Quantification of corticosteroid-induced skin vasoconstriction: visual ranking, chromameter measurement or digital image analysis
- Smith, Eric W, Haigh, John M, Surber, Christian
- Authors: Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 2002
- Language: English
- Type: text , Article
- Identifier: vital:6427 , http://hdl.handle.net/10962/d1006564
- Description: Topical corticosteroid formulations have been evaluated by visual grading protocols for many years. Toward a more objective methodology, several instrumental methods have been evaluated for applicability in quantifying the vasoconstriction side-effect that follows corticosteroid application to the skin. Although the chromameter has been adopted by regulatory bodies throughout the world as the current standard for topical bioequivalence determinations, there is considerable criticism of this instrument from several quarters. A preliminary comparison reported here indicates that digital image analysis provides statistically significant results that are similar to those obtained by visual assessment techniques, and shows considerably greater precision than that obtained by the chromameter. Continued evaluation of objective assessment techniques, such as digital imaging, and continued modernisation of regulatory bioequivalence requirements will assist in protecting patients and optimising clinical results.
- Full Text:
- Authors: Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 2002
- Language: English
- Type: text , Article
- Identifier: vital:6427 , http://hdl.handle.net/10962/d1006564
- Description: Topical corticosteroid formulations have been evaluated by visual grading protocols for many years. Toward a more objective methodology, several instrumental methods have been evaluated for applicability in quantifying the vasoconstriction side-effect that follows corticosteroid application to the skin. Although the chromameter has been adopted by regulatory bodies throughout the world as the current standard for topical bioequivalence determinations, there is considerable criticism of this instrument from several quarters. A preliminary comparison reported here indicates that digital image analysis provides statistically significant results that are similar to those obtained by visual assessment techniques, and shows considerably greater precision than that obtained by the chromameter. Continued evaluation of objective assessment techniques, such as digital imaging, and continued modernisation of regulatory bioequivalence requirements will assist in protecting patients and optimising clinical results.
- Full Text:
The toxicity of zinc to a selected macroinvertebrate, Adenophlebia auriculata (Ephemeroptera, Leptophlebiidae) method development
- Everitt, Victoria J, Scherman, Patricia A, Villet, Martin H
- Authors: Everitt, Victoria J , Scherman, Patricia A , Villet, Martin H
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442370 , vital:73979 , https://doi.org/10.2989/16085914.2002.9626572
- Description: The South African water quality guidelines for the protection of the aquatic environment are constantly being updated. The Centre for Aquatic Toxicology of the Institute for Water Research, Rhodes University, uses artificial streams and toxicological methods to contribute to the development and refinement of these guidelines. This study involved the use of 96-hour acute toxicity tests, using zinc sulphate as the toxicant, to determine the suitability of Adenophlebia auriculata as a potential indicator species of zinc pollution. As it is known that experimental environments (e.g. still versus flowing water systems) can influence the tolerance of a test species, the experimental system most suited to this species' abiotic requirements was determined. Static and recirculating systems were compared, with LC50 values calculated for the static systems being 91% lower than those calculated for the recirculating systems. The increased sensitivity to the toxicant under static conditions may be due to the animals being additionally stressed by the less favourable static environment. This suggests that recirculating systems are more suited for toxicity tests using this mayfly. Adenophlebia auriculata appears to be tolerant to zinc when compared to zinc LC50 values for other test species in the literature, and may therefore not be a suitable indicator of zinc pollution in an aquatic environment.
- Full Text:
- Authors: Everitt, Victoria J , Scherman, Patricia A , Villet, Martin H
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442370 , vital:73979 , https://doi.org/10.2989/16085914.2002.9626572
- Description: The South African water quality guidelines for the protection of the aquatic environment are constantly being updated. The Centre for Aquatic Toxicology of the Institute for Water Research, Rhodes University, uses artificial streams and toxicological methods to contribute to the development and refinement of these guidelines. This study involved the use of 96-hour acute toxicity tests, using zinc sulphate as the toxicant, to determine the suitability of Adenophlebia auriculata as a potential indicator species of zinc pollution. As it is known that experimental environments (e.g. still versus flowing water systems) can influence the tolerance of a test species, the experimental system most suited to this species' abiotic requirements was determined. Static and recirculating systems were compared, with LC50 values calculated for the static systems being 91% lower than those calculated for the recirculating systems. The increased sensitivity to the toxicant under static conditions may be due to the animals being additionally stressed by the less favourable static environment. This suggests that recirculating systems are more suited for toxicity tests using this mayfly. Adenophlebia auriculata appears to be tolerant to zinc when compared to zinc LC50 values for other test species in the literature, and may therefore not be a suitable indicator of zinc pollution in an aquatic environment.
- Full Text:
Africa as Renaissance: grotesque John Skelton's 1485 version of Diodorus Siculus
- Authors: Van Wyk Smith, Malvern
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457446 , vital:75638 , https://journals.co.za/doi/pdf/10.10520/AJA1011582X_161
- Description: Diodorus Siculus was a Sicilian Greek who round about the middle of the century before ChrISt'S birth began a mammoth history of the Mediterranean world that in its complete state of 40 books, mostly now lost, stretched from the legendary past down to Diodorus's own times. Of his Bibliotheca Historica, or Library of History, now only Books 1-5 and 11-20 survive, plus some fragments and paraphrases in other collections. The survival of the first five books, however, is particularly fortunate for my purposes, for this is the part in which Diodorus offers a seamless blend of legend and history to explain the origins of the peoples of the Mediterranean and adjacent parts.
- Full Text:
- Authors: Van Wyk Smith, Malvern
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457446 , vital:75638 , https://journals.co.za/doi/pdf/10.10520/AJA1011582X_161
- Description: Diodorus Siculus was a Sicilian Greek who round about the middle of the century before ChrISt'S birth began a mammoth history of the Mediterranean world that in its complete state of 40 books, mostly now lost, stretched from the legendary past down to Diodorus's own times. Of his Bibliotheca Historica, or Library of History, now only Books 1-5 and 11-20 survive, plus some fragments and paraphrases in other collections. The survival of the first five books, however, is particularly fortunate for my purposes, for this is the part in which Diodorus offers a seamless blend of legend and history to explain the origins of the peoples of the Mediterranean and adjacent parts.
- Full Text:
Campaigns Bulletin : The government is starving us to death!
- SAMWU
- Authors: SAMWU
- Date: May 2001
- Subjects: SAMWU
- Language: English, Zulu, Swati, Xhosa, sePedi, seSotho and Afrikaans
- Type: text
- Identifier: http://hdl.handle.net/10962/113537 , vital:33799
- Description: The wage talks are resuming on May 8th 2001. At the time of going to print, all provinces were holding marches all over the country to highlight our demands for a living wage. Currently on the table is a proposal by the conciliator that all parties should agree to accept an 8% across the board increase, and an increase in the minimum wage to R1900. Firstly this proposal has not yet been accepted by the employer. At the conciliation, the employer stuck to 5% only. Secondly this falls short of our demand. It means we will not get the R300 across the board. Any worker earning below R3800 per month is going to get an increase of less than R300. The hardest hit will be workers earning from R1700 - R3000 who will only get R136 - R240. There is nothing more we can get from conciliation or negotiations. It is now up to YOU the workers to decide if you will accept the 8% offer put on the table by the conciliator!
- Full Text:
- Authors: SAMWU
- Date: May 2001
- Subjects: SAMWU
- Language: English, Zulu, Swati, Xhosa, sePedi, seSotho and Afrikaans
- Type: text
- Identifier: http://hdl.handle.net/10962/113537 , vital:33799
- Description: The wage talks are resuming on May 8th 2001. At the time of going to print, all provinces were holding marches all over the country to highlight our demands for a living wage. Currently on the table is a proposal by the conciliator that all parties should agree to accept an 8% across the board increase, and an increase in the minimum wage to R1900. Firstly this proposal has not yet been accepted by the employer. At the conciliation, the employer stuck to 5% only. Secondly this falls short of our demand. It means we will not get the R300 across the board. Any worker earning below R3800 per month is going to get an increase of less than R300. The hardest hit will be workers earning from R1700 - R3000 who will only get R136 - R240. There is nothing more we can get from conciliation or negotiations. It is now up to YOU the workers to decide if you will accept the 8% offer put on the table by the conciliator!
- Full Text:
Campaigns Bulletin : The government is starving us to death!
- SAMWU
- Authors: SAMWU
- Date: May 2001
- Subjects: SAMWU
- Language: English, Zulu, Swati, Xhosa, sePedi, seSotho and Afrikaans
- Type: text
- Identifier: http://hdl.handle.net/10962/113438 , vital:33775
- Description: The wage talks are resuming on May 8th 2001. At the time of going to print, all provinces were holding marches all over the country to highlight our demands for a living wage. Currently on the table is a proposal by the conciliator that all parties should agree to accept an 8% across the board increase, and an increase in the minimum wage to R1900. Firstly this proposal has not yet been accepted by the employer. At the conciliation, the employer stuck to 5% only. Secondly this falls short of our demand. It means we will not get the R300 across the board. Any worker earning below R3800 per month is going to get an increase of less than R300. The hardest hit will be workers earning from R1700 - R3000 who will only get R136 - R240. There is nothing more we can get from conciliation or negotiations. It is now up to YOU the workers to decide if you will accept the 8% offer put on the table by the conciliator!
- Full Text:
- Authors: SAMWU
- Date: May 2001
- Subjects: SAMWU
- Language: English, Zulu, Swati, Xhosa, sePedi, seSotho and Afrikaans
- Type: text
- Identifier: http://hdl.handle.net/10962/113438 , vital:33775
- Description: The wage talks are resuming on May 8th 2001. At the time of going to print, all provinces were holding marches all over the country to highlight our demands for a living wage. Currently on the table is a proposal by the conciliator that all parties should agree to accept an 8% across the board increase, and an increase in the minimum wage to R1900. Firstly this proposal has not yet been accepted by the employer. At the conciliation, the employer stuck to 5% only. Secondly this falls short of our demand. It means we will not get the R300 across the board. Any worker earning below R3800 per month is going to get an increase of less than R300. The hardest hit will be workers earning from R1700 - R3000 who will only get R136 - R240. There is nothing more we can get from conciliation or negotiations. It is now up to YOU the workers to decide if you will accept the 8% offer put on the table by the conciliator!
- Full Text:
Changes in the abundance of cells in the anterior pituitary gland and the possible roles of luteinizing hormone, prolactin and progesterone in the control of delayed implantation in the straw-coloured fruit bat (Eidolon helvum)
- Simbauni, J A, Bernard, Ric T F
- Authors: Simbauni, J A , Bernard, Ric T F
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447131 , vital:74586 , https://doi.org/10.1080/15627020.2001.11657115
- Description: Eidolon helvum (Megachiroptera) is a large frugivorous bat found in equatorial and tropical Africa. The reproductive cycle is characterized by a three-month period of delayed implantation and the total length of pregnancy may be as much as 10 months. A histochemical study of the gonadotrophs and mammotrophs of the anterior pituitary, in conjunction with assays of LH-like, progesterone-like and prolactin-like immunoreactivity in the plasma suggest that during delayed implantation the gonadotrophs were inactive while the mammotrophs were active and plasma PRL-like immunoreactivity high. We interpret this as indicating that, in the straw-coloured fruit bat, implantation was inhibited by high levels of prolactin and, as such, the endocrine control of delayed implantation may be quite different from that described for other mammals.
- Full Text:
- Authors: Simbauni, J A , Bernard, Ric T F
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447131 , vital:74586 , https://doi.org/10.1080/15627020.2001.11657115
- Description: Eidolon helvum (Megachiroptera) is a large frugivorous bat found in equatorial and tropical Africa. The reproductive cycle is characterized by a three-month period of delayed implantation and the total length of pregnancy may be as much as 10 months. A histochemical study of the gonadotrophs and mammotrophs of the anterior pituitary, in conjunction with assays of LH-like, progesterone-like and prolactin-like immunoreactivity in the plasma suggest that during delayed implantation the gonadotrophs were inactive while the mammotrophs were active and plasma PRL-like immunoreactivity high. We interpret this as indicating that, in the straw-coloured fruit bat, implantation was inhibited by high levels of prolactin and, as such, the endocrine control of delayed implantation may be quite different from that described for other mammals.
- Full Text:
Enhancing military efficiency : a South African perspective
- Christie, Candice J, Todd, Andrew I
- Authors: Christie, Candice J , Todd, Andrew I
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6749 , http://hdl.handle.net/10962/d1009329
- Description: While extensive military research has been conducted in developed countries, very little work has been done on soldiers in industrially developing countries (IDCs). Although many aspects of marching are similar around the globe, the challenges facing soldiers in IDCs, and in particular South Africa, are unique. Since the 1990’s South Africa has seen a considerable shift in the morphological and cultural make-up of the South African National Defence Force (SANDF). The result is a mix of soldiers from a variety of ethnic backgrounds. Ethnic differences may ultimately impact performance particularly as research has postulated that Blacks and Whites may differ in body composition and body proportions. It is highly probable then that the universal recommendations of optimal marching speeds, load masses and gradients need to be modified to accommodate the diversity of soldiers which currently comprise the SANDF.
- Full Text:
- Authors: Christie, Candice J , Todd, Andrew I
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6749 , http://hdl.handle.net/10962/d1009329
- Description: While extensive military research has been conducted in developed countries, very little work has been done on soldiers in industrially developing countries (IDCs). Although many aspects of marching are similar around the globe, the challenges facing soldiers in IDCs, and in particular South Africa, are unique. Since the 1990’s South Africa has seen a considerable shift in the morphological and cultural make-up of the South African National Defence Force (SANDF). The result is a mix of soldiers from a variety of ethnic backgrounds. Ethnic differences may ultimately impact performance particularly as research has postulated that Blacks and Whites may differ in body composition and body proportions. It is highly probable then that the universal recommendations of optimal marching speeds, load masses and gradients need to be modified to accommodate the diversity of soldiers which currently comprise the SANDF.
- Full Text:
Implementation and applications of the distortion operator
- Authors: Bangay, Shaun D
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433382 , vital:72966 , https://doi.org/10.1145/513867.513872
- Description: The distortion operator transforms 2D images in a manner similar to image warping or morphing, allowing source pixels to be mapped to any destination pixel. This operator can be implemented on current hardware, allowing at least one distortion per frame at interactive frame rates. Potential applications are numerous, but those described include re-mapping images for correct projection onto curved screens, correcting camera distortion from multiple sources simultaneously, and allowing constant time dynamic texturing and lighting of a static scene which is independent of geometric complexity.
- Full Text:
- Authors: Bangay, Shaun D
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433382 , vital:72966 , https://doi.org/10.1145/513867.513872
- Description: The distortion operator transforms 2D images in a manner similar to image warping or morphing, allowing source pixels to be mapped to any destination pixel. This operator can be implemented on current hardware, allowing at least one distortion per frame at interactive frame rates. Potential applications are numerous, but those described include re-mapping images for correct projection onto curved screens, correcting camera distortion from multiple sources simultaneously, and allowing constant time dynamic texturing and lighting of a static scene which is independent of geometric complexity.
- Full Text:
Influences of food quality and quantity on the male reproductive organs of a seasonally breeding rodent, the pouched mouse (Saccostomus campestris), from a seasonal but unpredictable environment
- Tinney, Gregory M, Bernard, Ric T F, White, Rehema M
- Authors: Tinney, Gregory M , Bernard, Ric T F , White, Rehema M
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447258 , vital:74600 , https://doi.org/10.1080/15627020.2001.11657110
- Description: Reproduction in the pouched mouse (Saccostomus campestris) is inhibited in winter in the field and this seasonality is not controlled by photoperiod alone. The present study examines the hypothesis that reproduction in the pouched mouse is opportunistic (sensu Bronson 1989) and that the winter inhibition of reproduction is controlled by a reduction in either food quantity or quality. Food restriction (70 % of normal daily food intake) for six weeks, under short day conditions, was associated with a significant decrease in body fat index and mass of the accessory glands, testes and epididymides, while a high-fibre diet resulted in a significant reduction in fat index and masses of both the accessory glands and epididymides. A low-fibre/low-protein diet had no significant effect on either fat index or masses of the reproductive organs. Although the three experimental diets resulted in assimilation of significantly less energy than the controls, they did not inhibit spermatogenesis. We conclude that reproduction in the pouched mouse in the Eastern Cape Province is probably opportunistic and that the winter inhibition of reproduction may be controlled by a reduction in available energy which results from a combination of the lower ambient temperatures of winter and reduced food quantity and/or quality.
- Full Text:
- Authors: Tinney, Gregory M , Bernard, Ric T F , White, Rehema M
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447258 , vital:74600 , https://doi.org/10.1080/15627020.2001.11657110
- Description: Reproduction in the pouched mouse (Saccostomus campestris) is inhibited in winter in the field and this seasonality is not controlled by photoperiod alone. The present study examines the hypothesis that reproduction in the pouched mouse is opportunistic (sensu Bronson 1989) and that the winter inhibition of reproduction is controlled by a reduction in either food quantity or quality. Food restriction (70 % of normal daily food intake) for six weeks, under short day conditions, was associated with a significant decrease in body fat index and mass of the accessory glands, testes and epididymides, while a high-fibre diet resulted in a significant reduction in fat index and masses of both the accessory glands and epididymides. A low-fibre/low-protein diet had no significant effect on either fat index or masses of the reproductive organs. Although the three experimental diets resulted in assimilation of significantly less energy than the controls, they did not inhibit spermatogenesis. We conclude that reproduction in the pouched mouse in the Eastern Cape Province is probably opportunistic and that the winter inhibition of reproduction may be controlled by a reduction in available energy which results from a combination of the lower ambient temperatures of winter and reduced food quantity and/or quality.
- Full Text:
Magnitudes and temporal sequencing of load kinematics and kinetics for single-handed pulls
- Authors: MacKinnon, S N
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6747 , http://hdl.handle.net/10962/d1009327
- Description: This paper provides data regarding kinematics and kinetics during single-handed, submaximal pulls about various locations in the frontal plane for three loads (6, 12 and 18% lean body mass). Pulls were executed at two relative heights (elbow and eye) through two parasagittal planes also relative to subject morphology. Results indicate that in most cases load and pull location influence the occurrence of measured kinetic variables within a pull cycle but have little effect on the magnitude of these values. Findings from this study suggest that analyses of kinematic and kinetic movement histories may be required for a better understanding of the mechanical loading profiles upon operators engaged in such manual materials handling activities.
- Full Text:
- Authors: MacKinnon, S N
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6747 , http://hdl.handle.net/10962/d1009327
- Description: This paper provides data regarding kinematics and kinetics during single-handed, submaximal pulls about various locations in the frontal plane for three loads (6, 12 and 18% lean body mass). Pulls were executed at two relative heights (elbow and eye) through two parasagittal planes also relative to subject morphology. Results indicate that in most cases load and pull location influence the occurrence of measured kinetic variables within a pull cycle but have little effect on the magnitude of these values. Findings from this study suggest that analyses of kinematic and kinetic movement histories may be required for a better understanding of the mechanical loading profiles upon operators engaged in such manual materials handling activities.
- Full Text:
Occupation-simulating isokinetic strength of infantrymen in the South African National Defence Force
- Authors: James, Jonathan P
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6748 , http://hdl.handle.net/10962/d1009328
- Description: Isokinetic work-simulation packages have not been widely exploited by researchers and this study aimed to assess how effectively occupation-simulating tasks could identify the capabilities of recruits and be applied in the military context. In this study the isokinetic strength responses of military personnel (N=42) were recorded and used to establish benchmark data on a population not previously tested.
- Full Text:
Occupation-simulating isokinetic strength of infantrymen in the South African National Defence Force
- Authors: James, Jonathan P
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6748 , http://hdl.handle.net/10962/d1009328
- Description: Isokinetic work-simulation packages have not been widely exploited by researchers and this study aimed to assess how effectively occupation-simulating tasks could identify the capabilities of recruits and be applied in the military context. In this study the isokinetic strength responses of military personnel (N=42) were recorded and used to establish benchmark data on a population not previously tested.
- Full Text:
Rhodes University Graduation Ceremony 2001
- Authors: Rhodes University
- Date: 2001
- Language: English
- Type: text
- Identifier: vital:8146 , http://hdl.handle.net/10962/d1007296
- Description: Rhodes University Graduation Ceremonies 1820 Settlers National Monument Friday, 6 April 2001 at 10:30; 18:00 [and] Saturday, 7 April 2001 at 10:30 , Graduation Ceremony Christian Centre, Wyse Street, East London Friday, 1 May 2001 at 18:00
- Full Text:
- Authors: Rhodes University
- Date: 2001
- Language: English
- Type: text
- Identifier: vital:8146 , http://hdl.handle.net/10962/d1007296
- Description: Rhodes University Graduation Ceremonies 1820 Settlers National Monument Friday, 6 April 2001 at 10:30; 18:00 [and] Saturday, 7 April 2001 at 10:30 , Graduation Ceremony Christian Centre, Wyse Street, East London Friday, 1 May 2001 at 18:00
- Full Text:
StreetNet's progress to date and plans for the future
- Authors: StreetNet Association
- Date: 2001
- Subjects: StreetNet Association
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/162170 , vital:40769
- Description: The StreetNet offices were opened in February 2000, eighteen months ago. We are now half-way through our three-year programme to launch StreetNet as an international organisation of street vendors all over the world. tVhat progress has been made in the first eighteen months ? We have two people working part-time in the StreetNet office since February 2000. Pat Horn is the International Co-ordinator while Nozipho Lembethe is the International Administrator. We have been trying unsuccessfully to find a website manager/researcher to start working with us this year.
- Full Text:
- Authors: StreetNet Association
- Date: 2001
- Subjects: StreetNet Association
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/162170 , vital:40769
- Description: The StreetNet offices were opened in February 2000, eighteen months ago. We are now half-way through our three-year programme to launch StreetNet as an international organisation of street vendors all over the world. tVhat progress has been made in the first eighteen months ? We have two people working part-time in the StreetNet office since February 2000. Pat Horn is the International Co-ordinator while Nozipho Lembethe is the International Administrator. We have been trying unsuccessfully to find a website manager/researcher to start working with us this year.
- Full Text:
Three days to remember in Latin America
- Authors: StreetNet Association
- Date: 2001
- Subjects: StreetNet Association
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/162159 , vital:40767
- Description: What do a street vendor of traditional sweets in Venezuela, an indigenous vendor of flowers in Bolivia and an immigrant vendor of “empanadas” in Costa Rica have in common? A lot despite their different realities! For example, livelihoods that rely on production and sale on the streets or at markets that cost them years of struggle; goods frequently made with their own hands, battles against unsympathetic municipalities; harassment -sometimes violent - from the local police; the desire to organise themselves, which must overcome daily problems of leadership, politics and internal conflicts, and lack of resources to improve their situation or to help solve problems of their fellow vendors.
- Full Text:
- Authors: StreetNet Association
- Date: 2001
- Subjects: StreetNet Association
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/162159 , vital:40767
- Description: What do a street vendor of traditional sweets in Venezuela, an indigenous vendor of flowers in Bolivia and an immigrant vendor of “empanadas” in Costa Rica have in common? A lot despite their different realities! For example, livelihoods that rely on production and sale on the streets or at markets that cost them years of struggle; goods frequently made with their own hands, battles against unsympathetic municipalities; harassment -sometimes violent - from the local police; the desire to organise themselves, which must overcome daily problems of leadership, politics and internal conflicts, and lack of resources to improve their situation or to help solve problems of their fellow vendors.
- Full Text:
A taxonomic and ecological review of Pseudocloeon glaucum (Agnew)(Ephemeroptera: Baetidae)
- Lugo-Ortiz, C R, de Moor, Ferdy C, Barber-James, Helen M
- Authors: Lugo-Ortiz, C R , de Moor, Ferdy C , Barber-James, Helen M
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:7007 , http://hdl.handle.net/10962/d1008385
- Description: Pseudocloeon masai (Lugo-Ortiz and McCafferty), P. nadineae (Lugo-Ortiz and McCafferty) and P. quintum (Agnew) are junior subjective synonyms of P. glaucum (Agnew). Larvae of P. glaucum manifest a wide range of variation in mouthpart morphology, particularly with respect to the development of the distomedial process of segment 2 of the labial palps, body size, general body colour and abdominal colour pattern. Such variation is observed in different cohorts and populations, and explains why several names have been applied to the same species. Larvae of P. glaucum also have considerable ecological tolerance, accounting for the abundance and widespread distribution of the species in the Afrotropical Region. New records from Kenya, Lesotho, Namibia and Zimbabwe are provided.
- Full Text:
- Authors: Lugo-Ortiz, C R , de Moor, Ferdy C , Barber-James, Helen M
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:7007 , http://hdl.handle.net/10962/d1008385
- Description: Pseudocloeon masai (Lugo-Ortiz and McCafferty), P. nadineae (Lugo-Ortiz and McCafferty) and P. quintum (Agnew) are junior subjective synonyms of P. glaucum (Agnew). Larvae of P. glaucum manifest a wide range of variation in mouthpart morphology, particularly with respect to the development of the distomedial process of segment 2 of the labial palps, body size, general body colour and abdominal colour pattern. Such variation is observed in different cohorts and populations, and explains why several names have been applied to the same species. Larvae of P. glaucum also have considerable ecological tolerance, accounting for the abundance and widespread distribution of the species in the Afrotropical Region. New records from Kenya, Lesotho, Namibia and Zimbabwe are provided.
- Full Text:
Assessing the potential for biological invasion - the case of Ammophila arenaria in South Africa
- Hertling, Ursula M, Lubke, Roy
- Authors: Hertling, Ursula M , Lubke, Roy
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6518 , http://hdl.handle.net/10962/d1005947
- Description: Many plants, especially woody species, introduced into South Africa for ornamental or commercial purposes, have become invasive in a number of habitats. Because of the risk of an invasion of coastal dunes by yet another species, the European dune grass Ammophila arenaria, used as a dune stabilizer, is assessed using lists of attributes of invasive species and invasible ecosystems. It is impossible to predict plant invasions, but both invasive species as well as invaded ecosystems are often characterized by certain attributes which facilitate invasions. Many of the species attributes connected with invasion appear to apply to A. arenaria. Above all, the grass is characterized by ecological tolerance and vigorous rhizomatous reproduction. An important site attribute connected with invasion is an evolutionary history with isolation patterns, which applies to the South African Cape coast. We conclude also on the basis of the overseas experience, that the potential for A. arenaria to become invasive needs urgent investigation in the South African context.
- Full Text: false
- Authors: Hertling, Ursula M , Lubke, Roy
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6518 , http://hdl.handle.net/10962/d1005947
- Description: Many plants, especially woody species, introduced into South Africa for ornamental or commercial purposes, have become invasive in a number of habitats. Because of the risk of an invasion of coastal dunes by yet another species, the European dune grass Ammophila arenaria, used as a dune stabilizer, is assessed using lists of attributes of invasive species and invasible ecosystems. It is impossible to predict plant invasions, but both invasive species as well as invaded ecosystems are often characterized by certain attributes which facilitate invasions. Many of the species attributes connected with invasion appear to apply to A. arenaria. Above all, the grass is characterized by ecological tolerance and vigorous rhizomatous reproduction. An important site attribute connected with invasion is an evolutionary history with isolation patterns, which applies to the South African Cape coast. We conclude also on the basis of the overseas experience, that the potential for A. arenaria to become invasive needs urgent investigation in the South African context.
- Full Text: false
Campaigns Bulletin : Wage negotiations 2000
- SAMWU
- Authors: SAMWU
- Date: Apr 2000
- Subjects: SAMWU
- Language: English, Zulu, seSotho and Afrikaans
- Type: text
- Identifier: http://hdl.handle.net/10962/113558 , vital:33801
- Description: It is sad how the promises of a better life for all made by the government means so little for workers. Cosatu and Samwu mobilised our forces to ensure a victory for the ANC in the national and local government elections. Despite the fact that workers have put MPs into parliament and councillors into local government councils, we have yet to see any real benefit for workers. The 3rd and final round of negotiations delivered a big disappointment for Samwu. Once again we went into negotiations with high hopes of persuading Saiga to implement decent wage increases. Samwu’s position of R250 or 10% for workers earning less than R6 700 per month was very reasonable. Because we said that those earning more than R13 700 should get a 7% increase, this meant that the total cost to councils was only 9%, which is very affordable. Saiga moved its position in negotiations by 1%. They also tried to get us to give up our demand for a R250 increase by offering a minimum wage of R1600. As we know, most workers are earning more than that. Workers earning R1600 Saiga's 5% will mean a R80 increase. This is less than councillor's get for attending one meeting! Although the negotiators tried everything to try to reach a settlement, Saiga frustrated us at every turn.
- Full Text:
- Authors: SAMWU
- Date: Apr 2000
- Subjects: SAMWU
- Language: English, Zulu, seSotho and Afrikaans
- Type: text
- Identifier: http://hdl.handle.net/10962/113558 , vital:33801
- Description: It is sad how the promises of a better life for all made by the government means so little for workers. Cosatu and Samwu mobilised our forces to ensure a victory for the ANC in the national and local government elections. Despite the fact that workers have put MPs into parliament and councillors into local government councils, we have yet to see any real benefit for workers. The 3rd and final round of negotiations delivered a big disappointment for Samwu. Once again we went into negotiations with high hopes of persuading Saiga to implement decent wage increases. Samwu’s position of R250 or 10% for workers earning less than R6 700 per month was very reasonable. Because we said that those earning more than R13 700 should get a 7% increase, this meant that the total cost to councils was only 9%, which is very affordable. Saiga moved its position in negotiations by 1%. They also tried to get us to give up our demand for a R250 increase by offering a minimum wage of R1600. As we know, most workers are earning more than that. Workers earning R1600 Saiga's 5% will mean a R80 increase. This is less than councillor's get for attending one meeting! Although the negotiators tried everything to try to reach a settlement, Saiga frustrated us at every turn.
- Full Text:
Effect of wave exposure on growth and mortality rates of the mussel Perna perna: bottom up regulation of intertidal populations
- McQuaid, Christopher D, Lindsay, Tracy L
- Authors: McQuaid, Christopher D , Lindsay, Tracy L
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6955 , http://hdl.handle.net/10962/d1011994
- Description: The effect of wave exposure on the growth of low-shore populations of Perna perna (Linnaeus) was determined using 3 independent approaches at 6 sites on the south coast of South Africa: (1) Individual marking; notches were filed on the growing edges of mussels in situ. After 111 d, growth from the mark to the new growing edge was measured. (2) Internal shell-growth bands; mussels from the mark recapture experiment were used to establish that growth bands are laid down tidally. Unmarked individuals were then used to measure growth over the last 60 tides. (3) Shepherd¹s length-composition analysis (SLCA); growth rates were determined from length-frequency distributions in 11 samples collected at 6 wk intervals over 15 mo. All 3 approaches showed that growth rate was approximately twice as fast on exposed as on sheltered shores (ANCOVA, p < 0.05 in all cases). Mean length for the first year of growth (averaged for the 3 methods) was 47 and 22 mm, respectively. There were, however, considerable differences among methods. Marking provided the lowest estimates of growth rates, and SLCA the highest. The mean mortality index (Z yr-1) was significantly higher and annual survival rate lower for exposed shores, indicating faster turnover under exposed conditions. Mean longevity on exposed shores (2.6 yr) was only one-third of estimated longevity on sheltered shores (6.7 yr). These findings show that degree of exposure has important interactions with growth and mortality of mussels on the low shore, and that these effects are independent of the effects of exposure on density. The findings also indicate strong bottom up regulation of mussel populations.
- Full Text:
- Authors: McQuaid, Christopher D , Lindsay, Tracy L
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6955 , http://hdl.handle.net/10962/d1011994
- Description: The effect of wave exposure on the growth of low-shore populations of Perna perna (Linnaeus) was determined using 3 independent approaches at 6 sites on the south coast of South Africa: (1) Individual marking; notches were filed on the growing edges of mussels in situ. After 111 d, growth from the mark to the new growing edge was measured. (2) Internal shell-growth bands; mussels from the mark recapture experiment were used to establish that growth bands are laid down tidally. Unmarked individuals were then used to measure growth over the last 60 tides. (3) Shepherd¹s length-composition analysis (SLCA); growth rates were determined from length-frequency distributions in 11 samples collected at 6 wk intervals over 15 mo. All 3 approaches showed that growth rate was approximately twice as fast on exposed as on sheltered shores (ANCOVA, p < 0.05 in all cases). Mean length for the first year of growth (averaged for the 3 methods) was 47 and 22 mm, respectively. There were, however, considerable differences among methods. Marking provided the lowest estimates of growth rates, and SLCA the highest. The mean mortality index (Z yr-1) was significantly higher and annual survival rate lower for exposed shores, indicating faster turnover under exposed conditions. Mean longevity on exposed shores (2.6 yr) was only one-third of estimated longevity on sheltered shores (6.7 yr). These findings show that degree of exposure has important interactions with growth and mortality of mussels on the low shore, and that these effects are independent of the effects of exposure on density. The findings also indicate strong bottom up regulation of mussel populations.
- Full Text:
Histological validation of gonadal macroscopic staging criteria for Labeo cylindricus (Pisces: Cyprinidae).
- Booth, Anthony J, Weyl, Olaf L F
- Authors: Booth, Anthony J , Weyl, Olaf L F
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446824 , vital:74563 , https://hdl.handle.net/10520/EJC17754
- Description: Histological examination of gametogenesis revealed that the current staging criteria used to assess gonadal recrudescence of the redeye labeo, Labeo cylindricus, were adequate. Gametogenesis was qualitatively similar to that of freshwater teleosts with a clearly defined seasonal reproductive cycle. L. cylindricus undergoes seasonal gross morphological and cytological gonadal changes with previtellogenesis dominating during the winter, vitellogenic development during spring and summer culminating in large-scale spawning at the end of summer. Post-spawning mass atresia of oocytes was evident in autumn. The histological data presented support macroscopical evidence that L. cylindricus is a synchronous iteroparous spawner, reproducing over a short period each year throughout its life-span.
- Full Text:
- Authors: Booth, Anthony J , Weyl, Olaf L F
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446824 , vital:74563 , https://hdl.handle.net/10520/EJC17754
- Description: Histological examination of gametogenesis revealed that the current staging criteria used to assess gonadal recrudescence of the redeye labeo, Labeo cylindricus, were adequate. Gametogenesis was qualitatively similar to that of freshwater teleosts with a clearly defined seasonal reproductive cycle. L. cylindricus undergoes seasonal gross morphological and cytological gonadal changes with previtellogenesis dominating during the winter, vitellogenic development during spring and summer culminating in large-scale spawning at the end of summer. Post-spawning mass atresia of oocytes was evident in autumn. The histological data presented support macroscopical evidence that L. cylindricus is a synchronous iteroparous spawner, reproducing over a short period each year throughout its life-span.
- Full Text:
The exploitation of Upogebia africana (Crustacea: Thalassinidae) for bait in the Knysna Estuary
- Hodgson, Alan N, Allanson, Brian R, Cretchley, Robyn
- Authors: Hodgson, Alan N , Allanson, Brian R , Cretchley, Robyn
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6924 , http://hdl.handle.net/10962/d1011911
- Description: The activities of people collecting Upogebia africana for bait at six popular collecting sites in the Knysna Estuary were monitored from February 1995 until April 1996. Three groups of bait harvesters were identified on the basis of their source of income: subsistence fishers who rely on bait collecting and fishing for their income; supplementary fishers who catch fish to supplement their income; leisure anglers who draw no income from fishing. Two groups of collectors were identified based on methods of collecting bait and fishing: leisure anglers who collect bait using a prawn pusher or pump and fish using a rod and tackle; non-leisure fishers who collect using tin cans and fish with hand or planted lines. The average harvest of bait per collecting trip by leisure anglers was 59 mud prawns, whereas non-leisure fishers took 101 animals, twice the legal limit. The numbers of bait collectors present per mud bank were found to be highest on public holidays ([horizontal bar over]X = 43.5) and higher during the summer holidays ([horizontal bar over]X = 16.5) than during the spring/summer ([horizontal bar over]X = 8.6) and autumn/winter ([horizontal bar over]X = 4.6) periods. Most collectors spent 11-30 minutes on the mud banks. It was estimated that 1.86 x 10[superscript 6] U. africana or about 740 kg (dry mass) was removed by bait collectors annually from the six bait-collecting sites studied. This represented about 8.5% of the mud prawn stocks at these sites and about 0.9% of the entire estuary stock. 85% of the mud prawns taken as bait was removed by 77% of the bait collectors who were the non-leisure fishers.
- Full Text:
- Authors: Hodgson, Alan N , Allanson, Brian R , Cretchley, Robyn
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6924 , http://hdl.handle.net/10962/d1011911
- Description: The activities of people collecting Upogebia africana for bait at six popular collecting sites in the Knysna Estuary were monitored from February 1995 until April 1996. Three groups of bait harvesters were identified on the basis of their source of income: subsistence fishers who rely on bait collecting and fishing for their income; supplementary fishers who catch fish to supplement their income; leisure anglers who draw no income from fishing. Two groups of collectors were identified based on methods of collecting bait and fishing: leisure anglers who collect bait using a prawn pusher or pump and fish using a rod and tackle; non-leisure fishers who collect using tin cans and fish with hand or planted lines. The average harvest of bait per collecting trip by leisure anglers was 59 mud prawns, whereas non-leisure fishers took 101 animals, twice the legal limit. The numbers of bait collectors present per mud bank were found to be highest on public holidays ([horizontal bar over]X = 43.5) and higher during the summer holidays ([horizontal bar over]X = 16.5) than during the spring/summer ([horizontal bar over]X = 8.6) and autumn/winter ([horizontal bar over]X = 4.6) periods. Most collectors spent 11-30 minutes on the mud banks. It was estimated that 1.86 x 10[superscript 6] U. africana or about 740 kg (dry mass) was removed by bait collectors annually from the six bait-collecting sites studied. This represented about 8.5% of the mud prawn stocks at these sites and about 0.9% of the entire estuary stock. 85% of the mud prawns taken as bait was removed by 77% of the bait collectors who were the non-leisure fishers.
- Full Text: