452 research outputs found
A Spitzer Census of Transitional Protoplanetary Disks with AU-Scale Inner Holes
[abridged] Protoplanetary disks with AU-scale inner clearings, often referred
to as transitional disks, provide a unique sample for understanding disk
dissipation mechanisms and possible connections to planet formation.
Observations of young stellar clusters with the Spitzer Space Telescope have
amassed mid-infrared spectral energy distributions for thousands of star-disk
systems from which transition disks can be identified. From a sample of 8
relatively nearby young regions (d <= 400 pc), we have identified about 20 such
objects, which we term "classical" transition disks, spanning a wide range of
stellar age and mass. We also identified two additional categories representing
more ambiguous cases: "warm excess" objects with transition-like spectral
energy distributions but moderate excess at 5.8 microns, and "weak excess"
objects with smaller 24 micron excess that may be optically thin or exhibit
advanced dust grain growth and settling. From existing Halpha emission
measurements, we find evidence for different accretion activity among the three
categories, with a majority of the classical and warm excess transition objects
still accreting gas through their inner holes and onto the central stars, while
a smaller fraction of the weak transition objects are accreting at detectable
rates. We find a possible age dependence to the frequency of classical
transition objects, with fractions relative to the total population of disks in
a given region of a few percent at 1-2 Myr rising to 10-20% at 3-10 Myr. The
trend is even stronger if the weak and warm excess objects are included.
Classical transition disks appear to be less common, and weak transition disks
more common, around lower-mass stars (M <= 0.3 Msun).Comment: 34 pages, 7 figures; accepted to Ap
The c2d Spitzer Spectroscopic Survey Of Ices Around Low-Mass Young Stellar Objects. I. H2O And The 5-8 Mu M Bands
To study the physical and chemical evolution of ices in solar-mass systems, a spectral survey is conducted of a sample of 41 low-luminosity YSOs (L similar to 0.1-10 L-circle dot) using 3-38 mu m Spitzer and ground-based spectra. The sample is complemented with previously published Spitzer spectra of background stars and with ISO spectra of well-studied massive YSOs (L similar to 10(5) L-circle dot). The long-known 6.0 and 6.85 mu m bands are detected toward all sources, with the Class 0-type YSOs showing the deepest bands ever observed. The 6.0 mu m band is often deeper than expected from the bending mode of pure solid H2O. The additional 5-7 mu m absorption consists of five independent components, which, by comparison to laboratory studies, must be from at least eight different carriers. Much of this absorption is due to simple species likely formed by grain surface chemistry, at abundances of 1%-30% for CH3OH, 3%-8% for NH3, 1%-5% for HCOOH, similar to 6% for H2CO, and similar to 0.3% for HCOO- relative to solid H2O. The 6.85 mu m band has one or two carriers, of which one may be less volatile than H2O. Its carrier(s) formed early in the molecular cloud evolution and do not survive in the diffuse ISM. If an NH4+- containing salt is the carrier, its abundance relative to solid H2O is similar to 7%, demonstrating the efficiency of low-temperature acid-base chemistry or cosmic-ray-induced reactions. Possible origins are discussed for enigmatic, very broad absorption between 5 and 8 mu m. Finally, the same ices are observed toward massive and low-mass YSOs, indicating that processing by internal UV radiation fields is a minor factor in their early chemical evolution.NWO SpinozaNOVAEuropean Research Training Network PLANETS HPRN-CT-2002-00308NASA Origins NAG5-13050NASA Hubble Fellowship 01201.01NASA NAS 5-26555Astronom
Creating a Gold Medal Olympic and Paralympics Health Care Team: A Satisfaction Survey of the Mobile Medical Unit/Polyclinic Team Training for the Vancouver 2010 Winter Games
BACKGROUND:
The mobile medical unit/polyclinic (MMU/PC) was an essential part of the medical services to support ill or injured Olympic or Paralympics family during the 2010 Olympic and Paralympics winter games. The objective of this study was to survey the satisfaction of the clinical staff that completed the training programs prior to deployment to the MMU.
METHODS:
Medical personnel who participated in at least one of the four training programs, including (1) week-end sessions; (2) web-based modules; (3) just-in-time training; and (4) daily simulation exercises were invited to participate in a web-based survey and comment on their level of satisfaction with training program. RESULTS: A total of 64 (out of 94 who were invited) physicians, nurses and respiratory therapists completed the survey. All participants reported favorably that the MMU/PC training positively impacted their knowledge, skills and team functions while deployed at the MMU/PC during the 2010 Olympic Games. However, components of the training program were valued differently depending on clinical job title, years of experience, and prior experience in large scale events. Respondents with little or no experience working in large scale events (45%) rated daily simulations as the most valuable component of the training program for strengthening competencies and knowledge in clinical skills for working in large scale events.
CONCLUSION:
The multi-phase MMU/PC training was found to be beneficial for preparing the medical team for the 2010 Winter Games. In particular this survey demonstrates the effectiveness of simulation training programs on teamwork competencies in ad hoc groups
Detection of Thermal Emission from an Extrasolar Planet
We present Spitzer Space Telescope infrared photometric time series of the
transiting extrasolar planet system TrES-1. The data span a predicted time of
secondary eclipse, corresponding to the passage of the planet behind the star.
In both bands of our observations, we detect a flux decrement with a timing,
amplitude, and duration as predicted by published parameters of the system.
This signal represents the first direct detection of (i.e. the observation of
photons emitted by) a planet orbiting another star. The observed eclipse depths
(in units of relative flux) are 0.00066 +/- 0.00013 at 4.5um and 0.00225 +/-
0.00036 at 8.0um. These estimates provide the first observational constraints
on models of the thermal emission of hot Jupiters. Assuming that the planet
emits as a blackbody, we estimate an effective temperature of T_p=1060 +/- 50
K. Under the additional assumptions that the planet is in thermal equilibrium
with the radiation from the star and emits isotropically, we find a Bond albedo
of A = 0.31 +/- 0.14. This would imply that the planet absorbs the majority of
stellar radiation incident upon it, a conclusion of significant impact to
atmospheric models of these objects. We compare our data to a
previously-published model of the planetary thermal emission, which predicts
prominent spectral features in our observational bands due to water and carbon
monoxide. Based on the time of secondary eclipse, we present an upper limit on
the orbital eccentricity that is sufficiently small that we conclude that tidal
dissipation is unlikely to provide a significant source of energy interior to
the planet.(abridged)Comment: 20 pages, 4 figures, to appear in the Astrophysical Journal, 20 June
200
An Overview of Research and Evaluation Designs for Dissemination and Implementation
The wide variety of dissemination and implementation designs now being used to evaluate and improve health systems and outcomes warrants review of the scope, features, and limitations of these designs
Bodyweight Perceptions among Texas Women: The Effects of Religion, Race/Ethnicity, and Citizenship Status
Despite previous work exploring linkages between religious participation and health, little research has looked at the role of religion in affecting bodyweight perceptions. Using the theoretical model developed by Levin et al. (Sociol Q 36(1):157–173, 1995) on the multidimensionality of religious participation, we develop several hypotheses and test them by using data from the 2004 Survey of Texas Adults. We estimate multinomial logistic regression models to determine the relative risk of women perceiving themselves as overweight. Results indicate that religious attendance lowers risk of women perceiving themselves as very overweight. Citizenship status was an important factor for Latinas, with noncitizens being less likely to see themselves as overweight. We also test interaction effects between religion and race. Religious attendance and prayer have a moderating effect among Latina non-citizens so that among these women, attendance and prayer intensify perceptions of feeling less overweight when compared to their white counterparts. Among African American women, the effect of increased church attendance leads to perceptions of being overweight. Prayer is also a correlate of overweight perceptions but only among African American women. We close with a discussion that highlights key implications from our findings, note study limitations, and several promising avenues for future research
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Clinical multiplexed exome sequencing distinguishes adult oligodendroglial neoplasms from astrocytic and mixed lineage gliomas
Classifying adult gliomas remains largely a histologic diagnosis based on morphology; however astrocytic, oligodendroglial and mixed lineage tumors can display overlapping histologic features. We used multiplexed exome sequencing (OncoPanel) on 108 primary or recurrent adult gliomas, comprising 65 oligodendrogliomas, 28 astrocytomas and 15 mixed oligoastrocytomas to identify lesions that could enhance lineage classification. Mutations in TP53 (20/28, 71%) and ATRX (15/28, 54%) were enriched in astrocytic tumors compared to oligodendroglial tumors of which 4/65 (6%) had mutations in TP53 and 2/65 (3%) had ATRX mutations. We found that oligoastrocytomas harbored mutations in TP53 (80%, 12/15) and ATRX (60%, 9/15) at frequencies similar to pure astrocytic tumors, suggesting that oligoastrocytomas and astrocytomas may represent a single genetic or biological entity. p53 protein expression correlated with mutation status and showed significant increases in astrocytomas and oligoastrocytomas compared to oligodendrogliomas, a finding that also may facilitate accurate classification. Furthermore our OncoPanel analysis revealed that 15% of IDH1/2 mutant gliomas would not be detected by traditional IDH1 (p.R132H) antibody testing, supporting the use of genomic technologies in providing clinically relevant data. In all, our results demonstrate that multiplexed exome sequencing can support evaluation and classification of adult low-grade gliomas with a single clinical test
Protocol for implementation of family health history collection and decision support into primary care using a computerized family health history system
<p>Abstract</p> <p>Background</p> <p>The CDC's Family History Public Health Initiative encourages adoption and increase awareness of family health history. To meet these goals and develop a personalized medicine implementation science research agenda, the Genomedical Connection is using an implementation research (T3 research) framework to develop and integrate a self-administered computerized family history system with built-in decision support into 2 primary care clinics in North Carolina.</p> <p>Methods/Design</p> <p>The family health history system collects a three generation family history on 48 conditions and provides decision support (pedigree and tabular family history, provider recommendation report and patient summary report) for 4 pilot conditions: breast cancer, ovarian cancer, colon cancer, and thrombosis. All adult English-speaking, non-adopted, patients scheduled for well-visits are invited to complete the family health system prior to their appointment. Decision support documents are entered into the medical record and available to provider's prior to the appointment. In order to optimize integration, components were piloted by stakeholders prior to and during implementation. Primary outcomes are change in appropriate testing for hereditary thrombophilia and screening for breast cancer, colon cancer, and ovarian cancer one year after study enrollment. Secondary outcomes include implementation measures related to the benefits and burdens of the family health system and its impact on clinic workflow, patients' risk perception, and intention to change health related behaviors. Outcomes are assessed through chart review, patient surveys at baseline and follow-up, and provider surveys. Clinical validity of the decision support is calculated by comparing its recommendations to those made by a genetic counselor reviewing the same pedigree; and clinical utility is demonstrated through reclassification rates and changes in appropriate screening (the primary outcome).</p> <p>Discussion</p> <p>This study integrates a computerized family health history system within the context of a routine well-visit appointment to overcome many of the existing barriers to collection and use of family history information by primary care providers. Results of the implementation process, its acceptability to patients and providers, modifications necessary to optimize the system, and impact on clinical care can serve to guide future implementation projects for both family history and other tools of personalized medicine, such as health risk assessments.</p
Introducing BASE: the Biomes of Australian Soil Environments soil microbial diversity database
Microbial inhabitants of soils are important to ecosystem and planetary functions, yet there are large gaps in our knowledge of their diversity and ecology. The ‘Biomes of Australian Soil Environments’ (BASE) project has generated a database of microbial diversity with associated metadata across extensive environmental gradients at continental scale. As the characterisation of microbes rapidly expands, the BASE database provides an evolving platform for interrogating and integrating microbial diversity and function
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