Interstellar extinction at 10-20 microns

The IRAS low-resolution spectra (LRS) spectra of 117 stars of excellent signal/noise with optically thin silicate dust shells were analyzed. The stellar continua (assumed to be a cool black body) were subtracted, and the resulting dust shell spectra were fit with simple models F(sub lambda) assuming uniform mass loss and dust temperature as a function of distance from the star, calculated using the optical constants for silcates of Draine (1985). From the comparison of the spectra and the models, functions for the emissivity, kappa(sub lambda), were derived

Assessment team report on flight-critical systems research at NASA Langley Research Center

The quality, coverage, and distribution of effort of the flight-critical systems research program at NASA Langley Research Center was assessed. Within the scope of the Assessment Team's review, the research program was found to be very sound. All tasks under the current research program were at least partially addressing the industry needs. General recommendations made were to expand the program resources to provide additional coverage of high priority industry needs, including operations and maintenance, and to focus the program on an actual hardware and software system that is under development

The Weyl-Lanczos Equations and the Lanczos Wave Equation in 4 Dimensions as Systems in Involution

Using the work by Bampi and Caviglia, we write the Weyl-Lanczos equations as an exterior differential system. Using Janet-Riquier theory, we compute the Cartan characters for all spacetimes with a diagonal metric and for the plane wave spacetime since all spacetimes have a plane wave limit. We write the Lanczos wave equation as an exterior differential system and, with assistance from Janet-Riquier theory, we find that it forms a system in involution. This result can be derived from the scalar wave equation itself. We compute its Cartan characters and compare them with those of the Weyl-Lanczos equations.Comment: 18 pages, latex, no figures, references correcte

Measuring Operations: An Analysis of the Financial Statements of U.S. Private Colleges and Universities

As events in the business sector have highlighted, companies can play by the rules and yet produce misleading financial statements. This study examines the nongovernmental organizations that provide a substantial portion of higher education in the United States. We seek to determine whether private colleges and universities take advantage of the discretion available to them under accounting and auditing standards by presenting an operating measure in their statement of activities. We find that nearly 60 percent of schools report an operating measure but the items included or excluded from operations vary widely.This publication is Hauser Center Working Paper No. 17. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers

Using electrostatic potentials to predict DNA-binding sites on DNA-binding proteins

A method to detect DNA-binding sites on the surface of a protein structure is important for functional annotation. This work describes the analysis of residue patches on the surface of DNA-binding proteins and the development of a method of predicting DNA-binding sites using a single feature of these surface patches. Surface patches and the DNA-binding sites were initially analysed for accessibility, electrostatic potential, residue propensity, hydrophobicity and residue conservation. From this, it was observed that the DNA-binding sites were, in general, amongst the top 10% of patches with the largest positive electrostatic scores. This knowledge led to the development of a prediction method in which patches of surface residues were selected such that they excluded residues with negative electrostatic scores. This method was used to make predictions for a data set of 56 non-homologous DNA-binding proteins. Correct predictions made for 68% of the data set

Assessing Financial Vulnerability in the Nonprofit Sector

Effective nonprofit governance relies upon understanding an organization's financial condition and vulnerabilities. However, financial vulnerability of nonprofit organizations is a relatively new area of study. In this paper, we compare two models used to forecast bankruptcy in the corporate sector (Altman 1968 and Ohlson 1980) with the model used by nonprofit researchers (Tuckman and Chang 1991). We find that the Ohlson model has higher explanatory power than either Tuckman and Chang's or Altman's in predicting four different measures of financial vulnerability. However, we show that none of the models, individually or combined, are effective in predicting financial distress. We then propose a more comprehensive model of financial vulnerability by adding two new variables to represent reliance on commercial-type activities to generate revenues and endowment sufficiency. We find that this model outperforms Ohlson's model and performs substantially better in explaining and predicting financial vulnerability. Hence, the expanded model can be used as a guide for understanding the drivers of financial vulnerability and for identifying more effective proxies for nonprofit sector financial distress for use in future research. This publication is Hauser Center Working Paper No. 27. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers

Threonine 180 Is Required for G-protein-coupled Receptor Kinase 3- and β-Arrestin 2-mediated Desensitization of the µ-Opioid Receptor in Xenopus Oocytes

To determine the sites in the µ-opioid receptor (MOR) critical for agonist-dependent desensitization, we constructed and coexpressed MORs lacking potential phosphorylation sites along with G-protein activated inwardly rectifying potassium channels composed of Kir3.1 and Kir3.4 subunits in Xenopus oocytes. Activation of MOR by the stable enkephalin analogue, [D-Ala2,MePhe4,Glyol5]enkephalin, led to homologous MOR desensitization in oocytes coexpressing both G-protein-coupled receptor kinase 3 (GRK3) and beta -arrestin 2 (arr3). Coexpression with either GRK3 or arr3 individually did not significantly enhance desensitization of responses evoked by wild type MOR activation. Mutation of serine or threonine residues to alanines in the putative third cytoplasmic loop and truncation of the C-terminal tail did not block GRK/arr3-mediated desensitization of MOR. Instead, alanine substitution of a single threonine in the second cytoplasmic loop to produce MOR(T180A) was sufficient to block homologous desensitization. The insensitivity of MOR(T180A) might have resulted either from a block of arrestin activation or arrestin binding to MOR. To distinguish between these alternatives, we expressed a dominant positive arrestin, arr2(R169E), that desensitizes G protein-coupled receptors in an agonist-dependent but phosphorylation-independent manner. arr2(R169E) produced robust desensitization of MOR and MOR(T180A) in the absence of GRK3 coexpression. These results demonstrate that the T180A mutation probably blocks GRK3- and arr3-mediated desensitization of MOR by preventing a critical agonist-dependent receptor phosphorylation and suggest a novel GRK3 site of regulation not yet described for other G-protein-coupled receptors

Foster Youth Transitioning to Independent Living and Higher Education: A Phenomenological Study

The purpose of this transcendental phenomenological study was to describe the experiences of foster youth who aged out of foster care and enrolled in higher educational programs in rural areas of southern Virginia. The theory that guided this study was Maslow’s hierarchy of needs as it applied to higher educational pursuits of foster youth who had, or were about to, age out of foster care. Bronfenbrenner’s ecological systems theory also guided this study to identify additional barriers to higher education for foster youth. This phenomenological study used a transcendental research method. Data collection methods included face-to-face and phone interviews, focus groups, participant captions for picture cards, and data from intake documents and school records that provided accurate demographic information. Interviews and focus groups were conducted primarily by phone while captions, demographics, and consent were compiled through email, postal service, and participating school records. Moustakas’ modified method was used to analyze data for this study. The central research question for consideration was as follows: What are the lived experiences of foster youth who have aged out of foster care and enrolled in community college? The 12 participants for this study shared their unique life experiences as they aged out of foster care and enrolled in higher education programs. While the participants’ educational barriers differed to some degree, one commonality each faced was the lack of a dependable adult role model for encouragement and support. The impact of this missing element was evident in the life-choices of participants