Purification of large bicolorable graph states

We describe novel purification protocols for bicolorable graph states. The protocols scale efficiently for large graph states. We introduce a method of analysis that allows us to derive simple recursion relations characterizing their behavior as well as analytical expressions for their thresholds and fixed point behavior. We introduce two purification protocols with high threshold. They can, for graph degree four, tolerate 1% (3%) gate error or 20% (30%) local error.Comment: 12 pages, 5 figures, revtex; typos and clarifications adde

Mathematical writing in the elementary classroom

In this study, fourth and fifth grade students at River View Elementary participated in mathematics activities requiring written and oral dialogue. These dialogues were analyzed to determine how their mathematical understandings were reflected in their written and oral discussions. An examination of pre and post mathematical writing occurred to determine the effect the dialogue had on students\u27 mathematical writing. Students were given a mathematics problem to solve. After reading the mathematics problem, each student wrote questions they had regarding the problem as well as a request for additional information that they felt was needed to solve the problem. Students exchanged their writing with a classmate and responded to their questions and/or requests. After several repetitions of this sequence, each pair of students dialogued with another pair of students and discussed remaining questions and concerns regarding the problem. Students independently solved the story problem and justified their answer in writing. A class discussion was held and answers and justifications shared. This process resulted in significant gains in students\u27 ability to complete Brief Constructed Responses items modeled after the Maryland School Assessment. In addition, students\u27 beliefs about mathematics evolved from math as simply computing and a silent activity to math involving strategies and being a sensible activity

A synthesis of sand seas throughout the world

There are no author-identified significant results in this report

Casimir forces in the time domain II: Applications

Our preceding paper introduced a method to compute Casimir forces in arbitrary geometries and for arbitrary materials that was based on a finite-difference time-domain (FDTD) scheme. In this manuscript, we focus on the efficient implementation of our method for geometries of practical interest and extend our previous proof-of-concept algorithm in one dimension to problems in two and three dimensions, introducing a number of new optimizations. We consider Casimir piston-like problems with nonmonotonic and monotonic force dependence on sidewall separation, both for previously solved geometries to validate our method and also for new geometries involving magnetic sidewalls and/or cylindrical pistons. We include realistic dielectric materials to calculate the force between suspended silicon waveguides or on a suspended membrane with periodic grooves, also demonstrating the application of PML absorbing boundaries and/or periodic boundaries. In addition we apply this method to a realizable three-dimensional system in which a silica sphere is stably suspended in a fluid above an indented metallic substrate. More generally, the method allows off-the-shelf FDTD software, already supporting a wide variety of materials (including dielectric, magnetic, and even anisotropic materials) and boundary conditions, to be exploited for the Casimir problem.Comment: 11 pages, 12 figures. Includes additional examples (dispersive materials and fully three-dimensional systems

Industrial Benefits of Controlling Saltwater Intrusion in the Neches River

Environmental Economics and Policy,

‘I’m paying for my son’s upbringing with other people’s wages’. Community psychology praxis in a Sure Start Children’s Centre: The Great Yarmouth Father’s Project

THE GREAT YARMOUTH Father’s Project (GYFP) is presented as a community psychology example of ‘formulation beyond therapy’. A co-produced formulation is described that attempts to broaden under- standing of father’s experiences of early-years child and family services

Evidence for the Gompertz Curve in the Income Distribution of Brazil 1978-2005

This work presents an empirical study of the evolution of the personal income distribution in Brazil. Yearly samples available from 1978 to 2005 were studied and evidence was found that the complementary cumulative distribution of personal income for 99% of the economically less favorable population is well represented by a Gompertz curve of the form $G(x)=\exp [\exp (A-Bx)]$, where $x$ is the normalized individual income. The complementary cumulative distribution of the remaining 1% richest part of the population is well represented by a Pareto power law distribution $P(x)= \beta x^{-\alpha}$. This result means that similarly to other countries, Brazil's income distribution is characterized by a well defined two class system. The parameters $A$, $B$, $\alpha$, $\beta$ were determined by a mixture of boundary conditions, normalization and fitting methods for every year in the time span of this study. Since the Gompertz curve is characteristic of growth models, its presence here suggests that these patterns in income distribution could be a consequence of the growth dynamics of the underlying economic system. In addition, we found out that the percentage share of both the Gompertzian and Paretian components relative to the total income shows an approximate cycling pattern with periods of about 4 years and whose maximum and minimum peaks in each component alternate at about every 2 years. This finding suggests that the growth dynamics of Brazil's economic system might possibly follow a Goodwin-type class model dynamics based on the application of the Lotka-Volterra equation to economic growth and cycle.Comment: 22 pages, 15 figures, 4 tables. LaTeX. Accepted for publication in "The European Physical Journal B