9,379 research outputs found
IRS-TR 12001: Spectral Pointing-Induced Throughput Error and Spectral Shape in Short-Low Order 1
We investigate how the shape of a spectrum in the Short-Low module on the IRS
varies with its overall throughput, which depends on how well centered a source
is in the spectroscopic slit. Using flux ratios to quantify the overall slope
or color of the spectrum and plotting them vs. the overall throughput reveals a
double-valued function, which arises from asymmetries in the point spread
function. We use this plot as a means of determining which individual spectra
are valid for calibrating the IRS.Comment: 9 pages, 3 figure
Techniques for the observation of micrometeorite craters in metal substrates utilizing electron micrographic replica methods
Thin film replica technique for obtaining high quality electron micrographs of craters in metal substrates formed by microscopic hypervelocity particle impac
Luminosities and mass-loss rates of Local Group AGB stars and Red Supergiants
We aim to investigate mass loss and luminosity in a large sample of evolved
stars in several Local Group galaxies with a variety of metalliticies and
star-formation histories: the Small and Large Magellanic Cloud, and the Fornax,
Carina, and Sculptor dwarf spheroidal galaxies. Dust radiative transfer models
are presented for 225 carbon stars and 171 oxygen-rich evolved stars for which
spectra from the Infrared Spectrograph on Spitzer are available. The spectra
are complemented with available optical and infrared photometry to construct
spectral energy distributions. A minimization procedure was used to determine
luminosity and mass-loss rate (MLR). Pulsation periods were derived for a large
fraction of the sample based on a re-analysis of existing data. New deep K-band
photometry from the VMC survey and multi-epoch data from IRAC and
AllWISE/NEOWISE have allowed us to derive pulsation periods longer than 1000
days for some of the most heavily obscured and reddened objects. We derive
(dust) MLRs and luminosities for the entire sample. The estimated MLRs can
differ significantly from estimates for the same objects in the literature due
to differences in adopted optical constants (up to factors of several) and
details in the radiative transfer modelling. Updated parameters for the
super-AGB candidate MSX SMC 055 (IRAS 00483-7347) are presented. Its current
mass is estimated to be 8.5 +- 1.6 \msol, suggesting an initial mass well above
8~\msol. Using synthetic photometry, we present and discuss colour-colour and
colour-magnitude diagrams which can be expected from the James Webb Space
Telescope.Comment: A&A accepted. The full version (100 pages, 12 MB) with complete
tables and all figures of the appendices is available at
http://homepage.oma.be/marting/articlesgroen.htm
Meteorological regimes for the classification of aerospace air quality predictions for NASA-Kennedy Space Center
A method is described for developing a statistical air quality assessment for the launch of an aerospace vehicle from the Kennedy Space Center in terms of existing climatological data sets. The procedure can be refined as developing meteorological conditions are identified for use with the NASA-Marshall Space Flight Center Rocket Exhaust Effluent Diffusion (REED) description. Classical climatological regimes for the long range analysis can be narrowed as the synoptic and mesoscale structure is identified. Only broad synoptic regimes are identified at this stage of analysis. As the statistical data matrix is developed, synoptic regimes will be refined in terms of the resulting eigenvectors as applicable to aerospace air quality predictions
Neural regulation of cancer: from mechanobiology to inflammation.
Despite recent progress in cancer research, the exact nature of malignant transformation and its progression is still not fully understood. Particularly metastasis, which accounts for most cancer death, is a very complex process, and new treatment strategies require a more comprehensive understanding of underlying regulatory mechanisms. Recently, the sympathetic nervous system (SNS) has been implicated in cancer progression and beta-blockers have been identified as a novel strategy to limit metastasis. This review discusses evidence that SNS signaling regulates metastasis by modulating the physical characteristics of tumor cells, tumor-associated immune cells and the extracellular matrix (ECM). Altered mechanotype is an emerging hallmark of cancer cells that is linked to invasive phenotype and treatment resistance. Mechanotype also influences crosstalk between tumor cells and their environment, and may thus have a critical role in cancer progression. First, we discuss how neural signaling regulates metastasis and how SNS signaling regulates both biochemical and mechanical properties of tumor cells, immune cells and the ECM. We then review our current knowledge of the mechanobiology of cancer with a focus on metastasis. Next, we discuss links between SNS activity and tumor-associated inflammation, the mechanical properties of immune cells, and how the physical properties of the ECM regulate cancer and metastasis. Finally, we discuss the potential for clinical translation of our knowledge of cancer mechanobiology to improve diagnosis and treatment
Productivity of Florida Springs: Second semi-annual report to the Biology Division, Office of Naval Research progress from February 1, 1953 to June 30, 1953
During this second six months emphasis has been laid on developing a complete understanding of the metabolism of the Silver Springs ecosystem as an example of a community apparently in a steady state. Variation in phosphates, uptake of nitrates, and importance of boron have been estimated. Fluctuation of some major elements has been estimated. Examination of stomach contents has permitted trophic classifications of dominant species and the standing crops have been estimated for these species by number and by dry weight. From these a pyramid of mass has been constructed. Special attention has been paid to bacteria using 3 methods for comparison of Silver Springs with lakes and estimation of the standing crop. The oxygen gradient method has been repeated at half hourly intervals. A carbon-dioxide gradient method has also been used to check the oxygen and to obtain a photosynthetic quotient. Black and light Bell jar experiments have been initiated to obtain checks on the other production measurement and to obtain a community respiration rate. An approximate balance has resulted from estimates of production , respiration , and downstream loss. A flow rate diagram has been constructed to clarify definitions of efficiency and their relationship to a steady state system. Mr. Sloan has statistically verified the increase of insect number and variety away from the boils and demonstrated the reliability of quantitative dipping for aquatic insects. Plans for the third half year include detained and comparative study of the dominant algae and further estimates of rates of growth of all community components. (29pp.
Finding the future:evolving interaction design
The main aim of this project is to design and prototype a simplified example of a mobile operating system that makes use of both edge swipe control and 'smart' graphical instructions. The research will consider how these methods can be used to design a truly inclusive and accessible interface. The effectiveness of these features will be validated through user experiments and focus groups over the course of the project, with the findings of user testing used to inform design practice
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