Safety Is the Most Important Thing: How HOPE VI Helped Families

Examines whether the federal HOPE VI housing program has succeeded in its goal of improving residents' life circumstances and safety and alleviating their fear of crime. Based on surveys of residents at five Hope VI public housing sites

An Overview of Federal Support for Housing

The federal government commits substantial resources to support housing and mortgage markets through a combination of spending programs and tax expenditures (that is, subsidies conveyed through reductions in taxes). During the crisis of the past two years, the budgetary commitment expanded—to about $300 billion in fiscal year 2009—from the placement into conservatorship in September 2008 of the Federal National Mortgage Association (Fannie Mae) and the Federal Home Loan Mortgage Corporation (Freddie Mac) and the creation of new housing programs. This Congressional Budget Office (CBO) brief describes, in broad terms, the array of federal activities that support housing and the recent expansion of particular programs.

ImageSieve: Exploratory search of museum archives with named entity-based faceted browsing

Over the last few years, faceted search emerged as an attractive alternative to the traditional "text box" search and has become one of the standard ways of interaction on many e-commerce sites. However, these applications of faceted search are limited to domains where the objects of interests have already been classified along several independent dimensions, such as price, year, or brand. While automatic approaches to generate faceted search interfaces were proposed, it is not yet clear to what extent the automatically-produced interfaces will be useful to real users, and whether their quality can match or surpass their manually-produced predecessors. The goal of this paper is to introduce an exploratory search interface called ImageSieve, which shares many features with traditional faceted browsing, but can function without the use of traditional faceted metadata. ImageSieve uses automatically extracted and classified named entities, which play important roles in many domains (such as news collections, image archives, etc.). We describe one specific application of ImageSieve for image search. Here, named entities extracted from the descriptions of the retrieved images are used to organize a faceted browsing interface, which then helps users to make sense of and further explore the retrieved images. The results of a user study of ImageSieve demonstrate that a faceted search system based on named entities can help users explore large collections and find relevant information more effectively

Mentoring, teaching and professional transformation

No abstract available

Two-loop string theory and the DVV Vertex

We compute the two-loop contributions to the free energy in the null compacti¯cation of perturbative string theory at ¯nite temperature. The cases of bosonic, Type II and heterotic strings are all treated. The calculation exploits an explicit reductive parametrization of the moduli space of in¯nite-momentum frame string worldsheets in terms of branched cover instantons. Various arithmetic and physical properties of the instanton sums are described. Applications to symmetric product orbifold conformal ¯eld theories and to the matrix string theory conjecture are investigated by analyzing the correspondence be- tween the two-loop thermal partition function of DLCQ strings in °at space and the integrated two-point correlator of twist ¯elds in a symmetric product orbifold con- formal ¯eld theory at one-loop order. This is carried out by deriving combinatorial expressions for generic twist ¯eld correlation functions in permutation orbifolds us- ing the covering surface method, by deriving the one-loop modi¯cation of the twist ¯eld interaction vertex, and by relating the two-loop ¯nite temperature DLCQ string theory to the theory of Prym varieties for genus two covers of an elliptic curve. The case of bosonic Z2 orbifolds is worked out explicitly and precise agreement between both amplitudes is found. We use these techniques to derive explicit expressions for Z2 orbifold spin twist ¯eld correlation functions in the Type II and heterotic string theories.Engineering and Physical Sciences Research Council (EPSRC

Retaining effective urban teachers in the age of accountability: How do successful urban schools address staffing challenges?

Thesis (Ed.D.)--Boston UniversityMany urban schools struggle to retain their best teachers because of challenging work environments, poor salaries, and ineffective school leadership. The additional requirements of the No Child Left Behind legislation for teachers to be highly qualified and the increased academic requirements of raising students to a proficient level in reading and mathematics mean that these schools face additional challenges to retaining teachers. Little research has been done on teacher retention in relation to NCLB in urban schools, but the few studies available have suggested that NCLB has had a negative impact on teacher morale and retention in urban schools. The research project was a paired case study that examined teacher retention in four urban schools, contrasting two schools that showed improvement under NCLB in terms of student achievement with two schools that did not show improvement. This study used human resource data, teacher and principal interviews, and school improvement plans to answer the following three research questions: 1) Does the teacher retention rate remain constant as schools improve? 2) Is there a pattern of teacher retention in improving schools? 3) What do improving schools do to attract, train, and retain teachers? The results showed that all schools had increased levels of teacher retention from the beginning of the study until the end. Improving schools had slightly higher rates of teacher retention, especially among teachers who were determined to be desirable. There was some evidence that as student achievement rates rose in improving schools, so did the rate of teacher retention. Lastly, the findings suggest that schools that were improving were also schools that embodied many of the factors that teachers are looking for in a school, including strong school leadership, positive working conditions, and other supports for teachers new and experienced, such as professional development and mentoring. This study has several limitations, such as a small sample size and a limited pool of human resource data. The findings have important implications for urban school districts that are trying to retain quality teachers