bluuebunny/crossref_metadata_2025 huggingface dataset:
Mexican Pilgrimage, Migration, and Discovery of the Sacred
Authors: Sandell David P.
Published: October 2013

This article explores an analogical relationship between Mexican pilgrimage and migration to the United States. Toward this end, the article acknowledges pilgrimage scholarship that treats one of two, presumably mutually, exclusive objectives: (1) The formation of a social body, unstructured and free, and (2) fulfillment of individual motivations and institutional agendas. Pilgrims involved in migration undertake both objectives to reconcile differences and achieve an understanding of the sacred.
Measuring functional quality in the pediatric intensive care
Authors: Sussmane Jeffrey Brett
Published: October 2013

Defining, measuring and delivering quality is an important challenge facing Health Care. Health Care as a Service Industry may be described with two forms of quality: technical quality, and functional quality. (1) Our previously published technical study demonstrated a reproducible and scalable measure of the technical quality, without additional capital cost. (2) A technical study, and the application of any service or measurement of quality, may be sub optimal if pursued in isolation from the patient/family (customer) perception. This study measured the functional quality of a complex Health Care service from the patient/family perception, which is perhaps superior and more relevant. We have quantified and documented an excellent competitive franchise and competitive advantages for our services, in our market, as well as areas for improvement, without additional capital expense.
La littérature jeunesse en première année pour apprendre à lire et à écrire
Authors: Morin Marie-France , Montésinos-Gelet Isabelle , Parent Jennifer , Prévost Nathalie , Charron Annie , Ling Geneviève , Valiquette Véronique
Published: October 2013

Cette recherche vise à vérifier l’impact d’une approche intégrée du langage écrit qui implique le recours à la littérature jeunesse autour d’un thème unificateur (le loup). Au total, 93 sujets, répartis dans cinq classes de première année du primaire, ont été évalués en lecture (décodage et compréhension) et en écriture (orthographe et production de texte) lors d’un prétest et d’un post-test. Toutes les enseignantes du groupe expérimental (3 classes) ont adopté pour une période de dix semaines l’approche intégrée, les autres enseignantes (2 classes) ont utilisé des manuels. Nos résultats montrent l’intérêt d’adopter une telle approche lors de l’entrée dans la scolarisation, et ce, même pour les élèves à risque de vivre des difficultés avec la langue écrite.
Modèle d’intervention pour l’émergence de la littératie
Authors: Makdissi Hélène , Boisclair Andrée
Published: October 2013

Le présent article suggère une réflexion théorique concernant l’acte de lire. Sur la base de cette réflexion, une posture épistémologique socioconstructiviste est clairement prise pour structurer un modèle d’intervention de lecture interactive pouvant guider le jeune enfant dans la compréhension des textes avant même la scolarisation formelle. Pour illustrer la pertinence pédagogique de ce modèle, deux exemples d’enfants sourds sont présentés de façon comparative, l’un des enfants ayant bénéficié quotidiennement du modèle d’intervention autour de la lecture interactive.
De l’insertion professionnelle à l’autonomie économique : les contributions d’une expérience en alphabétisation populaire
Authors: Raymond Émilie , Comeau Yvan
Published: October 2013

Cet article rapporte les résultats d’une recherche touchant les phénomènes favorables à l’autonomie économique des personnes peu scolarisées, dans le cadre d’une pratique d’alphabétisation et dans une perspective de prise en charge individuelle et de transformation sociale. L’expérience décrite et analysée tente de relever le défi des conditions structurelles de l’exclusion des personnes peu scolarisées par la mise sur pied d’activités économiques placées sous leur responsabilité. Le processus de recherche a d’abord conduit à recadrer la notion d’insertion, puis à identifier quatre dimensions de l’alphabétisation s’inscrivant dans cette perspective : pédagogique, politique, économique et personnelle. Sur le plan de la recherche, l’observation systématique des sujets, associée à une analyse qualitative des verbalisations obtenues dans des entrevues semi-dirigées, a permis d’identifier les principes d’action susceptibles d’amener les participantes et les participants à développer une certaine autonomie économique.
Les réactions de directions d’écoles de milieux défavorisés aux caractéristiques des écoles performantes de milieux défavorisés
Authors: Archambault Jean , Harnois Li
Published: October 2013

La littérature scientifique sur la direction d’écoles de milieux défavorisés est peu abondante. Cependant, elle identifie des caractéristiques observées de façon récurrente dans les écoles performantes de milieux défavorisés. Dans le cadre d’un programme de recherche plus vaste visant à comprendre le travail de direction d’école de milieu défavorisé, nous avons utilisé ces caractéristiques afin de connaître les réactions de 45 directions d’écoles primaires de l’île de Montréal à leur égard. Bien que connaissant ces caractéristiques, plusieurs directions ont manifesté leurs réticences à l’effet que, dans les écoles performantes, l’apprentissage constitue la priorité. Nous présentons ici cette recherche effectuée en collaboration avec le Programme de soutien à l’école montréalaise (MELS) et nous discutons les résultats, qui nous surprennent.
L’intervention éducative, un construit théorique pour analyser les pratiques d’enseignement
Authors: Lenoir Yves
Published: October 2013

L’article présente les deux concepts centraux du cadre conceptuel mis en oeuvre pour analyser les pratiques d’enseignement en contexte et dans leur complexité, les concepts d’intervention éducative et de médiation. Il rappelle, dans un premier temps, les motifs qui ont conduit au choix de l’expression  « intervention éducative ». Dans un deuxième temps, nous distinguons entre la perspective empirique, opérationnelle et pragmatique qui caractérise dans l’usage cette expression et son appréhension en tant que construit théorique, particulièrement en soulignant les différents attributs. Enfin, dans un troisième temps, le concept de médiation est présenté, d’une part, à partir de sa spécificité historicosociale et dialectique dans tout processus d’objectivation, d’autre part, en établissant la distinction complémentaire entre la médiation cognitive relevant du sujet apprenant et la médiation pédagogicodidactique relevant de l’enseignant.
Le synopsis : un outil méthodologique pour comprendre la pratique enseignante
Authors: Blaser Christiane
Published: October 2013

L’article présente l’adaptation d’un outil méthodologique spécialisé, le synopsis, mis au point par le Groupe romand d’analyse du français enseigné (GRAFE), en Suisse. Conçu pour traiter et concentrer des données filmées en vue de décrire et comprendre des objets enseignés en classe de français, le synopsis a été adapté pour décrire et comprendre les pratiques enseignantes entourant les tâches de lecture et d’écriture en classe de science et d’histoire à l’école secondaire, au Québec. Le glissement de focus de l’objet enseigné vers les pratiques enseignantes a imposé des ajustements importants qui se justifient par la nécessité d’adéquation entre les outils et les objets de recherche.
L’édition théâtrale au service de l’éducation et de la nation (1800-1970)
Authors: Pouliot Suzanne
Published: October 2013

Dès le XIXe siècle, des maisons d’édition laïques (la Librairie Beauchemin et Granger Frères) publient des pièces de théâtre à connotation nationaliste à l’intention des collégiens des collèges classiques. Au XXe siècle, ce sont des maisons d’édition religieuses qui contribuent à diffuser des pièces de théâtre écrites intentionnellement pour les jeunes des collèges classiques. Les idéologies qui avaient cours, au début du XIXe siècle jusqu’au milieu du XXe siècle, vont imperceptiblement, au fil des décennies, se transformer pour faire place à de nouvelles conceptions éditoriales du théâtre arrimées aux préoccupations des jeunes adolescents, dans une société en mutation.
Pour une meilleure compréhension de l’estime de soi : liens entre la perception de soi et les indicateurs sociométriques
Authors: Genoud Philippe A.
Published: October 2013

L’objectif de cette recherche est d’explorer les liens entre l’estime de soi et les différents indicateurs sociométriques. Nous avons utilisé le questionnaire Reflet permettant ainsi de prendre en compte les perceptions de l’élève quant à ses relations dans la classe. Les analyses effectuées, portant sur un échantillon de 263 élèves, indiquent que le statut sociométrique imaginé apporte un élément supplémentaire à la compréhension de l’estime de soi dans le domaine social. Si les sympathies réciproques entre camarades dans la classe constituent un facteur important dans la construction de l’image de soi, nos résultats soulignent le caractère prédominant de la perception qu’a l’élève des relations qu’il entretient avec ses pairs.
Travail et dimension relationnelle chez des hommes : un espace ignoré mais réel
Authors: Spain Armelle , Bédard Lucille , Paiement Lucie
Published: October 2013

La dimension relationnelle, point d’ancrage du cheminement de carrière féminin et source de sens à leur travail, se retrouve-t-elle chez des hommes ? Si oui, quelle en est la nature et le rôle ? Ce texte présente les résultats de ce volet d’une étude qualitative plus vaste portant sur les cheminements de carrière masculins. Il aborde en premier lieu la présence et la nature de la dimension relationnelle et ensuite le rôle qu’elle a joué dans le parcours de chacun des 12 participants volontaires âgés de 24 à 62 ans. Dans un contexte de mutation du monde du travail, les conclusions montrent un aspect moins connu de l’engagement professionnel d’hommes et conduisent à des pistes d’intervention en counseling d’orientation.
Liens entre l’inadaptation scolaire des adolescents et des adolescentes judiciarisés et leur adaptation sociale et personnelle à l’âge adulte
Authors: Lanctôt Nadine
Published: October 2013

Cette étude vérifie si l’adaptation scolaire des adolescents et des adolescentes judiciarisés est associée à leur adaptation personnelle et sociale au début de l’âge adulte. Les dimensions suivantes sont évaluées : les conduites déviantes, les difficultés interpersonnelles et intrapersonnelles, le statut socioéconomique. L’échantillon est composé de 86 adolescentes et de 173 adolescents qui étaient judiciarisés en 1992-1993. Les résultats indiquent que l’inadaptation scolaire s’accompagne de conduites et d’attitudes déviantes chez les adolescents alors que chez les adolescentes, ce sont surtout des difficultés intériorisées qui se conjuguent aux difficultés scolaires. Toutefois, l’inadaptation scolaire n’est pas associée à une vulnérabilité accrue sur le plan socioéconomique. La précarité socioéconomique caractérise tout autant ceux et celles qui avaient une meilleure adaptation scolaire.
Vers une didactique de l’écriture littéraire du récit de fiction au primaire
Authors: Sorin Noëlle
Published: October 2013

Cette recherche, inspirée de la mission culturelle de l’école, s’inscrit en didactique de l’écriture littéraire au primaire. Cette didactique en émergence reposerait sur une certaine conceptualisation de l’écriture où l’investissement affectif et socioculturel du scripteur ainsi que sa créativité et son imaginaire seraient considérés en s’appuyant sur des dimensions culturelle, interprétative et axiologique. Ceci sous-entend que l’enseignant devra adopter une posture de lecteur plutôt que d’évaluateur. Or cette formation à la réception des récits des élèves pourrait être entreprise dès le baccalauréat en enseignement. C’est pourquoi à notre recherche sur le terrain s’ajoute un volet formation, en développant des compétences en didactique de l’écriture littéraire chez les étudiants. Nous les solliciterons notamment pour la validation pratique de dispositifs didactiques que nous élaborons afin de favoriser l’écriture littéraire.
Enseigner la syntaxe française au moyen de la bande dessinée : une recherche développement en formation initiale des maîtres
Authors: Boutin Jean-François
Published: October 2013

L’évolution de la théorie grammaticale au cours du XXe siècle aura finalement eu une incidence directe sur les derniers programmes de français au primaire (2001) et au secondaire (1995, 2004). De tels changements ne s’effectuèrent évidemment pas sans heurts, notamment chez les maîtres en pratique, les futurs maîtres et les élèves de la classe de français. L’enseignement-apprentissage de la syntaxe, désormais prioritaire, s’y révèle particulièrement sensible. Le présent texte rend compte d’une recherche développement en didactique de l’écriture qui vise à appuyer les maîtres et les élèves dans leur exploration de la phrase. La technique d’analyse développée et validée dans le cadre du projet s’appuie sur un matériau littéraire particulièrement motivant pour les élèves, mais rarement mobilisé en classe : la bande dessinée.
Contrats de travail et segmentation du marché du travail dans le secteur manufacturier camerounais
Authors: Fomba Kamga Benjamin
Published: October 2013

L’objectif de cet article est d’étudier les différentiels de salaires entre les différents contrats de travail observés dans les entreprises formelles du secteur manufacturier camerounais en utilisant une technique économétrique qui traite les statuts contractuels comme une variable endogène, discrète et multinomiale. La particularité du marché du travail camerounais est prise en compte à travers le caractère écrit ou verbal du contrat de travail. Les données utilisées ont été collectées dans le cadre du projet sur « Les conditions de travail dans le secteur manufacturier camerounais » réalisée en 2006. Les analyses économétriques basées sur un échantillon de 1809 employés permettent de montrer que : (i) les contrats de travail constituent une base de la segmentation du marché du travail, (ii) le différentiel salarial entre les employés sous contrat verbal et ceux sous contrat à durée déterminée est expliqué par la différence des caractéristiques entre les deux groupes d’employés alors que le différentiel salarial entre les employés sous contrat à durée indéterminée et ceux sous contrat à durée déterminée est mieux expliqué par la précarité de l’emploi c’est-à-dire le fait d’être sur le marché secondaire.
Le niveau des prix en Tunisie est-il déterminé par la politique budgétaire?
Authors: Djelassi Mouldi , Essid Lobna
Published: October 2013

L’économie tunisienne a connu une inflation faible et stable sans précédent suite aux réformes du programme d’ajustement structurel (PAS). L’objectif de cet article consiste à trouver des contacts entre les pratiques des politiques monétaire et budgétaire tunisiennes avec la littérature économique.

Afin de prendre en compte les effets réciproques entre le passif et l’actif du budget de l’État, nous adoptons une démarche en terme du modèle VAR ainsi que des tests de causalités de Granger. La théorie budgétaire du niveau des prix s’applique au cas de l’économie tunisienne où le surplus est exogène. Nous attribuons le niveau faible et stable de l’inflation à une politique budgétaire dominante et une politique monétaire qui cible le taux d’intérêt.
L’érémitisme en Nouvelle-France et la vocation singulière de Toussaint Cartier au XVIIIe siècle
Authors: La Charité Claude
Published: October 2013

Au siècle des Lumières, l’érémitisme est un phénomène marginal pour l’Église catholique qui lui préfère les ordres missionnaires. Le cas de Toussaint Cartier, qui vécut sur l’île Saint-Barnabé au large de Rimouski de 1728 jusqu’à sa mort en 1767, pourrait a priori donner à penser que la Nouvelle-France était plus favorable à ce type de vocation. Or, tel n’est manifestement pas le cas : le témoignage du marquis de Montcalm, la condamnation de l’érémitisme par le pape Benoît XIV, le cas de l’ermite de Trois-Pistoles au début du XVIIIe siècle et les dispositions de l’ancien droit civil à l’égard des ermites constituent autant de points de vue qui éclairent d’un jour nouveau la vocation énigmatique et problématique de Toussaint Cartier pour les institutions de son temps.
Changes in the Arctic Ocean CO2 sink (1996–2007): A regional model analysis
Authors: Manizza M. , Follows M. J. , Dutkiewicz S. , Menemenlis D. , Hill C. N. , Key R. M.
Published: October 2013

The rapid recent decline of Arctic Ocean sea ice area increases the flux of solar radiation available for primary production and the area of open water for air‐sea gas exchange. We use a regional physical‐biogeochemical model of the Arctic Ocean, forced by the National Centers for Environmental Prediction/National Center for Atmospheric Research atmospheric reanalysis, to evaluate the mean present‐day CO2 sink and its temporal evolution. During the 1996–2007 period, the model suggests that the Arctic average sea surface temperature warmed by 0.04°C a−1, that sea ice area decreased by ∼0.1 × 106 km2 a−1, and that the biological drawdown of dissolved inorganic carbon increased. The simulated 1996–2007 time‐mean Arctic Ocean CO2 sink is 58 ± 6 Tg C a−1. The increase in ice‐free ocean area and consequent carbon drawdown during this period enhances the CO2 sink by ∼1.4 Tg C a−1, consistent with estimates based on extrapolations of sparse data. A regional analysis suggests that during the 1996–2007 period, the shelf regions of the Laptev, East Siberian, Chukchi, and Beaufort Seas experienced an increase in the efficiency of their biological pump due to decreased sea ice area, especially during the 2004–2007 period, consistent with independently published estimates of primary production. In contrast, the CO2 sink in the Barents Sea is reduced during the 2004–2007 period due to a dominant control by warming and decreasing solubility. Thus, the effect of decreasing sea ice area and increasing sea surface temperature partially cancel, though the former is dominant.
The influence of mesoscale and submesoscale heterogeneity on ocean biogeochemical reactions
Authors: Levy M. , Martin A. P.
Published: October 2013

The oceanic circulation in the meso to submesoscale regime generates heterogeneity in the concentrations of biogeochemical components over these scales, horizontally between 1 and 100 km. Due to nonlinearities in the biogeochemical reactions, such as phytoplankton primary production and zooplankton grazing, this small‐scale heterogeneity can lead to departure from the mean field approximation, whereby plankton reactions are evaluated from mean distributions at coarser scale. Here we explore the magnitude of theseeddy reactionsand compare their strength to those of the more widely studiededdy transports. We use the termeddyto denote effects arising from scales smaller than ∼ 100 km. This is done using a submesoscale permitting biogeochemical model, representative of the seasonally varying subtropical and subpolar gyres. We found that theeddy reactionsassociated with primary production and grazing account for ±5–30%of productivity and grazing, respectively, depending on location and time of year, and are scale dependent: two thirds are due to heterogeneities at scales 30–100 km and one third to those at scales below 30 km. Moreover,eddy productivitiesare systematically negative, implying that production tends to be reduced by nonlinear interactions at the mesoscale and smaller. The opposite result is found foreddy grazing, which is generally positive. The contrasting effects result from vertical advection, which negatively correlates phytoplankton and nutrients and positively correlates phytoplankton and zooplankton in the meso to submesoscale range. Moreover, our results highlight the central role played by eddy reactions for ecological aspects and the distribution of organisms and by eddy transport for biogeochemical aspects and nutrient budgets.
Frequency‐dependent noise sources in the North Atlantic Ocean
Authors: Sergeant Amandine , Stutzmann Eléonore , Maggi Alessia , Schimmel Martin , Ardhuin Fabrice , Obrebski Mathias
Published: October 2013

Secondary microseisms are the most energetic waves in the noise spectra between 3 and 10 s. They are generated by ocean wave interactions and are predominantly Rayleigh waves. We study the associated noise sources in the North Atlantic Ocean by coupling noise polarization analysis and source mapping using an ocean wave model that takes into account coastal reflections. From the Rayleigh wave polarization analysis, we retrieve the back azimuth to the noise sources in the time‐frequency domain. Noise source modeling enables us to locate the associated generation areas at different times and frequencies. We analyze the distribution of secondary microseism sources in the North Atlantic Ocean using 20 broadband stations located in the Arctic and around the ocean. To model the noise sources we adjust empirically the ocean wave coastal reflection coefficient as a function of frequency. We find that coastal reflections must be taken into account for accurately modeling 7–10 s noise sources. These reflections can be neglected in the noise modeling for periods shorter than 7 s. We find a strong variability of back azimuths and source locations as a function of frequency. This variability is largely related to the local bathymetry. One direct cause of the time‐dependent and frequency‐dependent noise sources is the presence of sea‐ice that affects the amplitude and polarization of microseisms at stations in the Arctic only at periods shorter than 4 s.
Salinity dominance on the Indian Ocean Eastern Gyral current
Authors: Menezes Viviane V. , Phillips Helen E. , Schiller Andreas , Domingues Catia M. , Bindoff Nathaniel L.
Published: October 2013

This study demonstrates the importance of salinity gradients to the formation of the Eastern Gyral Current (EGC) in the South Indian Ocean. The EGC flows eastward near 15∘S, opposite to the direction predicted by classical theories of wind‐driven circulation and is a source of water for the Leeuwin Current. In the upper ocean, a strong salinity front exists between fresh water from the Indonesian Throughflow (ITF) in the South Equatorial Current (SEC) and salty subtropical waters. In that region, salinity overwhelms the temperature contribution to density gradients, generating eastward geostrophic shear and establishing the EGC. Without the salinity front the EGC cannot be maintained: If the salinity contribution is neglected in the calculation of geostrophic currents, the EGC vanishes. Our observational analysis associated with the fact that both Sverdrup and Ekman theories produce westward flows in the region strongly supports the idea that the EGC is a salinity‐driven current.
The ocean's gravitational potential energy budget in a coupled climate model
Authors: Butler E. D. , Oliver K. I. , Gregory J. M. , Tailleux R.
Published: October 2013

This study examines, in a unified fashion, the budgets of ocean gravitational potential energy (GPE) and available gravitational potential energy (AGPE) in the control simulation of the coupled atmosphere‐ocean general circulation model HadCM3. Only AGPE can be converted into kinetic energy by adiabatic processes. Diapycnal mixing supplies GPE but not AGPE, whereas the reverse is true of the combined effect of surface buoyancy forcing and convection. Mixing and buoyancy forcing thus play complementary roles in sustaining the large‐scale circulation. However, the largest globally integrated source of GPE is resolved advection (+0.57 TW) and the largest sink is through parameterized eddy transports (−0.82 TW). The effect of these adiabatic processes on AGPE is identical to their effect on GPE, except for perturbations to both budgets due to numerical leakage exacerbated by nonlinearities in the equation of state.
Interface Immobilization Chemistry of cRGD‐based Peptides Regulates Integrin Mediated Cell Adhesion
Authors: Pallarola Diego , Bochen Alexander , Boehm Heike , Rechenmacher Florian , Sobahi Tariq R. , Spatz Joachim P. , Kessler Horst
Published: October 2013

The interaction of specific surface receptors of the integrin family with different extracellular matrix‐based ligands is of utmost importance for the cellular adhesion process. A ligand consists of an integrin‐binding group, here cyclic RGDfX, a spacer molecule that lifts the integrin‐binding group from the surface and a surface anchoring group. c(‐RGDfX‐) peptides are bound to gold nanoparticle structured surfaces via polyproline, polyethylene glycol or aminohexanoic acid containing spacers of different lengths. Although keeping the integrin‐binding c(‐RGDfX‐) peptides constant for all compounds, changes of the ligand's spacer chemistry and length reveal significant differences in cell adhesion activation and focal adhesion formation. Polyproline‐based peptides demonstrate improved cell adhesion kinetics and focal adhesion formation compared with common aminohexanoic acid or polyethylene glycol spacers. Binding activity can additionally be improved by applying ligands with two head groups, inducing a multimeric effect. This study gives insights into spacer‐based differences in integrin‐driven cell adhesion processes and remarkably highlights the polyproline‐based spacers as suitable ligand‐presenting templates for surface functionalization.
Covalent Immobilization of β‐Galactosidase onto Amino‐Functionalized Polyvinyl Chloride Microspheres: Enzyme Immobilization and Characterization
Authors: Mohy Eldin M. S. , El‐Aassar M. R. , El. Zatahry A. A. , Al‐Sabah M. M. B.
Published: October 2013

In this study, β‐galactosidase (Aspergillus oryzae) was covalently immobilized onto aminated polyvinyl chloride (PVC) via glutaraldehyde coupling. Effect of immobilization conditions was investigated. The maximum obtained immobilization yield is 27 units g−1 while the maximum expressed activity is 12 µmol min−1 g−1. The optimum pH of the free enzyme was observed at 5.2, whereas the optimum pH of the immobilized one was schiffed to 4.4. The optimum temperature for both the free and immobilized forms was recognized at 60°C. A change in the temperature profile of the immobilized enzyme below 60°C was observed when response to the elevation temperature was less than that to the free counterpart. The Km and Vmax values of the free and immobilized β‐galactosidase were found to be 52.03 and 123.1 mM, and 6.12 and 9.98 µ mol/min, respectively. Lactose hydrolysis, 500 mL of 100 mM concentration, was studied using 400 units of either free or immobilized enzymes at pH 6.0 and 60°C. Almost 80% hydrolysis percentage has been obtained after 6 h hydrolysis time with immobilized enzyme compared with 63% hydrolysis percentage obtained after 2 h for the free counterpart. Investigation of the operational stability at 40°C shows that the immobilized enzyme kept its activity for 5 h over 10 successive lactose hydrolysis cycles, which provides potentials for practical application in milk and whey hydrolysis. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2014, 33, 21379; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21379
Synthesis of Novel Conductive Poly(p‐phenylenediamine)/ Fe3O4 Nanocomposite via Emulsion Polymerization and Investigation of Antioxidant Activity
Authors: Lakouraj Moslem Mansour , Zare Ehsan Nazarzadeh , Moghadam Peyman Najafi
Published: October 2013

The novel organic/inorganic conductive nanocomposites were synthesized via emulsion polymerization using sodium dodecyl sulfate as an anionic emulsifier and ammonium persulfate as an oxidant. The structure, morphology, and properties of the nanocomposite were characterized by Fourier transform infrared spectroscopy, Ultraviolet‐‐visible spectroscopy, X‐ray diffraction, thermogravimetric analysis (TGA), and field emission scanning electron microscopy. TGA results showed that the decomposition temperatures of nanocomposites were higher than the Poly(p‐phenylenediamine). All synthesized nanocomposites showed a semicrystalline pattern. The conductivity of nanocomposites was measured by the four‐probe method and it was found that the electrical conductivity of the nanocomposites increased by increasing the amount of Fe3O4 nanoparticles. The maximum electrical conductivity (3.15 × 10−3 S/cm) was obtained for a nanocomposite having 1:0.75 ratio of p‐phenylenediamine–Fe3O4. The obtained nanocomposites were analyzed for their antioxidant activities using 2, 2‐diphenyl‐1‐picrylhydrazyl assay and the results indicated a maximum antioxidant activity of 54% for the nanocomposite. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2014, 33, 21385; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21385
Influence of a Feed‐Opening Section on the Output and Selected Mechanical Properties of a Poly(Vinyl Chloride) Extrudate
Authors: Sikora Janusz W. , Samujło Bronisław , Dzwonkowski Janusz
Published: October 2013

Extrudate properties are largely shaped by the thermal and rheological phenomena occurring in the plasticizing systems of extruders, the channels and die of the extrusion head, the calibrator, and to a lesser extent, in other parts of extrusion lines. These phenomena are affected by barrel and screw design, the type of material being processed, its granulometry, and the technological parameters of the extrusion process. Studies were carried out on the dependency of the output and selected mechanical properties of a plasticized poly(vinyl chloride) (PVC) extrudate on rotational speed of the screw, the width of the feed opening, and the length of the pellets of input polymer. It was found that the parameters tested were affected to the largest extent by the screw‐rotational speed. A fivefold increase in screw‐rotational speed resulted in a few hundred percent increase in the output and a several dozen percent increase in the yield strength of the extrudate, with the highest value obtained for pellets whose length was close to their diameter. Reduction of the width of the feed opening from 1.0 to 0.6 D resulted in a slight increase in the yield strength and tensile strength. High output, yield strength, and tensile strength values of PVC are most readily achieved at high screw‐rotational speed, the smallest width of the feed opening, and the length of pellets close to their diameter. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2014, 33, 21388; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21388
Revisiting the steady states of NO/O2/C3H6 on monolithic Pt/BaO/Al2O3 using bifurcation analysis
Authors: Xu Wei , Lai Meng‐Long , Yu Wei‐Fang , Xu Jin
Published: October 2013

While NOx storage and reduction is periodically operated, steady‐state studies have been widely carried out to investigate the involved reaction mechanisms and effects of operating parameters. Due to the complex reaction chemistry and its coupling with transport phenomena, multiplicity may exist. A steady‐state monolith reactor model accounting for microkinetics and reaction heat effects was proposed in this study to avoid the evaluation of enthalpies of microreaction steps. Three simplified versions of the monolith model were developed based on various assumptions of the axial gradients. Steady‐state behaviors of NO/O2/C3H6 system were investigated. A predictor‐corrector (PC) continuation method that does not require explicit evaluation of Jacobian Matrix was developed to solve the nonlinear system with a variable parameter of feed temperature. Model predictions were compared with experimental results. © 2013 American Institute of Chemical Engineers AIChE J 60: 623–634, 2014
Assessment of gel formation in colloidal dispersions during mixing in turbulent jets
Authors: Soos Miroslav , Marchisio Daniele L. , Sefcik Jan
Published: October 2013

Onset of gel formation upon mixing between colloidal dispersions and coagulant solutions in turbulent jets was studied using a combination of computational fluid dynamics (CFD) and population balance equation (PBE). To describe the interaction between turbulence fluctuations and particle aggregation, a micromixing model based on presumed probability density function was implemented inside the CFD code. Furthermore, effect of the solid phase on the fluid flow was modeled through an effective viscosity of the mixture evaluated from PBE. The results are presented in the parameter space of the primary particle diameter and the solid volume fraction where strong interplay between mixing and aggregation mechanisms controls the gelation phenomena and consequently also the fluid dynamics. Simulation results are in good agreement with observations from gelation experiments of concentrated nanoparticle suspensions injected into coagulant solutions. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4567–4581, 2013
Clinical care in craniofacial microsomia: A review of current management recommendations and opportunities to advance research
Authors: Heike C.L. , Hing A.V. , Aspinall C.A. , Bartlett S.P. , Birgfeld C.B. , Drake A.F. , Pimenta L.A. , Sie K.C. , Urata M.M. , Vivaldi D. , Luquetti D.V.
Published: October 2013

Craniofacial microsomia (CFM) is a complex condition associated with microtia, mandibular hypoplasia, and preauricular tags. It is the second most common congenital facial condition treated in many craniofacial centers and requires longitudinal multidisciplinary patient care. The purpose of this article is to summarize current recommendations for clinical management and discuss opportunities to advance clinical research in CFM. © 2013 Wiley Periodicals, Inc.
Nützliche Alkalimetallamide für die Synthese: Lithium‐, Natrium‐ und Kaliumhexamethyldisilazide, ‐diisopropylamide und ‐tetramethylpiperidide
Authors: Mulvey Robert E. , Robertson Stuart D.
Published: October 2013

Nahezu jeder Synthesechemiker wird irgendwann einmal ein sperriges sekundäres Amid (R2N−) eingesetzt haben. Die drei bedeutendsten Beispiele dieser Art, Lithium‐1,1,1,3,3,3‐hexamethyldisilazid (LiHMDS), Lithiumdiisopropylamid (LiDA) und Lithium‐2,2,6,6‐tetramethylpiperidid (LiTMP), sind seit langem insbesondere für die Lithiierung (durch Li‐H‐Austausch) unentbehrliche Reagentien. Die Verbindungen zeigen die für Organolithiumverbindungen typischen Aggregationsphänomene und eine starke Lewis‐Acidität und können daher, abhängig vom Lösungsmittel, in unterschiedlichen Formen auftreten. Hier werden die Strukturen der drei Arten von Lithiumamiden gemeinsam mit ihren Natrium‐ und Kaliumkongeneren ohne Donorlösungsmittel sowie in Gegenwart von Tetrahydrofuran (THF) oder N,N,N′,N′‐Tetramethylethylendiamin (TMEDA) beschrieben. Zusätzlich werden auch Beispiele für Heteroalkalimetallamide mit zwei verschiedenen Metallen erläutert.
Laboratory study of an anti‐temperature and salt‐resistance surfactant‐polymer binary combinational flooding as EOR chemical
Authors: Lai Nanjun , Zhang Xue , Ye Zhongbin , Li Xi , Li Zhihao , Wen Yiping , Zhang Yan
Published: October 2013

Experimental studies were conducted to enhance the oil recovery by a surfactant‐polymer binary combinational flooding system. The surfactant‐polymer binary combinational flooding was obtained by mixing the surfactants with the poly(AM‐NVP‐AS)‐1 which was an anti‐temperature and salt‐resistance tercopolymer and successfully synthesized via free radical polymerization using acrylamide (AM), N‐vinyl pyrrolidone (NVP), allyl sulfonate (AS) as raw materials. The initiator was redox system including water‐soluble azo compound (AIBA·2HCl) and sodium bisulfite (NaHSO3). Petroleum carboxylate dodecyl dibasic carbonylic acid sodium (C12DAS) and carboxyl betaine dodecyl dimethyl betaine (C12DB) were selected in this article. Compared with the surfactant‐HPAM, the surfactant‐poly(AM‐NVP‐AS)‐1 binary combinational system showed higher apparent viscosity and lower interfacial tension at high temperature and salinity conditions as the result of a better capacity of anti‐temperature, salt‐resistance, and swept volume. The recovery could enhance over 17% based on the core flooding test under the mineralization of 10,000 mg/L at 65°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39984.
Synthesis of a biocompatible poly(2‐hydroxyethyl methacrylate)–chitosan core–shell hydrogel latex
Authors: Jenjob Somkieath , Ratanajanchai Montri , Mahattanadul Natshisa , Soodvilai Sunhapas , Sunintaboon Panya
Published: October 2013

Core–shell hydrogel latexes, composed of a poly(2‐hydroxyethyl methacrylate) (PHEMA) core chemically coated with chitosan (CS) shell, were synthesized via an emulsifier‐free emulsion polymerization, free radically initiated by a redox couple of tert‐butyl hydroperoxide and amine groups on CS itself. The variation of some polymerization parameters [e.g., polymerization time, CS/2‐hydroxyethyl methacrylate (HEMA) weight ratio, and content of crosslinker] was systematically investigated in this study. We found that the weight ratios between CS and the HEMA monomer influenced the course of polymerization, which was traced by the change in percentage monomer conversions, and the colloidal stability of the PHEMA–CS hydrogel latexes obtained. Moreover, the polymerization time affected their particle sizes and surface charges. For the colloidally stable PHEMA–CS hydrogel latexes, their sizes and charges ranged from 600 to 689 nm and from 32 to 51 mV, respectively. N,N′‐Methylene bisacrylamide was used as a crosslinking agent for the core component; this was found to be able to enhance the hydrogels' thermal stability and water uptake. Moreover, the 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide assay showed that 100% cell viability was achieved during the treatment of the PHEMA–CS latex (0.2–2.5 mg/mL) with Caco‐2 cells. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 40003.
Stability and Stabilization of Networked Control Systems Under Limited Communication Capacity and Variable Sampling
Authors: Liu Ying‐Ying , Che Wei‐Wei , Chu Yun‐Kai
Published: October 2013

This paper investigates the problem of quantized feedback control for networked control systems (NCSs) with time‐varying delays and time‐varying sampling intervals, wherein the physical plant is a continuous‐time, and the control input is a discrete‐time signal. By using an input delay approach and a sector bound method, the network induced delays, the signal quantization and sampling intervals are presented in one framework in the case of the state and the control input by quantization in a logarithmic form. We exploit a novel Lyapunov functional with discontinuity, taking full advantage of the NCS characteristic information including the bounds of delays, the bounds of sampling intervals and quantization parameters. In addition, it has been shown that the Lyapunov functional is decreased at the jump instants. Furthermore, we use the Leibniz‐Newton formula and free‐weighting matrix method to obtain the stability analysis and stabilization conditions which are dependent on the NCS characteristic information. The proposed stability analysis and stabilizing controller design conditions can be presented in term of linear matrix inequalities, which have less conservativeness and less computational complexity. Four examples demonstrate the effectiveness of the proposed methods.
Removal of naproxen and bezafibrate by activated sludge under aerobic conditions: Kinetics and effect of substrates
Authors: Tang Ying , Li Xiao‐Ming , Xu Zhen‐Cheng , Guo Qing‐Wei , Hong Cheng‐Yang , Bing Yong‐Xin
Published: October 2013

Naproxen and bezafibrate fall into the category of pharmaceuticals that have been widely detected in the aquatic environment, and one of the major sources is the effluent discharge from wastewater treatment plants. This study investigated the sorption and degradation kinetics of naproxen and bezafibrate in the presence of activated sludge under aerobic conditions. Experimental results indicated that the adsorption of pharmaceuticals by activated sludge was rapid, and the relative adsorbabilities of the two‐target compounds were based on their log Kow and pKa values. The adsorption data could be well interpreted by the pseudo–second‐order kinetic model. The degradation process could be described by the pseudo–first‐order kinetic model, whereas the pseudo–second‐order kinetics were also well suited to describe the degradation process of the selected compounds at low concentrations. Bezafibrate was more easily degraded by activated sludge compared with naproxen. The spiked concentration of the two‐target compounds was negatively correlated with k1 and k2s, indicating that the substrate inhibition effect occurred at the range of studied concentrations. Chemical oxygen demand (COD) did not associate with naproxen degradation; thus, COD is not an alternative method that could be applied to investigate natural organic matter's impact on degradation of pharmaceuticals by activated sludge.
Mini‐scale cultivation method enables expeditious plasmid production in Escherichia coli
Authors: Grunzel Petra , Pilarek Maciej , Steinbrück Dörte , Neubauer Antje , Brand Eva , Kumke Michael U. , Neubauer Peter , Krause Mirja
Published: October 2013

The standard procedure in the lab for plasmid isolation usually involves a 2‐mL, 16 h over‐night cultivation in 15‐mL bioreaction tubes in LB medium. This is time consuming, and not suitable for high‐throughput applications. This study shows that it is possible to produce plasmid DNA (pDNA) in a 1.5‐mL microcentrifuge tube with only 100 μL cultivation volume in less than 7 h with a simple protocol. Compared with the standard LB cultivation for pDNA production reaching a final pDNA concentration range of 1.5–4 μg mL–1, a 6‐ to 10‐fold increase in plasmid concentration (from 10 up to 25 μg mL–1 cultivation volume) is achieved using an optimized medium with an internal substrate delivery system (EnBase®). Different strains, plasmids, and the applicability of different inoculation tools (i.e. different starting ODs) were compared, demonstrating the robustness of the system. Additionally, dissolved oxygen was monitored in real time online, indicating that under optimized conditions oxygen limitation can be avoided. We developed a simple protocol with a significantly decreased procedure time, enabling simultaneous handling of more samples, while a consistent quality and a higher final pDNA concentration are ensured.
ADAM17‐mediated CD44 cleavage promotes orasphere formation or stemness and tumorigenesis in HNSCC
Authors: Kamarajan Pachiyappan , Shin Jae M , Qian Xu , Matte Bibiana , Zhu Joey Yizhou , Kapila Yvonne L.
Published: October 2013

CD44, an extracellular matrix (ECM) receptor, has been described as a cancer stem cell marker in multiple cancers, including head and neck squamous cell carcinoma (HNSCC). HNSCC orasphere formation or stemness was characterized by cleavage of CD44, and thus we hypothesized that this proteolytic processing may be critical to stemness and tumorigenesis. We tested this hypothesis by examining the mechanisms that regulate this process in vitro and in vivo, and by exploring its clinical relevance in human specimens. Sphere assays have been used to evaluate stemness in vitro. Spheres comprised of HNSCC cells or oraspheres and an oral cancer mouse model were used to examine the significance of CD44 cleavage using stable suppression and inhibition approaches. These mechanisms were also examined in HNSCC specimens. Oraspheres exhibited increased levels of CD44 cleavage compared to their adherent counterparts. Given that disintegrin and metalloproteinase domain‐containing protein 17 (ADAM17) is a major matrix metalloproteinase known to cleave CD44, we chemically inhibited and stably suppressed ADAM17 expression in HNSCC cells and found that these treatments blocked CD44 cleavage and abrogated orasphere formation. Furthermore, stable suppression of ADAM17 in HNSCC cells also diminished tumorigenesis in an oral cancer mouse model. Consistently, stable suppression of CD44 in HNSCC cells abrogated orasphere formation and inhibited tumorigenesis in vivo. The clinical relevance of these findings was confirmed in matched primary and metastatic human HNSCC specimens, which exhibited increased levels of ADAM17 expression and concomitant CD44 cleavage compared to controls. CD44 cleavage by ADAM17 is critical to orasphere formation or stemness and HNSCC tumorigenesis.
Phytochemical and Biological Studies of Chloranthus Medicinal Plants
Authors: Xu Yong‐Jiang
Published: October 2013

The plants of genus Chloranthus have been investigated in many chemical and pharmacological laboratories due to their complex secondary metabolites and diverse bioactivities. The aim of this review is to provide an up‐to‐date overview on the chemistry and bioactivity of the compounds isolated, mainly sesquiterpenoids and diterpenoids, from the genus Chloranthus over the past few decades.
Synthesis and Biological Assays of 9‐(Acylamino)homocamptothecins as DNA Topoisomerase I Inhibitors
Authors: Guo Wei , Dong Guoqiang , Zhu Lingjian , Liu Wenfeng , Zhuang Chunlin , Guo Zizhao , Yao Jianzhong , Sheng Chunquan , Zhang Huojun , Miao Zhenyuan , Zhang Wannian
Published: October 2013

In an effort to improve the stability of homocamptothecin and reduce the toxicity, novel homocamptothecin analogs with acylamino groups at C(9) were designed and synthesized. The cytotoxic activities of all the synthetic compounds against three cancer cell lines were evaluated by the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) assay, and irinotecan was used as reference compound. Compound 7c with a piperidinylacetamido group and 10a with phenylacetamido group at C(9) showed potent activities both in vitro and in vivo. In addition, they also revealed remarkable topoisomerase I inhibitions which were exhibited with well‐established bonds with amino acid residues Arg364 and Asp533 in the active pocket. On the basis of the biological activities, 7c and 10a would be potential candidates for further studies.
Application of Two‐Dimensional NMR Spectroscopy to Metabotyping Laboratory Escherichia coli Strains
Authors: Chae Young Kee , Kim Seol Hyun , Nam Youn‐Ki
Published: October 2013

NMR Spectroscopy has been established as a major tool for identification and quantification of metabolites in a living system. Since the metabolomics era began, one‐dimensional NMR spectroscopy has been intensively employed due to its simplicity and quickness. However, it has suffered from an inevitable overlap of signals, thus leading to inaccuracy in identification and quantification of metabolites. Two‐dimensional (2D) NMR has emerged as a viable alternative because it can offer higher accuracy in a reasonable amount of time. We employed 1H,13C‐HSQC to profile metabolites of six different laboratory E. coli strains. We identified 18 metabolites and observed clustering of six strains according to their metabolites. We compared the metabolites among the strains, and found that a) the strains specialized for protein production were segregated; b) XL1‐Blue separated itself from others by accumulating amino acids such as alanine, aspartate, glutamate, methionine, proline, and lysine; c) the strains specialized for cloning purpose were spread out from one another; and d) the strains originating from B strain were characterized by succinate accumulation. This work shows that 2D‐NMR can be applied to identify a strain from metabolite analysis, offering a possible alternative to genetic analysis to identify E. coli strains.
Immobilization of 5‐Fluorouridine on Chitosan
Authors: Malecki Edith , Viere Rebecca , Rosemeyer Helmut
Published: October 2013

The 2′,3′‐O‐levulinic acid derivative 2b of the cancerostatic 5‐fluorouridine as well as its N(3)‐farnesylated nucleolipid 2d were synthesized and coupled to H2O‐soluble chitosanes of different molecular weight and at various pH values (3.5–5.5) leading to 6 and 7. In addition, the coumarine fluorophore ATTO‐488 N(9)‐butanoate was bound to the biopolymer by a sequential‐coupling technique to afford 9 and 10. Moreover, chitosan foils were prepared, to which 2b was coupled. Their degradation by chitosanase (from Streptomyces sp. N174) was studied UV‐spectrophotometrically in a Franz diffusion cell.