Geologic map of the Hecate Chasma quadrangle (V-28), Venus
Stofan, Ellen R.; Guest, John E.; Brian, Antony W.
2012-01-01
The overall topography of V–28 consists of plains located slightly below mean planetary radius (MPR, 6051.84). The lowest regions are found in the rift trough (3.3 m below MPR), and the highest along the rift rim (4.3 km above MPR). The regions that are the roughest at Magellan radar wavelengths in the quadrangle occur along Hecate Chasma (root mean square [rms] slopes >10°), with most regions being relatively smooth (roughnesses comparable to the average Venus surface value of 2.84°). Emissivity values in the quadrangle are typical of most venusian plains regions, with a range in values for the quadrangle of 0.68–0.91. The highest emissivity values in the quadrangle lie at the highest elevations in the quadrangle (corona rims and interiors).
Geologic Map of the Aino Planitia (V46) Quadrangle, Venus 1:5,000,000
Stofan, Ellen R.; Guest, John E.
2003-01-01
The Aino Planitia quadrangle (V-46) extends from 25?-50? S. latitude, 60?-90? E. longitude. The quadrangle was mapped at 1:5,000,000 scale as part of the NASA Planetary Geologic Mapping Program. Aino Planitia is a lowland region in the southern hemisphere of Venus and is southwest of Thetis Regio in western Aphrodite Terra. It is dominated by low-lying plains units that are characterized by northeast-trending wrinkle ridges and numerous small volcanic edifices, including shields, domes, and cones. The quadrangle contains a major volcano, Kunapipi Mons, and portions of Juno Chasma. A northern extension of the Lada Terra highland is in the southwestern portion of the map. Eight coronae are mapped in the quadrangle, the largest of which is the 500-km-diameter Copia Corona. The region is dominated by plains that are interpreted to be of volcanic origin. Most of the plains units are composites of flow units of differing ages. The overall topography of V-46 consists of low-lying plains slightly below Mean Planetary Radius (MPR, 6051.84 km). The summit of Kunapipi Mons is the highest point in the quadrangle, at about 2.2 km above MPR; the lowest points in rifts and troughs are at about 1.7 km below MPR. The regions that are the roughest at Magellan radar wavelengths in the quadrangle occur along the rim of Copia Corona, with most regions being relatively smooth (roughness comparable to the average Venus surface. Emissivity values in the quadrangle vary from 0.82-0.90.
NASA Technical Reports Server (NTRS)
Head, James W.; Wilson, Lionel
1992-01-01
The production of magma reservoirs and neutral buoyancy zones (NBZs) on Venus and the implications of their development for the formation and evolution of volcanic landforms are examined. The high atmospheric pressure on Venus reduces volatile exsolution and generally serves to inhibit the formation of NBZs and shallow magma reservoirs. For a range of common terrestrial magma-volatile contents, magma ascending and erupting near or below mean planetary radius (MPR) should not stall at shallow magma reservoirs; such eruptions are characterized by relatively high total volumes and effusion rates. For the same range of volatile contents at 2 km above MPR, about half of the cases result in the direct ascent of magma to the surface and half in the production of neutral buoyancy zones. NBZs and shallow magma reservoirs begin to appear as gas content increases and are nominally shallower on Venus than on earth. For a fixed volatile content, NBZs become deeper with increasing elevation: over the range of elevations treated in this study (-1 km to +4.4 km) depths differ by a factor of 2-4. Factors that may account for the low height of volcanoes on Venus are discussed.
Geologic map of the Snegurochka Planitia quadrangle (V-1), Venus
Hurwitz, Debra M.; Head, James W.
2012-01-01
The Snegurochka Planitia region is a predominantly low-lying terrain that covers the north polar region of Venus, extending from lat 75° N. to 90° N. and from long 0° E. to 360° E. The plains associated with Snegurochka Planitia abut the highlands of Metis Mons to the south from approximately long 240° E. to 300° E. (V–6) and the highlands of Ishtar Terra to the south from approximately long 300° E. to 60° E. (Lakshmi Planum, V–7; Fortuna Tessera, V–2). The plains of Louhi Planitia also lie within the V–1 region and form the northern border with the highlands of Tethus Regio from approximately long 60° E. to 120° E. (V–3 Meskhent Tessera) and with the lowlands of both Atalanta Planitia (V–4) and the nearby deformed region containing a series of ridged belts (V–5, Pandrosos Dorsa) from approximately long 120° E. to 240° E. The plains generally lie between +500 m and -500 m of the mean planetary radius (MPR) of 6051.8 km, with the highest terrain in the region, the northernmost extent of Ishtar Terra (Itzpapalotl Tessera, lat 75° N., long ~315° E.), rising more than 6.4 km above MPR.
NASA Astrophysics Data System (ADS)
Haqq-Misra, Jacob; Wolf, Eric. T.; Joshi, Manoj; Zhang, Xi; Kopparapu, Ravi Kumar
2018-01-01
We investigate the atmospheric dynamics of terrestrial planets in synchronous rotation within the habitable zone of low-mass stars using the Community Atmosphere Model. The surface temperature contrast between the day and night hemispheres decreases with an increase in incident stellar flux, which is opposite the trend seen in gas giants. We define three dynamical regimes in terms of the equatorial Rossby deformation radius and the Rhines length. The slow rotation regime has a mean zonal circulation that spans from the day to the night sides, which occurs for planets around stars with effective temperatures of 3300–4500 K (rotation period > 20 days), with both the Rossby deformation radius and the Rhines length exceeding the planetary radius. Rapid rotators have a mean zonal circulation that partially spans a hemisphere and with banded cloud formation beneath the substellar point, which occurs for planets orbiting stars with effective temperatures of less than 3000 K (rotation period < 5 days), with the Rossby deformation radius less than the planetary radius. In between is the Rhines rotation regime, which retains a thermally direct circulation from the day side to the night side but also features midlatitude turbulence-driven zonal jets. Rhines rotators occur for planets around stars in the range of 3000–3300 K (rotation period ∼5–20 days), where the Rhines length is greater than the planetary radius but the Rossby deformation radius is less than the planetary radius. The dynamical state can be observationally inferred from a comparison of the morphologies of the thermal emission phase curves of synchronously rotating planets.
Building Better Planet Populations for EXOSIMS
NASA Astrophysics Data System (ADS)
Garrett, Daniel; Savransky, Dmitry
2018-01-01
The Exoplanet Open-Source Imaging Mission Simulator (EXOSIMS) software package simulates ensembles of space-based direct imaging surveys to provide a variety of science and engineering yield distributions for proposed mission designs. These mission simulations rely heavily on assumed distributions of planetary population parameters including semi-major axis, planetary radius, eccentricity, albedo, and orbital orientation to provide heuristics for target selection and to simulate planetary systems for detection and characterization. The distributions are encoded in PlanetPopulation modules within EXOSIMS which are selected by the user in the input JSON script when a simulation is run. The earliest written PlanetPopulation modules available in EXOSIMS are based on planet population models where the planetary parameters are considered to be independent from one another. While independent parameters allow for quick computation of heuristics and sampling for simulated planetary systems, results from planet-finding surveys have shown that many parameters (e.g., semi-major axis/orbital period and planetary radius) are not independent. We present new PlanetPopulation modules for EXOSIMS which are built on models based on planet-finding survey results where semi-major axis and planetary radius are not independent and provide methods for sampling their joint distribution. These new modules enhance the ability of EXOSIMS to simulate realistic planetary systems and give more realistic science yield distributions.
NASA Astrophysics Data System (ADS)
Crida, Aurélien; Ligi, Roxanne; Dorn, Caroline; Lebreton, Yveline
2018-06-01
The characterization of exoplanets relies on that of their host star. However, stellar evolution models cannot always be used to derive the mass and radius of individual stars, because many stellar internal parameters are poorly constrained. Here, we use the probability density functions (PDFs) of directly measured parameters to derive the joint PDF of the stellar and planetary mass and radius. Because combining the density and radius of the star is our most reliable way of determining its mass, we find that the stellar (respectively planetary) mass and radius are strongly (respectively moderately) correlated. We then use a generalized Bayesian inference analysis to characterize the possible interiors of 55 Cnc e. We quantify how our ability to constrain the interior improves by accounting for correlation. The information content of the mass–radius correlation is also compared with refractory element abundance constraints. We provide posterior distributions for all interior parameters of interest. Given all available data, we find that the radius of the gaseous envelope is 0.08+/- 0.05{R}p. A stronger correlation between the planetary mass and radius (potentially provided by a better estimate of the transit depth) would significantly improve interior characterization and reduce drastically the uncertainty on the gas envelope properties.
Johnston, H P; Hawley, P; White, S E; Gibson, I; Tidd, D M
1985-04-01
6-Mercaptopurine (MP)-sensitive and -resistant cell culture lines were used to further characterize the apparent ability of MP nucleotide derivatives to overcome resistance to the parent drug. 6-Mercaptopurine-9-beta-D-ribofuranoside 5'-monophosphate [MPRP], bis(6-mercaptopurine-9-beta-D-ribofuranoside)-5', 5"'-monophosphate [bis(MPR)P], bis(O2',O3'-dibutyryl-6-mercaptopurine-9-beta-D-ribofuranoside)-5', 5"'-monophosphate [bis(dibut.MPR)P], and O2',O3'-dibutyryl-6-mercaptopurine-9-beta-D-ribofuranoside 5'-monophosphate [dibut.MPRP] were tested for cytotoxic and/or growth inhibitory effects against MP-resistant sublines of V79 Chinese hamster lung fibroblasts (CH/TG) and L1210 mouse leukaemia cells (L1210/MPR) in which deficiencies of hypoxanthine-guanine phosphoribosyltransferase, and hence drug nucleotide forming capacity were the basis of resistance. L1210/MPR cells were totally resistant to 1 mM 6-mercaptopurine-9-beta-D-ribofuranoside [MPR] and 2 mM MPRP, but were inhibited by high concentrations (greater than 0.25 mM) of bis(MPR)P. These results suggested that bis(MPR)P was taken up by cells as the intact molecule since MPR and MPRP were its extracellular breakdown products. L1210/MPR cells were much more sensitive to the lipophilic bis(dibut.MPR)P derivative which had a predominantly cytotoxic action as judged by trypan blue staining and the ability of treated cells to produce macroscopic colonies in soft agar medium. However, cells killed by bis(dibut.MPR)P did not disintegrate appreciably over periods of up to 10 days. The effects of bis(dibut.MPR)P were probably the result of cellular uptake of the intact molecule. Dibut.MPRP showed minimal ability to inhibit L1210/MPR cells although this compound was a possible breakdown product of bis(dibut.MPR)P and a source of the same extracellular degradation products. The median cell size decreased in L1210/MPR cultures during exposure to both bis(MPR)P and bis(dibut.MPR)P. This effect was elicited more rapidly and at lower concentration by bis(dibut.MPR)P than by bis(MPR)P. In contrast, sodium butyrate, a breakdown product of bis(dibut.MPR)P induced increases in cell size at high concentration. Bis (dibut.MPR)P was also cytotoxic to MP-resistant CH/TG cells and was approximately 300 times more effective than bis(MRP)P and MPR which exhibited similar activity against this cell line. Bis(dibut.MPR)P and dibut.MPRP were equivalent and less active than MPR in their effects on MP-sensitive L1210/0 cells where their predominant mechanism of action was via degradation to release MPR.(ABSTRACT TRUNCATED AT 400 WORDS)
Johnston, H. P.; Hawley, P.; White, S. E.; Gibson, I.; Tidd, D. M.
1985-01-01
6-Mercaptopurine (MP)-sensitive and -resistant cell culture lines were used to further characterize the apparent ability of MP nucleotide derivatives to overcome resistance to the parent drug. 6-Mercaptopurine-9-beta-D-ribofuranoside 5'-monophosphate [MPRP], bis(6-mercaptopurine-9-beta-D-ribofuranoside)-5', 5"'-monophosphate [bis(MPR)P], bis(O2',O3'-dibutyryl-6-mercaptopurine-9-beta-D-ribofuranoside)-5', 5"'-monophosphate [bis(dibut.MPR)P], and O2',O3'-dibutyryl-6-mercaptopurine-9-beta-D-ribofuranoside 5'-monophosphate [dibut.MPRP] were tested for cytotoxic and/or growth inhibitory effects against MP-resistant sublines of V79 Chinese hamster lung fibroblasts (CH/TG) and L1210 mouse leukaemia cells (L1210/MPR) in which deficiencies of hypoxanthine-guanine phosphoribosyltransferase, and hence drug nucleotide forming capacity were the basis of resistance. L1210/MPR cells were totally resistant to 1 mM 6-mercaptopurine-9-beta-D-ribofuranoside [MPR] and 2 mM MPRP, but were inhibited by high concentrations (greater than 0.25 mM) of bis(MPR)P. These results suggested that bis(MPR)P was taken up by cells as the intact molecule since MPR and MPRP were its extracellular breakdown products. L1210/MPR cells were much more sensitive to the lipophilic bis(dibut.MPR)P derivative which had a predominantly cytotoxic action as judged by trypan blue staining and the ability of treated cells to produce macroscopic colonies in soft agar medium. However, cells killed by bis(dibut.MPR)P did not disintegrate appreciably over periods of up to 10 days. The effects of bis(dibut.MPR)P were probably the result of cellular uptake of the intact molecule. Dibut.MPRP showed minimal ability to inhibit L1210/MPR cells although this compound was a possible breakdown product of bis(dibut.MPR)P and a source of the same extracellular degradation products. The median cell size decreased in L1210/MPR cultures during exposure to both bis(MPR)P and bis(dibut.MPR)P. This effect was elicited more rapidly and at lower concentration by bis(dibut.MPR)P than by bis(MPR)P. In contrast, sodium butyrate, a breakdown product of bis(dibut.MPR)P induced increases in cell size at high concentration. Bis (dibut.MPR)P was also cytotoxic to MP-resistant CH/TG cells and was approximately 300 times more effective than bis(MRP)P and MPR which exhibited similar activity against this cell line. Bis(dibut.MPR)P and dibut.MPRP were equivalent and less active than MPR in their effects on MP-sensitive L1210/0 cells where their predominant mechanism of action was via degradation to release MPR.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3838480
Chao, Yu Wen; Lin, Jiu Jenq; Yang, Jing Lan; Wang, Wendy Tzyy-Jiuan
2016-01-01
Randomized controlled trial. Myofascial pain syndrome is characterized by myofascial trigger points (MTrPs) and fascia tenderness. We investigated the effects of manual pressure release (MPR) alone or in combination with taping (MPR/MKT) in subjects with MTrPs. Fifteen and 16 subjects received MPR and MPR/MKT respectively. Outcomes including Pressure pain threshold, muscle stiffness, mechanomyography were assessed at baseline, post-intervention and 7-days later. Pressure pain threshold improved significantly (d = 1.79, p < 0.005) in both groups. Significant improvement in muscle stiffness in the MPR/MKT group (0.27-0.49 mm) as compared to the MPR group (-0.02-0.23 mm). Mechanomyography amplitude in the MPR/MKT group was significantly higher than that of the MPR group (p < 0.05). MPR and MPR/MKT are effective in reducing pain in these subjects. MPR/MKT has a greater effect on muscle stiffness and contraction amplitude. IV. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.
NASA Technical Reports Server (NTRS)
Lissauer, Jack J.
2015-01-01
Kepler has vastly increased our knowledge of planets and planetary systems located close to stars. The new data shows surprising results for planetary abundances, planetary spacings and the distribution of planets on a mass-radius diagram. The implications of these results for theories of planet formation will be discussed.
A Spitzer Infrared Radius for the Transiting Extrasolar Planet HD 209458 b
NASA Technical Reports Server (NTRS)
Richardson, L. Jeremy; Harrington, Joseph; Seager, Sara; Deming, Drake
2007-01-01
We have measured the infrared transit of the extrasolar planet HD 209458 b using the Spitzer Space Telescope. We observed two primary eclipse events (one partial and one complete transit) using the 24 micrometer array of the Multiband Imaging Photometer for Spitzer (MIPS). We analyzed a total of 2392 individual images (10-second integrations) of the planetary system, recorded before, during, and after transit. We perform optimal photometry on the images and use the local zodiacal light as a short-term flux reference. At this long wavelength, the transit curve has a simple box-like shape, allowing robust solutions for the stellar and planetary radii independent of stellar limb darkening, which is negligible at 24 micrometers. We derive a stellar radius of R(sub *) = 1.06 plus or minus 0.07 solar radius, a planetary radius of R(sub p) = 1.26 plus or minus 0.08 R(sub J), and a stellar mass of 1.17 solar mass. Within the errors, our results agree with the measurements at visible wavelengths. The 24 micrometer radius of the planet therefore does not differ significantly compared to the visible result. We point out the potential for deriving extrasolar transiting planet radii to high accuracy using transit photometry at slightly shorter IR wavelengths where greater photometric precision is possible.
Matoba, Nobuyuki; Griffin, Tagan A; Mittman, Michele; Doran, Jeffrey D; Alfsen, Annette; Montefiori, David C; Hanson, Carl V; Bomsel, Morgane; Mor, Tsafrir S
2008-05-01
CTB-MPR(649-684), a translational fusion protein consisting of cholera toxin B subunit (CTB) and residues 649 684 of gp41 membrane proximal region (MPR), is a candidate vaccine aimed at blocking early steps of HIV-1 mucosal transmission. Bacterially produced CTB MPR(649-684) was purified to homogeneity by two affinity chromatography steps. Similar to gp41 and derivatives thereof, the MPR domain can specifically and reversibly self-associate. The affinities of the broadly-neutralizing monoclonal Abs 4E10 and 2F5 to CTB MPR(649-684) were equivalent to their nanomolar affinities toward an MPR peptide. The fusion protein's affinity to GM1 ganglioside was comparable to that of native CTB. Rabbits immunized with CTB-MPR(649-684) raised only a modest level of anti-MPR(649-684) Abs. However, a prime-boost immunization with CTB-MPR(649-684) and a second MPR(649-684)-based immunogen elicited a more productive anti-MPR(649-684) antibody response. These Abs strongly blocked the epithelial transcytosis of a primary subtype B HIV-1 isolate in a human tight epithelial model, expanding our previously reported results using a clade D virus. The Abs recognized epitopes at the N-terminal portion of the MPR peptide, away from the 2F5 and 4E10 epitopes and were not effective in neutralizing infection of CD4+ cells. These results indicate distinct vulnerabilities of two separate interactions of HIV-1 with human cells - Abs against the C-terminal portion of the MPR can neutralize CD4+-dependent infection, while Abs targeting the MPR's N-terminal portion can effectively block galactosyl ceramide dependent transcytosis. We propose that Abs induced by MPR(649-684)-based immunogens may provide broad protective value independent of infection neutralization.
Understanding the mass-radius relation for sub-Neptunes: radius as a proxy for composition
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lopez, Eric D.; Fortney, Jonathan J.
2014-09-01
Transiting planet surveys like Kepler have provided a wealth of information on the distribution of planetary radii, particularly for the new populations of super-Earth- and sub-Neptune-sized planets. In order to aid in the physical interpretation of these radii, we compute model radii for low-mass rocky planets with hydrogen-helium envelopes. We provide model radii for planets 1-20 M {sub ⊕}, with envelope fractions 0.01%-20%, levels of irradiation 0.1-1000 times Earth's, and ages from 100 Myr to 10 Gyr. In addition we provide simple analytic fits that summarize how radius depends on each of these parameters. Most importantly, we show that atmore » fixed H/He envelope fraction, radii show little dependence on mass for planets with more than ∼1% of their mass in their envelope. Consequently, planetary radius is to a first order a proxy for planetary composition, i.e., H/He envelope fraction, for Neptune- and sub-Neptune-sized planets. We recast the observed mass-radius relationship as a mass-composition relationship and discuss it in light of traditional core accretion theory. We discuss the transition from rocky super-Earths to sub-Neptune planets with large volatile envelopes. We suggest ∼1.75 R {sub ⊕} as a physically motivated dividing line between these two populations of planets. Finally, we discuss these results in light of the observed radius occurrence distribution found by Kepler.« less
Using the transit of Venus to probe the upper planetary atmosphere.
Reale, Fabio; Gambino, Angelo F; Micela, Giuseppina; Maggio, Antonio; Widemann, Thomas; Piccioni, Giuseppe
2015-06-23
During a planetary transit, atoms with high atomic number absorb short-wavelength radiation in the upper atmosphere, and the planet should appear larger during a primary transit observed in high-energy bands than in the optical band. Here we measure the radius of Venus with subpixel accuracy during the transit in 2012 observed in the optical, ultraviolet and soft X-rays with Hinode and Solar Dynamics Observatory missions. We find that, while Venus's optical radius is about 80 km larger than the solid body radius (the top of clouds and haze), the radius increases further by >70 km in the extreme ultraviolet and soft X-rays. This measures the altitude of the densest ion layers of Venus's ionosphere (CO2 and CO), useful for planning missions in situ, and a benchmark case for detecting transits of exoplanets in high-energy bands with future missions, such as the ESA Athena.
Identification of novel lysosomal matrix proteins by proteome analysis.
Kollmann, Katrin; Mutenda, Kudzai E; Balleininger, Martina; Eckermann, Ellen; von Figura, Kurt; Schmidt, Bernhard; Lübke, Torben
2005-10-01
The lysosomal matrix is estimated to contain about 50 different proteins. Most of the matrix proteins are acid hydrolases that depend on mannose 6-phosphate receptors (MPR) for targeting to lysosomes. Here, we describe a comprehensive proteome analysis of MPR-binding proteins from mouse. Mouse embryonic fibroblasts defective in both MPR (MPR 46-/- and MPR 300-/-) are known to secrete the lysosomal matrix proteins. Secretions of these cells were affinity purified using an affinity matrix derivatized with MPR46 and MPR300. In the protein fraction bound to the affinity matrix and eluted with mannose 6-phosphate, 34 known lysosomal matrix proteins, 4 candidate proteins of the lysosomal matrix and 4 non-lysosomal contaminants were identified by mass spectrometry after separation by two-dimensional gel electrophoresis or by multidimensional protein identification technology. For 3 of the candidate proteins, mammalian ependymin-related protein-2 (MERP-2), retinoid-inducible serine carboxypeptidase (RISC) and the hypothetical 66.3-kDa protein we could verify that C-terminally tagged forms bound in an M6P-dependent manner to an MPR-affinity matrix and were internalized via MPR-mediated endocytosis. Hence these 3 proteins are likely to represent hitherto unrecognized lysosomal matrix proteins.
Nasuno, Ryo; Hirase, Saeka; Norifune, Saki; Watanabe, Daisuke; Takagi, Hiroshi
2016-02-01
Previously, N-Acetyltransferase Mpr1 was suggested to be involved in a novel pathway of L-arginine biosynthesis in yeast. Our recent crystallographic analysis demonstrated that the overall structure of Mpr1 is a typical folding among proteins in the Gcn5-related N-acetyltransferase superfamily, and also provided clues to the design of mutations for improvement of the enzymatic functions. Here, we constructed new stable variants, Asn203Lys- and Asn203Arg-Mpr1, which exhibited 2.4-fold and 2.2-fold longer activity half-lives than wild-type Mpr1, respectively, by structure-based molecular design. The replacement of Asn203 with a basic amino acid was suggested to stabilize α-helix 2, which is important for the Mpr1 structure, probably by neutralizing its dipole. In addition, the combination of two amino acid substitutions at positions 65 and 203 in Mpr1, Phe65Leu, which was previously isolated by the screening from PCR random mutagenesis library of MPR1, and Asn203Lys or Asn203Arg, led to further stabilization of Mpr1. Our growth assay suggests that overexpression of the stable Mpr1 variants increase L-arginine synthesis in yeast cells. Our finding is the first report on the rational engineering of Mpr1 for thermostabilization and could be useful in the construction of new yeast strains with higher L-arginine synthetic activity and also improved fermentation ability. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.
Association of milking interval and milk production rate in an automatic milking system.
Penry, J F; Crump, P M; Hernandez, L L; Reinemann, D J
2018-02-01
The primary aim of this research was to describe the association between milking interval (MI) and milk production rate (MPR) at the quarter level in a large commercial farm using an automatic milking system. A secondary aim was to determine whether a 2-h decrease in MI would increase MPR at the cow level in midlactation multiparous cows. Six months of data from 1,280 cows were used to assess the association between MI (h) and quarter MPR (kg/h). Increasing MI was associated with decreased MPR for early, mid, and late lactation, both primiparous and multiparous cows, and all 4 quarter positions and across time. The decrease in MPR is approximately 2%/h of increasing MI for multiparous cows and 1.5%/h for primiparous cows. Regardless of quarter, multiparous cows had a greater MPR than primiparous cows, and rear quarters had greater MPR than front quarters. An experiment to test the causal relationship between changing MI and cow-level MPR was conducted using 26 animal pairs matched on MI, days in milk, and milk yield. During the 21-d treatment period, the average MI of treatment cows was decreased by 2.4 h compared with control cows. In both the 21-d treatment and 42-d posttreatment periods, no significant difference was found in cow-level MPR between the treatment and control groups. Despite the negative association between increasing MI and MPR being consistent across all assessed days in milk windows and all quarters, results from this experiment suggest that intervention to decrease MI might require an MI change greater than 2 h or be applied in early lactation to significantly increase MPR. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Bird-Gardiner, T; Arthur, P F; Barchia, I M; Donoghue, K A; Herd, R M
2017-10-01
Angus cattle from 2 beef cattle projects in which daily methane production (MPR) was measured were used in this study to examine the nature of the relationships among BW, DMI, and methane traits of beef cattle fed ad libitum on a roughage diet or a grain-based feedlot diet. In both projects methane was measured using the GreenFeed Emission Monitoring system, which provides multiple short-term breath measures of methane production. The data used for this study were from 119 Angus heifers over 15 d on a roughage diet and 326 Angus steers over 70 d on a feedlot diet. Mean (±SD) age, BW, and DMI were 372 ± 28 d, 355 ± 37 kg, and 8.1 ± 1.3 kg/d for the heifers and 554 ± 86 d, 577 ± 69 kg, and 13.3 ± 2.0 kg/d for the steers, respectively. The corresponding mean MPR was 212 g/d for heifers and 203 g/d for steers. Additional traits studied included methane yield (MY; MPR/DMI), methane intensity (MPR/BW), and 3 forms of residual methane production (RMP), which is a measure of actual minus predicted MPR. For RMP, RMP, and RMP predicted MPR were obtained by regression of MPR on BW, on DMI, and on both DMI and BW, respectively. The 2 data sets were analyzed separately using the same statistical procedures. For both feed types the relationships between MPR and DMI and between MPR and BW were both positive and linear. The correlation between MPR and DMI was similar to that between MPR and BW, although the correlations were stronger for the roughage diet ( = 0.75 for MPR vs. DMI; = 0.74 for MPR vs. BW) than the grain-based diet ( = 0.62 for MPR vs. DMI; = 0.66 for MPR vs. BW). The correlation between MY and DMI was negative and moderate for the roughage ( = -0.68) and grain-based ( = -0.59) diets, a finding that is different from the nonsignificant correlations reported in studies of cattle on a restricted roughage diet. The 3 RMP traits were strongly correlated ( values from 0.76 to 0.99) with each other for both the roughage and the grain-based diets, which indicates that using RMP to lower MPR could provide a result similar to using RMP in cattle. As feed intake (DMI) is more difficult to measure than BW, this result implies that under ad libitum feeding situations in which DMI cannot be measured, RMP can be used to identify higher- or lower-RMP animals with similar levels of effectiveness as RMP.
Robo-AO Kepler Survey. IV. The Effect of Nearby Stars on 3857 Planetary Candidate Systems
NASA Astrophysics Data System (ADS)
Ziegler, Carl; Law, Nicholas M.; Baranec, Christoph; Riddle, Reed; Duev, Dmitry A.; Howard, Ward; Jensen-Clem, Rebecca; Kulkarni, S. R.; Morton, Tim; Salama, Maïssa
2018-04-01
We present the overall statistical results from the Robo-AO Kepler planetary candidate survey, comprising of 3857 high-angular resolution observations of planetary candidate systems with Robo-AO, an automated laser adaptive optics system. These observations reveal previously unknown nearby stars blended with the planetary candidate host stars that alter the derived planetary radii or may be the source of an astrophysical false positive transit signal. In the first three papers in the survey, we detected 440 nearby stars around 3313 planetary candidate host stars. In this paper, we present observations of 532 planetary candidate host stars, detecting 94 companions around 88 stars; 84 of these companions have not previously been observed in high resolution. We also report 50 more-widely separated companions near 715 targets previously observed by Robo-AO. We derive corrected planetary radius estimates for the 814 planetary candidates in systems with a detected nearby star. If planetary candidates are equally likely to orbit the primary or secondary star, the radius estimates for planetary candidates in systems with likely bound nearby stars increase by a factor of 1.54, on average. We find that 35 previously believed rocky planet candidates are likely not rocky due to the presence of nearby stars. From the combined data sets from the complete Robo-AO KOI survey, we find that 14.5 ± 0.5% of planetary candidate hosts have a nearby star with 4″, while 1.2% have two nearby stars, and 0.08% have three. We find that 16% of Earth-sized, 13% of Neptune-sized, 14% of Saturn-sized, and 19% of Jupiter-sized planet candidates have detected nearby stars.
Na Pombejra, Sarisa; Salemi, Michelle; Phinney, Brett S.; Gelli, Angie
2017-01-01
Eukaryotic pathogens display multiple mechanisms for breaching the blood-brain barrier (BBB) and invading the central nervous system (CNS). Of the fungal spp., that cause disease in mammals, only some cross brain microvascular endothelial cells which constitute the BBB, and invade the brain. Cryptococcus neoformans, the leading cause of fungal meningoencephalitis, crosses the BBB directly by transcytosis or by co-opting monocytes. We previously determined that Mpr1, a secreted fungal metalloprotease, facilitates association of fungal cells to brain microvascular endothelial cells and we confirmed that the sole expression of CnMPR1 endowed S. cerevisiae with an ability to cross the BBB. Here, the gain of function conferred onto S. cerevisiae by CnMPR1 (i.e., Sc
Na Pombejra, Sarisa; Salemi, Michelle; Phinney, Brett S; Gelli, Angie
2017-01-01
Eukaryotic pathogens display multiple mechanisms for breaching the blood-brain barrier (BBB) and invading the central nervous system (CNS). Of the fungal spp., that cause disease in mammals, only some cross brain microvascular endothelial cells which constitute the BBB, and invade the brain. Cryptococcus neoformans , the leading cause of fungal meningoencephalitis, crosses the BBB directly by transcytosis or by co-opting monocytes. We previously determined that Mpr1, a secreted fungal metalloprotease, facilitates association of fungal cells to brain microvascular endothelial cells and we confirmed that the sole expression of Cn MPR1 endowed S. cerevisiae with an ability to cross the BBB. Here, the gain of function conferred onto S. cerevisiae by Cn MPR1 (i.e., Sc
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zeng, Li; Jacobsen, Stein B., E-mail: astrozeng@gmail.com, E-mail: jacobsen@neodymium.harvard.edu
In the past few years, the number of confirmed planets has grown above 2000. It is clear that they represent a diversity of structures not seen in our own solar system. In addition to very detailed interior modeling, it is valuable to have a simple analytical framework for describing planetary structures. The variational principle is a fundamental principle in physics, entailing that a physical system follows the trajectory, which minimizes its action. It is alternative to the differential equation formulation of a physical system. Applying the variational principle to the planetary interior can beautifully summarize the set of differential equationsmore » into one, which provides us some insight into the problem. From this principle, a universal mass–radius relation, an estimate of the error propagation from the equation of state to the mass–radius relation, and a form of the virial theorem applicable to planetary interiors are derived.« less
Alleyne, Emma; Gannon, Theresa A; Ó Ciardha, Caoilte; Wood, Jane L
2014-02-01
The literature on Multiple Perpetrator Rape (MPR) is scant; however, a significant proportion of sexual offending involves multiple perpetrators. In addition to the need for research with apprehended offenders of MPR, there is also a need to conduct research with members of the general public. Recent advances in the forensic literature have led to the development of self-report proclivity scales. These scales have enabled researchers to conduct evaluative studies sampling from members of the general public who may be perpetrators of sexual offenses and have remained undetected, or at highest risk of engaging in sexual offending. The current study describes the development and preliminary validation of the Multiple-Perpetrator Rape Interest Scale (M-PRIS), a vignette-based measure assessing community males' sexual arousal to MPR, behavioral propensity toward MPR and enjoyment of MPR. The findings show that the M-PRIS is a reliable measure of community males' sexual interest in MPR with high internal reliability and temporal stability. In a sample of university males we found that a large proportion (66%) did not emphatically reject an interest in MPR. We also found that rape-supportive cognitive distortions, antisocial attitudes, and high-risk sexual fantasies were predictors of sexual interest in MPR. We discuss these findings and the implications for further research employing proclivity measures referencing theory development and clinical practice.
Sasano, Yu; Takahashi, Shunsuke; Shima, Jun; Takagi, Hiroshi
2010-03-31
During bread-making processes, yeast cells are exposed to multiple stresses. Air-drying stress is one of the most harmful stresses by generation of reactive oxygen species (ROS). Previously, we discovered that the novel N-acetyltransferase Mpr1/2 confers oxidative stress tolerance by reducing intracellular ROS level in Saccharomyces cerevisiae Sigma1278b strain. In this study, we revealed that Japanese industrial baker's yeast possesses one MPR gene. The nucleotide sequence of the MPR gene in industrial baker's yeast was identical to the MPR2 gene in Sigma1278b strain. Gene disruption analysis showed that the MPR2 gene in industrial baker's yeast is involved in air-drying stress tolerance by reducing the intracellular oxidation levels. We also found that expression of the Lys63Arg and Phe65Leu variants with enhanced enzymatic activity and stability, respectively, increased the fermentation ability of bread dough after exposure to air-drying stress compared with the wild-type Mpr1. In addition, our recent study showed that industrial baker's yeast cells accumulating proline exhibited enhanced freeze tolerance in bread dough. Proline accumulation also enhanced the fermentation ability after air-drying stress treatment in industrial baker's yeast. Hence, the antioxidant enzyme Mpr1/2 could be promising for breeding novel yeast strains that are tolerant to air-drying stress. Copyright 2010 Elsevier B.V. All rights reserved.
A super-Earth transiting a nearby low-mass star.
Charbonneau, David; Berta, Zachory K; Irwin, Jonathan; Burke, Christopher J; Nutzman, Philip; Buchhave, Lars A; Lovis, Christophe; Bonfils, Xavier; Latham, David W; Udry, Stéphane; Murray-Clay, Ruth A; Holman, Matthew J; Falco, Emilio E; Winn, Joshua N; Queloz, Didier; Pepe, Francesco; Mayor, Michel; Delfosse, Xavier; Forveille, Thierry
2009-12-17
A decade ago, the detection of the first transiting extrasolar planet provided a direct constraint on its composition and opened the door to spectroscopic investigations of extrasolar planetary atmospheres. Because such characterization studies are feasible only for transiting systems that are both nearby and for which the planet-to-star radius ratio is relatively large, nearby small stars have been surveyed intensively. Doppler studies and microlensing have uncovered a population of planets with minimum masses of 1.9-10 times the Earth's mass (M[symbol:see text]), called super-Earths. The first constraint on the bulk composition of this novel class of planets was afforded by CoRoT-7b (refs 8, 9), but the distance and size of its star preclude atmospheric studies in the foreseeable future. Here we report observations of the transiting planet GJ 1214b, which has a mass of 6.55M[symbol:see text]), and a radius 2.68 times Earth's radius (R[symbol:see text]), indicating that it is intermediate in stature between Earth and the ice giants of the Solar System. We find that the planetary mass and radius are consistent with a composition of primarily water enshrouded by a hydrogen-helium envelope that is only 0.05% of the mass of the planet. The atmosphere is probably escaping hydrodynamically, indicating that it has undergone significant evolution during its history. The star is small and only 13 parsecs away, so the planetary atmosphere is amenable to study with current observatories.
Real-world clinical and economic outcomes for daily teriparatide patients in Japan.
Burge, Russel; Sato, Masayo; Sugihara, Tomoko
2016-11-01
A large medical and pharmacy claims database was used to evaluate outcomes in daily teriparatide (D-TPD) patients in Japan. 445 patients were identified (April 2008-July 2013) with 6+ months' pre- and 18+ months' post-index observation. D-TPD 20 µg subcutaneous injection is indicated for individuals at high risk of fracture. Descriptive analyses were conducted on clinical fractures, health care utilization, and costs. Adherence was measured by medication possession ratio (MPR) (High MPR > 0.8; 0.5 ≤ Medium MPR ≤ 0.8, Low MPR < 0.5). Adjusted analyses of Lower (Low + Medium) MPR vs. High MPR for fracture incidence and hospital admissions were performed using logistic and Poisson regression models; adjusted cost analyses used propensity bin bootstrapping methods. Baseline characteristics were: mean 74.7 years (standard deviation = 8.9); 90 % female; 20 % 1+ fracture. Post-index, 249 and 196 patients had High and Lower MPR, respectively. Mean incident fractures/1000 patient-years for Lower and High MPR patients were 77.4 and 57.7, respectively. Adjusted fracture risk was greater in Lower MPR patients [logistic odds ratio (OR) = 1.67, 95 % confidence interval 0.791-3.541; Poisson incidence rate ratio (IRR) = 1.505, 0.764-2.966]. Hospital admission risk was significantly greater in Lower than High MPR patients (OR = 1.85, 1.169-2.921; IRR = 1.47, 1.137-1.904). High MPR patients had numerically lower inpatient and total unadjusted costs than Lower MPR patients. Adjusted inpatient costs were significantly less in High MPR patients; outpatient and pharmacy costs were greater. Better adherence to D-TPD revealed a trend towards lower fracture risk, and significant reductions in hospital admissions and costs. The small sample size limited the robustness of these results.
Pang, Xiuhua; Samten, Buka; Cao, Guangxiang; Wang, Xisheng; Tvinnereim, Amy R; Chen, Xiu-Lan; Howard, Susan T
2013-01-01
The ESX-1 secretion system exports the immunomodulatory protein ESAT-6 and other proteins important in the pathogenesis of Mycobacterium tuberculosis. Components and substrates of ESX-1 are encoded at several loci, but the regulation of the encoding genes is only partially understood. In this study, we investigated the role of the MprAB two-component system in the regulation of ESX-1 activity. We determined that MprAB directly regulates the espA gene cluster, a locus necessary for ESX-1 function. Transcript mapping determined that the five genes in the cluster form an operon with two transcriptional start points, and several MprA binding sites were detected in the espA promoter. Expression analyses and promoter constructs indicated that MprAB represses the espA operon. However, the MprAB mutant Rv-D981 secreted lower levels of EspA, ESAT-6, and the ESX-1 substrate EspB than control strains. Secretion of CFP10, which is normally cosecreted with ESAT-6, was similar in Rv-D981 and control strains, further demonstrating aberrant ESX-1 activity in the mutant. ESAT-6 induces proinflammatory cytokines, and macrophages infected with Rv-D981 elicited lower levels of interleukin 1β (IL-1β) and tumor necrosis factor alpha (TNF-α), consistent with the reduced levels of ESAT-6. These findings indicate that MprAB modulates ESX-1 function and reveal a new role for MprAB in host-pathogen interactions.
More on Magnetic Spectra from Correlated Crustal Sources on Mars
NASA Technical Reports Server (NTRS)
Voorhies, C. V.
2005-01-01
The spectral method for distinguishing crustal from core-source magnetic fields has been re-examined, modified and applied to both a comprehensive geomagnetic field model and an altitude normalized magnetic map of Mars. These observational spectra are fairly fitted by theoretical forms expected from certain elementary classes of magnetic sources. For Earth we found fields from a core of radius 3512 plus or minus 64 km, in accord with the 3480 km seismologic radius, and a crust represented by a shell of random dipolar sources at radius 6367 plus or minus 14 km, just beneath the 6371.0 km mean radius. For Mars we found only a field from a crust represented in same way, but 46 plus or minus 10 km below the planetary mean radius of 3389.5 km, and with sources about 9.6 plus or minus 3.2 times stronger than Earth's. It is remarkable that the same simple theoretical form should fairly fit crustal magnetic spectra for both worlds and return crustal-source depth estimates of plausible magnitude. Evidently, the idea of an ensemble of compact, quasi-independent, magnetized regions within these planetary crusts has some merit. Yet such estimates, at best a kind of average, depend upon both the observational spectrum fitted and the physical basis of the theoretical spectrum.
Donoghue, K A; Bird-Gardiner, T; Arthur, P F; Herd, R M; Hegarty, R F
2016-04-01
Ruminants contribute 80% of the global livestock greenhouse gas (GHG) emissions mainly through the production of methane, a byproduct of enteric microbial fermentation primarily in the rumen. Hence, reducing enteric methane production is essential in any GHG emissions reduction strategy in livestock. Data on 1,046 young bulls and heifers from 2 performance-recording research herds of Angus cattle were analyzed to provide genetic and phenotypic variance and covariance estimates for methane emissions and production traits and to examine the interrelationships among these traits. The cattle were fed a roughage diet at 1.2 times their estimated maintenance energy requirements and measured for methane production rate (MPR) in open circuit respiration chambers for 48 h. Traits studied included DMI during the methane measurement period, MPR, and methane yield (MY; MPR/DMI), with means of 6.1 kg/d (SD 1.3), 132 g/d (SD 25), and 22.0 g/kg (SD 2.3) DMI, respectively. Four forms of residual methane production (RMP), which is a measure of actual minus predicted MPR, were evaluated. For the first 3 forms, predicted MPR was calculated using published equations. For the fourth (RMP), predicted MPR was obtained by regression of MPR on DMI. Growth and body composition traits evaluated were birth weight (BWT), weaning weight (WWT), yearling weight (YWT), final weight (FWT), and ultrasound measures of eye muscle area, rump fat depth, rib fat depth, and intramuscular fat. Heritability estimates were moderate for MPR (0.27 [SE 0.07]), MY (0.22 [SE 0.06]), and the RMP traits (0.19 [SE 0.06] for each), indicating that genetic improvement to reduce methane emissions is possible. The RMP traits and MY were strongly genetically correlated with each other (0.99 ± 0.01). The genetic correlation of MPR with MY as well as with the RMP traits was moderate (0.32 to 0.63). The genetic correlation between MPR and the growth traits (except BWT) was strong (0.79 to 0.86). These results indicate that selection for lower MPR may have undesired effect on animal productivity. On the other hand, MY and the RMPR were either not genetically correlated or weakly correlated with BWT, YWT, and FWT (-0.06 to 0.23) and body composition traits (-0.18 to 0.18). Therefore, selection for lower MY or RMPR would lead to lower MPR without impacting animal productivity. Where the use of a ratio trait (e.g., MY) is not desirable, selection on any of the forms of RMP would be an alternative.
La Terra: esperimenti a scuola
NASA Astrophysics Data System (ADS)
Roselli, Alessandra; D'Amico, Angelalucia; Pisegna, Daniela; Palma, Francesco; di Nardo, Giustino; Cofini, Marika; Cerasani, Paolo; Cerratti, Valentina
2006-02-01
Easy but effective methods used in past centuries allow rediscovery and good knowledge of the planet Earth. The latitude station and planetary radius were measured with Eratosthenes method. The gravity acceleration obtained from pendulum period was used to calculate the terrestrial mass and the density of internal planetary layers. Finally, the estimate of atmosphere density and geometrical thickness complete the view of the planet's properties.
Bayer, Arnold S; Mishra, Nagendra N; Chen, Liang; Kreiswirth, Barry N; Rubio, Aileen; Yang, Soo-Jin
2015-08-01
MprF is responsible for the lysinylation of phosphatidylglycerol (PG) to synthesize the positively charged phospholipid (PL) species, lysyl-PG (L-PG). It has been proposed that the single-nucleotide polymorphisms (SNPs) within the mprF open reading frame (ORF) are associated with a gain-in-function phenotype in terms of daptomycin resistance in Staphylococcus aureus. (Note that although the official term is daptomycin nonsusceptibility, we use the term daptomycin resistance in this paper for ease of presentation.) Using 22 daptomycin-susceptible (DAP(s))/daptomycin-resistant (DAP(r)) clinical methicillin-resistant S. aureus (MRSA) strain pairs, we assessed (i) the frequencies and distribution of putative mprF gain-in-function SNPs, (ii) the relationships of the SNPs to both daptomycin resistance and cross-resistance to the prototypical endovascular host defense peptide (HDP) thrombin-induced platelet microbicidal protein (tPMP), and (iii) the impact of mprF SNPs on positive surface charge phenotype and modifications of membrane PL profiles. Most of the mprF SNPs identified in our DAP(r) strains were clustered within the two MprF loci, (i) the central bifunctional domain and (ii) the C-terminal synthase domain. Moreover, we were able to correlate the presence and location of mprF SNPs in DAP(r) strains with HDP cross-resistance, positive surface charge, and L-PG profiles. Although DAP(r) strains with mprF SNPs in the bifunctional domain showed higher resistance to tPMPs than DAP(r) strains with SNPs in the synthase domain, this relationship was not observed in positive surface charge assays. These results demonstrated that both charge-mediated and -unrelated mechanisms are involved in DAP resistance and HDP cross-resistance in S. aureus. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
MPR-CT Imaging for Stapes Prosthesis: Accuracy and Clinical Significance.
Fang, Yanqing; Wang, Bing; Galvin, John J; Tao, Duoduo; Deng, Rui; Ou, Xiong; Liu, Yangwenyi; Dai, Peidong; Sha, Yan; Zhang, Tianyu; Chen, Bing
2016-04-01
The aims of this article are: 1) to re-evaluate the accuracy of multiple planar reconstruction computed tomography (MPR-CT) imaging on stapes-prosthesis parameters, and 2) to clarify possible relationships between prosthesis intravestibular depth and postoperative hearing outcomes. Seventy patients (46 women and 24 men; 32 right and 38 left sides) with the mean age of 40 years (range, 19-62 yr) with clinical otosclerosis. All patients underwent stapedotomy and were implanted with the same type of titanium piston prosthesis by the same surgeon. Postoperative MPR-CTs were obtained at patients' follow-up visits. The length and intravestibular depth of the stapes prosthesis (including absolute and relative depth) were calculated from the MPR-CT imaging. Relationships between the intravestibular depth of the prosthesis and hearing outcomes (pre- and postoperative audiograms) were analyzed using Spearman correlation analyses. The length of the prosthesis was overestimated by 1.8% (0.1 mm) by the MPR-CT imaging. Axial and coronal measurements were significantly correlated (p < 0.05). There was great intersubject variability in hearing outcomes differed insignificantly, regardless of intravestibular depth within the security range. No relationships were found between the intravestibular depth of the stapes prosthesis, as measured with MPR-CT, and postoperative hearing results. MPR-CT can provide an accurate estimation of stapes prosthesis parameters. However, the prosthesis intravestibular depth did not seem to affect postoperative hearing outcomes.
Planetary population synthesis coupled with atmospheric escape: a statistical view of evaporation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jin, Sheng; Ji, Jianghui; Mordasini, Christoph
2014-11-01
We apply hydrodynamic evaporation models to different synthetic planet populations that were obtained from a planet formation code based on the core-accretion paradigm. We investigated the evolution of the planet populations using several evaporation models, which are distinguished by the driving force of the escape flow (X-ray or EUV), the heating efficiency in energy-limited evaporation regimes, or both. Although the mass distribution of the planet populations is barely affected by evaporation, the radius distribution clearly shows a break at approximately 2 R {sub ⊕}. We find that evaporation can lead to a bimodal distribution of planetary sizes and to anmore » 'evaporation valley' running diagonally downward in the orbital distance—planetary radius plane, separating bare cores from low-mass planets that have kept some primordial H/He. Furthermore, this bimodal distribution is related to the initial characteristics of the planetary populations because low-mass planetary cores can only accrete small primordial H/He envelopes and their envelope masses are proportional to their core masses. We also find that the population-wide effect of evaporation is not sensitive to the heating efficiency of energy-limited description. However, in two extreme cases, namely without evaporation or with a 100% heating efficiency in an evaporation model, the final size distributions show significant differences; these two scenarios can be ruled out from the size distribution of Kepler candidates.« less
Adherence to anti-estrogen therapy in seniors with breast cancer: how well are we doing?
Trabulsi, Nora; Riedel, Kristen; Winslade, Nancy; Gregoire, Jean-Pierre; Meterissian, Sarkis; Abrahamovicz, Michal; Tamblyn, Robyn; Mayo, Nancy; Meguerditchian, Ari
2014-01-01
A third of breast cancers (BC) occur in women ≥65 years (seniors). Anti-estrogen therapy (AET) significantly reduces BC recurrence and death. This study characterizes determinants of adherence to AET in seniors with BC. Provincial cancer registry and administrative claims data were accessed for all non-metastatic BC diagnosed in Quebec (1998-2005) to identify seniors treated for 5 years with AET. Multivariate linear regression was used to assess the association with patient, disease, and physician characteristics and the 5-year medication possession ratio (MPR) for each patient. 4,715 women were included (mean age: 72.9). Mean MPR was 83.5%, 79% of patients reached a 5-year MPR of ≥80%, and 34% discontinued AET at some point during treatment. The cumulative probability of discontinuation was 33.8% (mean time to discontinuation 2.3 years). The MPR decreased with increasing age and non-BC related hospitalizations, p < 0.05. Each new medication added during the 5-years decreased the MPR by 0.3% (p < 0.05). Women with in situ disease, on antidepressants at baseline, or treated with Tamoxifen had a lower MPR by 6.5% (p = 0.0002), 4.7% (p = 0.003) and 6% (p = 0.001), respectively. Switching AET type was associated with a lower MPR by 5.3% (p = 0.002) if the switch occurred during the first year. Optimal 5-year adherence to AET in seniors with BC remained a challenge and medication discontinuation rates were high. Advanced age, increasing number of hospitalizations, in situ disease, baseline use of antidepressants, Tamoxifen (versus aromatase inhibitors), early switches of AET type, and newly added medications significantly reduced the MPR. © 2014 Wiley Periodicals, Inc.
Ho, Chen-Pei; Yeh, Jih-I; Wen, Shu-Hui; Lee, Tony Jer-Fu
2017-01-01
Abstract The aim of this study was to explore the associations among the medication regimen complexity index (MRCI), medical specialty, and medication possession ratio (MPR) in newly diagnosed hypertensive patients. Data from 19,859 newly diagnosed hypertensive patients were collected from 2,000,000 random samples of the National Health Insurance Research Database in Taiwan. All study participants were followed for 1 year after the first diagnosis of hypertension. MPR was defined as total days of antihypertensive drugs supplied/365 days. MRCI was calculated on the basis of the type of dosage forms, dosing frequency, and additional directions for use of antihypertensive drugs. Patients were further restricted to those who visited the same medical specialty to examine specialty-specific variations in the MRCI and MPR. The mean MPR was 54.83%, and the sample sizes for the low-, medium-, and high-MPR groups were 9806 (49.38%), 4619 (23.26%), and 5434 (27.36%), respectively. More than 50% of the patients visited the same medical specialty during the 1-year follow-up. The mean MRCI was 3.64; the cardiology specialty had the highest MRCI, and the family medicine specialty had the lowest. Multiple linear regression analyses showed that MRCI was negatively associated with MPR (β = −7.75, P ≤ .01) whether or not the patients visited the same medical specialty. For the patients who visited the same medical specialty, those treated by endocrinology and metabolism specialists had a significantly higher MPR (β = 9.87, P ≤ .01) than that of those treated by family medicine specialists. MRCI and medical specialty were both significantly associated with the MPR of newly diagnosed hypertensive patients. PMID:29137042
Yandell, C A; Dunbar, A J; Wheldrake, J F; Upton, Z
1999-09-17
The mammalian cation-independent mannose 6-phosphate receptor (CI-MPR) binds mannose 6-phosphate-bearing glycoproteins and insulin-like growth factor (IGF)-II. However, the CI-MPR from the opossum has been reported to bind bovine IGF-II with low affinity (Dahms, N. M., Brzycki-Wessell, M. A., Ramanujam, K. S., and Seetharam, B. (1993) Endocrinology 133, 440-446). This may reflect the use of a heterologous ligand, or it may represent the intrinsic binding affinity of this receptor. To examine the binding of IGF-II to a marsupial CI-MPR in a homologous system, we have previously purified kangaroo IGF-II (Yandell, C. A., Francis, G. L., Wheldrake, J. F., and Upton, Z. (1998) J. Endocrinol. 156, 195-204), and we now report the purification and characterization of the CI-MPR from kangaroo liver. The interaction of the kangaroo CI-MPR with IGF-II has been examined by ligand blotting, radioreceptor assay, and real-time biomolecular interaction analysis. Using both a heterologous and homologous approach, we have demonstrated that the kangaroo CI-MPR has a lower binding affinity for IGF-II than its eutherian (placental mammal) counterparts. Furthermore, real-time biomolecular interaction analysis revealed that the kangaroo CI-MPR has a higher affinity for kangaroo IGF-II than for human IGF-II. The cDNA sequence of the kangaroo CI-MPR indicates that there is considerable divergence in the area corresponding to the IGF-II binding site of the eutherian receptor. Thus, the acquisition of a high-affinity binding site for regulating IGF-II appears to be a recent event specific to the eutherian lineage.
Kleinman, Nathan L; Schaneman, Justin L; Lynch, Wendy D
2008-12-01
Measure the impact of insulin utilization on health costs and absenteeism. Compare outcomes between users of insulin glargine and other insulin. Using a large retrospective database, this regression analysis examined annual health costs and absenteeism among employees and spouses with type 2 diabetes who used insulin. The analysis studied impacts of medication possession ratio (MPR) and glargine use, controlling for demographic factors, salary, and prior health care. Higher MPR was associated with significantly lower health costs for patients with high prior costs. Glargine users' MPR was higher than other insulin users' MPR (66% vs 54%, P < 0.0001). Among all insulin users, those using glargine had significantly lower total ($6771 vs $7969, P = 0.0046) and circulatory-specific ($312 vs $636, P < 0.0001) costs. Insulin MPR and the use of insulin glargine were associated with lower health care costs.
Formation and Internal Structure of Terrestrial Planets, and Atmospheric Escape
NASA Astrophysics Data System (ADS)
Jin, S.
2014-11-01
As of 2014 April 21, over 1490 confirmed exoplanets and 3705 Kepler candidates have been detected. This implies that exoplanets may be ubiquitous in the universe. In this paper, we focus on the formation, evolution, and internal structure of terrestrial planets, and the atmospheric escape of close-in planets. In chapter 2, we investigate the dynamical evolution of planetary system after the protoplanetary disk has dissipated. We find that in the final assembly stage, the occurrence of terrestrial planets is quite common and in 40% of our simulations finally at least one planet is formed in the habitable zone. We also find that if there is a highly-inclined giant planet in the system, a great many bodies will be either driven out of the system, or collide with the giant planet or the central star. This will lead to the difficulty in planetary accretion. Moreover, our results show that planetary migration can lead to the formation of close-in planets. Besides migration, close-in terrestrial planets can also be formed by a collision-merger mechanism, which means that planetary embryos can kick terrestrial planets directly into orbits that are extremely close to their parent stars. In chapter 3, we construct numerically an internal structure model for terrestrial planets, and provide three kinds of possible internal structures of Europa (Jupiter's moon) based on this model. Then, we calculate the radii of low-mass exoplanets for various mass combinations of core and mantle, and find that some of them are inconsistent with the observed radius of rocky planets. This phenomenon can be explained only if there exists a large amount of water in the core, or they own gaseous envelopes. In chapter 4, we improve our planetary evolution codes using the semi-gray model of Guillot (2010), which includes the incident flux from the host star as a heating source in planetary atmosphere. The updated codes can solve the structure of the top radiative zone of intensely irradiated planets, and thus can simulate the atmospheric escape of close-in planets driven by strong stellar X-ray or EUV emissions. We find that low-mass planets are sensitive to the atmospheric escape, and they could lose all their initial H/He envelopes during the evolution. On the other hand, gas giant can only lose a small fraction of their initial envelopes. We then carry out a parameter study of atmospheric escape at the planetary core mass, envelope mass fraction, and semi-major axis space. We find that the most intense phase of evaporation occurs within the early 100 Myr. Afterwards, atmospheric escape only has a small impact on the planetary evolution. In chapter 5, we apply our new planetary evolution model to different synthetic planet populations that are directly produced by the core-accretion paradigm (Mordasini et al. 2012a,b). We show that although the mass distribution of the planet populations is hardly affected by evaporation, the radius distribution clearly shows a break around 2 R_{⊕}. This break leads to a bimodal distribution in planet sizes (Owen & Wu 2013). Furthermore, the bimodal distribution is related to the initial characteristics of the planetary populations. We find that in two extreme cases, namely without any evaporation or with a 100% heating efficiency in the evaporation model, the final radius distributions show significant differences compared to the radius distribution of Kepler candidates. In chapter 6, we introduce a radiative transfer model that can calculate the radiation spectrum of close-in exoplanets.
Kang, Kyoung-Mi; Mishra, Nagendra N; Park, Kun Taek; Lee, Gi-Yong; Park, Yong Ho; Bayer, Arnold S; Yang, Soo-Jin
2017-02-01
Daptomycin (DAP) has potent activity in vitro and in vivo against both methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains. DAP-resistance (DAP-R) in S. aureus has been mainly observed in MRSA strains, and has been linked to single nucleotide polymorphisms (SNPs) within the mprF gene leading to altered cell membrane (CM) phospholipid (PL) profiles, enhanced positive surface charge, and changes in CM fluidity. The current study was designed to delineate whether these same genotypic and phenotypic perturbations are demonstrated in clinically-derived DAP-R MSSA strains. We used three isogenic DAP-susceptible (DAP-S)/DAP-R strainpairs and compared: (i) presence of mprF SNPs, (ii) temporal expression profiles of the two key determinants (mprF and dltABCD) of net positive surface charge, (iii) increased production of mprF-dependent lysinylated-phosphatidylglycerol (L-PG), (iv) positive surface charge assays, and (v) susceptibility to cationic host defense peptides (HDPs) of neutrophil and platelet origins. Similar to prior data in MRSA, DAP-R (vs DAP-S) MSSA strains exhibited hallmark hot-spot SNPs in mprF, enhanced and dysregulated expression of both mprF and dltA, L-PG overproduction, HDP resistance and enhanced positive surface charge profiles. However, in contrast to most DAP-R MRSA strains, there were no changes in CM fluidity seen. Thus, charge repulsion via mprF-and dlt-mediated enhancement of positive surface charge may be the main mechanism to explain DAP-R in MSSA strains.
Rogers, Ian S.; Cury, Ricardo C.; Blankstein, Ron; Shapiro, Michael D.; Nieman, Koen; Hoffmann, Udo; Brady, Thomas J.; Abbara, Suhny
2010-01-01
Background Despite rapid advances in cardiac computed tomography (CT), a strategy for optimal visualization of perfusion abnormalities on CT has yet to be validated. Objective To evaluate the performance of several post-processing techniques of source data sets to detect and characterize perfusion defects in acute myocardial infarctions with cardiac CT. Methods Twenty-one subjects (18 men; 60 ± 13 years) that were successfully treated with percutaneous coronary intervention for ST-segment myocardial infarction underwent 64-slice cardiac CT and 1.5 Tesla cardiac MRI scans following revascularization. Delayed enhancement MRI images were analyzed to identify the location of infarcted myocardium. Contiguous short axis images of the left ventricular myocardium were created from the CT source images using 0.75mm multiplanar reconstruction (MPR), 5mm MPR, 5mm maximal intensity projection (MIP), and 5mm minimum intensity projection (MinIP) techniques. Segments already confirmed to contain infarction by MRI were then evaluated qualitatively and quantitatively with CT. Results Overall, 143 myocardial segments were analyzed. On qualitative analysis, the MinIP and thick MPR techniques had greater visibility and definition than the thin MPR and MIP techniques (p < 0.001). On quantitative analysis, the absolute difference in Hounsfield Unit (HU) attenuation between normal and infarcted segments was significantly greater for the MinIP (65.4 HU) and thin MPR (61.2 HU) techniques. However, the relative difference in HU attenuation was significantly greatest for the MinIP technique alone (95%, p < 0.001). Contrast to noise was greatest for the MinIP (4.2) and thick MPR (4.1) techniques (p < 0.001). Conclusion The results of our current investigation found that MinIP and thick MPR detected infarcted myocardium with greater visibility and definition than MIP and thin MPR. PMID:20579617
A new model for the (geo)magnetic power spectrum, with application to planetary dynamo radii
NASA Astrophysics Data System (ADS)
Langlais, Benoit; Amit, Hagay; Larnier, Hugo; Thébault, Erwan; Mocquet, Antoine
2014-09-01
We propose two new analytical expressions to fit the Mauersberger-Lowes geomagnetic field spectrum at the core-mantle boundary. These can be used to estimate the radius of the outer liquid core where the geodynamo operates, or more generally the radius of the planetary dynamo regions. We show that two sub-families of the geomagnetic field are independent of spherical harmonics degree n at the core-mantle boundary and exhibit flat spectra. The first is the non-zonal field, i.e., for spherical harmonics order m different from zero. The second is the quadrupole family, i.e., n+m even. The flatness of their spectra is motivated by the nearly axisymmetric time-average paleomagnetic field (for the non-zonal field) and the dominance of rotational effects in core dynamics (for the quadrupole family). We test our two expressions with two approaches using the reference case of the Earth. First we estimate at the seismic core radius the agreement between the actual spectrum and the theoretical one. Second we estimate the magnetic core radius, where the spectrum flattens. We show that both sub-families offer a better agreement with the actual spectrum compared with previously proposed analytical expressions, and predict a magnetic core radius within less than 10 km of the Earth's seismic core radius. These new expressions supersede previous ones to infer the core radius from geomagnetic field information because the low degree terms are not ignored. Our formalism is then applied to infer the radius of the dynamo regions on Jupiter, Saturn, Uranus and Neptune. The axisymmetric nature of the magnetic field of Saturn prevents the use of the non-zonal expression. For the three other planets both expressions converge and offer independent constraints on the internal structure of these planets. These non-zonal and quadrupole family expressions may be implemented to extrapolate the geomagnetic field spectrum beyond observable degrees, or to further regularize magnetic field models constructed from modern or historical observations.
Extended halos and intracluster light using Planetary Nebulae as tracers in nearby clusters
NASA Astrophysics Data System (ADS)
Arnaboldi, Magda
Since the first detection of intracluster planetary nebulae in 1996, imaging and spectroscopic surveys identified such stars to trace the radial extent and the kinematics of diffuse light in clusters. This topic of research is tightly linked with the studies of galaxy formation and evolution in dense environment, as the spatial distribution and kinematics of planetary nebulae in the outermost regions of galaxies and in the cluster cores is relevant for setting constraints on cosmological simulations. In this sense, extragalactic planetary nebulae play a very important role in the near-field cosmology, in order to measure the integrated mass as function of radius and the orbital distribution of stars in structures placed in the densest regions of the nearby universe.
NASA Technical Reports Server (NTRS)
Kubala, A.; Black, D.; Szebehely, V.
1993-01-01
A comparison is made between the stability criteria of Hill and that of Laplace to determine the stability of outer planetary orbits encircling binary stars. The restricted, analytically determined results of Hill's method by Szebehely and coworkers and the general, numerically integrated results of Laplace's method by Graziani and Black (1981) are compared for varying values of the mass parameter mu. For mu = 0 to 0.15, the closest orbit (lower limit of radius) an outer planet in a binary system can have and still remain stable is determined by Hill's stability criterion. For mu greater than 0.15, the critical radius is determined by Laplace's stability criterion. It appears that the Graziani-Black stability criterion describes the critical orbit within a few percent for all values of mu.
Evaluating Interpreter's Skill by Measurement of Prosody Recognition
NASA Astrophysics Data System (ADS)
Tanaka, Saori; Nakazono, Kaoru; Nishida, Masafumi; Horiuchi, Yasuo; Ichikawa, Akira
Sign language is a visual language in which main articulators are hands, torso, head, and face. For simultaneous interpreters of Japanese sign language (JSL) and spoken Japanese, it is very important to recognize not only the hands movement but also prosody such like head, eye, posture and facial expression. This is because prosody has grammatical rules for representing the case and modification relations in JSL. The goal of this study is to introduce an examination called MPR (Measurement of Prosody Recognition) and to demonstrate that it can be an indicator for the other general skills of interpreters. For this purpose, we conducted two experiments: the first studies the relationship between the interpreter's experience and the performance score on MPR (Experiment-1), and the second investigates the specific skill that can be estimated by MPR (Experiment-2). The data in Experiment-1 came from four interpreters who had more than 1-year experience as interpreters, and more four interpreters who had less than 1-year experience. The mean accuracy of MPR in the more experienced group was higher than that in the less experienced group. The data in Experiment-2 came from three high MPR interpreters and three low MPR interpreters. Two hearing subjects and three deaf subjects evaluated their skill in terms of the speech or sign interpretation skill, the reliability of interpretation, the expeditiousness, and the subjective sense of accomplishment for the ordering pizza task. The two experiments indicated a possibility that MPR could be useful for estimating if the interpreter is sufficiently experienced to interpret from sign language to spoken Japanese, and if they can work on the interpretation expeditiously without making the deaf or the hearing clients anxious. Finally we end this paper with suggestions for conclusions and future work.
Intra- and Interobserver Variability of Cochlear Length Measurements in Clinical CT.
Iyaniwura, John E; Elfarnawany, Mai; Riyahi-Alam, Sadegh; Sharma, Manas; Kassam, Zahra; Bureau, Yves; Parnes, Lorne S; Ladak, Hanif M; Agrawal, Sumit K
2017-07-01
The cochlear A-value measurement exhibits significant inter- and intraobserver variability, and its accuracy is dependent on the visualization method in clinical computed tomography (CT) images of the cochlea. An accurate estimate of the cochlear duct length (CDL) can be used to determine electrode choice, and frequency map the cochlea based on the Greenwood equation. Studies have described estimating the CDL using a single A-value measurement, however the observer variability has not been assessed. Clinical and micro-CT images of 20 cadaveric cochleae were acquired. Four specialists measured A-values on clinical CT images using both standard views and multiplanar reconstructed (MPR) views. Measurements were repeated to assess for intraobserver variability. Observer variabilities were evaluated using intra-class correlation and absolute differences. Accuracy was evaluated by comparison to the gold standard micro-CT images of the same specimens. Interobserver variability was good (average absolute difference: 0.77 ± 0.42 mm) using standard views and fair (average absolute difference: 0.90 ± 0.31 mm) using MPR views. Intraobserver variability had an average absolute difference of 0.31 ± 0.09 mm for the standard views and 0.38 ± 0.17 mm for the MPR views. MPR view measurements were more accurate than standard views, with average relative errors of 9.5 and 14.5%, respectively. There was significant observer variability in A-value measurements using both the standard and MPR views. Creating the MPR views increased variability between experts, however MPR views yielded more accurate results. Automated A-value measurement algorithms may help to reduce variability and increase accuracy in the future.
Lee, Ho-Hsien; Cherni, Irene; Yu, HongQi; ...
2014-08-20
CTB-MPR is a fusion protein between the B subunit of cholera toxin (CTB) and the membrane-proximal region of gp41 (MPR), the transmembrane envelope protein of Human immunodeficiency virus 1 (HIV-1), and has previously been shown to induce the production of anti-HIV-1 antibodies with antiviral functions. To further improve the design of this candidate vaccine, X-ray crystallography experiments were performed to obtain structural information about this fusion protein. Several variants of CTB-MPR were designed, constructed and recombinantly expressed in Escherichia coli . The first variant contained a flexible GPGP linker between CTB and MPR, and yielded crystals that diffracted to amore » resolution of 2.3 Å, but only the CTB region was detected in the electron-density map. A second variant, in which the CTB was directly attached to MPR, was shown to destabilize pentamer formation. A third construct containing a polyalanine linker between CTB and MPR proved to stabilize the pentameric form of the protein during purification. The purification procedure was shown to produce a homogeneously pure and monodisperse sample for crystallization. Initial crystallization experiments led to pseudo-crystals which were ordered in only two dimensions and were disordered in the third dimension. Nanocrystals obtained using the same precipitant showed promising X-ray diffraction to 5 Å resolution in femtosecond nanocrystallography experiments at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The results demonstrate the utility of femtosecond X-ray crystallography to enable structural analysis based on nano/microcrystals of a protein for which no macroscopic crystals ordered in three dimensions have been observed before.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, Ho-Hsien; Cherni, Irene; Yu, HongQi
CTB-MPR is a fusion protein between the B subunit of cholera toxin (CTB) and the membrane-proximal region of gp41 (MPR), the transmembrane envelope protein of Human immunodeficiency virus 1 (HIV-1), and has previously been shown to induce the production of anti-HIV-1 antibodies with antiviral functions. To further improve the design of this candidate vaccine, X-ray crystallography experiments were performed to obtain structural information about this fusion protein. Several variants of CTB-MPR were designed, constructed and recombinantly expressed in Escherichia coli . The first variant contained a flexible GPGP linker between CTB and MPR, and yielded crystals that diffracted to amore » resolution of 2.3 Å, but only the CTB region was detected in the electron-density map. A second variant, in which the CTB was directly attached to MPR, was shown to destabilize pentamer formation. A third construct containing a polyalanine linker between CTB and MPR proved to stabilize the pentameric form of the protein during purification. The purification procedure was shown to produce a homogeneously pure and monodisperse sample for crystallization. Initial crystallization experiments led to pseudo-crystals which were ordered in only two dimensions and were disordered in the third dimension. Nanocrystals obtained using the same precipitant showed promising X-ray diffraction to 5 Å resolution in femtosecond nanocrystallography experiments at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The results demonstrate the utility of femtosecond X-ray crystallography to enable structural analysis based on nano/microcrystals of a protein for which no macroscopic crystals ordered in three dimensions have been observed before.« less
Umeda, Masataka; Kempka, Laura; Weatherby, Amy; Greenlee, Brennan; Mansion, Kimberly
2016-04-01
Physical activity is important to manage symptom of fibromyalgia (FM); however, individuals with FM typically experience augmented muscle pain during exercise. This study examined the effects of caffeinated chewing gum on exercise-induced muscle pain in individuals with FM. This study was conducted with a double-blind, placebo-controlled, cross-over design. Twenty-three patients with FM completed a caffeine condition where they consumed a caffeinated chewing gum that contains 100mg of caffeine, and a placebo condition where they consumed a non-caffeinated chewing gum. They completed isometric handgrip exercise at 25% of their maximal strength for 3 min, and muscle pain rating (MPR) was recorded every 30s during exercise. Clinical pain severity was assessed in each condition using a pain questionnaire. The order of the two conditions was randomly determined. MPR increased during exercise, but caffeinated chewing gum did not attenuate the increase in MPR compared to placebo gum. Clinical pain severity was generally associated with the average MPR and the caffeine effects on MPR, calculated as difference in the average MPR between the two conditions. The results suggest that more symptomatic individuals with FM may experience greater exercise-induced muscle pain, but benefit more from caffeinated chewing gum to reduce exercise-induced muscle pain. Copyright © 2016 Elsevier Inc. All rights reserved.
Comparing HARPS and Kepler surveys. The alignment of multiple-planet systems
NASA Astrophysics Data System (ADS)
Figueira, P.; Marmier, M.; Boué, G.; Lovis, C.; Santos, N. C.; Montalto, M.; Udry, S.; Pepe, F.; Mayor, M.
2012-05-01
Context. The recent results of the HARPS and Kepler surveys provided us with a bounty of extrasolar systems. While the two teams extensively analyzed each of their data-sets, little work has been done comparing the two. Aims: We study a subset of the planetary population whose characterization is simultaneously within reach of both instruments. We compare the statistical properties of planets in systems with msini > 5-10 M⊕ and R > 2 R⊕, as inferred from the HARPS and Kepler surveys, respectively. If we assume that the underlying population has the same characteristics, the different detection sensitivity to the orbital inclination relative to the line of sight allows us to probe the planets' mutual inclination. Methods: We considered the frequency of systems with one, two, and three planets as dictated by HARPS data. We used Kepler's planetary period and host mass and radius distributions (corrected from detection bias) to model planetary systems in a simple, yet physically plausible way. We then varied the mutual inclination between planets in a system according to different prescriptions (completely aligned, Rayleigh distributions, and isotropic) and compared the transit frequencies with one, two, or three planets with those measured by Kepler. Results: The results show that the two datasets are compatible, a remarkable result especially because there are no tunable knobs other than the assumed inclination distribution. For msini cutoffs of 7-10 M⊕, which are those expected to correspond to the radius cutoff of 2 R⊕, we conclude that the results are better described by a Rayleigh distribution with a mode of 1° or smaller. We show that the best-fit scenario only becomes a Rayleigh distribution with a mode of 5° if we assume a quite extreme mass-radius relationship for the planetary population. Conclusions: These results have important consequences for our understanding of the role of several proposed formation and evolution mechanisms. They confirm that planets are likely to have been formed in a disk and show that most planetary systems evolve quietly without strong angular momentum exchanges such as those produced by Kozai mechanism or planet scattering.
Tan, Xi; Al-Dabagh, Amir; Davis, Scott A; Lin, Hsien-Chang; Balkrishnan, Rajesh; Chang, Jongwha; Feldman, Steven R
2013-06-01
Acne vulgaris is a common chronic disease that may require long-term treatment. Medication adherence is critical to acne management; non-adherence is a common reason for treatment failure and can lead to poor quality of life. The aim of the study was to examine medication adherence, healthcare costs, and utilization associated with acne drugs among acne patients in the USA. This was a retrospective cohort study from January 2004 to December 2007 using the Marketscan Medicaid Database, a national healthcare claims database. The study followed acne patients aged 0-64 years for 90 days after the first acne drug prescription to measure acne medication adherence, acne-related outpatient visits, and total acne-related healthcare costs. Adherence was measured among different acne drug classes using medication possession ratio (MPR). Multivariate regression analyses were conducted to assess the outcomes. The study included 24,438 eligible patients, of whom 89.39 % were under 18 years old. The average adherence rate to acne drugs (MPR) was 0.34, and only 11.74 % of the patients were adherent (MPR ≥0.80). Patients with drug refills had a higher adherence rate (MPR = 0.74) than who those without refills (MPR = 0.27). Factors significantly associated with adherence were age, comorbidity, gender, number of drug refills and number of drug classes used. Patients were more adherent to oral retinoids than any other acne drug classes (MPR = 0.78, 57 % adherent). Patients were less adherent to oral antibiotics (MPR = 0.21) and topical retinoids (MPR = 0.31). After controlling for medication use behavior, the use of oral antibiotics decreased the number of acne-related outpatient visits by 50.9 % (p < 0.001) and lowered acne-related total costs by 51.7 % (p < 0.001). Medication non-adherence is generally prevalent among young acne patients enrolled in Medicaid. The combination of a topical retinoid and an antibiotic agent may be a good choice given their associated healthcare outcomes and costs. However, adherence to these agents is not satisfactory. Therefore, developing specific strategies to improve adherence to these drugs among teenage acne patients is warranted.
NASA Technical Reports Server (NTRS)
Debes, John H.; Hoard, D. W.; Kilic, Mukremin; Wachter, Stefanie; Leisawitz, David T.; Cohen, Martin; Kirkpatrick, J. Davy; Griffith, Roger L.
2011-01-01
With the launch of the Wide-Field Infrared Survey Explorer (WISE), a new era of detecting planetary debris around white dwarfs (WDs) has begun with the WISE InfraRed Excesses around Degenerates (WIRED) Survey. The WIRED survey will be sensitive to substellar objects and dusty debris around WDs out to distances exceeding 100 pc, well beyond the completeness level of local WDs and covering a large fraction of known WDs detected with the SDSS DR4 WD catalog. In this paper, we report an initial result of the WIRED survey, the detection of the heavily polluted hydrogen WD (spectral type DAZ) GALEX Jl93156.S-KlI1745 at 3.35 and 4.6/Lm. We find that the excess is consistent with either a narrow dusty ring with an inner radius of 29 RWD. outer radius of 40 RWD, and a face-on inclination, or a disk with an inclination of 70 , an inner radius of 23 RWD. and an outer radius of 80 RWD. We also report initial optical spectroscopic monitoring of several metal lines present in the photosphere and find no variability in the line strengths or radial velocities of the lines. We rule out all but planetary mass companions to GALEXl931 out to 0.5 AU.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hauchecorne, A.; Meftah, M.; Irbah, A.
On 2012 June 5-6, the transit of Venus provided a rare opportunity to determine the radius of the Sun using solar imagers observing a well-defined object, namely, the planet and its atmosphere, partially occulting the Sun. A new method has been developed to estimate the solar radius during a planetary transit. It is based on the estimation of the spectral solar radiance decrease in a region around the contact between the planet and the Sun at the beginning of the ingress and at the end of the egress. The extrapolation to zero of the radiance decrease versus the Sun-to-Venus apparentmore » angular distance allows estimation of the solar radius at the time of first and fourth contacts. This method presents the advantage of being almost independent on the plate scale, the distortion, the refraction by the planetary atmosphere, and on the point-spread function of the imager. It has been applied to two space solar visible imagers, SODISM/PICARD and HMI/SDO. The found results are mutually consistent, despite their different error budgets: 959.''85 ± 0.''19 (1σ) for SODISM at 607.1 nm and 959.''90 ± 0.''06 (1σ) for HMI at 617.3 nm.« less
NASA Astrophysics Data System (ADS)
Sousa, S. G.; Santos, N. C.; Mortier, A.; Tsantaki, M.; Adibekyan, V.; Delgado Mena, E.; Israelian, G.; Rojas-Ayala, B.; Neves, V.
2015-04-01
Aims: In this work we derive new precise and homogeneous parameters for 37 stars with planets. For this purpose, we analyze high resolution spectra obtained by the NARVAL spectrograph for a sample composed of bright planet host stars in the northern hemisphere. The new parameters are included in the SWEET-Cat online catalogue. Methods: To ensure that the catalogue is homogeneous, we use our standard spectroscopic analysis procedure, ARES+MOOG, to derive effective temperatures, surface gravities, and metallicities. These spectroscopic stellar parameters are then used as input to compute the stellar mass and radius, which are fundamental for the derivation of the planetary mass and radius. Results: We show that the spectroscopic parameters, masses, and radii are generally in good agreement with the values available in online databases of exoplanets. There are some exceptions, especially for the evolved stars. These are analyzed in detail focusing on the effect of the stellar mass on the derived planetary mass. Conclusions: We conclude that the stellar mass estimations for giant stars should be managed with extreme caution when using them to compute the planetary masses. We report examples within this sample where the differences in planetary mass can be as high as 100% in the most extreme cases. Based on observations obtained at the Telescope Bernard Lyot (USR5026) operated by the Observatoire Midi-Pyrénées and the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique of France (Run ID L131N11 - OPTICON_2013A_027).
The sensor kinase MprB is required for Rhodococcus equi virulence.
MacArthur, Iain; Parreira, Valeria R; Lepp, Dion; Mutharia, Lucy M; Vazquez-Boland, José A; Prescott, John F
2011-01-10
Rhodococcus equi is a soil bacterium and, like Mycobacterium tuberculosis, a member of the mycolata. Through possession of a virulence plasmid, it has the ability to infect the alveolar macrophages of foals, resulting in pyogranulomatous bronchopneumonia. The virulence plasmid has an orphan two-component system (TCS) regulatory gene, orf8, mutation of which completely attenuates virulence. This study attempted to find the cognate sensor kinase (SK) of orf8. Annotation of the R. equi strain 103 genome identified 23 TCSs encoded on the chromosome, which were used in a DNA microarray to compare TCS gene transcription in murine macrophage-like cells to growth in vitro. This identified six SKs as significantly up-regulated during growth in macrophages. Mutants of these SKs were constructed and their ability to persist in macrophages was determined with one SK, MprB, found to be required for intracellular survival. The attenuation of the mprB- mutant, and its complementation, was confirmed in a mouse virulence assay. In silico analysis of the R. equi genome sequence identified an MprA binding box motif homologous to that of M. tuberculosis, on mprA, pepD, sigB and sigE. The results of this study also show that R. equi responds to the macrophage environment differently from M. tuberculosis. MprB is the first SK identified as required for R. equi virulence and intracellular survival. Copyright © 2010 Elsevier B.V. All rights reserved.
[Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT].
Kimura, Mikio; Usui, Junshi; Nozawa, Takeo
2007-03-20
In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT) . We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography (3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image.
Dos Santos, Denise Takehana; Costa e Silva, Adriana Paula Andrade; Vannier, Michael Walter; Cavalcanti, Marcelo Gusmão Paraiso
2004-12-01
The purpose of this study was to demonstrate the sensitivity and specificity of multislice computerized tomography (CT) for diagnosis of maxillofacial fractures following specific protocols using an independent workstation. The study population consisted of 56 patients with maxillofacial fractures who were submitted to a multislice CT. The original data were transferred to an independent workstation using volumetric imaging software to generate axial images and simultaneous multiplanar (MPR) and 3-dimensional (3D-CT) volume rendering reconstructed images. The images were then processed and interpreted by 2 examiners using the following protocols independently of each other: axial, MPR/axial, 3D-CT images, and the association of axial/MPR/3D images. The clinical/surgical findings were considered the gold standard corroborating the diagnosis of the fractures and their anatomic localization. The statistical analysis was carried out using validity and chi-squared tests. The association of axial/MPR/3D images indicated a higher sensitivity (range 95.8%) and specificity (range 99%) than the other methods regarding the analysis of all regions. CT imaging demonstrated high specificity and sensitivity for maxillofacial fractures. The association of axial/MPR/3D-CT images added important information in relationship to other CT protocols.
PHOTOMETRICALLY DERIVED MASSES AND RADII OF THE PLANET AND STAR IN THE TrES-2 SYSTEM
DOE Office of Scientific and Technical Information (OSTI.GOV)
Barclay, Thomas; Huber, Daniel; Rowe, Jason F.
We measure the mass and radius of the star and planet in the TrES-2 system using 2.7 years of observations by the Kepler spacecraft. The light curve shows evidence for ellipsoidal variations and Doppler beaming on a period consistent with the orbital period of the planet with amplitudes of 2.79{sup +0.44}{sub -0.62} and 3.44{sup +0.32}{sub -0.37} parts per million (ppm), respectively, and a difference between the dayside and the nightside planetary flux of 3.41{sup +0.55}{sub -0.82} ppm. We present an asteroseismic analysis of solar-like oscillations on TrES-2A which we use to calculate the stellar mass of 0.94 {+-} 0.05 M{submore » Sun} and radius of 0.95 {+-} 0.02 R{sub Sun }. Using these stellar parameters, a transit model fit and the phase-curve variations, we determine the planetary radius of 1.162{sup +0.020}{sub -0.024} R{sub Jup} and derive a mass for TrES-2b from the photometry of 1.44 {+-} 0.21 M{sub Jup}. The ratio of the ellipsoidal variation to the Doppler beaming amplitudes agrees to better than 2{sigma} with theoretical predications, while our measured planet mass and radius agree within 2{sigma} of previously published values based on spectroscopic radial velocity measurements. We measure a geometric albedo of 0.0136{sup +0.0022}{sub -0.0033} and an occultation (secondary eclipse) depth of 6.5{sup +1.7}{sub -1.8} ppm which we combined with the day/night planetary flux ratio to model the atmosphere of TrES-2b. We find that an atmosphere model that contains a temperature inversion is strongly preferred. We hypothesize that the Kepler bandpass probes a significantly greater atmospheric depth on the night side relative to the day side.« less
An overabundance of low-density Neptune-like planets
NASA Astrophysics Data System (ADS)
Cubillos, Patricio; Erkaev, Nikolai V.; Juvan, Ines; Fossati, Luca; Johnstone, Colin P.; Lammer, Helmut; Lendl, Monika; Odert, Petra; Kislyakova, Kristina G.
2017-04-01
We present a uniform analysis of the atmospheric escape rate of Neptune-like planets with estimated radius and mass (restricted to Mp < 30 M⊕). For each planet, we compute the restricted Jeans escape parameter, Λ, for a hydrogen atom evaluated at the planetary mass, radius, and equilibrium temperature. Values of Λ ≲ 20 suggest extremely high mass-loss rates. We identify 27 planets (out of 167) that are simultaneously consistent with hydrogen-dominated atmospheres and are expected to exhibit extreme mass-loss rates. We further estimate the mass-loss rates (Lhy) of these planets with tailored atmospheric hydrodynamic models. We compare Lhy to the energy-limited (maximum-possible high-energy driven) mass-loss rates. We confirm that 25 planets (15 per cent of the sample) exhibit extremely high mass-loss rates (Lhy > 0.1 M⌖ Gyr-1), well in excess of the energy-limited mass-loss rates. This constitutes a contradiction, since the hydrogen envelopes cannot be retained given the high mass-loss rates. We hypothesize that these planets are not truly under such high mass-loss rates. Instead, either hydrodynamic models overestimate the mass-loss rates, transit-timing-variation measurements underestimate the planetary masses, optical transit observations overestimate the planetary radii (due to high-altitude clouds), or Neptunes have consistently higher albedos than Jupiter planets. We conclude that at least one of these established estimations/techniques is consistently producing biased values for Neptune planets. Such an important fraction of exoplanets with misinterpreted parameters can significantly bias our view of populations studies, like the observed mass-radius distribution of exoplanets for example.
Magnetophonon resonance in multimode lattices and two-dimensional structures (DQW)
NASA Astrophysics Data System (ADS)
Ploch, D.; Sheregii, E.; Marchewka, M.; Tomaka, G.
2007-12-01
The experimental results obtained for the magneto-transport in the InGaAs/InAlAs double quantum wells (DQW) structures of two different shapes of wells are reported. The Magnetophonon Resonance (MPR) o was observed for both types of the structures at 77-125K temperatures in the pulsed magnetic field. Four kinds of LO-phonons are taken into account to interpret the MPR oscillations in DQW. The particularity of MPR in DQW is the great number Landau levels caused by SAS-splitting all electron states.
Herd, R M; Arthur, P F; Donoghue, K A; Bird, S H; Bird-Gardiner, T; Hegarty, R S
2014-11-01
Ruminants contribute up to 80% of greenhouse gas (GHG) emissions from livestock, and enteric methane production by ruminants is the main source of these GHG emissions. Hence, reducing enteric methane production is essential in any GHG emissions reduction strategy in livestock. Data from 2 performance-recording research herds of Angus cattle were used to evaluate a number of methane measures that target methane production (MPR) independent of feed intake and to examine their phenotypic relationships with growth and body composition. The data comprised 777 young bulls and heifers that were fed a roughage diet (ME of 9 MJ/kg DM) at 1.2 times their maintenance energy requirements and measured for MP in open circuit respiration chambers for 48 h. Methane traits evaluated included DMI during the methane measurement period, MPR, and methane yield (MY; MPR/DMI), with means (± SD) of 6.2 ± 1.4 kg/d, 187 ± 38 L/d, and 30.4 ± 3.5 L/kg, respectively. Four forms of residual MPR (RMP), which is a measure of actual minus predicted MPR, were evaluated. For the first 3 forms, predicted MPR was calculated using published equations. For the fourth (RMPR), predicted MPR was obtained by regression of MPR on DMI. Growth traits evaluated were BW at birth, weaning (200 d of age), yearling age (400 d of age), and 600 d of age, with means (± SD) of 34 ± 4.6, 238 ± 37, 357 ± 45, and 471 ± 53 kg, respectively. Body composition traits included ultrasound measures (600 d of age) of rib fat, rump fat, and eye muscle area, with means (± SD) of 3.8 ± 2.6 mm, 5.4 ± 3.8 mm, and 61 ± 7.7 cm(2), respectively. Methane production was positively correlated (r ± SE) with DMI (0.65 ± 0.02), MY (0.72 ± 0.02), the RMP traits (r from 0.65 to 0.79), the growth traits (r from 0.19 to 0.57), and the body composition traits (r from 0.13 to 0.29). Methane yield was, however, not correlated (r ± SE) with DMI (-0.02 ± 0.04) as well as the growth (r from -0.03 to 0.11) and body composition (r from 0.01 to 0.06) traits. All the RMP traits were strongly correlated to MY (r from 0.82 to 0.95). These results indicate that reducing MPR per se can have a negative impact on growth and body composition of cattle. Reducing MY, however, will likely have the effect of reducing MPR without impacting productivity. Where a ratio trait is undesirable, as in animal breeding, any of the RMP traits can be used instead of MY. However, where independence from DMI is desired, RMPR should be a trait worth considering.
Albar, Salwa A; Alwan, Nisreen A; Evans, Charlotte E L; Greenwood, Darren C; Cade, Janet E
2016-05-01
myfood24 Is an online 24-h dietary assessment tool developed for use among British adolescents and adults. Limited information is available regarding the validity of using new technology in assessing nutritional intake among adolescents. Thus, a relative validation of myfood24 against a face-to-face interviewer-administered 24-h multiple-pass recall (MPR) was conducted among seventy-five British adolescents aged 11-18 years. Participants were asked to complete myfood24 and an interviewer-administered MPR on the same day for 2 non-consecutive days at school. Total energy intake (EI) and nutrients recorded by the two methods were compared using intraclass correlation coefficients (ICC), Bland-Altman plots (using between and within-individual information) and weighted κ to assess the agreement. Energy, macronutrients and other reported nutrients from myfood24 demonstrated strong agreement with the interview MPR data, and ICC ranged from 0·46 for Na to 0·88 for EI. There was no significant bias between the two methods for EI, macronutrients and most reported nutrients. The mean difference between myfood24 and the interviewer-administered MPR for EI was -230 kJ (-55 kcal) (95 % CI -490, 30 kJ (-117, 7 kcal); P=0·4) with limits of agreement ranging between 39 % (3336 kJ (-797 kcal)) lower and 34 % (2874 kJ (687 kcal)) higher than the interviewer-administered MPR. There was good agreement in terms of classifying adolescents into tertiles of EI (κ w =0·64). The agreement between day 1 and day 2 was as good for myfood24 as for the interviewer-administered MPR, reflecting the reliability of myfood24. myfood24 Has the potential to collect dietary data of comparable quality with that of an interviewer-administered MPR.
Nasuno, Ryo; Hirano, Yoshinori; Itoh, Takafumi; Hakoshima, Toshio; Hibi, Takao; Takagi, Hiroshi
2013-01-01
Mpr1 (sigma1278b gene for proline-analog resistance 1), which was originally isolated as N-acetyltransferase detoxifying the proline analog l-azetidine-2-carboxylate, protects yeast cells from various oxidative stresses. Mpr1 mediates the l-proline and l-arginine metabolism by acetylating l-Δ1-pyrroline-5-carboxylate, leading to the l-arginine–dependent production of nitric oxide, which confers oxidative stress tolerance. Mpr1 belongs to the Gcn5-related N-acetyltransferase (GNAT) superfamily, but exhibits poor sequence homology with the GNAT enzymes and unique substrate specificity. Here, we present the X-ray crystal structure of Mpr1 and its complex with the substrate cis-4-hydroxy-l-proline at 1.9 and 2.3 Å resolution, respectively. Mpr1 is folded into α/β-structure with eight-stranded mixed β-sheets and six α-helices. The substrate binds to Asn135 and the backbone amide of Asn172 and Leu173, and the predicted acetyl-CoA–binding site is located near the backbone amide of Phe138 and the side chain of Asn178. Alanine substitution of Asn178, which can interact with the sulfur of acetyl-CoA, caused a large reduction in the apparent kcat value. The replacement of Asn135 led to a remarkable increase in the apparent Km value. These results indicate that Asn178 and Asn135 play an important role in catalysis and substrate recognition, respectively. Such a catalytic mechanism has not been reported in the GNAT proteins. Importantly, the amino acid substitutions in these residues increased the l-Δ1-pyrroline-5-carboxylate level in yeast cells exposed to heat stress, indicating that these residues are also crucial for its physiological functions. These studies provide some benefits of Mpr1 applications, such as the breeding of industrial yeasts and the development of antifungal drugs. PMID:23818613
Meyers, Juliana; Gajria, Kavita; Candrilli, Sean D; Fridman, Moshe; Sikirica, Vanja
2017-03-01
To assess stimulant adherence among children/adolescents with attention-deficit/hyperactivity disorder (ADHD) augmenting stimulants with guanfacine extended-release (GXR). Inclusion criteria: 6-17 years, ≥1 ADHD diagnosis, ≥1 long-acting and/or short-acting stimulant with GXR augmentation. Modified medication possession ratio (mMPR; days medication available/days in period, excluding medication holidays) was assessed; mMPR <0.80 nonadherent. Regression models assessed change in mMPR adjusting for demographic and clinical characteristics. Among patients nonadherent to stimulants pre-augmentation (n = 165), unadjusted mean (SD) pre- and post-stimulant mMPRs were 0.68 (0.11) and 0.87 (0.16). Adjusted mean change in mMPR was 0.20 for long-acting versus 0.18 for short-acting stimulants (p = 0.34). Among patients nonadherent to stimulants, GXR augmentation was associated with increased stimulant adherence.
Wang, Yong; Zhang, Damao; Liu, Xiaohong; ...
2018-01-06
Mixed-phase clouds containing both liquid droplets and ice particles occur frequently at high latitudes and in the midlatitude storm track regions. Simulations of the cloud phase partitioning between liquid and ice hydrometeors in state-of-the-art global climate models are still associated with large biases. For this study, the phase partitioning in terms of liquid mass phase ratio (MPR liq, defined as the ratio of liquid mass to total condensed water mass) simulated from the NCAR Community Atmosphere Model version 5 (CAM5) is evaluated against the observational data from A-Train satellite remote sensors. Modeled MPR liq is significantly lower than observations onmore » the global scale, especially in the Southern Hemisphere (e.g., Southern Ocean and the Antarctic). Sensitivity tests with CAM5 are conducted to investigate the distinct contributions of heterogeneous ice nucleation, shallow cumulus detrainment, and large-scale environment (e.g., winds, temperature, and water vapor) to the low MPR liq biases. Our results show that an aerosol-aware ice nucleation parameterization increases the MPR liq especially at temperatures colder than -20°C and significantly improves the model agreements with observations in the Polar regions in summer. The decrease of threshold temperature over which all detrained cloud water is liquid from 268 to 253 K enhances the MPR liq and improves the MPR liq mostly over the Southern Ocean. By constraining water vapor in CAM5 toward reanalysis, modeled low biases in many geographical regions are largely reduced through a significant decrease of cloud ice mass mixing ratio.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Yong; Zhang, Damao; Liu, Xiaohong
Mixed-phase clouds containing both liquid droplets and ice particles occur frequently at high latitudes and in the midlatitude storm track regions. Simulations of the cloud phase partitioning between liquid and ice hydrometeors in state-of-the-art global climate models are still associated with large biases. For this study, the phase partitioning in terms of liquid mass phase ratio (MPR liq, defined as the ratio of liquid mass to total condensed water mass) simulated from the NCAR Community Atmosphere Model version 5 (CAM5) is evaluated against the observational data from A-Train satellite remote sensors. Modeled MPR liq is significantly lower than observations onmore » the global scale, especially in the Southern Hemisphere (e.g., Southern Ocean and the Antarctic). Sensitivity tests with CAM5 are conducted to investigate the distinct contributions of heterogeneous ice nucleation, shallow cumulus detrainment, and large-scale environment (e.g., winds, temperature, and water vapor) to the low MPR liq biases. Our results show that an aerosol-aware ice nucleation parameterization increases the MPR liq especially at temperatures colder than -20°C and significantly improves the model agreements with observations in the Polar regions in summer. The decrease of threshold temperature over which all detrained cloud water is liquid from 268 to 253 K enhances the MPR liq and improves the MPR liq mostly over the Southern Ocean. By constraining water vapor in CAM5 toward reanalysis, modeled low biases in many geographical regions are largely reduced through a significant decrease of cloud ice mass mixing ratio.« less
1996-03-07
This image is a full-resolution mosaic of several images from NASA Magellan spacecraft. The radar smooth region in the northern part of the image is Lakshmi Planum, a high plateau region above the mean planetary radius. http://photojournal.jpl.nasa.gov/catalog/PIA00240
MOA-2012-BLG-505Lb: A Super-Earth-mass Planet That Probably Resides in the Galactic Bulge
NASA Astrophysics Data System (ADS)
Nagakane, M.; Sumi, T.; Koshimoto, N.; Bennett, D. P.; Bond, I. A.; Rattenbury, N.; Suzuki, D.; Abe, F.; Asakura, Y.; Barry, R.; Bhattacharya, A.; Donachie, M.; Fukui, A.; Hirao, Y.; Itow, Y.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Matsuo, T.; Muraki, Y.; Ohnishi, K.; Ranc, C.; Saito, To.; Sharan, A.; Shibai, H.; Sullivan, D. J.; Tristram, P. J.; Yamada, T.; Yonehara, A.; MOA Collaboration
2017-07-01
We report the discovery of a super-Earth-mass planet in the microlensing event MOA-2012-BLG-505. This event has the second shortest event timescale of t E = 10 ± 1 days where the observed data show evidence of a planetary companion. Our 15 minute high cadence survey observation schedule revealed the short subtle planetary signature. The system shows the well known close/wide degeneracy. The planet/host-star mass ratio is q = 2.1 × 10-4 and the projected separation normalized by the Einstein radius is s = 1.1 or 0.9 for the wide and close solutions, respectively. We estimate the physical parameters of the system by using a Bayesian analysis and find that the lens consists of a super-Earth with a mass of {6.7}-3.6+10.7 {M}\\oplus orbiting around a brown dwarf or late-M-dwarf host with a mass of {0.10}-0.05+0.16 {M}⊙ with a projected star-planet separation of {0.9}-0.2+0.3 {au}. The system is at a distance of 7.2 ± 1.1 kpc, I.e., it is likely to be in the Galactic bulge. The small angular Einstein radius (θ E = 0.12 ± 0.02 mas) and short event timescale are typical for a low-mass lens in the Galactic bulge. Such low-mass planetary systems in the Bulge are rare because the detection efficiency of planets in short microlensing events is relatively low. This discovery may suggest that such low-mass planetary systems are abundant in the Bulge and currently on-going high cadence survey programs will detect more such events and may reveal an abundance of such planetary systems.
NASA Astrophysics Data System (ADS)
Jin, Sheng; Mordasini, Christoph
2018-02-01
We use an end-to-end model of planet formation, thermodynamic evolution, and atmospheric escape to investigate how the statistical imprints of evaporation depend on the bulk composition of planetary cores (rocky versus icy). We find that the population-wide imprints like the location of the “evaporation valley” in the distance–radius plane and the corresponding bimodal radius distribution clearly differ depending on the bulk composition of the cores. Comparison with the observed position of the valley suggests that close-in low-mass Kepler planets have a predominantly Earth-like rocky composition. Combined with the excess of period ratios outside of MMR, this suggests that low-mass Kepler planets formed inside of the water iceline but were still undergoing orbital migration. The core radius becomes visible for planets losing all primordial H/He. For planets in this “triangle of evaporation” in the distance–radius plane, the degeneracy in composition is reduced. In the observed planetary mass–mean density diagram, we identify a trend to more volatile-rich compositions with an increasing radius (R/R ⊕ ≲ 1.6 rocky; 1.6–3.0 ices, and/or H/He ≳3: H/He). The mass–density diagram contains important information about formation and evolution. Its characteristic broken V-shape reveals the transitions from solid planets to low-mass core-dominated planets with H/He and finally to gas-dominated giants. Evaporation causes the density and orbital distance to be anticorrelated for low-mass planets in contrast to giants, where closer-in planets are less dense, likely due to inflation. The temporal evolution of the statistical properties reported here will be of interest for the PLATO 2.0 mission, which will observe the temporal dimension.
Characterization and role of a metalloprotease induced by chitin in Serratia sp. KCK.
Kim, Hyun-Soo; Golyshin, Peter N; Timmis, Kenneth N
2007-11-01
A metalloprotease induced by chitin in a new chitinolytic bacterium Serratia sp. Strain KCK was purified and characterized. Compared with other Serratia enzymes, it exhibited a rather broad pH activity range (pH 5.0-8.0), and thermostability. The cognate ORF, mpr, was cloned and expressed. Its deduced amino acid sequence showed high similarity to those of bacterial zinc-binding metalloproteases and a well-conserved serralysin family motif. Pretreatment of chitin with the Mpr protein promoted chitin degradation by chitinase A, which suggests that Mpr participates in, and facilitates, chitin degradation by this microorganism.
Solar System Number-Crunching.
ERIC Educational Resources Information Center
Albrecht, Bob; Firedrake, George
1997-01-01
Defines terrestrial and Jovian planets and provides directions to obtain planetary data from the National Space Science Data Center Web sites. Provides "number-crunching" activities for the terrestrial planets using Texas Instruments TI-83 graphing calculators: computing volumetric mean radius and volume, density, ellipticity, speed,…
Ahlberg, Johan; Lendaro, Eva; Hermansson, Liselotte; Håkansson, Bo; Ortiz-Catalan, Max
2018-01-01
The functionality of upper limb prostheses can be improved by intuitive control strategies that use bioelectric signals measured at the stump level. One such strategy is the decoding of motor volition via myoelectric pattern recognition (MPR), which has shown promising results in controlled environments and more recently in clinical practice. Moreover, not much has been reported about daily life implementation and real-time accuracy of these decoding algorithms. This paper introduces an alternative approach in which MPR allows intuitive control of four different grips and open/close in a multifunctional prosthetic hand. We conducted a clinical proof-of-concept in activities of daily life by constructing a self-contained, MPR-controlled, transradial prosthetic system provided with a novel user interface meant to log errors during real-time operation. The system was used for five days by a unilateral dysmelia subject whose hand had never developed, and who nevertheless learned to generate patterns of myoelectric activity, reported as intuitive, for multi-functional prosthetic control. The subject was instructed to manually log errors when they occurred via the user interface mounted on the prosthesis. This allowed the collection of information about prosthesis usage and real-time classification accuracy. The assessment of capacity for myoelectric control test was used to compare the proposed approach to the conventional prosthetic control approach, direct control. Regarding the MPR approach, the subject reported a more intuitive control when selecting the different grips, but also a higher uncertainty during proportional continuous movements. This paper represents an alternative to the conventional use of MPR, and this alternative may be particularly suitable for a certain type of amputee patients. Moreover, it represents a further validation of MPR with dysmelia cases. PMID:29637030
Mastinu, Enzo; Ahlberg, Johan; Lendaro, Eva; Hermansson, Liselotte; Hakansson, Bo; Ortiz-Catalan, Max
2018-01-01
The functionality of upper limb prostheses can be improved by intuitive control strategies that use bioelectric signals measured at the stump level. One such strategy is the decoding of motor volition via myoelectric pattern recognition (MPR), which has shown promising results in controlled environments and more recently in clinical practice. Moreover, not much has been reported about daily life implementation and real-time accuracy of these decoding algorithms. This paper introduces an alternative approach in which MPR allows intuitive control of four different grips and open/close in a multifunctional prosthetic hand. We conducted a clinical proof-of-concept in activities of daily life by constructing a self-contained, MPR-controlled, transradial prosthetic system provided with a novel user interface meant to log errors during real-time operation. The system was used for five days by a unilateral dysmelia subject whose hand had never developed, and who nevertheless learned to generate patterns of myoelectric activity, reported as intuitive, for multi-functional prosthetic control. The subject was instructed to manually log errors when they occurred via the user interface mounted on the prosthesis. This allowed the collection of information about prosthesis usage and real-time classification accuracy. The assessment of capacity for myoelectric control test was used to compare the proposed approach to the conventional prosthetic control approach, direct control. Regarding the MPR approach, the subject reported a more intuitive control when selecting the different grips, but also a higher uncertainty during proportional continuous movements. This paper represents an alternative to the conventional use of MPR, and this alternative may be particularly suitable for a certain type of amputee patients. Moreover, it represents a further validation of MPR with dysmelia cases.
The Direct Imaging Search for Earth 2.0: Quantifying Biases and Planetary False Positives
NASA Astrophysics Data System (ADS)
Guimond, Claire Marie; Cowan, Nicolas B.
2018-06-01
Direct imaging is likely the best way to characterize the atmospheres of Earth-sized exoplanets in the habitable zone of Sun-like stars. Previously, Stark et al. estimated the Earth twin yield of future direct imaging missions, such as LUVOIR and HabEx. We extend this analysis to other types of planets, which will act as false positives for Earth twins. We define an Earth twin as any exoplanet within half an e-folding of 1 au in semimajor axis and 1 {R}\\oplus in planetary radius, orbiting a G-dwarf. Using Monte Carlo analyses, we quantify the biases and planetary false-positive rates of Earth searches. That is, given a pale dot at the correct projected separation and brightness to be a candidate Earth, what are the odds that it is, in fact, an Earth twin? Our notional telescope has a diameter of 10 m, an inner working angle of 3λ/D, and an outer working angle of 10λ/D (62 mas and 206 mas at 1.0 μm). With no precursor knowledge and one visit per star, 77% of detected candidate Earths are actually un-Earths; their mean radius is 2.3 {R}\\oplus , a sub-Neptune. The odds improve if we image every planet at its optimal orbital phase, either by relying on precursor knowledge, or by performing multi-epoch direct imaging. In such a targeted search, 47% of detected Earth twin candidates are false positives, and they have a mean radius of 1.7 {R}\\oplus . The false-positive rate is insensitive to stellar spectral type and the assumption of circular orbits.
Characterization of the Wolf 1061 Planetary System
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kane, Stephen R.; Waters, Miranda A.; Von Braun, Kaspar
A critical component of exoplanetary studies is an exhaustive characterization of the host star, from which the planetary properties are frequently derived. Of particular value are the radius, temperature, and luminosity, which are key stellar parameters for studies of transit and habitability science. Here we present the results of new observations of Wolf 1061, known to host three super-Earths. Our observations from the Center for High Angular Resolution Astronomy interferometric array provide a direct stellar radius measurement of 0.3207±0.0088 R{sub ⊙}, from which we calculate the effective temperature and luminosity using spectral energy distribution models. We obtained 7 yr ofmore » precise, automated photometry that reveals the correct stellar rotation period of 89.3±1.8 days, finds no evidence of photometric transits, and confirms that the radial velocity signals are not due to stellar activity. Finally, our stellar properties are used to calculate the extent of the Habitable Zone (HZ) for the Wolf 1061 system, for which the optimistic boundaries are 0.09–0.23 au. Our simulations of the planetary orbital dynamics show that the eccentricity of the HZ planet oscillates to values as high as ∼0.15 as it exchanges angular momentum with the other planets in the system.« less
Improving SysSim's Planetary Occurrence Rate Estimates
NASA Astrophysics Data System (ADS)
Ashby, Keir; Ragozzine, Darin; Hsu, Danley; Ford, Eric B.
2017-10-01
Kepler's catalog of thousands of transiting planet candidates enables statistical characterization of the underlying planet occurrence rates as a function of period and radius. Due to geometric factors and general noise in measurements, we know that many planets--especially those with a small-radius and/or long-period--were not observed by Kepler.To account for Kepler's detection criteria, Hsu et al. 2017 expanded on work in Lissuaer et al. 2011 to develop the Planetary System Simulator or "SysSim". SysSim uses a forward model to generate simulated catalogs of exoplanet systems, determine which of those simulated planets would have been seen by Kepler in the presence of uncertainties, and then compares those “observed planets” to those actually seen by Kepler. It then uses Approximate Bayesian Computation to infer the posterior probability distributions of the input parameters used to generate the forward model. In Hsu et al. 2017, we focused on matching the observed frequency of planets by solving for the underlying occurrence rate for each bin in a 2-dimensional grid of radius and period. After summarizing the results of Hsu et al. 2017, we show new results that investigate the effect on occurrence rates from including more accurate completeness products (from the Kepler DR25 analysis) into SysSim.
Magnetostrophic balance in planetary dynamos - Predictions for Neptune's magnetosphere
NASA Technical Reports Server (NTRS)
Curtis, S. A.; Ness, N. F.
1986-01-01
With the purpose of estimating Neptune's magnetic field and its implications for nonthermal Neptune radio emissions, a new scaling law for planetary magnetic fields was developed in terms of externally observable parameters (the planet's mean density, radius, mass, rotation rate, and internal heat source luminosity). From a comparison of theory and observations by Voyager it was concluded that planetary dynamos are two-state systems with either zero intrinsic magnetic field (for planets with low internal heat source) or (for planets with the internal heat source sufficiently strong to drive convection) a magnetic field near the upper bound determined from magnetostrophic balance. It is noted that mass loading of the Neptune magnetosphere by Triton may play an important role in the generation of nonthermal radio emissions.
Moukarzel, Lea A; Sinno, Abdulrahman K; Fader, Amanda N; Tanner, Edward J
To compare operative times, surgical outcomes, and costs of robotic laparoendoscopic single-site (R-LESS) vs multiport robotic (MPR) total laparoscopic hysterectomy (TLH) with sentinel lymph node (SLN) mapping for low-risk endometrial cancer. Retrospective cohort study (Canadian Task Force classification II-2). Academic university hospital. Patients with a biopsy-proven diagnosis of complex atypical hyperplasia (CAH) or low-grade (1 or 2) endometrial cancer with body mass index <30 kg/m 2 and undergoing robotic TLH and SLN mapping between 2012 and 2016 were included. Surgical outcomes and cost data were collected retrospectively and analyzed based on the surgical approach with R-LESS vs MPR assistance. Twenty-seven patients who met the inclusion criteria were identified, including 14 patients who underwent R-LESS TLH with SLN mapping and 13 patients who underwent MPR TLH with SLN mapping. Median uterine weight was comparable in the 2 cohorts (111.3 g vs 83.8 g; p = .33). Operative and console times were equivalent with the R-LESS and MPR approaches (median, 175 minutes vs 184 minutes, p = .61 and 136 vs 140 minutes, p = .12, respectively). Median estimated blood loss was 50 mL in both cohorts. Successful bilateral SLN mapping occurred in 85.7% of the R-LESS procedures and 76.9% of MPR procedures. No intraoperative or 30-day complications were encountered, and all patients were discharged within 23 hours of surgery. MPR was associated with additional disposable instrument and drape costs of $460 to $660 compared with R-LESS, depending on the surgeon's instrument selection. Average total hospital charges were lower for R-LESS procedures ($13,410 vs $15,952; p < .05). In highly selected patients with CAH or low-grade endometrial cancer undergoing TLH and SLN mapping, R-LESS appears to result in equivalent perioperative outcomes as a MPR approach while offering a more cost-effective option. Further research is needed to determine the benefits of R-LESS procedures in the gynecologic oncology setting. Copyright © 2017 AAGL. Published by Elsevier Inc. All rights reserved.
Kuppahally, Suman S; Paloma, Allan; Craig Miller, D; Schnittger, Ingela; Liang, David
2008-01-01
A novel multiplanar reformatting (MPR) technique in three-dimensional transthoracic echocardiography (3D TTE) was used to precisely localize the prolapsed lateral segment of posterior mitral valve leaflet in a patient symptomatic with mitral valve prolapse (MVP) and moderate mitral regurgitation (MR) before undergoing mitral valve repair surgery. Transesophageal echocardiography was avoided based on the findings of this new technique by 3D TTE. It was noninvasive, quick, reproducible and reliable. Also, it did not need the time-consuming reconstruction of multiple cardiac images. Mitral valve repair surgery was subsequently performed based on the MPR findings and corroborated the findings from the MPR examination.
Magnetic properties of Proxima Centauri b analogues
NASA Astrophysics Data System (ADS)
Zuluaga, Jorge I.; Bustamante, Sebastian
2018-03-01
The discovery of a planet around the closest star to our Sun, Proxima Centauri, represents a quantum leap in the testability of exoplanetary models. Unlike any other discovered exoplanet, models of Proxima b could be contrasted against near future telescopic observations and far future in-situ measurements. In this paper we aim at predicting the planetary radius and the magnetic properties (dynamo lifetime and magnetic dipole moment) of Proxima b analogues (solid planets with masses of ∼ 1 - 3M⊕ , rotation periods of several days and habitable conditions). For this purpose we build a grid of planetary models with a wide range of compositions and masses. For each point in the grid we run the planetary evolution model developed in Zuluaga et al. (2013). Our model assumes small orbital eccentricity, negligible tidal heating and earth-like radiogenic mantle elements abundances. We devise a statistical methodology to estimate the posterior distribution of the desired planetary properties assuming simple lprior distributions for the orbital inclination and bulk composition. Our model predicts that Proxima b would have a mass 1.3 ≤Mp ≤ 2.3M⊕ and a radius Rp =1.4-0.2+0.3R⊕ . In our simulations, most Proxima b analogues develop intrinsic dynamos that last for ≥4 Gyr (the estimated age of the host star). If alive, the dynamo of Proxima b have a dipole moment ℳdip >0.32÷2.9×2.3ℳdip , ⊕ . These results are not restricted to Proxima b but they also apply to earth-like planets having similar observed properties.
NASA Astrophysics Data System (ADS)
Noack, L.; Wagner, F. W.; Plesa, A.-C.; Höning, D.; Sohl, F.; Breuer, D.; Rauer, H.
2012-04-01
Several space missions (CoRoT, Kepler and others) already provided promising candidates for terrestrial exoplanets (i.e. with masses less than about 10 Earth masses) and thereby triggered an exciting new research branch of planetary modelling to investigate the possible habitability of such planets. Earth analogues (low-mass planets with an Earth-like structure and composition) are likely to be found in the near future with new missions such as the proposed M3 mission PLATO. Planets may be more diverse in the universe than they are in the solar system. Our neighbouring planets in the habitable zone are all terrestrial by the means of being differentiated into an iron core, a silicate mantle and a crust. To reliably determine the interior structure of an exoplanet, measurements of mass and radius have to be sufficiently accurate (around +/-2% error allowed for the radius and +/-5% for the mass). An Earth-size planet with an Earth-like mass but an expected error of ~15% in mass for example may have either a Mercury-like, an Earth-like or a Moon-like (i.e. small iron core) structure [1,2]. Even though the atmospheric escape is not strongly influenced by the interior structure, the outgassing of volatiles and the likeliness of plate tectonics and an ongoing carbon-cycle may be very different. Our investigations show, that a planet with a small silicate mantle is less likely to shift into the plate-tectonics regime, cools faster (which may lead to the loss of a magnetic field after a short time) and outgasses less volatiles than a planet with the same mass but a large silicate mantle and small iron core. To be able to address the habitability of exoplanets, space missions such as PLATO, which can lead up to 2% accuracy in radius [3], are extremely important. Moreover, information about the occurrence of different planetary types helps us to better understand the formation of planetary systems and to further constrain the Drake's equation, which gives an estimate of the expected number of potentially habitable exoplanets in the universe.
32 CFR 635.13 - Amendment of records.
Code of Federal Regulations, 2010 CFR
2010-07-01
... delegable. If the decision is made to amend an MPR, a supplemental DA Form 3975 will be prepared. The supplemental DA Form 3975 will change information on the original DA Form 3975 and will be mailed to the... file the supplemental DA Form 3975 with the original MPR and notify the requestor of the amendment of...
Lysosome sorting of β-glucocerebrosidase by LIMP-2 is targeted by the mannose 6-phosphate receptor.
Zhao, Yuguang; Ren, Jingshan; Padilla-Parra, Sergi; Fry, Elizabeth E; Stuart, David I
2014-07-14
The integral membrane protein LIMP-2 has been a paradigm for mannose 6-phosphate receptor (MPR) independent lysosomal targeting, binding to β-glucocerebrosidase (β-GCase) and directing it to the lysosome, before dissociating in the late-endosomal/lysosomal compartments. Here we report structural results illuminating how LIMP-2 binds and releases β-GCase according to changes in pH, via a histidine trigger, and suggesting that LIMP-2 localizes the ceramide portion of the substrate adjacent to the β-GCase catalytic site. Remarkably, we find that LIMP-2 bears P-Man9GlcNAc2 covalently attached to residue N325, and that it binds MPR, via mannose 6-phosphate, with a similar affinity to that observed between LIMP-2 and β-GCase. The binding sites for β-GCase and the MPR are functionally separate, so that a stable ternary complex can be formed. By fluorescence lifetime imaging microscopy, we also demonstrate that LIMP-2 interacts with MPR in living cells. These results revise the accepted view of LIMP-2-β-GCase lysosomal targeting.
Magnetophonon resonance in double quantum wells
NASA Astrophysics Data System (ADS)
Ploch, D.; Sheregii, E. M.; Marchewka, M.; Wozny, M.; Tomaka, G.
2009-05-01
The experimental results obtained for the magnetotransport in pulsed magnetic fields in the InGaAs/InAlAs double quantum well (DQW) structures of two different shapes of wells and different values of the electron density are reported. The magnetophonon resonance (MPR) was observed for both types of structures within the temperature range 77-125 K. Four kinds of LO phonons are taken into account to interpret the MPR oscillations in the DQW and a method of the Landau level calculation in the DQW is elaborated for this aim. The peculiarity of the MPR in the DQW is the large number of the Landau levels caused by SAS splitting of the electron states (splitting on the symmetric and anti-symmetric states) and the large number of the phonon assistance electron transitions between Landau levels. The significant role of the carrier statistics is shown too. The behavior of the electron states in the DQWs at comparably high temperatures has been studied using the MPR. It is shown that the Huang and Manasreh [Manasreh [Phys. Rev. B 54, 2044 (1996)] model involving screening of exchange interaction is confirmed.
Water-maser emission from a planetary nebula with a magnetized torus.
Miranda, L F; Gómez, Y; Anglada, G; Torrelles, J M
2001-11-15
A star like the Sun becomes a planetary nebula towards the end of its life, when the envelope ejected during the earlier giant phase becomes photoionized as the surface of the remnant star reaches a temperature of approximately 30,000 K. The spherical symmetry of the giant phase is lost in the transition to a planetary nebula, when non-spherical shells and powerful jets develop. Molecules that were present in the giant envelope are progressively destroyed by the radiation. The water-vapour masers that are typical of the giant envelopes therefore are not expected to persist in planetary nebulae. Here we report the detection of water-maser emission from the planetary nebula K3-35. The masers are in a magnetized torus with a radius of about 85 astronomical units and are also found at the surprisingly large distance of about 5,000 astronomical units from the star, in the tips of bipolar lobes of gas. The precessing jets from K3-35 are probably involved in the excitation of the distant masers, although their existence is nevertheless puzzling. We infer that K3-35 is being observed at the very moment of its transformation from a giant star to a planetary nebula.
NASA Technical Reports Server (NTRS)
Okeefe, John D.; Ahrens, Thomas J.
1992-01-01
To obtain a quantitative understanding of the cratering process over a broad range of conditions, we have numerically computed the evolution of impact induced flow fields and calculated the time histories of the major measures of crater geometry (e.g., depth diameter, lip height ...) for variations in planetary gravity (0 to 10 exp 9 cm/sq seconds), material strength (0 to 140 kbar), thermodynamic properties, and impactor radius (0.05 to 5000 km). These results were fit into the framework of the scaling relations of Holsapple and Schmidt (1987). We describe the impact process in terms of four regimes: (1) penetration; (2) inertial; (3) terminal; and (4) relaxation.
Kumar, Joish Upendra; Kavitha, Y
2017-02-01
With the use of various surgical techniques, types of implants, the preoperative assessment of cochlear dimensions is becoming increasingly relevant prior to cochlear implantation. High resolution CISS protocol MRI gives a better assessment of membranous cochlea, cochlear nerve, and membranous labyrinth. Curved Multiplanar Reconstruction (MPR) algorithm provides better images that can be used for measuring dimensions of membranous cochlea. To ascertain the value of curved multiplanar reconstruction algorithm in high resolution 3-Dimensional T2 Weighted Gradient Echo Constructive Interference Steady State (3D T2W GRE CISS) imaging for accurate morphometry of membranous cochlea. Fourteen children underwent MRI for inner ear assessment. High resolution 3D T2W GRE CISS sequence was used to obtain images of cochlea. Curved MPR reconstruction algorithm was used to virtually uncoil the membranous cochlea on the volume images and cochlear measurements were done. Virtually uncoiled images of membranous cochlea of appropriate resolution were obtained from the volume data obtained from the high resolution 3D T2W GRE CISS images, after using curved MPR reconstruction algorithm mean membranous cochlear length in the children was 27.52 mm. Maximum apical turn diameter of membranous cochlea was 1.13 mm, mid turn diameter was 1.38 mm, basal turn diameter was 1.81 mm. Curved MPR reconstruction algorithm applied to CISS protocol images facilitates in getting appropriate quality images of membranous cochlea for accurate measurements.
Arshad, Mehreen; Goller, Carlos C; Pilla, Danielle; Schoenen, Frank J; Seed, Patrick C
2016-04-15
Uropathogenic Escherichia coli (UPEC), a leading cause of urinary tract and invasive infections worldwide, is rapidly acquiring multidrug resistance, hastening the need for selective new anti-infective agents. Here we demonstrate the molecular target of DU011, our previously discovered potent, nontoxic, small-molecule inhibitor of UPEC polysaccharide capsule biogenesis and virulence. Real-time polymerase chain reaction analysis and a target-overexpression drug-suppressor screen were used to localize the putative inhibitor target. A thermal shift assay quantified interactions between the target protein and the inhibitor, and a novel DNase protection assay measured chemical inhibition of protein-DNA interactions. Virulence of a regulatory target mutant was assessed in a murine sepsis model. MprA, a MarR family transcriptional repressor, was identified as the putative target of the DU011 inhibitor. Thermal shift measurements indicated the formation of a stable DU011-MprA complex, and DU011 abrogated MprA binding to its DNA promoter site. Knockout of mprA had effects similar to that of DU011 treatment of wild-type bacteria: a loss of encapsulation and complete attenuation in a murine sepsis model, without any negative change in antibiotic resistance. MprA regulates UPEC polysaccharide encapsulation, is essential for UPEC virulence, and can be targeted without inducing antibiotic resistance. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.
Tsai, M-S; Chuang, P-Y; Huang, C-H; Shih, S-R; Chang, W-T; Chen, N-C; Yu, P-H; Cheng, H-J; Tang, C-H; Chen, W-J
2015-12-01
An increased risk for ischaemic stroke has been reported in young hyperthyroidism patients independent of atrial fibrillation (AF). However, whether the use of antithyroid drugs in hyperthyroidism patients can reduce the occurrence of ischaemic stroke remains unclear. A total of 36,510 newly diagnosed hyperthyroidism patients during 2003-2006 were identified from the Taiwan National Health Insurance Research database. Each patient was individually tracked for 5 years from their index date (beginning the antithyroid drugs) to identify those who suffered from new episode of ischaemic stroke. Medication possession ratio (MPR) was used to represent the antithyroid drug compliance. The association between the MPR and the risk of stroke was examined. The stroke incidence rates for hyperthyroidism patients with age < 45 years and age ≥ 45 years were 0.42 and 3.76 per 1000 person-years, respectively. The patients aged < 45 years with MPR < 0.2 (adjusted hazard ratio, HR, 2.30; 95% CI, 1.13-4.70; p = 0.02) and 0.2 ≤ MPR < 0.4 (adjusted HR, 2.24; 95% CI, 1.06-4.72; p = 0.035) had a significantly increased risk of ischaemic stroke as compared to those with ≥ 0.6. In patients of the age ≥ 45 years, only the patients with MPR < 0.2 (adjusted HR, 1.44; 95% CI, 1.03-2.01; p = 0.036) had a significantly higher risk of ischaemic stroke as compared to those with MPR ≥ 0.6. In hyperthyroidism patients without AF, good antithyroid drugs compliance also reduced the incidence of stroke significantly (adjusted HR, range: 1.52-1.61; p = 0.02); but not in hyperthyroidism with AF. Hyperthyroidism patients with good antithyroid drug compliance had a lower risk of ischaemic stroke than patients with poor compliance. © 2015 John Wiley & Sons Ltd.
Low-contrast detectability in volume rendering: a phantom study on multidetector-row spiral CT data.
Shin, Hoen-Oh; Falck, Christian V; Galanski, Michael
2004-02-01
To cope with the increasing amount of CT data, there is growing interest in direct volume-rendering techniques (VRT) as a diagnostic tool. The aim of this phantom study was to analyze the low-contrast detectability (LCD) of VRT compared with multi-planar reformations (MPR). Soft tissue lesions were simulated by spheres of different diameters (3-8 mm). The average lesion density was 15 HU compared with a background density of 35 HU. Two different CT protocols with 40 and 150 mAs were performed on a multi-detector row CT. The scanning parameters were as following: 140 kV; 2x0.5-mm slice collimation; pitch 2 (table movement per rotation/single slice collimation), and reconstruction with 0.5-mm slice thickness at 0.5-mm interval. A B30 kernel was used for reconstruction. The VRT was performed by mapping Hounsfield values to gray levels equal to a CT window (center: 60 HU; window: 370 HU ). A linear ramp was applied for the opacity transfer function varying the maximum opacity between 0.1 and 1.0. A statistical method based on the Rose model was used to calculate the detection threshold depending on lesion size and image noise. Additionally, clinical data of 2 patients with three liver lesions of different sizes and density were evaluated. In VRT, LCD was most dependent on object size. Regarding lesions larger than 5 mm, VRT is significantly superior to MPR (p<0.05) for all opacity settings. In lesions sized 3-5 mm a maximum opacity level approximately 40-50% showed a near equivalent detectability in VRT and MPR. For higher opacity levels VRT was superior to MPR. Only for 3-mm lesions MPR performed slightly better in low-contrast detectability (p<0.05). Compared with MPR, VRT shows similar performance in LCD. Due to noise suppression effects, it is suited for visualization of data with high noise content.
High-precision photometry by telescope defocusing - VII. The ultrashort period planet WASP-103
NASA Astrophysics Data System (ADS)
Southworth, John; Mancini, L.; Ciceri, S.; Budaj, J.; Dominik, M.; Figuera Jaimes, R.; Haugbølle, T.; Jørgensen, U. G.; Popovas, A.; Rabus, M.; Rahvar, S.; von Essen, C.; Schmidt, R. W.; Wertz, O.; Alsubai, K. A.; Bozza, V.; Bramich, D. M.; Calchi Novati, S.; D'Ago, G.; Hinse, T. C.; Henning, Th.; Hundertmark, M.; Juncher, D.; Korhonen, H.; Skottfelt, J.; Snodgrass, C.; Starkey, D.; Surdej, J.
2015-02-01
We present 17 transit light curves of the ultrashort period planetary system WASP-103, a strong candidate for the detection of tidally-induced orbital decay. We use these to establish a high-precision reference epoch for transit timing studies. The time of the reference transit mid-point is now measured to an accuracy of 4.8 s, versus 67.4 s in the discovery paper, aiding future searches for orbital decay. With the help of published spectroscopic measurements and theoretical stellar models, we determine the physical properties of the system to high precision and present a detailed error budget for these calculations. The planet has a Roche lobe filling factor of 0.58, leading to a significant asphericity; we correct its measured mass and mean density for this phenomenon. A high-resolution Lucky Imaging observation shows no evidence for faint stars close enough to contaminate the point spread function of WASP-103. Our data were obtained in the Bessell RI and the SDSS griz passbands and yield a larger planet radius at bluer optical wavelengths, to a confidence level of 7.3σ. Interpreting this as an effect of Rayleigh scattering in the planetary atmosphere leads to a measurement of the planetary mass which is too small by a factor of 5, implying that Rayleigh scattering is not the main cause of the variation of radius with wavelength.
Darkow, Theodore; Henk, Henry J; Thomas, Simu K; Feng, Weiwei; Baladi, Jean-Francois; Goldberg, George A; Hatfield, Alan; Cortes, Jorge
2007-01-01
Identify treatment interruptions and non-adherence with imatinib; examine the clinical and patient characteristics related to treatment interruptions and non-adherence; and estimate the association between treatment interruptions and non-adherence with imatinib and healthcare costs for US managed care patients with chronic myeloid leukaemia (CML). This retrospective analysis utilised electronic healthcare claims data from a US managed care provider. Adult patients with CML (as determined by International Classification of Diseases, ninth revision, Clinical Modification [ICD-9-CM] diagnosis code) were identified who began treatment with imatinib from 1 June 2001 through 31 March 2004. Treatment interruptions (i.e. failure to refill imatinib within 30 days from the run-out date of the prior prescription) were identified during the 12-month follow-up period. Medication possession ratio (MPR), calculated as total days' supply of imatinib divided by 365, was also examined. Healthcare costs (i.e. paid amounts for all prescription medications and medical services received, including health plan and patient liability) were examined in three ways: (i) total healthcare costs; (ii) total healthcare costs exclusive of imatinib costs; and (iii) total medical costs. All costs were converted to US dollars (2004 values) using the medical component of the Consumer Price Index. MPR was modelled using ordinary least squares regression. Presence of treatment interruptions was modelled using logistic regression. The association between MPR and healthcare costs was estimated using a generalised linear model specified with a gamma error distribution and a log link. All models included adjustment for age, gender, number of concomitant medications, starting dose of imatinib and cancer complexity. A total of 267 patients were identified. Average age was approximately 50 years, and 43% were women. Mean MPR was 77.7%, with 31% of patients having a treatment interruption. However, all of these patients resumed imatinib within the study period. In this population, MPR decreased as the number of concomitant medications increased (p = 0.002), and was lower among women (p = 0.003), patients with high cancer complexity (p = 0.003) and patients with a higher starting dose of imatinib (p = 0.04). Women were approximately twice as likely as men to have a treatment interruption (p = 0.009), as were patients with a high cancer complexity (p = 0.03). After adjusting for the aforementioned covariates, MPR was found to be inversely associated with healthcare costs excluding imatinib (p < 0.001) and medical costs (p < 0.001). A 10% point difference in MPR was associated with a 14% difference in healthcare costs excluding imatinib and a 15% difference in medical costs. For example, patients with an MPR of 75% incur an additional 4072 US dollars in medical costs annually compared with patients with an MPR of 85%. Treatment interruptions and non-adherence with imatinib, both of which could lead to undesired clinical and economic outcomes, appear to be prevalent. Physicians and pharmacists should educate patients and closely monitor adherence to therapy, as improving adherence and limiting treatment interruptions may not only optimise clinical outcomes but also reduce the economic burden of CML.
An Outbreak of Itching in an Elementary School--A Case of Mass Psychogenic Response
ERIC Educational Resources Information Center
Halvorson, Heather; Crooks, Janet; LaHart, Daniel A.; Farrell, Katherine P.
2008-01-01
Mass psychogenic response (MPR), also referred to as epidemic hysteria, mass hysteria, or mass psychological illness, has been identified for over 600 years. MPR is a syndrome comprising a collection of symptoms, which are consistent with organic illness, but lack an identifiable cause, and which rapidly spread through socially connected groups…
NASA Astrophysics Data System (ADS)
Beatty, Thomas G.; Stevens, Daniel J.; Collins, Karen A.; Colón, Knicole D.; James, David J.; Kreidberg, Laura; Pepper, Joshua; Rodriguez, Joseph E.; Siverd, Robert J.; Stassun, Keivan G.; Kielkopf, John F.
2017-07-01
Using the Spitzer Space Telescope, we observed a transit at 3.6 μm of KELT-11b. We also observed three partial planetary transits from the ground. We simultaneously fit these observations, ground-based photometry from Pepper et al., radial velocity data from Pepper et al., and a spectral energy distribution (SED) model using catalog magnitudes and the Hipparcos parallax to the system. The only significant difference between our results and those of Pepper et al. is that we find the orbital period to be shorter by 37 s, 4.73610 ± 0.00003 versus 4.73653 ± 0.00006 days, and we measure a transit center time of {{BJD}}{TDB} 2457483.4310 ± 0.0007, which is 42 minutes earlier than predicted. Using our new photometry, we precisely measure the density of the star KELT-11 to 4%. By combining the parallax and catalog magnitudes of the system, we are able to measure the radius of KELT-11b essentially empirically. Coupled with the stellar density, this gives a parallactic mass and radius of 1.8 {M}⊙ and 2.9 {R}⊙ , which are each approximately 1σ higher than the adopted model-estimated mass and radius. If we conduct the same fit using the expected parallax uncertainty from the final Gaia data release, this difference increases to 4σ. The differences between the model and parallactic masses and radii for KELT-11 demonstrate the role that precise Gaia parallaxes, coupled with simultaneous photometric, radial velocity, and SED fitting, can play in determining stellar and planetary parameters. With high-precision photometry of transiting planets and high-precision Gaia parallaxes, the parallactic mass and radius uncertainties of stars become 1% and 3%, respectively. TESS is expected to discover 60-80 systems where these measurements will be possible. These parallactic mass and radius measurements have uncertainties small enough that they may provide observational input into the stellar models themselves.
The Secondary Eclipse and Transit of HD 209458b at 24 micron
NASA Astrophysics Data System (ADS)
Harrington, J.; Luszcz, S.; Deming, D.; Richardson, L. J.; Seager, S.
2005-08-01
We used the Multiband Imaging Photometer on the Spitzer Space Telescope to obtain 24-micron lightcurves for one secondary eclipse and half a transit of extrasolar planet HD 209458b behind/in front of its star. Optimal photometric extraction of the total system brightness gives S/N of ˜100 per 10-sec exposure. We measure the deficit of planetary flux in secondary eclipse at 55 ± 10 μ Jy, or 0.260 ± 0.046% of the stellar flux, giving a brightness temperature of 1130 ± 150 K. The secondary eclipse occurs within 7 min (1σ ) of the mid-time between transits, essentially eliminating the hypothesis that HD 209458b's radius is inflated by tidal dissipation due to an elliptical orbit. Such an orbit would have required a second planet in a resonant orbit. This measurement and a similar, simultaneously-submitted result for TrES-1 by Charbonneau et al. (2005) are the first direct measurements of radiation from confirmed extrasolar planets. We measure a preliminary transit depth of 1.559 ± 0.065% of the stellar flux. The stellar limb-darkening curve is flat to within the errors, as expected for this wavelength. Adopting a stellar radius of 1.18 ± 0.10 R⊙ (Cody and Sasselov 2002) gives a planetary radius of 1.43 ± 0.13 RJ, consistent with that derived from optical measurements. The large error bar prevents us from ruling out a significant wavelength dependence of the eclipsing radius, as might be be expected if a particulate coma were responsible for the inflated optical radius. Spitzer has acquired an additional complete transit; updated results will be presented at the conference. This work was supported by the NASA Origins of Solar Systems program and the Spitzer Space Telescope. LJR is an NRC research associate.
DISCOVERY AND ATMOSPHERIC CHARACTERIZATION OF GIANT PLANET KEPLER-12b: AN INFLATED RADIUS OUTLIER
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fortney, Jonathan J.; Nutzman, Philip; Demory, Brice-Olivier
We report the discovery of planet Kepler-12b (KOI-20), which at 1.695 {+-} 0.030 R{sub J} is among the handful of planets with super-inflated radii above 1.65 R{sub J}. Orbiting its slightly evolved G0 host with a 4.438 day period, this 0.431 {+-} 0.041 M{sub J} planet is the least irradiated within this largest-planet-radius group, which has important implications for planetary physics. The planet's inflated radius and low mass lead to a very low density of 0.111 {+-} 0.010 g cm{sup -3}. We detect the occultation of the planet at a significance of 3.7{sigma} in the Kepler bandpass. This yields amore » geometric albedo of 0.14 {+-} 0.04; the planetary flux is due to a combination of scattered light and emitted thermal flux. We use multiple observations with Warm Spitzer to detect the occultation at 7{sigma} and 4{sigma} in the 3.6 and 4.5 {mu}m bandpasses, respectively. The occultation photometry timing is consistent with a circular orbit at e < 0.01 (1{sigma}) and e < 0.09 (3{sigma}). The occultation detections across the three bands favor an atmospheric model with no dayside temperature inversion. The Kepler occultation detection provides significant leverage, but conclusions regarding temperature structure are preliminary, given our ignorance of opacity sources at optical wavelengths in hot Jupiter atmospheres. If Kepler-12b and HD 209458b, which intercept similar incident stellar fluxes, have the same heavy-element masses, the interior energy source needed to explain the large radius of Kepler-12b is three times larger than that of HD 209458b. This may suggest that more than one radius-inflation mechanism is at work for Kepler-12b or that it is less heavy-element rich than other transiting planets.« less
NASA Astrophysics Data System (ADS)
Alvarez-Meraz, R.; Nagel, E.; Rendon, F.; Barragan, O.
2017-10-01
We present a set of hydrodynamical models of a planetary system embedded in a protoplanetary disk in order to extract the number of dust structures formed in the disk, their masses and sizes, within optical depth ranges τ≤0.5, 0.5<τ<2 and τ≥2. The study of the structures shows: (1) an increase in the number of planets implies an increase in the creation rate of massive structures; (2) a lower planetary mass accretion corresponds to slower time effects for optically thin structures; (3) an increase in the number of planets allows a faster evolution of the structures in the Hill radius for the different optical depth ranges of the inner planets. An ad-hoc simulation was run using the available information of the stellar system V1247 Ori, leading to a model of a planetary system which explains the SED and is consistent with interferometric observations of structures.
Estimating the Magnetic Field Strength in Hot Jupiters
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yadav, Rakesh K.; Thorngren, Daniel P., E-mail: rakesh_yadav@fas.harvard.edu
A large fraction of known Jupiter-like exoplanets are inflated as compared to Jupiter. These “hot” Jupiters orbit close to their parent star and are bombarded with intense starlight. Many theories have been proposed to explain their radius inflation and several suggest that a small fraction of the incident starlight is injected into the planetary interior, which helps to puff up the planet. How will such energy injection affect the planetary dynamo? In this Letter, we estimate the surface magnetic field strength of hot Jupiters using scaling arguments that relate energy available in planetary interiors to the dynamo-generated magnetic fields. Wemore » find that if we take into account the energy injected in the planetary interior that is sufficient to inflate hot Jupiters to observed radii, then the resulting dynamo should be able generate magnetic fields that are more than an order of magnitude stronger than the Jovian values. Our analysis highlights the potential fundamental role of the stellar light in setting the field strength in hot Jupiters.« less
NASA Astrophysics Data System (ADS)
Unterborn, Cayman T.
2018-01-01
A planet’s mass-radius relationship alone is not a good indicator for its potential to be "Earth-like." While useful in coarse characterizations for distinguishing whether an exoplanet is water/atmosphere- or rock/iron-dominated, there is considerable degeneracy in using the mass-radius relation to determine the mineralogy and structure of a purely terrestrial planet like the Earth. The chemical link between host-stars and rocky planets and the utility of this connection in breaking the degeneracy in the mass-radius relationship is well documented. Given the breadth of observed stellar compositions, modeling the complex effects of these compositional variations on a terrestrial planet’s mineralogy, structure and temperature profile, and the potential pitfalls therein, falls within the purview of the geosciences.I will demonstrate here, the utility in adopting the composition of a terrestrial planet’s host star for contextualizing individual systems (e.g. TRAPPIST-1), as well as for the more general case of quantifying the geophysical consequences of stellar compositional diversity. This includes the potential for a host-star to produce planets able to undergo mantle convection, surface-to-interior degassing and long-term plate tectonics. As we search for truly “Earth-like” planets, we must move away from the simple density-driven definition of “Earth-like” and towards a more holistic view that includes both geochemistry and geophysics. Combining geophysical models and those of planetary formation with host-star abundance data, then, is of paramount importance. This will aid not only in our understanding of the mass-radius relationship but also provide foundational results necessary interpreting future atmospheric observations through the lens of surface-interior interactions (e.g. volcanism) and planetary evolution as a whole.
NASA Technical Reports Server (NTRS)
Dressing, Courtney D.; Newton, Elisabeth R.; Schlieder, Joshua E.; Charbomeau, David; Krutson, Heather A.; Vanderburg, Andrew; Sinukoff, Evan
2017-01-01
We present near-infrared spectra for 144 candidate planetary systems identified during Campaigns 1-7 of the NASA K2 Mission. The goal of the survey was to characterize planets orbiting low-mass stars, but our Infrared Telescope Facility/SpeX and Palomar/TripleSpec spectroscopic observations revealed that 49% of our targets were actually giant stars or hotter dwarfs reddened by interstellar extinction. For the 72 stars with spectra consistent with classification as cool dwarfs (spectral types K3-M4), we refined their stellar properties by applying empirical relations based on stars with interferometric radius measurements. Although our revised temperatures are generally consistent with those reported in the Ecliptic Plane Input Catalog (EPIC), our revised stellar radii are typically 0.13 solar radius (39%) larger than the EPIC values, which were based on model isochrones that have been shown to underestimate the radii of cool dwarfs. Our improved stellar characterizations will enable more efficient prioritization of K2 targets for follow-up studies.
Martian canyons and African rifts: Structural comparisons and implications
NASA Technical Reports Server (NTRS)
Frey, H. V.
1978-01-01
The resistant parts of the canyon walls of the Martian rift complex Valled Marineris were used to infer an earlier, less eroded reconstruction of the major roughs. The individual canyons were then compared with individual rifts of East Africa. When measured in units of planetary radius, Martian canyons show a distribution of lengths nearly identical to those in Africa, both for individual rifts and for compound rift systems. A common mechanism which scales with planetary radius is suggested. Martian canyons are significantly wider than African rifts. The overall pattern of the rift systems of Africa and Mars are quite different in that the African systems are composed of numerous small faults with highly variable trend. On Mars the trends are less variable; individual scarps are straighter for longer than on earth. This is probably due to the difference in tectonic histories of the two planets: the complex history of the earth and the resulting complicated basement structures influence the development of new rifts. The basement and lithosphere of Mars are inferred to be simple, reflecting a relatively inactive tectonic history prior to the formation of the canyonlands.
KEPLER-14b: A MASSIVE HOT JUPITER TRANSITING AN F STAR IN A CLOSE VISUAL BINARY
DOE Office of Scientific and Technical Information (OSTI.GOV)
Buchhave, Lars A.; Latham, David W.; Carter, Joshua A.
We present the discovery of a hot Jupiter transiting an F star in a close visual (0.''3 sky projected angular separation) binary system. The dilution of the host star's light by the nearly equal magnitude stellar companion ({approx}0.5 mag fainter) significantly affects the derived planetary parameters, and if left uncorrected, leads to an underestimate of the radius and mass of the planet by 10% and 60%, respectively. Other published exoplanets, which have not been observed with high-resolution imaging, could similarly have unresolved stellar companions and thus have incorrectly derived planetary parameters. Kepler-14b (KOI-98) has a period of P = 6.790more » days and, correcting for the dilution, has a mass of M{sub p} = 8.40{sup +0.35}{sub -0.34} M{sub J} and a radius of R{sub p} = 1.136{sup +0.073}{sub -0.054} R{sub J}, yielding a mean density of {rho}{sub p} = 7.1 {+-} 1.1 g cm{sup -3}.« less
The signatures of the parental cluster on field planetary systems
NASA Astrophysics Data System (ADS)
Cai, Maxwell Xu; Portegies Zwart, Simon; van Elteren, Arjen
2018-03-01
Due to the high stellar densities in young clusters, planetary systems formed in these environments are likely to have experienced perturbations from encounters with other stars. We carry out direct N-body simulations of multiplanet systems in star clusters to study the combined effects of stellar encounters and internal planetary dynamics. These planetary systems eventually become part of the Galactic field population as the parental cluster dissolves, which is where most presently known exoplanets are observed. We show that perturbations induced by stellar encounters lead to distinct signatures in the field planetary systems, most prominently, the excited orbital inclinations and eccentricities. Planetary systems that form within the cluster's half-mass radius are more prone to such perturbations. The orbital elements are most strongly excited in the outermost orbit, but the effect propagates to the entire planetary system through secular evolution. Planet ejections may occur long after a stellar encounter. The surviving planets in these reduced systems tend to have, on average, higher inclinations and larger eccentricities compared to systems that were perturbed less strongly. As soon as the parental star cluster dissolves, external perturbations stop affecting the escaped planetary systems, and further evolution proceeds on a relaxation time-scale. The outer regions of these ejected planetary systems tend to relax so slowly that their state carries the memory of their last strong encounter in the star cluster. Regardless of the stellar density, we observe a robust anticorrelation between multiplicity and mean inclination/eccentricity. We speculate that the `Kepler dichotomy' observed in field planetary systems is a natural consequence of their early evolution in the parental cluster.
Nicoziani, Paolo; Vilhardt, Frederik; Llorente, Alicia; Hilout, Leila; Courtoy, Pierre J.; Sandvig, Kirsten; van Deurs, Bo
2000-01-01
It is well established that dynamin is involved in clathrin-dependent endocytosis, but relatively little is known about possible intracellular functions of this GTPase. Using confocal imaging, we found that endogenous dynamin was associated with the plasma membrane, the trans-Golgi network, and a perinuclear cluster of cation-independent mannose 6-phosphate receptor (CI-MPR)–containing structures. By electron microscopy (EM), it was shown that these structures were late endosomes and that the endogenous dynamin was preferentially localized to tubulo-vesicular appendices on these late endosomes. Upon induction of the dominant-negative dynK44A mutant, confocal microscopy demonstrated a redistribution of the CI-MPR in mutant-expressing cells. Quantitative EM analysis of the ratio of CI-MPR to lysosome-associated membrane protein-1 in endosome profiles revealed a higher colocalization of the two markers in dynK44A-expressing cells than in control cells. Western blot analysis showed that dynK44A-expressing cells had an increased cellular procathepsin D content. Finally, EM revealed that in dynK44A-expressing cells, endosomal tubules containing CI-MPR were formed. These results are in contrast to recent reports that dynamin-2 is exclusively associated with endocytic structures at the plasma membrane. They suggest instead that endogenous dynamin also plays an important role in the molecular machinery behind the recycling of the CI-MPR from endosomes to the trans-Golgi network, and we propose that dynamin is required for the final scission of vesicles budding from endosome tubules. PMID:10679008
Gilmer, Todd P; Ojeda, Victoria D; Barrio, Concepcion; Fuentes, Dahlia; Garcia, Piedad; Lanouette, Nicole M; Lee, Kelly C
2009-02-01
The authors examined data for 7,784 Latino, Asian, and non-Latino white Medi-Cal beneficiaries with schizophrenia to determine the relationship between patients' preferred language for mental health services--English, Spanish, or an Asian language--and their adherence to treatment with antipsychotic medications. Data reflected 31,560 person-years from 1999 to 2004. Pharmacy records were analyzed to assess medication adherence by use of the medication possession ratio (MPR). Clients were defined as nonadherent (MPR<.5), partially adherent (MPR=.5-<.8), or adherent (MPR=.8-1.1) or as an excess filler of prescriptions (MPR<1.1). Regression models were used to examine adherence, hospitalization, and costs by race-ethnicity and language status. Latinos with limited English proficiency were more likely than English-proficient Latinos to be medication adherent (41% versus 36%; p<.001) and less likely to be excess fillers (15% versus 20%; p<.001). Asians with limited English proficiency were less likely than English-proficient Asians to be adherent (40% versus 45%; p=.034), more likely to be nonadherent (29% versus 22%; p<.001), and less likely to be excess fillers (13% versus 17%; p=.004). When analyses controlled for adherence and comorbidities, clients with limited English proficiency had lower rates of hospitalization and lower health care costs than English-proficient and white clients. Adherence to antipsychotic medications varied by English proficiency among and within ethnic groups. Policies supporting the training of bilingual and multicultural providers from ethnic minority groups and interventions that capitalize on patients' existing social support networks may improve adherence to treatment in linguistically diverse populations.
The Eclipsing Central Stars of the Planetary Nebulae Lo 16 and PHR J1040-5417
NASA Astrophysics Data System (ADS)
Hillwig, Todd C.; Frew, David; Jones, David; Crispo, Danielle
2017-01-01
Binary central stars of planetary nebula are a valuable tool in understanding common envelope evolution. In these cases both the resulting close binary system and the expanding envelope (the planetary nebula) can be studied directly. In order to compare observed systems with common envelope evolution models we need to determine precise physical parameters of the binaries and the nebulae. Eclipsing central stars provide us with the best opportunity to determine high precision values for mass, radius, and temperature of the component stars in these close binaries. We present photometry and spectroscopy for two of these eclipsing systems; the central stars of Lo 16 and PHR 1040-5417. Using light curves and radial velocity curves along with binary modeling we provide physical parameters for the stars in both of these systems.
ERIC Educational Resources Information Center
Glazerman, Steven; Seif, Elizabeth; Baxter, Gail
2008-01-01
This report examines the career trajectories of those who have successfully completed the Passport to Teaching certification offered by the American Board for Certification of Teacher Excellence (ABCTE) during its first years of existence. To elicit information on the career choices of Passport alumni, Mathematica Policy Research, Inc. (MPR)…
CoRoT-2b: a Tidally Inflated, Young Exoplanet?
NASA Astrophysics Data System (ADS)
Guillot, Tristan; Havel, M.
2009-09-01
CoRoT-2b is among the most anomalously large transiting exoplanet known. Due to its large mass (3.3 Mjup), its large radius ( 1.5 Rjup) cannot be explained by standard evolution models. Recipes that work for other anomalously large exoplanets (e.g. HD209458b), such as invoking kinetic energy transport in the planetary interior or increased opacities, clearly fail for CoRoT-2b. Interestingly, the planet's parent star is an active star with a large fraction (7 to 20%) of spots and a rapid rotation (4.5 days). We first model the star's evolution to accurately constrain the planetary parameters. We find that the stellar activity has little influence on the star's evolution and inferred parameters. However, stellar evolution models point towards two kind of solutions for the star-planet system: (i) a very young system (20-40 Ma) with a star still undergoing pre-main sequence contraction, and a planet which could have a radius as low as 1.4 Rjup, or (ii) a young main-sequence star (40 to 500 Ma) with a planet that is slightly more inflated ( 1.5 Rjup). In either case, planetary evolution models require a significant added internal energy to explain the inferred planet size: from a minimum of 3x1028 erg/s in case (i), to up to 1.5x1029 erg/s in case (ii). We find that evolution models consistently including planet/star tides are able to reproduce the inferred radius but only for a short period of time ( 10 Ma). This points towards a young age for the star/planet system and dissipation by tides due to either circularization or synchronization of the planet. Additional observations of the star (infrared excess due to disk?) and of the planet (precise Rossiter effect, IR secondary eclispe) would be highly valuable to understand the early evolution of star-exoplanet systems.
Killeen, Peter R.; Sitomer, Matthew T.
2008-01-01
Mathematical Principles of Reinforcement (MPR) is a theory of reinforcement schedules. This paper reviews the origin of the principles constituting MPR: arousal, association and constraint. Incentives invigorate responses, in particular those preceding and predicting the incentive. The process that generates an associative bond between stimuli, responses and incentives is called coupling. The combination of arousal and coupling constitutes reinforcement. Models of coupling play a central role in the evolution of the theory. The time required to respond constrains the maximum response rates, and generates a hyperbolic relation between rate of responding and rate of reinforcement. Models of control by ratio schedules are developed to illustrate the interaction of the principles. Correlations among parameters are incorporated into the structure of the models, and assumptions that were made in the original theory are refined in light of current data. PMID:12729968
Miron, T; Arditti, F; Konstantinovski, L; Rabinkov, A; Mirelman, D; Berrebi, A; Wilchek, M
2009-02-01
Biologically active S-allylthio derivatives of 6-mercaptopurine (6-MP) and 6-mercaptopurine riboside (6-MPR) were synthesized. The products, S-allylthio-6-mercaptopurine (SA-6MP) and S-allylthio-6-mercaptopurine riboside (SA-6MPR) were characterized. The antiproliferative activity of the new prodrugs was tested on human leukemia and monolayer cell lines, and compared to that of their parent reactants. The new prodrugs acted by a concentration-dependent mechanism. They inhibited cell proliferation and induced-apoptosis more efficiently than the parent molecules. Leukemia cell lines were more sensitive to the new prodrugs than monolayer cell lines. Higher hydrophobicity of the derivatives improves their penetration into cells, where upon reaction with glutathione, S-allylthioglutathione (GSSA) is formed, and 6-MP or 6-MPR is released for further processing.
A gaseous metal disk around a white dwarf.
Gänsicke, B T; Marsh, T R; Southworth, J; Rebassa-Mansergas, A
2006-12-22
The destiny of planetary systems through the late evolution of their host stars is very uncertain. We report a metal-rich gas disk around a moderately hot and young white dwarf. A dynamical model of the double-peaked emission lines constrains the outer disk radius to just 1.2 solar radii. The likely origin of the disk is a tidally disrupted asteroid, which has been destabilized from its initial orbit at a distance of more than 1000 solar radii by the interaction with a relatively massive planetesimal object or a planet. The white dwarf mass of 0.77 solar mass implies that planetary systems may form around high-mass stars.
Characterizing extrasolar planets
NASA Astrophysics Data System (ADS)
Brown, Timothy M.
Transiting extrasolar planets provide the best current opportunities for characterizing the physical properties of extrasolar planets. In this review, I first describe the geometry of planetary transits, and methods for detecting and refining the observations of such transits. I derive the methods by which transit light curves and radial velocity data can be analyzed to yield estimates of the planetary radius, mass, and orbital parameters. I also show how visible-light and infrared spectroscopy can be valuable tools for understanding the composition, temperature, and dynamics of the atmospheres of transiting planets. Finally, I relate the outcome of a participatory lecture-hall exercise relating to one term in the Drake equation, namely the lifetime of technical civilizations.
Gravitational microlensing by double stars and planetary systems
NASA Technical Reports Server (NTRS)
Mao, Shunde; Paczynski, Bohdan
1991-01-01
Almost all stars are in binary systems. When the separation between the two components is comparable to the Einstein ring radius corresponding to the combined mass of the binary acting as a gravitational lens, then an extra pair of images can be created, and the light curve of a lensed source becomes complicated. It is estimated that about 10 percent of all lensing episodes of the Galactic bulge stars will strongly display the binary nature of the lens. The effect is strong even if the companion is a planet. A massive search for microlensing of the Galactic bulge stars may lead to a discovery of the first extrasolar planetary systems.
Herd, R M; Velazco, J I; Arthur, P F; Hegarty, R F
2016-11-01
The objective of the study was to evaluate associations among animal performance and methane emission traits under feedlot conditions and in respiration chambers in Angus cattle bred to vary in residual feed intake (RFI), which is a measure of feed efficiency. Fifty-nine cattle were tested for feedlot RFI, of which 41 had methane production recorded on an ad libitum grain-based ration in the feedlot, 59 on a restricted grain-based ration in respiration chambers, and 57 on a restricted roughage ration in respiration chambers. The cattle became older and heavier as they went through the different phases of the experiment, but their feed intake (expressed as DMI) and daily emission of enteric methane (methane production rate; MPR) did not increase proportionally, as feed offered was restricted in the respiration chamber tests. Methane emissions by individual animals relative to their DMI were calculated as methane yield (MY; MPR/DMI) and as 2 measures of residual methane production (RMP and RMP), which were calculated as the difference between measured MPR and that predicted from feed intake by 2 different equations. Within each test regime, MPR was positively correlated ( = 0.28 to 0.61) with DMI. Phenotypic correlations for MY, RMP, and RMP between the feedlot test and the restricted grain test ( = 0.40 to 0.43) and between the restricted grain test and the restricted roughage test were moderate ( = 0.36 to 0.41) and moderate to strong between the feedlot test and the restricted roughage test ( = 0.54 to 0.58). These results indicate that the rankings of animals for methane production relative to feed consumed are relatively stable over the 3 test phases. Feedlot feed conversion ratio and RFI were not correlated with MPR in the feedlot test and grain-based chamber test but were negatively correlated with MPR in the chamber roughage test ( = -0.31 and -0.37). Both were negatively correlated with MY and RMP in the feedlot test ( = -0.42 to -0.54) and subsequent chamber roughage test ( = -0.27 to -0.49). Midparent estimated breeding values for RFI tended to be negatively correlated with MY and RMP in the feedlot test ( = -0.27 and -0.27) and were negatively correlated with MY, RMP, and RMP in the chamber roughage test ( = -0.33 to -0.36). These results showed that in young growing cattle, lower RFI was associated with higher MY, RMP, and RMP but had no significant association with MPR.
Isostatic compensation of Ishtar Terra, Venus
NASA Astrophysics Data System (ADS)
Kucinskas, Algis B.; Turcotte, Donald L.; Arkani-Hamed, Jafar
We have used spherical harmonic representations of the Venus topography and geopotential, obtained from Magellan data, to evaluate isostatic support in several areas within the Ishtar Terra highlands, including the Lakshmi plateau, its surrounding mountain belts, namely Akna and Freyja, and Maxwell Montes, and the Fortuna Tessera province. We find that topography in Ishtar is largely isostatically compensated (>80%). Regional geoidtopography variations in the subregions can be explained by a combination of Airy (crustal thickening) and thermal (lithospheric thinning) mechanisms, provided Venus has a thick reference thermal lithosphere (~300-400 km). With the exception of eastern Fortuna, low elevation areas (h<3-4 km above the mean planetary radius, MPR) with large geoidtopography ratios (GTR) seem to be associated, to various degrees, with thermal isostasy, whereas the higher areas (h>4 km above MPR) with small GTRs are almost certainly Airy compensated via thickened crust. Relatively large (>60 km) total Airy crustal thicknesses obtained in the western Ishtar mountain belts, together with a probable basalt-eclogite phase change, suggest a possible silicic composition for these structures, provided they are older than ~25-50 Ma. Lakshmi Planum seems essentially thermally supported, with the thermal lithosphere thinned to ~100 km. We suggest, as one possibility, that the lithospheric thinning process under Lakshmi is delamination of a dense eclogite lower lithosphere layer into the mantle. The decrease in GTR observed in Ishtar between Lakshmi to the west (GTR ~20 m/km), Maxwell and west Fortuna (GTR~8 m/km), and eastern Fortuna (GTR~4 m/km) may correspond to a decay in thermal compensation attributed to lithospheric delamination, which would be fairly recent (~100 Ma) in Lakshmi, partially decayed in west Fortuna, and absent in east Fortuna, where a mostly Airy-supported topography is essentially relaxed with no thermal uplift. Alternatively, if surficial concentrations in radiogenic elements were prevalent throughout the crust, partial melting of a thickened crust could account for the thermal uplift in Lakshmi and west Fortuna. The zero-elevation basaltic crustal thickness H ~24 km obtained for the east Fortuna Tessera region may be representative of the ambient crustal thickness in the Venus lowlands. Our findings support multicomponent models for tectonic and volcanic activity in Ishtar. The thick ambient crust and thermal lithosphere implied by this study agree with observational constraints such as support of extreme elevations, large topographic slopes, unrelaxed craters, and the thick elastic lithosphere suggested by flexure studies. If the ambient thermal lithosphere on Venus were to be relatively thin (~100-200 km), with a cold mantle and radiogenic elements concentrated in the crust, then thermal evolution on Venus may be in quasi-steady state, with the geodynamic evolution in monotonic decline. However, if the ambient thermal lithosphere is very thick (~300-400 km), as suggested by our thermal model fits, then it is consistent with the predictions of strongly unsteady state thermal evolution models and an interior which is currently heating up. This would support the view that catastrophic resurfacing on Venus might be episodic.
Geologic Map of the Greenaway Quadrangle (V-24), Venus
Lang, Nicholas P.; Hansen, Vicki L.
2010-01-01
The Greenaway quadrangle (V-24; lat 0 degrees -25 degrees N., long 120 degrees -150 degrees E.), Venus, derives its name from the impact crater Greenaway, centered at lat 22.9 degrees N., long 145.1 degrees E., in the northeastern part of the quadrangle. Greenaway was a well-noted writer and illustrator of children`s books in Britain during the nineteenth century. In Greenaway`s honor, the Library Association of Great Britain presents the annual Kate Greenaway Medal to an illustrator living and publishing in Britain who has produced the most distinguished children`s book illustrations for that year. The Greenaway quadrangle occupies an 8,400,000 km2 equatorial swath of lowlands and highlands. The map area is bounded by the crustal plateau, Thetis Regio, to the south and Gegute Tessera to the west. The rest of the quadrangle consists of part of Llorona Planitia, which is part of the vast lowlands that cover about 80 percent of Venus` surface. The southern map area marks the north edge of Aphrodite Terra, including Thetis Regio, that includes the highest topography in the quadrangle with elevations reaching >1 km above the Mean Planetary Radius (MPR; 6,051.84 km). Northern Aphrodite Terra abruptly slopes north to Llorona Planitia. A broad northeast-trending topographic arch pocked with coronae separates two northeast-trending elongate basins, Llorona Planitia on the east, that form depositional centers for shield and coronae-sourced materials; both basins drop to elevations of <-1 km. In addition to these major features, the map area hosts thousands of small volcanic constructs (shields); seven coronae; ribbon-tessera terrain; suites of faults, fractures, and wrinkle ridges; 23 impact craters; and one craterless splotch. Our goal for mapping the geology of the Greenaway quadrangle was to determine the geologic history for this region, which in turn provides insights into volcanic and tectonic processes that shaped the Venusian surface. Map relations illustrate that aerially expansive shield terrain (unit st) played a primary role and coronae played a secondary role in volcanic resurfacing across the map area.
Polyp measurement with CT colonography: multiple-reader, multiple-workstation comparison.
Young, Brett M; Fletcher, J G; Paulsen, Scott R; Booya, Fargol; Johnson, C Daniel; Johnson, Kristina T; Melton, Zackary; Rodysill, Drew; Mandrekar, Jay
2007-01-01
The risk of invasive colorectal cancer in colorectal polyps correlates with lesion size. Our purpose was to define the most accurate methods for measuring polyp size at CT colonography (CTC) using three models of workstations and multiple observers. Six reviewers measured 24 unique polyps of known size (5, 7, 10, and 12 mm), shape (sessile, flat, and pedunculated), and location (straight or curved bowel segment) using CTC data sets obtained at two doses (5 mAs and 65 mAs) and a previously described colonic phantom model. Reviewers measured the largest diameter of polyps on three proprietary workstations. Each polyp was measured with lung and soft-tissue windows on axial, 2D multiplanar reconstruction (MPR), and 3D images. There were significant differences among measurements obtained at various settings within each workstation (p < 0.0001). Measurements on 2D images were more accurate with lung window than with soft-tissue window settings (p < 0.0001). For the 65-mAs data set, the most accurate measurements were obtained in analysis of axial images with lung window, 2D MPR images with lung window, and 3D tissue cube images for Wizard, Advantage, and Vitrea workstations, respectively, without significant differences in accuracy among techniques (0.11 < p < 0.59). The mean absolute error values for these optimal settings were 0.48 mm, 0.61 mm, and 0.76 mm, respectively, for the three workstations. Within the ultralow-dose 5-mAs data set the best methods for Wizard, Advantage, and Vitrea were axial with lung window, 2D MPR with lung window, and 2D MPR with lung window, respectively. Use of nearly all measurement methods, except for the Vitrea 3D tissue cube and the Wizard 2D MPR with lung window, resulted in undermeasurement of the true size of the polyps. Use of CTC computer workstations facilitates accurate polyp measurement. For routine CTC examinations, polyps should be measured with lung window settings on 2D axial or MPR images (Wizard and Advantage) or 3D images (Vitrea). When these optimal methods are used, these three commercial workstations do not differ significantly in acquisition of accurate polyp measurements at routine dose settings.
Using the MDCT thick slab MinIP method for the follow-up of pulmonary emphysema.
Lan, Hai; Nishitani, Hiromu; Nishihara, Sadamitsu; Ueno, Junji; Takao, Shoichiro; Iwamoto, Seiji; Kawanaka, Takashi; Mahmut, Mawlan; Qingge, Si
2011-08-01
The purpose of this study was to evaluate the usefulness of thick slab minimum intensity projection (MinIP) as a follow-up method in patients with pulmonary emphysema. This method was used to determine the presence or absence of changes over time in the lung field based on multi-detector-row CT (MDCT) data. Among patients diagnosed with pulmonary emphysema who underwent 16-MDCT (slice thickness, 1 mm) twice at an interval of 6 months or more, 12 patients without changes in the lung field and 14 with clear changes in the lung field were selected as subjects. An image interpretation experiment was performed by five image interpreters. Pulmonary emphysema was followed up using two types of thick slab MinIP (thick slab MinIP 1 and 2) and multi-planar reformation (MPR), and the results of image interpretation were evaluated by receiver operating characteristic (ROC) analysis. In addition, the time required for image interpretation was compared among the three follow-up methods. The area under the ROC curve (Az) was 0.794 for thick slab MinIP 1, 0.778 for the thick slab MinIP 2, and 0.759 for MPR, showing no significant differences among the three methods. Individual differences in each item were significantly more marked for MPR than for thick slab MinIP. The time required for image interpretation was around 18 seconds for thick slab MinIP 1, 11 seconds for thick slab MinIP 2, and approximately 127 seconds for MPR, showing significant differences among the three methods. There were no significant differences in the results of image interpretation regarding the presence or absence of changes in the lung fields between thick slab MinIP and MPR. However, thick slab MinIP showed a shorter image interpretation time and smaller individual differences in the results among image interpreters than MPR, suggesting the usefulness of this method for determining the presence or absence of changes with time in the lung fields of patients with pulmonary emphysema.
Extended infrared emission around IRAS 21282 + 5050
NASA Technical Reports Server (NTRS)
Bregman, Jesse D.; Booth, John; Gilmore, D. K.; Kay, Laura; Rank, David
1992-01-01
Multiaperture 3-4-micron spectra along with K- and L-band images of the compact planetary nebula IRAS 21282 + 5050 show a 5 arcsec - 20 arcsec diameter nebula with structure similar to many other planetary nebulae. The spectral observations and the L-band image show evidence for extended PAH emission out to a radius of 20 arcsec, while the K-band image shows a 5 arcsec diameter nebula. An observed linear increase of integrated brightness with aperture size at L band implies a 1/r exp 2 volume emissivity for a spherically symmetric model. The spectral similarity of the emission in the small and large apertures suggests fluorescent emission by the PAHs. If the observed emission is from PAHs which formed during the planetary nebulae stage of IRAs 21282 + 5050, then PAHs have been forming for not less than 3000 yr. If the PAH emission is from material produced during the earlier red giant phase, then the formation time frame was much longer. The morphological and spectral similarity of IRAS 21282 + 5050 to many other planetary nebulae suggests that this phenomenon may be widespread, and that planetary nebulae may be a significant source of interstellar PAHs.
Planetary Interiors: Parametric Modeling of Global Geophysical Properties
NASA Astrophysics Data System (ADS)
Montgomery, W.; Jeanloz, R.
2004-12-01
Taking into account a realistic form of equation of state, we parameterize the degree to which bulk geophysical properties of planets are sensitive to gravitational self-compression. For example, the normalized moment of mass of a uniform-composition planet is C/Ma2 = 0.40 only in the limit of zero planetary size or incompressible material, and decreases toward 0.32 for finite compressibility as the planetary radius increases toward a = 104 km (M is planetary mass). Central density correspondingly increases from ρ 0, the surface density, toward 10 * ρ 0. Our calculations, based on the Eulerian finite-strain equation of state, make it possible to distinguish the effects of self-compression from the effects of non-uniformity (due either to changes in bulk composition or in phase with depth) as these influence planetary mass and moment of inertia relative to size. As observations of extra-solar planets can provide estimates of their mass and diameter (hence mean density), our formulation can account for the effects of compression in modeling the internal constitution and evolution of these objects. The effects of compression are especially important for giant and super-giant planets, such as the majority that have been observed to date.
Egede, Leonard E; Gebregziabher, Mulugeta; Dismuke, Clara E; Lynch, Cheryl P; Axon, R Neal; Zhao, Yumin; Mauldin, Patrick D
2012-12-01
To examine the longitudinal effects of medication nonadherence (MNA) on key costs and estimate potential savings from increased adherence using a novel methodology that accounts for shared correlation among cost categories. Veterans with type 2 diabetes (740,195) were followed from January 2002 until death, loss to follow-up, or December 2006. A novel multivariate, generalized, linear, mixed modeling approach was used to assess the differential effect of MNA, defined as medication possession ratio (MPR) ≥0.8 on healthcare costs. A sensitivity analysis was performed to assess potential cost savings at different MNA levels using the Consumer Price Index to adjust estimates to 2012 dollar value. Mean MPR for the full sample over 5 years was 0.78, with a mean of 0.93 for the adherent group and 0.58 for the MNA group. In fully adjusted models, all annual cost categories increased ∼3% per year (P = 0.001) during the 5-year study time period. MNA was associated with a 37% lower pharmacy cost, 7% lower outpatient cost, and 41% higher inpatient cost. Based on sensitivity analyses, improving adherence in the MNA group would result in annual estimated cost savings ranging from ∼$661 million (MPR <0.6 vs. ≥0.6) to ∼$1.16 billion (MPR <1 vs. 1). Maximal incremental annual savings would occur by raising MPR from <0.8 to ≥0.8 ($204,530,778) among MNA subjects. Aggressive strategies and policies are needed to achieve optimal medication adherence in diabetes. Such approaches may further the so-called "triple aim" of achieving better health, better quality care, and lower cost.
Feasibility of high-resolution quantitative perfusion analysis in patients with heart failure.
Sammut, Eva; Zarinabad, Niloufar; Wesolowski, Roman; Morton, Geraint; Chen, Zhong; Sohal, Manav; Carr-White, Gerry; Razavi, Reza; Chiribiri, Amedeo
2015-02-12
Cardiac magnetic resonance (CMR) is playing an expanding role in the assessment of patients with heart failure (HF). The assessment of myocardial perfusion status in HF can be challenging due to left ventricular (LV) remodelling and wall thinning, coexistent scar and respiratory artefacts. The aim of this study was to assess the feasibility of quantitative CMR myocardial perfusion analysis in patients with HF. A group of 58 patients with heart failure (HF; left ventricular ejection fraction, LVEF ≤ 50%) and 33 patients with normal LVEF (LVEF >50%), referred for suspected coronary artery disease, were studied. All subjects underwent quantitative first-pass stress perfusion imaging using adenosine according to standard acquisition protocols. The feasibility of quantitative perfusion analysis was then assessed using high-resolution, 3 T kt perfusion and voxel-wise Fermi deconvolution. 30/58 (52%) subjects in the HF group had underlying ischaemic aetiology. Perfusion abnormalities were seen amongst patients with ischaemic HF and patients with normal LV function. No regional perfusion defect was observed in the non-ischaemic HF group. Good agreement was found between visual and quantitative analysis across all groups. Absolute stress perfusion rate, myocardial perfusion reserve (MPR) and endocardial-epicardial MPR ratio identified areas with abnormal perfusion in the ischaemic HF group (p = 0.02; p = 0.04; p = 0.02, respectively). In the Normal LV group, MPR and endocardial-epicardial MPR ratio were able to distinguish between normal and abnormal segments (p = 0.04; p = 0.02 respectively). No significant differences of absolute stress perfusion rate or MPR were observed comparing visually normal segments amongst groups. Our results demonstrate the feasibility of high-resolution voxel-wise perfusion assessment in patients with HF.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, In Joon; Chung, Jin Wook, E-mail: chungjw@snu.ac.kr; Yin, Yong Hu
2015-10-15
PurposeThis study was designed to analyze retrospectively the performance of cone-beam computed tomography (CBCT) hepatic arteriography in depicting tumors and their feeders and to investigate the related determining factors in chemoembolization for hepatocellular carcinoma (HCC).MethodsEighty-six patients with 142 tumors satisfying the imaging diagnosis criteria of HCC were included in this study. The performance of CBCT hepatic arteriography for chemoembolization per tumor and per patient was evaluated using maximum intensity projection images alone (MIP analysis) or MIP combined with multiplanar reformation images (MIP + MPR analysis) regarding the following three aspects: tumor depiction, confidence of tumor feeder detection, and trackability of tumor feeders.more » Tumor size, tumor enhancement, tumor location, number of feeders, diaphragmatic motion, portal vein enhancement, and hepatic artery to parenchyma enhancement ratio were regarded as potential determining factors.ResultsTumors were depicted in 125 (88.0 %) and 142 tumors (100 %) on MIP and MIP + MPR analysis, respectively. Imaging performances on MIP and MIP + MPR analysis were good enough to perform subsegmental chemoembolization without additional angiographic investigation in 88 (62.0 %) and 128 tumors (90.1 %) on per-tumor basis and in 43 (50 %) and 73 (84.9 %) on per-patient basis, respectively. Significant determining factors for performance in MIP + MPR analysis on per tumor basis were tumor size (p = 0.030), tumor enhancement (0.005), tumor location (p = 0.001), and diaphragmatic motion (p < 0.001).ConclusionsCBCT hepatic arteriography provided sufficient information for subsegmental chemoembolization by depicting tumors and their feeders in the vast majority of patients. Combined analysis of MIP and MPR images was essential to enhance the performance of CBCT hepatic arteriography.« less
[Usefulness of curved coronal MPR imaging for the diagnosis of cervical radiculopathy].
Inukai, Chikage; Inukai, Takashi; Matsuo, Naoki; Shimizu, Ikuo; Goto, Hisaharu; Takagi, Teruhide; Takayasu, Masakazu
2010-03-01
In surgical treatment of cervical radiculopathy, localization of the responsible lesions by various imaging modalities is essential. Among them, MRI is non-invasive and plays a primary role in the assessment of spinal radicular symptoms. However, demonstration of nerve root compression is sometimes difficult by the conventional methods of MRI, such as T1 weighted (T1W) and T2 weighted (T2W) sagittal or axial images. We have applied a new technique of curved coronal multiplanar reconstruction (MPR) imaging for the diagnosis of cervical radiculopathy. Ten patients (4 male, 6 female) with ages between 31 and 79 year-old, who had clinical diagnosis of cervical radiculopathy, were included in this study. Seven patients underwent anterior key-hole foraminotomy to decompress the nerve root with successful results. All the patients had 3D MRI studies, such as true fast imaging with steady-state precession (FISP), 3DT2W sampling perfection with application optimized contrasts using different fillip angle evolution (SPACE), and 3D multi-echo data image combination (MEDIC) imagings in addition to the routine MRI (1.5 T Avanto, Siemens, Germany) with a phased array coil. The curved coronal MPR images were produced from these MRI data using a workstation. The nerve root compression was diagnosed by curved coronal MPR images in all the patients. The compression sites were compatible with those of the operative findings in 7 patients, who underwent surgical treatment. The MEDIC imagings were the most demonstrable to visualize the nerve root, while the 3D-space imagings were the next. The curved coronal MPR imaging is useful for the diagnosis of accurate localization of the compressing lesions in patients with cervical radiculopathy.
Olson, Linda J.; Jensen, Davin R.; Volkman, Brian F.; Kim, Jung-Ja P.; Peterson, Francis C.; Gundry, Rebekah L.; Dahms, Nancy M.
2015-01-01
The cation-independent mannose 6-phosphate receptor (CI-MPR) is a multifunctional protein that interacts with diverse ligands and plays central roles in autophagy, development, and tumor suppression. By delivering newly synthesized phosphomannosyl-containing acid hydrolases from the Golgi to endosomal compartments, CI-MPR is an essential component in the generation of lysosomes that are critical for the maintenance of cellular homeostasis. The ability of CI-MPR to interact with ~60 different acid hydrolases is facilitated by its large extracellular region, with four out of its 15 domains binding phosphomannosyl residues. Although the glycan specificity of CI-MPR has been elucidated, the molecular basis of carbohydrate binding has not been determined for two out of these four carbohydrate recognition domains (CRD). Here we report expression of CI-MPR’s CRD located in domain 5 that preferentially binds phosphodiester-containing glycans. Domain 5 of CI-MPR was expressed in Escherichia coli BL21 (DE3) cells as a fusion protein containing an N-terminal histidine tag and the small ubiquitin-like modifier (SUMO) protein. The His6-SUMO-CRD construct was recovered from inclusion bodies, refolded in buffer to facilitate disulfide bond formation, and subjected to Ni-NTA affinity chromatography and size exclusion chromatography. Surface plasmon resonance analyses demonstrated that the purified protein was active and bound phosphorylated glycans. Characterization by NMR spectroscopy revealed high quality 1H–15N HSQC spectra. Additionally, crystallization conditions were identified and a crystallographic data set of the CRD was collected to 1.8 Å resolution. Together, these studies demonstrate the feasibility of producing CI-MPR’s CRD suitable for three-dimensional structure determination by NMR spectroscopic and X-ray crystallographic approaches. PMID:25863146
Acharya, Kelly S; Keyhan, Sanaz; Acharya, Chaitanya R; Yeh, Jason S; Provost, Meredith P; Goldfarb, James M; Muasher, Suheil J
2016-09-01
To analyze donor oocyte cycles in the Society for Assisted Reproductive Technology (SART) registry to determine: 1) how many cycles complied with the 2009 American Society for Reproductive Medicine/SART embryo transfer guidelines; and 2) cycle outcomes according to the number of embryos transferred. For donor oocyte IVF with donor age <35 years, the consideration of single-embryo transfer was strongly recommended. Retrospective cohort study of United States national registry information. Not applicable. A total of 13,393 donor-recipient cycles from 2011 to 2012. Embryos transferred in donor IVF cycles. Percentage of compliant cycles, multiple pregnancy rate. There were 3,157 donor cleavage-stage transfers and 10,236 donor blastocyst transfers. In the cleavage-stage cycles, 88% met compliance criteria. The multiple pregnancy rate (MPR) was significantly higher in the noncompliant cycles. In a subanalysis of compliant cleavage-stage cycles, 91% transferred two embryos and only 9% single embryos. In those patients transferring two embryos, the MPR was significantly higher (33% vs. 1%). In blastocyst transfers, only 28% of the cycles met compliance criteria. The MPR was significantly higher in the noncompliant blastocyst cohort at 53% (compared with 2% in compliant cycles). The majority of donor cleavage-stage transfers are compliant with current guidelines, but the transfer of two embryos results in a significantly higher MPR compared with single-embryo transfer. The majority of donor blastocyst cycles are noncompliant, which appears to be driving an unacceptably high MPR in these cycles. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
Transnational Mortality Comparisons Between Archipelago and Mainland Puerto Ricans.
Colón-Ramos, Uriyoán; Rodríguez-Ayuso, Idania; Gebrekristos, Hirut T; Roess, Amira; Pérez, Cynthia M; Simonsen, Lone
2017-10-01
Puerto Ricans in the US experience higher deaths from diabetes and other causes compared to non-Hispanic Whites and other Hispanic groups. We compared mortality in Puerto Rico to that of Puerto Ricans in the US as a first step to investigate if similar or worse mortality patterns originate from the sending country (Puerto Rico). Age-adjusted death rates were generated using national vital statistics databases in the US and territories for all-cause and the top ten causes of death among Hispanics in 2009. Mortality ratios in the archipelago of Puerto Rico (APR) were compared to mainland US Puerto Ricans (MPR). Rates for other ethnic/racial groups (Mexican Americans, Cubans, and non-Hispanic Whites, Blacks, American Indians, and Asians) were calculated to provide a context. APR had significantly higher all-cause mortality and death rates for diabetes, nephritis, pneumonia/influenza, and homicide/assault compared to MPR (APR/MPR ratio for all-cause: 1.08, diabetes: 2.04, nephritis: 1.84, pneumonia/influenza: 1.33, homicide/assault: 3.15). Death rates for diabetes and homicide/assault (particularly among men) were higher among APR compared to any other racial/ethnic groups in the US. In contrast, deaths from heart disease, cancer, and chronic liver disease were significantly lower for APR compared to MPR (MPR/APR ratio 0.72, 0.91, 0.41, respectively). Among APR women, death rates for these causes were also lower compared to any other group in the US. Substantial mortality variability exists between Puerto Ricans in Puerto Rico and those in the US, re-emphasizing the need to study of how socio-environmental determinants of health differ in sending and receiving countries. Explanations for disparate rates include access to and availability of healthcare and unique factors related to the migration experience of this group.
Interventional spinal procedures guided and controlled by a 3D rotational angiographic unit.
Pedicelli, Alessandro; Verdolotti, Tommaso; Pompucci, Angelo; Desiderio, Flora; D'Argento, Francesco; Colosimo, Cesare; Bonomo, Lorenzo
2011-12-01
The aim of this paper is to demonstrate the usefulness of 2D multiplanar reformatting images (MPR) obtained from rotational acquisitions with cone-beam computed tomography technology during percutaneous extra-vascular spinal procedures performed in the angiography suite. We used a 3D rotational angiographic unit with a flat panel detector. MPR images were obtained from a rotational acquisition of 8 s (240 images at 30 fps), tube rotation of 180° and after post-processing of 5 s by a local work-station. Multislice CT (MSCT) is the best guidance system for spinal approaches permitting direct tomographic visualization of each spinal structure. Many operators, however, are trained with fluoroscopy, it is less expensive, allows real-time guidance, and in many centers the angiography suite is more frequently available for percutaneous procedures. We present our 6-year experience in fluoroscopy-guided spinal procedures, which were performed under different conditions using MPR images. We illustrate cases of vertebroplasty, epidural injections, selective foraminal nerve root block, facet block, percutaneous treatment of disc herniation and spine biopsy, all performed with the help of MPR images for guidance and control in the event of difficult or anatomically complex access. The integrated use of "CT-like" MPR images allows the execution of spinal procedures under fluoroscopy guidance alone in all cases of dorso-lumbar access, with evident limitation of risks and complications, and without need for recourse to MSCT guidance, thus eliminating CT-room time (often bearing high diagnostic charges), and avoiding organizational problems for procedures that need, for example, combined use of a C-arm in the CT room.
Gilmer, Todd P.; Ojeda, Victoria D.; Barrio, Concepcion; Fuentes, Dahlia; Garcia, Piedad; Lanouette, Nicole M.; Lee, Kelly C.
2011-01-01
OBJECTIVES We examined the relationship between preferred English, Spanish, or an Asian language for mental health services and adherence to treatment with antipsychotic medication and Medi-Cal beneficiaries with schizophrenia in San Diego, California. METHODS Data included 31,560 person-years from 1999–2004. Pharmacy records were analyzed to assess adherence to antipsychotic medication, based on the medication possession ratio (MPR). Clients were defined as nonadherent (MPR<0.5), partially adherent (0.5<=MPR<0.8), adherent (0.8<=MPR<=1.1), or as an excess filler (MPR>1.1). Regression models were used to examine adherence, hospitalization, and costs by race/ethnicity and language status. RESULTS Limited English proficient Latinos were more likely to be adherent to antipsychotic medications than English proficient Latinos (40.8% vs. 35.9%, P<0.001). Limited English proficient Latinos were less likely to be excess fillers than English proficient Latinos (15.1% vs. 20.4%, P<0.001). Limited English proficient Asians were less likely to be adherent than English proficient Asians (40.1% vs. 45.1%, P=0.034). Compared to English proficient Asians, limited English proficient Asians were more likely to be nonadherent (28.7% vs. 22.0%, P<0.001) and less likely to be excess fillers (12.5% vs. 17.4%, P=0.004). Controlling for adherence and comorbidities, limited English proficient clients had lower rates of hospitalization and health care costs than English proficient and white clients. CONCLUSIONS Adherence to antipsychotic medications varies among and within ethnic groups by English proficiency. Policies supporting the training of bilingual and multicultural ethnic minority providers, and interventions that capitalize on existing social support networks, may improve adherence to treatment among linguistically diverse populations. PMID:19176410
Captopril and 6-mercaptopurine: whose SH possesses higher antioxidant ability?
Li, Guo-Xiang; Liu, Zai-Qun
2009-12-01
Antioxidant capacities of captopril (CAP), 6-mercaptopurine (6-MP) and 9-(beta-D-ribofuranosyl)-6-mercaptopurine (6-MPR) were investigated by interacting them with 2,2'-diphenyl-1-picrylhydrazyl (DPPH), galvinoxyl radical, and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cation radical (ABTS(+)(*)), and by protecting DNA and erythrocyte against 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH) induced oxidation. It was found that CAP possessed the highest ability to donate the hydrogen atom in -SH to DPPH and galvinoxyl, while 6-MPR had the strongest ability to reduce ABTS(+)(*). In the process of protecting DNA and erythrocytes against AAPH-induced oxidation, CAP can trap 0.5 and 1.3 radicals, 6-MP can trap 0.6 and 2.2, and 6-MPR can trap 1.0 and 3.0 radicals, respectively. CAP can also protect erythrocytes against hemin-induced hemolysis.
The detection and characterization of a nontransiting planet by transit timing variations.
Nesvorný, David; Kipping, David M; Buchhave, Lars A; Bakos, Gáspár Á; Hartman, Joel; Schmitt, Allan R
2012-06-01
The Kepler mission is monitoring the brightness of ~150,000 stars, searching for evidence of planetary transits. As part of the Hunt for Exomoons with Kepler (HEK) project, we report a planetary system with two confirmed planets and one candidate planet discovered with the publicly available data for KOI-872. Planet b transits the host star with a period P(b) = 33.6 days and exhibits large transit timing variations indicative of a perturber. Dynamical modeling uniquely detects an outer nontransiting planet c near the 5:3 resonance (P(c) = 57.0 days) with a mass 0.37 times that of Jupiter. Transits of a third planetary candidate are also found: a 1.7-Earth radius super-Earth with a 6.8-day period. Our analysis indicates a system with nearly coplanar and circular orbits, reminiscent of the orderly arrangement within the solar system.
Evidence for Unresolved Exoplanet-hosting Binaries in Gaia DR2
NASA Astrophysics Data System (ADS)
Evans, Daniel F.
2018-05-01
This note describes an effort to detect additional stellar sources in known transiting exoplanet (TEP) systems, which are unresolved or barely resolved in the Gaia Data Release 2 (DR2) catalogue. The presence of multiple unresolved stars in photometric and spectroscopic observations of a transiting planetary system biases measurements of the planet's radius, mass, and atmospheric conditions. In addition to the effect on individual planetary systems, the presence of unresolved stars across the sample of known exoplanets biases our overall understanding of planetary systems, due to the systematic underestimation of both masses and radii. This work uses the Astrometric Goodness of Fit in the Along-Scan direction (GOF_AL) and the Astrometric Excess Noise as indicators of poorly-resolved binaries. Many known close binaries in the exoplanet host star sample have highly significant GOF_AL and Astrometric Excess Noise values, such as WASP-20AB with Astrometric Excess Noise significant at $4720\\sigma$ and GOF_AL=124.
Stellar occultation studies of the solar system
NASA Technical Reports Server (NTRS)
Elliot, J. L.
1979-01-01
The paper covers the principles, observational procedures, and results relating to occultations of stars by solar system bodies other than the moon. Physical processes involved in occultations are presented including (1) extinction by ring material, (2) differential refraction by a planetary atmosphere, (3) extinction by a planetary atmosphere, and (4) Fresnel diffraction by sharp edges. It is noted that from a sufficient number of immersion and emersion timings of a stellar occultation, the radius and ellipticity of the occulting body can be accurately determined. From an occultation by a planet having an atmosphere, temperature, pressure, and number density profiles can be obtained along with information about the composition of the atmosphere and the extinction.
Characterization of exoplanets from their formation. III. The statistics of planetary luminosities
NASA Astrophysics Data System (ADS)
Mordasini, C.; Marleau, G.-D.; Mollière, P.
2017-12-01
Context. This paper continues a series in which we predict the main observable characteristics of exoplanets based on their formation. In Paper I we described our global planet formation and evolution model that is based on the core accretion paradigm. In Paper II we studied the planetary mass-radius relationship with population syntheses. Aims: In this paper we present an extensive study of the statistics of planetary luminosities during both formation and evolution. Our results can be compared with individual directly imaged extrasolar (proto)planets and with statistical results from surveys. Methods: We calculated three populations of synthetic planets assuming different efficiencies of the accretional heating by gas and planetesimals during formation. We describe the temporal evolution of the planetary mass-luminosity relation. We investigate the relative importance of the shock and internal luminosity during formation, and predict a statistical version of the post-formation mass vs. entropy "tuning fork" diagram. Because the calculations now include deuterium burning we also update the planetary mass-radius relationship in time. Results: We find significant overlap between the high post-formation luminosities of planets forming with hot and cold gas accretion because of the core-mass effect. Variations in the individual formation histories of planets can still lead to a factor 5 to 20 spread in the post-formation luminosity at a given mass. However, if the gas accretional heating and planetesimal accretion rate during the runaway phase is unknown, the post-formation luminosity may exhibit a spread of as much as 2-3 orders of magnitude at a fixed mass. As a key result we predict a flat log-luminosity distribution for giant planets, and a steep increase towards lower luminosities due to the higher occurrence rate of low-mass (M ≲ 10-40 M⊕) planets. Future surveys may detect this upturn. Conclusions: Our results indicate that during formation an estimation of the planetary mass may be possible for cold gas accretion if the planetary gas accretion rate can be estimated. If it is unknown whether the planet still accretes gas, the spread in total luminosity (internal + accretional) at a given mass may be as large as two orders of magnitude, therefore inhibiting the mass estimation. Due to the core-mass effect even planets which underwent cold accretion can have large post-formation entropies and luminosities, such that alternative formation scenarios such as gravitational instabilities do not need to be invoked. Once the number of self-luminous exoplanets with known ages and luminosities increases, the resulting luminosity distributions may be compared with our predictions.
RECENT TRANSITS OF THE SUPER-EARTH EXOPLANET GJ 1214b
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sada, Pedro V.; Deming, Drake; Jackson, Brian
We report recent ground-based photometry of the transiting super-Earth exoplanet GJ 1214b at several wavelengths, including the infrared near 1.25 {mu}m (J band). We observed a J-band transit with the FLAMINGOS infrared imager and the 2.1 m telescope on Kitt Peak, and we observed several optical transits using a 0.5 m telescope on Kitt Peak and the 0.36 m Universidad de Monterrey Observatory telescope. Our high-precision J-band observations exploit the brightness of the M dwarf host star at this infrared wavelength as compared with the optical and are significantly less affected by stellar activity and limb darkening. We fit themore » J-band transit to obtain an independent determination of the planetary and stellar radii. Our radius for the planet (2.61{sup +0.30} {sub -0.11} R {sub +}) is in excellent agreement with the discovery value reported by Charbonneau et al. based on optical data. We demonstrate that the planetary radius is insensitive to degeneracies in the fitting process. We use all of our observations to improve the transit ephemeris, finding P = 1.5804043 {+-} 0.0000005 days and T {sub 0} = 2454964.94390 {+-} 0.00006 BJD.« less
Recent Transits of the Super-Earth Exoplanet GJ 1214B
NASA Technical Reports Server (NTRS)
Sada, Pedro V.; Deming, Drake; Jackson, Brian; Jennings, Donald E.; Peterson, Steven W.; Haase, Flynn; Bays, Kevin; OGorman, Eamon; Lundsford, Alan
2001-01-01
We report recent ground-based photometry of the transiting super-Earth exoplanet GJ1214b at several wavelengths, including the infrared near 1.25 microns (J-band). We observed a J-band transit with the FLAMINGOS infrared imager and the 2.1-meter telescope on Kitt Peak, and we observed several optical transits using a 0.5-meter telescope on Kitt Peak and the 0.36-meter Universidad de Monterrey Observatory telescope. Our high-precision J-band observations exploit the brightness of the M-dwarf host star at this infrared wavelength as compared to the optical, as well as being significantly less affected by stellar activity and limb darkening. We fit the J-band transit to obtain an independent determination of the planetary and stellar radii. Our radius for the planet (2.61 +0.30 / -0.11 Earth radii) is in excellent agreement with the discovery value reported by Charbonneau et al. based on optical data. We demonstrate that the planetary radius is insensitive to degeneracies in the fitting process. We use all of our observations to improve the transit ephemeris, finding P=1.5804043 +/- 0.0000005 days, and T0=2454964.94390 +/- 0.00006 BJD.
Recent Transits of the Super-Earth Exoplanet GJ 1214b
NASA Astrophysics Data System (ADS)
Sada, Pedro V.; Deming, Drake; Jackson, Brian; Jennings, Donald E.; Peterson, Steven W.; Haase, Flynn; Bays, Kevin; O'Gorman, Eamon; Lundsford, Alan
2010-09-01
We report recent ground-based photometry of the transiting super-Earth exoplanet GJ 1214b at several wavelengths, including the infrared near 1.25 μm (J band). We observed a J-band transit with the FLAMINGOS infrared imager and the 2.1 m telescope on Kitt Peak, and we observed several optical transits using a 0.5 m telescope on Kitt Peak and the 0.36 m Universidad de Monterrey Observatory telescope. Our high-precision J-band observations exploit the brightness of the M dwarf host star at this infrared wavelength as compared with the optical and are significantly less affected by stellar activity and limb darkening. We fit the J-band transit to obtain an independent determination of the planetary and stellar radii. Our radius for the planet (2.61+0.30 -0.11 R ⊕) is in excellent agreement with the discovery value reported by Charbonneau et al. based on optical data. We demonstrate that the planetary radius is insensitive to degeneracies in the fitting process. We use all of our observations to improve the transit ephemeris, finding P = 1.5804043 ± 0.0000005 days and T 0 = 2454964.94390 ± 0.00006 BJD.
NASA Technical Reports Server (NTRS)
Haugstad, B. S.; Eshleman, V. R.
1979-01-01
The dependence of the effects of planetary atmospheric turbulence on radio or optical wavelength in occultation experiments is discussed, and the analysis of Hubbard and Jokipii (1977) is criticized. It is argued that in deriving a necessary condition for the applicability of their method, Hubbard and Jokipii neglect a factor proportional to the square of the ratio of atmospheric or local Fresnel zone radius and the inner scale of turbulence, and fail to establish sufficient conditions, thereby omitting the square of the ratio of atmospheric scale height and the local Fresnel zone radius. The total discrepancy is said to mean that the results correspond to geometrical optics instead of wave optics, as claimed, thus being inapplicable in a dicussion of wavelength dependence. Calculations based on geometrical optics show that the bias in the average bending angle depends on the wavelength in the same way as does the bias in phase path caused by turbulence in a homogeneous atmosphere. Hubbard and Jokipii comment that the criterion of Haugstad and Eshleman is incorrect and show that there is a large wave optical domain where the results are independent of wavelength.
The abundance of Galactic planets from OGLE-III 2002 microlensing data
NASA Astrophysics Data System (ADS)
Snodgrass, Colin; Horne, Keith; Tsapras, Yiannis
2004-07-01
From the 389 OGLE-III 2002 observations of Galactic bulge microlensing events, we select 321 that are well described by a point-source point-lens light-curve model. From this sample we identify one event, 2002-BLG-055, that we regard as a strong planetary lensing candidate, and another, 2002-BLG-140, that is a possible candidate. If each of the 321 lens stars has one planet with a mass ratio q = m/M = 10-3 and orbit radius a = RE, the Einstein ring radius, analysis of detection efficiencies indicates that 14 planets should have been detectable with Δχ2 > 25. Assuming our candidate is due to planetary lensing, then the abundance of planets with q = 10-3 and a = RE is np ~ n/14 = 7 per cent. Conversion to physical units (Jupiter masses, MJup, and astronomical units, au) gives the abundance of `cool Jupiters' (m ~ MJup, a ~ 4 au) per lens star as np ~ n/5.5 = 18 per cent. The detection probability scales roughly with q and (Δχ2)-1/2, and drops off from a peak at a ~ 4 au like a Gaussian with a dispersion of 0.4 dex.
Raman spectroscopy of magneto-phonon resonances in graphene and graphite
NASA Astrophysics Data System (ADS)
Goler, Sarah; Yan, Jun; Pellegrini, Vittorio; Pinczuk, Aron
2012-08-01
The magneto-phonon resonance or MPR occurs in semiconductor materials when the energy spacing between Landau levels is continuously tuned to cross the energy of an optical phonon mode. MPRs have been largely explored in bulk semiconductors, in two-dimensional systems and in quantum dots. Recently there has been significant interest in the MPR interactions of the Dirac fermion magneto-excitons in graphene, and a rich splitting and anti-crossing phenomena of the even parity E2g long wavelength optical phonon mode have been theoretically proposed and experimentally observed. The MPR has been found to crucially depend on disorder in the graphene layer. This is a feature that creates new venues for the study of interplays between disorder and interactions in the atomic layers. We review here the fundamentals of MRP in graphene and the experimental Raman scattering works that have led to the observation of these phenomena in graphene and graphite.
Time-dependent simulations of disk-embedded planetary atmospheres
NASA Astrophysics Data System (ADS)
Stökl, A.; Dorfi, E. A.
2014-03-01
At the early stages of evolution of planetary systems, young Earth-like planets still embedded in the protoplanetary disk accumulate disk gas gravitationally into planetary atmospheres. The established way to study such atmospheres are hydrostatic models, even though in many cases the assumption of stationarity is unlikely to be fulfilled. Furthermore, such models rely on the specification of a planetary luminosity, attributed to a continuous, highly uncertain accretion of planetesimals onto the surface of the solid core. We present for the first time time-dependent, dynamic simulations of the accretion of nebula gas into an atmosphere around a proto-planet and the evolution of such embedded atmospheres while integrating the thermal energy budget of the solid core. The spherical symmetric models computed with the TAPIR-Code (short for The adaptive, implicit RHD-Code) range from the surface of the rocky core up to the Hill radius where the surrounding protoplanetary disk provides the boundary conditions. The TAPIR-Code includes the hydrodynamics equations, gray radiative transport and convective energy transport. The results indicate that diskembedded planetary atmospheres evolve along comparatively simple outlines and in particular settle, dependent on the mass of the solid core, at characteristic surface temperatures and planetary luminosities, quite independent on numerical parameters and initial conditions. For sufficiently massive cores, this evolution ultimately also leads to runaway accretion and the formation of a gas planet.
Blouin, Julie; Dragomir, Alice; Moride, Yola; Ste-Marie, Louis-Georges; Fernandes, Julio Cesar; Perreault, Sylvie
2008-01-01
AIMS To evaluate the association between noncompliance with alendronate and risedronate and the risk of nonvertebral osteoporotic fracture in community-dwelling elderly women. METHODS A nested case–control study was conducted using the Quebec administrative health databases. To be included in the cohort, women needed to be aged ≥ 68 years and to have initiated treatment with alendronate or risedronate between 1 January 2002 and 31 March 2005. Cases consisted of all women with an incident nonvertebral osteoporotic fracture occurring ≥ 1 year after initiation of therapy. Each case was matched with up to 20 controls using incidence density sampling, according to age (± 1 year) and follow-up duration. A woman was noncompliant if she had a medication possession ratio (MPR) <80% for total follow-up duration. Rate ratios (RR) for fracture were estimated through conditional logistic regression analysis, adjusting for potential confounders. RESULTS Among the 30 259 women included in the cohort, 1036 nonvertebral fracture cases were identified and were matched to 20 069 controls. Compared with women with a MPR ≥ 80%, those with a MPR < 80% had a greater risk of nonvertebral fracture [adjusted RR 1.27, 95% confidence interval (CI) 1.12, 1.44]. Considering hip fracture only, the multivariate model yielded similar results, (adjusted RR 1.28, 95% CI 1.02, 1.61). CONCLUSIONS Among community-dwelling elderly women, noncompliance with alendronate or risedronate is associated with an increased risk of nonvertebral fracture. WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT Compliance with alendronate and risedronate is suboptimal.Few studies have specifically evaluated the impact of noncompliance with alendronate or risedronate on the incidence of osteoporotic fractures in community-dwelling elderly women. WHAT THIS STUDY ADDS Among community-dwelling elderly women, noncompliance [defined as medication possession ratio (MPR) < 80%] with alendronate or risedronate was associated with a 27% increased risk of nonvertebral fracture [rate ratio (RR) 1.27, 95% confidence interval (CI) 1.12, 1.44].This study is the first to assess the impact of noncompliance with bisphosphonates in a subgroup of women aged > 80 years.Among women aged > 80 years, MPR < 80% was associated with a 48% greater risk of sustaining a nonvertebral fracture (RR 1.48, 95% CI 1.19, 1.85), compared with women with a MPR ≥ 80%. PMID:18460036
Transits and starspots in the WASP-6 planetary system
NASA Astrophysics Data System (ADS)
Tregloan-Reed, Jeremy; Southworth, John; Burgdorf, M.; Novati, S. Calchi; Dominik, M.; Finet, F.; Jørgensen, U. G.; Maier, G.; Mancini, L.; Prof, S.; Ricci, D.; Snodgrass, C.; Bozza, V.; Browne, P.; Dodds, P.; Gerner, T.; Harpsøe, K.; Hinse, T. C.; Hundertmark, M.; Kains, N.; Kerins, E.; Liebig, C.; Penny, M. T.; Rahvar, S.; Sahu, K.; Scarpetta, G.; Schäfer, S.; Schönebeck, F.; Skottfelt, J.; Surdej, J.
2015-06-01
We present updates to PRISM, a photometric transit-starspot model, and GEMC, a hybrid optimization code combining MCMC and a genetic algorithm. We then present high-precision photometry of four transits in the WASP-6 planetary system, two of which contain a starspot anomaly. All four transits were modelled using PRISM and GEMC, and the physical properties of the system calculated. We find the mass and radius of the host star to be 0.836 ± 0.063 M⊙ and 0.864 ± 0.024 R⊙, respectively. For the planet, we find a mass of 0.485 ± 0.027 MJup, a radius of 1.230 ± 0.035 RJup and a density of 0.244 ± 0.014 ρJup. These values are consistent with those found in the literature. In the likely hypothesis that the two spot anomalies are caused by the same starspot or starspot complex, we measure the stars rotation period and velocity to be 23.80 ± 0.15 d and 1.78 ± 0.20 km s-1, respectively, at a colatitude of 75.8°. We find that the sky-projected angle between the stellar spin axis and the planetary orbital axis is λ = 7.2° ± 3.7°, indicating axial alignment. Our results are consistent with and more precise than published spectroscopic measurements of the Rossiter-McLaughlin effect. These results suggest that WASP-6 b formed at a much greater distance from its host star and suffered orbital decay through tidal interactions with the protoplanetary disc.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jenkins, Jon M.; Caldwell, Douglas A.; Borucki, William J.
We report on the discovery and the Rossiter-McLaughlin (R-M) effect of Kepler-8b, a transiting planet identified by the NASA Kepler Mission. Kepler photometry and Keck-HIRES radial velocities yield the radius and mass of the planet around this F8IV subgiant host star. The planet has a radius R{sub P} = 1.419 R{sub J} and a mass M{sub P} = 0.60 M{sub J}, yielding a density of 0.26 g cm{sup -3}, one of the lowest planetary densities known. The orbital period is P = 3.523 days and the orbital semimajor axis is 0.0483{sup +0.0006}{sub -0.0012} AU. The star has a large rotationalmore » vsin i of 10.5 {+-} 0.7 km s{sup -1} and is relatively faint (V {approx} 13.89 mag); both properties are deleterious to precise Doppler measurements. The velocities are indeed noisy, with scatter of 30 m s{sup -1}, but exhibit a period and phase that are consistent with those implied by transit photometry. We securely detect the R-M effect, confirming the planet's existence and establishing its orbit as prograde. We measure an inclination between the projected planetary orbital axis and the projected stellar rotation axis of {lambda} = -26.{sup 0}4 {+-} 10.{sup 0}1, indicating a significant inclination of the planetary orbit. R-M measurements of a large sample of transiting planets from Kepler will provide a statistically robust measure of the true distribution of spin-orbit orientations for hot Jupiters around F and early G stars.« less
NASA Astrophysics Data System (ADS)
Pradhan, P. C.; Bhartiya, S.; Singh, A.; Majhi, A.; Gome, A.; Dhawan, R.; Nayak, M.; Sahoo, P. K.; Rai, S. K.; Reddy, V. R.
2017-08-01
We present fabrication and structural analysis of two different multilayer grating structures. W/B4C based lamellar multilayer grating (LMG) was studied for high resolution monochomator application near soft x-ray region ( 1.5 keV). Whereas NbC/Si based multilayer phase-shift reflector (MPR) was studied for high reflection at normal incidence near Si L-edge ( 99 eV) and simultaneously to suppress the unwanted vacuum ultraviolet / infrared radiation. The grating patterns of different periods down to D = 10 micron were fabricated on Si substrates by using photolithography, and multilayers (MLs) of different periodicity (d = 10 to 2 nm) and number of layer pairs (15 to 100) were coated using sputtering techniques by optimizing the process parameters. The LMG and MPR samples are characterized by x-ray reflectivity (XRR) and atomic force microscopy (AFM) measurements. XRR results show successive higher order Bragg peaks that reveal a well-defined vertical periodic structure in LMG, MPR and ML structures. The lateral periodicity of the grating and depth of the rectangular groves were analyzed using AFM. The AFM results show good quality of lateral periodic structures in terms of groove profile. The effect of the process parameters on the microstructure (both on vertical and lateral patterns) of ML, LMG and MPR were analyzed.
HAT-P-32b AND HAT-P-33b: TWO HIGHLY INFLATED HOT JUPITERS TRANSITING HIGH-JITTER STARS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hartman, J. D.; Bakos, G. A.; Torres, G.
2011-11-20
We report the discovery of two exoplanets transiting high-jitter stars. HAT-P-32b orbits the bright V = 11.289 late-F-early-G dwarf star GSC 3281-00800, with a period P = 2.150008 {+-} 0.000001 d. The stellar and planetary masses and radii depend on the eccentricity of the system, which is poorly constrained due to the high-velocity jitter ({approx}80 m s{sup -1}). Assuming a circular orbit, the star has a mass of 1.16 {+-} 0.04 M{sub Sun} and radius of 1.22 {+-} 0.02 R{sub Sun }, while the planet has a mass of 0.860 {+-} 0.164 M{sub J} and a radius of 1.789 {+-}more » 0.025 R{sub J}. The second planet, HAT-P-33b, orbits the bright V = 11.188 late-F dwarf star GSC 2461-00988, with a period P = 3.474474 {+-} 0.000001 d. As for HAT-P-32, the stellar and planetary masses and radii of HAT-P-33 depend on the eccentricity, which is poorly constrained due to the high jitter ({approx}50 m s{sup -1}). In this case, spectral line bisector spans (BSs) are significantly anti-correlated with the radial velocity residuals, and we are able to use this correlation to reduce the residual rms to {approx}35 m s{sup -1}. We find that the star has a mass of 1.38 {+-} 0.04 M{sub Sun} and a radius of 1.64 {+-} 0.03 R{sub Sun} while the planet has a mass of 0.762 {+-} 0.101 M{sub J} and a radius of 1.686 {+-} 0.045 R{sub J} for an assumed circular orbit. Due to the large BS variations exhibited by both stars we rely on detailed modeling of the photometric light curves to rule out blend scenarios. Both planets are among the largest radii transiting planets discovered to date.« less
Yu, Huifeng; Tudor, Daniela; Alfsen, Annette; Labrosse, Beatrice; Clavel, François; Bomsel, Morgane
2008-01-01
The membrane proximal region (MPR) of the transmembrane subunit, gp41, of the HIV envelope glycoprotein plays a critical role in HIV-1 infection of CD4+ target cells and CD4-independent mucosal entry. It contains continuous epitopes recognized by neutralizing IgG antibodies 2F5, 4E10 and Z13, and is therefore considered to be a promising target for vaccine design. Moreover, some MPR-derived peptides, such as T20 (enfuvirtide), are in clinical use as HIV-1 inhibitors. We have shown that an extended MPR peptide, P5, harbouring the lectin-like domain of gp41 and a calcium-binding site, is implicated in the interaction of HIV with its mucosal receptor. We now investigate the potential antiviral activities of P5 and other such long MPR-derived peptides. Structural studies of gp41 MPR-derived peptides using circular dichroism showed that the peptides P5 (a.a.628–683), P1 (a.a.648–683), P5L (a.a.613–683) and P7 (a.a.613–746) displayed a well-defined α-helical structure. Peptides P5 inhibited HIV-1 envelope mediated cell-cell fusion and infection of peripheral blood mononuclear cells by both X4- and R5-tropic HIV-1 strains, whereas peptides P5 mutated in the calcium binding site or P1 lacked antiviral activity, when P5L blocked cell fusion in contrast to P7. Strikingly, P5 inhibited CD4-dependent infection by T20-resistant R5-tropic HIV-1 variants. Cell-cell fusion studies indicated that the anti-HIV-1 activity of P5, unlike T20, could not be abrogated in the presence of the N-terminal leucine zipper domain (LZ). These results suggested that P5 could serve as a potent fusion inhibitor. PMID:18925934
Characterization of Streptococcus bovis from the rumen of the dromedary camel and Rusa deer.
Ghali, M B; Scott, P T; Al Jassim, R A M
2004-01-01
Isolation and characterization of Streptococcus bovis from the dromedary camel and Rusa deer. Bacteria were isolated from the rumen contents of four camels and two deer fed lucerne hay by culturing on the semi-selective medium MRS agar. Based on Gram morphology and RFLP analysis seven isolates, MPR1, MPR2, MPR3, MPR4, MPR5, RD09 and RD11 were selected and putatively identified as Streptococcus. The identity of these isolates was later confirmed by comparative DNA sequence analysis of the 16S rRNA gene with the homologous sequence from S. bovis strains, JB1, C14b1, NCFB2476, SbR1, SbR7 and Sb5, from cattle and sheep, and the Streptococcus equinus strain NCD01037T. The percentage similarity amongst all strains was >99%, confirming the identification of the camel isolates as S. bovis. The strains were further characterized by their ability to utilize a range of carbohydrates, the production of volatile fatty acids (VFA) and lactate and the determination of the doubling time in basal medium 10 supplemented with glucose. All the isolates produced l-lactate as a major fermentation end product, while four of five camel isolates produced VFA. The range of carbohydrates utilized by all the strains tested, including those from cattle and sheep were identical, except that all camel isolates and the deer isolate RD11 were additionally able to utilize arabinose. Streptococcus bovis was successfully isolated from the rumen of camels and deer, and shown by molecular and biochemical characterization to be almost identical to S. bovis isolates from cattle and sheep. Streptococcus bovis is considered a key lactic acid producing bacterium from the gastrointestinal tract of ruminants, and has been implicated as a causative agent of lactic acidosis. This study is the first report of the isolation and characterization of S. bovis from the dromedary camel and Rusa deer, and suggests a major contributive role of this bacterium to fermentative acidosis.
Poliakov, Eugenia; Samuel, William; Duncan, Todd; Gutierrez, Danielle B.; Mata, Nathan L.; Redmond, T. Michael
2017-01-01
The therapeutic capacity of fenretinide (N-[4-hydroxyphenyl] retinamide; 4-HPR) has been demonstrated for several conditions, including cancer, obesity, diabetes, and ocular disease. Yet, the mechanisms of action for its pleiotropic effects are still undefined. We hypothesized that investigation of two of the major physiological metabolites of fenretinide, N-[4-methoxyphenyl]retinamide (MPR) and 4-oxo-N-(4-hydroxyphenyl)retinamide (3-keto-HPR), might begin to resolve the multifaceted effects of this synthetic retinoid. We analyzed the effects of fenretinide, MPR, 3-keto-HPR, and the non-retinoid RBP4 ligand A1120, on the activity of known targets of fenretinide, stearoyl-CoA desaturase 1 (SCD1) and dihydroceramide Δ4-desaturase 1 (DES1) in ARPE-19 cells, and purified recombinant mouse beta-carotene oxygenase 1 (BCO1) in vitro. Lipids and retinoids were extracted and quantified by liquid chromatography-mass spectrometry and reversed phase HPLC, respectively. The data demonstrate that while fenretinide is an inhibitor of the activities of these three enzymes, that 3-keto-HPR is a more potent inhibitor of all three enzymes, potentially mediating most of the in vivo beneficial effects of fenretinide. However, while MPR does not affect SCD1 and DES1 activity, it is a potent specific inhibitor of BCO1. We conclude that a deeper understanding of the mechanisms of action of fenretinide and its metabolites provides new avenues for therapeutic specificity. For example, administration of 3-keto-HPR instead of fenretinide may be preferential if inhibition of SCD1 or DES1 activity is the goal (cancer), while MPR may be better for BCO1 modulation (carotenoid metabolism). Continued investigation of fenretinide metabolites in the context of fenretinide’s various therapeutic uses will begin to resolve the pleotropic nature of this compound. PMID:28448568
Hero, Christel; Svensson, Ann-Marie; Franzén, Stefan; Miftaraj, Mervete; Gudbjörnsdottir, Soffia; Eeg-Olofsson, Katarina; Eliasson, Björn; Andersson Sundell, Karolina
2018-01-01
Objectives To analyse the association between refill adherence to lipid-lowering medications, and the risk of cardiovascular disease (CVD) and mortality in patients with type 2 diabetes mellitus. Design Cohort study. Setting National population-based cohort of Swedish patients with type 2 diabetes mellitus. Participants 86 568 patients aged ≥18 years, registered with type 2 diabetes mellitus in the Swedish National Diabetes Register, who filled at least one prescription for lipid-lowering medication use during 2007–2010, 87% for primary prevention. Exposure and outcome measures Refill adherence of implementation was assessed using the medication possession ratio (MPR), representing the proportion of days with medications on hand during an 18-month exposure period. MPR was categorised by five levels (≤20%, 21%–40%, 41%–60%, 61%–80% and >80%). Patients without medications on hand for ≥180 days were defined as non-persistent. Risk of CVD (myocardial infarction, ischaemic heart disease, stroke and unstable angina) and mortality by level of MPR and persistence was analysed after the exposure period using Cox proportional hazards regression and Kaplan-Meier, adjusted for demographics, socioeconomic status, concurrent medications and clinical characteristics. Results The hazard ratios for CVD ranged 1.33–2.36 in primary prevention patients and 1.19–1.58 in secondary prevention patients, for those with MPR ≤80% (p<0.0001). The mortality risk was similar regardless of MPR level. The CVD risk was 74% higher in primary prevention patients and 33% higher in secondary prevention patients, for those who were non-persistent (p<0.0001). The mortality risk was 6% higher in primary prevention patients and 18% higher in secondary prevention patients, for non-persistent patients (p<0.0001). Conclusions Higher refill adherence to lipid-lowering medications was associated with lower risk of CVD in primary and secondary prevention patients with type 2 diabetes mellitus. PMID:29602853
Longitudinal safety evaluation of connected vehicles' platooning on expressways.
Rahman, Md Sharikur; Abdel-Aty, Mohamed
2018-08-01
Connected vehicles (CV) technology has recently drawn an increasing attention from governments, vehicle manufacturers, and researchers. One of the biggest issues facing CVs popularization associates it with the market penetration rate (MPR). The full market penetration of CVs might not be accomplished recently. Therefore, traffic flow will likely be composed of a mixture of conventional vehicles and CVs. In this context, the study of CV MPR is worthwhile in the CV transition period. The overarching goal of this study was to evaluate longitudinal safety of CV platoons by comparing the implementation of managed-lane CV platoons and all lanes CV platoons (with same MPR) over non-CV scenario. This study applied the CV concept on a congested expressway (SR408) in Florida to improve traffic safety. The Intelligent Driver Model (IDM) along with the platooning concept were used to regulate the driving behavior of CV platoons with an assumption that the CVs would follow this behavior in real-world. A high-level control algorithm of CVs in a managed-lane was proposed in order to form platoons with three joining strategies: rear join, front join, and cut-in joint. Five surrogate safety measures, standard deviation of speed, time exposed time-to-collision (TET), time integrated time-to-collision (TIT), time exposed rear-end crash risk index (TERCRI), and sideswipe crash risk (SSCR) were utilized as indicators for safety evaluation. The results showed that both CV approaches (i.e., managed-lane CV platoons, and all lanes CV platoons) significantly improved the longitudinal safety in the studied expressway compared to the non-CV scenario. In terms of surrogate safety measures, the managed-lane CV platoons significantly outperformed all lanes CV platoons with the same MPR. Different time-to-collision (TTC) thresholds were also tested and showed similar results on traffic safety. Results of this study provide useful insight for the management of CV MPR as managed-lane CV platoons. Copyright © 2017 Elsevier Ltd. All rights reserved.
Larghat, Abdulghani M; Swoboda, Peter P; Biglands, John D; Kearney, Mark T; Greenwood, John P; Plein, Sven
2014-12-01
Type 2 diabetes mellitus is an independent risk factor for the development of heart failure. To better understand the mechanism by which this occurs, we investigated cardiac structure, function, and perfusion in patients with and without diabetes. Sixty-five patients with no stenosis >30% on invasive coronary angiography were categorized into diabetes (19) and non-diabetes (46) which was further categorized into prediabetes (30) and controls (16) according to the American Diabetes Association guidelines. Each patient underwent comprehensive cardiovascular magnetic resonance assessment. Left-ventricular (LV) mass, relative wall mass (RWM), Lagrangian circumferential strain, LV torsion, and myocardial perfusion reserve (MPR) were calculated. LV mass was higher in diabetics than non-diabetics (112.8 ± 39.7 vs. 91.5 ± 21.3 g, P = 0.01) and in diabetics than prediabetics (112.8 ± 39.7 vs. 90.3 ± 18.7 g, P = 0.02). LV torsion angle was higher in diabetics than non-diabetics (9.65 ± 1.90 vs. 8.59 ± 1.91°, P = 0.047), and MPR was lower in diabetics than non-diabetics (2.10 ± 0.76 vs. 2.84 ± 1.25 mL/g/min, P = 0.01). There was significant correlation between MPR and early diastolic strain rate (r = -0.310, P = 0.01) and LV torsion (r = -0.306, P = 0.01). In multivariable linear regression analysis, non-diabetics waist-hip ratio, but not body mass index, had a significant association with RWM (Beta = 0.34, P = 0.02). Patients with diabetes have increased LV mass, LV torsion, and decreased MPR. There is a significant association between decreased MPR and increased LV torsion suggesting a possible mechanistic link between microvascular disease and cardiac dysfunction in diabetes. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.
NASA Astrophysics Data System (ADS)
Maciejewski, G.; Raetz, St.; Nettelmann, N.; Seeliger, M.; Adam, C.; Nowak, G.; Neuhäuser, R.
2011-11-01
Context. The WASP-10 planetary system is intriguing because different values of radius have been reported for its transiting exoplanet. The host star exhibits activity in terms of photometric variability, which is caused by the rotational modulation of the spots. Moreover, a periodic modulation has been discovered in transit timing of WASP-10 b, which could be a sign of an additional body perturbing the orbital motion of the transiting planet. Aims: We attempt to refine the physical parameters of the system, in particular the planetary radius, which is crucial for studying the internal structure of the transiting planet. We also determine new mid-transit times to confirm or refute observed anomalies in transit timing. Methods: We acquired high-precision light curves for four transits of WASP-10 b in 2010. Assuming various limb-darkening laws, we generated best-fit models and redetermined parameters of the system. The prayer-bead method and Monte Carlo simulations were used to derive error estimates. Results: Three transit light curves exhibit signatures of the occultations of dark spots by the planet during its passage across the stellar disk. The influence of stellar activity on transit depth is taken into account while determining system parameters. The radius of WASP-10 b is found to be no greater than 1.03+0.07-0.03 Jupiter radii, a value significantly smaller than most previous studies indicate. We calculate interior structure models of the planet, assuming a two-layer structure with one homogeneous envelope atop a rock core. The high value of the WASP-10 b's mean density allows one to consider the planet's internal structure including 270 to 450 Earth masses of heavy elements. Our new mid-transit times confirm that transit timing cannot be explained by a constant period if all literature data points are considered. They are consistent with the ephemeris assuming a periodic variation of transit timing. We show that possible starspot features affecting the transit's ingress or egress cannot reproduce variations in transit timing at the observed amplitude. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA), operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofisica de Andalucia (CSIC).Photometric data are available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/535/A7
Gifts from Exoplanetary Transits
NASA Astrophysics Data System (ADS)
Narita, Norio
2009-08-01
The discovery of transiting extrasolar planets has enabled us to do a number of interesting studies. Transit photometry reveals the radius and the orbital inclination of transiting planets, which allows us to learn the true mass and density of the respective planets by the combined information from radial velocity (RV) measurements. In addition, follow-up observations of transiting planets, looking at such things as secondary eclipses, transit timing variations, transmission spectroscopy, and the Rossiter-McLaughlin effect, provide us information about their dayside temperatures, unseen bodies in systems, planetary atmospheres, and the obliquity of planetary orbits. Such observational information, which will provide us a greater understanding of extrasolar planets, is available only for transiting planets. Here, I briefly summarize what we can learn from transiting planets and introduce previous studies.
Planetary Moon Cycler Trajectories
NASA Technical Reports Server (NTRS)
Russell, Ryan P.; Strange, Nathan J.
2007-01-01
Free-return cycler trajectories repeatedly shuttle a spacecraft between two bodies using little or no fuel. Here, the cycler architecture is proposed as a complementary and alternative method for designing planetary moon tours. Previously applied enumerative cycler search and optimization techniques are generalized and specifically implemented in the Jovian and Saturnian moon systems. In addition, the algorithms are tested for general use to find non-Earth heliocentric cyclers. Overall, hundreds of ideal model ballistic cycler geometries are found and several representative cases are documented and discussed. Many of the ideal model solutions are found to remain ballistic in a zero radius sphere of influence patched conic ephemeris model, and preliminary work in a high-fidelity fully integrated model demonstrates near-ballistic cycles for several example cases.
OGLE 2003-BLG-235/MOA 2003-BLG-53: A Planetary Microlensing Event
NASA Astrophysics Data System (ADS)
Bond, I. A.; Udalski, A.; Jaroszyński, M.; Rattenbury, N. J.; Paczyński, B.; Soszyński, I.; Wyrzykowski, L.; Szymański, M. K.; Kubiak, M.; Szewczyk, O.; Żebruń, K.; Pietrzyński, G.; Abe, F.; Bennett, D. P.; Eguchi, S.; Furuta, Y.; Hearnshaw, J. B.; Kamiya, K.; Kilmartin, P. M.; Kurata, Y.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Noda, S.; Okajima, K.; Sako, T.; Sekiguchi, T.; Sullivan, D. J.; Sumi, T.; Tristram, P. J.; Yanagisawa, T.; Yock, P. C. M.; OGLE Collaboration
2004-05-01
We present observations of the unusual microlensing event OGLE 2003-BLG-235/MOA 2003-BLG-53. In this event, a short-duration (~7 days) low-amplitude deviation in the light curve due to a single-lens profile was observed in both the MOA (Microlensing Observations in Astrophysics) and OGLE (Optical Gravitational Lensing Experiment) survey observations. We find that the observed features of the light curve can only be reproduced using a binary microlensing model with an extreme (planetary) mass ratio of 0.0039+11-07 for the lensing system. If the lens system comprises a main-sequence primary, we infer that the secondary is a planet of about 1.5 Jupiter masses with an orbital radius of ~3 AU.
NOMINAL VALUES FOR SELECTED SOLAR AND PLANETARY QUANTITIES: IAU 2015 RESOLUTION B3
DOE Office of Scientific and Technical Information (OSTI.GOV)
Prša, Andrej; Harmanec, Petr; Torres, Guillermo
In this brief communication we provide the rationale for and the outcome of the International Astronomical Union (IAU) resolution vote at the XXIXth General Assembly in Honolulu, Hawaii, in 2015, on recommended nominal conversion constants for selected solar and planetary properties. The problem addressed by the resolution is a lack of established conversion constants between solar and planetary values and SI units: a missing standard has caused a proliferation of solar values (e.g., solar radius, solar irradiance, solar luminosity, solar effective temperature, and solar mass parameter) in the literature, with cited solar values typically based on best estimates at the timemore » of paper writing. As precision of observations increases, a set of consistent values becomes increasingly important. To address this, an IAU Working Group on Nominal Units for Stellar and Planetary Astronomy formed in 2011, uniting experts from the solar, stellar, planetary, exoplanetary, and fundamental astronomy, as well as from general standards fields to converge on optimal values for nominal conversion constants. The effort resulted in the IAU 2015 Resolution B3, passed at the IAU General Assembly by a large majority. The resolution recommends the use of nominal solar and planetary values, which are by definition exact and are expressed in SI units. These nominal values should be understood as conversion factors only, not as the true solar/planetary properties or current best estimates. Authors and journal editors are urged to join in using the standard values set forth by this resolution in future work and publications to help minimize further confusion.« less
Nominal Values for Selected Solar and Planetary Quantities: IAU 2015 Resolution B3
NASA Astrophysics Data System (ADS)
Prša, Andrej; Harmanec, Petr; Torres, Guillermo; Mamajek, Eric; Asplund, Martin; Capitaine, Nicole; Christensen-Dalsgaard, Jørgen; Depagne, Éric; Haberreiter, Margit; Hekker, Saskia; Hilton, James; Kopp, Greg; Kostov, Veselin; Kurtz, Donald W.; Laskar, Jacques; Mason, Brian D.; Milone, Eugene F.; Montgomery, Michele; Richards, Mercedes; Schmutz, Werner; Schou, Jesper; Stewart, Susan G.
2016-08-01
In this brief communication we provide the rationale for and the outcome of the International Astronomical Union (IAU) resolution vote at the XXIXth General Assembly in Honolulu, Hawaii, in 2015, on recommended nominal conversion constants for selected solar and planetary properties. The problem addressed by the resolution is a lack of established conversion constants between solar and planetary values and SI units: a missing standard has caused a proliferation of solar values (e.g., solar radius, solar irradiance, solar luminosity, solar effective temperature, and solar mass parameter) in the literature, with cited solar values typically based on best estimates at the time of paper writing. As precision of observations increases, a set of consistent values becomes increasingly important. To address this, an IAU Working Group on Nominal Units for Stellar and Planetary Astronomy formed in 2011, uniting experts from the solar, stellar, planetary, exoplanetary, and fundamental astronomy, as well as from general standards fields to converge on optimal values for nominal conversion constants. The effort resulted in the IAU 2015 Resolution B3, passed at the IAU General Assembly by a large majority. The resolution recommends the use of nominal solar and planetary values, which are by definition exact and are expressed in SI units. These nominal values should be understood as conversion factors only, not as the true solar/planetary properties or current best estimates. Authors and journal editors are urged to join in using the standard values set forth by this resolution in future work and publications to help minimize further confusion.
NASA Astrophysics Data System (ADS)
Aizawa, Masataka; Masuda, Kento; Kawahara, Hajime; Suto, Yasushi
2018-05-01
We perform a systematic search for rings around 168 Kepler planet candidates with sufficient signal-to-noise ratios that are selected from all of the short-cadence data. We fit ringed and ringless models to their light curves and compare the fitting results to search for the signatures of planetary rings. First, we identify 29 tentative systems, for which the ringed models exhibit statistically significant improvement over the ringless models. The light curves of those systems are individually examined, but we are not able to identify any candidate that indicates evidence for rings. In turn, we find several mechanisms of false positives that would produce ringlike signals, and the null detection enables us to place upper limits on the size of the rings. Furthermore, assuming the tidal alignment between axes of the planetary rings and orbits, we conclude that the occurrence rate of rings larger than twice the planetary radius is less than 15%. Even though the majority of our targets are short-period planets, our null detection provides statistical and quantitative constraints on largely uncertain theoretical models of the origin, formation, and evolution of planetary rings.
Lysosomal enzymes and their receptors in invertebrates: an evolutionary perspective.
Kumar, Nadimpalli Siva; Bhamidimarri, Poorna M
2015-01-01
Lysosomal biogenesis is an important process in eukaryotic cells to maintain cellular homeostasis. The key components that are involved in the biogenesis such as the lysosomal enzymes, their modifications and the mannose 6-phosphate receptors have been well studied and their evolutionary conservation across mammalian and non-mammalian vertebrates is clearly established. Invertebrate lysosomal biogenesis pathway on the other hand is not well studied. Although, details on mannose 6-phosphate receptors and enzymes involved in lysosomal enzyme modifications were reported earlier, a clear cut pathway has not been established. Recent research on the invertebrate species involving biogenesis of lysosomal enzymes suggests a possible conserved pathway in invertebrates. This review presents certain observations based on these processes that include biochemical, immunological and functional studies. Major conclusions include conservation of MPR-dependent pathway in higher invertebrates and recent evidence suggests that MPR-independent pathway might have been more prominent among lower invertebrates. The possible components of MPR-independent pathway that may play a role in lysosomal enzyme targeting are also discussed here.
HAT-P-20b-HAT-P-23b: FOUR MASSIVE TRANSITING EXTRASOLAR PLANETS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bakos, G. A.; Hartman, J.; Torres, G.
We report the discovery of four relatively massive (2-7 M{sub J}) transiting extrasolar planets. HAT-P-20b orbits the moderately bright V = 11.339 K3 dwarf star GSC 1910-00239 on a circular orbit, with a period P = 2.875317 {+-} 0.000004 days, transit epoch T{sub c} = 2455080.92661 {+-} 0.00021 (BJD{sub UTC}), and transit duration 0.0770 {+-} 0.0008 days. The host star has a mass of 0.76 {+-} 0.03 M{sub Sun }, radius of 0.69 {+-} 0.02 R{sub Sun }, effective temperature 4595 {+-} 80 K, and metallicity [Fe/H] = +0.35 {+-} 0.08. The planetary companion has a mass of 7.246 {+-}more » 0.187 M{sub J} and a radius of 0.867 {+-} 0.033 R{sub J} yielding a mean density of 13.78 {+-} 1.50 g cm{sup -3}. HAT-P-21b orbits the V = 11.685 G3 dwarf star GSC 3013-01229 on an eccentric (e = 0.228 {+-} 0.016) orbit, with a period P = 4.124481 {+-} 0.000007 days, transit epoch T{sub c} = 2454996.41312 {+-} 0.00069, and transit duration 0.1530 {+-} 0.0027 days. The host star has a mass of 0.95 {+-} 0.04 M{sub Sun }, radius of 1.10 {+-} 0.08 R{sub Sun }, effective temperature 5588 {+-} 80 K, and metallicity [Fe/H] = +0.01 {+-} 0.08. The planetary companion has a mass of 4.063 {+-} 0.161 M{sub J} and a radius of 1.024 {+-} 0.092 R{sub J} yielding a mean density of 4.68{sup +1.59}{sub -0.99} g cm{sup -3}. HAT-P-21b is a borderline object between the pM and pL class planets, and the transits occur near apastron. HAT-P-22b orbits the bright V = 9.732 G5 dwarf star HD 233731 on a circular orbit, with a period P = 3.212220 {+-} 0.000009 days, transit epoch T{sub c} = 2454930.22001 {+-} 0.00025, and transit duration 0.1196 {+-} 0.0014 days. The host star has a mass of 0.92 {+-} 0.03 M{sub Sun }, radius of 1.04 {+-} 0.04 R{sub Sun }, effective temperature 5302 {+-} 80 K, and metallicity [Fe/H] = +0.24 {+-} 0.08. The planet has a mass of 2.147 {+-} 0.061 M{sub J} and a compact radius of 1.080 {+-} 0.058 R{sub J} yielding a mean density of 2.11{sup +0.40}{sub -0.29} g cm{sup -3}. The host star also harbors an M-dwarf companion at a wide separation. Finally, HAT-P-23b orbits the V = 12.432 G0 dwarf star GSC 1632-01396 on a close to circular orbit, with a period P = 1.212884 {+-} 0.000002 days, transit epoch T{sub c} = 2454852.26464 {+-} 0.00018, and transit duration 0.0908 {+-} 0.0007 days. The host star has a mass of 1.13 {+-} 0.04 M{sub Sun }, radius of 1.20 {+-} 0.07 R{sub Sun }, effective temperature 5905 {+-} 80 K, and metallicity [Fe/H] = +0.15 {+-} 0.04. The planetary companion has a mass of 2.090 {+-} 0.111 M{sub J} and a radius of 1.368 {+-} 0.090 R{sub J} yielding a mean density of 1.01 {+-} 0.18 g cm{sup -3}. HAT-P-23b is an inflated and massive hot Jupiter on a very short period orbit, and has one of the shortest characteristic infall times (7.5{sup +2.9}{sub -1.8} Myr) before it gets engulfed by the star.« less
Quantification of resolution in multiplanar reconstructions for digital breast tomosynthesis
NASA Astrophysics Data System (ADS)
Vent, Trevor L.; Acciavatti, Raymond J.; Kwon, Young Joon; Maidment, Andrew D. A.
2016-03-01
Multiplanar reconstruction (MPR) in digital breast tomosynthesis (DBT) allows tomographic images to be portrayed in various orientations. We have conducted research to determine the resolution of tomosynthesis MPR. We built a phantom that houses a star test pattern to measure resolution. This phantom provides three rotational degrees of freedom. The design consists of two hemispheres with longitudinal and latitudinal grooves that reference angular increments. When joined together, the hemispheres form a dome that sits inside a cylindrical encasement. The cylindrical encasement contains reference notches to match the longitudinal and latitudinal grooves that guide the phantom's rotations. With this design, any orientation of the star-pattern can be analyzed. Images of the star-pattern were acquired using a DBT mammography system at the Hospital of the University of Pennsylvania. Images taken were reconstructed and analyzed by two different methods. First, the maximum visible frequency (in line pairs per millimeter) of the star test pattern was measured. Then, the contrast was calculated at a fixed spatial frequency. These analyses confirm that resolution decreases with tilt relative to the breast support. They also confirm that resolution in tomosynthesis MPR is dependent on object orientation. Current results verify that the existence of super-resolution depends on the orientation of the frequency; the direction parallel to x-ray tube motion shows super-resolution. In conclusion, this study demonstrates that the direction of the spatial frequency relative to the motion of the x-ray tube is a determinant of resolution in MPR for DBT.
Berti, Andrew D.; Baines, Sarah L.; Howden, Benjamin P.; Sakoulas, George; Nizet, Victor; Proctor, Richard A.
2015-01-01
Daptomycin is increasingly used in combination with other antibiotics to enhance antimicrobial efficacy and/or to mitigate the emergence of daptomycin nonsusceptibility (DNS). This study used a clinical methicillin-resistant Staphylococcus aureus (MRSA) strain in which DNS emerged upon therapy to examine the influence of antibiotic combinations on the development of mutations in specific genes (mprF, rpoBC, dltA, cls2, and yycFG) previously associated with DNS. Whole genomes of bacteria obtained following 28 days of in vitro exposure to daptomycin with or without adjunctive clarithromycin, linezolid, oxacillin, or trimethoprim-sulfamethoxazole were sequenced, and the sequences were compared to that of the progenitor isolate. The addition of oxacillin to medium containing daptomycin prevented the emergence of mprF mutation but did not prevent rpoBC mutation (P < 0.01). These isolates maintained susceptibility to daptomycin during the combined exposure (median MIC, 1 mg/liter). Daptomycin plus clarithromycin or linezolid resulted in low-level (1.5 to 8 mg/liter) and high-level (12 to 96 mg/liter) DNS, respectively, and did not prevent mprF mutation. However, these same combinations prevented rpoBC mutation. Daptomycin alone or combined with linezolid or trimethoprim-sulfamethoxazole resulted in high-level DNS and mutations in mprF plus rpoBC, cls2, and yycFG. Combining daptomycin with different antimicrobials alters the mutational space available for DNS development, thereby favoring the development of predictable collateral susceptibilities. PMID:25733508
Berti, Andrew D; Baines, Sarah L; Howden, Benjamin P; Sakoulas, George; Nizet, Victor; Proctor, Richard A; Rose, Warren E
2015-05-01
Daptomycin is increasingly used in combination with other antibiotics to enhance antimicrobial efficacy and/or to mitigate the emergence of daptomycin nonsusceptibility (DNS). This study used a clinical methicillin-resistant Staphylococcus aureus (MRSA) strain in which DNS emerged upon therapy to examine the influence of antibiotic combinations on the development of mutations in specific genes (mprF, rpoBC, dltA, cls2, and yycFG) previously associated with DNS. Whole genomes of bacteria obtained following 28 days of in vitro exposure to daptomycin with or without adjunctive clarithromycin, linezolid, oxacillin, or trimethoprim-sulfamethoxazole were sequenced, and the sequences were compared to that of the progenitor isolate. The addition of oxacillin to medium containing daptomycin prevented the emergence of mprF mutation but did not prevent rpoBC mutation (P < 0.01). These isolates maintained susceptibility to daptomycin during the combined exposure (median MIC, 1 mg/liter). Daptomycin plus clarithromycin or linezolid resulted in low-level (1.5 to 8 mg/liter) and high-level (12 to 96 mg/liter) DNS, respectively, and did not prevent mprF mutation. However, these same combinations prevented rpoBC mutation. Daptomycin alone or combined with linezolid or trimethoprim-sulfamethoxazole resulted in high-level DNS and mutations in mprF plus rpoBC, cls2, and yycFG. Combining daptomycin with different antimicrobials alters the mutational space available for DNS development, thereby favoring the development of predictable collateral susceptibilities. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
NASA Astrophysics Data System (ADS)
Park, Hyo Seon; Oh, Byung Kwan
2018-03-01
This paper presents a new approach for the damage detection of building structures under ambient excitation based on the inherent modal characteristics. In this study, without the extraction of modal parameters widely utilized in the previous studies on damage detection, a new index called the modal participation ratio (MPR), which is a representative value of the modal response extracted from dynamic responses measured in ambient vibration tests, is proposed to evaluate the change of the system of a structure according to the reduction of the story stiffness. The relationship between the MPR, representing a modal contribution for a specific mode and degree of freedom in buildings, and the story stiffness damage factor (SSDF), representing the extent of reduction in the story stiffness, is analyzed in various damage scenarios. From the analyses with three examples, several rules for the damage localization of building structures are found based on the characteristics of the MPR variation for the first mode subject to change in the SSDF. In addition, a damage severity function, derived from the relationship between the MPR for the first mode in the lowest story and the SSDF, is constructed to identify the severity of story stiffness reduction. Furthermore, the locations and severities of multiple damages are identified via the superposition of the presented damage severity functions. The presented method was applied to detect damage in a three-dimensional reinforced concrete (RC) structure.
Takagi, H; Shichiri, M; Takemura, M; Mohri, M; Nakamori, S
2000-08-01
We discovered on the chromosome of Saccharomyces cerevisiae Sigma 1278b novel genes involved in L-proline analogue L-azetidine-2-carboxylic acid resistance which are not present in the standard laboratory strains. The 5.4 kb-DNA fragment was cloned from the genomic library of the L-azetidine-2-carboxylic acid-resistant mutant derived from a cross between S. cerevisiae strains S288C and Sigma 1278b. The nucleotide sequence of a 4.5-kb segment exhibited no identity with the sequence in the genome project involving strain S288C. Deletion analysis indicated that one open reading frame encoding a predicted protein of 229 amino acids is indispensable for L-azetidine-2-carboxylic acid resistance. The protein sequence was found to be a member of the N-acetyltransferase superfamily. Genomic Southern analysis and gene disruption showed that two copies of the novel gene with one amino acid change at position 85 required for L-azetidine-2-carboxylic acid resistance were present on chromosomes X and XIV of Sigma 1278b background strains. When this novel MPR1 or MPR2 gene (sigma 1278b gene for L-proline analogue resistance) was introduced into the other S. cerevisiae strains, all of the recombinants were resistant to L-azetidine-2-carboxylic acid, indicating that both MPR1 and MPR2 are expressed and have a global function in S. cerevisiae.
Core-powered mass-loss and the radius distribution of small exoplanets
NASA Astrophysics Data System (ADS)
Ginzburg, Sivan; Schlichting, Hilke E.; Sari, Re'em
2018-05-01
Recent observations identify a valley in the radius distribution of small exoplanets, with planets in the range 1.5-2.0 R⊕ significantly less common than somewhat smaller or larger planets. This valley may suggest a bimodal population of rocky planets that are either engulfed by massive gas envelopes that significantly enlarge their radius, or do not have detectable atmospheres at all. One explanation of such a bimodal distribution is atmospheric erosion by high-energy stellar photons. We investigate an alternative mechanism: the luminosity of the cooling rocky core, which can completely erode light envelopes while preserving heavy ones, produces a deficit of intermediate sized planets. We evolve planetary populations that are derived from observations using a simple analytical prescription, accounting self-consistently for envelope accretion, cooling and mass-loss, and demonstrate that core-powered mass-loss naturally reproduces the observed radius distribution, regardless of the high-energy incident flux. Observations of planets around different stellar types may distinguish between photoevaporation, which is powered by the high-energy tail of the stellar radiation, and core-powered mass-loss, which depends on the bolometric flux through the planet's equilibrium temperature that sets both its cooling and mass-loss rates.
Interior phase transformations and mass-radius relationships of silicon-carbon planets
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wilson, Hugh F.; Militzer, Burkhard, E-mail: hughfw@gmail.com
2014-09-20
Planets such as 55 Cancri e orbiting stars with a high carbon-to-oxygen ratio may consist primarily of silicon and carbon, with successive layers of carbon, silicon carbide, and iron. The behavior of silicon-carbon materials at the extreme pressures prevalent in planetary interiors, however, has not yet been sufficiently understood. In this work, we use simulations based on density functional theory to determine high-pressure phase transitions in the silicon-carbon system, including the prediction of new stable compounds with Si{sub 2}C and SiC{sub 2} stoichiometry at high pressures. We compute equations of state for these silicon-carbon compounds as a function of pressure,more » and hence derive interior structural models and mass-radius relationships for planets composed of silicon and carbon. Notably, we predict a substantially smaller radius for SiC planets than in previous models, and find that mass radius relationships for SiC planets are indistinguishable from those of silicate planets. We also compute a new equation of state for iron. We rederive interior models for 55 Cancri e and are able to place more stringent restrictions on its composition.« less
NASA Astrophysics Data System (ADS)
Young, Eliot F.; Young, L. A.; Buie, M.
2007-10-01
The size of Pluto has been difficult to measure. Stellar occultations by Pluto have not yet probed altitudes lower than 1198 km, assuming the clear atmosphere model of Elliot, Person and Qu (2003). Differential refraction by Pluto's atmosphere attenuates the light from an occulted star to a level that is indistinguishable from the zero-level baseline long before Pluto's solid surface is a factor. Since Charon has no detectable atmosphere, its radius was well determined from a stellar occultation in 2005 (Gulbis et al. 2006, Sicardy et al. 2006). Combined with the mutual event photometry (Charon transited Pluto every 6.38 days between 1986 through 1992) - for which differential refraction is a negligible effect - the well-known radius of Charon translates into a more accurate radius for Pluto's solid surface. Our preliminary solid radius estimate for Pluto is 1161 km. We will discuss error bars and the correlations of this determination with Pluto albedo maps. We will also discuss the implications for Pluto's thermal profile, surface temperature and pressure, and constraints on the presence of a haze layer. This work is funded by NASA's Planetary Astronomy program. References Elliot, J.L., Person, M.J., & Qu, S. 2003, "Analysis of Stellar Occultation Data. II. Inversion, with Application to Pluto and Triton." AJ, 126, 1041. Gulbis, A.A.S. et al. 2006, "Charon's radius and atmospheric constraints from observations of a stellar occultation." Nature, 49, 48. Sicardy, B. et al. 2006, "Charon's size and an upper limit on its atmosphere from a stellar occultation." Nature, 49, 52.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Van Eylen, V.; Lindholm Nielsen, M.; Hinrup, B.
2013-09-10
With years of Kepler data currently available, the measurement of variations in planetary transit depths over time can now be attempted. To do so, it is of primary importance to understand which systematic effects may affect the measurement of transits. We aim to measure the stability of Kepler measurements over years of observations. We present a study of the depth of about 500 transit events of the Hot Jupiter HAT-P-7b, using 14 quarters (Q0-Q13) of data from the Kepler satellite. We find a systematic variation in the depth of the primary transit, related to quarters of data and recurring yearly.more » These seasonal variations are about 1%. Within seasons, we find no evidence for trends. We speculate that the cause of the seasonal variations could be unknown field crowding or instrumental artifacts. Our results show that care must be taken when combining transits throughout different quarters of Kepler data. Measuring the relative planetary radius of HAT-P-7b without taking these systematic effects into account leads to unrealistically low error estimates. This effect could be present in all Kepler targets. If so, relative radius measurements of all Hot Jupiters to a precision much better than 1% are unrealistic.« less
OGLE-2013-BLG-1761Lb: A Massive Planet around an M/K Dwarf
NASA Astrophysics Data System (ADS)
Hirao, Y.; Udalski, A.; Sumi, T.; Bennett, D. P.; Koshimoto, N.; Bond, I. A.; Rattenbury, N. J.; Suzuki, D.; and; Abe, F.; Asakura, Y.; Barry, R. K.; Bhattacharya, A.; Donachie, M.; Evans, P.; Fukui, A.; Itow, Y.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Matsuo, T.; Muraki, Y.; Nagakane, M.; Ohnishi, K.; Ranc, C.; Saito, To.; Sharan, A.; Shibai, H.; Sullivan, D. J.; Tristram, P. J.; Yamada, T.; Yamada, T.; Yonehara, A.; MOA Collaboration; Poleski, R.; Skowron, J.; Mróz, P.; Szymański, M. K.; Kozłowski, S.; Pietrukowicz, P.; Soszyński, I.; Wyrzykowski, Ł.; Ulaczyk, K.; OGLE Collaboration
2017-07-01
We report the discovery and the analysis of the planetary microlensing event, OGLE-2013-BLG-1761. There are some degenerate solutions in this event because the planetary anomaly is only sparsely sampled. However, the detailed light-curve analysis ruled out all stellar binary models and shows the lens to be a planetary system. There is the so-called close/wide degeneracy in the solutions with the planet/host mass ratio of q ˜ (7.0 ± 2.0) × 10-3 and q ˜ (8.1 ± 2.6) × 10-3 with the projected separation in Einstein radius units of s = 0.95 (close) and s = 1.18 (wide), respectively. The microlens parallax effect is not detected, but the finite source effect is detected. Our Bayesian analysis indicates that the lens system is located DL=6.9-1.2+1.0 kpc away from us and the host star is an M/K dwarf with a mass of ML=0.33-0.19+0.32 M⊙ orbited by a super-Jupiter mass planet with a mass of mP=2.7-1.5+2.5 MJup at the projected separation of a\\perp=1.8-0.5+0.5 au. The preference of the large lens distance in the Bayesian analysis is due to the relatively large observed source star radius. The distance and other physical parameters may be constrained by the future high-resolution imaging by large ground telescopes or HST. If the estimated lens distance is correct, then this planet provides another sample for testing the claimed deficit of planets in the Galactic bulge.
OGLE-2013-BLG-1761Lb: A Massive Planet around an MK Dwarf
NASA Technical Reports Server (NTRS)
Hirao, Y.; Udalski, A.; Sumi, T.; Bennett, D. P.; Koshimoto, N.; Bond, I. A.; Rattenbury, N. J.; Suzuki, D.; Abe, F.; Asakura, Y.;
2017-01-01
We report the discovery and the analysis of the planetary microlensing event, OGLE-2013-BLG-1761. There are some degenerate solutions in this event because the planetary anomaly is only sparsely sampled. However, the detailed light curve analysis ruled out all stellar binary models and shows the lens to be a planetary system. There is the so-called close wide degeneracy in the solutions with the planet host mass ratio of q approx.(7.0+/-2.0) x 10(exp -3) and q approx.(8.1+/-2.6) x 10(exp -3) with the projected separation in Einstein radius units of s = 0.95 (close) and s = 1.18(wide), respectively. The microlens parallax effect is not detected, but the finite source effect is detected. Our Bayesian analysis indicates that the lens system is located -D(sub L) = 6.9(+ 1.0 -1.2)kpc away from us and the host star is an M/K dwarf with amass of M(sub L) = 0.33(+ 0.32- 1.9)Stellar Mass orbited by a super-Jupiter mass planet with a mass of m(sub p) = 2.7(+ 2.5 - 1.5) M(sub Jup) at the projected separation of a(sub l) = 1.8(+ 0.5 -0.5)au. The preference of the large lens distance in the Bayesian analysis is due to the relatively large observed source star radius. The distance and other physical parameters may be constrained by the future high-resolution imaging by large ground telescopes or HST. If the estimated lens distance is correct, then this planet provides another sample for testing the claimed deficit of planets in the Galactic bulge.
NASA Astrophysics Data System (ADS)
Beth, A.; Garnier, P.; Toublanc, D.; Dandouras, I.; Mazelle, C.
2016-12-01
The planetary exospheres are poorly known in their outer parts, since the neutral densities are low compared with the instruments detection capabilities. The exospheric models are thus often the main source of information at such high altitudes. We present a new way to take into account analytically the additional effect of the stellar radiation pressure on planetary exospheres. In a series of papers, we present with a Hamiltonian approach the effect of the radiation pressure on dynamical trajectories, density profiles and escaping thermal flux. Our work is a generalization of the study by Bishop and Chamberlain [1989] Icarus, 81, 145-163. In this third paper, we investigate the effect of the stellar radiation pressure on the Circular Restricted Three Body Problem (CR3BP), called also the photogravitational CR3BP, and its implication on the escape and the stability of planetary exospheres, especially for hot Jupiters. In particular, we describe the transformation of the equipotentials and the location of the Lagrange points, and we provide a modified equation for the Hill sphere radius that includes the influence of the radiation pressure. Finally, an application to the hot Jupiter HD 209458b and hot Neptune GJ 436b reveals the existence of a blow-off escape regime induced by the stellar radiation pressure.
Numerical simulation of an experimental analogue of a planetary magnetosphere
NASA Astrophysics Data System (ADS)
Liao, Andy Sha; Li, Shule; Hartigan, Patrick; Graham, Peter; Fiksel, Gennady; Frank, Adam; Foster, John; Kuranz, Carolyn
2015-12-01
Recent improvements to the Omega Laser Facility's magneto-inertial fusion electrical discharge system (MIFEDS) have made it possible to generate strong enough magnetic fields in the laboratory to begin to address the physics of magnetized astrophysical flows. Here, we adapt the MHD code AstroBEAR to create 2D numerical models of an experimental analogue of a planetary magnetosphere. We track the secular evolution of the magnetosphere analogue and we show that the magnetospheric components such as the magnetopause, magnetosheath, and bow shock, should all be observable in experimental optical band thermal bremsstrahlung emissivity maps, assuming equilibrium charge state distributions of the plasma. When the magnetosphere analogue nears the steady state, the mid-plane altitude of the magnetopause from the wire surface scales as the one-half power of the ratio of the magnetic pressure at the surface of the free wire to the ram pressure of an unobstructed wind; the mid-plane thickness of the magnetosheath is directly related to the radius of the magnetopause. This behavior conforms to Chapman and Ferraro's theory of planetary magnetospheres. Although the radial dependence of the magnetic field strength differs between the case of a current-carrying wire and a typical planetary object, the major morphological features that develop when a supersonic flow passes either system are identical. Hence, this experimental concept is an attractive one for studying the dynamics of planetary magnetospheres in a controlled environment.
Planet Hunters, Undergraduate Research, and Detection of Extrasolar Planet Kepler-818 b
NASA Astrophysics Data System (ADS)
Baker, David; Crannell, Graham; Duncan, James; Hays, Aryn; Hendrix, Landon
2017-01-01
Detection of extrasolar planets provides an excellent research opportunity for undergraduate students. In Spring 2012, we searched for transiting extrasolar planets using Kepler spacecraft data in our Research Experience in Physics course at Austin College. Offered during the regular academic year, these Research Experience courses engage students in the scientific process, including proposal writing, paper submission, peer review, and oral presentations. Since 2004, over 190 undergraduate students have conducted authentic scientific research through Research Experience courses at Austin College.Zooniverse’s citizen science Planet Hunters web site offered an efficient method for rapid analysis of Kepler data. Light curves from over 5000 stars were analyzed, of which 2.3% showed planetary candidates already tagged by the Kepler team. Another 1.5% of the light curves suggested eclipsing binary stars, and 1.6% of the light curves had simulated planets for training purposes.One of the stars with possible planetary transits had not yet been listed as a planetary candidate. We reported possible transits for Kepler ID 4282872, which later was promoted to planetary candidate KOI-1325 in 2012 and confirmed to host extrasolar planet Kepler-818 b in 2016 (Morton et al. 2016). Kepler-818 b is a “hot Neptune” with period 10.04 days, flux decrease during transit ~0.4%, planetary radius 4.69 Earth radii, and semi-major axis 0.089 au.
Phase Variations, Transits and Eclipses of the Misfit CoRoT-2b
NASA Astrophysics Data System (ADS)
Cowan, Nicolas; Deming, Drake; Gillon, Michael; Knutson, Heather; Madhusudhan, Nikku; Rauscher, Emily
2011-05-01
We propose to observe the nearby transiting hot Jupiter CoRoT-2b for a little over one planetary orbit on two occasions, yielding two secondary eclipses, a transit, and a full phase curve in each of the 3.6 and 4.5 micron channels. These data will help resolve the unique nature of this bloated planet: CoRoT-2b is the only hot Jupiter that is poorly fit by either inverted or non-inverted spectral models (Deming et al. 2011). Two hypotheses have been proposed to explain the peculiar mid-IR colors of CoRoT-2b, and thermal phase measurements with Spitzer's continuous, high-precision photometry will be able to distinguish between them: the planet has a non-inverted atmosphere but is losing mass to its host star, or the planet has a peculiar kind of temperature inversion due to mysterious atmospheric scatterers. CoRoT-2b is also among the most inflated hot Jupiters and, because of its relatively large mass, cannot be reconciled with interior evolution models, despite a small but non-zero eccentricity. A recent planetary collision may be necessary to explain the planet's youthful radius (Guillot & Havel 2011). Finally, the planet's extremely young host star, CoRoT-2, is the most chromospherically active of all transit hosts. This appears to be a common thread connecting all of its planet's peculiarities: the high UV flux of the star will drive mass loss, as well as photochemistry. Most importantly, the radius measurement of the planet at optical wavelengths may be contaminated by star spots. Mid-IR transit measurements from Spitzer will help resolve the mystery of CoRoT-2b's inflated radius.
A POSSIBLE CARBON-RICH INTERIOR IN SUPER-EARTH 55 Cancri e
DOE Office of Scientific and Technical Information (OSTI.GOV)
Madhusudhan, Nikku; Lee, Kanani K. M.; Mousis, Olivier, E-mail: Nikku.Madhusudhan@yale.edu
Terrestrial planets in the solar system, such as the Earth, are oxygen-rich, with silicates and iron being the most common minerals in their interiors. However, the true chemical diversity of rocky planets orbiting other stars is yet unknown. Mass and radius measurements are used to constrain the interior compositions of super-Earths (exoplanets with masses of 1-10 M{sub Circled-Plus }), and are typically interpreted with planetary interior models that assume Earth-centric oxygen-rich compositions. Using such models, the super-Earth 55 Cancri e (mass 8 M{sub Circled-Plus }, radius 2 R{sub Circled-Plus }) has been suggested to bear an interior composition consisting ofmore » Fe, silicates, and an envelope ({approx}> 10% by mass) of supercritical water. We report that the mass and radius of 55 Cancri e can also be explained by a carbon-rich solid interior made of Fe, C, SiC, and/or silicates and without a volatile envelope. While the data allow Fe mass fractions of up to 40%, a wide range of C, SiC, and/or silicate mass fractions are possible. A carbon-rich 55 Cancri e is also plausible if its protoplanetary disk bore the same composition as its host star, which has been reported to be carbon-rich. However, more precise estimates of the stellar elemental abundances and observations of the planetary atmosphere are required to further constrain its interior composition. The possibility of a C-rich interior in 55 Cancri e opens a new regime of geochemistry and geophysics in extraterrestrial rocky planets, compared to terrestrial planets in the solar system.« less
The nuclear regions of NGC 3311 and NGC 7768 imaged with the Hubble Space Telescope Planetary Camera
NASA Technical Reports Server (NTRS)
Grillmair, Carl J.; Faber, S.M.; Lauer, Tod R.; Baum, William A.; Lynds, Roger C.; O'Neil, Earl J., Jr.; Shaya, Edward J.
1994-01-01
We present high-resolution, V band images of the central regions of the brightest cluster ellipticals NGC 3311 and NGC 7768 taken with the Planetary Camera of the Hubble Space Telescope. The nuclei of both galaxies are found to be obscured by dust, though the morphology of the dust is quite different in the two cases. The dust cloud which obscures the central 3 arcsec of NGC 3311 is complex and irregular, while the central region of NGC 7768 contains a disk of material similar in appearance and scale to that recently observed in HST images of NGC 4261. The bright, relatively blue source detected in ground-based studies of NGC 3311 is marginally resolved and is likely to be a site of ongoing star formation. We examine the distribution of globular clusters in the central regions of NGC 3311. The gradient in the surface density profile of the cluster system is significantly shallower than that found by previous investigators at larger radii. We find a core radius for the cluster distribution of 12 plus or minus 3 kpc, which is even larger than the core radius of the globular cluster system surrounding M87. It is also an order of magnitude larger than the upper limit on the core radius of NGC 3311's stellar light and suggests that the central field-star population and the globular cluster system are dynamically distinct. We briefly discuss possible sources for the cold/warm interstellar material in early-type galaxies. While the issue has not been resolved, models which involve galactic wind failure appear to be mo st naturally consistent with the observations.
NASA Astrophysics Data System (ADS)
D'Angelo, G.
2016-12-01
D'Angelo & Bodenheimer (2013, ApJ, 778, 77) performed global 3D radiation-hydrodynamics disk-planet simulations aimed at studying envelope formation around planetary cores, during the phase of sustained planetesimal accretion. The calculations modeled cores of 5, 10, and 15 Earth masses orbiting a sun-like star in a protoplanetary disk extending from ap/2 to 2ap in radius, ap=5 or 10 AU being the core's orbital radius. The gas equation of state - for a solar mixture of H2, H, He - accounted for translational, rotational, and vibrational states, for molecular dissociation and atomic ionization, and for radiation energy. Dust opacity calculations applied the Mie theory to multiple grain species whose size distributions ranged from 5e-6 to 1 mm. Mesh refinement via grid nesting allowed the planets' envelopes to be resolved at the core-radius length scale. Passive tracers were used to determine the volume of gas bound to a core, defining the envelope, and resulting in planet radii comparable to the Bondi radius. The energy budjet included contributions from the accretion of solids on the cores, whose rates were self-consistently computed with a 1D planet formation code. At this stage of the planet's growth, gravitational energy released in the envelope by solids' accretion far exceeds that released by gas accretion. These models are used to determine the gravitational torques exerted by the disk's gas on the planet and the resulting orbital migration rates. Since the envelope radius is a direct product of the models, they allow for a non-ambiguous assessment of the torques exerted by gas not bound to the planet. Additionally, since planets' envelopes are fully resolved, thermal and dynamical effects on the surrounding disk's gas are accurately taken into account. The computed migration rates are compared to those obtained from existing semi-analytical formulations for planets orbiting in isothermal and adiabatic disks. Because these formulations do not account for thermodynamical interactions between the planet's envelope and the disk's gas, the numerical models are also used to quanitfy the impact of short-scale tidal interactions on the total torque acting on the planet. Computing resources were provided by the NASA High-End Computing Program through the NASA Advanced Supercomputing Division at Ames Research Center.
Mercury's magnetosphere after MESSENGER's first flyby.
Slavin, James A; Acuña, Mario H; Anderson, Brian J; Baker, Daniel N; Benna, Mehdi; Gloeckler, George; Gold, Robert E; Ho, George C; Killen, Rosemary M; Korth, Haje; Krimigis, Stamatios M; McNutt, Ralph L; Nittler, Larry R; Raines, Jim M; Schriver, David; Solomon, Sean C; Starr, Richard D; Trávnícek, Pavel; Zurbuchen, Thomas H
2008-07-04
Observations by MESSENGER show that Mercury's magnetosphere is immersed in a comet-like cloud of planetary ions. The most abundant, Na+, is broadly distributed but exhibits flux maxima in the magnetosheath, where the local plasma flow speed is high, and near the spacecraft's closest approach, where atmospheric density should peak. The magnetic field showed reconnection signatures in the form of flux transfer events, azimuthal rotations consistent with Kelvin-Helmholtz waves along the magnetopause, and extensive ultralow-frequency wave activity. Two outbound current sheet boundaries were observed, across which the magnetic field decreased in a manner suggestive of a double magnetopause. The separation of these current layers, comparable to the gyro-radius of a Na+ pickup ion entering the magnetosphere after being accelerated in the magnetosheath, may indicate a planetary ion boundary layer.
The historical tension between astronomical theory and observation
NASA Astrophysics Data System (ADS)
Gingerich, O.
A review of instances in the history of astronomy wherein conflicts between the results of theory and observation occurred, to be later ameliorated or exaggerated by further evidence, is presented. Among the examples are Aristotle's arguments that the form of a celestial body will always be spherical to evenly distribute the mass, and the currently held concept that all celestial objects greater than a few kilometers in radius will be spherical due to gravitational forces. Ptolemy's observations of planetary orbits, however, are noted to have accurately resulted in a numerical model which did not factually represent planetary orbits. It is noted that observation is usually performed with a theory in mind, and interpretation is therefore hindered from clear analysis of phenomena which do not conform to previously held mental models.
Karlsson, Sofia Axia; Hero, Christel; Svensson, Ann-Marie; Franzén, Stefan; Miftaraj, Mervete; Gudbjörnsdottir, Soffia; Eeg-Olofsson, Katarina; Eliasson, Björn; Andersson Sundell, Karolina
2018-03-30
To analyse the association between refill adherence to lipid-lowering medications, and the risk of cardiovascular disease (CVD) and mortality in patients with type 2 diabetes mellitus. Cohort study. National population-based cohort of Swedish patients with type 2 diabetes mellitus. 86 568 patients aged ≥18 years, registered with type 2 diabetes mellitus in the Swedish National Diabetes Register, who filled at least one prescription for lipid-lowering medication use during 2007-2010, 87% for primary prevention. Refill adherence of implementation was assessed using the medication possession ratio (MPR), representing the proportion of days with medications on hand during an 18-month exposure period. MPR was categorised by five levels (≤20%, 21%-40%, 41%-60%, 61%-80% and >80%). Patients without medications on hand for ≥180 days were defined as non-persistent. Risk of CVD (myocardial infarction, ischaemic heart disease, stroke and unstable angina) and mortality by level of MPR and persistence was analysed after the exposure period using Cox proportional hazards regression and Kaplan-Meier, adjusted for demographics, socioeconomic status, concurrent medications and clinical characteristics. The hazard ratios for CVD ranged 1.33-2.36 in primary prevention patients and 1.19-1.58 in secondary prevention patients, for those with MPR ≤80% (p<0.0001). The mortality risk was similar regardless of MPR level. The CVD risk was 74% higher in primary prevention patients and 33% higher in secondary prevention patients, for those who were non-persistent (p<0.0001). The mortality risk was 6% higher in primary prevention patients and 18% higher in secondary prevention patients, for non-persistent patients (p<0.0001). Higher refill adherence to lipid-lowering medications was associated with lower risk of CVD in primary and secondary prevention patients with type 2 diabetes mellitus. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Weycker, D; Lamerato, L; Schooley, S; Macarios, D; Siu Woodworth, T; Yurgin, N; Oster, G
2013-04-01
In clinical practice, adherence with bisphosphonate therapy varies greatly among women with osteoporosis or osteopenia. Our study suggests that better adherence with bisphosphonates confers tangible benefits in terms of graded increases in bone mineral density. Interventions to improve drug adherence should be an important component of disease management. In clinical trials, bisphosphonates have been found to increase bone mineral density (BMD) in women with osteoporosis or osteopenia. In clinical practice, where drug adherence is more variable, change in BMD with bisphosphonate therapy-overall and by level of adherence-is largely unknown. A retrospective cohort study was conducted at Henry Ford Health System (Detroit, MI, USA). Study subjects were women who had low BMD at the left total hip (T-score<-1.0), began oral bisphosphonate therapy, and had ≥1 BMD measurements at the left total hip≥6 months following treatment initiation. Change in BMD was calculated between the most recent pretreatment scan and the first follow-up scan. Adherence (i.e., medication possession ratio (MPR)) was measured from therapy initiation to the first follow-up scan. Among 644 subjects, mean age was 66 years, pretreatment BMD was 0.73 g/cm2, and pretreatment T-score was -1.8. Over a mean follow-up of 27.1 months, mean MPR was 0.57 (95% CI, 0.54 and 0.59), and mean percentage change in BMD was 1.5% (1.1 and 1.9%). Within the MPR strata (five consecutive equi-intervals, from low (0-0.19) to high (0.80-1.0)), mean change in BMD was -0.8% (-1.6 and 0.1%), 0.7% (-0.3 and 1.7%), 2.1% (1.1 and 3.0%), 2.1% (1.4 and 2.9%), and 2.9% (2.3 and 3.5%), respectively. In adjusted analyses, percentage change in BMD was higher (by 1.4-3.4%, p<0.05 for all) in the highest four MPR intervals, respectively, versus MPR 0-0.19. Among women with osteoporosis or osteopenia in clinical practice, better adherence with bisphosphonates appears to confer tangible benefits in terms of increases in BMD.
Wang, Steven; Alfieri, Thomas; Ramakrishnan, Karthik; Braunhofer, Peter; Newsome, Britt A
2014-11-01
Phosphate binders (PBs) account for about one half of the daily pill burden for US hemodialysis (HD) patients, which may reduce adherence. Adherence can be estimated by the medication possession ratio (MPR), which is defined as the proportion of time a patient had sufficient medication to have taken it as prescribed. Gaps of time between prescription fills lower the patient's MPR. We assessed the association of PB pill burden and adherence (MPR) with phosphorus goal attainment. Using pharmacy management program data, HD patients on PB monotherapy were tracked from first PB fill during 1 January 2007-30 June 2011 for 1 year, or until PB change or censoring. Data were assessed with generalized linear models. We analyzed 8616 patients. Higher pill burden was associated with lower adherence. Lower adherence tended to be associated with higher mean phosphorus levels and lower percentage of patients with serum phosphorus ≤5.5 mg/dL (P < 0.001). The association between adherence and these clinical outcomes was most pronounced in the lowest and highest pill burden strata (<3, >3-6, >12-15, >15). Adherence, as measured by the MPR, was negatively related to higher pill burden and phosphorus levels and positively related to patients in the phosphorus target range. Within pill burden strata, phosphorus increased and patients in the target range generally decreased with decreasing adherence, suggesting that patients prescribed fewer PB pills are less likely to have treatment gaps, and may be more likely to achieve phosphorus targets. © The Author 2013. Published by Oxford University Press on behalf of ERA-EDTA.
Life Cycle analysis data and results for geothermal and other electricity generation technologies
Sullivan, John
2013-06-04
Life cycle analysis (LCA) is an environmental assessment method that quantifies the environmental performance of a product system over its entire lifetime, from cradle to grave. Based on a set of relevant metrics, the method is aptly suited for comparing the environmental performance of competing products systems. This file contains LCA data and results for electric power production including geothermal power. The LCA for electric power has been broken down into two life cycle stages, namely plant and fuel cycles. Relevant metrics include the energy ratio and greenhouse gas (GHG) ratios, where the former is the ratio of system input energy to total lifetime electrical energy out and the latter is the ratio of the sum of all incurred greenhouse gases (in CO2 equivalents) divided by the same energy output. Specific information included herein are material to power (MPR) ratios for a range of power technologies for conventional thermoelectric, renewables (including three geothermal power technologies), and coproduced natural gas/geothermal power. For the geothermal power scenarios, the MPRs include the casing, cement, diesel, and water requirements for drilling wells and topside piping. Also included herein are energy and GHG ratios for plant and fuel cycle stages for the range of considered electricity generating technologies. Some of this information are MPR data extracted directly from the literature or from models (eg. ICARUS – a subset of ASPEN models) and others (energy and GHG ratios) are results calculated using GREET models and MPR data. MPR data for wells included herein were based on the Argonne well materials model and GETEM well count results.
Patient-Centered Tablet Application for Improving Medication Adherence after a Drug-Eluting Stent.
Shah, Vicki; Dileep, Anandu; Dickens, Carolyn; Groo, Vicki; Welland, Betty; Field, Jerry; Baumann, Matthew; Flores, Jose D; Shroff, Adhir; Zhao, Zhongsheng; Yao, Yingwei; Wilkie, Diana J; Boyd, Andrew D
2016-01-01
This study's objective was to evaluate a patient-centered educational electronic tablet application, "My Interventional Drug-Eluting Stent Educational App" (MyIDEA) to see if there was an increase in patient knowledge about dual antiplatelet therapy (DAPT) and medication possession ratio (MPR) compared to treatment as usual. In a pilot project, 24 elderly (≥50 years old) research participants were recruited after a drug-eluting stent. Eleven were randomized to the control arm and 13 to the interventional arm. All the participants completed psychological and knowledge questionnaires. Adherence was assessed through MPR, which was calculated at 3 months for all participants who were scheduled for second and third follow-up visits. Relative to control, the interventional group had a 10% average increase in MPR. As compared to the interventional group, more patients in the control group had poor adherence (<80% MPR). The psychological data revealed a single imbalance in anxiety between the control and interventional groups. On average, interventional participants spent 21 min using MyIDEA. Consumer health informatics has enabled us to engage patients with their health data using novel methods. Consumer health technology needs to focus more on patient knowledge and engagement to improve long-term health. MyIDEA takes a unique approach in targeting DAPT from the onset. MyIDEA leverages patient-centered information with clinical care and the electronic health record highlighting the patients' role as a team member in their own health care. The patients think critically about adverse events and how to solve issues before leaving the hospital.
Honda, O; Yanagawa, M; Inoue, A; Kikuyama, A; Yoshida, S; Sumikawa, H; Tobino, K; Koyama, M; Tomiyama, N
2011-04-01
We investigated the image quality of multiplanar reconstruction (MPR) using adaptive statistical iterative reconstruction (ASIR). Inflated and fixed lungs were scanned with a garnet detector CT in high-resolution mode (HR mode) or non-high-resolution (HR) mode, and MPR images were then reconstructed. Observers compared 15 MPR images of ASIR (40%) and ASIR (80%) with those of ASIR (0%), and assessed image quality using a visual five-point scale (1, definitely inferior; 5, definitely superior), with particular emphasis on normal pulmonary structures, artefacts, noise and overall image quality. The mean overall image quality scores in HR mode were 3.67 with ASIR (40%) and 4.97 with ASIR (80%). Those in non-HR mode were 3.27 with ASIR (40%) and 3.90 with ASIR (80%). The mean artefact scores in HR mode were 3.13 with ASIR (40%) and 3.63 with ASIR (80%), but those in non-HR mode were 2.87 with ASIR (40%) and 2.53 with ASIR (80%). The mean scores of the other parameters were greater than 3, whereas those in HR mode were higher than those in non-HR mode. There were significant differences between ASIR (40%) and ASIR (80%) in overall image quality (p<0.01). Contrast medium in the injection syringe was scanned to analyse image quality; ASIR did not suppress the severe artefacts of contrast medium. In general, MPR image quality with ASIR (80%) was superior to that with ASIR (40%). However, there was an increased incidence of artefacts by ASIR when CT images were obtained in non-HR mode.
Effect of disease management on prescription drug treatment: what is the right quality measure?
Mattke, Soeren; Jain, Arvind K; Sloss, Elizabeth M; Hirscher, Randy; Bergamo, Giacomo; O'Leary, June F
2007-04-01
Measures of medication adherence have become common parameters with which disease management (DM) programs are being evaluated, leading to the question of how this concept should be measured in the particular context of a DM intervention. We hypothesize that DM improves adherence to prescriptions more than the rate with which prescriptions are being filled. We used health plan claims data to construct 13 common measures of medication adherence for five chronic conditions. The measures were operationalized in three different ways: the Prescription Fill Rate (PFR), which requires only one prescription; the Medication Possession Ratio (MPR), which requires a supply that covers at least 80% of the year; and the Length of Gap (LOG), which requires no gap greater than 30 days between prescriptions. We compared results from a baseline year to results during the first year of a DM program. Changes in adherence were quite small in the first year of the intervention, with no changes greater than six percentage points. In the intervention year, three measures showed a significant increase based on all three operational definitions, but two measures paradoxically decreased based on the PFR. For both, the MPR and the LOG suggested either no change or significant improvement. None of the MPR and LOG measures pointed toward significantly lower compliance in the intervention year. Different ways to operationalize the concept of medication adherence can lead to fundamentally different conclusions. While more complex, MPR- and LOG-based measures could be more appropriate for DM evaluation. Our initial results, however, need to be confirmed by data covering longer term follow-up.
Chondrule Formation in Bow Shocks around Eccentric Planetary Embryos
NASA Astrophysics Data System (ADS)
Morris, Melissa A.; Boley, Aaron C.; Desch, Steven J.; Athanassiadou, Themis
2012-06-01
Recent isotopic studies of Martian meteorites by Dauphas & Pourmand have established that large (~3000 km radius) planetary embryos existed in the solar nebula at the same time that chondrules—millimeter-sized igneous inclusions found in meteorites—were forming. We model the formation of chondrules by passage through bow shocks around such a planetary embryo on an eccentric orbit. We numerically model the hydrodynamics of the flow and find that such large bodies retain an atmosphere with Kelvin-Helmholtz instabilities allowing mixing of this atmosphere with the gas and particles flowing past the embryo. We calculate the trajectories of chondrules flowing past the body and find that they are not accreted by the protoplanet, but may instead flow through volatiles outgassed from the planet's magma ocean. In contrast, chondrules are accreted onto smaller planetesimals. We calculate the thermal histories of chondrules passing through the bow shock. We find that peak temperatures and cooling rates are consistent with the formation of the dominant, porphyritic texture of most chondrules, assuming a modest enhancement above the likely solar nebula average value of chondrule densities (by a factor of 10), attributable to settling of chondrule precursors to the midplane of the disk or turbulent concentration. We calculate the rate at which a planetary embryo's eccentricity is damped and conclude that a single planetary embryo scattered into an eccentric orbit can, over ~105 years, produce ~1024 g of chondrules. In principle, a small number (1-10) of eccentric planetary embryos can melt the observed mass of chondrules in a manner consistent with all known constraints.
Infrared spectroscopy of the transiting extrasolar planet HD 209458 b during secondary eclipse
NASA Astrophysics Data System (ADS)
Richardson, Lee Jeremy
2003-10-01
We present spectroscopic observations that place strong limits on the atmospheric structure of the transiting extrasolar planet HD 209458 b. The discovery of the transit has led to several new observations that have provided the most de tailed information on the physical properties of a planet outside the solar system. These observations have concentrated on the primary eclipse, the time at which the planet crosses in front of the star as seen from Earth. The measurements have determined the basic physical characteristics of the planet, including radius, mass, average density, and orbital inclination, and have even refined values of the stellar mass and radius. Transmission spectroscopy of the system during primary eclipse resulted in the first detection of the atmosphere of an extrasolar planet, with the measurement of the sodium doublet. The present work discusses the first reported attempts to detect the secondary eclipse, or the disappearance of the planet behind the star, in the infrared. We devise the method of ‘occultation spectroscopy’ to detect the planetary spectrum, by searching in combined light for subtle changes in the shape of the spectrum as the planet passes behind the star. Predicted secondary eclipse events were observed from the Very Large Telescope (VLT) on UT 8 and 15 July 2001 using the Infrared Spectrometer and Array Camera (3.5 3.7 μm). Further observations from the NASA Infrared Telescope Facility (IRTF) using the SpeX instrument (1.9 4.2 μm) included two predicted secondary eclipse events on UT 20 and 27 September 2001. Analysis of these data reveal a statistically significant non- detection of the planetary spectrum. The results place strong limits on the structure of the planetary atmosphere and reject widely-accepted models for the planet that assume the incident stellar radiation is completely absorbed and re-emitted in the substellar hemisphere. Situations that remain consistent with our data include an isothermal atmosphere or the presence of a high absorptive or reflective cloud. The latter case is also consistent with the observed low sodium abundance from transmission spectroscopy. These results represent the strongest limits to date on the temperature structure of the planetary atmosphere.
NASA Astrophysics Data System (ADS)
Moriarty, John; Ballard, Sarah
2016-11-01
NASA’s Kepler Mission uncovered a wealth of planetary systems, many with planets on short-period orbits. These short-period systems reside around 50% of Sun-like stars and are similarly prevalent around M dwarfs. Their formation and subsequent evolution is the subject of active debate. In this paper, we simulate late-stage, in situ planet formation across a grid of planetesimal disks with varying surface density profiles and total mass. We compare simulation results with observable characteristics of the Kepler sample. We identify mixture models with different primordial planetesimal disk properties that self-consistently recover the multiplicity, radius, period and period ratio, and duration ratio distributions of the Kepler planets. We draw three main conclusions. (1) We favor a “frozen-in” narrative for systems of short-period planets, in which they are stable over long timescales, as opposed to metastable. (2) The “Kepler dichotomy,” an observed phenomenon of the Kepler sample wherein the architectures of planetary systems appear to either vary significantly or have multiple modes, can naturally be explained by formation within planetesimal disks with varying surface density profiles. Finally, (3) we quantify the nature of the “Kepler dichotomy” for both GK stars and M dwarfs, and find that it varies with stellar type. While the mode of planet formation that accounts for high multiplicity systems occurs in 24% ± 7% of planetary systems orbiting GK stars, it occurs in 63% ± 16% of planetary systems orbiting M dwarfs.
The Detectability of Radio Auroral Emission from Proxima b
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burkhart, Blakesley; Loeb, Abraham
Magnetically active stars possess stellar winds whose interactions with planetary magnetic fields produce radio auroral emission. We examine the detectability of radio auroral emission from Proxima b, the closest known exosolar planet orbiting our nearest neighboring star, Proxima Centauri. Using the radiometric Bode’s law, we estimate the radio flux produced by the interaction of Proxima Centauri’s stellar wind and Proxima b’s magnetosphere for different planetary magnetic field strengths. For plausible planetary masses, Proxima b could produce radio fluxes of 100 mJy or more in a frequency range of 0.02–3 MHz for planetary magnetic field strengths of 0.007–1 G. According tomore » recent MHD models that vary the orbital parameters of the system, this emission is expected to be highly variable. This variability is due to large fluctuations in the size of Proxima b’s magnetosphere as it crosses the equatorial streamer regions of dense stellar wind and high dynamic pressure. Using the MHD model of Garraffo et al. for the variation of the magnetosphere radius during the orbit, we estimate that the observed radio flux can vary nearly by an order of magnitude over the 11.2-day period of Proxima b. The detailed amplitude variation depends on the stellar wind, orbital, and planetary magnetic field parameters. We discuss observing strategies for proposed future space-based observatories to reach frequencies below the ionospheric cutoff (∼10 MHz), which would be required to detect the signal we investigate.« less
Magnetic Fields Recorded by Chondrules Formed in Nebular Shocks
NASA Astrophysics Data System (ADS)
Mai, Chuhong; Desch, Steven J.; Boley, Aaron C.; Weiss, Benjamin P.
2018-04-01
Recent laboratory efforts have constrained the remanent magnetizations of chondrules and the magnetic field strengths to which the chondrules were exposed as they cooled below their Curie points. An outstanding question is whether the inferred paleofields represent the background magnetic field of the solar nebula or were unique to the chondrule-forming environment. We investigate the amplification of the magnetic field above background values for two proposed chondrule formation mechanisms, large-scale nebular shocks and planetary bow shocks. Behind large-scale shocks, the magnetic field parallel to the shock front is amplified by factors of ∼10–30, regardless of the magnetic diffusivity. Therefore, chondrules melted in these shocks probably recorded an amplified magnetic field. Behind planetary bow shocks, the field amplification is sensitive to the magnetic diffusivity. We compute the gas properties behind a bow shock around a 3000 km radius planetary embryo, with and without atmospheres, using hydrodynamics models. We calculate the ionization state of the hot, shocked gas, including thermionic emission from dust, thermal ionization of gas-phase potassium atoms, and the magnetic diffusivity due to Ohmic dissipation and ambipolar diffusion. We find that the diffusivity is sufficiently large that magnetic fields have already relaxed to background values in the shock downstream where chondrules acquire magnetizations, and that these locations are sufficiently far from the planetary embryos that chondrules should not have recorded a significant putative dynamo field generated on these bodies. We conclude that, if melted in planetary bow shocks, chondrules probably recorded the background nebular field.
NASA Astrophysics Data System (ADS)
Southworth, John; Mancini, L.; Tregloan-Reed, J.; Calchi Novati, S.; Ciceri, S.; D'Ago, G.; Delrez, L.; Dominik, M.; Evans, D. F.; Gillon, M.; Jehin, E.; Jørgensen, U. G.; Haugbølle, T.; Lendl, M.; Arena, C.; Barbieri, L.; Barbieri, M.; Corfini, G.; Lopresti, C.; Marchini, A.; Marino, G.; Alsubai, K. A.; Bozza, V.; Bramich, D. M.; Jaimes, R. Figuera; Hinse, T. C.; Henning, Th.; Hundertmark, M.; Juncher, D.; Korhonen, H.; Popovas, A.; Rabus, M.; Rahvar, S.; Schmidt, R. W.; Skottfelt, J.; Snodgrass, C.; Starkey, D.; Surdej, J.; Wertz, O.
2015-12-01
Transits in the WASP-57 planetary system have been found to occur half an hour earlier than expected. We present 10 transit light curves from amateur telescopes, on which this discovery was based, 13 transit light curves from professional facilities which confirm and refine this finding, and high-resolution imaging which show no evidence for nearby companions. We use these data to determine a new and precise orbital ephemeris, and measure the physical properties of the system. Our revised orbital period is 4.5 s shorter than found from the discovery data alone, which explains the early occurrence of the transits. We also find both the star and planet to be larger and less massive than previously thought. The measured mass and radius of the planet are now consistent with theoretical models of gas giants containing no heavy-element core, as expected for the subsolar metallicity of the host star. Two transits were observed simultaneously in four passbands. We use the resulting light curves to measure the planet's radius as a function of wavelength, finding that our data are sufficient in principle but not in practise to constrain its atmospheric properties. We conclude with a discussion of the current and future status of transmission photometry studies for probing the atmospheres of gas-giant transiting planets.
Directly Imaged Giant Planets: What Do We Hope to Learn?
NASA Technical Reports Server (NTRS)
Marley, Mark
2015-01-01
As we move into an era when GPI and SPHERE are (hopefully) discovering and characterizing new young giant planets, it is worthwhile to step back and review our science goals for young giant planets. Of course for individual planets we ideally would hope to measure mass, radius, atmospheric composition, temperature, and cloud properties, but how do these characteristics fit into our broader understanding of planetary system origin and evolution theories? In my presentation I will review both the specifics of what we hope to learn from newly discovered young worlds as well as how these characteristics inform our broader understanding of giant planets and planetary systems. Finally I will consider the limitations realistic datasets will place on our ability to understand newly discovered planets, illustrating with data from any new such worlds that are available by the conference date.
pt5m - a 0.5 m robotic telescope on La Palma
NASA Astrophysics Data System (ADS)
Hardy, L. K.; Butterley, T.; Dhillon, V. S.; Littlefair, S. P.; Wilson, R. W.
2015-12-01
pt5m is a 0.5 m robotic telescope located on the roof of the 4.2 m William Herschel Telescope (WHT) building, at the Roque de los Muchachos Observatory, La Palma. Using a five-position filter wheel and CCD detector, and bespoke control software, pt5m provides a high-quality robotic observing facility. The telescope first began robotic observing in 2012, and is now contributing to transient follow-up and time-resolved astronomical studies. In this paper, we present the scientific motivation behind pt5m, as well as the specifications and unique features of the facility. We also present an example of the science we have performed with pt5m, where we measure the radius of the transiting exoplanet WASP-33b. We find a planetary radius of 1.603 ± 0.014RJ.
NASA Astrophysics Data System (ADS)
Cabrera, J.; Csizmadia, Sz.; Montagnier, G.; Fridlund, M.; Ammler-von Eiff, M.; Chaintreuil, S.; Damiani, C.; Deleuil, M.; Ferraz-Mello, S.; Ferrigno, A.; Gandolfi, D.; Guillot, T.; Guenther, E. W.; Hatzes, A.; Hébrard, G.; Klagyivik, P.; Parviainen, H.; Pasternacki, Th.; Pätzold, M.; Sebastian, D.; Tadeu dos Santos, M.; Wuchterl, G.; Aigrain, S.; Alonso, R.; Almenara, J.-M.; Armstrong, J. D.; Auvergne, M.; Baglin, A.; Barge, P.; Barros, S. C. C.; Bonomo, A. S.; Bordé, P.; Bouchy, F.; Carpano, S.; Chaffey, C.; Deeg, H. J.; Díaz, R. F.; Dvorak, R.; Erikson, A.; Grziwa, S.; Korth, J.; Lammer, H.; Lindsay, C.; Mazeh, T.; Moutou, C.; Ofir, A.; Ollivier, M.; Pallé, E.; Rauer, H.; Rouan, D.; Samuel, B.; Santerne, A.; Schneider, J.
2015-07-01
Context. We present the discovery of two transiting extrasolar planets by the satellite CoRoT. Aims: We aim at a characterization of the planetary bulk parameters, which allow us to further investigate the formation and evolution of the planetary systems and the main properties of the host stars. Methods: We used the transit light curve to characterize the planetary parameters relative to the stellar parameters. The analysis of HARPS spectra established the planetary nature of the detections, providing their masses. Further photometric and spectroscopic ground-based observations provided stellar parameters (log g, Teff, v sin i) to characterize the host stars. Our model takes the geometry of the transit to constrain the stellar density into account, which when linked to stellar evolutionary models, determines the bulk parameters of the star. Because of the asymmetric shape of the light curve of one of the planets, we had to include the possibility in our model that the stellar surface was not strictly spherical. Results: We present the planetary parameters of CoRoT-28b, a Jupiter-sized planet (mass 0.484 ± 0.087 MJup; radius 0.955 ± 0.066 RJup) orbiting an evolved star with an orbital period of 5.208 51 ± 0.000 38 days, and CoRoT-29b, another Jupiter-sized planet (mass 0.85 ± 0.20 MJup; radius 0.90 ± 0.16 RJup) orbiting an oblate star with an orbital period of 2.850 570 ± 0.000 006 days. The reason behind the asymmetry of the transit shape is not understood at this point. Conclusions: These two new planetary systems have very interesting properties and deserve further study, particularly in the case of the star CoRoT-29. The CoRoT space mission, launched on December 27th 2006, was developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany, and Spain. Based on observations obtained with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in time allocated by OPTICON and the Spanish Time Allocation Committee (CAT). The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement number RG226604 (OPTICON). This work makes use of observations from the LCOGT network.Appendices are available in electronic form at http://www.aanda.org
A photometric study of the hot exoplanet WASP-19b
NASA Astrophysics Data System (ADS)
Lendl, M.; Gillon, M.; Queloz, D.; Alonso, R.; Fumel, A.; Jehin, E.; Naef, D.
2013-04-01
Context. The sample of hot Jupiters that have been studied in great detail is still growing. In particular, when the planet transits its host star, it is possible to measure the planetary radius and the planet mass (with radial velocity data). For the study of planetary atmospheres, it is essential to obtain transit and occultation measurements at multiple wavelengths. Aims: We aim to characterize the transiting hot Jupiter WASP-19b by deriving accurate and precise planetary parameters from a dedicated observing campaign of transits and occultations. Methods: We have obtained a total of 14 transit lightcurves in the r'-Gunn, I-Cousins, z'-Gunn, and I + z' filters and 10 occultation lightcurves in z'-Gunn using EulerCam on the Euler-Swiss telescope and TRAPPIST. We also obtained one lightcurve through the narrow-band NB1190 filter of HAWK-I on the VLT measuring an occultation at 1.19 μm. We performed a global MCMC analysis of all new data, together with some archive data in order to refine the planetary parameters and to measure the occultation depths in z'-band and at 1.19 μm. Results: We measure a planetary radius of Rp = 1.376 ± 0.046 RJ, a planetary mass of Mp = 1.165 ± 0.068 MJ, and find a very low eccentricity of e = 0.0077-0.0032+0.0068, compatible with a circular orbit. We have detected the z'-band occultation at 3σ significance and measure it to be δFocc,z' = 352 ± 116 ppm, more than a factor of 2 smaller than previously published. The occultation at 1.19 μm is only marginally constrained at δFocc,NB1190 = 1711-726+745 ppm. Conclusions: We show that the detection of occultations in the visible range is within reach, even for 1 m class telescopes if a considerable number of individual events are observed. Our results suggest an oxygen-dominated atmosphere of WASP-19b, making the planet an interesting test case for oxygen-rich planets without temperature inversion. Based on photometric observations made with HAWK-I on the ESO VLT/UT4 (Prog. ID 084.C-0532), EulerCam on the Euler-Swiss telescope and the Belgian TRAPPIST telescope, as well as archive data from the Faulkes South Telescope, CORALIE on the Euler-Swiss telescope, HARPS on the ESO 3.6 m telescope (Prog. ID 084-C-0185), and HAWK-I (Prog. ID 083.C-0377(A)).The photometric time series data in this work are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A2
Adherence with bisphosphonate therapy in US veterans with rheumatoid arthritis.
Richards, J Steuart; Cannon, Grant W; Hayden, Candace L; Amdur, Richard L; Lazaro, Deana; Mikuls, Ted R; Reimold, Andreas M; Caplan, Liron; Johnson, Dannette S; Schwab, Pascale; Cherascu, Bogdan N; Kerr, Gail S
2012-12-01
Pharmacy Benefits Management program data for patients enrolled in the Veterans Affairs Rheumatoid Arthritis (VARA) registry were linked with clinical data to determine bisphosphonate adherence and persistence among US veterans with rheumatoid arthritis (RA) and to determine factors associated with adherence. The primary outcome measures were the duration of bisphosphonate therapy and the medication possession ratio (MPR). Patients with an MPR <0.80 were classified as nonadherent. Potential covariates considered in the analysis included patient demographics, RA disease activity and severity parameters, and factors associated with osteoporosis risk. Associations of patient factors with duration of therapy and adherence were examined using multivariable regression modeling. Bisphosphonates were prescribed to 573 (41.5%) of 1,382 VARA subjects. The mean ± SD duration of therapy for bisphosphonates was 39.2 ± 31.4 months. A longer duration of therapy correlated with older age, more years of education, and dual x-ray absorptiometry testing. The mean ± SD MPR of VARA subjects for bisphosphonate therapy was 0.69 ± 0.28; 302 (52.7%) were nonadherent. In multivariate analyses, nonadherence with bisphosphonate therapy was associated with a longer duration of RA disease (odds ratio [OR] 1.02, 95% confidence interval [95% CI] 1.00-1.04) and duration of bisphosphonate therapy >32 months (OR 1.63, 95% CI 1.04-2.57). Whites were less likely to have a low MPR compared with nonwhites (OR 0.52, 95% CI 0.30-0.88). Nonadherence with bisphosphonates was common in this cohort of RA patients and was associated with nonwhite ethnicity, a longer duration of RA disease, and a greater duration of bisphosphonate therapy. Copyright © 2012 by the American College of Rheumatology.
Feldman, Candace H.; Yazdany, Jinoos; Guan, Hongshu; Solomon, Daniel H.; Costenbader, Karen H.
2015-01-01
Objective We examined whether nonadherence to hydroxychloroquine (HCQ) or immunosuppressive medications (IS) was associated with higher subsequent acute care utilization among Medicaid beneficiaries with systemic lupus erythematosus (SLE). Methods We utilized U.S. Medicaid data from 2000–2006 to identify adults 18–64 years with SLE who were new users of HCQ or IS. We defined the index date as receipt of HCQ or IS without use in the prior six months. We measured adherence using the medication possession ratio (MPR), the proportion of days covered by total days supply dispensed, for one-year post-index date. Our outcomes were all-cause and SLE-related emergency department (ED) visits and hospitalizations in the subsequent year. We used multivariable Poisson regression models to examine the association between nonadherence (MPR<80%) and acute care utilization adjusting for sociodemographics and comorbidities. Results We identified 9,600 HCQ new users and 3,829 IS new users with SLE. The mean MPR for HCQ was 47.8% (SD 30.3) and for IS, 42.7% (SD 30.7). 79% of HCQ users and 83% of IS users were nonadherent (MPR<80%). In multivariable models, among HCQ users, the incidence rate ratio (IRR) of ED visits was 1.55 (95% CI 1.43–1.69) and the IRR of hospitalizations was 1.37 (95% CI 1.25–1.50), comparing nonadherers to adherers. For IS users, the IRR of ED visits was 1.64 (95% CI 1.42–1.89) and of hospitalizations was 1.67 (95% CI 1.41–1.96) for nonadherers versus adherers. Conclusion In this cohort, nonadherence to HCQ and IS was common and was associated with significantly higher subsequent acute care utilization. PMID:26097166
Ude, Miriam; Schuessel, Katrin; Quinzler, Renate; Leuner, Kristina; Müller, Walter E; Schulz, Martin
2011-09-01
For treatment success in chronic diseases such as hypertension, adequate adherence to long-term pharmacotherapy is a prerequisite. The purpose of this study was to evaluate whether switching from brand name ramipril to a generic product after patent expiry may negatively affect patients' refill compliance. Claims data for ambulatory prescriptions within the statutory health insurance system were evaluated. Patients were included if they had filled a ramipril prescription (index) for either brand name or generic ramipril products between September 2003 and June 2004. Patients had to be continuously treated with ramipril for at least 12 months before and after the index date. Patients with a change from brand name to generic product or vice versa during follow-up after the index date were excluded from the analyses, as were patients who could not be unequivocally allocated to characteristics of covariates. Refill compliance was analysed by calculating the medication possession ratio (MPR), assuming that patients were prescribed one unit dose per day (MPR(UD)). In total, 142,690 and 79,191 patients were classified as brand name or generic therapy, respectively. Median MPR(UD) values were 0.95 and 0.96 (P < 0.001). In a logistic regression model adjusting for covariates, the probability for noncompliance (MPR(UD) < 0.8) was marginally lower in the generic compared with the brand name group (odds ratio 0.926, 99% confidence interval 0.901-0.951, P < 0.001). These results suggest that refill compliance is not negatively affected by a physician-induced switch from brand name to generic ramipril products after patent expiry.
Medication possession ratio predicts antiretroviral regimens persistence in Peru.
Salinas, Jorge L; Alave, Jorge L; Westfall, Andrew O; Paz, Jorge; Moran, Fiorella; Carbajal-Gonzalez, Danny; Callacondo, David; Avalos, Odalie; Rodriguez, Martin; Gotuzzo, Eduardo; Echevarria, Juan; Willig, James H
2013-01-01
In developing nations, the use of operational parameters (OPs) in the prediction of clinical care represents a missed opportunity to enhance the care process. We modeled the impact of multiple measurements of antiretroviral treatment (ART) adherence on antiretroviral treatment outcomes in Peru. Retrospective cohort study including ART naïve, non-pregnant, adults initiating therapy at Hospital Nacional Cayetano Heredia, Lima-Peru (2006-2010). Three OPs were defined: 1) Medication possession ratio (MPR): days with antiretrovirals dispensed/days on first-line therapy; 2) Laboratory monitory constancy (LMC): proportion of 6 months intervals with ≥1 viral load or CD4 reported; 3) Clinic visit constancy (CVC): proportion of 6 months intervals with ≥1 clinic visit. Three multi-variable Cox proportional hazard (PH) models (one per OP) were fit for (1) time of first-line ART persistence and (2) time to second-line virologic failure. All models were adjusted for socio-demographic, clinical and laboratory variables. 856 patients were included in first-line persistence analyses, median age was 35.6 years [29.4-42.9] and most were male (624; 73%). In multivariable PH models, MPR (per 10% increase HR=0.66; 95%CI=0.61-0.71) and LMC (per 10% increase 0.83; 0.71-0.96) were associated with prolonged time on first-line therapies. Among 79 individuals included in time to second-line virologic failure analyses, MPR was the only OP independently associated with prolonged time to second-line virologic failure (per 10% increase 0.88; 0.77-0.99). The capture and utilization of program level parameters such as MPR can provide valuable insight into patient-level treatment outcomes.
Kim, Hyun-Woo; Shin, Hang-Sik; Han, Sun-Kee; Oh, Sae-Eun
2007-03-01
This study investigated the effects of food waste constituents on thermophilic (55 degrees C) anaerobic codigestion of sewage sludge and food waste by using statistical techniques based on biochemical methane potential tests. Various combinations of grain, vegetable, and meat as cosubstrate were tested, and then the data of methane potential (MP), methane production rate (MPR), and first-order kinetic constant of hydrolysis (kH) were collected for further analyses. Response surface methodology by the Box-Behnken design can verify the effects and their interactions of three variables on responses efficiently. MP was mainly affected by grain, whereas MPR and kH were affected by both vegetable and meat. Estimated polynomial regression models can properly explain the variability of experimental data with a high-adjusted R2 of 0.727, 0.836, and 0.915, respectively. By applying a series of optimization techniques, it was possible to find the proper criteria of cosubstrate. The optimal cosubstrate region was suggested based on overlay contours of overall mean responses. With the desirability contour plots, it was found that optimal conditions of cosubstrate for the maximum MPR (56.6 mL of CH4/g of chemical oxygen demand [COD]/day) were 0.71 g of COD/L of grain, 0.18 g of COD/L of vegetable, and 0.38 g of COD/L of meat by the simultaneous consideration of MP, MPR, and kH. Within the range of each factor examined, the corresponding optimal ratio of sewage sludge to cosubstrate was 71:29 as the COD basis. Elaborate discussions could yield practical operational strategies for the enhanced thermophilic anaerobic codigestion of sewage sludge and food waste.
Improving Satellite Quantitative Precipitation Estimation Using GOES-Retrieved Cloud Optical Depth
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stenz, Ronald; Dong, Xiquan; Xi, Baike
To address significant gaps in ground-based radar coverage and rain gauge networks in the U.S., geostationary satellite quantitative precipitation estimates (QPEs) such as the Self-Calibrating Multivariate Precipitation Retrievals (SCaMPR) can be used to fill in both the spatial and temporal gaps of ground-based measurements. Additionally, with the launch of GOES-R, the temporal resolution of satellite QPEs may be comparable to that of Weather Service Radar-1988 Doppler (WSR-88D) volume scans as GOES images will be available every five minutes. However, while satellite QPEs have strengths in spatial coverage and temporal resolution, they face limitations particularly during convective events. Deep Convective Systemsmore » (DCSs) have large cloud shields with similar brightness temperatures (BTs) over nearly the entire system, but widely varying precipitation rates beneath these clouds. Geostationary satellite QPEs relying on the indirect relationship between BTs and precipitation rates often suffer from large errors because anvil regions (little/no precipitation) cannot be distinguished from rain-cores (heavy precipitation) using only BTs. However, a combination of BTs and optical depth (τ) has been found to reduce overestimates of precipitation in anvil regions (Stenz et al. 2014). A new rain mask algorithm incorporating both τ and BTs has been developed, and its application to the existing SCaMPR algorithm was evaluated. The performance of the modified SCaMPR was evaluated using traditional skill scores and a more detailed analysis of performance in individual DCS components by utilizing the Feng et al. (2012) classification algorithm. SCaMPR estimates with the new rain mask applied benefited from significantly reduced overestimates of precipitation in anvil regions and overall improvements in skill scores.« less
Woodhams, Reiko; Nishimaki, Hiroshi; Fujii, Kaoru; Kakita, Satoko; Hayakawa, Kazushige
2010-10-01
The purpose of this study was to assess the efficacy of multidetector-row CT (MDCT) for the diagnosis of non-occlusive mesenteric ischemia (NOMI) by analyzing morphology and diameter of superior mesenteric artery (SMA). We assessed whether MDCT was as useful as angiography for the diagnosis of NOMI. Four patients who were diagnosed with NOMI were retrospectively analyzed. All patients had 8-row MDCT followed by laparotomy. Two of them underwent angiography after MDCT. The morphology and diameter of SMA of these cases was analyzed on multi-planar reconstructed (MPR) images. The mean diameter of SMA of NOMI cases was compared to that of 13 control cases. MPR images of all NOMI cases showed irregular narrowing of the SMA, spasm of the arcades of SMA, and poor demonstration of intramural vessels. MPR images of two patients who had angiography were concordant with their angiograms. The mean diameter of SMA of NOMI patients was 3.4±1.1mm, which was statistically smaller than that of 13 control patients, 6.0±1.5mm (P<0.05, Wilcoxon rank sum tests). Angiography has been recognized essential for the diagnosis of NOMI. This study shows the possibility of MDCT to be an equivalently useful modality compared to angiography for the diagnosis of NOMI by interpreting morphologic appearance and diameter of SMA. Introduction of MDCT in the decision tree of NOMI treatment may bring the benefit of prompt diagnosis and subsequent early and efficient initiation of therapy, which may improve the mortality. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.
Association of cinacalcet adherence and costs in patients on dialysis.
Lee, Andrew; Song, Xue; Khan, Irfan; Belozeroff, Vasily; Goodman, William; Fulcher, Nicole; Diakun, David
2011-01-01
In addition to negative impacts on clinical effectiveness in treating secondary hyperparathyroidism, low adherence to cinacalcet may have negative impacts on healthcare costs. This study assessed the relationship between medication adherence and healthcare costs among US patients on dialysis given cinacalcet to manage secondary hyperparathyroidism. Retrospective cohort study of patients who were receiving dialysis with an initial cinacalcet prescription between January 2004 and April 2010 and who survived ≥12 months. Longitudinal, integrated medical, and pharmacy claims data from the MarketScan? database were used to calculate medication possession ratios (MPR) over 12 months and to examine the association of adherence with inpatient, outpatient, emergency room, outpatient medication, and total costs while controlling for patient characteristics, co-morbid medical conditions, and concomitant medication MPR in a multivariate regression model. Patients were dichotomized as adherent (<180 days refill gap) or non-adherent (≥180 day refill gap). Adherent patients were further dichotomized as low adherent (<0.8 MPR) and high adherent (≥0.8 MPR). The final study cohort included 4923 patients. After 12 months, 46% were non-adherent, 27% were low adherent, and 28% were high adherent. Greater cinacalcet adherence was associated with significantly lower inpatient costs with cost-savings of a greater magnitude than the increased medication costs. This study demonstrated that low adherence to cinacalcet, which may be associated with undesirable clinical and health-economic outcomes, is common. Despite limitations inherent in retrospective studies of claims databases, such as unobserved confounding, non-discrimination between prescription fill and actual use, and not knowing the reasons for non-adherence, these results suggest that inpatient cost savings of $8899, more than offset higher medication costs of $5858 associated with increased cinacalcet adherence.
Cramer, J A; Benedict, Á; Muszbek, N; Keskinaslan, A; Khan, Z M
2008-01-01
Objectives To review studies of patient compliance/persistence with cardiovascular or antidiabetic medication published since the year 2000; to compare the methods used to measure compliance/persistence across studies; to compare reported compliance/persistence rates across therapeutic classes and to assess whether compliance/persistence correlates with clinical outcomes. Methods English language papers published between January 2000 and November 2005 investigating patient compliance/persistence with cardiovascular or antidiabetic medication were identified through searches of the MEDLINE and EMBASE databases. Definitions and measurements of compliance/persistence were compared across therapeutic areas using contingency tables. Results Of the 139 studies analysed, 32% focused on hypertension, 27% on diabetes and 13% on dyslipidaemia. The remainder covered coronary heart disease and cardiovascular disease (CVD) in general. The most frequently reported measure of compliance was the 12-month medication possession ratio (MPR). The overall mean MPR was 72%, and the MPR did not differ significantly between treatment classes (range: 67–76%). The average proportion of patients with an MPR of > 80% was 59% overall, 64% for antihypertensives, 58% for oral antidiabetics, 51% for lipid-lowering agents and 69% in studies of multiple treatments, again with no significant difference between treatment classes. The average 12-month persistence rate was 63% and was similar across therapeutic classes. Good compliance had a positive effect on outcome in 73% of the studies examining clinical outcomes. Conclusions Non-compliance with cardiovascular and antidiabetic medication is a significant problem, with around 30% of days ‘on therapy’ not covered by medication and only 59% of patients taking medication for more than 80% of their days ‘on therapy’ in a year. Good compliance has a positive effect on clinical outcome, suggesting that the management of CVD may be improved by improving patient compliance. PMID:17983433
Honda, O; Yanagawa, M; Inoue, A; Kikuyama, A; Yoshida, S; Sumikawa, H; Tobino, K; Koyama, M; Tomiyama, N
2011-01-01
Objective We investigated the image quality of multiplanar reconstruction (MPR) using adaptive statistical iterative reconstruction (ASIR). Methods Inflated and fixed lungs were scanned with a garnet detector CT in high-resolution mode (HR mode) or non-high-resolution (HR) mode, and MPR images were then reconstructed. Observers compared 15 MPR images of ASIR (40%) and ASIR (80%) with those of ASIR (0%), and assessed image quality using a visual five-point scale (1, definitely inferior; 5, definitely superior), with particular emphasis on normal pulmonary structures, artefacts, noise and overall image quality. Results The mean overall image quality scores in HR mode were 3.67 with ASIR (40%) and 4.97 with ASIR (80%). Those in non-HR mode were 3.27 with ASIR (40%) and 3.90 with ASIR (80%). The mean artefact scores in HR mode were 3.13 with ASIR (40%) and 3.63 with ASIR (80%), but those in non-HR mode were 2.87 with ASIR (40%) and 2.53 with ASIR (80%). The mean scores of the other parameters were greater than 3, whereas those in HR mode were higher than those in non-HR mode. There were significant differences between ASIR (40%) and ASIR (80%) in overall image quality (p<0.01). Contrast medium in the injection syringe was scanned to analyse image quality; ASIR did not suppress the severe artefacts of contrast medium. Conclusion In general, MPR image quality with ASIR (80%) was superior to that with ASIR (40%). However, there was an increased incidence of artefacts by ASIR when CT images were obtained in non-HR mode. PMID:21081572
Adherence to Antiretroviral Therapy in Turkey: Results from the ACTHIV-IST Study Group.
Yildiz Sevgi, Dilek; Gunduz, Alper; Altuntas Aydin, Ozlem; Mete, Bilgul; Sargin, Fatma; Kumbasar Karaosmanoglu, Hayat; Uzun, Nuray; Yemisen, Mucahit; Dokmetas, Ilyas; Tabak, Fehmi
2017-12-01
Maintaining optimal adherence to antiretroviral therapy (ART) is essential for optimizing the management of HIV infection. The aim of this study is to explore ART adherence rates in Turkey. Included in this study were a total of 263 HIV-infected patients followed up by the ACTHIV-IST (ACTion against HIV in Istanbul) Study Group affiliated with four tertiary hospitals. The study population included patients 18 years of age or older who were on ART for over 12 months. Adherence was assessed by the medication possession ratio (MPR) calculated for each patient using data (a list of all drugs dispensed within the previous year for that patient) obtained from pharmacy medication records. In addition, patients completed a self-report questionnaire addressing missed doses and the AIDS Clinical Trials Group (ACTG) adherence questionnaire. The study was reviewed and approved by the Ethics Committee of Cerrahpasa Medical Faculty. Patient ages ranged from 19 to 71 years. Two hundred and thirty-one patients were male (88%). Two hundred and twenty-four patients (85%) had optimal adherence (MPR ≥95%). During the course of ART, 236 patients (90%) reported no missed doses in the past 4 days of their treatment, whereas 206 patients (78%) reported no missed doses in the past month. Simply forgetting was the most common reason for nonadherence. MPR was associated with virologic rebound. Major factors affecting adherence were being female, taking antituberculosis drugs, having an opportunistic infection, being able to take all or most of the medication as directed, and being aware of the need to take medication exactly as instructed to prevent the development of drug resistance. Adherence to ART measured by MPR and self-report surveys is relatively high in Turkey when compared with other countries, which probably led to high ART success rates.
McIDAS-eXplorer: A version of McIDAS for planetary applications
NASA Technical Reports Server (NTRS)
Limaye, Sanjay S.; Saunders, R. Stephen; Sromovsky, Lawrence A.; Martin, Michael
1994-01-01
McIDAS-eXplorer is a set of software tools developed for analysis of planetary data published by the Planetary Data System on CD-ROM's. It is built upon McIDAS-X, an environment which has been in use nearly two decades now for earth weather satellite data applications in research and routine operations. The environment allows convenient access, navigation, analysis, display, and animation of planetary data by utilizing the full calibration data accompanying the planetary data. Support currently exists for Voyager images of the giant planets and their satellites; Magellan radar images (F-MIDR and C-MIDR's, global map products (GxDR's), and altimetry data (ARCDR's)); Galileo SSI images of the earth, moon, and Venus; Viking Mars images and MDIM's as well as most earth based telescopic images of solar system objects (FITS). The NAIF/JPL SPICE kernels are used for image navigation when available. For data without the SPICE kernels (such as the bulk of the Voyager Jupiter and Saturn imagery and Pioneer Orbiter images of Venus), tools based on NAIF toolkit allow the user to navigate the images interactively. Multiple navigation types can be attached to a given image (e.g., for ring navigation and planet navigation in the same image). Tools are available to perform common image processing tasks such as digital filtering, cartographic mapping, map overlays, and data extraction. It is also possible to have different planetary radii for an object such as Venus which requires a different radius for the surface and for the cloud level. A graphical user interface based on Tel-Tk scripting language is provided (UNIX only at present) for using the environment and also to provide on-line help. It is possible for end users to add applications of their own to the environment at any time.
K2-111 b - a short period super-Earth transiting a metal poor, evolved old star
NASA Astrophysics Data System (ADS)
Fridlund, Malcolm; Gaidos, Eric; Barragán, Oscar; Persson, Carina M.; Gandolfi, Davide; Cabrera, Juan; Hirano, Teruyuki; Kuzuhara, Masayuki; Csizmadia, Sz.; Nowak, Grzegorz; Endl, Michael; Grziwa, Sascha; Korth, Judith; Pfaff, Jeremias; Bitsch, Bertram; Johansen, Anders; Mustill, Alexander J.; Davies, Melvyn B.; Deeg, Hans J.; Palle, Enric; Cochran, William D.; Eigmüller, Philipp; Erikson, Anders; Guenther, Eike; Hatzes, Artie P.; Kiilerich, Amanda; Kudo, Tomoyuki; MacQueen, Phillip; Narita, Norio; Nespral, David; Pätzold, Martin; Prieto-Arranz, Jorge; Rauer, Heike; Van Eylen, Vincent
2017-07-01
Context. From a light curve acquired through the K2 space mission, the star K2-111(EPIC 210894022) has been identified as possibly orbited by a transiting planet. Aims: Our aim is to confirm the planetary nature of the object and derive its fundamental parameters. Methods: We analyse the light curve variations during the planetary transit using packages developed specifically for exoplanetary transits. Reconnaissance spectroscopy and radial velocity observations have been obtained using three separate telescope and spectrograph combinations. The spectroscopic synthesis package SME has been used to derive the stellar photospheric parameters that were used as input to various stellar evolutionary tracks in order to derive the parameters of the system. The planetary transit was also validated to occur on the assumed host star through adaptive imaging and statistical analysis. Results: The star is found to be located in the background of the Hyades cluster at a distance at least 4 times further away from Earth than the cluster itself. The spectrum and the space velocities of K2-111 strongly suggest it to be a member of the thick disk population. The co-added high-resolution spectra show that that it is a metal poor ([Fe/H] = - 0.53 ± 0.05 dex) and α-rich somewhat evolved solar-like star of spectral type G3. We find Teff = 5730 ± 50 K, log g⋆ = 4.15 ± 0.1 cgs, and derive a radius of R⋆ = 1.3 ± 0.1 R⊙ and a mass of M⋆ = 0.88 ± 0.02 M⊙. The currently available radial velocity data confirms a super-Earth class planet with a mass of 8.6 ± 3.9 M⊕ and a radius of 1.9 ± 0.2 R⊕. A second more massive object with a period longer than about 120 days is indicated by a long-term radial velocity drift. Conclusions: The radial velocity detection together with the imaging confirms with a high level of significance that the transit signature is caused by a planet orbiting the star K2-111. This planet is also confirmed in the radial velocity data. A second more massive object (planet, brown dwarf, or star) has been detected in the radial velocity signature. With an age of ≳10 Gyr this system is one of the oldest where planets are hitherto detected. Further studies of this planetary system are important since it contains information about the planetary formation process during a very early epoch of the history of our Galaxy.
High precision localization of intracerebral hemorrhage based on 3D MPR on head CT images
NASA Astrophysics Data System (ADS)
Sun, Jianyong; Hou, Xiaoshuai; Sun, Shujie; Zhang, Jianguo
2017-03-01
The key step for minimally invasive intracerebral hemorrhage surgery is precisely positioning the hematoma location in the brain before and during the hematoma surgery, which can significantly improves the success rate of puncture hematoma. We designed a 3D computerized surgical plan (CSP) workstation precisely to locate brain hematoma based on Multi-Planar Reconstruction (MPR) visualization technique. We used ten patients' CT/MR studies to verify our designed CSP intracerebral hemorrhage localization method. With the doctor's assessment and comparing with the results of manual measurements, the output of CSP WS for hematoma surgery is more precise and reliable than manual procedure.
Abu Taleb, Walaa; Rehan Youssef, Aliaa; Saleh, Amir
2016-10-01
Manual pressure release (MPR) is a popular treatment of trigger points. Yet, treatment response may be influenced by inconsistent application of pressure. Further, it may contribute to increased risk of work-related musculoskeletal disorders of the wrist and hand in therapists. Therefore, this study aimed at introducing a novel method to apply pressure using the algometer and to compare its effectiveness to MPR. Forty-five volunteers with active trigger points of the upper trapezius received algometer pressure release (APR), MPR, or sham ultrasound (US). Pain pressure threshold (PPT) and contralateral active and passive neck side-bending ranges were assessed at baseline and immediately after a single session. Results showed no significant differences in post-treatment PPT between the study groups (p > 0.05). The APR group showed a significant increase in passive side-bending range compared with the two other groups, whereas active range improved in the APR compared with the US group (p < 0.05). Our results show that using algometer to apply pressure release to upper trapezius trigger points is more effective compared with manual release and sham US. Copyright © 2016 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Energy and Resources Group, University of California, Berkeley; Darghouth, Naim R.; Barbose, Galen
2011-06-01
Net metering has become a widespread mechanism in the U.S. for supporting customer adoption of distributed photovoltaics (PV), but has faced challenges as PV installations grow to a larger share of generation in a number of states. This paper examines the value of the bill savings that customers receive under net metering, and the associated role of retail rate design, based on a sample of approximately two hundred residential customers of California's two largest electric utilities. We find that the bill savings per kWh of PV electricity generated varies by more than a factor of four across the customers inmore » the sample, which is largely attributable to the inclining block structure of the utilities' residential retail rates. We also compare the bill savings under net metering to that received under three potential alternative compensation mechanisms, based on California's Market Price Referent (MPR). We find that net metering provides significantly greater bill savings than a full MPR-based feed-in tariff, but only modestly greater savings than alternative mechanisms under which hourly or monthly net excess generation is compensated at the MPR rate.« less
Brunetti, C R; Burke, R L; Hoflack, B; Ludwig, T; Dingwell, K S; Johnson, D C
1995-01-01
Herpes simplex virus (HSV) glycoprotein D (gD) is essential for virus entry into cells, is modified with mannose-6-phosphate (M-6-P), and binds to both the 275-kDa M-6-P receptor (MPR) and the 46-kDa MPR (C. R. Brunetti, R. L. Burke, S. Kornfeld, W. Gregory, K. S. Dingwell, F. Masiarz, and D. C. Johnson, J. Biol. Chem. 269:17067-17074, 1994). Since MPRs are found on the surfaces of mammalian cells, we tested the hypothesis that MPRs could serve as receptors for HSV during virus entry into cells. A soluble form of the 275-kDa MPR, derived from fetal bovine serum, inhibited HSV plaques on monkey Vero cells, as did polyclonal rabbit anti-MPR antibodies. In addition, the number and size of HSV plaques were reduced when cells were treated with bovine serum albumin conjugated with pentamannose-phosphate (PM-PO4-BSA), a bulky ligand which can serve as a high-affinity ligand for MPRs. These data imply that HSV can use MPRs to enter cells; however, other molecules must also serve as receptors for HSV because a reasonable fraction of virus could enter cells treated with even the highest concentrations of these inhibitors. Consistent with the possibility that there are other receptors, HSV produced the same number of plaques on MPR-deficient mouse fibroblasts as were produced on normal mouse fibroblasts, but there was no inhibition with PM-PO4-BSA with either of these embryonic mouse cells. Together, these results demonstrate that HSV does not rely solely on MPRs to enter cells, although MPRs apparently play some role in virus entry into some cell types and, perhaps, act as one of a number of cell surface molecules that can facilitate entry. We also found that HSV produced small plaques on human fibroblasts derived from patients with pseudo-Hurler's polydystrophy, cells in which glycoproteins are not modified with M-6-P residues and yet production of infectious HSV particles was not altered in the pseudo-Hurler cells. In addition, HSV plaque size was reduced by PM-PO4-BSA; therefore, it appears that M-6-P residues and MPRs are required for efficient transmission of HSV between cells, a process which differs in some respects from entry of exogenous virus particles. PMID:7745699
Ippolito, Davide; Drago, Silvia Girolama; Franzesi, Cammillo Talei; Fior, Davide; Sironi, Sandro
2016-01-01
AIM: To assess the diagnostic accuracy of multidetector-row computed tomography (MDCT) as compared with conventional magnetic resonance imaging (MRI), in identifying mesorectal fascia (MRF) invasion in rectal cancer patients. METHODS: Ninety-one patients with biopsy proven rectal adenocarcinoma referred for thoracic and abdominal CT staging were enrolled in this study. The contrast-enhanced MDCT scans were performed on a 256 row scanner (ICT, Philips) with the following acquisition parameters: tube voltage 120 KV, tube current 150-300 mAs. Imaging data were reviewed as axial and as multiplanar reconstructions (MPRs) images along the rectal tumor axis. MRI study, performed on 1.5 T with dedicated phased array multicoil, included multiplanar T2 and axial T1 sequences and diffusion weighted images (DWI). Axial and MPR CT images independently were compared to MRI and MRF involvement was determined. Diagnostic accuracy of both modalities was compared and statistically analyzed. RESULTS: According to MRI, the MRF was involved in 51 patients and not involved in 40 patients. DWI allowed to recognize the tumor as a focal mass with high signal intensity on high b-value images, compared with the signal of the normal adjacent rectal wall or with the lower tissue signal intensity background. The number of patients correctly staged by the native axial CT images was 71 out of 91 (41 with involved MRF; 30 with not involved MRF), while by using the MPR 80 patients were correctly staged (45 with involved MRF; 35 with not involved MRF). Local tumor staging suggested by MDCT agreed with those of MRI, obtaining for CT axial images sensitivity and specificity of 80.4% and 75%, positive predictive value (PPV) 80.4%, negative predictive value (NPV) 75% and accuracy 78%; while performing MPR the sensitivity and specificity increased to 88% and 87.5%, PPV was 90%, NPV 85.36% and accuracy 88%. MPR images showed higher diagnostic accuracy, in terms of MRF involvement, than native axial images, as compared to the reference magnetic resonance images. The difference in accuracy was statistically significant (P = 0.02). CONCLUSION: New generation CT scanner, using high resolution MPR images, represents a reliable diagnostic tool in assessment of loco-regional and whole body staging of advanced rectal cancer, especially in patients with MRI contraindications. PMID:27239115
Patterson, Mark E; Blalock, Susan J; Smith, Andrew J; Murray, Michael D
2011-05-01
High prescription copayments may create barriers to care, resulting in medication nonadherence. Although many studies have examined these associations in commercially insured patients with chronic disease, few have examined β-blocker effects in heart failure patients. Associations between β-blocker prescription copayment levels and medication nonadherence were examined within commercially insured beneficiaries with a diagnosis of heart failure. Heart failure patients were identified as those with at least 1 inpatient claim or 2 outpatient claims with an associated International Classification of Diagnosis, 9th Edition (ICD-9) code of 428.x, in addition to those with at least 2 β-blocker claims. Copayment levels were defined in using $5.00 (USD) interval categories, and adherence was defined using the medication possession ratio (MPR). Ordinary least squares (OLS), fixed effects (FE), and random effect (RE) models were used to estimate associations between copayment level and MPR. Logistic regression was used to estimate the probability of nonadherence (MPR < 0.80) conditional upon copayment level. Regressions controlled for patient demographics, health status, prior hospitalizations, and concomitant medication use. The highest β-blocker copayment level ($26+) had an average MPR that was 0.07 (95% CI, -0.11 to -0.03), 0.08 (95% CI, -0.12 to -0.04), and 0.09 (95% CI, -0.17 to -0.02) units lower than β-blocker copayment level ($0 to $1) in the OLS, RE, and FE models, respectively. Copayment levels $21-$25 and $26+ were significantly associated with an increased risk of medication nonadherence (OR = 1.64; 95% CI, 1.1-2.4; and OR = 2.5; 95%, CI 1.6-4, respectively). Commercially insured heart failure patients aged ≥50 years who are prescribed higher costing β-blockers may have up to an average 9% decrease in annual β-blocker medication supply as well as an increased risk of nonadherence (MPR <0.80). Results need to be interpreted with caution given the potential of selection bias due to selective prescribing. Associations between copayment levels and nonadherence need to be further explored given the adverse health consequences of nonadherence to β-blockers. Copyright © 2011. Published by EM Inc USA.
On the radius of habitable planets
NASA Astrophysics Data System (ADS)
Alibert, Y.
2014-01-01
Context. The conditions that a planet must fulfill to be habitable are not precisely known. However, it is comparatively easier to define conditions under which a planet is very likely not habitable. Finding such conditions is important as it can help select, in an ensemble of potentially observable planets, which ones should be observed in greater detail for characterization studies. Aims: Assuming, as in the Earth, that the presence of a C-cycle is a necessary condition for long-term habitability, we derive, as a function of the planetary mass, a radius above which a planet is likely not habitable. We compute the maximum radius a planet can have to fulfill two constraints: surface conditions compatible with the existence of liquid water, and no ice layer at the bottom of a putative global ocean. We demonstrate that, above a given radius, these two constraints cannot be met. Methods: We compute internal structure models of planets, using a five-layer model (core, inner mantle, outer mantle, ocean, and atmosphere), for different masses and composition of the planets (in particular, the Fe/Si ratio of the planet). Results: Our results show that for planets in the super-Earth mass range (1-12 M⊕), the maximum that a planet, with a composition similar to that of the Earth, can have varies between 1.7 and 2.2 R⊕. This radius is reduced when considering planets with higher Fe/Si ratios and taking radiation into account when computing the gas envelope structure. Conclusions: These results can be used to infer, from radius and mass determinations using high-precision transit observations like those that will soon be performed by the CHaracterizing ExOPlanet Satellite (CHEOPS), which planets are very likely not habitable, and therefore which ones should be considered as best targets for further habitability studies.
The Possibility of Multiple Habitable Worlds Orbiting Binary Stars
NASA Astrophysics Data System (ADS)
Mason, P. A.
2014-03-01
Are there planetary systems for which there is life on multiple worlds? Where are these fruitful planetary systems and how do we detect them? In order to address these questions; conditions which enable life and those that prevent or destroy it must be considered. Many constraints are specific to planetary systems, independent of the number of worlds in habitable zones. For instance, life on rocky planets or moons likely requires the right abundance of volatiles and radiogenic elements for prolonged geologic activity. Catastrophic sterilization events such as nearby supernovae and gamma-ray bursts affect entire planetary systems not just specific worlds. Giant planets may either enhance or disrupt the development of complex life within a given system. It might be rare for planetary systems to possess qualities that promote life and lucky enough to avoid cataclysm. However, multiple habitable planets may provide enhanced chances for advanced life to develop. The best predictor of life on one habitable zone planet might be the presence of life on its neighbor as panspermia may occur in planetary systems with several habitable worlds. Circumbinary habitability may go hand in hand with habitability of multiple worlds. The circumstances in which the Binary Habitability Mechanism (BHM) operates are reviewed. In some cases, the early synchronization of the primary's rotation with the binary period results in a reduction of XUV flux and stellar winds. Main sequence binaries with periods in the 10-50 days provide excellent habitable environments, within which multiple worlds may thrive. Planets and moons in these habitable zones need less magnetic protection than their single star counterparts. Exomoons orbiting a Neptune-like planet, within a BHM protected habitable zone, are expected to be habitable over a wide range of semimajor axes due to a larger planetary Hill radius. A result confirmed by numerical orbital calculations. Binaries containing a solar type star with a lower mass companion provide enhanced habitable zones as well as improved photosynthetic flux for habitable zone worlds.
Types of Information Expected from a Photometric Search for Extra-Solar Planets
NASA Technical Reports Server (NTRS)
Borucki, William; Koch, David; Bell, James, III; Cuzzi, Jeffrey N. (Technical Monitor)
1994-01-01
The current theory postulates that planets are a consequence of the formation of stars from viscous accretion disks. Condensation from the hotter, inner portion of the accretion disk favors the formation of small rocky planets in the inner portion and the formation of gas giants in the cuter, cooler part. Consequently, terrestrial-type planets in inner orbits must be commonplace (Wetheril 1991). From the geometry of the situation (Borucki and Summers 1984), it can be shown that 1% of those planetary systems that resemble our solar system should show transits for Earth-sized (or larger) planets. Thus a photometric satellite that uses a wide field of view telescope and a large CCD array to simultaneously monitor 5000 target stars should detect 50 planetary systems. To verify that regularly recurring transits are occurring rather than statistical fluctuations of the stellar flux, demands observations that extend over several orbital periods so that the constancy of the orbital period, signal amplitude, and duration can be measured. Therefore, to examine the region from Mercury's orbit to that of the Earth requires a duration of three years whereas a search out to the orbit of mars requires about six years. The results of the observations should provide estimates of the distributions of planetary size and orbital radius, and the frequency of planetary systems that have Earth-sized planets in inner orbits. Because approximately one half of the star systems observed will be binary systems, the frequency of planetary systems orbit ' ing either one or both of the stars can also be determined. Furthermore, the complexity of the photometric signature of a planet transiting a pair of stars provides enough information to estimate the eccentricities of the planetary orbits. In summary, the statistical evidence from a photometric search of solar-like stars should be able to either confirm or deny the applicability of the current theory of planet formation and provide new information about the stability of planetary orbits in binary star systems.
OGLE-2017-BLG-0482Lb: A Microlensing Super-Earth Orbiting a Low-mass Host Star
NASA Astrophysics Data System (ADS)
Han, C.; Hirao, Y.; Udalski, A.; Lee, C.-U.; Bozza, V.; Gould, A.; and; Abe, F.; Barry, R.; Bond, I. A.; Bennett, D. P.; Bhattacharya, A.; Donachie, M.; Evans, P.; Fukui, A.; Itow, Y.; Kawasaki, K.; Koshimoto, N.; Li, M. C. A.; Ling, C. H.; Matsubara, Y.; Miyazaki, S.; Munakata, H.; Muraki, Y.; Nagakane, M.; Ohnishi, K.; Ranc, C.; Rattenbury, N.; Saito, T.; Sharan, A.; Sullivan, D. J.; Sumi, T.; Suzuki, D.; Tristram, P. J.; Yamada, T.; Yonehara, A.; The MOA Collaboration; Mróz, P.; Poleski, R.; Kozłowski, S.; Soszyński, I.; Pietrukowicz, P.; Skowron, J.; Szymański, M. K.; Ulaczyk, K.; Pawlak, M.; Rybicki, K.; Iwanek, P.; The OGLE Collaboration; Albrow, M. D.; Chung, S.-J.; Hwang, K.-H.; Jung, Y. K.; Kim, D.; Kim, W.-T.; Kim, H.-W.; Ryu, Y.-H.; Shin, I.-G.; Shvartzvald, Y.; Yee, J. C.; Zhu, W.; Cha, S.-M.; Kim, S.-L.; Kim, D.-J.; Lee, D.-J.; Lee, Y.; Park, B.-G.; Pogge, R. W.; The KMTNet Collaboration
2018-05-01
We report the discovery of a planetary system in which a super-Earth orbits a late M-dwarf host. The planetary system was found from the analysis of the microlensing event OGLE-2017-BLG-0482, wherein the planet signal appears as a short-term anomaly to the smooth lensing light curve produced by the host. Despite its weak signal and short duration, the planetary signal was firmly detected from the dense and continuous coverage by three microlensing surveys. We find a planet/host mass ratio of q ∼ 1.4 × 10‑4. We measure the microlens parallax {π }{{E}} from the long-term deviation in the observed lensing light curve, but the angular Einstein radius {θ }{{E}} cannot be measured because the source trajectory did not cross the planet-induced caustic. Using the measured event timescale and the microlens parallax, we find that the masses of the planet and the host are {M}{{p}}={9.0}-4.5+9.0 {M}\\oplus and {M}host}={0.20}-0.10+0.20 {M}ȯ , respectively, and the projected separation between them is {a}\\perp ={1.8}-0.7+0.6 au. The estimated distance to the lens is {D}{{L}}={5.8}-2.1+1.8 kpc. The discovery of the planetary system demonstrates that microlensing provides an important method to detect low-mass planets orbiting low-mass stars.
MAGNETIC SCALING LAWS FOR THE ATMOSPHERES OF HOT GIANT EXOPLANETS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Menou, Kristen
2012-02-01
We present scaling laws for advection, radiation, magnetic drag, and ohmic dissipation in the atmospheres of hot giant exoplanets. In the limit of weak thermal ionization, ohmic dissipation increases with the planetary equilibrium temperature (T{sub eq} {approx}> 1000 K) faster than the insolation power does, eventually reaching values {approx}> 1% of the insolation power, which may be sufficient to inflate the radii of hot Jupiters. At higher T{sub eq} values still magnetic drag rapidly brakes the atmospheric winds, which reduces the associated ohmic dissipation power. For example, for a planetary field strength B = 10 G, the fiducial scaling lawsmore » indicate that ohmic dissipation exceeds 1% of the insolation power over the equilibrium temperature range T{sub eq} {approx} 1300-2000 K, with a peak contribution at T{sub eq} {approx} 1600 K. Evidence for magnetically dragged winds at the planetary thermal photosphere could emerge in the form of reduced longitudinal offsets for the dayside infrared hotspot. This suggests the possibility of an anticorrelation between the amount of hotspot offset and the degree of radius inflation, linking the atmospheric and interior properties of hot giant exoplanets in an observationally testable way. While providing a useful framework to explore the magnetic scenario, the scaling laws also reveal strong parameter dependencies, in particular with respect to the unknown planetary magnetic field strength.« less
A Population Study of Gaseous Exoplanets
NASA Astrophysics Data System (ADS)
Tsiaras, A.; Waldmann, I. P.; Zingales, T.; Rocchetto, M.; Morello, G.; Damiano, M.; Karpouzas, K.; Tinetti, G.; McKemmish, L. K.; Tennyson, J.; Yurchenko, S. N.
2018-04-01
We present here the analysis of 30 gaseous extrasolar planets, with temperatures between 600 and 2400 K and radii between 0.35 and 1.9 R Jup. The quality of the HST/WFC3 spatially scanned data combined with our specialized analysis tools allow us to study the largest and most self-consistent sample of exoplanetary transmission spectra to date and examine the collective behavior of warm and hot gaseous planets rather than isolated case studies. We define a new metric, the Atmospheric Detectability Index (ADI) to evaluate the statistical significance of an atmospheric detection and find statistically significant atmospheres in around 16 planets out of the 30 analyzed. For most of the Jupiters in our sample, we find the detectability of their atmospheres to be dependent on the planetary radius but not on the planetary mass. This indicates that planetary gravity plays a secondary role in the state of gaseous planetary atmospheres. We detect the presence of water vapour in all of the statistically detectable atmospheres, and we cannot rule out its presence in the atmospheres of the others. In addition, TiO and/or VO signatures are detected with 4σ confidence in WASP-76 b, and they are most likely present in WASP-121 b. We find no correlation between expected signal-to-noise and atmospheric detectability for most targets. This has important implications for future large-scale surveys.
A new statistical distance scale for planetary nebulae
NASA Astrophysics Data System (ADS)
Ali, Alaa; Ismail, H. A.; Alsolami, Z.
2015-05-01
In the first part of the present article we discuss the consistency among different individual distance methods of Galactic planetary nebulae, while in the second part we develop a new statistical distance scale based on a calibrating sample of well determined distances. A set composed of 315 planetary nebulae with individual distances are extracted from the literature. Inspecting the data set indicates that the accuracy of distances is varying among different individual methods and also among different sources where the same individual method was applied. Therefore, we derive a reliable weighted mean distance for each object by considering the influence of the distance error and the weight of each individual method. The results reveal that the discussed individual methods are consistent with each other, except the gravity method that produces higher distances compared to other individual methods. From the initial data set, we construct a standard calibrating sample consists of 82 objects. This sample is restricted only to the objects with distances determined from at least two different individual methods, except few objects with trusted distances determined from the trigonometric, spectroscopic, and cluster membership methods. In addition to the well determined distances for this sample, it shows a lot of advantages over that used in the prior distance scales. This sample is used to recalibrate the mass-radius and radio surface brightness temperature-radius relationships. An average error of ˜30 % is estimated for the new distance scale. The newly distance scale is compared with the most widely used statistical scales in literature, where the results show that it is roughly similar to the majority of them within ˜±20 % difference. Furthermore, the new scale yields a weighted mean distance to the Galactic center of 7.6±1.35 kpc, which in good agreement with the very recent measure of Malkin 2013.
Discovery and Rossiter-Mclaughlin Effect of Exoplanet Kepler-8b
NASA Astrophysics Data System (ADS)
Jenkins, Jon M.; Borucki, William J.; Koch, David G.; Marcy, Geoffrey W.; Cochran, William D.; Welsh, William F.; Basri, Gibor; Batalha, Natalie M.; Buchhave, Lars A.; Brown, Timothy M.; Caldwell, Douglas A.; Dunham, Edward W.; Endl, Michael; Fischer, Debra A.; Gautier, Thomas N., III; Geary, John C.; Gilliland, Ronald L.; Howell, Steve B.; Isaacson, Howard; Johnson, John Asher; Latham, David W.; Lissauer, Jack J.; Monet, David G.; Rowe, Jason F.; Sasselov, Dimitar D.; Howard, Andrew W.; MacQueen, Phillip; Orosz, Jerome A.; Chandrasekaran, Hema; Twicken, Joseph D.; Bryson, Stephen T.; Quintana, Elisa V.; Clarke, Bruce D.; Li, Jie; Allen, Christopher; Tenenbaum, Peter; Wu, Hayley; Meibom, Søren; Klaus, Todd C.; Middour, Christopher K.; Cote, Miles T.; McCauliff, Sean; Girouard, Forrest R.; Gunter, Jay P.; Wohler, Bill; Hall, Jennifer R.; Ibrahim, Khadeejah; Kamal Uddin, AKM; Wu, Michael S.; Bhavsar, Paresh A.; Van Cleve, Jeffrey; Pletcher, David L.; Dotson, Jessie L.; Haas, Michael R.
2010-12-01
We report on the discovery and the Rossiter-McLaughlin (R-M) effect of Kepler-8b, a transiting planet identified by the NASA Kepler Mission. Kepler photometry and Keck-HIRES radial velocities yield the radius and mass of the planet around this F8IV subgiant host star. The planet has a radius R P = 1.419 R J and a mass M P = 0.60 M J, yielding a density of 0.26 g cm-3, one of the lowest planetary densities known. The orbital period is P = 3.523 days and the orbital semimajor axis is 0.0483+0.0006 -0.0012 AU. The star has a large rotational vsin i of 10.5 ± 0.7 km s-1 and is relatively faint (V ≈ 13.89 mag); both properties are deleterious to precise Doppler measurements. The velocities are indeed noisy, with scatter of 30 m s-1, but exhibit a period and phase that are consistent with those implied by transit photometry. We securely detect the R-M effect, confirming the planet's existence and establishing its orbit as prograde. We measure an inclination between the projected planetary orbital axis and the projected stellar rotation axis of λ = -26fdg4 ± 10fdg1, indicating a significant inclination of the planetary orbit. R-M measurements of a large sample of transiting planets from Kepler will provide a statistically robust measure of the true distribution of spin-orbit orientations for hot Jupiters around F and early G stars. Based in part on observations obtained at the W. M. Keck Observatory, which is operated as a scientific partnership between the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.
Computation of the Transmitted and Polarized Scattered Fluxes by the Exoplanet HD 189733b in X-Rays
DOE Office of Scientific and Technical Information (OSTI.GOV)
Marin, Frédéric; Grosso, Nicolas, E-mail: frederic.marin@astro.unistra.fr
2017-02-01
Thousands of exoplanets have been detected, but only one exoplanetary transit was potentially observed in X-rays from HD 189733A. What makes the detection of exoplanets so difficult in this band? To answer this question, we run Monte-Carlo radiative transfer simulations to estimate the amount of X-ray flux reprocessed by HD 189733b. Despite its extended evaporating atmosphere, we find that the X-ray absorption radius of HD 189733b at 0.7 keV, which is the mean energy of the photons detected in the 0.25–2 keV energy band by XMM-Newton , is ∼1.01 times the planetary radius for an atmosphere of atomic hydrogen andmore » helium (including ions), and produces a maximum depth of ∼2.1% at ∼±46 minutes from the center of the planetary transit on the geometrically thick and optically thin corona. We compute numerically in the 0.25–2 keV energy band that this maximum depth is only of ∼1.6% at ∼±47 minutes from the transit center, and not very sensitive to the metal abundance, assuming that adding metals in the atmosphere would not dramatically change the density–temperature profile. Regarding a direct detection of HD 189733b in X-rays, we find that the amount of flux reprocessed by the exoplanetary atmosphere varies with the orbital phase, spanning between three and five orders of magnitude fainter than the flux of the primary star. Additionally, the degree of linear polarization emerging from HD 189733b is <0.003%, with maximums detected near planetary greatest elongations. This implies that both the modulation of the X-ray flux with the orbital phase and the scatter-induced continuum polarization cannot be observed with current X-ray facilities.« less
Radial diffusion in magnetodiscs. [charged particle motion in planetary or stellar magnetosphere
NASA Technical Reports Server (NTRS)
Birmingham, T. J.
1985-01-01
The orbits of charged particles in magnetodiscs are considered. The bounce motion is assumed adiabatic except for transits of a small equatorial region of weak magnetic field strength and high field curvature. Previous theory and modeling have shown that particles scatter randomly in pitch angle with each passage through the equator. A peaked distribution thus diffuses in pitch angle on the time scale of many bounces. It is argued in this paper that spatial diffusion is a further consequence when the magnetodisc has a longitudinal asymmetry. A general expression for DLL, the diffusion of equatorial crossing radii, is derived. DLL is evaluated explicitly for ions in Jupiter's 20-35 radii magnetodisc, assumed to be represented by Connerney et al.'s (1982) Voyager model plus a small image dipole asymmetry. Rates are energy, species, and space dependent but can average as much as a few tenths of a planetary radius per bounce period.
The occurrence of planets and other substellar bodies around white dwarfs using K2
NASA Astrophysics Data System (ADS)
van Sluijs, L.; Van Eylen, V.
2018-03-01
The majority of stars both host planetary systems and evolve into a white dwarf (WD). To understand their post-main-sequence planetary system evolution, we present a search for transiting/eclipsing planets and other substellar bodies (SBs) around WDs using a sample of 1148 WDs observed by K2. Using transit injections, we estimate the completeness of our search. We place constraints on the occurrence of planets and SBs around WDs as a function of planet radius and orbital period. For short-period (P < 40 d) small objects, from asteroid-sized to 1.5 R⊕, these are the strongest constraints known to date. We further constrain the occurrence of hot Jupiters ( < 1.5 per cent), habitable zone Earth-sized planets ( < 28 per cent), and disintegrating short-period planets ( ˜ 12 per cent). We blindly recovered all previously known eclipsing objects, providing confidence in our analysis, and make all light curves publicly available.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bieryla, A.; Latham, D. W.; Buchhave, L. A.
We report the discovery of the transiting extrasolar planet HAT-P-49b. The planet transits the bright (V = 10.3) slightly evolved F-star HD 340099 with a mass of 1.54 M {sub ☉} and a radius of 1.83 R {sub ☉}. HAT-P-49b is orbiting one of the 25 brightest stars to host a transiting planet which makes this a favorable candidate for detailed follow-up. This system is an especially strong target for Rossiter-McLaughlin follow-up due to the host star's fast rotation, 16 km s{sup –1}. The planetary companion has a period of 2.6915 days, mass of 1.73 M {sub J}, and radiusmore » of 1.41 R {sub J}. The planetary characteristics are consistent with that of a classical hot Jupiter but we note that this is the fourth most massive star to host a transiting planet with both M{sub p} and R{sub p} well determined.« less
FRESIP: A Discovery Mission Concept To Find Earth-Sized Planets Around Solar Like Stars
NASA Technical Reports Server (NTRS)
Borucki, William; Koch, D.; Dunham, E.; Cullers, D.; Webster, L.; Granados, A.; Ford, C.; Reitsema, H.; Cochran, W.; Bell, J.;
1994-01-01
The current nebular theory postulates that planets are. a consequence of the formation of stars from viscous accretion disks. Condensation from the accretion disk favors the formation of small rocky planets in the hot inner region, and the formation of gas giants in the cool outer region. Consequently, terrestrial-type planet in inner orbits should be commonplace. From geometrical considerations , Borucki and Summers have shown that 1% of planetary systems resembling our solar system should show transits for Earth-sized (or larger) planets. Thus a photometric satellite that uses a wide field of view telescope and a large detector array to simultaneously monitor 5000 target stars should detect 50 planetary systems. To differentiate regularly recurring transits from statistical fluctuations of the stellar flux, one must observe over several orbital periods so that the false positive rate can be reduced to one event or less. A one-meter aperture telescope placed in a halo orbit about either the L1 or L2 Lagrange points and viewing perpendicular to both the orbital and ecliptic planes can view continuously for the required period because neither the Sun, Earth, or Moon would enter the field of view. Model calculations show that the observations should provide statistically significant estimates of the distributions of planetary size, orbital radius, coplanarity, and the frequency of planetary systems that have Earth-sized planets in inner orbits. Because approximately one half of the star systems observed will be binary systems, the frequency of planetary systems orbiting either one or both of the stars can also be determined.
K2-137 b: an Earth-sized planet in a 4.3-h orbit around an M-dwarf
NASA Astrophysics Data System (ADS)
Smith, A. M. S.; Cabrera, J.; Csizmadia, Sz; Dai, F.; Gandolfi, D.; Hirano, T.; Winn, J. N.; Albrecht, S.; Alonso, R.; Antoniciello, G.; Barragán, O.; Deeg, H.; Eigmüller, Ph; Endl, M.; Erikson, A.; Fridlund, M.; Fukui, A.; Grziwa, S.; Guenther, E. W.; Hatzes, A. P.; Hidalgo, D.; Howard, A. W.; Isaacson, H.; Korth, J.; Kuzuhara, M.; Livingston, J.; Narita, N.; Nespral, D.; Nowak, G.; Palle, E.; Pätzold, M.; Persson, C. M.; Petigura, E.; Prieto-Arranz, J.; Rauer, H.; Ribas, I.; Van Eylen, V.
2018-03-01
We report the discovery in K2's Campaign 10 of a transiting terrestrial planet in an ultra-short-period orbit around an M3-dwarf. K2-137 b completes an orbit in only 4.3 h, the second shortest orbital period of any known planet, just 4 min longer than that of KOI 1843.03, which also orbits an M-dwarf. Using a combination of archival images, adaptive optics imaging, radial velocity measurements, and light-curve modelling, we show that no plausible eclipsing binary scenario can explain the K2 light curve, and thus confirm the planetary nature of the system. The planet, whose radius we determine to be 0.89 ± 0.09 R⊕, and which must have an iron mass fraction greater than 0.45, orbits a star of mass 0.463 ± 0.052 M⊙ and radius 0.442 ± 0.044 R⊙.
A DWARF TRANSITIONAL PROTOPLANETARY DISK AROUND XZ TAU B
DOE Office of Scientific and Technical Information (OSTI.GOV)
Osorio, Mayra; Macías, Enrique; Anglada, Guillem
We report the discovery of a dwarf protoplanetary disk around the star XZ Tau B that shows all the features of a classical transitional disk but on a much smaller scale. The disk has been imaged with the Atacama Large Millimeter/submillimeter Array (ALMA), revealing that its dust emission has a quite small radius of ∼3.4 au and presents a central cavity of ∼1.3 au in radius that we attribute to clearing by a compact system of orbiting (proto)planets. Given the very small radii involved, evolution is expected to be much faster in this disk (observable changes in a few months)more » than in classical disks (observable changes requiring decades) and easy to monitor with observations in the near future. From our modeling we estimate that the mass of the disk is large enough to form a compact planetary system.« less
Response of Ambulatory Human Subjects to Artificial Gravity (Short Radius Centrifugation)
NASA Technical Reports Server (NTRS)
Paloski, William H.; Arya, Maneesh; Newby, Nathaniel; Tucker, Jon-Michael; Jarchow, Thomas; Young, Laurence
2006-01-01
Prolonged exposure to microgravity results in significant adaptive changes, including cardiovascular deconditioning, muscle atrophy, bone loss, and sensorimotor reorganization, that place individuals at risk for performing physical activities after return to a gravitational environment. Planned missions to Mars include unprecedented hypogravity exposures that would likely result in unacceptable risks to crews. Artificial gravity (AG) paradigms may offer multisystem protection from the untoward effects of adaptation to the microgravity of space or the hypogravity of planetary surfaces. While the most effective AG designs would employ a rotating spacecraft, perceived issues may preclude their use. The questions of whether and how intermittent AG produced by a short radius centrifuge (SRC) could be employed have therefore sprung to the forefront of operational research. In preparing for a series of intermittent AG trials in subjects deconditioned by bed rest, we have examined the responses of several healthy, ambulatory subjects to SRC exposures.
EVOLUTIONARY MODELS OF SUPER-EARTHS AND MINI-NEPTUNES INCORPORATING COOLING AND MASS LOSS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Howe, Alex R.; Burrows, Adam, E-mail: arhowe@astro.princeton.edu, E-mail: burrows@astro.princeton.edu
We construct models of the structural evolution of super-Earth- and mini-Neptune-type exoplanets with H{sub 2}–He envelopes, incorporating radiative cooling and XUV-driven mass loss. We conduct a parameter study of these models, focusing on initial mass, radius, and envelope mass fractions, as well as orbital distance, metallicity, and the specific prescription for mass loss. From these calculations, we investigate how the observed masses and radii of exoplanets today relate to the distribution of their initial conditions. Orbital distance and the initial envelope mass fraction are the most important factors determining planetary evolution, particularly radius evolution. Initial mass also becomes important belowmore » a “turnoff mass,” which varies with orbital distance, with mass–radius curves being approximately flat for higher masses. Initial radius is the least important parameter we study, with very little difference between the hot start and cold start limits after an age of 100 Myr. Model sets with no mass loss fail to produce results consistent with observations, but a plausible range of mass-loss scenarios is allowed. In addition, we present scenarios for the formation of the Kepler-11 planets. Our best fit to observations of Kepler-11b and Kepler-11c involves formation beyond the snow line, after which they moved inward, circularized, and underwent a reduced degree of mass loss.« less
Magnetohydrodynamics with Embedded Particle-in-Cell Simulation of Mercury's Magnetosphere
NASA Astrophysics Data System (ADS)
Chen, Y.; Toth, G.; Jia, X.; Gombosi, T. I.; Markidis, S.
2015-12-01
Mercury's magnetosphere is much more dynamic than other planetary magnetospheres because of Mercury's weak intrinsic magnetic field and its proximity to the Sun. Magnetic reconnection and Kelvin-Helmholtz phenomena occur in Mercury's magnetopause and magnetotail at higher frequencies than in other planetary magnetosphere. For instance, chains of flux transfer events (FTEs) on the magnetopause, have been frequentlyobserved by the the MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) spacecraft (Slavin et al., 2012). Because ion Larmor radius is comparable to typical spatial scales in Mercury's magnetosphere, finite Larmor radius effects need to be accounted for. In addition, it is important to take in account non-ideal dissipation mechanisms to accurately describe magnetic reconnection. A kinetic approach allows us to model these phenomena accurately. However, kinetic global simulations, even for small-size magnetospheres like Mercury's, are currently unfeasible because of the high computational cost. In this work, we carry out global simulations of Mercury's magnetosphere with the recently developed MHD-EPIC model, which is a two-way coupling of the extended magnetohydrodynamic (XMHD) code BATS-R-US with the implicit Particle-in-Cell (PIC) model iPIC3D. The PIC model can cover the regions where kinetic effects are most important, such as reconnection sites. The BATS-R-US code, on the other hand, can efficiently handle the rest of the computational domain where the MHD or Hall MHD description is sufficient. We will present our preliminary results and comparison with MESSENGER observations.
Planetary Nebulae in the UWISH2 survey
NASA Astrophysics Data System (ADS)
Gledhill, T. M.; Froebrich, D.; Campbell-White, J.; Jones, A. M.
2018-06-01
Near-infrared imaging in the 1 - 0 S(1) emission line of molecular hydrogen is able to detect planetary nebulae (PNe) that are hidden from optical emission line surveys. We present images of 307 objects from the UWISH2 survey of the northern Galactic Plane, and with the aid of mid-infrared colour diagnostics draw up a list of 291 PN candidates. The majority, 183, are new detections and 85 per cent of these are not present in H α surveys of the region. We find that more than half (54 per cent) of objects have a bipolar morphology and that some objects previously considered as elliptical or point-source in H α imaging, appear bipolar in UWISH2 images. By considering a small subset of objects for which physical radii are available from the H α surface brightness-radius relation, we find evidence that the H2 surface brightness remains roughly constant over a factor 20 range of radii from 0.03 to 0.6 pc, encompassing most of the visible lifetime of a PN. This leads to the H α surface brightness becoming comparable to that of H2 at large radius (>0.5 pc). By combining the number of UWISH2 PNe without H α detection with an estimate of the PN detection efficiency in H2 emission, we estimate that PN numbers from H α surveys may underestimate the true PN number by a factor between 1.5 and 2.5 within the UWISH2 survey area.
The mass of the super-Earth orbiting the brightest Kepler planet hosting star
NASA Astrophysics Data System (ADS)
Lopez-Morales, Mercedes; HARPS-N Team
2016-01-01
HD 179070, aka Kepler-21, is a V = 8.25 oscillating F6IV star and the brightest exoplanet host discovered by Kepler. An early analysis of the Q0 - Q5 Kepler light curves by Howell et al. (2012) revealed transits of a planetary companion, Kepler-21b, with a radius of 1.6 R_Earth and an orbital period of 2.7857 days. However, they could not determine the mass of the planet from the initial radial velocity observations with Keck-HIRES, and were only able to impose a 2s upper limit of about 10 M_Earth. Here we present 82 new radial velocity observations of this system obtained with the HARPS-N spectrograph. We detect the Doppler shift signal of Kepler-21b at the 3.6s level, and measure a planetary mass of 5.9 ± 1.6 M_Earth. We also update the radius of the planet to 1.65 ± 0.08 R_Earth, using the now available Kepler Q0 - Q17 photometry for this target. The mass of Kepler-21b appears to fall on the apparent dividing line between super-Earths that have lost all the material in their outer layers and those that have retained a significant amount of volatiles. Based on our results Kepler-21b belongs to the first group. Acknowledgement: This work was supported by funding from the NASA XRP Program and the John Templeton Foundation.
Gene encoding a novel extracellular metalloprotease in Bacillus subtilis.
Sloma, A; Rudolph, C F; Rufo, G A; Sullivan, B J; Theriault, K A; Ally, D; Pero, J
1990-01-01
The gene for a novel extracellular metalloprotease was cloned, and its nucleotide sequence was determined. The gene (mpr) encodes a primary product of 313 amino acids that has little similarity to other known Bacillus proteases. The amino acid sequence of the mature protease was preceded by a signal sequence of approximately 34 amino acids and a pro sequence of 58 amino acids. Four cysteine residues were found in the deduced amino acid sequence of the mature protein, indicating the possible presence of disulfide bonds. The mpr gene mapped in the cysA-aroI region of the chromosome and was not required for growth or sporulation. Images FIG. 2 FIG. 7 PMID:2105291
NASA Astrophysics Data System (ADS)
Yang, C. L.; Du, R. R.; Pfeiffer, L. N.; West, K. W.
2006-07-01
Using a two-axis magnet, we have studied experimentally the influence of a parallel magnetic field (B//) on microwave-induced resistance oscillations (MIROs) and zero-resistance states (ZRS) previously discovered in a high-mobility two-dimensional electron system. We have observed a strong suppression of MIRO/ZRS by a modest B//˜1T . In Hall bar samples, magnetoplasmon resonance (MPR) has also been observed concurrently with the MIRO/ZRS. In contrast to the suppression of MIRO/ZRS, the MPR peak is apparently enhanced by B// . These findings cannot be explained by a simple modification of single-particle energy spectrum and/or scattering parameters by B// .
Vasilenko, A M; Agasarov, L G; Sharipova, M M
The review presents data on the non-pharmacological methods and technologies for the prevention and management of meteopathic reactions (MPR) applied in Russia for the treatment of the patients suffering from obstructive and cardiovascular diseases. It is assumed, based on the concept of heliogeophysical imprinting, that the major factors responsible for the development of MPR are the disturbances of electromagnetic homeostasis. The acupuncture points and channels are regarded as a system designed for the maintenance of electromagnetic balance in the human body. In this context, it is proposed to encourage the application of the methods of electro-diagnostics and reflexology for the prevention and correction of meteopathic reactions.
NASA Astrophysics Data System (ADS)
Noda, S.; Ishiwatari, M.; Nakajima, K.; Takahashi, Y. O.; Takehiro, S.; Onishi, M.; Hashimoto, G. L.; Kuramoto, K.; Hayashi, Y.-Y.
2017-01-01
In order to investigate a possible variety of atmospheric states realized on a synchronously rotating aquaplanet, an experiment studying the impact of planetary rotation rate is performed using an atmospheric general circulation model (GCM) with simplified hydrological and radiative processes. The entire planetary surface is covered with a swamp ocean. The value of planetary rotation rate is varied from zero to the Earth's, while other parameters such as planetary radius, mean molecular weight and total mass of atmospheric dry components, and solar constant are set to the present Earth's values. The integration results show that the atmosphere reaches statistically equilibrium states for all runs; none of the calculated cases exemplifies the runaway greenhouse state. The circulation patterns obtained are classified into four types: Type-I characterized by the dominance of a day-night thermally direct circulation, Type-II characterized by a zonal wave number one resonant Rossby wave over a meridionally broad westerly jet on the equator, Type-III characterized by a long time scale north-south asymmetric variation, and Type-IV characterized by a pair of mid-latitude westerly jets. With the increase of planetary rotation rate, the circulation evolves from Type-I to Type-II and then to Type-III gradually and smoothly, whereas the change from Type-III to Type-IV is abrupt and discontinuous. Over a finite range of planetary rotation rate, both Types-III and -IV emerge as statistically steady states, constituting multiple equilibria. In spite of the substantial changes in circulation, the net energy transport from the day side to the night side remains almost insensitive to planetary rotation rate, although the partition into dry static energy and latent heat energy transports changes. The reason for this notable insensitivity is that the outgoing longwave radiation over the broad area of the day side is constrained by the radiation limit of a moist atmosphere, so that the transport to the night side, which is determined as the difference between the incoming solar radiation and the radiation limit, cannot change greatly.
Mapping the Pressure-radius Relationship of Exoplanets
NASA Astrophysics Data System (ADS)
Cubillos, Patricio; Fossati, Luca; Kubyshkina, Darya
2017-10-01
The radius of a planet is one of the most physically meaningful and readily accessible parameters of extra-solar planets. This parameter is extensively used in the literature to compare planets or study trends in the know population of exoplanets. However, in an atmosphere, the concept of a planet radius is inherently fuzzy. The atmospheric pressures probed by trasmission (transit) or emission (eclipse) spectra are not directly constrained by the observations, they vary as a function of the atmospheric properties and observing wavelengths, and further correlate with the atmospheric properties producing degenerate solutions.Here, we characterize the properties of exoplanet radii using a radiative-transfer model to compute clear- atmosphere transmission and emission spectra of gas-dominated planets. We explore a wide range of planetary temperatures, masses, and radii, sampling from 300 to 3000 K and Jupiter- to Earth-like values. We will discuss how transit and photospheric radii vary over the parameter space, and map the global trends in the atmospheric pressures associated with these radii. We will also highlight the biases introduced by the choice of an observing band, or the assumption of a clear/cloudy atmosphere, and the relevance that these biases take as better instrumentation improves the precision of photometric observations.
Physical properties of the HAT-P-23 and WASP-48 planetary systems from multi-colour photometry
NASA Astrophysics Data System (ADS)
Ciceri, S.; Mancini, L.; Southworth, J.; Bruni, I.; Nikolov, N.; D'Ago, G.; Schröder, T.; Bozza, V.; Tregloan-Reed, J.; Henning, Th.
2015-05-01
Context. Accurate and repeated photometric follow-up observations of planetary transit events are important to precisely characterize the physical properties of exoplanets. A good knowledge of the main characteristics of the exoplanets is fundamental in order to trace their origin and evolution. Multi-band photometric observations play an important role in this process. Aims: By using new photometric data, we computed precise estimates of the physical properties of two transiting planetary systems at equilibrium temperatures of ~2000 K. Methods: We present new broadband, multi-colour photometric observations obtained using three small class telescopes and the telescope-defocussing technique. In particular we obtained 11 and 10 light curves covering 8 and 7 transits of HAT-P-23 and WASP-48, respectively. For each of the two targets, one transit event was simultaneously observed through four optical filters. One transit of WASP-48 b was monitored with two telescopes from the same observatory. The physical parameters of the systems were obtained by fitting the transit light curves with jktebop and from published spectroscopic measurements. Results: We have revised the physical parameters of the two planetary systems, finding a smaller radius for both HAT-P-23 b and WASP-48 b, Rb = 1.224 ± 0.037 RJup and Rb = 1.396 ± 0.051 RJup, respectively, than those measured in the discovery papers (Rb = 1.368 ± 0.090 RJup and Rb = 1.67 ± 0.10 RJup). The density of the two planets are higher than those previously published (ρb ~ 1.1 and ~0.3 ρjup for HAT-P-23 and WASP-48, respectively) hence the two hot Jupiters are no longer located in a parameter space region of highly inflated planets. An analysis of the variation of the planet's measured radius as a function of optical wavelength reveals flat transmission spectra within the experimental uncertainties. We also confirm the presence of the eclipsing contact binary NSVS-3071474 in the same field of view of WASP-48, for which we refine the value of the period to be 0.459 d. The photometric light curves are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A54
HAT-P-18b AND HAT-P-19b: TWO LOW-DENSITY SATURN-MASS PLANETS TRANSITING METAL-RICH K STARS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hartman, J. D.; Bakos, G. A.; Torres, G.
2011-01-01
We report the discovery of two new transiting extrasolar planets. HAT-P-18b orbits the V = 12.759 K2 dwarf star GSC 2594-00646, with a period P = 5.508023 {+-} 0.000006 days, transit epoch T{sub c} = 2454715.02174 {+-} 0.00020 (BJD), and transit duration 0.1131 {+-} 0.0009 days. The host star has a mass of 0.77 {+-} 0.03 M{sub sun}, radius of 0.75 {+-} 0.04 R{sub sun}, effective temperature 4803 {+-} 80 K, and metallicity [Fe/H] = +0.10 {+-} 0.08. The planetary companion has a mass of 0.197 {+-} 0.013 M{sub J} and radius of 0.995 {+-} 0.052 R{sub J}, yielding amore » mean density of 0.25 {+-} 0.04 g cm{sup -3}. HAT-P-19b orbits the V = 12.901 K1 dwarf star GSC 2283-00589, with a period P = 4.008778 {+-} 0.000006 days, transit epoch T{sub c} = 2455091.53417 {+-} 0.00034 (BJD), and transit duration 0.1182 {+-} 0.0014 days. The host star has a mass of 0.84 {+-} 0.04 M{sub sun}, radius of 0.82 {+-} 0.05 R{sub sun}, effective temperature 4990 {+-} 130 K, and metallicity [Fe/H] = +0.23 {+-} 0.08. The planetary companion has a mass of 0.292 {+-} 0.018 M{sub J} and radius of 1.132 {+-} 0.072 R{sub J}, yielding a mean density of 0.25 {+-} 0.04 g cm{sup -3}. The radial velocity residuals for HAT-P-19 exhibit a linear trend in time, which indicates the presence of a third body in the system. Comparing these observations with theoretical models, we find that HAT-P-18b and HAT-P-19b are each consistent with a hydrogen-helium-dominated gas giant planet with negligible core mass. HAT-P-18b and HAT-P-19b join HAT-P-12b and WASP-21b in an emerging group of low-density Saturn-mass planets, with negligible inferred core masses. However, unlike HAT-P-12b and WASP-21b, both HAT-P-18b and HAT-P-19b orbit stars with super-solar metallicity. This calls into question the heretofore suggestive correlation between the inferred core mass and host star metallicity for Saturn-mass planets.« less
Yang, Zhuo; Howard, David H; Will, Julie; Loustalot, Fleetwood; Ritchey, Matthew; Roy, Kakoli
2016-05-01
We assessed the impact of antihypertensive medication (AHM) adherence on the incidence and associated Medicaid costs of acute cardiovascular disease (CVD) events among Medicaid beneficiaries. The study cohort (n=59,037) consists of nonelderly adults continuously enrolled (36 mo and above) in a Medicaid fee-for-service program. AHM adherence was calculated using the medication possession ratio (MPR) and stratified to low (MPR<60%), moderate (60%≤MPR<80%), and high (MPR≥80%) levels. We used a proportional hazard model to estimate risk for acute CVD events and generalized linear models to estimate Medicaid per-patient-per-year costs. Low and moderate adherence subgroups had about 1.8 and 1.4 times higher risk of acute CVD events, compared with high adherence subgroup. By adherence level, Medicaid per-patient per-year costs for (1) CVD-related emergency department visits and hospitalizations were $661 (low), $479 (moderate), and $343 (high) and (2) AHMs were $430 (low), $604 (moderate), and $664 (high). Costs for CVD events and AHMs combined were similar across adherence subgroups. Lower adherence to AHM was associated with progressively higher CVD risk. The increase in medication cost from higher AHM adherence was offset solely by reduced Medicaid spending on acute CVD events.
R, Jewkes; Y, Sikweyiya; K, Dunkle; R, Morrell
2015-07-07
Studies of rape of women seldom distinguish between men's participation in acts of single and multiple perpetrator rape. Multiple perpetrator rape (MPR) occurs globally with serious consequences for women. In South Africa it is a cultural practice with defined circumstances in which it commonly occurs. Prevention requires an understanding of whether it is a context specific intensification of single perpetrator rape, or a distinctly different practice of different men. This paper aims to address this question. We conducted a cross-sectional household study with a multi-stage, randomly selected sample of 1686 men aged 18-49 who completed a questionnaire administered using an Audio-enhanced Personal Digital Assistant. We attempted to fit an ordered logistic regression model for factors associated with rape perpetration. 27.6 % of men had raped and 8.8 % had perpetrated multiple perpetrator rape (MPR). Thus 31.9 % of men who had ever raped had done so with other perpetrators. An ordered regression model was fitted, showing that the same associated factors, albeit at higher prevalence, are associated with SPR and MPR. Multiple perpetrator rape appears as an intensified form of single perpetrator rape, rather than a different form of rape. Prevention approaches need to be mainstreamed among young men.
MODELING OPERANT BEHAVIOR IN THE PARKINSONIAN RAT
Avila, Irene; Reilly, Mark P.; Sanabria, Federico; Posadas-Sánchez, Diana; Chavez, Claudia L.; Banerjee, Nikhil; Killeen, Peter; Castañeda, Edward
2009-01-01
Mathematical principles of reinforcement (MPR; Killeen, 1994) is a quantitative model of operant behavior that contains 3 parameters representing motor capacity (δ), motivation (a), and short term memory (λ). The present study applied MPR to characterize the effects of bilateral infusions of 6-OHDA into the substantia nigra pars compacta in the rat, a model of Parkinson’s disease. Rats were trained to lever press under a 5-component fixed ratio (5, 15, 30, 60, and 100) schedule of food reinforcement. Rats were tested for 15 days prior to dopamine lesions and again for 15 days post-lesion. To characterize functional loss relative to lesion size, rats were grouped according to the extent and the degree of lateralization of their dopamine loss. Response rates decreased as a function of dopamine depletion, primarily at intermediate ratios. MPR accounted for 98% of variance in pre- and post-lesion response rates. Consistent with reported disruptions in motor behavior induced by dopaminergic lesions, estimates of δ increased when dopamine was severely depleted. There was no support for different estimates of a based on pre- and post-lesion performance of any lesion group, suggesting that dopamine loss has negligible effects on incentive motivation. The present study demonstrates the usefulness of combining operant techniques with a theoretical model to better understand the effects of a neurochemical manipulation. PMID:19073222
Toward seamless hydrologic predictions across spatial scales
NASA Astrophysics Data System (ADS)
Samaniego, Luis; Kumar, Rohini; Thober, Stephan; Rakovec, Oldrich; Zink, Matthias; Wanders, Niko; Eisner, Stephanie; Müller Schmied, Hannes; Sutanudjaja, Edwin H.; Warrach-Sagi, Kirsten; Attinger, Sabine
2017-09-01
Land surface and hydrologic models (LSMs/HMs) are used at diverse spatial resolutions ranging from catchment-scale (1-10 km) to global-scale (over 50 km) applications. Applying the same model structure at different spatial scales requires that the model estimates similar fluxes independent of the chosen resolution, i.e., fulfills a flux-matching condition across scales. An analysis of state-of-the-art LSMs and HMs reveals that most do not have consistent hydrologic parameter fields. Multiple experiments with the mHM, Noah-MP, PCR-GLOBWB, and WaterGAP models demonstrate the pitfalls of deficient parameterization practices currently used in most operational models, which are insufficient to satisfy the flux-matching condition. These examples demonstrate that J. Dooge's 1982 statement on the unsolved problem of parameterization in these models remains true. Based on a review of existing parameter regionalization techniques, we postulate that the multiscale parameter regionalization (MPR) technique offers a practical and robust method that provides consistent (seamless) parameter and flux fields across scales. Herein, we develop a general model protocol to describe how MPR can be applied to a particular model and present an example application using the PCR-GLOBWB model. Finally, we discuss potential advantages and limitations of MPR in obtaining the seamless prediction of hydrological fluxes and states across spatial scales.
Association of p60c-src with endosomal membranes in mammalian fibroblasts
1992-01-01
We have examined the subcellular localization of p60c-src in mammalian fibroblasts. Analysis of indirect immunofluorescence by three- dimensional optical sectioning microscopy revealed a granular cytoplasmic staining that co-localized with the microtubule organizing center. Immunofluorescence experiments with antibodies against a number of membrane markers demonstrated a striking co-localization between p60c-src and the cation-dependent mannose-6-phosphate receptor (CI- MPR), a marker that identifies endosomes. Both p60c-src and the CI-MPR were found to cluster at the spindle poles throughout mitosis. In addition, treatment of interphase and mitotic cells with brefeldin A resulted in a clustering of p60c-src and CI-MPR at a peri-centriolar position. Biochemical fractionation of cellular membranes showed that a major proportion of p60c-src co-enriched with endocytic membranes. Treatment of membranes containing HRP to alter their apparent density also altered the density of p60c-src-containing membranes. Similar density shift experiments with total cellular membranes revealed that the majority of membrane-associated p60c-src in the cell is associated with endosomes, while very little is associated with plasma membranes. These results support a role for p60c-src in the regulation of endosomal membranes and protein trafficking. PMID:1378446
de Castro, María Luisa; Sanromán, Luciano; Martín, Alicia; Figueira, Montserrat; Martínez, Noemi; Hernández, Vicent; Del Campo, Victor; Pineda, Juan R; Martínez-Cadilla, Jesús; Pereira, Santos; Rodríguez Prada, José Ignacio
2017-08-01
Medication non-adherence in inflammatory bowel disease (IBD) has a negative impact on disease outcome. Different tools have been proposed to assess non-adherence. We aimed to compare a self-administered scale and a pharmacy refill index as a reliable measure of medication adherence and to determine what factors are related to adherence. Consecutive non-active IBD outpatients were asked to fill in the self-reported Morisky Medication Adherence Scale (MMAS-8) and the Beliefs about Medication Questionnaire (BMQ). Pharmacy refill data were reviewed from the previous three or six months and the medication possession ratio (MPR) was calculated. Non-adherence was defined as MMAS-8 scores < 6 or MPR < 0.8. Two-hundred and three patients were enrolled (60% ulcerative colitis, 40% Crohn's disease); 51% were men, and the mean age was 46.3 (14) years. Seventy-four per cent of patients were on monotherapy and 26% on combination therapy; altogether, 65% received mesalazine, 46% thiopurines and 16% anti-tumor necrosis factor alfa. Non-adherence rate assessed by MPR was 37% and 22.4% by MMAS-8. Receiver operator curve analysis using a MMAS-8 cut-off of six gave an area under the curve of 0.6 (95% CI 0.5-0.7), p = 0.001. This score had an 85% sensitivity and 34% specificity to predict medication non-adherence, with negative and positive predictive values of 57% and 70% respectively. High scores in the BMQ potential for harm of medication were significantly associated with MPR non-adherence (p = 0.01). The accuracy of MMAS-8 to identify medication non-adherence in inactive IBD outpatients in our setting is poor due to a low specificity and a negative predictive value. Psychosocial factors such as beliefs about medication seem to be related to IBD non-adherence.
Robertson, Teisha A; Cooke, Catherine E; Wang, Jingshu; Shaya, Fadia T; Lee, Helen Y
2008-11-01
To determine the effect of medication burden on persistent use of newly added lipid-lowering (LL) drugs among patients with hypertension. This retrospective database study used medical and pharmacy claims from a mid-Atlantic managed care organization. The cohort was obtained from continuous member enrollment in pharmacy and medical benefits from January 1, 2003, to December 31, 2005. Prescription claims were obtained for 18 months following the date of the first filled LL prescription (ie, index date). Patients were stratified into patients who changed LL drug or strength (group 1) and patients who did not change LL drug or strength (group 2). The primary outcome measure was persistence to newly added LL therapy. Persistence was defined by the length of time a member remained on therapy following the index date. The secondary outcome measure was the medication possession ratio (MPR). The MPR was calculated as the ratio of the sum of the days' supply of prescription filled divided by the number of days filled, plus the days' supply for the final prescription fill. Associations between the daily medication burden, defined as the number of unique drug products, and the outcome measures were analyzed. In the cohort of 3058 patients, the mean medication burden was 2.9 medications. Medication burden was positively associated with persistence and MPR through 18 months. Patients who had greater medication burden had longer persistence (P <.001). Likewise, patients who had greater medication burden had higher MPRs and were more likely to be considered adherent (MPR, >80%) (P < .001 for both). Patients with higher medication burden had greater adherence to newly added LL therapy. Medication burden should not deter clinicians from adding LL therapy. Among patients with added LL therapy, more attention should focus on patients who have changes to their LL regimen compared with patients who continue on the same LL prescription.
Value-Based Benefit Design to Improve Medication Adherence for Employees with Anxiety or Depression.
Reid, Kimberly J; Aguilar, Kathleen M; Thompson, Eric; Miller, Ross M
2015-01-01
Through reduced out-of-pocket costs and wellness offerings, value-based benefit design (VBBD) is a promising strategy to improve medication adherence and other health-related outcomes across populations. There is limited evidence, however, of the effectiveness of these policy-level changes among individuals with anxiety or depression. To assess the impact of a multifaceted VBBD policy that incorporates waived copayments, wellness offerings, and on-site services on medication adherence among plan members with anxiety or depression, and to explore how this intervention and its resulting improved adherence affects other health-related outcomes. A retrospective longitudinal pre/post design was utilized to measure outcomes before and after the VBBD policy change. Repeated measures statistical regression models with correlated error terms were utilized to evaluate outcomes among employees of a self-insured global health company and their spouses (N = 529) who had anxiety or depression after the VBBD policy change. A multivariable linear regression model was chosen as the best fit to evaluate a change in medication possession ratio (MPR) after comparing parameters for several distributions. The repeated measures multivariable regression models were adjusted for baseline MPR and potential confounders, including continuous age, sex, continuous modified Charlson Comorbidity Index, and the continuous number of prescriptions filled that year. The outcomes were assessed for the 1 year before the policy change (January 1, 2011, through December 31, 2011) and for 2 years after the change (January 1, 2012, through December 31, 2013). The primary outcome was a change in MPR. The secondary outcomes included healthcare utilization, medical or pharmacy costs, the initiation of medication, generic medication use, and employee absenteeism (the total number of sick days). The implementation of the VBBD strategy was associated with a significant increase in average MPR (0.65 vs 0.61 in the pre-VBBD period; P = .004), the initiation of new medications for anxiety or depression (31.4% vs 29.5%, respectively; P = .033), and the filling of generic medications for anxiety or depression (85.1% vs 80.5%, respectively; P <.001). A multivariable adjusted analysis revealed a 0.05 increase in MPR after the benefit enhancement (P = .002). Healthcare utilization, costs, and absenteeism were not statistically different before and after the VBBD policy change. The VBBD strategy was associated with improved medication adherence and cost-conscious medication use. Future analyses should explore whether these trends persist over time, and if they can further impact healthcare utilization, cost, and absenteeism.
Nutrition in advanced age: dietary assessment in the Newcastle 85+ study.
Adamson, A J; Collerton, J; Davies, K; Foster, E; Jagger, C; Stamp, E; Mathers, J C; Kirkwood, T
2009-02-01
Assessing food choice and/or nutrient intake in older people, particularly the oldest old (85 years and over), presents particular challenges. In some cases the respondent may have little or no involvement in food acquisition or preparation, in others, cognitive/memory impairment may restrict the ability to recall intake, or physical limitations may affect the ability to record intake. The assessment may therefore need to involve whoever provides care for the older person, of whom there may be more than one. For these reasons, there is a need for validated methods for dietary assessment in large populations within this age range. The need is particularly acute in view of the secular increase in the numbers of older people and the interest in the role of nutrition in maintaining health and ameliorating age-related decline. This paper describes a comparison of two different methods of dietary assessment within the Newcastle 85+ Study; a UK cohort study of health and ageing in the oldest old. Two methods, the food frequency questionnaire (FFQ) (based on broad recall of the previous 12 months intake) and the repeated multiple pass recall (MPR) tool (based on detailed recall of the previous day's intake on two separate occasions), were applied in two different groups of approximately 85 individuals aged 85 years. FFQ data were collected during a pilot study conducted between 2003 and 2004, MPR data were collected in the main Newcastle study in 2006. Relative validity was measured by calculation of the ratio of reported energy intake to estimated basal metabolic rate (EI/BMR) and by comparison with dietary intakes reported for subjects of similar age in the UK National Diet and Nutrition Survey. EI/BMR ratios for MPR were 1.56 and 1.39 for men and women, respectively, and for FFQ were 2.18 and 2.14. The FFQ was found to overestimate energy and nutrient intake considerably. The MPR gave more realistic estimates of energy and nutrient intakes, and was found to be acceptable for use in this population group. However, use of this tool required greater investigator (nurse) time, extra resources for training and quality assurance and additional time and expertise in data processing. In the Newcastle 85+ Study, where the overall aims include detailed investigation of diet in relation to many variables describing biological, clinical and psychosocial status, we concluded that MPR was the preferable method, although there remains a need for non-subjective methods for assessing dietary intake, that is, biomarker approaches, which can give a comprehensive and objective assessment of dietary exposure.
Lawrence, David B; Ragucci, Kelly R; Long, Laura B; Parris, Beth S; Helfer, Lisa A
2006-01-01
There is limited information in the primary literature regarding the relationship of medication adherence to attainment of glycosylated hemoglobin A1c (A1c) goals. The 2 oral antihyperglycemic medications, sulfonylurea and/or metformin, were chosen for retrospective analysis because they are the 2 most common oral medications used by patients with diabetes. To describe the relationship between adherence with 1 or both of 2 oral antihyperglycemic medications (sulfonylurea and metformin) and A1c goal attainment for health maintenance organization (HMO) patients enrolled in a diabetes disease management program. This was a retrospective, descriptive evaluation of patients enrolled in a managed care diabetes disease management program in a 188,000-member independent practice association model HMO located in the Southeast. The dataset in this analysis contained demographic, enrollment, pharmacy claims, and clinical laboratory data. Continuously enrolled patients were included if there was a documented A1c value obtained at least 90 days after the initial oral antihyperglycemic medication (sulfonylurea or metformin) prescription index date. The medication possession ratio (MPR) was calculated from the pharmacy claim records and correlated with the A1c value. A total of 42% of patients on sulfonylurea therapy and 46% of those on metformin reached an A1c goal of < or = 7.0%. For patients taking a sulfonylurea, the mean MPR for those who reached the predetermined A1c goal (< or = 7.0) was 0.82 (0.29) compared with 0.72 (0.31) for those patients who did not reach the A1c target goal (P < 0.001). For patients taking metformin, the mean MPR for those who reached the predetermined A1c goal was 0.77 (0.3) versus 0.62 (0.3) for those patients who did not reach the A1c target goal (P < 0.001). A Pearson correlation analysis revealed a positive relationship between the MPR and A1c for sulfonylurea (r = -0.295, P < 0.001) and for metformin (r = -0.285, P < 0.001). For those patients taking both sulfonylurea and metformin, the Pearson correlation analysis showed a positive relationship between the 2 MPRs (r = 0.65, P < 0.001). Medication adherence as measured by the MPR was higher for patients taking a sulfonylurea or metformin who reached the target A1c goal of d7.0% compared with patients taking these drugs who did not reach the target A1c goal.
Secular cooling of Earth as a source of intraplate stress
NASA Technical Reports Server (NTRS)
Solomon, Sean C.
1987-01-01
The once popular idea that changes in planetary volume play an important role in terrestrial orogeny and tectonics was generally discarded with the acceptance of plate tectonics. It is nonetheless likely that the Earth has been steadily cooling over the past 3-4 billion years, and the global contraction that accompanied such cooling would have led to a secular decrease in the radius of curvature of the plates. The implications of this global cooling and contraction are explored here for the intraplate stress field and the evolution of continental plates.
VizieR Online Data Catalog: Binarity in planetary nebula central stars (De Marco+ 2013)
NASA Astrophysics Data System (ADS)
De Marco O.; Passy, J.-C.; Frew, D. J.; Moe, M.; Jacoby, G. H.
2014-01-01
The sample presented here consists of 30 central stars of PN which were selected solely based on their low PN surface brightness (radius of the PN is larger than ~25arcsec in most cases) as well as on the faint V magnitudes of their central stars. The observations were acquired during eight nights between 2007 October 30 and November 6 at the 2.1-m telescope at the Kitt Peak National Observatory. However, the data from nights 2 and 8 were not photometric. (5 data files).
Planetary mass function and planetary systems
NASA Astrophysics Data System (ADS)
Dominik, M.
2011-02-01
With planets orbiting stars, a planetary mass function should not be seen as a low-mass extension of the stellar mass function, but a proper formalism needs to take care of the fact that the statistical properties of planet populations are linked to the properties of their respective host stars. This can be accounted for by describing planet populations by means of a differential planetary mass-radius-orbit function, which together with the fraction of stars with given properties that are orbited by planets and the stellar mass function allows the derivation of all statistics for any considered sample. These fundamental functions provide a framework for comparing statistics that result from different observing techniques and campaigns which all have their very specific selection procedures and detection efficiencies. Moreover, recent results both from gravitational microlensing campaigns and radial-velocity surveys of stars indicate that planets tend to cluster in systems rather than being the lonely child of their respective parent star. While planetary multiplicity in an observed system becomes obvious with the detection of several planets, its quantitative assessment however comes with the challenge to exclude the presence of further planets. Current exoplanet samples begin to give us first hints at the population statistics, whereas pictures of planet parameter space in its full complexity call for samples that are 2-4 orders of magnitude larger. In order to derive meaningful statistics, however, planet detection campaigns need to be designed in such a way that well-defined fully deterministic target selection, monitoring and detection criteria are applied. The probabilistic nature of gravitational microlensing makes this technique an illustrative example of all the encountered challenges and uncertainties.
Thermal evolution and differentiation of planetesimals and planetary embryos
NASA Astrophysics Data System (ADS)
Šrámek, Ondřej; Milelli, Laura; Ricard, Yanick; Labrosse, Stéphane
2012-01-01
In early Solar System during the runaway growth stage of planetary formation, the distribution of planetary bodies progressively evolved from a large number of planetesimals to a smaller number of objects with a few dominant embryos. Here, we study the possible thermal and compositional evolution of these planetesimals and planetary embryos in a series of models with increasing complexities. We show that the heating stages of planetesimals by the radioactive decay of now extinct isotopes (in particular 26Al) and by impact heating can occur in two stages or simultaneously. Depending on the accretion rate, melting occurs from the center outward, in a shallow outer shell progressing inward, or in the two locations. We discuss the regime domains of these situations and show that the exponent β that controls the planetary growth rate R˙∝Rβ of planetesimals plays a crucial role. For a given terminal radius and accretion duration, the increase of β maintains the planetesimals very small until the end of accretion, and therefore allows radioactive heating to be radiated away before a large mass can be accreted. To melt the center of ˜500 km planetesimal during its runaway growth stage, with the value β = 2 predicted by astrophysicists, it needs to be formed within a couple of million years after condensation of the first solids. We then develop a multiphase model where the phase changes and phase separations by compaction are taken into account in 1-D spherical geometry. Our model handles simultaneously metal and silicates in both solid and liquid states. The segregation of the protocore decreases the efficiency of radiogenic heating by confining the 26Al in the outer silicate shell. Various types of planetesimals partly differentiated and sometimes differentiated in multiple metal-silicate layers can be obtained.
Toxic epidermal necrolysis following morbilli-parotitis-rubella vaccination.
Dobrosavljevic, D; Milinkovic, M V; Nikolic, M M
1999-07-01
We present the first reported case of toxic epidermal necrolysis (TEN) caused by morbilli-parotitis-rubella (MPR) vaccine. A 13-year-old girl developed TEN 7 days after she received live, attenuated, triple MPR vaccine. The history of drug intake and any illness was negative. At admission the patient was acutely ill with high fever. The whole body was erythematous. The epidermis was wrinkled and the Nikolsky sign was positive. Numerous erosions were present on the lips and genital region. On the seventh day of illness, the eruption involved 80% of the skin. Systemic corticosteroid therapy was not employed. The skin and mucosal defects completely epithelized by the end of the third week of illness. Mild keratoconjunctivitis sicca remained because of permanent cup cell damage.
A population study of hot Jupiter atmospheres
NASA Astrophysics Data System (ADS)
Tsiaras, A.; Waldmann, I. P.; Zingales, T.; Rocchetto, M.; Damiano, M.; Karpouzas, K.; Tinetti, G.; McKemmish, L. K.; Tennyson, J.; Yrchenko, S. N.
2017-09-01
In the past two decades, we have learnt that every star hosts more than one planet. While the hunt for new exoplanets is on-going, the current sample of more than 3500 confirmed planets reveals a wide spectrum of planetary characteristics. While small planets appear to be the most common, the big and gaseous planets play a key role in the process of planetary formation. We present here the analysis of 30 gaseous extra-solar planets, with temperatures between 600 and 2400 K and radii between 0.35 and 1.9 Jupiter radii. These planets were spectroscopically observed with the Wide Field Camera 3 on-board the Hubble Space Telescope, which is currently one of the most successful instruments for observing exoplanetary atmospheres. The quality of the HST/WFC3 spatially-scanned data combined with our specialised analysis tools, allows us to create the largest and most self-consistent sample of exoplanetary transmission spectra to date and study the collective behaviour of warm and hot gaseous planets rather than isolated case-studies. We define a new metric, the Atmospheric Detectability Index (ADI) to evaluate the statistical significance of an atmospheric detection and find statistically significant atmospheres around 16 planets. For most of the Jupiters in our sample we find the detectability of their atmospheres to be dependent on the planetary radius but not on the planetary mass. This indicates that planetary gravity is a secondary factor in the evolution of planetary atmospheres. We detect the presence of water vapour in all the statistically detectable atmospheres and we cannot rule out its presence in the atmospheres of the others. In addition, TiO and/or VO signatures are detected with 4σ confidence in WASP-76 b, and they are most likely present on WASP-121 b. We find no correlation between expected signal-to-noise and atmospheric detectability for most targets. This has important implications for future large-scale surveys.
Precession effects on a liquid planetary core
NASA Astrophysics Data System (ADS)
Liu, Min; Li, Li-Gang
2018-02-01
Motivated by the desire to understand the rich dynamics of precessionally driven flow in a liquid planetary core, we investigate, through numerical simulations, the precessing fluid motion in a rotating cylindrical annulus, which simultaneously possesses slow precession. The same problemhas been studied extensively in cylinders, where the precessing flow is characterized by three key parameters: the Ekman number E, the Poincaré number Po and the radius-height aspect ratio Γ. While in an annulus, there is another parameter, the inner-radius-height aspect ratio ϒ, which also plays an important role in controlling the structure and evolution of the flow. By decomposing the nonlinear solution into a set of inertial modes, we demonstrate the properties of both weakly and moderately precessing flows. It is found that, when the precessional force is weak, the flow is stable with a constant amplitude of kinetic energy. As the precessional force increases, our simulation suggests that the nonlinear interaction between the boundary effects and the inertial modes can trigger more turbulence, introducing a transitional regime of rich dynamics to disordered flow. The inertial mode u 111, followed by u 113 or u 112, always dominates the precessing flow when 0.001 ≤ Po ≤ 0.05, ranging from weak to moderate precession. Moreover, the precessing flow in an annulus shows more stability than in a cylinder which is likely to be caused by the effect of the inner boundary that restricts the growth of resonant and non-resonant inertial modes. Furthermore, the mechanism of triadic resonance is not found in the transitional regime from a laminar to disordered flow.
Rossby Waves in the Protoplanetary Nebula
NASA Technical Reports Server (NTRS)
Sheehan, Daniel P.
1998-01-01
Fluid waves and instabilities are considered critical to the evolution of protoplanetary nebulae, particularly for their roles in mass, angular momentum, and energy transport. A number have been identified, however, notably absent, is an influential wave commonly found in planetary atmospheres and oceans: the planetary Rossby wave (PRW). Since, in the Earth's atmosphere, the PRW is of primary importance in shaping large-scale meteorological phenomena, it is reasonable to consider whether it might have similar importance in the protoplanetary nebula. The thrust of the research project this summer (1998) was to determine whether a nebular analog to the PRW is viable, a so-called nebular Rossby wave (NRW), and if so, to explore possible ramifications of this wave to the evolution of the nebula. This work was carried out primarily by S. Davis, J. Cuzzi and me, with significant discussions with P. Cassen. We believe we have established a good case for the NRW and as a result believe we have opened up a new and possibly interesting line of research in regard to the nebular development, in particular with regard to zonal jet formation, a potent accretion mechanism, and possible ties to vortex formation. The standard model of the protoplanetary nebula consists of a large disk of gas with about 1% entrained dust gravitationally bound to a large central mass, m(sub c) i.e., the protostar. The planet-forming region of the disk extends to roughly 100 A.U. in radius. Disk thickness, H, is believed to be on the order of 10-100 times less than disk radius. Disk lifetime is on the order of a million years.
NASA Technical Reports Server (NTRS)
Farley, Rodger
2007-01-01
PlanetaryBalloon Version 5.0 is a software package for the design of meridionally lobed planetary balloons. It operates in a Windows environment, and programming was done in Visual Basic 6. By including the effects of circular lobes with load tapes, skin mass, hoop and meridional stress, and elasticity in the structural elements, a more accurate balloon shape of practical construction can be determined as well as the room-temperature cut pattern for the gore shapes. The computer algorithm is formulated for sizing meridionally lobed balloons for any generalized atmosphere or planet. This also covers zero-pressure, over-pressure, and super-pressure balloons. Low circumferential loads with meridionally reinforced load tapes will produce shapes close to what are known as the "natural shape." The software allows for the design of constant angle, constant radius, or constant hoop stress balloons. It uses the desired payload capacity for given atmospheric conditions and determines the required volume, allowing users to design exactly to their requirements. The formulations are generalized to use any lift gas (or mixture of gases), any atmosphere, or any planet as described by the local acceleration of gravity. PlanetaryBalloon software has a comprehensive user manual that covers features ranging from, but not limited to, buoyancy and super-pressure, convenient design equations, shape formulation, and orthotropic stress/strain.
Accurate parameters of the oldest known rocky-exoplanet hosting system: Kepler-10 revisited
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fogtmann-Schulz, Alexandra; Hinrup, Brian; Van Eylen, Vincent
2014-02-01
Since the discovery of Kepler-10, the system has received considerable interest because it contains a small, rocky planet which orbits the star in less than a day. The system's parameters, announced by the Kepler team and subsequently used in further research, were based on only five months of data. We have reanalyzed this system using the full span of 29 months of Kepler photometric data, and obtained improved information about its star and the planets. A detailed asteroseismic analysis of the extended time series provides a significant improvement on the stellar parameters: not only can we state that Kepler-10 ismore » the oldest known rocky-planet-harboring system at 10.41 ± 1.36 Gyr, but these parameters combined with improved planetary parameters from new transit fits gives us the radius of Kepler-10b to within just 125 km. A new analysis of the full planetary phase curve leads to new estimates on the planetary temperature and albedo, which remain degenerate in the Kepler band. Our modeling suggests that the flux level during the occultation is slightly lower than at the transit wings, which would imply that the nightside of this planet has a non-negligible temperature.« less
Evolution of the Magnetic Field during Chondrule Formation in Planetary Bow Shocks
NASA Astrophysics Data System (ADS)
Mai, Chuhong; Desch, Steven; Boley, Aaron C.
2016-10-01
Recent laboratory efforts (Fu et al., 2014, 2015) have constrained the remanent magnetizations of chondrules and the magnetic field strengths they were exposed to as they cooled below their Curie points. An outstanding question is whether these fields represent the background magnetic field of the solar nebula or were unique to the chondrule-forming environment. We investigate the amplification of the magnetic field above background values in a planetary bow shock, which is one proposed mechanism for chondrule formation. We use a hydrodynamic code to model the temperature and pressure around a 3000 km-radius planetary embryo as it moves supersonically through the nebula gas. We calculate the ionization of hot, shocked gas considering thermionic emission of electrons and ions from grains and thermal ionization of potassium. We calculate the magnetic diffusion rate, including Ohmic dissipation and ambipolar diffusion (assuming a magnetic field strength comparable to 0.5 G). We compute the steady-state magnetic field around in the bow shock and find that behind the planet the field is amplified, but everywhere else it quickly diffuses out of the shocked region and recovers the background value. We consider the trajectories taken by chondrules behind the shock and present likely values of the magnetic field amplification experienced by chondrules as they cool after melting in the shock.
Davis, Keith L; Edin, Heather M; Allen, Jeffery K
2010-03-15
We estimated the prevalence of medication nonadherence in Parkinson's disease (PD) and the association between treatment nonadherence and healthcare costs. Insurance claims from over 30 US health plans were analyzed. Inclusion criteria were as follows: PD diagnosis, >or=1 PD-related prescription between 1/1/1997 and 12/31/2004, continuous health plan enrollment for >or=6 months before and >or=12 months after first PD prescription. Adherence, all-cause healthcare utilization, and all-cause costs were evaluated over 12 months post-treatment initiation. Adherence was measured using the medication possession ratio (MPR), with MPR < 0.8 defining nonadherence. Among patients identified for inclusion (N = 3,119), 58% were male and mean age was 69 years. Mean MPR was 0.58 and 61% of patients were nonadherent. Unadjusted mean medical costs were significantly higher (P < 0.01) among nonadherers ($15,826) compared with adherers ($9,228), although nonadherers had lower prescription drug costs ($2,684 vs. $3,854; P < 0.05). After controlling for confounders in multivariable analyses, a large positive relationship between nonadherence and both medical and total healthcare costs remained (+$3,451, P < 0.0001 and +$2,383, P = 0.0053, respectively). Medication adherence in PD is suboptimal and nonadherence may be associated with increased healthcare costs despite offsets from reduced drug intake. Efforts to promote medication adherence in PD may lead to cost savings for managed care systems.
Liu, Chuan; Gao, Peng; Xu, Shang-Cheng; Wang, Yuan; Chen, Chun-Hai; He, Min-Di; Yu, Zheng-Ping; Zhang, Lei; Zhou, Zhou
2013-11-01
To evaluate whether exposure to mobile phone radiation (MPR) can induce DNA damage in male germ cells. A mouse spermatocyte-derived GC-2 cell line was exposed to a commercial mobile phone handset once every 20 min in standby, listen, dialed or dialing modes for 24 h. DNA damage was determined using an alkaline comet assay. The levels of DNA damage were significantly increased following exposure to MPR in the listen, dialed and dialing modes. Moreover, there were significantly higher increases in the dialed and dialing modes than in the listen mode. Interestingly, these results were consistent with the radiation intensities of these modes. However, the DNA damage effects of MPR in the dialing mode were efficiently attenuated by melatonin pretreatment. These results regarding mode-dependent DNA damage have important implications for the safety of inappropriate mobile phone use by males of reproductive age and also suggest a simple preventive measure: Keeping mobile phones as far away from our body as possible, not only during conversations but during 'dialed' and 'dialing' operation modes. Since the 'dialed' mode is actually part of the standby mode, mobile phones should be kept at a safe distance from our body even during standby operation. Furthermore, the protective role of melatonin suggests that it may be a promising pharmacological candidate for preventing mobile phone use-related reproductive impairments.
Kim, Bomi; Lee, Hyung-Chul; Kim, Seong-Hun; Kim, Yongil; Son, Woosung; Kim, Seong Sik
2018-05-01
This study examined cone-beam computed tomography (CBCT)-derived multiplanar-reconstructed (MPR) cross-sections to clarify the salient characteristics of patients with skeletal class III malocclusion with midface deficiency (MD). The horizontal and sagittal plane intersection points were identified for middle-third facial analysis in 40 patients in the MD or normal (N) groups. MPR images acquired parallel to each horizontal plane were used for length and angular measurements. A comparison of the MD and N groups revealed significant differences in the zygoma prominence among female patients. The convex zygomatic area in the N group was larger than that in the MD group, and the inferior part of the midface in the N group was smaller than that in the MD group for both male and female patients. A significant difference was observed in the concave middle maxillary area among male patients. This study was conducted to demonstrate the difference between MD and normal face through MPR images derived from CBCT. Male patients in the MD group had a more flattened face than did those in the N group. Female patients in the MD group showed a concave-shaped lower section of the zygoma, which tended to have more severe MD. These findings indicate that orthognathic surgery to improve skeletal discrepancy requires different approaches in male and female patients.
A web-based instruction module for interpretation of craniofacial cone beam CT anatomy.
Hassan, B A; Jacobs, R; Scarfe, W C; Al-Rawi, W T
2007-09-01
To develop a web-based module for learner instruction in the interpretation and recognition of osseous anatomy on craniofacial cone-beam CT (CBCT) images. Volumetric datasets from three CBCT systems were acquired (i-CAT, NewTom 3G and AccuiTomo FPD) for various subjects using equipment-specific scanning protocols. The datasets were processed using multiple software to provide two-dimensional (2D) multiplanar reformatted (MPR) images (e.g. sagittal, coronal and axial) and three-dimensional (3D) visual representations (e.g. maximum intensity projection, minimum intensity projection, ray sum, surface and volume rendering). Distinct didactic modules which illustrate the principles of CBCT systems, guided navigation of the volumetric dataset, and anatomic correlation of 3D models and 2D MPR graphics were developed using a hybrid combination of web authoring and image analysis techniques. Interactive web multimedia instruction was facilitated by the use of dynamic highlighting and labelling, and rendered video illustrations, supplemented with didactic textual material. HTML coding and Java scripting were heavily implemented for the blending of the educational modules. An interactive, multimedia educational tool for visualizing the morphology and interrelationships of osseous craniofacial anatomy, as depicted on CBCT MPR and 3D images, was designed and implemented. The present design of a web-based instruction module may assist radiologists and clinicians in learning how to recognize and interpret the craniofacial anatomy of CBCT based images more efficiently.
Some aspects of core formation in Mercury
NASA Technical Reports Server (NTRS)
Solomon, S. C.
1976-01-01
Some questions dealing with the nature and history of a large metallic core within Mercury are considered. These include the existence of a core, its size, whether it is fluid or solid, the timescale for core formation, the geological consequences of core formation, and whether such consequences are consistent with the surface geology. Several indirect lines of evidence are discussed which suggest the presence of a large iron-rich core. A core-formation model is examined in which core infall is accompanied by an increase of 17 km in planetary radius, an increase of 700 K in mean internal temperature, and substantial melting of the mantle. It is argued that if the core differentiated from an originally homogeneous planet, that event must have predated the oldest geological units comprising most of the planetary surface. A convective dynamo model for the source of Mercury's magnetic field is shown to conflict with cosmochemical models that do not predict a substantial radiogenic heat source in the core.
CALIBRATION OF EQUILIBRIUM TIDE THEORY FOR EXTRASOLAR PLANET SYSTEMS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hansen, Brad M. S., E-mail: hansen@astro.ucla.ed
2010-11-01
We provide an 'effective theory' of tidal dissipation in extrasolar planet systems by empirically calibrating a model for the equilibrium tide. The model is valid to high order in eccentricity and parameterized by two constants of bulk dissipation-one for dissipation in the planet and one for dissipation in the host star. We are able to consistently describe the distribution of extrasolar planetary systems in terms of period, eccentricity, and mass (with a lower limit of a Saturn mass) with this simple model. Our model is consistent with the survival of short-period exoplanet systems, but not with the circularization period ofmore » equal mass stellar binaries, suggesting that the latter systems experience a higher level of dissipation than exoplanet host stars. Our model is also not consistent with the explanation of inflated planetary radii as resulting from tidal dissipation. The paucity of short-period planets around evolved A stars is explained as the result of enhanced tidal inspiral resulting from the increase in stellar radius with evolution.« less
CLOSE BINARIES WITH INFRARED EXCESS: DESTROYERS OF WORLDS?
DOE Office of Scientific and Technical Information (OSTI.GOV)
Matranga, M.; Drake, J. J.; Kashyap, V. L.
2010-09-10
We present the results of a Spitzer photometric investigation into the IR excesses of close binary systems. In a sample of 10 objects, excesses in Infrared Array Camera and MIPS24 bands implying the presence of warm dust are found for 3. For two objects, we do not find excesses reported in earlier IRAS studies. We discuss the results in the context of the scenario suggested by Rhee and co-workers, in which warm dust is continuously created by destructive collisions between planetary bodies. A simple numerical model for the steady-state distribution of dust in one IR excess system shows a centralmore » clearing of radius 0.22 AU caused by dynamical perturbations from the binary star. This is consistent with the size of the central clearing derived from the Spitzer spectral energy distribution. We conclude that close binaries could be efficient 'destroyers of worlds' and lead to destabilization of the orbits of their planetary progeny by magnetically driven angular momentum loss and secular shrinkage of the binary separation.« less
Prospects for the future investigations of Mercury by the BepiColombo Laser Altimeter (BELA)
NASA Astrophysics Data System (ADS)
Steinbrügge, Gregor; Stark, Alexander; Hussmann, Hauke; Wickhusen, Kai; Oberst, Jürgen
2017-04-01
The flight model of the BepiColombo Laser Altimeter (BELA) has recently been delivered for integration on the Mercury Planetary Orbiter (MPO). We performed numerical simulations of the instrument performance expected in flight based on the measured BELA flight model (FM) parameters. In particular, we study measurement performance of topography, slopes, albedo, and roughness. Further, we analyzed the orbit evolution of the MPO based on most recent Mercury gravity data from MESSENGER. This allows us to estimate local and global topographic coverage, as well as the potential for estimates of the tidal Love number h2. Also possible implications of BELA science data on Mercury's interior structure, especially on the core radius and the mantle rheology, will be assessed. BELA is built by the Institute of Physics of the University of Bern and the DLR Institute of Planetary Research in cooperation with the Instituto de Astrofisica de Andalucia of the Consejo Superior de Investigaciones Cientificas (CSIC) and the Max-Planck-Institute for Solar System Research (MPS).
NASA Technical Reports Server (NTRS)
Dibenedetto, F.
1973-01-01
By application of Lyttleton's theory for the formation of comets, it is shown that a possible mechanism for the origin and formation of a concentration of cosmic particles around the earth and the other planets of the solar system exists. In the vicinity of the neutral point, where the velocity of colliding particles is not greater than 6 km/s, it is found that if the solid particles after collision must remain in a solid state, there can be no possibility of accretion for Mercury, Mars, and the Moon, where the maximum value of the distance of the center of the planet to the asymptotic trajectory is less than the radius of the planet. On the other hand, the capture radii of microparticles in solid form varies from a minimum of 2.95 planetary radii for Venus and 3.47 for the Earth, to about 986 for Jupiter.
Stability considerations of packed multi-planet systems
NASA Astrophysics Data System (ADS)
Gratia, Pierre; Lissauer, Jack
2018-04-01
I will present our first results of the outcomes of five packed, Earth-mass planetary simulations around a Sun-like star, whose initial separations in terms of their semi-major axes is determined by a multiple of their mutual Hill radius, the parameter beta. In our simulations, we will vary beta between 3.5 and and 9, with a special emphasis on the region around 8.5, where stability times are wildly different for small increments of beta. While the zero initial eccentricity case has been investigated before, we expand on it by allowing for initial nonzero eccentricities of one or more planets. Furthermore, we increase the simulated time by up to one order of magnitude reaching billions of orbits. This of course will determine more accurately the fate of systems that take a long time to go unstable. Both of these investigations have not been done before, thus our findings improve our understanding of the stabilities of closely-spaced planetary systems.
Two Earth-sized planets orbiting Kepler-20.
Fressin, Francois; Torres, Guillermo; Rowe, Jason F; Charbonneau, David; Rogers, Leslie A; Ballard, Sarah; Batalha, Natalie M; Borucki, William J; Bryson, Stephen T; Buchhave, Lars A; Ciardi, David R; Désert, Jean-Michel; Dressing, Courtney D; Fabrycky, Daniel C; Ford, Eric B; Gautier, Thomas N; Henze, Christopher E; Holman, Matthew J; Howard, Andrew; Howell, Steve B; Jenkins, Jon M; Koch, David G; Latham, David W; Lissauer, Jack J; Marcy, Geoffrey W; Quinn, Samuel N; Ragozzine, Darin; Sasselov, Dimitar D; Seager, Sara; Barclay, Thomas; Mullally, Fergal; Seader, Shawn E; Still, Martin; Twicken, Joseph D; Thompson, Susan E; Uddin, Kamal
2011-12-20
Since the discovery of the first extrasolar giant planets around Sun-like stars, evolving observational capabilities have brought us closer to the detection of true Earth analogues. The size of an exoplanet can be determined when it periodically passes in front of (transits) its parent star, causing a decrease in starlight proportional to its radius. The smallest exoplanet hitherto discovered has a radius 1.42 times that of the Earth's radius (R(⊕)), and hence has 2.9 times its volume. Here we report the discovery of two planets, one Earth-sized (1.03R(⊕)) and the other smaller than the Earth (0.87R(⊕)), orbiting the star Kepler-20, which is already known to host three other, larger, transiting planets. The gravitational pull of the new planets on the parent star is too small to measure with current instrumentation. We apply a statistical method to show that the likelihood of the planetary interpretation of the transit signals is more than three orders of magnitude larger than that of the alternative hypothesis that the signals result from an eclipsing binary star. Theoretical considerations imply that these planets are rocky, with a composition of iron and silicate. The outer planet could have developed a thick water vapour atmosphere.
NASA Technical Reports Server (NTRS)
Courtin, Regis; Wagener, Richard; Mckay, Christopher P.; Caldwell, John; Fricke, Karl-Heinrich
1991-01-01
The theoretical model developed by McKay et al. (1989) to characterize the size distribution, thermal structure, and chemical composition of the stratospheric haze of Titan is applied to new 220-335-nm albedo measurements obtained with the long-wavelength prime camera of the IUE during August 1987. Data and model predictions are presented in extensive graphs and discussed in detail. It is shown that a simple model with particles of one size at a given altitude does not accurately reproduce the observed features in all spectral regions, but that good general agreement is obtained using a model with a uniformly mixed layer at 150-600 km and a bimodal distribution of small 'polymer' haze particles (radius less than 20 nm) and larger haze particles (radius 100-500 nm). The number densities implied by this model require, however, a mechanism such as electrostatic charging or reaction kinetics to inhibit coagulation of the smaller particles.
The Discovery and Mass Measurement of a New Ultra-short-period Planet: K2-131b
NASA Astrophysics Data System (ADS)
Dai, Fei; Winn, Joshua N.; Gandolfi, Davide; Wang, Sharon X.; Teske, Johanna K.; Burt, Jennifer; Albrecht, Simon; Barragán, Oscar; Cochran, William D.; Endl, Michael; Fridlund, Malcolm; Hatzes, Artie P.; Hirano, Teruyuki; Hirsch, Lea A.; Johnson, Marshall C.; Justesen, Anders Bo; Livingston, John; Persson, Carina M.; Prieto-Arranz, Jorge; Vanderburg, Andrew; Alonso, Roi; Antoniciello, Giuliano; Arriagada, Pamela; Butler, R. P.; Cabrera, Juan; Crane, Jeffrey D.; Cusano, Felice; Csizmadia, Szilárd; Deeg, Hans; Dieterich, Sergio B.; Eigmüller, Philipp; Erikson, Anders; Everett, Mark E.; Fukui, Akihiko; Grziwa, Sascha; Guenther, Eike W.; Henry, Gregory W.; Howell, Steve B.; Johnson, John Asher; Korth, Judith; Kuzuhara, Masayuki; Narita, Norio; Nespral, David; Nowak, Grzegorz; Palle, Enric; Pätzold, Martin; Rauer, Heike; Montañés Rodríguez, Pilar; Shectman, Stephen A.; Smith, Alexis M. S.; Thompson, Ian B.; Van Eylen, Vincent; Williamson, Michael W.; Wittenmyer, Robert A.
2017-12-01
We report the discovery of a new ultra-short-period planet and summarize the properties of all such planets for which the mass and radius have been measured. The new planet, K2-131b, was discovered in K2 Campaign 10. It has a radius of {1.81}-0.12+0.16 {R}\\oplus and orbits a G dwarf with a period of 8.9 hr. Radial velocities obtained with Magellan/PFS and TNG/HARPS-N show evidence for stellar activity along with orbital motion. We determined the planetary mass using two different methods: (1) the “floating chunk offset” method, based only on changes in velocity observed on the same night; and (2) a Gaussian process regression based on both the radial velocity and photometric time series. The results are consistent and lead to a mass measurement of 6.5+/- 1.6 {M}\\oplus and a mean density of {6.0}-2.7+3.0 g cm-3.
NASA Astrophysics Data System (ADS)
Bonomo, A. S.; Sozzetti, A.; Lovis, C.; Malavolta, L.; Rice, K.; Buchhave, L. A.; Sasselov, D.; Cameron, A. C.; Latham, D. W.; Molinari, E.; Pepe, F.; Udry, S.; Affer, L.; Charbonneau, D.; Cosentino, R.; Dressing, C. D.; Dumusque, X.; Figueira, P.; Fiorenzano, A. F. M.; Gettel, S.; Harutyunyan, A.; Haywood, R. D.; Horne, K.; Lopez-Morales, M.; Mayor, M.; Micela, G.; Motalebi, F.; Nascimbeni, V.; Phillips, D. F.; Piotto, G.; Pollacco, D.; Queloz, D.; Ségransan, D.; Szentgyorgyi, A.; Watson, C.
2014-12-01
We characterize the planetary system Kepler-101 by performing a combined differential evolution Markov chain Monte Carlo analysis of Kepler data and forty radial velocities obtained with the HARPS-N spectrograph. This system was previously validated and is composed of a hot super-Neptune, Kepler-101b, and an Earth-sized planet, Kepler-101c. These two planets orbit the slightly evolved and metal-rich G-type star in 3.49 and 6.03 days, respectively. With mass Mp = 51.1-4.7+ 5.1 M⊕, radius Rp = 5.77-0.79+ 0.85 R⊕, and density ρp = 1.45-0.48+ 0.83 g cm-3, Kepler-101b is the first fully characterized super-Neptune, and its density suggests that heavy elements make up a significant fraction of its interior; more than 60% of its total mass. Kepler-101c has a radius of 1.25-0.17+ 0.19 R⊕, which implies the absence of any H/He envelope, but its mass could not be determined because of the relative faintness of the parent star for highly precise radial-velocity measurements (Kp = 13.8) and the limited number of radial velocities. The 1σ upper limit, Mp< 3.8 M⊕, excludes a pure iron composition with a probability of 68.3%. The architecture of the planetary system Kepler-101 - containing a close-in giant planet and an outer Earth-sized planet with a period ratio slightly larger than the 3:2 resonance - is certainly of interest for scenarios of planet formation and evolution. This system does not follow thepreviously reported trend that the larger planet has the longer period in the majority of Kepler systems of planet pairs with at least one Neptune-sized or larger planet. Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.Table 2 is available in electronic form at http://www.aanda.org
Constraining the interior density profile of a Jovian planet from precision gravity field data
NASA Astrophysics Data System (ADS)
Movshovitz, Naor; Fortney, Jonathan J.; Helled, Ravit; Hubbard, William B.; Thorngren, Daniel; Mankovich, Chris; Wahl, Sean; Militzer, Burkhard; Durante, Daniele
2017-10-01
The external gravity field of a planetary body is determined by the distribution of mass in its interior. Therefore, a measurement of the external field, properly interpreted, tells us about the interior density profile, ρ(r), which in turn can be used to constrain the composition in the interior and thereby learn about the formation mechanism of the planet. Planetary gravity fields are usually described by the coefficients in an expansion of the gravitational potential. Recently, high precision measurements of these coefficients for Jupiter and Saturn have been made by the radio science instruments on the Juno and Cassini spacecraft, respectively.The resulting coefficients come with an associated uncertainty. And while the task of matching a given density profile with a given set of gravity coefficients is relatively straightforward, the question of how best to account for the uncertainty is not. In essentially all prior work on matching models to gravity field data, inferences about planetary structure have rested on imperfect knowledge of the H/He equation of state and on the assumption of an adiabatic interior. Here we wish to vastly expand the phase space of such calculations. We present a framework for describing all the possible interior density structures of a Jovian planet, constrained only by a given set of gravity coefficients and their associated uncertainties. Our approach is statistical. We produce a random sample of ρ(a) curves drawn from the underlying (and unknown) probability distribution of all curves, where ρ is the density on an interior level surface with equatorial radius a. Since the resulting set of density curves is a random sample, that is, curves appear with frequency proportional to the likelihood of their being consistent with the measured gravity, we can compute probability distributions for any quantity that is a function of ρ, such as central pressure, oblateness, core mass and radius, etc. Our approach is also bayesian, in that it can utilize any prior assumptions about the planet's interior, as necessary, without being overly constrained by them.We demonstrate this approach with a sample of Jupiter interior models based on recent Juno data and discuss prospects for Saturn.
THE DOUBLE-DEGENERATE NUCLEUS OF THE PLANETARY NEBULA TS 01: A CLOSE BINARY EVOLUTION SHOWCASE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tovmassian, Gagik; Richer, Michael G.; Yungelson, Lev
2010-05-01
We present a detailed investigation of SBS 1150+599A, a close binary star hosted by the planetary nebula PN G135.9+55.9 (TS 01). The nebula, located in the Galactic halo, is the most oxygen-poor known to date and is the only one known to harbor a double degenerate core. We present XMM-Newton observations of this object, which allowed the detection of the previously invisible component of the binary core, whose existence was inferred so far only from radial velocity (RV) and photometric variations. The parameters of the binary system were deduced from a wealth of information via three independent routes using themore » spectral energy distribution (from the infrared to X-rays), the light and RV curves, and a detailed model atmosphere fitting of the stellar absorption features of the optical/UV component. We find that the cool component must have a mass of 0.54 {+-} 0.2 M{sub sun}, an average effective temperature, T{sub eff}, of 58,000 {+-} 3000 K, a mean radius of 0.43 {+-} 0.3 R{sub sun}, a gravity, log g = 5.0 {+-} 0.3, and that it nearly fills its Roche lobe. Its surface elemental abundances are found to be: 12 + log He/H = 10.95 {+-} 0.04 dex, 12 + log C/H = 7.20 {+-} 0.3 dex, 12 + log N/H < 6.92, and 12 + log O/H < 6.80, in overall agreement with the chemical composition of the planetary nebula. The hot component has T{sub eff} = 160-180 kK, a luminosity of about {approx}10{sup 4} L{sub sun} and a radius slightly larger than that of a white dwarf. It is probably bloated and heated as a result of intense accretion and nuclear burning on its surface in the past. The total mass of the binary system is very close to the Chandrasekhar limit. This makes TS 01 one of the best Type Ia supernova progenitor candidates. We propose two possible scenarios for the evolution of the system up to its present stage.« less
NASA Astrophysics Data System (ADS)
Hasson, Shabeh ul; Pascale, Salvatore; Lucarini, Valerio; Böhner, Jürgen
2016-11-01
We review the skill of thirty coupled climate models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) in terms of reproducing properties of the seasonal cycle of precipitation over the major river basins of South and Southeast Asia (Indus, Ganges, Brahmaputra and Mekong) for the historical period (1961-2000). We also present how these models represent the impact of climate change by the end of century (2061-2100) under the extreme scenario RCP8.5. First, we assess the models' ability to reproduce the observed timings of the monsoon onset and the rate of rapid fractional accumulation (RFA) slope - a measure of seasonality within the active monsoon period. Secondly, we apply a threshold-independent seasonality index (SI) - a multiplicative measure of precipitation (P) and extent of its concentration relative to uniform distribution (relative entropy - RE). We apply SI distinctly over the monsoonal precipitation regime (MPR), westerly precipitation regime (WPR) and annual precipitation. For the present climate, neither any single model nor the multi-model mean performs best in all chosen metrics. Models show overall a modest skill in suggesting right timings of the monsoon onset while the RFA slope is generally underestimated. One third of the models fail to capture the monsoon signal over the Indus basin. Mostly, the estimates for SI during WPR are higher than observed for all basins. When looking at MPR, the models typically simulate an SI higher (lower) than observed for the Ganges and Brahmaputra (Indus and Mekong) basins, following the pattern of overestimation (underestimation) of precipitation. Most of the models are biased negative (positive) for RE estimates over the Brahmaputra and Mekong (Indus and Ganges) basins, implying the extent of precipitation concentration for MPR and number of dry days within WPR lower (higher) than observed for these basins. Such skill of the CMIP5 models in representing the present-day monsoonal hydroclimatology poses some caveats on their ability to represent correctly the climate change signal. Nevertheless, considering the majority-model agreement as a measure of robustness for the qualitative scale projected future changes, we find a slightly delayed onset, and a general increase in the RFA slope and in the extent of precipitation concentration (RE) for MPR. Overall, a modest inter-model agreement suggests an increase in the seasonality of MPR and a less intermittent WPR for all basins and for most of the study domain. The SI-based indicator of change in the monsoonal domain suggests its extension westward over northwest India and Pakistan and northward over China. These findings have serious implications for the food and water security of the region in the future.
2012-01-01
Background During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS), leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO) synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T) and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. Results We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS generation and that increased NO plays an important role in baking-associated stress tolerance. Conclusions In this work, we clarified the importance of Put1- and Mpr1-mediated NO generation from proline to the baking-associated stress tolerance in industrial baker's yeast. We also demonstrated that baker's yeast that enhances the proline and NO synthetic pathway by expressing the Pro1-I150T and Mpr1-F65L variants showed improved fermentation ability under multiple baking-associated stress conditions. From a biotechnological perspective, the enhancement of proline and NO synthesis could be promising for breeding novel baker's yeast strains. PMID:22462683
Sasano, Yu; Haitani, Yutaka; Hashida, Keisuke; Ohtsu, Iwao; Shima, Jun; Takagi, Hiroshi
2012-04-01
During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS), leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO) synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T) and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS generation and that increased NO plays an important role in baking-associated stress tolerance. In this work, we clarified the importance of Put1- and Mpr1-mediated NO generation from proline to the baking-associated stress tolerance in industrial baker's yeast. We also demonstrated that baker's yeast that enhances the proline and NO synthetic pathway by expressing the Pro1-I150T and Mpr1-F65L variants showed improved fermentation ability under multiple baking-associated stress conditions. From a biotechnological perspective, the enhancement of proline and NO synthesis could be promising for breeding novel baker's yeast strains.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Badhai, Jhasketan; Das, Subrata K.
The genus Marinomonas comprises Gram negative bacteria which are widespread in the marine environment and there is no report on the genomic analysis of SXT/R391 ICEs derived from this group of bacteria. This study describes the genomic features of three new SXT/R391 integrating conjugating elements (ICEs) identified in the genome of Marinomonas fungiae JCM 18476 T (ICE MfuInd1a and ICE MfuInd1b) and in Marinomonas profundimaris strain D104 (ICE MprChn1). Structural organizations of the three ICEs were similar to the typical SXT/R391 family of ICEs and showed high degree of conservation in the core genes. Sequence analysis revealed ICE MfuInd1b andmore » ICE MprChn1 were inserted into the genome at 5'-end of an typical host prfC gene, while ICE MfuInd1a was inserted at 5'-end of an atypical hipA-like gene. Despite their coexistence, the ICE MfuInd1a and ICE MfuInd1b were not present in a tandem fashion in the genome of M. fungiae. Phylogenetic analyses revealed the three ICEs either evolved independently or high degrees of recombination events had masked their evolution from a common SXT ancestor. Further, we found that the typical entry exclusion mechanism mediated by the TraG/EeX protein pair was likely defective in preventing the conjugative transfer of a second copy of the same S (SXT) group ICE into the M. fungiae genome due to mutations. Our analysis showed the presence of 16, 25, and 27 variable genes in the hotspots of ICE MfuInd1a, ICE MfuInd1b, and ICE MprChn1, respectively, many of which were not reported earlier for SXT/R391 ICEs. Sequence analysis predicted these hot spot regions were shaped by acquisition of genes through homologous recombination between the SXT and R391 related ICEs or mobile genetic elements present in disparate marine bacteria. Multidrug resistance genes which are hallmark feature of SXT/R391 ICEs were not present in either of the two ICEs from M. fungiae but were present within a transposon cassette in the HS-1 of the ICE MprChn1 from M. profundimaris. Lastly, our data provided information on the genetic diversity and predicted functions encoded by variable genes present in the hotspot regions of these new ICEs.« less
Badhai, Jhasketan; Das, Subrata K.
2016-11-25
The genus Marinomonas comprises Gram negative bacteria which are widespread in the marine environment and there is no report on the genomic analysis of SXT/R391 ICEs derived from this group of bacteria. This study describes the genomic features of three new SXT/R391 integrating conjugating elements (ICEs) identified in the genome of Marinomonas fungiae JCM 18476 T (ICE MfuInd1a and ICE MfuInd1b) and in Marinomonas profundimaris strain D104 (ICE MprChn1). Structural organizations of the three ICEs were similar to the typical SXT/R391 family of ICEs and showed high degree of conservation in the core genes. Sequence analysis revealed ICE MfuInd1b andmore » ICE MprChn1 were inserted into the genome at 5'-end of an typical host prfC gene, while ICE MfuInd1a was inserted at 5'-end of an atypical hipA-like gene. Despite their coexistence, the ICE MfuInd1a and ICE MfuInd1b were not present in a tandem fashion in the genome of M. fungiae. Phylogenetic analyses revealed the three ICEs either evolved independently or high degrees of recombination events had masked their evolution from a common SXT ancestor. Further, we found that the typical entry exclusion mechanism mediated by the TraG/EeX protein pair was likely defective in preventing the conjugative transfer of a second copy of the same S (SXT) group ICE into the M. fungiae genome due to mutations. Our analysis showed the presence of 16, 25, and 27 variable genes in the hotspots of ICE MfuInd1a, ICE MfuInd1b, and ICE MprChn1, respectively, many of which were not reported earlier for SXT/R391 ICEs. Sequence analysis predicted these hot spot regions were shaped by acquisition of genes through homologous recombination between the SXT and R391 related ICEs or mobile genetic elements present in disparate marine bacteria. Multidrug resistance genes which are hallmark feature of SXT/R391 ICEs were not present in either of the two ICEs from M. fungiae but were present within a transposon cassette in the HS-1 of the ICE MprChn1 from M. profundimaris. Lastly, our data provided information on the genetic diversity and predicted functions encoded by variable genes present in the hotspot regions of these new ICEs.« less
Extrasolar Planets & The Power of the Dark Side
DOE Office of Scientific and Technical Information (OSTI.GOV)
Charbonneau, David
It is only in the last decade that we have direct evidence for planets orbiting nearby Sun-like stars. If such planets happen to pass in front of their stars, we are presented with a golden opportunity to learn about the nature of these objects. Measurements of the dimming of starlight and gravitational wobble allow us to derive the planetary radius and mass, and, by inference, its composition. Recently, we used the Hubble Telescope to detect and study the atmosphere of an extrasolar planet for the first time. I will describe what we have learned about these planets
MGS Radio Science Measurements of Atmospheric Dynamics on Mars
NASA Astrophysics Data System (ADS)
Hinson, D. P.
2001-12-01
The Sun-synchronous, polar orbit of Mars Global Surveyor (MGS) provides frequent opportunities for radio occultation sounding of the neutral atmosphere. The basic result of each experiment is a profile of pressure and temperature versus planetocentric radius and geopotential. More than 4000 profiles were obtained during the 687-day mapping phase of the mission, and additional observations are underway. These measurements allow detailed characterization of planetary-scale dynamics, including stationary planetary (or Rossby) waves and transient waves produced by instability. For example, both types of dynamics were observed near 67° S during midwinter of the southern hemisphere (Ls=134° --160° ). Planetary waves are the most prominent dynamical feature in this subset of data. At zonal wave number s=1, both the temperature and geopotential fields tilt westward with increasing height, as expected for vertically-propagating planetary waves forced at the surface. The wave-2 structure is more nearly barotropic. The amplitude in geopotential height at Ls=150° increases from ~200 m near the surface to ~700 m at 10 Pa. The corresponding meridional wind speed increases from ~5 m s-1 near the surface to ~20 m s-1 at 10 Pa. Traveling ``baroclinic'' waves also appear intermittently during this interval. The dominant mode has a period of ~2 sols, s=3, and a peak amplitude of ~7 K at 300 Pa. Stong zonal variations in eddy amplitude signal the presence of a possible ``storm zone'' at 150° --330° E longitude. This talk will include other examples of these phenomena as well as comparisons with computer simulations by a Martian general circulation model (MGCM).
The Devil in the Dark: A Fully Self-Consistent Seismic Model for Venus
NASA Astrophysics Data System (ADS)
Unterborn, C. T.; Schmerr, N. C.; Irving, J. C. E.
2017-12-01
The bulk composition and structure of Venus is unknown despite accounting for 40% of the mass of all the terrestrial planets in our Solar System. As we expand the scope of planetary science to include those planets around other stars, the lack of measurements of basic planetary properties such as moment of inertia, core-size and thermal profile for Venus hinders our ability to compare the potential uniqueness of the Earth and our Solar System to other planetary systems. Here we present fully self-consistent, whole-planet density and seismic velocity profiles calculated using the ExoPlex and BurnMan software packages for various potential Venusian compositions. Using these models, we explore the seismological implications of the different thermal and compositional initial conditions, taking into account phase transitions due to changes in pressure, temperature as well as composition. Using mass-radius constraints, we examine both the centre frequencies of normal mode oscillations and the waveforms and travel times of body waves. Seismic phases which interact with the core, phase transitions in the mantle, and shallower parts of Venus are considered. We also consider the detectability and transmission of these seismic waves from within the dense atmosphere of Venus. Our work provides coupled compositional-seismological reference models for the terrestrial planet in our Solar System of which we know the least. Furthermore, these results point to the potential wealth of fundamental scientific insights into Venus and Earth, as well as exoplanets, which could be gained by including a seismometer on future planetary exploration missions to Venus, the devil in the dark.
2013-01-01
Background Adherence to disease-modifying therapies (DMTs) results in the reduction of the number and severity of relapses and delays the progression of multiple sclerosis (MS). Patients with lower adherence rates experience more inpatient visits and higher MS-related medical costs. Fingolimod, the first oral DMT approved by the US Food and Drug Administration, may improve the access and compliance to MS treatment when compared to injectable DMTs. Methods This retrospective cohort study used pharmacy claims from Medco Health Solutions, Inc., of patients who initiated DMTs between October 2010 and February 2011. Initiation was defined as no prescription fills for the same DMT in the prior 12 months. Patients without a DMT prescription fill 12 months before the index date were considered naïve users. Compliance was measured via proportion of days covered (PDC) and medication possession ratio (MPR) for 12 months post-index. Discontinuation was defined as a ≥60-day gap of index DMT supply. Cox proportional hazard models compared time to discontinuation between cohorts. Results Of 1,891 MS patients (mean age: 45.7; female: 76.4%), 13.1% initiated fingolimod, 10.7% interferon beta-1b, 20.0% intramuscular interferon beta-1a, 18.8% subcutaneous interferon beta-1a, and 37.4% glatiramer acetate. Patients initiating fingolimod had highest average PDC and MPR in both experienced (fingolimod: mean PDC=0.83, 73.7% with PDC≥0.8; mean MPR=0.92, 90.5% with MPR≥0.8) and naïve DMT users (fingolimod: mean PDC=0.80, 66.7% with PDC≥0.8; mean MPR=0.90, 87.4% with MPR≥0.8). The proportion of patients discontinuing index DMT within 12 months was significantly lower for the fingolimod cohort (naïve: 31.3%; experienced: 25.7%). Adjusted results found that patients receiving self-injected DMTs discontinued significantly sooner than fingolimod users. This association was generally stronger in experienced DMT users. Conclusions Fingolimod initiators were more compliant, less likely to discontinue treatment, and discontinued later than patients who initiated self-injected DMT. PMID:24093542
Tixier, Philippe; Germon, Amandine; Rakotobe, Veromanitra; Phillips-Mora, Wilbert; Maximova, Siela; Avelino, Jacques
2017-01-01
Moniliophthora Pod Rot (MPR) caused by the fungus Moniliophthora roreri (Cif.) Evans et al., is one of the main limiting factors of cocoa production in Latin America. Currently insufficient information on the biology and epidemiology of the pathogen limits the development of efficient management options to control MPR. This research aims to elucidate MPR development through the following daily microclimatic variables: minimum and maximum temperatures, wetness frequency, average temperature and relative humidity in the highly susceptible cacao clone Pound-7 (incidence = 86% 2008–2013 average). A total of 55 cohorts totaling 2,268 pods of 3–10 cm length, one to two months of age, were tagged weekly. Pods were assessed throughout their lifetime, every one or two weeks, and classified in 3 different categories: healthy, diseased with no sporulation, diseased with sporulating lesions. As a first step, we used Generalized Linear Mixed Models (GLMM) to determine with no a priori the period (when and for how long) each climatic variable was better related with the appearance of symptoms and sporulation. Then the significance of the candidate variables was tested in a complete GLMM. Daily average wetness frequency from day 14 to day 1, before tagging, and daily average maximum temperature from day 4 to day 21, after tagging, were the most explanatory variables of the symptoms appearance. The former was positively linked with the symptoms appearance when the latter exhibited a maximum at 30°C. The most important variables influencing sporulation were daily average minimum temperature from day 35 to day 58 and daily average maximum temperature from day 37 to day 48, both after tagging. Minimum temperature was negatively linked with the sporulation while maximum temperature was positively linked. Results indicated that the fungal microclimatic requirements vary from the early to the late cycle stages, possibly due to the pathogen’s long latent period. This information is valuable for development of new conceptual models for MPR and improvement of control methods. PMID:28972981
Leandro-Muñoz, Mariela E; Tixier, Philippe; Germon, Amandine; Rakotobe, Veromanitra; Phillips-Mora, Wilbert; Maximova, Siela; Avelino, Jacques
2017-01-01
Moniliophthora Pod Rot (MPR) caused by the fungus Moniliophthora roreri (Cif.) Evans et al., is one of the main limiting factors of cocoa production in Latin America. Currently insufficient information on the biology and epidemiology of the pathogen limits the development of efficient management options to control MPR. This research aims to elucidate MPR development through the following daily microclimatic variables: minimum and maximum temperatures, wetness frequency, average temperature and relative humidity in the highly susceptible cacao clone Pound-7 (incidence = 86% 2008-2013 average). A total of 55 cohorts totaling 2,268 pods of 3-10 cm length, one to two months of age, were tagged weekly. Pods were assessed throughout their lifetime, every one or two weeks, and classified in 3 different categories: healthy, diseased with no sporulation, diseased with sporulating lesions. As a first step, we used Generalized Linear Mixed Models (GLMM) to determine with no a priori the period (when and for how long) each climatic variable was better related with the appearance of symptoms and sporulation. Then the significance of the candidate variables was tested in a complete GLMM. Daily average wetness frequency from day 14 to day 1, before tagging, and daily average maximum temperature from day 4 to day 21, after tagging, were the most explanatory variables of the symptoms appearance. The former was positively linked with the symptoms appearance when the latter exhibited a maximum at 30°C. The most important variables influencing sporulation were daily average minimum temperature from day 35 to day 58 and daily average maximum temperature from day 37 to day 48, both after tagging. Minimum temperature was negatively linked with the sporulation while maximum temperature was positively linked. Results indicated that the fungal microclimatic requirements vary from the early to the late cycle stages, possibly due to the pathogen's long latent period. This information is valuable for development of new conceptual models for MPR and improvement of control methods.
Rainfall Estimation over the Nile Basin using an Adapted Version of the SCaMPR Algorithm
NASA Astrophysics Data System (ADS)
Habib, E. H.; Kuligowski, R. J.; Elshamy, M. E.; Ali, M. A.; Haile, A.; Amin, D.; Eldin, A.
2011-12-01
Management of Egypt's Aswan High Dam is critical not only for flood control on the Nile but also for ensuring adequate water supplies for most of Egypt since rainfall is scarce over the vast majority of its land area. However, reservoir inflow is driven by rainfall over Sudan, Ethiopia, Uganda, and several other countries from which routine rain gauge data are sparse. Satellite-derived estimates of rainfall offer a much more detailed and timely set of data to form a basis for decisions on the operation of the dam. A single-channel infrared algorithm is currently in operational use at the Egyptian Nile Forecast Center (NFC). This study reports on the adaptation of a multi-spectral, multi-instrument satellite rainfall estimation algorithm (Self-Calibrating Multivariate Precipitation Retrieval, SCaMPR) for operational application over the Nile Basin. The algorithm uses a set of rainfall predictors from multi-spectral Infrared cloud top observations and self-calibrates them to a set of predictands from Microwave (MW) rain rate estimates. For application over the Nile Basin, the SCaMPR algorithm uses multiple satellite IR channels recently available to NFC from the Spinning Enhanced Visible and Infrared Imager (SEVIRI). Microwave rain rates are acquired from multiple sources such as SSM/I, SSMIS, AMSU, AMSR-E, and TMI. The algorithm has two main steps: rain/no-rain separation using discriminant analysis, and rain rate estimation using stepwise linear regression. We test two modes of algorithm calibration: real-time calibration with continuous updates of coefficients with newly coming MW rain rates, and calibration using static coefficients that are derived from IR-MW data from past observations. We also compare the SCaMPR algorithm to other global-scale satellite rainfall algorithms (e.g., 'Tropical Rainfall Measuring Mission (TRMM) and other sources' (TRMM-3B42) product, and the National Oceanographic and Atmospheric Administration Climate Prediction Center (NOAA-CPC) CMORPH product. The algorithm has several potential future applications such as: improving the performance accuracy of hydrologic forecasting models over the Nile Basin, and utilizing the enhanced rainfall datasets and better-calibrated hydrologic models to assess the impacts of climate change on the region's water availability.
Cotté, François-Emery; Mercier, Florence; De Pouvourville, Gérard
2008-12-01
Nonadherence to treatment is an important determinant of long-term outcomes in women with osteoporosis. This study was conducted to investigate the association between adherence and osteoporotic fracture risk and to identify optimal thresholds for good compliance and persistence. A secondary objective was to perform a preliminary evaluation of the cost consequences of adherence. This was a retrospective case-control analysis. Data were derived from the Thales prescription database, which contains information on >1.6 million patients in the primary health care setting in France. Cases were women aged >or=50 years who had an osteoporosis-related fracture in 2006. For each case, 5 matched controls were randomly selected. Both compliance and persistence aspects of treatment adherence were examined. Compliance was estimated based on the medication possession ratio (MPR). Persistence was calculated as the time from the initial filling of a prescription for osteoporosis medication until its discontinuation. The mean (SD) MPR was lower in cases compared with controls (58.8% [34.7%] vs 72.1% [28.8%], respectively; P < 0.001). Cases were more likely than controls to discontinue osteoporosis treatment (50.0% vs 25.3%; P < 0.001), yielding a significantly lower proportion of patients who were still persistent at 1 year (34.1% vs 40.9%; P < 0.001). MPR was the best predictor of fracture risk, with an area under the receiver-operating-characteristic curve that was higher than that for persistence (0.59 vs 0.55). The optimal MPR threshold for predicting fracture risk was >or=68.0%. Compared with less-compliant women, women who achieved this threshold had a 51% reduction in fracture risk. The difference in annual drug expenditure between women achieving this threshold and those who did not was approximately euro300. The optimal threshold for persistence with therapy was at least 6 months. Attaining this threshold was associated with a 28% reduction in fracture risk compared with less-persistent women. In this study, better treatment adherence was associated with a greater reduction in fracture risk. Compliance appeared to predict fracture risk better than did persistence.
Doannio, J M; Dossou-Yovo, J; Diarrassouba, S; Chauvancy, G; Darriet, F; Chandre, F; Henry, M C; Nzeyimana, I; Guillet, P; Carnevale, P
1999-01-01
The efficacy of permethrin-treated Olyset Net mosquito nets on malaria transmission and morbidity was studied in Kafine, a village located in the savanna region of the Cote d'Ivoire in Africa. After collecting sociodemographic, entomological, and parasitological data, bednets were distributed first in the southern half of the village and then in the whole village. Throughout the study period, mosquito specimens were captured on the skin of inhabitants at four points in the village between 6 PM and 6 AM both inside (but outside bednets) and outside houses. Prior to distribution of bednets, the mean biting rate (MBR) by Anopheles gambiae was 77.4 bites per man per night (b/m/n). The mean parturity rate (MPR) was 40.6 p. 100, the sporozootic index (SI) was 0.99 p. 100, and the mean entomological inoculation rate (MEIR) was 0.7 infectious bites per man per night (b+/m/n). Six months after distribution of bednets in the southern half of the village, MBR was 80.2 b/m/n, MPR was 32 p. 100, SI was 1.8 p. 100, and MEIR was 0.83 b+/m/n. After extending distribution to the whole village, data from November 1996 to July 1997 were as follows: MBR, 67.8 b/m/n; MPR, 20.1 p. 100; SI, 0.65 p. 100; and MEIR, 0.66 p. 100. From August 1977 to July 1998, data were as follows: MBR, 102.6 b/m/n; MPR, 26.2 p. 100; SI, 1.15 p. 100; and MEIR, 0.74 b+/m/n. Comparative analysis of these data showed that use of bednets had no effect on the bite or entomological inoculation rate. This is in agreement with the documented resistance of vectors in the study zone to permethrin. Despite the known stimulation/repulsion effect of permethrin, use of treated bednets had no real impact on transmission. This inefficacy could be related to the high prevalence (80 p. 100) of the Kdr gene (responsible for resistance) in the savanna form of Anopheles gambiae.
Mastinu, Enzo; Ortiz-Catalan, Max; Hakansson, Bo
2015-01-01
Compact and low-noise Analog Front-Ends (AFEs) are becoming increasingly important for the acquisition of bioelectric signals in portable system. In this work, we compare two popular AFEs available on the market, namely the ADS1299 (Texas Instruments) and the RHA2216 (Intan Technologies). This work develops towards the identification of suitable acquisition modules to design an affordable, reliable and portable device for electromyography (EMG) acquisition and prosthetic control. Device features such as Common Mode Rejection (CMR), Input Referred Noise (IRN) and Signal to Noise Ratio (SNR) were evaluated, as well as the resulting accuracy in myoelectric pattern recognition (MPR) for the decoding of motion intention. Results reported better noise performances and higher MPR accuracy for the ADS1299 and similar SNR values for both devices.
Hutsell, Blake A.; Newland, M. Christopher
2013-01-01
Previous studies of inbred mouse strains have shown reinforcer-strain interactions that may potentially mask differences among strains in memory performance. The present research examined the effects of two qualitatively different reinforcers (heterogeneous mix of flavored pellets and sweetened-condensed milk) on responding maintained by fixed-ratio schedules of reinforcement in three inbred strains of mice (BALB/c, C57BL/6, & DBA/2). Responses rates for all strains were a bitonic (inverted U) function of the size of the fixed-ratio schedule and were generally higher when responding was maintained by milk. For the DBA/2 and C57BL/6 and to a lesser extent the BALB/c, milk primarily increased response rates at moderate fixed ratios, but not at the largest fixed ratios tested. A formal model of ratio-schedule performance, Mathematical Principles of Reinforcement (MPR), was applied to the response rate functions of individual mice. According to MPR, the differences in response rates maintained by pellets and milk were mostly due to changes in motoric processes as indicated by changes in the minimum response time (δ) produced by each reinforcer type and not specific activation (a), a model term that represents value and is correlated with reinforcer magnitude and the break point obtained under progressive ratio schedules. In addition, MPR also revealed that, although affected by reinforcer type, a parameter interpreted as the rate of saturation of working memory (λ), differed among the strains. PMID:23357283
Moniruzzaman, Akm; Fazel, Seena; McCandless, Lawrence; Procyshyn, Ric; Somers, Julian M.
2017-01-01
Abstract Adherence to antipsychotic medication is a significant challenge among homeless patients. No experimental trials have investigated the impact of Housing First on adherence among patients with schizophrenia. We investigated whether Housing First in congregate and scattered-site configurations resulted in superior adherence compared to usual care. Adult participants (n = 165) met criteria for homelessness, schizophrenia, and initiation of antipsychotic pharmacotherapy prior to recruitment to an unblinded, 3-arm randomized controlled trial in Vancouver, Canada. Randomization arms were: congregate Housing First (CHF) with on-site supports (including physician and pharmacy services); scattered-site Housing First (SHF) with Assertive Community Treatment; or treatment as usual (TAU) consisting of existing services. Participants were followed for an average of 2.6 years. Adherence to antipsychotic medication was measured using the medication possession ratio (MPR), and 1-way ANOVA was used to compare outcomes between the 3 conditions. Data were drawn from comprehensive pharmacy records. Prior to randomization, mean MPR among participants was very low (0.44–0.48). Mean MPR in the follow-up period was significantly different between study arms (P < .001) and approached the guideline threshold of 0.80 in SHF. Compared to TAU, antipsychotic adherence was significantly higher in SHF but not in CHF. The results demonstrate that further implementation of SHF is indicated among homeless people with schizophrenia, and that urgent action is needed to address very low levels of antipsychotic adherence in this population (trial registration: ISRCTN57595077). PMID:27665002
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kipping, D. M.; Bakos, G. A.; Hartman, J.
We report the discovery of HAT-P-24b, a transiting extrasolar planet orbiting the moderately bright V = 11.818 F8 dwarf star GSC 0774-01441, with a period P = 3.3552464 {+-} 0.0000071 days, transit epoch T{sub c} = 2455216.97669 {+-} 0.00024 (BJD)11, and transit duration 3.653 {+-} 0.025 hr. The host star has a mass of 1.191 {+-} 0.042 M{sub sun}, radius of 1.317 {+-} 0.068 R{sub sun}, effective temperature 6373 {+-} 80 K, and a low metallicity of [Fe/H] = -0.16 {+-} 0.08. The planetary companion has a mass of 0.681 {+-} 0.031 M{sub J} and radius of 1.243 {+-} 0.072more » R{sub J} yielding a mean density of 0.439 {+-} 0.069 g cm{sup -3}. By repeating our global fits with different parameter sets, we have performed a critical investigation of the fitting techniques used for previous Hungarian-made Automated Telescope planetary discoveries. We find that the system properties are robust against the choice of priors. The effects of fixed versus fitted limb darkening are also examined. HAT-P-24b probably maintains a small eccentricity of e = 0.052{sup +0.022}{sub -0.017}, which is accepted over the circular orbit model with false alarm probability 5.8%. In the absence of eccentricity pumping, this result suggests that HAT-P-24b experiences less tidal dissipation than Jupiter. Due to relatively rapid stellar rotation, we estimate that HAT-P-24b should exhibit one of the largest known Rossiter-McLaughlin effect amplitudes for an exoplanet ({Delta}V{sub RM} {approx_equal} 95 m s{sup -1}) and thus a precise measurement of the sky-projected spin-orbit alignment should be possible.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, Jae-Min; Irwin, Patrick G. J.; Fletcher, Leigh N.
A number of observations have shown that Rayleigh scattering by aerosols dominates the transmission spectrum of HD 189733b at wavelengths shortward of 1 μm. In this study, we retrieve a range of aerosol distributions consistent with transmission spectroscopy between 0.3-24 μm that were recently re-analyzed by Pont et al. To constrain the particle size and the optical depth of the aerosol layer, we investigate the degeneracies between aerosol composition, temperature, planetary radius, and molecular abundances that prevent unique solutions for transit spectroscopy. Assuming that the aerosol is composed of MgSiO{sub 3}, we suggest that a vertically uniform aerosol layer overmore » all pressures with a monodisperse particle size smaller than about 0.1 μm and an optical depth in the range 0.002-0.02 at 1 μm provides statistically meaningful solutions for the day/night terminator regions of HD 189733b. Generally, we find that a uniform aerosol layer provide adequate fits to the data if the optical depth is less than 0.1 and the particle size is smaller than 0.1 μm, irrespective of the atmospheric temperature, planetary radius, aerosol composition, and gaseous molecules. Strong constraints on the aerosol properties are provided by spectra at wavelengths shortward of 1 μm as well as longward of 8 μm, if the aerosol material has absorption features in this region. We show that these are the optimal wavelengths for quantifying the effects of aerosols, which may guide the design of future space observations. The present investigation indicates that the current data offer sufficient information to constrain some of the aerosol properties of HD189733b, but the chemistry in the terminator regions remains uncertain.« less
The hunt for exomoons with Kepler (HEK). IV. A search for moons around eight M dwarfs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kipping, D. M., E-mail: dkipping@cfa.harvard.edu; Nesvorný, D.; Buchhave, L. A.
2014-03-20
With their smaller radii and high cosmic abundance, transiting planets around cool stars hold a unique appeal. As part of our ongoing project to measure the occurrence rate of extrasolar moons, in this work we present results from a survey focusing on eight Kepler planetary candidates associated with M dwarfs. Using photodynamical modeling and Bayesian multimodal nested sampling, we find no compelling evidence for an exomoon in these eight systems. Upper limits on the presence of such bodies probe down to masses of ∼0.4 M {sub ⊕} in the best case. For KOI-314, we are able to confirm the planetarymore » nature of two out of the three known transiting candidates using transit timing variations. Of particular interest is KOI-314c, which is found to have a mass of 1.0{sub −0.3}{sup +0.4} M {sub ⊕}, making it the lowest mass transiting planet discovered to date. With a radius of 1.61{sub −0.15}{sup +0.16} R {sub ⊕}, this Earth-mass world is likely enveloped by a significant gaseous envelope comprising ≥17{sub −13}{sup +12}% of the planet by radius. We also find evidence to support the planetary nature of KOI-784 via transit timing, but we advocate further observations to verify the signals. In both systems, we infer that the inner planet has a higher density than the outer world, which may be indicative of photo-evaporation. These results highlight both the ability of Kepler to search for sub-Earth-mass moons and the exciting ancillary science that often results from such efforts.« less
NASA Astrophysics Data System (ADS)
Kochemasov, G. G.
2012-09-01
Often observed a sensible difference in appearance and structure between tropical and extra-t ropical zones of various heavenly bodies including rocky and gas planets, satellites and Sun (Fig. 6) compels to look for a common reason of such phenomenon [1-3]. All bodies rotate and their spherical shape makes zones at different lat itudes to have differing angular momenta as a distance to the rotation axis diminishes gradually from the equator to the poles (Fig. 1) (this is felt particularly when one launches rockets into space -preferable cheaper launches are from the equatorial regions - Kourou in the French Guyana is better than Baikonur in Kazakhstan). One of remarkable changes occurs at tropics. As a total rotating planetary body tends to have angular momenta of its tectonic blocks equilibrated it starts mechanisms leveling this basic physical property. At tropical zones (bulged also due to the rotation ellipsoid) the outer shell - crust as a consequence tends to be destroyed, sunk, subsided and shrunk; a density of crust material changes; the atmosphere reacts changing chemistry and structure; in terrestrial anthroposphere man looses its mass and stature (well known pygmioidness process). Ext ratropical belts, on the contrary, tend to add material and increase radius. Thus, a body tends to be like a cucumber but mighty gravity always makes it globular. According to the Le Chatelier rule mechanisms with opposing tendencies also begin to act. However, traces of this cosmic "struggle" very often are seen on surfaces of heavenly bodies as structurally distinguished tropical and extra-t ropical zones (Fig. 1, 6) [1-3]. At Mars the widespread "enigmatic" chaotic and fretted terrains at the highland-lowland boundary could be considered as traces of the crust destruction along the wide tropical belt (Fig. 2-4). A system of hillocks and their relics, mesas, ridges, cliffs and separating them depressions or plains (deep up to 1-2 km) is controlled by a crosscutting tectonics or makes a complicated mix (Fig. 3, 4). Prevailing subsidence here is characteristic. The depressions were used and additionally sculptured by moving ices and flowing waters in the past of martian geologic history. On the contrary, wide extra -tropical belts of pedestal craters with broad effusions of fluid-rich material (Fig. 5) obviously help to mend defective momentum. A comparison with Earth is to the point. There also the wide planetary long tropical zone is marked by destruction of the crust. It is demonstrated by development of numerous islands of the Malay Archipelago (the Sunda Isls., Maluku Isls., Philippines) between the Southeastern Asia and Australia. In Africa and South America huge depressions of the Congo and Amazon Rivers develop where the Archean crust is subsided to depths of more than 2 km. In the Pacific along the equator numerous islands of Micronesia occur (massive corals mark subsiding basaltic summits). Subsidence of the basaltic oceanic crust is followed by an intensive folding and faulting of basalt and sedimentary layers as a larger mass must be held by a smaller space (a planetary radius is diminishing). The central Atlantic is very demonstrative in this sense suffering huge transform fault zones being replaced by more quite tectonics to the north and south where basaltic effusions (plateau-basalts) form large provinces. This addition of dense basalts to the upper crust level helps to increase angular momentum of the extra-t ropical blocks. Recent results from the DAWN mission show that the mini-planet Vesta also has the same structurally deformed equatorial belt. But at Vesta the equatorial belt is subsided and faulted (broken by tight series of parallel grabens) having been squeezed into smaller space because of diminishing planetary radius (Fig. 6) Thus, Mars, as other planetary bodies, suffers a fundamental re-building of its wide topical zone (supertectonics) as a necessary natural response to the angular momentum adjustment (equilibrat ion) of its different latitude belts (tropics and extra-tropics). This re-building started at the very earlier stages of its geologic history and, certainly, influenced other planetary wide processes. Fig. 1.Differing angular momenta (M) of the equatorial and ext ra-equatorial zones of a rotating globular body.
NASA Astrophysics Data System (ADS)
Cridland, A. J.; Pudritz, Ralph E.; Birnstiel, Tilman; Cleeves, L. Ilsedore; Bergin, Edwin A.
2017-08-01
We present the next step in a series of papers devoted to connecting the composition of the atmospheres of forming planets with the chemistry of their natal evolving protoplanetary discs. The model presented here computes the coupled chemical and dust evolution of the disc and the formation of three planets per disc model. Our three canonical planet traps produce a Jupiter near 1 AU, a Hot Jupiter and a Super-Earth. We study the dependence of the final orbital radius, mass, and atmospheric chemistry of planets forming in disc models with initial disc masses that vary by 0.02 M⊙ above and below our fiducial model (M_{disc,0} = 0.1 M_{⊙}). We compute C/O and C/N for the atmospheres formed in our three models and find that C/Oplanet ˜ C/O_{disc}, which does not vary strongly between different planets formed in our model. The nitrogen content of atmospheres can vary in planets that grow in different disc models. These differences are related to the formation history of the planet, the time and location that the planet accretes its atmosphere, and are encoded in the bulk abundance of NH3. These results suggest that future observations of atmospheric NH3 and an estimation of the planetary C/O and C/N can inform the formation history of particular planetary systems.
PHYSICAL PROPERTIES OF THE 0.94-DAY PERIOD TRANSITING PLANETARY SYSTEM WASP-18
DOE Office of Scientific and Technical Information (OSTI.GOV)
Southworth, John; Anderson, D. R.; Maxted, P. F. L.
2009-12-10
We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocusing we achieve a photometric precision of 0.47-0.83 mmag per observation over complete transit events. The data are analyzed using the JKTEBOP code and three different sets of stellar evolutionary models. We find the mass and radius of the planet to be M {sub b} = 10.43 +- 0.30 +- 0.24 M {sub Jup} and R {sub b} = 1.165 +- 0.055 +- 0.014 R {sub Jup} (statistical and systematic errors), respectively. Themore » systematic errors in the orbital separation and the stellar and planetary masses, arising from the use of theoretical predictions, are of a similar size to the statistical errors and set a limit on our understanding of the WASP-18 system. We point out that seven of the nine known massive transiting planets (M {sub b} > 3 M {sub Jup}) have eccentric orbits, whereas significant orbital eccentricity has been detected for only four of the 46 less-massive planets. This may indicate that there are two different populations of transiting planets, but could also be explained by observational biases. Further radial velocity observations of low-mass planets will make it possible to choose between these two scenarios.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fabrycky, Daniel C.; Lissauer, Jack J.; Rowe, Jason F.
We report on the orbital architectures of Kepler systems having multiple-planet candidates identified in the analysis of data from the first six quarters of Kepler data and reported by Batalha et al. (2013). These data show 899 transiting planet candidates in 365 multiple-planet systems and provide a powerful means to study the statistical properties of planetary systems. Using a generic mass-radius relationship, we find that only two pairs of planets in these candidate systems (out of 761 pairs total) appear to be on Hill-unstable orbits, indicating ∼96% of the candidate planetary systems are correctly interpreted as true systems. We findmore » that planet pairs show little statistical preference to be near mean-motion resonances. We identify an asymmetry in the distribution of period ratios near first-order resonances (e.g., 2:1, 3:2), with an excess of planet pairs lying wide of resonance and relatively few lying narrow of resonance. Finally, based upon the transit duration ratios of adjacent planets in each system, we find that the interior planet tends to have a smaller transit impact parameter than the exterior planet does. This finding suggests that the mode of the mutual inclinations of planetary orbital planes is in the range 1.°0-2.°2, for the packed systems of small planets probed by these observations.« less
WASP-117b: a 10-day-period Saturn in an eccentric and misaligned orbit
NASA Astrophysics Data System (ADS)
Lendl, M.; Triaud, A. H. M. J.; Anderson, D. R.; Collier Cameron, A.; Delrez, L.; Doyle, A. P.; Gillon, M.; Hellier, C.; Jehin, E.; Maxted, P. F. L.; Neveu-VanMalle, M.; Pepe, F.; Pollacco, D.; Queloz, D.; Ségransan, D.; Smalley, B.; Smith, A. M. S.; Udry, S.; Van Grootel, V.; West, R. G.
2014-08-01
We report the discovery of WASP-117b, the first planet with a period beyond 10 days found by the WASP survey. The planet has a mass of Mp = 0.2755 ± 0.0089 MJ, a radius of Rp= 1.021_{-0.065+0.076 Rjup} and is in an eccentric (e = 0.302 ± 0.023), 10.02165 ± 0.00055 d orbit around a main-sequence F9 star. The host star's brightness (V = 10.15 mag) makes WASP-117 a good target for follow-up observations, and with a periastron planetary equilibrium temperature of Teq= 1225_{-39+36} K and a low planetary mean density (ρp= 0.259_{-0.048+0.054 ρjup}) it is one of the best targets for transmission spectroscopy among planets with periods around 10 days. From a measurement of the Rossiter-McLaughlin effect, we infer a projected angle between the planetary orbit and stellar spin axes of β = -44 ± 11 deg, and we further derive an orbital obliquity of ψ = 69.6 +4.7-4.1 deg. Owing to the large orbital separation, tidal forces causing orbital circularization and realignment of the planetary orbit with the stellar plane are weak, having had little impact on the planetary orbit over the system lifetime. WASP-117b joins a small sample of transiting giant planets with well characterized orbits at periods above 8 days. Based on data obtained with WASP-South, CORALIE and EulerCam at the Euler-Swiss telescope, TRAPPIST, and HARPS at the ESO 3.6 m telescope (Prog. IDs 087.C-0649, 089.C-0151, 090.C-0540)Photometric and radial velocities are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/568/A81
NASA Astrophysics Data System (ADS)
Stoekl, Alexander; Dorfi, Ernst
2014-05-01
In the early, embedded phase of evolution of terrestrial planets, the planetary core accumulates gas from the circumstellar disk into a planetary envelope. This atmosphere is very significant for the further thermal evolution of the planet by forming an insulation around the rocky core. The disk-captured envelope is also the staring point for the atmospheric evolution where the atmosphere is modified by outgassing from the planetary core and atmospheric mass loss once the planet is exposed to the radiation field of the host star. The final amount of persistent atmosphere around the evolved planet very much characterizes the planet and is a key criterion for habitability. The established way to study disk accumulated atmospheres are hydrostatic models, even though in many cases the assumption of stationarity is unlikely to be fulfilled. We present, for the first time, time-dependent radiation hydrodynamics simulations of the accumulation process and the interaction between the disk-nebula gas and the planetary core. The calculations were performed with the TAPIR-Code (short for The adaptive, implicit RHD-Code) in spherical symmetry solving the equations of hydrodynamics, gray radiative transport, and convective energy transport. The models range from the surface of the solid core up to the Hill radius where the planetary envelope merges into the surrounding protoplanetary disk. Our results show that the time-scale of gas capturing and atmospheric growth strongly depends on the mass of the solid core. The amount of atmosphere accumulated during the lifetime of the protoplanetary disk (typically a few Myr) varies accordingly with the mass of the planet. Thus, a core with Mars-mass will end up with about 10 bar of atmosphere while for an Earth-mass core, the surface pressure reaches several 1000 bar. Even larger planets with several Earth masses quickly capture massive envelopes which in turn become gravitationally unstable leading to runaway accretion and the eventual formation of a gas planet.
NASA Astrophysics Data System (ADS)
Léger, A.; Rouan, D.; Schneider, J.; Barge, P.; Fridlund, M.; Samuel, B.; Ollivier, M.; Guenther, E.; Deleuil, M.; Deeg, H. J.; Auvergne, M.; Alonso, R.; Aigrain, S.; Alapini, A.; Almenara, J. M.; Baglin, A.; Barbieri, M.; Bruntt, H.; Bordé, P.; Bouchy, F.; Cabrera, J.; Catala, C.; Carone, L.; Carpano, S.; Csizmadia, Sz.; Dvorak, R.; Erikson, A.; Ferraz-Mello, S.; Foing, B.; Fressin, F.; Gandolfi, D.; Gillon, M.; Gondoin, Ph.; Grasset, O.; Guillot, T.; Hatzes, A.; Hébrard, G.; Jorda, L.; Lammer, H.; Llebaria, A.; Loeillet, B.; Mayor, M.; Mazeh, T.; Moutou, C.; Pätzold, M.; Pont, F.; Queloz, D.; Rauer, H.; Renner, S.; Samadi, R.; Shporer, A.; Sotin, Ch.; Tingley, B.; Wuchterl, G.; Adda, M.; Agogu, P.; Appourchaux, T.; Ballans, H.; Baron, P.; Beaufort, T.; Bellenger, R.; Berlin, R.; Bernardi, P.; Blouin, D.; Baudin, F.; Bodin, P.; Boisnard, L.; Boit, L.; Bonneau, F.; Borzeix, S.; Briet, R.; Buey, J.-T.; Butler, B.; Cailleau, D.; Cautain, R.; Chabaud, P.-Y.; Chaintreuil, S.; Chiavassa, F.; Costes, V.; Cuna Parrho, V.; de Oliveira Fialho, F.; Decaudin, M.; Defise, J.-M.; Djalal, S.; Epstein, G.; Exil, G.-E.; Fauré, C.; Fenouillet, T.; Gaboriaud, A.; Gallic, A.; Gamet, P.; Gavalda, P.; Grolleau, E.; Gruneisen, R.; Gueguen, L.; Guis, V.; Guivarc'h, V.; Guterman, P.; Hallouard, D.; Hasiba, J.; Heuripeau, F.; Huntzinger, G.; Hustaix, H.; Imad, C.; Imbert, C.; Johlander, B.; Jouret, M.; Journoud, P.; Karioty, F.; Kerjean, L.; Lafaille, V.; Lafond, L.; Lam-Trong, T.; Landiech, P.; Lapeyrere, V.; Larqué, T.; Laudet, P.; Lautier, N.; Lecann, H.; Lefevre, L.; Leruyet, B.; Levacher, P.; Magnan, A.; Mazy, E.; Mertens, F.; Mesnager, J.-M.; Meunier, J.-C.; Michel, J.-P.; Monjoin, W.; Naudet, D.; Nguyen-Kim, K.; Orcesi, J.-L.; Ottacher, H.; Perez, R.; Peter, G.; Plasson, P.; Plesseria, J.-Y.; Pontet, B.; Pradines, A.; Quentin, C.; Reynaud, J.-L.; Rolland, G.; Rollenhagen, F.; Romagnan, R.; Russ, N.; Schmidt, R.; Schwartz, N.; Sebbag, I.; Sedes, G.; Smit, H.; Steller, M. B.; Sunter, W.; Surace, C.; Tello, M.; Tiphène, D.; Toulouse, P.; Ulmer, B.; Vandermarcq, O.; Vergnault, E.; Vuillemin, A.; Zanatta, P.
2009-10-01
Aims: We report the discovery of very shallow (Δ F/F ≈ 3.4× 10-4), periodic dips in the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite, which we interpret as caused by a transiting companion. We describe the 3-colour CoRoT data and complementary ground-based observations that support the planetary nature of the companion. Methods: We used CoRoT colours information, good angular resolution ground-based photometric observations in- and out- of transit, adaptive optics imaging, near-infrared spectroscopy, and preliminary results from radial velocity measurements, to test the diluted eclipsing binary scenarios. The parameters of the host star were derived from optical spectra, which were then combined with the CoRoT light curve to derive parameters of the companion. Results: We examined all conceivable cases of false positives carefully, and all the tests support the planetary hypothesis. Blends with separation >0.40´´or triple systems are almost excluded with a 8 × 10-4 risk left. We conclude that, inasmuch we have been exhaustive, we have discovered a planetary companion, named CoRoT-7b, for which we derive a period of 0.853 59 ± 3 × 10-5 day and a radius of Rp = 1.68 ± 0.09 R_Earth. Analysis of preliminary radial velocity data yields an upper limit of 21 M_Earth for the companion mass, supporting the finding. Conclusions: CoRoT-7b is very likely the first Super-Earth with a measured radius. This object illustrates what will probably become a common situation with missions such as Kepler, namely the need to establish the planetary origin of transits in the absence of a firm radial velocity detection and mass measurement. The composition of CoRoT-7b remains loosely constrained without a precise mass. A very high surface temperature on its irradiated face, ≈1800-2600 K at the substellar point, and a very low one, ≈50 K, on its dark face assuming no atmosphere, have been derived. The CoRoT space mission, launched on 27 December 2006, has been developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA, Germany, and Spain. First CoRoT data are available to the public from the CoRoT archive: http://idoc-corot.ias.u-psud.fr. The complementary observations were obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by NRC in Canada, INSU-CNRS in France, and the University of Hawaii; ESO Telescopes at the La Silla and Paranal Observatories under programme ID 081.C-0413(C), DDT 282.C-5015; the IAC80 telescope operated by the Instituto de Astrofísica de Tenerife at the Observatorio del Teide; the Isaac Newton Telescope (INT), operated on the island of La Palma by the Isaac Newton group in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrofisica de Canarias; and at the Anglo-Australian Telescope that have been funded by the Optical Infrared Coordination network (OPTICON), a major international collaboration supported by the Research Infrastructures Programme of the European Commissions Sixth Framework Programme; Radial-velocity observations were obtained with the SOPHIE spectrograph at the 1.93m telescope of Observatoire de Haute Provence, France.
TrES-5: A MASSIVE JUPITER-SIZED PLANET TRANSITING A COOL G DWARF
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mandushev, Georgi; Dunham, Edward W.; Quinn, Samuel N.
2011-11-10
We report the discovery of TrES-5, a massive hot Jupiter that transits the star GSC 03949-00967 every 1.48 days. From spectroscopy of the star we estimate a stellar effective temperature of T{sub eff} = 5171 {+-} 36 K, and from high-precision B, R, and I photometry of the transit we constrain the ratio of the semimajor axis a and the stellar radius R{sub *} to be a/R{sub *} = 6.07 {+-} 0.14. We compare these values to model stellar isochrones to obtain a stellar mass of M{sub *} = 0.893 {+-} 0.024 M{sub Sun }. Based on this estimate andmore » the photometric time series, we constrain the stellar radius to be R{sub *} = 0.866 {+-} 0.013 R{sub Sun} and the planet radius to be R{sub p} = 1.209 {+-} 0.021 R{sub J}. We model our radial-velocity data assuming a circular orbit and find a planetary mass of 1.778 {+-} 0.063 M{sub J}. Our radial-velocity observations rule out line-bisector variations that would indicate a specious detection resulting from a blend of an eclipsing binary system. TrES-5 orbits one of the faintest stars with transiting planets found to date from the ground and demonstrates that precise photometry and followup spectroscopy are possible, albeit challenging, even for such faint stars.« less
NASA Astrophysics Data System (ADS)
Lillo-Box, J.; Barrado, D.; Moya, A.; Montesinos, B.; Montalbán, J.; Bayo, A.; Barbieri, M.; Régulo, C.; Mancini, L.; Bouy, H.; Henning, T.
2014-02-01
Context. The evolution of planetary systems is intimately linked to the evolution of their host stars. Our understanding of the whole planetary evolution process is based on the wide planet diversity observed so far. Only a few tens of planets have been discovered orbiting stars ascending the red giant branch. Although several theories have been proposed, the question of how planets die remains open owing to the small number statistics, making it clear that the sample of planets around post-main sequence stars needs to be enlarged. Aims: In this work we study the giant star Kepler-91 (KOI-2133) in order to determine the nature of a transiting companion. This system was detected by the Kepler Space Telescope, which identified small dims in its light curve with a period of 6.246580 ± 0.000082 days. However, its planetary confirmation is needed due to the large pixel size of the Kepler camera, which can hide other stellar configurations able to mimic planet-like transit events. Methods: We analysed Kepler photometry to 1) re-calculate transit parameters; 2) study the light-curve modulations; and 3) to perform an asteroseismic analysis (accurate stellar parameter determination) by identifying solar-like oscillations on the periodogram. We also used a high-resolution and high signal-to-noise ratio spectrum obtained with the Calar Alto Fiber-fed Échelle spectrograph (CAFE) to measure stellar properties. Additionally, false-positive scenarios were rejected by obtaining high-resolution images with the AstraLux lucky imaging camera on the 2.2 m telescope at the Calar Alto Observatory. Results: We confirm the planetary nature of the object transiting the star Kepler-91 by deriving a mass of Mp=0.88+0.17-0.33 MJup and a planetary radius of Rp=1.384+0.011-0.054 RJup. Asteroseismic analysis produces a stellar radius of R⋆ = 6.30 ± 0.16 R⊙ and a mass of M⋆ = 1.31 ± 0.10 M⊙. We find that its eccentric orbit (e=0.066+0.013-0.017) is just 1.32+0.07-0.22 R⋆ away from the stellar atmosphere at the pericentre. We also detected three small dims in the phase-folded light curve. The combination of two of them agrees with the theoretical characteristics expected for secondary eclipse. Conclusions: Kepler-91b could be the previous stage of the planet engulfment, which has recently been detected for BD+48 740. Our estimations show that Kepler-91b will be swallowed by its host star in less than 55 Myr. Among the confirmed planets around giant stars, this is the closest to its host star. At pericentre, the star subtends an angle of 48°, covering around 10% of the sky as seen from the planet. The planetary atmosphere seems to be inflated probably due to the high stellar irradiation. Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut fur Astronomie (Heidelberg) and the Instituto de Astrofísica de Andalucía (IAA-CSIC, Granada).Appendix A is available in electronic form at http://www.aanda.org
Detection of Planetary Emission from the Exoplanet TrES-2 Using Spitzer/IRAC
NASA Technical Reports Server (NTRS)
Donovan, Francis T.; Charbonneau, David; Harrington, Joseph; Madhusudhan, N.; Seager, Sara; Deming, Drake; Knutson, Heather A.
2010-01-01
We present here the results of our observations of TrES-2 using the Infrared Array Camera on Spitzer. We monitored this transiting system during two secondary eclipses, when the planetary emission is blocked by the star. The resulting decrease in flux is 0.127% +/- 0.021%, 0.230% +/- 0.024%, 0.199% +/- 0.054%, and 0.359% +/- 0.060% at 3.6 microns, 4.5 microns, 5.8 microns, and 8.0 microns, respectively. We show that three of these flux contrasts are well fit by a blackbody spectrum with T(sub eff) = 1500 K, as well as by a more detailed model spectrum of a planetary atmosphere. The observed planet-to-star flux ratios in all four lRAC channels can be explained by models with and without a thermal inversion in the atmosphere of TrES-2, although with different atmospheric chemistry. Based on the assumption of thermochemical equilibrium, the chemical composition of the inversion model seems more plausible, making it a more favorable scenario. TrES-2 also falls in the category of highly irradiated planets which have been theoretically predicted to exhibit thermal inversions. However, more observations at infrared and visible wavelengths would be needed to confirm a thermal inversion in this system. Furthermore, we find that the times of the secondary eclipses are consistent with previously published times of transit and the expectation from a circular orbit. This implies that TrES-2 most likely has a circular orbit, and thus does not obtain additional thermal energy from tidal dissipation of a non-zero orbital eccentricity, a proposed explanation for the large radius of this planet. Key words: eclipses - infrared: stars - planetary systems - stars: individual (OSC 03549-02811) - techniques: photometric
NASA Astrophysics Data System (ADS)
Dimech, J. L.; Weber, R. C.; Knapmeyer-Endrun, B.; Arnold, R.; Savage, M. K.
2016-12-01
The field of planetary science is poised for a major advance with the upcoming InSight mission to Mars due to launch in May 2018. Seismic analysis techniques adapted for use on planetary data are therefore highly relevant to the field. The heart of this project is in the application of new seismic analysis techniques to the lunar seismic dataset to learn more about the Moon's crust and mantle structure, with particular emphasis on `deep' moonquakes which are situated half-way between the lunar surface and its core with no surface expression. Techniques proven to work on the Moon might also be beneficial for InSight and future planetary seismology missions which face similar technical challenges. The techniques include: (1) an event-detection and classification algorithm based on `Hidden Markov Models' to reclassify known moonquakes and look for new ones. Apollo 17 gravimeter and geophone data will also be included in this effort. (2) Measurements of anisotropy in the lunar mantle and crust using `shear-wave splitting'. Preliminary measurements on deep moonquakes using the MFAST program are encouraging, and continued evaluation may reveal new structural information on the Moon's mantle. (3) Probabilistic moonquake locations using NonLinLoc, a non-linear hypocenter location technique, using a modified version of the codes designed to work with the Moon's radius. Successful application may provide a new catalog of moonquake locations with rigorous uncertainty information, which would be a valuable input into: (4) new fault plane constraints from focal mechanisms using a novel approach to Bayes' theorem which factor in uncertainties in hypocenter coordinates and S-P amplitude ratios. Preliminary results, such as shear-wave splitting measurements, will be presented and discussed.
Did 26Al and impact-induced heating differentiate Mercury?
NASA Astrophysics Data System (ADS)
Bhatia, G. K.; Sahijpal, S.
2017-02-01
Numerical models dealing with the planetary scale differentiation of Mercury are presented with the short-lived nuclide, 26Al, as the major heat source along with the impact-induced heating during the accretion of planets. These two heat sources are considered to have caused differentiation of Mars, a planet with size comparable to Mercury. The chronological records and the thermal modeling of Mars indicate an early differentiation during the initial 1 million years (Ma) of the formation of the solar system. We theorize that in case Mercury also accreted over an identical time scale, the two heat sources could have differentiated the planets. Although unlike Mars there is no chronological record of Mercury's differentiation, the proposed mechanism is worth investigation. We demonstrate distinct viable scenarios for a wide range of planetary compositions that could have produced the internal structure of Mercury as deduced by the MESSENGER mission, with a metallic iron (Fe-Ni-FeS) core of radius 2000 km and a silicate mantle thickness of 400 km. The initial compositions were derived from the enstatite and CB (Bencubbin) chondrites that were formed in the reducing environments of the early solar system. We have also considered distinct planetary accretion scenarios to understand their influence on thermal processing. The majority of our models would require impact-induced mantle stripping of Mercury by hit and run mechanism with a protoplanet subsequent to its differentiation in order to produce the right size of mantle. However, this can be avoided if we increase the Fe-Ni-FeS contents to 71% by weight. Finally, the models presented here can be used to understand the differentiation of Mercury-like exoplanets and the planetary embryos of Venus and Earth.
Equation of state of iron under core conditions of large rocky exoplanets
NASA Astrophysics Data System (ADS)
Smith, Raymond F.; Fratanduono, Dayne E.; Braun, David G.; Duffy, Thomas S.; Wicks, June K.; Celliers, Peter M.; Ali, Suzanne J.; Fernandez-Pañella, Amalia; Kraus, Richard G.; Swift, Damian C.; Collins, Gilbert W.; Eggert, Jon H.
2018-04-01
The recent discovery of thousands of planets outside our Solar System raises fundamental questions about the variety of planetary types and their corresponding interior structures and dynamics. To better understand these objects, there is a strong need to constrain material properties at the extreme pressures found within planetary interiors1,2. Here we used high-powered lasers at the National Ignition Facility to ramp compress iron over nanosecond timescales to 1.4 TPa (14 million atmospheres)—a pressure four times higher than for previous static compression data. A Lagrangian sound-speed analysis was used to determine pressure, density and sound speed along a continuous isentropic compression path. Our peak pressures are comparable to those predicted at the centre of a terrestrial-type exoplanet of three to four Earth masses3, representing the first absolute equation of state measurements for iron at such conditions. These results provide an experiment-based mass-radius relationship for a hypothetical pure iron planet that can be used to evaluate plausible compositional space for large, rocky exoplanets.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hirano, Teruyuki; Sanchis-Ojeda, Roberto; Winn, Joshua N.
We present a test for spin-orbit alignment for the host stars of 25 candidate planetary systems detected by the Kepler spacecraft. The inclination angle of each star's rotation axis was estimated from its rotation period, rotational line broadening, and radius. The rotation periods were determined using the Kepler photometric time series. The rotational line broadening was determined from high-resolution optical spectra with the Subaru High Dispersion Spectrograph. Those same spectra were used to determine the star's photospheric parameters (effective temperature, surface gravity, metallicity), which were then interpreted with stellar-evolutionary models to determine stellar radii. We combine the new sample withmore » the seven stars from our previous work on this subject, finding that the stars show a statistical tendency to have inclinations near 90°, in alignment with the planetary orbits. Possible spin-orbit misalignments are seen in several systems, including three multiple-planet systems (KOI-304, 988, 2261). Ideally, these systems should be scrutinized with complementary techniques, such as the Rossiter-McLaughlin effect, starspot-crossing anomalies, or asteroseismology, but the measurements will be difficult owing to the relatively faint apparent magnitudes and small transit signals in these systems.« less
Equation of state of iron under core conditions of large rocky exoplanets
NASA Astrophysics Data System (ADS)
Smith, Raymond F.; Fratanduono, Dayne E.; Braun, David G.; Duffy, Thomas S.; Wicks, June K.; Celliers, Peter M.; Ali, Suzanne J.; Fernandez-Pañella, Amalia; Kraus, Richard G.; Swift, Damian C.; Collins, Gilbert W.; Eggert, Jon H.
2018-06-01
The recent discovery of thousands of planets outside our Solar System raises fundamental questions about the variety of planetary types and their corresponding interior structures and dynamics. To better understand these objects, there is a strong need to constrain material properties at the extreme pressures found within planetary interiors1,2. Here we used high-powered lasers at the National Ignition Facility to ramp compress iron over nanosecond timescales to 1.4 TPa (14 million atmospheres)—a pressure four times higher than for previous static compression data. A Lagrangian sound-speed analysis was used to determine pressure, density and sound speed along a continuous isentropic compression path. Our peak pressures are comparable to those predicted at the centre of a terrestrial-type exoplanet of three to four Earth masses3, representing the first absolute equation of state measurements for iron at such conditions. These results provide an experiment-based mass-radius relationship for a hypothetical pure iron planet that can be used to evaluate plausible compositional space for large, rocky exoplanets.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yan, F.; Zhao, G.; Fosbury, R. A. E.
Due to stellar rotation, the observed radial velocity of a star varies during the transit of a planet across its surface, a phenomenon known as the Rossiter–McLaughlin (RM) effect. The amplitude of the RM effect is related to the radius of the planet which, because of differential absorption in the planetary atmosphere, depends on wavelength. Therefore, the wavelength-dependent RM effect can be used to probe the planetary atmosphere. We measure for the first time the RM effect of the Earth transiting the Sun using a lunar eclipse observed with the ESO High Accuracy Radial velocity Planet Searcher spectrograph. We analyzemore » the observed RM effect at different wavelengths to obtain the transmission spectrum of the Earth’s atmosphere after the correction of the solar limb-darkening and the convective blueshift. The ozone Chappuis band absorption as well as the Rayleigh scattering features are clearly detectable with this technique. Our observation demonstrates that the RM effect can be an effective technique for exoplanet atmosphere characterization. Its particular asset is that photometric reference stars are not required, circumventing the principal challenge for transmission spectroscopy studies of exoplanet atmospheres using large ground-based telescopes.« less
Constraints on Planetary Companions in the Magnification A=256 Microlensing Event OGLE-2003-BLG-423
NASA Astrophysics Data System (ADS)
Yoo, Jaiyul; DePoy, D. L.; Gal-Yam, A.; Gaudi, B. S.; Gould, A.; Han, C.; Lipkin, Y.; Maoz, D.; Ofek, E. O.; Park, B.-G.; Pogge, R. W.; Mu Fun Collaboration; Szymański, M. K.; Udalski, A.; Szewczyk, O.; Kubiak, M.; Żebruń, K.; Pietrzyński, G.; Soszyński, I.; Wyrzykowski, Ł.; OGLE Collaboration
2004-12-01
We develop a new method of modeling microlensing events based on a Monte Carlo simulation that incorporates both a Galactic model and the constraints imposed by the observed characteristics of the event. The method provides an unbiased way to analyze the event, especially when parameters are poorly constrained by the observed light curve. We apply this method to search for planetary companions of the lens in OGLE-2003-BLG-423, whose maximum magnification Amax=256+/-43 (or Amax=400+/-115 from the light-curve data alone) is the highest among single-lens events ever recorded. The method permits us for the first time to place constraints directly in the planet mass-projected physical separation plane rather than in the mass ratio-Einstein radius plane as was done previously. For example, Jovian-mass companions of main-sequence stars at 2.5 AU are excluded with 80% efficiency. Based in part on observations obtained with the 1.3 m Warsaw Telescope at the Las Campanas Observatory of the Carnegie Institution of Washington.
Modeling mantle convection in the spherical annulus
NASA Astrophysics Data System (ADS)
Hernlund, John W.; Tackley, Paul J.
2008-12-01
Most methods for modeling mantle convection in a two-dimensional (2D) circular annular domain suffer from innate shortcomings in their ability to capture several characteristics of the spherical shell geometry of planetary mantles. While methods such as rescaling the inner and outer radius to reduce anomalous effects in a 2D polar cylindrical coordinate system have been introduced and widely implemented, such fixes may have other drawbacks that adversely affect the outcome of some kinds of mantle convection studies. Here we propose a new approach that we term the "spherical annulus," which is a 2D slice that bisects the spherical shell and is quantitatively formulated at the equator of a spherical polar coordinate system after neglecting terms in the governing equations related to variations in latitude. Spherical scaling is retained in this approximation since the Jacobian function remains proportional to the square of the radius. We present example calculations to show that the behavior of convection in the spherical annulus compares favorably against calculations performed in other 2D annular domains when measured relative to those in a fully three-dimensional (3D) spherical shell.
Restrictions on the detection of the Super-Earth in Solar system
NASA Astrophysics Data System (ADS)
Vidmachenko, A. P.
2018-05-01
For assessment of visibility of possible 9th planet, we use the infrared observations obtained by the "Wide-Field Infrared Survey Explorer". It turned out that the telescope could not see an analog of the planet of the giant Saturn at a distance of up to 30000 AU. This circumstance allowed us to estimate that at distances up to 1000 AU it would be clearly visible planetary body with a radius of more than 11,000 km; that is, a planet with mass of about 10 Earth masses and "earth" density (5520 kg/m3). If we take into account that the density of the "average" TNO differs little from 2000 kg/m3, that the radius of such "Super-Earth" with a mass of about 10 Earth masses - will increase to 19200 km. Then the limit of detection of a possible 9th planet will increase by almost 4 times: up to 4000 AU. And since the "WISE" telescope did not "see" even Saturn, that our estimates unequivocally suggest that there is no "Super-Earth" at a distance up to 1000 AU in the Solar system.
Energetic particle signatures of satellites and rings in Neptune's magnetosphere
NASA Technical Reports Server (NTRS)
Selesnick, R. S.; Stone, E. C.
1992-01-01
The cosmic ray system on Voyager 2 found a trapped radiation environment in Neptune's inner magnetosphere which is controlled primarily by absorption at the rings and satellite surfaces. The intensity of electrons with kinetic energies approximately greater than 1 MeV shows particularly strong and narrow signatures associated with absorption by the satellite 1989N1 at an orbital radius of 4.75 Neptune radii. Closer to the planet are several signatures of the inner satellites and rings. Absorption limits the intensity of the inner radiation belt sufficiently for the maximum intensity to occur outside the orbit of 1989N1 at a magnetic L shell of about 7. Radial profiles of the electron phase space density show that electrons diffuse inward from a source in the outer magnetosphere. Many of the inward-diffusing electrons are absorbed upon reaching a satellite orbital radius, but the finite absorption efficiency allows some of the electrons to pass by unaffected. The locations of the satellite and ring signatures also provide constraints on the nondipolar components of the planetary magnetic field.
On Geomagnetism and Paleomagnetism I
NASA Technical Reports Server (NTRS)
Voorhies, Coerte V.
2000-01-01
A partial description of Earth's broad scale, core-source magnetic field has been developed and tested three ways. The description features an expected, or mean, spatial magnetic power spectrum that is approximately inversely proportional to horizontal wavenumber atop Earth's core. This multipole spectrum describes a magnetic energy range; it is not steep enough for Gubbins' magnetic dissipation range. Temporal variations of core multipole powers about mean values are to be expected and are described statistically, via trial probability distribution functions, instead of deterministically, via trial solution of closed transport equations. The distributions considered here are closed and neither require nor prohibit magnetic isotropy. The description is therefore applicable to, and tested against, both dipole and low degree non-dipole fields. In Part 1, a physical basis for an expectation spectrum is developed and checked. The description is then combined with main field models of twentieth century satellite and surface geomagnetic field measurements to make testable predictions of the radius of Earth's core. The predicted core radius is 0.7% above the 3480 km seismological value. Partial descriptions of other planetary dipole fields are noted.
Kepler-22b: A 2.4 EARTH-RADIUS PLANET IN THE HABITABLE ZONE OF A SUN-LIKE STAR
DOE Office of Scientific and Technical Information (OSTI.GOV)
Borucki, William J.; Koch, David G.; Bryson, Stephen T.
A search of the time-series photometry from NASA's Kepler spacecraft reveals a transiting planet candidate orbiting the 11th magnitude G5 dwarf KIC 10593626 with a period of 290 days. The characteristics of the host star are well constrained by high-resolution spectroscopy combined with an asteroseismic analysis of the Kepler photometry, leading to an estimated mass and radius of 0.970 {+-} 0.060 M{sub Sun} and 0.979 {+-} 0.020 R{sub Sun }. The depth of 492 {+-} 10 ppm for the three observed transits yields a radius of 2.38 {+-} 0.13 Re for the planet. The system passes a battery of testsmore » for false positives, including reconnaissance spectroscopy, high-resolution imaging, and centroid motion. A full BLENDER analysis provides further validation of the planet interpretation by showing that contamination of the target by an eclipsing system would rarely mimic the observed shape of the transits. The final validation of the planet is provided by 16 radial velocities (RVs) obtained with the High Resolution Echelle Spectrometer on Keck I over a one-year span. Although the velocities do not lead to a reliable orbit and mass determination, they are able to constrain the mass to a 3{sigma} upper limit of 124 M{sub Circled-Plus }, safely in the regime of planetary masses, thus earning the designation Kepler-22b. The radiative equilibrium temperature is 262 K for a planet in Kepler-22b's orbit. Although there is no evidence that Kepler-22b is a rocky planet, it is the first confirmed planet with a measured radius to orbit in the habitable zone of any star other than the Sun.« less
HABITABILITY OF EXOMOONS AT THE HILL OR TIDAL LOCKING RADIUS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hinkel, Natalie R.; Kane, Stephen R., E-mail: natalie.hinkel@gmail.com
2013-09-01
Moons orbiting extrasolar planets are the next class of object to be observed and characterized for possible habitability. Like the host-planets to their host-star, exomoons have a limiting radius at which they may be gravitationally bound, or the Hill radius. In addition, they also have a distance at which they will become tidally locked and therefore in synchronous rotation with the planet. We have examined the flux phase profile of a simulated, hypothetical moon orbiting at a distant radius around the confirmed exoplanets {mu} Ara b, HD 28185 b, BD +14 4559 b, and HD 73534 b. The irradiated fluxmore » on a moon at its furthest, stable distance from the planet achieves its largest flux gradient, which places a limit on the flux ranges expected for subsequent (observed) moons closer in orbit to the planet. We have also analyzed the effect of planetary eccentricity on the flux on the moon, examining planets that traverse the habitable zone either fully or partially during their orbit. Looking solely at the stellar contributions, we find that moons around planets that are totally within the habitable zone experience thermal equilibrium temperatures above the runaway greenhouse limit, requiring a small heat redistribution efficiency. In contrast, exomoons orbiting planets that only spend a fraction of their time within the habitable zone require a heat redistribution efficiency near 100% in order to achieve temperatures suitable for habitability. This means that a planet does not need to spend its entire orbit within the habitable zone in order for the exomoon to be habitable. Because the applied systems comprise giant planets around bright stars, we believe that the transit detection method is most likely to yield an exomoon discovery.« less
Allopurinol use in a New Zealand population: prevalence and adherence.
Horsburgh, Simon; Norris, Pauline; Becket, Gordon; Arroll, Bruce; Crampton, Peter; Cumming, Jacqueline; Keown, Shirley; Herbison, Peter
2014-07-01
Allopurinol is effective for the control of gout and its long-term complications when taken consistently. There is evidence that adherence to allopurinol therapy varies across population groups. This may exacerbate differences in the burden of gout on population groups and needs to be accurately assessed. The aim of this study was to describe the prevalence of allopurinol use in a region of New Zealand using community pharmacy dispensing data and to examine the levels of suboptimal adherence in various population groups. Data from all community pharmacy dispensing databases in a New Zealand region were collected for a year covering 2005/2006 giving a near complete picture of dispensings to area residents. Prevalence of allopurinol use in the region by age, sex, ethnicity and socioeconomic position was calculated. Adherence was assessed using the medication possession ratio (MPR), with a MPR of 0.80 indicative of suboptimal adherence. Multiple logistic regression was used to explore variations in suboptimal adherence across population groups. A total of 953 people received allopurinol in the study year (prevalence 3%). Prevalence was higher in males (6%) than in females (1%) and Māori (5%) than non-Māori (3%). The overall MPR during the study was 0.88, with 161 (22%) of patients using allopurinol having suboptimal adherence. Non-Māori were 54% less likely to have suboptimal allopurinol adherence compared to Māori (95% CI 0.30-0.72, p = 0.001). These findings are consistent with those from other studies nationally and internationally and point to the important role for health professionals in improving patient adherence to an effective gout treatment.
Computed tomography of ball pythons (Python regius) in curled recumbency.
Hedley, Joanna; Eatwell, Kevin; Schwarz, Tobias
2014-01-01
Anesthesia and tube restraint methods are often required for computed tomography (CT) of snakes due to their natural tendency to curl up. However, these restraint methods may cause animal stress. The aim of this study was to determine whether the CT appearance of the lungs differs for ball pythons in a curled position vs. tube restraint. Whole body CT was performed on ten clinically healthy ball pythons, first in curled and then in straight positions restrained in a tube. Curved multiplanar reformatted (MPR) lung images from curled position scans were compared with standard MPR lung images from straight position scans. Lung attenuation and thickness were measured at three locations for each scan. Time for positioning and scanning was 12 ± 5 min shorter for curled snakes compared to tube restraint. Lung parenchyma thickness and attenuation declined from cranial to caudal on both straight and curled position images. Mean lung parenchyma thickness was greater in curled images at locations 1 (P = 0.048) and 3 (P = 0.044). Mean lung parenchyma thickness decreased between location 1 and 2 by 86-87% (straight: curled) and between location 1 and 3 by 51-50% (straight: curled). Mean lung attenuation at location 1 was significantly greater on curled position images than tube restraint images (P = 0.043). Findings indicated that CT evaluation of the lungs is feasible for ball pythons positioned in curled recumbency if curved MPR is available. However, lung parenchyma thickness and attenuation in some locations may vary from those acquired using tube restraint. © 2014 American College of Veterinary Radiology.
Petrović, Kosta; Turkalj, Ivan; Stojanović, Sanja; Vucaj-Cirilović, Viktorija; Nikolić, Olivera; Stojiljković, Dragana
2013-08-01
Computerized tomography (CT), especially multidetector CT (MDCT), has had a revolutionary impact in diagnostic in traumatized patients. The aim of the study was to identify and compare the frequency of injuries to bone structures of the thorax displayed with 5-mm-thick axial CT slices and thin-slice (MDCT) examination with the use of 3D reconstructions, primarily multiplanar reformations (MPR). This prospective study included 61 patients with blunt trauma submitted to CT scan of the thorax as initial assessment. The two experienced radiologists inde pendently and separately described the findings for 5-mm-thick axial CT slices (5 mm CT) as in monoslice CT examination; MPR and other 3D reconstructions along with thin-slice axial sections which were available in modern MDCT technologies. After describing thin-slice examination in case of disagreement in the findings, the examiners redescribed thin-slice examination together which was ultimately considered as a real, true finding. No statistically significant difference in interobserver evaluation of 5 mm CT examination was recorded (p > 0.05). Evaluation of fractures of sternum with 5 mm CT and MDCT showed a statistically significant difference (p < 0.05) in favor of better display of injury by MDCT examination. MDCT is a powerful diagnostic tool that can describe higher number of bone fractures of the chest in traumatized patients compared to 5 mm CT, especially in the region of sternum for which a statistical significance was obtained using MPR. Moreover, the importance of MDCT is also set by easier and more accurate determination of the level of bone injury.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dugas, Alexandre; Therasse, Eric; Kauffmann, Claude
2012-08-15
Purpose: To compare different methods measuring abdominal aortic aneurysm (AAA) maximal diameter (Dmax) and its progression on multidetector computed tomography (MDCT) scan. Materials and Methods: Forty AAA patients with two MDCT scans acquired at different times (baseline and follow-up) were included. Three observers measured AAA diameters by seven different methods: on axial images (anteroposterior, transverse, maximal, and short-axis views) and on multiplanar reformation (MPR) images (coronal, sagittal, and orthogonal views). Diameter measurement and progression were compared over time for the seven methods. Reproducibility of measurement methods was assessed by intraclass correlation coefficient (ICC) and Bland-Altman analysis. Results: Dmax, as measuredmore » on axial slices at baseline and follow-up (FU) MDCTs, was greater than that measured using the orthogonal method (p = 0.046 for baseline and 0.028 for FU), whereas Dmax measured with the orthogonal method was greater those using all other measurement methods (p-value range: <0.0001-0.03) but anteroposterior diameter (p = 0.18 baseline and 0.10 FU). The greatest interobserver ICCs were obtained for the orthogonal and transverse methods (0.972) at baseline and for the orthogonal and sagittal MPR images at FU (0.973 and 0.977). Interobserver ICC of the orthogonal method to document AAA progression was greater (ICC = 0.833) than measurements taken on axial images (ICC = 0.662-0.780) and single-plane MPR images (0.772-0.817). Conclusion: AAA Dmax measured on MDCT axial slices overestimates aneurysm size. Diameter as measured by the orthogonal method is more reproducible, especially to document AAA progression.« less
NASA Astrophysics Data System (ADS)
Kumar, Vijay; Mariappan, C. R.
2018-05-01
The Ni doped ZnCo2O4 mesoporous rods were synthesized via a simple hydrothermal approach. Structural properties of the sample were characterized by means of powder X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA), scanning electron microscope and high-resolution transmission electron microscopy. The surface area of mesoporous rods Zn0.8Ni0.2Co2O4 (MPR=0.2) found to be ˜56 m2g-1 and with pore size of ˜10 nm from N2 absorption isotherm data. The crystal structure with lattice parameter of (MPR=0.2) is found to be 8.138 Å. The average crystallite size is found to be 12 nm from XRD data. TGA study reveals the phase formation temperature of sample is 450 °C. Electron microscopic studies reveal that the mesoporous rods are constituted by a plenty of nanosized crystalline particles. The electrochemical properties of the sample was studied by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurement in three-electrode configuration with 6M KOH as the electrolyte. The specific capacitance (Cs) of (MPR=0.2) used as a working electrode found to be 2021 Fg-1 at a scan rate of 2 mVs-1. Furthermore electrochemical cycling stability of mesoporous rods is examined by GCD with different current densities. It shows maximum Cs of 628.75 Fg-1 at 2.5 Ag-1 and retention is found to be ˜96% of its initial value even after 1000 cycles.
Luo, Mingyue; Duan, Chaijie; Qiu, Jianping; Li, Wenru; Zhu, Dongyun; Cai, Wenli
2015-01-01
To evaluate the diagnostic value of multidetector CT (MDCT) and its multiplanar reformation (MPR), volume rendering (VR) and virtual bronchoscopy (VB) postprocessing techniques for primary trachea and main bronchus tumors. Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology. Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6), tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16), extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm-56.0 mm, n = 14; no clear border with right atelectasis, n = 1), longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm-68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1), morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1) and extents (mild, n = 5; moderate, n = 7; severe, n = 19), distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10), and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density without obvious enhancement, n = 1). MDCT and its MPR, VR and VB images have respective advantages and disadvantages. Their combination could complement to each other to accurately detect locations, natures (benignancy, malignancy or low malignancy), and quantities (extramural invasions, longitudinal involvements, extents of luminal stenoses, distances between main bronchus tumors and trachea carinae) of primary trachea and main bronchus tumors with crucial information for surgical treatment, are highly useful diagnostic methods for primary trachea and main bronchus tumors.
The origin of the moon and the single-impact hypothesis III.
Benz, W; Cameron, A G; Melosh, H J
1989-01-01
In previous papers in this series the smoothed particle hydrodynamics method (SPH) has been used to explore the conditions in which a major planetary collision may have been responsible for the formation of the Moon. In Paper II (W. Benz, W.L. Slattery, and A.G.W. Cameron 1987, Icarus 71, 30-45) it was found that the optimum conditions were obtained when the mass ratio of the impactor to the protoearth was 0.136. In the present paper we investigate the importance of the equation of state by running this optimum case several times and varying the equation of state and other related parameters. The two equations of state compared are the Tillotson (used in the previous papers) and the CHART D/CSQ ANEOS. Because of differences in these equations of state, including the fact that different types of rocks were used in association with each, it was not possible to prepare initial planetary models that were comparable in every respect, so several different simulations were necessary in which different planetary parameters were matched between the equations of state. We also used a new version of the SPH code. The results reaffirmed the previous principal conclusions: the collisions produced a disk of rocky material in orbit, with most of the material derived from the impacting object. These results indicate that the equation of state is not a critical factor in determining the amount of material thrown into orbit. This confirms the conclusions of Paper II that gravitational torques, and not pressure gradients, inject the orbiting mass. However, the way this mass is distributed in orbit is affected by the equation of state and the choice of rock material, the Tillotson equation for granite giving slightly larger mean orbital radius for the particles left in orbit than the ANEOS dunite for the same impact parameter. We also find, compared to Paper II, that in all subsequent cases the new SPH code leads to a slightly less extended prelunar accretion disk. We think this is due to the new shape adopted for the kernel. A few additional calculations were made to test the effects of increasing the impact parameter on the calculations, other parameters remaining unchanged. The motivation for this was that solar tides will have reduced the Earth-Moon angular momentum somewhat over the course of time. An increment of 6% in the angular momentum of the collision increases the amount of iron-free material in orbit and its mean orbital radius, but more than that leaves increasing amounts of iron in orbit (the iron has a small mean orbital radius). The debris from the destroyed impacting object tends to form a straight rotating bar which is very effective in transferring angular momentum. If the material near the end of the bar extends well beyond the Roche lobe, it may become unstable against gravitational clumping.
Construction of Martian Interior Model
NASA Astrophysics Data System (ADS)
Zharkov, V. N.; Gudkova, T. V.
2005-09-01
We present the results of extensive numerical modeling of the Martian interior. Yoder et al. in 2003 reported a mean moment of inertia of Mars that was somewhat smaller than the previously used value and the Love number k 2 obtained from observations of solar tides on Mars. These values of k 2 and the mean moment of inertia impose a strong new constraint on the model of the planet. The models of the Martian interior are elastic, while k 2 contains both elastic and inelastic components. We thoroughly examined the problem of partitioning the Love number k 2 into elastic and inelastic components. The information necessary to construct models of the planet (observation data, choice of a chemical model, and the cosmogonic aspect of the problem) are discussed in the introduction. The model of the planet comprises four submodels—a model of the outer porous layer, a model of the consolidated crust, a model of the silicate mantle, and a core model. We estimated the possible content of hydrogen in the core of Mars. The following parameters were varied while constructing the models: the ferric number of the mantle (Fe#) and the sulfur and hydrogen content in the core. We used experimental data concerning the pressure and temperature dependence of elastic properties of minerals and the information about the behavior of Fe(γ-Fe ), FeS, FeH, and their mixtures at high P and T. The model density, pressure, temperature, and compressional and shear velocities are given as functions of the planetary radius. The trial model M13 has the following parameters: Fe#=0.20; 14 wt % of sulfur in the core; 50 mol % of hydrogen in the core; the core mass is 20.9 wt %; the core radius is 1699 km; the pressure at the mantle-core boundary is 20.4 GPa; the crust thickness is 50 km; Fe is 25.6 wt %; the Fe/Si weight ratio is 1.58, and there is no perovskite layer. The model gives a radius of the Martian core within 1600 1820 km while ≥30 mol % of hydrogen is incorporated into the core. When the inelasticity of the Martian interior is taken into account, the Love number k 2 increases by several thousandths; therefore, the model radius of the planetary core increases as well. The prognostic value of the Chandler period of Mars is 199.5 days, including one day due to inelasticity. Finally, we calculated parameters of the equilibrium figure of Mars for the M13 model: J
Kepler-447b: a hot-Jupiter with an extremely grazing transit
NASA Astrophysics Data System (ADS)
Lillo-Box, J.; Barrado, D.; Santos, N. C.; Mancini, L.; Figueira, P.; Ciceri, S.; Henning, Th.
2015-05-01
We present the radial velocity confirmation of the extrasolar planet Kepler-447b, initially detected as a candidate by the Kepler mission. In this work, we analyzeits transit signal and the radial velocity data obtained with the Calar Alto Fiber-fed Echelle spectrograph (CAFE). By simultaneously modeling both datasets, we obtain the orbital and physical properties of the system. According to our results, Kepler-447b is a Jupiter-mass planet (Mp = 1.37+0.48-0.46 MJup), with an estimated radius of Rp = 1.65+0.59-0.56 RJup (uncertainties provided in this work are 3σ unless specified). This translates into a sub-Jupiter density. The planet revolves every ~7.8 days in a slightly eccentric orbit (e = 0.123+0.037-0.036) around a G8V star with detected activity in the Kepler light curve. Kepler-447b transits its host with a large impact parameter (b = 1.076+0.112-0.086), which is one of the few planetary grazing transits confirmed so far and the first in the Kepler large crop of exoplanets. We estimate that only around 20% of the projected planet disk occults the stellar disk. The relatively large uncertainties in the planet radius are due to the large impact parameter and short duration of the transit. Planetary transits with large impact parameters (and in particular grazing transits) can be used to detect and analyze interesting configurations, such as additional perturbing bodies, stellar pulsations, rotation of a non-spherical planet, or polar spot-crossing events. All these scenarios will periodically modify the transit properties (depth, duration, and time of mid-transit), which could be detectable with sufficiently accurate photometry. Short-cadence photometric data (at the 1-min level) would help in the search for these exotic configurations in grazing planetary transits like that of Kepler-447b. This system could then be an excellent target for the forthcoming missions TESS and CHEOPS, which will provide the required photometric precision and cadence to study this type of transit. Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max- Planck-Institut für Astronomie (Heidelberg) and the Instituto de Astrofísica de Andalucía (IAA-CSIC, Granada).
KELT-20b: A Giant Planet with a Period of P ˜ 3.5 days Transiting the V ˜ 7.6 Early A Star HD 185603
NASA Astrophysics Data System (ADS)
Lund, Michael B.; Rodriguez, Joseph E.; Zhou, George; Gaudi, B. Scott; Stassun, Keivan G.; Johnson, Marshall C.; Bieryla, Allyson; Oelkers, Ryan J.; Stevens, Daniel J.; Collins, Karen A.; Penev, Kaloyan; Quinn, Samuel N.; Latham, David W.; Villanueva, Steven, Jr.; Eastman, Jason D.; Kielkopf, John F.; Oberst, Thomas E.; Jensen, Eric L. N.; Cohen, David H.; Joner, Michael D.; Stephens, Denise C.; Relles, Howard; Corfini, Giorgio; Gregorio, Joao; Zambelli, Roberto; Esquerdo, Gilbert A.; Calkins, Michael L.; Berlind, Perry; Ciardi, David R.; Dressing, Courtney; Patel, Rahul; Gagnon, Patrick; Gonzales, Erica; Beatty, Thomas G.; Siverd, Robert J.; Labadie-Bartz, Jonathan; Kuhn, Rudolf B.; Colón, Knicole D.; James, David; Pepper, Joshua; Fulton, Benjamin J.; McLeod, Kim K.; Stockdale, Christopher; Calchi Novati, Sebastiano; DePoy, D. L.; Gould, Andrew; Marshall, Jennifer L.; Trueblood, Mark; Trueblood, Patricia; Johnson, John A.; Wright, Jason; McCrady, Nate; Wittenmyer, Robert A.; Johnson, Samson A.; Sergi, Anthony; Wilson, Maurice; Sliski, David H.
2017-11-01
We report the discovery of KELT-20b, a hot Jupiter transiting a V˜ 7.6 early A star, HD 185603, with an orbital period of P≃ 3.47 days. Archival and follow-up photometry, Gaia parallax, radial velocities, Doppler tomography, and AO imaging were used to confirm the planetary nature of KELT-20b and characterize the system. From global modeling we infer that KELT-20 is a rapidly rotating (v\\sin {I}* ≃ 120 {km} {{{s}}}-1) A2V star with an effective temperature of {T}{eff}={8730}-260+250 K, mass of {M}* ={1.76}-0.20+0.14 {M}⊙ , radius of {R}* ={1.561}-0.064+0.058 {R}⊙ , surface gravity of {log}{g}* ={4.292}-0.020+0.017, and age of ≲ 600 {Myr}. The planetary companion has a radius of {R}P={1.735}-0.075+0.070 {R}{{J}}, a semimajor axis of a={0.0542}-0.0021+0.0014 au, and a linear ephemeris of {{BJD}}{TDB}=2457503.120049+/- 0.000190 +E(3.4741070+/- 0.0000019). We place a 3σ upper limit of ˜ 3.5 {M}{{J}} on the mass of the planet. Doppler tomographic measurements indicate that the planetary orbit normal is well aligned with the projected spin axis of the star (λ =3\\buildrel{\\circ}\\over{.} 4+/- 2\\buildrel{\\circ}\\over{.} 1). The inclination of the star is constrained to 24\\buildrel{\\circ}\\over{.} 4< {I}* < 155\\buildrel{\\circ}\\over{.} 6, implying a three-dimensional spin-orbit alignment of 1\\buildrel{\\circ}\\over{.} 3< \\psi < 69\\buildrel{\\circ}\\over{.} 8. KELT-20b receives an insolation flux of ˜ 8× {10}9 {erg} {{{s}}}-1 {{cm}}-2, implying an equilibrium temperature of of ˜2250 K, assuming zero albedo and complete heat redistribution. Due to the high stellar {T}{eff}, KELT-20b also receives an ultraviolet (wavelength d≤slant 91.2 nm) insolation flux of ˜ 9.1× {10}4 {erg} {{{s}}}-1 {{cm}}-2, possibly indicating significant atmospheric ablation. Together with WASP-33, Kepler-13 A, HAT-P-57, KELT-17, and KELT-9, KELT-20 is the sixth A star host of a transiting giant planet, and the third-brightest host (in V) of a transiting planet.
Irregular Variability In Kepler Photometry
NASA Astrophysics Data System (ADS)
Schlecker, Martin
2016-12-01
The transit method is the most successful tool for exoplanet discovery to date. With more than half of all known exoplanets discovered by Kepler using this method, the mission also revealed a number of objects with dimming events that defy the common explanations, the most prominent being KIC 8462852 aka ``Tabby's star''. I embarked on a search for objects with such irregular transit signatures in the data of K2, the two-wheeled successor mission of Kepler. My method is a combination of automated pre-selection of targets showing downward flux excursions and visual light curve inspection of the selected subset comprising about SI{1.5}% of the initial sample. In addition, I developed a tool to constrain the effective temperature of a planet-hosting star from photometry alone. This software finds broad application in any science case where a photometric spectral type estimate is necessary. I used existing transit models and Bayesian inference to perform a Markov Chain Monte Carlo (MCMC) analysis of a planetary candidate I discovered. This putative gas giant is in a SI{1.32}day circular orbit with an exceptionally tight orbital radius of a ≈ 0.012 AU. My analysis revealed a scaled planetary radius of R_{p}/R_star = 0.0927±0.0026 and an edge-on orientation with an inclination i=89.8+3.0-3.4. EPIC 217393088.01 is one of the closest-orbiting exoplanets ever detected and the first giant planet with such a small orbital radius. An additional major finding of my search is EPIC 220262993, which exhibits aperiodic, asymmetric dips in flux with rapid dimming rates and up to SI{˜25}% depth, lasting for SIrange{2}{4} day. In previous works based on optical and mid-infrared photometry, this object was inconsistently classified as a possible quasar or a white dwarf. We conducted follow-up observations both photometrically with GROND on the MPI/ESO SI{2.2} meter telescope in La Silla (Chile) and spectroscopically with FIRE on the Magellan/Baade SI{6.5} meter telescope. With additional spectroscopy using ESI on the Keck rom{2} SI{10} meter telescope we were able to distinguish between these cases: EPIC 220262993 is a quasar with redshift z=1.42. This is the only known exemplar showing deep dips in flux on such a short time scale.
NASA Technical Reports Server (NTRS)
Suzuki, D.; Bennett, D. P.; Sumi, T.; Bond, I. A.; Rogers, L. A.; Abe, F.; Asakura, Y.; Bhattacharya, A.; Donachie, M.; Freeman, M.;
2016-01-01
We report the results of the statistical analysis of planetary signals discovered in MOA-II microlensing survey alert system events from 2007 to 2012. We determine the survey sensitivity as a function of planet star mass ratio, q, and projected planet star separation, s, in Einstein radius units. We find that the mass-ratio function is not a single power law, but has a change in slope at q approx.10(exp -4), corresponding to approx. 20 Stellar Mass for the median host-star mass of approx. 0.6 M. We find significant planetary signals in 23 of the 1474 alert events that are well-characterized by the MOA-II survey data alone. Data from other groups are used only to characterize planetary signals that have been identified in the MOA data alone. The distribution of mass ratios and separations of the planets found in our sample are well fit by a broken power-law model. We also combine this analysis with the previous analyses of Gould et al. and Cassan et al., bringing the total sample to 30 planets. The unbroken power-law model is disfavored with a p-value of 0.0022, which corresponds to a Bayes factor of 27 favoring the broken power-law model. These results imply that cold Neptunes are likely to be the most common type of planets beyond the snow line.
NASA Astrophysics Data System (ADS)
Lucarini, Valerio
2017-04-01
We review the skill of thirty coupled climate models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) in terms of reproducing properties of the seasonal cycle of precipitation over the major river basins of South and Southeast Asia (Indus, Ganges, Brahmaputra and Mekong) for the historical period (1961-2000). We also present how these models represent the impact of climate change by the end of century (2061-2100) under the extreme scenario RCP8.5. First, we assess the models' ability to reproduce the observed timings of the monsoon onset and the rate of rapid fractional accumulation (RFA) slope — a measure of seasonality within the active monsoon period. Secondly, we apply a threshold-independent seasonality index (SI) — a multiplicative measure of precipitation (P) and extent of its concentration relative to uniform distribution (relative entropy — RE). We apply SI distinctly over the monsoonal precipitation regime (MPR), westerly precipitation regime (WPR) and annual precipitation. For the present climate, neither any single model nor the multi-model mean performs best in all chosen metrics. Models show overall a modest skill in suggesting right timings of the monsoon onset while the RFA slope is generally underestimated. One third of the models fail to capture the monsoon signal over the Indus basin. Mostly, the estimates for SI during WPR are higher than observed for all basins. When looking at MPR, the models typically simulate an SI higher (lower) than observed for the Ganges and Brahmaputra (Indus and Mekong) basins, following the pattern of overestimation (underestimation) of precipitation. Most of the models are biased negative (positive) for RE estimates over the Brahmaputra and Mekong (Indus and Ganges) basins, implying the extent of precipitation concentration for MPR and number of dry days within WPR lower (higher) than observed for these basins. Such skill of the CMIP5 models in representing the present-day monsoonal hydroclimatology poses some caveats on their ability to represent correctly the climate change signal. Nevertheless, considering the majority-model agreement as a measure of robustness for the qualitative scale projected future changes, we find a slightly delayed onset, and a general increase in the RFA slope and in the extent of precipitation concentration (RE) for MPR. Overall, a modest inter-model agreement suggests an increase in the seasonality of MPR and a less intermittent WPR for all basins and for most of the study domain. The SI-based indicator of change in the monsoonal domain suggests its extension westward over northwest India and Pakistan and northward over China. These findings have serious implications for the food and water security of the region in the future. Reference Ul Hasson, S., Pascale, S., Lucarini, V., & Böhner, J. (2016). Seasonal cycle of precipitation over major river basins in South and Southeast Asia: A review of the CMIP5 climate models data for present climate and future climate projections. Atmospheric Research, 180, 42-63. doi:10.1016/j.atmosres.2016.05.008
Change in the chemical composition of infalling gas forming a disk around a protostar.
Sakai, Nami; Sakai, Takeshi; Hirota, Tomoya; Watanabe, Yoshimasa; Ceccarelli, Cecilia; Kahane, Claudine; Bottinelli, Sandrine; Caux, Emmanuel; Demyk, Karine; Vastel, Charlotte; Coutens, Audrey; Taquet, Vianney; Ohashi, Nagayoshi; Takakuwa, Shigehisa; Yen, Hsi-Wei; Aikawa, Yuri; Yamamoto, Satoshi
2014-03-06
IRAS 04368+2557 is a solar-type (low-mass) protostar embedded in a protostellar core (L1527) in the Taurus molecular cloud, which is only 140 parsecs away from Earth, making it the closest large star-forming region. The protostellar envelope has a flattened shape with a diameter of a thousand astronomical units (1 AU is the distance from Earth to the Sun), and is infalling and rotating. It also has a protostellar disk with a radius of 90 AU (ref. 6), from which a planetary system is expected to form. The interstellar gas, mainly consisting of hydrogen molecules, undergoes a change in density of about three orders of magnitude as it collapses from the envelope into the disk, while being heated from 10 kelvin to over 100 kelvin in the mid-plane, but it has hitherto not been possible to explore changes in chemical composition associated with this collapse. Here we report that the unsaturated hydrocarbon molecule cyclic-C3H2 resides in the infalling rotating envelope, whereas sulphur monoxide (SO) is enhanced in the transition zone at the radius of the centrifugal barrier (100 ± 20 AU), which is the radius at which the kinetic energy of the infalling gas is converted to rotational energy. Such a drastic change in chemistry at the centrifugal barrier was not anticipated, but is probably caused by the discontinuous infalling motion at the centrifugal barrier and local heating processes there.
Curkendall, S; Patel, V; Gleeson, M; Campbell, R S; Zagari, M; Dubois, R
2008-10-15
To assess the impact of patient out-of-pocket (OOP) expenditures on adherence and persistence with biologics in patients with rheumatoid arthritis (RA). An inception cohort of RA patients with pharmacy claims for etanercept or adalimumab during 2002-2004 was selected from an insurance claims database of self-insured employer health plans (n=2,285) in the US. Adherence was defined as medication possession ratio (MPR): the proportion of the 365 followup days covered by days supply. Persistence was determined using a survival analysis of therapy discontinuation during followup. Patient OOP cost was measured as the patient's coinsurance and copayments per week of therapy, and as the proportion of the total medication charges paid by the patient. Multivariate linear regression models of MPR and proportional hazards models of persistence were used to estimate the impact of cost, adjusting for insurance type and demographic and clinical variables. Mean +/- SD OOP expenditures averaged $7.84+/-$14.15 per week. Most patients (92%) paid less than $20 OOP for therapy/week. The mean +/- SD MPR was 0.52+/-0.31. Adherence significantly decreased with increased weekly OOP (coeff= -0.0035, P<0.0001) and with a higher proportion of therapy costs paid by patients (coeff= -0.8794, P<0.0001), translating into approximately 1 week of therapy lost per $5.50 increase in weekly OOP. Patients whose weekly cost exceeded $50 were more likely to discontinue than patients with lower costs (hazard ratio 1.58, P<0.001). Most patients pay less than $20/week for biologics, but a small number have high OOP expenses, associated with lower medication compliance. The adverse impact of high OOP costs on adherence, persistence, and outcomes must be considered when making decisions about increasing copayments.
Castelnovo, Luca F; Magnaghi, Valerio; Thomas, Peter
2017-09-28
The role played by progestogens in modulating Schwann cell pathophysiology is well established. Progestogens exert their effects in these cells through both classical genomic and non-genomic mechanisms, the latter mediated by the GABA-A receptor. However, there is evidence that other receptors may be involved. Membrane progesterone receptors (mPRs) are novel 7-transmembrane receptors coupled to G proteins that have been characterized in different tissues and cells, including the central nervous system (CNS). The mPRs were shown to mediate some of progestogens' neuroprotective effects in the CNS, and to be upregulated in glial cells after traumatic brain injury. Based on this evidence, this paper investigated the possible involvement of mPRs in mediating progestogen actions in S42 Schwann cells. All five mPR isoforms and progesterone receptor membrane component 1 (PGRMC1) were detected in Schwann cells, and were present on the cell membrane. Progesterone and the mPR-specific agonist, Org-OD-02-0 (02) bound to these membranes, indicating the presence of functional mPRs. The mPR agonist 02 rapidly increased cell migration in an in vitro assay, suggesting a putative role of mPRs in the nerve regeneration process. Treatment with pertussis toxin and 8-Br-cAMP blocked 02-induced cell migration, suggesting this progestogen action is mediated by activation of an inhibitory G protein, leading to a decrease in intracellular cAMP levels. In contrast, long-term mPR activation led to increased expression levels of myelin associated glycoprotein (MAG). Taken together, these findings show that mPRs are present and active in Schwann cells and have a role in modulating their physiological processes. Copyright © 2017 Elsevier Inc. All rights reserved.
Jacob, Louis; Hamer, Hajo M; Kostev, Karel
2017-10-01
The goal of this study was to analyze adherence to antiepileptic drugs (AED) in children and adolescents treated in pediatric practices in Germany. The present study included patients aged between 2 and 17years who were diagnosed with epilepsy (ICD-10: G40) and had received at least two prescriptions of AED between January 2006 and December 2015 in 243 pediatric practices in Germany. The medication possession ratio (MPR) was used to estimate adherence, and patients with a MPR greater than 80% were considered adherent. The impact of patient and drug characteristics on adherence was analyzed using a multivariate logistic regression model. A total of 5214 patients were included. Mean age was 10.9years (SD=4.9years). The overall MPR was 88.8% (SD=34.1%), and 68.9% of patients were considered adherent. Children aged 5years or younger were more adherent to AED than those aged between 14 and 17years (OR=1.22, 95% CI: 1.07-1.39). Individuals living in western Germany were also found to be more adherent than those living in eastern Germany (OR=1.71, 95% CI: 1.55-1.88). Asthma as a comorbidity (OR=1.59, 95% CI: 1.29-1.96) was positively and attention-deficit hyperactivity disorder (OR=0.81, 95% CI: 0.71-0.93) negatively associated with treatment adherence. Finally, no significant association was found between adherence and the type of AED. Two-thirds of children and adolescents suffering from epilepsy in Germany were adherent to AED. Age, place of residence, and comorbidities were significantly associated with adherence. Copyright © 2017 Elsevier Inc. All rights reserved.
Ramm, Georg; Slot, Jan Willem; James, David E.; Stoorvogel, Willem
2000-01-01
Insulin treatment of fat cells results in the translocation of the insulin-responsive glucose transporter type 4, GLUT4, from intracellular compartments to the plasma membrane. However, the precise nature of these intracellular GLUT4-carrying compartments is debated. To resolve the nature of these compartments, we have performed an extensive morphological analysis of GLUT4-containing compartments, using a novel immunocytochemical technique enabling high labeling efficiency and 3-d resolution of cytoplasmic rims isolated from rat epididymal adipocytes. In basal cells, GLUT4 was localized to three morphologically distinct intracellular structures: small vesicles, tubules, and vacuoles. In response to insulin the increase of GLUT4 at the cell surface was compensated by a decrease in small vesicles, whereas the amount in tubules and vacuoles was unchanged. Under basal conditions, many small GLUT4 positive vesicles also contained IRAP (88%) and the v-SNARE, VAMP2 (57%) but not markers of sorting endosomes (EEA1), late endosomes, or lysosomes (lgp120). A largely distinct population of GLUT4 vesicles (56%) contained the cation-dependent mannose 6-phosphate receptor (CD-MPR), a marker protein that shuttles between endosomes and the trans-Golgi network (TGN). In response to insulin, GLUT4 was recruited both from VAMP2 and CD-MPR positive vesicles. However, while the concentration of GLUT4 in the remaining VAMP2-positive vesicles was unchanged, the concentration of GLUT4 in CD-MPR-positive vesicles decreased. Taken together, we provide morphological evidence indicating that, in response to insulin, GLUT4 is recruited to the plasma membrane by fusion of preexisting VAMP2-carrying vesicles as well as by sorting from the dynamic endosomal-TGN system. PMID:11102509
Hong, Minha; Lee, Won Hye; Moon, Duk Soo; Lee, Sang Min; Chung, Un-Sun; Bahn, Geon Ho
2014-08-01
The purpose of this study was to investigate factors for pharmacotherapy adherence in patients with attention-deficit/hyperactivity disorder (ADHD), with an emphasis on medication possession ratio (MPR). The medical records of 300 clinic-treated youth diagnosed with ADHD were retrospectively reviewed. Patients from March 2005 through January 2009 were diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, 4(th) ed., Text Revision (DSM-IV-TR) and psychological tests. Patients were classified based on the time period from the initial visit to the last visit. We selectively compared the early dropout group within 6 months and the long-term medication group over 36 months (LMed) to identify long-term follow-up characteristics. The short-term follow-up group was divided into an early dropout group without pharmacotherapy commencement (EDO) and a short-term medication group (SMed). Sociodemographic data, psychological test scores, and average MPR of the EDO, SMed, and LMed groups were compared. The number of EDO patients was 69 (23.0%) out of the 300 total patients who were studied, and there were 59 SMed patients (19.3%), and 60 LMed patients (20.0%). Compared with other groups, the EDO group included significantly more younger patients, younger parents, higher maternal education level, lower Short Form Korean-Conners' Parent Rating Scale (K-CPRS) score, and higher full scale and performance intelligence quotient (IQ). There was no significant correlation between the average MPR and the treatment duration. Within the first 6 months of visiting the hospital, >40% of the patients dropped out of treatment regardless of methylphenidate (MPH) use. Twenty percent of the subjects showed adherence to MPH medication after 36 months.
Hsu, Chung-Yuan; Lin, Yu-Sheng; Su, Yu-Jih; Lin, Hsing-Fen; Lin, Ming-Shyan; Syu, Ya-Jhu; Cheng, Tien-Tsai; Yu, Shan-Fu; Chen, Jia-Feng; Chen, Tien-Hsing
2017-12-01
The incidence of thromboembolism in patients with SLE is higher than that in the general population. HCQ, widely used to treat lupus, may have vascular protective effects. The aim of this study was to determine whether long-term HCQ exposure is associated with decreased thromboembolism risk in SLE. We designed a prospective cohort study within an SLE population based on the National Health Insurance Research Database in Taiwan. We divided participants into HCQ and control groups according to HCQ prescription during the first year. These groups were defined by medication possession ratio (MPR) ⩾80% and MPR = 0%, respectively. Patients with an MPR between 0 and 80% were excluded. The primary outcome was a composite vascular event, including acute coronary syndrome, ischaemic stroke, pulmonary embolism, deep vein thrombosis and peripheral arterial disease 1 year after inclusion. We excluded patients from the cohort if they had outcomes within the first year. A total of 8397 patients were eligible for analysis. After propensity-score matching, we included 1946 patients in each group. During a mean follow-up of 7.4 years, the number of events was 139 in the HCQ group (7.1%) and 149 in the control group (7.7%). The risk of vascular events in the HCQ group was similar to that in the control group (hazard ratio = 0.91; 95% CI: 0.72, 1.15). Further subgroup analyses confirmed no statistically significant differences between the groups. Long-term HCQ appears to have no vascular protective effect in patients with SLE. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com
Prevalence and cost of nonadherence with antiepileptic drugs in an adult managed care population.
Davis, Keith L; Candrilli, Sean D; Edin, Heather M
2008-03-01
This study assessed the extent of refill nonadherence with antiepileptic drugs (AEDs) and the potential association between AED nonadherence and health care costs in an adult-managed care population. Retrospective claims from the PharMetrics database were analyzed. Inclusion criteria were: age > or =21, epilepsy diagnosis between January 01, 2000 and March 12, 2005, > or =2 AED prescriptions, and continuous health plan enrollment for > or =6 months prior to and > or =12 months following AED initiation. Adherence was evaluated using the medication possession ratio (MPR). Patients with an MPR <0.8 were classified as nonadherent. Multivariate regression was used to assess the effect of AED nonadherence on annualized cost outcomes. Regression covariates included patient demographics, Charlson Comorbidity Index (CCI), and follow-up duration. Among patients meeting all inclusion criteria (N = 10,892), 58% were female, mean age was 44 years, mean CCI was 0.94, and mean follow-up was 27 months. Mean MPR was 0.78 and 39% of patients were nonadherent. AED nonadherence was associated with an increased likelihood of hospitalization (odds ratio [OR]= 1.110, p = 0.013) and emergency room (ER) admission (OR = 1.479, p < 0.0001), as well as increased inpatient and ER costs of $1,799 and $260 (both p = 0.001), respectively, per patient per year. Outpatient and other ancillary costs were not significantly affected by nonadherence. A large net positive effect of nonadherence on total annual health care costs remained (+$1,466, p = 0.034) despite an offset from reduced prescription drug intake. Adherence with AEDs among adult epilepsy patients is suboptimal and nonadherence appears to be associated with increased health care costs. Efforts to promote AED adherence may lead to cost savings for managed care systems.
Association of Continuity of Primary Care and Statin Adherence.
Warren, James R; Falster, Michael O; Tran, Bich; Jorm, Louisa
2015-01-01
Deficiencies in medication adherence are a major barrier to effectiveness of chronic condition management. Continuity of primary care may promote adherence. We assessed the association of continuity of primary care with adherence to long-term medication as exemplified by statins. We linked data from a prospective study of 267,091 Australians aged 45 years and over to national data sets on prescription reimbursements, general practice claims, hospitalisations and deaths. For participants having a statin dispense within 90 days of study entry, we computed medication possession ratio (MPR) and usual provider continuity index (UPI) for the subsequent two years. We used multivariate Poisson regression to calculate the relative risk (RR) and 95% confidence interval (CI) for the association between tertiles of UPI and MPR adjusted for socio-demographic and health-related patient factors, including age, gender, remoteness of residence, smoking, alcohol intake, fruit and vegetable intake, physical activity, prior heart disease and speaking a language other than English at home. We performed a comparison approach using propensity score matching on a subset of the sample. 36,144 participants were eligible and included in the analysis among whom 58% had UPI greater than 75%. UPI was significantly associated with 5% increased MPR for statin adherence (95% CI 1.04-1.06) for highest versus lowest tertile. Dichotomised analysis using a cut-off of UPI at 75% showed a similar effect size. The association between UPI and statin adherence was independent of socio-demographic and health-related factors. Stratification analyses further showed a stronger association among those who were new to statins (RR 1.33, 95% CI 1.15-1.54). Greater continuity of care has a positive association with medication adherence for statins which is independent of socio-demographic and health-related factors.
Hero, Christel; Eliasson, Björn; Franzén, Stefan; Svensson, Ann‐Marie; Miftaraj, Mervete; Gudbjörnsdottir, Soffia; Eeg‐Olofsson, Katarina; Andersson Sundell, Karolina
2017-01-01
Abstract Purpose This study aimed to describe and compare refill adherence and persistence to lipid‐lowering medicines in patients with type 2 diabetes by previous cardiovascular disease (CVD). Methods We followed 97 595 patients (58% men; 23% with previous CVD) who were 18 years of age or older when initiating lipid‐lowering medicines in 2007–2010 until first fill of multi‐dose dispensed medicines, death, or 3 years. Using personal identity numbers, we linked individuals' data from the Swedish Prescribed Drug Register, the Swedish National Diabetes Register, the National Patient Register, the Cause of Death Register, and the Longitudinal Integration Database for Health Insurance and Labour Market Studies. We assessed refill adherence using the medication possession ratio (MPR) and the maximum gap method, and measured persistence from initiation to discontinuation of treatment or until 3 years after initiation. We analyzed differences in refill adherence and persistence by previous CVD in multiple regression models, adjusted for socioeconomic status, concurrent medicines, and clinical characteristics. Results The mean age of the study population was 64 years, 80% were born in Sweden, and 56% filled prescriptions for diabetes medicines. Mean MPR was 71%, 39% were adherent according to the maximum gap method, and mean persistence was 758 days. Patients with previous CVD showed higher MPR (3%) and lower risk for discontinuing treatment (12%) compared with patients without previous CVD (P < 0.0001). Conclusions Patients with previous CVD were more likely to be adherent to treatment and had lower risk for discontinuation compared with patients without previous CVD. PMID:28799214
Saraste, Antti; Ukkonen, Heikki; Varis, Antti; Vasankari, Tuija; Tunturi, Satu; Taittonen, Markku; Rautakorpi, Pirkka; Luotolahti, Matti; Airaksinen, K E Juhani; Knuuti, Juhani
2015-04-01
Epidural spinal cord stimulation (SCS) provides symptom relief in refractory angina pectoris, but its mechanism of action remains incompletely understood. We studied effects of short-term SCS therapy on myocardial ischaemia tolerance, myocardial perfusion reserve (MPR), and endothelium-mediated vasodilatation induced by cold pressor test (CPT) in patients with refractory angina pectoris. We prospectively recruited 18 patients with refractory angina pectoris and studied them after implantation of SCS device at baseline before starting the therapy and after 3 weeks of continuous SCS therapy. Myocardial ischaemia was evaluated by dobutamine stress echocardiography. Global and regional myocardial blood flow (MBF) were measured using positron emission tomography and (15)O-water at rest, during adenosine stress, and in response to CPT. Systemic haemodynamics were comparable before and after 3 weeks of SCS at rest, during adenosine stress and during CPT. Appearance of angina pectoris induced by dobutamine stress was delayed after SCS therapy. Global MPR increased (P = 0.02) from 1.7 ± 0.6 at baseline to 2.0 ± 0.6 after 3-week SCS therapy. This was associated with a significant reduction in global MBF at rest and increase in MBF induced by adenosine in the ischaemic regions. Global MBF response to CPT was improved after SCS (0.27 ± 0.20 vs. 0.40 ± 0.15, P = 0.03). Short-term SCS therapy improved myocardial ischaemia tolerance, absolute MPR, and endothelium-mediated vasomotor function in refractory angina pectoris, indicating that this therapy can alleviate myocardial perfusion abnormalities in advanced CAD. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.
Diagnostic validity of hematologic parameters in evaluation of massive pulmonary embolism.
Ates, Hale; Ates, Ihsan; Kundi, Harun; Yilmaz, Fatma Meric
2017-09-01
The aim of this study was to determine the hematologic parameter with the highest diagnostic differentiation in the identification of massive acute pulmonary embolism (APE). A retrospective study was performed on patients diagnosing with APE between June 2014 and June 2016. All radiological and laboratory parameters of patients were scanned through the electronic information management system of the hospital. PLR was obtained from the ratio of platelet count to lymphocyte count, NLR was obtained from the ratio of neutrophil count to lymphocyte count, WMR was obtained from white blood cell in mean platelet volume ratio, MPR was obtained from the ratio of mean platelet volume to platelet count, and RPR was obtained from the ratio of red distribution width to platelet count. Six hundred and thirty-nine patients consisting of 292 males (45.7%) and 347 females (54.3%) were included in the research. Independent predictors of massive risk as compared to sub-massive group were; pulmonary arterial systolic pressure (PASP) (OR=1.40; P=.001), PLR (OR=1.59; P<.001), NLR (OR=2.22; P<.001), WMR (OR=1.22; P<.001), MPR (OR=0.33; P<.001), and RPR (OR=0.68; P<.001). Upon evaluation of the diagnostic differentiation of these risk factors for massive APE by employing receiver operating characteristic curve analysis, it was determined that PLR (AUC±SE=0.877±0.015; P<.001), and NLR (AUC±SE=0.893±0.013; P<.001) have similar diagnostic differentiation in diagnosing massive APE and these two parameters are superior over PASP, MPR, WMR, and RPR. We determined that the levels of NLR and PLR are superior to other parameters in the determination of clinical severity in APE cases. © 2016 Wiley Periodicals, Inc.
Steed, Molly E; Hall, Ashley D; Salimnia, Hossein; Kaatz, Glenn W; Kaye, Keith S; Rybak, Michael J
2013-12-01
Despite studies examining daptomycin non-susceptible (DNS) Staphylococcus aureus, examination of the stability and population profiles is limited. The objective was to evaluate the stability, population profiles, and daptomycin activity against DNS isolates. The stability of 12 consecutive clinical DNS strains was evaluated by minimum inhibitory concentration (MICs) and population analysis profiles before and after 5 days of serial passage. Two pairs of DNS S. aureus having the same daptomycin MIC but different daptomycin population profiles were evaluated via an in vitro pharmacokinetic/pharmacodynamic (PK/PD) model of simulated endocardial vegetations for 96 h against daptomycin 6 and 10 mg/kg/day. The sequence of mprF was determined for these isolates before and after 96 h of daptomycin exposure in the in vitro PK/PD model. Daptomycin MIC values were 2-4 mg/L (via Microscan) for the 12 clinical isolates; 9 were confirmed DNS and 3 were within 1 tube dilution of Microscan (daptomycin MIC 1 mg/L). All were stable to serial passage. There was variation in the isolates susceptibility to daptomycin on population analysis (daptomycin population AUC 14.01-26.85). The killing patterns of daptomycin 6 and 10 mg/kg/day differed between isolates with a left-shift and right-shift population profile to daptomycin. Two strains developed additional mprF mutations during daptomycin exposure in the in vitro PK/PD model resulting in P314L, L826F, S337L and a novel Q326Stop mutation. The collection of DNS isolates was stable and displayed variation in susceptibility to daptomycin on population profile. Further research examining this clinical relevance is warranted.
Anam, Khairul; Al-Jumaily, Adel
2017-01-01
The success of myoelectric pattern recognition (M-PR) mostly relies on the features extracted and classifier employed. This paper proposes and evaluates a fast classifier, extreme learning machine (ELM), to classify individual and combined finger movements on amputees and non-amputees. ELM is a single hidden layer feed-forward network (SLFN) that avoids iterative learning by determining input weights randomly and output weights analytically. Therefore, it can accelerate the training time of SLFNs. In addition to the classifier evaluation, this paper evaluates various feature combinations to improve the performance of M-PR and investigate some feature projections to improve the class separability of the features. Different from other studies on the implementation of ELM in the myoelectric controller, this paper presents a complete and thorough investigation of various types of ELMs including the node-based and kernel-based ELM. Furthermore, this paper provides comparisons of ELMs and other well-known classifiers such as linear discriminant analysis (LDA), k-nearest neighbour (kNN), support vector machine (SVM) and least-square SVM (LS-SVM). The experimental results show the most accurate ELM classifier is radial basis function ELM (RBF-ELM). The comparison of RBF-ELM and other well-known classifiers shows that RBF-ELM is as accurate as SVM and LS-SVM but faster than the SVM family; it is superior to LDA and kNN. The experimental results also indicate that the accuracy gap of the M-PR on the amputees and non-amputees is not too much with the accuracy of 98.55% on amputees and 99.5% on the non-amputees using six electromyography (EMG) channels. Copyright © 2016 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Mizukami, N.; Clark, M. P.; Newman, A. J.; Wood, A.; Gutmann, E. D.
2017-12-01
Estimating spatially distributed model parameters is a grand challenge for large domain hydrologic modeling, especially in the context of hydrologic model applications such as streamflow forecasting. Multi-scale Parameter Regionalization (MPR) is a promising technique that accounts for the effects of fine-scale geophysical attributes (e.g., soil texture, land cover, topography, climate) on model parameters and nonlinear scaling effects on model parameters. MPR computes model parameters with transfer functions (TFs) that relate geophysical attributes to model parameters at the native input data resolution and then scales them using scaling functions to the spatial resolution of the model implementation. One of the biggest challenges in the use of MPR is identification of TFs for each model parameter: both functional forms and geophysical predictors. TFs used to estimate the parameters of hydrologic models typically rely on previous studies or were derived in an ad-hoc, heuristic manner, potentially not utilizing maximum information content contained in the geophysical attributes for optimal parameter identification. Thus, it is necessary to first uncover relationships among geophysical attributes, model parameters, and hydrologic processes (i.e., hydrologic signatures) to obtain insight into which and to what extent geophysical attributes are related to model parameters. We perform multivariate statistical analysis on a large-sample catchment data set including various geophysical attributes as well as constrained VIC model parameters at 671 unimpaired basins over the CONUS. We first calibrate VIC model at each catchment to obtain constrained parameter sets. Additionally, parameter sets sampled during the calibration process are used for sensitivity analysis using various hydrologic signatures as objectives to understand the relationships among geophysical attributes, parameters, and hydrologic processes.
Naresh, Nivedita K; Chen, Xiao; Roy, Rene J; Antkowiak, Patrick F; Annex, Brian H; Epstein, Frederick H
2015-03-01
Gene-modified mice may be used to elucidate molecular mechanisms underlying abnormal myocardial blow flow (MBF). We sought to develop a quantitative myocardial perfusion imaging technique for mice and to test the hypothesis that myocardial perfusion reserve (MPR) is reduced in a mouse model of diet-induced obesity (DIO). A dual-contrast saturation-recovery sequence with ky -t undersampling and a motion-compensated compressed sensing reconstruction algorithm was developed for first-pass MRI on a small-bore 7 Tesla system. Control mice were imaged at rest and with the vasodilators ATL313 and Regadenoson (n = 6 each). In addition, we imaged mice fed a high-fat diet (HFD) for 24 weeks. In control mice, MBF was 5.7 ± 0.8 mL/g/min at rest and it increased to 11.8 ± 0.6 mL/g/min with ATL313 and to 10.4 ± 0.3 mL/g/min with Regadenoson. In HFD mice, we detected normal resting MBF (5.6 ± 0.4 versus 5.0 ± 0.3 on control diet), low MBF at stress (7.7 ± 0.4 versus 10.4 ± 0.3 on control diet, P < 0.05), and reduced MPR (1.4 ± 0.2 versus 2.0 ± 0.3 on control diet, P < 0.05). Accelerated dual-contrast first-pass MRI with motion-compensated compressed sensing provides spatiotemporal resolution suitable for measuring MBF in free-breathing mice, and detected reduced MPR in DIO mice. These techniques may be used to study molecular mechanisms that underlie abnormal myocardial perfusion. © 2014 Wiley Periodicals, Inc.
Naresh, Nivedita K.; Chen, Xiao; Roy, Rene J.; Antkowiak, Patrick F.; Annex, Brian H.; Epstein, Frederick H.
2014-01-01
Background Gene-modified mice may be used to elucidate molecular mechanisms underlying abnormal myocardial blood flow (MBF). We sought to develop a quantitative myocardial perfusion imaging technique for mice and to test the hypothesis that myocardial perfusion reserve (MPR) is reduced in a mouse model of diet-induced obesity (DIO). Methods A dual-contrast saturation-recovery sequence with ky-t undersampling and a motion-compensated compressed sensing reconstruction algorithm was developed for first-pass MRI on a small-bore 7T system. Control mice were imaged at rest and with the vasodilators ATL313 and Regadenoson (n=6 each). In addition, we imaged mice fed a high-fat diet (HFD) for 24 weeks. Results In control mice, MBF was 5.7±0.8 ml/g/min at rest and it increased to 11.8±0.6 ml/g/min with ATL313 and to 10.4±0.3 ml/g/min with Regadenoson. In HFD mice we detected normal resting MBF (5.6±0.4 vs. 5.0±0.3 on control diet), low MBF at stress (7.7±0.4 vs. 10.4±0.3 on control diet, p<0.05), and reduced MPR (1.4±0.2 vs. 2.0±0.3 on control diet, p<0.05). Conclusions Accelerated dual-contrast first-pass MRI with motion-compensated compressed sensing provides spatiotemporal resolution suitable for measuring MBF in free-breathing mice, and detected reduced MPR in DIO mice. These techniques may be used to study molecular mechanisms that underlie abnormal myocardial perfusion. PMID:24760707
Rossby wave instability in astrophysical discs
NASA Astrophysics Data System (ADS)
Lovelace, R. V. E.; Romanova, M. M.
2014-08-01
A brief review is given of the Rossby wave instability in astrophysical discs. In non-self-gravitating discs, around for example a newly forming stars, the instability can be triggered by an axisymmetric bump at some radius r0 in the disc surface mass-density. It gives rise to exponentially growing non-axisymmetric perturbation (\\propto \\exp \\,({ { i}}m\\phi ) , m = 1,2,…) in the vicinity of r0 consisting of anticyclonic vortices. These vortices are regions of high pressure and consequently act to trap dust particles which in turn can facilitate planetesimal growth in proto-planetary discs. The Rossby vortices in the discs around stars and black holes may cause the observed quasi-periodic modulations of the disc's thermal emission.
NASA Astrophysics Data System (ADS)
Denis, C.; Ibrahim, A.
Self-consistent parametric earth models are discussed in terms of a flexible numerical code. The density profile of each layer is represented as a polynomial, and figures of gravity, mass, mean density, hydrostatic pressure, and moment of inertia are derived. The polynomial representation also allows computation of the first order flattening of the internal strata of some models, using a Gauss-Legendre quadrature with a rapidly converging iteration technique. Agreement with measured geophysical data is obtained, and algorithm for estimation of the geometric flattening for any equidense surface identified by its fractional radius is developed. The program can also be applied in studies of planetary and stellar models.
NASA Technical Reports Server (NTRS)
Leake, M. A.
1982-01-01
Various linear and areal measurements of Mercury's first quadrant which were used in geological map preparation, map analysis, and statistical surveys of crater densities are discussed. Accuracy of each method rests on the determination of the scale of the photograph, i.e., the conversion factor between distances on the planet (in km) and distances on the photograph (in cm). Measurement errors arise due to uncertainty in Mercury's radius, poor resolution, poor coverage, high Sun angle illumination in the limb regions, planetary curvature, limited precision in measuring instruments, and inaccuracies in the printed map scales. Estimates are given for these errors.
[Fetal neurosonography using 3-dimensional multiplanar sonography].
Chaoui, R; Heling, K S; Kainer, F; Karl, K
2012-04-01
This review focuses on the examination of the fetal brain, using three-dimensional (3D) ultrasound and the multiplanar rendering mode (MPR). The routine examination of the brain is achieved with axial planes but a dedicated fetal neurosonogram requires additional coronal and sagittal views, in order to provide a complete view of the different brain structures. Because these planes are difficult to obtain under many conditions, the present paper shows how 3D MPR allows one to obtain 1 or multiple reconstructed images from a digital volume. The display can be either as orthogonal planes, tomographic planes with parallel slices or as one single plane of the region of interest, which can be selected by the examiner. This approach allows easily the demonstration of the corpus callosum, the cerebellar vermis, the three-horn view, the foetal hippocampus and other regions. In addition, early neurosonography of the developing brain from the 7th week of pregnancy onwards can be achieved. © Georg Thieme Verlag KG Stuttgart · New York.
Modeling and control for closed environment plant production systems
NASA Technical Reports Server (NTRS)
Fleisher, David H.; Ting, K. C.; Janes, H. W. (Principal Investigator)
2002-01-01
A computer program was developed to study multiple crop production and control in controlled environment plant production systems. The program simulates crop growth and development under nominal and off-nominal environments. Time-series crop models for wheat (Triticum aestivum), soybean (Glycine max), and white potato (Solanum tuberosum) are integrated with a model-based predictive controller. The controller evaluates and compensates for effects of environmental disturbances on crop production scheduling. The crop models consist of a set of nonlinear polynomial equations, six for each crop, developed using multivariate polynomial regression (MPR). Simulated data from DSSAT crop models, previously modified for crop production in controlled environments with hydroponics under elevated atmospheric carbon dioxide concentration, were used for the MPR fitting. The model-based predictive controller adjusts light intensity, air temperature, and carbon dioxide concentration set points in response to environmental perturbations. Control signals are determined from minimization of a cost function, which is based on the weighted control effort and squared-error between the system response and desired reference signal.
New MPRu instrument for neutron emission spectroscopy at JET
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sjoestrand, H.; Giacomelli, L.; Andersson Sunden, E.
The MPRu is an upgrade of the magnetic proton recoil (MPR) neutron spectrometer that has been used for 14 MeV DT neutron measurements at JET during the DTE1 (1997) and TTE (2003) campaigns. In this contribution the principles of the MPR and its upgrade will be presented. The MPRu allows measurements of the full range of fusion relevant neutron energies, 1.5-18 MeV, including the 14 MeV DT neutrons, now with significantly reduced background, and also new high-quality measurements of the 2.5 MeV DD neutron component. This improvement is made possible by the use of a new proton recoil detector inmore » combination with custom-built transient recorder cards. The importance of these instrumental improvements for extending the use of the MPRu in diagnosis of D and DT plasmas will be discussed. Results from the first 2.5 MeV measurements performed with the MPRu during JET high level commissioning in April 2006 are presented.« less
Injury among stimulant-treated youth with ADHD.
Marcus, Steven C; Wan, George J; Zhang, Huabin F; Olfson, Mark
2008-07-01
To assess risk factors for injury among children and adolescents treated with stimulants for ADHD. An analysis was performed of pharmacy and service claims data from 2000-2003 California Medicaid (Medi-Cal) focusing on children and adolescents ages 6 to 17 years who initiated stimulant therapy for ADHD. Bivariate and multivariate analyses were performed to examine associations of demographic and clinical characteristics with injury. In a Cox proportional hazard model that controlled for background patient characteristics, patients ages 13 to 17 years, male gender, prescription of anxiolytic/hypnotic medications, and diagnosis of a mood disorder were each independently associated with increased risk of injury, whereas African American ancestry and other minority racial/ethnic ancestry were associated with lower risk. Youth with high stimulant medication possession ratios (MPR) had a nonsignificantly lower risk of injury as compared to those with a low stimulant MPR. These findings reveal several patient characteristics that may be associated with increased risk of injury among children and adolescents treated for ADHD.
Compositional mapping of planetary moons by mass spectrometry of dust ejecta
NASA Astrophysics Data System (ADS)
Postberg, Frank; Grün, Eberhard; Horanyi, Mihaly; Kempf, Sascha; Krüger, Harald; Schmidt, Jürgen; Spahn, Frank; Srama, Ralf; Sternovsky, Zoltan; Trieloff, Mario
2011-11-01
Classical methods to analyze the surface composition of atmosphereless planetary objects from an orbiter are IR and gamma ray spectroscopy and neutron backscatter measurements. The idea to analyze surface properties with an in-situ instrument has been proposed by Johnson et al. (1998). There, it was suggested to analyze Europa's thin atmosphere with an ion and neutral gas spectrometer. Since the atmospheric components are released by sputtering of the moon's surface, they provide a link to surface composition. Here we present an improved, complementary method to analyze rocky or icy dust particles as samples of planetary objects from which they were ejected. Such particles, generated by the ambient meteoroid bombardment that erodes the surface, are naturally present on all atmosphereless moons and planets. The planetary bodies are enshrouded in clouds of ballistic dust particles, which are characteristic samples of their surfaces. In situ mass spectroscopic analysis of these dust particles impacting onto a detector of an orbiting spacecraft reveals their composition. Recent instrumental developments and tests allow the chemical characterization of ice and dust particles encountered at speeds as low as 1 km/s and an accurate reconstruction of their trajectories. Depending on the sampling altitude, a dust trajectory sensor can trace back the origin of each analyzed grain with about 10 km accuracy at the surface. Since the detection rates are of the order of thousand per orbit, a spatially resolved mapping of the surface composition can be achieved. Certain bodies (e.g., Europa) with particularly dense dust clouds, could provide impact statistics that allow for compositional mapping even on single flybys. Dust impact velocities are in general sufficiently high at orbiters about planetary objects with a radius >1000 km and with only a thin or no atmosphere. In this work we focus on the scientific benefit of a dust spectrometer on a spacecraft orbiting Earth's Moon as well as Jupiter's Galilean satellites. This 'dust spectrometer' approach provides key chemical and isotopic constraints for varying provinces or geological formations on the surfaces, leading to better understanding of the body's geological evolution.
Lammer, Helmut; Holmström, Mats; Panchenko, Mykhaylo; Odert, Petra; Erkaev, Nikolai V.; Leitzinger, Martin; Khodachenko, Maxim L.; Kulikov, Yuri N.; Güdel, Manuel; Hanslmeier, Arnold
2013-01-01
Abstract We studied the interactions between the stellar wind plasma flow of a typical M star, such as GJ 436, and the hydrogen-rich upper atmosphere of an Earth-like planet and a “super-Earth” with a radius of 2 REarth and a mass of 10 MEarth, located within the habitable zone at ∼0.24 AU. We investigated the formation of extended atomic hydrogen coronae under the influences of the stellar XUV flux (soft X-rays and EUV), stellar wind density and velocity, shape of a planetary obstacle (e.g., magnetosphere, ionopause), and the loss of planetary pickup ions on the evolution of hydrogen-dominated upper atmospheres. Stellar XUV fluxes that are 1, 10, 50, and 100 times higher compared to that of the present-day Sun were considered, and the formation of high-energy neutral hydrogen clouds around the planets due to the charge-exchange reaction under various stellar conditions was modeled. Charge-exchange between stellar wind protons with planetary hydrogen atoms, and photoionization, lead to the production of initially cold ions of planetary origin. We found that the ion production rates for the studied planets can vary over a wide range, from ∼1.0×1025 s−1 to ∼5.3×1030 s−1, depending on the stellar wind conditions and the assumed XUV exposure of the upper atmosphere. Our findings indicate that most likely the majority of these planetary ions are picked up by the stellar wind and lost from the planet. Finally, we estimated the long-time nonthermal ion pickup escape for the studied planets and compared them with the thermal escape. According to our estimates, nonthermal escape of picked-up ionized hydrogen atoms over a planet's lifetime within the habitable zone of an M dwarf varies between ∼0.4 Earth ocean equivalent amounts of hydrogen (EOH) to <3 EOH and usually is several times smaller in comparison to the thermal atmospheric escape rates. Key Words: Stellar activity—Low-mass stars—Early atmospheres—Earth-like exoplanets—Energetic neutral atoms—Ion escape—Habitability. Astrobiology 13, 1030–1048. PMID:24283926
Kislyakova, Kristina G; Lammer, Helmut; Holmström, Mats; Panchenko, Mykhaylo; Odert, Petra; Erkaev, Nikolai V; Leitzinger, Martin; Khodachenko, Maxim L; Kulikov, Yuri N; Güdel, Manuel; Hanslmeier, Arnold
2013-11-01
We studied the interactions between the stellar wind plasma flow of a typical M star, such as GJ 436, and the hydrogen-rich upper atmosphere of an Earth-like planet and a "super-Earth" with a radius of 2 R(Earth) and a mass of 10 M(Earth), located within the habitable zone at ∼0.24 AU. We investigated the formation of extended atomic hydrogen coronae under the influences of the stellar XUV flux (soft X-rays and EUV), stellar wind density and velocity, shape of a planetary obstacle (e.g., magnetosphere, ionopause), and the loss of planetary pickup ions on the evolution of hydrogen-dominated upper atmospheres. Stellar XUV fluxes that are 1, 10, 50, and 100 times higher compared to that of the present-day Sun were considered, and the formation of high-energy neutral hydrogen clouds around the planets due to the charge-exchange reaction under various stellar conditions was modeled. Charge-exchange between stellar wind protons with planetary hydrogen atoms, and photoionization, lead to the production of initially cold ions of planetary origin. We found that the ion production rates for the studied planets can vary over a wide range, from ∼1.0×10²⁵ s⁻¹ to ∼5.3×10³⁰ s⁻¹, depending on the stellar wind conditions and the assumed XUV exposure of the upper atmosphere. Our findings indicate that most likely the majority of these planetary ions are picked up by the stellar wind and lost from the planet. Finally, we estimated the long-time nonthermal ion pickup escape for the studied planets and compared them with the thermal escape. According to our estimates, nonthermal escape of picked-up ionized hydrogen atoms over a planet's lifetime within the habitable zone of an M dwarf varies between ∼0.4 Earth ocean equivalent amounts of hydrogen (EO(H)) to <3 EO(H) and usually is several times smaller in comparison to the thermal atmospheric escape rates.
K2-139 b: a low-mass warm Jupiter on a 29-d orbit transiting an active K0 V star
NASA Astrophysics Data System (ADS)
Barragán, O.; Gandolfi, D.; Smith, A. M. S.; Deeg, H. J.; Fridlund, M. C. V.; Persson, C. M.; Donati, P.; Endl, M.; Csizmadia, Sz; Grziwa, S.; Nespral, D.; Hatzes, A. P.; Cochran, W. D.; Fossati, L.; Brems, S. S.; Cabrera, J.; Cusano, F.; Eigmüller, Ph; Eiroa, C.; Erikson, A.; Guenther, E.; Korth, J.; Lorenzo-Oliveira, D.; Mancini, L.; Pätzold, M.; Prieto-Arranz, J.; Rauer, H.; Rebollido, I.; Saario, J.; Zakhozhay, O. V.
2018-04-01
We announce the discovery of K2-139 b (EPIC 218916923 b), a transiting warm-Jupiter (Teq = 547 ± 25 K) on a 29-d orbit around an active (log R^' _HK = -4.46 ± 0.06) K0 V star in K2 Campaign 7. We derive the system's parameters by combining the K2 photometry with ground-based follow-up observations. With a mass of 0.387 _{ - 0.075 } ^ {+ 0.083 }MJ and radius of 0.808 _{ - 0.033 } ^ {+ 0.034 }RJ, K2-139 b is one of the transiting warm Jupiters with the lowest mass known to date. The planetary mean density of 0.91 _{ - 0.20} ^ { + 0.24 } g cm-3can be explained with a core of ˜50 M⊕. Given the brightness of the host star (V = 11.653 mag), the relatively short transit duration (˜5 h), and the expected amplitude of the Rossiter-McLaughlin effect (˜25m s-1), K2-139 is an ideal target to measure the spin-orbit angle of a planetary system hosting a warm Jupiter.
SIMP J013656.5+093347 Is Likely a Planetary-mass Object in the Carina-Near Moving Group
NASA Astrophysics Data System (ADS)
Gagné, Jonathan; Faherty, Jacqueline K.; Burgasser, Adam J.; Artigau, Étienne; Bouchard, Sandie; Albert, Loïc; Lafrenière, David; Doyon, René; Bardalez Gagliuffi, Daniella C.
2017-05-01
We report on the discovery that the nearby (˜6 pc) photometrically variable T2.5 dwarf SIMP J013656.5+093347 is a likely member of the ˜200 Myr old Carina-Near moving group with a probability of >99.9% based on its full kinematics. Our v\\sin I measurement of 50.9 ± 0.8 km s-1 combined with the known rotation period inferred from variability measurements provide a lower limit of 1.01 ± 0.02 {R}{Jup} on the radius of SIMP 0136+0933, an independent verification that it must be younger than ˜950 Myr, according to evolution models. We estimate a field interloper probability of 0.2% based on the density of field T0-T5 dwarfs. At the age of Carina-Near, SIMP 0136+0933 has an estimated mass of 12.7 ± 1.0 {M}{Jup} and is predicted to have burned roughly half of its original deuterium. SIMP 0136+0933 is the closest known young moving group member to the Sun and is one of only a few known young T dwarfs, making it an important benchmark for understanding the atmospheres of young planetary-mass objects.
The Stability of Tidal Equilibrium for Hierarchical Star-Planet-Moon Systems
NASA Astrophysics Data System (ADS)
Adams, Fred C.
2018-04-01
Motivated by the current search for exomoons, this talk considers the stability of tidal equilibrium for hierarchical three-body systems containing a star, a planet, and a moon. In this treatment, the energy and angular momentum budgets include contributions from the planetary orbit, lunar orbit, stellar spin, planetary spin, and lunar spin. The goal is to determine the optimized energy state of the system subject to the constraint of constant angular momentum. Due to the lack of a closed form solution for the full three-body problem, however, we must use use an approximate description of the orbits. We first consider the Keplerian limit and find that the critical energy states are saddle points, rather than minima, so that these hierarchical systems have no stable tidal equilibrium states. We then generalize the calculation so that the lunar orbit is described by a time-averaged version of the circular restricted three-body problem. In this latter case, the critical energy state is a shallow minimum, so that a tidal equilibrium state exists. In both cases, however, the lunar orbit for the critical point lies outside the boundary (roughly half the Hill radius) where (previous) numerical simulations indicate dynamical instability.
Gravity results from Pioneer 10 Doppler data. [during Jupiter encounter
NASA Technical Reports Server (NTRS)
Anderson, J. D.; Null, G. W.; Wong, S. K.
1974-01-01
Two-way Doppler data received from Pioneer 10 during its encounter with Jupiter have been analyzed, and preliminary results have been obtained on the mass and the gravity field of Jupiter and on the masses of the four Galilean satellites. The ratios of the masses of the satellites to the mass of Jupiter are approximately 0.00004696 for Io, 0.00002565 for Europa, 0.00007845 for Ganymede, and 0.00005603 for Callisto (all error estimates presented in this paper are standard errors; those for Pioneer 10 represent our evaluation of the real errors as distinguished from formal errors). The ratio of the mass of the sun to the mass of the Jupiter system is about 1047.342, which is in good agreement with recent determinations from the motions of asteroids. The second- and fourth-degree zonal harmonic coefficients in the gravity field of Jupiter are 0.014720 and -0.00065, respectively, based on an equatorial planetary radius of 71,400 km, and the derived dynamical oblateness is 0.0647 at the same radius. The Pioneer 10 data are consistent with the assumption that Jupiter is in hydrostatic equilibrium at all levels.
Bayesian Analysis of Hot Jupiter Radius Anomalies Points to Ohmic Dissipation
NASA Astrophysics Data System (ADS)
Thorngren, Daniel; Fortney, Jonathan
2018-01-01
The cause of the unexpectedly large radii of hot Jupiters has been the subject of many hypotheses over the past 15 years and is one of the long-standing open issues in exoplanetary physics. In our work, we seek to examine the population of 300 hot Jupiters to identify a model that best explains their radii. Using a hierarchical Bayesian framework, we match structure evolution models to the observed giant planets’ masses, radii, and ages, with a prior for bulk composition based on the mass from Thorngren et al. (2016). We consider various models for the relationship between heating efficiency (the fraction of flux absorbed into the interior) and incident flux. For the first time, we are able to derive this heating efficiency as a function of planetary T_eq. Models in which the heating efficiency decreases at the higher temperatures (above ~1600 K) are strongly and statistically significantly preferred. Of the published models for the radius anomaly, only the Ohmic dissipation model predicts this feature, which it explains as being the result of magnetic drag reducing atmospheric wind speeds. We interpret our results as evidence in favor of the Ohmic dissipation model.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eigmüller, Philipp; Csizmadia, Szilard; Smith, Alexis M. S.
We report the characterization and independent detection of K2-60b, as well as the detection and characterization of K2-107b, two transiting hot gaseous planets from the K2 space mission. We confirm the planetary nature of the two systems and determine their fundamental parameters combining the K2 time-series data with FIES@NOT and HARPS-N@TNG spectroscopic observations. K2-60b has a radius of 0.683 ± 0.037 R {sub Jup} and a mass of 0.426 ± 0.037 M {sub Jup} and orbits a G4 V star with an orbital period of 3.00267 ± 0.00006 days. K2-107b has a radius of 1.44 ± 0.15 R {sub Jup} and a mass of 0.84 ± 0.08 M {sub Jup} andmore » orbits an F9 IV star every 3.31392 ± 0.00002 days. K2-60b is among the few planets at the edge of the so-called “desert” of short-period sub-Jovian planets. K2-107b is a highly inflated Jovian planet orbiting an evolved star about to leave the main sequence.« less
Compositional Constraints on the Best Characterized Rocky Exoplanet, Kepler-36 b
NASA Astrophysics Data System (ADS)
Rogers, Leslie; Deck, Katherine; Lissauer, Jack J.; Carter, Joshua A.
2015-01-01
Kepler-36 is an extreme planetary system, consisting of two transiting sub-Neptune-size planets that revolve around a sub-giant star with orbital periods of 13.84 and 16.24 days. Mutual gravitational interactions between the two planets perturb the planets' transit times, allowing the planets' masses to be measured. Despite the similarity of their masses and orbital radii, the planets show a stark contrast in their mean densities; the inner planet (Kepler-36 b) is more than eight times as dense as its outer companion planet (Kepler-36 c). We perform a photo-dynamical analysis of the Kepler-36 system based on more than three years of Kepler photometry. With N-body integrations of initial conditions sampled from the photo-dynamical fits, we further refine the properties of the system by ruling out solutions that show large-scale instability within 5 Giga-days. Ultimately, we measure the planets' masses within 4.2% precision, and the planets' radii with 1.8% precision. Kepler-36 b is currently the rocky exoplanet with the most precisely measured mass and radius. Kepler-36 b's mass and radius are consistent with an Earth-like composition, and an iron-enhanced Mercury-like composition is ruled out.
Compositional Constraints on the Best Characterized Rocky Exoplanet, Kepler-36 b
NASA Astrophysics Data System (ADS)
Rogers, Leslie Anne; Deck, Katherine; Lissauer, Jack; Carter, Joshua
2015-08-01
Kepler-36 is an extreme planetary system, consisting of two transiting sub-Neptune-size planets that revolve around a sub-giant star with orbital periods of 13.84 and 16.24 days. Mutual gravitational interactions between the two planets perturb the planets' transit times, allowing the planets' masses to be measured. Despite the similarity of their masses and orbital radii, the planets show a stark contrast in their mean densities; the inner planet (Kepler-36 b) is more than eight times as dense as its outer companion planet (Kepler-36 c). We perform a photo-dynamical analysis of the Kepler-36 system based on more than three years of Kepler photometry. With N-body integrations of initial conditions sampled from the photo-dynamical fits, we further refine the properties of the system by ruling out solutions that show large scale instability within 5 Giga-days. Ultimately, we measure the planets' masses within 4.2% precision, and the planets' radii with 1.8% precision. Kepler-36 b is currently the rocky exoplanet with the most precisely measured mass and radius. Kepler-36 b’s mass and radius are consistent with a Earth-like composition, and an iron-enhanced Mercury-like composition is ruled out.
Compositional Constraints on the Best Characterized Rocky Exoplanet, Kepler-36 b
NASA Astrophysics Data System (ADS)
Rogers, L.; Deck, K.; Lissauer, J. J.; Carter, J.
2014-12-01
Kepler-36 is an extreme planetary system, consisting of two transiting sub-Neptune-size planets that revolve around a sub-giant star with orbital periods of 13.84 and 16.24 days. Mutual gravitational interactions between the two planets perturb the planets' transit times, allowing the planets' masses to be measured. Despite the similarity of their masses and orbital radii, the planets show a stark contrast in their mean densities; the inner planet (Kepler-36 b) is more than eight times as dense as its outer companion planet (Kepler-36 c). We perform a photo-dynamical analysis of the Kepler-36 system based on more than three years of Kepler photometry. With N-body integrations of initial conditions sampled from the photo-dynamical fits, we further refine the properties of the system by ruling out solutions that show large scale instability within 5 Giga-days. Ultimately, we measure the planets' masses within 4.2% precision, and the planets' radii with 1.8% precision. Kepler-36 b is currently the rocky exoplanet with the most precisely measured mass and radius. Kepler-36 b's mass and radius are consistent with a Earth-like composition, and an iron-enhanced Mercury-like composition is ruled out.
Refining Parameters of the XO-5 Planetary System with High-Precision Transit Photometry
NASA Astrophysics Data System (ADS)
Maciejewski, G.; Seeliger, M.; Adam, Ch.; Raetz, St.; Neuhäuser, R.
2011-03-01
Studies of transiting extrasolar planets provide unique opportunity to get to know the internal structure of those worlds. The transiting exoplanet XO-5 b was found to have an anomalously high Safronov number and surface gravity. Our aim was to refine parameters of this intriguing system and search for signs of transit timing variations. We gathered high-precision light curves for two transits of XO-5 b. Assuming three different limb darkening laws, we found the best-fitting model and redetermined parameters of the system, including planet-to-star radius ratio, impact parameter and central time of transits. Error estimates were derived by the prayer bead method and Monte Carlo simulations. Although system's parameters obtained by us were found to agree with previous studies within one sigma, the planet was found to be notable smaller with the radius of 1.03+0.06-0.05 Jupiter radii. Our results confirm the high Safronov number and surface gravity of the planet. With two new mid-transit times, the ephemeris was refined to BJDTDB=(2454485.66842±0.00028)+(4.1877537±0.000017)E. No significant transit timing variation was detected.
Rapid rotators revisited: absolute dimensions of KOI-13
NASA Astrophysics Data System (ADS)
Howarth, Ian D.; Morello, Giuseppe
2017-09-01
We analyse Kepler light-curves of the exoplanet Kepler Object of Interest no. 13b (KOI-13b) transiting its moderately rapidly rotating (gravity-darkened) parent star. A physical model, with minimal ad hoc free parameters, reproduces the time-averaged light-curve at the ˜10 parts per million level. We demonstrate that this Roche-model solution allows the absolute dimensions of the system to be determined from the star's projected equatorial rotation speed, ve sin I*, without any additional assumptions; we find a planetary radius RP = (1.33 ± 0.05) R♃, stellar polar radius Rp★ = (1.55 ± 0.06) R⊙, combined mass M* + MP( ≃ M*) = (1.47 ± 0.17) M⊙ and distance d ≃ (370 ± 25) pc, where the errors are dominated by uncertainties in relative flux contribution of the visual-binary companion KOI-13B. The implied stellar rotation period is within ˜5 per cent of the non-orbital, 25.43-hr signal found in the Kepler photometry. We show that the model accurately reproduces independent tomographic observations, and yields an offset between orbital and stellar-rotation angular-momentum vectors of 60.25° ± 0.05°.
Plan of Action: JASPER Management Prestart Review (Surrogate Material Experiment)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cooper, W E
2000-12-05
The Lawrence Livermore National Laboratory (LLNL) Joint Actinide Shock Physics Experimental Research (JASPER) Facility is being developed at the Nevada Test Site (NTS) to conduct shock physics experiments on special nuclear material and other actinide materials. JASPER will use a two-stage, light-gas gun to shoot projectiles at actinide targets. Projectile velocities will range from 1 to 8 km/s, inducing pressures in the target material up to 6 Mbar. The JASPER gas gun has been designed to match the critical dimensions of the two-stage, light-gas gun in Building 341 of LLNL. The goal in copying the LLNL gun design is tomore » take advantage of the extensive ballistics database that exists and to minimize the effort spent on gun characterization in the initial facility start-up. A siting study conducted by an inter-Laboratory team identified Able Site in Area 27 of the NTS as the best location for the JASPER gas gun. Able Site consists of three major buildings that had previously been used to support the nuclear test program. In April 1999, Able Site was decommissioned as a Nuclear Explosive Assembly Facility and turned back to the DOE for other uses. Construction and facility modifications at Able Site to support the JASPER project started in April 1999 and were completed in September 1999. The gas gun and the secondary confinement chamber (SCC) were installed in early 2000. During the year, all facility and operational systems were brought on line. Initial system integration demonstrations were completed in September 2000. The facility is anticipated to be operational by August 2001, and the expected life cycle for the facility is 10 years. LLNL Nevada Experiments and Operations (N) Program has established a Management Prestart Review (MPR) team to determine the readiness of the JASPER personnel and facilities to initiate surrogate-material experiments. The review coincides with the completion of authorization-basis documents and physical subsystems, which have undergone appropriate formal engineering design reviews. This MPR will affirm the quality of those reviews, their findings/resolutions, and will look most closely at systems integration requirements and demonstrations that will have undergone technical acceptance reviews before the formal MPR action. Closure of MPR findings will finalize requirements for a DOE/NV Real Estate/Operations Permit (REOP) for surrogate-material experiments. Upon completion of that experiment series and the establishment of capabilities for incorporating SNM into future experiments, the team will convene again as part of the process of authorizing those activities.« less
Plan of Action: JASPER Management Prestart Review (Surrogate Material Experiments)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cooper, W.E.
2000-09-29
The Lawrence Livermore National Laboratory (LLNL) Joint Actinide Shock Physics Experimental Research (JASPER) Facility is being developed at the Nevada Test Site (NTS) to conduct shock physics experiments on special nuclear material and other actinide materials. JASPER will use a two-stage, light-gas gun to shoot projectiles at actinide targets. Projectile velocities will range from 1 to 8 km/s, inducing pressures in the target material up to 6 Mbar. The JASPER gas gun has been designed to match the critical dimensions of the two-stage, light-gas gun in Building 341 of LLNL. The goal in copying the LLNL gun design is tomore » take advantage of the extensive ballistics database that exists and to minimize the effort spent on gun characterization in the initial facility start-up. A siting study conducted by an inter-Laboratory team identified Able Site in Area 27 of the NTS as the best location for the JASPER gas gun. Able Site consists of three major buildings that had previously been used to support the nuclear test program. In April 1999, Able Site was decommissioned as a Nuclear Explosive Assembly Facility and turned back to the DOE for other uses. Construction and facility modifications at Able Site to support the JASPER project started in April 1999 and were completed in September 1999. The gas gun and the secondary confinement chamber (SCC) were installed in early 2000. During the year, all facility and operational systems were brought on line. Initial system integration demonstrations were completed in September 2000. The facility is anticipated to be operational by August 2001, and the expected life cycle for the facility is 10 years. LLNL Nevada Experiments and Operations (N) Program has established a Management Prestart Review (MPR) team to determine the readiness of the JASPER personnel and facilities to initiate surrogate-material experiments. The review coincides with the completion of authorization-basis documents and physical subsystems, which have undergone appropriate formal engineering design reviews. This MPR will affirm the quality of those reviews, their findings/resolutions, and will look most closely at systems integration requirements and demonstrations that will have undergone technical acceptance reviews before the formal MPR action. Closure of MPR findings will finalize requirements for a DOE/NV Real Estate/Operations Permit (REOP) for surrogate-material experiments. Upon completion of that experiment series and the establishment of capabilities for incorporating SNM into future experiments, the team will convene again as part of the process of authorizing those activities.« less
Luo, Mingyue; Duan, Chaijie; Qiu, Jianping; Li, Wenru; Zhu, Dongyun; Cai, Wenli
2015-01-01
Purpose To evaluate the diagnostic value of multidetector CT (MDCT) and its multiplanar reformation (MPR), volume rendering (VR) and virtual bronchoscopy (VB) postprocessing techniques for primary trachea and main bronchus tumors. Methods Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology. Results Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6), tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16), extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm—56.0 mm, n = 14; no clear border with right atelectasis, n = 1), longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm—68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1), morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1) and extents (mild, n = 5; moderate, n = 7; severe, n = 19), distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10), and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density without obvious enhancement, n = 1). Conclusion MDCT and its MPR, VR and VB images have respective advantages and disadvantages. Their combination could complement to each other to accurately detect locations, natures (benignancy, malignancy or low malignancy), and quantities (extramural invasions, longitudinal involvements, extents of luminal stenoses, distances between main bronchus tumors and trachea carinae) of primary trachea and main bronchus tumors with crucial information for surgical treatment, are highly useful diagnostic methods for primary trachea and main bronchus tumors. PMID:26332466
Indexing of exoplanets in search for potential habitability: application to Mars-like worlds
NASA Astrophysics Data System (ADS)
Kashyap Jagadeesh, Madhu; Gudennavar, Shivappa B.; Doshi, Urmi; Safonova, Margarita
2017-08-01
Study of exoplanets is one of the main goals of present research in planetary sciences and astrobiology. Analysis of huge planetary data from space missions such as CoRoT and Kepler is directed ultimately at finding a planet similar to Earth—the Earth's twin, and answering the question of potential exo-habitability. The Earth Similarity Index (ESI) is a first step in this quest, ranging from 1 (Earth) to 0 (totally dissimilar to Earth). It was defined for the four physical parameters of a planet: radius, density, escape velocity and surface temperature. The ESI is further sub-divided into interior ESI (geometrical mean of radius and density) and surface ESI (geometrical mean of escape velocity and surface temperature). The challenge here is to determine which exoplanet parameter(s) is important in finding this similarity; how exactly the individual parameters entering the interior ESI and surface ESI are contributing to the global ESI. Since the surface temperature entering surface ESI is a non-observable quantity, it is difficult to determine its value. Using the known data for the Solar System objects, we established the calibration relation between surface and equilibrium temperatures to devise an effective way to estimate the value of the surface temperature of exoplanets. ESI is a first step in determining potential exo-habitability that may not be very similar to a terrestrial life. A new approach, called Mars Similarity Index (MSI), is introduced to identify planets that may be habitable to the extreme forms of life. MSI is defined in the range between 1 (present Mars) and 0 (dissimilar to present Mars) and uses the same physical parameters as ESI. We are interested in Mars-like planets to search for planets that may host the extreme life forms, such as the ones living in extreme environments on Earth; for example, methane on Mars may be a product of the methane-specific extremophile life form metabolism.
NASA Astrophysics Data System (ADS)
Mancini, L.; Southworth, J.; Ciceri, S.; Tregloan-Reed, J.; Crossfield, I.; Nikolov, N.; Bruni, I.; Zambelli, R.; Henning, Th.
2014-09-01
We present 17 high-precision light curves of five transits of the planet Qatar-2 b, obtained from four defocused 2 m-class telescopes. Three of the transits were observed simultaneously in the Sloan g'r'i'z' passbands using the seven-beam Gamma Ray Burst Optical and Near-Infrared Detector imager on the MPG/ESO 2.2-m telescope. A fourth was observed simultaneously in Gunn grz using the Centro Astronómico Hispano Alemán 2.2-m telescope with Bonn University Simultaneous Camera, and in r using the Cassini 1.52-m telescope. Every light curve shows small anomalies due to the passage of the planetary shadow over a cool spot on the surface of the host star. We fit the light curves with the PRISM+GEMC model to obtain the photometric parameters of the system and the position, size and contrast of each spot. We use these photometric parameters and published spectroscopic measurements to obtain the physical properties of the system to high precision, finding a larger radius and lower density for both star and planet than previously thought. By tracking the change in position of one star-spot between two transit observations, we measure the orbital obliquity of Qatar-2 b to be λ = 4.3° ± 4.5°, strongly indicating an alignment of the stellar spin with the orbit of the planet. We calculate the rotation period and velocity of the cool host star to be 11.5 ± 0.2 d and 3.28 ± 0.04 km s-1 at a colatitude of 74°. We assemble the planet's transmission spectrum over the 386-976 nm wavelength range and search for variations of the measured radius of Qatar-2 b as a function of wavelength. Our analysis highlights a possible H2/He Rayleigh scattering in the blue.
Stellar and Planetary Parameters for K2 's Late-type Dwarf Systems from C1 to C5
DOE Office of Scientific and Technical Information (OSTI.GOV)
Martinez, Arturo O.; Crossfield, Ian J. M.; Peacock, Sarah
The NASA K2 mission uses photometry to find planets transiting stars of various types. M dwarfs are of high interest since they host more short-period planets than any other type of main-sequence star and transiting planets around M dwarfs have deeper transits compared to other main-sequence stars. In this paper, we present stellar parameters from K and M dwarfs hosting transiting planet candidates discovered by our team. Using the SOFI spectrograph on the European Southern Observatory’s New Technology Telescope, we obtained R ≈ 1000 J -, H -, and K -band (0.95–2.52 μ m) spectra of 34 late-type K2 planetmore » and candidate planet host systems and 12 bright K4–M5 dwarfs with interferometrically measured radii and effective temperatures. Out of our 34 late-type K2 targets, we identify 27 of these stars as M dwarfs. We measure equivalent widths of spectral features, derive calibration relations using stars with interferometric measurements, and estimate stellar radii, effective temperatures, masses, and luminosities for the K2 planet hosts. Our calibrations provide radii and temperatures with median uncertainties of 0.059 R {sub ⊙} (16.09%) and 160 K (4.33%), respectively. We then reassess the radii and equilibrium temperatures of known and candidate planets based on our spectroscopically derived stellar parameters. Since a planet’s radius and equilibrium temperature depend on the parameters of its host star, our study provides more precise planetary parameters for planets and candidates orbiting late-type stars observed with K2 . We find a median planet radius and an equilibrium temperature of approximately 3 R {sub ⊕} and 500 K, respectively, with several systems (K2-18b and K2-72e) receiving near-Earth-like levels of incident irradiation.« less
PHOTOMETRIC ORBITS OF EXTRASOLAR PLANETS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brown, Robert A.
We define and analyze the photometric orbit (PhO) of an extrasolar planet observed in reflected light. In our definition, the PhO is a Keplerian entity with six parameters: semimajor axis, eccentricity, mean anomaly at some particular time, argument of periastron, inclination angle, and effective radius, which is the square root of the geometric albedo times the planetary radius. Preliminarily, we assume a Lambertian phase function. We study in detail the case of short-period giant planets (SPGPs) and observational parameters relevant to the Kepler mission: 20 ppm photometry with normal errors, 6.5 hr cadence, and three-year duration. We define a relevantmore » 'planetary population of interest' in terms of probability distributions of the PhO parameters. We perform Monte Carlo experiments to estimate the ability to detect planets and to recover PhO parameters from light curves. We calibrate the completeness of a periodogram search technique, and find structure caused by degeneracy. We recover full orbital solutions from synthetic Kepler data sets and estimate the median errors in recovered PhO parameters. We treat in depth a case of a Jupiter body-double. For the stated assumptions, we find that Kepler should obtain orbital solutions for many of the 100-760 SPGP that Jenkins and Doyle estimate Kepler will discover. Because most or all of these discoveries will be followed up by ground-based radial velocity observations, the estimates of inclination angle from the PhO may enable the calculation of true companion masses: Kepler photometry may break the 'msin i' degeneracy. PhO observations may be difficult. There is uncertainty about how low the albedos of SPGPs actually are, about their phase functions, and about a possible noise floor due to systematic errors from instrumental and stellar sources. Nevertheless, simple detection of SPGPs in reflected light should be robust in the regime of Kepler photometry, and estimates of all six orbital parameters may be feasible in at least a subset of cases.« less
Precise masses for the transiting planetary system HD 106315 with HARPS
NASA Astrophysics Data System (ADS)
Barros, S. C. C.; Gosselin, H.; Lillo-Box, J.; Bayliss, D.; Delgado Mena, E.; Brugger, B.; Santerne, A.; Armstrong, D. J.; Adibekyan, V.; Armstrong, J. D.; Barrado, D.; Bento, J.; Boisse, I.; Bonomo, A. S.; Bouchy, F.; Brown, D. J. A.; Cochran, W. D.; Collier Cameron, A.; Deleuil, M.; Demangeon, O.; Díaz, R. F.; Doyle, A.; Dumusque, X.; Ehrenreich, D.; Espinoza, N.; Faedi, F.; Faria, J. P.; Figueira, P.; Foxell, E.; Hébrard, G.; Hojjatpanah, S.; Jackman, J.; Lendl, M.; Ligi, R.; Lovis, C.; Melo, C.; Mousis, O.; Neal, J. J.; Osborn, H. P.; Pollacco, D.; Santos, N. C.; Sefako, R.; Shporer, A.; Sousa, S. G.; Triaud, A. H. M. J.; Udry, S.; Vigan, A.; Wyttenbach, A.
2017-12-01
Context. The multi-planetary system HD 106315 was recently found in K2 data. The planets have periods of Pb 9.55 and Pc 21.06 days, and radii of rb = 2.44 ± 0.17 R⊕ and rc = 4.35 ± 0.23 R⊕ . The brightness of the host star (V = 9.0 mag) makes it an excellent target for transmission spectroscopy. However, to interpret transmission spectra it is crucial to measure the planetary masses. Aims: We obtained high precision radial velocities for HD 106315 to determine the mass of the two transiting planets discovered with Kepler K2. Our successful observation strategy was carefully tailored to mitigate the effect of stellar variability. Methods: We modelled the new radial velocity data together with the K2 transit photometry and a new ground-based partial transit of HD 106315c to derive system parameters. Results: We estimate the mass of HD 106315b to be 12.6 ± 3.2 M⊕ and the density to be 4.7 ± 1.7 g cm-3, while for HD 106315c we estimate a mass of 15.2 ± 3.7 M⊕ and a density of 1.01 ± 0.29 g cm-3. Hence, despite planet c having a radius almost twice as large as planet b, their masses are consistent with one another. Conclusions: We conclude that HD 106315c has a thick hydrogen-helium gaseous envelope. A detailed investigation of HD 106315b using a planetary interior model constrains the core mass fraction to be 5-29%, and the water mass fraction to be 10-50%. An alternative, not considered by our model, is that HD 106315b is composed of a large rocky core with a thick H-He envelope. Transmission spectroscopy of these planets will give insight into their atmospheric compositions and also help constrain their core compositions. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 198.C-0168.
A brief visit from a red and extremely elongated interstellar asteroid.
Meech, Karen J; Weryk, Robert; Micheli, Marco; Kleyna, Jan T; Hainaut, Olivier R; Jedicke, Robert; Wainscoat, Richard J; Chambers, Kenneth C; Keane, Jacqueline V; Petric, Andreea; Denneau, Larry; Magnier, Eugene; Berger, Travis; Huber, Mark E; Flewelling, Heather; Waters, Chris; Schunova-Lilly, Eva; Chastel, Serge
2017-12-21
None of the approximately 750,000 known asteroids and comets in the Solar System is thought to have originated outside it, despite models of the formation of planetary systems suggesting that orbital migration of giant planets ejects a large fraction of the original planetesimals into interstellar space. The high predicted number density of icy interstellar objects (2.4 × 10 -4 per cubic astronomical unit) suggests that some should have been detected, yet hitherto none has been seen. Many decades of asteroid and comet characterization have yielded formation models that explain the mass distribution, chemical abundances and planetary configuration of the Solar System today, but there has been no way of telling whether the Solar System is typical of planetary systems. Here we report observations and analysis of the object 1I/2017 U1 ('Oumuamua) that demonstrate its extrasolar trajectory, and that thus enable comparisons to be made between material from another planetary system and from our own. Our observations during the brief visit by the object to the inner Solar System reveal it to be asteroidal, with no hint of cometary activity despite an approach within 0.25 astronomical units of the Sun. Spectroscopic measurements show that the surface of the object is spectrally red, consistent with comets or organic-rich asteroids that reside within the Solar System. Light-curve observations indicate that the object has an extremely oblong shape, with a length about ten times its width, and a mean radius of about 102 metres assuming an albedo of 0.04. No known objects in the Solar System have such extreme dimensions. The presence of 'Oumuamua in the Solar System suggests that previous estimates of the number density of interstellar objects, based on the assumption that all such objects were cometary, were pessimistically low. Planned upgrades to contemporary asteroid survey instruments and improved data processing techniques are likely to result in the detection of more interstellar objects in the coming years.
Wyoming Career and Technical Education Policy Analysis
ERIC Educational Resources Information Center
MPR Associates, Inc., 2009
2009-01-01
This policy analysis was produced for the Wyoming Department of Administration and Information by MPR Associates, Inc. Its purpose was to examine federal and state policy related to career and technical education (CTE) to determine whether existing policy (in the form of statutes, rules, regulations, and guidance) could either promote or impede…
NASA Astrophysics Data System (ADS)
Feng, Y. Katherina; Robinson, Tyler D.; Fortney, Jonathan J.; Lupu, Roxana E.; Marley, Mark S.; Lewis, Nikole K.; Macintosh, Bruce; Line, Michael R.
2018-05-01
Space-based high-contrast imaging mission concepts for studying rocky exoplanets in reflected light are currently under community study. We develop an inverse modeling framework to estimate the science return of such missions given different instrument design considerations. By combining an exoplanet albedo model, instrument noise model, and ensemble Markov chain Monte Carlo sampler, we explore retrievals of atmospheric and planetary properties for Earth twins as a function of signal-to-noise ratio (S/N) and resolution (R). Our forward model includes Rayleigh-scattering, single-layer water clouds with patchy coverage, and pressure-dependent absorption due to water vapor, oxygen, and ozone. We simulate data at R = 70 and 140 from 0.4 to 1.0 μm with S/N = 5, 10, 15, and 20 at 550 nm (i.e., for HabEx/LUVOIR-type instruments). At these same S/Ns, we simulate data for WFIRST paired with a starshade, which includes two photometric points between 0.48 and 0.6 μm and R = 50 spectroscopy from 0.6 to 0.97 μm. Given our noise model for WFIRST-type detectors, we find that weak detections of water vapor, ozone, and oxygen can be achieved with observations with at least R = 70/S/N = 15 or R = 140/S/N = 10 for improved detections. Meaningful constraints are only achieved with R = 140/S/N = 20 data. The WFIRST data offer limited diagnostic information, needing at least S/N = 20 to weakly detect gases. Most scenarios place limits on planetary radius but cannot constrain surface gravity and, thus, planetary mass.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ballard, Sarah; Charbonneau, David; Fressin, Francois
We present the validation and characterization of Kepler-61b: a 2.15 R{sub Circled-Plus} planet orbiting near the inner edge of the habitable zone of a low-mass star. Our characterization of the host star Kepler-61 is based upon a comparison with a set of spectroscopically similar stars with directly measured radii and temperatures. We apply a stellar prior drawn from the weighted mean of these properties, in tandem with the Kepler photometry, to infer a planetary radius for Kepler-61b of 2.15 {+-} 0.13 R{sub Circled-Plus} and an equilibrium temperature of 273 {+-} 13 K (given its period of 59.87756 {+-} 0.00020 daysmore » and assuming a planetary albedo of 0.3). The technique of leveraging the physical properties of nearby ''proxy'' stars allows for an independent check on stellar characterization via the traditional measurements with stellar spectra and evolutionary models. In this case, such a check had implications for the putative habitability of Kepler-61b: the planet is 10% warmer and larger than inferred from K-band spectral characterization. From the Kepler photometry, we estimate a stellar rotation period of 36 days, which implies a stellar age of >1 Gyr. We summarize the evidence for the planetary nature of the Kepler-61 transit signal, which we conclude is 30,000 times more likely to be due to a planet than a blend scenario. Finally, we discuss possible compositions for Kepler-61b with a comparison to theoretical models as well as to known exoplanets with similar radii and dynamically measured masses.« less
Robotic laser adaptive optics imaging of 715 Kepler exoplanet candidates using Robo-AO
DOE Office of Scientific and Technical Information (OSTI.GOV)
Law, Nicholas M.; Ziegler, Carl; Morton, Tim
2014-08-10
The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging to search for blended nearby stars, which may be physically associated companions and/or responsible for transit false positives. In this paper, we present the results from the 2012 observing season, searching for stars close to 715 Kepler planet candidate hosts. We find 53 companions, 43 of which are new discoveries. We detail the Robo-AO survey data reduction methods including a method of using the large ensemble of target observations as mutual point-spread-function references, along with a new automated companion-detection algorithm designedmore » for large adaptive optics surveys. Our survey is sensitive to objects from ≈0.''15 to 2.''5 separation, with magnitude differences up to Δm ≈ 6. We measure an overall nearby-star probability for Kepler planet candidates of 7.4% ± 1.0%, and calculate the effects of each detected nearby star on the Kepler-measured planetary radius. We discuss several Kepler Objects of Interest (KOIs) of particular interest, including KOI-191 and KOI-1151, which are both multi-planet systems with detected stellar companions whose unusual planetary system architecture might be best explained if they are 'coincident multiple' systems, with several transiting planets shared between the two stars. Finally, we find 98% confidence evidence that short-period giant planets are two to three times more likely than longer-period planets to be found in wide stellar binaries.« less
THE INTERSTELLAR MEDIUM IN THE KEPLER SEARCH VOLUME
DOE Office of Scientific and Technical Information (OSTI.GOV)
Johnson, Marshall C.; Redfield, Seth; Jensen, Adam G., E-mail: mjohnson@astro.as.utexas.edu
2015-07-10
The properties of the interstellar medium (ISM) surrounding a planetary system can impact planetary climate through a number of mechanisms, including changing the size of the astrosphere (one of the major shields for cosmic rays) as well as direct deposition of material into planetary atmospheres. In order to constrain the ambient ISM conditions for exoplanetary systems, we present observations of interstellar Na i and K i absorption toward seventeen early type stars in the Kepler prime mission field of view (FOV). We identify 39 Na i and 8 K i velocity components, and attribute these to 11 ISM clouds. Sixmore » of these are detected toward more than one star, and for these clouds we put limits on the cloud properties, including distance and hydrogen number density. We identify one cloud with significant (≳1.5 cm{sup −3}) hydrogen number density located within the nominal ∼100 pc boundary of the Local Bubble. We identify systems with confirmed planets within the Kepler FOV that could lie within these ISM clouds, and estimate upper limits on the astrosphere sizes of these systems under the assumption that they do lie within these clouds. Under this condition, the Kepler-20, 42, and 445 multiplanet systems could have compressed astrospheres much smaller than the present-day heliosphere. Among the known habitable zone planet hosts, Kepler-186 could have an astrosphere somewhat smaller than the heliosphere, while Kepler-437 and KOI-4427 could have astrospheres much larger than the heliosphere. The thick disk star Kepler-444 may have an astrosphere just a few AU in radius.« less
Low-Mass Stars and Their Companions
NASA Astrophysics Data System (ADS)
Montet, Benjamin Tyler
In this thesis, I present seven studies aimed towards better understanding the demographics and physical properties of M dwarfs and their companions. These studies focus in turn on planetary, brown dwarf, and stellar companions to M dwarfs. I begin with an analysis of radial velocity and transit timing analyses of multi-transiting planetary systems, finding that if both signals are measured to sufficiently high precision the stellar and planetary masses can be measured to a high precision, eliminating a need for stellar models which may have systematic errors. I then combine long-term radial velocity monitoring and a direct imaging campaign to measure the occurrence rate of giant planets around M dwarfs. I find that 6.5 +/- 3.0% of M dwarfs host a Jupiter mass or larger planet within 20 AU, with a strong dependence on stellar metallicity. I then present two papers analyzing the LHS 6343 system, which contains a widely separated M dwarf binary (AB). Star A hosts a transiting brown dwarf (LHS 6343 C) with a 12.7 day period. By combining radial velocity data with transit photometry, I am able to measure the mass and radius of the brown dwarf to 2% precision, the most precise measurement of a brown dwarf to date. I then analyze four secondary eclipses of the LHS 6343 AC system as observed by Spitzer in order to measure the luminosity of the brown dwarf in both Spitzer bandpasses. I find the brown dwarf is consistent with theoretical models of an 1100 K T dwarf at an age of 5 Gyr and empirical observations of field T5-6 dwarfs with temperatures of 1070 +/- 130 K. This is the first non-inflated brown dwarf with a measured mass, radius, and multi-band photometry, making it an ideal test of evolutionary models of field brown dwarfs. Next, I present the results of an astrometric and radial velocity campaign to measure the orbit and masses of both stars in the GJ 3305 AB system, an M+M binary comoving with 51 Eridani, a more massive star with a directly imaged planetary companion. I compare the masses of both stars to largely untested theoretical models of young M dwarfs, finding that the models are consistent with the measured mass of star A but slightly overpredict the luminosity of star B. In the final two science chapters I focus on space-based transit surveys, present and future. First, I present the first catalog of statistically validated planets from the K2 mission, as well as updated stellar and planetary parameters for all systems with candidate planets in the first K2 field. The catalog includes K2-18b, a ``mini-Neptune'' planet that receives a stellar insolation consistent with the level that the Earth receives from the Sun, making it a useful comparison against planets of a similar size that are highly irradiated, such as GJ 1214 b. Finally, I present predictions for the WFIRST mission. While designed largely as a microlensing mission, I find it will be able to detect as many as 30,000 transiting planets towards the galactic bulge, providing information about how planet occurrence changes across the galaxy. These planets will be able to be confirmed largely through direct detection of their secondary eclipses. Moreover, I find that more than 50% of the planets it detects smaller than Neptune will be found around M dwarf hosts.
NASA Astrophysics Data System (ADS)
Line, Michael
The field of transiting exoplanet atmosphere characterization has grown considerably over the past decade given the wealth of photometric and spectroscopic data from the Hubble and Spitzer space telescopes. In order to interpret these data, atmospheric models combined with Bayesian approaches are required. From spectra, these approaches permit us to infer fundamental atmospheric properties and how their compositions can relate back to planet formation. However, such approaches must make a wide range of assumptions regarding the physics/parameterizations included in the model atmospheres. There has yet to be a comprehensive investigation exploring how these model assumptions influence our interpretations of exoplanetary spectra. Understanding the impact of these assumptions is especially important since the James Webb Space Telescope (JWST) is expected to invest a substantial portion of its time observing transiting planet atmospheres. It is therefore prudent to optimize and enhance our tools to maximize the scientific return from the revolutionary data to come. The primary goal of the proposed work is to determine the pieces of information we can robustly learn from transiting planet spectra as obtained by JWST and other future, space-based platforms, by investigating commonly overlooked model assumptions. We propose to explore the following effects and how they impact our ability to infer exoplanet atmospheric properties: 1. Stellar/Planetary Uncertainties: Transit/occultation eclipse depths and subsequent planetary spectra are measured relative to their host stars. How do stellar uncertainties, on radius, effective temperature, metallicity, and gravity, as well as uncertainties in the planetary radius and gravity, propagate into the uncertainties on atmospheric composition and thermal structure? Will these uncertainties significantly bias our atmospheric interpretations? Is it possible to use the relative measurements of the planetary spectra to provide additional constraints on the stellar properties? 2. The "1D" Assumption: Atmospheres are inherently three-dimensional. Many exoplanet atmosphere models, especially within retrieval frameworks, assume 1D physics and chemistry when interpreting spectra. How does this "1D" atmosphere assumption bias our interpretation of exoplanet spectra? Do we have to consider global temperature variations such as day-night contrasts or hot spots? What about spatially inhomogeneous molecular abundances and clouds? How will this change our interpretations of phase resolved spectra? 3. Clouds/Hazes: Understanding how clouds/hazes impact transit spectra is absolutely critical if we are to obtain proper estimates of basic atmospheric quantities. How do the assumptions in cloud physics bias our inferences of molecular abundances in transmission? What kind of data (wavelengths, signal-to-noise, resolution) do we need to infer cloud composition, vertical extent, spatial distribution (patchy or global), and size distributions? The proposed work is relevant and timely to the scope of the NASA Exoplanet Research program. The proposed work aims to further develop the critical theoretical modeling tools required to rigorously interpret transiting exoplanet atmosphere data in order to maximize the science return from JWST and beyond. This work will serve as a benchmark study for defining the data (wavelength ranges, signal-to-noises, and resolutions) required from a modeling perspective to "characterize exoplanets and their atmospheres in order to inform target and operational choices for current NASA missions, and/or targeting, operational, and formulation data for future NASA observatories". Doing so will allow us to better "understand the chemical and physical processes of exoplanets (their atmospheres)" which will ultimately " improve understanding of the origins of exoplanetary systems" through robust planetary elemental abundance determinations.
Mandel, Joshua; Jonikas, Magdalena; Ramoni, Rachel Badovinac; Kohane, Isaac S; Mandl, Kenneth D
2013-01-01
Background Non-adherence to prescribed medications is a serious health problem in the United States, costing an estimated $100 billion per year. While poor adherence should be addressable with point of care health information technology, integrating new solutions with existing electronic health records (EHR) systems require customization within each organization, which is difficult because of the monolithic software design of most EHR products. Objective The objective of this study was to create a published algorithm for predicting medication adherence problems easily accessible at the point of care through a Web application that runs on the Substitutable Medical Apps, Reusuable Technologies (SMART) platform. The SMART platform is an emerging framework that enables EHR systems to behave as “iPhone like platforms” by exhibiting an application programming interface for easy addition and deletion of third party apps. The app is presented as a point of care solution to monitoring medication adherence as well as a sufficiently general, modular application that may serve as an example and template for other SMART apps. Methods The widely used, open source Django framework was used together with the SMART platform to create the interoperable components of this app. Django uses Python as its core programming language. This allows statistical and mathematical modules to be created from a large array of Python numerical libraries and assembled together with the core app to create flexible and sophisticated EHR functionality. Algorithms that predict individual adherence are derived from a retrospective study of dispensed medication claims from a large private insurance plan. Patients’ prescription fill information is accessed through the SMART framework and the embedded algorithms compute adherence information, including predicted adherence one year after the first prescription fill. Open source graphing software is used to display patient medication information and the results of statistical prediction of future adherence on a clinician-facing Web interface. Results The user interface allows the physician to quickly review all medications in a patient record for potential non-adherence problems. A gap-check and current medication possession ratio (MPR) threshold test are applied to all medications in the record to test for current non-adherence. Predictions of 1-year non-adherence are made for certain drug classes for which external data was available. Information is presented graphically to indicate present non-adherence, or predicted non-adherence at one year, based on early prescription fulfillment patterns. The MPR Monitor app is installed in the SMART reference container as the “MPR Monitor”, where it is publically available for use and testing. MPR is an acronym for Medication Possession Ratio, a commonly used measure of adherence to a prescribed medication regime. This app may be used as an example for creating additional functionality by replacing statistical and display algorithms with new code in a cycle of rapid prototyping and implementation or as a framework for a new SMART app. Conclusions The MPR Monitor app is a useful pilot project for monitoring medication adherence. It also provides an example that integrates several open source software components, including the Python-based Django Web framework and python-based graphics, to build a SMART app that allows complex decision support methods to be encapsulated to enhance EHR functionality. PMID:23876796
Bosl, William; Mandel, Joshua; Jonikas, Magdalena; Ramoni, Rachel Badovinac; Kohane, Isaac S; Mandl, Kenneth D
2013-07-22
Non-adherence to prescribed medications is a serious health problem in the United States, costing an estimated $100 billion per year. While poor adherence should be addressable with point of care health information technology, integrating new solutions with existing electronic health records (EHR) systems require customization within each organization, which is difficult because of the monolithic software design of most EHR products. The objective of this study was to create a published algorithm for predicting medication adherence problems easily accessible at the point of care through a Web application that runs on the Substitutable Medical Apps, Reusuable Technologies (SMART) platform. The SMART platform is an emerging framework that enables EHR systems to behave as "iPhone like platforms" by exhibiting an application programming interface for easy addition and deletion of third party apps. The app is presented as a point of care solution to monitoring medication adherence as well as a sufficiently general, modular application that may serve as an example and template for other SMART apps. The widely used, open source Django framework was used together with the SMART platform to create the interoperable components of this app. Django uses Python as its core programming language. This allows statistical and mathematical modules to be created from a large array of Python numerical libraries and assembled together with the core app to create flexible and sophisticated EHR functionality. Algorithms that predict individual adherence are derived from a retrospective study of dispensed medication claims from a large private insurance plan. Patients' prescription fill information is accessed through the SMART framework and the embedded algorithms compute adherence information, including predicted adherence one year after the first prescription fill. Open source graphing software is used to display patient medication information and the results of statistical prediction of future adherence on a clinician-facing Web interface. The user interface allows the physician to quickly review all medications in a patient record for potential non-adherence problems. A gap-check and current medication possession ratio (MPR) threshold test are applied to all medications in the record to test for current non-adherence. Predictions of 1-year non-adherence are made for certain drug classes for which external data was available. Information is presented graphically to indicate present non-adherence, or predicted non-adherence at one year, based on early prescription fulfillment patterns. The MPR Monitor app is installed in the SMART reference container as the "MPR Monitor", where it is publically available for use and testing. MPR is an acronym for Medication Possession Ratio, a commonly used measure of adherence to a prescribed medication regime. This app may be used as an example for creating additional functionality by replacing statistical and display algorithms with new code in a cycle of rapid prototyping and implementation or as a framework for a new SMART app. The MPR Monitor app is a useful pilot project for monitoring medication adherence. It also provides an example that integrates several open source software components, including the Python-based Django Web framework and python-based graphics, to build a SMART app that allows complex decision support methods to be encapsulated to enhance EHR functionality.
A HARDCORE model for constraining an exoplanet's core size
NASA Astrophysics Data System (ADS)
Suissa, Gabrielle; Chen, Jingjing; Kipping, David
2018-05-01
The interior structure of an exoplanet is hidden from direct view yet likely plays a crucial role in influencing the habitability of the Earth analogues. Inferences of the interior structure are impeded by a fundamental degeneracy that exists between any model comprising more than two layers and observations constraining just two bulk parameters: mass and radius. In this work, we show that although the inverse problem is indeed degenerate, there exists two boundary conditions that enables one to infer the minimum and maximum core radius fraction, CRFmin and CRFmax. These hold true even for planets with light volatile envelopes, but require the planet to be fully differentiated and that layers denser than iron are forbidden. With both bounds in hand, a marginal CRF can also be inferred by sampling in-between. After validating on the Earth, we apply our method to Kepler-36b and measure CRFmin = (0.50 ± 0.07), CRFmax = (0.78 ± 0.02), and CRFmarg = (0.64 ± 0.11), broadly consistent with the Earth's true CRF value of 0.55. We apply our method to a suite of hypothetical measurements of synthetic planets to serve as a sensitivity analysis. We find that CRFmin and CRFmax have recovered uncertainties proportional to the relative error on the planetary density, but CRFmarg saturates to between 0.03 and 0.16 once (Δρ/ρ) drops below 1-2 per cent. This implies that mass and radius alone cannot provide any better constraints on internal composition once bulk density constraints hit around a per cent, providing a clear target for observers.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lopez, Eric D.; Fortney, Jonathan J.
2013-10-10
We use models of coupled thermal evolution and photo-evaporative mass loss to understand the formation and evolution of the Kepler-36 system. We show that the large contrast in mean planetary density observed by Carter et al. can be explained as a natural consequence of photo-evaporation from planets that formed with similar initial compositions. However, rather than being due to differences in XUV irradiation between the planets, we find that this contrast is due to the difference in the masses of the planets' rock/iron cores and the impact that this has on mass-loss evolution. We explore in detail how our coupledmore » models depend on irradiation, mass, age, composition, and the efficiency of mass loss. Based on fits to large numbers of coupled evolution and mass-loss runs, we provide analytic fits to understand threshold XUV fluxes for significant atmospheric loss, as a function of core mass and mass-loss efficiency. Finally we discuss these results in the context of recent studies of the radius distribution of Kepler candidates. Using our parameter study, we make testable predictions for the frequency of sub-Neptune-sized planets. We show that 1.8-4.0 R{sub ⊕} planets should become significantly less common on orbits within 10 days and discuss the possibility of a narrow 'occurrence valley' in the radius-flux distribution. Moreover, we describe how photo-evaporation provides a natural explanation for the recent observations of Ciardi et al. that inner planets are preferentially smaller within the systems.« less
EVAPORATION OF ICY PLANETESIMALS DUE TO BOW SHOCKS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tanaka, Kyoko K.; Yamamoto, Tetsuo; Tanaka, Hidekazu
2013-02-20
We present the novel concept of evaporation of planetesimals as a result of bow shocks associated with planetesimals orbiting with supersonic velocities relative to the gas in a protoplanetary disk. We evaluate the evaporation rates of the planetesimals based on a simple model describing planetesimal heating and evaporation by the bow shock. We find that icy planetesimals with radius {approx}>100 km evaporate efficiently even outside the snow line in the stage of planetary oligarchic growth, where strong bow shocks are produced by gravitational perturbations from protoplanets. The obtained results suggest that the formation of gas giant planets is suppressed owingmore » to insufficient accretion of icy planetesimals onto the protoplanet within the {approx}<5 AU disk region.« less
NASA Astrophysics Data System (ADS)
Masood, W.; Mirza, Arshad M.
2014-04-01
A set of nonlinear equations governing the dynamics of finite amplitude drift-ion acoustic-waves is derived for sheared ion flows parallel and perpendicular to the ambient magnetic field in the presence of Cairns and Kappa distributed electrons. It is shown that stationary solution of the nonlinear equations can be represented in the form of a tripolar vortex for specific profiles of the equilibrium sheared flows. The tripolar vortices are, however, observed to form on a scale of the order of ion Larmor radius ρ i which is calculated to be around a Kilometer for the plasma parameters found in the Saturn's E-ring. The relevance of the present investigation in planetary environments is also pointed out.
FORMATION OF A PROPELLER STRUCTURE BY A MOONLET IN A DENSE PLANETARY RING
DOE Office of Scientific and Technical Information (OSTI.GOV)
Michikoshi, Shugo; Kokubo, Eiichiro, E-mail: michikoshi@cfca.jp, E-mail: kokubo@th.nao.ac.jp
2011-05-10
The Cassini spacecraft discovered a propeller-shaped structure in Saturn's A. This propeller structure is thought to be formed by gravitational scattering of ring particles by an unseen embedded moonlet. Self-gravity wakes are prevalent in dense rings due to gravitational instability. Strong gravitational wakes affect the propeller structure. Here, we derive the condition for the formation of a propeller structure by a moonlet embedded in a dense ring with gravitational wakes. We find that a propeller structure is formed when the wavelength of the gravitational wakes is smaller than the Hill radius of the moonlet. We confirm this formation condition bymore » performing numerical simulations. This condition is consistent with observations of propeller structures in Saturn's A.« less
The halo of M 49 and its environment as traced by planetary nebulae populations
NASA Astrophysics Data System (ADS)
Hartke, J.; Arnaboldi, M.; Longobardi, A.; Gerhard, O.; Freeman, K. C.; Okamura, S.; Nakata, F.
2017-07-01
Context. The galaxy M 49 (NGC 4472) is the brightest early-type galaxy in the Virgo Cluster. It is located in subcluster B and has an unusually blue, metal-poor outer halo. Planetary nebulae (PNe) are excellent tracers of diffuse galaxy and intragroup light (IGL). Aims: We aim to present a photometric survey of PNe in the galaxy's extended halo to characterise its PN population, as well as the surrounding IGL of the subcluster B. Methods: PNe were identified based on their bright [OIII]5007 Å emission and absence of a broad-band continuum through automated detection techniques. Results: We identify 738 PNe out to a radius of 155 kpc from M 49's centre from which we define a complete sample of 624 PNe within a limiting magnitude of m5007,lim = 28.8. Comparing the PN number density to the broad-band stellar surface brightness profile, we find a variation of the PN-specific frequency (α-parameter) with radius. The outer halo beyond 60kpc has a 3.2 times higher α-parameter compared to the main galaxy halo (α2.5,innerM 49 = (3.20 ± 0.43) × 10-9 PN L-1⊙,bol), which is likely due to contribution from the surrounding blue IGL. We use the planetary nebulae luminosity function (PNLF) as an indicator of distance and stellar population. Its slope, which correlates empirically with galaxy type, varies within the inner halo. In the eastern quadrant of M 49, the PNLF slope is shallower, indicating an additional localised, bright PN population following an accretion event, likely that of the dwarf irregular galaxy VCC1249. We also determined a distance modulus of μPNLF = 31.29+ 0.07-0.08 for M 49, corresponding to a physical distance of 18.1 ± 0.6 Mpc, which agrees with a recent surface-brightness fluctuations distance. Conclusions: The PN populations in the outer halo of M 49 are consistent with the presence of a main Sérsic galaxy halo with a slight (B - V) colour gradient of 10-4 mag arcsec-1 surrounded by IGL with a very blue colour of (B - V) = 0.25 and a constant surface brightness μV = 28.0 mag arcsec-2. Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan under programme S14A-006.
NASA Astrophysics Data System (ADS)
Estrada, P. R.; Mosqueira, I.
2003-05-01
Mosqueira and Estrada (2003a) argue that following giant planet accretion a largely quiescent circumplanetary disk may form with most of the mass inside a radius located outside, but perhaps close to, the centrifugal radius rc = RH/48, where the specific angular momentum of the collapsing giant planet gaseous envelope achieves centrifugal balance, and extending as far as the irregular satellites at RH/5 due to the high specific angular momentum of parcels of gas accreted from distances several times RH during the final stages of planetary growth (Lubow et al. 1999). Provided that allowances are made for the capture of Triton from heliocentric orbit, this picture fits well with the primordial satellite systems of all four giant planets. Because strong gas turbulence would smooth out the gas surface density of the disk, this description can only apply if the turbulence subsides as planetary accretion ceases. Although the viability of a hydrodynamic shear instability in Keplerian disks that can sustain significant post-accretion turbulence and drive evolution of the gas disk is in serious doubt (see Mosqueira et al. this conference), the possibility has not yet been totally ruled out. This leads us to consider gas-poor scenarios that might produce a close-in regular satellite system. To this end, we re-examine the ideas of Safronov et al. (1986) to see whether a gas-free (or nearly gas-free) model can be made consistent with the extent of the regular satellites of the giant planets. In this model, planetesimals containing most of the mass of solids (Mizuno et al. 1978; Weidenschilling 1997) that are de-coupled from the gas and whose dynamics must be followed independently are collisionally captured and form a swarm of circumplanetary objects lasting for perhaps ˜ 106 years. While such a swarm might occupy a significant fraction of the Hill radius of the planet, the small net angular momentum of the swarm might lead to the formation of close-in prograde satellites as observed. A key point that this model must contend with is how to capture sufficient mass to form the Galilean satellites while still making Callisto partially differentiated. Other points of comparison with the model of Mosqueira and Estrada (2003a, b) may be briefly discussed (such as the concentration of mass in Titan, the apparent lack of objects between the regular and irregular satellites, the low density of the small Saturnian satellites, and the compositional gradient of the Galilean satellites).
Global Lunar Geochemistry and Its Significant Parallel With Terrestrial One
NASA Astrophysics Data System (ADS)
Kochemasov, G.
Planetary geochemistry reflects planetary tectonic pattern. The most global tectonic feature is the ubiquitous dichotomy (Theorem 1, [1]) with one hemisphere of a di- minished radius (concave) opposed by the convex hemisphere with an increased ra- dius. The terrestrial case is well known: the pressed in Pacific hemisphere is opposed by the bulging out continental one. This tectonics finds its demonstration in global geochemistry: the concave part is filled with denser basalts, rich in Fe, Ti, and the convex part is built of more acidic less dense lithologies, on average of andesitic composition. Much smaller Moon (almost 100 times less massive) reveals the same tectonic-geochemical construction. The near concave side is occupied by Procellarum basin and large marea filled with dense basalts rich in Fe, Ti. The far convex side is built of less dense anarthosites. On both planetary bodies the convex hemispheres are complicated by large subsided sectors (Theorem 2, [1]) filled with, as required by Theorem 4 [1], denser basalts. At Earth it is the Indoceanic sector, on the Moon the South Pole-Aitken basin. Genetically they are similar and constitute regular parts of global tectono-geochemistry (here there is no place for random impact or plate tec- tonic origin of these deep global depressions, they are components of "wave1-wave2" produced structures). The Lunar Prospector global geochemical coverage [2] allows to make lunar - terrestrial parallels not only in dichotomic distribution of iron and ti- tanium but also in distribution of potassium and thorium marking a contact between two dichotomic hemispheres. At Earth the seismically active contact is famous by its andesitic volcanism. Andesites comparative to basalts are richer in K and Th. On the Moon this transitional zone between the dichotomic halves is enriched with Th and K as well [2]. The transition to highlands requires less dense than mare basalts lithologies and they appear as feldspar-rich KREEP basalts enriched with K and Th. The geochemical parallel between two planetary bodies is not occasional and is a con- sequence of the wave planetary tectonics. References: [1] Kochemasov G.G. (1999) Theorems of wave planetary tectonics //Geophys. Res. Abstr., v.1, #3, 700; [2]Chevrel 1 S.D., Pinet P.C., Daydou Y. et al (2001) Global scale multielement analysis of the lunar surface using iron, titanium and thorium abundances // 34th Vernadsky-Brown microsymposium. Topics in comparative planetology. Moscow, Vernadsky Inst., Oct. 8-9, 2001,Abstracts, (CD-ROM).
30 CFR 250.1159 - May the Regional Supervisor limit my well or reservoir production rates?
Code of Federal Regulations, 2010 CFR
2010-07-01
... reservoir production rates? 250.1159 Section 250.1159 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and... reservoir production rates? (a) The Regional Supervisor may set a Maximum Production Rate (MPR) for a...
Kim, Ki-Hyun; Susaya, Janice; Cho, Jinwoo; Parker, David
2012-01-01
Commercial standard gas generators are often complex and expensive devices. The objective of this research was to assess the performance of a simplified glass impinger system for standard gas generation from a permeation tube (PT) device. The performance of the impinger standard gas generation system was assessed for four aromatic VOCs (benzene, toluene, ethylbenzene, and m-xylene; BTEX) at varying flow rates (FR) of 50 to 800 mL·min−1. Because actual permeation rate (APR) values deviated from those computed by the manufacturer's formula (MPR), new empirical relationships were developed to derive the predicted PR (PPR) of the target components. Experimental results corrected by such a formula indicate that the compatibility between the APR and MPR generally increased with low FR, while the reproducibility was generally reduced with decreasing flow rate. Although compatibility between different PRs is at a relatively small and narrow FR range, the use of correction formula is recommendable for the accurate use of PT. PMID:23112641
Pulmonary Artery Aneurysm/Pseudoaneurysm, a Delayed Complication of Lung Abscess: A Case Report.
Oguma, Tsuyoshi; Morise, Masahiro; Harada, Kazuki; Tanaka, Jun; Sato, Masako; Horio, Yukihiro; Takiguchi, Hiroto; Tomomatsu, Hiromi; Tomomatsu, Katsuyoshi; Takihara, Takahisa; Niimi, Kyoko; Hayama, Naoki; Aoki, Takuya; Urano, Tetsuya; Ito, Chihiro; Koizumi, Jun; Asano, Koichiro
2015-09-20
Massive hemoptysis mostly arises from the bronchial arteries; however, bleeding can also occur from a lesion in injured pulmonary arteries, such as pulmonary artery aneurysm/pseudoaneurysm (PAA/PAP), during pulmonary infection. A 66-year-old man was admitted with a diagnosis of lung abscess in the right lower lobe that was complicated with pyothorax. Intravenous administration of antibiotics and thoracic drainage successfully controlled the infection and inflammation until day 16, when the patient began to exhibit hemoptysis and bloody pleural effusion. Enhanced computed tomography (CT) with multi-planer reconstruction (MPR) images showed a highly enhanced mass inside the abscess fed by the pulmonary artery, suggesting PAA/PAP. Pulmonary angiography confirmed PAA/PAP, and embolization with coils successfully stopped both the bleeding into the sputum and pleural effusion, with a collapsed aneurysm visible on chest CT scan. Clinicians should consider the possibility of PAA/PAP in the differential diagnosis of hemoptysis during the treatment of patients with lung abscess. MPR CT is helpful for the diagnosis of PAA/PAP and its feeding vessels.
Boczek, Christelle; Frauger, Elisabeth; Micallef, Joëlle; Allaria-Lapierre, Véronique; Reggio, Patrick; Sciortino, Vincent
2012-01-01
To assess the national market penetration rate (PR) of generic high-dosage buprenorphine (HDB) in 2008 and its evolution since their marketing (2006), and making a point for each dosage and at regional level. Retrospective study over data using national and regional health reimbursement database over three years (2006-2008). In 2008, the generic HDB's national MPR was 31%. The PR for each dosage were 45% for 0.4 mg, 36% for 2 mg and 19% for 8 mg. The (PR) based on Defined Daily Dose (DDD) was 23% in 2008, 15% in 2007 and 4% in 2006. In 2008, at the regional level, disparities were observed in the adjusted penetration rate from 15% in Île de France to 39% in Champagne Ardennes Lorraine. The national PR of generic HDB has increased. There are differences in MPR in terms of dosage and area. However, this PR is still low (in 2008, 82% of the delivered drugs are generics). © 2012 Société Française de Pharmacologie et de Thérapeutique.
Photometric Determination of Ammonium and Phosphate in Seawater Medium Using a Microplate Reader.
Ruppersberg, Hanna S; Goebel, Maren R; Kleinert, Svea I; Wünsch, Daniel; Trautwein, Kathleen; Rabus, Ralf
2017-01-01
To more efficiently process the large sample numbers for quantitative determination of ammonium (NH4+) and phosphate (orthophosphate, PO43-) generated during comprehensive growth experiments with the marine Roseobacter group member Phaeobacter inhibens DSM 17395, specific colorimetric assays employing a microplate reader (MPR) were established. The NH4+ assay is based on the reaction of NH4+ with hypochlorite and salicylate, yielding a limit of detection of 14 µM, a limit of quantitation of 36 µM, and a linear range for quantitative determination up to 200 µM. The PO43-assay is based on the complex formation of PO43- with ammonium molybdate in the presence of ascorbate and zinc acetate, yielding a limit of detection of 13 µM, a limit of quantitation of 50 µM, and a linear range for quantitative determination up to 1 mM. Both MPR-based assays allowed for fast (significantly lower than 1 h) analysis of 21 samples plus standards for calibration (all measured in triplicates) and showed only low variation across a large collection of biological samples. © 2017 S. Karger AG, Basel.
Cone beam computed tomography in veterinary dentistry.
Van Thielen, Bert; Siguenza, Francis; Hassan, Bassam
2012-01-01
The purpose of this study was to assess the feasibility of cone beam computed tomography (CBCT) in imaging dogs and cats for diagnostic dental veterinary applications. CBCT scans of heads of six dogs and two cats were made. Dental panoramic and multi-planar reformatted (MPR) para-sagittal reconstructions were created using specialized software. Image quality and visibility of anatomical landmarks were subjectively assessed by two observers. Good image quality was obtained for the MPR para-sagittal reconstructions through multiple teeth. The image quality of the panoramic reconstructions of dogs was moderate while the panoramic reconstructions of cats were poor since the images were associated with an increased noise level. Segmental panoramic reconstructions of the mouth seem to be useful for studying the dental anatomy especially in dogs. The results of this study using human dental CBCT technology demonstrate the potential of this scanning technology in veterinary medicine. Unfortunately, the moderate image quality obtained with the CBCT technique reported here seems to be inferior to the diagnostic image quality obtained from 2-dimensional dental radiographs. Further research is required to optimize scanning and reconstruction protocols for veterinary applications.
Nakano, Shogo; Yoshida, Miwa; Fujii, Kimihito; Yorozuya, Kyoko; Kousaka, Junko; Mouri, Yukako; Fukutomi, Takashi; Ohshima, Yukihiko; Kimura, Junko; Ishiguchi, Tsuneo
2012-01-01
This study verified that recently developed real-time virtual sonography (RVS) to coordinate a sonography image and the magnetic resonance imaging (MRI) multiplanar reconstruction (MPR) with magnetic navigation was useful. The purpose of this study was to evaluate the accuracy of RVS to sonographically identify enhancing lesions by breast MRI. Between December 2008 and May 2009, RVS was performed in 51 consecutive patients with 63 enhancing lesions. MRI was performed with the patients in the supine position using a 1.5-T imager with a body surface coil to achieve the same position as with sonography. To assess the accuracy of the RVS, the following three issues were analyzed: (i) The sonographic detection rate of enhancing lesions, (ii) the comparison of the tumor size measured by sonography and the MRI-MPR and (iii) the positioning errors as the distance from the actual sonographic position to the expected MRI position in 3-D. Among the 63 enhancing lesions, 42 (67%) lesions were identified by conventional B-mode, whereas the remaining 21 (33%) initial conventional B-mode occult lesions were identified by RVS alone. The sonographic size of the lesions detected by RVS alone was significantly smaller than that of lesions detected by conventional B-mode (p < 0.001). The mean tumor size provided by RVS was 12.3 mm for real-time sonography and 14.1 mm for MRI-MPR (r = 0.848, p < 0.001). The mean positioning errors for the transverse and sagittal planes and the depth from the skin were 7.7, 6.9 and 2.8 mm, respectively. The overall mean 3D positioning error was 12.0 mm. Our results suggest that RVS has good targeting accuracy to directly compare a sonographic image with MRI results without operator dependence. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Vincent, Salom Gnana Thanga; Reshmi, R. R.; Hassan, S. Junaid; Nair, K. Deepa; Varma, Ajayakumar
2017-11-01
Anaerobic microbial communities in the anoxic zones degrade organic matter in estuarine sediments. Thermodynamic energy yield for the oxidation reactions with various electron acceptors decreases in the order of O2> NO3- > Mn4+> Fe3+> SO42- > CO2. The predominant terminal electron accepting (TEA) process has an influence on the biogeochemical cycles of nutrients as well as the production of important greenhouse gases such as nitrous oxide and methane from estuarine sediments. The research questions of this study were (1) what are the environmental factors (pH, salinity, organic carbon, sulphate, redox potential) explaining variability in TEA activities such as nitrate reduction rate (NRR), iron reduction rate (IRR), sulphate reduction rate (SRR) and methane production rate (MPR) and (2) which is the predominant TEA process during degradation of organic matter. To determine the TEA activities, sediment samples collected from 13 sampling stations of Ashtamudi estuary during monsoon 2014 and summer 2015 were incubated with sulphate depleted artificial seawater, under anaerobic conditions for 72 h, in microcosms. Spatial variations dominated temporal variations for environmental variables. Nevertheless, biogeochemical processes showed a distinct seasonal variation. Total TEA activity was higher during summer than monsoon, indicating the higher heterotrophic microbial activity favored by high temperature. Individually, SRR was the maximum during summer, while NRR, IRR and MPR were the maximum during monsoon. Sulphate reduction was observed to be the predominant electron accepting process in all sampling stations with cumulative values of 3125.79 and 4046.07 nmol cm-3 day-1 during monsoon and summer respectively. This was followed by NRR, IRR and MPR. Although thermodynamically more favorable, NRR could not predominate due to scarcity of nitrate in sediments. Nevertheless, two-fold and five-fold increase in methanogenesis and denitrification were observed respectively during monsoon in sampling stations, which cannot be ignored, owing to the importance of methane and nitrous oxide as a potent greenhouse gas.
DOE`s annealing prototype demonstration projects
DOE Office of Scientific and Technical Information (OSTI.GOV)
Warren, J.; Nakos, J.; Rochau, G.
1997-02-01
One of the challenges U.S. utilities face in addressing technical issues associated with the aging of nuclear power plants is the long-term effect of plant operation on reactor pressure vessels (RPVs). As a nuclear plant operates, its RPV is exposed to neutrons. For certain plants, this neutron exposure can cause embrittlement of some of the RPV welds which can shorten the useful life of the RPV. This RPV embrittlement issue has the potential to affect the continued operation of a number of operating U.S. pressurized water reactor (PWR) plants. However, RPV material properties affected by long-term irradiation are recoverable throughmore » a thermal annealing treatment of the RPV. Although a dozen Russian-designed RPVs and several U.S. military vessels have been successfully annealed, U.S. utilities have stated that a successful annealing demonstration of a U.S. RPV is a prerequisite for annealing a licensed U.S. nuclear power plant. In May 1995, the Department of Energy`s Sandia National Laboratories awarded two cost-shared contracts to evaluate the feasibility of annealing U.S. licensed plants by conducting an anneal of an installed RPV using two different heating technologies. The contracts were awarded to the American Society of Mechanical Engineers (ASME) Center for Research and Technology Development (CRTD) and MPR Associates (MPR). The ASME team completed its annealing prototype demonstration in July 1996, using an indirect gas furnace at the uncompleted Public Service of Indiana`s Marble Hill nuclear power plant. The MPR team`s annealing prototype demonstration was scheduled to be completed in early 1997, using a direct heat electrical furnace at the uncompleted Consumers Power Company`s nuclear power plant at Midland, Michigan. This paper describes the Department`s annealing prototype demonstration goals and objectives; the tasks, deliverables, and results to date for each annealing prototype demonstration; and the remaining annealing technology challenges.« less
NASA Astrophysics Data System (ADS)
Noh, Seong Jin; Rakovec, Oldrich; Kumar, Rohini; Samaniego, Luis
2016-04-01
There have been tremendous improvements in distributed hydrologic modeling (DHM) which made a process-based simulation with a high spatiotemporal resolution applicable on a large spatial scale. Despite of increasing information on heterogeneous property of a catchment, DHM is still subject to uncertainties inherently coming from model structure, parameters and input forcing. Sequential data assimilation (DA) may facilitate improved streamflow prediction via DHM using real-time observations to correct internal model states. In conventional DA methods such as state updating, parametric uncertainty is, however, often ignored mainly due to practical limitations of methodology to specify modeling uncertainty with limited ensemble members. If parametric uncertainty related with routing and runoff components is not incorporated properly, predictive uncertainty by DHM may be insufficient to capture dynamics of observations, which may deteriorate predictability. Recently, a multi-scale parameter regionalization (MPR) method was proposed to make hydrologic predictions at different scales using a same set of model parameters without losing much of the model performance. The MPR method incorporated within the mesoscale hydrologic model (mHM, http://www.ufz.de/mhm) could effectively represent and control uncertainty of high-dimensional parameters in a distributed model using global parameters. In this study, we present a global multi-parametric ensemble approach to incorporate parametric uncertainty of DHM in DA to improve streamflow predictions. To effectively represent and control uncertainty of high-dimensional parameters with limited number of ensemble, MPR method is incorporated with DA. Lagged particle filtering is utilized to consider the response times and non-Gaussian characteristics of internal hydrologic processes. The hindcasting experiments are implemented to evaluate impacts of the proposed DA method on streamflow predictions in multiple European river basins having different climate and catchment characteristics. Because augmentation of parameters is not required within an assimilation window, the approach could be stable with limited ensemble members and viable for practical uses.
Moss, Alan C; Lillis, Yvonne; Edwards George, Jessica B; Choudhry, Niteesh K; Berg, Anders H; Cheifetz, Adam S; Horowitz, Gary; Leffler, Dan A
2014-12-01
Poor adherence to mesalamine is common and driven by a combination of lifestyle and behavioral factors, as well as health beliefs. We sought to develop a valid tool to identify barriers to patient adherence and predict those at risk for future nonadherence. A 10-item survey was developed from patient-reported barriers to adherence. The survey was administered to 106 patients with ulcerative colitis who were prescribed mesalamine, and correlated with prospectively collected 12-month pharmacy refills (medication possession ratio (MPR)), urine levels of salicylates, and self-reported adherence (Morisky Medication Adherence Scale (MMAS)-8). From the initial 10-item survey, 8 items correlated highly with the MMAS-8 score at enrollment. Computer-generated randomization produced a derivation cohort of 60 subjects and a validation cohort of 46 subjects to assess the survey items in their ability to predict future adherence. Two items from the patient survey correlated with objective measures of long-term adherence: their belief in the importance of maintenance mesalamine even when in remission and their concerns about side effects. The additive score based on these two items correlated with 12-month MPR in both the derivation and validation cohorts (P<0.05). Scores on these two items were associated with a higher risk of being nonadherent over the subsequent 12 months (relative risk (RR) =2.2, 95% confidence interval=1.5-3.5, P=0.04). The area under the curve for the performance of this 2-item tool was greater than that of the 10-item MMAS-8 score for predicting MPR scores over 12 months (area under the curve 0.7 vs. 0.5). Patients' beliefs about the need for maintenance mesalamine and their concerns about side effects influence their adherence to mesalamine over time. These concerns could easily be raised in practice to identify patients at risk of nonadherence (Clinical Trial number NCT01349504).
Long, Judith A; Wang, Andrew; Medvedeva, Elina L; Eisen, Susan V; Gordon, Adam J; Kreyenbuhl, Julie; Marcus, Steven C
2014-08-01
Persons with serious mental illness (SMI) may benefit from collocation of medical and mental health healthcare professionals and services in attending to their chronic comorbid medical conditions. We evaluated and compared glucose control and diabetes medication adherence among patients with SMI who received collocated care to those not receiving collocated care (which we call usual care). We performed a cross-sectional, observational cohort study of 363 veteran patients with type 2 diabetes and SMI who received care from one of three Veterans Affairs medical facilities: two sites that provided both collocated and usual care and one site that provided only usual care. Through a survey, laboratory tests, and medical records, we assessed patient characteristics, glucose control as measured by a current HbA1c, and adherence to diabetes medication as measured by the medication possession ration (MPR) and self-report. In the sample, the mean HbA1c was 7.4% (57 mmol/mol), the mean MPR was 80%, and 51% reported perfect adherence to their diabetes medications. In both unadjusted and adjusted analyses, there were no differences in glucose control and medication adherence by collocation of care. Patients seen in collocated care tended to have better HbA1c levels (β = -0.149; P = 0.393) and MPR values (β = 0.34; P = 0.132) and worse self-reported adherence (odds ratio 0.71; P = 0.143), but these were not statistically significant. In a population of veterans with comorbid diabetes and SMI, patients on average had good glucose control and medication adherence regardless of where they received primary care. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.
3D numerical model of the southern polar giant impact for the formation of the Martian dichotomy
NASA Astrophysics Data System (ADS)
Leone, Giovanni; Tackley, Paul J.; Gerya, Taras; May, David A.; Zhu, Guizhi
2013-04-01
Lack of volcanism and/or crustal flows in the northern lowlands poses serious problems to the hypothesis of formation of the Borealis basin by giant impact in the Northern Polar region of Mars. We use numerical modeling integrated with a geologic and volcanologic study of the surface of Mars to investigate an alternative process of formation that involves a giant impact on the South Pole, resulting in a hemispherical magma pond and resulting thicker crust. We have performed 3D simulations of Martian evolution from the immediate post-impact stage to the present day for different combinations of impactor sizes and compositions, ranging from 900 km radius and sideritic composition (up to 80% radius iron) to 1750 km radius and mesosiderite-type composition (50% radius iron; nickel neglected at the moment). The main reason for considering siderites is the presence of M-type asteroids like 16 Psyche (and several others) in the asteroid belt, the likely remnants of larger parent bodies in the 1-2 AU range which then migrated to their current position after giant impacts with protoplanets. We assume an impactor speed similar to the escape velocity of the target body, consistent with N-body simulations. Our results show that this is a viable formation hypothesis for the southern highlands. Our preferred scenario is of a lunar sized impactor of 1600 km radius with a 70% iron (by radius) fraction, hitting the south Pole at a speed of 5 km/s (the escape velocity of Mars), melting much of the interior and 1/2 of the planetary surface with the creation of a magma ocean that formed the highlands upon cooling and solidification. Regarding timing, we find that this should have happened after 4 Ma after CAI, because before this the strong heating from short-lived radiogenic elements coupled with the thermal anomaly generated by the giant impact would erase by re-melting any newly formed crust. Using a combination of I3ELVIS (immediate post-impact and core formation) and STAGYY (long-term) thermo-mechanical codes, we are now studying the long-term consequences of such a giant impact: a) thermal and compositional effect on core formation; b) triggering of a transient magnetic field, traces of which have been detected on both the hemispheres; c) start-up of migrating mantle plumes from the southern polar region to the equator following two preferential paths, northwest to Tharsis and northeast to Elysium.
Verbiscer, Anne J; Skrutskie, Michael F; Hamilton, Douglas P
2009-10-22
Most planetary rings in the Solar System lie within a few radii of their host body, because at these distances gravitational accelerations inhibit satellite formation. The best known exceptions are Jupiter's gossamer rings and Saturn's E ring, broad sheets of dust that extend outward until they fade from view at five to ten planetary radii. Source satellites continuously supply the dust, which is subsequently lost in collisions or by radial transport. Here we report that Saturn has an enormous ring associated with its outer moon Phoebe, extending from at least 128R(S) to 207R(S) (Saturn's radius R(S) is 60,330 km). The ring's vertical thickness of 40R(S) matches the range of vertical motion of Phoebe along its orbit. Dynamical considerations argue that these ring particles span the Saturnian system from the main rings to the edges of interplanetary space. The ring's normal optical depth of approximately 2 x 10(-8) is comparable to that of Jupiter's faintest gossamer ring, although its particle number density is several hundred times smaller. Repeated impacts on Phoebe, from both interplanetary and circumplanetary particle populations, probably keep the ring populated with material. Ring particles smaller than centimetres in size slowly migrate inward and many of them ultimately strike the dark leading face of Iapetus.
A Hot White Dwarf SDSS J134430.11+032423.1 with a Planetary Debris Disk
NASA Astrophysics Data System (ADS)
Li, Lifang; Zhang, Fenghui; Kong, Xiaoyang; Han, Quanwang; Li, Jiansha
2017-02-01
We discovered a debris disk around hot white dwarf (WD) SDSS J134430.11+032423.1 (SDSS J1344+0324). The effective temperature [{T}{eff} = 26,071(±163) K], surface gravity [{log}g=7.88(2)], and mass [M=0.58(1) {M}⊙ ] of this WD have been redetermined based on the analysis of its SDSS spectrum. We found that SDSS J1344+0324 is currently the hottest WD with a debris disk. Two spectra observed by SDSS at different times show that this object is similar to SDSS J1228+1040 with variable near-IR Ca II triplet emissions from a gaseous disk. The parameters of the debris disk are derived from the IR excess analysis of SDSS J1344+0324. We found that the disk is the coolest of all debris disks around WDs, and that the inner and outer radii are very close to the tide radius of the WD. Thus, the debris disk is very narrow (about 0.22 {R}⊙ ). This implies that it might be a newly formed disk resulting from the tidal disruption of a rocky planetary body that has just entered the tide volume of the WD. This might provide strong observational evidence for the formation of debris disks around WDs.
Revealing the structure and dust content of debris disks on solar systems scales with GPI
NASA Astrophysics Data System (ADS)
Duchene, Gaspard; Fitzgerald, Michael P.; Kalas, Paul; Graham, James R.; Arriaga, Pauline; Bruzzone, Sebastian; Chen, Christine; Dawson, Rebekah Ilene; Dong, Ruobing; Draper, Zachary; Esposito, Thomas; Follette, Katherine; Hung, Li-Wei; Lawler, Samantha; Metchev, Stanimir; Millar-Blanchaer, Max; Murray-Clay, Ruth; Perrin, Marshall D.; Rameau, Julien; Wang, Jason; Wolff, Schuyler; Macintosh, Bruce; GPIES Team
2016-01-01
High contrast scattered light images offer the best prospect to assess the detailed geometry and structure of dusty debris disks. In turn, such images can yield profound insight on the architecture of the underlying planetary system as dust grains respond to the gravitational pull of planetary bodies. A new generation of extreme adaptive optics systems now enables an unprecedented exploration of circumstellar disks on solar system scales. Here we review the new science derived from over a dozen debris disks imaged with the Gemini Planet Imager (GPI) as part of the GPI Exoplanet Survey (GPIES). In addition to its exquisite imaging capability, GPI's polarimetric mode provides invaluable insight on the dust content of each disk, in most cases for the very first time. These early results typically reveal narrow belts of material with evacuated regions roughly 50-100 AU in radius, subtle asymmetries in structure and high degree of linear polarization. We will provide an overview of the disk observations made during the GPIES campaign to date and will discuss in more detail some of the most remarkable systems.This work is supported by grants NSF AST-0909188, -1411868, -1413718; NASA NNX-15AD95G, -14AJ80G, -11AD21G; and the NExSS research network.
Characterizing Protoplanetary Disks in a Young Binary in Orion
NASA Astrophysics Data System (ADS)
Powell, Jonas; Hughes, A. Meredith; Mann, Rita; Flaherty, Kevin; Di Francesco, James; Williams, Jonathan
2018-01-01
Planetary systems form in circumstellar disks of gas and dust surrounding young stars. One open question in the study of planet formation involves understanding how different environments affect the properties of the disks and planets they generate. Understanding the properties of disks in high-mass star forming regions (SFRs) is critical since most stars - probably including our Sun - form in those regions. By comparing the disks in high-mass SFRs to those in better-studied low-mass SFRs we can learn about the role environment plays in planet formation. Here we present 0.5" resolution observations of the young two-disk binary system V2434 Ori in the Orion Nebula from the Atacama Large Millimeter/submillimeter Array (ALMA) in molecular line tracers of CO(3-2), HCN(4-3), HCO+(4-3) and CS(7-6). We model each disk’s mass, radius, temperature structure, and molecular abundances, by creating synthetic images using an LTE ray-tracing code and comparing simulated observations with the ALMA data in the visibility domain. We then compare our results to a previous study of molecular line emission from a single Orion proplyd, modeled using similar methods, and to previously characterized disks in low-mass SFRs to investigate the role of environment in disk chemistry and planetary system formation.
NASA Astrophysics Data System (ADS)
Raymond, Sean N.; Armitage, Philip J.; Veras, Dimitri; Quintana, Elisa V.; Barclay, Thomas
2018-05-01
'Oumuamua, the first bona fide interstellar planetesimal, was discovered passing through our Solar system on a hyperbolic orbit. This object was likely dynamically ejected from an extrasolar planetary system after a series of close encounters with gas giant planets. To account for 'Oumuamua's detection, simple arguments suggest that ˜1 M⊕ of planetesimals are ejected per solar mass of Galactic stars. However, that value assumes mono-sized planetesimals. If the planetesimal mass distribution is instead top-heavy, the inferred mass in interstellar planetesimals increases to an implausibly high value. The tension between theoretical expectations for the planetesimal mass function and the observation of 'Oumuamua can be relieved if a small fraction ({˜ } 0.1-1 {per cent}) of planetesimals are tidally disrupted on the pathway to ejection into 'Oumuamua-sized fragments. Using a large suite of simulations of giant planet dynamics including planetesimals, we confirm that 0.1-1 per cent of planetesimals pass within the tidal disruption radius of a gas giant on their pathway to ejection. 'Oumuamua may thus represent a surviving fragment of a disrupted planetesimal. Finally, we argue that an asteroidal composition is dynamically disfavoured for 'Oumuamua, as asteroidal planetesimals are both less abundant and ejected at a lower efficiency than cometary planetesimals.
Measuring the Number of M Dwarfs per M Dwarf Using Kepler Eclipsing Binaries
NASA Astrophysics Data System (ADS)
Shan, Yutong; Johnson, John A.; Morton, Timothy D.
2015-11-01
We measure the binarity of detached M dwarfs in the Kepler field with orbital periods in the range of 1-90 days. Kepler’s photometric precision and nearly continuous monitoring of stellar targets over time baselines ranging from 3 months to 4 years make its detection efficiency for eclipsing binaries nearly complete over this period range and for all radius ratios. Our investigation employs a statistical framework akin to that used for inferring planetary occurrence rates from planetary transits. The obvious simplification is that eclipsing binaries have a vastly improved detection efficiency that is limited chiefly by their geometric probabilities to eclipse. For the M-dwarf sample observed by the Kepler Mission, the fractional incidence of eclipsing binaries implies that there are {0.11}-0.04+0.02 close stellar companions per apparently single M dwarf. Our measured binarity is higher than previous inferences of the occurrence rate of close binaries via radial velocity techniques, at roughly the 2σ level. This study represents the first use of eclipsing binary detections from a high quality transiting planet mission to infer binary statistics. Application of this statistical framework to the eclipsing binaries discovered by future transit surveys will establish better constraints on short-period M+M binary rate, as well as binarity measurements for stars of other spectral types.
ARCHITECTURE AND DYNAMICS OF KEPLER'S CANDIDATE MULTIPLE TRANSITING PLANET SYSTEMS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lissauer, Jack J.; Jenkins, Jon M.; Borucki, William J.
About one-third of the {approx}1200 transiting planet candidates detected in the first four months of Kepler data are members of multiple candidate systems. There are 115 target stars with two candidate transiting planets, 45 with three, 8 with four, and 1 each with five and six. We characterize the dynamical properties of these candidate multi-planet systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean-motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to bemore » in resonance, particularly near the 2:1 resonance. We find that virtually all candidate systems are stable, as tested by numerical integrations that assume a nominal mass-radius relationship. Several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. Using the observed multiplicity frequencies, we find that a single population of planetary systems that matches the higher multiplicities underpredicts the number of singly transiting systems. We provide constraints on the true multiplicity and mutual inclination distribution of the multi-candidate systems, revealing a population of systems with multiple super-Earth-size and Neptune-size planets with low to moderate mutual inclinations.« less
Hypervelocity impacts and magnetization of small bodies in the Solar System
NASA Technical Reports Server (NTRS)
Chen, Guangqing; Ahrens, Thomas J.; Hide, Raymond
1995-01-01
The observed magnetism of asteroids such as Gaspra and Ida (and other small bodies in the solar system including the Moon and meteorites) may have resulted from an impact-induced shock wave producing a thermodynamic state in which iron-nickel alloy, dispersed in a silicate matrix, is driven from the usual low-temperature, low-pressure, alpha, kaemacite, phase to the paramagnetic, epsilon (hcp), phase. The magnetization was acquired upon rarefaction and reentry into the ferromagnetic, alpha, structure. The degree of remagnetization depends on the strength of the ambient field, which may have been associated with a Solar-System-wide magnetic field. A transient field induced by the impact event itself may have resulted in a significant, or possibly, even a dominant contribution, as well. The scaling law of Housen et al. (Housen, K. R., R. M. Schmidt, and K. A. Holsapple 1991) for catastrophic asteroid impact disaggregation imposes a constraint on the degree to which small planetary bodies may be magnetized and yet survive fragmentation by the same event. Our modeling results show it is possible that Ida was magnetized when a large impact fractured a 125 +/- 22-km-radius protoasteroid to form the Koronis family. Similarly, we calculate that Gaspra could be a magnetized fragment of a 45 +/- 15 km-radius protoasteroid.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Johnson, John Asher; Morton, T. D.; Winn, J. N.
We report the discovery of HAT-P-30b, a transiting exoplanet orbiting the V = 10.419 dwarf star GSC 0208-00722. The planet has a period P = 2.810595 {+-} 0.000005 days, transit epoch T{sub c} = 2455456.46561 {+-} 0.00037 (BJD), and transit duration 0.0887 {+-} 0.0015 days. The host star has a mass of 1.24 {+-} 0.04 M{sub sun}, radius of 1.21 {+-} 0.05 R{sub sun}, effective temperature of 6304 {+-} 88 K, and metallicity [Fe/H] = +0.13 {+-} 0.08. The planetary companion has a mass of 0.711 {+-} 0.028 M{sub J} and radius of 1.340 {+-} 0.065 R{sub J} yielding amore » mean density of 0.37 {+-} 0.05 g cm{sup -3}. We also present radial velocity measurements that were obtained throughout a transit that exhibit the Rossiter-McLaughlin effect. By modeling this effect, we measure an angle of {lambda} = 73.{sup 0}5 {+-} 9.{sup 0}0 between the sky projections of the planet's orbit normal and the star's spin axis. HAT-P-30b represents another example of a close-in planet on a highly tilted orbit, and conforms to the previously noted pattern that tilted orbits are more common around stars with T{sub eff*} {approx}> 6250 K.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tang, Ya-Wen; Dutrey, Anne; Guilloteau, Stéphane
We aim to unveil the observational imprint of physical mechanisms that govern planetary formation in the young, multiple system GG Tau A. We present ALMA observations of {sup 12}CO and {sup 13}CO 3–2 and 0.9 mm continuum emission with 0.″35 resolution. The {sup 12}CO 3–2 emission, found within the cavity of the circumternary dust ring (at radius <180 au) where no {sup 13}CO emission is detected, confirms the presence of CO gas near the circumstellar disk of GG Tau Aa. The outer disk and the recently detected hot spot lying at the outer edge of the dust ring are mappedmore » both in {sup 12}CO and {sup 13}CO. The gas emission in the outer disk can be radially decomposed as a series of slightly overlapping Gaussian rings, suggesting the presence of unresolved gaps or dips. The dip closest to the disk center lies at a radius very close to the hot spot location at ∼250–260 au. The CO excitation conditions indicate that the outer disk remains in the shadow of the ring. The hot spot probably results from local heating processes. The two latter points reinforce the hypothesis that the hot spot is created by an embedded proto-planet shepherding the outer disk.« less
Structural history of Maxwell Montes, Venus: Implications for Venusian mountain belt formation
NASA Astrophysics Data System (ADS)
Keep, Myra; Hansen, Vicki L.
1994-12-01
Models for Venusian mountain belt formation are important for understanding planetary geodynamic mechanisms. A range of data sets at various scales must be considered in geodynamic modelling. Long wavelength data, such as gravity and geoid to topography ratios, need constraints from smaller-scale observations of the surface. Pre-Magellan images of the Venusian surface were not of high enough resolution to observe details of surface deformation. High-resolution Magellan images of Maxwell Montes and the other deformation belts allow us to determine the nature of surfce deformation. With these images we can begin to understand the constraints that surface deformation places on planetary dynamic models. Maxwell Montes and three other deformation belts (Akna, Freyja, and Danu montes) surround the highland plateau Lakshmi Planum in Venus, northern hemisphere. Maxwell, the highest of these belts, stands 11 km above mean planetary radius. We present a detailed structural and kinematic study of Maxwell Montes. Key observations include (1) dominant structural fabrics are broadly distributed and show little change in spacing relative to elevation changes of several kilometers; (2) the spacing, wavelength, and inferred amplitude of mapped structures are small, (3) interpreted extensional structures occur only in areas of steep slope, with no extension at the highest topographic levels; and (4) deformation terminates abruptly at the base of steep slopes. One implication of these observations is that topography is independent of thin-skinned, broadly distributed, Maxwell deformation. Maxwell is apparently stable, with no observed extensional collapse. We propose a ``deformation-from-below'' model for Maxwell, in which the crust deforms passively over structurally imbricated and thickened lower crust. This model may have implications for the other deformation belts.
Structural history of Maxwell Montes, Venus: Implications for Venusian mountain belt formation
NASA Astrophysics Data System (ADS)
Keep, Myra; Hansen, Vicki L.
1994-12-01
Models for Venusian mountain belt formation are important for understanding planetary geodynamic mechanisms. A range of data sets at various scales must be considered in geodynamic modelling. Long wavelength data, such as gravity and geoid to topography ratios, need constraints from smaller-scale observations of the surface. Pre-Magellan images of the Venusian surface were not of high enough resolution to observe details of surface deformation. High-resolution Magellan images of Maxwell Montes and the other deformation belts allow us to determine the nature of surface deformation. With these images we can begin to understand the constraints that surface deformation places on planetary dynamic models. Maxwell Montes and three other deformation belts (Akna, Freyja, and Danu montes) surround the highland plateau Lakshmi Planum in Venus' northern hemisphere. Maxwell, the highest of these belts, stands 11 km above mean planetary radius. We present a detailed structural and kinematic study of Maxwell Montes. Key observations include (1) dominant structure fabrics are broadly distributed and show little change in spacing relative to elevation changes of several kilometers; (2) the spacing, wavelength and inferred amplitude of mapped structures are small; (3) interpreted extensional structures occur only in areas of steep slope, with no extension at the highest topographic levels; and (4) deformation terminates abruptly at the base of steep slopes. One implications of these observations is that topography is independent of thin-skinned, broadly distributed, Maxwell deformation. Maxwell is apparently stable, with no observed extensional collapse. We propose a 'deformation-from-below' model for Maxwell, in which the crust deforms passively over structurally imbricated and thickened lower crust. This model may have implications for the other deformation belts.
Modeling the Surface Temperature of Earth-like Planets
NASA Astrophysics Data System (ADS)
Vladilo, Giovanni; Silva, Laura; Murante, Giuseppe; Filippi, Luca; Provenzale, Antonello
2015-05-01
We introduce a novel Earth-like planet surface temperature model (ESTM) for habitability studies based on the spatial-temporal distribution of planetary surface temperatures. The ESTM adopts a surface energy balance model (EBM) complemented by: radiative-convective atmospheric column calculations, a set of physically based parameterizations of meridional transport, and descriptions of surface and cloud properties more refined than in standard EBMs. The parameterization is valid for rotating terrestrial planets with shallow atmospheres and moderate values of axis obliquity (ɛ ≲ 45{}^\\circ ). Comparison with a 3D model of atmospheric dynamics from the literature shows that the equator-to-pole temperature differences predicted by the two models agree within ≈ 5 K when the rotation rate, insolation, surface pressure and planet radius are varied in the intervals 0.5≲ {Ω }/{{{Ω }}\\oplus }≲ 2, 0.75≲ S/{{S}\\circ }≲ 1.25, 0.3≲ p/(1 bar)≲ 10, and 0.5≲ R/{{R}\\oplus }≲ 2, respectively. The ESTM has an extremely low computational cost and can be used when the planetary parameters are scarcely known (as for most exoplanets) and/or whenever many runs for different parameter configurations are needed. Model simulations of a test-case exoplanet (Kepler-62e) indicate that an uncertainty in surface pressure within the range expected for terrestrial planets may impact the mean temperature by ˜ 60 K. Within the limits of validity of the ESTM, the impact of surface pressure is larger than that predicted by uncertainties in rotation rate, axis obliquity, and ocean fractions. We discuss the possibility of performing a statistical ranking of planetary habitability taking advantage of the flexibility of the ESTM.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Faigler, S.; Mazeh, T.
We analyzed the Kepler light curves of four transiting hot Jupiter systems—KOI-13, HAT-P-7, TrES-2, and Kepler-76, which show BEaming, Ellipsoidal, and Reflection (BEER) phase modulations. The mass of the four planets can be estimated from either the beaming or the ellipsoidal amplitude, given the mass and radius of their parent stars. For KOI-13, HAT-P-7, and Kepler-76 we find that the beaming-based planetary mass estimate is larger than the mass estimated from the ellipsoidal amplitude, consistent with previous studies. This apparent discrepancy may be explained by equatorial superrotation of the planet atmosphere, which induces an angle shift of the planet reflection/emissionmore » phase modulation, as was suggested for Kepler-76 in the first paper of this series. We propose a modified BEER model that supports superrotation, assuming either a Lambertian or geometric reflection/emission phase function, and provides a photometry-consistent estimate of the planetary mass. Our analysis shows that for Kepler-76 and HAT-P-7, the Lambertian superrotation BEER model is highly preferable over an unshifted null model, while for KOI-13 it is preferable only at a 1.4σ level. For TrES-2 we do not find such preference. For all four systems the Lambertian superrotation model mass estimates are in excellent agreement with the planetary masses derived from, or constrained by, radial velocity measurements. This makes the Lambertian superrotation BEER model a viable tool for estimating the masses of hot Jupiters from photometry alone. We conclude that hot Jupiter superrotation may be a common phenomenon that can be detected in the visual light curves of Kepler.« less
Assessing Planetary Habitability: Don't Forget Exotic Life!
NASA Astrophysics Data System (ADS)
Schulze-Makuch, Dirk
2012-05-01
With the confirmed detection of more than 700 exoplanets, the temptation looms large to constrain the search for extraterrestrial life to Earth-type planets, which have a similar distance to their star, a similar radius, mass and density. Yet, a look even within our Solar System points to a variety of localities to which life could have adapted to outside of the so-called Habitable Zone (HZ). Examples include the hydrocarbon lakes on Titan, the subsurface ocean environment of Europa, the near- surface environment of Mars, and the lower atmosphere of Venus. Recent Earth analog work and extremophile investigations support this notion, such as the discovery of a large microbial community in a liquid asphalt lake in Trinidad (as analog to Titan) or the discovery of a cryptoendolithic habitat in the Antarctic desert, which exists inside rocks, such as beneath sandstone surfaces and dolerite clasts, and supports a variety of eukaryotic algae, fungi, and cyanobacteria (as analog to Mars). We developed a Planetary Habitability Index (PHI, Schulze-Makuch et al., 2011), which was developed to prioritize exoplanets not based on their similarity to Earth, but whether the extraterrestrial environment could, in principle, be a suitable habitat for life. The index includes parameters that are considered to be essential for life such as the presence of a solid substrate, an atmosphere, energy sources, polymeric chemistry, and liquids on the planetary surface. However, the index does not require that this liquid is water or that the energy source is light (though the presence of light is a definite advantage). Applying the PHI to our Solar System, Earth comes in first, with Titan second, and Mars third.
Application of an Evolution Strategy in Planetary Ephemeris Optimization
NASA Astrophysics Data System (ADS)
Mai, E.
2016-12-01
Classical planetary ephemeris construction comprises three major steps, which are performed iteratively: simultaneous numerical integration of coupled equations of motion of a multi-body system (propagator step), reduction of thousands of observations (reduction step), and optimization of various selected model parameters (adjustment step). This traditional approach is challenged by ongoing refinements in force modeling, e.g. inclusion of much more significant minor bodies, an ever-growing number of planetary observations, e.g. vast amount of spacecraft tracking data, etc. To master the high computational burden and in order to circumvent the need for inversion of huge normal equation matrices, we propose an alternative ephemeris construction method. The main idea is to solve the overall optimization problem by a straightforward direct evaluation of the whole set of mathematical formulas involved, rather than to solve it as an inverse problem with all its tacit mathematical assumptions and numerical difficulties. We replace the usual gradient search by a stochastic search, namely an evolution strategy, the latter of which is also perfect for the exploitation of parallel computing capabilities. Furthermore, this new approach enables multi-criteria optimization and time-varying optima. This issue will become important in future once ephemeris construction is just one part of even larger optimization problems, e.g. the combined and consistent determination of the physical state (orbit, size, shape, rotation, gravity,…) of celestial bodies (planets, satellites, asteroids, or comets), and if one seeks near real-time solutions. Here we outline the general idea and discuss first results. As an example, we present a simultaneous optimization of high-correlated asteroidal ring model parameters (total mass and heliocentric radius), based on simulations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Van Eylen, V.; Lund, M. N.; Aguirre, V. Silva
2014-02-10
We confirm the Kepler planet candidate Kepler-410A b (KOI-42b) as a Neptune-sized exoplanet on a 17.8 day, eccentric orbit around the bright (K {sub p} = 9.4) star Kepler-410A (KOI-42A). This is the third brightest confirmed planet host star in the Kepler field and one of the brightest hosts of all currently known transiting exoplanets. Kepler-410 consists of a blend between the fast rotating planet host star (Kepler-410A) and a fainter star (Kepler-410B), which has complicated the confirmation of the planetary candidate. Employing asteroseismology, using constraints from the transit light curve, adaptive optics and speckle images, and Spitzer transit observations,more » we demonstrate that the candidate can only be an exoplanet orbiting Kepler-410A. We determine via asteroseismology the following stellar and planetary parameters with high precision; M {sub *} = 1.214 ± 0.033 M {sub ☉}, R {sub *} = 1.352 ± 0.010 R {sub ☉}, age =2.76 ± 0.54 Gyr, planetary radius (2.838 ± 0.054 R {sub ⊕}), and orbital eccentricity (0.17{sub −0.06}{sup +0.07}). In addition, rotational splitting of the pulsation modes allows for a measurement of Kepler-410A's inclination and rotation rate. Our measurement of an inclination of 82.5{sub −2.5}{sup +7.5} [°] indicates a low obliquity in this system. Transit timing variations indicate the presence of at least one additional (non-transiting) planet (Kepler-410A c) in the system.« less
DETECTION OF PLANETARY EMISSION FROM THE EXOPLANET TrES-2 USING SPITZER/IRAC
DOE Office of Scientific and Technical Information (OSTI.GOV)
O'Donovan, Francis T.; Charbonneau, David; Knutson, Heather A.
2010-02-20
We present here the results of our observations of TrES-2 using the Infrared Array Camera on Spitzer. We monitored this transiting system during two secondary eclipses, when the planetary emission is blocked by the star. The resulting decrease in flux is 0.127% +- 0.021%, 0.230% +- 0.024%, 0.199% +- 0.054%, and 0.359% +- 0.060% at 3.6 {mu}m, 4.5 {mu}m, 5.8 {mu}m, and 8.0 {mu}m, respectively. We show that three of these flux contrasts are well fit by a blackbody spectrum with T{sub eff} = 1500 K, as well as by a more detailed model spectrum of a planetary atmosphere. Themore » observed planet-to-star flux ratios in all four IRAC channels can be explained by models with and without a thermal inversion in the atmosphere of TrES-2, although with different atmospheric chemistry. Based on the assumption of thermochemical equilibrium, the chemical composition of the inversion model seems more plausible, making it a more favorable scenario. TrES-2 also falls in the category of highly irradiated planets which have been theoretically predicted to exhibit thermal inversions. However, more observations at infrared and visible wavelengths would be needed to confirm a thermal inversion in this system. Furthermore, we find that the times of the secondary eclipses are consistent with previously published times of transit and the expectation from a circular orbit. This implies that TrES-2 most likely has a circular orbit, and thus does not obtain additional thermal energy from tidal dissipation of a non-zero orbital eccentricity, a proposed explanation for the large radius of this planet.« less
A Search for Planetary Transits of the Star HD 187123 by Spot Filter CCD Differential Photometry
NASA Technical Reports Server (NTRS)
Castellano, T.; DeVincenzi, D. (Technical Monitor)
2000-01-01
A novel method for performing high precision, time series CCD differential photometry of bright stars using a spot filter, is demonstrated. Results for several nights of observing of the 51 Pegasi b-type planet bearing star HD 187123 are presented. Photometric precision of 0.0015 - 0.0023 magnitudes is achieved. No transits are observed at the epochs predicted from the radial velocity observation. If the planet orbiting HD 187123 at 0.0415 AU is an inflated Jupiter similar in radius to HD 209458b it would have been detected at the greater than 6(sigma), level if the orbital inclination is near 90 degrees and at the greater than 3(sigma), level if the orbital inclination is as small as 82.7 degrees.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wallace, Joshua; Tremaine, Scott; Chambers, John, E-mail: joshuajw@princeton.edu
Collisional fragmentation is shown to not be a barrier to rocky planet formation at small distances from the host star. Simple analytic arguments demonstrate that rocky planet formation via collisions of homogeneous gravity-dominated bodies is possible down to distances of order the Roche radius ( r {sub Roche}). Extensive N -body simulations with initial bodies ≳1700 km that include plausible models for fragmentation and merging of gravity-dominated bodies confirm this conclusion and demonstrate that rocky planet formation is possible down to ∼1.1 r {sub Roche}. At smaller distances, tidal effects cause collisions to be too fragmenting to allow mass buildupmore » to a final, dynamically stable planetary system. We argue that even differentiated bodies can accumulate to form planets at distances that are not much larger than r {sub Roche}.« less
Spectroscopic observations of the symbiotic binary RW Hydrae
NASA Technical Reports Server (NTRS)
Kenyon, Scott J.; Fernandez-Castro, Telmo
1987-01-01
Ultraviolet/optical spectrophotometry and infrared photometry show that the symbiotic binary RW Hya is comprised of an M giant (with L of about 1000 solar luminosities) and a compact object (with L of about 200 solar luminosities) which resembles the central star of a planetary nebula. The luminosity of the hot component is produced by a nuclear shell source which is replenished by the wind of the red giant at a rate of about 10 to the -8th solar mass/yr. Results indicate that the binary is surrounded by an H II region (of radius of about 10 AU) which gives rise to the observed emission lines and radio emission. The He(2+) and O(2+) regions are found to be confined to the immediate vicinity of the hot component.
Evaluating ARRA Programs and Other Educational Reforms: A Guide for States
ERIC Educational Resources Information Center
Perez-Johnson, Irma; Walters, Kirk; Puma, Michael; Herman, Rebecca; Garet, Michael; Heppen, Jessica; Lemke, Mariann; Aladjem, Daniel; Amin, Samia; Burghardt, John
2011-01-01
The American Institutes for Research (AIR) and Mathematica Policy Research (MPR) developed this guide to help you consider evaluation issues likely to arise as you launch ARRA-funded initiatives and other educational reform activities. Many states are already involved in evaluation, so many of the ideas presented here may be familiar. The authors…
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-19
.... Owner-provided capital contributions in the form of a cash infusion. A cash infusion cannot be a loan... one pre-application form. If a consolidation is proposed, all projects to be consolidated will be listed on one pre-application form. To be a complex transaction, at the MPR closing, the Agency assumes...
Judging Student Achievement: Why Getting the Right Data Matters. An MPR/NCEA Policy Brief
ERIC Educational Resources Information Center
Anderson, Sharon; Fowler, Donna; Klein, Steve
2005-01-01
States are engaged in serious efforts to raise student achievement, paying particular attention to narrowing the achievement gap between high- and low-performing students that has persisted in public schools for decades. The achievement gap is particularly troubling because, all too often, those at low achievement levels are minority, special…
Seeking Assistance: Who Gets Financial Aid at California Community Colleges. MPR Research Brief
ERIC Educational Resources Information Center
Woo, Jennie H.
2009-01-01
California community colleges (CCC) enroll nearly one-quarter of the nation's community college students. Low fees and open-admission policies in this sector provide critical access to many students who otherwise might not attend college. This is particularly true of low-income students, at least one-quarter of all CCC students. Even though CCCs…
NASA Astrophysics Data System (ADS)
Koerner, D. W.; Ressler, M. E.; Werner, M. W.; Backman, D. E.
1998-08-01
We report the discovery of a circumstellar disk around the young A0 star HR 4796 in thermal infrared imaging carried out at the W. M. Keck Observatory. By fitting a model of the emission from a flat dusty disk to an image at λ=20.8 μm, we derive a disk inclination, i=72deg+6deg-9deg from face-on, with the long axis of emission at P.A. 28deg+/-6deg. The intensity of emission does not decrease with radius, as expected for circumstellar disks, but increases outward from the star, peaking near both ends of the elongated structure. We simulate this appearance by varying the inner radius in our model and find an inner hole in the disk with radius Rin=55+/-15 AU. This value corresponds to the radial distance of our own Kuiper belt and may suggest a source of dust in the collision of cometesimals. By contrast with the appearance at 20.8 μm, excess emission at λ=12.5 μm is faint and concentrated at the stellar position. Similar emission is also detected at 20.8 μm in residual subtraction of the best-fit model from the image. The intensity and ratio of flux densities at the two wavelengths could be accounted for by a tenuous dust component that is confined within a few AU of the star with mean temperature of a few hundred degrees K, similar to that of zodiacal dust in our own solar system. The morphology of dust emission from HR 4796 (age 10 Myr) suggests that its disk is in a transitional planet-forming stage, between that of massive gaseous protostellar disks and more tenuous debris disks such as the one detected around Vega.
HAT-P-16b: A 4 M J Planet Transiting a Bright Star on an Eccentric Orbit
NASA Astrophysics Data System (ADS)
Buchhave, L. A.; Bakos, G. Á.; Hartman, J. D.; Torres, G.; Kovács, G.; Latham, D. W.; Noyes, R. W.; Esquerdo, G. A.; Everett, M.; Howard, A. W.; Marcy, G. W.; Fischer, D. A.; Johnson, J. A.; Andersen, J.; Fűrész, G.; Perumpilly, G.; Sasselov, D. D.; Stefanik, R. P.; Béky, B.; Lázár, J.; Papp, I.; Sári, P.
2010-09-01
We report the discovery of HAT-P-16b, a transiting extrasolar planet orbiting the V = 10.8 mag F8 dwarf GSC 2792-01700, with a period P = 2.775960 ± 0.000003 days, transit epoch Tc = 2455027.59293 ± 0.00031 (BJD10), and transit duration 0.1276 ± 0.0013 days. The host star has a mass of 1.22 ± 0.04 M sun, radius of 1.24 ± 0.05 R sun, effective temperature 6158 ± 80 K, and metallicity [Fe/H] = +0.17 ± 0.08. The planetary companion has a mass of 4.193 ± 0.094 M J and radius of 1.289 ± 0.066 R J, yielding a mean density of 2.42 ± 0.35 g cm-3. Comparing these observed characteristics with recent theoretical models, we find that HAT-P-16b is consistent with a 1 Gyr H/He-dominated gas giant planet. HAT-P-16b resides in a sparsely populated region of the mass-radius diagram and has a non-zero eccentricity of e = 0.036 with a significance of 10σ. Based in part on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Based in part on observations obtained at the W. M. Keck Observatory, which is operated by the University of California and the California Institute of Technology. Keck time has been granted by NASA (N018Hr).
Viscous dissipation of energy at the stage of accumulation of the Earth
NASA Astrophysics Data System (ADS)
Yurie Khachay, Professor; Olga Hachay, Professor; Antipin, Alexandr
2017-04-01
In the papers [1,2] it is published the differentiation model of the proto planet cloud during the accumulation of the Earth's group planets. In [2] it was shown that the energy released during the decay of short-lived radioactive elements in the small size more than 50 km, it is enough that the temperature inside of the protoplanet becomes larger than the temperature of iron melting. It provides a realization of the matter differentiation process and convection development inside the inner envelopes. With increasing of the Earth, the forming region of the outer core remains in a molten state, although the power and viscosity of the layer changed. In [3] it is shown that during the sequence of growth changes of accumulated protoplanets, the main contribution of heat is provided first by radioactive sources, and then heated from above by converting the kinetic energy during the growing impact inside the Earth, and finally heated from below. That provides three types of driving mechanisms of convection: internal heat sources; heated top; heated from bottom and chemical-thermal convection. At all stages of proto Earth's development the convective heat-mass transfer becomes a most significant factor in the dynamics of the planet. However, the heat release due to friction in the viscous liquid of the outer core up to now was not still considered, or it was considered only for the formed planetary envelopes with a constant radius. In this paper we present the first results of thermal evolution numerical modeling of 3D spherical segment for a protoplanet with increasing radius and accounting random falling of bodies and particles. To describe the planetary accumulation Safronov equation is used [4]. For the quantitative account of the released heat by viscous friction a system of hydro dynamic equations for a viscous liquid is used. The obtained results show that the heat input due to viscous friction heat release at the early stage of planetary accumulation was very significant. That influence is defined by a set of factors. It was changed the width of the formed outer core. It was changed the distribution of the temperature and hydrostatic pressure inside the core and reciprocally the viscosity of the matter. It had been changed the orbit parameters of the system Earth-Moon. The received results depend from the parameters, the values of which are known with large degree of uncertainty. They have to be specified during next researchers. This work was supported by grant RFBRI №16-05-00540 References. 1. V.Anfilogov,Y. Khachay ,2005, Possible variant of matter differentiation on the initial stage of Earth's forming //DAN, 2005, V. 403, № 6, p. 803-806. 2.V.Anfilogov,Y.Khachay ,2015, Some Aspects of the Solar System Formation. Springer Briefs of the Earth Sciences. -75p 3.Khachay Yu.V., Hachay O.A. Heat production by the viscous dissipation of energy at the stage of accumulation of the Earth. Geophysical Research AbstractsVol. 18, EGU2016-2825, 2016 4. Khachay Yu. Realization of thermal Convection into the initial Earth's Core on the Stage of planetary Accumulation // Geophysical Research Abstracts, Vol. 17, EGU2015-2211, 2015.
NASA Astrophysics Data System (ADS)
Babyakin, Alexander; Polozkov, Igor; Golitsyn, Georgy; Efimenko, Natalia; Zherlitsina, Liubov; Povolotskaya, Nina; Senik, Irina; Chalaya, Elena; Artamonova, Maria; Pogarski, Fedor
2010-05-01
The current global climate change is determined by changes in the structure of weather conditions, whose impact on the health of various regions of the planet has not been studied sufficiently. To study this effect on the low-altitude mountains resort of Kislovodsk (southern Russia) multi-factor assessment of the impact of the environment on human health is carried out. There were taking in account atmosphere condition, atmospheric aerosol pollution relationship with atmospheric circulation, the level of pollution matching with different types of weather, and, on the base of analysis of meteopathic reactions (MPR), the extent of their biotropism was revealed. Two sides of weather-climatic influences - specific and nonspecific - are interconnected. They manifest themselves differently in humans with different levels of regulation of vital activity and the adaptive capacity of the organism to the complex environmental effects. This complicates the precise physiological basis of quantitative criteria for the prediction of "biotropic" (adverse) weathers. Nevertheless, clinical observations have shown the existence of the "limiting" physiological bound on the size of medical-meteorological modules (MMM). The reactions of the organism to unfavorable weather factors on the results of a questionnaire monitoring surveillance of patients treated in clinics of Federal State Institution "Pyatigorsk State Research Institute of Curortology, FMBA of Russia" (PSRIC), in comparison with clinical data, have identified various MPR of the organism, the clinical manifestation of which depends on age, sex of the patient, the availability of principal and attendant pathology, reactivity, etc. Analysis of the results of clinical observation, cases of medical aid appealability to the station an ambulance at the sudden ill health, as well as the uptake of advice of sick people among immigrants during their short stay at the resort, and the local population, allowed the first approximation to clarify the criteria for "pathogenicity" of various weather conditions and the factors of air pollution. These criteria were put in a new technology of the Medical Weather Forecast (MWF). In this technology it is proposed to use the integrated Weather Pathogenicity Index (WPI), which is calculated as a weighted average of biotropism indices of various MMM, which include: the dynamics and day to day variability of temperature, pressure and humidity, wind speed, weight content of oxygen and natural air ions in the surface atmosphere, cloudiness, atmospheric phenomena, geomagnetic activity, the ultraviolet index (by UVB solar radiation), the integrated illumination by the sun, the heat conditions of the human. For each of the MMM the five physiological grades of the effects of weather on human adaptation to weather of magnitude and dynamics of WPI are marked out: indifferent, weak, moderate, harsh and overly harsh, according to which the degree of "pathogenicity" of the weather is estimating. Pathogenicity is indicated by quantitative number of medical types of weather (I - a very good weather, II - good weather, III - adverse weather, and IV - a particularly adverse weather). According to the forms of the pressure relief on the sea level, 850 hPa, and 500 hPa, the nature of atmospheric stratification and the presence of atmospheric fronts in the medical types of weather the type of atmospheric circulation is evaluating (anticyclonic - "A", cyclonic - "B", frontal - "C"), which defines a subtype of weather and the possible nature of meteopathia (hypotensive, hypoxic, spastic, etc.). Innovations of the new technology are associated with the introduction of a methodology for the preparation of MWF the modified classifiers to determine the gradation of biotropism degree for various MMM, confirmed by the results of comprehensive empirical medical and climatic studies using dynamic and synoptic weather forecasting making by Hydrometeocenter of Russia and forecast of atmospheric pollution making by Obukhov Institute of Atmospheric Physics RAS. The average weighted WPI forms the basis of weather type number, synoptic weather forecast allows you to define a subtype of the weather. This classification is used in the system of MWF in the resorts of Caucasian Mineral Waters (mountainous region of Northern Caucasus), making for the purpose of timely warnings of medical personnel of medical institutions to strengthen health surveillance and, if necessary, conduct prevention of MPR. MPR to changing weather conditions are most manifest in connection with resettlement of patients from their places of permanent residence to the unusual climatic conditions of the resort. In this regard, in order to enhance the spa rehabilitation of meteosensitive patients with coronary artery disease at PSRIC a physiological method was developed for early and routine prophylaxis of maladaptive pathological and, above all, MPR using the method of transcranial electric-pulse meso-diencephalic modulation by MDMK-4 apparatus with a frontooccipital location of the electrodes. Clinical manifestation of the MPR in adverse weather conditions in patients with coronary artery disease, hypertension with dysadaptation syndrome is characterized by frequent recurrences of angina, rhythm disorders, cerebral symptoms, vascular crisis, violations in the field of psycho-emotional area and other disorders. These meteopathies are eliminated with high efficiency using the MDMK-4 apparatus in individually selected modes at the planned rate of prophylaxis for 10 procedures. In order to urgent MPR prevention the procedures can be used situationally. The high preventive and curative effects of transcranial electric-pulse meso-diencephalic modulation of the MDMK-4 apparatus is shown by positive dynamics of the clinical status of patients, including data on the MPR test survey, the Kerdem vegetative index, rheoencephalography indicators, electrocardiography, neurovascular reactivity, Holter monitoring of blood pressure and ECG. For children with respiratory diseases PSRIC developed a number of effective methods to increase organism resistance to the effects of environmental factors through the use of artificial microclimate chambers and methods of climatic treatment. Thus, a comprehensive study has expanded our understanding of the impact of the environment on human health, to refine the criteria of selected biotropic situations related to the influence of atmospheric pollution, to improve the efficiency of the MWF system in mountain resorts of the North Caucasus, to develop ways to prevent meteopathies of patients with cardio-vascular and respiratory systems. The investigation was fulfilled in the frames of Program of Presidium of the Russian Academy of Sciences "Basic Sciences - for Medicine" and RFBR grant No. 07-05-12069-ofi_a.
NASA Astrophysics Data System (ADS)
Movshovitz, N.; Fortney, J. J.; Helled, R.; Hubbard, W. B.; Mankovich, C.; Thorngren, D.; Wahl, S. M.; Militzer, B.; Durante, D.
2017-12-01
The external gravity field of a planetary body is determined by the distribution of mass in its interior. Therefore, a measurement of the external field, properlyinterpreted, tells us about the interior density profile, ρ(r), which in turn can be used to constrain the composition in the interior and thereby learn about theformation mechanism of the planet. Recently, very high precision measurements of the gravity coefficients for Saturn have been made by the radio science instrument on the Cassini spacecraft during its Grand Finale orbits. The resulting coefficients come with an associated uncertainty. The task of matching a given density profile to a given set of gravity coefficients is relatively straightforward, but the question of how to best account for the uncertainty is not. In essentially all prior work on matching models to gravity field data inferences about planetary structure have rested on assumptions regarding the imperfectly known H/He equation of state and the assumption of an adiabatic interior. Here we wish to vastly expand the phase space of such calculations. We present a framework for describing all the possible interior density structures of a Jovian planet constrained by a given set of gravity coefficients and their associated uncertainties. Our approach is statistical. We produce a random sample of ρ(a) curves drawn from the underlying (and unknown) probability distribution of all curves, where ρ is the density on an interior level surface with equatorial radius a. Since the resulting set of density curves is a random sample, that is, curves appear with frequency proportional to the likelihood of their being consistent with the measured gravity, we can compute probability distributions for any quantity that is a function of ρ, such as central pressure, oblateness, core mass and radius, etc. Our approach is also Bayesian, in that it can utilize any prior assumptions about the planet's interior, as necessary, without being overly constrained by them. We apply this approach to produce a sample of Saturn interior models based on gravity data from Grand Finale orbits and discuss their implications.
Report of the IAU Working Group on cartographic coordinates and rotational elements: 2009
Archinal, B.A.; A'Hearn, M.F.; Bowell, E.; Conrad, A.; Consolmagno, G.J.; Courtin, R.; Fukushima, T.; Hestroffer, D.; Hilton, J.L.; Krasinsky, G.A.; Neumann, G.; Oberst, J.; Seidelmann, P.K.; Stooke, P.; Tholen, D.J.; Thomas, P.C.; Williams, I.P.
2010-01-01
Every three years the IAU Working Group on Cartographic Coordinates and Rotational Elements revises tables giving the directions of the poles of rotation and the prime meridians of the planets, satellites, minor planets, and comets. This report takes into account the IAU Working Group for Planetary System Nomenclature (WGPSN) and the IAU Committee on Small Body Nomenclature (CSBN) definition of dwarf planets, introduces improved values for the pole and rotation rate of Mercury, returns the rotation rate of Jupiter to a previous value, introduces improved values for the rotation of five satellites of Saturn, and adds the equatorial radius of the Sun for comparison. It also adds or updates size and shape information for the Earth, Mars’ satellites Deimos and Phobos, the four Galilean satellites of Jupiter, and 22 satellites of Saturn. Pole, rotation, and size information has been added for the asteroids (21) Lutetia, (511) Davida, and (2867) Šteins. Pole and rotation information has been added for (2) Pallas and (21) Lutetia. Pole and rotation and mean radius information has been added for (1) Ceres. Pole information has been updated for (4) Vesta. The high precision realization for the pole and rotation rate of the Moon is updated. Alternative orientation models for Mars, Jupiter, and Saturn are noted. The Working Group also reaffirms that once an observable feature at a defined longitude is chosen, a longitude definition origin should not change except under unusual circumstances. It is also noted that alternative coordinate systems may exist for various (e.g. dynamical) purposes, but specific cartographic coordinate system information continues to be recommended for each body. The Working Group elaborates on its purpose, and also announces its plans to occasionally provide limited updates to its recommendations via its website, in order to address community needs for some updates more often than every 3 years. Brief recommendations are also made to the general planetary community regarding the need for controlled products, and improved or consensus rotation models for Mars, Jupiter, and Saturn.
Report of the IAU Working Group on cartographic coordinates and rotational elements: 2009
Archinal, Brent A.; A’Hearn, Michael F.; Bowell, Edward; Conrad, Al; Consolmagno, Guy J.; Courtin, Regis; Fukushima, Toshio; Hestroffer, Daniel; Hilton, James L.; Krasinsky, Georgij A.; Neumann, Gregory; Oberst, Jurgen; Seidelmann, P. Kenneth; Stooke, Philip; Tholen, David J.; Thomas, Peter C.; Williams, Iwan P.
2010-01-01
Every three years the IAU Working Group on Cartographic Coordinates and Rotational Elements revises tables giving the directions of the poles of rotation and the prime meridians of the planets, satellites, minor planets, and comets. This report takes into account the IAU Working Group for Planetary System Nomenclature (WGPSN) and the IAU Committee on Small Body Nomenclature (CSBN) definition of dwarf planets, introduces improved values for the pole and rotation rate of Mercury, returns the rotation rate of Jupiter to a previous value, introduces improved values for the rotation of five satellites of Saturn, and adds the equatorial radius of the Sun for comparison. It also adds or updates size and shape information for the Earth, Mars’ satellites Deimos and Phobos, the four Galilean satellites of Jupiter, and 22 satellites of Saturn. Pole, rotation, and size information has been added for the asteroids (21) Lutetia, (511) Davida, and (2867) Šteins. Pole and rotation information has been added for (2) Pallas and (21) Lutetia. Pole and rotation and mean radius information has been added for (1) Ceres. Pole information has been updated for (4) Vesta. The high precision realization for the pole and rotation rate of the Moon is updated. Alternative orientation models for Mars, Jupiter, and Saturn are noted. The Working Group also reaffirms that once an observable feature at a defined longitude is chosen, a longitude definition origin should not change except under unusual circumstances. It is also noted that alternative coordinate systems may exist for various (e.g. dynamical) purposes, but specific cartographic coordinate system information continues to be recommended for each body. The Working Group elaborates on its purpose, and also announces its plans to occasionally provide limited updates to its recommendations via its website, in order to address community needs for some updates more often than every 3 years. Brief recommendations are also made to the general planetary community regarding the need for controlled products, and improved or consensus rotation models for Mars, Jupiter, and Saturn.
Super-Earth and Sub-Neptune Exoplanets: a First Look from the MEarth Project
NASA Astrophysics Data System (ADS)
Berta, Zachory K.
Exoplanets that transit nearby M dwarfs allow us to measure the sizes, masses, and atmospheric properties of distant worlds. Between 2008 and 2013, we searched for such planets with the MEarth Project, a photometric survey of the closest and smallest main-sequence stars. This thesis uses the first planet discovered with MEarth, the warm 2.7 Earth radius exoplanet GJ1214b, to explore the possibilities that planets transiting M dwarfs provide. First, we perform a broad reconnaissance of the GJ1214b planetary system to refine the system's physical properties. We fit many transits to improve the planetary parameters, use starspots to measure GJ1214's rotation period (>50 days), and search for additional transiting planets, placing strong limits on habitable-zone Neptune-sized exoplanets in the system. We present Hubble Space Telescope observations of GJ1214b's atmosphere. We find the transmission spectrum to be flat between 1.1 and 1.7 microns, ruling out at 8 sigma the presence of a clear hydrogen-rich envelope that had been proposed to explain GJ1214b's large radius. Additional observations will determine whether the absence of deep absorption features in GJ1214b's transmission spectrum is due to the masking influence of high altitude clouds or to the presence of a compact, hydrogen-poor atmosphere. We describe a new algorithm to find transiting planets in light curves plagued by stellar variability and systematic noise sources. This Method to Include Starspots and Systematics in the Marginalized Probability of a Lone Eclipse (MISS MarPLE) reliably assesses the significance of individual transit events, a necessary requirement for detecting habitable zone planets from the ground with MEarth. We compare MEarth's achieved sensitivity to planet occurrence statistics from the NASA Kepler Mission, and find that MEarth's single discovery of GJ1214b is consistent with expectations. We find that warm Neptunes are rare around mid-to-late M dwarfs (<0.15 planets/star). Capitalizing on knowledge from Kepler, we propose a new strategy to boost MEarth's sensitivity to smaller and cooler exoplanets, and increase the expected yield of the survey by 2.5x.
Khodachenko, Maxim L; Ribas, Ignasi; Lammer, Helmut; Griessmeier, Jean-Mathias; Leitner, Martin; Selsis, Franck; Eiroa, Carlos; Hanslmeier, Arnold; Biernat, Helfried K; Farrugia, Charles J; Rucker, Helmut O
2007-02-01
Low mass M- and K-type stars are much more numerous in the solar neighborhood than solar-like G-type stars. Therefore, some of them may appear as interesting candidates for the target star lists of terrestrial exoplanet (i.e., planets with mass, radius, and internal parameters identical to Earth) search programs like Darwin (ESA) or the Terrestrial Planet Finder Coronagraph/Inferometer (NASA). The higher level of stellar activity of low mass M stars, as compared to solar-like G stars, as well as the closer orbital distances of their habitable zones (HZs), means that terrestrial-type exoplanets within HZs of these stars are more influenced by stellar activity than one would expect for a planet in an HZ of a solar-like star. Here we examine the influences of stellar coronal mass ejection (CME) activity on planetary environments and the role CMEs may play in the definition of habitability criterion for the terrestrial type exoplanets near M stars. We pay attention to the fact that exoplanets within HZs that are in close proximity to low mass M stars may become tidally locked, which, in turn, can result in relatively weak intrinsic planetary magnetic moments. Taking into account existing observational data and models that involve the Sun and related hypothetical parameters of extrasolar CMEs (density, velocity, size, and occurrence rate), we show that Earth-like exoplanets within close-in HZs should experience a continuous CME exposure over long periods of time. This fact, together with small magnetic moments of tidally locked exoplanets, may result in little or no magnetospheric protection of planetary atmospheres from a dense flow of CME plasma. Magnetospheric standoff distances of weakly magnetized Earth-like exoplanets at orbital distances
NASA Astrophysics Data System (ADS)
Unterborn, C. T.; Desch, S. J.; Johnson, J. A.; Panero, W. R.; Teske, J. K.; Hinkel, N. R.
2016-12-01
The Earth is unique in our Solar System. It is the only planet known to undergo plate tectonics. It has a magnetic field as result of an outer liquid iron core that protects the surface from Solar radiation. What is not known, however, is whether the Earth is unique among all terrestrial planets outside our Solar System. The population of potentially Earth-like planets will only continue to grow. The TESS mission, launching in 2017, is designed to identify rocky planets around bright, nearby stars across the whole sky. Of the 5,000 potential transit-like signals detected, only 100 will be selected for follow-up spectroscopy. From this subsample, only 50 planets are expected to have both mass and radius measurements, thus allowing for detailed modeling of the planetary interior and potential surface processes. As we search for habitable worlds within this sample, then, understanding which TESS objects of interest (TOI) warrant detailed and time-intensive follow-up observations is of paramount importance. Recent surveys of dwarf planetary host and non-host stars find variations in the major terrestrial planet element abundances (Mg, Fe, Si) of between 10% and 400% of Solar. Additionally, the terrestrial exoplanet record shows planets ranging in size from sub-Mercury to super-Earth. How this stellar compositional diversity is translated into resultant exoplanet physical properties including its mineralogy and structure is not known. Here, we present results of models blending equilibrium condensation sequence computations for determining initial planetesimal composition with geophysical interior calculations for multiple stellar abundance catalogues. This benchmarked and generalized approach allows us to predict the mineralogy and structure of an "average" exoplanet in these planetary systems, thus informing their potential to be "Earth-like." This combination of astro- and geophysical models provides us with a self-consistent method with which to compare planetary systems, thus improving our ability to prioritize "Earth-like" targets for follow-up observations within the TOI dataset. Furthermore, the methods described herein afford us an opportunity to explore rocky planet diversity as a whole and truly begin to answer the question, "Is the Earth special?"
NASA Astrophysics Data System (ADS)
Hiyagon, H.; Sugiura, N.; Kita, N. T.; Kimura, M.; Morishita, Y.; Takehana, Y.
2016-08-01
In order to clarify the origin of the eclogitic clasts found in the NWA801 (CR2) chondrite (Kimura et al., 2013), especially, that of the high pressure and temperature (P-T) condition (∼3 GPa and ∼1000 °C), we conducted ion microprobe analyses of oxygen isotopes and rare earth element (REE) abundances in the clasts. Oxygen isotopic compositions of the graphite-bearing lithology (GBL) and graphite-free lithology (GFL) show a slope ∼0.6 correlation slightly below the CR-CH-CB chondrites field in the O three-isotope-diagram, with a large variation for the former and almost homogeneous composition for the latter. The average REE abundances of the two lithologies show almost unfractionated patterns. Based on these newly obtained data, as well as mineralogical observations, bulk chemistry, and considerations about diffusion timescales for various elements, we discuss in detail the formation history of the clasts. Consistency of the geothermobarometers used by Kimura et al. (2013), suggesting equilibration of various elements among different mineral pairs, provides a strong constraint for the duration of the high P-T condition. We suggest that the high P-T condition lasted 102-103 years. This clearly precludes a shock high pressure (HP) model, and hence, strongly supports a static HP model. A static HP model requires a Moon-sized planetary body of ∼1500 km in radius. Furthermore, it implies two successive violent collisions, first at the formation of the large planetary body, when the clasts were placed its deep interior, and second, at the disruption of the large planetary body, when the clasts were expelled out of the parent body and later on transported to the accretion region of the CR chondrites. We also discuss possible origin of O isotopic variations in GBL, and presence/absence of graphite in GBL/GFL, respectively, in relation to smelting possibly occurred during the igneous process(es) which formed the two lithologies. Finally we present a possible formation scenario of the eclogitic clasts.
Characterizing K2 Planetary Systems Orbiting Cool Dwarfs
NASA Astrophysics Data System (ADS)
Dressing, Courtney D.; Newton, Elisabeth R.; Schlieder, Joshua; Vanderburg, Andrew; Charbonneau, David; Knutson, Heather; K2C2
2017-01-01
The NASA K2 mission is using the repurposed Kepler spacecraft to search for transiting planets in multiple fields along the ecliptic plane. K2 observes 10,000 - 30,000 stars in each field for roughly 80 days, which is too short to observe multiple transits of planets in the habitable zones of Sun-like stars, but long enough to detect potentially habitable planets orbiting low-mass dwarfs. Accordingly, M and K dwarfs are frequently nominated as K2 Guest Observer targets and K2 has already observed significantly more low-mass stars than the original Kepler mission. While the K2 data are therefore an enticing resource for studying the properties and frequency of planetary systems orbiting low-mass stars, many K2 cool dwarfs are not well-characterized. We are refining the properties of K2 planetary systems orbiting cool dwarfs by acquiring medium-resolution NIR spectra with SpeX on the IRTF and TripleSpec on the Palomar 200". In our initial sample of 144 potential cool dwarfs hosting candidate planetary systems detected by K2, we noted a high contamination rate from giants (16%) and reddened hotter dwarfs (31%). After employing empirically-based relations to determine the temperatures, radii, masses, luminosities, and metallicities of K2 planet candidate host stars, we found that our new cool dwarf radius estimates were 10-40% larger than the initial values, indicating that the radii of the associated planet candidates were also underestimated. Refining the stellar parameters allows us to identify astrophysical false positives and better constrain the radii and insolation flux environments of bona fide transiting planets. I will present our resulting catalog of system properties and highlight the most attractive K2 planets for radial velocity mass measurement and atmospheric characterization with Spitzer, HST, JWST, and the next generation of extremely large ground- and space-based telescopes. We gratefully acknowledge funding from the NASA Sagan Fellowship Program, the NASA K2 Guest Observer Program, the NASA XRP Program, the John Templeton Foundation, the National Science Foundation Astronomy & Astrophysics Postdoctoral Program, and the National Science Foundation Graduate Research Fellowship Program.
ERIC Educational Resources Information Center
Wine, Jennifer; Janson, Natasha; Siegel, Peter; Bennett, Christopher
2013-01-01
This report documents the methodological procedures and evaluations of the 2008/09 Baccalaureate and Beyond Longitudinal Study (B&B:08/09). RTI, with the assistance of MPR, conducted B&B:08/09 for the National Center for Education Statistics (NCES) of the U.S. Department of Education. Chapter 1 describes the background, legislative…
"We the People" Curriculum: Results of Pilot Test. A Report to the Center for Civic Education
ERIC Educational Resources Information Center
Hartry, Ardice; Porter, Kristie
2004-01-01
In the United States, civic educators are debating the need to mandate the inclusion of civic education in high school curriculum. This report describes the result of a pilot test for one curriculum, "We the People: the Citizen and the Constitution." In January 2003, the Center for Civic Education contracted with MPR Associates, Inc. to…
Moreno, Luisa Z; Paixão, Renata; Gobbi, Débora D S; Raimundo, Daniele C; Ferreira, Thais P; Moreno, Andrea M; Hofer, Ernesto; Reis, Cristhiane M F; Matté, Glavur R; Matté, Maria H
2014-04-15
Listeria species are susceptible to most antibiotics. However, over the last decade, increasing reports of multidrug-resistant Listeria spp. from various sources have prompted public health concerns. The objective of this study was to characterize the antibiotic susceptibility of Listeria spp. and the genetic mechanisms that confer resistance. Forty-six Listeria spp. isolates were studied, and their minimal inhibitory concentrations of antibiotics were determined by microdilution using Sensititre standard susceptibility MIC plates. The isolates were screened for the presence of gyrA, parC, lde, lsa(A), lnu(A), and mprF by PCR, and the amplified genes were sequenced. All isolates were susceptible to penicillin, ampicillin, tetracycline, erythromycin, and carbapenems. Resistance to clindamycin, daptomycin, and oxacillin was found among L. monocytogenes and L. innocua, and all species possessed at least intermediate resistance to fluoroquinolones. GyrA, parC, and mprF were detected in all isolates; however, mutations were found only in gyrA sequences. A high daptomycin MIC, as reported previously, was observed, suggesting an intrinsic resistance of Listeria spp. to daptomycin. These results are consistent with reports of emerging resistance in Listeria spp. and emphasize the need for further genotypic characterization of antibiotic resistance in this genus.
The GARP Complex Is Involved in Intracellular Cholesterol Transport via Targeting NPC2 to Lysosomes.
Wei, Jian; Zhang, Ying-Yu; Luo, Jie; Wang, Ju-Qiong; Zhou, Yu-Xia; Miao, Hong-Hua; Shi, Xiong-Jie; Qu, Yu-Xiu; Xu, Jie; Li, Bo-Liang; Song, Bao-Liang
2017-06-27
Proper intracellular cholesterol trafficking is critical for cellular function. Two lysosome-resident proteins, NPC1 and NPC2, mediate the egress of low-density lipoprotein-derived cholesterol from lysosomes. However, other proteins involved in this process remain largely unknown. Through amphotericin B-based selection, we isolated two cholesterol transport-defective cell lines. Subsequent whole-transcriptome-sequencing analysis revealed two cell lines bearing the same mutation in the vacuolar protein sorting 53 (Vps53) gene. Depletion of VPS53 or other subunits of the Golgi-associated retrograde protein (GARP) complex impaired NPC2 sorting to lysosomes and caused cholesterol accumulation. GARP deficiency blocked the retrieval of the cation-independent mannose 6-phosphate receptor (CI-MPR) to the trans-Golgi network. Further, Vps54 mutant mice displayed reduced cellular NPC2 protein levels and increased cholesterol accumulation, underscoring the physiological role of the GARP complex in cholesterol transport. We conclude that the GARP complex contributes to intracellular cholesterol transport by targeting NPC2 to lysosomes in a CI-MPR-dependent manner. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.
Stur, Karoline; Karlhofer, Franz M; Stingl, Georg
2007-04-01
The clinical spectrum of cutaneous eruptions comprises benign variants like maculopapular rashes (MPRs) and potentially life-threatening events such as toxic epidermal necrolysis (TEN). Apoptosis of keratinocytes is a common histopathological feature of all these drug eruptions. As in skin lesions of TEN and Stevens-Johnson syndrome patients, apoptosis of keratinocytes is often accompanied by an only sparse cellular infiltrate, a soluble fatty acid synthetase ligand (sFASL)-mediated mechanism of keratinocyte cell death is postulated. In MPR patients, evidence for the occurrence of a similar process could not be established so far. We therefore examined sera and lesional skin sections from patients with clinical variants of drug eruptions for FASL expression using a sandwich ELISA and immunohistochemistry, respectively. As controls, healthy persons and patients with other inflammatory skin diseases such as viral exanthema were analyzed. Elevated levels of FASL were detected not only in TEN patients but also in sera and lesional skin of patients with MPR. In contrast, sFASL was repeatedly negative in all viral exanthemas and healthy controls tested. Thus, determination of sFASL serum concentration may represent a discriminating tool between drug rashes and viral exanthemas.
Is the Brazilian pharmaceutical policy ensuring population access to essential medicines?
Bertoldi, Andréa Dâmaso; Helfer, Ana Paula; Camargo, Aline L; Tavares, Noêmia U L; Kanavos, Panos
2012-03-21
To evaluate medicine prices, availability and affordability in Brazil, considering the differences across three types of medicines (originator brands, generics and similar medicines) and different types of facilities (private pharmacies, public sector pharmacies and "popular pharmacies"). Data on prices and availability of 50 medicines were collected in 56 pharmacies across six cities in Southern Brazil using the World Health Organization / Health Action International methodology. Median prices obtained were divided by international reference prices to derive the median price ratio (MPR). In the private sector, prices were 8.6 MPR for similar medicines, 11.3 MRP for generics and 18.7 MRP for originator brands, respectively. Mean availability was 65%, 74% and 48% for originator brands, generics and similar medicines, respectively. In the public sector, mean availability of similar medicines was 2-7 times higher than that of generics. Mean overall availability in the public sector ranged from 68.8% to 81.7%. In "popular pharmacies", mean availability was greater than 90% in all cities. Availability of medicines in the public sector does not meet the challenge of supplying essential medicines to the entire population, as stated in the Brazilian constitution. This has unavoidable repercussions for affordability, particularly amongst the lower socio-economic strata.
Usefulness of biological fingerprint in magnetic resonance imaging for patient verification.
Ueda, Yasuyuki; Morishita, Junji; Kudomi, Shohei; Ueda, Katsuhiko
2016-09-01
The purpose of our study is to investigate the feasibility of automated patient verification using multi-planar reconstruction (MPR) images generated from three-dimensional magnetic resonance (MR) imaging of the brain. Several anatomy-related MPR images generated from three-dimensional fast scout scan of each MR examination were used as biological fingerprint images in this study. The database of this study consisted of 730 temporal pairs of MR examination of the brain. We calculated the correlation value between current and prior biological fingerprint images of the same patient and also all combinations of two images for different patients to evaluate the effectiveness of our method for patient verification. The best performance of our system were as follows: a half-total error rate of 1.59 % with a false acceptance rate of 0.023 % and a false rejection rate of 3.15 %, an equal error rate of 1.37 %, and a rank-one identification rate of 98.6 %. Our method makes it possible to verify the identity of the patient using only some existing medical images without the addition of incidental equipment. Also, our method will contribute to patient misidentification error management caused by human errors.
NASA Astrophysics Data System (ADS)
Engle, J. A.; Riousset, J. A.
2016-12-01
In order to determine the most effective geometry of a lightning rod, one must first understand the physical difference between their current designs. Benjamin Franklin's original theory of sharp tipped rods suggests an increase of local electric field, while Moore et al.'s (2000) studies of rounded tips evince an increased probability of strike (Moore et al., 2000; Gibson et al., 2009).In this analysis, the plasma discharge is produced between two electrodes with a high potential difference, resulting in ionization of the neutral gas particle. This process, when done at low current and low temperature can create a corona discharges, which can be observed as a luminescent emission. The Cartesian geometry known as Paschen, or Townsend, theory is particularly well suited to model experimental laboratory scenario, however, it is limited in its applicability to lightning rods. Franklin's sharp tip and Moore et al.'s (2000) rounded tip fundamentally differ in the radius of curvature of the upper end of the rod. As a first approximation, the rod can be modelled as an equipotential conducting sphere above the ground. Hence, we expand the classic Cartesian geometry into spherical and cylindrical geometries. In this work we explore the effects of shifting from the classical parallel plate analysis to spherical and cylindrical geometries more adapted for studies of lightning rods or power lines. Utilizing Townsend's equation for corona discharge, we estimate a critical radius and minimum breakdown voltage that allows ionization of the air around an electrode. Additionally, we explore the influence of the gas in which the discharge develops. We use BOLSIG+, a numerical solver for the Boltzmann equation, to calculate Townsend coefficients for CO2-rich atmospheric conditions. This allows us to expand the scope of this study to other planetary bodies such as Mars (Hagelaar, 2005). We solve the problem both numerically and analytically to present simplified formulas per each geometry and gas mixture. The development of a numerical framework will ultimately let us test the influence of additional parameters such as background ionization, initiation criterion, and charge conservation on the values of the critical radius and minimum breakdown voltage.
Selections from 2017: Atmosphere Around an Earth-Like Planet
NASA Astrophysics Data System (ADS)
Kohler, Susanna
2017-12-01
Editors note:In these last two weeks of 2017, well be looking at a few selections that we havent yet discussed on AAS Nova from among the most-downloaded paperspublished in AAS journals this year. The usual posting schedule will resume in January.Detection of the Atmosphere of the 1.6 M Exoplanet GJ 1132 bPublished March2017Main takeaway:An atmosphere was detected around the roughly Earth-size exoplanet GJ 1132 b using a telescope at the European Southern Observatory in Chile. A team of scientists led byJohn Southworth (Keele University) found features indicating the presence of an atmosphere in theobservationsof this 1.6-Earth-mass planet as it transits an M-dwarf host star. This is the lowest-mass planet with a detected atmosphere thus far.Why its interesting:M dwarfs are among the most common stars in our galaxy, and weve found manyEarth-sizeexoplanets in or near the habitable zones around M-dwarf hosts. But M dwarfs are also more magnetically active than stars like our Sun, suggesting that the planets in M-dwarfhabitable zones may not be able to support life due to stellar activity eroding their atmospheres. The detection of an atmosphere around GJ 1132 b suggests that some planets orbiting M dwarfsare able to retain their atmospheres which meansthat these planetsmay be an interesting place to search for life after all.How the atmosphere was detected:The measured planetary radius for GJ 1132 b as a function of the wavelength used to observe it. [Southworth et al. 2017]When measuring the radius of GJ 1132 b based on its transits, the authors noticed that the planet appeared to be largerwhen observed in some wavelengths than in others. This can beexplained if the planet has asurface radius of 1.4 Earth radii, overlaid by an atmosphere that extends out another few tenths of an Earth radius. The atmosphere, which may consist of water vapor or methane, is transparent to some wavelengths and absorbs others which is why the apparent size of the planet changes acrosswavelength bands.CitationJohn Southworth et al 2017 AJ 153 191. doi:10.3847/1538-3881/aa6477
New MOST Photometry of the 55 Cancri System
NASA Astrophysics Data System (ADS)
Dragomir, Diana; Matthews, Jaymie M.; Winn, Joshua N.; Rowe, Jason F.
2014-04-01
Since the discovery of its transiting nature, the super-Earth 55 Cnc e has become one of the most enthusiastically studied exoplanets, having been observed spectroscopically and photometrically, in the ultraviolet, optical and infrared regimes. To this rapidly growing data set, we contribute 42 days of new, nearly continuous MOST photometry of the 55 Cnc system. Our analysis of these observations together with the discovery photometry obtained in 2011 allows us to determine the planetary radius (1.990+0.084 -0.080) and orbital period (0.7365417+0.0000025 -0.0000028) of 55 Cnc e with unprecedented precision. We also followed up on the out-of-transit phase variation first observed in the 2011 photometry, and set an upper limit on the depth of the planet's secondary eclipse, leading to an upper limit on its geometric albedo of 0.6.
Characterizing Giant Exoplanets through Multiwavelength Transit Observations: HAT-P-5 b
NASA Astrophysics Data System (ADS)
PeQueen, David Jeffrey; Cole, Jackson Lane; Gardner, Cristilyn N.; Garver, Bethany Ray; Jarka, Kyla L.; Kar, Aman; McGough, Aylin M.; Rivera, Daniel Ivan; Kasper, David; Jang-Condell, Hannah; Kobulnicky, Henry; Dale, Daniel
2018-01-01
During the summer of 2017, we observed hot Jupiter-type exoplanet transit events using the Wyoming Infrared Observatory’s 2.3 meter telescope. We observed 14 unique exoplanets during transit events; one such target was HAT-P-5 b. In total, we collected 53 usable science images in the Sloan filter set, particularly with the g’, r’, z’, and i’ band wavelength filters. This exoplanet transited approximately 40 minutes earlier than the currently published literature suggests. After reducing the data and running a Markov chain Monte Carlo analysis, we present results describing the planetary radius, semi-major axis, orbital period, and inclination of HAT-P-5 b. Characteristics of Rayleigh scattering are present in the atmosphere of this exoplanet. This work is supported by the National Science Foundation under REU grant AST 1560461.
Venus mountain-top mineralogy: Misconceptions about pyrite as the high radar-reflecting phase
NASA Technical Reports Server (NTRS)
Burns, Roger G.; Straub, Darcy W.
1993-01-01
Altitude-dependent, high radar-reflectivity surfaces on Venus are observed on most mountainous volcanic terranes above a planetary radius of about 6054 km. However, high radar-reflectivity areas also occur at lower altitudes in some impact craters and plain terranes. Pyrite (FeS2) is commonly believed to be responsible for the high radar reflectivities at high elevations on Venus, on account of large dielectric constants measured for sulfide-bearing rocks that were erroneously attributed to pyrite instead of pyrrhotite. Pentlandite-pyrrhotite assemblages may be responsible for high reflectivities associated with impact craters on the Venusian surface, by analogy with Fe-Ni sulfide deposits occurring in terrestrial astroblemes. Mixed-valence Fe(2+)-Fe(3+) silicates, including oxyhornblende, oxybiotite, and ilvaite, may contribute to high radar reflecting surfaces on mountain-tops of Venus.
High-frequency flux transfer events detected near Mercury
NASA Astrophysics Data System (ADS)
Schultz, Colin
2013-01-01
The physical process that creates connections between the magnetic fields emanating from the Sun and a planet—a process known as magnetic reconnection—creates a portal through which solar plasma can penetrate the planetary magnetic field. The opening of these portals, known as flux transfer events (FTEs), takes place roughly every 8 minutes at Earth and spawns a rope of streaming plasma that is typically about half of the radius of the Earth. As early as 1985, scientists analyzing the Mariner 10 observations, collected during their 1974-1975 flybys, have known that FTEs also occur at Mercury. However, using the measurements returned from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft now orbiting Mercury, Slavin et al. found that Mercurial flux transfer events are proportionally much larger, stronger, and more frequent than those at Earth.
Inward migration of the TRAPPIST-1 planets as inferred from their water-rich compositions
NASA Astrophysics Data System (ADS)
Unterborn, Cayman T.; Desch, Steven J.; Hinkel, Natalie R.; Lorenzo, Alejandro
2018-04-01
Multiple planet systems provide an ideal laboratory for probing exoplanet composition, formation history and potential habitability. For the TRAPPIST-1 planets, the planetary radii are well established from transits1,2, with reasonable mass estimates coming from transit timing variations2,3 and dynamical modelling4. The low bulk densities of the TRAPPIST-1 planets demand substantial volatile content. Here we show, using mass-radius-composition models, that TRAPPIST-1f and g probably contain substantial (≥50 wt%) water/ice, with TRAPPIST-1 b and c being significantly drier (≤15 wt%). We propose that this gradient of water mass fractions implies that planets f and g formed outside the primordial snow line whereas b and c formed within it. We find that, compared with planets in our Solar System that also formed within the snow line, TRAPPIST-1b and c contain hundreds more oceans of water. We demonstrate that the extent and timescale of migration in the TRAPPIST-1 system depends on how rapidly the planets formed and the relative location of the primordial snow line. This work provides a framework for understanding the differences between the protoplanetary disks of our Solar System versus M dwarfs. Our results provide key insights into the volatile budgets, timescales of planet formation and migration history of M dwarf systems, probably the most common type of planetary host in the Galaxy.
Growth of asteroids, planetary embryos, and Kuiper belt objects by chondrule accretion
Johansen, Anders; Low, Mordecai-Mark Mac; Lacerda, Pedro; Bizzarro, Martin
2015-01-01
Chondrules are millimeter-sized spherules that dominate primitive meteorites (chondrites) originating from the asteroid belt. The incorporation of chondrules into asteroidal bodies must be an important step in planet formation, but the mechanism is not understood. We show that the main growth of asteroids can result from gas drag–assisted accretion of chondrules. The largest planetesimals of a population with a characteristic radius of 100 km undergo runaway accretion of chondrules within ~3 My, forming planetary embryos up to Mars’s size along with smaller asteroids whose size distribution matches that of main belt asteroids. The aerodynamical accretion leads to size sorting of chondrules consistent with chondrites. Accretion of millimeter-sized chondrules and ice particles drives the growth of planetesimals beyond the ice line as well, but the growth time increases above the disc lifetime outside of 25 AU. The contribution of direct planetesimal accretion to the growth of both asteroids and Kuiper belt objects is minor. In contrast, planetesimal accretion and chondrule accretion play more equal roles in the formation of Moon-sized embryos in the terrestrial planet formation region. These embryos are isolated from each other and accrete planetesimals only at a low rate. However, the continued accretion of chondrules destabilizes the oligarchic configuration and leads to the formation of Mars-sized embryos and terrestrial planets by a combination of direct chondrule accretion and giant impacts. PMID:26601169
Growth of asteroids, planetary embryos, and Kuiper belt objects by chondrule accretion
NASA Astrophysics Data System (ADS)
Johansen, Anders; Mac Low, Mordecai-Mark; Lacerda, Pedro; Bizzarro, Martin
2015-04-01
Chondrules are millimeter-sized spherules that dominate primitive meteorites (chondrites) originating from the asteroid belt. The incorporation of chondrules into asteroidal bodies must be an important step in planet formation, but the mechanism is not understood. We show that the main growth of asteroids can result from gas drag-assisted accretion of chondrules. The largest planetesimals of a population with a characteristic radius of 100 km undergo runaway accretion of chondrules within ~3 My, forming planetary embryos up to Mars's size along with smaller asteroids whose size distribution matches that of main belt asteroids. The aerodynamical accretion leads to size sorting of chondrules consistent with chondrites. Accretion of millimeter-sized chondrules and ice particles drives the growth of planetesimals beyond the ice line as well, but the growth time increases above the disc lifetime outside of 25 AU. The contribution of direct planetesimal accretion to the growth of both asteroids and Kuiper belt objects is minor. In contrast, planetesimal accretion and chondrule accretion play more equal roles in the formation of Moon-sized embryos in the terrestrial planet formation region. These embryos are isolated from each other and accrete planetesimals only at a low rate. However, the continued accretion of chondrules destabilizes the oligarchic configuration and leads to the formation of Mars-sized embryos and terrestrial planets by a combination of direct chondrule accretion and giant impacts.
Growth of asteroids, planetary embryos, and Kuiper belt objects by chondrule accretion.
Johansen, Anders; Low, Mordecai-Mark Mac; Lacerda, Pedro; Bizzarro, Martin
2015-04-01
Chondrules are millimeter-sized spherules that dominate primitive meteorites (chondrites) originating from the asteroid belt. The incorporation of chondrules into asteroidal bodies must be an important step in planet formation, but the mechanism is not understood. We show that the main growth of asteroids can result from gas drag-assisted accretion of chondrules. The largest planetesimals of a population with a characteristic radius of 100 km undergo runaway accretion of chondrules within ~3 My, forming planetary embryos up to Mars's size along with smaller asteroids whose size distribution matches that of main belt asteroids. The aerodynamical accretion leads to size sorting of chondrules consistent with chondrites. Accretion of millimeter-sized chondrules and ice particles drives the growth of planetesimals beyond the ice line as well, but the growth time increases above the disc lifetime outside of 25 AU. The contribution of direct planetesimal accretion to the growth of both asteroids and Kuiper belt objects is minor. In contrast, planetesimal accretion and chondrule accretion play more equal roles in the formation of Moon-sized embryos in the terrestrial planet formation region. These embryos are isolated from each other and accrete planetesimals only at a low rate. However, the continued accretion of chondrules destabilizes the oligarchic configuration and leads to the formation of Mars-sized embryos and terrestrial planets by a combination of direct chondrule accretion and giant impacts.
Kepler-432 b: a massive planet in a highly eccentric orbit transiting a red giant
NASA Astrophysics Data System (ADS)
Ciceri, S.; Lillo-Box, J.; Southworth, J.; Mancini, L.; Henning, Th.; Barrado, D.
2015-01-01
We report the first disclosure of the planetary nature of Kepler-432 b (aka Kepler object of interest KOI-1299.01). We accurately constrained its mass and eccentricity by high-precision radial velocity measurements obtained with the CAFE spectrograph at the CAHA 2.2-m telescope. By simultaneously fitting these new data and Kepler photometry, we found that Kepler-432 b is a dense transiting exoplanet with a mass of Mp = 4.87 ± 0.48MJup and radius of Rp = 1.120 ± 0.036RJup. The planet revolves every 52.5 d around a K giant star that ascends the red giant branch, and it moves on a highly eccentric orbit with e = 0.535 ± 0.030. By analysing two near-IR high-resolution images, we found that a star is located at 1.1'' from Kepler-432, but it is too faint to cause significant effects on the transit depth. Together with Kepler-56 and Kepler-91, Kepler-432 occupies an almost-desert region of parameter space, which is important for constraining the evolutionary processes of planetary systems. RV data (Table A.1) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/573/L5
Multi-Planetary Systems: Observations and Models of Dynamical Interactions
NASA Technical Reports Server (NTRS)
Lissauer, Jack J.
2018-01-01
More than 600 multi-planet systems are known. The vast majority of these systems have been discovered by NASA's Kepler spacecraft, but dozens were found using the Doppler technique, the first multi-exoplanet system was identified through pulsar timing, and the most massive system has been found using imaging. More than one-third of the 4000+ planet candidates found by NASA's Kepler spacecraft are associated with target stars that have more than one planet candidate, and the large number of such Kepler "multis" tells us that flat multiplanet systems like our Solar System are common. Virtually all of Kepler candidate multis are stable, as tested by numerical integrations that assume a physically motivated mass-radius relationship. Statistical studies performed on these candidate systems reveal a great deal about the architecture of planetary systems, including the typical spacing of orbits and flatness. The characteristics of several of the most interesting confirmed multi-exoplanet systems will also be discussed.HR 8799's four massive planets orbit tens of AU from their host star and travel on nearly circular orbits. PSR B1257+12 has three much smaller planets orbiting close to a neutron star. Both represent extremes and show that planet formation is a robust process that produces a diversity of outcomes. Although both exomoons and Trojan (triangle Lagrange point) planets have been searched for, neither has yet been found.
Model-independent Exoplanet Transit Spectroscopy
NASA Astrophysics Data System (ADS)
Aronson, Erik; Piskunov, Nikolai
2018-05-01
We propose a new data analysis method for obtaining transmission spectra of exoplanet atmospheres and brightness variation across the stellar disk from transit observations. The new method is capable of recovering exoplanet atmosphere absorption spectra and stellar specific intensities without relying on theoretical models of stars and planets. We simultaneously fit both stellar specific intensity and planetary radius directly to transit light curves. This allows stellar models to be removed from the data analysis. Furthermore, we use a data quality weighted filtering technique to achieve an optimal trade-off between spectral resolution and reconstruction fidelity homogenizing the signal-to-noise ratio across the wavelength range. Such an approach is more efficient than conventional data binning onto a low-resolution wavelength grid. We demonstrate that our analysis is capable of reproducing results achieved by using an explicit quadratic limb-darkening equation and that the filtering technique helps eliminate spurious spectral features in regions with strong telluric absorption. The method is applied to the VLT FORS2 observations of the exoplanets GJ 1214 b and WASP-49 b, and our results are in agreement with previous studies. Comparisons between obtained stellar specific intensity and numerical models indicates that the method is capable of accurately reconstructing the specific intensity. The proposed method enables more robust characterization of exoplanetary atmospheres by separating derivation of planetary transmission and stellar specific intensity spectra (that is model-independent) from chemical and physical interpretation.
ERIC Educational Resources Information Center
Cohen, Rhoda; KewalRamani, Angelina; Nogales, Renee; Ohls, James; Sinclair, Michael
2004-01-01
This report describes research that Mathematica Policy Research, Inc. (MPR) has conducted for the U.S. Department of Agriculture (USDA), Food and Nutrition Service (FNS), to develop methods to track the use of "competitive foods" in schools over time. Competitive foods are foods from a la carte cafeteria sales, vending machines, school stores,…
ERIC Educational Resources Information Center
Glazerman, Steven; Myers, David
2004-01-01
In October 2002, the Institute of Education Sciences (IES) contracted with Mathematica Policy Research, Inc. (MRP) to help identify issues pertinent to the evaluation of Title I and to propose feasible evaluation design strategies. This design effort took its lead from two sources: (1) the Title I Independent Review Panel (IRP); and (2) a more…
Cannon, Grant W; Mikuls, Ted R; Hayden, Candace L; Ying, Jian; Curtis, Jeffrey R; Reimold, Andreas M; Caplan, Liron; Kerr, Gail S; Richards, J Steuart; Johnson, Dannette S; Sauer, Brian C
2011-12-01
The Veterans Affairs (VA) Rheumatoid Arthritis (VARA) registry and the VA Pharmacy Benefits Management database were linked to determine the association of methotrexate (MTX) adherence with rheumatoid arthritis (RA) disease activity. For each patient, the medication possession ratio (MPR) was calculated for the first episode of MTX exposure of a duration of ≥12 weeks for both new and established MTX users. High MTX adherence was defined as an MPR ≥0.80 and low MTX adherence was defined as an MPR <0.80. For each patient, the mean Disease Activity Score with 28 joints (DAS28) score, erythrocyte sedimentation rate (ESR), and C-reaction protein (CRP) level observed during registry followup were compared in high- versus low-adherence groups. In 455 RA patients, the prescribed doses of MTX (mean ± SD 16 ± 4 mg versus 16 ± 4 mg; P = 0.6) were similar in high-adherence patients (n = 370) in comparison to low-adherence patients (n = 85). However, the actual observed MTX doses taken by patients were significantly higher in the high-adherence group (mean ± SD 16 ± 5 mg versus 11 ± 3 mg; P < 0.001). DAS28 (mean ± SD 3.6 ± 1.2 versus 3.9 ± 1.5; P < 0.02), ESR (mean ± SD 24 ± 18 versus 29 ± 24 mm/hour; P = 0.05), and CRP level (mean ± SD 1.2 ± 1.3 versus 1.6 ± 1.5 mg/dl; P < 0.03) were lower in the high-adherence group compared to those with low MTX adherence. These variances were not explained by differences in baseline demographic features, concurrent treatments, or whether MTX was initiated before or after VARA enrollment. High MTX adherence was associated with improved clinical outcomes in RA patients treated with MTX. Adjustment for potential confounders did not alter the estimated effect of adherence. These results demonstrate the advantages of being able to merge clinical observations with pharmacy databases to evaluate antirheumatic drugs in clinical practice. Copyright © 2011 by the American College of Rheumatology.
Ivanova, J I; Bergman, R E; Birnbaum, H G; Phillips, A L; Stewart, M; Meletiche, D M
2012-01-01
To compare rates of severe relapse and total direct and indirect costs over a 2-year period between US-based employees with multiple sclerosis (MS) who were adherent and non-adherent to disease-modifying drugs (DMDs). Employees with ≥1 MS diagnosis (ICD-9-CM: 340.x) and ≥1 DMD pharmacy claim between 1/1/2002-12/31/2007 were identified from a large US administrative claims database. Patients had continuous coverage ≥6 months before (baseline) and ≥24 months after (study period) their index date (first DMD claim). Adherence was measured using medication possession ratio (MPR) over the study period. Patients with MPR ≥80% were considered adherent (n = 448) and those with MPR <80% as non-adherent (n = 200). Multivariate analyses were used to compare rates of severe relapse (inpatient or Emergency Department visit with MS diagnosis) and costs in 2007 dollars between DMD adherent and non-adherent patients. Direct costs were calculated as reimbursements to providers for medical services and prescription drugs excluding DMDs. Indirect costs included disability and medically-related absenteeism costs. DMD adherent patients were on average older (43.5 vs 41.8 years, p = 0.015) and more likely to be male (38.6% vs 26.0%, p = 0.002) compared with non-adherent patients. Adherent patients had lower rates of depression, higher rates of previous DMD use, and higher baseline MS-related costs. After adjusting for differences in baseline characteristics, DMD adherent patients had a lower rate of severe relapse (12.4% vs 19.9%, p = 0.013) and lower total (direct and indirect) costs ($14,095 vs $16,638, p = 0.048) over the 2-year study period. In this study, DMD adherence was associated with a significantly lower rate of severe relapse and lower total costs over 2 years. Causality cannot be inferred because adherence and outcomes were measured over the same period. The study was subject to limitations associated with use of claims data and the absence of clinical measures.
Jewkes, Rachel; Nduna, Mzikazi; Jama-Shai, Nwabisa; Chirwa, Esnat; Dunkle, Kristin
2016-01-01
Interventions to prevent rape perpetration must be designed to address its drivers. This paper seeks to extend understanding of drivers of single and multiple perpetrator rape (referred to here as SPR and MPR respectively) and the relationships between socio-economic status, childhood trauma, peer pressure, other masculine behaviours and rape. 1370 young men aged 15 to 26 were interviewed as part of the randomised controlled trial evaluation of Stepping Stones in the rural Eastern Cape. We used multinomial to compare the characteristics of men who reported rape perpetration at baseline. We used structural equation modelling (SEM) to examine pathways to rape perpetration. 76.1% of young men had never raped, 10.0% had perpetrated SPR and 13.9% MPR. The factors associated with both MPR and SPR (compared to never having raped) were indicators of socio-economic status (SES), childhood trauma, sexual coercion by a woman, drug and alcohol use, peer pressure susceptibility, having had transactional sex, multiple sexual partners and being physically violent towards a partner. The SEM showed the relationship between SES and rape perpetration to be mediated by gender inequitable masculinity. It was complex as there was a direct path indicating that SES correlated with the masculinity variable directly such that men of higher SES had more gender inequitable masculinities, and indirect path mediated by peer pressure resistance indicated that the former pertained so long as men lacked peer pressure resistance. Having a higher SES conveyed greater resistance for some men. There was also a path mediated through childhood trauma, such that men of lower SES were more likely to have a higher childhood trauma exposure and this correlated with a higher likelihood of having the gender inequitable masculinity (with or without the mediating effect of peer pressure resistance). Both higher and lower socio-economic status were associated with raping. Prevention of rape perpetration must focus on changing men's gender ideals, entitlements and inequitable practices. Reducing poverty and adverse childhood experiences should also be of benefit.
Jewkes, Rachel; Nduna, Mzikazi; Jama-Shai, Nwabisa; Chirwa, Esnat; Dunkle, Kristin
2016-01-01
Background Interventions to prevent rape perpetration must be designed to address its drivers. This paper seeks to extend understanding of drivers of single and multiple perpetrator rape (referred to here as SPR and MPR respectively) and the relationships between socio-economic status, childhood trauma, peer pressure, other masculine behaviours and rape. Method 1370 young men aged 15 to 26 were interviewed as part of the randomised controlled trial evaluation of Stepping Stones in the rural Eastern Cape. We used multinomial to compare the characteristics of men who reported rape perpetration at baseline. We used structural equation modelling (SEM) to examine pathways to rape perpetration. Results 76.1% of young men had never raped, 10.0% had perpetrated SPR and 13.9% MPR. The factors associated with both MPR and SPR (compared to never having raped) were indicators of socio-economic status (SES), childhood trauma, sexual coercion by a woman, drug and alcohol use, peer pressure susceptibility, having had transactional sex, multiple sexual partners and being physically violent towards a partner. The SEM showed the relationship between SES and rape perpetration to be mediated by gender inequitable masculinity. It was complex as there was a direct path indicating that SES correlated with the masculinity variable directly such that men of higher SES had more gender inequitable masculinities, and indirect path mediated by peer pressure resistance indicated that the former pertained so long as men lacked peer pressure resistance. Having a higher SES conveyed greater resistance for some men. There was also a path mediated through childhood trauma, such that men of lower SES were more likely to have a higher childhood trauma exposure and this correlated with a higher likelihood of having the gender inequitable masculinity (with or without the mediating effect of peer pressure resistance). Discussion Both higher and lower socio-economic status were associated with raping. Prevention of rape perpetration must focus on changing men’s gender ideals, entitlements and inequitable practices. Reducing poverty and adverse childhood experiences should also be of benefit. PMID:27182972
Ward, M A; Xu, Y; Viswanathan, H N; Stolshek, B S; Clay, B; Adams, J L; Kallich, J D; Fine, S; Saag, K G
2013-04-01
We examined the association between osteoporosis treatment change and adherence, incident fractures, and healthcare costs among Medicare Advantage Prescription Drug (MAPD) plan members. Treatment change was associated with a small but significant increase in adherence, but was not associated with incident fracture or total healthcare costs. Overall adherence remained low. We examined the association between osteoporosis treatment change and adherence, incident fractures, and healthcare costs among MAPD plan members in a large US health plan. We conducted a retrospective cohort study of MAPD plan members aged≥50 years newly initiated on an osteoporosis medication between 1 January 2006 and 31 December 2008. Members were identified as having or not having an osteoporosis treatment change within 12 months after initiating osteoporosis medication. Logistic regression analyses and difference-in-difference (DID) generalized linear models were used to investigate the association between osteoporosis treatment change and (1) adherence to treatment, (2) incident fracture, and (3) healthcare costs at 12 and 24 months follow-up. Of the 33,823 members newly initiated on osteoporosis treatment, 3,573 (10.6%) changed osteoporosis treatment within 12 months. After controlling for covariates, osteoporosis treatment change was associated with significantly higher odds of being adherent (medication possession ratio [MPR]≥0.8) at 12 months (odds ratio [OR]=1.18) and 24 months (OR=1.13) follow-up. However, overall adherence remained low (MPR=0.59 and 0.51 for the change cohort and MPR=0.51 and 0.44 for the no-change cohort at 12 and 24 months, respectively). Osteoporosis treatment change was not significantly associated with incident fracture (OR=1.00 at 12 months and OR=0.98 at 24 months) or total direct healthcare costs (p>0.4) in the DID analysis, but was associated with higher pharmacy costs (p<0.004). Osteoporosis treatment change was associated with a small but significant increase in adherence, but was not associated with incident fracture or total healthcare costs in the MAPD plan population. Overall adherence to therapy remained low.
NASA Astrophysics Data System (ADS)
Sorí, Rogert; Nieto, Raquel; Drumond, Anita; Vicente-Serrano, Sergio M.; Gimeno, Luis
2017-12-01
The atmospheric branch of the hydrological cycle over the Indus, Ganges, and Brahmaputra river basins (IRB, GRB, and BRB respectively) in the South Asian region was investigated. The 3-dimensional model FLEXPART v9.0 was utilized. An important advantage of this model is that it permits the computation of the freshwater budget on air parcel trajectories both backward and forward in time from 0.1 to 1000 hPa in the atmospheric vertical column. The analysis was conducted for the westerly precipitation regime (WPR) (November-April) and the monsoonal precipitation regime (MPR) (May-October) in the period from 1981 to 2015. The main terrestrial and oceanic climatological moisture sources for the IRB, GRB, and BRB and their contribution to precipitation over the basins were identified. For the three basins, the most important moisture sources for precipitation are (i) in the continental regions, the land masses to the west of the basins (in this case called western Asia), the Indian region (IR), and the basin itself, and (ii) from the ocean, the utmost sources being the Indian Ocean (IO) and the Bay of Bengal (BB), and it is remarkable that despite the amount of moisture reaching the Indus and Ganges basins from land sources, the moisture supply from the IO seems to be first associated with the rapid increase or decrease in precipitation over the sources in the MPR. The technique of the composites was used to analyse how the moisture uptake values spatially vary from the sources (the budget of evaporation minus precipitation (E - P) was computed in a backward experiment from the basins) but during the pre-onset and pre-demise dates of the monsoonal rainfall over each basin; this confirmed that over the last days of the monsoon at the basins, the moisture uptake areas decrease in the IO. The Indian region, the Indian Ocean, the Bay of Bengal, and the basins themselves are the main sources of moisture responsible for negative (positive) anomalies of moisture contribution to the basins during composites of driest (wettest) WPR and MPR.
Six High-precision Transits of OGLE-TR-113b
NASA Astrophysics Data System (ADS)
Adams, E. R.; López-Morales, M.; Elliot, J. L.; Seager, S.; Osip, D. J.
2010-10-01
We present six new transits of the hot Jupiter OGLE-TR-113b observed with MagIC on the Magellan Telescopes between 2007 January and 2009 May. We update the system parameters and revise the planetary radius to Rp = 1.084 ± 0.029RJ , where the error is dominated by stellar radius uncertainties. The new transit midtimes reveal no transit timing variations from a constant ephemeris of greater than 13 ± 28 s over two years, placing an upper limit of 1-2 M ⊕ on the mass of any perturber in a 1:2 or 2:1 mean-motion resonance with OGLE-TR-113b. Combining the new transit epochs with five epochs published between 2002 and 2006, we find hints that the orbital period of the planet may not be constant, with the best fit indicating a decrease of \\dot{P}=-60± 15 ms yr-1. If real, this change in period could result from either a long-period (more than eight years) timing variation due to a massive external perturber or more intriguingly from the orbital decay of the planet. The detection of a changing period is still tentative and requires additional observations, but if confirmed it would enable direct tests of tidal stability and dynamical models of close-in planets. This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.
Erosion Dynamics during Phoenix Landing on Mars
NASA Astrophysics Data System (ADS)
Mehta, M.; Renno, N. O.; Grover, R. M.; Sengupta, A.
2008-12-01
Unique from past planetary surface missions, the Phoenix spacecraft used pulsed retro-rockets to land on the northern polar region of Mars. Mainly viscous shear erosion caused by descent jets had minimally altered previous landing sites. Here we report novel simulations of surface modification by pulsed thruster plumes, and assess the erosion processes leading to the first exposure of ice below the Martian regolith. At Mars atmospheric pressure, we find that the repetitive injection of high pressure gas into porous soil by the pulsed engines leads to the propagation of cyclic radial shock waves within the soil. We show that these shock waves cause 'explosive erosion' and excavate the regolith down to the ice table in a radius of ~75 cm under the lander. Moreover, coarse and fine particles are ejected outward to a radius of 3 m and ~20 m from the thrusters, respectively. The results of our simulations are confirmed by images of the Phoenix landing site and provide important insights into the geology, glaciology and geomorphology of the landing site. These erosion dynamics may lead to ammonia hydrates and ammonium salts, but may demonstrate limited soil contamination. By comparing results from the landing site and our simulations, we come to the initial conclusions that the Martian arctic regolith has high porosity and permeability, mixture of fines with coarse particles, and exhibit cohesive stresses greater than 0.9 kPa.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tsang, David; Cumming, Andrew; Turner, Neal J., E-mail: dtsang@physics.mcgill.ca
2014-02-20
We show that the first order (non-co-orbital) corotation torques are significantly modified by entropy gradients in a non-barotropic protoplanetary disk. Such non-barotropic torques can dramatically alter the balance that, for barotropic cases, results in the net eccentricity damping for giant gap-clearing planets embedded in the disk. We demonstrate that stellar illumination can heat the gap enough for the planet's orbital eccentricity to instead be excited. We also discuss the 'Eccentricity Valley' noted in the known exoplanet population, where low-metallicity stars have a deficit of eccentric planets between ∼0.1 and ∼1 AU compared to metal-rich systems. We show that this featuremore » in the planet distribution may be due to the self-shadowing of the disk by a rim located at the dust sublimation radius ∼0.1 AU, which is known to exist for several T Tauri systems. In the shadowed region between ∼0.1 and ∼1 AU, lack of gap insolation allows disk interactions to damp eccentricity. Outside such shadowed regions stellar illumination can heat the planetary gaps and drive eccentricity growth for giant planets. We suggest that the self-shadowing does not arise at higher metallicity due to the increased optical depth of the gas interior to the dust sublimation radius.« less
NASA Astrophysics Data System (ADS)
Wilson, Robert F.; Teske, Johanna; Majewski, Steven R.; Cunha, Katia; Smith, Verne; Souto, Diogo; Bender, Chad; Mahadevan, Suvrath; Troup, Nicholas; Allende Prieto, Carlos; Stassun, Keivan G.; Skrutskie, Michael F.; Almeida, Andrés; García-Hernández, D. A.; Zamora, Olga; Brinkmann, Jonathan
2018-02-01
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has observed ∼600 transiting exoplanets and exoplanet candidates from Kepler (Kepler Objects of Interest, KOIs), most with ≥18 epochs. The combined multi-epoch spectra are of high signal-to-noise ratio (typically ≥100) and yield precise stellar parameters and chemical abundances. We first confirm the ability of the APOGEE abundance pipeline, ASPCAP, to derive reliable [Fe/H] and effective temperatures for FGK dwarf stars—the primary Kepler host stellar type—by comparing the ASPCAP-derived stellar parameters with those from independent high-resolution spectroscopic characterizations for 221 dwarf stars in the literature. With a sample of 282 close-in (P< 100 days) KOIs observed in the APOGEE KOI goal program, we find a correlation between orbital period and host star [Fe/H] characterized by a critical period, {P}{crit}={8.3}-4.1+0.1 days, below which small exoplanets orbit statistically more metal-enriched host stars. This effect may trace a metallicity dependence of the protoplanetary disk inner radius at the time of planet formation or may be a result of rocky planet ingestion driven by inward planetary migration. We also consider that this may trace a metallicity dependence of the dust sublimation radius, but we find no statistically significant correlation with host {T}{eff} and orbital period to support such a claim.
A Comparative Study of WASP-67 b and HAT-P-38 b from WFC3 Data
NASA Astrophysics Data System (ADS)
Bruno, Giovanni; Lewis, Nikole K.; Stevenson, Kevin B.; Filippazzo, Joseph; Hill, Matthew; Fraine, Jonathan D.; Wakeford, Hannah R.; Deming, Drake; Kilpatrick, Brian; Line, Michael R.; Morley, Caroline V.; Collins, Karen A.; Conti, Dennis M.; Garlitz, Joseph; Rodriguez, Joseph E.
2018-02-01
Atmospheric temperature and planetary gravity are thought to be the main parameters affecting cloud formation in giant exoplanet atmospheres. Recent attempts to understand cloud formation have explored wide regions of the equilibrium temperature-gravity parameter space. In this study, we instead compare the case of two giant planets with nearly identical equilibrium temperature (T eq ∼ 1050 K) and gravity (g ∼ 10 m s‑1). During HST Cycle 23, we collected WFC3/G141 observations of the two planets, WASP-67 b and HAT-P-38 b. HAT-P-38 b, with mass 0.42 M J and radius 1.4 R J, exhibits a relatively clear atmosphere with a clear detection of water. We refine the orbital period of this planet with new observations, obtaining P = 4.6403294 ± 0.0000055 days. WASP-67 b, with mass 0.27 M J and radius 0.83 R J, shows a more muted water absorption feature than that of HAT-P-38 b, indicating either a higher cloud deck in the atmosphere or a more metal-rich composition. The difference in the spectra supports the hypothesis that giant exoplanet atmospheres carry traces of their formation history. Future observations in the visible and mid-infrared are needed to probe the aerosol properties and constrain the evolutionary scenario of these planets.
Compositional Mapping of Planetary moons by Mass Spectrometry of Dust Ejecta
NASA Astrophysics Data System (ADS)
Postberg, F.; Gruen, E.; Horanyi, M.; Kempf, S.; Krüger, H.; Schmidt, J.; Spahn, F.; Srama, R.; Sternovsky, Z.; Trieloff, M.
2011-12-01
Classical methods to analyze the surface composition of planetary objects from a space craft are IR and gamma ray spectroscopy and neutron backscatter measurements. We present a complementary method to analyze rocky or icy dust particles as samples of planetary objects from where they were ejected. Such particles, generated by the ambient meteoroid bombardment that erodes the surface, are naturally present on all atmosphereless moons and planets - they are enshrouded in clouds of ballistic dust particles. In situ mass spectroscopic analysis of these grains impacting on to a detector on a spacecraft reveals their composition as characteristic samples of planetary surfaces at flybys or from an orbiter. The well established approach of dust detection by impact ionization has recently shown its capabilities by analyzing ice particles expelled by subsurface salt water on Saturn's moon Enceladus. Applying the method on micro-meteoroid ejecta of less active moons would allow for the qualitative and quantitative analysis of a huge number of samples from various surface areas, thus combining the advantages of remote sensing and a lander. Utilizing the heritage of the dust detectors onboard Ghiotto, Ulysses, Galileo, and Cassini a variety of improved, low-mass lab-models have been build and tested. They allow the chemical characterization of ice and dust particles encountered at speeds as low as 1 km/s and an accurate reconstruction of their trajectories. Depending on the sampling altitude, a dust trajectory sensor can trace back the origin of each analyzed grain with about 10 km accuracy at the surface. Since achievable detection rates are on the order of thousand per orbit, an orbiter can create a compositional map of samples taken from a greater part of the surface. Flybies allow an investigation of certain surface areas of interest. Dust impact velocities are in general sufficiently high for impact ionization at orbiters about planetary objects with a radius of at least 1000km and with only a thin or no atmosphere. Thus, this method is ideal on a spacecraft orbiting Earth's Moon or Jupiter's Galilean satellites. The approach has a ppm-level sensitivity to salts and many rock forming materials as well as water and organic compounds. It provides key chemical and isotopic constraints for varying provinces or geological formations on the surfaces, leading to better understanding of the body's geological evolution. Regions which were subject to endogenic or exogenic alteration (resurfacing, radiation, old/new regions) could be distinguished and investigated. In particular exchange processes with subsurface ocean on the Galileian moons could be determined with high quantitative precision.
Planetary Defense From Space: Part 2 (Simple) Asteroid Deflection Law
NASA Astrophysics Data System (ADS)
Maccone, Claudio
2006-06-01
A system of two space bases housing missiles for an efficient Planetary Defense of the Earth from asteroids and comets was firstly proposed by this author in 2002. It was then shown that the five Lagrangian points of the Earth Moon system lead naturally to only two unmistakable locations of these two space bases within the sphere of influence of the Earth. These locations are the two Lagrangian points L1 (in between the Earth and the Moon) and L3 (in the direction opposite to the Moon from the Earth). In fact, placing missiles based at L1 and L3 would enable the missiles to deflect the trajectory of incoming asteroids by hitting them orthogonally to their impact trajectory toward the Earth, thus maximizing the deflection at best. It was also shown that confocal conics are the only class of missile trajectories fulfilling this “best orthogonal deflection” requirement. The mathematical theory developed by the author in the years 2002 2004 was just the beginning of a more expanded research program about the Planetary Defense. In fact, while those papers developed the formal Keplerian theory of the Optimal Planetary Defense achievable from the Earth Moon Lagrangian points L1 and L3, this paper is devoted to the proof of a simple “(small) asteroid deflection law” relating directly the following variables to each other:the speed of the arriving asteroid with respect to the Earth (known from the astrometric observations);the asteroid's size and density (also supposed to be known from astronomical observations of various types);the “security radius” of the Earth, that is, the minimal sphere around the Earth outside which we must force the asteroid to fly if we want to be safe on Earth. Typically, we assume the security radius to equal about 10,000 km from the Earth center, but this number might be changed by more refined analyses, especially in the case of “rubble pile” asteroids;the distance from the Earth of the two Lagrangian points L1 and L3 where the defense missiles are to be housed;the deflecting missile's data, namely its mass and especially its “extra-boost”, that is, the extra-energy by which the missile must hit the asteroid to achieve the requested minimal deflection outside the security radius around the Earth.This discovery of the simple “asteroid deflection law” presented in this paper was possible because:In the vicinity of the Earth, the hyperbola of the arriving asteroid is nearly the same as its own asymptote, namely, the asteroid's hyperbola is very much like a straight line. We call this approximation the line/circle approximation. Although “rough” compared to the ordinary Keplerian theory, this approximation simplifies the mathematical problem to such an extent that two simple, final equations can be derived.The confocal missile trajectory, orthogonal to this straight line, ceases then to be an ellipse to become just a circle centered at the Earth. This fact also simplifies things greatly. Our results are thus to be regarded as a good engineering approximation, valid for a preliminary astronautical design of the missiles and bases at L1 and L3.Still, many more sophisticated refinements would be needed for a complete Planetary Defense System:taking into account many perturbation forces of all kinds acting on both the asteroids and missiles shot from L1 and L3;adding more (non-optimal) trajectories of missiles shot from either the Lagrangian points L4 and L5 of the Earth Moon system or from the surface of the Moon itself;encompassing the full range of missiles currently available to the USA (and possibly other countries) so as to really see “which missiles could divert which asteroids”, even just within the very simplified scheme proposed in this paper.In summary: outlined for the first time in February 2002, our Confocal Planetary Defense concept is a simplified Keplerian Theory that already proved simple enough to catch the attention of scholars, popular writers, and representatives of the US Military. These developments would hopefully mark the beginning of a general mathematical vision for building an efficient Planetary Defense System in space and in the vicinity of the Earth, although not on the surface of the Earth itself! We must make a real progress beyond academic papers, Hollywood movies and secret military plans, before asteroids like 99942 Apophis get close enough to destroy us in 2029 or a little later.
An Exoplanet Spinning Up Its Star
NASA Astrophysics Data System (ADS)
Kohler, Susanna
2016-11-01
We know that the large masses of stars govern the orbits of the planets that circle them but a large, close-in planet can also influence the rotation of its host star. A recently discovered, unusual hot Jupiter may be causing its star to spin faster than it should.Exotic PlanetsHot Jupiters are gas giants of roughly Jupiters size that orbit close in to their host stars. Though these planets are easy to detect their large sizes and frequent transits mean surveys have a good chance of catching them we havent found many of them, suggesting that planetary systems containing hot Jupiters are fairly unusual.The period-folded light curve of HATS-18, revealing the transit of the hot Jupiter HATS-18b. The period is P=0.8378 days. [Penev et al. 2016]Studying this exotic population of planets, however, can help us to better understand how gas giants form and evolve in planetary systems. New observations of hot Jupiters may also reveal how stars and close-in planets interact through radiation, gravity, and magnetic fields.The recent discovery of a transiting hot Jupiter a little over 2000 light-years away therefore presents an exciting opportunity!A Speeding GiantThe discovery of HATS-18b, a planet of roughly 2 times Jupiters mass and 1.3 times its radius, was announced in a study led by Kaloyan Penev (Princeton University). The planet was discovered using the HATSouth transit survey network, which includes instruments in Chile, Namibia, and Australia, and follow-up photometry and spectroscopy was conducted at a variety of ground-based observatories.HATS-18bs properties are particularly unusual: this hot Jupiter is zipping around its host star which is very similar to the Sun at the incredible pace of one orbit every 0.84 days. HATS-18bs orbit is more than 20 times closer to its host star than Mercurys is to the Sun, bringing it so close it nearly grazes the stars surface!Size of the planetary orbit relative to the stellar radius as a function of the stellar rotation period, for transiting planets with orbital periods shorter than 2 days and masses greater than 0.1 Jupiter masses. HATS-18b is denoted by the red star. [Penev et al. 2016]Tidal InteractionsWhat happens when a massive planet orbits this close to its star? Tidal interactions between the star and the planet cause tidal dissipation in the star, resulting in decay of the planets orbit. But there may be an additional effect of this interaction in the case of HATS-18b, the authors claim: the planet may be transferring some of its angular momentum to the star.As stars age, they should gradually spin slower as they lose angular momentum viastellar winds. But Penev and collaborators note that this exoplanets host star, HATS-18, spins roughly three times as fast asits inferred age suggests it should. The authors conclude that the angular momentum lost by the planet as its orbit shrinks is deposited in the star, causing the star to spin up.HATS-18 is an excellent laboratory for studying how very short-period planets interact with their stars in fact, Penev and collaborators have already used their observations of the system to constrain models of tidal dissipation from Sun-like stars. Additional observations of HATS-18 and other short-period systems should allow us to further test models of how planetary systems form and evolve.CitationK. Penev et al 2016 AJ 152 127. doi:10.3847/0004-6256/152/5/127
HAT-P-18b and HAT-P-19b: Two Low-density Saturn-mass Planets Transiting Metal-rich K Stars
NASA Astrophysics Data System (ADS)
Hartman, J. D.; Bakos, G. Á.; Sato, B.; Torres, G.; Noyes, R. W.; Latham, D. W.; Kovács, G.; Fischer, D. A.; Howard, A. W.; Johnson, J. A.; Marcy, G. W.; Buchhave, L. A.; Füresz, G.; Perumpilly, G.; Béky, B.; Stefanik, R. P.; Sasselov, D. D.; Esquerdo, G. A.; Everett, M.; Csubry, Z.; Lázár, J.; Papp, I.; Sári, P.
2011-01-01
We report the discovery of two new transiting extrasolar planets. HAT-P-18b orbits the V = 12.759 K2 dwarf star GSC 2594-00646, with a period P = 5.508023 ± 0.000006 days, transit epoch Tc = 2454715.02174 ± 0.00020 (BJD), and transit duration 0.1131 ± 0.0009 days. The host star has a mass of 0.77 ± 0.03 M sun, radius of 0.75 ± 0.04 R sun, effective temperature 4803 ± 80 K, and metallicity [Fe/H] = +0.10 ± 0.08. The planetary companion has a mass of 0.197 ± 0.013 M J and radius of 0.995 ± 0.052 R J, yielding a mean density of 0.25 ± 0.04 g cm-3. HAT-P-19b orbits the V = 12.901 K1 dwarf star GSC 2283-00589, with a period P = 4.008778 ± 0.000006 days, transit epoch Tc = 2455091.53417 ± 0.00034 (BJD), and transit duration 0.1182 ± 0.0014 days. The host star has a mass of 0.84 ± 0.04 M sun, radius of 0.82 ± 0.05 R sun, effective temperature 4990 ± 130 K, and metallicity [Fe/H] = +0.23 ± 0.08. The planetary companion has a mass of 0.292 ± 0.018 M J and radius of 1.132 ± 0.072 R J, yielding a mean density of 0.25 ± 0.04 g cm-3. The radial velocity residuals for HAT-P-19 exhibit a linear trend in time, which indicates the presence of a third body in the system. Comparing these observations with theoretical models, we find that HAT-P-18b and HAT-P-19b are each consistent with a hydrogen-helium-dominated gas giant planet with negligible core mass. HAT-P-18b and HAT-P-19b join HAT-P-12b and WASP-21b in an emerging group of low-density Saturn-mass planets, with negligible inferred core masses. However, unlike HAT-P-12b and WASP-21b, both HAT-P-18b and HAT-P-19b orbit stars with super-solar metallicity. This calls into question the heretofore suggestive correlation between the inferred core mass and host star metallicity for Saturn-mass planets. Based in part on observations obtained at the W. M. Keck Observatory, which is operated by the University of California and the California Institute of Technology. Keck time has been granted by NOAO (A146Hr, A201Hr, and A264Hr), NASA (N018Hr, N049Hr, N128Hr, and N167Hr), and by the NOAO Keck-Gemini time exchange program (G329Hr). Based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Based in part on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.
1985-09-13
MAS Wins Contract to Service Air Force Planes (ANTARA NEWS BULLETIN, 3 Aug 85) Leaders Receive Messages of Thanks From MPR (KPL, 14 Aug 85...Dissolve Batasan ( BUSINESS DAY, 16 Aug 85) 31 Author on ’Quid-Pro-Quo’ in Sabah Claim (Nelly Sindayen; BULLETIN TODAY, 2 Jul 85) 32 Columnist...Exchange ( BUSINESS DAY, 16 Aug 85) 49 Batasan Speaker Yniguez ’Welcomed’ USSR Peace Efforts (Cross-reference) Bigornia Comments on USSR Aid to
Space-Time Processing for Tactical Mobile Ad Hoc Networks
2008-08-01
vision for multiple concurrent communication settings, i.e., a many-to-many framework where multi-packet transmissions (MPTs) and multi-packet...modelling framework of capacity-delay tradeoffs We have introduced the first unified modeling framework for the computation of fundamental limits o We...dalities in wireless n twor i-packet modelling framework to account for the use of m lti-packet reception (MPR) f ad hoc networks with MPT under
Mongolia Report, Number 357, People’s Education Law of the MPR
1983-02-25
right is guaranteed by universal incomplete secondary education for school -age children, and in the future conditions will be established for the...8217 native language, free in- struction in all types of educational institutions and vocational-technical schools in accord with the established system...unity of educational-developmental work, and cooperation between school , family and society in educating children; 8) There is a close tie between
Is the Brazilian pharmaceutical policy ensuring population access to essential medicines?
2012-01-01
Background To evaluate medicine prices, availability and affordability in Brazil, considering the differences across three types of medicines (originator brands, generics and similar medicines) and different types of facilities (private pharmacies, public sector pharmacies and “popular pharmacies”). Methods Data on prices and availability of 50 medicines were collected in 56 pharmacies across six cities in Southern Brazil using the World Health Organization / Health Action International methodology. Median prices obtained were divided by international reference prices to derive the median price ratio (MPR). Results In the private sector, prices were 8.6 MPR for similar medicines, 11.3 MRP for generics and 18.7 MRP for originator brands, respectively. Mean availability was 65%, 74% and 48% for originator brands, generics and similar medicines, respectively. In the public sector, mean availability of similar medicines was 2–7 times higher than that of generics. Mean overall availability in the public sector ranged from 68.8% to 81.7%. In “popular pharmacies”, mean availability was greater than 90% in all cities. Conclusions Availability of medicines in the public sector does not meet the challenge of supplying essential medicines to the entire population, as stated in the Brazilian constitution. This has unavoidable repercussions for affordability, particularly amongst the lower socio-economic strata. PMID:22436555
The association between exercise enjoyment and physical activity in women with fibromyalgia.
Umeda, M; Marino, C A; Lee, W; Hilliard, S C
2014-11-01
Evidence suggests the role of physical activity (PA) in management of clinical symptoms of fibromyalgia. However, very little is known regarding the psychological correlates of PA in patients with fibromyalgia. Therefore, this study examined the association between exercise enjoyment (EE) and PA in women with fibromyalgia. 19 women with fibromyalgia completed a laboratory session, where EE was assessed using a self-report questionnaire immediately after 20 min of light-intensity biking. Muscle pain ratings (MPR) in the legs were assessed during exercise, and changes in clinical pain intensity after exercise were computed. PA was assessed subjectively using a self-report questionnaire and objectively using an accelerometer for one week. Results from correlation analyses indicated that EE was associated with the self-reported amount of PA (rs=0.61, R(2)=0.37, p<0.01) and the minutes spent for moderate intensity PA (rs=0.48, R(2)=0.23, p<0.05). However, neither MPR nor changes in clinical pain intensity were associated with PA. These results suggest that EE may serve as a determinant of PA in women with fibromyalgia. Future research is needed to develop interventions to maximize EE to promote PA in this clinical population. © Georg Thieme Verlag KG Stuttgart · New York.
Vasilenko, A M; Rozanov, A L; Sharipova, M M; Chukaeva, O G
The present article was designed to report the results of the electropuncture diagnostics (EPD) with the use of the 'Prognoz' electropunctural device obtained during the examination of 12 patients who experienced meteopathic reactions (MPR) during magnetic storms. The most frequently detected changes were deviations affecting the acupuncture channels (AC) of the heart, pericardium and triple energizer. The latter underwent the most pronounced deviation from the 'balanced condition'. In 2 cases out of the three (66,6%), its hypofunction was documented The pericardium channel was characterized by extreme asymmetry of its left and right branches. To a lesser extent, a similar asymmetry was apparent in the acupuncture channels of the heart. The present pilot study revealed the noticeable changed in the functional state of two AC (pericardium and triple energizer) in people suffering from meteopathic reactions. It is concluded that the further studies involving a larger population of the weather-dependent subjects is likely to identify other sensitive acupuncture channels; the analysis of their functional condition may be instrumental in determining the typical MPR profiles based on the results of the evaluation of the effectiveness of electropunctural diagnostics. The newly detected patterns may be useful for the development of the personalized approach to the prediction, prevention, and relief of the meteopathic reactions.
A scaling law for accretion zone sizes
NASA Technical Reports Server (NTRS)
Greenzweig, Yuval; Lissauer, Jack J.
1987-01-01
Current theories of runaway planetary accretion require small random velocities of the accreted particles. Two body gravitational accretion cross sections which ignore tidal perturbations of the Sun are not valid for the slow encounters which occur at low relative velocities. Wetherill and Cox have studied accretion cross sections for rocky protoplanets orbiting at 1 AU. Using analytic methods based on Hill's lunar theory, one can scale these results for protoplanets that occupy the same fraction of their Hill sphere as does a rocky body at 1 AU. Generalization to bodies of different sizes is achieved here by numerical integrations of the three-body problem. Starting at initial positions far from the accreting body, test particles are allowed to encounter the body once, and the cross section is computed. A power law is found relating the cross section to the radius of the accreting body (of fixed mass).
Gravity Field and Internal Structure of Mercury from MESSENGER
NASA Technical Reports Server (NTRS)
Smith, David E.; Zuber, Maria T.; Phillips, Roger J.; Solomon, Sean C.; Hauck, Steven A., II; Lemoine, Frank G.; Mazarico, Erwan; Neumann, Gregory A.; Peale, Stanton J.; Margot, Jean-Luc;
2012-01-01
Radio tracking of the MESSENGER spacecraft has provided a model of Mercury's gravity field. In the northern hemisphere, several large gravity anomalies, including candidate mass concentrations (mascons), exceed 100 milli-Galileos (mgal). Mercury's northern hemisphere crust is thicker at low latitudes and thinner in the polar region and shows evidence for thinning beneath some impact basins. The low-degree gravity field, combined with planetary spin parameters, yields the moment of inertia C/M(R(exp 2) = 0.353 +/- 0.017, where M and R are Mercury's mass and radius, and a ratio of the moment of inertia of Mercury's solid outer shell to that of the planet of C(sub m)/C = 0.452 +/- 0.035. A model for Mercury s radial density distribution consistent with these results includes a solid silicate crust and mantle overlying a solid iron-sulfide layer and an iron-rich liquid outer core and perhaps a solid inner core.
Magellan: Radar performance and data products
Pettengill, G.H.; Ford, P.G.; Johnson, W.T.K.; Raney, R.K.; Soderblom, L.A.
1991-01-01
The Magellan Venus orbiter carries only one scientific instrument: a 12.6-centimeter-wavelength radar system shared among three data-taking modes. The syntheticaperture mode images radar echoes from the Venus surface at a resolution of between 120 and 300 meters, depending on spacecraft altitude. In the altimetric mode, relative height measurement accuracies may approach 5 meters, depending on the terrain's roughness, although orbital uncertainties place a floor of about 50 meters on the absolute uncertainty. In areas of extremely rough topography, accuracy is limited by the inherent line-of-sight radar resolution of about 88 meters. The maximum elevation observed to date, corresponding to a planetary radius of 6062 kilometers, lies within Maxwell Mons. When used as a thermal emission radiometer, the system can determine surface emissivities to an absolute accuracy of about 0.02. Mosaicked and archival digital data products will be released in compact disk (CDROM) format.
Magnetic field of jupiter and its interaction with the solar wind.
Smith, E J; Davis, L; Jones, D E; Colburn, D S; Coleman, P J; Dyal, P; Sonett, C P
1974-01-25
Jupiter's magnetic field and its interaction with the magnetized solar wind were observed with the Pioneer 10 vector helium magnetometer. The magnetic dipole is directed opposite to that of the earth with a moment of 4.0 gauss R(J)(3) (R(J), Jupiter radius), and an inclination of 15 degrees lying in a system III meridian of 230 degrees . The dipole is offset about 0.1 R(J) north of the equatorial plane and about 0.2 R(J) toward longitude 170 degrees . There is severe stretching of the planetary field parallel to the equator throughout the outer magnetosphere, accompanied by a systematic departure from meridian planes. The field configuration implies substantial plasma effects inside the magnetosphere, such as thermal pressure, centrifugal forces, and differential rotation. As at the earth, the outer boundary is thin, nor diffuse, and there is a detached bow shock.
Lakshmi Planum: A distinctive highland volcanic province
NASA Astrophysics Data System (ADS)
Roberts, Kari M.; Head, James W.
Lakshmi Planum, a broad smooth plain located in western Ishtar Terra and containing two large oval depressions (Colette and Sacajawea), has been interpreted as a highland plain of volcanic origin. Lakshmi is situated 3 to 5 km above the mean planetary radius and is surrounded on all sides by bands of mountains interpreted to be of compressional tectonic origin. Four primary characteristics distinguish Lakshmi from other volcanic regions known on the planet, such as Beta Regio: (1) high altitude, (2) plateau-like nature, (3) the presence of very large, low volcanic constructs with distinctive central calderas, and (4) its compressional tectonic surroundings. Building on the previous work of Pronin, the objective is to establish the detailed nature of the volcanic deposits on Lakshmi, interpret eruption styles and conditions, sketch out an eruption history, and determine the relationship between volcanism and the tectonic environment of the region.
NASA Technical Reports Server (NTRS)
1990-01-01
This image is a full-resolution mosaic of several Magellan images and is centered at 61 degrees north latitude and 341 degrees east longitude. The image is 250 kilometers wide (150 miles). The radar smooth region in the northern part of the image is Lakshmi Planum, a high plateau region roughly 3.5 kilometers (2.2 miles) above the mean planetary radius. Lakshmi Planum is ringed by intensely deformed terrain, some of which is shown in the southern portion of the image and is called Clotho Tessera. The 64-kilometer (40 mile) diameter circular feature in the image is a depression called Siddons and may be a volcanic caldera. This view is supported by the collapsed lava tubes surrounding the feature. By carefully studying this and other surrounding images scientists hope to discover what tectonic and volcanic processes formed this complex region. The solid black parts of the image represent data gaps that may be filled in by the Magellan extended mission.