Persisting correlations of a central spin coupled to large spin baths

The decohering environment of a quantum bit is often described by the coupling to a large bath of spins. The quantum bit itself can be seen as a spin $S=1/2$ which is commonly called the central spin. The resulting central spin model describes an important mechanism of decoherence. We provide mathematically rigorous bounds for a persisting magnetization of the central spin in this model with and without magnetic field. In particular, we show that there is a well defined limit of infinite number of bath spins. Only if the fraction of very weakly coupled bath spins tends to 100\% does no magnetization persist.Comment: 19 pages, 15 figures, rigorous bounds for the central spin mode

PROPERTY DEVELOPMENT:AN EVALUATION OF DECISION SUPPORT SYSTEMS

Although there are a number of development approaches proposed in the decision support systems (DSS) literature, there appears to be a preference for prototyping over structured approaches. This paper describes the analysis stage of a DSS for the Property Development Department (PDS) at the Palmerston North City Council, New Zealand. The PDS role involves many ill-structured decisions with a large number of stakeholders. The paper describes the selection process for the methodology, analysing criteria for selection, and proposes a structured process for this analysis. The paper provides insights into when structured approaches are more appropriate for the development of DSS based on the type and complexity of the decisions supporte

Saving Our Homes: The Lessons of Community Struggles to Preserve Affordable Housing in Chicago\u27s Uptown

Over the past 25 years we have witnessed declining federal investment in affordable housing at the same time as there has been growth in low-income households. During this same quarter of a century we have seen a shift from a national War on Poverty to federal policies that treat poor adults and children as hopeless, undeserving citizens. In this new era of fiscal constraints there is no talk about meeting basic nutritional, housing, health care, and educational needs. A chorus of new conservative leaders claims to be speaking for the suffering middle class. The media increasingly talk of the haves and the have-nots. It is not easy to hear talk of helping the working poor over the din of politicians seeking to protect the family and traditional American values. This report is an effort to give voice to some of those working poor who have been struggling to preserve the affordable housing that is their road to self-sufficiency. It is the story about Uptown, a Chicago community which is about as American as it gets. Like the traditional urban communities in American cities in the late 1800s and early 1900s, our community is filled with immigrants who came to the United States, sometimes escaping persecution in their homelands and other times hoping to improve their quality of life through hard work in the land of opportunity. The names by the doorbells are not McGuire, Ianello, or Schmidt; they are Thu, Asoegwu, and Lopez

Housing Discrimination and Economic Opportunity in the Chicago Region

In 1990, the Human Relations Foundation of Chicago was created in response to a publication called Report on Race, Ethnic and Religious Tensions in Chicago, released by the Chicago Community Trust Human Relations Task Force in 1989. The human relations task force released recommendations for the creation of a foundation to energize efforts to combat racism. The Human Relations Foundation of Chicago implements the recommendations of the task force\u27s report, targeting Chicago leadership by concentrating on issues related to, but not limited to, housing, education, religion, media, government and business. Continued racial and ethnic segregation has continuing implications for the social, political, cultural, and economic vitality of Chicago region. Not only does this segregation affect how and where residents of our communities interact with each other, but by limiting free access to housing, education, and jobs a significant portion of the region\u27s population is being held back from sharing in opportunities and from realizing their full potential social, economic, cultural, and political contributions to Chicago and its surrounding communities. This report demonstrates the reality of such concentrations, and analyzes why they persist. We are particularly interested in assessing the impact of housing discrimination on job and wealth opportunities for people of color. Findings and recommendations are drawn from reports on this subject written since the last series of reports commissioned by the Human Relations Foundation of Chicago in 1990

Intravascular stenting for stenosis of aortocoronary venous bypass grafts

AbstractTo test the ability of endoluminal stents to prevent saphenous vein graft restenosis after balloon angioplasty, 13 patients with angina and previous coronary bypass surgery underwent implantation of one or more stents into 14 stenosed grafts. Implantation was technically successful in all cases and there were no major in-hospital complications. During a median follow-up interval of 7 months (range 2 to 26), 10 patients (77%) underwent follow-up angiography. Seven patients remained asymptomatic or in improved condition without further intervention; three patients had further angioplasty with stent implantation for a new stenosis in the same graft. Two patients (20%) developed within-stent restenosis. There was one death from progressive congestive heart failure 7 months after implantation. No patient had a myocardial infarction or needed surgical revascularization during the follow-up period.In selected cases, stent implantation appears to be a promising new technique that may decrease the incidence of restenosis after balloon angioplasty in venous bypass grafts. The rate of complications is low. Further experience and longer follow-up will be needed before definite recommendations can be made about its use

Blocking entry of hepatitis B and D viruses to hepatocytes as a novel immunotherapy for treating chronic infections

Background. Chronic hepatitis B and D virus (HBV/HDV) infections can cause cancer. Current HBV therapy using nucleoside analogues (NAs) is life-long and reduces but does not eliminate the risk of cancer. A hallmark of chronic hepatitis B is a dysfunctional HBV-specific T-cell response. We therefore designed an immunotherapy driven by naive healthy T cells specific for the HDV antigen (HDAg) to bypass the need for HBV-specific T cells in order to prime PreS1-specific T cells and PreS1 antibodies blocking HBV entry. Methods. Ten combinations of PreS1 and/or HDAg sequences were evaluated for induction of PreS1 antibodies and HBV- and HDV-specific T cells in vitro and in vivo. Neutralization of HBV by PreS1-specific murine and rabbit antibodies was evaluated in cell culture, and rabbit anti-PreS1 were tested for neutralization of HBV in mice repopulated with human hepatocytes. Results. The best vaccine candidate induced T cells to PreS1 and HDAg, and PreS1 antibodies blocking HBV entry in vitro. Importantly, adoptive transfer of PreS1 antibodies prevented, or modulated, HBV infection after a subsequent challenge in humanized mice. Conclusions. We here describe a novel immunotherapy for chronic HBV/HDV that targets viral entry to complement NAs and coming therapies inhibiting viral maturation

Protocol for a population-based study of rheumatic heart disease prevalence and cardiovascular outcomes among schoolchildren in Nepal

Rheumatic heart disease (RHD) remains a major contributor to morbidity and mortality in developing countries. The reported prevalence rates of RHD are highly variable and mainly attributable to differences in the sensitivity of either clinical screening to detect advanced heart disease or echocardiographic evaluation where disease is diagnosed earlier across a continuous spectrum. The clinical significance of diagnosis of subclinical RHD by echocardiographic screening and early implementation of secondary prevention has not been clearly established. METHODS AND ANALYSIS: The authors designed a cross-sectional survey to determine the prevalence of RHD in children from private and public schools between the age of 5 and 15 years in urban and rural areas of Eastern Nepal using both cardiac auscultation and echocardiographic evaluation. Children with RHD will be treated with secondary prevention and enrolled in a prospective cohort study. The authors will compare the prevalence rates by cardiac auscultation and echocardiography, determine risk factors associated with diagnosis and progression of RHD, investigate social and economic barriers for receiving adequate cardiac care and assess clinical outcomes with regular medical surveillance as a function of stage of disease at the time of diagnosis. Prospective clinical studies investigating the impact of secondary prevention for subclinical RHD on long-term clinical outcome will be of central relevance for future health resource utilisation in developing countries. ETHICS AND DISSEMINATION: The study was considered ethically uncritical and was given an exempt status by the ethics committee at University of Bern, Switzerland. The study has been submitted to the National Nepal Health Research Council and was registered with http://www.ClinicalTrials.gov (NCT01550068). The study findings will be reported in peer-reviewed publications. CLINICALTRIALS.GOV IDENTIFIER: NCT01550068

The Uptown Housing and Land Use Study

In the Fall of 2000, State Representative Larry McKeon, at the urging of local community groups and residents, commissioned Loyola University Chicago’s Center for Urban Research and Learning (CURL) to provide an analysis of relevant data regarding housing and land use in the Uptown community. A Local Advisory Council (LAC) was created to review, evaluate, and advise the project staff as they collected and analyzed data sets. For the past two years, researchers at CURL have worked with Organization of the NorthEast (ONE), Representative McKeon, and the LAC to collect and analyze data from a variety of sources. The goal of this report is to provide to all stakeholders and parties engaged in the Uptown community a comprehensive and accurate profile of Uptown and the changes that have been occurring within the community over the past decade, based on data collected from a wide range of reliable sources. The community, thus informed, will be better able to address the issues and concerns of all its residents