Environmental analysis of the chemical release module

The environmental analysis of the Chemical Release Module (a free flying spacecraft deployed from the space shuttle to perform chemical release experiments) is reviewed. Considerations of possible effects of the injectants on human health, ionosphere, weather, ground based optical astronomical observations, and satellite operations are included. It is concluded that no deleterious environmental effects of widespread or long lasting nature are anticipated from chemical releases in the upper atmosphere of the type indicated for the program

Collective modes and correlations in one-component plasmas

The static and time-dependent potential and surface charge correlations in a plasma with a boundary are computed for different shapes of the boundary. The case of a spheroidal or spherical one-component plasma is studied in detail because experimental results are available for such systems. Also, since there is some knowlegde both experimental and theoretical about the electrostatic collective modes of these plasmas, the time-dependent correlations are computed using a method involving these modes.Comment: 20 pages, plain TeX, submitted to Phys. Rev.

Educating Undergraduates for Democracy and Efficacy and the 2006 Penn Democracy Project

Most political socialization research has focused on children, because this formative time provides the foundation for an individual’s political self. However, both life experiences and changing societal roles of an individual as he/she ages suggests that political values can change throughout life. In particular, the lifecycle has certain moments that are particularly apt to political growth. One of these moments is college. Universities are currently rediscovering an important goal of their institution - preparing citizens for positive participation in society. Further, students are at an important “role changing moment,” as they move from childhood to adulthood. The college moment is the focus of the Penn Democracy Project. This study has surveyed Penn undergraduates over four years to understand what effect the undergraduate experience has on students. The study has found that college brings profound personal change and challenges, and on the whole, causes students to be less civically minded. Even students who had strong political influences as children are not immune to the pressures of this period. This paper does not attempt to argue whether universities should have a responsibility to focus on the political socialization of its students. Every study of childhood development acknowledged the role of the classroom in political socialization, and current movements argue that universities should devote more attention to this as well. The paper only argues that universities do have a significant impact on students, and as an important institution in a democracy, can improve how it affects students. Overall, the study suggests that college is a transitional stage for students, and has a negative affect on student values. However, there are many opportunities to change that, and steer students in a positive direction, graduating civically minded scholars. In particular, schools can focus on empowering students – showing them that they can make a difference in the problems they see in society. The college experience for many can be discouraging, but a focus on building efficacy and showing students that they have the ability to impact their classroom, campus, or community can encourage democratic development

The Pegg-Barnett Formalism and Covariant Phase Observables

We compare the Pegg-Barnett (PB) formalism with the covariant phase observable approach to the problem of quantum phase and show that PB-formalism gives essentially the same results as the canonical (covariant) phase observable. We also show that PB-formalism can be extended to cover all covariant phase observables including the covariant phase observable arising from the angle margin of the Husimi Q-function.Comment: 10 page

Evidence of polariton induced transparency in a single organic quantum wire

The resonant interaction between quasi-one dimensional excitons and photons is investigated. For a single isolated organic quantum wire, embedded in its single crystal monomer matrix, the strong exciton-photon coupling regime is reached. This is evidenced by the suppression of the resonant excitonic absorption arising when the system eigenstate is a polariton. These observations demonstrate that the resonant excitonic absorption in a semiconductor can be understood in terms of a balance between the exciton coherence time and the Rabi period between exciton-like and photon-like states of the polariton.Comment: 9 pages and 4 figure

Sustaining Collection Value: Managing Collection/Item Metadata Relationships

Many aspects of managing collection/item metadata relationships are critical to sustaining collection value over time. Metadata at the collection-level not only provides context for finding, understanding, and using the items in the collection, but is often essential to the particular research and scholarly activities the collection is designed to support. Contemporary retrieval systems, which search across collections, usually ignore collection level metadata. Alternative approaches, informed by collection-level information, will require an understanding of the various kinds of relationships that can obtain between collection-level and item-level metadata. This paper outlines the problem and describes a project that is developing a logic-based framework for classifying collection-level/item-level metadata relationships. This framework will support (i) metadata specification developers defining metadata elements, (ii) metadata librarians describing objects, and (iii) system designers implementing systems that help users take advantage of collection-level metadata.Institute for Museum and Libary Services (Grant #LG06070020)published or submitted for publicationis peer reviewe

A microeconometric analysis of risk aversion and the decision to self-insure

This study estimates a von Neumann-Morgenstern utility function using market data and microeconometric methods. We investigate the decision whether to purchase insurance against the risk of telephone line trouble in the home. Using the choices of approximately 10,000 residential customers, we determine the shape of the utility function and the degree of risk aversion. We find that risk aversion varies systematically in the population and varies with the level of income and that the observed choice behavior is consistent with expected utility maximization

Joint genomic and proteomic analysis identifies meta-trait characteristics of virulent and non-virulent Staphylococcus aureus strains

Staphylococcus aureus is an opportunistic pathogen of humans and warm-blooded animals and presents a growing threat in terms of multi-drug resistance. Despite numerous studies, the basis of staphylococcal virulence and switching between commensal and pathogenic phenotypes is not fully understood. Using genomics, we show here that S. aureus strains exhibiting virulent (VIR) and non-virulent (NVIR) phenotypes in a chicken embryo infection model genetically fall into two separate groups, with the VIR group being much more cohesive than the NVIR group. Significantly, the genes encoding known staphylococcal virulence factors, such as clumping factors, are either found in different allelic variants in the genomes of NVIR strains (compared to VIR strains) or are inactive pseudogenes. Moreover, the pyruvate carboxylase and gamma-aminobutyrate permease genes, which were previously linked with virulence, are pseudogenized in NVIR strain ch22. Further, we use comprehensive proteomics tools to characterize strains that show opposing phenotypes in a chicken embryo virulence model. VIR strain CH21 had an elevated level of diapolycopene oxygenase involved in staphyloxanthin production (protection against free radicals) and expressed a higher level of immunoglobulin-binding protein Sbi on its surface compared to NVIR strain ch22. Furthermore, joint genomic and proteomic approaches linked the elevated production of superoxide dismutase and DNA-binding protein by NVIR strain ch22 with gene duplications

Method and apparatus for providing a seamless tiled display

A display for producing a seamless composite image from at least two discrete images. The display includes one or more projectors for projecting each of the discrete images separately onto a screen such that at least one of the discrete images overlaps at least one other of the discrete images by more than 25 percent. The amount of overlap that is required to reduce the seams of the composite image to an acceptable level over a predetermined viewing angle depends on a number of factors including the field-of-view and aperture size of the projectors, the screen gain profile, etc. For rear-projection screens and some front projection screens, an overlap of more than 25 percent is acceptable

A Micro-Econometric Analysis of Risk-Aversion and the Decision to Self-Insure

This study estimates a von Neumann-Morgenstern utility function using market data and micro-econometric methods. We investigate the decision whether to purchase insurance against the risk of telephone line trouble in the home. Using the choices of approximately 10,000 residential customers, we determine the shape of the utility function and the degree of risk-aversion. We find that risk-aversion varies systematically in the population and varies with the level of income and that the observed choice behavior is consistent with expected utility maximization. We are unable to detect the presence of ambiguity effects or over-weighting of low-probability events