Far infrared interferometers in space would enable extraordinary measurements of the early universe, the formation of galaxies, stars, and planets, and would have great discovery potential. Half the ...luminosity of the universe and 98% of the photons released since the Big Bang appear at far-IR and submillimeter wavelengths (40 to 500 /spl mu/m). Because the Earth's atmosphere prevents sensitive observations from the ground at wavelengths shorter than about 300 /spl mu/m, and large effective apertures are required to achieve sub-arcsecond angular resolution, this is one of the last unexplored frontiers of observational astronomy. We present the engineering and technology requirements that stem from a set of compelling scientific goals and discuss possible configurations for two proposed NASA missions, the Space Infrared Interferometric Telescope (SPIRIT) and the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS).
OBJECTIVE: Emergency Medicine (EM) residents perform a number of off-service rotations throughout their training. The utility of these rotations in enhancing their knowledge and performance in these ...areas has not been studied. We have previously shown that the majority of off-service rotations do not improve inservice scores. We will evaluate whether an orthopedic off-service rotation (ORTH) will improve resident skills in orthopedics. METHODS: Published criteria for skills and knowledge that should be obtained during an ORTH were reviewed. Based upon these criteria, we developed a novel tool to evaluate practical skills learned during the ORTH. This included splint application (SA), performance of a specialized orthopedic examination (EX) and radiographic interpretation and general knowledge (XR). A committee of EM trained physicians devised scoring criteria. A 100-point scale was devised among the 3 areas: SA 27%, EX 25%, XR 48%. The same EM physicians tested all subjects. Residents who had completed an ORTH were compared to those who had not completed an ORTH. Comparisons were made only between residents of the same post-graduate year. Data was analyzed by Student's t-Tests. Alpha was set at 0.05. RESULTS: 8 subjects were tested, 4 prior to their ORTH, and 4 after completing their ORTH. Results were as follows: With ORTH Without ORTH P-value SA 61.3% +/- 29.3% 68.5% +/- 21.1% 0.70 EX 64.5% +/- 14.3% 65.0% +/- 15.1% 0.96 XR 67.5% +/- 16.0% 61.8% +/- 13.7% 0.61 Total 65.3% +/- 16.7% 64.3% +/- 6.7% 0.92 CONCLUSION: The ORTH did not appear to affect the subject's ability to perform on the examination. This data correlates with results obtained from previous studies of performance on inservice examinations. Reevaluation of off-service rotations for EM residents is essential. Validation of these results in multiple centers is necessary. Development of tools to evaluate residents in other off-service rotation is warranted.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Heavy charged-particle radiation has unique physical characteristics that offer several advantages over photons and protons for stereotactic radiosurgery of intracranial AVMs. These include improved ...dose distributions with depth in tissue, small angle of lateral scattering, and sharp distal fall-off of dose in the Bragg ionization peak. Under multi-institutionally approved clinical trials, we have used stereotactic helium-ion Bragg peak radiosurgery to treat approximately 400 patients with symptomatic, surgically inaccessible vascular malformations at the UCB-LBL 184-in synchrocyclotron and bevatron. Treatment planning for stereotactic heavy charged-particle radiosurgery for intracranial vascular disorders integrates anatomic and physical information from the stereotactic cerebral angiogram and stereotactic CT and MR imaging scans for each patient, using computerized treatment-planning calculations for optimal isodose contour distribution. The shape of an intracranial AVM is associated strongly with its treatability and potential clinical outcome. In this respect, heavy charged-particle radiosurgery has distinct advantages over other radiosurgical methods; the unique physical properties allow the shaping of individual beams to encompass the contours of large and complexly shaped AVMs, while sparing important adjacent neural structures. We have had a long-term dose-searching clinical protocol in collaboration with SUMC and UCSF and have followed up over 300 patients for more than 2 years. Initially, treatment doses ranged from 45 GyE to 35 GyE. Currently, total doses up to 25 GyE are delivered to treatment volumes ranging from 0.1 cm3 to 70 cm3. This represents a relatively homogeneous dose distribution, with the 90% isodose surface contoured to the periphery of the lesion; there is considerable protection of normal adjacent brain tissues, and most of the brain receives no radiation exposure. Dose selection depends on the volume, shape, and location of the AVM and several other factors, including the volume of normal brain that must be traversed by the plateau portion of the charged-particle beam. The first 230 patients have been evaluated clinically to the end of 1989. Using the clinical grading of Drake, about 90% of the patients had an excellent or good neurologic grade, about 5% had a poor grade, and about 5% had progression of disease and died, or died as a result of unrelated intercurrent illness. Neuroradiologic follow-up to the end of 1989 indicated the following rates of complete angiographic obliteration 3 years after treatment: 90% to 95% for AVM treatment volumes less than 4 cm3, 90% to 95% for volumes 4 to 14 cm3, and 60% to 70% for volumes greater than 14 cm3.
Plasma prorenin is an inactive form of renin (EC 3.4.99.19) that can be converted to active renin in acid-treated plasma by an endogenous serine protease that is active at alkaline pH (alkaline phase ...activation). To identify this enzyme we first tested the ability of Hageman factor fragments, plasma kallikrein (EC 3.4.21.8), and plasmin (EC 3.4.21.7) to activate prorenin in acid-treated plasma. All three enzymes initiated prorenin activation; 50% activation was achieved with Hageman factor fragments at 1 $\mu $g/ml, plasma kallikrein at 2-4 $\mu $g/ml, or plasmin at 5-10 $\mu $g/ml. We then showed that the alkaline phase of acid activation occurred normally in plasminogen-free plasma but was almost completely absent in plasmas deficient in either Hageman factor or prekallikrein; alkaline phase activation was restored to these latter plasmas when equal parts were mixed together. Therefore, both Hageman factor and prekallikrein were required for alkaline phase activation to occur. We then found that, although plasma kallikrein could activate prorenin in plasma deficient in either Hageman factor or prekallikrein, Hageman factor fragments were unable to activate prorenin in prekallikrein-deficient plasma. These studies demonstrate that alkaline phase prorenin activation is initiated by Hageman factor-dependent conversion of prekallikrein to kallikrein which, in turn, leads to activation of prorenin. In this fashion, we have revealed a possible link between the coagulation-kinin pathway and the renin-angiotension system.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
The Disk Detective citizen science project aims to find new stars with 22 micron excess emission from circumstellar dust using data from NASA's WISE mission. Initial cuts on the AllWISE catalog ...provide an input catalog of 277,686 sources. Volunteers then view images of each source online in 10 different bands to identify false-positives (galaxies, background stars, interstellar matter, image artifacts, etc.). Sources that survive this online vetting are followed up with spectroscopy on the FLWO Tillinghast telescope. This approach should allow us to unleash the full potential of WISE for finding new debris disks and protoplanetary disks. We announce a first list of 37 new disk candidates discovered by the project, and we describe our vetting and follow-up process. One of these systems appears to contain the first debris disk discovered around a star with a white dwarf companion: HD 74389. We also report four newly discovered classical Be stars (HD 6612, HD 7406, HD 164137, and HD 218546) and a new detection of 22 micron excess around a previously known debris disk host star, HD 22128.
Data from the Diffuse Infrared Background Experiment (DIRBE) instrument aboard the Cosmic Background Explorer Satellite (COBE) spacecraft have been used to examine the near and far infrared ...signatures of the interplanetary dust (IPD) bands. Images of the dust band pairs at ecliptic latitudes of +/- 1.4 deg and +/- 10 deg have been produced at DIRBE wavelengths from 1.25 to 100 micrometers. The observations at the shorter wavelengths provide the first evidence of scattered sunlight from particles responsible for the dust bands. It is found that the grains in the bands and those in the smooth IPD cloud have similar spectral energy distributions, suggesting similar compositions and possibly a common origin. The scattering albedos from 1.25 to 3.5 micrometers for the grains in the dust bands and those in the IPD cloud are 0.22 and 0.29, respectively. The 10 deg band pair is cooler (185 +/- 10 K) than the smooth interplanetary dust cloud (259 +/- 10 K). From both parallactic and thermal analyses, the implied location of the grains responsible for the peak brightness of the 10 deg band pair is 2.1 +/- 0.1 AU the Sun A parallactic distance of 1.4 +/- 0.2 AU is found for the peak of the 1.4 deg band pair.
We present the largest sample of flares ever compiled for a single M dwarf, the active M4 star GJ 1243. Over 6100 individual flare events, with energies ranging from \(10^{29}\) to \(10^{33}\) erg, ...are found in 11 months of 1-minute cadence data from Kepler. This sample is unique for its completeness and dynamic range. We have developed automated tools for finding flares in short-cadence Kepler light curves, and performed extensive validation and classification of the sample by eye. From this pristine sample of flares we generate a median flare template. This template shows that two exponential cooling phases are present during the white-light flare decay, providing fundamental constraints for models of flare physics. The template is also used as a basis function to decompose complex multi-peaked flares, allowing us to study the energy distribution of these events. Only a small number of flare events are not well fit by our template. We find that complex, multi-peaked flares occur in over 80% of flares with a duration of 50 minutes or greater. The underlying distribution of flare durations for events 10 minutes and longer appears to follow a broken power law. Our results support the idea that sympathetic flaring may be responsible for some complex flare events.
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