A New Day for Youth: Creating Sustainable Quality in Out-of-School Time

Reviews research on best practices and examines the elements needed to create and sustain high-quality afterschool and summer programs. Recommends a framework for improving staff capacity and training, support structures and leadership, and activities

Interrelation between radio and X-ray signatures of drifting subpulses in pulsars

We examined a model of partially screened gap region above the polar cap, in which the electron-positron plasma generated by sparking discharges coexists with thermionic flow ejected by the bombardment of the surface beneath these sparks. Our special interest was the polar cap heating rate and the subpulse drifting rate, both phenomena presumably associated with sparks operating at the polar cap. We investigated correlation between the intrinsic drift rate and polar cap heating rate and found that they are coupled to each other in such a way that the thermal X-ray luminosity $L_x$ from heated polar cap depends only on the observational tertiary subpulse drift periodicity $\hat{P}_3$ (polar cap carousel time). Within our model of partially screened gap we derived the simple formula relating $L_x$ and $\hat{P}_3$, and showed that it holds for PSRs B0943$+$10 and B1133+16, which are the only two pulsars in which both $L_x$ and $\hat{P}_3$ are presently known.Comment: 4 page

The Parallelometer: a mechanical device to study curvature

A simple mechanical device is introduced, the parallelometer, that can be used to measure curvatures of surfaces. The device can be used as a practical illustration of parallel transport of a vector and to study Berry phase shift when it is carried along a loop on the surface. Its connection to the Foucault pendulum is discussed. The experimental results can be successfully compared with the theoretical expectations. The experiment is inexpensive and conceptually easy to perform and understand for a beginner