822 research outputs found
Learning experiences of students during integrated management of childhood illness (IMCI) training
Published ArticleThe aim of the study on which this article is based was to reflect on the learning experiences of students during integrated management of childhood illness (IMCI) training in an undergraduate programme. IMCI is a set of guidelines that was established by the World Health Organisation (WHO) for cost-effective quality care for children younger than five to prevent diseases and death (WHO, 2004). Skilled primary healthcare workers are required to provide quality care at first contact with these children. The IMCI package was presented as an integral part of the second-year module that focuses on primary healthcare. In order to improve the quality of health services and refocus the health system on primary health-care (South Africa Department of Health, 2010), students have to demonstrate that they have achieved competence. According to Killen (2000:188), competence is a holistic term and focuses on knowledge, skills and values instead of competencies, which refer to specific capabilities. Primary health-care workers who act competently will integrate foundational IMCI knowledge with skills and values as well as with the ability to verify their decisions (Killen, 2000:188). Aqualitative, exploratory and descriptive research design was used to investigate the IMCI learning experiences. Such experiences are one of the indications whether training has been successful and how it can be improved (Suski, 2004:222). Data was collected by means of nominal-group technique (NGT) interviews with second-year nursing students of the training school who complied with the criteria for inclusion. NGT interviews were used effectively to evaluate clinical interaction, education and training.The findings reflected the different emotions experienced during teaching and learning as having been positive, negative or neutral. The consideration of negative emotions will assist with the improvement of IMCI teaching and learning, but all these findings can be useful for other higher-education institutions that present or plan to present IMCI training
Theory and practice of the quintile ranking of schools in South Africa: A financial management perspective
Equitable funding of public schools to reduce the disparities in education inherited by the post-apartheid government of South Africa in 1994 has become a priority. The Amended National Norms and Standards for School Funding (ANNSSF) required the ranking of schools into one of five quintiles of which Quintile 1 represents the poorest schools and Quintile 5 the most affluent. This amendment determines that schools serving impoverished communities should receive more funding. However, challenges exist regarding the implementation of the system, as well as the calculation base for maintenance allocation. In this study we used semi-structured interviews to collect data from 24 respondents from urban and township schools in Gauteng. Participants were selected by means of purposive sampling. Permission to conduct the research was obtained from the Gauteng Department of Education, the university’s Ethics Committee and the school governing bodies. We handled financial information from schools with utmost confidentiality. We identified themes from interview transcriptions and we analysed schools’ financial statements. The main findings relate to inaccuracies in quintile ranking, which result in inadequate and unfair school funding, which impact on schools’ maintenance and learning and teaching. It is recommended that a more holistic approach should be followed to achieve equity in education.Keywords: disparity; education funding; no-fee schools; poverty score; quintile ranking; school fee exemption formul
Analyzing SN2003Z with PHOENIX
We present synthetic spectra around maximum for the type II supernova SN
2003Z, which was first detected on January 29.7 2003. Comparison with observed
spectra aim at the determination of physical parameters for SN 2003Z. Synthetic
spectra are calculated with our stellar atmosphere code PHOENIX. It solves the
special relativistic equation of radiative transfer, including large
NLTE-calculations and line blanketing by design, in 1-dimensional spherical
symmetry. The observed spectra were obtained at the 3.5 meter telescope at
Calar Alto. The TWIN instrument was used so that a spectral range from about
3600 to 7500 Angstroem was covered. The spectra were taken on Feb. 4, 5, 9, and
11, 2003. The physical parameters of the models give the luminosities, a range
of possible velocity profiles for the SN, an estimate of the colour excess, and
the observed metalicity.Comment: 8 figure
Bayesian Analysis of Two Stellar Populations in Galactic Globular Clusters II: NGC 5024, NGC 5272, and NGC 6352
We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival
ACS Treasury observations of Galactic Globular Clusters to find and
characterize two stellar populations in NGC 5024 (M53), NGC 5272 (M3), and NGC
6352. For these three clusters, both single and double-population analyses are
used to determine a best fit isochrone(s). We employ a sophisticated Bayesian
analysis technique to simultaneously fit the cluster parameters (age, distance,
absorption, and metallicity) that characterize each cluster. For the
two-population analysis, unique population level helium values are also fit to
each distinct population of the cluster and the relative proportions of the
populations are determined. We find differences in helium ranging from
0.05 to 0.11 for these three clusters. Model grids with solar
-element abundances ([/Fe] =0.0) and enhanced -elements
([/Fe]=0.4) are adopted.Comment: ApJ, 21 pages, 14 figures, 7 table
Supernovae in isolated galaxies, in pairs and in groups of galaxies
In order to investigate the influence of the environment on the supernova
(SN) production we have performed a statistical investigation of the SNe
discovered in isolated galaxies, in pairs and in groups of galaxies. 22 SNe in
18 isolated galaxies, 48 SNe in 40 galaxies members of 37 pairs and 211 SNe in
170 galaxies members of 116 groups have been selected and studied. We found
that the radial distributions of core-collapse SNe in galaxies located in
different environments are similar, and consistent with that reported by
Bartunov, Makarova & Tsvetkov (1992). SNe discovered in pairs do not privilege
a particular direction with respect to the companion galaxy. Also the azimuthal
distributions inside the hosts members of galaxy groups are consistent with
being isotropics. The fact that SNe are more frequent in the brighter
components of the pairs and groups is expected from the dependence of the SN
rates on the galaxy luminosity. There is an indication that the SN rate is
higher in galaxy pairs compared with that in groups. This can be related to the
enhanced star formation rate in strongly interacting systems. It is concluded
that, with the possible exception of strongly interacting system, the parent
galaxy environment has no direct influence on the SN productionComment: 10 pages, accepted for publication to MNRA
Bayesian estimates of astronomical time delays between gravitationally lensed stochastic light curves
The gravitational field of a galaxy can act as a lens and deflect the light emitted by a more distant object such as a quasar. Strong gravitational lensing causes multiple images of the same quasar to ap- pear in the sky. Since the light in each gravitationally lensed image traverses a different path length from the quasar to the Earth, fluc- tuations in the source brightness are observed in the several images at different times. The time delay between these fluctuations can be used to constrain cosmological parameters and can be inferred from the time series of brightness data or light curves of each image. To estimate the time delay, we construct a model based on a state- space representation for irregularly observed time series generated by a latent continuous-time Ornstein-Uhlenbeck process. We account for microlensing, an additional source of independent long-term ex- trinsic variability, via a polynomial regression. Our Bayesian strategy adopts a Metropolis-Hastings within Gibbs sampler. We improve the sampler by using an ancillarity-sufficiency interweaving strategy and adaptive Markov chain Monte Carlo. We introduce a profile likeli- hood of the time delay as an approximation of its marginal posterior distribution. The Bayesian and profile likelihood approaches comple- ment each other, producing almost identical results; the Bayesian method is more principled but the profile likelihood is simpler to implement. We demonstrate our estimation strategy using simulated data of doubly- and quadruply-lensed quasars, and observed data from quasars Q0957+561 and J1029+2623
The X-ray Spectrum and Light Curve of Supernova 1995N
We report on multi-epoch X-ray observations of the Type IIn (narrow emission
line) supernova SN 1995N with the ROSAT and ASCA satellites. The January 1998
ASCA X-ray spectrum is well fitted by a thermal bremsstrahlung (kT~10 keV,
N_H~6e20 cm^-2) or power-law (alpha~1.7, N_H~1e21 cm^-2) model. The X-ray light
curve shows evidence for significant flux evolution between August 1996 and
January 1998: the count rate from the source decreased by 30% between our
August 1996 and August 1997 ROSAT observations, and the X-ray luminosity most
likely increased by a factor of ~2 between our August 1997 ROSAT and January
1998 ASCA observations, although evolution of the spectral shape over this
interval is not ruled out. The high X-ray luminosity, L_X~1e41 erg/sec, places
SN 1995N in a small group of Type IIn supernovae with strong circumstellar
interaction, and the evolving X-ray luminosity suggests that the circumstellar
medium is distributed inhomogeneously.Comment: MNRAS accepted. 6 pages, 2 figures; uses mn.sty and psfi
Statistical analysis of stellar evolution
Color-Magnitude Diagrams (CMDs) are plots that compare the magnitudes
(luminosities) of stars in different wavelengths of light (colors). High
nonlinear correlations among the mass, color, and surface temperature of newly
formed stars induce a long narrow curved point cloud in a CMD known as the main
sequence. Aging stars form new CMD groups of red giants and white dwarfs. The
physical processes that govern this evolution can be described with
mathematical models and explored using complex computer models. These
calculations are designed to predict the plotted magnitudes as a function of
parameters of scientific interest, such as stellar age, mass, and metallicity.
Here, we describe how we use the computer models as a component of a complex
likelihood function in a Bayesian analysis that requires sophisticated
computing, corrects for contamination of the data by field stars, accounts for
complications caused by unresolved binary-star systems, and aims to compare
competing physics-based computer models of stellar evolution.Comment: Published in at http://dx.doi.org/10.1214/08-AOAS219 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Standardizing type Ia supernovae optical brightness using near-infrared rebrightening time
Accurate standardization of Type Ia supernovae (SNIa) is instrumental to the usage of SNIa as distance indicators. We analyse a homogeneous sample of 22 low-z SNIa, observed by the Carnegie Supernova Project in the optical and near-infrared (NIR). We study the time of the second peak in the J band, t2, as an alternative standardization parameter of SNIa peak optical brightness, as measured by the standard SALT2 parameter mB. We use BAHAMAS, a Bayesian hierarchical model for SNIa cosmology, to estimate the residual scatter in the Hubble diagram. We find that in the absence of a colour correction, t2 is a better standardization parameter compared to stretch: t2 has a 1\u3c3 posterior interval for the Hubble residual scatter of \u3c3\u394\u3bc = (0.250, 0.257) mag, compared to \u3c3\u394\u3bc = (0.280, 0.287) mag when stretch (x1) alone is used. We demonstrate that when employed together with a colour correction, t2 and stretch lead to similar residual scatter. Using colour, stretch and t2 jointly as standardization parameters does not result in any further reduction in scatter, suggesting that t2 carries redundant information with respect to stretch and colour. With a much larger SNIa NIR sample at higher redshift in the future, t2 could be a useful quantity to perform robustness checks of the standardization procedure
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