Anti-oesophageal cancer activity in extracts of deep-water Marion Island sponges
- Authors: Davies-Coleman, Michael T , Froneman, P William , Keyzers, Robert A , Whibley, Catherine , Hendricks, Denver T , Samaai, Toufiek , McQuaid, Christopher D
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6569 , http://hdl.handle.net/10962/d1004132
- Description: Oesophageal cancer is one of the most common causes of cancer-related deaths in South African black males. The limited efficacy of chemotherapeutic agents to treat this disease has prompted a search for potential new chemical entities with anticancer properties. We report here on the evidence for anti-oesophageal cancer activity in the methanolic extracts of five species of sponges dredged from a depth of approximately 100 m in the vicinity of Marion Island in the Southern Ocean during the autumn of 2004.
- Full Text:
- Date Issued: 2005
Progress in ringing : an African experience
- Authors: Lewis, Colin A
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6172 , http://hdl.handle.net/10962/d1012363
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2005
Evolution of Labeo victorianus predates the Pleistocene desiccation of Lake Victoria: evidence from mitochondrial DNA sequence variation
- Authors: Rutaisire, Justus , Booth, Anthony J , Masembe, C , Nyakaana, S , Muwanika, V B
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6762 , http://hdl.handle.net/10962/d1007924
- Description: Geological data show that Lake Victoria dried out some 15 000 years ago. These data suggest that the entire faunal diversity within the lake has evolved since this time. However, mitochondrial DNA sequence diversity in the endemic cyprinid fish, Labeo victorianus, was high (24 haplotypes in 38 individuals; percentage sequence divergence of 0.74%), suggesting that the evolution of this species predates this Late Pleistocene climatological event. This finding is consistent with what has been reported earlier for cichlid fishes in the lake.
- Full Text:
- Date Issued: 2004
The bells of north western Transkei, South Africa
- Authors: Lewis, Colin A
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6183 , http://hdl.handle.net/10962/d1012379 , http://www.ringingworld.co.uk
- Description: [From Introduction] Few of the many visitors to South Africa journey into the isolated country east of Queenstown and south of Elliot, in the rugged basin and range country of that part of the Transkei. That is largely a forgotten land, hidden south of the Mount Arthur range from the rolling grasslands of the Drakensburg foothills and their commercial farms. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2004
Glasbury man made Clyro bells
- Authors: Lewis, Colin A
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6182 , http://hdl.handle.net/10962/d1012377
- Description: [From Introduction] There must have been great excitement in Clyro in 1708. The existing four bells in St Michael's Church were recast by Henry Williams, the bell founder from Glasbury, into a ring of five bells. The work was apparently paid for by the owners of two of the great houses in the parish: Cabalva and Lloyney. Little is known of the four bells that existed in Clyro before Williams began his work, although they appear to have been larger than the five bells cast from their metal. The four bells swung side by side in a wooden frame in the tower of the church. This frame was altered in 1708 to accommodate bells of smaller dimensions and a fifth bell pit was added at right angles to the others. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2003
A scientific note on the natural merger of two honeybee colonies (Apis mellifera capensis)
- Authors: Neumann, Peter , Pirk, Christian W W , Hepburn, H Randall , Radloff, Sarah E
- Date: 2001
- Language: English
- Type: text , Article
- Identifier: vital:6912 , http://hdl.handle.net/10962/d1011875
- Description: Natural mergers of honeybee colonies are commonplace in tropical Africa (Hepburn and Radloff, 1998), but their consequences on organizational structure are unknown. Here we determine the spatial distribution and division of labor of workers (Apis mellifera capensis Esch.) following a merger of two colonies. Two unrelated colonies (each ~3000 bees) were placed in threeframe observation hives. When workers emerged from the sealed brood of each colony, they were individually labeled and reintroduced into their respective mother hives. They are referred to as cohorts Aand B, each comprising 300 workers of the same age. The behaviors and positions of all labeled workers and queens were recorded twice daily for 24 days (Kolmes, 1989; Pirk et al., 2000). On day 14 colony B was dequeened, left its nest and merged with colony A on day 15.
- Full Text:
- Date Issued: 2001
New bells, new founder - Hillandale, South Africa
- Authors: Lewis, Colin A
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6163 , http://hdl.handle.net/10962/d1012350
- Description: On the afternoon of Sunday 2nd May 1999, the first ring of bells cast in Africa, the bells at Hillandale, were rung for the first time. This is the second ring of bells to be installed in an institution established by the Order of the Holy Cross, and the seventh ring in South Africa and the tenth ring in Africa. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 1999
Temporal variability in the effects of grazing by the territorial limpet Patella longicosta on the productivity of the crustose alga Ralfsia verrucosa
- Authors: Kaehler, Sven , Froneman, P William
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6935 , http://hdl.handle.net/10962/d1011956
- Description: This study reports the effects of grazing by the territorial limpet Patella longicosta on the productivity of the encrusting alga Ralfsia verrucosa. Grazing significantly increased algal growth during the first month of the study (August). Simulated grazing by brushing also enhanced productivity. However, the productivity of grazed and ungrazed algae did not differ significantly during the ensuing three months. As the growth of ungrazed plants remained the same throughout the study, the elevated productivity of grazed plants during August was attributed to increased limpet activity. The variation in grazer-induced algal growth was possibly associated with increased feeding when the limpets embark on energetically costly periods of reproduction.
- Full Text: false
- Date Issued: 1999
Testing chemical markers on granivorous birds
- Authors: Steele, G R , Whittington-Jones, Craig A , Craig, Adrian J F K
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6936 , http://hdl.handle.net/10962/d1011957
- Description: We tested two substances (oxytetracycline and rhodamine B) that can be added to food or water of free-living birds, and serve as markers in their plumage for later identification. Oxytetracycline produced no detectable changes in the plumage of red bishops or redbilled queleas. Rhodamine B fed to captive birds produced fluorescence in the wing feathers when viewed under ultraviolet light. This fluorescence lasted for at least 14 weeks, and was retained until feathers were moulted. Rhodamine B may thus be useful in identifying birds using a specific feeding site, and for studies of moult and feather growth.
- Full Text: false
- Date Issued: 1999
The requirements for accurate analysis of pharmaceutical research at South African Universities
- Authors: Haigh, John M , Smith, Eric W
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6367 , http://hdl.handle.net/10962/d1006067
- Description: International Pharmaceutical Abstracts is a valuable database for pharmaceutical research, although the multisiciplinary nature of this field implies that the database should only be the starting point of a search. This database is totally inappropriate for comparing outputs of individual pharmacy teaching institutions.
- Full Text:
- Date Issued: 1998
Bells and bellfounders of the Eastern Cape, South Africa
- Authors: Lewis, Colin A
- Date: 1997
- Language: English
- Type: Article
- Identifier: vital:6179 , http://hdl.handle.net/10962/d1012372 , http://www.ringingworld.co.uk
- Description: [From Introduction] Although there is only one ring of bells in the whole of the Eastern Cape almost every church, and many chapels, have one or more bells. No systematic study of these bells had yet been made, but cursory examination suggests that many British founders exported bells to that area in the late 19th century and in the 20th century. American founders of steel bells also peddled their wares with considerable success. The Irish bell founder: Matthew O'Byrne sold at least five bells to clients in the Eastern Cape, the largest of which weighed 16 cwts. In the 1950s the Swiss founder, Ruetschi, of Aarau, cast at least four beautiful bells that are now in the Transkei. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 1997
The use of wood ash for the protection of stored cowpea seed (Vigna unguiculata (L.) Walp.) against Bruchidae (Coleoptera)
- Authors: Katanga Apuuli, J , Villet, Martin H
- Date: 1996
- Language: English
- Type: Article
- Identifier: vital:6864 , http://hdl.handle.net/10962/d1011196
- Description: Dry wood-ash has been reported to provide effective, cheap and safe control of several pests of stored seeds by providing mechanical protection, especially if it is thoroughly mixed with the seed. Mixtures of seed and either clays, ash, talc, or sand are among the earliest recommendations for controlling bruchids in beans (Metcalf 1917; Headlee 1924; Subramanian 1935; Deay & Amos 1936; Lever 1941). Such use of ash has been reported on subsistence farms in Uganda (Davies 1970). However, little is known of the actual ratios of ash and beans needed for effective protection, or of the mechanism of protection. These issues motivated this investigation.
- Full Text:
- Date Issued: 1996
The effects of elevated and ambient temperature conditions on dilutions of fluocinolone acetonide ointment assessed using the human skin-blanching assay
- Authors: Haigh, John M , Smith, Eric W
- Date: 1995
- Language: English
- Type: text , Article
- Identifier: vital:6380 , http://hdl.handle.net/10962/d1006298
- Description: Topical corticosteroid formulations have been in use now for some 30 years and many methods are available for the in vivo assessment of these preparations. Of all the assays described in the literature, the one first advocated by McKenzie and Stoughton, the so-called vasoconstrictor assay, is one of the most reliable if performed by experienced researchers using - the optimised methodology. Topical application of corticosteroids produces a whitening (blanching) of the skin, the intensity of which is directly proportional to the clinical efficacy of the formulation. Assessment of the degree of blanching produced is therefore of use in determining the rate and extent of corticosteroid release' from the semi-solid base through the stratum corneum. Since it is the degree of blanching which is measured, we prefer to call this test the human skin blanching assay. Some of the main advantages of this assay technique are that normal healthy skin is used therefore persons with dermatological complaints are not compromised, it is not painful for the volunteers, it is non-invasive and several formulations can be evaluated simultaneously. Most commercially available topical corticosteroid preparations have been formulated in such a way as to provide optimum release of the active ingredient from the base through the stratum corneum. Despite this fact, many practitioners often prescribe dilutions of topical corticosteroid formulations, presumably in an effort to reduce the unwanted side effects. This could be problematic; dilution with an incompatible base could destroy the delivery environment thus considerably reducing the efficacy of the formulation. The method of dilution could also play a role in the suitability of the final preparation. The objective of this work was to determine the effects of two different dilutions of fluocinolone ointment at both ambient and elevated temperature on the blanching produced by the dilutions and, by inference, the relative clinical efficacies of these dilutions compared to the full strength product.
- Full Text:
- Date Issued: 1995
Comparative blanching activities of some topical corticosteroid containing lotions
- Authors: Meyer, I , Kanfer, Isadore , Haigh, John M
- Date: 1981
- Language: English
- Type: Article
- Identifier: vital:6398 , http://hdl.handle.net/10962/d1006324
- Description: The blanching activities of Betnovate and Celestoderm-V lotions (betamethasone-17-valerate, 0,1%) and Diprosone lotion (betamethasone dipropionate, 0,55%) were determined by measuring their ability to cause blanching of human skin after topical application. Betnovate and Celestoderm-V lotions produced almost identical blanching profiles. Diprosone lotion displayed a statistically significant superior blanching acitivity over both Betnovate and Celestoderm-V lotions over the whole timespan of the trial.
- Full Text:
- Date Issued: 1981
Le test de McKenzie-Stoughton: méthode de mesure de l’effect réservoir
- Authors: Woodford, R , Haigh, John M , Barry, B W
- Date: 1981
- Language: French
- Type: Article
- Identifier: vital:6448 , http://hdl.handle.net/10962/d1006635
- Description: A la suite de I'observation que firent Mac Kenzie et Stoughton en 1962, montrant que I'application locale de cortico'ldes anti-inflammatoires peut produire un blanchiment de la peau, des tests ont ete mis au point pour apprecier la constitution d'une telle paleur chez des sujets volontaires. Les techniques qui ont ete publiees sont variables quant a la methode d'application (avec ou sans occlusion), la duree d'application du cortico'lde (.c'est-a-dire duree breve de 6 a 8 heures ou prolongee de 16 a 20 heures) et quant a la methode d'appreciation de la reponse, enregistree par exemple comme etant presente ou absente, ou bien cotee, soit avec une simple lecture,. soit avec des lectures repetees, pendant un certain temps. Les auteurs ont mis au point des essais standart de vasoconstriction avec et sans occlusion, pour apprecier les preparations quant a leur efficacite clinique pour determiner la biodisponibilite des cortico'ldes a partir des supports pour applications locales. A condition que I'investigateur et Ie volontaire se conforment strictement au protocole du test les methodes suivantes ont une precision surprenante d'appreciation (Barry et Woodford, 1978).
- Full Text:
- Date Issued: 1981