Effect of the rate and duration of forced air cooling on the quality of Imperial apricots and Pioneer and Songold plums

The original publication is available at http://www.actahort.org/books/682/682_218.htmGel breakdown (GB) and overripeness (OR) remain the biggest internal Problems with Prunus armeniaca L. ‘Imperial’, which makes the biggest contribution to the total volume of apricots exported from South Africa per annum. Prunus salicina L. ‘Pioneer’, an early season South African plum cultivar, ripens quickly on and off the tree which results in rejections for soft fruit at packing and on arrival overseas. ‘Songold’, a yellow, midseason plum cultivar tends to develop GB and OR during cold-storage in some seasons, which renders the fruit inedible and results in high rejection rates. Prompt cooling and good temperature management are essential to lower the rate of physiological deterioration of stone fruit. In some commercial depots in South Africa, forced air cooling (FAC) of stone fruit can take as long as 48 to 72 h, depending on the type of packaging. Consequently, the objective of this study was to determine the effect of the rate and duration of FAC on the fruit quality of different stone fruit cultivars. Fruit was subjected to the following FAC rates at a delivery air temperature of -1.0°C to a pulp temperature of 0°C for 6 h, 12 h, 24 h stepwise cooling and 48 h stepwise cooling for the apricot, and 12 h, 24 h, 48 h stepwise cooling, and 72 h stepwise cooling for the two plum cultivars. The fruit was evaluated after cold-storage and a simulated shelf-life period. The trial was conducted in two consecutive seasons. ‘Imperial’ apricots had the best internal quality after 6 h of FAC, ‘Pioneer’ plums were not affected by FAC rate or duration, and ‘Songold’ plums had the best internal quality when FAC was applied for 12 h and longer. These results on plums demonstrate that cultivar differences must be considered when drawing up handling protocols for stone fruit, as a blanket recommendation may lead to the induction of quality defects

On the Computation of Blow-up Solutions for Semilinear ODEs and Parabolic PDEs

We introduce an adaptive numerical method for computing blow-up solutions for ODEs and well-known reaction-diffusion equations. The method is based on the implicit midpoint method and the implicit Euler method. We demonstrate that the method produces superior results to the adaptive PECE-implicit method and the MATLAB solver of comparable order

Praxis Mapping: A methodology for evaluating the political impacts of international projects

This report describes the participatory development of a process we have used to consider the political implications of a climate justice project we worked on together from 2010 to 2013, called Strengthening the role of civil society in water sector governance towards climate change adaptation in African cities – Durban, Maputo, Nairobi (see http://ccaa.irisyorku.ca). This project was funded by the International Development Research Centre (IDRC) and the U.K. Department for International Development (DFID) through their Climate Change Adaptation in Africa programme.This research was supported by the International Development Research Centr

Higher Order Compact Finite Difference Schemes for Unsteady Boundary Layer Flow Problems

We investigate the applicability of the compact finite difference relaxation method (CFDRM) in solving unsteady boundary layer flow problems modelled by nonlinear partial differential equations. The CFDRM utilizes the Gauss-Seidel approach of decoupling algebraic equations to linearize the governing equations and solve the resulting system of ordinary differential equations using compact finite difference schemes. The CFDRM has only been used to solve ordinary differential equations modelling boundary layer problems. This work extends its applications to nonlinear partial differential equations modelling unsteady boundary layer flows. The CFDRM is validated on two examples and the results are compared to results of the Keller-box method

The Epidermiology of Hairstyle related african hair disdorders, in and Urban Township in South Africa

The hair of indigenous people of Africa varies from the north to the south of the continent. Although the variation in hair colour from light brown to black occurs, the most significant difference is in the curls which are tightest, and spiral, in indigenous sub Saharan Africans. African hair for the purpose of this thesis refers to the latter hair phenotype. The unique morphology of this hair type is associated with specific responses to grooming. In addition hairstyle preferences may be influenced by politics and fashion. Specific scalp disorders have been anecdotally reported to be more prevalent in Africans. These are acne (folliculitis) keloidalis (AKN), central centrifugal cicatricial alopecia (CCCA) and traction alopecia (TA). For many years all these conditions have been suspected to have a causal association with hairstyles. However, preliminary investigation suggested a lack of population studies demonstrating the latter association. In addition the possible influence of the unique African hair follicle on disease pathogenesis had not been determined. The aims of this thesis were to: Present a systematic 1. literature review of published prevalence and incidence data on the above three conditions. 2. Conduct cross sectional studies to investigate the prevalence of AKN, CCCA and TA in a population of school children and adults and the prevalence of different hairstyles, and to describe any associations between hairstyles and disease. 3. Develop and test for reliability a new severity scoring system for TA the commonest of the above conditions [the marginal traction alopecia severity (M-TAS) scoring instrument]. 4. Evaluate the determinants of both TA presence and severity in African females using data from our cross sectional studies in school children and adults