The significance of the Cape trade route to economic activity in the Cape colony: a medium-term business cycle analysis

Trade is a critical component of economic growth in newly settled societies. This paper tests the impact of ship traffic on the Cape economy using a time series smoothing technique borrowed from the business cycle literature and employing an econometric procedure to test for long-run relationships. The results suggest a strong systematic co-movement between wheat production and ship traffic, with less evidence for wine production and stock herding activities. While ship traffic created demand for wheat exports, the size of the co-movement provides evidence that ship traffic also stimulated local demand through secondary and tertiary sector activities, supporting the hypothesis that ship traffic acted as a catalyst for growth in the Cape economy.Colonial trade, Cape of Good Hope, Dutch East India, Band-pass filter, Medium-term fluctuations, Business cycle, South Africa, Ships, Harvest cycles, Colonial economy

An adaptive neuro fuzzy inference system to model the uniaxial compressive strength of cemented hydraulic backfill

Purpose. The purpose of this paper is to develop the models for predicting the uniaxial compressive strength (UCS) of cemented hydraulic backfill (CHB), a widely used technique for filling underground voids created by mining operations as it provides the high strength required for safe and economical working environment and allows the use of waste rock from mining operations as well as tailings from mineral processing plants as ingredients. Methods. In this study, different modelling techniques such as conventional linear, nonlinear multiple regression and one of the evolving soft computing methods, adaptive neuro fuzzy inference system (ANFIS), were used for the prediction of UCS, the main criterion used to design backfill recipe. Findings. Statistical performance indices used to evaluate the efficiency of the developed models indicated that the ANFIS model can effectively be implemented for designing CHB with desired UCS. As proved by the performance indicators ANFIS model gives more compatible results with the expert opinion and current literature than conventional modelling techniques. Originality. In order to construct the models a very large database, containing more than 1600 UCS test results, was used. In addition to widely used conventional regression based modelling techniques, one of the evolving soft computing methods, ANFIS was employed. Numerical examples showing the implementation of constructed models were provided. Practical implementation. As proved by the statistical performance indicators, the developed models can be used for a reliable prediction of the UCS of CHB. However, more accurate results can be achieved by expanding the database and by constructing improved models using the algorithm presented in this paper.Мета. Побудова моделей для прогнозування межі міцності при одноосьовому стисканні цементної гідравлічної закладки для заповнення вироблених просторів шахт. Методика. Для досягнення поставленої мети були використані різні методи моделювання: лінійна та нелінійна множинна регресія, а також порівняно недавно став популярним метод програмування – адаптивне нейронечітке логічне виведення (ANFIS). За їх допомогою було спрогнозовано зміну міцності на одноосьове стискання, що є ключовим показником для визначення складу закладної суміші. Для побудови моделей використана значна база даних, яка включає результати більш ніж 1600 випробувань на одноосьове стискання. Лабораторними дослідженнями також визначалися властивості закладних матеріалів і суміші. Результати. Модель ANFIS дала найкращу продуктивність з урахуванням статистичних показників ефективності, таких як середня абсолютна процентна похибка і змінний обліковий запис. Статистичні показники продуктивності, які використовуються для оцінки ефективності розроблених моделей, свідчать, що моделювання за допомогою ANFIS дозволяє отримати результати, які більше відповідають експертній оцінці та даним з сучасної літератури, ніж інформація, отримана за допомогою традиційного моделювання. Встановлено, що на відміну від регресивного моделювання, ANFIS не вимагає заздалегідь визначених математичних рівнянь для взаємозв’язку між вхідними та вихідними змінними і використовує наданий набір даних для ефективного визначення структури моделі. Наукова новизна. Вперше для прогнозування міцності при одноосьовому стисканні були використані не лише традиційні способи моделювання, засновані на регресії, а й інноваційний метод програмування – адаптивне нейронечітке логічне виведення ANFIS. У статті наведені чисельні приклади впровадження нових побудованих моделей. Практична значимість. Статистичні індикатори продуктивності показали, що розроблені моделі можуть бути використані для надійного прогнозування міцності при одноосьовому стисканні й оптимальної рецептури закладної суміші. Однак, щоб отримати більш точні результати, необхідно мати більш широку базу даних і створити більш досконалі моделі на основі алгоритму, запропонованому в даній статті.Цель. Построение моделей для прогнозирования предела прочности при одноосном сжатии цементной гидравлической закладки для заполнения выработанных пространств шахт. Методика. Для достижения поставленной цели были использованы различные методы моделирования: линейная и нелинейная множественная регрессия, а также сравнительно недавно ставший популярным метод программирования – адаптивный нейронечеткий логический вывод (ANFIS). С их помощью было спрогнозировано изменение прочности на одноосное сжатие, что является ключевым показателем для определения состава закладочной смеси. Для построения моделей использована обширная база данных, которая включает результаты более чем 1600 испытаний на одноосное сжатие. Лабораторными исследованиями также определялись свойства закладочных материалов и смеси. Результаты. Модель ANFIS дала наилучшую производительность с учетом статистических показателей эффективности, таких как средняя абсолютная процентная погрешность и переменная учетная запись. Статистические показатели производительности, используемые для оценки эффективности разработанных моделей, свидетельствуют, что моделирование с помощью ANFIS позволяет получить результаты, которые более соответствуют экспертной оценке и данным из современной литературы, чем информация, полученная при помощи традиционного моделирования. Установлено, что в отличие от регрессионного моделирования, ANFIS не требует заранее определенных математических уравнений для взаимосвязи между входными и выходными переменными и использует предоставленный набор данных для эффективного определения структуры модели. Научная новизна. Впервые для прогнозирования прочности при одноосном сжатии были использованы не только традиционные способы моделирования, основанные на регрессии, но и инновационный метод программирования – адаптивный нейронечеткий логический вывод ANFIS. В статье приведены численные примеры внедрения новых построенных моделей. Практическая значимость. Статистические индикаторы производительности показали, что разработанные модели могут быть использованы для надежного прогнозирования прочности при одноосном сжатии и оптимальной рецептуры закладочной смеси. Однако, чтобы получить более точные результаты, необходимо иметь более широкую базу данных и создать более совершенные модели на основе алгоритма, предложенного в данной статье.The authors thank the staff and the managers of Jinfeng underground gold mine for their helps and cooperation during field and laboratory studies. The company is also acknowledged for the permission to use and publish the data

Communicative action: the Habermasian and Freirean dialogical approach to participatory communication for social change in a post-1994 South Africa

Despite its almost four decade mainstay, the field of parti-cipatory communication for social change still experiences a definitional and pragmatic problem regarding what exactly participation is (cf. Jacobson & Storey, 2004; Chambers, 1994; Melkote & Steeves, 2001; Rogers, 1976; Lerner, 1964; Schramm, 1964; Servaes, 1995). What remains is a vastly under-theorised field of participatory communication for social change. This article examines the possibility of participatory communication approaching the Habermasian “ideal speech situation” in which people, as communicators, are seen as having a value in their own right and not simply regarded as a means to an end (cf. Habermas, 1984; 1987; 1989). Consistent with the Freirean “liberal pedagogy”, the praxis of dialogical communication or intersubjective communication is seen as putting right the “participative” quality of participatory com-munication (cf. Freire, 1970). For both theorists, transformative action can only occur if reflective and collective learning occurs in linguistically constructed settings where the normative dimensions of truth (logos), rightfulness (ethos) and truthfulness (pathos) are raised and met in the developmental conversation. This is especially significant in a globalised world and fragmented, post-bourgeois public sphere where debate among developmental stakeholders is becoming more marginal, in-strumentalist, and less public. Based on available analyses of development communication literature, this article proposes that the chosen dialogical approaches share a type of communi-cative behaviour (i.e. action theoretic), rather than representing a particular paradigm or school of thought. This could offer further definitional clarification of proper participatory communi-cation for social change in a post-1994 South Africa

Living with Inflammatory Bowel Disease: A review of qualitative research studies

© 2018 Elsevier Ltd Background: Inflammatory Bowel Disease is a chronic, untreatable condition represented by two illnesses, Crohn's and Ulcerative Colitis. Despite high incidence in well-developed industrialised countries, and the significant impact of symptoms on patient's quality of life, little is known about living with Inflammatory Bowel Disease. Aim: To explore the patients’ experiences of living with Inflammatory Bowel Disease. Design: A qualitative systematic review. Data sources: CINAHL, Medline, British Nursing Index and PsycINFO were searched using the following keywords: Inflammatory Bowel Disease AND experiences. We have limited the search to studies published in English from 2000 to 2017. Review method: Thematic synthesis. Results: Data from 23 studies, identified that fatigue, incontinence and uncertainty about future, body image, and lack of information from healthcare professionals dominated the experiences of those living with Inflammatory Bowel Disease. Also, patients living with Inflammatory Bowel Disease were reluctant to disclose their illness due to lack of public awareness and stigma surrounding symptoms. From these, an overarching theme has been identified: Living in isolation and exclusion. Conclusion: Patients with Inflammatory Bowel Disease face a variety of problems, often their priorities and those of healthcare professionals differ greatly. Healthcare professionals have little evidence needed to provide adequate, holistic care to this group. With a rise in the Inflammatory Bowel Disease population in newly industrialised countries it is estimated that the condition is turning into a global disease, potentially making long term care unsustainable. More evidence is needed to understand the concerns of this group

Effect of Irrigation with Diluted Winery Wastewater on the Performance of Two Grass Cover Crops in Vineyards

Pennisetum glaucum L. cv. Babala (pearl millet) established as a summer catch crop followed by Avena sativa L. cv Palinup (oats) established as a winter catch crop were irrigated with winery wastewater diluted to eight chemical oxygen demand (COD) levels ranging between 100 mg/L and 3 000 mg/L. The diluted wastewater treatments were compared to irrigation with river water. The dry matter production (DMP) of oats, if not preceded by pearl millet, tended to improve when irrigated with winery wastewater. Growth of pearl millet peaked during the period when 91% of the diluted winery wastewater was applied. Winery wastewater improved the DMP of pearl millet. No trends were observed in the nutrient levels of the above-ground growth of the two interception crops. However, Na levels increased over time. Using both species, too high levels of macro-nutrients were intercepted, but insignificant amounts of Na were removed. Irrigation with winery wastewater with COD levels between 1 500 mg/L and 2 500 mg/L may be sustainable if only pearl millet is employed as an interception crop. Fertiliser needed to maintain the nutrient balance in the soil resulted in an additional cost of approximately R2 800/ha/yr. However, the fodder may provide an income in excess of R15 000/ha/yr

Yellowfish and Tigerfish Haematology

No Abstrac

Toxicological consequences of pesticidal use in the Republic of South Africa

Chemicals used in agricultural activities, could possibly be the most potent group of compounds used on a regular basis by employees representing a significant fraction of the unskilled, economically active, labour market of a country. Certainly, such a statement will hold true for South Africa and probably for most Third World and developing states. All chemical compounds contain the inherent property of being toxic and/or hazardous. However, pesticides are chemicals intentionally used to kill. They are therefore not avoidable and in contrast to other chemicals are used only because of their ability to kill. As in most other countries in the world, poisoning in the Republic of South Africa is to be expected due to the use of pesticides. In the handling of pesticides, statistics show South Africa to be vulnerable to an appreciable number of deaths and poisoning cases. There could be a number of reasons for this phenomenon, two of them probably being ignorance and negligence on the part of officers in charge of handling pesticides, and perhaps the most important, the exploitation of unskilled labour in applying and handling pesticides. It is believed that the South African agricultural industry represents both the First and Third World and should thus be ideally suited for investigating: (1) acute intoxication due to chemicals used in the agricultural industry. It was found that the annual consumption of pesticides in the Republic of South Africa results in a dose of approximately 250 mg/m² which compares very favourably with consumption rates of developed countries. An analysis of the products registered indicates a total of 1 211 products containing 359 different active ingredients. The three chemical groups responsible for 73% of the poisoning cases (organophosphates 55%, carbamates 14%, organochlorines 4%) are with the exception of pyrethroids, also the chemicals most frequently formulated. Products containing these three chemical groups constitute only 41% of all formulated products, but are responsible for 73% of all intoxications. It is concluded that the poisoning rate by pesticides is appreciably higher than officially notified, and that the fatality rate could be two orders of magnitude higher than developed countries. A compendium - the first of its kind in South Africa for use by hospitals and clinical practitioners and containing trade names, chemical classification, active ingredients, toxicology, symptomatology and proposed treatment procedures for each product, is presented as an appendix. (2) chronic exposure to residues of agricultural products in the diet of South Africans is investigated. Food intake data was calculated from 24-hour dietary recall studies. Residues of only 4 compounds were present in 33 composite, ready-to-eat foods, consisting of 5 538 foodstuffs sampled over a period of one-year country wide, and representing 142 different food items categorised into 11 food groups. The residues found were well within acceptable levels and compare very favourably with those found in the diets of developed countries. It has to be concluded that possible chronic exposure due to agricultural chemical contaminants, to the white population at least, does not exist, and emphasises a sound regulatory policy towards the use of these chemicals in South Africa. (3) a hypothesis of this study that it is not possible that neither the inherent toxicities of pesticidal compounds, nor a paucity of knowledge about the toxicological, chemical and physical properties of these compounds could be mainly responsible for the numerous intoxications recorded annually. An epidemiological 400 case study (descriptive design), investigated the contribution by occupational, environmental, cultural and socio-economic variables to poisoning. The numerous effects by these variables are described and amongst many others, it is concluded that the recommendations of the World Health Organization to classify pesticides by hazard, is confusing to illiterate and semi-educated users and should not be recommended to developing countries