Corepressor diversification by alternative mRNA splicing is species specific.

BackgroundSMRT and NCoR are corepressor paralogs that help mediate transcriptional repression by a variety of transcription factors, including the nuclear hormone receptors. The functions of both corepressors are extensively diversified in mice by alternative mRNA splicing, generating a series of protein variants that differ in different tissues and that exert different, even diametrically opposite, biochemical and biological effects from one another.ResultsWe report here that the alternative splicing previously reported for SMRT appears to be a relatively recent evolutionary phenomenon, with only one of these previously identified sites utilized in a teleost fish and a limited additional number of the additional known sites utilized in a bird, reptile, and marsupial. In contrast, extensive SMRT alternative splicing at these sites was detected among the placental mammals. The alternative splicing of NCoR previously identified in mice (and shown to regulate lipid and carbohydrate metabolism) is likely to have arisen separately and after that of SMRT, and includes an example of convergent evolution.ConclusionsWe propose that the functions of both SMRT and NCoR have been diversified by alternative splicing during evolution to allow customization for different purposes in different tissues and different species

SINGLE MOLECULE FRET OF LACI-DNA-IPTG LOOP CONFORMATIONS

This work focuses on the Escherichia coli lactose repressor protein (LacI) which represses expression of the lac operon. In order to repress transcription, the tetrameric LacI protein binds a primary promoter-proximal operator, O1, and one of two auxiliary operators, O2 or O3. The binding of these two sites to a single LacI molecule occurs via DNA loop formation. Induction of the lac operon by allolactose reduces the affinity of LacI for DNA, but induction does not completely prevent looping in vivo. The synthetic inducer isopropyl-β-D-thiogalactoside (IPTG) acts similarly to allolactose. Model DNA constructs have been used to demonstrate, through fluorescence resonance energy transfer (FRET) analysis, that LacI may change conformation in order to form more than one loop structure. This work employs single molecule FRET to investigate LacI-induced loop formation in DNA looping constructs, as a function of IPTG concentration, on freely diffusing LacI-DNA complexes. The results include evidence for the persistence of DNA loop formation under at saturating IPTG concentration, and they provide a detailed view of how LacI conformation affects DNA loop formation. In addition, this work explores possible changes in geometry in LacI-induced DNA loops through the use of model DNA constructs that produce alternative loop topologies. We propose that inducer-bound LacI-DNA looped complexes may control the kinetics of induction and re-repression of the operon

Welcome to the Dance: Partnering Up Taxonomies and Research

This presentation will connect research on teaching strategies that promote certain kinds of learning with major learning taxonomies in the literature. First, there will be a visual comparison of taxonomies to show differences and commonalities. If we consider a taxonomy as a concept map, inconsistencies seen in these comparisons should not be surprising since they were created by different groups of qualified educators. Second, there will be a partnering up of findings from research about instructional strategies that work for different types of learning. This will place us in a better position to judge the value of a taxonomy and discuss: (1) What are the competing concepts in the taxonomies? (2) How does research on “what works” and the “events of learning” align with those concepts? (3) Does this alignment offer practical guidance for teaching

New Teacher Induction Programs in Tennessee: Formal, Informal, and Influential Practices

The researcher examined beginning teacher induction programs in large and small districts in Tennessee for the 1997-1998 school year. Types of induction, formal and informal, were examined. The study looked at the teacher attitudes of job satisfaction, job adjustment, and socialization into the profession of teaching. The research design included five questions with two hypotheses used for testing differences between teacher attitudes in large and small systems. Beginning first-year teachers were surveyed and asked to rate their induction program as to best practices. Teachers rated the occurrence of activities in seven areas and how supportive activities were in their roles as beginning teachers. The questions were tested and statistically analyzed using chi-square and analysis of variance procedures. No differences were found in the occurrence of induction activities in large and small systems. No differences were found in how supportive an event was in large and small systems. A difference was found in job adjustment between large and small systems, but not in job satisfaction or socialization into the profession. Recommendations for further research were made to augment the study

Dimensional perturbation theory for vibration-rotation spectra of linear triatomic molecules

A very efficient large-order perturbation theory is formulated for the nuclear motion of a linear triatomic molecule. To demonstrate the method, all of the experimentally observed rotational energies, with values of $J$ almost up to 100, for the ground and first excited vibrational states of CO$_2$ and for the ground vibrational states of N$_2$O and of OCS are calculated. All coupling between vibration and rotation is included. The perturbation expansions reported here are rapidly convergent. The perturbation parameter is $D^{-1/2}$, where $D$ is the dimensionality of space. Increasing $D$ is qualitatively similar to increasing the angular momentum quantum number $J$. Therefore, this approach is especially suited for states with high rotational excitation. The computational cost of the method scales only as $JN_v^{5/3}$, where $N_v$ is the size of the vibrational basis set.Comment: submitted to Journal of Chemical Physics, 23 pages, REVTeX, no figure

Developing the Next Generation of Distance Supervision

Student teaching has long been an essential component of teacher education programs, and effective supervision is essential for successful internship experiences. Pre-service students’ needs must be weighed against the limitation of time and access for the university supervisor, often a full-time faculty member who has a formidable teaching load and other responsibilities. Additionally, direct, in-person observations can create observer effect, altering the reality of what is actually being observed. This article examines one university’s use of distant supervision utilizing technology to aid in the virtual classroom observations and conferencing to allow an elementary education major to student teach in a rural southwest Kansas school

Examining 'window dressing' : the views of black police associations on recruitment and training

In a previous issue of this journal, Ellis Cashmore (2002 Cashmore, E. 2002. ‘Behind the window dressing: minority ethnic police perspectives on cultural diversity’. Journal of Ethnic and Migration Studies, 28(2): 327–41. [Taylor & Francis Online], [CSA], [Google Scholar] ) discussed two key issues currently confronting police constabularies in England and Wales: the recruitment of minority ethnic officers and civilian staff, and the impact of diversity training now in place for all police officers. Cashmore argued that not only are these policies ineffective in enhancing cultural diversity within constabularies, but that they are harmful, presenting a false outward image of effective action. This article examines Cashmore's arguments and develops them in light of findings from recent research on Black Police Associations (BPAs) in England and Wales. Our findings firstly suggest that, because of heavy involvement with these initiatives and the close relationship BPAs have developed with senior management (in comparison to non-BPA members), they must be considered in any discussion of minority ethnic recruitment and diversity training. In addition, the majority of the officers we interviewed were supportive of current recruitment and training programmes. Secondly, we argue that BPAs are helping to change the nature of the overall police culture to a certain extent. Many minority ethnic officers no longer feel they must downplay their ethnicity as members of constabularies

Furthering alternative cultures of valuation in higher education research

The value of higher education is often implicit or assumed in educational research. The underlying and antecedent premises that shape and influence debates about value remain unchallenged which perpetuates the dominant, but limiting, terms of the debate and fosters reductionism. I proceed on the premise that analyses of value are not self–supporting or self-referential but are embedded within prevailing cultures of valuation. I contend that challenging, and providing alternatives to, dominant narratives of higher education requires an appreciation of those cultures. I therefore highlight some of the existing cultures of valuation and their influence. I then propose Sayer’s concept of lay normativity as a culture of valuation and discuss how it translates into the practices of research into higher education, specifically the practice of analysis. I animate the discussion by detecting the presence of lay normativity in the evaluative space of the capability approach