Search results for "Porte"
showing 10 items of 1894 documents
Collaborative Learning and Computer-Supported Collaborative Learning Environments
2008
A focus on purely individual cognition has set a stage to social construction of knowledge. New learning environments, in many cases supported by computer technology, are often based on collaborating and sharing expertise. As a result research on Computer Supported Collaborative learning (CSCL) environments is a significant and growing field, which actively seeks new methods to resolve the challenges of human learning across diverse levels of interaction in a modern information society. In this chapter we will discuss the concept of collaborative learning and the issues involved in using information and communication technology to support collaborative learning. We begin with the definition…
Expression of solute carrier 7A4 (SLC7A4) in the plasma membrane is not sufficient to mediate amino acid transport activity.
2002
Member 4 of human solute carrier family 7 (SLC7A4) exhibits significant sequence homology with the SLC7 subfamily of human cationic amino acid transporters (hCATs) [Sperandeo, Borsani, Incerti, Zollo, Rossi, Zuffardi, Castaldo, Taglialatela, Andria and Sebastio (1998) Genomics 49, 230–236]. It is therefore often referred to as hCAT-4 even though no convincing transport activity has been shown for this protein. We expressed SLC7A4 in Xenopus laevis oocytes, but could not detect any transport activity for cationic, neutral or anionic amino acids or for the polyamine putrescine. In addition, human glioblastoma cells stably overexpressing a fusion protein between SLC7A4 and the enhanced green f…
Activation of classical protein kinase C reduces the expression of human cationic amino acid transporter 3 (hCAT-3) in the plasma membrane
2005
We have previously shown that activation of PKC (protein kinase C) results in internalization of hCAT-1 [human CAT-1 (cationic amino acid transporter 1)] and a decrease in arginine transport [Rotmann, Strand, Martiné and Closs (2004) J. Biol. Chem. 279, 54185–54192]. However, others found increased transport rates for arginine in response to PKC activation, suggesting a differential effect of PKC on different CAT isoforms. Therefore we investigated the effect of PKC on hCAT-3, an isoform expressed in thymus, brain, ovary, uterus and mammary gland. In Xenopus laevis oocytes and human U373MG glioblastoma cells, hCAT-3-mediated L-arginine transport was significantly reduced upon treatment with…
Introduction aux théories et aux méthodes de la mesure en sciences psychologiques et en sciences de l'éducation
2004
Recyclable Heterogeneous and Low-Loading Homogeneous Chiral Imidazolidinone Catalysts for α-Alkylation of Aldehydes
2014
Two polystyrene-supported and six homogeneous MacMillan imidazolidinone catalysts were prepared and tested for the asymmetric α-alkylation of propanal with benzodithiolylium tetrafluoroborate. The chiral imidazolidinone was linked to polystyrene through the N-3 atom or through the phenyl ring and their catalytic activity was compared with that of their unsupported precursors. This comparison has allowed us to find an unsupported catalyst that displays high catalytic activity down to 5 or 2 mol % at room temperature with a high level of enantioselectivity also when used with hexanal and 3-phenylpropanal. In addition, one of the heterogeneous materials was revealed to be highly recyclable for…
Reflection Assignment as a Tool to Support Students’ Metacognitive Awareness in the Context of Computer-Supported Collaborative Learning
2021
The present study explores the potential of a reflection assignment as a tool for supporting master’s degree students’ metacognitive skills in the context of computer-supported collaborative learning (CSCL). The research question (RQ) is formulated as follows: How does a regularly submitted reflection assignment support the development of students’ individual metacognitive awareness in the context of CSCL? The empirical data is a text corpus (7878 words) extracted from individual students’ (N = 13) reflection assignments (N = 65) submitted during one semester. Qualitative content analysis was employed to analyze the data. The results demonstrate that by the end of the course, the students s…
Cellular cation exchange in arterial hypertension: Effects of insulin resistance
1993
La recente riforma della disciplina italiana del subappalto nella prospettiva del bid rigging
2023
L’articolo analizza in chiave critica la disciplina nazionale del subappalto nell’ambito delle gare pubbliche, così come recentemente riformata a seguito di diversi interventi normativi in ottemperanza alla procedura d’infrazione avviata dalla Commissione UE. Stando alla tesi dell’A., l’attuale quadro normativo – caratterizzato dalla quasi totale eliminazione delle limitazioni previgenti (probabilmente anche spingendosi oltre ciò che la Commissione UE ha richiesto) – difetta nel trovare un equo bilanciamento tra il principio della massima partecipazione alla gara, da un lato, e l’esigenza di prevenire e svelare potenziali condotte collusive, dall’altro. La suddetta conclusione, peraltro, ap…
Primo rinvenimento di Juniperus sabina L. sul massiccio del Pollino, Italia meridionale
1992
Viene segnalata per la prima volta la presenza di Juniperus sabina L. sul massiccio del Pollino, dove la specie è stata rinvenuta in habitat rupicolo in due stazioni ricadenti rispettivamente in territorio calabrese e lucano. Le stazioni vengono caratterizzate dal punto di vista floristico ed ecologico.