91 research outputs found
Breakthrough Capability for UVOIR Space Astronomy: Reaching the Darkest Sky
We describe how availability of new solar electric propulsion (SEP) technology can substantially increase the science capability of space astronomy missions working within the near-UV to far-infrared (UVOIR) spectrum by making dark sky orbits accessible for the first time. We present two case studies in which SEP is used to enable a 700 kg Explorer-class and 7000 kg flagship-class observatory payload to reach an orbit beyond where the zodiacal dust limits observatory sensitivity. The resulting scientific performance advantage relative to a Sun-Earth L2 point (SEL2) orbit is presented and discussed. We find that making SEP available to astrophysics Explorers can enable this small payload program to rival the science performance of much larger long development-time systems. Similarly, we find that astrophysics utilization of high power SEP being developed for the Asteroid Redirect Robotics Mission (ARRM) can have a substantial impact on the sensitivity performance of heavier flagship-class astrophysics payloads such as the UVOIR successor to the James Webb Space Telescope
CANDELS Multi-wavelength Catalogs: Source Detection and Photometry in the GOODS-South Field
We present a UV-to-mid infrared multi-wavelength catalog in the
CANDELS/GOODS-S field, combining the newly obtained CANDELS HST/WFC3 F105W,
F125W, and F160W data with existing public data. The catalog is based on source
detection in the WFC3 F160W band. The F160W mosaic includes the data from
CANDELS deep and wide observations as well as previous ERS and HUDF09 programs.
The mosaic reaches a 5 limiting depth (within an aperture of radius
0.17 arcsec) of 27.4, 28.2, and 29.7 AB for CANDELS wide, deep, and HUDF
regions, respectively. The catalog contains 34930 sources with the
representative 50% completeness reaching 25.9, 26.6, and 28.1 AB in the F160W
band for the three regions. In addition to WFC3 bands, the catalog also
includes data from UV (U-band from both CTIO/MOSAIC and VLT/VIMOS), optical
(HST/ACS F435W, F606W, F775W, F814W, and F850LP), and infrared (HST/WFC3 F098M,
VLT/ISAAC Ks, VLT/HAWK-I Ks, and Spitzer/IRAC 3.6, 4.5, 5.8, 8.0 m)
observations. The catalog is validated via stellar colors, comparison with
other published catalogs, zeropoint offsets determined from the best-fit
templates of the spectral energy distribution of spectroscopically observed
objects, and the accuracy of photometric redshifts. The catalog is able to
detect unreddened star-forming (passive) galaxies with stellar mass of
10^{10}M_\odot at a 50% completeness level to z3.4 (2.8), 4.6 (3.2), and
7.0 (4.2) in the three regions. As an example of application, the catalog is
used to select both star-forming and passive galaxies at z2--4 via the
Balmer break. It is also used to study the color--magnitude diagram of galaxies
at 0<z<4.Comment: The full resolution article is now published in ApJS (2013, 207, 24).
22 pages, 21 figures, and 5 tables. The catalogue is available on the CANDELS
website: http://candels.ucolick.org/data_access/GOODS-S.html MAST:
http://archive.stsci.edu/prepds/candels and Rainbow Database:
https://arcoiris.ucolick.org/Rainbow_navigator_public and
https://rainbowx.fis.ucm.es/Rainbow_navigator_publi
ACC/AHA guidelines for percutaneous coronary intervention (revision of the 1993 PTCA guidelines)—executive summary21When citing this document, the American College of Cardiology and the American Heart Association would appreciate the following citation format: Smith SC, Jr, Dove JT, Jacobs AK, Kennedy JW, Kereiakes D, Kern MJ, Kuntz RE, Popma JJ, Schaff HV, Williams DO. ACC/AHA guidelines for percutaneous coronary intervention: executive summary and recommendations: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the 1993 Guidelines for Percutaneous Transluminal Coronary Angioplasty). J Am Coll Cardiol 2001;37:2215–38.22Address for reprints: a single reprint of this document is available by calling 800-253-4636 (US only) or writing the American College of Cardiology, Educational Services, 9111 Old Georgetown Road, Bethesda, MD 20814-1699. This document (reprint no. 71-0205), as well as the companion full-text guideline (reprint no. 71-0206), are available on the ACC Web site at www.acc.organd the AHA Web site at http://www.americanheart.org. To purchase additional reprints (specify version): up to 999 copies, call 800-611-6083 (US only) or fax 413-665-2671; 1000 or more copies, call 214-706-1466, fax 214-691-6342; or E-mail: [email protected]. A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee to revise the 1993 guidelines for percutaneous transluminal coronary angioplasty) endorsed by the Society for Cardiac Angiography and Interventions
Digital aspirations:'Wrong number' mobile-phone relationships and experimental ethics among women entrepreneurs in rural Bangladesh
ACCESS: Design and Sub-System Performance
Establishing improved spectrophotometric standards is important for a broad range of missions and is relevant to many astrophysical problems. ACCESS, "Absolute Color Calibration Experiment for Standard Stars", is a series of rocket-borne sub-orbital missions and ground-based experiments designed to enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 -1.7 micrometer bandpass
Effect of hypoxia and Beraprost sodium on human pulmonary arterial smooth muscle cell proliferation: the role of p27kip1
<p>Abstract</p> <p>Background</p> <p>Hypoxia induces the proliferation of pulmonary arterial smooth muscle cell (PASMC) <it>in vivo </it>and <it>in vitro</it>, and prostacyclin analogues are thought to inhibit the growth of PASMC. Previous studies suggest that p27<sup>kip1</sup>, a kind of cyclin-dependent kinase inhibitor, play an important role in the smooth muscle cell proliferation. However, the mechanism of hypoxia and the subcellular interactions between p27<sup>kip1 </sup>and prostacyclin analogues in human pulmonary arterial smooth muscle cell (HPASMC) are not fully understood.</p> <p>Methods</p> <p>We investigated the role of p27<sup>kip1 </sup>in the ability of Beraprost sodium (BPS; a stable prostacyclin analogue) to inhibit the proliferation of HPASMC during hypoxia. To clarify the biological effects of hypoxic air exposure and BPS on HPASMC, the cells were cultured in a hypoxic chamber under various oxygen concentrations (0.1–21%). Thereafter, DNA synthesis was measured as bromodeoxyuridine (BrdU) incorporation, the cell cycle was analyzed by flow cytometry with propidium iodide staining. The p27<sup>kip1 </sup>mRNA and protein expression and it's stability was measured by real-time RT-PCR and Western blotting. Further, we assessed the role of p27<sup>kip1 </sup>in HPASMC proliferation using p27<sup>kip1 </sup>gene knockdown using small interfering RNA (siRNA) transfection.</p> <p>Results</p> <p>Although severe hypoxia (0.1% oxygen) suppressed the proliferation of serum-stimulated HPASMC, moderate hypoxia (2% oxygen) enhanced proliferation in accordance with enhanced p27<sup>kip1 </sup>protein degradation, whereas BPS suppressed HPASMC proliferation under both hypoxic and normoxic conditions by suppressing p27<sup>kip1 </sup>degradation with intracellular cAMP-elevation. The 8-bromo-cyclic adenosine monophosphate (8-Br-cAMP), a cAMP analogue, had similar action as BPS in the regulation of p27<sup>kip1</sup>. Moderate hypoxia did not affect the stability of p27<sup>kip1 </sup>protein expression, but PDGF, known as major hypoxia-induced growth factors, significantly decreased p27<sup>kip1 </sup>protein stability. We also demonstrated that BPS and 8-Br-cAMP suppressed HPASMC proliferation under both hypoxic and normoxic conditions by blocking p27<sup>kip1 </sup>mRNA degradation. Furthermore, p27<sup>kip1 </sup>gene silencing partially attenuated the effects of BPS and partially restored hypoxia-induced proliferation.</p> <p>Conclusion</p> <p>Our study suggests that moderate hypoxia induces HPASMC proliferation, which is partially dependent of p27<sup>kip1 </sup>down-regulation probably <it>via </it>the induction of growth factors such as PDGF, and BPS inhibits both the cell proliferation and p27<sup>kip1 </sup>mRNA degradation through cAMP pathway.</p
ACC/AHA guidelines for percutaneous coronary intervention (revision of the 1993 PTCA guidelines) - Executive summary: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the 1993 Guidelines for Percutaneous Transluminal Coronary angioplasty) Endorsed by the society for Cardiac Angiography and Interventions
The American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines was formed to gather information and make recommendations about appropriate use of technology for the diagnosis and treatment of patients with cardiovascular disease. Percutaneous coronary interventions (PCI) are an important group of technologies in this regard. Although initially limited to PTCA, and termed percutaneous transluminal coronary angioplasty (PTCA), PCI now includes other new techniques capable of relieving coronary narrowing. Accordingly, in this document, rotational atherectomy, directional atherectomy, extraction atherectomy, laser angioplasty, implantation of intracoronary stents and other catheter devices for treating coronary atherosclerosis are considered components of PCI. In this context PTCA will be used to refer to those studies using primarily PTCA while PCI will refer to the broader group of percutaneous techniques. These new technologies have impacted the effectiveness and safety profile initially established for PTCA. Moreover, important advances have occurred in the use of adjunctive medical therapies such as glycoprotein (GP) IIb/IIIa receptor blockers. In addition, since publication of the previous Guidelines in 1993, greater experience in the performance of PCI in patients with acute coronary syndromes and in community hospital settings has been gained. In view of these developments, further review and revision of the guidelines is warranted. This document reflects the opinion of the third ACC/AHA committee charged with revising the guidelines for PTCA to include the broader group of technologies now termed PCI
ACC/AHA guidelines for percutaneous coronary intervention (revision of the 1993 PTCA guidelines) - Executive summary
The American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines was formed to gather information and make recommendations about appropriate use of technology for the diagnosis and treatment of patients with cardiovascular disease. Percutaneous coronary interventions (PCI) are an important group of technologies in this regard. Although initially limited to PTCA, and termed percutaneous transluminal coronary angioplasty (PTCA), PCI now includes other new techniques capable of relieving coronary narrowing. Accordingly, in this document, rotational atherectomy, directional atherectomy, extraction atherectomy, laser angioplasty, implantation of intracoronary stents and other catheter devices for treating coronary atherosclerosis are considered components of PCI. In this context PTCA will be used to refer to those studies using primarily PTCA while PCI will refer to the broader group of percutaneous techniques. These new technologies have impacted the effectiveness and safety profile initially established for PTCA. Moreover, important advances have occurred in the use of adjunctive medical therapies such as glycoprotein (GP) IIb/IIIa receptor blockers. In addition, since publication of the previous Guidelines in 1993, greater experience in the performance of PCI in patients with acute coronary syndromes and in community hospital settings has been gained. In view of these developments, further review and revision of the guidelines is warranted. This document reflects the opinion of the third ACC/AHA committee charged with revising the guidelines for PTCA to include the broader group of technologies now termed PCI
Syndromics: A Bioinformatics Approach for Neurotrauma Research
Substantial scientific progress has been made in the past 50 years in delineating many of the biological mechanisms involved in the primary and secondary injuries following trauma to the spinal cord and brain. These advances have highlighted numerous potential therapeutic approaches that may help restore function after injury. Despite these advances, bench-to-bedside translation has remained elusive. Translational testing of novel therapies requires standardized measures of function for comparison across different laboratories, paradigms, and species. Although numerous functional assessments have been developed in animal models, it remains unclear how to best integrate this information to describe the complete translational “syndrome” produced by neurotrauma. The present paper describes a multivariate statistical framework for integrating diverse neurotrauma data and reviews the few papers to date that have taken an information-intensive approach for basic neurotrauma research. We argue that these papers can be described as the seminal works of a new field that we call “syndromics”, which aim to apply informatics tools to disease models to characterize the full set of mechanistic inter-relationships from multi-scale data. In the future, centralized databases of raw neurotrauma data will enable better syndromic approaches and aid future translational research, leading to more efficient testing regimens and more clinically relevant findings
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