126 research outputs found
The Hawaii Infrared Parallax Program. VI. The Fundamental Properties of 1000+ Ultracool Dwarfs and Planetary-mass Objects Using Optical to Mid-IR SEDs and Comparison to BT-Settl and ATMO 2020 Model Atmospheres
We derive the bolometric luminosities () of 865 field-age
and 189 young ultracool dwarfs (spectral types M6-T9, including 40 new
discoveries presented here) by directly integrating flux-calibrated optical to
mid-IR spectral energy distributions (SEDs). The SEDs consist of low-resolution
( 150) near-IR (0.8-2.5 m) spectra (including new spectra for 97
objects), optical photometry from the Pan-STARRS1 survey, and mid-IR photometry
from the CatWISE2020 survey and Spitzer/IRAC. Our
calculations benefit from recent advances in parallaxes from Gaia, Spitzer, and
UKIRT, as well as new parallaxes for 19 objects from CFHT and Pan-STARRS1
presented here. Coupling our measurements with a new uniform
age analysis for all objects, we estimate substellar masses, radii, surface
gravities, and effective temperatures () using evolutionary
models. We construct empirical relationships for and
as functions of spectral type and absolute magnitude,
determine bolometric corrections in optical and infrared bandpasses, and study
the correlation between evolutionary model-derived surface gravities and
near-IR gravity classes. Our sample enables a detailed characterization of
BT-Settl and ATMO 2020 atmospheric model systematics as a function of spectral
type and position in the near-IR color-magnitude diagram. We find the greatest
discrepancies between atmospheric and evolutionary model-derived
(up to 800 K) and radii (up to 2.0 ) at
the M/L transition boundary. With 1054 objects, this work constitutes the
largest sample to date of ultracool dwarfs with determinations of their
fundamental parameters.Comment: Resubmitted to The Astrophysical Journal (ApJ) after a positive
referee report. 51 pages, 29 figures, 7 tables. Data presented in this work:
https://doi.org/10.5281/zenodo.8315643. Scripts associated with methods:
https://github.com/cosmicoder/HIPPVI-Cod
Influenza Outbreaks during World Youth Day 2008 Mass Gathering
Novel viruses were introduced and seasonal viruses were amplified
Cash transfers to enhance TB control: lessons from the HIV response
Background: The World Health Organization prioritises a more holistic global response to end the tuberculosis (TB) epidemic by 2030. Based on experiences in the HIV response, social protection, and in particular cash transfers, show promise for contributing to this. Currently, individual-level evidence for the potential of cash transfers to prevent TB by addressing the structural social determinants of disease is lacking. To identify priority actions for the TB research agenda, we appraised efforts by the HIV response to establish the role of cash transfers in preventing HIV infection.
Main body
The HIV response has evaluated the effects of cash transfers on risky sexual behaviours and HIV incidence. Work has also evaluated the added effects of supplementing cash transfers with psychosocial support. The HIV response has focused research on populations with disproportionate HIV risk, and used a mix of explanatory evaluations, which use ideal conditions, and pragmatic evaluations, which use operational conditions, to generate evidence that is both causally valid and applicable to the real world. It has always collaborated with multiple stakeholders in funding and evaluating projects. Learning from the HIV response, priority actions for the TB response should be to investigate the effect of cash transfers on intermediary social determinants of active TB disease, and TB incidence, as well as the added effects of supplementing cash transfers with psychosocial support. Work should be focused on key groups in high burden settings, and look to build a combination of explanatory and pragmatic evidence to inform policy decisions in this field. To achieve this, there is an urgent need to facilitate collaborations between groups interested in evaluating the impact of cash transfers on TB risk.
Conclusions
The HIV response highlights several priority actions necessary for the TB response to establish the potential of cash transfers to prevent TB by addresing the structural social determinants of disease
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Development of Neutron Absorbers to Support Disposal of DOE SNF
The National Spent Nuclear Fuel Program, located at the Idaho National Engineering and Environmental Laboratory, coordinates and integrates national efforts in management and disposal of U.S. Department of Energy (DOE)- owned . These management functions include using the DOE standardized canister for packaging, storage, treatment, transport, and long-term disposal. Nuclear criticality control measures are needed in these canisters because of the enrichment and total quantity of fissile material in some types of the DOE spent nuclear fuel. This paper will report the test results of one alloy heat from a metallurgical development program that is developing nickelchromium- molybdenum-gadolinium alloys for nuclear criticality control in the DOE standardized canister. Gadolinium has been chosen as the neutron absorption alloying element due to its high thermal neutron absorption cross section. The microstructure, mechanical properties, and corrosion resistance of various alloys will be presented. These corrosion resistant, structural alloys can be used to fabricate components of spent nuclear fuel storage racks, storage canisters and internal structural baskets, and transportation cask internals. The focus of this work is to qualify these materials for American Society of Mechanical Engineers code qualification and acceptance in the Yucca Mountain Repository
During the summer 2009 outbreak of "swine flu" in Scotland what respiratory pathogens were diagnosed as H1N1/2009?
<p>Abstract</p> <p>Background</p> <p>During the April-July 2009 outbreak of H1N1/2009 in scotland the West of Scotland Specialist Virology Centre (WoSSVC) in Glasgow tested > 16 000 clinical samples for H1N1/2009. Most were from patients clinically diagnosed with H1N1/2009. Out of these, 9% were positive. This study sought to determine what respiratory pathogens were misdiagnosed as cases of H1N1/2009 during this time.</p> <p>Methods</p> <p>We examined the results from 3247 samples which were sent to the laboratory during April-July 2009. All were from patients clinically diagnosed as having H1N1/2009 (based on accepted criteria) and all were given a full respiratory screen using real time reverse transcriptase polymerase chain reaction (rtRT-PCR) assays.</p> <p>Results</p> <p>In total, respiratory pathogens were detected in 27.9% (95% confidence interval, 26.3-29.5%) of the samples submitted. Numerous pathogens were detected, the most common of which were rhinovirus (8.9% (95% confidence interval, 7.9-9.9%)), parainfluenza 1 (1.9% (95% confidence interval, 1.4-2.4%)) and 3 (4.1% (95% confidence interval, 3.3-4.9%)), and adenovirus ((3.5% (95% confidence interval, 2.9-4.2%)).</p> <p>Conclusions</p> <p>This study highlights the problems of using a clinical algorithm to detect H1N1/2009. Clinicians frequently misdiagnosed common respiratory pathogens as H1N1/2009 during the spring/summer outbreak in Scotland. Many undesirable consequences would have resulted, relating to treatment, infection control, and public health surveillance.</p
Married Black men's opinions as to why Black women are disproportionately single: A qualitative study
Abstract This study's purpose was to explore the reasons Black women are disproportionately single according to the unique viewpoint of married Black men. The sample comprises 52 married Black men who resided in northeast Georgia (mean age = 43). Qualitative interviews were conducted in 2010 as part of the Pathways to Marriage study. The authors analyzed the data in a collaborative fashion and utilized content analyses to explore the relationships in the data, which were derived from qualitative interviews with the men. Findings on the reasons for the disproportionality of singlehood among Black women reflected these four themes: gender relations, marriage education and socialization, individual development, and a preference for gay/lesbian relationships. Recommendations for future research are discussed. Recent estimates highlight an important trend-Black women are less likely to enter into marriage or remarry than are Blac
Barriers and facilitators to HIV testing and linkage to primary care: narratives of people with advanced HIV in the Southeast
Persons with unrecognized HIV infection forgo timely clinical intervention and may unknowingly transmit HIV to partners. However, in the United States, unrecognized infection and late diagnosis are common. To understand barriers and facilitators to HIV testing and care, we conducted a qualitative study of 24 HIV infected persons attending a Southeastern HIV clinic who presented with clinically advanced illness. The primary barrier to HIV testing prior to diagnosis was perception of risk; consequently, most participants were diagnosed after the onset of clinical symptoms. While most patients were anxious to initiate care rapidly after diagnosis, some felt frustrated by the passive process of connecting to specialty care. The first visit with an HIV care provider was identified as critical in the coping process for many patients. Implications for the implementation of recent CDC HIV routine screening guidelines are discussed
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Stem cells and cancer immunotherapy: Arrowhead’s 2nd annual cancer immunotherapy conference
Investigators from academia and industry gathered on April 4 and 5, 2013, in Washington DC at the Arrowhead’s 2nd Annual Cancer Immunotherapy Conference. Two complementary concepts were discussed: cancer “stem cells” as targets and therapeutic platforms based on stem cells
The 1.6 micron near infrared nuclei of 3C radio galaxies: Jets, thermal emission or scattered light?
Using HST NICMOS 2 observations we have measured 1.6-micron near infrared
nuclear luminosities of 100 3CR radio galaxies with z<0.3, by modeling and
subtracting the extended emission from the host galaxy. We performed a
multi-wavelength statistical analysis (including optical and radio data) of the
properties of the nuclei following classification of the objects into FRI and
FRII, and LIG (low-ionization galaxies), HIG (high-ionization galaxies) and BLO
(broad-lined objects) using the radio morphology and optical spectra,
respectively. The correlations among near infrared, optical, and radio nuclear
luminosity support the idea that the near infrared nuclear emission of FRIs has
a non-thermal origin. Despite the difference in radio morphology, the
multi-wavelength properties of FRII LIG nuclei are statistically
indistinguishable from those of FRIs, an indication of a common structure of
the central engine. All BLOs show an unresolved near infrared nucleus and a
large near infrared excess with respect to FRII LIGs and FRIs of equal radio
core luminosity. This requires the presence of an additional (and dominant)
component other than the non-thermal light. Considering the shape of their
spectral energy distribution, we ascribe the origin of their near infrared
light to hot circumnuclear dust. A near infrared excess is also found in HIGs,
but their nuclei are substantially fainter than those of BLO. This result
indicates that substantial obscuration along the line-of-sight to the nuclei is
still present at 1.6 micron. Nonetheless, HIGs nuclei cannot simply be
explained in terms of dust obscuration: a significant contribution from light
reflected in a circumnuclear scattering region is needed to account for their
multiwavelength properties.Comment: 20 pages, 16 figures. Accepted for publication on Ap
Seventeen Famous Economists Weigh in on Copyright: The Role of Theory, Empirics, and Network Effects
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