Less than perfect quantum wavefunctions in momentum-space: How phi(p) senses disturbances in the force

We develop a systematic approach to determine the large |p| behavior of the momentum-space wavefunction, phi(p), of a one-dimensional quantum system for wich the position-space wavefunction, psi(x), has a discontinuous derivative at any order. We find that if the k-th derivative of the potential energy function has a discontinuity, there is a corresponding discontinuity in psi^{(k+2)}(x) at the same point. This discontinuity leads directly to a power-law tail in the momentum-space wavefunction proportional to 1/p^{k+3}. A number of familiar pedagogical examples are examined in this context, leading to a general derivation of the result.Comment: 22 pages, 2 figures. To appear in Am. J. Phy

The Challenge of Leadership in an Increasingly Diverse Society

Commencement address given by Louis W. Sullivan, President Emeritus, Morehouse School of Medicine and U. S. Secretary of Health and Human Services, to the Autumn 2002 graduating class of The Ohio State University, St. John Arena, Columbus, Ohio, December 13, 2002

Missing Persons: Minorities in the Health Professions, A Report of the Sullivan Commission on Diversity in the Healthcare Workforce

There is an imbalance in the makeup of the nation’s physicians, dentists, and nurses. This imbalance contributes to the gap in health status and the impaired access to health care experienced by a significant portion of our population. The Sullivan Commission on Diversity in the Healthcare Workforce finds that African Americans, Hispanics, American Indians, and certain segments of the nation’s Asian/Pacific Islander population are not present in significant numbers. Rather, they are missing! While some outstanding physicians, dentists, and nurses are minorities, access to a health professions career remains largely separate and unequal. This report, Missing Persons: Minorities in the Health Professions, examines the root causes of this challenge and provides detailed recommendations on how to increase the representation of minorities in the nation’s medical, dental, and nursing workforce.https://www.aacnnursing.org

Topological mirror symmetry with fluxes

Motivated by SU(3) structure compactifications, we show explicitly how to construct half--flat topological mirrors to Calabi--Yau manifolds with NS fluxes. Units of flux are exchanged with torsion factors in the cohomology of the mirror; this is the topological complement of previous differential--geometric mirror rules. The construction modifies explicit SYZ fibrations for compact Calabi--Yaus. The results are of independent interest for SU(3) compactifications. For example one can exhibit explicitly which massive forms should be used for Kaluza--Klein reduction, proving previous conjectures. Formality shows that these forms carry no topological information; this is also confirmed by infrared limits and old classification theorems.Comment: 35 pages, 5 figure

Telomere disruption results in non-random formation of de novo dicentric chromosomes involving acrocentric human chromosomes

Copyright: © 2010 Stimpson et al.Genome rearrangement often produces chromosomes with two centromeres (dicentrics) that are inherently unstable because of bridge formation and breakage during cell division. However, mammalian dicentrics, and particularly those in humans, can be quite stable, usually because one centromere is functionally silenced. Molecular mechanisms of centromere inactivation are poorly understood since there are few systems to experimentally create dicentric human chromosomes. Here, we describe a human cell culture model that enriches for de novo dicentrics. We demonstrate that transient disruption of human telomere structure non-randomly produces dicentric fusions involving acrocentric chromosomes. The induced dicentrics vary in structure near fusion breakpoints and like naturally-occurring dicentrics, exhibit various inter-centromeric distances. Many functional dicentrics persist for months after formation. Even those with distantly spaced centromeres remain functionally dicentric for 20 cell generations. Other dicentrics within the population reflect centromere inactivation. In some cases, centromere inactivation occurs by an apparently epigenetic mechanism. In other dicentrics, the size of the alpha-satellite DNA array associated with CENP-A is reduced compared to the same array before dicentric formation. Extrachromosomal fragments that contained CENP-A often appear in the same cells as dicentrics. Some of these fragments are derived from the same alpha-satellite DNA array as inactivated centromeres. Our results indicate that dicentric human chromosomes undergo alternative fates after formation. Many retain two active centromeres and are stable through multiple cell divisions. Others undergo centromere inactivation. This event occurs within a broad temporal window and can involve deletion of chromatin that marks the locus as a site for CENP-A maintenance/replenishment.This work was supported by the Tumorzentrum Heidelberg/Mannheim grant (D.10026941)and by March of Dimes Research Foundation grant #1-FY06-377 and NIH R01 GM069514

Using Unexpected Recalls to Examine the Long-Term Earnings Effects of Job Displacement

This paper examines the long-term earnings consequences of permanent layoffs initiated during the early 1990s, using a sample of Massachusetts workers who enrolled in Job Training Partnership Act Title III programs, and who remained strongly attached to the state's labor force. The comparison group is formed by workers who were unexpectedly recalled. On average, recalled workers incurred substantial annual earnings reductions upon reemployment. Nevertheless, one decade later, permanently displaced workers were still earning between 11 and 17 percent less per year than recalled workers with comparable pre-layoff skills and experience. Workers with limited education experienced particularly large earnings reductions from permanent job loss

Candidate Events in a Search for Muon Antineutrino to Electron Antineutrino Oscillations

A search for \nuebar's in excess of the number expected from conventional sources has been made using the Liquid Scintillator Neutrino Detector, located 30 m from a proton beam dump at LAMPF. A \nuebar signal was detected via the reaction \nuebar\,p \rightarrow e^{+}\,n with $e^+$ energy between 36 and 60\mev, followed by a $\gamma$ from $np\rightarrow d\gamma$ (2.2\mev). Using strict cuts to identify $\gamma$'s correlated with positrons results in a signal of 9 events, with an expected background of $2.1 \pm 0.3$. A likelihood fit to the entire $e^+$ sample yields a total excess of $16.4^{+9.7}_{-8.9}\pm 3.3$ events, where the second uncertainty is systematic. If this excess is attributed to neutrino oscillations of the type \numubar\rightarrow\nuebar, it corresponds to an oscillation probability of ($0.34^{+0.20}_{-0.18}\pm 0.07$)\%.Comment: 3 PS figures; corrected TeX file (April 21, 1995