A theory of anisotropic viscoelastic sandwich shells

Anisotropic viscoelastic shell theor

Measurement of Photon Statistics with Live Photoreceptor Cells

We analyzed the electrophysiological response of an isolated rod photoreceptor of Xenopus laevis under stimulation by coherent and pseudo-thermal light sources. Using the suction electrode technique for single cell recordings and a fiber optics setup for light delivery allowed measurements of the major statistical characteristics of the rod response. The results indicate differences in average responses of rod cells to coherent and pseudo-thermal light of the same intensity and also differences in signal-to-noise ratios and second order intensity correlation functions. These findings should be relevant for interdisciplinary studies seeking applications of quantum optics in biology.Comment: 6 pages, 7 figure

Recoverin Regulates Light-dependent Phosphodiesterase Activity in Retinal Rods

The Ca2+-binding protein recoverin may regulate visual transduction in retinal rods and cones, but its functional role and mechanism of action remain controversial. We compared the photoresponses of rods from control mice and from mice in which the recoverin gene was knocked out. Our analysis indicates that Ca2+-recoverin prolongs the dark-adapted flash response and increases the rod's sensitivity to dim steady light. Knockout rods had faster Ca2+ dynamics, indicating that recoverin is a significant Ca2+ buffer in the outer segment, but incorporation of exogenous buffer did not restore wild-type behavior. We infer that Ca2+-recoverin potentiates light-triggered phosphodiesterase activity, probably by effectively prolonging the catalytic activity of photoexcited rhodopsin

Developmental Evaluation in Theory versus Practice: Lessons from Three Developmental Evaluation Pilots

Background. Developmental Evaluation (DE) practitioners turn to DE theory to make design and implementation decisions. However, DE practitioners can experience difficulty in fully understanding how to implement DE using theory because it is method agnostic (Patton, 2016). Instead, DE is a principle-based approach. Purpose. This article presents an empirical examination of how DE theory was (or was not) applied during three DE pilots. Our analysis aims to better understand how DE theory is used in practice to expand the evidence base and strengthen future DE implementation. Setting. A consortium of three organizations implemented three DE pilots through the United States Agency for International Development (USAID) from November 2016 to September 2019. The authors—who participated in the consortium—did not implement the DEs but instead conducted a study or meta-evaluation across the DE pilots. Data Collection and Analysis. This article focuses on the results of an ex post facto analysis of three DE pilots based on the entire DE implementation experience. For each DE studied, we used mixed methods to collect data on the effectiveness of the DE approach, to identify adaptations to strengthen DE implementation in the USAID context, and to measure its value to stakeholders. Data included more than 100 hours of interviews, 465 pages of qualitative data, and 30 surveys completed by DE participants. Findings. We find that the ability to apply the DE principles in practice is influenced, in no particular order, by DE participant buy-in to the DE, the Developmental Evaluator’s aptitude, support and resources available to the Developmental Evaluator, and the number of DE participants. We also find that buy-in can change and this should be closely monitored throughout a DE to inform whether a DE should be paused or prematurely ended. Keywords: Developmental Evaluation; developmental evaluator skills; buy-in; DE practice; DE funder; meta-evaluatio

Analysis of D Pellet Injection Experiments in the W7-AS Stellarator

A centrifugal injector was used to inject deuterium pellets (with 3--5 x 10{sup 19} atoms) at approx. equal 600 m/s into current-less, nearly shear-less plasmas in the Wendelstein 7-AS (W7-AS) stellarator. The D pellet was injected horizontally at a location where the non-circular and non-axisymmetric plasma cross section is nearly triangular. Visible-light TV pictures usually showed the pellet as a single ablating mass in the plasma, although the pellet occasionally broke in two or splintered into a cloud of small particles. The density evolution following pellet injection and the effect of pellet injection on energy confinement and fluctuations are discussed