676 research outputs found

    Shifting from Ideal to Critical Multiculturalism in Canadian Teacher Education Programs: Examining the Challenges

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    This paper describes a recent initiative designed to provide support for teacher candidates from culturally diverse backgrounds as they traverse a one-year teacher education program in Canada. Results and discussion are based on qualitative data from an information survey, student-professor conversations, a review of seminar documents and processes, and observations and reflections made by professors conducting the seminar. Overall, the Language and Cultural Engagement Seminar was successful in providing a supportive environment in which complicated and politically volatile issues, which would otherwise have remained unacknowledged, were discussed openly. The main concerns expressed by participants were the communication concern (grammar, vocabulary, pronunciation, accent, etc.), concern for power and authority in the classroom, and the socio-cultural acceptance concern. Power and communication concerns diminished when teacher candidates felt a level of cultural acceptance in the classroom; therefore, we propose that socio-cultural acceptance be investigated in future research into the concern construct. Since differential pronunciation had the effect of positioning teacher candidates on the periphery of classroom discourse, we concluded that acceptance of accent diversity (lack thereof) was one barrier between ideal (policy) and experienced (lived) multi-cultures. Cet article décrit une initiative récente désignée à procurer un soutien aux étudiants-maîtres provenant de divers milieux socio-culturels pendant l\u27année de leur formation au Canada. Les résultats et les discussions sont basés sur les données qualitatives obtenues d\u27une surveillance de renseignements, des conversations entre professeurs et étudiants, une revision des documents et processus obtenus pendant un colloque et des observations et réflexions faites par les professeurs conduisant ce colloque. En général le colloque Language and Cultural Engagement Seminar a réussi à offrir un mileu positif dans lequel des problèmes compliqués ou explosifs, qui auraient pu passer inapperçus, avaient été discutés franchement. Les principales inquiétudes citées par les participants sont: l\u27inquiétude sur la communication (grammaire, vocabulaire, prononciation, accent, etc.), l\u27inquiétude concernant l\u27autorité et le pouvoir en classe. et l\u27inquiétude de n\u27être pas acceptés à cause de leurs antécédents socio-culturels. Mais les inquiétudes sur le pouvoir et la communication sont diminuées quand les étudiants-maîtres sentaient qu\u27ils atteignaient un certain niveau d\u27acceptation culturelle en classe. Nous proposons que l\u27acceptation socio-culturelle deviendra un sujet de recherche plus poussé dans l\u27avenir. Comme la prononciation différentielle avait l\u27effet de placer les instituteurs aux périphéries du discours en classe, nous avions conclu que l\u27acceptation des accents divers (ou le manque de) est une barrière entre l\u27idéal (politique) et l\u27expérience (vécue) d\u27un milieu à cultures multiples

    Streptococcus thermophilus : to survive, or not to survive the gastrointestinal tract, that is the question!

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    The probiotic market is increasing world-wide as well as the number of products marketed as probiotics. Among the latter, many products contain Streptococcus thermophilus strains at several dosages. However, the scientific evidence that should support the probiotic status of those S. thermophilus strains is often contradictory. This review analyses the scientific literature aimed to assess the ability of S. thermophilus strains to survive the human gastrointestinal tract by discussing the scientific validity of the methods applied for the bacterial recovery and identification from stool samples. This review highlights that in most of the intervention studies reviewed, the identification of S. thermophilus strains from stools was not carried out with the necessary taxonomic accuracy to avoid their misidentification with Streptococcus salivarius, a common human commensal and a species phylogenetically close to S. thermophilus. Moreover, this review highlights how critical the accurate taxonomic identification of S. thermophilus in metagenomics-based studies can be

    Micorrización de plantulas en contendor de Pinus nigra con Suillus granulates bajo condiciones de campo

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    Seedling mycorrhization acts as an efficient tool for improving the quality of seedlings. In this study, the effectiveness of Suillus granulatus, originating from Pinus heldreichii forests (Montenegro), to produce containerized ectomycorrhizal seedlings of autochthonous Pinus nigra in open field conditions was investigated. Spore (106, 107, 108) and vegetative (1:16, 1:8, 1:4) inoculation on ectomycorrhizal formation and seedling growth were tested. Spore and vegetative inoculums of autochthonous Pisolithus arhizus were used in the same trial as additional control treatments. The utilization of vegetative and spore inoculums of autochthonous S. granulatus has proven to be an effective method of obtaining containerized ectomycorrhizal P. nigra seedlings under open field conditions after 11 months. S. granulatus spore inoculations resulted in well developed ectomycorrhiza, decreasing the growth of the P. nigra seedlings in the first growing season. Mycelial inoculations resulted in slightly developed S. granulatus ectomycorrhiza, which increased the growth of the seedlings. Therefore, it would be feasible to use spore inocula of S. granulatus, with 106 spores per plant, to produce ectomycorrhizal P. nigra plants on a large scale. Controlled mycorrhizal inoculation of seedlings is not a common practice in Montenegrin and Serbian nurseries; as such, the obtained results will contribute to the enhancement of nursery production of Pinus nigra and other conifers. This also could be assumed as a starting point for many further efforts and investigations with autochthonous fungal and plant material in this region.La micorrización de plántulas actúa como una herramienta eficaz para la mejora de la calidad de los brinzales. En este estudio se investiga la eficacia de Suillus granulatus, procedentes de bosques de Pinus heldreichii (Montenegro), para producir plántulas ectomicorrícicas en contenedores de Pinus nigra autóctonos en condiciones de campo. Se ensayaron inoculacion por esporas (106, 107, 108) y vegetativa (1:16, 1:8, 1:4) para la formación ectomicorrízica y el crecimiento de las plántulas. Se utilizó inóculo de esporas y vegetativo de Pisolithus arhizus autóctonos en el mismo ensayo como tratamiento control. La utilización de inóculos vegetativos y esporas de S. granulatus autóctonos ha demostrado ser un método eficaz para la obtención de plantas en contenedor ectomicorrícicas de P. nigra bajo condiciones de campo después de 11 meses. La inoculación de esporas de S. granulatus produjeron un buen desarrollo ectomicorrizas, disminuyendo el crecimiento de las plántulas de P. nigra en la primera estación de crecimiento. Las inoculaciones miceliales produjeron un escaso desarrollo ectomicorrizico de S. granulatus, con aumento en el crecimiento de las plántulas. Por lo tanto, sería factible el uso de inóculos de esporas de S. granulatus, con 106 esporas por planta, para producir plantas ectomicorrícicas de P. nigra a gran escala. La inoculación micorrízica controlada de plántulas no es una práctica común en los viveros de Serbia y Montenegro y, como tal, los resultados obtenidos contribuirán a la mejora de la producción en viveros de Pinus nigra y otras coníferas. Esto también podría ser asumido como un punto de partida para futuras investigaciones con material autóctono de hongos y plantas en esta región

    Solid-state ion exchange of Fe in small pore SSZ-13 zeolite: Characterization of the exchanged species and their relevance for the NOx SCR reaction

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    Solid state ion exchange was performed for the successful introduction of Fe cations in the small pore CHA structured SSZ-13 zeolite. The produced catalysts were characterized by IR and UV-Vis spectroscopies and thermally programmed reaction techniques to probe the Fe sites formed during the exchange and the catalytic activity for the NOx SCR reaction. The results indicate that highly dispersed and heterogeneous Fe sites are formed, and the type depends on the Al distribution in the zeolite. Dimeric Fe species are formed preferentially at the start of the exchange on the 6- and 8-member rings that contain at least two Al exchange sites and once these sites are fully saturated the Fe is exchanged as isolated cations

    Uticaj supstituenata na IR, 1H- i 13C-NMR spektralne podatke N-(supstituisanih fenil)-2-cijanoacetamida - korelaciona analiza

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    Linear free energy relationships (LFER) were applied to the IR, H-1- and C-13-NMR spectral data of N-(substituted phenyl)-2-cyanoacetamides. A variety of substituents were employed for phenyl substitution and fairly good correlations were obtained using the simple Hammett and the Hammett-Taft dual substituent parameter equations. The correlation results of the substituent induced C-13-NMR chemical shifts (SCS) of the Cl, C=O and N-H atom indicated different sensitivity with respect to electronic substituent effects. A better correlation of the SCSc=O with a combination of electrophllic and nucleophilic substituent constants indicated a significant contribution of extended resonance interaction (pi-delocalization) within the pi(1)-unit. The conformations of the investigated compounds were studied using the OFT B3LYP/6-311G** method and, together with the results of C-13-NMR and IR spectroscopic studies, a better insight into the influence of such a structure on the transmission of electronic substituent effects was obtained.Principi linearnih korelacija slobodnih energija (LFER) su primenjeni na IR, 1H- i 13C-NMR spektralne podatke N-(supstituisanih fenil)-2-cijanoacetamida. Pri sintezi N-(supstituisanih fenil)-2-cijanoacetamida izvršen je zadovoljavajući izbor supstituenata u pogledu elektronskih svojstava kako bi se adekvatno sagledao uticaj elektronskih efekata supstituenata na pomeranja u IR, 1H- i 13C-NMR spektralnim podacima. Primenom proste Hametove jednačine dobijene su zadovoljavajuće korelacije. Na osnovu korelacionih rezultata uočen je primaran uticaj elektronskih efekata na SCS (supstituentom indukovana hemijska pomeranja) vrednosti N-H vodonika, C1 i C=O ugljenika ispitivanih jedinjenja. Korelacioni rezultati za C=O ugljenik se značajno popravljaju ako se koristi kombinacija Ϭ+ i Ϭ- konstanti supstituenata, takozvane elektrofilne i nukleofilne konstante supstituenata, što ukazuje na postojanje značajne proširene rezonancione interakcije supstituenata i elektronske gustine karbonilne grupe. Vrednosti konstanti proporcionalnosti pF i pR za sve atome, ukazuju na približno isti doprinos efekta polja i rezonancionog efekta supstituenata. Efekat polja je nešto izraženji na N-H vodoniku, i za sve atome pokazuje značajne razlike u odnosu na njihov položaj u molekulskoj strukturi ispitivanih jedinjenja. Uticaj efekata supstituenata na IR vibracije istezanja N-H (simetrične i antisimetrične), C=O i CN veze je prevashodno elektronske prirode što se može zaključiti na osnovu dobrih korelacija dobijenih primenom Hametove jednačine i Ϭ parametara supstituenata. Osim toga izvršena je optimizacija geometrije ispitivanih jedinjenja primenom DFT B3LYP/ 6-311G**metode, pri čemu je nađeno da je trans-izomer nešto stabilnji, izuzev u slučaju jedinjenja 3. Supstituisana fenil-grupa i amidna grupa, kod trans-izomera, su približno koplanarne, dok se kod cis- izomera uočava značajna devijacija koja je značajno određena elektronskim efektima prisutnog supstituenta. Takođe je ispitivan položaj cis/trans ravnoteže u ugjen-tetrahloridu, i na osnovu rezultata FT/R analize, kada je prisutan H, CH3, OCH3, Br, i COOH supstituent, nađeno je da je cis izomer u velikom višku, a za ostala jedinjenja utvrđeno je postojanje ravnoteže cis- i trans-izomera

    Reverse Micelle Strategy for the Synthesis of MnOx-TiO2Active Catalysts for NH3-Selective Catalytic Reduction of NOxat Both Low Temperature and Low Mn Content

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    MnOx-TiO2catalysts (0, 1, 5, and 10 wt % Mn nominal content) for NH3-SCR (selective catalytic reduction) of NOxhave been synthesized by the reverse micelle-assisted sol-gel procedure, with the aim of improving the dispersion of the active phase, usually poor when obtained by other synthesis methods (e.g., impregnation) and thereby lowering its amount. For comparison, a sample at nominal 10 wt % Mn was obtained by impregnation of the (undoped) TiO2sample. The catalysts were characterized by using an integrated multitechnique approach, encompassing X-ray diffraction followed by Rietveld refinement, micro-Raman spectroscopy, N2isotherm measurement at −196 °C, energy-dispersive X-ray analysis, diffuse reflectance UV-vis spectroscopy, temperature-programmed reduction technique, and X-ray photoelectron spectroscopy. The obtained results prove that the reverse micelle sol-gel approach allowed for enhancing the catalytic activity, in that the catalysts were active in a broad temperature range at a substantially low Mn loading, as compared to the impregnated catalyst. Particularly, the 5 wt % Mn catalyst showed the best NH3-SCR activity in terms of both NOxconversion (ca. 90%) and the amount of produced N2O (ca. 50 ppm) in the 200-250 °C temperature range

    Human amniotic fluid glycoproteins expressing sialyl Lewis carbohydrate antigens stimulate progesterone production in human trophoblasts in vitro

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    Background: Progesterone is thought to mediate immune modulator effects by regulating uterine responsiveness. The aim of the study was to clarify the effect of transferrin and glycodelin A (former name PP14) as sialyl Lewis X-expressing glycoproteins on the release of progesterone by trophoblast cells in vitro. Methods: Cytotrophoblast cells were prepared from human term placentas by standard dispersion of villous tissue followed by a Percoll gradient centrifugation step. Trophoblasts were incubated with varying concentrations (50-300 mug/ml) of human amniotic fluid- and serum-transferrin as well as with glycodelin A. Culture supernatants were assayed for progesterone, human chorionic gonadotropin (hCG) and cortisol by enzyme immunometric methods. Results: The release of progesterone is increased in amniotic fluid transferrin- and glycodelin A-treated trophoblast cell cultures compared to untreated trophoblast cells. There is no relation between transferrin and the hCG or cortisol production of trophoblast cells. Conclusion: The results suggest that sialyl Lewis carbohydrate antigen-expressing amniotic fluid glycoproteins modulate the endocrine function of trophoblasts in culture by upregulating progesterone production. Copyright (C) 2004 S. Karger AG, Basel

    Task and spatial frequency modulations of object processing: an EEG study.

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    Visual object processing may follow a coarse-to-fine sequence imposed by fast processing of low spatial frequencies (LSF) and slow processing of high spatial frequencies (HSF). Objects can be categorized at varying levels of specificity: the superordinate (e.g. animal), the basic (e.g. dog), or the subordinate (e.g. Border Collie). We tested whether superordinate and more specific categorization depend on different spatial frequency ranges, and whether any such dependencies might be revealed by or influence signals recorded using EEG. We used event-related potentials (ERPs) and time-frequency (TF) analysis to examine the time course of object processing while participants performed either a grammatical gender-classification task (which generally forces basic-level categorization) or a living/non-living judgement (superordinate categorization) on everyday, real-life objects. Objects were filtered to contain only HSF or LSF. We found a greater positivity and greater negativity for HSF than for LSF pictures in the P1 and N1 respectively, but no effects of task on either component. A later, fronto-central negativity (N350) was more negative in the gender-classification task than the superordinate categorization task, which may indicate that this component relates to semantic or syntactic processing. We found no significant effects of task or spatial frequency on evoked or total gamma band responses. Our results demonstrate early differences in processing of HSF and LSF content that were not modulated by categorization task, with later responses reflecting such higher-level cognitive factors

    Total Electron Temperature Derived from Quasi-Thermal Noise Spectroscopy In the Pristine Solar Wind: Parker Solar Probe Observations

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    The Quasi-thermal noise (QTN) technique is a reliable tool to yield accurate measurements of the electron parameters in the solar wind. We apply this method on Parker Solar Probe (PSP) observations to derive the total electron temperature (TeT_e) from the linear fit of the high-frequency part of the QTN spectra acquired by the RFS/FIELDS instrument, and present a combination of 12-day period of observations around each perihelion from Encounter One (E01) to Ten (E10) (with E08 not included) with the heliocentric distance varying from about 13 to 60 solar radii (RR_\odot{}). We find that the total electron temperature decreases with the distance as \simR0.66R^{-0.66}, which is much slower than adiabatic. The extrapolated TeT_e based on PSP observations is consistent with the exospheric solar wind model prediction at \sim10 RR_\odot{}, Helios observations at \sim0.3 AU and Wind observations at 1 AU. Also, TeT_e, extrapolated back to 10 RR_\odot{}, is almost the same as the strahl electron temperature TsT_s (measured by SPAN-E) which is considered to be closely related to or even almost equal to the coronal electron temperature. Furthermore, the radial TeT_e profiles in the slower solar wind (or flux tube with larger mass flux) are steeper than those in the faster solar wind (or flux tube with smaller mass flux). More pronounced anticorrelated VpV_p-TeT_e is observed when the solar wind is slower and closer to the Sun.Comment: 10 pages, 7 figures, and Astronomy & Astrophysics Accepte
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