bluuebunny/crossref_metadata_2025_split huggingface dataset:
Engineering investigations on the potentiality of the thermoformability of HDPE charged by wood flours in the thermoforming part
Authors: Erchiqui F. , Godard F. , Gakwaya A. , Koubaa A. , Vincent M. , Kaddami H. 
Published: May 2009

AbstractA dynamic finite element method is used to analyze the thermoformability of composites containing wood and a thermoplastic matrix for five different proportions of wood flour. Linear viscoelastic properties can be obtained by small amplitude oscillatory shear tests and the viscoelastic behavior is characterized using the Lodge model. To account for enclosed gas volume, which inflates the thermoplastic composite membrane, a thermodynamic approach is used to express the external work in terms of a closed volume. Pressure load is deduced by thermodynamic law using the Redlich–Kwong gas equation. The Lagrangian method together with the assumption of membrane theory is used in the finite element implementation. In addition, the influence of air flow on thickness and stress and the energy required to form a thin polymeric part in the thermoforming process are analyzed for five different proportions of wood flour in the HDPE material. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Synthesis and characterization of poly(acrylic acid‐co‐acrylamide)/hydrotalcite nanocomposite hydrogels for carbonic anhydrase immobilization
Authors: Zhang Ya‐Tao , Fan Li‐Hai , Zhi Tian‐Tian , Zhang Lin , Huang He , Chen Huan‐Lin 
Published: May 2009

AbstractTo combine the advantages of a biopolymer with hydrotalcite in an enzyme immobilization system, the intercalation polymerization was used to prepare poly(acrylic acid‐co‐acrylamide)/hydrotalcite (PAA‐AAm/HT) nanocomposite hydrogels using sodium methyl allyl sulfonate as intercalation agent. Transmission electron microscopy, X‐ray diffraction, and Fourier transform infrared spectroscopy results revealed that sodium methyl allyl sulfonate chains entered into the interlayer of HT, the interaction between them has taken place, and HT was dramatically exfoliated into nanoscale and homogeneously dispersed in the PAA‐AAm matrix. Transmission electron microscopy and cryo scanning electron microscope results showed that dried hydrogels were regular spherical particles, and swollen hydrogels revealed homogeneous porous network structures. Then, PAA‐AAm/HT nanocomposite hydrogels were used to immobilize carbonic anhydrase (CA), and the CO2 hydration activities of free enzyme and immobilized enzyme were evaluated. Results showed that immobilized CA retained the majority of the enzyme activity. The reason may be the formation of a microenvironment almost all of which is composed of free water inside the porous network structures. Therefore, the immobilized CA is of great potential in the removal of trace CO2 from the closed spaces. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3232–3240, 2009
Microstructure and piezoelectric properties of Li‐doped Bi0.5(Na0.825K0.175)0.5TiO3 piezoelectric ceramics
Authors: Chen Xiaoming , Liao Yunwen , Mao Lijun , Deng Yilan , Wang Huaiping , Chen Qiang , Zhu Jiliang , Xiao Dingquan , Zhu Jianguo , Xu Guangliang 
Published: May 2009

AbstractPiezoelectric ceramics Bi0.5(Na0.825K0.175)0.5TiO3 + x wt% Li2CO3 (abbreviated as BNKTL‐x) with x ranging from 0 to 10 were synthesized by conventional solid‐state reaction. XRD results reveal that the ceramics possess pure perovskite phase from x = 0 to x = 1.0. The SEM micrographs show that ceramics have a dense microstructure with a fine grain size at 1145 °C when x < 5.0. The measurements of dielectric and piezoelectric properties indicate that the optimum piezoelectric properties constant d33 = 174 pC/N at x = 0.5 and planar electromechanical coupling factor kp = 29.7% at x = 0.75 are observed. The depolarization temperature Td of BNKTL‐1.0 ceramics is above 170 °C. It is apparent that the ceramics can be employed in practical applications. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of ecosystem retrogression on stable nitrogen and carbon isotopes of plants, soils and consumer organisms in boreal forest islands
Authors: Hyodo Fujio , Wardle David A. 
Published: May 2009

AbstractIn the prolonged absence of catastrophic disturbance, ecosystem retrogression occurs, and this involves increased nutrient limitation, and reduced aboveground and belowground ecosystem processes rates. Little is known about how the nitrogen and carbon stable isotope ratios (δ15N and δ13C) of plants, soils and consumer organisms respond to retrogression in boreal forests. We investigated a 5000 year chronosequence of forested islands in the boreal zone of northern Sweden, for which the time since lightning‐induced wildfire increases with decreasing island size, leading to ecosystem retrogression. For this system, tissue δ15N of three abundant plant species (Betula pubescens, Vaccinium myrtillus and Pleurozium schreberi) and humus all increased as retrogression proceeded. This is probably due to enhanced ecosystem inputs of N by biological fixation, and greater dependency of the plants on organic N during retrogression. The δ13C of B. pubescens and plant‐derived humus also increased during retrogression, probably through nutrient limitation increasing plant physiological stress. Unlike the plants, δ15N of invertebrates (lycosid spiders and ants) did not increase during retrogression, probably because of their partial dependence on aquatic‐derived prey that had a variable δ15N signature. The δ13C of the invertebrates increased as retrogression proceeded and converged towards that of an aquatic prey source (chironomid flies), suggesting increased dependence on aquatic‐derived prey during retrogression. These results show that measurement of δ15N and δ13C of plants, soils, and consumers across the same environmental gradient can provide insights into environmental factors that drive both the aboveground and belowground subsystems, as well as the linkages between them. Copyright © 2009 John Wiley & Sons, Ltd.
Development of a high throughput environment for the optimization of process parameters for the solvothermal synthesis of isomerization catalysts
Authors: Mentges Michael , Richter Rudolf , Maier Wilhelm F. 
Published: May 2009

AbstractA completely parallelized workflow for the solvothermal synthesis of potential isomerization catalysts has been developed. With design of experiment methodologies, the influence of the process parameters such as water content, detergent type and concentration, synthesis temperature and shaking of the reaction mixture has been studied. The catalyst porosity was tested in high throughput by monitoring the heat of adsorption of probe molecules with emissivity corrected infrared thermography (EC‐IRT). The potential of the optimized materials was tested in a conventional plug‐flow reactor with the isomerization of 4‐Methyl‐1‐pentene as test reaction. In this study, two new isomerization catalysts have been identified, which are highly porous and outperform the reference zeolites Mordenite and Na‐Y at the conditions studied. Copyright © 2009 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 1: 000‐000, 2009
Imaging Features of Constrictive Pericarditis: Beyond Pericardial Thickening
Authors: Napolitano Giuseppe , Pressacco Josephine , Paquet Eleonore 
Published: May 2009

Constrictive pericarditis is caused by adhesions between the visceral and parietal layers of the pericardium and progressive pericardial fibrosis that restricts diastolic filling of the heart. Later on, the thickened pericardium may calcify. Despite a better understanding of the pathophysiologic basis of the imaging findings in constrictive pericarditis and the recent advent of magnetic resonance imaging (MRI) technology, which has dramatically improved the visualization of the pericardium, the diagnosis of constrictive pericarditis remains a challenge in many cases. In patients with clinical suspicion of underlying constrictive pericarditis, the most important radiologic diagnostic feature is abnormal pericardial thickening, which can be shown readily by computed tomography (CT) and especially by MRI, and is highly suggestive of constrictive pericarditis. Nevertheless, a thickened pericardium does not always indicate constrictive pericarditis. Furthermore, constrictive pericarditis can occur without pericardial thickening.
Statistical behaviour of the leaves of Riccati foliations
Authors: BONATTI CH. , GÓMEZ-MONT X. , VILA-FREYER R. 
Published: May 2009

AbstractWe introduce the geodesic flow on the leaves of a holomorphic foliation with leaves of dimension one and hyperbolic, corresponding to the unique complete metric of curvature −1 compatible with its conformal structure. We do these for the foliations associated to Riccati equations, which are the projectivization of the solutions of linear ordinary differential equations over a finite Riemann surface of hyperbolic type S, and may be described by a representation ρ:π1(S)→GL(n,ℂ). We give conditions under which the foliated geodesic flow has a generic repeller–attractor statistical dynamics. That is, there are measures μ− and μ+ such that for almost any initial condition with respect to the Lebesgue measure class the statistical average of the foliated geodesic flow converges for negative time to μ− and for positive time to μ+ (i.e. μ+ is the unique Sinaï, Ruelle and Bowen (SRB)-measure and its basin has total Lebesgue measure). These measures are ergodic with respect to the foliated geodesic flow. These measures are also invariant under a foliated horocycle flow and they project to a harmonic measure for the Riccati foliation, which plays the role of an attractor for the statistical behaviour of the leaves of the foliation.
Multifractal analysis of the Lyapunov exponent for the backward continued fraction map
Authors: IOMMI GODOFREDO 
Published: May 2009

AbstractIn this paper we study the multifractal spectrum of Lyapunov exponents for interval maps with infinitely many branches and a parabolic fixed point. It turns out that, in strong contrast with the hyperbolic case, the domain of the spectrum is unbounded and points of non-differentiability might exist. Moreover, the spectrum is not concave. We establish conditions that ensure the existence of inflection points. To the best of our knowledge this is the first time that conditions of this type have been given. We also study the thermodynamic formalism for such maps. We prove that the pressure function is real analytic in a certain interval and then becomes equal to zero. We also discuss the existence and uniqueness of equilibrium measures. In order to do so, we introduce a family of countable Markov shifts that can be thought of as a generalization of the renewal shift.
The Rényi entropy function and the large deviation of short return times
Authors: HAYDN NICOLAI , VAIENTI SANDRO 
Published: May 2009

AbstractWe consider the Rényi entropy function for weaklyψ-mixing systems. The first main result of the paper establishes existence and regularity properties. The second main result is obtaining the decay rate for the large deviation of the return time to cylinder sets; we show that it is exponential with a rate given by the Rényi entropy function. Finally, we also obtain bounds for the free energy.
Web 2 technologies for Net Native language learners: a “social CALL”
Authors: Kárpáti Andrea 
Published: May 2009

AbstractIn order to make optimal educational use of social spaces offered by thousands of international communities in the second generation web applications termed Web 2 or Social Web, ICT competences as well as social skills are needed for both teachers and learners. The paper outlines differences in competence structures of Net Natives (who came of age in the 21st century) and the Net Generation of the 1980s and 1990s who evolve in response to changes between Web 1 and Web 2 technologies.Virtual educational environments in the age of the Social Web represent a perfect embodiment of the Constructionist paradigm: they offer shared discussion and work spaces instead of presentation tools, coaching utilities instead of help desks, and digital learning resource repositories instead of ready-made learning materials. LRE, the European Learning Resource Exchange, and several collaborative web based services and applications will be presented, to illustrate the interrelated change in educational software design and use.New teaching and learning aids require and at the same time inspire new educational theories. The trialogical learning paradigm that invites all educational stakeholders to work on shared objects of inquiry and development and thus develop epistemic agency will be offered as a foundation for a ‘social CALL’.
Machine translation in foreign language learning: language learners’ and tutors’ perceptions of its advantages and disadvantages
Authors: Niño Ana 
Published: May 2009

AbstractThis paper presents a snapshot of what has been investigated in terms of the relationship between machine translation (MT) and foreign language (FL) teaching and learning. For this purpose four different roles of MT in the language class have been identified: MT as a bad model, MT as a good model, MT as a vocational training tool (especially in the form of translation memories, pre-editing and post-editing), and MT as a “CALL tool”. Subsequently, some of the implications of the use of MT and of free online MT for FL learning are outlined and discussed along with practical examples for language teaching purposes. Finally, qualitative data, drawn from our empirical investigation are presented as synthesized findings pertaining to the perceptions of language learners and tutors in relation to the use of MT and, in particular, free online MT as a language tool.
Pharmakotherapie bei Angsterkrankungen
Authors: Plag Jens , Siegmund Anja , Ströhle Andreas 
Published: May 2009

Die moderne Psychopharmakotherapie von Angsterkrankungen begann mit der Beobachtung von Donald Klein und Max Fink, dass Imipramin antipanisch wirksam ist. Darauf aufbauend wurde die heute gebräuchliche Klassifikation von Angsterkrankungen entwickelt. Die akut anxiolytisch wirksamen Benzodiazepine sollten aufgrund von Nebenwirkungen und dem Missbrauchs- und Abhängigkeitspotenzials nur in Ausnahmenfällen angewendet werden. Derzeit werden selektive Serotonin- bzw. Serotonin- und Noradrenalin-Rückaufnahme-Inhibitoren als Mittel der ersten Wahl in der Psychopharmakotherapie von Angsterkrankungen angesehen. Daneben sind Pregabalin und Buspiron zur Behandlung der generalisierten Angststörung und Moclobemid zur Behandlung der sozialen Phobie zugelassen. Auch wenn einzelne Studien eine kurz- bis mittelfristige Überlegenheit der Kombination von Psychopharmakotherapie und Psychotherapie beschreiben, scheint diese langfristig, insbesondere nach Beendigung der Pharmakotherapie keine eindeutigen Vorteile zu besitzen. Ein neuer Ansatz zur Kombination von Pharmakotherapie und Psychotherapie wurde ausgehend von präklinischen Befunden entwickelt, die die molekularen Mechanismen von Konditionierung und Extinktion näher charakterisiert haben. Als partieller Agonist an der Glycin-Bindungsstelle des NMDA-Rezeptors verstärkt D-Cycloserin expositionsassoziierte Extinktion. Erste klinische Studien bestätigen die extinktionsfördernde Wirkung von D-Cycloserin bei Patienten mit Höhenangst, sozialer Phobie aber auch bei Zwangsstörungen. Bereits heute sind gut wirksame und verträgliche Substanzen zur Psychopharmakotherapie von Angsterkrankungen verfügbar. Die Anwendung neuerer, aus präklinischen Befunden abgeleiteten Therapiestrategien im klinischen Alltag muss noch weiter untersucht werden.
Insights into bacterial cellulose biosynthesis by functional metagenomics on Antarctic soil samples
Authors: Berlemont Renaud , Delsaute Maud , Pipers Delphine , D'Amico Salvino , Feller Georges , Galleni Moreno , Power Pablo 
Published: May 2009

Abstract
In this study, the mining of an Antarctic soil sample by functional metagenomics allowed the isolation of a cold-adapted protein (RBcel1) that hydrolyzes only carboxymethyl cellulose. The new enzyme is related to family 5 of the glycosyl hydrolase (GH5) protein from Pseudomonas stutzeri (Pst_2494) and does not possess a carbohydrate-binding domain. The protein was produced and purified to homogeneity. RBcel1 displayed an endoglucanase activity, producing cellobiose and cellotriose, using carboxymethyl cellulose as a substrate. Moreover, the study of pH and the thermal dependence of the hydrolytic activity shows that RBcel1 was active from pH 6 to pH 9 and remained significantly active when temperature decreased (18% of activity at 10 °C). It is interesting that RBcel1 was able to synthetize non-reticulated cellulose using cellobiose as a substrate. Moreover, by a combination of bioinformatics and enzyme analysis, the physiological relevance of the RBcel1 protein and its mesophilic homologous Pst_2494 protein from P. stutzeri, A1501, was established as the key enzymes involved in the production of cellulose by bacteria. In addition, RBcel1 and Pst_2494 are the two primary enzymes belonging to the GH5 family involved in this process.
Biodiversity of benthic microbial communities in bioturbated coastal sediments is controlled by geochemical microniches
Authors: Bertics Victoria J , Ziebis Wiebke 
Published: May 2009

Abstract
We used a combination of field and laboratory approaches to address how the bioturbation activity of two crustaceans, the ghost shrimp Neotrypaea californiensis and the fiddler crab Uca crenulata, affects the microbial diversity in the seabed of a coastal lagoon (Catalina Harbor, Santa Catalina Island, CA, USA). Detailed geochemical analyses, including oxygen microsensor measurements, were performed to characterize environmental parameters. We used a whole-assemblage fingerprinting approach (ARISA: amplified ribosomal intergenic spacer analysis) to compare bacterial diversity along geochemical gradients and in relation to subsurface microniches. The two crustaceans have different burrowing behaviors. The ghost shrimp maintains complex, deep-reaching burrows and permanently lives subterranean, supplying its burrow with oxygen-rich water. In contrast, the fiddler crab constructs simpler, J-shaped burrows, which it does not inhabit permanently and does not actively ventilate. Our goal was to address how varying environmental parameters affect benthic microbial communities. An important question in benthic microbial ecology has been whether burrows support similar or unique communities compared with the sediment surface. Our results showed that sediment surface microbial communities are distinct from subsurface assemblages and that different burrow types support diverse bacterial taxa. Statistical comparisons by canonical correspondence analysis indicated that the availability of oxidants (oxygen, nitrate, ferric iron) play a key role in determining the presence and abundance of different taxa. When geochemical parameters were alike, microbial communities associated with burrows showed significant similarity to sediment surface communities. Our study provides implications on the community structure of microbial communities in marine sediments and the factors controlling their distribution.
Influence of Auditory Stimulation Rates on Evoked Potentials during General Anesthesia
Authors: McNeer Richard R. , Bohórquez Jorge , Özdamar Özcan 
Published: May 2009

Background
The auditory middle-latency response (transient) and the 40-Hz auditory steady state response (ASSR) are modulated by anesthetics. However, the quantitative relation between these evoked responses is difficult to obtain because of technical limitations of the recording methods used to obtain transients at high stimulation rates. This study uses continuous-loop averaging deconvolution to fill this technical gap and to study the relation between the transient and ASSR waveform during general anesthesia.

Methods
The authors recorded 5- and 40-Hz transients and 40-Hz ASSRs in 13 subjects during general anesthesia. The 5- and 40-Hz transients were used to predict the 40-Hz ASSR by linearly superimposing the transient waveforms. The predicted and recorded ASSRs were analyzed and compared using phasor and Hotelling T(2) analyses.

Results
Grand-averaged recordings revealed differences in the early middle-latency peaks between 5- and 40-Hz transients, e.g., the peak P(x) was present only in 5-Hz transient. Only the predicted 40-Hz ASSR derived from the 40-Hz transient matched the actual ASSR. Phasor analysis showed that the early peaks contribute significantly to the steady state waveform, and this explains why 5-Hz transient does not predict the 40-Hz ASSR. Oscillations in both the 5- and 40-Hz transients were observed during anesthesia.

Discussion
The 40-Hz ASSR represents a composite waveform and arises when transient waveforms elicited with a 40-Hz stimulation rate are overlapped and superimposed. During general anesthesia, the morphology of the transient is dependent on the rate of stimulus presentation. The composite nature of the ASSR may explain nonmonotonic anesthetic dose-response relations observed by others.
Systematic Review of Questionnaires Measuring Patient Satisfaction in Ambulatory Anesthesia
Authors: Chanthong Pratamaporn , Abrishami Amir , Wong Jean , Herrera Francisco , Chung Frances 
Published: May 2009

Background
Patient satisfaction has become an important component of quality improvement in ambulatory anesthesia services. However, it is difficult to measure due to its subjective and complex psychological construct. Psychometric methodology has been successfully used to evaluate this outcome. The authors conducted a systematic review to evaluate questionnaires to measure patient satisfaction with ambulatory anesthesia.

Methods
A systematic literature search of The Cochrane Library, MEDLINE, EMBASE, CINAHL, HAPI, PsycINFO, and Dissertation Abstracts was performed to identify studies on questionnaires evaluating patient satisfaction after ambulatory anesthesia. The authors included the articles that used multiple-item questionnaires, and the questionnaires were assessed with the strategy of psychometric questionnaire construction, validity, reliability, and acceptability.

Results
The authors scanned 131 articles yielded by our search strategy. Eleven articles were included in the study. Two questionnaires, IOWA Satisfaction with Anesthesia Scale and Evaluation du Vecu de I'Anesthesie Generale, fulfilled the criteria, but the latter was not developed specifically for ambulatory anesthesia, whereas Iowa Satisfaction with Anesthesia Scale was designed only for monitored anesthesia patients.

Conclusions
In a large number of trials, patient satisfaction has been evaluated using overall satisfaction or nonvalidated questionnaires. Only a few studies have developed questionnaires with rigorous psychometric methods to measure patient satisfaction with anesthesia care. At this time, there is still no valid or reliable questionnaire for measuring patient satisfaction in ambulatory anesthesia. Further study should be conducted to develop standardized instruments to measure this outcome.