Development Studies Working Paper, no. 36

Black business development in South Africa has been restricted by discriminatory legislation, regulation and custom for many years. Black entrepreneurs have been deliberately and systematically excluded from access to economic opportunities which might have facilitated their participation in moulding the national economy. This situation stemmed from a widely-held White view that Blacks should not have a permanent stake in non- "homeland" South African towns and that the interests of White business should be protected (Hart, 1972). Given these circumstances, Black business has not developed and diversified with the growth of capitalism in South Africa. In fact, capitalism's predominant interest in the Black population has been as labour units, not as partners in economic ventures. Those Blacks in business who have grown, and have established relatively successful business ventures, have done so despite the obstacles devised by the system. The successful Black businessman, therefore, reflects a particular brand of entrepreneurship characterised by determination, tenacity and a capacity to adapt over and above that which is usually required for survival in a competitive environment. The nature and scale of businesses to which Blacks were allowed access was limited to those which provide the daily domestic necessities of urban Black communities; ie, mainly convenience retailing (Davies, 1972). Black businessmen were also denied the right to acquire land in urban areas and such businesses as were allowed had to be conducted from rented premises. Thus, Black experience of crucial elements of entrepreneural development (such as locational choice, market selection and capital formation through property ownership) has been minimal, and so conditional that the aspirations of all but the most determined businessmen have been severely inhibited. Even the most competent Black entrepreneur has not been able to stray very far from the mould of "trader", which has become the stereotype of Black business. Hence, most business ventures in urban Black townships are associated with convenience retailing and service activities, mainly of modest proportions and not necessarily a reflection of the individual's business choice. The underdeveloped status of Black entrepreneurship in South Africa is thus due entirely to their exclusion from opportunities to gain experience, to take risks and to compete. The view of Blacks as not having an interest in, or an aptitude for, business is little more than a transparent rationalisation for institutionalised racism. The apparent lack of competitiveness amongst Blacks is the result of a complex set of inequities imposed over decades of "relative deprivation in terms of upbringing, nutritional standards, education and training, medical services, entrepreneural and professional opportunities, and horizontal and vertical mobility" (Leatt et al, 1986). It is against this background that the situation of Black business in Port Elizabeth must be seen.Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER

Development Studies Working Paper, no. 62

The emergence of development and other kinds of forums in South Africa is but one manifestation of the process of dynamic change that characterises the nineties. The Eastern Cape is no exception in this regard and, in terms of regional forums, its people and institutions have been in the vanguard of the phenomenon in the country. By providing opportunities for discussion, consultation and interaction at an unprecedented scale, the forum movement has brought many diverse people together and forged hitherto unlikely relationships. The Development Studies Unit has been part of that process, and this Working Paper reflects upon the origins, intent and prospects of the forum movement up to the run-up to the April 1994 elections. It is a baseline document that will be revisited in due course to assess the extent to which the movement has made a difference and where its subsequent future lies. The work was undertaken principally with the DSU’s own resources, together with assistance from the Urban Foundation, and reflects the outcome of a significant proportion of the DSU’s recent research involvements.Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER

Development Studies Working Paper, no. 37

Fest-Quest '87 was an attempt to secure information from visitors to the Standard Bank National Festival of the Arts held in Grahamstown from July 3 to July 11 1987. From the outset, this was an ambitious undertaking especially in view of the kinds of people and the ambient atmosphere associated with nine hectic days of cultural injection and serious literary and artistic discourse, interspersed with revelry and novel experiences; none of which is particularly conducive to filling in a lengthy questionnaire. Nevertheless, the exercise was well worth the effort and a number of lessons have been learned about how such a survey might be better conducted in future.Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER

Development Studies Working Paper, no. 42

The Development Studies Unit (DSU) seeks to identify and promote strategies and mechanisms for creating jobs in the Eastern Cape. In general, this approach seeks to alleviate the effects of endemic poverty amongst Black communities in the region and to facilitate their economic empowerment. Securing these goals is considered to be vitally important in the development process; which, in turn, consists of finding appropriate ways and means to create opportunities for impoverished communities to take control of their own destinies and to establish themselves as an economic force in the region.Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER

Empirical relations for the accurate estimation of stellar masses and radii

In this work, we have taken advantage of the most recent accurate stellar characterizations carried out using asteroseismology, eclipsing binaries and interferometry to evaluate a comprehensive set of empirical relations for the estimation of stellar masses and radii. We have gathered a total of 934 stars -- of which around two-thirds are on the Main Sequence -- that are characterized with different levels of precision, most of them having estimates of M, R, Teff, L, g, density, and [Fe/H]. We have deliberately used a heterogeneous sample (in terms of characterizing techniques and spectroscopic types) to reduce the influence of possible biases coming from the observation, reduction, and analysis methods used to obtain the stellar parameters. We have studied a total of 576 linear combinations of Teff, L, g, density, and [Fe/H] (and their logarithms) to be used as independent variables to estimate M or R. We have used an error-in-variables linear regression algorithm to extract the relations and to ensure the fair treatment of the uncertainties. We present a total of 38 new or revised relations that have an adj-R2 regression statistic higher than 0.85, and a relative accuracy and precision better than 10% for almost all the cases. The relations cover almost all the possible combinations of observables, ensuring that, whatever list of observables is available, there is at least one relation for estimating the stellar mass and radius.Comment: 49 Pages, 17 figures, 11 tables, accepted for publication in ApJ

Changing the νmax⁡\nu_{\max} Scaling Relation: The Need For a Mean Molecular Weight Term

The scaling relations that relate the average asteroseismic parameters $\Delta \nu$ and $\nu_{\max}$ to the global properties of stars are used quite extensively to determine stellar properties. While the $\Delta \nu$ scaling relation has been examined carefully and the deviations from the relation have been well documented, the $\nu_{\max}$ scaling relation has not been examined as extensively. In this paper we examine the $\nu_{\max}$ scaling relation using a set of stellar models constructed to have a wide range of mass, metallicity, and age. We find that as with $\Delta \nu$, $\nu_{\max}$ does not follow the simple scaling relation. The most visible deviation is because of a mean molecular weight term and a $\Gamma_1$ term that are commonly ignored. The remaining deviation is more difficult to address. We find that the influence of the scaling relation errors on asteroseismically derived values of $\log g$ are well within uncertainties. The influence of the errors on mass and radius estimates is small for main sequence and subgiants, but can be quite large for red giants.Comment: 15 pages, 14 figures, accepted for publication in Ap

MetR-Regulated Vibrio cholerae Metabolism Is Required for Virulence

LysR-type transcriptional regulators (LTTRs) are the largest, most diverse family of prokaryotic transcription factors, with regulatory roles spanning metabolism, cell growth and division, and pathogenesis. Using a sequence-defined transposon mutant library, we screened a panel of V. cholerae El Tor mutants to identify LTTRs required for host intestinal colonization. Surprisingly, out of 38 LTTRs, only one severely affected intestinal colonization in the suckling mouse model of cholera: the methionine metabolism regulator, MetR. Genetic analysis of genes influenced by MetR revealed that glyA1 and metJ were also required for intestinal colonization. Chromatin immunoprecipitation of MetR and quantitative reverse transcription-PCR (qRT-PCR) confirmed interaction with and regulation of glyA1, indicating that misregulation of glyA1 is likely responsible for the colonization defect observed in the metR mutant. The glyA1 mutant was auxotrophic for glycine but exhibited wild-type trimethoprim sensitivity, making folate deficiency an unlikely cause of its colonization defect. MetJ regulatory mutants are not auxotrophic but are likely altered in the regulation of amino acid-biosynthetic pathways, including those for methionine, glycine, and serine, and this misregulation likely explains its colonization defect. However, mutants defective in methionine, serine, and cysteine biosynthesis exhibited wild-type virulence, suggesting that these amino acids can be scavenged in vivo. Taken together, our results suggest that glycine biosynthesis may be required to alleviate an in vivo nutritional restriction in the mouse intestine; however, additional roles for glycine may exist. Irrespective of the precise nature of this requirement, this study illustrates the importance of pathogen metabolism, and the regulation thereof, as a virulence factor

K2P2^2 −- A photometry pipeline for the K2 mission

With the loss of a second reaction wheel, resulting in the inability to point continuously and stably at the same field of view, the NASA Kepler satellite recently entered a new mode of observation known as the K2 mission. The data from this redesigned mission present a specific challenge; the targets systematically drift in position on a ~6 hour time scale, inducing a significant instrumental signal in the photometric time series --- this greatly impacts the ability to detect planetary signals and perform asteroseismic analysis. Here we detail our version of a reduction pipeline for K2 target pixel data, which automatically: defines masks for all targets in a given frame; extracts the target's flux- and position time series; corrects the time series based on the apparent movement on the CCD (either in 1D or 2D) combined with the correction of instrumental and/or planetary signals via the KASOC filter (Handberg & Lund 2014), thus rendering the time series ready for asteroseismic analysis; computes power spectra for all targets, and identifies potential contaminations between targets. From a test of our pipeline on a sample of targets from the K2 campaign 0, the recovery of data for multiple targets increases the amount of potential light curves by a factor ${\geq}10$. Our pipeline could be applied to the upcoming TESS (Ricker et al. 2014) and PLATO 2.0 (Rauer et al. 2013) missions.Comment: 14 pages, 20 figures, Accepted for publication in The Astrophysical Journal (Apj

Radar water-level measurement for open channels

Presented during the Third international conference on irrigation and drainage held March 30 - April 2, 2005 in San Diego, California. The theme of the conference was "Water district management and governance."Includes bibliographical references.The U.S. Geological Survey is investigating the performance of radars used for water-level measurement. This paper presents data collected using the Design Analysis Associates H-360 radar sensor in the laboratory and in the field. (The use of firm, trade, and brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey.) Radar water-level measurements at field sites were compared either to pressure sensor or float measurements by using simple statistical comparisons and frequency analysis with Fourier transforms of the data. Laboratory testing checked the performance of the radar sensor over the operating temperature range. Field data comparison and laboratory temperature testing indicate that the unit has an accuracy of about 0.03 feet except for windy conditions, when errors of -0.30 feet can occur.Sponsored by USCID; co-sponsored by Association of California Water Agencies and International Network for Participatory Irrigation Management

Spatial incoherence of solar granulation: a global analysis using BiSON 2B data

A poor understanding of the impact of convective turbulence in the outer layers of the Sun and Sun-like stars challenges the advance towards an improved understanding of their internal structure and dynamics. Assessing and calibrating these effects is therefore of great importance. Here we study the spatial coherence of granulation noise and oscillation modes in the Sun, with the aim of exploiting any incoherence to beat-down observed granulation noise, hence improving the detection of low-frequency p-modes. Using data from the BiSON 2B instrument, we assess the coherence between different atmospheric heights and between different surface regions. We find that granulation noise from the different atmospheric heights probed is largely incoherent; frequency regions dominated by oscillations are almost fully coherent. We find a randomised phase difference for the granulation noise, and a near zero difference for the evanescent oscillations. A reduction of the incoherent granulation noise is shown by application of the cross-spectrum.Comment: 8 pages, 7 figures, MNRAS in pres