bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonlinear optical fiber based high resolution all‐optical waveform sampling
Authors: Andrekson P.A. , Westlund M. 
Published: November 2007

AbstractWhen there is a need to accurately characterize optical waveforms and, it is not surprising that some of the best, albeit only recently established, techniques to do this rely on all‐optical phenomena. Some basic reasons why all‐optical sampling holds great promise as a very useful tool well into the foreseeable future are that there are no ringing phenomena with associated waveform distortion as in electronic sampling due to impedance mismatch, and that the time resolution can be made extremely high (⩽ 1 ps) while yet also offering high sensitivity for e.g. eye diagram (a superposition of all ‘1’ and ‘0’ in a data sequence that is widely used in telecommunications testing) and statistical analysis. In this paper, we review recent developments in optical fiber‐based sampling of optical waveforms. In particular, we describe the state‐of‐the‐art in terms of the various performance measures as well as their trade‐offs.
An Exploration of Needs for Connotative Messages during Image Search Process
Authors: Yoon JungWon 
Published: November 2007

AbstractThis study aims to provide an understanding of the information seeking process for image documents by focusing on needs for connotative messages. For this purpose, this study attempted to investigate and compare three stages of the image search process in terms of use of image attributes. The three stages of the image search process are identified as initiation, representation and selection, and image attribute levels are defined as color, denotative, and connotative attributes. Data was collected from a survey questionnaire composed of Likert scales, open questionnaires, and Semantic Differential scales. The study found that while color, denotative, and connotative attributes were all considered important by users, color itself did not have critical impact during the representing and selecting stages. Denotative and connotative attributes were important across the overall search process and users employed diverse denotative and connotative terms for finding a satisfactory image under a given task. This study also demonstrated that affective attributes of an image can be represented with reduced dimensions using Semantic Differential scales, and that reduced dimensions can be used to indicate more meaningful and relevant images.
What Can Searching Behavior Tell Us About the Difficulty of Information Tasks? A Study of Web Navigation
Authors: Gwizdka Jacek , Spence Ian 
Published: November 2007

AbstractTask has been recognized as an influential factor in information seeking behavior. An increasing number of studies are concentrating on the specific characteristics of the task as independent variables to explain associated information‐seeking activities. This paper examines the relationships between operational measures of information search behavior, subjectively perceived post‐task difficulty and objective task complexity in the context of factual information‐seeking tasks on the web. A question‐driven, web‐based information‐finding study was conducted in a controlled experimental setting. The study participants performed nine search tasks of varying complexity. Subjective task difficulty was found to be correlated with many measures that characterize the searcher's activities. Four of those measures, the number of the unique web pages visited, the time spent on each page, the degree of deviation from the optimal path and the degree of the navigation path's linearity, were found to be good predictors of subjective task difficulty. Objective task complexity was found to affect the relative importance of those predictors and to affect subjective assessment of task difficulty.
Different types of human interaction in online discussion: An examination of using online discussion forum
Authors: Lee Jeong‐Mee 
Published: November 2007

AbstractThe primary purpose of this study is to explore the nature of the use of asynchronous computer‐mediated communication in an online academic learning environment. Additionally the study will provide an analysis of students' participations in discussion forums as well as a construct of the types of patterns of students' interactions in two online classes. A total of 47 students (in two different online classes) evaluated their perception of the discussion forum. Three out of 16 weeks' discussion forum were archived, and a total of 214 postings were examined to find out distinct types of interactions. Four types of interactions were extracted, based upon which, students were asked to rate which type of responses they were most likely to post and which types of interactions they were most likely to respond to. Correlations were examined between types of posts and types of interactions. It was found that there was significant correlation between types of interactions and types of interactions that were likely to be responded to.
Researching wikipedia ‐ current approaches and new directions
Authors: Ayers Phoebe 
Published: November 2007

AbstractWikipedia (<http://www.wikipedia.org >), an international, multi‐lingual and collaboratively produced free online encyclopedia, has experienced massive growth since its inception in 2001. The site has become the world's single largest encyclopedia as well as one of the world's most diverse online communities. Because of these factors, the site provides a unique view into the processes of collaborative work and the factors that go into producing encyclopedic content. To date, there has been no unified review of the current research that is taking place on and about Wikipedia, and indeed there have been few formal studies of the site, despite its growing importance. This project is a review of social science and information science studies of the site, focusing on research methods and categorizing the areas of the site that have been studied so far. Studies of Wikipedia have focused primarily on the social dynamics of contributors (such as how disputes are resolved and why contributors participate), and the content of Wikipedia (such as whether it is an accurate source), but due to the unique collaborative processes on Wikipedia these two areas are deeply intertwined.
Development of de novo urge incontinence in women post sling: The role of preoperative urodynamics in assessing the risk
Authors: Alperin Marianna , Abrahams‐Gessel Shafika , Wakamatsu May M. 
Published: November 2007

AbstractAimsThe study was undertaken to investigate if there are specific identifiable risk factors on the preoperative history or urodynamics testing associated with an increased risk for the development of symptoms of de novo urge urinary incontinence after a minimally invasive sling procedure.MethodsTwo hundred eighty‐one women who had undergone minimally invasive sling surgery for stress urinary incontinence between January 2000 and December 2003 were identified. The records of 92 patients were included in this review.ResultsTwenty‐five patients (27%) reported urge urinary incontinence on postoperative questioning. Clinical and urodynamic parameters were correlated with the development of de novo urge urinary incontinence. Preoperative history parameters were not predictive of the increased risk of de novo urge urinary incontinence, with the exception of increased preoperative daytime frequency (OR 3.3 (1.2, 9.1)). Of 16 women whose detrusor pressure during the filling phase of cystometry exceeded 15 cm H2O, de novo urge urinary incontinence developed in 9 (56%) vs. 16 (21%) of 76 women, whose detrusor pressure was ≤ 15 cm H2O (OR 4.6 (1.4, 15.0)).ConclusionsDirected patient history is only minimally helpful in the identification of women at increased risk for the development of de novo urge urinary incontinence, with the exception of the complaint of increased daytime frequency. Women with elevated detrusor pressure during the filling phase of cystometry were more likely to develop urge urinary incontinence postoperatively. Therefore, we suggest that preoperative urodynamic evaluation, and specifically detrusor pressure > 15 cm H2O may help identify patients at increased risk of developing de novo urge urinary incontinence following the minimally invasive sling procedure. Neurourol. Urodynam. 27:407–411, 2008. © 2007 Wiley‐Liss, Inc.
Types and categories of personal projects: a revelatory means of understanding human occupation
Authors: Brooke Kathleen E , Desmarais Carolyn D , Forwell Susan J 
Published: November 2007

AbstractChoice of activity and the way it is described may have little to do with the presence of disease and may or may not align with predetermined conceptual or practice frameworks. The present study examines data previously collected by use of Personal Projects Analysis (PPA) in order to compare the types of projects listed by people with and without multiple sclerosis and to compare the categories of projects selected by both groups to those pre‐established in the literature. Secondary analysis tests the differences and similarities in the types of personal projects between two groups, multiple sclerosis (n = 38) and control group (n = 25), matched for demographic characteristics. The analysis compares the categories of personal projects generated by people in both cohorts to pre‐established frameworks. No significant difference was found between the types of personal projects chosen by the two cohorts. For 57.2% of participants the self‐generated categories matched those from the literature, whereas it diverged for 18.2% of the categories of personal projects generated by participants. The study demonstrates that people with and without multiple sclerosis engage in activities that are similar despite the presence of multiple sclerosis, and that category systems should be used cautiously. Copyright © 2007 John Wiley & Sons, Ltd.
Fluoro‐protected carbazole main‐chain polymers as a new class of stable blue emitting polymers
Authors: Kun Harismah , Yi Hunan , Johnson Richard G. , Iraqi Ahmed 
Published: November 2007

AbstractThe protection of the 3,6‐positions of 9‐alkyl‐9H‐carbazole repeat units with fluorine substituents in 2,7‐linked main‐chain polymers as well as in copolymers with triaryl amine repeat units affords blue emitting materials with enhanced electrolytic stability. The electronic conjugation of this new class of materials is more extended than that of the equivalent polymers where the 3,6‐positions are protected with methyl substitutions as a result of the smaller steric hindrance of their fluorine substituents. Attachment of fluorine‐protecting groups at the 3,6‐positions of carbazole repeat units in the homopolymers resulted in materials with relatively high ionization potentials (5.71 eV). However, introduction of triaryl amine comonomers as alternating repeat units provided carbazole/triaryl amine copolymers with a low ionization potential (5.25 eV), a very high quantum yield of fluorescence in solution (0.96), and narrow emission bands [full width at half maximum (FWHM) = 52 nm]. The preparation of this new class of materials together with a study of their electronic and photophysical properties is presented. Copyright © 2007 John Wiley & Sons, Ltd.
Hypoxia‐inducible factor 1α is essential for hypoxic p27 induction in endometrioid endometrial carcinoma
Authors: Horrée N , Gort EH , van der Groep P , Heintz APM , Vooijs M , van Diest PJ 
Published: November 2007

AbstractHypoxia‐inducible factor 1α (HIF‐1α) plays an essential role in the adaptive response of cells to hypoxia. The cyclin‐dependent kinase inhibitor p27(Kip1) is highly expressed in the normal endometrium but is lost during endometrial carcinogenesis. However, in high‐grade cancers, p27 re‐expression is observed. We analysed the role of HIF‐1α in hypoxia‐induced expression of p27 in vitro and in vivo in endometrial cancer. Paraffin‐embedded specimens from endometrioid endometrial carcinoma (n = 39) were stained immunohistochemically for HIF‐1α, p27, and Ki67. HEC1B, an endometrial carcinoma cell line, was cultured under normoxic or hypoxic conditions in the presence or absence of transiently expressed short hairpin RNAs targeting HIF‐1α. Protein expression of p27 and HIF‐1α was assessed by western blotting. Immunohistochemical staining revealed perinecrotic HIF‐1α expression in 67% of the cases and p27 staining centrally in the tumour islands, mostly around necrosis, in 46% of the cases. In 50% of the tumours with perinecrotic HIF‐1α expression, p27 and HIF‐1α perinecrotic/central co‐localization was observed. In these tumour sections, hypoxia‐associated p27 expression showed less proliferation around necrosis. Analysis of cultured endometrial carcinoma cells demonstrated that p27 protein expression is induced by hypoxia. This induction was abrogated by transient knockdown of HIF‐1α using RNAi. Furthermore, hypoxia induced cell cycle arrest in HEC1B cells. We conclude that, in endometrioid endometrial carcinoma, p27 re‐expression by hypoxia is HIF‐1α‐dependent and leads to cell cycle arrest. This may contribute to the survival of cancer cells in hypoxic parts of the tumour. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Blood transfusion therapy is feasible in a clinical trial setting in children with sickle cell disease and silent cerebral infarcts
Authors: King Allison A. , Noetzel Michael , White Desirée A. , McKinstry Robert C. , DeBaun Michael R. 
Published: November 2007

AbstractBackgroundSilent cerebral infarcts are both morbid and progressive in children with sickle cell disease (SCD). While blood transfusion therapy is effective primary and secondary stroke prevention, the efficacy and acceptance of blood transfusion therapy for children with silent cerebral infarcts is unknown. The overall goals of this study were to determine the feasibility and short‐term efficacy of blood transfusion therapy for silent cerebral infarcts.ProcedureWe conducted a single‐arm feasibility intervention study. Children with SCD and silent cerebral infarcts received blood transfusion therapy. Short‐term efficacy was defined as no progression of MRI findings on repeat MRI.ResultsTen children enrolled in the study, and nine were evaluable. Five were male. The average age was 10.0 years (range 3.1–16.8). Seven of nine completed the transfusion therapy for over 2 years, with an average duration of therapy of 2.7 years (range 1–6). Twenty infarcts and four cases of Moya Moya were present on the initial MRI. Seven of nine subjects had repeat MRIs. Of these seven, there were a total of 18 infarcts. One infarct increased in size and one case of Moya Moya progressed on repeat MRI. All other lesions were stable or became smaller in diameter while on transfusion therapy during the time of follow up (mean 3.9 years, range 2.1–5.7).ConclusionsBlood transfusion therapy is a feasible therapy for the prevention of progression of silent cerebral infarcts. Pediatr Blood Cancer 2008;50:599–602. © 2007 Wiley‐Liss, Inc.
High performance thermoplastic composites: Study on the mechanical, thermal, and electrical resistivity properties of carbon fiber‐reinforced polyetheretherketone and polyethersulphone
Authors: Saleem Anjum , Frormann Lars , Iqbal Azhar 
Published: November 2007

AbstractHigh temperature processing thermoplastic polymers, polyetheretherketone (PEEK) and polyethersulphone (PES), were melt blended with carbon fibers (CFs) to make composites. These composites were investigated for their mechanical, thermal, and electrical properties. Mechanical properties that are expressed in terms of storage modulus, loss, and damping were enhanced with the addition of CFs. Thermal properties were determined by DSC and TGA. These methods help to understand the effects of fiber content and fiber–matrix adhesion in the composites. Composites were also tested for their electrical and thermal conductivity because CFs leave the composites thermally and electrically conductive. CFs enhanced the crystallinity of the PEEK appreciably that in turn influenced thermal conductivity, electrical resistivity, and the stiffness of PEEK/CF (composites of PEEK with CFs). PES/CF (composites of PES with CF) shows a different behavior due to the amorphous nature of PES. The work involves one filler and two different matrices, and so it provides an interesting comparison of how matrix morphology can influence the properties of composites. POLYM. COMPOS. 28:785–796, 2007. © 2007 Society of Plastics Engineers.
Filler–rubber interactions in α_cellulose‐filled styrene butadiene rubber composites
Authors: Haghighat M. , Khorasani S. Nouri , Zadhoush A. 
Published: November 2007

AbstractIn this study, the interactions between rubber and fillers in α_cellulose‐filled styrene butadiene rubber (SBR) composites were investigated. The results obtained from the tensile and tear strength, abrasion resistance, and hardness indicate that addition of 5‐phr α_cellulose into compound not only does not affect rubber–carbon black bond but improves the mentioned physicomechanical properties. In this study, the type of carbon black was changed from N 330 to N 550. The main purpose of this investigation was to observe the possible changes in physicomechanical properties due to this change. Obtained results show that overall observation of the trends of results do not change with type of carbon black. It can be concluded that the presence of α_cellulose does not have significant influence on the performance of carbon black in the compounds used. POLYM. COMPOS., 28:748–754, 2007. © 2007 Society of Plastics Engineers
Interaction of silica and carbon black fillers with natural rubber/poly(ethylene‐co‐vinyl acetate) matrix by swelling studies
Authors: Sujith A. , Unnikrishnan G. , Radhakrishnan C.K. , Padmini M. 
Published: November 2007

AbstractThe interaction of a black filler and a white filler, which are extensively used in the rubber industry, with natural rubber/poly (ethylene‐co‐vinyl acetate) (NR/EVA) blends vulcanized by DCP has been examined by equilibrium swelling technique. Blends loaded with intermediate super abrasion furnace black (ISAF) and those with silica (SiO2), of same loading, have been used. The silica incorporated blends sorbed a higher amount of aromatic solvents, compared with the ISAF filled blends, when NR was the continuous phase. However, the silica filled systems showed lower sorption characteristics when EVA became the continuous phase. This has been explained in terms of the differences in the interaction between the filler particles and the blend components. The swelling coefficient, diffusion coefficient, and molar mass between crosslinks have been computed to complement the experimental observations. POLYM. COMPOS., 28:705–712, 2007. © 2007 Society of Plastics Engineers
Thermodegradation kinetics of epoxy/DDS/POSS system
Authors: Zhang Zengping , Liang Guozheng , Ren Penggang , Wang Jieliang 
Published: November 2007

AbstractThe thermodegradation kinetics of a hybrid inorganic–organic epoxy system formed by diglycidyl ether of bisphenol A, DGEBA/DDS, modified with octahedral oligomeric silsesquioxane, octa(aminopropylsilsesquioxane) was studied. The average activation energy of thermodegradation of this system was calculated by the integral method developed by Flynn–Wall–Ozawa (E = 105.01 kJ mol−1) and by Coats and Redfern method (E = 113.07 kJ mol−1). Lifetime and half‐life time of the materials system were predicted using the kinetic parameters. The results obtained from the two methods accorded well with each other. POLYM. COMPOS., 28:755–761, 2007. © 2007 Society of Plastics Engineers
Composite screen‐printed thick films for high dielectric constant devices: Bi4Ti3O12–CaCu3Ti4O12 films
Authors: Sabóia K.D.A. , Fechine P.B.A. , Santos M.R.P. , Freire F.N.A. , Pereira F.M.M. , Sombra A.S.B. 
Published: November 2007

AbstractIn this paper, we did a study of the effect of the presence of BIT (Bi4Ti3O12) in the dielectric and optical properties of the CaCu3Ti4O12 (CCTO) thick films. The films were prepared by the solid sate procedure. Mechanical alloying followed by the solid state procedure has been used successfully to produce powders of CaCu3Ti4O12 (CCTO) and BIT (Bi4Ti3O12) to be used in the composites. We also look at the effect of the grain size of the BIT and CCTO in the final properties of the composite film. The samples were studied using X‐Ray diffraction, scanning electron microscopy (SEM), Raman and infrared spectroscopy. We also did a study of the dielectric function (K) and dielectric loss (D) of the films. The role played by the grain size of CCTO and BIT in the dielectric constant and structural properties of the films are discussed. These measurements confirm the potential use of such materials for small high dielectric planar devices. These films are also attractive for capacitor applications and certainly for microelectronics, microwave devices (mobile phones for example), where the miniaturization of the devices is crucial. POLYM. COMPOS., 28:771–777, 2007. © 2007 Society of Plastics Engineers
Origin of deterioration in mechanical properties of glass fiber reinforced nylon 6,6 composites by aqueous ethylene glycol solution
Authors: Hong John Hee , Dhevi D. Manjula , Lee Jong Soon , Kim Kap Jin 
Published: November 2007

AbstractGlass fiber reinforced nylon 6,6 (GFNY66) composites widely used for automotive applications undergo degradation when repeatedly exposed to aqueous ethylene glycol (EG) solution, resulting in significantly reduced mechanical properties. Hence, it is important to clearly understand the degradation and hydrogen bond breaking mechanism of nylon 6,6 (NY66) and interfacial failure mechanism in GFNY66 (when exposed to aqueous EG solution) in order to improve the mechanical properties of recycled NY66. From ATR‐IR spectra of NY66 immersed in aqueous EG solution at 108°C for varying intervals of time, the shifting of amide‐I band (νCO) at 1640 cm−1 towards lower frequency with increasing immersion time may be attributed to the breakage of intra‐ and intermolecular H‐bonding between amides in NY66 followed by the new formation of H‐bonding between amide group in NY66 and hydroxyl group in the absorbed EG. GPC data revealed the reduction in molecular weight due to the absorption of EG into NY66 matrix leading to chain scission of NY66. GFNY66 samples treated with aqueous EG solution exhibited pronounced deterioration in mechanical properties because of the interfacial failure between glass fiber and NY66 matrix as well as molecular weight reduction caused by the absorbed EG solution. POLYM. COMPOS., 28:778–784, 2007. © 2007 Society of Plastics Engineers
Micromechanical modeling of fiber reinforced composites based on elastoplasticity and its application for 3D braided glass/Kevlar composites
Authors: Kim Ji Hoon , Ryou Hansun , Lee Myoung‐Gyu , Chung Kwansoo , Youn Jae Ryoun , Kang Tae Jin 
Published: November 2007

AbstractMicromechanical modeling to calculate the mechanical properties of fiber reinforced composites is proposed. To describe the mechanical behavior of the yarn and the matrix, which are the main constituents of fiber reinforced composites, the elastoplastic constitutive law was adopted. In particular, anisotropic elastoplasticity based on Hill's orthotropic yield function and anisotropic kinematic hardening was utilized for the yarn, while the isotropic elastoplastic constitutive law was applied for the matrix. The effective properties of the unit cell in fiber reinforced composites were then calculated based on the finite element method. For verification, the method was successfully applied for 3D braided glass/Kevlar fiber reinforced composites in both linear elastic and nonlinear inelastic ranges. POLYM. COMPOS., 28:722–732, 2007. © 2007 Society of Plastics Engineers