Josephson Coupling through a Quantum Dot

We derive, via fourth order perturbation theory, an expression for the Josephson current through a gated interacting quantum dot. We analyze our expression for two different models of the superconductor-dot-superconductor (SDS) system. When the matrix elements connecting dot and leads are featureless constants, we compute the Josephson coupling J_c as a function of the gate voltage and Coulomb interaction. In the diffusive dot limit, we compute the probability distribution P(J_c) of Josephson couplings. In both cases, pi junction behavior (J_c < 0) is possible, and is not simply dependent on the parity of the dot occupancy.Comment: 9 pages; 3 encapsulated PostScript figure

LEARNING TO TEACH ADVENTURE EDUCATION: PRE-SERVICE TEACHERS’ PERSPECTIVES AND EXPERIENCES

Feiman-Nemser (2008) noted the importance of teacher education on the development of teachers, and “how teachers acquire, generate and learn to use knowledge in teaching” (p. 698). The purpose of this investigation was to examine aspects of adventure education for which pre-service teachers’ (PTs) planned, and subsequently taught during a teaching practice (TP) placement. We also sought to gain an understanding of the challenges these PTs faced when teaching this content as part of a physical education curriculum. Data were collected through schemes of work (SoW) and lesson plans (LPs), researcher field notes, a focus group interview, and post lesson discussion. Analysis of data sources revealed little alignment between what PTs planned and what they taught. Attempts were made to incorporate debriefing into lessons but no adventure principles were integrated (Full Value Contract (FVC), Experiential Learning Cycle (ELC) or Challenge with/by Choice (CbC). Challenges that impacted the delivery of lessons included lack of resources and facilities, and perceived student resistance. Findings suggested PTs misunderstood the adventure principles and struggled with adapting and applying knowledge during teaching practice. PTs often focussed on ‘filling time’ as opposed to teaching toward student learning. Further study is needed to examine how teacher education is delivered and what adventure experiences PTs enter teacher education with, to understand why and what PTs plan for and teach and what influences their decisions

Comment on Viscous Stability of Relativistic Keplerian Accretion Disks

Recently Ghosh (1998) reported a new regime of instability in Keplerian accretion disks which is caused by relativistic effects. This instability appears in the gas pressure dominated region when all relativistic corrections to the disk structure equations are taken into account. We show that he uses the stability criterion in completely wrong way leading to inappropriate conclusions. We perform a standard stability analysis to show that no unstable region can be found when the relativistic disk is gas pressure dominated.Comment: 9 pages, 4 figures, uses aasms4.sty, submitted for ApJ Letter

'It's the other assessment that is the key': three Norwegian physical education teachers' engagement (or not) with assessment for learning

peer-reviewedThe international agenda for assessment continues to convey a growing interest in assessment for learning (AfL) as a tool to support learning and enhance teaching. Complementing this, the recent literature on assessment in physical education acknowledges the need for physical educators to integrate AfL into their teaching and assessment practice as an important part of the future development of the subject. Appreciating that physical education must be recognized as part of the larger movement culture in society and is a place to learn about movement culture, this study explores how AfL is understood and enacted by physical education teachers and the extent to which such enactment complements or challenges learning movement cultures within physical education. This study shares how three Norwegian physical education teachers used AfL to term what they were practicing with respect to assessment in physical education. We follow the interactions of the selected teachers throughout focus groups, using the empirical data as our 'dialogue partner' in reconstructing and discussing their assessment stories. We conclude that the need of embedding AfL in learning theory may well be one of the strongest challenges to enacting AfL in physical education. We acknowledge that not only are most existing theories of learning defined cognitively, but also that learning connected to physical education and activity is, to a large extent, practical and embodied, and also linked to the powerful discourses of sport and related areas such as health.PUBLISHEDpeer-reviewe

Analysis of an Electromagnetic Mitigation Scheme for Reentry Telemetry Through Plasma

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76726/1/AIAA-37395-105.pd

Nonlinear description of transversal motion in a laminar boundary layer with streaks

The nonlinear streamwise growth of a spanwise periodic array of steady streaks in a flat plate boundary layer is numerically computed using the well known Reduced Navier-Stokes formulation. It is found that the flow configuration changes substantially when the amplitude of the streaks grows and the nonlinear effects come into play. The transversal motion (in the wall normal-spanwise plane), which is normally not considered, becomes non-negligible in the nonlinear regime, and it strongly distorts the streamwise velocity profiles, which end up being quite different from those predicted by the linear theory. We analyze in detail the resulting flow patterns for the nonlinearly saturated streaks, and compare them with available experimental results

Effects of Reynolds Number and Flapping Kinematics on Hovering Aerodynamics

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76695/1/AIAA-2007-129-236.pd

A novel approach for the generation of genetically modified mammary epithelial cell cultures yields new insights into TGF-beta signaling in the mammary gland

Abstract Introduction Molecular dissection of the signaling pathways that underlie complex biological responses in the mammary epithelium is limited by the difficulty of propagating large numbers of mouse mammary epithelial cells, and by the inability of ribonucleic acid interference-based knockdown approaches to fully ablate gene function. Here we describe a method for the generation of conditionally immortalized mammary epithelial cells with defined genetic defects, and we show how such cells can be used to investigate complex signal transduction processes using the transforming growth factor beta (TGF&#946;)/Smad pathway as an example. Methods We intercrossed the previously described H-2Kb-tsA58 transgenic mouse (Immortomouse), which expresses a temperature-sensitive mutant of the simian virus-40 large T-antigen (tsTAg), with mice of differing Smad genotypes. Conditionally immortalized mammary epithelial cell cultures were derived from the virgin mammary glands of offspring of these crosses and were used to assess the Smad dependency of different biological responses to TGF&#946;. Results IMECs could be propagated indefinitely at permissive temperatures and had a stable epithelial phenotype, resembling primary mammary epithelial cells with respect to several criteria, including responsiveness to TGF&#946;. Using this panel of cells, we demonstrated that Smad3, but not Smad2, is necessary for TGF&#946;-induced apoptotic, growth inhibitory and epithelial-to-mesenchymal transition responses, whereas either Smad2 or Smad3 can support TGF&#946;-induced invasion as long as a threshold level of total Smad is exceeded. Conclusions The present work demonstrates the practicality and utility of generating conditionally immortalized mammary epithelial cell lines from genetically modified Immortomice for detailed investigation of complex signaling pathways in the mammary epithelium.http://deepblue.lib.umich.edu/bitstream/2027.42/78285/1/bcr2728.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78285/2/bcr2728.pdfPeer Reviewe