NASA/DOE/DOD nuclear propulsion technology planning: Summary of FY 1991 interagency panel results

Interagency (NASA/DOE/DOD) technical panels worked in 1991 to evaluate critical nuclear propulsion issues, compare nuclear propulsion concepts for a manned Mars mission on a consistent basis, and to continue planning a technology development project for the Space Exploration Initiative (SEI). Panels were formed to address mission analysis, nuclear facilities, safety policy, nuclear fuels and materials, nuclear electric propulsion technology, and nuclear thermal propulsion technology. A summary of the results and recommendations of the panels is presented

An X-Ray Spectroscopic Study of the SMC X-1/Sk 160 System

We have investigated the composition and distribution of the wind of Sk 160, the supergiant companion of the X-ray star SMC X-1, by comparing an X-ray spectrum of the source, obtained with the ASCA observatory, during an eclipse with the computed spectra of reprocessed radiation from circumstellar matter with various density distributions. We show that the metal abundance in the wind of Sk 160 is no greater than a few tenths of solar, as has been determined for other objects in the Magellanic Clouds. We also show that the observed X-ray spectrum is not consistent with the density distributions of circumstellar matter of the spherically symmetric form derived for line-driven winds, nor with the density distribution derived from a hydrodynamic simulation of the X-ray perturbed and line-driven wind by Blondin & Woo (1995).Comment: 35 pages including 16 figures, uses AASTeX v5.0.2, accepted to Ap

Improving the validity of activity of daily living dependency risk assessment

OBJECTIVES: Efforts to prevent activity of daily living (ADL) dependency may be improved through models that assess older adults' dependency risk. We evaluated whether cognition and gait speed measures improve the predictive validity of interview-based models. METHOD: Participants were 8,095 self-respondents in the 2006 Health and Retirement Survey who were aged 65 years or over and independent in five ADLs. Incident ADL dependency was determined from the 2008 interview. Models were developed using random 2/3rd cohorts and validated in the remaining 1/3rd. RESULTS: Compared to a c-statistic of 0.79 in the best interview model, the model including cognitive measures had c-statistics of 0.82 and 0.80 while the best fitting gait speed model had c-statistics of 0.83 and 0.79 in the development and validation cohorts, respectively. CONCLUSION: Two relatively brief models, one that requires an in-person assessment and one that does not, had excellent validity for predicting incident ADL dependency but did not significantly improve the predictive validity of the best fitting interview-based models

Validity and reliability of the Self-Reported Physical Fitness (SRFit) survey

BACKGROUND: An accurate physical fitness survey could be useful in research and clinical care. PURPOSE: To estimate the validity and reliability of a Self-Reported Fitness (SRFit) survey; an instrument that estimates muscular fitness, flexibility, cardiovascular endurance, BMI, and body composition (BC) in adults ≥ 40 years of age. METHODS: 201 participants completed the SF-36 Physical Function Subscale, International Physical Activity Questionnaire (IPAQ), Older Adults' Desire for Physical Competence Scale (Rejeski), the SRFit survey, and the Rikli and Jones Senior Fitness Test. BC, height and weight were measured. SRFit survey items described BC, BMI, and Senior Fitness Test movements. Correlations between the Senior Fitness Test and the SRFit survey assessed concurrent validity. Cronbach's Alpha measured internal consistency within each SRFit domain. SRFit domain scores were compared with SF-36, IPAQ, and Rejeski survey scores to assess construct validity. Intraclass correlations evaluated test-retest reliability. RESULTS: Correlations between SRFit and the Senior Fitness Test domains ranged from 0.35 to 0.79. Cronbach's Alpha scores were .75 to .85. Correlations between SRFit and other survey scores were -0.23 to 0.72 and in the expected direction. Intraclass correlation coefficients were 0.79 to 0.93. All P-values were 0.001. CONCLUSION: Initial evaluation supports the SRFit survey's validity and reliability

Thermal Destabilization of Azurin by Fatty Acid Ionic Liquids

Azurin is a mixed-structure redox protein involved in bacterial denitrification. Previous studies have shown that azurin is destabilized by imidazolium chloride ionic liquids (ImCl ILs) that can form micelles in aqueous solution, likely by micellar encapsulation. In these ImCl ILs the micelles form from the imidazolium cations. A relatively new class of ionic liquids is fatty acid ionic liquids (FAILs), in which the anion is a fatty acid. In FAILs micelles can form from the fatty acid anions. This presentation presents the results of a thermal unfolding study of azurin in the presence of FAILs in solution. The FAILs tetramethylguanidinium decanoate and choline decanoate both strongly destabilize azurin when present above their critical micelle concentrations, while decanoic acid alone does not affect azurin (at the same concentration). The results point to the special nature of the FAILs and their interactions with the azurin structure and may be related to how the protein is encapsulated by FAIL micelles

Small Scale Response and Modeling of Periodically Forced Turbulence

The response of the small scales of isotropic turbulence to periodic large scale forcing is studied using two-point closures. The frequency response of the turbulent kinetic energy and dissipation rate, and the phase shifts between production, energy and dissipation are determined as functions of Reynolds number. It is observed that the amplitude and phase of the dissipation exhibit nontrivial frequency and Reynolds number dependence that reveals a filtering effect of the energy cascade. Perturbation analysis is applied to understand this behavior which is shown to depend on distant interactions between widely separated scales of motion. Finally, the extent to which finite dimensional models (standard two-equation models and various generalizations) can reproduce the observed behavior is discussed

The Grizzly, September 23, 1983

Security Measures Enacted • Rape Suspect Arrested • Union Welcomes Director • President\u27s Corner • Letters to the Editor • What to do With Your First $10,000 • Art Exhibit Opens • French Professor Earns Doctorate • Bloodmobile is Back • The New Invasion • Some People Never Give Up • Math, Science Teachers Needed • Ursinus Welcomes New Faculty • Calling All Diabetics: Wanna be a Guinea Pig? • New Look Bears Score Grid Upset • Field Hockey Off to Fine Start • Seniors Anchor U.C. Soccer • Sports Profilehttps://digitalcommons.ursinus.edu/grizzlynews/1101/thumbnail.jp

The Grizzly, October 21, 1983

The Book Store Dilemma • NYT Editor Tells Missile Story • Gorch Fock Arrives • German President Ends Conference • Registration for Spring Semester 1984 • Club Sponsors Health Run • APO\u27s Credit Card Drive • Cantatas for College Choir • Reformation Discussion • Mandragola Features Freshmen, Fago, Frazier • What Sting Sings • French Thriller • Doctor Talks Health • Grizzlies Drop Heartbreaker to Hopkins • Bear Pack Strives to Overcome Adversity • Phys. Ed Club Sponsors Health Run • U.C. Soccer Bids for MAC Berthhttps://digitalcommons.ursinus.edu/grizzlynews/1104/thumbnail.jp

Leukotriene B4, an activation product of mast cells, is a chemoattractant for their progenitors

Mast cells are tissue-resident cells with important functions in allergy and inflammation. Pluripotential hematopoietic stem cells in the bone marrow give rise to committed mast cell progenitors that transit via the blood to tissues throughout the body, where they mature. Knowledge is limited about the factors that release mast cell progenitors from the bone marrow or recruit them to remote tissues. Mouse femoral bone marrow cells were cultured with IL-3 for 2 wk and a range of chemotactic agents were tested on the c-kit+ population. Cells were remarkably refractory and no chemotaxis was induced by any chemokines tested. However, supernatants from activated mature mast cells induced pronounced chemotaxis, with the active principle identified as leukotriene (LT) B4. Other activation products were inactive. LTB4 was highly chemotactic for 2-wk-old cells, but not mature cells, correlating with a loss of mRNA for the LTB4 receptor, BLT1. Immature cells also accumulated in vivo in response to intradermally injected LTB4. Furthermore, LTB4 was highly potent in attracting mast cell progenitors from freshly isolated bone marrow cell suspensions. Finally, LTB4 was a potent chemoattractant for human cord blood–derived immature, but not mature, mast cells. These results suggest an autocrine role for LTB4 in regulating tissue mast cell numbers

The Grizzly, October 28, 1983

CampusBooks Speaks Out • C and C Course Offered • Zack Is Back In Bronze • Peace Rally Held • Give Us A Little Bit Of Credit • Respect Is Goal Of Liberal Education • Homecoming: A Big Success • Nobel Prize Awarded • Spirit Week Begins • The Talented Two-Some • The Stone Age is Back • Crown Royal Features Ultimate Competition • Lady Bears Prepare For Penn State Rivalry • U.C. Soccer Continues Winning Ways • Grizziles Roll Over Lebanon Valleyhttps://digitalcommons.ursinus.edu/grizzlynews/1105/thumbnail.jp