Drinfeld-Manin Instanton and Its Noncommutative Generalization

The Drinfeld-Manin construction of U(N) instanton is reformulated in the ADHM formulism, which gives explicit general solutions of the ADHM constraints for U(N) (N>=2k-1) k-instantons. For the N<2k-1 case, implicit results are given systematically as further constraints, which can be used to the collective coordinate integral. We find that this formulism can be easily generalized to the noncommutative case, where the explicit solutions are as well obtained.Comment: 17 pages, LaTeX, references added, mailing address added, clarifications adde

Anti-de-Sitter Island-Universes from 5D Standing Waves

We construct simple standing wave solutions in a 5D space-time with a ghost scalar field. The nodes of these standing waves are 'islands' of 4D Minkowski space-time. For the 5D model with increasing (decreasing) warp factor there are a finite (infinite) number of nodes and thus Minkowski island-universes having different parameters, such as gravitational and cosmological constants. This feature is similar to the assumptions of the landscape models, which postulate a large number of universes with different parameters. This standing wave solution also provides a new localization mechanism - matter fields can reside only on Minkowski 'islands', where the background space-time does not oscillate.Comment: 14 page pre-print format. Discussion about connection to Weyl gravity added and "E&M" localization method added. To be published MPL

Gauge invariance of dimension two condensate in Yang-Mills theory

Gauge independence of dimension two condensate in Yang-Mills theory is demonstrated by using a noncommutative theory technique.Comment: 7 page

Connecting does not necessarily mean learning: Course handbooks as mediating tools in school-university partnerships

This is the author's accepted manuscript (titled "Course handbooks as mediating tools in learning to teach"). The final published article is available from the link below. Copyright @ 2011 American Association of Colleges for Teacher Education.Partnerships between schools and universities in England use course handbooks to guide student teacher learning during long field experiences. Using data from a yearlong ethnographic study of a postgraduate certificate of education programme in one English university, the function of course handbooks in mediating learning in two high school subject departments (history and modern foreign languages) is analyzed. Informed by Cultural Historical Activity Theory, the analysis focuses on the handbooks as mediating tools in the school-based teacher education activity systems. Qualitative differences in the mediating functions of the handbooks-in-use are examined and this leads to a consideration of the potential of such tools for teacher learning in school–university partnerships. Following Zeichner’s call for rethinking the relationships between schools and universities, the article argues that strong structural connections between different institutional sites do not necessarily enhance student teacher learning

Factors associated with post-arrest withdrawal of life-sustaining therapy.

INTRODUCTION: Most successfully resuscitated cardiac arrest patients do not survive to hospital discharge. Many have withdrawal of life sustaining therapy (WLST) as a result of the perception of poor neurologic prognosis. The characteristics of these patients and differences in their post-arrest care are largely unknown. METHODS: Utilizing the Penn Alliance for Therapeutic Hypothermia Registry, we identified a cohort of 1311 post-arrest patients from 26 hospitals from 2010 to 2014 who remained comatose after return of spontaneous circulation. We stratified patients by whether they had WLST post-arrest and analyzed demographic, arrest, and post-arrest variables. RESULTS: In our cohort, 565 (43%) patients had WLST. In multivariate regression, patients who had WLST were less likely to go to the cardiac catheterization lab (OR 0.40; 95% CI: 0.26-0.62) and had shorter hospital stays (OR 0.93; 95% CI: 0.91-0.95). When multivariate regression was limited to patient demographics and arrest characteristics, patients with WLST were older (OR 1.18; 95% CI: 1.07-1.31 by decade), had a longer arrest duration (OR 1.14; 95% CI: 1.05-1.25 per 10min), more likely to be female (OR: 1.41; 95% CI: 1.01-1.96), and less likely to have a witnessed arrest (OR 0.65; 95% CI: 0.42-0.98). CONCLUSION: Patients with WLST differ in terms of demographic, arrest, and post-arrest characteristics and treatments from those who did not have WLST. Failure to account for this variability could affect both clinical practice and the interpretation of research

Testing Spatial Noncommutativity via Rydberg Atoms

The possibility of testing spatial noncommutativity via Rydberg atoms is explored. An atomic dipole of a cold Rydberg atom is arranged in appropriate electric and magnetic field, so that the motion of the dipole is constrained to be planar and rotationally symmetric. Spatial noncommutativity leads to that the canonical angular momentum possesses fractional values. In the limit of vanishing kinetic energy, the dominate value of the lowest canonical angular momentum takes $\hbar/2$. Furthermore, in the limit of eliminating magnetic field, the dominate value of the lowest canonical angular momentum changes from $\hbar/2$ to $\hbar/4$. This result is a clear signal of spatial noncommutativity. An experimental verification of this prediction is suggested.Comment: 10 pages. Physical Review Letters (in press

Greener One-pot Synthesis of Chromeno Oxazin and Oxazin Quinoline Derivatives and their Antibacterial Activity

An efficient green method for the synthesis of oxazino quinoline-2-amine derivatives, oxazino quinoline derivatives and chromeno oxazin-5-one derivatives have been synthesized through cyclization of aromatic aldehyde, ammonium acetate, substituted amides and 8-hydroxy-quinoline or 4-hydroxy coumarin by one-pot condensation method is described. The synthesized compounds are characterized by FT-IR, 1H NMR and MASS spectral techniques and are screened further for biological activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis using cup plate method and disc diffusion method

Constraints, gauge symmetries, and noncommutative gravity in two dimensions

After an introduction into the subject we show how one constructs a canonical formalism in space-time noncommutative theories which allows to define the notion of first-class constraints and to analyse gauge symmetries. We use this formalism to perform a noncommutative deformation of two-dimensional string gravity (also known as Witten black hole).Comment: Based on lectures given at IFSAP-2004 (St.Petersburg), to be submitted to Theor. Math. Phys., dedicated to Yu.V.Novozhilov on the occasion of his 80th birthda

Evidence for Extremely High Dust Polarization Efficiency in NGC 3184

Recent studies have found the Type II-plateau supernova (SN) 1999gi to be highly polarized (p_max = 5.8%, where p_max is the highest degree of polarization measured in the optical bandpass; Leonard & Filippenko 2001) and minimally reddened (E[B-V] = 0.21 +/- 0.09 mag; Leonard et al. 2002). From multiple lines of evidence, including the convincing fit of a ``Serkowski'' interstellar polarization (ISP) curve to the continuum polarization shape, we conclude that the bulk of the observed polarization is likely due to dust along the line of sight (l-o-s), and is not intrinsic to SN 1999gi. We present new spectropolarimetric observations of four distant Galactic stars close to the l-o-s to SN 1999gi (two are within 0.02 degrees), and find that all are null to within 0.2%, effectively eliminating Galactic dust as the cause of the high polarization. The high ISP coupled with the low reddening implies an extraordinarily high polarization efficiency for the dust along this l-o-s in NGC 3184: ISP / E(B-V) = 31^{+22}_{-9} % mag^{-1}. This is inconsistent with the empirical Galactic limit (ISP / E[B-V] < 9% mag^{-1}), and represents the highest polarization efficiency yet confirmed for a single sight line in either the Milky Way or an external galaxy.Comment: 27 pages, accepted for publication by the Astronomical Journa