27,353 research outputs found

    Pulsation of EE Cam

    Full text link
    EE Cam is a previously little studied Delta Scuti pulsator with amplitudes between those of the HADS (High-Amplitude Delta Scuti stars) group and the average low-amplitude pulsators. Since the size of stellar rotation determines both which pulsation modes are selected by the star as well as their amplitudes, the star offers a great opportunity to examine the astrophysical connections. Extensive photometric measurements covering several months were carried out. 15 significant pulsation frequencies were extracted. The dominant mode at 4.934 cd−1^{-1} was identified as a radial mode by examining the phase shifts at different wavelengths. Medium-dispersion spectra yielded a vsin⁥iv\sin i value of 40±340 \pm 3 km s−1^{-1}. This shows that EE Cam belongs to the important transition region between the HADS and normal Delta Scuti stars.Comment: 13 pages, 3 figures, 3 table

    Plasma Sterilization Technology for Spacecraft Applications

    Get PDF
    The application of plasma gas technology to sterilization and decontamination of spacecraft components is considered. Areas investigated include: effective sterilizing ranges of four separate gases; lethal constituents of a plasma environment; effectiveness of plasma against a diverse group of microorganisms; penetrating efficiency of plasmas for sterilization; and compatibility of spacecraft materials with plasma environments. Results demonstrated that plasma gas, specifically helium plasma, is a highly effective sterilant and is compatible with spacecraft materials

    Understanding the measurement of hunger and food insecurity in the elderly

    Get PDF
    The elderly are one of the population subgroups at greatest risk for hunger and food insecurity. To date, no accurate measures of this problem have been developed. What is needed are a thorough understanding of the phenomenon, and an assessment of how the elderly perceive and answer items commonly used to measure hunger and food insecurity in other subgroups. In-depth, open-ended interviews were conducted with forty-one low-income urban black and rural white residents of upstate New York. Results suggest a conceptual framework of food insecurity in the elderly with two significant differences from frameworks proposed for younger families: the major role of health problems and physical disabilities, and the impact of personal history on perceptions of food insecurity. In a telephone follow-up (approximately six months after the initial interviews) twenty-four respondents were asked commonly used food insecurity questionnaire items from six different sources. Results suggest that hunger and food insecurity among the elderly can be measured directly. The commonly used measures tested here will help categorize the stages of food insecurity. However, these direct measures might underestimate the prevalence of food insecurity because of a perceived reluctance to report problems with food.

    NMR Dynamics Investigation of Ligand-Induced Changes of Main and Side-Chain Arginine N-H’s in Human Phosphomevalonate Kinase

    Get PDF
    Phosphomevalonate kinase (PMK) catalyzes phosphoryl transfer from adenosine triphosphate (ATP) to mevalonate 5-phosphate (M5P) on the pathway for synthesizing cholesterol and other isoprenoids. To permit this reaction, its substrates must be brought proximal, which would result in a significant and repulsive buildup of negative charge. To facilitate this difficult task, PMK contains 17 arginines and eight lysines. However, the way in which this charge neutralization and binding is achieved, from a structural and dynamics perspective, is not known. More broadly, the role of arginine side-chain dynamics in binding of charged substrates has not been experimentally defined for any protein to date. Herein we report a characterization of changes to the dynamical state of the arginine side chains in PMK due to binding of its highly charged substrates, ATP and M5P. These studies were facilitated by the use of arginine-selective labeling to eliminate spectral overlap. Model-free analysis indicated that while substrate binding has little effect on the arginine backbone dynamics, binding of either substrate leads to significant rigidification of the arginine side chains throughout the protein, even those that are \u3e8 Å from the binding site. Such a global rigidification of arginine side chains is unprecedented and suggests that there are long-range electrostatic interactions of sufficient strength to restrict the motion of arginine side chains on the picosecond-to-nanosecond time scale. It will be interesting to see whether such effects are general for arginine residues in proteins that bind highly charged substrates, once additional studies of arginine side-chain dynamics are reported

    Nutritional Consequences of Food Insecurity in a Rural New York State County

    Get PDF
    This study of women with children in a rural county of upstate New York examined the relationships of food insecurity and income with two nutritional consequences (adiposity and fruit and vegetables consumption), and assessed whether disordered eating patterns is a mediator for the effects of food insecurity and income on these nutritional consequences. Each of 193 respondents was interviewed twice in her home. Data were collected on household food stores, socioeconomic and demographic characteristics, methods of obtaining food, food program participation, household expenditures, food intake, the Radimer/Cornell hunger and food insecurity items, height, weight, frequency of fruit and vegetable consumption, and disordered eating patterns. Regression analysis was used to analyze the relationships of body mass index and an obesity classification with height, income, education, single parenthood, employment, food insecurity, disordered eating, and frequency of fruit and vegetable consumption. Regression analysis was also used to examine the relationships of disordered eating and frequency of fruit and vegetable consumption with the other variables. Lower income and unemployment were related to higher adiposity. The effects of income on adiposity were not mediated through disordered eating patterns or through fruit and vegetable consumption. Food insecurity was related to adiposity, and part of this effect of food insecurity was mediated through disordered eating. This mediating effect of disordered eating partially explained why those experiencing the least severe food insecurity were more likely to be overweight than those who were food secure, but those experiencing the most severe food insecurity were less likely to be overweight than those who were food secure. Food insecurity was related to lower fruit and vegetable consumption, but this did not translate into effects on adiposity.

    Feed ingredient composition for beef cattle (2005)

    Get PDF
    It is essential to know feedstuff nutrient content in order to properly formulate beef cattle diets. This publication provides estimates of the nutrient composition of feedstuffs that are used commonly in Missouri.Revised October 2005 -- Extension website

    El crimen de los oligarcas corcirenses (Th. III 70.4)

    Get PDF
    At Th. 3.70.4, a number of Corcyraean oligarchs are convicted of illegally ‘cutting stakes’ (τέΌΜΔÎčÎœ Ï‡ÎŹÏÎ±Îșας) in two local sanctuaries. The significance of this charge is disputed among commentators. We offer detailed support of Hornblower’s conclusion that the Corcyraean oligarchs are charged with cutting saplings from sacred land for use as vine-stakes in their own fields. Our argument places Thucydides’ account of events in a larger philological, ecological and social framework, and suggests that the details of the accusation help establish abuse of communally controlled natural resources and the court system as prodromal stages in the social deterioration that ultimately produces the stasis on Corcyra and by implication elsewhere as well.En Th. III 70.4 se acusa a un grupo de oligarcas de Corcira por ‘cortar estacas’ (τέΌΜΔÎčÎœ Ï‡ÎŹÏÎ±Îșας) ilegalmente en dos santuarios locales. Los comentaristas discuten el significado de esta acusaciĂłn. Ofrecemos apoyo detallado a la conclusiĂłn de Hornblower, segĂșn la cual se acusa a los oligarcas corcirenses de cortar ĂĄrboles jĂłvenes de terreno sagrado para usarlos como puntales de viñas en sus campos privados. Nuestro argumento sitĂșa el relato de TucĂ­dides en un marco filolĂłgico, ecolĂłgico y social mĂĄs amplio, y sugiere que los detalles de la acusaciĂłn ayudan a establecer el abuso de recursos naturales controlados por la comunidad y el sistema judicial como fases preliminares en el deterioro social que terminĂł produciendo la stasis en Corcira e implĂ­citamente tambiĂ©n en otros lugares

    Intensified array camera imaging of solid surface combustion aboard the NASA Learjet

    Get PDF
    An intensified array camera was used to image weakly luminous flames spreading over thermally thin paper samples in a low gravity environment aboard the NASA-Lewis Learjet. The aircraft offers 10 to 20 sec of reduced gravity during execution of a Keplerian trajectory and allows the use of instrumentation that is delicate or requires higher electrical power than is available in drop towers. The intensified array camera is a charge intensified device type that responds to light between 400 and 900 nm and has a minimum sensitivity of 10(exp 6) footcandles. The paper sample, either ashless filter paper or a lab wiper, burns inside a sealed chamber which is filled with 21, 18, or 15 pct. oxygen in nitrogen at one atmosphere. The camera views the edge of the paper and its output is recorded on videotape. Flame positions are measured every 0.1 sec to calculate flame spread rates. Comparisons with drop tower data indicate that the flame shapes and spread rates are affected by the residual g level in the aircraft
    • 

    corecore