Theory and practice in initial teacher education : the British context

The argument I lead towards in this paper, however, is that while there is indeed a theory-practice problem, conventional diagnoses and associated solutions, far from solving the problem may well have exacerbated it. I shall argue that we need a more comprehensive diagnosis, basic to which must be an understanding of the assumptions which course structures in teacher education institutions have embodied and an honesty on the part of all of us - teacher educators, teachers and administrators - about the extent to which our own assumptions, attitudes and practices might hinder rather than help our student-teachers to make that vital theory-practice synthesis. I write about the context I know best, that in Britain. I make no comparisons with or extrapolations to the Maltese context: that is for others to do.peer-reviewe

“Scholarship is a Conversation”: Discourse, Attribution, and Twitter’s Role in Information Literacy Instruction

When addressing scholarly attribution, citation, and plagiarism in one-shot instruction sessions, librarians often fail to present these issues in a manner that has relevance for students. Librarians often focus on intellectual honesty and the potential ramifications of plagiarism, both individual pursuits, rather than explaining that by creating an academic work, students are participating in academic discourse. Within Pluralizing Plagiarism, Anson argues that scholarly attribution instruction that emphasizes “policy, detection, and punishment” is antithetical to the mission of institutions of higher learning – the education of students (Anson, 2008). One of the major deficiencies of this compliance-based instruction is that it presents students with a false dichotomy that does not align with their authentic life experiences; plagiarism is demonstrated as a black and white issue, rather than existing in shades of gray. Students who have come of age within a twenty-first century information ecosystem rife with remix and parody culture will likely find teaching that presents the re-use of source material as a non-nuanced issue unconvincing. Because students respond positively to instruction that aligns with their authentic experiences, this suggests that librarians need to develop new methods for teaching attribution and scholarly discourse that not only recognize the nuance inherent to these topics, but also presents these concepts within a familiar framework (Klipfel, 2014). As a familiar platform for social interaction with multiple avenues for giving credit and a shorter timescale, Twitter presents an opportunity to place attribution, plagiarism, and integrity into a humanizing, real world context that models how discourse unfolds in an authentic manner for learners. By embedding attribution instruction into a meaningful context, librarians and other educators can make substantial and much needed improvements to traditional compliance-based instruction, which is often built upon the slow, rigid, and unfamiliar patterns of how to cite scholarly works

The Human Cytomegalovirus Fc Receptor gp68 Binds the Fc CH2-CH3 Interface of Immunoglobulin G

Recognition of immunoglobulin G (IgG) by surface receptors for the Fc domain of immunoglobulin G (Fc{gamma}), Fc{gamma}Rs, can trigger both humoral and cellular immune responses. Two human cytomegalovirus (HCMV)-encoded type I transmembrane receptors with Fc{gamma}-binding properties (vFc{gamma}Rs), gp34 and gp68, have been identified on the surface of HCMV-infected cells and are assumed to confer protection against IgG-mediated immunity. Here we show that Fc{gamma} recognition by both vFc{gamma}Rs occurs independently of N-linked glycosylation of Fc{gamma}, in contrast with the properties of host Fc{gamma}Rs. To gain further insight into the interaction with Fc{gamma}, truncation mutants of the vFc{gamma}R gp68 ectodomain were probed for Fc{gamma} binding, resulting in localization of the Fc{gamma} binding site on gp68 to residues 71 to 289, a region including an immunoglobulin-like domain. Gel filtration and biosensor binding experiments revealed that, unlike host Fc{gamma}Rs but similar to the herpes simplex virus type 1 (HSV-1) Fc receptor gE-gI, gp68 binds to the CH2-CH3 interdomain interface of the Fc{gamma} dimer with a nanomolar affinity and a 2:1 stoichiometry. Unlike gE-gI, which binds Fc{gamma} at the slightly basic pH of the extracellular milieu but not at the acidic pH of endosomes, the gp68/Fc{gamma} complex is stable at pH values from 5.6 to pH 8.1. These data indicate that the mechanistic details of Fc binding by HCMV gp68 differ from those of host Fc{gamma}Rs and from that of HSV-1 gE-gI, suggesting distinct functional and recognition properties

Differential Hox expression in murine embryonic stem cell models of normal and malignant hematopoiesis

The Hox family are master transcriptional regulators of developmental processes, including hematopoiesis. The Hox regulators, caudal homeobox factors (Cdx1-4), and Meis1, along with several individual Hox proteins, are implicated in stem cell expansion during embryonic development, with gene dosage playing a significant role in the overall function of the integrated Hox network. To investigate the role of this network in normal and aberrant, early hematopoiesis, we employed an in vitro embryonic stem cell differentiation system, which recapitulates mouse developmental hematopoiesis. Expression profiles of Hox, Pbx1, and Meis1 genes were quantified at distinct stages during the hematopoietic differentiation process and compared with the effects of expressing the leukemic oncogene Tel/PDGFR;2. During normal differentiation the Hoxa cluster, Pbx1 and Meis1 predominated, with a marked reduction in the majority of Hox genes (27/39) and Meis1 occurring during hematopoietic commitment. Only the posterior Hoxa cluster genes (a9, a10, a11, and a13) maintained or increased expression at the hematopoietic colony stage. Cdx4, Meis1, and a subset of Hox genes, including a7 and a9, were differentially expressed after short-term oncogenic (Tel/PDGFR;2) induction. Whereas Hoxa4-10, b1, b2, b4, and b9 were upregulated during oncogenic driven myelomonocytic differentiation. Heterodimers between Hoxa7/Hoxa9, Meis1, and Pbx have previously been implicated in regulating target genes involved in hematopoietic stem cell (HSC) expansion and leukemic progression. These results provide direct evidence that transcriptional flux through the Hox network occurs at very early stages during hematopoietic differentiation and validates embryonic stem cell models for gaining insights into the genetic regulation of normal and malignant hematopoiesis

The differential regulation of Lck kinase phosphorylation sites by CD45 is critical for T cell receptor signaling responses

SummaryThe molecular mechanisms whereby the CD45 tyrosine phosphatase (PTPase) regulates T cell receptor (TCR) signaling responses remain to be elucidated. To investigate this question, we have reconstituted CD45 (encoded by Ptprc)-deficient mice, which display severe defects in thymic development, with five different expression levels of transgenic CD45RO, or with mutant PTPase null or PTPase-low CD45R0. Whereas CD45 PTPase activity was absolutely required for the reconstitution of thymic development, only 3% of wild-type CD45 activity restored T cell numbers and normal cytotoxic T cell responses. Lowering the CD45 expression increased CD4 lineage commitment. Peripheral T cells with very low activity of CD45 phosphatase displayed reduced TCR signaling, whereas intermediate activity caused hyperactivation of CD4+ and CD8+ T cells. These results are explained by a rheostat mechanism whereby CD45 differentially regulates the negatively acting pTyr-505 and positively acting pTyr-394 p56lck tyrosine kinase phosphorylation sites. We propose that high wild-type CD45 expression is necessary to dephosphorylate p56lck pTyr-394, suppressing CD4 T+ cell lineage commitment and hyperactivity

The Retweet of Academia: Using Twitter to Improve Information Literacy Instruction

When addressing citation and plagiarism within one shot instruction sessions, librarians often fail to present these issues in a manner that has relevance for students. Librarians often focus on intellectual honesty and the potential ramifications of plagiarism, rather than explaining that by creating an academic work, students are participating in academic discourse. To improve information literacy instruction, librarians need to seek out new models for citation and plagiarism that engage students. By using Twitter and presenting citations and bibliographies as the “Retweet of Academia,” librarians can offer classic bibliographic instruction in an innovative and exciting way. Twitter timelines portray how discourse unfolds in real time, and in a visual medium that has relevance for students. Additionally, Twitter is designed to encourage users to share ideas and content. Like citation style guides, Twitter as a platform and a community has developed features and conventions that allow users to properly credit the ideas and content of other users. Recently, popular Twitter accounts have been identified as plagiarizing content, making this instruction timely as well. During the Fall 2013 semester at the University of Maryland – College Park, we began to use Twitter as a tool for teaching plagiarism within a select number of library instruction sessions, and plan to introduce the method into more sessions in the upcoming Spring 2014 semester. This lightning talk will discuss how we have used Twitter to teach plagiarism, as well as describe our early experiences with using this pedagogical method. We will also address a few of our goals for further research.Previous educational literature contends that undergraduate students need more basic instruction on citation and plagiarism. Meanwhile, citation management systems such as EndNote Web, Zotero, and Mendeley are becoming increasingly robust and sophisticated. As a result, libraries have begun to create systematic support for integrating these software applications into their service offerings. The confluence of these two trends suggests an opportunity for libraries to shift the emphasis of their citation instruction. Rather than focusing on specific mechanics of citation styles, libraries can emphasize instruction on the topics of plagiarism and citation more broadly. Librarians should use this opportunity to develop new instructional models and pedagogical methods for delivering citation and plagiarism instruction that have relevance for students today. By using Twitter to depict citations and bibliographies as the “Retweet of Academia,” librarians can offer classic bibliographic instruction in an innovative and exciting way

Changes in fibrin clot properties in patients after Roux en-Y gastric bypass surgery

Background: Obesity is a complex condition associated with prothrombotic fibrin networks that are resistant to fibrinolysis. Altered fibrin clot properties enhance cardiovascular risk and associate with a poorer prognosis following acute ischemic events. Bariatric surgery is commonly employed to improve cardiometabolic outcomes in obese individuals. However, the effects of this surgical intervention on fibrin clot properties have not been comprehensively studied. Methods: The fibrin clot properties of 32 obese individuals before and 9-months after Roux en-Y gastric bypass (RYGB) surgery were determined using turbidimetric analysis. Correlation and regression analyses were used to identify relationships between clot properties and anthropomorphic and clinical measures. Results: RYGB surgery resulted in a significant reduction in adiposity-associated anthropometric measures as well as improvements in glycaemia and lipid profile. Clot maximum absorbance was reduced from 0.43 ± 0.11 at baseline to 0.29 ± 0.10 at 9 months post-surgery (p < 0.0001), while fibrin clot lysis time failed to show a difference. The change in maximum absorbance was not caused by alterations in fibrinogen levels, while PAI-1 concentration was significantly increased after surgery from 10,560 ± 6,681 pg/ml to 15,290 ± 6,559 pg/ml (p = 0.0093). Correlation and regression analysis indicated that maximum absorbance was influenced by markers of adiposity as well as HbA1c and hs-CRP concentrations. Conclusions: RYGB surgery led to a decrease in the maximum absorbance of the fibrin clot. Values of maximum absorbance were associated with measures of glycaemic control and inflammation. In contrast to previous reports, fibrin clot lysis time was not affected after surgery.Peer reviewe

Chaotic Observer-based Synchronization Under Information Constraints

Limit possibilities of observer-based synchronization systems under information constraints (limited information capacity of the coupling channel) are evaluated. We give theoretical analysis for multi-dimensional drive-response systems represented in the Lurie form (linear part plus nonlinearity depending only on measurable outputs). It is shown that the upper bound of the limit synchronization error (LSE) is proportional to the upper bound of the transmission error. As a consequence, the upper and lower bounds of LSE are proportional to the maximum rate of the coupling signal and inversely proportional to the information transmission rate (channel capacity). Optimality of the binary coding for coders with one-step memory is established. The results are applied to synchronization of two chaotic Chua systems coupled via a channel with limited capacity.Comment: 7 pages, 6 figures, 27 reference