5,031 research outputs found
Administrative automation in a scientific environment
Although the scientific personnel at GSFC were advanced in the development and use of hardware and software for scientific applications, resistance to the use of automation or purchase of terminals, software and services, specifically for administrative functions was widespread. The approach used to address problems and constraints and plans for administrative automation within the Space and Earth Sciences Directorate are delineated. Accomplishments thus far include reduction of paperwork and manual efforts; improved communications through telemail and committees; additional support staff; increased awareness at all levels on ergonomic concerns and the need for training; better equipment; improved ADP skills through experience; management commitment; and an overall strategy for automating
The development and initial validation of the Perinatal Mental Health Awareness scale in student midwives
Background & aim: Perinatal mental health problems have been demonstrated to impact upon maternal, and fetal/child outcomes. Despite the global evidence and a policy-driven responsibility for identification of these problems, research demonstrates that student midwives/midwives lack knowledge and confidence to assess, identify, and manage them. A similar context is evident for learning disabilities, despite the holistic care philosophy of midwifery. A brief assessment tool to identify knowledge and confidence defecits and strengths within a holistic care framework could support curriculum development. This study sought to develop a Perinatal Mental Health Awareness scale and evaluate its psychometric properties in student midwives.Methods: We employed a cross-sectional and exploratory instrument development and evaluation design to determine the measurement veracity of the new scale.Results: The scale demonstrated good psychometric properties, revealing three subscales mapping onto (i) mental health symptoms, (ii) physical/medical issues and (iii) learning disability. Results indicated a clear differentiation in scores across the subscales, indicating comparative deficits in mental health domains.Conclusion: Our findings facilitate confidence in the psychometric robustness of the measure. The scale enables student midwives to assess and compare different domains of midwifery practice, in line with a holistic model of midwifery care. A focus on physical health in midwifery education appears to disadvantage knowledge and confidence for managing mental health problems in a midwifery context. This valuable finding highlights the potential need for curriculum rebalancing. The measure offers the opportunity to assess and develop curriculum/training provision and monitor the effectiveness of subsequent curricular developments
On How to Extend the NIR Tully-Fisher Relation to be Truly All-Sky
Dust extinction and stellar confusion by the Milky Way reduce the efficiency
of detecting galaxies at low Galactic latitudes, creating the so-called Zone of
Avoidance. This stands as a stumbling block in charting the distribution of
galaxies and cosmic flow fields, and therewith our understanding of the local
dynamics in the Universe (CMB dipole, convergence radius of bulk flows). For
instance, ZoA galaxies are generally excluded from the whole-sky Tully-Fisher
Surveys () even if catalogued. We show here that by
fine-tuning the near-infrared TF relation, there is no reason not to extend
peculiar velocity surveys deeper into the ZoA. Accurate axial ratios ()
are crucial to both the TF sample selection and the resulting TF distances. We
simulate the effect of dust extinction on the geometrical properties of
galaxies. As expected, galaxies appear rounder with increasing obscuration
level, even affecting existing TF samples. We derive correction models and
demonstrate that we can reliably reproduce the intrinsic axial ratio from the
observed value up to extinction level of about mag (
mag), we also recover a fair fraction of galaxies that otherwise would fall out
of an uncorrected inclination limited galaxy sample. We present a
re-calibration of the 2MTF relation in the NIR , , and -bands for
isophotal rather than total magnitudes, using their same calibration sample.
Both TF relations exhibit similar scatter at high Galactic latitudes. However,
the isophotal TF relation results in a significant improvement in the scatter
for galaxies in the ZoA, and low surface brightness galaxies in general,
because isophotal apertures are more robust in the face of significant stellar
confusion.Comment: 12 pages, 10 figures, 4 tables, accepted for publication in MNRA
Effects of cobalt in nickel-base superalloys
The role of cobalt in a representative wrought nickel-base superalloy was determined. The results show cobalt affecting the solubility of elements in the gamma matrix, resulting in enhanced gamma' volume fraction, in the stabilization of MC-type carbides, and in the stabilization of sigma phase. In the particular alloy studied, these microstructural and microchemistry changes are insufficient in extent to impact on tensile strength, yield strength, and in the ductilities. Depending on the heat treatment, creep and stress rupture resistance can be cobalt sensitive. In the coarse grain, fully solutioned and aged condition, all of the alloy's 17% cobalt can be replaced by nickel without deleteriously affecting this resistance. In the fine grain, partially solutioned and aged condition, this resistance is deleteriously affected only when one-half or more of the initial cobalt content is removed. The structure and property results are discussed with respect to existing theories and with respect to other recent and earlier findings on the impact of cobalt, if any, on the performance of nickel-base superalloys
Galaxy peculiar velocities in the Zone of Avoidance
Dust extinction and stellar confusion of the Milky Way hinder the detection
of galaxies at low Galactic latitude, creating the so-called Zone of Avoidance
(ZoA). This has hampered our understanding of the local dynamics, cosmic flow
fields and the origin of the Cosmic Microwave Background dipole. The ZoA () is also excluded from the "whole-sky" Two Micron All-Sky Survey
(2MASS) Redshift Survey (2MRS) and 2MASS Tully-Fisher Survey (2MTF). The latter
aims to provide distances and peculiar velocities for all bright inclined 2MASS
galaxies with \leq 11\hbox{.\!\!^{\rm m}}25. Correspondingly,
knowledge about the density distribution in the ZoA remains limited to
statistical interpolations. To improve on this bias we pursued two different
surveys to fill in the southern and northern ZoA. These data will allow a
direct measurement of galaxy peculiar velocities. In this paper we will present
a newly derived optimized Tully-Fisher (TF) relation that allow accurate
measures of galaxy distances and peculiar velocities for dust-obscured
galaxies. We discuss further corrections for magnitudes and biases and present
some preliminary results on flow fields in the southern ZoA.Comment: 6 pages, 3 figures, to appear in Proceedings of SAIP2013, the 58th
Annual Conference of the South African Institute of Physics, edited by Roelf
Botha and Thulani Jili (SAIP and University of Zululand, 2014). ISBN:
978-0-620-62819-
From Spitzer Galaxy Photometry to Tully-Fisher Distances
This paper involves a data release of the observational campaign: Cosmicflows
with Spitzer (CFS). Surface photometry of the 1270 galaxies constituting the
survey is presented. An additional ~ 400 galaxies from various other Spitzer
surveys are also analyzed. CFS complements the Spitzer Survey of Stellar
Structure in Galaxies, that provides photometry for an additional 2352
galaxies, by extending observations to low galactic latitudes (|b|<30 degrees).
Among these galaxies are calibrators, selected in K band, of the Tully-Fisher
relation. The addition of new calibrators demonstrate the robustness of the
previously released calibration. Our estimate of the Hubble constant using
supernova host galaxies is unchanged, H0 = 75.2 +/- 3.3 km/s/Mpc.
Distance-derived radial peculiar velocities, for the 1935 galaxies with all the
available parameters, will be incorporated into a new data release of the
Cosmicflows project. The size of the previous catalog will be increased by 20%,
including spatial regions close to the Zone of Avoidance.Comment: Accepted for publication in MNRAS, 16 pages, 14 figures, 6 table
Groups of dwarf galaxies in the Local supercluster
We present a project on study of groups composed of dwarf galaxies only. We
selected such structures using HyperLEDA and NED databases with visual
inspection on SDSS images and on digital copy of POSS. The groups are
characterized by size of few tens of kpc and line-of-sight velocity dispersion
about 18 km/s. Our groups similar to associations of nearby dwarfs from Tully
et al. (2006). This specific population of multiple dwarf galaxies such as
IZw18 may contain significant amount of dark matter. It is very likely that we
see them at the stage just before merging of its components.Comment: 6 pages, 4 figures; the proceedings of the conference "A Universe of
dwarf galaxies" (Lyon, June 14-18, 2010
Discovery of Highly Obscured Galaxies in the Zone of Avoidance
We report the discovery of twenty-five previously unknown galaxies in the
Zone of Avoidance. Our systematic search for extended extra-galactic sources in
the GLIMPSE and MIPSGAL mid-infrared surveys of the Galactic plane has revealed
two overdensities of these sources, located around l ~ 47 and 55 degrees and
|b| less than 1 degree in the Sagitta-Aquila region. These overdensities are
consistent with the local large-scale structure found at similar Galactic
longitude and extending from |b| ~ 4 to 40 degrees. We show that the infrared
spectral energy distribution of these sources is indeed consistent with those
of normal galaxies. Photometric estimates of their redshift indicate that the
majority of these galaxies are found in the redshift range z = 0.01 - 0.05,
with one source located at z = 0.07. Comparison with known sources in the local
Universe reveals that these galaxies are located at similar overdensities in
redshift space. These new galaxies are the first evidence of a bridge linking
the large-scale structure between both sides of the Galactic plane at very low
Galactic latitude and clearly demonstrate the feasibility of detecting galaxies
in the Zone of Avoidance using mid-to-far infrared surveys.Comment: Accepted for publication in the Astronomical Journal, 28 pages, 5
tables, 11 figure
- …
