Anomaly Cancelation in Field Theory and F-theory on a Circle

We study the manifestation of local gauge anomalies of four- and six-dimensional field theories in the lower-dimensional Kaluza-Klein theory obtained after circle compactification. We identify a convenient set of transformations acting on the whole tower of massless and massive states and investigate their action on the low-energy effective theories in the Coulomb branch. The maps employ higher-dimensional large gauge transformations and precisely yield the anomaly cancelation conditions when acting on the one-loop induced Chern-Simons terms in the three- and five-dimensional effective theory. The arising symmetries are argued to play a key role in the study of the M-theory to F-theory limit on Calabi-Yau manifolds. For example, using the fact that all fully resolved F-theory geometries inducing multiple Abelian gauge groups or non-Abelian groups admit a certain set of symmetries, we are able to generally show the cancelation of pure Abelian or pure non-Abelian anomalies in these models.Comment: 48 pages, 2 figures; v2: typos corrected, comments on circle fluxes adde

Educator\u27s Implementation of the Connecticut Guidelines for the Identification and Education of Children and Youth with Autism

The Problem As the number of children with autism needing educational support continues to increase, combined with the limited availability of resources, this study aims to examine how educators responsible for teaching children with autism have experienced implementation of the Connecticut Guidelines for the Identification and Education of Children and Youth with Autism (2005), (Guidelines). At this time there have been no studies done in the State of Connecticut to assess the implementation of the components for effective education of children with autism, as set forth in the Connecticut Guidelines. Method The Connecticut Autism Needs Survey, an on-line self-report survey designed for this study, was used to collect cross sectional data reflecting special education teachers practices and attitudes towards the Connecticut Guidelines for Identification and Education of Children and Youth with Autism. The first three research questions assess participants experience with implementation, level of difficulty implementing and level of importance of the Connecticut Guidelines for Identification and Education of Children and Youth with Autism. To further explore implementation, level of difficulty implementing and importance the data was examined specifically for teachers practice with 17 recommended evidence based practices for students with autism. The responses to the questions were analyzed using descriptive statistics. Three additional research questions address the association between the dependent variables reported on in the first three questions and the predictor variables of (a) years of experience, (b) assignment, (c) place, (d) region of the state, (e) number of students on caseload, (f) percentage of students with ASD on caseload, or (g) personal relationship. The dependent variable for each question and the 7 predictor variables were analyzed using logistic regression. Results The findings reveal 89.5% of respondents were either not familiar with the Connecticut Guidelines or found them difficult to implement. Additionally, the findings suggest an association between a special educator’s use of the Connecticut Guidelines and the specificity of their role and tenure. Teachers who are primarily responsible for students with autism were more likely to use the Guidelines than were teachers who were responsible for providing specialized instruction to students with a range of disabilities. The research found that special education teachers in private schools were nine times less likely to rate the Connecticut Guidelines as difficult to implement than teachers in public schools. The findings suggest teachers with more experience were slightly more likely to implement the Connecticut Guidelines. Interestingly, the findings identified teachers who have a personal relationship were twice as likely to use the Guidelines as those who did not. Three of the most critical evidence-based strategies for educating students with autism: pivotal response training, video modeling, and voice output communication aide had the lowest percentage of implementation and were perceived as not important by teachers. Conclusions The results show the Connecticut Guidelines are not used or viewed as important by the majority of special education teachers in Connecticut. The Guidelines were written 10 years ago and much has changed in the field of autism over that time period. It appears it is time to reexamine and make changes to the Connecticut Guidelines

How Do Quasicrystals Grow?

Using molecular simulations, we show that the aperiodic growth of quasicrystals is controlled by the ability of the growing quasicrystal `nucleus' to incorporate kinetically trapped atoms into the solid phase with minimal rearrangement. In the system under investigation, which forms a dodecagonal quasicrystal, we show that this process occurs through the assimilation of stable icosahedral clusters by the growing quasicrystal. Our results demonstrate how local atomic interactions give rise to the long-range aperiodicity of quasicrystals.Comment: 4 pages, 4 figures. Figures and text have been updated to the final version of the articl

On the universal X-ray luminosity function of binary X-ray sources in galaxies

The empirically determined universal power-law shape of X-ray luminosity function of high mass X-ray binaries in galaxies is explained by fundamental mass-luminosity and mass-radius relations for massive stars.Comment: 4 pages, plain LaTeX, no figures. Submitted to Astronomy Letter

Mixture of ultracold lithium and cesium atoms in an optical dipole trap

We present the first simultaneous trapping of two different ultracold atomic species in a conservative trap. Lithium and cesium atoms are stored in an optical dipole trap formed by the focus of a CO$_2$ laser. Techniques for loading both species of atoms are discussed and observations of elastic and inelastic collisions between the two species are presented. A model for sympathetic cooling of two species with strongly different mass in the presence of slow evaporation is developed. From the observed Cs-induced evaporation of Li atoms we estimate a cross section for cold elastic Li-Cs collisions.Comment: 10 pages 9 figures, submitted to Appl. Phys. B; v2: Corrected evaporation formulas and some postscript problem

What makes health systems resilient? A qualitative analysis of the perspectives of Swiss NGOs

BACKGROUND: Resilience has become relevant than ever before with the advent of increasing and intensifying shocks on the health system and its amplified effects due to globalization. Using the example of non-state actors based in Switzerland, the aim of this study is to explore how and to what extent NGOs with an interest in global health have dealt with unexpected shocks on the health systems of their partner countries and to reflect on the practical implications of resilience for the multiple actors involved. Consequently, this paper analyses the key attributes of resilience that targeted investments may influence, and the different roles key stakeholders may assume to build resilience. METHODS: This is a descriptive and exploratory qualitative study analysing the perspectives on health system resilience of Swiss-based NGOs through 20 in-depth interviews. Analysis proceeded using a data-driven thematic analysis closely following the framework method. An analytical framework was developed and applied systematically resulting in a complete framework matrix. The results are categorised into the expected role of the governments, the role of the NGOs, and practical future steps for building health system resilience. RESULTS: The following four key 'foundations of resilience' were found to be dominant for unleashing greater resilience attributes regardless of the nature of shocks: 'realigned relationships,' 'foresight,' 'motivation,' and 'emergency preparedness.' The attribute to 'integrate' was shown to be one of the most crucial characteristics of resilience expected of the national governments from the NGOs, which points to the heightened role of governance. Meanwhile, as a key stakeholder group that is becoming inevitably more powerful in international development cooperation and global health governance, non-state actors namely the NGOs saw themselves in a unique position to facilitate knowledge exchange and to support long-term adaptations of innovative solutions that are increasing in demand. The strongest determinant of resilience in the health system was the degree of investments made for building long-term infrastructures and human resource development which are well-functioning prior to any potential crisis. CONCLUSIONS: Health system resilience is a collective endeavour and a result of many stakeholders' consistent and targeted investments. These investments open up new opportunities to seek innovative solutions and to keep diverse actors in global health accountable. The experiences and perspectives of Swiss NGOs in this article highlight the vital role NGOs may play in building resilient health systems in their partner countries. Specifically, strong governance, a bi-directional knowledge exchange, and the focus on leveraging science for impact can draw greater potential of resilience in the health systems. Governments and the NGOs have unique points of contribution in this journey towards resilience and bear the responsibility to support governments to prioritise investing in the key 'foundations of resilience' in order to activate greater attributes of resilience. Resilience building will not only prepare countries for future shocks but bridge the disparate health and development agenda in order to better address the nexus between humanitarian aid and development cooperation

Five-Brane Superpotentials, Blow-Up Geometries and SU(3) Structure Manifolds

We investigate the dynamics of space-time filling five-branes wrapped on curves in heterotic and orientifold Calabi-Yau compactifications. We first study the leading N=1 scalar potential on the infinite deformation space of the brane-curve around a supersymmetric configuration. The higher order potential is also determined by a brane superpotential which we compute for a subset of light deformations. We argue that these deformations map to new complex structure deformations of a non-Calabi-Yau manifold which is obtained by blowing up the brane-curve into a four-cycle and by replacing the brane by background fluxes. This translates the original brane-bulk system into a unifying geometrical formulation. Using this blow-up geometry we compute the complete set of open-closed Picard-Fuchs differential equations and identify the brane superpotential at special points in the field space for five-branes in toric Calabi-Yau hypersurfaces. This has an interpretation in open mirror symmetry and enables us to list compact disk instanton invariants. As a first step towards promoting the blow-up geometry to a supersymmetric heterotic background we propose a non-Kaehler SU(3) structure and an identification of the three-form flux.Comment: 95 pages, 4 figures; v2: Minor corrections, references update