bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of time from diagnosis to start of radiotherapy on children with diffuse intrinsic pontine glioma
Authors: Pai Panandiker Atmaram S. , Wong J. Karen , Nedelka Michele A. , Wu Shengjie , Gajjar Amar , Broniscer Alberto 
Published: January 2014

BackgroundChildren with diffuse intrinsic pontine glioma (DIPG) continue to have poor outcomes, and radiotherapy (RT) is the only temporarily effective treatment. In this retrospective analysis, we studied the effect of time from diagnosis to start of RT on event‐free survival (EFS) and overall survival (OS) in children with DIPG.MethodsRecords of children (n = 95) with DIPG treated with RT at a single institution between April 1999 and September 2009 were analyzed. RT was delivered at doses of 54.0–55.8 Gy at 1.8 Gy per fraction, and children were followed prospectively. The effect of gender, race, interruption during treatment course, age at diagnosis, duration of symptoms prior to diagnosis, use of protocol‐based chemotherapy, and time from diagnosis to initiation of RT on EFS and OS was assessed by the Cox proportional hazards model.ResultsTime as a continuous variable from diagnosis to start of RT did not affect outcome. Time dichotomized to ≤14 days significantly affected OS (hazard ratio [HR] = 1.70, P = 0.014) and race other than white or black affected EFS (HR = 2.32, P = 0.017). The 95 patients had a 6‐month EFS and OS of 60 ± 5% and 94.7 ± 2.3%, respectively, and a 12‐month EFS and OS of 11.6 ± 3.1% and 49.5 ± 5%, respectively.ConclusionsTime as a continuous variable did not affect OS or EFS in our cohort; however, children treated within 2 weeks of diagnosis had poor outcomes. Although rapid initiation of RT is desirable, our findings do not support intensive efforts aimed at shortening delays from diagnosis to start of RT. Pediatr Blood Cancer 2014;61:1180–1183. © 2014 Wiley Periodicals, Inc.
Propensity score balance measures in pharmacoepidemiology: a simulation study
Authors: Ali M. Sanni , Groenwold Rolf H. H. , Pestman Wiebe R. , Belitser Svetlana V. , Roes Kit C. B. , Hoes Arno W. , de Boer Anthonius , Klungel Olaf H. 
Published: January 2014

ABSTRACTBackgroundConditional on the propensity score (PS), treated and untreated subjects have similar distribution of observed baseline characteristics when the PS model is appropriately specified. The performance of several PS balance measures in assessing the balance of covariates achieved by a specific PS model and selecting the optimal PS model was evaluated in simulation studies. However, these studies involved only normally distributed covariates. Comparisons in binary or mixed covariate distributions with rare outcomes, typical of pharmacoepidemiologic settings, are scarce.MethodsMonte Carlo simulations were performed to examine the performance of different balance measures in terms of selecting an optimal PS model, thus reduction in bias. The balance of covariates between treatment groups was assessed using the absolute standardized difference, the Kolmogorov–Smirnov distance, the Lévy distance, and the overlapping coefficient. Spearman's correlation coefficient (r) between each of these balance measures and bias were calculated.ResultsIn large sample sizes (n ≥ 1000), all balance measures were similarly correlated with bias (rranging between 0.50 and 0.68) irrespective of the treatment effect's strength and frequency of the outcome. In smaller sample sizes with mixed binary and continuous covariate distributions, these correlations were low for all balance measures (rranging between 0.11 and 0.43), except for the absolute standardized difference (r = 0.51).ConclusionsThe absolute standardized difference, which is an easy‐to‐calculate balance measure, displayed consistently better performance across different simulation scenarios. Therefore, it should be the balance measure of choice for measuring and reporting the amount of balance reached, and for selecting the final PS model. Copyright © 2014 John Wiley & Sons, Ltd.
Secondary phase formation in Zn‐rich Cu2ZnSnSe4‐based solar cells annealed in low pressure and temperature conditions
Authors: Fairbrother Andrew , Fontané Xavier , Izquierdo‐Roca Victor , Placidi Marcel , Sylla Dioulde , Espindola‐Rodriguez Moises , López‐Mariño Simón , Pulgarín Fabian A. , Vigil‐Galán Osvaldo , Pérez‐Rodríguez Alejandro , Saucedo Edgardo 
Published: January 2014

ABSTRACTZn‐rich Cu2ZnSnSe4 (CZTSe) films were prepared by a two‐step process consisting in the DC‐magnetron sputtering deposition of a metallic stack precursor followed by a reactive anneal under a Se + Sn containing atmosphere. Precursor composition and annealing temperature were varied in order to analyze their effects on the morphological, structural, and optoelectronic properties of the films and solar cell devices. Raman scattering measurements show the presence of ZnSe as the main secondary phase in the films, as well as the presence of SnSe at the back absorber region of the films processed with lower Zn‐excess values and annealing temperatures. The ZnSe phase is found to accumulate more towards the surface of the absorber in samples with lower Zn‐excess and lower temperature annealing, while increasing Zn‐excess and annealing temperature promote its aggregation towards the back absorber region of the devices. These measurements indicate a strong dependence of these process variables in secondary phase formation and accumulation. In a preliminary optimization of both the composition and reactive annealing process, a solar cell with 4.8% efficiency has been fabricated, and potential mechanisms limiting device efficiency in these devices are discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Is bismuth subsalicylate an effective nontoxic catalyst for plga synthesis?
Authors: Duval Charlotte , Nouvel Cécile , Six Jean‐Luc 
Published: January 2014

ABSTRACTPoly(d,l‐lactide‐co‐glycolide) (PLGA) copolyesters are commonly used in biomedical applications. Researches were carried out on nontoxic or low‐toxic catalysts that are enough efficient to provide short polymerization times, adequate microstructure chains and similar properties than the commercial PLGA materials. In this study, PLGA were synthesized by ring‐opening copolymerization (ROP) using three different catalysts. Stannous octoate is the first catalyst we used, as it is very efficient, even its toxicity is still on debate. Two others low‐toxic catalysts [zinc lactate and bismuth subsalicylate (BiSS)] were also evaluated. The comparison of these ROP was realized in terms of kinetics and control of the polymerization. Then, the influence of the catalyst on the PLGA microstructure chains is reported. Finally, abiotic hydrolytic degradation rate is studied. Results described in this article show that BiSS is one very attractive catalyst to produce low toxic PLGA for biomedical applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2014,52, 1130–1138
Multiple levels hydrophobic modification of polymeric substrates by UV‐grafting polymerization with TFEMA as monomer
Authors: Chen Yanning , Chen Dong , Ma Yuhong , Yang Wantai 
Published: January 2014

ABSTRACTThe hydrophobic solid surface modification with fluorine‐containing monomers has received tremendous attention because of its unique structure and excellent property. However, these hydrophobic films normally suffer from two major problems: one is weak interface interaction between fluoropolymers and substrates, and the other is the high cost of fluorine‐containing monomers. Herein, with the aim of feasible industrial application, a facile in situ UV photo‐grafting method is reported, which could ensure the formation of chemical bonds between fluoropolymer‐grafted layer and substrate with a low cost commercial 2,2,2‐trifluoroethyl methacrylate (TFEMA) as monomer. With low‐density polyethylene (LDPE) film as a model substrate, four kinds of poly‐TFEMA‐grafted layer are fabricated on LDPE films with different surface morphologies: polymer brush, polymer network, crosslinked nanoparticles, and a micro‐ and nanoscale hierarchical structure. The experimental results showed that the water contact angles (CAs) of the LDPE films grafted with polymer brush, polymer network, and crosslinked nanoparticles were (103 ± 2)°, (95 ± 2)°, and (122 ± 2)°, respectively, which were much higher than that of LDPE film. The introduction of micro‐ and nanoscale hierarchical structures can dramatically improve the surface roughness, which will further enhance the film hydrophobicity, and the water CA can reach as high as (140 ± 1)°. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1059–1067
Social support, self‐efficacy for decision‐making, and follow‐up care use in long‐term cancer survivors
Authors: Forsythe Laura P. , Alfano Catherine M. , Kent Erin E. , Weaver Kathryn E. , Bellizzi Keith , Arora Neeraj , Aziz Noreen , Keel Gretchen , Rowland Julia H. 
Published: January 2014

AbstractObjectiveCancer survivors play an important role in coordinating their follow‐up care and making treatment‐related decisions. Little is known about how modifiable factors such as social support are associated with active participation in follow‐up care. This study tests associations between social support, cancer‐related follow‐up care use, and self‐efficacy for participation in decision‐making related to follow‐up care (SEDM). We also identified sociodemographic and clinical factors associated with social support among long‐term survivors.MethodsThe FOllow‐up Care Use among Survivors study is a cross‐sectional, population‐based survey of breast, prostate, colon, and gynecologic cancer survivors (n = 1522) 4–14 years post‐diagnosis. Multivariable regression models were used to test associations between perceived social support (tangible and emotional/informational support modeled separately), follow‐up care use (past 2 years), and SEDM, as well as to identify factors associated with perceived support.ResultsNeither support type was associated with follow‐up care use (all p > 0.05), although marital status was uniquely, positively associated with follow‐up care use (p < 0.05). Both tangible support (B for a standard deviation increase (SE) = 9.75(3.15), p < 0.05) and emotional/informational support (B(SE) = 12.61(3.05), p < 0.001) were modestly associated with SEDM. Being married, having adequate financial resources, history of recurrence, and better perceived health status were associated with higher perceived tangible and emotional support (all p < 0.05).ConclusionsWhile perceived social support may facilitate survivor efficacy for participation in decision‐making during cancer follow‐up care, other factors, including marital satisfaction, appear to influence follow‐up care use. Marital status and social support may be important factors to consider in survivorship care planning. Copyright © 2014 John Wiley & Sons, Ltd.
Resistance to herbicides inhibiting the biosynthesis of very‐long‐chain fatty acids
Authors: Busi Roberto 
Published: January 2014

AbstractHerbicides that act by inhibiting the biosynthesis of very‐long‐chain fatty acids (VLCFAs) have been used to control grass weeds in major crops throughout the world for the past 60 years. VLCFA‐inhibiting herbicides are generally highly selective in crops, induce similar symptoms in susceptible grasses and can be found within the herbicide groups classified by the HRAC as K3 and N. Even after many years of continuous use, only 12 grass weed species have evolved resistance to VLCFA‐inhibiting herbicides. Here, the cases of resistance that have evolved in major grass weed species belonging to the Avena, Echinochloa and Lolium genera in three different agricultural systems are reviewed. In particular we explore the possible reasons why VLCFA herbicides have been slow to select resistant weeds, outline the herbicide mode of action and discuss the resistance mechanisms that are most likely to have been selected. © 2014 Society of Chemical Industry
Switching adaptive learning control for nonlinearly parameterized systems with disturbance of unknown periods
Authors: Yu Miao , Huang Deqing 
Published: January 2014

SummaryIn this paper, a logic‐based switching adaptive learning control mechanism is proposed for a class of nonlinearly parameterized systems with disturbance of unknown periods. The switching algorithms include two parts: one is to stabilize the nonlinearly parameterized uncertainties, the other is to learn the periodic bounded disturbance. An adaptive control method with fully saturated periodic adaptation law is presented to take advantage of the periodic and bounded property of the disturbance. It is shown that under the proposed control designs, the asymptotic convergence is ensured irrespective of initial conditions with all the signals in the closed‐loop system bounded. An illustrative example is given to show the validity of the switching adaptive learning control. Copyright © 2014 John Wiley & Sons, Ltd.
An Integrative Framework for the Analysis of Multiple and Multimodal Representations for Meaning‐Making in Science Education
Authors: TANG KOK‐SING , DELGADO CESAR , MOJE ELIZABETH BIRR 
Published: January 2014

ABSTRACTThis paper presents an integrative framework for analyzing science meaning‐making with representations. It integrates the research on multiple representations and multimodal representations by identifying and leveraging the differences in their units of analysis in two dimensions: timescale and compositional grain size. Timescale considers the duration of time a learner typically spends on one or more representations. Compositional grain size refers to the elements of interest within a representation, ranging from components such as visual elements, words, or symbols, to a representation as a whole. Research on multiple representations focuses on the practice of re‐representing science concepts through different representations and is typically of long timescale and large grain size. Research on multimodal representations tends to consider how learners integrate the components of a representation to produce meaning; it is usually of finer grain size and shorter timescale. In the integrative framework, each type of analysis on multiple and multimodal representations plays a mutually complementary role in illuminating students’ learning with representations. The framework is illustrated through the analysis of instructional episodes of middle school students using representations to learn nanoscience concepts over the course of a lesson unit. Finally, recommendations for new research directions stemming from this framework are presented.
Managing hot flushes in men receiving androgen deprivation therapy for prostate cancer
Authors: Khan Atia , Lewis Rachel , Hughes Simon 
Published: January 2014

AbstractIn this series, the authors present cases of men being treated with androgen deprivation therapy, and highlight management strategies to prevent and treat associated toxicities. In this fourth article, the authors consider the management of hot flushes. Copyright © 2014 John Wiley & Sons
Baptism in the Jordan River: immersing in a contested transboundary watercourse
Authors: de Châtel Francesca 
Published: January 2014

As the boundary of the Holy Land and the site of the baptism of Jesus Christ, the Jordan River is the most important river in Christianity. For centuries, pilgrims have traveled long distances to immerse themselves in this holy water and despite its relatively small size, the image of the ‘mighty’ Jordan has come to dominate popular imaginations. Over the past century, however, the Jordan has fallen victim to the ongoing regional conflict and suffered severe environmental degradation. Once a meandering river full of rapids and cascades, the Jordan has been extensively developed, with dams, diversion canals, and large‐scale irrigation projects on the river, its tributaries, and headwaters. As a result, flow has been reduced to about one tenth of the historic value and water quality has sharply deteriorated, with raw sewage, saline flows, and agricultural run‐off polluting the remaining water. Yet despite the river's changed physical state, the Jordan's mythical status and its association with defining moments of Jewish and Christian history continue to dominate collective imaginations in the religious realm, with nearly a million annual visitors at the three baptism sites in Israel, Jordan, and the West Bank. Why is there such a disconnect between the physical river and its spiritual counterpart? How can the sense of indifference and lack of awareness about the degradation of this holy river be explained? And what can be done to restore the Jordan River?This article is categorized under:

Water and Life > Conservation, Management, and Awareness
Water and Life > Stresses and Pressures on Ecosystems
Human Water > Water as Imagined and Represented
Understanding the dynamics of black carbon and associated contaminants in glacial systems
Authors: Hodson Andrew J. 
Published: January 2014

More than one billion people depend upon glaciers for water, yet this exploitation is seldom underpinned by science‐led water management practice. Previous work has detected that glaciers store and then subsequently release contaminants to downstream ecosystems, revealing a potentially harmful legacy that needs to be managed in conjunction with contemporary atmospheric pollution and climate change. Remarkably, while several classes of harmful organic pollutants have been considered in this context, almost no attention has been given to black carbon, a dark aerosol that is host to several adsorbed contaminants and that greatly increases glacier melt by enhancing the absorption of solar radiation. The future impact of black carbon upon glacier melt and contaminant release cannot be managed until we know how much historical black carbon is stored in Earth's glaciers. Further, as the residence time of ice within many mountain glaciers is between 100 and 1000 years, major changes in these impacts can be anticipated in the near future. A case is therefore made for using glacier dynamic models to understand the distribution of postindustrial, contaminated ice within glaciers, so that their impacts upon melt water quantity and quality can be forecast. A research framework is proposed that ranges from high flux, dynamic glaciers which are replete with postindustrial ice, to low flux, polar glaciers which are unlikely to become replete before they disappear. Research into the processing of contaminants following their melt‐out is also required, because microbial processes will lead to their bioflocculation and biodegradation on glacier surfaces.This article is categorized under:

Water and Life > Nature of Freshwater Ecosystems
Wind turbine boundary layer arrays for Cartesian and staggered configurations‐Part I, flow field and power measurements
Authors: Hamilton Nicholas , Melius Matthew , Cal Raúl Bayoán 
Published: January 2014

AbstractModel wind turbine arrays were developed for the purpose of investigating the wake interaction and turbine canopy layer in a standard cartesian and row‐offset turbine array configurations. Stereographic particle image velocimetry was used to collect flow data upstream and downstream of entrance and exit row turbines in each configuration. Wakes for all cases were analyzed for energy content and recovery behavior including entrainment of high‐momentum flow from above the turbine canopy layer. The row‐offset arrangement of turbines within an array grants an increase in streamwise spacing of devices and allows for greater wake remediation between successive rows. These effects are seen in exit row turbine wakes as changes to statistical quantities including the in‐plane Reynolds stress, , and the production of turbulence. The recovery of wakes also strongly mitigates the perceived underperformance of wind turbines within an array. The flux of kinetic energy is demonstrated to be more localized in the entrance rows and in the offset arrangement. Extreme values for the flux of kinetic energy are about 7.5% less in the exit row of the cartesian arrangement than in the offset arrangement. Measurements of mechanical torque at entrance and exit row turbines lead to curves of power coefficient and demonstrate an increase in efficiency in row‐offset configurations. Copyright © 2014 John Wiley & Sons, Ltd.
Preventing wind turbine overspeed in highly turbulent wind events using disturbance accommodating control and light detection and ranging
Authors: Pace A. , Johnson K. , Wright A. 
Published: January 2014

AbstractLight detection and ranging (LIDAR) systems can be used to provide wind inflow information to a wind turbine controller before the wind reaches the turbine. Both fatigue and extreme load reduction are possible as a result; in this research, we propose a LIDAR‐based controller designed to prevent emergency shutdowns caused by rotor overspeed. This switching controller consists of a disturbance accommodating control (DAC)‐based baseline controller and a different DAC linearized about a reduced generator speed for extreme events, also referred to as an extreme event controller. Switching between the controllers was performed using linear interpolation over various transition times, depending on how early the extreme event could be detected. If a gust of wind is detected using LIDAR measurements evaluated by a one‐sided cumulative summation algorithm, a relatively long transition time can be used. Switching can also be based on a large output estimation error, εy, in which case the transition time is shorter. Once the extreme event passed, control is switched from the extreme event controller back to the baseline DAC. This switching controller resulted in fewer overspeeds when compared with the modified baseline controller, which is a gain scheduled DAC. By preventing overspeeds, the switching controller increased the mean power the wind turbine generated over a simulated 10 min period. Copyright © 2014 John Wiley & Sons, Ltd.
Matching experimental and numerical data of dynamic power train loads by modeling of defects
Authors: Heege Andreas , Hemmelmann Jan 
Published: January 2014

AbstractDefects on wind turbines such as power train misalignments or blade pitch angle deviations are dealt with. These defects cause additional dynamic excitations and thus can reduce the fatigue life of wind turbine components.In order to improve the reliability of dynamic load computations and related fatigue dimensioning of wind turbines, a highly discretized simulation model that incorporates potential system defects is set up. A sensitivity analysis of the impact of system defects on power train dynamics is performed. Experimental measurements of gearbox orbital paths and of the corresponding torque arm loads could be reproduced with good correlation when the simulation model was complemented by power train misalignments and by blade pitch angle deviations. Comparisons of experimental and numerical data are presented in time and frequency domains. Feasible consequences about the impact of alignment defects on the resulting fatigue damage are presented. Copyright © 2014 John Wiley & Sons, Ltd.