bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the role of marginal confounder prevalence – implications for the high‐dimensional propensity score algorithm
Authors: Schuster Tibor , Pang Menglan , Platt Robert W. 
Published: April 2015

AbstractPurposeThe high‐dimensional propensity score algorithm attempts to improve control of confounding in typical treatment effect studies in pharmacoepidemiology and is increasingly being used for the analysis of large administrative databases. Within this multi‐step variable selection algorithm, the marginal prevalence of non‐zero covariate values is considered to be an indicator for a count variable's potential confounding impact. We investigate the role of the marginal prevalence of confounder variables on potentially caused bias magnitudes when estimating risk ratios in point exposure studies with binary outcomes.MethodsWe apply the law of total probability in conjunction with an established bias formula to derive and illustrate relative bias boundaries with respect to marginal confounder prevalence.ResultsWe show that maximum possible bias magnitudes can occur at any marginal prevalence level of a binary confounder variable. In particular, we demonstrate that, in case of rare or very common exposures, low and high prevalent confounder variables can still have large confounding impact on estimated risk ratios.ConclusionsCovariate pre‐selection by prevalence may lead to sub‐optimal confounder sampling within the high‐dimensional propensity score algorithm. While we believe that the high‐dimensional propensity score has important benefits in large‐scale pharmacoepidemiologic studies, we recommend omitting the prevalence‐based empirical identification of candidate covariates. Copyright © 2015 John Wiley & Sons, Ltd.
Diselenocarbamates, novel initiators in ATRP of styrene
Authors: Gao Feng , Pan Xiangqiang , Zhu Jian , Zhang Zhengbiao , Zhang Wei , Zhu Xiulin 
Published: April 2015

ABSTRACTThe atom transfer radical polymerizations (ATRPs) of styrene initiated by diselenocarbamates were carried out for the first time. The polymerization showed first‐order kinetic with respect to the monomer concentration, and the molecular weights of the obtained polymers increased linearly with the monomer conversions with narrow molecular weight distributions (as low as 1.16). The results of chain extension, 1H NMR, UV–vis, and MALDI‐TOF MS confirmed that the resultant polystyrene possessed some degree of living diselenocarbamates terminal. However, significant amounts of dead polymers (about 53%) were also found. This work offered an alternative type of ATRP initiator, and the seleno‐terminated polymers may be useful in biotechnological and biomedical applications. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1927–1933
Water‐stable copolymers containing isocyanate moiety protected by hydrophobic styrene segment and their reaction with amines
Authors: Seto Ryota , Matsumoto Kozo , Endo Takeshi 
Published: April 2015

ABSTRACTReactive isocyanate groups were protected and stabilized by the hydrophobic styrene segment and acquired high tolerance toward water. Copolymers containing isocyanate groups were synthesized by a radical copolymerization of 2‐propenyl isocyanate (2PI) and styrene (St). The stability of the obtained copolymers on water was examined to find that isocyanate groups were protected by the hydrophobic polystyrene segment and were stable on water and these isocyanates reacted with primary amines including amino acids to form urea selectively on water. Primary amines with a higher octanol‐water partition coefficient or smaller steric hindrance were more reactive to the isocyanate groups in the side chain of the copolymer. The protection of reactive isocyanate groups using the hydrophobic styrene segment did not give side products which are produced in the usual chemical protection/deprotection process. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1934–1940
Demonstration of isospecific free radical polymerization of acrylate controlled by conformation and chirality of monomer
Authors: Tanaka Hitoshi , Matsubara Yoshitaka , Kusunoki Katsuhiko , Saito Naoki , Kibayashi Tatsuya 
Published: April 2015

ABSTRACTRadical polymerization of lactic acid‐based chiral and achiral methylene dioxolanones, a model for conformationally s‐cis locked acrylate, was carried out with AIBN to demonstrate an isospecific free radical polymerization controlled by chirality and conformation of monomer. Polymerization of the dioxolanones proceeded smoothly without ring opening to give a polymer with moderate molecular weight and 100% of maximum isotacticity. ESR spectrum indicated a twisted conformation of the growing poly(methylene dioxolanone) radical in contrast to an acyclic analogous radical, suggesting a restriction of the free rotation around main chain CαCβ bond of the growing radical center. Chirality as well as the polarity and bulkiness of monomer affected the polymer tacticity, and chiral alkyl substituent would afford a high isotactic polymer, in which higher the enantiomeric excess of the monomer was, higher the isotacticity of the polymer was. While, achiral or polar substituents including dibenzyl and trichloromethyl groups would afford an atactic polymer. In addition, glass transition temperature (Tg) of the resulting polymers was significantly high, ranging from 172.2 to 229.8 °C, and even for an isotactic polymer Tg was as high as 206.8 °C. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2007–2016
Web framework points: an effort estimation methodology for Web application development using a content management framework
Authors: Barabino Giulio , Concas Giulio , Corona Erika , Grechi Daniele , Marchesi Michele , Tigano Danilo 
Published: April 2015

AbstractWeb applications are among the most popular and relevant kinds of application. Most Web applications are developed using a content management framework (CMF). CMF helps to accelerate the publication of large amounts of information and the development of Web applications. However, developing Web applications through CMF is not exempt from cost and time overruns, as in traditional software projects. Currently, there is no estimation model able to adequately measure the effort of developing a Web application.This work presents a new methodology, called web framework points, to estimate the effort of Web applications developed with CMF. Web framework points is a hybrid methodology, composed of a sizing phase, which follows specific guidelines, and an effort estimation phase, obtained by applying a cost model to the size model of the project to estimate. The sizing of the project takes into account not only usual functional requirements, as in function points analysis, but also elements specific for developing a Web application through CMF. We also present the experimental validation of the proposed methodology, performed on a dataset of 29 real‐world projects, of which 83% show an estimation error of less than 25%. Copyright © 2015 John Wiley & Sons, Ltd.
Ambulatory respiratory rate trends identify patients at higher risk of worsening heart failure in implantable cardioverter defibrillator and biventricular device recipients: a novel ambulatory parameter to optimize heart failure management
Authors: Goetze Stephan , Zhang Yi , An Qi , Averina Viktoria , Lambiase Pier , Schilling Richard , Trappe Hans-Joachim , Winter Siegmund , Wold Nicholas , Manola Ljubomir , Kestens Dries 
Published: April 2015

Abstract

Purpose
Respiratory distress is the primary driver for heart failure (HF) hospitalization. Implantable pacemakers and defibrillators are capable of monitoring respiratory rate (RR) in ambulatory HF patients. We investigated changes in RR prior to HF hospitalizations and its near-term risk stratification power.

Methods
NOTICE-HF was an international multi-center study. Patients were implanted with an implantable cardioverter defibrillator or cardiac resynchronization therapy defibrillator, capable of trending daily maximum, median, and minimum RR (maxRR, medRR, minRR). RR from 120 patients with 9 months of follow-up was analyzed. One-tailed Student’s t test was used to compare RR values prior to HF events to baseline defined as 4 weeks prior to the events. A Cox regression model was used to calculate the hazard ratios (HR) for the 30-day HF hospitalization risk based on RR values in the preceding month.

Results
Daily maxRR, medRR, and minRR were significantly elevated prior to HF events compared to baseline (ΔmaxRR 1.8 ± 3.0; p = 0.02; ΔmedRR, 2.1 ± 2.8; p = 0.007; ΔminRR, 1.5 ± 2.1, p = 0.008). Risk of experiencing HF events within 30-days was increased if the standard deviation of medRR over the preceding month was above 1.0 br/min (HR = 12.3, 95 % confidence interval (CI) 2.57–59, p = 0.002). The risk remained high after adjusting for clinical variables that differed at enrollment.

Conclusion
Ambulatory daily respiratory rate trends may be a valuable addition to standard management for HF patients.
The role of delinquency, proactive aggression, psychopathy and behavioral school engagement in reported youth gang membership
Authors: Ang Rebecca P. , Huan Vivien S. , Chan Wei Teng , Cheong Siew Ann , Leaw Jia Ning 
Published: April 2015

ABSTRACTGiven the robust positive association between gangs and crime, a better understanding of factors related to reported youth gang membership is critical and especially since youth in gangs are a universal concern. The present study investigated the role of delinquency, proactive aggression, psychopathy and behavioral school engagement in reported youth gang membership using a large sample of 1027 Singapore adolescents. Results from logistic regression showed that delinquency, proactive aggression, and behavioral school engagement were statistically significant risk factors for reported youth gang membership, and that psychopathy was not related to reported gang membership. Implications for prevention and intervention work with respect to youth gang membership were discussed. In particular, strengthening students' engagement with school and meaningful school‐related activities and developing supportive teacher–student relationships are particularly important in working with young people with respect to prevention work. Additionally, the present study's theoretical and empirical contributions were also discussed.
Prevalence and pattern of rape among girls and women attending Enugu State University Teaching Hospital, southeast Nigeria
Authors: Ohayi Robsam S. , Ezugwu Euzebus C. , Chigbu Chibuike O. , Arinze‐Onyia Susan U. , Iyoke Chukwuemeka A. 
Published: April 2015

AbstractObjectiveTo determine the prevalence and pattern of rape in Enugu, southeast Nigeria.MethodsA prospective descriptive study was conducted among female survivors of rape who presented at the emergency gynecologic and/or forensic unit of Enugu State University Teaching Hospital between February 2012 and July 2013. Data were collected via a pretested interviewer‐administered questionnaire.ResultsAmong 1374 gynecologic emergencies, there were 121 (8.8%) rape cases. The mean age of the rape survivors was 13.1 ± 8.1 years. Ninety (74.4%) survivors were younger than 18 years. At least 72 hours had passed since the rape for 74 (61.2%) cases. The perpetrator was known to 74 (82.2%) patients younger than 18 years and 18 (58.1%) aged at least 18 years (P = 0.013). The location of the rape was the bush or an uncompleted building for 36 (29.8%) and the perpetrator's residence for another 36 (29.8%). Four (3.3%) individuals became pregnant after the rape.ConclusionA considerable proportion of patients with gynecologic emergencies had been raped. Individuals should be encouraged to report to the hospital quickly to prevent unwanted pregnancy and sexually transmitted infections.
Management and outcomes of pregnancies among women with HIV in Oxford, UK, in 2008–2012
Authors: Montgomery‐Taylor Sarah , Hemelaar Joris 
Published: April 2015

AbstractObjectiveTo evaluate the management and outcomes of pregnancies among women with HIV infection.MethodsA retrospective cohort study was undertaken of pregnant women with HIV who delivered at one center in the UK in 2008–2012. Case notes were reviewed and detailed information extracted regarding obstetric and virological management.ResultsOverall, 61 pregnancies were included; 43% (26/60) were unplanned and 39% (22/57) booked late. HIV infection was diagnosed during pregnancy for 32% (19/60); 71% (12/17) were diagnosed after the first trimester. At booking, 47% of women (28/60) were not on treatment, all but one of whom commenced treatment, either for maternal reasons (CD4 count < 350 cells per mm3; 48% [13/27]) or prevention of mother‐to‐child‐transmission (52% [14/27]). Viral load was high (> 50 copies per mL) at delivery for 13% of women (8/61). Delivery was by cesarean for 74% [45/61]. One neonate was diagnosed with HIV infection. There were 6 (10%) preterm births, 9 (15%) cases of low birth weight, 11 (18%) small‐for‐gestational‐age neonates, and 1 (2%) stillbirth.ConclusionBetter pregnancy planning, earlier booking and HIV diagnosis, and optimal antiretroviral treatment should increase the proportion of women with a low viral load (< 50 copies per mL) at delivery, lead to more vaginal deliveries, and further reduce mother‐to‐child transmission of HIV.
A double‐blind randomized controlled trial of mifepristone or placebo before buccal misoprostol for abortion at 14–21 weeks of pregnancy
Authors: Dabash Rasha , Chelli Héla , Hajri Selma , Shochet Tara , Raghavan Sheila , Winikoff Beverly 
Published: April 2015

AbstractObjectiveTo assess differences in outcomes of misoprostol with or without mifepristone for second‐trimester abortion.MethodsA randomized, double‐blind, placebo‐controlled trial of buccal misoprostol following placebo or 200 mg mifepristone was done in Tunisia among women presenting for abortions at 14–21 weeks of pregnancy between August 2009 and December 2011. Women with a live fetus, a closed cervical os, no cervical bleeding, and no contraindications to study drugs were eligible and underwent randomization (block size 10). Participants returned 24 hours later to receive 400 μg buccal misoprostol every 3 hours until complete fetal and placental expulsion (maximum 10 doses, five per 24‐hour period). The primary outcomes were rates of complete uterine evacuation at 48 hours and time to expulsion.ResultsA total of 120 women were evenly randomized to treatment. Complete uterine evacuation at 48 hours was recorded in 55 (91.7%) women in the combined group versus 43 (71.7%) in the misoprostol alone group (relative risk 1.28; 95% confidence interval 1.07–1.53). Mean time to complete abortion was 10.4 ± 6.6 hours in the group who received mifepristone versus 20.6 ± 9.7 hours in the misoprostol alone group (P < 0.001). Side effects were similar in both groups.ConclusionAdding mifepristone before misoprostol can improve the quality of second‐trimester abortion care by making the process faster.ClinicalTrials.gov: NCT00969982.
Field Ultrasound Evaluation of Central Volume Status and Acute Mountain Sickness
Authors: Pitman Justin T. , Thapa Ghan B. , Stuart Harris N. 
Published: April 2015

Objective To investigate whether ultrasonography can be used for field volume status assessment and to determine whether a detectable difference in intravascular volume exists in individuals with acute mountain sickness (AMS) compared with those without. Methods Study was performed at the Himalayan Rescue Association Clinic in Manang, Nepal, located on the Annapurna trekking circuit at an altitude of 3519 m (11545 feet). A convenience sample was taken from individuals trekking over 5 to 8 days from 760 m (2490 feet) to 3519 m (11,545 feet), comparing asymptomatic trekkers vs those who experienced AMS. Subjects were evaluated for AMS based on the Lake Louise AMS Questionnaire (LLS ≥ 3 indicates AMS). After medical screening examination, both groups (control, n = 51; AMS, n = 18) underwent ultrasonography to obtain measurements of inferior vena cava collapsibility index (IVC CI) and left ventricular outflow tract velocity–time integral (LVOT VTI) before and after a passive leg raise (PLR) maneuver. Results There was no statistically significant difference between groups regarding change in heart rate before and after PLR, or IVC CI; however, there was a statistically significant greater increase in LVOT VTI after PLR maneuver in control group subjects compared with those with AMS (18.96% control vs 11.71% AMS; P < .01). Conclusions Ultrasonography is a useful tool in the assessment of intravascular volume at altitude. In this sample, we found ultrasonographic evidence that subjects with AMS have a higher intravascular volume than asymptomatic individuals. These data support the hypothesis that individuals with AMS have decreased altitude-related diuresis compared with asymptomatic individuals.
NaD excess objects and its implications on initial mass function
Authors: Yi Sukyoung K. , Jeong Hyunjin 
Published: April 2015

Abstractvan Dokkum and Conroy (2010) have heralded the possible implication of NaI 8200A lines on extra bottom-heavy IMF of bright elliptical galaxies. A flurry of papers have followed it and revisited the half a century old issue all over again from various angles. For a sanity check, we investigate on the issue this time using the better measured NaD 5900A line instead. We found from the SDSS database that a large (~ 10%) fraction of galaxies (both early and late types) exhibit strong NaD lines and that the same bottom-heavy models of van Dokkum and Conroy that reproduced the strong NaI 8200 lines of elliptical galaxies are not capable of reproducing NaD line strengths at all. The mystery prevails. This article is mainly a review of our recent paper (Jeong et al. 2013).
Applying galactic archeology to massive galaxies using deep imaging surveys
Authors: Duc Pierre-Alain 
Published: April 2015

AbstractVarious programs aimed at exploring the still largely unknown low surface brightness Universe with deep imaging optical surveys have recently started. They open a new window for studies of galaxy evolution, pushing the technique of galactic archeology outside the Local Group (LG). The method, based on the detection and analysis of the diffuse light emitted by collisional debris or extended stellar halos (rather than on stellar counts as done for LG systems), faces however a number of technical difficulties, like the contamination of the images by reflection halos and Galactic cirrus. I review here the on-going efforts to address them and highlight the preliminary promising results obtained with a systematic survey with MegaCam on the CFHT of nearby massive early-type galaxies done as part of the ATLAS3D, NGVS and MATLAS collaborations.
The evolution of the ages and metallicities of massive galaxies since z = 0.7
Authors: Gallazzi Anna , Bell Eric F. , Zibetti Stefano , Brinchmann Jarle , Kelson Daniel D. 
Published: April 2015

AbstractWe present results on the stellar population properties of massive galaxies at z = 0.7 based on deep, medium-resolution IMACS spectra for a sample of ~ 70 galaxies in the ECDFS with M* > 1010M⊙. The age–mass and stellar metallicity–mass relations for the population as a whole have a similar shape as the local relations over the probed mass range, but offset to ages younger by ~ 4 Gyr and metallicities lower by ~ 0.13 dex. Quiescent galaxies alone have stellar ages and metallicities consistent with passive evolution onto the local quiescent galaxies relations. The evolution in metallicity is driven by star-forming galaxies. However a significant fraction of massive star-forming galaxies have metallicities comparable to those of local quiescent galaxies. If quenched at z < 0.7 they can provide the necessary population to reproduce the scatter in age and metallicity of local quiescent galaxies.
Habitat Use and Fishery Dynamics of a Heavily Exploited Coastal Migrant, Spanish Mackerel
Authors: Schrandt Meagan N. , Powers Sean P. , Mareska John F. 
Published: April 2015

Abstract
Spanish Mackerel Scomberomorus maculatus support important commercial and recreational fisheries in the Gulf of Mexico (GOM). Although federally managed because of interstate migrations, harvest, essential fish habitat consideration, and management are largely state issues. Contrary to the accepted paradigm of a well-mixed stock from the GOM to the Atlantic, Spanish Mackerel have been suggested to exhibit reduced movement, and hence mixing, which could lead to areas of localized depletion within the larger stock. We addressed how local abundance patterns responded to changes in harvest pressure, evaluated migration patterns via examining temporal trends in abundance, and determined whether the spatial abundance patterns resembled habitat specialization or generalization. Abundance trends of Spanish Mackerel in Alabama have remained relatively constant from 2001 to 2011 despite a significant increase in commercial harvesting. Seasonal patterns of catch rates coincided with the proposed annual migration. We also observed adult Spanish Mackerel in low salinities (0–10‰) at the mouth of Mobile River during the fall when river discharge is relatively low. This extends the known range of estuarine habitat use by adult Spanish Mackerel. Because Mobile Bay includes various habitat types differing from surf zone and coastal ocean habitats typically inhabited by Spanish Mackerel, capturing Spanish Mackerel near the mouth of Mobile River provides evidence for a habitat generalist strategy. Based on a relatively constant abundance index and year-class strength, the stock seems to be relatively stable even after a drastic increase in commercial harvests in Alabama and heavy exploitation of age-1–3 Spanish Mackerel. The resilience of catch rate trends to changes in local harvest pressure as well as evidence of synchrony among areas in terms of migration suggest the Alabama fishery is influenced by population dynamics of a larger population.
Received July 3, 2014; accepted January 12, 2015
Conformational sampling and structure prediction of multiple interacting loops in soluble andβ-barrel membrane proteins using multi-loop distance-guided chain-growth Monte Carlo method
Authors: Tang Ke , Wong Samuel W.K. , Liu Jun S. , Zhang Jinfeng , Liang Jie 
Published: April 2015

AbstractMotivation: Loops in proteins are often involved in biochemical functions. Their irregularity and flexibility make experimental structure determination and computational modeling challenging. Most current loop modeling methods focus on modeling single loops. In protein structure prediction, multiple loops often need to be modeled simultaneously. As interactions among loops in spatial proximity can be rather complex, sampling the conformations of multiple interacting loops is a challenging task.Results: In this study, we report a new method called multi-loop Distance-guided Sequential chain-Growth Monte Carlo (M-DiSGro) for prediction of the conformations of multiple interacting loops in proteins. Our method achieves an average RMSD of 1.93 Å for lowest energy conformations of 36 pairs of interacting protein loops with the total length ranging from 12 to 24 residues. We further constructed a data set containing proteins with 2, 3 and 4 interacting loops. For the most challenging target proteins with four loops, the average RMSD of the lowest energy conformations is 2.35 Å. Our method is also tested for predicting multiple loops in β-barrel membrane proteins. For outer-membrane protein G, the lowest energy conformation has a RMSD of 2.62 Å for the three extracellular interacting loops with a total length of 34 residues (12, 12 and 10 residues in each loop).Availability and implementation: The software is freely available at: tanto.bioe.uic.edu/m-DiSGro.Contact: jinfeng@stat.fsu.edu or jliang@uic.eduSupplementary information: Supplementary data are available at Bioinformatics online.