Five thousand years of sustainability? : a case study on Gedeo land use (Southern Ethiopia)

Key words : Ethiopia, Gedeo, ensete , pacemaker , spacemaker , placemaker, agroforest, agro-ecosystem, sustainability, biodiversity.The present volume is a study of an ancient way of land use, over five thousand years old, by the Gedeo in Ethiopia. The densely populated Gedeo country (500 persons per km 2) covers highlands (range 1200 to 3000m asl) between 5 oand 7 oNorth and 38 oand 40 oEast, in the escarpment of the Rift Valley facing Lake Abaya. Based on perennial cropping, emphasis on trees in particular lends the "agroforests" a forest-like appearance. Ensete ( Ensete ventricosum (Welw.) Cheesman Musaceae) and Yirga-Chaffee, one of the world's renowned cultivars of Coffea arabica L. Rubiaceae, is grown under these trees. Largely due to their unique cropping system, the Gedeo are immune to soil erosion and famines, ravaging the Ethiopian highlands at intervals. The central theme of the present ecological study is to understand theoretical and practical aspects of the holistic Gedeo land use better, and to contribute to the design capability of the farmers. Theoretically, farm design is examined from the perspective of forest ecology. The concepts of eco-unit and agro/silvatic mosaic , at the lowest and highest levels, respectively, provide more insight in agroforests as blocks of forests, with humans assuming the roles performed by some natural forces in forests. Therefore, these agroforests remain multivalent resources. Empirically, the design is examined as farmers' day-to-day management of these resources. The study provides a strong theoretical basis in favor of Gedeo land use with its complex mix of elements to represent a multiple purpose land use from which modern day agriculture and forestry emerged as overspecialized offshoots. Gedeo land use harmonises aspects of production and protection. Agroforest components are divided into core and subsidiary components. The first type has a pacemaker role (regulation of agro-ecosystem rhythm), a spacemaker role (provision of biotope space for other crops) and/or a placemaker role (provision of living space, or niches for other organisms). Ensete and various multipurpose tree species fulfil the latter function. Annual crops, the coffee or farm animals are regarded as "fillers". Ensete , with its anatomical water-stocking and storage mechanisms and with its fibrous root system forming a mat-like structure 30 to 60 cm deep which on decomposition yields organic matter for soil maintenance, is more than a mere crop. The higher carrying capacity of Gedeo "agroforests" is traced back to the high productivity of ensete (over 5.6 tons ha -1year -1) and judicious use of accompanying crops. It has been found that six mature ensete plants ( gantticho type) feed an adult during a year. A farm household of seven persons then needs an area of no more than 0.2 hectare for a sustainable yearly supply of 42 ensete plants, gantticho type. Management is based on either single or multiple rotations. The latter is explained, using ensete as an example. Analyses revealed that the soils are clay-loam, their pH (H 2 O) ranging between 5 and 6. The limiting factor is available phosphorus (range 1.0 to 4.0 ppm). Organic matter (%) ranged between 4 and 5, total nitrogen (%) between 0.3 to 0.5, and cation exchange capacity (meq/100g soil) from 21.0 to 25.0. Gedeo soil management is organic, using as inputs crop by-products, leaf litter from multipurpose trees and "weeds", domestic wastes, rotation of dwelling sites and farmyard manure. In achieving sustained products and services from "agroforest" components, farmers' effort is mainly directed at optimisation of the interrelationships among diverse components. Number and/or mass of "agroforest" components to be harvested and planted are balanced. This fully corresponds to the Central-European concept of sustained yield forestry. No organism is intrinsically harmful to the farmers. The weedy flora, for instance, is used to protect future yield, first by providing physical cover to the soil, second by conserving soil nutrients in its biomass, later to be released to "crop" plants by mulching the weedy biomass.Gedeo land use contains elements of shifting cultivation, the basis of farmers' management at the level of an agro/silvatic-mosaic . Like in shifting cultivation, vegetation is used to regenerate exhausted land. However, unlike in shifting cultivation, this enables production and regeneration, simultaneously. Whereas shifting cultivators burn and convert mature forest plots, the Gedeo synchronize harvest and replanting. In this way, continuous use of the same plot of land is ensured indefinitely. It is concluded that this way of land use is best suited to the mountainous terrain of the Gedeo country. It is argued that through the judicious use of high-yielding and environment-friendly ensete , subsistence agriculture can stave off the recurring famine and drought-ridden image of Ethiopia. The level of employment provided by Gedeo "agroforests" is declining as a result of growing population. Therefore, there is an urgent need for assistance. The present productivity of these systems can be enhanced by carefully redesigning existing composting processes. Finding better marketing channels for the produce of the "agroforests" is a priority in the short term. Thus, organically grown arabica coffee from the Gedeo "agroforests" should be certified and processed in situ . Unused biotopes for integrating components in the system still exist or can be opened up in Gedeo "agroforests", e.g., for a multipurpose tree species such as Morinaga sp. (locally called shiferaw ), a leguminous timber tree, the leaves of which are eaten as a vegetable. Diverse species of wild mushrooms can be domesticated. Generally, ways and means should be found for cultivation of miniature crops of high value in the soil and the canopy, particularly tiny organisms such as nitrogen-processing bacteria, mycorrhizal and edible fungi (diverse mushrooms) or medicinal lichens. The Rift Valley and its inhabitants were a source of civilized human development for millennia. The present study demonstrates that principles of sustainability were successfully woven in at least some of their societies. This book therefore advocates building on this basis by studying and teaching these principles as a base for new, sustainable land use design in the Twenty First Century

Comparative in vitro transportation of pentamidine across the blood-brain barrier using polycaprolactone nanoparticles and phosphatidylcholine liposomes

Nanoparticles (NPs) have gained importance in addressing drug delivery challenges across biological barriers. Here, we reformulated pentamidine, a drug used to treat Human African Trypanosomiasis (HAT) in polymer based nanoparticles and liposomes and compared their capability to enhance pentamidine penetration across blood brain barrier (BBB). Size, polydispersity index, zeta potential, morphology, pentamidine loading and drug release profiles were determined by various methods. Cytotoxicity was tested against the immortalized mouse brain endothelioma cells over 96 h. Moreover, cells monolayer integrity and transportation ability were examined for 24 h. Pentamidine-loaded polycaprolactone (PCL) nanoparticles had a mean size of 267.58, PDI of 0.25 and zeta potential of –28.1 mV and pentamidine-loaded liposomes had a mean size of 119.61 nm, PDI of 0.25 and zeta potential 11.78. Pentamidine loading was 0.16 µg/mg (w/w) and 0.17 µg/mg (w/w) in PCL NPs and liposomes respectively. PCL nanoparticles and liposomes released 12.13% and 22.21% of pentamidine respectively after 24 h. Liposomes transported 87% of the dose, PCL NPs 66% of the dose and free pentamidine penetration was 63% of the dose. These results suggest that liposomes are comparatively promising nanocarriers for transportation of pentamidine across BBB

A post-market quality assessment of first-line, fixed-dose combination antiretrovirals in South Africa

South Africa has the world’s largest antiretroviral (ARV) program and despite having stringent upstream medicine’s regulatory oversight, the post-market reassessment of ARV quality is prohibitively resource intensive. The aim of this study was to evaluate and compare the post-market quality of four fixed-dose combination (FDC) generics containing efavirenz (EFV) 600 mg, emtricitabine 200 mg, and tenofovir 300 mg against the innovator, Atripla® and according to the International Pharmacopoeia (IP). Generic tablet samples, sourced from a South African provincial depot, were subjected to the identification, content assay, dissolution, uniformity of weight and disintegration tests. An in-house reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated in lieu of the RP-HPLC IP method which proved to be unsuitable. All samples passed the identification, assay, uniformity of weight and disintegration tests and one generic FDC failed the dissolution test (at both stage 1 and 2), releasing 62.23% (standard deviation 20.43) of EFV in 30 minutes. One generic first-line ARV combination that is currently supplied to the South African public health sector was found to be substandard and this reinforces the need for routine ARV post-market surveillance, as well as reliable compendial methods to facilitate this undertaking

Intrinsic and Synthetic Stable Isotope Marking of Tsetse Flies

The sterile insect technique has been successfully used to eliminate tsetse populations in a number of programs. Program monitoring in the field relies on the ability to accurately differentiate released sterile insects from wild insects so that estimates can be made of the ratio of sterile males to wild males. Typically, released flies are marked with a dye, which is not always reliable. The difference in isotopic signatures between wild and factory-reared populations could be a reliable and intrinsic secondary marker to complement existing marking methods. Isotopic signatures are natural differences in stable isotope composition of organisms due to discrimination against the heavier isotopes during some biological processes. As the isotopic signature of an organism is mainly dependent on what it eats; by feeding factory-reared flies isotopically different diets to those of the wild population it is possible to intrinsically mark the flies. To test this approach unlabeled samples of Glossina pallidipes (Austen) (Diptera: Glossinidae) from a mass rearing facility and wild populations were analyzed to determine whether there were any natural differences in signatures that could be used as markers. In addition experiments were conducted in which the blood diet was supplemented with isotopically enriched compounds and the persistence of the marker in the offspring determined. There were distinct natural isotopic differences between factory reared and wild tsetse populations that could be reliably used as population markers. It was also possible to rear artificially isotopically labeled flies using simple technology and these flies were clearly distinguishable from wild populations with greater than 95% certainty after 85 days of “release”. These techniques could be readily adopted for use in SIT programs as complimentary marking techniques

Improvements to a key contributor of frequency control : the co-ordination of guide vane operation in a pumped storage plant

Includes bibliographical references.The South African grid has been experiencing small reserve margins from 2008 and this will continue until the new power stations are integrated onto the grid. This is a time where the frequency control performance has become an important indicator to see how the power plants are able to deal with the restoration of frequency specifically during peak times. A study was done to identify the systems/aspects which at the time contribute a considerable amount to frequency control or could affect frequency in the medium to long term. From this, the co-ordination of the guide vanes at pumped storage plants was selected. Pumped storage units exhibit a non-minimum phase characteristic which can negatively affect the frequency response on the grid. Attempts were made to improve this system’s contribution to frequency control. To achieve this, the main waterway, including surge tank and guide vanes of a pumped storage station were modelled in a thermal-hydraulic simulation environment. With the model it was possible to realise the reverse power phenomenon inherent in pumped storage plants. The model was validated with similar studies in the literature and pumped storage plant data. A selection of scenarios with various guide vane operation techniques were proposed to improve the performance of two connected units during load changes. Some of the techniques produced improvement in the reverse power characteristic while others produced deterioration in the performance due to coupling of the unit using a common penstock but enjoyed an improvement in the plant net output. The study showed that it is possible to reproduce the non-minimum phase characteristic of a pumped storage plant using thermal-hydraulic models, and that various control schemes can be tested using the model. This paves the way for more elaborate control scheme evaluations, including those that look at coordination of all the pumped storage plants on a network

The effects of social media on the revitalisation of feminism and coloured women's identity politics

Thesis (MA)--Stellenbosch University, 2019.ENGLISH ABSTRACT: Despite the movement towards cultivating a democracy since 1994, South Africa is a country which still faces many challenges as a result of political and racial remnants of the Apartheid regime. With Apartheid’s segregating classification system etched in the minds of South Africans, a sense of hierarchal and binary thinking is still present. Today, Coloured women remain a marginalised demographic, due to longstanding racial and cultural stereotypes, deprecating visual representations, and media’s capacity to perpetuate and normalises these limiting typecasts. This marginalised demographic has recently begun to re-negotiate female Coloured identity norms across contemporary visual platforms of representation, specifically within the social media space. The purpose of this study is to investigate the postfeminist digital manifestation and reproduction of cultural, racial, sexual, gendered and religious identities within the social media domain, with specific reference to three Coloured South African women, namely Patty Monroe, Aisha Baker and Kim Windvogel. This study is approached from a mixed-methods perspective, employing an interpretive process of gathering and analysing data. This process involved a voluntary electronic survey which circulated online via snowball sampling methods, visual content analyses of social media posts, and structured interviews with case study individuals. The investigation highlighted themes regarding self-representation and self-presentation, submission and subversion, and agency, sexual responsibility and gender. This exploration of online visual depictions of Coloured South African women is an attempt to ascertain the existence of a postfeminist rhetoric that is a revitalisation (rather than a rejection) of the traditional feminist ethos. Issues surrounding private and public, exposure and concealment, and sexuality and modesty also emerged during the data analysis process. My findings include that a postfeminist rhetoric, which is an acknowledgement of and expansion upon classic feminist ideals, does exist. Imagery that employs this rhetoric provides a new means of representivity and an affirmative narrative for Coloured South African women; a contemporary way of seeing beyond longstanding, limiting racial and cultural representations. This rhetoric is arguably progressing towards a more intersectional approach to Coloured womanhood. It is further suggested that that an intersectional feminism, which adopts a sense of interdisciplinarity, be the next wave of enquiry when researching the Coloured demographic.AFRIKAANSE OPSOMMING: Suid-Afrika poog sedert 1994 om ‘n demokrasie in stand te hou, maar ten spyte hiervan, word die land steeds daagliks met talle kwessies van die verlede gekonfronteer. Hierdie kwessies hou verband met die politiek en rassisme wat gepaardgaan met die Apartheidsregime. Suid-Afrikaners het steeds ‘n sterk geheue van die segregasie-klassifikasiesisteem van Apartheid wat daartoe bydra dat daar steeds in ons hedendaagse samelewing ‘n teenwoordigheid van hiërargiese en binêre sienswyses is. In die Suid-Afrikaanse samelewing word kleurlingvroue as gevolg van jarelange rasse- en kulturele stereotipes steeds as ‘n gemarginaliseerde gemeenskap gesien. Dit word versterk deur verskeie visuele uitbeeldings wat afkeurend van aard is en die media wat die beperkende rolle van kleurlingvroue normaliseer. Ondanks die struikelblokke het hierdie gemarginaliseerde gemeenskap onlangs begin om hierdie identiteitsnorme van kleurlingvroue deur middel van kontemporêre visuele platvorms binne die sosialemedia-ruimte te herskep. Die doel van hierdie studie is om ondersoek in te stel na die postfeministiese digitale manifestasies en hoe kulturele, rasse, seksuele, geslag en religieuse identiteite binne die sosialemediagemeenskap herskep word. Die drie kleurlingvroue wat die fokus van hierdie studie is, is Patty Monroe, Aisha Baker en Kim Windvogel. Die studie word benader vanuit ‘n gemengde-metode studieperspektief en behels ‘n interpretatiewe proses van dataversameling en –analise. ‘n Vrywillige elektroniese opname wat aanlyn via ‘n sneeubal-streekproef gesirkuleer het, asook visuele inhoudsanalises en gestruktureerde onderhoude met die betrokke individue word by dié proses ingesluit. Hierdie studie beklemoon verder verskeie kwessies soos selfuitbeelding en –aanbieding, onderdanigheid en ondermyning, en seksuele verantwoordelikheid en geslag. Die ondersoek na aanlyn visuele uitbeeldings van kleurlingvroue in die Suid-Afrikaanse gemeenskap poog om die bestaan van ‘n postfeministiese retoriek as ‘n herlewing — eerder as ‘n verwerping — van die trandisionele, feministiese etos vas te stel. Tydens die data-analise proses is verskeie ander kwessies aangeraak wat handel oor privaatheid en publiek, blootstelling en verbloeming, en seksualiteit en diskresie. Die bevindings van hierdie studie is dat ‘n postfeministiese retoriek, wat ‘n erkenning en uitbreiding van klassieke feministiese ideale is, steeds bestaan. Beelde wat hierdie retoriek bewerkstellig bied ‘n nuwe manier van Stellenbosch University https://scholar.sun.ac.za iv teenwoordigheid en ‘n regstellende narratief vir Suid-Afrikaanse kleurlingvroue aan — ‘n hedendaagse manier om verby jarelange, beperkende rasse- en kulturele uitbeeldings te kyk. Hierdie retoriek is sistematies besig om te ontwikkel tot ‘n interseksionele benadering van kleurling vroulikheid. Verder word voorgestel dat interseksionele feminisme, wat ‘n gevoel van interdissiplinariteit gee, die volgende groot onderwerpskwessie sal wees wanneer daar navorsing gedoen word oor die demografie van kleurlingvroue in Suid-Afrika

Five thousand years of sustainability? : a case study on Gedeo land use (Southern Ethiopia)

Key words : Ethiopia, Gedeo, ensete , pacemaker , spacemaker , placemaker, agroforest, agro-ecosystem, sustainability, biodiversity.The present volume is a study of an ancient way of land use, over five thousand years old, by the Gedeo in Ethiopia. The densely populated Gedeo country (500 persons per km 2) covers highlands (range 1200 to 3000m asl) between 5 oand 7 oNorth and 38 oand 40 oEast, in the escarpment of the Rift Valley facing Lake Abaya. Based on perennial cropping, emphasis on trees in particular lends the "agroforests" a forest-like appearance. Ensete ( Ensete ventricosum (Welw.) Cheesman Musaceae) and Yirga-Chaffee, one of the world's renowned cultivars of Coffea arabica L. Rubiaceae, is grown under these trees. Largely due to their unique cropping system, the Gedeo are immune to soil erosion and famines, ravaging the Ethiopian highlands at intervals. The central theme of the present ecological study is to understand theoretical and practical aspects of the holistic Gedeo land use better, and to contribute to the design capability of the farmers. Theoretically, farm design is examined from the perspective of forest ecology. The concepts of eco-unit and agro/silvatic mosaic , at the lowest and highest levels, respectively, provide more insight in agroforests as blocks of forests, with humans assuming the roles performed by some natural forces in forests. Therefore, these agroforests remain multivalent resources. Empirically, the design is examined as farmers' day-to-day management of these resources. The study provides a strong theoretical basis in favor of Gedeo land use with its complex mix of elements to represent a multiple purpose land use from which modern day agriculture and forestry emerged as overspecialized offshoots. Gedeo land use harmonises aspects of production and protection. Agroforest components are divided into core and subsidiary components. The first type has a pacemaker role (regulation of agro-ecosystem rhythm), a spacemaker role (provision of biotope space for other crops) and/or a placemaker role (provision of living space, or niches for other organisms). Ensete and various multipurpose tree species fulfil the latter function. Annual crops, the coffee or farm animals are regarded as "fillers". Ensete , with its anatomical water-stocking and storage mechanisms and with its fibrous root system forming a mat-like structure 30 to 60 cm deep which on decomposition yields organic matter for soil maintenance, is more than a mere crop. The higher carrying capacity of Gedeo "agroforests" is traced back to the high productivity of ensete (over 5.6 tons ha -1year -1) and judicious use of accompanying crops. It has been found that six mature ensete plants ( gantticho type) feed an adult during a year. A farm household of seven persons then needs an area of no more than 0.2 hectare for a sustainable yearly supply of 42 ensete plants, gantticho type. Management is based on either single or multiple rotations. The latter is explained, using ensete as an example. Analyses revealed that the soils are clay-loam, their pH (H 2 O) ranging between 5 and 6. The limiting factor is available phosphorus (range 1.0 to 4.0 ppm). Organic matter (%) ranged between 4 and 5, total nitrogen (%) between 0.3 to 0.5, and cation exchange capacity (meq/100g soil) from 21.0 to 25.0. Gedeo soil management is organic, using as inputs crop by-products, leaf litter from multipurpose trees and "weeds", domestic wastes, rotation of dwelling sites and farmyard manure. In achieving sustained products and services from "agroforest" components, farmers' effort is mainly directed at optimisation of the interrelationships among diverse components. Number and/or mass of "agroforest" components to be harvested and planted are balanced. This fully corresponds to the Central-European concept of sustained yield forestry. No organism is intrinsically harmful to the farmers. The weedy flora, for instance, is used to protect future yield, first by providing physical cover to the soil, second by conserving soil nutrients in its biomass, later to be released to "crop" plants by mulching the weedy biomass.Gedeo land use contains elements of shifting cultivation, the basis of farmers' management at the level of an agro/silvatic-mosaic . Like in shifting cultivation, vegetation is used to regenerate exhausted land. However, unlike in shifting cultivation, this enables production and regeneration, simultaneously. Whereas shifting cultivators burn and convert mature forest plots, the Gedeo synchronize harvest and replanting. In this way, continuous use of the same plot of land is ensured indefinitely. It is concluded that this way of land use is best suited to the mountainous terrain of the Gedeo country. It is argued that through the judicious use of high-yielding and environment-friendly ensete , subsistence agriculture can stave off the recurring famine and drought-ridden image of Ethiopia. The level of employment provided by Gedeo "agroforests" is declining as a result of growing population. Therefore, there is an urgent need for assistance. The present productivity of these systems can be enhanced by carefully redesigning existing composting processes. Finding better marketing channels for the produce of the "agroforests" is a priority in the short term. Thus, organically grown arabica coffee from the Gedeo "agroforests" should be certified and processed in situ . Unused biotopes for integrating components in the system still exist or can be opened up in Gedeo "agroforests", e.g., for a multipurpose tree species such as Morinaga sp. (locally called shiferaw ), a leguminous timber tree, the leaves of which are eaten as a vegetable. Diverse species of wild mushrooms can be domesticated. Generally, ways and means should be found for cultivation of miniature crops of high value in the soil and the canopy, particularly tiny organisms such as nitrogen-processing bacteria, mycorrhizal and edible fungi (diverse mushrooms) or medicinal lichens. The Rift Valley and its inhabitants were a source of civilized human development for millennia. The present study demonstrates that principles of sustainability were successfully woven in at least some of their societies. This book therefore advocates building on this basis by studying and teaching these principles as a base for new, sustainable land use design in the Twenty First Century

Ace Kings tenor saxophonist, Kippie Moekesti

Kippie Moekesti passinonately playing his tener saxophone.Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD

Dual-drug co-crystal synthesis for synergistic in vitro effect of three key first-line antiretroviral drugs

Two pharmaceutical solid state co-crystals EFZA and NEF of two non-nucleoside reverse transcriptase inhibitors (efavirenz, EFV and nevirapine, NVP) and a nucleoside reverse transcriptase inhibitor, zidovudine (AZT) were prepared. Currently, these drugs are essential in various front-line HIV treatment regimens due to their potential in the management of HIV infection. Solid-state principles and solvent-assisted grinding were used for screening of co-crystal preparation. Characterization was carried out using DSC, HSM and TGA, then complimented by FT-IR spectral data and powder X-ray diffraction. HPLC analysis was used for a solubility assays. Both co-crystals indicated different thermal behaviour compared to the individual drug components. Differences in vibrational modes within the spectral region and the unique powder X-ray patterns confirmed the identity of EFZA and NEF as new molecular derivatives. Quantitative studies using HPLC indicated an enhanced solubility of the co-crystals at different pH values compared to the parent compounds; thus making these interesting candidates for future formulation6

Radargrammetry helps fight hunger in Ethiopia

This paper reports the operational implementation of radargrammetry for the production of Digital Elevation Models, or DEMs, to areas of rugged topography. The Southern Ethiopian Highlands east of lake Abaya, with elevations between ca. 900 and 4,400 meters, were mapped. Currently available topographical maps are of insufficient quality to assist a study of the area's unique land use system, which is arguably the oldest and most durably sustained land use system of the planet. Without external inputs or terracing, the land use system maintains soil fertility and staves-off hunger. It has been doing so during the past 30 years of unrest and civil war, in one of the most crowded regions of Ethiopia. However, the central role of the staple crop enset within the land use system and its production cycles has hardly been the subject of scientific study. Understanding of this system is most likely to be relevant to enhancement of health and productivity in many regions of the world. Upon the request of the Agricultural Bureau for Gedeo Zone, geocoded and georeferenced topographical maps with accuracy of 20 meters (x, y and z) were made by PRIVATEERS N.V. on the basis of RADARSAT multiincidence (S2/S7) images. These maps are now incorporated as the basic layer within the Bureau's GIS system. Map production techniques proved to be cost effective and relevant; especially for mountainous areas with poor accessability where correct geographic information is not available. The ease of orientation proved of invaluable help to rationalize execution and planning of cost-effective environmental field work and reporting