5,360 research outputs found
Investigations of scaling laws for jet impingement
The statistical properties of tangential flows over surfaces were investigated by two techniques. In one, a laser-Doppler velocimeter was used in a smoke-laden jet to measure one-point statistical properties, including mean velocities, turbulent intensities, intermittencies, autocorrelations, and power spectral densities. In the other technique, free stream and surface pressure probes connected to 1/8 inch microphones were used to obtain single point rms and 1/3 octave pressures, as well as two point cross correlations, the latter being converted to auto spectra, amplitude ratios, phase lags, and coherences. The results of these studies support the vortex model of jets, give some insights into the effects of surface impingement, and confirm that jet diameter and velocity are the scaling parameters for circular jets, while Reynolds number is relatively unimportant
Developing multilingual pedagogies and research through language study and reflection
Globalization and increased transnational migration underscore the need for educational responses to multilingualism and multilingual discourses. One way to heighten awareness of multilingual pedagogies (while simultaneously providing data for multilingual research) is the use of reflective language study and journaling by language educators/researchers. The purpose of this collaborative autoethnography, which focuses on the United States, is to demonstrate how this can be accomplished in language teacher education courses to help raise awareness and interest of how to capitalize on students’ linguistic and cultural resources. Data for this study included three participant/researcher journals and observational notes from collaborative discussions among researcher/participants about the lived experiences of multilingual language educators as they studied a new language and wrote about their experiences. Findings reveal possibilities for future research in cross-linguistic transfer as well as the teaching of multilingual pedagogies and issues of social justice as it relates to multilingual education
Uniform non-stoichiometric titanium nitride thin films for improved kinetic inductance detector array
We describe the fabrication of homogeneous sub-stoichiometric titanium
nitride films for microwave kinetic inductance detector (mKID) arrays. Using a
6 inch sputtering target and a homogeneous nitrogen inlet, the variation of the
critical temperature over a 2 inch wafer was reduced to <25 %. Measurements of
a 132-pixel mKID array from these films reveal a sensitivity of 16 kHz/pW in
the 100 GHz band, comparable to the best aluminium mKIDs. We measured a noise
equivalent power of NEP = 3.6e-15 W/Hz^(1/2). Finally, we describe possible
routes to further improve the performance of these TiN mKID arrays.Comment: 7 pages, 4 figures, submitted to Journal of low temperature physics,
Proceedings of LTD-1
Black swans, cognition and the power of learning from failure
Failure carries undeniable stigma and is difficult to confront for individuals, teams, and organizations. Disciplines such as commercial and military aviation, medicine, and business have long histories of grappling with it, beginning with the recognition that failure is inevitable in every human endeavor. While conservation may arguably be more complex, conservation professionals can draw upon the research and experience of these other disciplines to institutionalize activities and attitudes that foster learning from failures, whether they are minor setbacks or major disasters. Understanding the role of individual cognitive biases, team psychological safety, and organizational willingness to support critical self-examination all contribute to creating a cultural shift in conservation to one that is open to the learning opportunity that failure provides. This new approach to managing failure is a necessary next step in the evolution of conservation effectiveness. This article is protected by copyright. All rights reserved
Knockdown of TFIIS by RNA silencing inhibits cancer cell proliferation and induces apoptosis
<p>Abstract</p> <p>Background</p> <p>A common element among cancer cells is the presence of improperly controlled transcription. In these cells, the degree of specific activation of some genes is abnormal, and altering the aberrant transcription may therefore directly target cancer. TFIIS is a transcription elongation factor, which directly binds the transcription motor, RNA Polymerase II and allows it to read through various transcription arrest sites. We report on RNA interference of TFIIS, a transcription elongation factor, and its affect on proliferation of cancer cells in culture.</p> <p>Methods</p> <p>RNA interference was performed by transfecting siRNA to specifically knock down TFIIS expression in MCF7, MCF10A, PL45 and A549 cells. Levels of TFIIS expression were determined by the Quantigene method, and relative protein levels of TFIIS, c-myc and p53 were determined by C-ELISA. Induction of apoptosis was determined by an enzymatic Caspase 3/7 assay, as well as a non-enzymatic assay detecting cytoplasmic mono- and oligonucleosomes. A gene array analysis was conducted for effects of TFIIS siRNA on MCF7 and MCF10A cell lines.</p> <p>Results</p> <p>Knockdown of TFIIS reduced cancer cell proliferation in breast, lung and pancreatic cancer cell lines. More specifically, TFIIS knockdown in the MCF7 breast cancer cell line induced cancer cell death and increased c-myc and p53 expression whereas TFIIS knockdown in the non-cancerous breast cell line MCF10A was less affected. Differential effects of TFIIS knockdown in MCF7 and MCF10A cells included the estrogenic, c-myc and p53 pathways, as observed by C-ELISA and gene array, and were likely involved in MCF7 cell-death.</p> <p>Conclusion</p> <p>Although transcription is a fundamental process, targeting select core transcription factors may provide for a new and potent avenue for cancer therapeutics. In the present study, knockdown of TFIIS inhibited cancer cell proliferation, suggesting that TFIIS could be studied as a potential cancer target within the transcription machinery.</p
Local and nonlocal solvable structures in ODEs reduction
Solvable structures, likewise solvable algebras of local symmetries, can be
used to integrate scalar ODEs by quadratures. Solvable structures, however, are
particularly suitable for the integration of ODEs with a lack of local
symmetries. In fact, under regularity assumptions, any given ODE always admits
solvable structures even though finding them in general could be a very
difficult task. In practice a noteworthy simplification may come by computing
solvable structures which are adapted to some admitted symmetry algebra. In
this paper we consider solvable structures adapted to local and nonlocal
symmetry algebras of any order (i.e., classical and higher). In particular we
introduce the notion of nonlocal solvable structure
Cascading the use of Web 2.0 technology in secondary schools in the United Kingdom: identifying the barriers beyond pre-service training
This paper reports on research that took place at Nottingham Trent University and Sheffield Hallam University, United Kingdom, over two years. The research focuses on the use of Web 2.0 technology, specifically web logs, with pre-service teachers, both during their university programme and the first year of teaching as full-time newly qualified teachers (NQTs). The purpose of this research was to add a developing body of knowledge by identifying whether technology used by pre-service teachers during their training course can be cascaded into their practice once qualified. Key findings identify a number of enablers and barriers to cascading technology in the classroom; these include curriculum time, pupil skills and support. The research concludes that early professional support and development should be on-going and assumptions about new teachers as champions of cascading innovative use of Web 2 technologies into their practice as NQTs may be over optimisti
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