The Effect of Diffusion on the Particle Spectra in Pulsar Wind Nebulae

A possible way to calculate particle spectra as a function of position in pulsar wind nebulae is to solve a Fokker-Planck transport equation. This paper presents numerical solutions to the transport equation with the processes of convection, diffusion, adiabatic losses, and synchrotron radiation included. In the first part of the paper the steady-state version of the transport equation is solved as a function of position and energy. This is done to distinguish the various effects of the aforementioned processes on the solutions to the transport equation. The second part of the paper deals with a time-dependent solution to the transport equation, specifically taking into account the effect of a moving outer boundary. The paper highlights the fact that diffusion can play a significant role in reducing the amount of synchrotron losses, leading to a modification in the expected particle spectra. These modified spectra can explain the change in the photon index of the synchrotron emission as a function of position. The solutions presented in this paper are not limited to pulsar wind nebulae, but can be applied to any similar central source system, e.g. globular clusters

Ecocide, the integrity of creation and the rights of the next generation

Environmental Ethics is currently a highly important theme in Christian Ethics. This is due to the disturbing results of the current ecological research. Scholars today speak of �ecocide� � a term which describes the on-going destruction of ecosystems by means of pollution, deforestation, modern warfare, toxic waste and the increase in poverty. Of special concern is the accusation that Christianity with its emphasis on the dominium terrae is partly to blame for this state of affairs. This article investigates the magnitude of ecocide as well as the historical influences of Christianity. It focuses on a re-assessment of the Christian approach as well as the responsibilities of governments, educators, churches and corporations to take care of creation and the rights of the future generation

Die dwaling van 'n gechristianiseerde staatskool

Sedert baie jare is daar ’n kfagtige werking tot verandering in ons skoolwese te bespeur, ’n werking wat met die tyd magtiger aangegroei het, omdat dit gedra is deur die lewende geloof in Christus, en diekragtige woord van die Almagtige

The National Food Consumption Survey (NFCS): South Africa, 1999

Objective: The aim of the National Food Consumption Survey (NFCS) in South Africa was to determine the nutrient intakes and anthropometric status of children (1-9 years old), as well as factors that influence their dietary intake. Design: This was a cross-sectional survey of a nationally representative sample of all children aged 1-9 years in South Africa. A nationally representative sample with provincial representation was selected using 1996 Census information. Subjects: Of the 3120 children who were originally sampled data were obtained from 2894, a response rate of 93%. Methods: The sociodemographic status of each household was assessed by a questionnaire. Dietary intake was assessed by means of a 24-hour recall and a food-frequency questionnaire from the caregivers of the children. Food purchasing practices were determined by means of a food procurement questionnaire. Hunger was assessed by a modified hunger scale questionnaire. Nutritional status was determined by means of anthropometric measurements: height, weight, head circumference and arm circumference. Results: At the national level, stunting (height-for-age below minus two standard deviations (< -2SD) from the reference median) was by far the most common nutritional disorder, affecting nearly one in five children. The children least affected (17%) were those living in urban areas. Even with regard to the latter, however, children living in informal urban areas were more severely affected (20%) compared with those living in formal urban areas (16%). A similar pattern emerged for the prevalence of underweight (weight-for-age < -2SD), with one in 10 children being affected at the national level. Furthermore, one in 10 (13%) and one in four (26%) children aged 1-3 years had an energy intake less than half and less than two-thirds of their daily energy needs, respectively. For South African children as a whole, the intakes of energy, calcium, iron, zinc, selenium, vitamins A, D, C and E, riboflavin, niacin, vitamin B6 and folic acid were below two-thirds of the Recommended Dietary Allowances. At the national level, data from the 24-hour recalls indicated that the most commonly consumed food items were maize, sugar, tea, whole milk and brown bread. For South African children overall, one in two households (52%) experienced hunger, one in four (23%) were at risk of hunger and only one in four households (25%) appeared food-secure. Conclusion: The NFCS indicated that a large majority of households were food-insecure and that energy deficit and micronutrient deficiencies were common, resulting in a high prevalence of stunting. These results were used as motivation for the introduction of mandatory fortification in South Africa. © The Authors 2005.Conference Pape

Factors that Contributed to the Growth of the Kenya Assemblies of God Church: An Analysis of Multi-paradigms

Many churches in Africa lack recorded history for various reasons, such as scarcity of funds and/or scholars in the field of church history (cf. Kalu, 1993:166ff). This situation is more prevalent among the Pentecostal movements which, initially and for genuine reasons, were anti-intellectualist and emphasized ministry alone (Clark & Lederle et al, 1983:41; McNamee, 1974:27; and Hollenweger). Another possible explanation results from the fact that these churches are relatively young compared to their counterpart mainline churches. This lack of recorded history poses a hindrance to any efforts in evaluating the growth of such churches. There is an immediate need to understand the complex nature of the Pentecostal churches and how growth is motivated within their congregations. This is only possible if history is documented. Marwick (1989: 14) states that as memory is to the individual, so history is to the community or society. To fully appreciate history, it is necessary to have it recorded, not just for the present but also for future generations. A church may not be able to adequately evaluate its growth or understand itself without recorded history. This fact applies also to Assemblies of God Church (hereafter KAG) as one of the major Pentecostal movements in Kenya and other parts of the world (Anderson, 1992 & 1993; and Saayman, 1993). Recorded history is a treasure to any people, society or organisation (Brumback, 1977:iii). If history is not recorded within the life-span of pioneer members, it is likely that when the pioneers have departed, important information that makes the history complete, may die with them. The KAG church has over three decades worth of history and obviously, most of the pioneer members (both missionaries and nationals) are either gone or leaving the stage, one way or the other. As such, a reflection on its history is timely for the purpose of . evaluating both its growth and significance (cf. McIntire, 1984:40)

Kung’s Theory of Paradigm Shifts in Church History: An Evaluation

The theory of paradigms is a broad subject that has been discussed extensively from various perspectives including science, religion and history. Its strengths and weaknesses have been aptly considered. This research article seeks to investigate the extent of the theory\u27s applicability to church history. The question that we wish to address is: To what extent, is this theory of paradigms applicable in explaining the changes that have taken place through the history of Christianity

Kung’s Theory of Paradigm Shifts in Church History: An Evaluation

The theory of paradigms is a broad subject that has been discussed extensively from various perspectives including science, religion and history. Its strengths and weaknesses have been aptly considered. This research article seeks to investigate the extent of the theory\u27s applicability to church history. The question that we wish to address is: To what extent, is this theory of paradigms applicable in explaining the changes that have taken place through the history of Christianity

’n Psigo-opvoedkundige ondersoek na enkele vooronderstellings en konsepte onderliggend aan die Neurolinguistiese Programmeringsmodel

A psycho-educational investigation into a few suppositions and concepts underlying the Neuro-linguistic Programming model In the early 1970s a model was developed to identify the therapeutic methods that were used by outstanding psychologists. Eventually the so-called Neuro-linguistic Programming (NLP) model was introduced and this model is still used today in many fields such as in psychotherapy with children, in teaching, in the business world and so forth. The purpose of this article is to shed more light on the main presuppositions and concepts underlying the NLP model. This investigation will mainly be undertaken from a psycho-educational perspective. It will, however, also be attempted to concentrate on application possibilities (if any) of NLP concepts, taking a Christian point of departure. The most important NPL concepts will be discussed in relation to children on their way to adulthood, whether they are in therapy or in a classroom situation. In conclusion, while referring to the relevance of NLP in psycho-education, certain transcendental-critical perspectives will be provided concerning the most important concepts and presuppositions of NLP