358 research outputs found

    Link2Practice: A Model of Ongoing Teacher and Teacher Candidate Professional Learning

    Get PDF
    A common complaint about teacher education programs is that it follows a linear model—where theory and teaching skills are learned at the university and then applied in practicum experiences—that is inadequate and does not accurately represent teacher candidates’(TC) experiences (Brouwer & Korthagen, 2005; Korthagen, Loughran & Russell, 2006). Indeed, teacher education programs have long been faced with the challenge of a “theory/practice divide”, creating what has been seen as a mechanistic separation between university programs (where it is implied theory is learned) and the practicum (where it is implied skills and strategies are learned). This divide continues once teacher candidates become teachers in their own classrooms, where the divide further widens by valuing of the practical over the theoretical. We need a new frame of reference to understand teacher education as a whole (throughout a professional career), as emerging from interconnected, non-linear, and at times unpredictable structures. Teacher education programs should form in relation to teacher professional learning, student learning, and the realities of dynamically evolving modern-day schools. In our institutions, the ongoing tension between learning sites of campus and schools is reduced in the teacher education partnership called Link2Practice, where TCs’ courses are integrated in a school district program with teachers who are making inquiries into their practice. This partnership responds to the increasing need for educators to understand and remain current about the interactions between TCs, K-12 public schools’ students and the pedagogy practices, informed by theory, that they advocate. This paper describes the development of the Link2Practice model and discusses its importance for teacher education. Keywords: Teacher education; partnerships; integration; professional learning On reproche souvent aux programmes de formation des enseignants de suivre un modĂšle linĂ©aire—selon lequel la thĂ©orie et les compĂ©tences pĂ©dagogiques sont acquises Ă  l’universitĂ© pour ensuite ĂȘtre appliquĂ©es pendant les stages—qui est inadĂ©quat et qui ne reprĂ©sente pas avec exactitude les expĂ©riences des stagiaires (Brouwer & Korthagen, 2005; Korthagen, Loughran & Russell, 2006). En effet, les programmes de formation des enseignants font face depuis longtemps au dĂ©fi que reprĂ©sente l’écart entre la thĂ©orie et la pratique ayant crĂ©Ă© ce qu’on perçoit comme Ă©tant une sĂ©paration mĂ©caniste entre les programmes universitaires (oĂč il est sous-entendu que les Ă©tudiants apprennent la thĂ©orie) et les stages (oĂč il est sous-entendu que les Ă©tudiants apprennent des habiletĂ©s et des stratĂ©gies). Cet Ă©cart se poursuit quand les stagiaires commencent Ă  enseigner dans leur propre salle de classe et se creuse par la valorisation de la pratique aux dĂ©pens de la thĂ©orie. Il nous faut un nouveau cadre de rĂ©fĂ©rence qui permettra de comprendre la formation des enseignants dans son ensemble (tout au long de la carriĂšre d’enseignant) comme produit de structures interconnectĂ©es, non linĂ©aires et parfois imprĂ©visibles. Les programmes de formation des enseignants devraient exister en relation avec le perfectionnement professionnel des enseignants, l’apprentissage des Ă©lĂšves et les rĂ©alitĂ©s des Ă©coles modernes en Ă©volution dynamique. Dans nos institutions, la tension constante entre les deux sites d’apprentissage—le campus et les Ă©coles—est rĂ©duit grĂące Ă  un partenariat Ă©ducatif nommĂ© Link2Practice par lequel les stagiaires sont intĂ©grĂ©s dans un programme de district scolaire avec des enseignants qui font enquĂȘte sur leur pratique. Ce partenariat rĂ©pond au besoin croissant qu’ont les enseignants de comprendre les interactions entre les stagiaires, les Ă©lĂšves M-12 des Ă©coles publiques et les pratiques pĂ©dagogiques informĂ©es par la thĂ©orie qu’ils prĂ©conisent, et de rester au courant de ces interactions. Cet article dĂ©crit le dĂ©veloppement du modĂšle Link2Practice et discute de son importance dans la formation des enseignants. Mots clĂ©s : formation des enseignants; partenariats; intĂ©gration; perfectionnement professionne

    Using chlorhexidine varnish to prevent early childhood caries in American Indian children

    Full text link
    Objectives: To test the efficacy of 10% chlorhexidine (CHX) dental varnish applied to the mothers' dentition in preventing caries in American Indian children. Methods: This was a placebo‐controlled, double‐blind, randomized clinical trial. Mother–child pairs were enrolled when the child was 4.5‐6.0 months. Mothers received 4 weekly applications of the study treatment (CHX or placebo) followed by single applications when her child was age 12 and 18 months. Children received caries examinations at enrollment, 12, 18 and 24 months. Analyses were limited to the intent‐to‐treat (ITT) group: children whose mothers received the first study treatment and who received at least one post‐baseline exam. The outcome variable was the number of new carious surfaces (NNCS) at the child's last visit. Wilcoxon nonparametric and Fisher's exact tests were used to test differences between the active and placebo groups. Results: We randomized 414 mother–child pairs, with 367 (88.6%) included in the ITT group (active = 188, placebo = 179). The proportion of children caries‐free at their final exam was 51.1% and 50.8% for the active and placebo groups ( P  > 0.99). The mean NNCS for the active and placebo groups was 3.82 (standard deviation [SD] = 8.18) and 3.80 (SD = 6.08), respectively ( P  = 0.54). The proportion with NNCS > 6 was 18.1% for active children versus 27.9% for placebo (relative risk [RR] = 0.65, P  = 0.03). The number needed to treat to shift one child from NNCS > 6 to a lower severity was 10.2. Conclusions: In this population CHX varnish did not reduce the mean NNCS or proportion of children with caries, but did reduce the proportion with severe caries.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96744/1/jphd348.pd

    A comparison of skinfolds and leg-to-leg bioelectrical impedance for the assessment of body composition in children

    Get PDF
    BACKGROUND: This field-based investigation examined the congruence between skinfolds and bioelectrical impedance in assessing body composition in children. METHODS: Subjects were 162 female and 160 male children 10–15 years of age. Skinfold measures obtained at the triceps and medial calf and a leg-to-leg bioelectrical impedance system were used to determine percent fat using child-specific equations. Pearson product moment correlations were performed on the percent fat values obtained using skinfolds and bioelectric impedance for the entire data set. Separate correlations were also conducted on gender and age/gender subsets. Dependent t tests were used to compare the two techniques. RESULTS: Percent fat did not differ between skinfolds and bioelectrical impedance for the total subject pool. Bioelectrical impedance overestimated percent fat in girls by 2.6% and underestimated percent fat in boys by 1.7% (p < 0.01). Correlations between skinfolds and bioelectrical impedance ranged from r = 0.51 to r = 0.90. CONCLUSIONS: Leg-to-leg bioelectrical impedance may be a viable alternative field assessment technique that is comparable to skinfolds. The small differences in percent fat between the two techniques may have limited practical significance in school-based health-fitness settings

    A comparison of skinfolds and leg-to-leg bioelectrical impedance for the assessment of body composition in children

    Get PDF
    BACKGROUND: This field-based investigation examined the congruence between skinfolds and bioelectrical impedance in assessing body composition in children. METHODS: Subjects were 162 female and 160 male children 10–15 years of age. Skinfold measures obtained at the triceps and medial calf and a leg-to-leg bioelectrical impedance system were used to determine percent fat using child-specific equations. Pearson product moment correlations were performed on the percent fat values obtained using skinfolds and bioelectric impedance for the entire data set. Separate correlations were also conducted on gender and age/gender subsets. Dependent t tests were used to compare the two techniques. RESULTS: Percent fat did not differ between skinfolds and bioelectrical impedance for the total subject pool. Bioelectrical impedance overestimated percent fat in girls by 2.6% and underestimated percent fat in boys by 1.7% (p < 0.01). Correlations between skinfolds and bioelectrical impedance ranged from r = 0.51 to r = 0.90. CONCLUSIONS: Leg-to-leg bioelectrical impedance may be a viable alternative field assessment technique that is comparable to skinfolds. The small differences in percent fat between the two techniques may have limited practical significance in school-based health-fitness settings

    Reservoir Computing with Delayed Input for Fast and Easy Optimization

    Get PDF
    Reservoir computing is a machine learning method that uses the response of a dynamical system to a certain input in order to solve a task. As the training scheme only involves optimising the weights of the responses of the dynamical system, this method is particularly suited for hardware implementation. Furthermore, the inherent memory of dynamical systems which are suitable for use as reservoirs mean that this method has the potential to perform well on time series prediction tasks, as well as other tasks with time dependence. However, reservoir computing still requires extensive task dependent parameter optimisation in order to achieve good performance. We demonstrate that by including a time-delayed version of the input for various time series prediction tasks, good performance can be achieved with an unoptimised reservoir. Furthermore, we show that by including the appropriate time-delayed input, one unaltered reservoir can perform well on six different time series prediction tasks at a very low computational expense. Our approach is of particular relevance to hardware implemented reservoirs, as one does not necessarily have access to pertinent optimisation parameters in physical systems but the inclusion of an additional input is generally possible

    Reservoir Computing with Delayed Input for Fast and Easy Optimisation

    Get PDF
    Reservoir computing is a machine learning method that solves tasks using the response of a dynamical system to a certain input. As the training scheme only involves optimising the weights of the responses of the dynamical system, this method is particularly suited for hardware implementation. Furthermore, the inherent memory of dynamical systems which are suitable for use as reservoirs mean that this method has the potential to perform well on time series prediction tasks, as well as other tasks with time dependence. However, reservoir computing still requires extensive task-dependent parameter optimisation in order to achieve good performance. We demonstrate that by including a time-delayed version of the input for various time series prediction tasks, good performance can be achieved with an unoptimised reservoir. Furthermore, we show that by including the appropriate time-delayed input, one unaltered reservoir can perform well on six different time series prediction tasks at a very low computational expense. Our approach is of particular relevance to hardware implemented reservoirs, as one does not necessarily have access to pertinent optimisation parameters in physical systems but the inclusion of an additional input is generally possible

    Reservoir Computing with Delayed Input for Fast and Easy Optimization

    Get PDF
    Reservoir computing is a machine learning method that solves tasks using the response of a dynamical system to a certain input. As the training scheme only involves optimising the weights of the responses of the dynamical system, this method is particularly suited for hardware implementation. Furthermore, the inherent memory of dynamical systems which are suitable for use as reservoirs mean that this method has the potential to perform well on time series prediction tasks, as well as other tasks with time dependence. However, reservoir computing still requires extensive task-dependent parameter optimisation in order to achieve good performance. We demonstrate that by including a time-delayed version of the input for various time series prediction tasks, good performance can be achieved with an unoptimised reservoir. Furthermore, we show that by including the appropriate time-delayed input, one unaltered reservoir can perform well on six different time series prediction tasks at a very low computational expense. Our approach is of particular relevance to hardware implemented reservoirs, as one does not necessarily have access to pertinent optimisation parameters in physical systems but the inclusion of an additional input is generally possible

    MicroRNA 146a (miR-146a) Is Over-Expressed during Prion Disease and Modulates the Innate Immune Response and the Microglial Activation State

    Get PDF
    Increasing evidence supports the involvement of microRNAs (miRNAs) in inflammatory and immune processes in prion neuropathogenesis. MiRNAs are small, non-coding RNA molecules which are emerging as key regulators of numerous cellular processes. We established miR-146a over-expression in prion-infected mouse brain tissues concurrent with the onset of prion deposition and appearance of activated microglia. Expression profiling of a variety of central nervous system derived cell-lines revealed that miR-146a is preferentially expressed in cells of microglial lineage. Prominent up-regulation of miR-146a was evident in the microglial cell lines BV-2 following TLR2 or TLR4 activation and also EOC 13.31 via TLR2 that reached a maximum 24–48 hours post-stimulation, concomitant with the return to basal levels of transcription of induced cytokines. Gain- and loss-of-function studies with miR-146a revealed a substantial deregulation of inflammatory response pathways in response to TLR2 stimulation. Significant transcriptional alterations in response to miR-146a perturbation included downstream mediators of the pro-inflammatory transcription factor, nuclear factor-kappa B (NF-ÎșB) and the JAK-STAT signaling pathway. Microarray analysis also predicts a role for miR-146a regulation of morphological changes in microglial activation states as well as phagocytic mediators of the oxidative burst such as CYBA and NOS3. Based on our results, we propose a role for miR-146a as a potent modulator of microglial function by regulating the activation state during prion induced neurodegeneration

    Sea urchin vault structure, composition, and differential localization during development

    Get PDF
    BACKGROUND: Vaults are intriguing ribonucleoprotein assemblies with an unknown function that are conserved among higher eukaryotes. The Pacific coast sea urchin, Strongylocentrotus purpuratus, is an invertebrate model organism that is evolutionarily closer to humans than Drosophila and C. elegans, neither of which possesses vaults. Here we compare the structures of sea urchin and mammalian vaults and analyze the subcellular distribution of vaults during sea urchin embryogenesis. RESULTS: The sequence of the sea urchin major vault protein (MVP) was assembled from expressed sequence tags and genome traces, and the predicted protein was found to have 64% identity and 81% similarity to rat MVP. Sea urchin MVP includes seven ~50 residue repeats in the N-terminal half of the protein and a predicted coiled coil domain in the C-terminus, as does rat MVP. A cryoelectron microscopy (cryoEM) reconstruction of isolated sea urchin vaults reveals the assembly to have a barrel-shaped external structure that is nearly identical to the rat vault structure. Analysis of the molecular composition of the sea urchin vault indicates that it contains components that may be homologs of the mammalian vault RNA component (vRNA) and protein components (VPARP and TEP1). The sea urchin vault appears to have additional protein components in the molecular weight range of 14–55 kDa that might correspond to molecular contents. Confocal experiments indicate a dramatic relocalization of MVP from the cytoplasm to the nucleus during sea urchin embryogenesis. CONCLUSIONS: These results are suggestive of a role for the vault in delivering macromolecules to the nucleus during development
    • 

    corecore