Seiberg-Witten maps and noncommutative Yang-Mills theories for arbitrary gauge groups

Seiberg-Witten maps and a recently proposed construction of noncommutative Yang-Mills theories (with matter fields) for arbitrary gauge groups are reformulated so that their existence to all orders is manifest. The ambiguities of the construction which originate from the freedom in the Seiberg-Witten map are discussed with regard to the question whether they can lead to inequivalent models, i.e., models not related by field redefinitions.Comment: 12 pages; references added, minor misprints correcte

Understanding the Stigma and Feasibility of Opening a Safe Injection Facility in Baltimore City: A Qualitative Case Study

Supervised injection facilities (SIFs) are medically supervised facilities designed to provide a hygienic environment in which drug users can consume illicit drugs intravenously. SIFs can be cost saving, help to reduce transmission of disease, and decrease drug overdoses. There are no SIFs in the United States. In this study we used a multiple case study design to understand the stigma surrounding the use of a SIF and the feasibility of implementing the drug prevention strategy in Baltimore City by comparing experiences with opening a SIF in Sydney, Australia. We interviewed one healthcare worker at the Sydney SIF and ten community stakeholders in Baltimore City. Interviewees were asked about community stigma of SIFs, drug use, and feasibility of opening a SIF in Baltimore City. Six overarching themes were established including lack of trust, lack of public education, fear of police, concern about efficacy of harm reduction programs, drug user stigma, and concerns about implementation. Findings suggest that stigma surrounding drug use and drug users is the most important aspect in shaping the participant\u27s varied perceptions of SIFs. Participants believed that for any change to occur, there must be multi-tiered collaboration at the level of government, healthcare, community, and law enforcement

Social, Economic and Health Costs of Unintended Teen Pregnancy: The Circle of Care Intervention Program in Troup County, Georgia

Unintended teenage pregnancy in the United States is a public health concern with ramifications that include a variety of social, economic and health costs. It has been estimated that adolescents giving birth before the age of 18 cost the United States at least $9.1 billion dollars annually (NCPTUP, 2008). Latest available national data indicate a slight increase in rates of unintended teen pregnancy after a 15 year period of steady decline. The unintended teen pregnancy rate in Troup County, Georgia in 2006 was 51.9/1,000 which was higher than the national average of 41.9/1,000(Kids Count, 2008). The purpose of this study was to review the Circle of Care intervention program, a collaborative multi-agency teen pregnancy prevention program. The Circle of Care program was developed in 1997 through the efforts of multiple community partner organizations. These organizations included the local school system, the Division of Family and Children Services, Public Health, Troup County Family Connection, the local teen clinic, the local hospital and other organizations. Participants in the Circle of Care program receive multiple services, including case management, a family assessment, parenting classes, home visits from the case manager, family planning assistance, services from the teen health clinic and the Division of Family and Children Services. Preliminary data indicate that Circle of Care participants gained social, economic and health benefits from participation in the program including: higher rates of high school enrollment, no repeat pregnancies, and no reported incidences of child abuse or child neglect. Projected cost savings from these outcomes are also reported. Preliminary examination of the Circle of Care program supports the efficacy of multi-level, collaborative efforts to reduce unintended teen pregnancy and subsequent social, economic and health risks. Future research should examine longer term outcomes of this program

A deformation of AdS_5 x S^5

We analyse a one parameter family of supersymmetric solutions of type IIB supergravity that includes AdS_5 x S^5. For small values of the parameter the solutions are causally well-behaved, but beyond a critical value closed timelike curves (CTC's) appear. The solutions are holographically dual to N=4 supersymmetric Yang-Mills theory on a non-conformally flat background with non-vanishing R-currents. We compute the holographic energy-momentum tensor for the spacetime and show that it remains finite even when the CTC's appear. The solutions, as well as the uplift of some recently discovered AdS_5 black hole solutions, are shown to preserve precisely two supersymmetries.Comment: 16 pages, v2: typos corrected and references adde

Boundary States for Supertubes in Flat Spacetime and Godel Universe

We construct boundary states for supertubes in the flat spacetime. The T-dual objects of supertubes are moving spiral D1-branes (D-helices). Since we can obtain these D-helices from the usual D1-branes via null deformation, we can construct the boundary states for these moving D-helices in the covariant formalism. Using these boundary states, we calculate the vacuum amplitude between two supertubes in the closed string channel and read the open string spectrum via the open closed duality. We find there are critical values of the energy for on-shell open strings on the supertubes due to the non-trivial stringy correction. We also consider supertubes in the type IIA Godel universe in order to use them as probes of closed timelike curves. This universe is the T-dual of the maximally supersymmetric type IIB PP-wave background. Since the null deformations of D-branes are also allowed in this PP-wave, we can construct the boundary states for supertubes in the type IIA Godel universe in the same way. We obtain the open string spectrum on the supertube from the vacuum amplitude between supertubes. As a consequence, we find that the tachyonic instability of open strings on the supertube, which is the signal of closed time like curves, disappears due to the stringy correction.Comment: 26 pages, 3 figures, v2: explanations added, references added, v3: explanations adde

Use of Crown Areas in Odontometric Analyses

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67062/2/10.1177_00220345770560073101.pd

The Seiberg-Witten Map for a Time-dependent Background

In this paper the Seiberg-Witten map for a time-dependent background related to a null-brane orbifold is studied. The commutation relations of the coordinates are linear, i.e. it is an example of the Lie algebra type. The equivalence map between the Kontsevich star product for this background and the Weyl-Moyal star product for a background with constant noncommutativity parameter is also studied.Comment: latex, 13 pages, references added and some misprints correcte

Dualities in M-theory and Born-Infeld Theory

We discuss two examples of duality. The first arises in the context of toroidal compactification of the discrete light cone quantization of M-theory. In the presence of nontrivial moduli coming from the M-theory three form, it has been conjectured that the system is described by supersymmetric Yang-Mills gauge theory on a noncommutative torus. We are able to provide evidence for this conjecture, by showing that the dualities of this M-theory compactification, which correspond to T-duality in Type IIA string theory, are also dualities of the noncommutative supersymmetric Yang-Mills description. One can also consider this as evidence for the accuracy of the Matrix Theory description of M-theory in this background. The second type of duality is the self-duality of theories with U(1) gauge fields. After discussing the general theory of duality invariance for theories with complex gauge fields, we are able to find a generalization of the well known U(1) Born-Infeld theory that contains any number of gauge fields and which is invariant under the maximal duality group. We then find a supersymmetric extension of our results, and also show that our results can be extended to find Born-Infeld type actions in any even dimensional spacetime

The Relationship Between Food Deserts, Farmers’ Markets and Food Assistance in Georgia Census Tracts

Background: Due to inadequate resources and limited access to healthy foods, residents of food deserts struggle to maintain a well-balanced, nutritious diet. These factors increase the risk of developing obesity and diet-related chronic diseases. Local farmers’ markets serve as community-level interventions, bringing healthy food to food deserts. Over the past two decades, farmers’ markets have been growing in numbers nationally. The present study explores the relationship between food deserts, placement of farmers’ markets, and availability of food assistance programs in Georgia. Methods: Data are from the 2014 USDA Food Desert Atlas and the USDA Farmers’ Market Directory. Farmers’ market addresses were geocoded in ArcGIS 10.2. Descriptive statistics and spatial visualization were used to explore census tract-level relationships. Results: Of the Georgia census tracts, 20% are food deserts. Of these, 7.2% have a farmers’ market within their boundary, compared to 5.7% of non-food desert tracts. Of these markets, 3.2% accept Famers’ Market Nutrition Program (FMNP) coupons, 9.6% accept Women, Infants, and Children Fruit and Vegetable Checks (WIC-FVC), and 21.6% accept Supplemental Nutrition Assistance Program (SNAP) benefits. Conclusions: Few farmers’ markets in Georgia are located in food deserts, and few accept food assistance programs. Fresh food remains inaccessible to low-income residents in these areas and lack of access to fresh food is associated with dietrelated chronic diseases. To reduce food insecurity, farmers’ markets could accept food assistance program funds. Additional farmers’ markets could be established in food deserts to increase availability of healthy food, reducing the risk of developing obesity and diet-related chronic diseases