195 research outputs found
The Fornax Spectroscopic Survey: The Number of Unresolved Compact Galaxies
We describe a sample of thirteen bright (18.5<Bj<20.1) compact galaxies at
low redshift (0.05<z<0.21) behind the Fornax Cluster. These galaxies are
unresolved on UK Schmidt sky survey plates, so would be missing from most
galaxy catalogs compiled from this material. The objects were found during
initial observations of The Fornax Spectroscopic Survey. This project is using
the Two-degree Field spectrograph on the Anglo-Australian Telescope to obtain
spectra for a complete sample of all 14000 objects, stellar and non-stellar,
with 16.5<Bj<19.7, in a 12 square degree area centered on the Fornax cluster of
galaxies. The surface density of compact galaxies with magnitudes 16.5<Bj<19.7
is 7+/-3 /sq.deg., representing 2.8+/-1.6% of all local (z<0.2) galaxies to
this limit. There are 12+/-3 /sq.deg. with 16.5<Bj<20.2. They are luminous
(-21.5<Mb<-18.0, for H0=50 km/s/mpc) and most have strong emission lines (H
alpha equivalent widths of 40-200 A) and small sizes typical of luminous HII
galaxies and compact narrow emission line galaxies. Four out of thirteen have
red colors and early-type spectra, so are unlikely to have been detected in any
previous surveys.Comment: LaTeX source; 5 pages including 3 figures; uses emulateapj.st
The HIPASS survey of the Galactic plane in Radio Recombination Lines
We present a Radio Recombination Line (RRL) survey of the Galactic Plane from
the HI Parkes All-sky Survey and associated Zone of Avoidance survey, which
mapped the region l=196degr -- 0degr --52degr and |b| < 5degr at 1.4 GHz and
14.4 arcmin resolution. We combine three RRLs, H168, H167, and
H166 to derive fully sampled maps of the diffuse ionized emission along
the inner Galactic plane. The velocity information, at a resolution of 20 km/s,
allows us to study the spatial distribution of the ionized gas and compare it
with that of the molecular gas, as traced by CO. The longitude-velocity diagram
shows that the RRL emission is mostly associated with CO gas from the molecular
ring and is concentrated within the inner 30degr of longitude. A map of the
free-free emission in this region of the Galaxy is derived from the
line-integrated RRL emission, assuming an electron temperature gradient with
Galactocentric radius of K/kpc. Based on the thermal continuum map
we extracted a catalogue of 317 compact (<15 arcmin) sources, with flux
densities, sizes and velocities. We report the first RRL observations of the
southern ionized lobe in the Galactic centre. The line profiles and velocities
suggest that this degree-scale structure is in rotation. We also present new
evidence of diffuse ionized gas in the 3-kpc arm. Helium and carbon RRLs are
detected in this survey. The He line is mostly observed towards HII regions,
whereas the C line is also detected further away from the source of ionization.
These data represent the first observations of diffuse C RRLs in the Galactic
plane at a frequency of 1.4 GHz.Comment: 20 pages, 14 figures. MNRAS accepte
The Fornax spectroscopic survey I. Survey strategy and preliminary results on the redshift distribution of a complete sample of stars and galaxies
The Fornax Spectroscopic Survey will use the Two degree Field spectrograph (2dF) of the Anglo-Australian Telescope to obtain spectra for a complete sample of all 14000 objects with 16.5<=Bj<=19.7 in a 12 square degree area centred on the Fornax Cluster. By selecting all objects---both stars and galaxies---independent of morphology, we cover a much larger range of surface brightness and scale size than previous surveys. In this paper we present results from the first 2dF field. Redshift distributions and velocity structures are shown for all observed objects in the direction of Fornax, including Galactic stars, galaxies in and around the Fornax Cluster, and for the background galaxy population. The velocity data for the stars show the contributions from the different Galactic components, plus a small tail to high velocities. We find no galaxies in the foreground to the cluster in our 2dF field. The Fornax Cluster is clearly defined kinematically. The mean velocity from the 26 cluster members having reliable redshifts is 1560+/-80 km/s. They show a velocity dispersion of 380+/-50 km/s. Large-scale structure can be traced behind the cluster to a redshift beyond z=0.3. Background compact galaxies and low surface brightness galaxies are found to follow the general galaxy distribution
Public health implications of changing patterns of recruitment into the South African mining industry, 1973–2012: a database analysis
A derivation of the free-free emission on the Galactic plane between l=20 and 44 degrees
We present the derivation of the free-free emission on the Galactic plane
between l=20 and 44 degrees and |b| < 4 degrees, using Radio Recombination Line
(RRL) data from the HI Parkes All-Sky Survey (HIPASS). Following an upgrade on
the RRL data reduction technique, which improves significantly the quality of
the final RRL spectra, we have extended the analysis to three times the area
covered in Alves et al. (2010). The final RRL map has an angular resolution of
14.8 arcmin and a velocity resolution of 20 km/s.
A map of the electron temperature (Te) of the ionised gas is derived for the
area under study using the line and continuum data from the present survey. The
mean Te on the Galactic plane is 6000 K. The first direct measure of the
free-free emission is obtained based on the derived Te map. Subtraction of this
thermal component from the total continuum leaves the first direct measure of
the synchrotron emission at 1.4 GHz. A narrow component of width 2 degrees is
identified in the latitude distribution of the synchrotron emission. We present
a list of HII regions and SNRs extracted from the present free-free and
synchrotron maps, where we confirm the synchrotron nature of three objects:
G41.12-0.21, G41.15+0.39 and G35.59-0.44. We also identify a bright (42 Jy) new
double radio galaxy, J1841-0152, previously unrecognised owing to the high
optical extinction in the region.
The latitude distribution for the RRL-derived free-free emission shows that
the WMAP Maximum Entropy Method (MEM) is too high by ~ 50 per cent, in
agreement with other recent results. The extension of this study to the inner
Galaxy region l=-50 to 50 degrees will allow a better overall comparison of the
RRL result with WMAP.Comment: 17 pages, 15 figures. Submitted to MNRA
HcRed, a Genetically Encoded Fluorescent Binary Cross-Linking Agent for Cross-Linking of Mitochondrial ATP Synthase in Saccharomyces cerevisiae
Genetically encoded fluorescent cross-linking agents represent powerful tools useful both for visualising and modulating protein interactions in living cells. The far-red fluorescent protein HcRed, which is fluorescent only in a dimer form, can be used to promote the homo-dimerisation of target proteins, and thereby yield useful information about biological processes. We have in yeast cells expressed HcRed fused to a subunit of mitochondrial ATP synthase (mtATPase). This resulted in cross-linking of the large multi-subunit mtATPase complex within the inner-membrane of the mitochondrion. Fluorescence microscopy revealed aberrant mitochondrial morphology, and mtATPase complexes isolated from mitochondria were recovered as fluorescent dimers under conditions where complexes from control mitochondria were recovered as monomers. When viewed by electron microscopy normal cristae were absent from mitochondria in cells in which mATPase complexes were cross-linked. mtATPase dimers are believed to be the building blocks that are assembled into supramolecular mtATPase ribbons that promote the formation of mitochondrial cristae. We propose that HcRed cross-links mATPase complexes in the mitochondrial membrane hindering the normal assembly/disassembly of the supramolecular forms of mtATPase
Calcium-sensing receptor antagonists abrogate airway hyperresponsiveness and inflammation in allergic asthma
Airway hyperresponsiveness and inflammation are fundamental hallmarks of allergic asthma that are accompanied by increases in certain polycations, such as eosinophil cationic protein. Levels of these cations in body fluids correlate with asthma severity. We show that polycations and elevated extracellular calcium activate the human recombinant and native calcium-sensing receptor (CaSR), leading to intracellular calcium mobilization, cyclic adenosine monophosphate breakdown, and p38 mitogen-activated protein kinase phosphorylation in airway smooth muscle (ASM) cells. These effects can be prevented by CaSR antagonists, termed calcilytics. Moreover, asthmatic patients and allergen-sensitized mice expressed more CaSR in ASMs than did their healthy counterparts. Indeed, polycations induced hyperreactivity in mouse bronchi, and this effect was prevented by calcilytics and absent in mice with CaSR ablation from ASM. Calcilytics also reduced airway hyperresponsiveness and inflammation in allergen-sensitized mice in vivo. These data show that a functional CaSR is up-regulated in asthmatic ASM and targeted by locally produced polycations to induce hyperresponsiveness and inflammation. Thus, calcilytics may represent effective asthma therapeutics
Including the public in pandemic planning: a deliberative approach
Background: Against a background of pandemic threat posed by SARS and avian H5N1 influenza, this study used deliberative forums to elucidate informed community perspectives on aspects of pandemic planning. Methods: Two deliberative forums were carried out with members of the South Australian community. The forums were supported by a qualitative study with adults and youths, systematic reviews of the literature and the involvement of an extended group of academic experts and policy makers. The forum discussions were recorded with simultaneous transcription and analysed thematically. Results: Participants allocated scarce resources of antiviral drugs and pandemic vaccine based on a desire to preserve society function in a time of crisis. Participants were divided on the acceptability of social distancing and quarantine measures. However, should such measures be adopted, they thought that reasonable financial, household and psychological support was essential. In addition, provided such support was present, the participants, in general, were willing to impose strict sanctions on those who violated quarantine and social distancing measures. Conclusions: The recommendations from the forums suggest that the implementation of pandemic plans in a severe pandemic will be challenging, but not impossible. Implementation may be more successful if the public is engaged in pandemic planning before a pandemic, effective communication of key points is practiced before and during a pandemic and if judicious use is made of supportive measures to assist those in quarantine or affected by social isolation measures.Annette J Braunack-Mayer, Jackie M Street, Wendy A Rogers, Rodney Givney, John R Moss, Janet E Hiller, Flu Views tea
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