bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mobile Phones and Education in Sub‐Saharan Africa: From Youth Practice to Public Policy
Authors: Porter Gina , Hampshire Kate , Milner James , Munthali Alister , Robson Elsbeth , de Lannoy Ariane , Bango Andisiwe , Gunguluza Nwabisa , Mashiri Mac , Tanle Augustine , Abane Albert 
Published: June 2015

AbstractYoung people's use of mobile phones is expanding exponentially across Africa. Its transformative potential is exciting, but findings presented in this paper indicate how the downside of mobile phone use in African schools is becoming increasingly apparent. Drawing on mixed‐methods field research in 24 sites across Ghana, Malawi and South Africa and associated discussions with educational institutions, public policy makers and network providers, we examine the current state of play and offer suggestions towards a more satisfactory alignment of practice and policy which promotes the more positive aspects of phone use in educational contexts and militates against more damaging ones. © 2015 The Authors. Journal of International Development published by John Wiley & Sons Ltd.
Cultural study and problem‐solving gains: Effects of study abroad, openness, and choice
Authors: Cho Jaee , Morris Michael W. 
Published: June 2015

SummaryPast research indicates that foreign experience helps problem solving because the experience of adapting one's lifestyle imparts cognitive flexibility. We propose that an independent process involves studying cultural traditions and systems, which imparts foreign concepts that enable unconventional solutions. If so, advantages on unconventionality problems should be associated with experiences studying of another culture, such as typically occurs in study‐abroad programs. The link should be especially strong for individuals with personalities high in openness and in contexts featuring choice. A survey of MBA students' past foreign stays found that greater study abroad was associated with more unconventional solutions and provided mixed support for the two moderating conditions. Study 2 experimentally varied the presence of choice before putting participants through a simulated foreign internship featuring study and situations demanding adaptation. Subsequent solutions to a product design problem were more conventionally Asian and (marginally) less conventionally American in the choice condition, and these effects were mediated by the amount of foreign knowledge acquisition. Implications for selecting employees and developing employees on the basis of foreign experiences are discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Soil attributes and plant production changes in a tropical littoral wetland
Authors: Dold Christian , Becker Mathias 
Published: June 2015

AbstractLake Naivasha is a freshwater lake in the East African Rift Valley. With continued lake level declines between 1980 and 2011, the newly exposed land areas were gradually taken for agricultural use. The resulting chronosequences allow for an analysis of the effects of land use duration on nutrient dynamics and agricultural production. Transects representing land use durations of 0–30 (cropland) and 15–30 years (pasture) were established on soils formed on alluvial deposits and lacustrine sediments. We assessed changes in topsoil nitrogen (N) stocks (t ha−1), ammonium mineralization potential (N‐supplying capacity), and plant‐available P with increasing durations of land use. An additional greenhouse experiment studied the responses of kikuyu grass (Cenchrus clandestinus) and maize (Zea mays) in potted topsoil collected from differnt land‐use types and chronosequence positions. With increasing duration of land use we noted a significant decline (P< 5%) in soil N contents under both pasture and cropland uses, following a model of exponential decay. The N stocks decreased at 84 kg ha−1a−1and a decay rate constant of 0.019 a−1in pasture soil within 15 years, and at 75 kg ha−1a−1with a decay rate‐constant of 0.013 a−1in cropland soil within 30 years. While the ammonium‐N mineralization potential also decreased with land use duration, the trends were significant only in lacustrine pasture soils. Plant‐available P did not show any trends that were related to the duration of land use. Kikuyu grass and maize accumulated less dry matter and N as the duration of use increased. This biomass accumulation was significantly related to soil N. A continued mineralization of soil organic matter has possibly contributed to the observed soil N depletion over time. The continuous agricultural use of the littoral wetland zone of Lake Naivasha is likely to entail declining production potentials for both pastures and food crops.
The Importance of Internal Resources and Capabilities and Destination Resources to Explain Firm Competitive Position in the Spanish Tourism Industry
Authors: Camisón César , Puig‐Denia Alba , Forés Beatriz , Fabra María Eugenia , Muñoz Azahara , Muñoz Martínez CÉSAR 
Published: June 2015

AbstractThis study draws on the Resource‐Based View to analyze the effects of distinctive competences in tourism firms and location in a tourism district on competitive position, and explores the moderating effects of the tourism destination. Multiple linear regression was used to test the research hypotheses on a sample of 1019 Spanish tourism firms. Results reveal that financial resources and dynamic and production capabilities favor a better competitive position for tourism firms in general; however, coordination and marketing capabilities are key factors for firms embedded in a tourism district, while dynamic capabilities have a negative effect in this case. Copyright © 2015 John Wiley & Sons, Ltd.
Soft PEG‐Hydrogels with Independently Tunable Stiffness and RGDS‐Content for Cell Adhesion Studies
Authors: M. Jonker Anika , A. Bode Saskia , H. Kusters Addie , van Hest Jan C. M. , Löwik Dennis W. P. M. 
Published: June 2015

AbstractPoly(ethylene)glycol (PEG)‐based hydrogels are often used as matrix material for cell culturing. An efficient method to prepare soft PEG gels is by cross‐linking via copper‐free strain‐promoted azide‐alkyne cycloaddition (SPAAC). Here, the effect of polymer density and RGDS‐content on hydrogel formation and cell adhesion was studied, by varying the total polymer content (10, 20 and 30 mg · mL−1) and the amount of RGDS moieties (0–100%) independently of each other. Rheology studies confirmed the soft nature of the hydrogels (G′ = 25–2 298 Pa). HOS cells are able to adhere well to all RGDS‐containing gels. Interestingly, both HeLa cells and NIH 3T3 fibroblasts showed substantial adherence to 10 and 20 mg · mL−1 gels, but with increased hydrogel stiffness (30 mg · mL−1), their cellular adhesion decreased significantly.
Novel Insights into Pressure‐Sensitive Adhesives Based on Plant Oils
Authors: Maaßen Wiebke , Oelmann Stefan , Peter David , Oswald Walter , Willenbacher Norbert , Meier Michael A. R. 
Published: June 2015

This work investigates the synthesis of bio‐based pressure‐sensitive adhesives and their characterization in terms of mechanical properties relevant to processing and application. The synthesis of monomers based on various fatty acids derived from vegetable oils as renewable feedstock via a one‐step, a two‐step, and a three‐step route is described. The resulting monomers are polymerized via free radical polymerization resulting in high molecular weight polymers with adhesive properties. Adhesives are also obtained as aqueous dispersions by means of miniemulsion polymerization. In particular, the monomer acrylated methyl oleate (4ac) and the thereof derived polymer are intensively studied. The synthesized homopolymers show characteristic mechanical and adhesive properties similar to conventional pressure sensitive adhesives.
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Modeling Acrylic Acid Radical Polymerization in Aqueous Solution
Authors: Wittenberg Nils F. G. , Preusser Calista , Kattner Hendrik , Stach Marek , Lacík Igor , Hutchinson Robin A. , Buback Michael 
Published: June 2015

AbstractBatch radical polymerization of 5–40 wt% non‐ionized acrylic acid (AA) in aqueous solution has been studied between 35 and 90 °C under variation of initiator concentration and type as well as upon addition of different levels of 2‐mercaptoethanol as chain‐transfer agent (CTA). Chain‐length‐dependent termination was taken into account in a model developed to describe the system, as high amounts of CTA have an impact on polymerization kinetics due to reduced chain length. The model also considers the 1,5‐hydrogen shift (backbiting) reaction that transforms the secondary propagating radical into a tertiary midchain radical, with the backbiting reaction quantified via 13C NMR. The model developed is the most comprehensive treatment to date of this complex polymerization system and is able to represent monomer conversion profiles and polymer molar mass distributions over a wide range of conditions.
Parallel preconditioners and multigrid solvers for stochastic polynomial chaos discretizations of the diffusion equation at the large scale
Authors: Lee Barry 
Published: June 2015

SummaryThis paper presents parallel preconditioners and multigrid solvers for solving linear systems of equations arising from stochastic polynomial chaos formulations of the diffusion equation with random coefficients. These preconditioners and solvers are extensions of the preconditioner developed in an earlier paper for strongly coupled systems of elliptic partial differential equations that are norm equivalent to systems that can be factored into an algebraic coupling component and a diagonal differential component. The first preconditioner, which is applied to the norm equivalent system, is obtained by sparsifying the inverse of the algebraic coupling component. This sparsification leads to an efficient method for solving these systems at the large scale, even for problems with large statistical variations in the random coefficients. An extension of this preconditioner leads to stand‐alone multigrid methods that can be applied directly to the actual system rather than to the norm equivalent system. These multigrid methods exploit the algebraic/differential factorization of the norm equivalent systems to produce variable‐decoupled systems on the coarse levels. Moreover, the structure of these methods allows easy software implementation through re‐use of robust high‐performance software such as the Hypre library package. Two‐grid matrix bounds will be established, and numerical results will be given. Copyright © 2015 John Wiley & Sons, Ltd.
Clonality analysis of combined Brenner and mucinous tumours of the ovary reveals their monoclonal origin
Authors: Wang Yihong , Wu Ren‐chin , Shwartz Lauren Ende , Haley Lisa , Lin Ming‐tse , Shih Ie‐ming , Kurman Robert J 
Published: June 2015

AbstractThe derivation of ovarian intestinal‐type mucinous tumours is not well established. Some are derived from teratomas but the origin of the majority is not clear. It has been recently proposed that the non‐germ cell group may be derived from Brenner tumours, as the association of a mucinous tumour with a Brenner tumour is frequently observed. In order to explore the histogenesis of these neoplasms, we undertook a clonality analysis of the two components of ten combined Brenner and mucinous tumours using a human androgen receptor gene (HUMARA) assay. All eight informative cases of ten showed a concordant X‐chromosome inactivation pattern between the two tumour components, indicative of a shared clonal origin (p = 0.0039). Microsatellite genotyping in five of the combined tumours displayed an identical heterozygous pattern with paired Fallopian tube tissue, indicative of a somatic cell origin. In addition, paired box protein 8, a highly sensitive Müllerian epithelial marker, was not detected by immunohistochemistry in either tumour component in any of the ten tumours, suggesting that this subset of mucinous tumours does not originate from Müllerian‐derived epithelium. In conclusion, this study demonstrates that in combined mucinous and Brenner tumours, there is a shared clonal relationship between the two different tumour components and suggests that some pure mucinous tumours may develop from a Brenner tumour in which the Brenner tumour component becomes compressed and obliterated by an expanding mucinous neoplasm. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
CD47 deficiency ameliorates autoimmune nephritis in Faslpr mice by suppressing IgG autoantibody production
Authors: Shi Lei , Bian Zhen , Chen Celia XJ , Guo Ya‐Nan , Lv Zhiyuan , Zeng Caihong , Liu Zhihong , Zen Ke , Liu Yuan 
Published: June 2015

AbstractCD47, a self‐recognition marker, plays an important role in both innate and adaptive immune responses. To explore the potential role of CD47 in activation of autoreactive T and B cells and the production of autoantibodies in autoimmune disease, especially systemic lupus erythematosus (SLE), we have generated CD47 knockout Faslpr (CD47−/−−Faslpr) mice and examined histopathological changes in the kidneys, cumulative survival rates, proteinuria, extent of splenomegaly and autoantibodies, serum chemistry and immunological parameters. In comparison with Faslpr mice, CD47−/−−Faslpr mice exhibit a prolonged lifespan and delayed autoimmune nephritis, including glomerular cell proliferation, basement membrane thickening, acute tubular atrophy and vacuolization. CD47−/−−Faslpr mice have lower levels of proteinuria, associated with reduced deposition of complement C3 and C1q, and IgG but not IgM in the glomeruli, compared to age‐matched Faslpr mice. Serum levels of antinuclear antibodies and anti‐double‐stranded DNA antibodies are significantly lower in CD47−/−−Faslpr than in Faslpr mice. CD47−/−–Faslpr mice also display less pronounced splenomegaly than Faslpr mice. The mechanistic studies further suggest that CD47 deficiency impairs the antigenic challenge‐induced production of IgG but not IgM, and that this effect is associated with reduction of T follicular cells and impairment of germinal centre development in lymphoid tissues. In conclusion, our results demonstrate that CD47 deficiency ameliorates lupus nephritis in Faslpr mice via suppression of IgG autoantibody production. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The clonal relationships between pre‐cancer and cancer revealed by ultra‐deep sequencing
Authors: Wood Henry M , Conway Caroline , Daly Catherine , Chalkley Rebecca , Berri Stefano , Senguven Burcu , Stead Lucy , Ross Lisa , Egan Philip , Chengot Preetha , Graham Jennifer , Sethi Neeraj , Ong Thian K , High Alec , MacLennan Kenneth , Rabbitts Pamela 
Published: June 2015

AbstractThe study of the relationships between pre‐cancer and cancer and identification of early driver mutations is becoming increasingly important as the value of molecular markers of early disease and personalised drug targets is recognized, especially now the extent of clonal heterogeneity in fully invasive disease is being realized. It has been assumed that pre‐cancerous lesions exhibit a fairly passive progression to invasive disease; the degree to which they, too, are heterogeneous is unknown. We performed ultra‐deep sequencing of thousands of selected mutations, together with copy number analysis, from multiple, matched pre‐invasive lesions, primary tumours and metastases from five patients with oral cancer, some with multiple primary tumours presenting either synchronously or metachronously, totalling 75 samples. This allowed the clonal relationships between the samples to be observed for each patient. We expose for the first time the unexpected variety and complexity of the relationships between this group of oral dysplasias and their associated carcinomas and, ultimately, the diversity of processes by which tumours are initiated, spread and metastasize. Instead of a series of genomic precursors of their adjacent invasive disease, we have shown dysplasia to be a distinct dynamic entity, refuting the belief that pre‐cancer and invasive tumours with a close spatial relationship always have linearly related genomes. We show that oral pre‐cancer exhibits considerable subclonal heterogeneity in its own right, that mutational changes in pre‐cancer do not predict the onset of invasion, and that the genomic pathway to invasion is neither unified nor predictable. Sequence data from this study have been deposited in the European Nucleotide Archive, Accession No. PRJEB6588. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Determination of terpenoid indole alkaloids in hairy roots of Rhazya stricta (Apocynaceae) by GC‐MS
Authors: Akhgari Amir , Laakso Into , Seppänen‐Laakso Tuulikki , Yrjönen Teijo , Vuorela Heikki , Oksman‐Caldentey Kirsi‐Marja , Rischer Heiko 
Published: June 2015

AbstractIntroductionRhazya stricta Decne. (Apocynaceae) is a medicinal plant rich in terpenoid indole alkaloids (TIAs), some of which possess important pharmacological properties. The study material including transgenic hairy root cultures have been developed and their potential for alkaloid production are being investigated.ObjectiveIn this study, a comprehensive GC‐MS method for qualitative and quantitative analysis of alkaloids from Rhazya hairy roots was developed.MethodsThe composition of alkaloids was determined by using GC‐MS. In quantification, the ratio between alkaloid and internal standard was based on extracted ion from total ion current (TIC) analyses.ResultsThe developed method was validated. An acceptable precision with RSD ≤ 8% over a linear range of 1 to 100 µg/mL was achieved. The accuracy of the method was within 94–107%. Analysis of hairy root extracts indicated the occurrence of a total of 20 TIAs. Six of them, pleiocarpamine, fluorocarpamine, vincamine, ajmalicine and two yohimbine isomers are reported here for the first time in Rhazya. Trimethylsilyl (TMS) derivatisation of the extracts resulted in the separation of two isomers for yohimbine and also for vallesiachotamine. Clearly improved chromatographic profiles of TMS‐derivatives were observed for vincanine and for minor compounds vincamine and rhazine.ConclusionThe results show that the present GC‐MS method is reliable and well applicable for studying the variation of indole alkaloids in Rhazya samples. Copyright © 2015 John Wiley & Sons, Ltd.
Development of a rapid immunochromatographic strip test for the detection of Mulberroside A
Authors: Inyai Chadathorn , Komaikul Jukrapun , Kitisripanya Tharita , Tanaka Hiroyuki , Sritularak Boonchoo , Putalun Waraporn 
Published: June 2015

AbstractIntroductionMulberroside A (MuA) is the major active anti‐tyrosinase compound in the root bark extract of Morus alba L. (Moraceae). Typically, MuA is widely employed as an active ingredient in whitening cosmetics. A rapid and simple assay system utilizing a small quantity of test sample is essential for the detection of MuA in large number of samples. An immunoassay using highly specific MuA polyclonal antibodies may be useful for the determination of small quantities of MuA in test samples.ObjectiveTo establish a rapid qualitative MuA test, an immunochromatographic strip test was developed using anti‐MuA polyclonal antibodies (anti‐MuA PAb).MethodologyThe qualitative assay was based on a competitive immunoassay where the detection reagent consisted of anti‐MuA PAb colored with colloidal gold particles. The capture reagent was a MuA‐ovalbumin (MuA‐OVA) conjugate immobilized on the test strip membrane.ResultsA sample containing MuA and the detection reagent were incubated together with immobilized capture reagent on a nitrocellulose membrane. When MuA was present, it competed with the immobilized conjugates on the strip membrane to bind a limited amount of colored antibodies; thus, a positive sample showed no color on the capture spot zone. The detection limit for the strip test was 2 µg/mL. The developed immunochromatographic strip test was utilized to determine MuA in plants, medical preparations and cosmetic samples.ConclusionThis immunochromatographic strip test is advantageous as a rapid, simple and sensitive screening method for the detection of MuA in plant extracts, cosmetic samples and pharmaceutical products.
Prenatal diagnosis and postnatal outcome of massive abdominal aortic aneurysms—a case report
Authors: Bills Victoria L. , Smithson Sarah F. , Tsai‐Goodman Beverly , Tometski Andrew , Overton Timothy G. 
Published: June 2015

What's already known about this topic?

Vascular aneurysm is an extremely rare fetal abnormality and is usually secondary to genetic defects of vascular development such as Marfan, Loeys–Dietz and Ehler's–Danlos Type IV syndromes.
What does this study add?

This is the first report of massive fetal aortic aneurysms occurring as a sporadic event, documenting the postnatal pathophysiological consequences and the inadequacy of effective postnatal surgical correction.
© 2015 John Wiley & Sons, Ltd.
Undiagnosed heterotopic pregnancy, maternal hemorrhagic shock, and ischemic stroke in the intrauterine fetus
Authors: Ezzati Mohammad , Shamshirsaz Alireza A. , Haeri Sina 
Published: June 2015

AbstractHeterotopic pregnancy occurs rarely following natural conception; however, intrauterine embryo transfer following in vitro fertilization is a known risk factor for its occurrence. A 29‐year‐old woman presented with acute abdomen at 14w5d gestation following in vitro fertilization–embryo treatment. A ruptured heterotopic gestation in the left fallopian tube was identified at laparoscopy and treated by salpingectomy. Subsequently, at 21‐week gestation, routine sonogram demonstrated bilateral ventriculomegaly in the intrauterine fetus. Fetal magnetic resonance imaging was highly suggestive of ischemic brain injury, most likely attributable to the maternal hypovolemic shock because of ruptured heterotopic gestation. The pregnancy was terminated by intracardiac injection and induction of labor. Timely diagnosis of heterotopic pregnancy requires a high index of suspicion as diagnostic delays can have catastrophic consequences for the mother and/or the intrauterine fetus. © 2015 John Wiley & Sons, Ltd.
Ultrasonographic prediction of birth weight discordance in twin pregnancies
Authors: van de Waarsenburg M. K. , Hack K. E. A. , Rijpma R. J. , Mulder E. J. H. , Pistorius L. , Derks J. B. 
Published: June 2015

AbstractObjectiveThis study aimed to assess the accuracy of the ultrasonographic prediction of intertwin birth weight discordance based on crown–rump length, estimated fetal weight (EFW) and abdominal circumference.MethodWe retrospectively studied variables of prenatal surveillance of 281 twin pregnancies at the University Medical Centre Utrecht, between 2008 and 2011.ResultsFifteen per cent of twins had a birth weight discordance of ≥20%. One twin more commonly had intrauterine growth restriction in the birth weight discordance group compared with the concordantly grown group (69% vs 20%, respectively). Sonographically, EFW discrepancy and increased abdominal circumference ratio were significantly correlated with birth weight discordance. The negative predictive values were high (92% and 87%, respectively). The best prediction of weight discordance was given by EFW discordance at the last ultrasound before delivery.ConclusionIntertwin birth weight discordance is best predicted by an intertwin EFW discordance at the last ultrasound. If discordance is not suspected by ultrasound, the vast majority had no birth weight discordance. In case of birth weight discordance, the presence of at least one growth‐restricted twin is very likely. However, because around 20% of concordantly grown twin pairs comprise at least one intrauterine growth restriction infant, one cannot rely on weight discordance alone. © 2015 John Wiley & Sons, Ltd.