Exploring young children's voices:A study on the content of children's expressions related to school contexts

Oers, H.J.M. van [Promotor]Popeijus, H.L. [Copromotor]Geldens, J.J.M. [Copromotor

Listening to Young Children’s Voices: The Evaluation of a Coding System

Listening to young children’s voices is an issue with increasing relevance for many researchers in the field of early childhood research. At the same time, teachers and researchers are faced with challenges to provide children with possibilities to express their notions, and to find ways of comprehending children’s voices. In our research we aim to provide a method for listening to, and analyzing young children’s voices on educational issues. In this article we describe a new step in our research in which we are dealing with the issues of validity and reliability for the evaluation of our coding system: is our coding system for analyzing young children’s voices valid and reliable

Listening to young children's voices: the evaluation of a coding system

Listening to young children’s voices is an issue with increasing relevance for many researchers in the field of early childhood research. At the same time, teachers and researchers are faced with challenges to provide children with possibilities to express their notions, and to find ways of comprehending children’s voices. In our research we aim to provide a method for listening to, and analyzing young children’s voices on educational issues. In this article we describe a new step in our research in which we are dealing with the issues of validity and reliability for the evaluation of our coding system: is our coding system for analyzing young children’s voices valid and reliable? Escuchar las voces de niños pequeños es un tema de creciente relevancia para muchos investigadores en el campo de estudios sobre la infancia. Al mismo tiempo, profesorado y personal investigador se encuentran con retos para dar a los niños posibilidades de expresar sus nociones y encontrar formas de comprender sus voces. En nuestra investigación nos proponemos proveer un método para escuchar y analizar las voces de los niños acerca de temas educativos. En este artículo describimos un nuevo paso en nuestra investigación en la que estamos trabajando cuestiones de validez y fiabilidad para la evaluación de un sistema de codificación: Es nuestro sistema de codificación para analizar las voces de los niños válido y fiable

Using the Car in a Fragile Rural Tourist Destination: A Social Representations Perspective

The visitor experience of place is inextricably linked to our ability to travel around an area at will, yet this mobility creates many problems especially in scenic rural areas of the UK. The study presented here attempts to unravel visitors’ experiences of mobility using Moscovici’s social representations approach. Travel diaries were employed to explore visitors’ transport choices and mobility patterns during the peak season in Purbeck, Dorset, UK. Analysis focuses on how such patterns reflect a social representation of mobility and the implications this has for visitor travel at destinations

Protein tyrosine phosphorylation is involved in osmoregulation of ionic conductances

Using the human Intestine 407 cell line as a model, we investigated a possible role for tyrosine kinase(s) in regulating the ion efflux pathways induced by hyposmotic stimulation (regulatory volume decrease, RVD). Pretreatment of 125I(-)-and 86Rb(+)-loaded cells with the phosphotyrosine phosphatase inhibitor sodium orthovanadate (200 microM) potentiated isotope efflux triggered by mild hypotonicity (10-20%) but did not further increase the efflux in response to more vigorous osmotic stimulation (30% hypotonicity). The tyrosine kinase inhibitors herbimycin A and genistein largely reduced the osmoshock-induced efflux in both control and vanadate-pretreated cells, while not affecting calcium-activated 86Rb+ efflux. Potentiation of the RVD response by vanadate was confirmed by direct measurements of hypotonicity-induced changes in cell volume. Hypotonic shock alone triggered a rapid and transient increase in tyrosine phosphorylation of several proteins as well as phosphorylation of mitogen-activated protein kinase. Furthermore, the potentiating effects of vanadate on hypotonicity-induced ion efflux and mitogen-activated protein (MAP) kinase phosphorylation were mimicked by epidermal growth factor. Neither vanadate nor epidermal growth factor provoked a RVD-like ionic response under isotonic conditions. These results indicate that tyrosine phosphorylation is an essential step in the RVD response and suggest a novel role of growth factors in the cellular defense against osmotic stress

Neuronal differentiation of embryonic stem cells

AbstractNeuronal differentiation from totipotent precursors in vitro, is thought to require two signals: first a biophysical state (cellular aggregation) followed by a biochemical signal (retinoic acid treatment). In investigating the properties of retinoic acid-differentiated embryonic stem cell lines. However, we noted that retinoic acid treatment without prior aggregation, is sufficient to induce expression of the neuronal markers GAP-43 and NF-165. In agreement, immunohistochemistry revealed the presence of GAP-43 positive cells in these embryonic stem cell monolayers after three days of retinoic acid (RA) treatment. Furthermore an NF-165 positive subpopulation of cells was clearly observed after 4–5 days of RA treatment. The expression of these neuronal markers coincided with the appearance of electrically excitable cells, as assayed with whole cell patch clamp recording. We conclude that for neuronal differentiation of totipotent embryonic stem cells in vitro, one biochemical signal, i.e. retinoic acid treatment, is sufficient

Type I collagen limits VEGFR-2 signaling by a SHP2 protein-tyrosine phosphatase-dependent mechanism 1.

During angiogenesis, a combined action between newly secreted extracellular matrix proteins and the repertoire of integrins expressed by endothelial cells contributes in the regulation of their biological functions. Extracellular matrix-engaged integrins influence tyrosine kinase receptors, thus promoting a regulatory cross-talk between adhesive and soluble stimuli. For instance, vitronectin has been reported to positively regulate VEGFR-2. Here, we show that collagen I downregulates VEGF-A-mediated VEGFR-2 activation. This activity requires the tyrosine phosphatase SHP2, which is recruited to the activated VEGFR-2 when cells are plated on collagen I, but not on vitronectin. Constitutive expression of SHP2(C459S) mutant inhibits the negative role of collagen I on VEGFR-2 phosphorylation. VEGFR-2 undergoes internalisation, which is associated with dynamin II phosphorylation. Expression of SHP2(C459S) impairs receptor internalisation suggesting that SHP2-dependent dephosphorylation regulates this process. These findings demonstrate that collagen I in provisional extracellular matrix surrounding nascent capillaries triggers a signaling pathway that negatively regulates angiogenesis

From mode choice to modal diversion: A new behavioural paradigm and an application to the study of the demand for innovative transport services

We analyse past research efforts that focus on modal diversion in the transport sector, as opposed to the classical mode choice concept, showing the added value of this alternative framework that emerges from the existing scientific literature. The modal diversion paradigm is then used to assess the relative importance of the technical performances of transport services on one hand and of the subjective factors of its potential users on the other, when forecasting the use of a new means among a group of white-collars working in a French research institute. We quantitatively show that multimodal habits and cognitive attitudes have an importance that is in general not negligible for this group, compared to that of the transport services performances, even if only these latter are routinely considered by engineers and planners. Beyond this, we find that the role of self-related factors further increased when the group was less familiar with the technological background and the subsequent operation of the new system, such as in the case of demand responsive transport service

Simultaneous measurement of excitation-contraction coupling parameters identifies mechanisms underlying contractile responses of hiPSC-derived cardiomyocytes

Cardiomyocytes from human induced pluripotent stem cells (hiPSC-CMs) are increasingly recognized as valuable for determining the effects of drugs on ion channels but they do not always accurately predict contractile responses of the human heart. This is in part attributable to their immaturity but the sensitivity of measurement tools may also be limiting. Measuring action potential, calcium flux or contraction individually misses critical information that is captured when interrogating the complete excitation-contraction coupling cascade simultaneously. Here, we develop an hypothesis-based statistical algorithm that identifies mechanisms of action. We design and build a high-speed optical system to measure action potential, cytosolic calcium and contraction simultaneously using fluorescent sensors. These measurements are automatically processed, quantified and then assessed by the algorithm. Multiplexing these three critical physical features of hiPSC-CMs allows identification of all major drug classes affecting contractility with detectio

Novel, multiphasic gene-activated matrices for gradient based multi-gene delivery

Univ Fed Sao Paulo, Dept Med, Sao Paulo, BrazilUniversidade Federal de São Paulo (UNIFESP), Dept Med, Sao Paulo, BrazilWeb of Scienc