A point mutation of integrin beta 1 subunit blocks binding of alpha 5 beta 1 to fibronectin and invasin but not recruitment to adhesion plaques.

A point mutation in a highly conserved region of the beta 1 subunit, Asp130 to Ala (D130A) substitution, abrogates the Arg-Gly-Asp (RGD)-dependent binding of alpha 5 beta 1 to fibronectin (FN) without disrupting gross structure or heterodimer assembly. The D130A mutation also interferes with binding to invasin, a ligand that lacks RGD sequence. In spite of the lack of detectable FN binding by alpha 5 beta 1(D130A), it was recruited to adhesion plaques formed on FN by endogenous hamster receptors. Thus, intact ligand binding function is not required for recruitment of alpha 5 beta 1 to adhesion plaques. Overexpression of beta 1(D130A) partially interfered with endogenous alpha 5 beta 1 function, thus defining a dominant negative beta 1 integrin mutation

Distinct functions of integrin alpha and beta subunit cytoplasmic domains in cell spreading and formation of focal adhesions.

Integrin-mediated cell adhesion often results in cell spreading and the formation of focal adhesions. We exploited the capacity of recombinant human alpha IIb beta 3 integrin to endow heterologous cells with the ability to adhere and spread on fibrinogen to study the role of integrin cytoplasmic domains in initiation of cell spreading and focal adhesions. The same constructs were also used to analyze the role of the cytoplasmic domains in maintenance of the fidelity of the integrin repertoire at focal adhesions. Truncation mutants of the cytoplasmic domain of alpha IIb did not interfere with the ability of alpha IIb beta 3 to initiate cell spreading and form focal adhesions. Nevertheless, deletion of the alpha IIb cytoplasmic domain allowed indiscriminate recruitment of alpha IIb beta 3 to focal adhesions formed by other integrins. Truncation of the beta 3 subunit cytoplasmic domain abolished cell spreading mediated by alpha IIb beta 3 and also abrogated recruitment of alpha IIb beta 3 to focal adhesions. This truncation also dramatically impaired the ability of alpha IIb beta 3 to mediate the contraction of fibrin gels. In contrast, the beta 3 subunit cytoplasmic truncation did not reduce the fibrinogen binding affinity of alpha IIb beta 3. Thus, the integrin beta 3 subunit cytoplasmic domain is necessary and sufficient for initiation of cell spreading and focal adhesion formation. Further, the beta 3 cytoplasmic domain is required for the transmission of intracellular contractile forces to fibrin gels. The alpha subunit cytoplasmic domain maintains the fidelity of recruitment of the integrins to focal adhesions and thus regulates their repertoire of integrins

The complex relationship between students’ critical thinking and epistemological beliefs in the context of problem solving

The study utilized a multi-method approach to explore the connection between critical thinking and epistemological beliefs in a specific problem-solving situation. Data drawn from a sample of ten third-year bioscience students were collected using a combination of a cognitive lab and a performance task from the Collegiate Learning Assessment (CLA). The cognitive-lab data were analysed using thematic analysis. The findings showed that students’ epistemological beliefs were interwoven into their critical thinking: students used critical thinking as a tool (1) for enhancing understanding and (2) for determining truth or falsehood. Based on this classification, students could be placed in one of two qualitative profiles, either (1) thorough processing or (2) superficial processing. The results indicated that students who showed superficial processing palmed off justification for knowing on authoritative figures. In contrast to previous studies these students did not consider knowledge to be absolutely certain or unquestionable. The findings also show that students with thorough processing believed knowledge to be tentative and fallible, but did not share the relativist view of knowledge where any claim counts because all knowledge is relative. All ten students shared a fallibilist view of knowledge.Peer reviewe

Discipline-Specific Compared to Generic Training of Teachers in Higher Education

A recurrent theme arising in the higher education sector is the suitability and effectiveness of generic versus discipline-specific training of university teachers, who are often recruited based on their disciplinary specialties to become teachers in higher education. We compared two groups of participants who had undergone training using a generic post-graduate certificate in higher education (PGCertGeneric) versus a discipline-specific course in veterinary education (PGCertVetEd). The study was conducted using a survey that allowed comparison of participants who completed PGCertGeneric (n=21) with PGCertVetEd (n=22). Results indicated that participants from both PGCertGeneric and PGCertVetEd considered teaching to be satisfying and important to their careers, valued the teaching observation component of the course, and identified similar training needs. However, the participants of the PGCertVetEd felt that the course made them better teachers, valued the relevance of the components taught, understood course design better, were encouraged to do further courses/reading in teaching and learning, changed their teaching as a result of the course, and were less stressed about teaching as compared to the PGCertGeneric participants (p<.05). It is likely that the PGCertVetEd, which was designed and developed by veterinarians with a wider understanding of the veterinary sector, helped the participants perceive the training course as suited to their needs

Binding Properties and Stability of the Ras-Association Domain of Rap1-GTP Interacting Adapter Molecule (RIAM)

The Rap1-GTP interacting adapter protein (RIAM) is an important protein in Rap1-mediated integrin activation. By binding to both Rap1 GTPase and talin, RIAM recruits talin to the cell membrane, thus facilitating talin-dependent integrin activation. In this article, we studied the role of the RIAM Ras-association (RA) and pleckstrin-homology (PH) domains in the interaction with Rap1. We found that the RA domain was sufficient for GTP-dependent interaction with Rap1B, and the addition of the PH domain did not change the binding affinity. We also detected GTP-independent interaction of Rap1B with the N-terminus of RIAM. In addition, we found that the PH domain stabilized the RA domain both in vitro and in cells

A cross-cultural comparison of student learning patterns in higher education

Marambe, K. N., Vermunt, J. D., & Boshuizen, H. P. A. (2012). A cross-cultural comparison of student learning patterns in higher education. Higher Education, 64(3), 299-316. doi:10.1007/s10734-011-9494-zThe aim of this study was to compare student learning patterns in higher education across different cultures. A meta-analysis was performed on three large-scale studies that had used the same research instrument: the Inventory of learning Styles (ILS). The studies were conducted in the two Asian countries Sri Lanka and Indonesia and the European country The Netherlands. Students reported use of learning strategies, metacognitive strategies, conceptions of learning and learning orientations were compared in two ways: by analyses of variance of students' mean scale scores on ILS scales, as well as by comparing the factor structures of the ILS-scales between the three studies. Results showed most differences in student learning patterns between Asian and European students. However, many differences were identified between students from the two Asian countries as well. The Asian learner turned out to be a myth. Moreover, Sri Lankan students made the least use of memorising strategies of all groups. That Asian learners would have a propensity for rote learning turned out to be a myth as well. Some patterns of learning turned out to be universal and occurred in all groups, other patterns were found only among the Asian or the European students. The findings are discussed in terms of learning environment and culture as explanatory factors. Practical implications for student mobility in an international context are derived

The importance of context: an exploration of factors influencing the adoption of student-centered teaching among chemistry, biology, and physics faculty

Background: Research at the secondary and postsecondary levels has clearly demonstrated the critical role that individual and contextual characteristics play in instructors’ decision to adopt educational innovations. Although recent research has shed light on factors influencing the teaching practices of science, technology, engineering, and mathematics (STEM) faculty, it is still not well understood how unique departmental environments impact faculty adoption of evidence-based instructional practices (EBIPs) within the context of a single institution. In this study, we sought to characterize the communication channels utilized by STEM faculty, as well as the contextual and individual factors that influence the teaching practices of STEM faculty at the departmental level. Accordingly, we collected survey and observational data from the chemistry, biology, and physics faculty at a single large research-intensive university in the USA. We then compared the influencing factors experienced by faculty in these different departments to their instructional practices. Results: Analyses of the survey data reveal disciplinary differences in the factors influencing adoption of EBIPs. In particular, the physics faculty (n = 15) had primarily student-centered views about teaching and experienced the most positive contextual factors toward adoption of EBIPs. At the other end of the spectrum, the chemistry faculty (n = 20) had primarily teacher-centered views and experienced contextual factors that hindered the adoption of student-centered practices. Biology faculty (n = 25) fell between these two groups. Classroom observational data reflected these differences: The physics classrooms were significantly more student-centered than the chemistry classrooms. Conclusions: This study demonstrates that disciplinary differences exist in the contextual factors teaching conceptions that STEM faculty experience and hold, even among faculty within the same institution. Moreover, it shows that these differences are associated to the level of adoption of student-centered teaching practices. This work has thus identified the critical need to carefully characterize STEM faculty’s departmental environment and conceptions about teaching before engaging in instructional reform efforts, and to adapt reform activities to account for these factors. The results of this study also caution the over generalization of findings from a study focused on one type of STEM faculty in one environment to all STEM faculty in any environment

Fashion, the media and age: How women’s magazines use fashion to negotiate age identities

The article explores the role of women’s magazines in the negotiation of later life identities, focussing on the treatment of fashion and dress. It locates the analysis in debates about the changing nature of later years with the emergence of Third Age identities, and the role of consumption in these. Focussed on the treatment of fashion and age, it analyses four UK magazines: three chosen to represent the older market (Woman & Home, Saga, Yours), and one to represent mainstream fashion (Vogue). It is based on interviews with four editors and analysis of the content of the magazines. The article analyses the media strategies that journalists use to negotiate tensions in the presentation of fashion for this group and their role in supporting new formations of age