The development of test beds to support the definition and evolution of the Space Station Freedom power system

Since the beginning of the Space Station Freedom Program (SSFP), the Lewis Research Center (LeRC) and the Rocketdyne Division of Rockwell International have had extensive efforts underway to develop test beds to support the definition of the detailed electrical power system design. Because of the extensive redirections that have taken place in the Space Station Freedom Program in the past several years, the test bed effort was forced to accommodate a large number of changes. A short history of these program changes and their impact on the LeRC test beds is presented to understand how the current test bed configuration has evolved. The current test objectives and the development approach for the current DC Test Bed are discussed. A description of the test bed configuration, along with its power and controller hardware and its software components, is presented. Next, the uses of the test bed during the mature design and verification phase of SSFP are examined. Finally, the uses of the test bed in operation and evolution of the SSF are addressed

Spectral Evidence for Widespread Galaxy Outflows at z>4

We present discovery spectra of a sample of eight lensed galaxies at high redshift, 3.7<z<5.2, selected by their red colors in the fields of four massive clusters: A1689, A2219, A2390, and AC114. Metal absorption lines are detected and observed to be blueshifted by 300-800 km/s with respect to the centroid of Ly-alpha emission. A correlation is found between this blueshift and the equivalent width of the metal lines, which we interpret as a broadening of saturated absorption lines caused by a dispersion in the outflow velocity of interstellar gas. Local starburst galaxies show similar behavior, associated with obvious gas outflows. We also find a trend of increasing equivalent width of Ly-alpha emission with redshift, which may be a genuine evolutionary effect towards younger stellar populations at high redshift with less developed stellar continua. No obvious emission is detected below the Lyman limit in any of our spectra, nor in deep U or B-band images. The UV continua are reproduced well by early B-stars, although some dust absorption would allow a fit to hotter stars. After correcting for the lensing, we derive small physical sizes for our objects, ~0.5-5 kpc/h for a flat cosmology with Omega_m=0.3, Omega_Lambda=0.7. The lensed images are only marginally resolved in good seeing despite their close proximity to the critical curve, where large arcs are visible and hence high magnifications of up to ~20x are inferred. Two objects show a clear spatial extension of the Ly-alpha emission relative to the continuum starlight, indicating a ``breakout'' of the gas. The sizes of our galaxies together with their large gas motion suggests that outflows of gas are common at high redshift and associated with galaxy formation.Comment: 48 pages, 16 figures, ApJ, in press. Manuscript with full resolution color images available at (http://astro.princeton.edu/~bfrye

BIMA and Keck Imaging of the Radio Ring PKS 1830-211

We discuss BIMA (Berkeley Illinois Maryland Association) data and present new high quality optical and near-IR Keck images of the bright radio ring PKS 1830-211. Applying a powerful new deconvolution algorithm we have been able to identify both images of the radio source. In addition we recover an extended source in the optical, consistent with the expected location of the lensing galaxy. The source counterparts are very red, I-K=7, suggesting strong Galactic absorption with additional absorption by the lensing galaxy at z=0.885, and consistent with the detection of high redshift molecules in the lens.Comment: To be published in the ASP Conference Proceedings, 'Highly Redshifted Radio Lines', Greenbank, W

LensPerfect: Gravitational Lens Massmap Reconstructions Yielding Exact Reproduction of All Multiple Images

We present a new approach to gravitational lens massmap reconstruction. Our massmap solutions perfectly reproduce the positions, fluxes, and shears of all multiple images. And each massmap accurately recovers the underlying mass distribution to a resolution limited by the number of multiple images detected. We demonstrate our technique given a mock galaxy cluster similar to Abell 1689 which gravitationally lenses 19 mock background galaxies to produce 93 multiple images. We also explore cases in which far fewer multiple images are observed, such as four multiple images of a single galaxy. Massmap solutions are never unique, and our method makes it possible to explore an extremely flexible range of physical (and unphysical) solutions, all of which perfectly reproduce the data given. Each reconfiguration of the source galaxies produces a new massmap solution. An optimization routine is provided to find those source positions (and redshifts, within uncertainties) which produce the "most physical" massmap solution, according to a new figure of merit developed here. Our method imposes no assumptions about the slope of the radial profile nor mass following light. But unlike "non-parametric" grid-based methods, the number of free parameters we solve for is only as many as the number of observable constraints (or slightly greater if fluxes are constrained). For each set of source positions and redshifts, massmap solutions are obtained "instantly" via direct matrix inversion by smoothly interpolating the deflection field using a recently developed mathematical technique. Our LensPerfect software is straightforward and easy to use and is made publicly available via our website.Comment: 17 pages, 18 figures, accepted by ApJ. Software and full-color version of paper available at http://www.its.caltech.edu/~coe/LensPerfect

Size dependence of the photoinduced magnetism and long-range ordering in Prussian blue analog nanoparticles of rubidium cobalt hexacyanoferrate

Nanoparticles of rubidium cobalt hexacyanoferrate (Rb$_j$Co$_k$[Fe(CN)$_6$]$_l \cdot n$H$_2$O) were synthesized using different concentrations of the polyvinylpyrrolidone (PVP) to produce four different batches of particles with characteristic diameters ranging from 3 to 13 nm. Upon illumination with white light at 5 K, the magnetization of these particles increases. The long-range ferrimagnetic ordering temperatures and the coercive fields evolve with nanoparticle size. At 2 K, particles with diameters less than approximately 10 nm provide a Curie-like magnetic signal.Comment: 10 pages, 6 figures in text, expanded text and dat

The Nature of Blue Cores in Spheroids: a Possible Connection with AGN and Star Formation

We investigate the physical nature of blue cores in early-type galaxies through the first multi-wavelength analysis of a serendipitously discovered field blue-nucleated spheroid in the background of the deep ACS/WFC griz multicolor observations of the cluster Abell 1689. The resolved g-r, r-i and i-z color maps reveal a prominent blue core identifying this galaxy as a ``typical'' case study, exhibiting variations of 0.5-1.0 mag in color between the center and the outer regions, opposite to the expectations of reddened metallicity induced gradients in passively evolved ellipticals. From a Magellan-Clay spectrum we secure the galaxy redshift at $z=0.624$. We find a strong X-ray source coincident with the spheroid galaxy. Spectral features and a high X-ray luminosity indicate the presence of an AGN in the galaxy. However, a comparison of the X-ray luminosity to a sample derived from the Chandra Deep Field South displays Lx to be comparable to Type I/QSO galaxies while the optical flux is consistent with a normal star-forming galaxy. We conclude that the galaxy's non-thermal component dominates at high-energy wavelengths while we associate the spheroid blue light with the stellar spectrum of normal star-forming galaxies. We argue about a probable association between the presence of blue cores in spheroids and AGN activity.Comment: Accepted for publication in the Astrophysical Journal. 6 pages, 3 figures. Full resolution images available at http://acs.pha.jhu.edu/~felipe/e-print

Pharmacometabolomics reveals racial differences in response to atenolol treatment.

Antihypertensive drugs are among the most commonly prescribed drugs for chronic disease worldwide. The response to antihypertensive drugs varies substantially between individuals and important factors such as race that contribute to this heterogeneity are poorly understood. In this study we use metabolomics, a global biochemical approach to investigate biochemical changes induced by the beta-adrenergic receptor blocker atenolol in Caucasians and African Americans. Plasma from individuals treated with atenolol was collected at baseline (untreated) and after a 9 week treatment period and analyzed using a GC-TOF metabolomics platform. The metabolomic signature of atenolol exposure included saturated (palmitic), monounsaturated (oleic, palmitoleic) and polyunsaturated (arachidonic, linoleic) free fatty acids, which decreased in Caucasians after treatment but were not different in African Americans (p&lt;0.0005, q&lt;0.03). Similarly, the ketone body 3-hydroxybutyrate was significantly decreased in Caucasians by 33% (p&lt;0.0001, q&lt;0.0001) but was unchanged in African Americans. The contribution of genetic variation in genes that encode lipases to the racial differences in atenolol-induced changes in fatty acids was examined. SNP rs9652472 in LIPC was found to be associated with the change in oleic acid in Caucasians (p&lt;0.0005) but not African Americans, whereas the PLA2G4C SNP rs7250148 associated with oleic acid change in African Americans (p&lt;0.0001) but not Caucasians. Together, these data indicate that atenolol-induced changes in the metabolome are dependent on race and genotype. This study represents a first step of a pharmacometabolomic approach to phenotype patients with hypertension and gain mechanistic insights into racial variability in changes that occur with atenolol treatment, which may influence response to the drug

Validation and application of a liquid chromatography–tandem mass spectrometric method for quantification of the drug transport probe fexofenadine in human plasma using 96-well filter plates

A rapid method to determine fexofenadine concentrations in human plasma using protein precipitation in 96-well plates and liquid chromatography-tandem mass spectrometry was validated. Plasma proteins were precipitated with acetonitrile containing the internal standard fexofenadine-d6, mixed briefly, and then filtered into a collection plate. The resulting filtrate was diluted and injected onto a Phenomenex Gemini C18 (50 × 2.0 mm, 5 micron) analytical column. The mobile phase consisted of 0.1% formic acid, 5 mM ammonium acetate in deionized water and methanol (35:65, v/v). The flow rate was 0.2 ml/min and the total run time was 2 min. Detection of the analytes was achieved using positive ion electrospray ionization and high resolution multiple reaction monitoring mode (H-SRM). The linear standard curve ranged from 1 to 500 ng/ml and the precision and accuracy (intra- and inter-run) were within 4.3% and 8.0%, respectively. The method has been applied successfully to determine fexofenadine concentrations in human plasma samples obtained from subjects administered a single oral dose of fexofenadine. The method is rapid, sensitive, selective and directly applicable to human pharmacokinetic studies involving fexofenadine

Rheumatoid arthritis is an independent risk factor for multi-vessel coronary artery disease: a case control study

The risk for cardiovascular (CV) disease is increased in rheumatoid arthritis (RA) but data on the burden of coronary atherosclerosis in patients with RA are lacking. We conducted a retrospective case-control study of Olmsted County (MN, USA) residents with RA and new-onset coronary artery disease (CAD) (n = 75) in comparison with age-and sex-matched controls with newly diagnosed CAD (n = 128). Angiographic scores of the first coronary angiogram and data on CV risk factors and CV events on follow-up were obtained by chart abstraction. Patients with RA were more likely to have multi-vessel coronary involvement at first coronary angiogram compared with controls (P = 0.002). Risk factors for CAD including diabetes, hypertension, hyperlipidemia, and smoking history were not significantly different in the two cohorts. RA remained a significant risk factor for multi-vessel disease after adjustment for age, sex and history of hyperlipidemia. The overall rate of CV events was similar in RA patients and controls; however, there was a trend for increased CV death in patients with RA. In a nested cohort of patients with RA and CAD (n = 27), we measured levels of pro-inflammatory CD4(+)CD28(null )T cells by flow cytometry. These T cells have been previously implicated in the pathogenesis of CAD and RA. Indeed, CD4(+)CD28(null )T cells were significantly higher in patients with CAD and co-existent RA than in controls with stable angina (P = 0.001) and reached levels found in patients with acute coronary syndromes. Patients with RA are at increased risk for multi-vessel CAD, although the risk of CV events was not increased in our study population. Expansion of CD4(+)CD28(null )T cells in these patients may contribute to the progression of atherosclerosis

Isolation of a SIR-like gene, SIR-T8, that is overexpressed in thyroid carcinoma cell lines and tissues

We used subtractive library screening to identify the changes that occur in gene expression during thyroid cell neoplastic transformation. Complementary DNA from normal thyroid cells (HTC 2) was subtracted from a complementary DNA library constructed from a human thyroid papillary carcinoma cell line. The library was screened for genes upregulated in human thyroid papillary carcinoma cell line cells, and several cDNA clones were isolated. One of these clones has a sirtuin core and high homology with the human silent information regulator protein family. This clone, designated ‘SIR-T8’, was overexpressed in human thyroid carcinoma cell lines and tissues, but not in adenomas. The human SIR-T8 protein has a molecular weight of 39 kDa and is primarily located in the cytoplasm under the nuclear membrane. The SIR-T8 gene is located on chromosome 17q25-1