Day-Night and Energy Dependence of MSW Solar Neutrinos for Maximal Mixing

It has been stated in the literature that the case of maximal mixing angle for \nu_e leads to no day-night effect for solar neutrinos and an energy independent flux suppression of 1/2. While the case of maximal mixing angle and \Delta m^2 in the MSW range does lead to suppression of the electron neutrinos reaching the earth from the sun by P_S=1/2, the situation is different for neutrinos that have passed through the earth. We make the pedagogical point that, just as with smaller mixing angles, the earth regenerates the |\nu_1> state from the predominantly |\nu_2 > state reaching the earth, leading to coherent interference effects. This regeneration can lead to a day-night effect and an energy dependence of the suppression of solar electron neutrinos, even for the case of maximal mixing. For large mixing angles, the energy dependence of the day-night asymmetry depends heavily on Delta m^2. With a sufficiently sensitive measurement of the day-night effect, this energy dependence could be used to distinguish among the large mixing angle solutions of the solar neutrino problem.Comment: JHEP style, 22 pages, 7 figures. References added, and minor rewordin

How Can Increased Parental Involvement Facilitate Greater Student Engagement and Academic Success Within One RGV Middle School

The purpose of this study is to explore how can increased parental involvement be encouraged in the K-12 school in the Rio Grande Valley in order to facilitate greater student engagement and academic success. An action research project will be done to explore middle school teachers’ perspectives on parental involvement and the effect it has on student academics. Research will take place in Sunview Middle School were interviews, observations will be conducted to teachers, parental involvement assistant and administrator. Data will assist to improve and promote the parental involvement program to assist all stakeholders and better assist our students

The Midpoint Rule as a Variational--Symplectic Integrator. I. Hamiltonian Systems

Numerical algorithms based on variational and symplectic integrators exhibit special features that make them promising candidates for application to general relativity and other constrained Hamiltonian systems. This paper lays part of the foundation for such applications. The midpoint rule for Hamilton's equations is examined from the perspectives of variational and symplectic integrators. It is shown that the midpoint rule preserves the symplectic form, conserves Noether charges, and exhibits excellent long--term energy behavior. The energy behavior is explained by the result, shown here, that the midpoint rule exactly conserves a phase space function that is close to the Hamiltonian. The presentation includes several examples.Comment: 11 pages, 8 figures, REVTe

Subclustering and Luminous-Dark Matter Segregation in Galaxy Clusters

We have performed a series of N-body experiments on Connection Machine-5 in order to simulate the formation of galaxy clusters gravitationally dominated by a massive dark background. In accordance with previous authors we find an extremely inhomogeneous evolution where subcondensations are continually formed and merged. The final distribution of galaxies is more centrally condensed than that of dark matter particles. We have analyzed the origin of this galaxy-dark matter segregation and also the origin of subclustering leading to this effect. We have then analysed, analytically and numerically, the dependence of final segregation on the physical parameters characterizing the model of protocluster. We also find that such a segregation persists even when inelastic encounters of dark halos around galaxies are taken into account. We conclude that this effect cannot be in general avoided in any hierarchical clustering scenario.Comment: 26 pages plus 13 figures (4 of which, not included, available upon request to [email protected]), postscript, Preprint OP-9303

Experience of Anti-VEGF Treatment and Clinical Levels of Depression and Anxiety in Patients With Wet Age-Related Macular Degeneration

PURPOSE: To investigate detailed patient experiences specific to receiving vascular endothelial growth factor inhibitors (anti-VEGF) for wet age-related macular degeneration (wAMD), and to acquire a snapshot of the frequency of clinically significant levels of depression, anxiety, and posttraumatic stress among patients and levels of burden in patients’ carers. DESIGN: Observational cross-sectional mixed-methods study. METHODS: Three hundred patients with wAMD receiving anti-VEGF treatment and 100 patient carers were recruited. Qualitative data on patients’ experience of treatment were collected using a structured survey. Standardized validated questionnaires were used to quantify clinically significant levels of anxiety, depression, and posttraumatic stress, as well as cognitive function and carers’ burden. RESULTS: Qualitative data showed that 56% of patients (n =132) reported anxiety related to antiVEGF treatment. The main sources of anxiety were fear of going blind owing to intravitreal injections and concerns about treatment effectiveness, rather than around pain. From validated questionnaires, 17% of patients (n= 52) showed clinical levels of anxiety and 12% (n =36) showed clinical levels of depression. Depression levels, but not anxiety, were significantly higher in patients who received up to 3 injections compared with patients who received from 4 to 12 injections (analysis of variance [ANOVA] P = .027) and compared with patients who received more than 12 injections (ANOVA P = .001). CONCLUSIONS: Anti-VEGF treatment is often experienced with some anxiety related to treatment, regardless of the number of injections received. Clinical levels of depression seem to be more frequent in patients at early stages of anti-VEGF treatment. Strategies to improve patient experience of treatment and minimize morbidity are suggested

Higher Order Force Gradient Symplectic Algorithms

We show that a recently discovered fourth order symplectic algorithm, which requires one evaluation of force gradient in addition to three evaluations of the force, when iterated to higher order, yielded algorithms that are far superior to similarly iterated higher order algorithms based on the standard Forest-Ruth algorithm. We gauge the accuracy of each algorithm by comparing the step-size independent error functions associated with energy conservation and the rotation of the Laplace-Runge-Lenz vector when solving a highly eccentric Kepler problem. For orders 6, 8, 10 and 12, the new algorithms are approximately a factor of $10^3$, $10^4$, $10^4$ and $10^5$ better.Comment: 23 pages, 10 figure