5,428 research outputs found
Sunyaev-Zel'dovich Effects from Quasars in Galaxies and Groups
The energy fed by active galactic nuclei to the surrounding diffuse baryons
changes their amount, temperature, and distribution; so in groups and in member
galaxies it affects the X-ray luminosity and also the Sunyaev-Zel'dovich
effect. Here we compute how the latter is enhanced by the transient blastwave
driven by an active quasar, and is depressed when the equilibrium is recovered
with a depleted density. We constrain such depressions and enhancements with
the masses of relic black holes in galaxies and the X-ray luminosities in
groups. We discuss how all these linked observables can tell the quasar
contribution to the thermal history of the baryons pervading galaxies and
groups.Comment: 4 pages, 3 figures, uses REVTeX4 and emulateapj.cls. Accepted by ApJ
Spin and rotational symmetries in unrestricted Hartree Fock states of quantum dots
Ground state energies are obtained using the unrestricted Hartree Fock method
for up to four interacting electrons parabolically confined in a quantum dot
subject to a magnetic field. Restoring spin and rotational symmetries we
recover Hund first rule. With increasing magnetic field, crossovers between
ground states with different quantum numbers are found for fixed electron
number that are not reproduced by the unrestricted Hartree Fock approximation.
These are consistent with the ones obtained with more refined techniques. We
confirm the presence of a spin blockade due to a spin mismatch in the ground
states of three and four electrons.Comment: 16 Pages, 2 figures, accepted for publication on New Journal of
Physic
Are X-ray properties of loose groups different from those of compact groups?
We compare the X-ray properties of loose and compact galaxy groups, using a
combined sample of 42 groups. We find that we are unable to separate loose and
compact groups on the luminosity-temperature relation, the luminosity-velocity
dispersion relation or the velocity dispersion-temperature relation using
equally weighted errors. This suggests that the distinction between compact and
loose groups is not a fundamental one, and we argue that a more useful
distinction is that between X-ray bright and X-ray faint systems. Given their
similarity in X-ray properties, we combine the loose and compact subsamples to
derive relations based on the full sample. This provides the highest
statistical quality results to date on the way in which the correlations in
X-ray properties of low mass systems depart from those seen in rich clusters.Comment: 6 pages, 6 figures. Accepted for publication in MNRA
Recovery of smell sense loss by mepolizumab in a patient allergic to dermatophagoides and affected by chronic rhinosinusitis with nasal polyps
Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) frequently presents with dysfunction or loss of the
sense of smell, resulting in a signifcant impairment in quality of life. The medical treatments currently available may
improve the olfactory function in patients with CRSwNP, but such an outcome is generally only transitory. We report
the case of a patient with CRSwNP who completely recovered from smell sense loss by treatment with mepolizumab.
Case presentation: The patient was a 62-year-old female who has severe asthma induced by allergy to Dermatophagoides and concomitant CRSwNP. Any treatment for the latter, including oral and injective corticosteroids, was unsuccessful in the loss of smell. Due to the satisfaction of admission criteria to mepolizumab treatment for severe asthma,
treatment was initiated on March 2018, resulting in good clinical control of both asthma and CRSwNP, and particularly
in complete recovery of the smell loss after 4 months of treatment and still persisting.
Conclusion: In this case report, the treatment with mepolizumab in a patient allergic to Dermatophagoides and
afected by CRSwNP was associated with an improvement of anosmia. That fnding may be explained by a reduction
of the nasal obstruction by nasal polyp
Does Consumer Time Preference Affect Label Use?
Diet-related chronic diseases, such as overweight and obesity, are worrisome not only from a medical point of view, but also in terms of monetary expenditures, these health problems are strictly linked to sizeable sanitary costs (Chou et al., 2004; Yaniv et al., 2009; Cawley and Meyerhoefer, 2012; Ruhm, 2012). These costs are mainly due to the purchase of medical care (direct costs), and to the loss of productivity caused by hill-health (indirect costs) (Rosin, 2008). To challenge these problems and improve public health it is of particular importance to study the determinants of food consumption, and understand the best way to effectively address consumers toward healthy eating.To this purpose, one of the most investigated topics in the last decades has been the role of food-related information. Economists have found evidences that food information can exert a positive effect in increasing consumer nutrition knowledge and in promoting healthier consumption. Hence, policy makers have proposed different policy interventions to provide consumers with more, and more detailed, information. These information measures have included the diffusion of dietary guidelines, the promotion of nutritional education programs in the schools, and also specific campaigns to increase public awareness concerning fruit and vegetables consumption or the negative effects of some unhealthy food and drinks.In this context, another and maybe more direct way to provide consumers with food-related information is represented by on-package food labels, which currently constitute the principal tool through which consumers can easily acquire information about food products. The key role of food labels in making individuals able to do more conscious diet choices has been well established by the main findings of the economic literature (Drichoutis et al., 2006; Drichoutis et al., 2008a; Drichoutis et al., 2009; Norgaard and Brunso 2009; Barreiro-HurlĂš et al., 2010). Therefore, given the importance of on-packaging information, the EU has recently introduced the EU Regulation No. 1169/2011, published in October 2011, in order to make labels even more effective and boost their utility for consumers. This new low has established some rules concerning mandatory information, nutritional facts and also the graphical standards allowed on food labels in all the EU. Nonetheless, consumers are not always willing to make use of the information reported on labels, and this makes of crucial importance to investigate and understand which factors can be able to discourage consumers in using labels
Use of balloon catheter dilation and steroid-eluting stent in light and severe rhinosinusitis of frontal sinus: a multicenter retrospective randomized study
OBJECTIVE: Frontal sinus surgery has an increased rate of re-stenosis, if compared to other sinuses, that mainly depends on recurrent inflammation and abnormal scarring at the frontal recess; its reduction represents one of the keys of therapeutic success. Balloon catheter dilation (BCD) and implantable sinus stents/spacers represent strategies to improve sinus ventilation respecting the integrity of mucosa and reducing abnormal post-surgical scarring. The purpose of this study is to evaluate the effectiveness, safety and correct indication for the use of BCD and a non-absorbable stent (Relieva Stratusâą MicroFlow spacer) in the management of chronic rhinosinusitis (CRS) of the frontal sinus. PATIENTS AND METHODS: In this multicentric retrospective study we included a population of 76 frontal sinuses with non-polypoid CRS. Forty-one frontal sinuses were treated with BCD alone and 35 with BCD + Spacer. We analysed both radiological (Lund-McKay CT scoring modified by Zienrich) and symptomatologic results (SNOT-20 questionnaire) before surgery and after 12 months, dividing patients in two main groups: group âLâ (light/mild frontal CRS) and group âSâ (moderate/severe frontal CRS). RESULTS: Our results confirm a good safety and effectiveness of BCD in management of frontal CRS and show a good safety, although without significant effectiveness, of Relieva Stratusâą MicroFlow spacer when added to BCD in the management of light and severe frontal CRS. CONCLUSIONS: BCD is an option in management of frontal CRS; the use of stents/spacers could become a new and effective tool in management of CSR, both in addition to standard therapies and in patients where the use of systemic drugs is contraindicated
Expectations For an Interferometric Sunyaev-Zel'dovich Effect Survey for Galaxy Clusters
Non-targeted surveys for galaxy clusters using the Sunyaev-Zel'dovich effect
(SZE) will yield valuable information on both cosmology and evolution of the
intra-cluster medium (ICM). The redshift distribution of detected clusters will
constrain cosmology, while the properties of the discovered clusters will be
important for studies of the ICM and galaxy formation. Estimating survey yields
requires a detailed model for both cluster properties and the survey strategy.
We address this by making mock observations of galaxy clusters in cosmological
hydrodynamical simulations. The mock observatory consists of an interferometric
array of ten 2.5 m diameter telescopes, operating at a central frequency of 30
GHz with a bandwidth of 8 GHz. We find that clusters with a mass above will be detected at any redshift, with the
exact limit showing a very modest redshift dependence. Using a Press-Schechter
prescription for evolving the number densities of clusters with redshift, we
determine that such a survey should find hundreds of galaxy clusters per year,
many at high redshifts and relatively low mass -- an important regime uniquely
accessible to SZE surveys. Currently favored cosmological models predict
roughly 25 clusters per square degree.Comment: revised to match published versio
Large Eddy Simulation/Conditional Moment Closure modeling of swirl-stabilized non-premixed flames with local extinction
This is the accepted manuscript. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S1540748914000558.The Large Eddy Simulation (LES)/three-dimensional Conditional Moment Closure (3D-CMC) model
with detailed chemistry and finite-volume formulation is employed to simulate a swirl-stabilized nonpremixed
flame with local extinction. The results demonstrate generally good agreement with the
measurements concerning velocity, flame shape, and statistics of flame lift-off, but the penetration of fuel
jet into the recirculation zone is under-predicted possibly due to the over-predicted swirl velocities in the
chamber. Localized extinctions are seen in the LES, in agreement with experiment. The local extinction
event is shown by very low heat release rate and hydroxyl mass fraction and reduced temperature, and is
accompanied by relatively high scalar dissipation. In mixture fraction space, CMC cells with strong
turbulence-chemistry interaction and local extinction show relatively large fluctuations between fully
burning and intermediate distributions. The probability density functions of conditional reactedness,
which shows how far the conditionally-filtered scalars are from reference fully burning profiles, indicate
that for CMC cells with local extinction, some reactive scalars demonstrate pronounced bimodality while
for those cells with strong reactivity the PDFs are very narrow.HZ acknowledges the financial support from EPSRC through a Dorothy Hodgkin Postgraduate
Award
Compact X-ray Sources in Nearby Galaxy Nuclei
We have found compact, near-nuclear X-ray sources in 21 (54\%) of a complete
sample of 39 nearby face-on spiral and elliptical galaxies with available ROSAT
HRI data. ROSAT X-ray luminosities (0.2 2.4 keV) of these compact X-ray
sources are 1010 erg~s. The mean displacement
between the location of the compact X-ray source and the optical photometric
center of the galaxy is 390 pc. ASCA spectra of six of the 21 galaxies
show the presence of a hard component with relatively steep (
2.5) spectral slope. A multicolor disk blackbody plus power-law model fits the
data from the spiral galaxies well, suggesting that the X-ray objects in these
galaxies may be similar to a black hole candidate (BHC) in its soft (high)
state. ASCA data from the elliptical galaxies indicate that hot (kT
0.7 keV) gas dominates the emission. The fact that the spectral slope of the
spiral galaxy sources is steeper than in normal type 1 active galactic nuclei
(AGNs) and that relatively low absorbing columns (N 10
cm) were found to the power-law component indicates that these objects
are somehow geometrically and/or physically different from AGNs in normal
active galaxies. The X-ray sources in the spiral galaxies may be BHCs,
low-luminosity AGNs, or possibly X-ray luminous supernovae. We estimate the
black hole masses of the X-ray sources in the spiral galaxies (if they are BHCs
or AGNs) to be 1010 M. The X-ray sources in the
elliptical galaxies may be BHCs, AGNs or young X-ray supernova also.Comment: 4 pages, TeX, two postscript figures, to be published in proceedings
of 32nd COSPAR Session E1.2 (1998 July 15-17 Nagoya) "The AGN-Normal Galaxy
Connection
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