Quantum Hall-like effect for cold atoms in non-Abelian gauge potentials

We study the transport of cold fermionic atoms trapped in optical lattices in the presence of artificial Abelian or non-Abelian gauge potentials. Such external potentials can be created in optical lattices in which atom tunneling is laser assisted and described by commutative or non-commutative tunneling operators. We show that the Hall-like transverse conductivity of such systems is quantized by relating the transverse conductivity to topological invariants known as Chern numbers. We show that this quantization is robust in non-Abelian potentials. The different integer values of this conductivity are explicitly computed for a specific non-Abelian system which leads to a fractal phase diagram.Comment: 6 pages, 2 figure

Digital Repositories and Open Access: Information Without Limits

For many libraries, the Digital Repository has become the main storage center for materials created by the community they serve. Such materials can include important historical records, local newspapers, community newsletters, as well as articles, presentations, data sets, images, videos and other multimedia items. In this way, the repository takes on a central role in placing free, open access materials into the hands of the public. While many repositories are currently managed by universities, their benefits reach beyond the walls of academia to include K-12 students as well as the public at large. Thus, all librarians are encouraged to utilize the materials housed in repositories during their educational programming. Doing so has the advantage of providing reliable information at no cost to their patrons while at the same time creating ties between the university and the local community. Furthermore, the use of open access materials during instruction sessions and reference interactions presents the librarian with many opportunities to discuss the increased importance of fair use and intellectual property issues

Prescription Drug Coverage and Elderly Medicare Spending

The introduction of Medicare Part D has generated interest in the cost of providing drug coverage to the elderly. Of paramount importance -- often unaccounted for in budget estimates -- are the salutary effects that increased prescription drug use might have on other Medicare spending. This paper uses longitudinal data from the Medicare Current Beneficiary Survey (MCBS) to estimate how prescription drug benefits affect Medicare spending. We compare spending and service use for Medigap enrollees with and without drug coverage. Because of concerns about selection, we use variation in supply-side regulations of the individual insurance market -- including guaranteed issue and community rating -- as instruments for prescription drug coverage. We employ a discrete factor model to control for individual-level heterogeneity that might induce bias in the effects of drug coverage. Medigap prescription drug coverage increases drug spending by $170 or 22$350 or 13% (in 2000 dollars). Medigap prescription drug coverage reduces Medicare Part B spending, but the estimates are not statistically significant. Overall, a $1 increase in prescription drug spending is associated with a$2.06 reduction in Medicare spending. Furthermore, the substitution effect decreases as income rises, and thus provides support for the low-income assistance program of Medicare Part D.

Socioeconomic Differences in the Adoption of New Medical Technologies

New medical technologies hold tremendous promise for improving population health, but they also raise concerns about exacerbating already large differences in health by socioeconomic status (SES). If effective treatments are more rapidly adopted by the better educated, SES health disparities may initially expand even though the health of those in all groups eventually improves. Hypertension provides a useful case study. It is an important risk factor for developing cardiovascular disease, the condition is relatively common, and there are large differences in rates of hypertension by education. This paper examines the short and long-term diffusion of two important classes of anti-hypertensives - ACE inhibitors and calcium channel blockers - over the last twenty-five years. Using three prominent medical surveys, we find no evidence that the diffusion of these drugs into medical practice favored one education group relative to another. The findings suggest that - at least for hypertension - SES differences in the adoption of new medical technologies are not an important reason for the SES health gradient.

Unmet Needs of Unaccompanied Minors from Central America: Perceptions of Professionals from Multiple Sectors

Background: In recent years, there has been a significant influx of Central American youth who cross the U.S.-Mexico border without a parent or legal guardian. While federal procedures are established to oversee the treatment and placement of unaccompanied minors, less is known about the needs of unaccompanied minors and available services afterthey are placed in appropriate custody. Methods: Purposive and strategic sampling of professionals from medical, social work, education and legal fields was conducted. Fourteen informants were recruited across the U.S. for confidential semi-structured interviews, which were audio recorded and transcribed in 2016 to 2017. Standard anthropological methods were employed, including immersion and crystallization techniques that incorporated within-case and across-case analytic strategies. Results: Recruited informants had previous or current direct experience working with immigrant minors for three or more years in addition to extensive public health experience. Unaccompanied minors were described as predominantly adolescent boys, ranging from 2 to 18 years old. Children faced unmet mental, medical and psychosocial needs that are interconnected and largely unmet due to children’s legal status and ineligibility to access services in most jurisdictions. The most pressing challenge affecting the health of youth was their immigration status. Across sectors,informants revealed an imbalance between the growing demand for services, including legal counsel, and the limited supply of professionals and well-funded services to meet children’s complex needs. Informants emphasized the value of trauma-informed practice, Spanish language proficiency, child-informed practice and intercultural awareness and humility towards their clients as key features of equipped professionals working with this vulnerable population. Regardless of sector, professionals emphasized the importance of culturally-informed care to immigrant youth. Building these skills is associated with greater confidence to provide services to unaccompanied minors, many of whom have experienced as significant burden of childhood trauma. Conclusions: The health needs of unaccompanied minors are complex and span across medical, social work, education, and legal fields. Interdisciplinary collaboration is needed to address the challenges faced by unaccompanied minors in their efforts to integrate themselves into their new communities and promote their resilience. Promising initiatives include co-location of inter-sector services for increased access and efficiency of services and development of professional trainings and resources for professionals in sectors that serve this population

QCD effects on "stable" micro black holes at the LHC

If Micro Black Holes (MBHs) can be produced at the LHC, they will decay very fast. We study hypothetical MBHs that do not decay; in particular, QCD effects on accretion by MBHs that are produced at rest. We explain why accretion of a nucleon by such MBHs is associated with pion emission. This pion emission results in a kick to the MBHs, such that their velocities are large enough to escape the Earth. Our study provides an extra assurance that MBHs which might be produced at the LHC are not dangerous.Comment: 10 page