441 research outputs found
Exploring the Relevance and Quality of the VaRemba Initiation School Curriculum and its Impact on Formal Schooling in a Rural District in Zimbabwe
The study explores the relevance and quality of the VaRemba initiation school curriculum and analyses its impact on formal education. A case study design was used to come up with a descriptive, interpretive as well as an evaluative account of the initiation curriculum and its impact on formal schooling in Chomusenda village in Mberengwa district of Zimbabwe. Interviews, questionnaires, observations and analysis of records were used to gather data from teachers, initiates and elderly community members. The study established that the VaRemba initiation curriculum perpetuates gender stereotypical roles and has some aspects which are unsustainable and in tension with formal schooling. Girls are channeled towards reproductive roles and the private sphere while boys are geared for productive roles and public sphere. High dropout from formal schooling is witnessed soon after initiation, as the initiation curriculum seems to tell initiates that they are âripeâ for adult life. However, the curriculum has aspects that contribute to moral development of young people. The study recommends a paradigm shift, to embrace the ubuntu philosophy in the two education systems as a way to harmonise them
A Markov model for the effects of virological failure on HIV/AIDS progression in tuberculosis co-infected patients receiving antiretroviral therapy in a rural clinic in northern South Africa
Background. The goal of antiretroviral therapy (ART) is to suppress viral replication to undetectable levels. These low viral load (VL) levels may not be attained in some patients, a situation representing potential virological failure during the course of treatment.Objectives. To present the results of a Markov model exploring how virological failure and active tuberculosis (TB) affect the progression of HIV in patients on ART.Methods. A continuous-time non-homogeneous Markov model was used to model the progression of HIV/AIDS in patients on combination ART (cART). We define seven states in our model. The first five states are based on VL levels and the other two are absorbing states: death and withdrawal from the study. The effects of TB co-infection, baseline VL, lactic acidosis and treatment failure on transition intensities were assessed.Results. The model shows that VL-based transition intensities do not follow a constant rate; rather, there are two different trends in HIV/AIDS progression. The first trend is an increase in the prevalence of state 1 (undetectable VL levels) in the first 0.5 years of treatment. The second trend follows thereafter and shows a slow decrease. Within the first 0.5 years of therapeutic intervention, the undetectable VL state is therefore attainable from any VL state. However, when virological failure occurs, there is an increased risk of death. Developing active TB while on cART increases the risk of viral rebound from undetectable levels to VLs between 50 and 10Â 000 copies/mL by ~1.03-fold. From a VL between 10Â 000 and 100Â 000 copies/mL, developing TB while on cART increases the rate of viral rebound by ~2.5-fold. However, if TB is detected and treated at enrolment, rates of viral rebound from undetectable levels are reduced.Conclusions. The model confirms that virological failure, coupled with developing active TB while on cART, increases mortality rates irrespective of patient CD4+ count status. It also suggests that while TB at the time of cART initiation does not increase the risk of viral rebound, development of active TB after cART initiation does increase this risk. These findings highlight the importance of strengthening VL monitoring, which should be performed every 2 months, especially in patients with TB, and addressing unsuppressed VLs appropriately if they are detected.
HI 2334+26: An Extended HI Cloud near Abell 2634
We report the serendipitous discovery of a large HI cloud with an associated
HI mass of M and a heliocentric velocity
8800 \kms, located near the periphery of the cluster of galaxies Abell 2634.
Its velocity field appears to be very quiescent, as no gradients in the peak
velocity are seen over its extent of 143 by 103 kpc. The
distribution of gas is poorly resolved spatially, and it is thus difficult at
this time to ascertain the nature of the cloud. At least two relatively small,
actively star--forming galaxies appear to be embedded in the HI gas, which may
(a) be an extended gaseous envelope surrounding one or both galaxies, (b) have
been spread over a large region by a severe episode of tidal disruption or (c)
have been affected by the ram pressure resulting from its motion through the
intracluster gas of A2634.Comment: 12 pages plus 2 tables (AAS LaTeX macro v3.0), 4 figures not
included. To appear in the A
Redshifts for 2410 Galaxies in the Century Survey Region
The `Century Survey' strip covers 102 square degrees within the limits 8.5h
\leq \alpha_{1950} \leq 16.5h, 29.0 degrees \leq \delta_{1950} \leq 30.0
degrees. The strip passes through the Corona Borealis supercluster and the
outer region of the Coma cluster.
Within the Century Survey region, we have measured 2410 redshifts which
constitute four overlapping complete redshift surveys: (1) 1728 galaxies with
Kron-Cousins R_{phot} \leq 16.13 covering the entire strip, (2) 507 galaxies
with R_{phot} \leq 16.4 in the right ascension range 8h 32m \leq \alpha_{1950}
\leq 10h 45m, (3) 1251 galaxies with absorption- and K-corrected R_{CCD, corr}
\leq 16.2 covering the right ascension range 8.5h \leq \alpha_{1950} \leq 13.5h
and (4) 1255 galaxies with absorption- and K-corrected V_{CCD, corr} \leq 16.7
also covering the right ascension range 8.5h \leq \alpha_{1950} \leq 13.5h. All
of these redshift samples are more than 98 % complete to the specified
magnitude limit.Comment: 18 pages, 9 figures, 3 tables, 2 abbreviated tables. In press, to
appear in Astronomical Journal, Dec. 2001 issu
Complete genome sequences of novel anelloviruses from laboratory rats
Anelloviruses are nonenveloped single-stranded DNA viruses infecting a wide range of mammals. We report three complete ge-nomes of novel anelloviruses detected in laboratory rats. Phylogenetic analysis demonstrates that these viruses are related to but distinct from recently described rodent Torque teno viruses (RoTTVs) found in wild rodent species
Mixed valency in cerium oxide crystallographic phases: Determination of valence of the different cerium sites by the bond valence method
We have applied the bond valence method to cerium oxides to determine the
oxidation states of the Ce ion at the various site symmetries of the crystals.
The crystals studied include cerium dioxide and the two sesquioxides along with
some selected intermediate phases which are crystallographically well
characterized. Our results indicate that cerium dioxide has a mixed-valence
ground state with an f-electron population on the Ce site of 0.27 while both
the A- and C-sesquioxides have a nearly pure f^1 configuration. The Ce sites in
most of the intermediate oxides have non-integral valences. Furthermore, many
of these valences are different from the values predicted from a naive
consideration of the stoichiometric valence of the compound
The HST Key Project on the Extragalactic Distance Scale. XXII. The Discovery of Cepheids in NGC 1326-A
We report on the detection of Cepheids and the first distance measurement to
the spiral galaxy NGC 1326-A, a member of the Fornax cluster of galaxies. We
have employed data obtained with the Wide Field and Planetary Camera 2 on board
the Hubble Space Telescope. Over a 49 day interval, a total of twelve V-band
(F555W) and eight I-band (F814W) epochs of observation were obtained. Two
photometric reduction packages, ALLFRAME and DoPHOT, have been employed to
obtain photometry measures from the three Wide Field CCDs. Variability analysis
yields a total of 17 Cepheids in common with both photometry datasets, with
periods ranging between 10 and 50 days. Of these 14 Cepheids with high-quality
lightcurves are used to fit the V and I period-luminosity relations and derive
apparent distance moduli, assuming a Large Magellanic Cloud distance modulus
(m-M) (LMC) = 18.50 +- 0.10 mag and color excess E(B-V) = 0.10 mag. Assuming
A(V)/E(V-I) = 2.45, the DoPHOT data yield a true distance modulus to NGC 1326-A
of (m-M)_0 = 31.36 +- 0.17 (random) +- 0.13 (systematic) mag, corresponding to
a distance of 18.7 \pm 1.5 (random) \pm 1.2 (systematic) Mpc. The derived
distance to NGC 1326-A is in good agreement with the distance derived
previously to NGC 1365, another spiral galaxy member of the Fornax cluster.
However the distances to both galaxies are significantly lower than to NGC
1425, a third Cepheid calibrator in the outer parts of the cluster.Comment: 33 pages A gzipped tar file containing 12 figures can be obtained
from http://www.ipac.caltech.edu/H0kp/n1326a/n1326a.htm
The HST Key Project on the Extragalactic Distance Scale XXV. A Recalibration of Cepheid Distances to Type Ia Supernovae and the Value of the Hubble Constant
Cepheid-based distances to seven Type Ia supernovae (SNe)-host galaxies have
been derived using the standard HST Key Project on the Extragalactic Distance
Scale pipeline. For the first time, this allows for a transparent comparison of
data accumulated as part of three different HST projects, the Key Project, the
Sandage et al. Type Ia SNe program, and the Tanvir et al. Leo I Group study.
Re-analyzing the Tanvir et al. galaxy and six Sandage et al. galaxies we find a
mean (weighted) offset in true distance moduli of 0.12+/-0.07 mag -- i.e., 6%
in linear distance -- in the sense of reducing the distance scale, or
increasing H0. Adopting the reddening-corrected Hubble relations of Suntzeff et
al. (1999), tied to a zero point based upon SNe~1990N, 1981B, 1998bu, 1989B,
1972E and 1960F and the photometric calibration of Hill et al. (1998), leads to
a Hubble constant of H0=68+/-2(random)+/-5(systematic) km/s/Mpc. Adopting the
Kennicutt et al. (1998) Cepheid period-luminosity-metallicity dependency
decreases the inferred H0 by 4%. The H0 result from Type Ia SNe is now in good
agreement, to within their respective uncertainties, with that from the
Tully-Fisher and surface brightness fluctuation relations.Comment: Accepted for publication in The Astrophysical Journal. 62 pages,
LaTeX, 9 Postscript figures. Also available at
http://casa.colorado.edu/~bgibson/publications.htm
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