Accounting of computer system use in EXEC 8

EXEC 8 modified multiprogramming system to log core time and central processing uni

Can’t Get Here from There: The Decision to Apply to a Selective Institution

Students from low-income families are greatly underrepresented at selective colleges and universities in the United States. In an attempt to increase applications from low-income students, some institutions have developed programs involving increased recruitment of and more attractive financial aid packages for students from low-income families. However, relatively little research has looked at the factors that are important in the college application decision-making process, and in particular how the importance of some factors may be different for low-income students. This paper uses data from the National Education Longitudinal Study of 1988 and the National Longitudinal Survey of Youth, 1997 cohort to analyze the factors influencing students\u27 college application decisions, with a focus on the decision to apply to a selective four-year institution. We analyze how the influence of distance from a student’s home during high school to a selective college or university and average tuition levels at selective institutions located nearby vary with the a student’s family income. Our results show that the further a student lives from a selective college, the less likely they are to apply to one, and this effect seems to be stronger than that of average tuition levels in the student’s state. Although the effect of distance does not differ for low-income students, they are most heavily impacted due to the geographic mismatch of low-income students and selective institutions. Personal, family (in particular, parent’s education) and high school characteristics also prove to be very influential when students are deciding whether or not to apply to a selective institution

Human B1 Cell Frequency: Isolation and Analysis of Human B1 Cells

Controversy over the frequency of human B1 cells in normal individuals has arisen as different labs have begun to employ non-uniform techniques to study this population. The phenotypic profile and relative paucity of circulating human B1 cells place constraints on methodology to identify and isolate this population. Multiple steps must be optimized to insure accurate enumeration and optimal purification. In the course of working with human B1 cells we have developed a successful strategy that provides consistent analysis of B1 cells for frequency determination and efficient isolation of B1 cells for functional studies. Here we discuss issues attendant to identifying human B1 cells and outline a carefully optimized approach that leads to uniform and reproducible data

B cells in the aging immune system: time to consider B-1 cells

The investigation of immune senescence has uncovered many changes in B cell development, maintenance, and function with increasing age. However, most of these studies have focused on conventional B cell subsets in the spleen. The B-1 cell subset is an essential arm of the innate immune system, which in general has been understudied in terms of immune senescence. Here, we review what is currently known about B cells during aging and go on to describe why B-1 cell biology is an important component of the aging immune system in the context of diseases that most affect the aged population

Effective field theory approach to Casimir interactions on soft matter surfaces

We utilize an effective field theory approach to calculate Casimir interactions between objects bound to thermally fluctuating fluid surfaces or interfaces. This approach circumvents the complicated constraints imposed by such objects on the functional integration measure by reverting to a point particle representation. To capture the finite size effects, we perturb the Hamiltonian by DH that encapsulates the particles' response to external fields. DH is systematically expanded in a series of terms, each of which scales homogeneously in the two power counting parameters: \lambda \equiv R/r, the ratio of the typical object size (R) to the typical distance between them (r), and delta=kB T/k, where k is the modulus characterizing the surface energy. The coefficients of the terms in DH correspond to generalized polarizabilities and thus the formalism applies to rigid as well as deformable objects. Singularities induced by the point particle description can be dealt with using standard renormalization techniques. We first illustrate and verify our approach by re-deriving known pair forces between circular objects bound to films or membranes. To demonstrate its efficiency and versatility, we then derive a number of new results: The triplet interactions present in these systems, a higher order correction to the film interaction, and general scaling laws for the leading order interaction valid for objects of arbitrary shape and internal flexibility.Comment: 4 pages, 1 figur

Sneutrino Dark Matter: Symmetry Protection and Cosmic Ray Anomalies

We present an R-parity conserving model of sneutrino dark matter within a Higgs-philic U(1)' extension of the minimal supersymmetric standard model. In this theory, the mu parameter and light Dirac neutrino masses are generated naturally upon the breaking of the U(1)' gauge symmetry. The leptonic and hadronic decays of sneutrinos in this model, taken to be the lightest and next-to-lightest superpartners, allow for a natural fit to the recent results reported by the PAMELA experiment.Comment: Revised to match the published version; 11 pages (2 column format), 1 table, 6 figures, to appear in PR