2,290 research outputs found
An algorithmic approach to diagnosing asthma in older patients in general practice
The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.WHAT WE NEED TO KNOW: How effective would an algorithm be in helping general practitioners diagnose asthma? What proportion of older people with undiagnosed asthma fail to recognise symptoms? What proportion of the population believe asthma does not occur in the older population? What systems or supports do GPs need to diagnose asthma more effectively? WHAT WE NEED TO DO: Work on developing a gold standard for asthma diagnosis. Develop prototype algorithms for general practice discussion. Conduct a general practice study to assess the effectiveness of an algorithm. In conjunction with GPs, develop a pilot program to increase awareness of the current asthma problem. Conduct focus-group research to identify why some people do not believe they can develop asthma for the first time in adult life. Conduct focus-group research to identify why some adults do not attribute asthma symptoms to asthma. Conduct focus groups with GPs to identify what support is needed to diagnose asthma more effectively. Consult with all stakeholders before an intervention is used. Evaluate any interventions used.Richard E Ruffin, David H Wilson, Sarah L Appleton and Robert J Adam
Undiagnosed asthma in older people: an underestimated problem
The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.WHAT WE NEED TO KNOW: Are older people with respiratory symptoms aware this could be asthma? Which explanations for undiagnosed asthma apply most commonly in older Australians with asthma? Can we improve awareness of asthma in older people with undiagnosed asthma? Is the possibility of asthma in older people firmly established on the general practitioners’ radar screen? What reasons most often determine whether GPs perform spirometry in their practice? WHAT WE NEED TO DO: Conduct a representative population study to assess whether older Australians recognise respiratory symptoms as being asthma and are reporting these symptoms. Conduct and evaluate a pilot asthma health promotion program for older people. Conduct a controlled therapeutic trial of people with undiagnosed asthma to assess treatment benefits and produce treatment recommendations. Identify whether the prominence of asthma in older people can be brought to the attention of GPs. Analyse more carefully the issues associated with innovation of office spirometry.David H Wilson, Sarah L Appleton, Robert J Adams and Richard E Ruffi
Deep Herschel view of obscured star formation in the Bullet cluster
We use deep, five band (100–500 μm) data from the Herschel Lensing Survey (HLS) to fully constrain the obscured star formation rate, SFR_(FIR), of galaxies in the Bullet cluster (z = 0.296), and a smaller background system (z = 0.35) in the same field. Herschel detects 23 Bullet cluster members with a total SFRFIR = 144±14 M_☉ yr^(-1). On average, the background system contains brighter far-infrared (FIR) galaxies, with ~50% higher SFRFIR (21 galaxies; 207 ± 9 M_☉ yr^(-1)). SFRs extrapolated from 24 μm flux via recent templates (SFR_(24 µm)) agree well with SFRFIR for ~60% of the cluster galaxies. In the remaining ~40%, SFR24 µm underestimates SFR_(FIR) due to a significant excess in observed S_(100)/S_(24) (rest frame S_(75)/S_(18)) compared to templates of the same FIR luminosity
Stellar disks of Collisional Ring Galaxies I. New multiband images, Radial intensity and color profiles, and confrontation with N-body simulations
We present new multi-band imaging data in the optical (BVRI and Halpha) and
near infrared bands (JHK) of 15 candidate ring galaxies from the sample of
Appleton & Marston (1997). We use these data to obtain color composite images,
global magnitudes and colors of both the ring galaxy and its companion(s), and
radial profiles of intensity and colors. We find that only nine of the observed
galaxies have multi-band morphologies expected for the classical collisional
scenario of ring formation, indicating the high degree of contamination of the
ring galaxy sample by galaxies without a clear ring morphology. The radial
intensity profiles, obtained by masking the off-centered nucleus, peak at the
position of the ring, with the profiles in the continuum bands broader than
that in the Halpha line. The images as well as the radial intensity and color
profiles clearly demonstrate the existence of the pre-collisional stellar disk
outside the star-forming ring, which is in general bluer than the disk internal
to the ring. The stellar disk seems to have retained its size, with the disk
outside the ring having a shorter exponential scale length as compared to the
values expected in normal spiral galaxies of comparable masses. The rings in
our sample of galaxies are found to be located preferentially at around
half-way through the stellar disk. The most likely reason for this preference
is bias against detecting rings when they are close to the center (they would
be confused with the resonant rings), and at the edge of the disk the gas
surface density may be below the critical density required for star formation.
Most of the observed characteristics point to relatively recent collisions (<80
Myr ago) according to the N-body simulations of Gerber et al. (1996).Comment: To appear in AJ issue of September 2008. High resolution color image
of Figure 2 and other supplementary images are available at
http://www.inaoep.mx/~ydm/rings
The Role of a Hot Gas Environment on the Evolution of Galaxies
Most spiral galaxies are found in galaxy groups with low velocity
dispersions; most E/S0 galaxies are found in galaxy groups with relatively high
velocity dispersions. The mass of the hot gas we can observe in the E/S0 groups
via their thermal X-ray emission is, on average, as much as the baryonic mass
of the galaxies in these groups. By comparison, galaxy clusters have as much or
more hot gas than stellar mass. Hot gas in S-rich groups, however, is of low
enough temperature for its X-ray emission to suffer heavy absorption due to
Galactic HI and related observational effects, and hence is hard to detect. We
postulate that such lower temperature hot gas does exist in low velocity
dispersion, S-rich groups, and explore the consequences of this assumption. For
a wide range of metallicity and density, hot gas in S-rich groups can cool in
far less than a Hubble time. If such gas exists and can cool, especially when
interacting with HI in existing galaxies, then it can help link together a
number of disparate observations, both Galactic and extragalactic, that are
otherwise difficult to understand.Comment: 16 pages with one figure. ApJ Letters, in pres
Spatially Resolved Spitzer-IRS Spectroscopy of the Central Region of M82
We present high spatial resolution (~ 35 parsec) 5-38 um spectra of the
central region of M82, taken with the Spitzer Infrared Spectrograph. From these
spectra we determined the fluxes and equivalent widths of key diagnostic
features, such as the [NeII]12.8um, [NeIII]15.5um, and H_2 S(1)17.03um lines,
and the broad mid-IR polycyclic aromatic hydrocarbon (PAH) emission features in
six representative regions and analysed the spatial distribution of these lines
and their ratios across the central region. We find a good correlation of the
dust extinction with the CO 1-0 emission. The PAH emission follows closely the
ionization structure along the galactic disk. The observed variations of the
diagnostic PAH ratios across M82 can be explained by extinction effects, within
systematic uncertainties. The 16-18um PAH complex is very prominent, and its
equivalent width is enhanced outwards from the galactic plane. We interpret
this as a consequence of the variation of the UV radiation field. The EWs of
the 11.3um PAH feature and the H_2 S(1) line correlate closely, and we conclude
that shocks in the outflow regions have no measurable influence on the H_2
emission. The [NeIII]/[NeII] ratio is on average low at ~0.18, and shows little
variations across the plane, indicating that the dominant stellar population is
evolved (5 - 6 Myr) and well distributed. There is a slight increase of the
ratio with distance from the galactic plane of M82 which we attribute to a
decrease in gas density. Our observations indicate that the star formation rate
has decreased significantly in the last 5 Myr. The quantities of dust and
molecular gas in the central area of the galaxy argue against starvation and
for negative feedback processes, observable through the strong extra-planar
outflows.Comment: 15 pages, 12 figures, 3 tables, ApJ, emulateap
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