Chris McGregor
- Authors: Atkins, Ronald
- Subjects: McGregor, Chris -- 1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians , Queen Elizabeth Hall
- Language: English
- Type: Article
- Identifier: vital:13477 , http://hdl.handle.net/10962/d1001399 , McGregor, Chris -- 1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians , Queen Elizabeth Hall
- Description: Photocopied article from the newspaper The Guardian about a concert by Chris McGregor's Brotherhood of Breath at the QEH (Queen Elisabeth Hall), London, England.
- Full Text:
- Authors: Atkins, Ronald
- Subjects: McGregor, Chris -- 1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians , Queen Elizabeth Hall
- Language: English
- Type: Article
- Identifier: vital:13477 , http://hdl.handle.net/10962/d1001399 , McGregor, Chris -- 1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians , Queen Elizabeth Hall
- Description: Photocopied article from the newspaper The Guardian about a concert by Chris McGregor's Brotherhood of Breath at the QEH (Queen Elisabeth Hall), London, England.
- Full Text:
Efficacy of solar power units for small-scale businesses in a remote rural area, South Africa
- Hajat, A, Banks, D, Aiken, R, Shackleton, Charlie M
- Authors: Hajat, A , Banks, D , Aiken, R , Shackleton, Charlie M
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6636 , http://hdl.handle.net/10962/d1006860
- Description: Much work has considered the practicalities and affordability of solar systems for domestic energy supplies in remote rural areas. There is less understanding of its utility for small-scale business enterprises in such areas. We examined the patterns of use of two 12 V and one 24 V systems for small-scale enterprises housed in transportable containers. Monitoring of load shed and top of charge indicated that the 12 V systems were inadequate to meet the requirements of the enterprises. The 24 V operation performed a lot better. Despite some technical limitations the system offered a number of social, economic and environmental positives; primarily the offering of business products not otherwise available in the area, incomes to the entrepreneurs and greater connectivity with regional centres through office services such as cell-phone charging and faxing. Customers of the small-scale enterprises felt that their presence in the area saved them some money because they no longer had to travel as frequently to regional urban centres.
- Full Text:
- Date Issued: 2009
- Authors: Hajat, A , Banks, D , Aiken, R , Shackleton, Charlie M
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6636 , http://hdl.handle.net/10962/d1006860
- Description: Much work has considered the practicalities and affordability of solar systems for domestic energy supplies in remote rural areas. There is less understanding of its utility for small-scale business enterprises in such areas. We examined the patterns of use of two 12 V and one 24 V systems for small-scale enterprises housed in transportable containers. Monitoring of load shed and top of charge indicated that the 12 V systems were inadequate to meet the requirements of the enterprises. The 24 V operation performed a lot better. Despite some technical limitations the system offered a number of social, economic and environmental positives; primarily the offering of business products not otherwise available in the area, incomes to the entrepreneurs and greater connectivity with regional centres through office services such as cell-phone charging and faxing. Customers of the small-scale enterprises felt that their presence in the area saved them some money because they no longer had to travel as frequently to regional urban centres.
- Full Text:
- Date Issued: 2009
Think: A Review of International Struggles
- Date: 1994-07
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/33833 , vital:33087 , Bulk File 7
- Description: 'Think' is a journal related to the Unity Movement. The author is Hosea Jaffe a long-standing NEUM theoretician who went into exile in the 1960s but remained an active member.
- Full Text: false
- Date Issued: 1994-07
- Date: 1994-07
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/33833 , vital:33087 , Bulk File 7
- Description: 'Think' is a journal related to the Unity Movement. The author is Hosea Jaffe a long-standing NEUM theoretician who went into exile in the 1960s but remained an active member.
- Full Text: false
- Date Issued: 1994-07
McJazz
- Unknown
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Jazz
- Language: English
- Type: Article
- Identifier: vital:13728 , http://hdl.handle.net/10962/d1012741
- Description: Photocopied article about Chris McGregor and his Zulu band. A portrait of Chris McGregor is accompanying this article.
- Full Text:
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Jazz
- Language: English
- Type: Article
- Identifier: vital:13728 , http://hdl.handle.net/10962/d1012741
- Description: Photocopied article about Chris McGregor and his Zulu band. A portrait of Chris McGregor is accompanying this article.
- Full Text:
Elucidation of the complex Baylis-Hillman reaction of 3-methoxy-2-nitrobenzaldehyde with methyl vinyl ketone
- Idahosa, Kenudi C, Molefe, Duduzile M, Pakade, Vusumzi E, Brown, Michael E
- Authors: Idahosa, Kenudi C , Molefe, Duduzile M , Pakade, Vusumzi E , Brown, Michael E
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6574 , http://hdl.handle.net/10962/d1004137
- Description: DABCO-catalyzed reaction of 3-methoxy-2-nitrobenzaldehyde with methyl vinyl ketone (MVK) affords a mixture of products, comprising the ‘normal’ Baylis-Hillman adduct, theMVKdimer and a pair of diastereomeric bis-(MVK)Baylis-Hillman adducts. 1HNMRspectroscopy-based kinetic studies have provided clear insights into the competing pathways and product distribution in this complex reaction.
- Full Text:
- Date Issued: 2011
- Authors: Idahosa, Kenudi C , Molefe, Duduzile M , Pakade, Vusumzi E , Brown, Michael E
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6574 , http://hdl.handle.net/10962/d1004137
- Description: DABCO-catalyzed reaction of 3-methoxy-2-nitrobenzaldehyde with methyl vinyl ketone (MVK) affords a mixture of products, comprising the ‘normal’ Baylis-Hillman adduct, theMVKdimer and a pair of diastereomeric bis-(MVK)Baylis-Hillman adducts. 1HNMRspectroscopy-based kinetic studies have provided clear insights into the competing pathways and product distribution in this complex reaction.
- Full Text:
- Date Issued: 2011
Teenage motherhood and the regulation of mothering in the scientific literature: the South African example
- Authors: Macleod, Catriona I
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6256 , http://hdl.handle.net/10962/d1007874
- Description: The mainstream literature on teenage pregnancy highlights teenagers' inadequate mothering as an area of disquiet. `Revisionists', such as feminist critics, point out that a confluence of negative social factors is implicated in teenagers' mothering abilities. Whether arguing that teenagers make bad mothers or defending them against this, the literature relies on the `invention of "good" mothering'. In this article I highlight the taken-for-granted assumptions concerning mothering (mothering as an essentialized dyad; mothering as a skill; motherhood as a pathway to adulthood; fathering as the absent trace) appearing in the scientific literature on teenage pregnancy in South Africa. I indicate how these assumptions are implicated in the regulation of mothering through the positioning of the teenage mother as the pathologized other, the splitting of the public from the private, domestic space of mothering, and the legitimation of the professionalization of mothering. I explore the gendered implications of the representations of mothering in this literature.
- Full Text:
- Date Issued: 2001
- Authors: Macleod, Catriona I
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6256 , http://hdl.handle.net/10962/d1007874
- Description: The mainstream literature on teenage pregnancy highlights teenagers' inadequate mothering as an area of disquiet. `Revisionists', such as feminist critics, point out that a confluence of negative social factors is implicated in teenagers' mothering abilities. Whether arguing that teenagers make bad mothers or defending them against this, the literature relies on the `invention of "good" mothering'. In this article I highlight the taken-for-granted assumptions concerning mothering (mothering as an essentialized dyad; mothering as a skill; motherhood as a pathway to adulthood; fathering as the absent trace) appearing in the scientific literature on teenage pregnancy in South Africa. I indicate how these assumptions are implicated in the regulation of mothering through the positioning of the teenage mother as the pathologized other, the splitting of the public from the private, domestic space of mothering, and the legitimation of the professionalization of mothering. I explore the gendered implications of the representations of mothering in this literature.
- Full Text:
- Date Issued: 2001
Jimmy Riadore: organ-builder, bell-ringer and hanger of the bells at St George's Cathedral, Cape Town
- Authors: Lewis, Colin A
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6190 , http://hdl.handle.net/10962/d1012396
- Description: Born in Lewes, Sussex, Jimmy Riadore came to South Africa in 1958. Organs, bells and clocks have been the focus of his life, and he has tuned, built, repaired and restored them all over southern Africa. Recently he has extended his careful ministrations to St Helena. , 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: 2009
- Authors: Lewis, Colin A
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6190 , http://hdl.handle.net/10962/d1012396
- Description: Born in Lewes, Sussex, Jimmy Riadore came to South Africa in 1958. Organs, bells and clocks have been the focus of his life, and he has tuned, built, repaired and restored them all over southern Africa. Recently he has extended his careful ministrations to St Helena. , 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: 2009
Good Chemistry
- Authors: Grange, Helen
- Date: 2011
- Subjects: Nyokong, Tebello , Africa-Arab State 2009 Unesco-L'Oreal Award for Women in Science
- Language: English
- Type: Article , text
- Identifier: vital:7185 , http://hdl.handle.net/10962/d1006276 , Nyokong, Tebello , Africa-Arab State 2009 Unesco-L'Oreal Award for Women in Science
- Description: Helen Grange profiles four women who've fearlessly taken on the complex predominantly male-dominated field of science.
- Full Text:
- Date Issued: 2011
- Authors: Grange, Helen
- Date: 2011
- Subjects: Nyokong, Tebello , Africa-Arab State 2009 Unesco-L'Oreal Award for Women in Science
- Language: English
- Type: Article , text
- Identifier: vital:7185 , http://hdl.handle.net/10962/d1006276 , Nyokong, Tebello , Africa-Arab State 2009 Unesco-L'Oreal Award for Women in Science
- Description: Helen Grange profiles four women who've fearlessly taken on the complex predominantly male-dominated field of science.
- Full Text:
- Date Issued: 2011
APDUSA Views
- Date: 1993-12
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/32718 , vital:32314 , Bulk File 7
- Description: APDUSA Views was published by the African People’s Democratic Union of Southern Africa (Natal), an affiliate of the New Unity Movement.
- Full Text: false
- Date Issued: 1993-12
- Date: 1993-12
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/32718 , vital:32314 , Bulk File 7
- Description: APDUSA Views was published by the African People’s Democratic Union of Southern Africa (Natal), an affiliate of the New Unity Movement.
- Full Text: false
- Date Issued: 1993-12
A change of the seaward boundary of Goukamma Marine Protected Area could increase conservation and fishery benefits
- Gotz, A, Kerwath, S E, Attwood, Colin G
- Authors: Gotz, A , Kerwath, S E , Attwood, Colin G
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:7147 , http://hdl.handle.net/10962/d1011846 , https://doi.org/10.4102/sajs.v105i9/10.102
- Description: Goukamma Marine Protected Area (MPA) on the South African temperate South Coast has been shown to be effective in maintaining a spawning stock of roman, Chrysoblephus laticeps (Sparidae). The larval ecology and the oceanographic conditions in the area suggest a good potential for the enhancement of roman stocks outside the reserve through larval dispersal. A high rate of illegal fishing just inside the seaward boundary of the MPA could severely compromise its function.We suggest that a change of the seaward boundary of the reserve to coincide with a latitudinal line could increase its function as a harvest refuge for resident reef fishes such as roman, facilitate voluntary compliance and monitoring and prosecution of illegal fishing without a significant negative impact on the commercial linefishing fleet in the area. Simple adjustments such as the one proposed here could be attempted at a number of South African MPAs as they would be beneficial to achieve fishery and conservation goals alike.
- Full Text:
- Date Issued: 2009
- Authors: Gotz, A , Kerwath, S E , Attwood, Colin G
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:7147 , http://hdl.handle.net/10962/d1011846 , https://doi.org/10.4102/sajs.v105i9/10.102
- Description: Goukamma Marine Protected Area (MPA) on the South African temperate South Coast has been shown to be effective in maintaining a spawning stock of roman, Chrysoblephus laticeps (Sparidae). The larval ecology and the oceanographic conditions in the area suggest a good potential for the enhancement of roman stocks outside the reserve through larval dispersal. A high rate of illegal fishing just inside the seaward boundary of the MPA could severely compromise its function.We suggest that a change of the seaward boundary of the reserve to coincide with a latitudinal line could increase its function as a harvest refuge for resident reef fishes such as roman, facilitate voluntary compliance and monitoring and prosecution of illegal fishing without a significant negative impact on the commercial linefishing fleet in the area. Simple adjustments such as the one proposed here could be attempted at a number of South African MPAs as they would be beneficial to achieve fishery and conservation goals alike.
- Full Text:
- Date Issued: 2009
Environmental limits to the distribution of Scaevola plumieri along the South African coast
- Peter, Craig I, Ripley, Bradley S, Robertson, Mark P
- Authors: Peter, Craig I , Ripley, Bradley S , Robertson, Mark P
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6533 , http://hdl.handle.net/10962/d1005974
- Description: Scaevola plumieri is an important pioneer on many tropical and subtropical sand dunes, forming a large perennial subterranean plant with only the tips of the branches emerging above accreting sand. In South Africa it is the dominant pioneer on sandy beaches along the east coast, less abundant on the south coast and absent from the southwest and west coasts. Transpiration rates (E) of S. plumieri are predictably related to atmospheric vapour pressure deficit under a wide range of conditions and can therefore be predicted from measurement of ambient temperature and relative humidity. Scaling measurements of E at the leaf level to the canopy level has been demonstrated previously. Using a geographic information system, digital maps of regional climatic variables were used to calculate digital maps of potential transpiration from mean monthly temperature and relative humidity values, effectively scaling canopy level transpiration rates to a regional level. Monthly potential transpiration was subtracted from the monthly median rainfall to produce a map of mean monthly water balance. Seasonal growth was correlated with seasonal water balance. Localities along the coast with water deficits in summer corresponded with the recorded absence of S. plumieri, which grows and reproduces most actively in the summer months. This suggests that reduced water availability during the summer growth period limits the distribution of S. plumieri along the southwest coast, where water deficits develop in summer. Temperature is also important in limiting the distribution of S. plumieri on the southwest coast of South Africa through its effects on the growth and phenology of the plant.
- Full Text:
- Date Issued: 2003
- Authors: Peter, Craig I , Ripley, Bradley S , Robertson, Mark P
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6533 , http://hdl.handle.net/10962/d1005974
- Description: Scaevola plumieri is an important pioneer on many tropical and subtropical sand dunes, forming a large perennial subterranean plant with only the tips of the branches emerging above accreting sand. In South Africa it is the dominant pioneer on sandy beaches along the east coast, less abundant on the south coast and absent from the southwest and west coasts. Transpiration rates (E) of S. plumieri are predictably related to atmospheric vapour pressure deficit under a wide range of conditions and can therefore be predicted from measurement of ambient temperature and relative humidity. Scaling measurements of E at the leaf level to the canopy level has been demonstrated previously. Using a geographic information system, digital maps of regional climatic variables were used to calculate digital maps of potential transpiration from mean monthly temperature and relative humidity values, effectively scaling canopy level transpiration rates to a regional level. Monthly potential transpiration was subtracted from the monthly median rainfall to produce a map of mean monthly water balance. Seasonal growth was correlated with seasonal water balance. Localities along the coast with water deficits in summer corresponded with the recorded absence of S. plumieri, which grows and reproduces most actively in the summer months. This suggests that reduced water availability during the summer growth period limits the distribution of S. plumieri along the southwest coast, where water deficits develop in summer. Temperature is also important in limiting the distribution of S. plumieri on the southwest coast of South Africa through its effects on the growth and phenology of the plant.
- Full Text:
- Date Issued: 2003
Spatial variation in the macrobenthic assemblages of intertidal seagrass along the long axis of an estuary
- Barnes, R S K, Ellwood, M D F
- Authors: Barnes, R S K , Ellwood, M D F
- Date: 2014-05-29
- Language: English
- Type: Article
- Identifier: vital:6870 , http://hdl.handle.net/10962/d1011513
- Description: Invertebrate macrofaunal biodiversity within intertidal seagrass meadows was investigated over a salinity gradient of <5–35 in the Knysna estuarine system (Garden Route National Park, South Africa). Rather than the classic gradual decline in species richness with distance from the mouth there were zones of considerable faunal stability separated by relatively sharp discontinuities. At the point upstream at which salinity regularly falls below 30, the rich, diverse and highly spatially variable downstream faunal assemblage changed to a less rich, less diverse and more uniform one that dominated the upstream stretch without any further upstream reduction in richness. Nevertheless, without loss of overall richness, assemblage composition changed, again rapidly, in the upper region of the upstream stretch to a zone dominated by the microgastropod Hydrobia, which otherwise occurs in the Knysna system only in highly sheltered regions of the downstream stretch where it is also dominant. The upstream faunal assemblage was a subset of that in the marine-influenced downstream region not a different replacing one. Position along the estuarine gradient accounted for 29% of total assemblage variation. Overall faunal abundance declined with distance upstream until the Hydrobia zone where it rose sharply, but there was no evidence of increase in density of those species remaining on putative release from competition.
- Full Text:
- Authors: Barnes, R S K , Ellwood, M D F
- Date: 2014-05-29
- Language: English
- Type: Article
- Identifier: vital:6870 , http://hdl.handle.net/10962/d1011513
- Description: Invertebrate macrofaunal biodiversity within intertidal seagrass meadows was investigated over a salinity gradient of <5–35 in the Knysna estuarine system (Garden Route National Park, South Africa). Rather than the classic gradual decline in species richness with distance from the mouth there were zones of considerable faunal stability separated by relatively sharp discontinuities. At the point upstream at which salinity regularly falls below 30, the rich, diverse and highly spatially variable downstream faunal assemblage changed to a less rich, less diverse and more uniform one that dominated the upstream stretch without any further upstream reduction in richness. Nevertheless, without loss of overall richness, assemblage composition changed, again rapidly, in the upper region of the upstream stretch to a zone dominated by the microgastropod Hydrobia, which otherwise occurs in the Knysna system only in highly sheltered regions of the downstream stretch where it is also dominant. The upstream faunal assemblage was a subset of that in the marine-influenced downstream region not a different replacing one. Position along the estuarine gradient accounted for 29% of total assemblage variation. Overall faunal abundance declined with distance upstream until the Hydrobia zone where it rose sharply, but there was no evidence of increase in density of those species remaining on putative release from competition.
- Full Text:
The effects of buffer molarity, agitation rate and mesh size on verapamil release from modified release mini-tablets using USP Apparatus 3
- Khamanga, Sandile M, Walker, Roderick B
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6386 , http://hdl.handle.net/10962/d1006307
- Description: The effects of agitation rate, buffer molarity,and mesh size on the dissolution rate of verapamil hydrochloride from sustained release matrix tablets were studied using USP Apparatus 3. Eudragit® and Carbopol® were used as rate-retarding polymers in tablets prepared by wet granulation.The study was conducted to determine whether the drugs exhibit similar release characteristics when tested under the same dissolution conditions. It was found that the dissolution rate of verapamil hydrochloride was affected by the variables assessed in these studies.
- Full Text:
- Date Issued: 2007
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6386 , http://hdl.handle.net/10962/d1006307
- Description: The effects of agitation rate, buffer molarity,and mesh size on the dissolution rate of verapamil hydrochloride from sustained release matrix tablets were studied using USP Apparatus 3. Eudragit® and Carbopol® were used as rate-retarding polymers in tablets prepared by wet granulation.The study was conducted to determine whether the drugs exhibit similar release characteristics when tested under the same dissolution conditions. It was found that the dissolution rate of verapamil hydrochloride was affected by the variables assessed in these studies.
- Full Text:
- Date Issued: 2007
First evidence for the Cenomanian-Turonian oceanic anoxic event (OAE2, Bonarelli event) from the Ionian Zone, western continental Greece
- Karakitsios, V, Tsikos, Harilaos, Van Breugel, Y, Koletti, L, Sinninghe Damsté, J S, Jenkyns, H C
- Authors: Karakitsios, V , Tsikos, Harilaos , Van Breugel, Y , Koletti, L , Sinninghe Damsté, J S , Jenkyns, H C
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6735 , http://hdl.handle.net/10962/d1007547
- Description: Integrated biostratigraphic (planktonic foraminifera, calcareous nannofossils), chemostratigraphic (bulk C and O isotopes) and compound-specific organic geochemical studies of a mid-Cretaceous pelagic carbonate—black shale succession of the Ionian Zone (western Greece), provide the first evidence for the Cenomanian–Turonian oceanic anoxic event (OAE2, ‘Bonarelli’ event) in mainland Greece. The event is manifested by the occurrence of a relatively thin (35 cm), yet exceptionally organic carbon-rich (44.5 wt% TOC), carbonate-free black shale, near the Cenomanian–Turonian boundary within the Vigla limestone formation (Berriasian–Turonian). Compared to the ‘Bonarelli’ black-shale interval from the type locality of OAE2 in Marche–Umbria, Italy, this black shale exhibits greatly reduced stratigraphic thickness, coupled with a considerable relative enrichment in TOC. Isotopically, enriched δ[superscript 13]C values for both bulk organic matter (−22.2‰) and specific organic compounds are up to 5‰ higher than those of underlying organic-rich strata of the Aptian-lower Albian Vigla Shale member, and thus compare very well with similar values of Cenomanian–Turonian black shale occurrences elsewhere. The relative predominance of bacterial hopanoids in the saturated, apolar lipid fraction of the OAE2 black shale of the Ionian Zone supports recent findings suggesting the abundance of N[subscript 2]-fixing cyanobacteria in Cretaceous oceans during the Cenomanian–Turonian and early Aptian oceanic anoxic events.
- Full Text:
- Date Issued: 2007
- Authors: Karakitsios, V , Tsikos, Harilaos , Van Breugel, Y , Koletti, L , Sinninghe Damsté, J S , Jenkyns, H C
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6735 , http://hdl.handle.net/10962/d1007547
- Description: Integrated biostratigraphic (planktonic foraminifera, calcareous nannofossils), chemostratigraphic (bulk C and O isotopes) and compound-specific organic geochemical studies of a mid-Cretaceous pelagic carbonate—black shale succession of the Ionian Zone (western Greece), provide the first evidence for the Cenomanian–Turonian oceanic anoxic event (OAE2, ‘Bonarelli’ event) in mainland Greece. The event is manifested by the occurrence of a relatively thin (35 cm), yet exceptionally organic carbon-rich (44.5 wt% TOC), carbonate-free black shale, near the Cenomanian–Turonian boundary within the Vigla limestone formation (Berriasian–Turonian). Compared to the ‘Bonarelli’ black-shale interval from the type locality of OAE2 in Marche–Umbria, Italy, this black shale exhibits greatly reduced stratigraphic thickness, coupled with a considerable relative enrichment in TOC. Isotopically, enriched δ[superscript 13]C values for both bulk organic matter (−22.2‰) and specific organic compounds are up to 5‰ higher than those of underlying organic-rich strata of the Aptian-lower Albian Vigla Shale member, and thus compare very well with similar values of Cenomanian–Turonian black shale occurrences elsewhere. The relative predominance of bacterial hopanoids in the saturated, apolar lipid fraction of the OAE2 black shale of the Ionian Zone supports recent findings suggesting the abundance of N[subscript 2]-fixing cyanobacteria in Cretaceous oceans during the Cenomanian–Turonian and early Aptian oceanic anoxic events.
- Full Text:
- Date Issued: 2007
The Educational Journal
- Date: 1976-08
- Subjects: Education –- South Africa , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/35319 , vital:33702 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa.
- Full Text: false
- Date Issued: 1976-08
- Date: 1976-08
- Subjects: Education –- South Africa , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/35319 , vital:33702 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa.
- Full Text: false
- Date Issued: 1976-08
M 87 at metre wavelengths: the LOFAR picture
- Smirnov, Oleg M, De Gasperin, F, Orrú, E, Murgia, M, Merloni, A, Falcke, H, Beck, R, Beswick, R, Bîrzan, L, Bonafede, A, Brüggen, M
- Authors: Smirnov, Oleg M , De Gasperin, F , Orrú, E , Murgia, M , Merloni, A , Falcke, H , Beck, R , Beswick, R , Bîrzan, L , Bonafede, A , Brüggen, M
- Date: 2012
- Subjects: radiation mechanisms: non-thermal, galaxies: active, galaxies: individual: M 87, galaxies: clusters: individual: Virgo, galaxies: jets, radio continuum: galaxies
- Language: English
- Type: Article
- Identifier: vital:6821 , http://hdl.handle.net/10962/d1004434
- Description: Context.M 87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4 × 109 M⊙, whose activity is responsible for the extended (80 kpc) radio lobes that surround the galaxy. The energy generated by matter falling onto the central black hole is ejected and transferred to the intra-cluster medium via a relativistic jet and morphologically complex systems of buoyant bubbles, which rise towards the edges of the extended halo. Aims. To place constraints on past activity cycles of the active nucleus, images of M 87 were produced at low radio frequencies never explored before at these high spatial resolution and dynamic range. To disentangle different synchrotron models and place constraints on source magnetic field, age and energetics, we also performed a detailed spectral analysis of M 87 extended radio-halo. Methods. We present the first observations made with the new Low-Frequency Array (LOFAR) of M 87 at frequencies down to 20 MHz. Three observations were conducted, at 15−30 MHz, 30−77 MHz and 116−162 MHz. We used these observations together with archival data to produce a low-frequency spectral index map and to perform a spectral analysis in the wide frequency range 30 MHz–10 GHz. Results. We do not find any sign of new extended emissions; on the contrary the source appears well confined by the high pressure of the intra-cluster medium. A continuous injection of relativistic electrons is the model that best fits our data, and provides a scenario in which the lobes are still supplied by fresh relativistic particles from the active galactic nuclei. We suggest that the discrepancy between the low-frequency radio-spectral slope in the core and in the halo implies a strong adiabatic expansion of the plasma as soon as it leaves the core area. The extended halo has an equipartition magnetic field strength of ≃10 μG, which increases to ≃13 μG in the zones where the particle flows are more active. The continuous injection model for synchrotron ageing provides an age for the halo of ≃40 Myr, which in turn provides a jet kinetic power of 6−10 × 1044 erg s-1.
- Full Text:
- Date Issued: 2012
- Authors: Smirnov, Oleg M , De Gasperin, F , Orrú, E , Murgia, M , Merloni, A , Falcke, H , Beck, R , Beswick, R , Bîrzan, L , Bonafede, A , Brüggen, M
- Date: 2012
- Subjects: radiation mechanisms: non-thermal, galaxies: active, galaxies: individual: M 87, galaxies: clusters: individual: Virgo, galaxies: jets, radio continuum: galaxies
- Language: English
- Type: Article
- Identifier: vital:6821 , http://hdl.handle.net/10962/d1004434
- Description: Context.M 87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4 × 109 M⊙, whose activity is responsible for the extended (80 kpc) radio lobes that surround the galaxy. The energy generated by matter falling onto the central black hole is ejected and transferred to the intra-cluster medium via a relativistic jet and morphologically complex systems of buoyant bubbles, which rise towards the edges of the extended halo. Aims. To place constraints on past activity cycles of the active nucleus, images of M 87 were produced at low radio frequencies never explored before at these high spatial resolution and dynamic range. To disentangle different synchrotron models and place constraints on source magnetic field, age and energetics, we also performed a detailed spectral analysis of M 87 extended radio-halo. Methods. We present the first observations made with the new Low-Frequency Array (LOFAR) of M 87 at frequencies down to 20 MHz. Three observations were conducted, at 15−30 MHz, 30−77 MHz and 116−162 MHz. We used these observations together with archival data to produce a low-frequency spectral index map and to perform a spectral analysis in the wide frequency range 30 MHz–10 GHz. Results. We do not find any sign of new extended emissions; on the contrary the source appears well confined by the high pressure of the intra-cluster medium. A continuous injection of relativistic electrons is the model that best fits our data, and provides a scenario in which the lobes are still supplied by fresh relativistic particles from the active galactic nuclei. We suggest that the discrepancy between the low-frequency radio-spectral slope in the core and in the halo implies a strong adiabatic expansion of the plasma as soon as it leaves the core area. The extended halo has an equipartition magnetic field strength of ≃10 μG, which increases to ≃13 μG in the zones where the particle flows are more active. The continuous injection model for synchrotron ageing provides an age for the halo of ≃40 Myr, which in turn provides a jet kinetic power of 6−10 × 1044 erg s-1.
- Full Text:
- Date Issued: 2012
The Educational Journal
- Date: 1981-02
- Subjects: Education –- South Africa , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/36336 , vital:33923 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa.
- Full Text: false
- Date Issued: 1981-02
- Date: 1981-02
- Subjects: Education –- South Africa , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/36336 , vital:33923 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa.
- Full Text: false
- Date Issued: 1981-02
The human skin blanching assay for in vivo topical corticosteroid assessment. II. Subject- and observer-dependent variation in blanching responses
- Haigh, John M, Meyer, Eric, Smith, Eric W, Kanfer, Isadore
- Authors: Haigh, John M , Meyer, Eric , Smith, Eric W , Kanfer, Isadore
- Date: 1997
- Language: English
- Type: text , Article
- Identifier: vital:6382 , http://hdl.handle.net/10962/d1006300
- Description: The human skin blanching (vasoconstriction) assay for the assessment of topical corticosteroids has been in use for over 30 years, the intensity of the drug-induced blanching being assessed subjectively by eye. Both arms of several male and female volunteers are used for product application and more than one observer is used to estimate the degree of induced blanching. There are, therefore, numerous variables which are inherent in the assay procedure. This investigation consisted of three identical trials performed at 8-week intervals, utilising the same 18 volunteers and the same three observers in an attempt to address the question of reproducibility of the assay. From the results obtained it is clear that the assay methodology is capable of consistently distinguishing, on a rank order basis, between preparations which show similar blanching (chemically-equivalent formulations). The similarity of the results for the three individual trials gives considerable confidence to results produced using this methodology. An experiment designed to test the reproducibility of the blanching scores showed that the observers are capable of producing identical results even though visual observation is highly subjective.
- Full Text:
- Date Issued: 1997
- Authors: Haigh, John M , Meyer, Eric , Smith, Eric W , Kanfer, Isadore
- Date: 1997
- Language: English
- Type: text , Article
- Identifier: vital:6382 , http://hdl.handle.net/10962/d1006300
- Description: The human skin blanching (vasoconstriction) assay for the assessment of topical corticosteroids has been in use for over 30 years, the intensity of the drug-induced blanching being assessed subjectively by eye. Both arms of several male and female volunteers are used for product application and more than one observer is used to estimate the degree of induced blanching. There are, therefore, numerous variables which are inherent in the assay procedure. This investigation consisted of three identical trials performed at 8-week intervals, utilising the same 18 volunteers and the same three observers in an attempt to address the question of reproducibility of the assay. From the results obtained it is clear that the assay methodology is capable of consistently distinguishing, on a rank order basis, between preparations which show similar blanching (chemically-equivalent formulations). The similarity of the results for the three individual trials gives considerable confidence to results produced using this methodology. An experiment designed to test the reproducibility of the blanching scores showed that the observers are capable of producing identical results even though visual observation is highly subjective.
- Full Text:
- Date Issued: 1997
The Educational Journal
- Date: 2013-03
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38619 , vital:34840 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2013-03
- Date: 2013-03
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38619 , vital:34840 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2013-03
The Educational Journal
- Date: 2014-11
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/41657 , vital:36552 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2014-11
- Date: 2014-11
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/41657 , vital:36552 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2014-11