367 research outputs found
Automated Reminders to Promote Radon Testing in a Lung Cancer Case Control Study
One of the four pilot projects of the Lung Cancer Initiative sponsored by the Department of Defense measures radon levels in the participants homes. Radon exposure is the second leading cause of Lung Cancer. The case-control study has a targeted accrual of 1800 with a case-control ratio of 1:4. The long-term radon kits remain in the home for 90 days and the participants are asked to mail the test kit to the company for analysis. In order to maximize the test kit return rate, reminder calls to the participants occurred 90 days after the home visit
Models and metaphors: complexity theory and through-life management in the built environment
Complexity thinking may have both modelling and metaphorical applications in the through-life management of the built environment. These two distinct approaches are examined and compared. In the first instance, some of the sources of complexity in the design, construction and maintenance of the built environment are identified. The metaphorical use of complexity in management thinking and its application in the built environment are briefly examined. This is followed by an exploration of modelling techniques relevant to built environment concerns. Non-linear and complex mathematical techniques such as fuzzy logic, cellular automata and attractors, may be applicable to their analysis. Existing software tools are identified and examples of successful built environment applications of complexity modelling are given. Some issues that arise include the definition of phenomena in a mathematically usable way, the functionality of available software and the possibility of going beyond representational modelling. Further questions arising from the application of complexity thinking are discussed, including the possibilities for confusion that arise from the use of metaphor. The metaphor of a 'commentary machine' is suggested as a possible way forward and it is suggested that an appropriate linguistic analysis can in certain situations reduce perceived complexity
Spectroscopic confirmation of two luminous galaxies at a redshift of 14
The first observations of the James Webb Space Telescope (JWST) have revolutionized our understanding of the Universe by identifying galaxies at redshift z â 13 (refs. 1â3). In addition, the discovery of many luminous galaxies at Cosmic Dawn (z > 10) has suggested that galaxies developed rapidly, in apparent tension with many standard models4â8. However, most of these galaxies lack spectroscopic confirmation, so their distances and properties are uncertain. Here we present JWST Advanced Deep Extragalactic SurveyâNear-Infrared Spectrograph spectroscopic confirmation of two luminous galaxies at z=14.32â0.20+0.08 and z = 13.90 ± 0.17. The spectra reveal ultraviolet continua with prominent Lyman-α breaks but no detected emission lines. This discovery proves that luminous galaxies were already in place 300 million years after the Big Bang and are more common than what was expected before JWST. The most distant of the two galaxies is unexpectedly luminous and is spatially resolved with a radius of 260 parsecs. Considering also the very steep ultraviolet slope of the second galaxy, we conclude that both are dominated by stellar continuum emission, showing that the excess of luminous galaxies in the early Universe cannot be entirely explained by accretion onto black holes. Galaxy formation models will need to address the existence of such large and luminous galaxies so early in cosmic history
Strain- and host species-specific inflammasome activation, IL-1ÎČ release, and cell death in macrophages infected with uropathogenic Escherichia coli.
Uropathogenic Escherichia coli (UPEC) is the main etiological agent of urinary tract infections (UTIs). Little is known about interactions between UPEC and the inflammasome, a key innate immune pathway. Here we show that UPEC strains CFT073 and UTI89 trigger inflammasome activation and lytic cell death in human macrophages. Several other UPEC strains, including two multidrug-resistant ST131 isolates, did not kill macrophages. In mouse macrophages, UTI89 triggered cell death only at a high multiplicity of infection, and CFT073-mediated inflammasome responses were completely NLRP3-dependent. Surprisingly, CFT073- and UTI89-mediated responses only partially depended on NLRP3 in human macrophages. In these cells, NLRP3 was required for interleukin-1 beta (IL-1 beta) maturation, but contributed only marginally to cell death. Similarly, caspase-1 inhibition did not block cell death in human macrophages. In keeping with such differences, the pore-forming toxin a-hemolysin mediated a substantial proportion of CFT073-triggered IL-1 beta secretion in mousebut nothumanmacrophages. There wasalso a more substantial alpha-hemolysin-independent cell death response in human vs. mouse macrophages. Thus, in mouse macrophages, CFT073-triggered inflammasome responses are completely NLRP3-dependent, and largely alpha-hemolysin-dependent. In contrast, UPEC activates an NLRP3-independent cell death pathway and an alpha-hemolysin-independent IL-1 beta secretion pathway in human macrophages. This has important implications for understanding UTI in humans
What is the nature of Little Red Dots and what is not, MIRI SMILES edition
We study little red dots (LRD) detected by JADES and covered by the SMILES
MIRI survey. Our sample contains 31 sources, % detected in the two
bluest MIRI bands, 40% in redder filters. The median/quartiles redshifts are
(55% spectroscopic). We analyze the rest-frame ultraviolet
through near/mid-infrared spectral energy distributions of LRDs combining
NIRCam and MIRI observations, using a variety of modeling techniques that
include emission from stars, dust, and (un)obscured active galactic nuclei
(AGN). The NIRCamMIRI colors, for m, are bluer than direct
pure emission from AGN tori; the spectral slope flattens in the rest-frame
near-infrared, consistent with a 1.6 m stellar bump. Both observations
imply that stellar emission makes the dominant contribution at these
wavelengths, expediting a stellar mass estimation: the median/quartiles are
. The number density of LRDs is
Mpc, accounting for % of the global population
of galaxies with similar redshifts and masses. The flat ultraviolet spectral
range is dominated by young stars. The rest-frame near/mid-infrared (2-4
m) spectral slope reveals significant amounts of dust (bolometric stellar
attenuation mag) heated by strong radiation fields arising from
highly embedded compact sources. Our models imply kpc heating knots,
containing dust-enshrouded OB stars or an AGN producing a similar radiation
field, obscured by mag. We conclude that LRDs are extremely
intense and compact starburst galaxies with mass-weighted ages 5-10 Myr, very
efficient in producing dust, their global energy output dominated by the direct
and dust-recycled emission from OB stars, with some contribution from obscured
AGN in the mid-infrared.Comment: Accepted for publication in ApJ, LRD average models provided in
https://tinyurl.com/lrdmodel
What Is the Nature of Little Red Dots and what Is Not, MIRI SMILES Edition
We study 31 little red dots (LRD) detected by JADES/NIRCam and covered by the SMILES/MIRI survey, of which âŒ70% are detected in the two bluest MIRI bands and 40% in redder MIRI filters. The median/quartiles redshifts are z=6.95.97.7 (55% spectroscopic). The spectral slopes flatten in the rest-frame near-infrared, consistent with a 1.6 ÎŒm stellar bump but bluer than direct pure emission from active galactic nuclei (AGN) tori. The apparent dominance of stellar emission at these wavelengths for many LRDs expedites stellar mass estimation: the median/quartiles are logMâ/Mâ=9.49.19.7 . The number density of LRDs is 10â4.0±0.1 Mpcâ3, accounting for 14% ± 3% of the global population of galaxies with similar redshifts and masses. The rest-frame near-/mid-infrared (2â4 ÎŒm) spectral slope reveals significant amounts of warm dust (bolometric attenuation âŒ3â4 mag). Our spectral energy distribution modeling implies the presence of 10 mag. We find a wide variety in the nature of LRDs. However, the best-fitting models for many of them correspond to extremely intense and compact starburst galaxies with mass-weighted ages 5â10 Myr, very efficient in producing dust, with their global energy output dominated by the direct (in the flat rest-frame ultraviolet and optical spectral range) and dust-recycled emission from OB stars with some contribution from an obscured AGN (in the infrared)
Atmospheric neutrino oscillations with three neutrinos and a mass hierarchy
A comprehensive formalism for the description of neutrino oscillations in the
Earth in a general scheme with three massive neutrinos and the mass hierarchy
m_1<<m_2<<m_3 is presented. Using this formalism, which is valid both in vacuum
and in a medium, the matter effect on the oscillations of low-energy neutrinos
is discussed, pointing out the existence of very long oscillations which are
independent of the neutrino masses and the neutrino energy, and are very
sensitive to the matter density along the neutrino trajectory. As an example of
application of the formulation, a fit of the Kamiokande atmospheric neutrino
data with the matter effect taken into account for neutrinos propagating in the
Earth is presented. The results of the fit indicate that 4*10^{-3} eV^2 < m_3^2
nu_e,
nu_munu_tau, nu_enu_tau) could be large. Hence, long-baseline experiments
with reactor (CHOOZ and Palo Verde) and accelerator (K2K, MINOS and ICARUS)
neutrinos could observe neutrino oscillations in all channels with a relatively
large statistics.Comment: 42 pages, including 7 figure
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