226 research outputs found
The Cosmic Web Imager: An integral field spectrograph for the Hale Telescope at Palomar Observatory: Instrument design and first results
We describe the Cosmic Web Imager (CWI), a UV-VIS integral field spectrograph designed for the Hale 200" telescope at the Palomar Observatory. CWI has been built specifically for the observation of diffuse radiation. The instrument field of view is 60" x 40" with spectral resolving power of R ~5000 and seeing limited spatial resolution. It utilizes volume phase holographic gratings and is intended to cover the spectral range 3800Å to 9500Å with an instantaneous bandwidth of ~450Å. CWI saw first light in July 2009, and conducted its first successful scientific observations in May 2010
Prognostic Value of E/E′ Ratio in Patients With Unoperated Severe Aortic Stenosis
ObjectivesThe aim of this study was to evaluate the value of clinical and echo-Doppler parameters for the prognosis of unoperated severe aortic stenosis (AS).BackgroundApproximately one-third of severe, symptomatic AS patients are denied surgery. Risk stratification of unoperated AS is important to determine eligibility for percutaneous aortic valve replacement, an evolving treatment option for AS patients deemed suboptimal for surgical aortic valve replacement.MethodsWe retrospectively compared clinical and echo-Doppler parameters between survivors and nonsurvivors of 125 patients with unoperated severe AS.ResultsThe 1-year survival rate was 62.4%. In univariate analysis, survivors compared with nonsurvivors were younger (80.0 ± 10.9 years vs. 84.9 ± 11.1 years, p = 0.02), had a greater left ventricular ejection fraction (LVEF) (55 ± 15% vs. 50 ± 16%, p = 0.042), a higher left ventricular stroke volume (63 ± 19 ml vs. 56 ± 13 ml, p = 0.015), a lower E/E′ ratio (12.19 ± 5.7 vs. 16.87 ± 7.43, p < 0.001), and a lower prevalence of E/E′ >15 (20% vs. 55%, p < 0.001). Symptomatic status was nonsignificantly different between survivors and nonsurvivors. In patients with an LVEF ≥50%, the subgroup with E/E′ ≤15 and with E/E′ >15 had a 73.8% and 47.8% 1-year survival rate, respectively (p = 0.027). In the patients with an LVEF <50%, the patients with E/E′ ≤15 and those with E/E′ >15 demonstrated a 70.6% and 22.3% 1-year survival rate, respectively (p = 0.003). In multivariate analysis, significant predictors of mortality were E/E′ >15 and a combination of E/E′ >15 and B-type natriuretic peptide >300 ng/ml: adjusted mortality risk 2.34 (95% confidence interval (CI) 1.27 to 4.33, p = 0.0072) and 2.59 (95% CI 1.21 to 5.55, p = 0.014), respectively.ConclusionsThe E/E′ ratio is the single most predictive clinical and echo-Doppler parameter in the assessment of overall prognosis in patients with unoperated severe AS. LVEF was a significant predictor of survival only in the univariate analysis. B-type natriuretic peptide alone was not a predictor of prognosis in the study population. However, the combination of E/E′ and B-type natriuretic peptide is even more predictive of the 1-year prognosis
Xanthomonas oligomers and polymers:the complexity of elicitation and suppression of host innate immunity
Bacterial oligomers and polymers play opposite roles:MAMPs interact with each other and with host cell walls during induction of calcium signalling, which is supressed by bacterial EPS
The On-Orbit Performance of the Galaxy Evolution Explorer
We report the first year on-orbit performance results for the Galaxy
Evolution Explorer (GALEX), a NASA Small Explorer that is performing a survey
of the sky in two ultraviolet bands. The instrument comprises a 50 cm diameter
modified Ritchey-Chretien telescope with a 1.25 degree field of view,
selectable imaging and objective grism spectroscopic modes, and an innovative
optical system with a thin-film multilayer dichroic beam splitter that enables
simultaneous imaging by a pair of photon counting, microchannel plate, delay
line readout detectors. Initial measurements demonstrate that GALEX is
performing well, meeting its requirements for resolution, efficiency,
astrometry, bandpass definition and survey sensitivity.Comment: This paper will be published as part of the Galaxy Evolution Explorer
(GALEX) Astrophysical Journal Letters Special Issu
Etiology of Severe Non-malaria Febrile Illness in Northern Tanzania: A Prospective Cohort Study.
The syndrome of fever is a commonly presenting complaint among persons seeking healthcare in low-resource areas, yet the public health community has not approached fever in a comprehensive manner. In many areas, malaria is over-diagnosed, and patients without malaria have poor outcomes. We prospectively studied a cohort of 870 pediatric and adult febrile admissions to two hospitals in northern Tanzania over the period of one year using conventional standard diagnostic tests to establish fever etiology. Malaria was the clinical diagnosis for 528 (60.7%), but was the actual cause of fever in only 14 (1.6%). By contrast, bacterial, mycobacterial, and fungal bloodstream infections accounted for 85 (9.8%), 14 (1.6%), and 25 (2.9%) febrile admissions, respectively. Acute bacterial zoonoses were identified among 118 (26.2%) of febrile admissions; 16 (13.6%) had brucellosis, 40 (33.9%) leptospirosis, 24 (20.3%) had Q fever, 36 (30.5%) had spotted fever group rickettsioses, and 2 (1.8%) had typhus group rickettsioses. In addition, 55 (7.9%) participants had a confirmed acute arbovirus infection, all due to chikungunya. No patient had a bacterial zoonosis or an arbovirus infection included in the admission differential diagnosis. Malaria was uncommon and over-diagnosed, whereas invasive infections were underappreciated. Bacterial zoonoses and arbovirus infections were highly prevalent yet overlooked. An integrated approach to the syndrome of fever in resource-limited areas is needed to improve patient outcomes and to rationally target disease control efforts
PTF10fqs: A Luminous Red Nova in the Spiral Galaxy Messier 99
The Palomar Transient Factory (PTF) is systematically charting the optical
transient and variable sky. A primary science driver of PTF is building a
complete inventory of transients in the local Universe (distance less than 200
Mpc). Here, we report the discovery of PTF10fqs, a transient in the luminosity
"gap" between novae and supernovae. Located on a spiral arm of Messier 99, PTF
10fqs has a peak luminosity of Mr = -12.3, red color (g-r = 1.0) and is slowly
evolving (decayed by 1 mag in 68 days). It has a spectrum dominated by
intermediate-width H (930 km/s) and narrow calcium emission lines. The
explosion signature (the light curve and spectra) is overall similar to thatof
M85OT2006-1, SN2008S, and NGC300OT. The origin of these events is shrouded in
mystery and controversy (and in some cases, in dust). PTF10fqs shows some
evidence of a broad feature (around 8600A) that may suggest very large
velocities (10,000 km/s) in this explosion. Ongoing surveys can be expected to
find a few such events per year. Sensitive spectroscopy, infrared monitoring
and statistics (e.g. disk versus bulge) will eventually make it possible for
astronomers to unravel the nature of these mysterious explosions.Comment: 12 pages, 12 figures, Replaced with published versio
The Extreme Hosts of Extreme Supernovae
We use GALEX ultraviolet (UV) and optical integrated photometry of the hosts
of seventeen luminous supernovae (LSNe, having peak M_V < -21) and compare them
to a sample of 26,000 galaxies from a cross-match between the SDSS DR4 spectral
catalog and GALEX interim release 1.1. We place the LSNe hosts on the galaxy
NUV-r versus M_r color magnitude diagram (CMD) with the larger sample to
illustrate how extreme they are. The LSN hosts appear to favor low-density
regions of the galaxy CMD falling on the blue edge of the blue cloud toward the
low luminosity end. From the UV-optical photometry, we estimate the star
formation history of the LSN hosts. The hosts have moderately low star
formation rates (SFRs) and low stellar masses (M_*) resulting in high specific
star formation rates (sSFR). Compared with the larger sample, the LSN hosts
occupy low-density regions of a diagram plotting sSFR versus M_* in the area
having higher sSFR and lower M_*. This preference for low M_*, high sSFR hosts
implies the LSNe are produced by an effect having to do with their local
environment. The correlation of mass with metallicity suggests that perhaps
wind-driven mass loss is the factor that prevents LSNe from arising in
higher-mass, higher-metallicity hosts. The massive progenitors of the LSNe
(>100 M_sun), by appearing in low-SFR hosts, are potential tests for theories
of the initial mass function that limit the maximum mass of a star based on the
SFR.Comment: 8 pages, 3 figures, 2 tables, accepted to ApJ, amended references and
updated SN designation
Organizational factors and depression management in community-based primary care settings
Abstract Background Evidence-based quality improvement models for depression have not been fully implemented in routine primary care settings. To date, few studies have examined the organizational factors associated with depression management in real-world primary care practice. To successfully implement quality improvement models for depression, there must be a better understanding of the relevant organizational structure and processes of the primary care setting. The objective of this study is to describe these organizational features of routine primary care practice, and the organization of depression care, using survey questions derived from an evidence-based framework. Methods We used this framework to implement a survey of 27 practices comprised of 49 unique offices within a large primary care practice network in western Pennsylvania. Survey questions addressed practice structure (e.g., human resources, leadership, information technology (IT) infrastructure, and external incentives) and process features (e.g., staff performance, degree of integrated depression care, and IT performance). Results The results of our survey demonstrated substantial variation across the practice network of organizational factors pertinent to implementation of evidence-based depression management. Notably, quality improvement capability and IT infrastructure were widespread, but specific application to depression care differed between practices, as did coordination and communication tasks surrounding depression treatment. Conclusions The primary care practices in the network that we surveyed are at differing stages in their organization and implementation of evidence-based depression management. Practical surveys such as this may serve to better direct implementation of these quality improvement strategies for depression by improving understanding of the organizational barriers and facilitators that exist within both practices and practice networks. In addition, survey information can inform efforts of individual primary care practices in customizing intervention strategies to improve depression management.http://deepblue.lib.umich.edu/bitstream/2027.42/78269/1/1748-5908-4-84.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78269/2/1748-5908-4-84-S1.PDFhttp://deepblue.lib.umich.edu/bitstream/2027.42/78269/3/1748-5908-4-84.pdfPeer Reviewe
Neonicotinoids thiamethoxam and clothianidin adversely affect the colonisation of invertebrate populations in aquatic microcosms
Surface waters are sometimes contaminated with neonicotinoids: a widespread, persistent, systemic class of insecticide with leaching potential. Previous ecotoxicological investigations of this chemical class in aquatic ecosystems have largely focused on the impacts of the neonicotinoid imidacloprid; few empirical, manipulative studies have investigated the effect on invertebrate abundances of two other neonicotinoids which are now more widely used: clothianidin and thiamethoxam. In this study, we employ a simple microcosm semi-field design, incorporating a one-off contamination event, to investigate the effect of these pesticides at field-realistic levels (ranging from 0 to 15 ppb) on invertebrate colonisation and survival in small ephemeral ponds. In line with previous research on neonicotinoid impacts on aquatic invertebrates, significant negative effects of both neonicotinoids were found. There were clear differences between the two chemicals, with thiamethoxam generally producing stronger negative effects than clothianidin. Populations of Chironomids (Diptera) and Ostracoda were negatively affected by both chemicals, while Culicidae appeared to be unaffected by clothianidin at the doses used. Our data demonstrate that field-realistic concentrations of neonicotinoids are likely to reduce populations of invertebrates found in ephemeral ponds, which may have knock on effects up the food chain. We highlight the importance of developing pesticide monitoring schemes for European surface waters
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