23,257 research outputs found
Cluster Winds Blow along Supercluster Axes
Within Abell galaxy clusters containing wide-angle tailed radio sources,
there is evidence of a ``prevailing wind'' which directs the WAT jets. We study
the alignment of WAT jets and nearby clusters to test the idea that this wind
may be a fossil of drainage along large-scale supercluster axes. We also test
this idea with a study of the alignment of WAT jets and supercluster axes.
Statistical test neighbours indicate no alignment of WAT jets towards nearest
clusters, but do indicate approximately 98% confidence in alignment with the
long axis of the supercluster in which the cluster lies. We find a preferred
scale for such superclusters of order 25 Mpc .Comment: Latex, 5 pages, with 5 postscript figures. To be published in MNRAS.
Slight revisions to coincide with journal text. Linked to color image at
http://kusmos.phsx.ukans.edu/~melott/images/A2634SUW.jp
Aerospace Planning in the 1970\u27s
The Aerospace Industry has reacted swiftly to the complex management and technological problems created by the mushrooming space requirements. Whereas a quick reaction capability to specific demands of the National Space Program has worked well in the past, a tightening of the Federal purse strings now and in the 1970\u27s will present new management challenges. New techniques for long range planning and management control are evolving. An analysis of the more significant techniques leads to a recommendation for survival and fiscal growth in the future by applying these new techniques to analyze, decide, plan and control aerospace operations.
The Aerospace industry has demonstrated a fantastic ability to adapt and to grow during the 1960\u27s. A remarkable conversion of technological capability from military aircraft and electronics systems design into the conceiving, designing, testing and flying of sophisticated craft in the hostile space environment has been accomplished. Growth of the industry and its component parts has been explosive, but primarily in response to external geopolitical pressures. The magnitude and direction of these pressures are beginning to change as the geopolitical situation gyrates. New pressures are being created by economic and technological change. The industry cannot maintain an attitude of responding only to the needs as they arrive. Time will no longer permit such a luxury
Disorders of sex development: mothers’ experiences of support
Abstract
Background: An increasing body of research has sought to determine the impact of Disorders of Sex Development (DSD) on the family of the affected child. Little is currently understood about the support needs of the family and how well these needs are met.
Methods: Interpretive Phenomenological Analysis was used to analyse semi-structured interviews with eight mothers of children with DSD about their experiences of support.
Results: Four master themes emerged which encapsulated (a) the stages in their child’s development when mothers most needed support, (b) the importance of developing an understanding of the child’s condition, (c) the lack of acknowledgement of the emotional needs of the parent and (d) the importance of having close and trusted networks for support. Continuity and availability of support were considered important and while all participants prioritised maintaining privacy about the condition, a minority felt that this impacted the level of support they received.
Conclusions: Key time points for support were identified and while some felt that they were well supported others felt that the support available did not meet their emotional needs. Clinical implications and directions for future research were considered
On equivariant characteristic ideals of real classes
Let be an odd prime, an abelian totally real number field,
its cyclotomic -extension,
We give an explicit description of the equivariant characteristic ideal of
over for all odd by applying M. Witte's formulation of an equivariant main conjecture (or
"limit theorem") due to Burns and Greither. This could shed some light on
Greenberg's conjecture on the vanishing of the -invariant of
$F_\infty/F.
A Universal Temperature Profile for Galaxy Clusters
We investigate the predicted present-day temperature profiles of the hot,
X-ray emitting gas in galaxy clusters for two cosmological models - a current
best-guess LCDM model and standard cold dark matter (SCDM). Our
numerically-simulated "catalogs" of clusters are derived from high-resolution
(15/h kpc) simulations which make use of a sophisticated, Eulerian-based,
Adaptive Mesh-Refinement (AMR) code that faithfully captures the shocks which
are essential for correctly modelling cluster temperatures. We show that the
temperature structure on Mpc-scales is highly complex and non-isothermal.
However, the temperature profiles of the simulated LCDM and SCDM clusters are
remarkably similar and drop-off as
where and . This decrease
is in good agreement with the observational results of Markevitch et al.(1998)
but diverges, primarily in the innermost regions, from their fit which assumes
a polytropic equation of state. Our result is also in good agreement with a
recent sample of clusters observed by BeppoSAX though there is some indication
of missing physics at small radii (). We discuss the
interpretation of our results and make predictions for new x-ray observations
that will extend to larger radii than previously possible. Finally, we show
that, for , our universal temperature profile is consistent with
our most recent simulations which include both radiative cooling and supernovae
feedback.Comment: 8 pages, 6 figures, accepted for publication in ApJ, full-page
version of Fig. 2 at
http://www.cita.utoronto.ca/+AH4-cloken/PAPERS/UTP/f2.ep
The space station: Human factors and productivity
Human factor researchers and engineers are making inputs into the early stages of the design of the Space Station to improve both the quality of life and work on-orbit. Effective integration of the human factors information related to various Intravehicular Activity (IVA), Extravehicular Activity (EVA), and teletobotics systems during the Space Station design will result in increased productivity, increased flexibility of the Space Stations systems, lower cost of operations, improved reliability, and increased safety for the crew onboard the Space Station. The major features of productivity examined include the cognitive and physical effort involved in work, the accuracy of worker output and ability to maintain performance at a high level of accuracy, the speed and temporal efficiency with which a worker performs, crewmember satisfaction with their work environment, and the relation between performance and cost
- …