐nuclear NMR spectroscopy, and mass spectrometry. Crystal structures were obtained for [Si(CH=CH2)2CH2]3 and [Si(CH2–CH2SiCl3)2CH2]3.
Active learning for extended finite state machines
Authors: Cassel Sofia , Howar Falk , Jonsson Bengt , Steffen Bernhard
Published: February 2016

We present a black-box active learning algorithm for inferring extended finite state machines (EFSM)s by dynamic black-box analysis. EFSMs can be used to model both data flow and control behavior of software and hardware components. Different dialects of EFSMs are widely used in tools for model-based software development, verification, and testing. Our algorithm infers a class of EFSMs called
register automata
. Register automata have a finite control structure, extended with variables (registers), assignments, and guards. Our algorithm is parameterized on a particular
theory
, i.e., a set of operations and tests on the data domain that can be used in guards.

Key to our learning technique is a novel learning model based on so-called
tree queries
. The learning algorithm uses tree queries to infer symbolic data constraints on parameters, e.g., sequence numbers, time stamps, identifiers, or even simple arithmetic. We describe sufficient conditions for the properties that the symbolic constraints provided by a tree query in general must have to be usable in our learning model. We also show that, under these conditions, our framework induces a generalization of the classical Nerode equivalence and canonical automata construction to the symbolic setting. We have evaluated our algorithm in a black-box scenario, where tree queries are realized through (black-box) testing. Our case studies include connection establishment in TCP and a priority queue from the Java Class Library.
Resolving taxonomic uncertainty in vulnerable elasmobranchs: are the Madeira skate (Raja maderensis) and the thornback ray (Raja clavata) distinct species?
Authors: Ball Rachel E. , Serra-Pereira Barbara , Ellis Jim , Genner Martin J. , Iglésias Samuel , Johnson Andrew F. , Jones Catherine S. , Leslie Rob , Lewis Jennifer , Mariani Stefano , Menezes Gui , Neat Francis , Noble Leslie R. , Sims David W. , Griffiths Andrew M.
Published: February 2016

Skates and rays constitute the most speciose group of chondrichthyan fishes, yet are characterised by remarkable levels of morphological and ecological conservatism. They can be challenging to identify, which makes monitoring species compositions for fisheries management purposes problematic. Owing to their slow growth and low fecundity, skates are vulnerable to exploitation and species exhibiting endemism or limited ranges are considered to be the most at risk. The Madeira skateRaja maderensisis endemic and classified as ‘Data Deficient’ by the IUCN, yet its taxonomic distinctiveness from the morphologically similar and more wide-ranging thornback rayRaja clavatais unresolved. This study evaluated the sequence divergence of both the variable control region and cytochrome oxidase I ‘DNA barcode’ gene of the mitochondrial genome to elucidate the genetic differentiation of specimens identified asR. maderensisandR. clavatacollected across much of their geographic ranges. Genetic evidence was insufficient to support the different species designations. However regardless of putative species identification, individuals occupying waters around the Azores and North African Seamounts represent an evolutionarily significant unit worthy of special consideration for conservation management.
Duplex Ultrasonography Has Limited Utility in Detection of Postoperative DVT after Primary Total Joint Arthroplasty
Authors: Vira Shaleen , Ramme Austin J. , Alaia Michael J. , Steiger David , Vigdorchik Jonathan M. , Jaffe Frederick
Published: February 2016

Background

Duplex ultrasound is routinely used to evaluate suspected deep venous thrombosis after total joint arthroplasty. When there is a clinical suspicion for a pulmonary embolism, a chest angiogram (chest CTA) is concomitantly obtained.

Questions/Purposes

Two questions were addressed: First, for the population of patients who receive duplex ultrasound after total joint arthroplasty, what is the rate of positive results? Second, for these patients, how many of these also undergo chest CTA for clinical suspicion of pulmonary embolus and how many of these tests are positive? Furthermore, what is the correlation between duplex ultrasound results and chest CTA results?

Methods

A retrospective chart review was conducted of total joint replacement patients in 2011 at a single institution. Inclusion criteria were adult patients who underwent a postoperative duplex ultrasonography for clinical suspicion of deep venous thrombosis (DVT). Demographic data, result of duplex scan, clinical indications for obtaining the duplex scan, and DVT prophylaxis used were recorded. Additionally, if a chest CTA was obtained for clinical suspicion for pulmonary embolus, results and clinical indication for obtaining the test were recorded. The rate of positive results for duplex ultrasonography and chest CTA was computed and correlated based on clinical indications.

Results

Two hundred ninety-five patients underwent duplex ultrasonography of which only 0.7% were positive for a DVT. One hundred three patients underwent a chest CTA for clinical suspicion of a pulmonary embolism (PE) of which 26 revealed a pulmonary embolus, none of which had a positive duplex ultrasound.

Conclusion

Postoperative duplex scans have a low rate of positive results. A substantial number of patients with negative duplex results subsequently underwent chest CTA for clinical suspicion for which a pulmonary embolus was found, presumably resulting from a DVT despite negative duplex ultrasound result. A negative duplex ultrasonography should not rule out the presence of a DVT which can embolize to the lungs and thus should not preclude further workup when clinical suspicion exists for a pulmonary embolus.
Prevalence of vitamin D deficiency in mothers and their newborns in a Tunisian population
Authors: Ayadi Imene D. , Nouaili Emira B.H. , Talbi Emna , Ghdemssi Aicha , Rached Chiraz , Bahlous Afef , Gammoudi Amel , Hamouda Sonia Ben , Bouguerra Badreddine , Bouzid Kehna , Abdelmoula Jouda , Marrakchi Zahra
Published: February 2016

Objective

To assess vitamin D status in mothers and their newborns and identify predictive factors of vitamin D deficiency.

Methods

A cross‐sectional study was undertaken of healthy women and their full‐term newborns delivered at the Charles Nicolle Hospital, Tunis, Tunisia, between October and November 2012. Maternal and neonatal serum 25‐hydroxy vitamin D (25(OH)D) concentrations were measured. Correlations were tested.

Results

Overall, 87 mothers and their newborns were enrolled. No mother or neonate had an adequate vitamin D status. Mean maternal and neonatal serum 25(OH)D concentrations were 6.82 ± 5.14 ng/mL (range 3.60–23.77) and 5.92 ± 4.15 ng/mL (range 3.60–22.28), respectively. Vitamin D deficiency (serum 25(OH)D < 20 ng/mL) was found in 84 (97%) mothers and 85 (98%) neonates, of whom 76 (87%) and 78 (90%), respectively, had severe deficiency (serum 25(OH)D < 12 ng/mL). Maternal serum 25(OH)D showed a strong positive correlation with neonatal serum 25(OH)D (r = 0.69, P < 0.001). Maternal dietary vitamin D intake was the only factor shown to be associated with serum 25(OH)D concentrations (P < 0.05).

Conclusion

Vitamin D deficiency is prevalent among Tunisian mothers and their neonates.
Prediction of vaginal birth after cesarean delivery
Authors: Bhide Amarnath , Caric Vedrana , Arulkumaran Sabaratnam
Published: February 2016

Objective

To examine factors associated with successful vaginal birth after cesarean (VBAC) and to validate a previously established prediction model.

Methods

In a retrospective study, data were obtained for women with one prior low‐transverse cesarean procedure who underwent a trial of labor with a cephalic singleton pregnancy at term at one UK hospital between January 2000 and August 2013. Univariate analysis and logistic regression analysis were used to identify maternal demographic characteristics significantly associated with successful VBAC and factors independently associated with this outcome, respectively. A prediction model was built, and predicted probabilities were compared with observed frequencies. For validation, probabilities were also calculated by a previous prediction model.

Results

Overall, 1463 women formed the cohort. Successful vaginal delivery was achieved in 1050 (71.8%) women. The only factors significantly associated with unsuccessful VBAC were Asian (odds ratio [OR] 1.59, 95% confidence interval [CI] 1.14–2.23) or African (OR 1.80, 95% CI 1.23–2.64) ethnic origin, and previous cesarean for failure to progress (OR 6.39, 95% CI 4.81–8.49). The predicted and observed probability of successful VBAC were well correlated (Spearman ρ, 0.905; P = 0.002). The established prediction model was less accurate.

Conclusion

Previous cesarean performed for failure to progress and Asian/African ethnic origin were associated with unsuccessful VBAC. The performance of a previous prediction model was inferior.
Cost‐effectiveness of two interventions for the prevention of postpartum hemorrhage in Senegal
Authors: Vlassoff Michael , Diallo Alioune , Philbin Jesse , Kost Kathryn , Bankole Akin
Published: February 2016

Objective

To compare, at the community level, the cost‐effectiveness of oxytocin and misoprostol for the prevention of postpartum hemorrhage (PPH).

Methods

The present cost‐effectiveness study used data collected during a randomized trial that compared the prophylactic effectiveness of misoprostol and oxytocin for the prevention of PPH in a rural setting in Senegal between June 6 and September 21 2013. The two interventions were compared, with referral to a higher level facility owing to PPH being the outcome measure. The costs and effects were calculated for two hypothetical cohorts of patients delivering during a 1‐year period, with each cohort receiving one intervention. A comparison with a third hypothetical cohort receiving the current standard of care was included. A sensitivity analysis was performed to estimate the impact of variations in model assumptions.

Results

The cost per PPH referral averted was US$ 38.96 for misoprostol and US$ 119.15 for oxytocin. In all the scenarios modeled the misoprostol intervention dominated, except in the worst‐case scenario, where the oxytocin intervention demonstrated slightly better cost‐effectiveness.

Conclusion

The use of misoprostol for PPH prophylaxis could be cost effective and improve maternal outcomes in low‐income settings.
Inequalities in dementia incidence between six racial and ethnic groups over 14 years
Authors: Mayeda Elizabeth Rose , Glymour M.Maria , Quesenberry Charles P. , Whitmer Rachel A.
Published: February 2016

Introduction

Reducing racial/ethnic disparities is a primary objective of the National Alzheimer's Plan (NAPA), yet direct comparisons within large samples representing diversity of the United States are lacking.

Methods

Dementia incidence from January 1, 2000 to December 31, 2013 and a 25‐year cumulative risk in 274,283 health care members aged 64+ (n = 18,778 African‐American, n = 4543 American Indian/Alaska Native [AIAN], n = 21,000 Latino, n = 440 Pacific Islander, n = 206,490 white, n = 23,032 Asian‐Americans). Cox proportional hazard models were adjusted for age, sex, medical utilization, and comorbidities.

Results

Dementia incidence (n = 59,555) was highest for African‐Americans (26.6/1000 person‐years) and AIANs (22.2/1000 person‐years); intermediate for Latinos (19.6/1000 person‐years), Pacific Islanders (19.6/1000 person‐years), and whites (19.3/1000 person‐years) and lowest among Asian‐Americans (15.2/1000 person‐years). Risk was 65% greater for African‐Americans (hazard ratio = 1.65; 95% confidence interval = 1.58–1.72) versus Asian‐Americans. Cumulative 25‐year risk at age 65 was as follows: 38% African‐Americans, 35% AIANs, 32% Latino, 25% Pacific Islanders, 30% white, and 28% Asian‐Americans.

Discussion

Dementia rates varied over 60% between groups, providing a comprehensive benchmark for the NAPA goal of reducing disparities.
The Social Contract Model of Corporate Purpose and Responsibility
Authors: Hsieh Nien-hê
Published: February 2016

Of the many developments in business ethics that Thomas Donaldson has helped pioneer, one is the application of social contract theory to address questions about the responsibilities of business actors. InCorporations and Morality, Donaldson develops one of the most sustained and comprehensive accounts that aims to justify the existence of for-profit corporations and to specify and ground their responsibilities. In order to further our understanding about the purpose and responsibilities of productive organizations, and as a contribution to the scholarship on Donaldson’s thought, this paper gathers together the critical responses to Donaldson’s account along with Donaldson’s replies to his critics. The paper argues that we would do well to continue engaging with Donaldson’s account because of its distinctive and challenging conception of the purpose and responsibilities of productive organizations, but that many of the insights to be gained come from reframing the role played by social contract theory.
SMEs and Certified Management Standards: The Effect of Motives and Timing on Implementation and Commitment
Authors: Iatridis Konstantinos , Kuznetsov Andrei , Whyman Philip B.
Published: February 2016

Existing research on certifiable management standards (CMS) and corporate social responsibility (CSR) tends to focus on large companies and is characterised by disagreement about the role of these standards as drivers of CSR. We contribute to the literature by shifting the analytical focus to the behaviour of small and medium-sized enterprises (SMEs) that subscribe to multiple CSR related standards. We argue that, in respect of motive and commitment, SMEs are not as different from large companies as the literature suggests, as they are guided by similar institutional and economic motives. Results, based on ISO 9001, ISO 14001 and OHSAS 18001 certified SMEs in Greece, demonstrate that later adopters are more susceptible to coercive and mimetic motives and are less likely to commit fully to the CMS requirements, while earlier adopters react to normative motives and considerations of internal efficiency gains and tend to carry out CMS requirements with greater diligence.
On multiple recurrence and other properties of ‘nice’ infinite measure-preserving transformations
Authors: AARONSON JON , NAKADA HITOSHI
Published: February 2016

We discuss multiple versions of rational ergodicity and rational weak mixing for ‘nice’ transformations, including Markov shifts, certain interval maps and hyperbolic geodesic flows. These properties entail multiple recurrence.
Breaching the Social Contract: Crises of Democratic Representation and Patterns of Extreme Right Party Support
Authors: Halikiopoulou Daphne , Vasilopoulou Sofia
Published: February 2016

Why has the extreme right Greek Golden Dawn, a party with clear links to fascism, experienced a rise defying all theories that claim that such a party is unlikely to win in post-Second World War Europe? And, if we accept that economic crisis is an explanation for this, why has such a phenomenon not occurred in other countries that have similar conducive conditions, such as Portugal and Spain? This article addresses this puzzle by: (1) carrying out a controlled comparison of Greece, Portugal and Spain; and (2) showing that the rise of the extreme right is not a question of intensity of economic crisis. Rather it is the nature of the crisis – that is, economic versus overall crisis of democratic representation – that facilitates the rise of the extreme right. We argue that extreme right parties are more likely to experience an increase in their support when economic crisis culminates into an overall crisis of democratic representation. Economic crisis is likely to become a political crisis when severe issues of governability impact upon the ability of the state to fulfil its social contract obligations. This breach of the social contract is accompanied by declining levels of trust in state institutions, resulting in party system collapse.
A Model-Based Product Evaluation Protocol for Comparison of Safety-Engineered Protection Mechanisms of Winged Blood Collection Needles
Authors: Haupt C. , Spaeth J. , Ahne T. , Goebel U. , Steinmann D.
Published: February 2016

OBJECTIVE

To evaluate differences in product characteristics and user preferences of safety-engineered protection mechanisms of winged blood collection needles.

DESIGN

Randomized model-based simulation study.

SETTING

University medical center.

PARTICIPANTS

A total of 33 third-year medical students.

METHODS

Venipuncture was performed using winged blood collection needles with 4 different safety mechanisms: (a) Venofix Safety, (b) BD Vacutainer Push Button, (c) Safety-Multifly, and (d) Surshield Surflo. Each needle type was used in 3 consecutive tries: there was an uninstructed first handling, then instructions were given according to the operating manual; subsequently, a first trial and second trial were conducted. Study end points included successful activation, activation time, single-handed activation, correct activation, possible risk of needlestick injury, possibility of deactivation, and preferred safety mechanism.

RESULTS

The overall successful activation rate during the second trial was equal for all 4 devices (94%–100%). Median activation time was (a) 7 s, (b) 2 s, (c) 9 s, and (d) 7 s. Single-handed activation during the second trial was (a) 18%, (b) 82%, (c) 15%, and (d) 45%. Correct activation during the second trial was (a) 3%, (b) 64%, (c) 15%, and (d) 39%. Possible risk of needlestick injury during the second trial was highest with (d). Possibility of deactivation was (a) 0%, (b) 12%, (c) 9%, and (d) 18%. Individual preferences for each system were (a) 11, (b) 17, (c) 5, and (d) 0. The main reason for preference was the comprehensive safety mechanism.

CONCLUSION

Significant differences exist between safety mechanisms of winged blood collection needles.

Infect Control Hosp Epidemiol2016;37:505–511