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 ‘ripe’ 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 10 000 copies/mL by ~1.03-fold. From a VL between 10 000 and 100 000 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.

Space, the original frontier

S.S. was supported by BBSRC Discovery Fellowship (BB/S01019X/1).Over fifty years of work on animal cognition, enthusiasms for different topics can wax and wane. Interest in spatial cognition, once popular, has more recently waned. Some of this change, however, is only apparent, as research on spatial cognition continues to evolve and produce new scientific innovations. Indeed, recent technological developments has enabled us to now address questions raised from classic early studies. Here we review several key examples where past and present research approaches have intersected to provide new answers to old questions concerning spatial memory in food-storing birds and other laboratory animals, navigation in birds and insects, and spatial cognition in wild hummingbirds.Publisher PDFPeer reviewe

The Tip of the Red Giant Branch Distance to the Large Magellanic Cloud

We present the I-band luminosity function of the red giant branch stars in the Large Magellanic Cloud (LMC) using the data from the Magellanic Clouds Photometric Survey (Zaritsky, Harris & Thompson, 1997). Selecting stars in uncrowded, low-extinction regions, a discontinuity in the luminosity function is observed at I_0 = 14.54 mag. Identifying this feature with the tip of the red giant branch (TRGB), and adopting an absolute TRGB magnitude of -4.05 +- 0.04 mag based on the calibration of Lee, Freedman & Madore (1993), we obtain a distance modulus of 18.59 +- 0.09 (random) +- 0.16 (systematic) mag. If the theoretical TRGB calibration provided by Cassisi & Salaris (1997) is adopted instead, the derived distance would be 4% greater. The LMC distance modulus reported here, 18.59 +- 0.09, is larger by 0.09 mag (1-sigma) than the value that is most commonly used in the extragalactic distance scale calibrated by the period-luminosity relation of the Cepheid variable stars. Our TRGB distance modulus agrees with several RR Lyrae distances to the LMC based on HIPPARCOS parallaxes. Finally, we note that using the same MCPS data, we obtain a distance modulus of 18.29 +- 0.03 mag using the red clump method, which is shorter by 0.3 mag compared to the TRGB estimate.Comment: 19 pages, 5 figure

Observation of the Halo of NGC 3077 Near the "Garland" Region Using the Hubble Space Telescope

We report the detection of upper main sequence stars and red giant branch stars in the halo of an amorphous galaxy, NGC3077. The observations were made using Wide Field Planetary Camera~2 on board the Hubble Space Telescope. The red giant branch luminosity function in I-band shows a sudden discontinuity at I = 24.0 +- 0.1 mag. Identifying this with the tip of the red giant branch (TRGB), and adopting the calibration provided by Lee, Freedman, & Madore (1993) and the foreground extinction of A_B = 0.21 mag, we obtain a distance modulus of (m-M)_0 = 27.93 +- 0.14(random) +- 0.16(sys). This value agrees well with the distance estimates of four other galaxies in the M81 Group. In addition to the RGB stars, we observe a concentration of upper main sequence stars in the halo of NGC3077, which coincides partially with a feature known as the ``Garland''. Using Padua isochrones, these stars are estimated to be <150 Myrs old. Assuming that the nearest encounter between NGC3077 and M81 occurred 280 Myrs ago as predicted by the numerical simulations (Yun 1997), the observed upper main sequence stars are likely the results of the star formation triggered by the M81-NGC3077 tidal interaction.Comment: 15 pages, 8 figures. Accepted for publication in Astrophysical Journa

A Database of Cepheid Distance Moduli and TRGB, GCLF, PNLF and SBF Data Useful for Distance Determinations

We present a compilation of Cepheid distance moduli and data for four secondary distance indicators that employ stars in the old stellar populations: the planetary nebula luminosity function (PNLF), the globular cluster luminosity function (GCLF), the tip of the red giant branch (TRGB), and the surface brightness fluctuation (SBF) method. The database includes all data published as of July 15, 1999. The main strength of this compilation resides in all data being on a consistent and homogeneous system: all Cepheid distances are derived using the same calibration of the period-luminosity relation, the treatment of errors is consistent for all indicators, measurements which are not considered reliable are excluded. As such, the database is ideal for inter-comparing any of the distance indicators considered, or for deriving a Cepheid calibration to any secondary distance indicator. Specifically, the database includes: 1) Cepheid distances, extinctions and metallicities; 2) apparent magnitudes of the PNLF cutoff; 3) apparent magnitudes and colors of the turnover of the GCLF (both in the V- and B-bands); 4) apparent magnitudes of the TRGB (in the I-band) and V-I colors at and 0.5 magnitudes fainter than the TRGB; 5) apparent surface brightness fluctuation magnitudes I, K', K_short, and using the F814W filter with the HST/WFPC2. In addition, for every galaxy in the database we give reddening estimates from DIRBE/IRAS as well as HI maps, J2000 coordinates, Hubble and T-type morphological classification, apparent total magnitude in B, and systemic velocity. (Abridged)Comment: Accepted for publication in the Astrophysical Journal Supplement Series. Because of space limitations, the figures included are low resolution bitmap images. Original figures can be found at http://www.astro.ucla.edu/~laura/pub.ht

The Star Formation Demographics of Galaxies in the Local Volume

We examine the connections between the current global star formation activity, luminosity, dynamical mass and morphology of galaxies in the Local Volume, using H-alpha data from the 11 Mpc H-alpha and Ultraviolet Galaxy Survey (11HUGS). Taking the equivalent width (EW) of the H-alpha emission line as a tracer of the specific star formation rate, we analyze the distribution of galaxies in the M_B-EW and rotational velocity (V_{max})-EW planes. Star-forming galaxies show two characteristic transitions in these planes. A narrowing of the galaxy locus occurs at M_B~-15 and V_{max}~50 km/s, where the scatter in the logarithmic EWs drops by a factor of two as the luminosities/masses increase, and galaxy morphologies shift from predominately irregular to late-type spiral. Another transition occurs at M_B~-19 and V_{max}~120 km/s, above which the sequence turns off toward lower EWs and becomes mostly populated by intermediate and early-type bulge-prominent spirals. Between these two transitions, the mean logarithmic EW appears to remain constant at 30 A. We comment on how these features reflect established empirical relationships, and provide clues for identifying the large-scale physical processes that both drive and regulate star formation, with emphasis on the low-mass galaxies that dominate our approximately volume-limited sample.Comment: 5 pages, accepted for publication in ApJL pending editing for lengt