Identification of three new proto-Planetary Nebulae exhibiting the unidentified feature at 21 um

Among its great findings, the IRAS mission showed the existence of an unidentified mid-IR feature around 21 um. Since its discovery, this feature has been detected in all C-rich proto-PNe of intermediate spectral type (A-G) and - weakly - in a few PNe and AGB stars, but the nature of its carriers remains unknown. In this paper, we show the detection of this feature in the spectra of three new stars transiting from the AGB to the PN stage obtained with the Spitzer Space Telescope. Following a recent suggestion, we try to model the SEDs of our targets with amorphous carbon and FeO, which might be responsible for the unidentified feature. The fit thus obtained is not completely satisfactory, since the shape of the feature is not well matched. In the attempt to relate the unidentified feature to other dust features, we retrieved mid-IR spectra of all the 21-um sources currently known from ISO and Spitzer on-line archives and noticed a correlation between the flux emitted in the 21-um feature and that emitted at 7 and 11 um (PAH bands and HAC broad emission). Such a correlation may point to a common nature of the carriers.Comment: Accepted for publication in Ap

SOFIA/FORCAST and Spitzer/IRAC Imaging of the Ultra Compact H II Region W3(OH) and Associated Protostars in W3

We present infrared observations of the ultra-compact H II region W3(OH) made by the FORCAST instrument aboard SOFIA and by Spitzer/IRAC. We contribute new wavelength data to the spectral energy distribution, which constrains the optical depth, grain size distribution, and temperature gradient of the dusty shell surrounding the H II region. We model the dust component as a spherical shell containing an inner cavity with radius ~ 600 AU, irradiated by a central star of type O9 and temperature ~ 31,000 K. The total luminosity of this system is 71,000 L_solar. An observed excess of 2.2 - 4.5 microns emission in the SED can be explained by our viewing a cavity opening or clumpiness in the shell structure whereby radiation from the warm interior of the shell can escape. We claim to detect the nearby water maser source W3 (H2O) at 31.4 and 37.1 microns using beam deconvolution of the FORCAST images. We constrain the flux densities of this object at 19.7 - 37.1 microns. Additionally, we present in situ observations of four young stellar and protostellar objects in the SOFIA field, presumably associated with the W3 molecular cloud. Results from the model SED fitting tool of Robitaille et al. (2006, 2007} suggest that two objects (2MASS J02270352+6152357 and 2MASS J02270824+6152281) are intermediate-luminosity (~ 236 - 432 L_solar) protostars; one object (2MASS J02270887+6152344) is either a high-mass protostar with luminosity 3000 L_solar or a less massive young star with a substantial circumstellar disk but depleted envelope; and one object (2MASS J02270743+6152281) is an intermediate-luminosity (~ 768 L_solar) protostar nearing the end of its envelope accretion phase or a young star surrounded by a circumstellar disk with no appreciable circumstellar envelope.Comment: 12 pages, 8 figures, 2 tables, accepted by Ap

The use of high-throughput sequencing to investigate an outbreak of glycopeptide-resistant Enterococcus faecium with a novel quinupristin-dalfopristin resistance mechanism.

High-throughput sequencing (HTS) has successfully identified novel resistance genes in enterococci and determined clonal relatedness in outbreak analysis. We report the use of HTS to investigate two concurrent outbreaks of glycopeptide-resistant Enterococcus faecium (GRE) with an uncharacterised resistance mechanism to quinupristin-dalfopristin (QD).Seven QD-resistant and five QD-susceptible GRE isolates from a two-centre outbreak were studied. HTS was performed to identify genes or predicted proteins that were associated with the QD-resistant phenotype. MLST and SNP typing on HTS data was used to determine clonal relatedness.Comparative genomic analysis confirmed this GRE outbreak involved two distinct clones (ST80 and ST192). HTS confirmed the absence of known QD resistance genes, suggesting a novel mechanism was conferring resistance. Genomic analysis identified two significant genetic determinants with explanatory power for the high level of QD resistance in the ST80 QD-resistant clone: an additional 56aa leader sequence at the N-terminus of the lsaE gene and a transposon containing seven genes encoding proteins with possible drug or drug-target modification activities. However, HTS was unable to conclusively determine the QD resistance mechanism and did not reveal any genetic basis for QD resistance in the ST192 clone. This study highlights the usefulness of HTS in deciphering the degree of relatedness in two concurrent GRE outbreaks. Although HTS was able to reveal some genetic candidates for uncharacterised QD resistance, this study demonstrates the limitations of HTS as a tool for identifying putative determinants of resistance to QD

Spitzer/IRAC Limits to Planetary Companions of Fomalhaut and epsilon Eridani

Fomalhaut and epsilon Eridani are two young, nearby stars that possess extended debris disks whose structures suggest the presence of perturbing planetary objects. With its high sensitivity and stable point spread function, Spitzer/IRAC is uniquely capable of detecting cool, Jupiter-like planetary companions whose peak emission is predicted to occur near 4.5 um. We report on deep IRAC imaging of these two stars, taken at 3.6 and 4.5 um using subarray mode and in all four channels in wider-field full array mode. Observations acquired at two different telescope roll angles allowed faint surrounding objects to be separated from the stellar diffraction pattern. No companion candidates were detected at the reported position of Fomalhaut b with 3 sigma model-dependent mass upper limits of 3 MJ (for an age of 200 Myr). Around epsilon Eridani we instead set a limit of 4 and <1 MJ (1 Gyr model age) at the inner and outer edge of the sub-millimeter debris ring, respectively. These results are consistent with non-detections in recent near-infrared imaging searches, and set the strongest limits to date on the presence of planets outside epsilon Eridani sub-millimeter ring.Comment: Accepted by The Astrophysical Journal. Request electronic-only plates to M. Marengo ([email protected]

Phase I dose-escalation trial of the oral AKT inhibitor uprosertib in combination with the oral MEK1/MEK2 inhibitor trametinib in patients with solid tumors.

PurposeThis study aimed to determine the safety, tolerability, and recommended phase II doses of trametinib plus uprosertib (GSK2141795) in patients with solid tumors likely to be sensitive to MEK and/or AKT inhibition.MethodsThis was a phase I, open-label, dose-escalation, and dose-expansion study in patients with triple-negative breast cancer or BRAF-wild type advanced melanoma. The primary outcome of the expansion study was investigator-assessed response. Among 126 enrolled patients, 63 received continuous oral daily dosing of trametinib and uprosertib, 29 received various alternative dosing schedules, and 34 were enrolled into expansion cohorts. Doses tested in the expansion cohort were trametinib 1.5&nbsp;mg once daily (QD) + uprosertib 50&nbsp;mg QD.ResultsAdverse events (AEs) were consistent with those reported in monotherapy studies but occurred at lower doses and with greater severity. Diarrhea was the most common dose-limiting toxicity; diarrhea and rash were particularly difficult to tolerate. Overall, 59% and 6% of patients reported AEs with a maximum severity of grade 3 and 4, respectively. Poor tolerability prevented adequate delivery of uprosertib with trametinib at a concentration predicted to have clinical activity. The study was terminated early based on futility in the continuous-dosing expansion cohorts and a lack of pharmacological or therapeutic advantage with intermittent dosing. The objective response rate was &lt; 5% (1 complete response, 5 partial responses).ConclusionsContinuous and intermittent dosing of trametinib in combination with uprosertib was not tolerated, and minimal clinical activity was observed in all schedules tested

Spitzer 24 um Images of Planetary Nebulae

Spitzer MIPS 24 um images were obtained for 36 Galactic planetary nebulae (PNe) whose central stars are hot white dwarfs (WDs) or pre-WDs with effective temperatures of ~100,000 K or higher. Diffuse 24 um emission is detected in 28 of these PNe. The eight non-detections are angularly large PNe with very low H-alpha surface brightnesses. We find three types of correspondence between the 24 um emission and H-alpha line emission of these PNe: six show 24 um emission more extended than H-alpha emission, nine have a similar extent at 24 um and H-alpha, and 13 show diffuse 24 um emission near the center of the H-alpha shell. The sizes and surface brightnesses of these three groups of PNe and the non-detections suggest an evolutionary sequence, with the youngest ones being brightest and the most evolved ones undetected. The 24 um band emission from these PNe is attributed to [O IV] 25.9 um and [Ne V] 24.3 um line emission and dust continuum emission, but the relative contributions of these three components depend on the temperature of the central star and the distribution of gas and dust in the nebula.Comment: 24 pages, 8 figures, to appear in the Astronomical Journal, September issue. Relace previous file; two references are added and typos are correcte

Contract Aware Components, 10 years after

The notion of contract aware components has been published roughly ten years ago and is now becoming mainstream in several fields where the usage of software components is seen as critical. The goal of this paper is to survey domains such as Embedded Systems or Service Oriented Architecture where the notion of contract aware components has been influential. For each of these domains we briefly describe what has been done with this idea and we discuss the remaining challenges.Comment: In Proceedings WCSI 2010, arXiv:1010.233

Circumstellar Structure around Evolved Stars in the Cygnus-X Star Formation Region

We present observations of newly discovered 24 micron circumstellar structures detected with the Multiband Imaging Photometer for Spitzer (MIPS) around three evolved stars in the Cygnus-X star forming region. One of the objects, BD+43 3710, has a bipolar nebula, possibly due to an outflow or a torus of material. A second, HBHA 4202-22, a Wolf-Rayet candidate, shows a circular shell of 24 micron emission suggestive of either a limb-brightened shell or disk seen face-on. No diffuse emission was detected around either of these two objects in the Spitzer 3.6-8 micron Infrared Array Camera (IRAC) bands. The third object is the luminous blue variable candidate G79.29+0.46. We resolved the previously known inner ring in all four IRAC bands. The 24 micron emission from the inner ring extends ~1.2 arcmin beyond the shorter wavelength emission, well beyond what can be attributed to the difference in resolutions between MIPS and IRAC. Additionally, we have discovered an outer ring of 24 micron emission, possibly due to an earlier episode of mass loss. For the two shell stars, we present the results of radiative transfer models, constraining the stellar and dust shell parameters. The shells are composed of amorphous carbon grains, plus polycyclic aromatic hydrocarbons in the case of G79.29+0.46. Both G79.29+0.46 and HBHA 4202-22 lie behind the main Cygnus-X cloud. Although G79.29+0.46 may simply be on the far side of the cloud, HBHA 4202-22 is unrelated to the Cygnus-X star formation region.Comment: Accepted by A

Thermal Emission of WASP-14b Revealed with Three Spitzer Eclipses

Exoplanet WASP-14b is a highly irradiated, transiting hot Jupiter. Joshi et al. calculate an equilibrium temperature Teq of 1866 K for zero albedo and reemission from the entire planet, a mass of 7.3 +/- 0.5 Jupiter masses and a radius of 1.28 +/- 0.08 Jupiter radii. Its mean density of 4.6 g/cm3 is one of the highest known for planets with periods less than 3 days. We obtained three secondary eclipse light curves with the Spitzer Space Telescope. The eclipse depths from the best jointly fit model are $0.224\%$ +/- $0.018\%$ at 4.5 {\mu}m and $0.181\%$ +/- $0.022\%$ at 8.0 {\mu}m. The corresponding brightness temperatures are 2212 +/- 94 K and 1590 +/- 116 K. A slight ambiguity between systematic models suggests a conservative 3.6 {\mu}m eclipse depth of $0.19\%$ +/- $0.01\%$ and brightness temperature of 2242 +/- 55 K. Although extremely irradiated, WASP-14b does not show any distinct evidence of a thermal inversion. In addition, the present data nominally favor models with day night energy redistribution less than $~30\%$. The current data are generally consistent with oxygen-rich as well as carbon-rich compositions, although an oxygen-rich composition provides a marginally better fit. We confirm a significant eccentricity of e = 0.087 +/- 0.002 and refine other orbital parameters.Comment: 16 pages, 16 figure

Coccidioidomycosis among Workers at an Archeological Site, Northeastern Utah

In 2001, an outbreak of acute respiratory disease occurred among persons working at a Native American archeological site at Dinosaur National Monument in northeastern Utah. Epidemiologic and environmental investigations were undertaken to determine the cause of the outbreak. A clinical case was defined by the presence of at least two of the following symptoms: self-reported fever, shortness of breath, or cough. Ten workers met the clinical case definition; 9 had serologic confirmation of coccidioidomycosis, and 8 were hospitalized. All 10 were present during sifting of dirt through screens on June 19; symptoms began 9–12 days later (median 10). Coccidioidomycosis also developed in a worker at the site in September 2001. A serosurvey among 40 other Dinosaur National Monument workers did not find serologic evidence of recent infection. This outbreak documents a new endemic focus of coccidioidomycosis, extending northward its known geographic distribution in Utah by approximately 200 miles