Topics in electrodynamics of moving media Final report, 1 May 1965 - 1 May 1966

Electrodynamics of moving medi

Electrodynamics of moving media First semiannual report, 1 May - 1 Nov. 1965

Electrodynamics of moving media - Minkowski covariant formulation - Radiation due to oscillating dipole in vacuum - Field of moving charge in bounded region and Cerenkov radiatio

Can students' feedback literacy be improved? A scoping review of interventions

Student feedback literacy has been the subject of much conceptual literature; however, relatively little intervention research has investigated how and if it can be developed. Further, no evaluation of the current empirical literature has been conducted to assess which elements of feedback literacy can be successfully improved in practice, and which elements need further investigation. This paper seeks to explore how different aspects of feedback literacy have been developed in higher education. A scoping review was conducted to address the foci, nature and success of interventions. The review found evidence that educational interventions enhanced feedback literacy in students, such as managing perceptions and attitudes, and having more confidence and agency in the feedback process. While some interventions have an effect on influencing student feedback literacy, both improved study design and intervention design are required to make the most of future feedback literacy interventions

Fermat's principle of least time in the presence of uniformly moving boundaries and media

The refraction of a light ray by a homogeneous, isotropic and non-dispersive transparent material half-space in uniform rectilinear motion is investigated theoretically. The approach is an amalgamation of the original Fermat's principle and the fact that an isotropic optical medium at rest becomes optically anisotropic in a frame where the medium is moving at a constant velocity. Two cases of motion are considered: a) the material half-space is moving parallel to the interface; b) the material half-space is moving perpendicular to the interface. In each case, a detailed analysis of the obtained refraction formula is provided, and in the latter case, an intriguing backward refraction of light is noticed and thoroughly discussed. The results confirm the validity of Fermat's principle when the optical media and the boundaries between them are moving at relativistic speeds.Comment: 11 pages, 6 figures, RevTeX 4, comments welcome; V2: revised, Fig. 7 added; V3: several typos corrected, accepted for publication in European Journal of Physics (online at: http://stacks.iop.org/EJP/28/933

PT-Symmetric Quantum Theory Defined in a Krein Space

We provide a mathematical framework for PT-symmetric quantum theory, which is applicable irrespective of whether a system is defined on R or a complex contour, whether PT symmetry is unbroken, and so on. The linear space in which PT-symmetric quantum theory is naturally defined is a Krein space constructed by introducing an indefinite metric into a Hilbert space composed of square integrable complex functions in a complex contour. We show that in this Krein space every PT-symmetric operator is P-Hermitian if and only if it has transposition symmetry as well, from which the characteristic properties of the PT-symmetric Hamiltonians found in the literature follow. Some possible ways to construct physical theories are discussed within the restriction to the class K(H).Comment: 8 pages, no figures; Refs. added, minor revisio

A Peptide of SPARC Interferes with the Interaction between Caspase8 and Bcl2 to Resensitize Chemoresistant Tumors and Enhance Their Regression In Vivo

SPARC, a matricellular protein with tumor suppressor properties in certain human cancers, was initially identified in a genome-wide analysis of differentially expressed genes in chemotherapy resistance. Its exciting new role as a potential chemosensitizer arises from its ability to augment the apoptotic cascade, although the exact mechanisms are unclear. This study further examines the mechanism by which SPARC may be promoting apoptosis and identifies a smaller peptide analogue with greater chemosensitizing and tumor-regressing properties than the native protein. We examined the possibility that the apoptosis-enhancing activity of SPARC could reside within one of its three biological domains (N-terminus (NT), the follistatin-like (FS), or extracellular (EC) domains), and identified the N-terminus as the region with its chemosensitizing properties. These results were not only confirmed by studies utilizing stable cell lines overexpressing the different domains of SPARC, but as well, with a synthetic 51-aa peptide spanning the NT-domain. It revealed that the NT-domain induced a significantly greater reduction in cell viability than SPARC, and that it enhanced the apoptotic cascade via its activation of caspase 8. Moreover, in chemotherapy resistant human colon, breast and pancreatic cancer cells, its chemosensitizing properties also depended on its ability to dissociate Bcl2 from caspase 8. These observations translated to clinically significant findings in that, in-vivo, mouse tumor xenografts overexpressing the NT-domain of SPARC had significantly greater sensitivity to chemotherapy and tumor regression, even when compared to the highly-sensitive SPARC-overexpressing tumors. Our results identified an interplay between the NT-domain, Bcl2 and caspase 8 that helps augment apoptosis and as a consequence, a tumor's response to therapy. This NT-domain of SPARC and its 51-aa peptide are highly efficacious in modulating and enhancing apoptosis, thereby conferring greater chemosensitivity to resistant tumors. Our findings provide additional insight into mechanisms involved in chemotherapy resistance and a potential novel therapeutic that specifically targets this devastating phenomenon

Assessment for inclusion: rethinking contemporary strategies in assessment design

Assessment has multiple purposes, one of which is to judge if students have met outcomes at the requisite level. Underperformance in assessment is frequently positioned as a problem of the student and attributed to student diversity and/or background characteristics. However, the assessment might also be inequitable and therefore exclude students inappropriately. To be inclusive, assessment design needs to be reconsidered, and educators should look beyond simplistic categories of disability or social equity groups, towards considering and accounting for diversity on many spectra. This article introduces the concept of assessment for inclusion, which seeks to ensure diverse students are not disadvantaged through assessment practices. Assumptions in assessment design are problematised from this point of view, and three central concerns relating to assessment traditions, assessment expectations, and academic integrity are interrogated. Contemporary design strategies of authentic assessment, programmatic assessment, and assessment for distinctiveness are then harnessed to illustrate approaches to assessment for inclusion. Assessment for inclusion therefore builds on the synergies between inclusive practice and good assessment design

Novel Phases and Finite-Size Scaling in Two-Species Asymmetric Diffusive Processes

We study a stochastic lattice gas of particles undergoing asymmetric diffusion in two dimensions. Transitions between a low-density uniform phase and high-density non-uniform phases characterized by localized or extended structure are found. We develop a mean-field theory which relates coarse-grained parameters to microscopic ones. Detailed predictions for finite-size ($L$) scaling and density profiles agree excellently with simulations. Unusual large-$L$ behavior of the transition point parallel to that of self-organized sandpile models is found.Comment: 7 pages, plus 6 figures uuencoded, compressed and appended after source code, LATeX, to be published as a Phys. Rev. Let