Defining motivation: perspectives from early childhood educators

Thesis (M.Ed.)--University of Hawaii at Manoa, 2005.Motivation is suggested to be an important link to learning and achievement. However, it is unclear what previous researchers refer to as motivation because of the plethora of terms that are associated with motivation. The purpose of this study was to examine the definition of motivation in young children through the perspectives of Head Start early childhood educators. The Defining Motivation in Early Childhood survey was developed to examine motivation in terms of characteristics, indicators, origin, influence, and strategies that teachers use to promote it in a classroom setting. On the basis of factor analyses of the survey, as well as focus group interviews, a child's personal interest in a task or activity was suggested to be a defining belief of motivation in young children

Modulation of MHC expression on human endothelial cells by sera from patients with systemic lupus erythematosus

10.1006/clin.1993.1133Clinical Immunology and Immunopathology683321-326CLII

Membrane Trafficking of Heterotrimeric G Proteins via the Endoplasmic Reticulum and Golgi

Membrane targeting of G-protein αβγ heterotrimers was investigated in live cells by use of Gα and Gγ subunits tagged with spectral mutants of green fluorescent protein. Unlike Ras proteins, Gβγ contains a single targeting signal, the CAAX motif, which directed the dimer to the endoplasmic reticulum. Endomembrane localization of farnesylated Gγ(1), but not geranylgeranylated Gγ(2), required carboxyl methylation. Targeting of the heterotrimer to the plasma membrane (PM) required coexpression of all three subunits, combining the CAAX motif of Gγ with the fatty acyl modifications of Gα. Gα associated with Gβγ on the Golgi and palmitoylation of Gα was required for translocation of the heterotrimer to the PM. Thus, two separate signals, analogous to the dual-signal targeting mechanism of Ras proteins, cooperate to target heterotrimeric G proteins to the PM via the endomembrane

Integrin α1β1 (VLA-1) mediates adhesion of activated intraepithelial lymphocytes to collagen

Intraepithelial lymphocytes (IELs) from human intestinal epithelium are memory CD8+ T cells that bind to epithelial cells through human mycosal lymphocyte (HML)-1 and to mesenchymal cells through very late activation antigen-4 (VLA-4). Their binding of extracellular matrix proteins and the mechanism involved were tested. Activated 51Cr-labelled lymphocytes were incubated in protein-coated microwells with various additives. After washing, the adherent cells were detected by radioactivity. The percentages of activated IELs that bound to collagen types I and IV were 20 and 31%, respectively; fewer bound to fibronectin or laminin. Compared to interleukin-2-activated peripheral blood CD8+ T lymphocytes, more IELs bound collagen IV and fewer bound fibronectin. IEL adhesion to collagen (but not fibronectin or laminin) was up-regulated by antibody ligation of CD2 or by protein kinase C stimulation by phorbol ester; staurosporine reduced binding, while herbimycin, phytohaemagglutinin and CD3 ligation had no effect. Antibody-blocking of integrin VLA-1 subunits α1 (CD49a) and β1 (CD18) inhibited adhesion to collagen type I by 82±6% and to type IV by 94±1% (P < 0·001), implicating VLA-1 as the main collagen receptor for IELs. Cell adhesion was dependent on extracellular divalent cations, a characteristic event of VLA-1 never before shown for IELs: manganese and magnesium ions supported binding in a dose-dependent manner; calcium ions inhibited their effectiveness. Therefore, IELs bind collagen through integrin α1β1 after protein kinase C activation. Adhesion is modulated by divalent cations