4,717 research outputs found
JHK Imaging and Photometry of Low z QSOs and Radio Galaxy
We describe J,H,K deep imaging of 90 arcmin fields around 4 QSOs and one
Radio galaxy at redshifts in the range 0.06 to 0.30, and show their images,
luminosity profiles, and NIR 2-colour diagrams of objects. We find that the QSO
hosts are all resolved, and compare them with previous CCD images. The host
galaxy colours are consistent with old and young stellar populations at the QSO
redshift. The colours of nearby galaxies suggest that all the AGN live in
groups of generally smaller companion galaxies, mostly with evolved populations
at the same redshift. The two radio-loud objects live in richer cluster
environments than the others. Gissel population models indicate reddening in
the galaxies, star-forming regions, and possibly a systematic H-K offset. The
QSO luminosity profiles are complex and reveal some of their tidal disturbance
and star-formation history.Comment: 22 pages of text (latex), 2 tables )latex), and 15 figures
(postscript). Accepted for publication in AJ, February 1997. Also available
at http://www.dao.nrc.ca/DAO/SCIENCE/science.htm
IMAGING OF LOW REDSHIFT QSOs WITH WFPC2
Observations with the PC2 CCD of the Hubble Space Telescope are described of
two bright QSOs of redshift ~0.3. 1403+434 is IR-bright and radio-quiet, and
2201+315 is radio-loud with extended structure. Exposures were taken with the
F702W and F555W filters. The images are deconvolved on their own and combined
with 0.5 arcsec ground-based images. Both host galaxies have the form and
luminosity of bright ellipticals, with nuclei of 1-2 times higher luminosity.
1403+434 is strongly interacting while 2201+315 may be in later stages of a
merger, both with a smaller companion. Both host galaxies have compact knots
and other small-scale peculiar features. Some general remarks are made based on
the total program sample of 6 QSOs.Comment: 11 pages, Plain TeX, 3 figures available from [email protected] To
appear in the Astronomical Journal
Evolution of luminous IRAS galaxies: Radio imaging
In a recent study of IRAS galaxies' optical morphologies, we found that luminous IR sources lie in the IR color-luminosity plane in groups which separate out by optical spectroscopic type and also by degree of tidal disturbance. We found that the most luminous steep-IR-spectrum sources are generally galaxies in the initial stages of a major tidal interaction. Galaxies with active nuclei were generally found to have flatter IR spectra, to cover a range of IR luminosity, and to be in the later stages of a tidal interaction. We proposed a sequence of events by which luminous IR sources evolve: they start as interacting or merging galaxies, some develop active nuclei, and most undergo extensive star-formation in their central regions. Another way to study these objects and their individual evolution is to study their radio morphologies. Radio emission may arise at a detectable level from supernovae in star-forming regions and/or the appearance of an active nucleus can be accompanied by a nuclear radio source (which may develop extended structure). Therefore, the compact radio structure may trace the evolution of the inner regions of IRAS-luminous sources. If the radio sources are triggered by the interactions, we would expect to find the radio morphology related to the optical 'interactivity' of the systems. Here, we explore using the radio emission of IRAS galaxies as a possible tracer of galaxy evolution. We present and discuss observations of the compact radio morphology of 111 luminous IRAS-selected active galaxies covering a wide range of IR and optical properties
Reporting ethics committee approval and patient consent by study design in five general medical journals.
BACKGROUND: Authors are required to describe in their manuscripts ethical approval from an appropriate committee and how consent was obtained from participants when research involves human participants. OBJECTIVE: To assess the reporting of these protections for several study designs in general medical journals. DESIGN: A consecutive series of research papers published in the Annals of Internal Medicine, BMJ, JAMA, Lancet and The New England Journal of Medicine between February and May 2003 were reviewed for the reporting of ethical approval and patient consent. Ethical approval, name of approving committee, type of consent, data source and whether the study used data collected as part of a study reported elsewhere were recorded. Differences in failure to report approval and consent by study design, journal and vulnerable study population were evaluated using multivariable logistic regression. RESULTS: Ethical approval and consent were not mentioned in 31% and 47% of manuscripts, respectively. 88 (27%) papers failed to report both approval and consent. Failure to mention ethical approval or consent was significantly more likely in all study designs (except case-control and qualitative studies) than in randomised controlled trials (RCTs). Failure to mention approval was most common in the BMJ and was significantly more likely than in The New England Journal of Medicine. Failure to mention consent was most common in the BMJ and was significantly more likely than in all other journals. No significant differences in approval or consent were found when comparing studies of vulnerable and non-vulnerable participants. CONCLUSION: The reporting of ethical approval and consent in RCTs has improved, but journals are less good at reporting this information for other study designs. Journals should publish this information for all research on human participants
The sensory acceptance of fibre-enriched cereal foods:a meta-analysis
Improved understanding of the sensory responses to fibre fortification may assist manufacturers and health promotion efforts. The effects of fibre fortification (or modified ingredients) on sensory acceptability of baked cereal foods (bread, cookies, muffins) were estimated by linear random-effects meta-analysis of twenty eligible studies (869 panellists, 34% male). As little as 2 g per 100 g fortification caused moderate–large reductions in overall acceptability, flavour acceptability, and appearance acceptability in most items, with cookies most negatively affected. Fortification of base nonfortified foods with low initial acceptability improved acceptability; however, at higher basic levels, fortification lowered acceptability. Fortification improved texture acceptability of muffins and bread with low base acceptability, but lowered texture acceptability when base acceptability was high. Flavour improvement of muffins with fortification decreased with increasing base food acceptability. Fibre fortification of baked cereal foods lowers acceptability, but food format and base food acceptability affect the magnitude and direction of responses. Refining fibre fortification approaches could improve consumer uptake
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Dependence of drop speed on nozzle diameter, viscosity and drive amplitude in drop-on-demand ink-jet printing
Results of recent experiments and numerical simulations are presented, which have been used to establish empirical rules for
the dependence of drop speed on nozzle diameter and drive amplitude for Newtonian and non-Newtonian fluids printed with a
range of different ink-jet print-head technologies. Experiments were carried out with Xaar, MicroFab and Spectra Dimatix print heads and with solutions of polystyrene in diethyl phthalate as model fluids. These results are compared with
predictions from recent numerical codes developed by collaborators in the University of Leeds, and from simple models for drop-on-demand fluid jetting resulting from physical law
RoboJam: A Musical Mixture Density Network for Collaborative Touchscreen Interaction
RoboJam is a machine-learning system for generating music that assists users
of a touchscreen music app by performing responses to their short
improvisations. This system uses a recurrent artificial neural network to
generate sequences of touchscreen interactions and absolute timings, rather
than high-level musical notes. To accomplish this, RoboJam's network uses a
mixture density layer to predict appropriate touch interaction locations in
space and time. In this paper, we describe the design and implementation of
RoboJam's network and how it has been integrated into a touchscreen music app.
A preliminary evaluation analyses the system in terms of training, musical
generation and user interaction
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