'Here's to you, Mrs Robinson' : peculiarities and paragraph 29 in determining the treatment of domestic partnerships
- Authors: Kruuse, Helen
- Date: 2009
- Language: English
- Type: Article , text
- Identifier: vital:26388 , http://hdl.handle.net/10962/54083
- Description: There is always need of persons not only to discover new truths, and point out when what were once truths are true no longer, but also to commence new practices, and set the example of more enlightened conduct. The law is one of the important architects of social norms. At times, it can be a tool to solve problems, eradicate inequalities, and advance the rights of the disadvantaged. At other times, the law is an anchor and a constraint upon social and ideological advances. With regards to equality and non-traditional partnerships, it seems that law falls into this latter category.
- Full Text:
- Date Issued: 2009
- Authors: Kruuse, Helen
- Date: 2009
- Language: English
- Type: Article , text
- Identifier: vital:26388 , http://hdl.handle.net/10962/54083
- Description: There is always need of persons not only to discover new truths, and point out when what were once truths are true no longer, but also to commence new practices, and set the example of more enlightened conduct. The law is one of the important architects of social norms. At times, it can be a tool to solve problems, eradicate inequalities, and advance the rights of the disadvantaged. At other times, the law is an anchor and a constraint upon social and ideological advances. With regards to equality and non-traditional partnerships, it seems that law falls into this latter category.
- Full Text:
- Date Issued: 2009
Creating a virtual classroom: evaluating the use of online discussion forums to increase teaching and learning activities
- Authors: Bezuidenhout, L Peta
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6070 , http://hdl.handle.net/10962/d1004635
- Description: In teaching large classes, the educationally beneficial informal interaction between students and between lecturer and students is generally reduced, while effective use of both students’ and lecturer’s time is often a challenge. During student consultations, especially over the already stressful test and examination periods, many of the questions asked by the students are the same or similar. The lecturer needs to respond to each query by providing the same detailed explanation for the problem, resulting in ineffective use of time for the lecturer, while students waste time waiting for an appointment, or more often, simply don’t bother to follow up on any queries they may have. Having a social presence is important for students’ cognitive development, but in a large class posing questions or interrogating issues during a lecture appears to be challenging for many students. It is often not easy for students to initiate discussions or establish relationships with peers or the lecturer due to feelings of vulnerability and due to the size and impersonal atmosphere of the lecture theatre. This paper deals with the introduction of online discussion forums in an introductory accounting course and the benefits and problems experienced by the students, tutors and lecturer as a result thereof. Feedback received from these participants is discussed. The introduction and use of these forums resulted in a virtual classroom being created, where significantly more teaching and learning activities took place, to the benefit of all participants. Participation could have been peripheral -in the form of simply reading discussions; or active – through posting questions, or responding to questions.
- Full Text:
- Date Issued: 2009
- Authors: Bezuidenhout, L Peta
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6070 , http://hdl.handle.net/10962/d1004635
- Description: In teaching large classes, the educationally beneficial informal interaction between students and between lecturer and students is generally reduced, while effective use of both students’ and lecturer’s time is often a challenge. During student consultations, especially over the already stressful test and examination periods, many of the questions asked by the students are the same or similar. The lecturer needs to respond to each query by providing the same detailed explanation for the problem, resulting in ineffective use of time for the lecturer, while students waste time waiting for an appointment, or more often, simply don’t bother to follow up on any queries they may have. Having a social presence is important for students’ cognitive development, but in a large class posing questions or interrogating issues during a lecture appears to be challenging for many students. It is often not easy for students to initiate discussions or establish relationships with peers or the lecturer due to feelings of vulnerability and due to the size and impersonal atmosphere of the lecture theatre. This paper deals with the introduction of online discussion forums in an introductory accounting course and the benefits and problems experienced by the students, tutors and lecturer as a result thereof. Feedback received from these participants is discussed. The introduction and use of these forums resulted in a virtual classroom being created, where significantly more teaching and learning activities took place, to the benefit of all participants. Participation could have been peripheral -in the form of simply reading discussions; or active – through posting questions, or responding to questions.
- Full Text:
- Date Issued: 2009
Conceptualising the more knowledgeable other within a multi-directional ZPD:
- Authors: Graven, Mellony
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69519 , vital:29545 , https://doi.org/10.1007/s10649-017-9768-1
- Description: From a Marxian/Vygotskian perspective, learning is social in origin and it happens in the presence of others that are more knowledgeable. Extending this view to the learning of mathematics, such learning also becomes inseparable from the presence of others (people and artefacts). Researchers over decades have studied different interactions to see how such learning with others occurs, what is the role of the (more knowledgeable) other, and if at all this role alternates between the participants. In this paper, we looked at a 5-year-old’s (Lila) interaction with her mother (Mellony) and a television remote control as Lila attempted to count in threes using the three by three physical layout of the numbered buttons 1–9 on the remote control. We specifically looked at the emergence of the Zone of Proximal Development (ZPD) as Lila’s attention was caught by the properties of the remote control and by her mother’s questions. We also pay attention to how the role of the more knowledgeable other alternates among the participants. Our findings suggest that Lila, at times, used resources provided by the physical properties of the remote control and sometimes, used resources provided by Mellony to think about the task of counting in threes. In Lila’s interaction, we interpreted a multi-directional ZPD as the role of the more knowledgeable other alternated between Mellony, Lila and the remote control.
- Full Text:
- Date Issued: 2009
- Authors: Graven, Mellony
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69519 , vital:29545 , https://doi.org/10.1007/s10649-017-9768-1
- Description: From a Marxian/Vygotskian perspective, learning is social in origin and it happens in the presence of others that are more knowledgeable. Extending this view to the learning of mathematics, such learning also becomes inseparable from the presence of others (people and artefacts). Researchers over decades have studied different interactions to see how such learning with others occurs, what is the role of the (more knowledgeable) other, and if at all this role alternates between the participants. In this paper, we looked at a 5-year-old’s (Lila) interaction with her mother (Mellony) and a television remote control as Lila attempted to count in threes using the three by three physical layout of the numbered buttons 1–9 on the remote control. We specifically looked at the emergence of the Zone of Proximal Development (ZPD) as Lila’s attention was caught by the properties of the remote control and by her mother’s questions. We also pay attention to how the role of the more knowledgeable other alternates among the participants. Our findings suggest that Lila, at times, used resources provided by the physical properties of the remote control and sometimes, used resources provided by Mellony to think about the task of counting in threes. In Lila’s interaction, we interpreted a multi-directional ZPD as the role of the more knowledgeable other alternated between Mellony, Lila and the remote control.
- Full Text:
- Date Issued: 2009
'Come back when you are 65, Sir': discrimination in respect of access to social assistance for the elderly
- Authors: Krüger, Rósaan
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71119 , vital:29786 , http://www.ldd.org.za/images/stories/Ready_for_publication/V10-2_Come_back_65.pdf
- Description: Messrs Roberts, Whitebooi, Casling and Visagie are four elderly gentlemen who live in poverty in Gelvandale, Port Elizabeth. At the end of 2005 they wished to apply for social assistance from the State. At the time of their applications, the men were over the age of 60, but none of them had attained the age of 65. Had they been female, they would have qualified for social assistance in the form of old age pensions at the age of 60. 'These pensions would not have made them rich, but would have enabled them to sustain themselves.
- Full Text:
- Date Issued: 2009
- Authors: Krüger, Rósaan
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71119 , vital:29786 , http://www.ldd.org.za/images/stories/Ready_for_publication/V10-2_Come_back_65.pdf
- Description: Messrs Roberts, Whitebooi, Casling and Visagie are four elderly gentlemen who live in poverty in Gelvandale, Port Elizabeth. At the end of 2005 they wished to apply for social assistance from the State. At the time of their applications, the men were over the age of 60, but none of them had attained the age of 65. Had they been female, they would have qualified for social assistance in the form of old age pensions at the age of 60. 'These pensions would not have made them rich, but would have enabled them to sustain themselves.
- Full Text:
- Date Issued: 2009
Rapid method for the quantitative determination of efavirenz in human plasma
- Kanfer, Isadore, Mogatle, Seloi
- Authors: Kanfer, Isadore , Mogatle, Seloi
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6388 , http://hdl.handle.net/10962/d1006309
- Description: A pharmacokinetic interaction study between efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor used in the treatment of HIV-1 infection, and an African traditional medicine, African potato in human subjects was undertaken. This necessitated the development and validation of a quantitative method for the analysis of EFV in plasma. A simple mobile phase consisting of 0.1 M formic acid, acetonitrile and methanol (43:52:5) was pumped at a low flow rate of 0.3 ml/min through a reverse phase Phenomenex® Luna C18 (2) (5 μm, 150 mm × 2.0 mm i.d.) column maintained at 40 °C. Diclofenac sodium was used as an internal standard (IS) and EFV and IS were monitored at 247 nm and 275 nm, respectively. A simple and rapid sample preparation involved the addition of mobile phase to 100 μl of plasma to precipitate plasma proteins followed by direct injection of 10 μl of supernatant onto the column. The procedures were validated according to international standards with good reproducibility and linear response (r = 0.9990). The intra- and inter-day accuracies were between 12.3 and 17.7% at the LLOQ and between −5.8 and 9.1% for the QC samples. The intra- and inter-day precision of EFV determinations were 5.1 or less and 7.2% RSD or less, respectively across the entire QC concentration range. Mean recovery based on high, medium and low quality control standards ranged between 92.7 and 94.1% with %RSD values better than 3%. Plasma samples were evaluated for short-term (ambient temperature for 6 h) and long-term (−10 ± 2 °C for 60 days) storage conditions and were found to be stable. The method described is cost-effective and has the necessary accuracy and precision for the rapid quantitative determination of EFV in human plasma.
- Full Text:
- Date Issued: 2009
- Authors: Kanfer, Isadore , Mogatle, Seloi
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6388 , http://hdl.handle.net/10962/d1006309
- Description: A pharmacokinetic interaction study between efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor used in the treatment of HIV-1 infection, and an African traditional medicine, African potato in human subjects was undertaken. This necessitated the development and validation of a quantitative method for the analysis of EFV in plasma. A simple mobile phase consisting of 0.1 M formic acid, acetonitrile and methanol (43:52:5) was pumped at a low flow rate of 0.3 ml/min through a reverse phase Phenomenex® Luna C18 (2) (5 μm, 150 mm × 2.0 mm i.d.) column maintained at 40 °C. Diclofenac sodium was used as an internal standard (IS) and EFV and IS were monitored at 247 nm and 275 nm, respectively. A simple and rapid sample preparation involved the addition of mobile phase to 100 μl of plasma to precipitate plasma proteins followed by direct injection of 10 μl of supernatant onto the column. The procedures were validated according to international standards with good reproducibility and linear response (r = 0.9990). The intra- and inter-day accuracies were between 12.3 and 17.7% at the LLOQ and between −5.8 and 9.1% for the QC samples. The intra- and inter-day precision of EFV determinations were 5.1 or less and 7.2% RSD or less, respectively across the entire QC concentration range. Mean recovery based on high, medium and low quality control standards ranged between 92.7 and 94.1% with %RSD values better than 3%. Plasma samples were evaluated for short-term (ambient temperature for 6 h) and long-term (−10 ± 2 °C for 60 days) storage conditions and were found to be stable. The method described is cost-effective and has the necessary accuracy and precision for the rapid quantitative determination of EFV in human plasma.
- Full Text:
- Date Issued: 2009
Growth and longevity of Exosphaeroma hylocoetes (Isopoda) under varying conditions of salinity and temperature
- Henninger, Tony O, Froneman, P William, Booth, Anthony J, Hodgson, Alan N
- Authors: Henninger, Tony O , Froneman, P William , Booth, Anthony J , Hodgson, Alan N
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124571 , vital:35630 , https://doi.org/10.3377/004.045.0118
- Description: Numerous studies have documented the importance of both temperature and salinity in influencing aquatic crustacean metabolic processes such as respiration and growth. For example, increased water temperatures have been shown to increase respiration rates in various species of shrimp (Chen & Nan 1993; Spanonopoulos-Hernándeza et al. 2005; Allan et al. 2006), and copepods (Isla & Perissinotto 2004). The response of invertebrates to changes in salinity is more complex, largely reflecting their evolutionary origins (Kinne 1966). For example, juvenile blue swimming crabs, Portunus pelagicus, displayed significantly faster growth and higher survival in response to increasingsalinity (Romano & Zeng 2006). Additional factors that may influence the growth rates of crustaceans include photoperiod (Gambardella et al. 1997), food availability (Shuster & Guthrie 1999) and sex (Newman et al. 2007).
- Full Text:
- Date Issued: 2010
- Authors: Henninger, Tony O , Froneman, P William , Booth, Anthony J , Hodgson, Alan N
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124571 , vital:35630 , https://doi.org/10.3377/004.045.0118
- Description: Numerous studies have documented the importance of both temperature and salinity in influencing aquatic crustacean metabolic processes such as respiration and growth. For example, increased water temperatures have been shown to increase respiration rates in various species of shrimp (Chen & Nan 1993; Spanonopoulos-Hernándeza et al. 2005; Allan et al. 2006), and copepods (Isla & Perissinotto 2004). The response of invertebrates to changes in salinity is more complex, largely reflecting their evolutionary origins (Kinne 1966). For example, juvenile blue swimming crabs, Portunus pelagicus, displayed significantly faster growth and higher survival in response to increasingsalinity (Romano & Zeng 2006). Additional factors that may influence the growth rates of crustaceans include photoperiod (Gambardella et al. 1997), food availability (Shuster & Guthrie 1999) and sex (Newman et al. 2007).
- Full Text:
- Date Issued: 2010
Editorial: environmental-education research in the year of COP 15
- Lotz-Sisitka, Heila, Kronlid, David O
- Authors: Lotz-Sisitka, Heila , Kronlid, David O
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67356 , vital:29080 , https://www.ajol.info/index.php/sajee/article/view/122784
- Description: publisher version , Introduction: This year there has literally been a cacophony surrounding the implications of climate change, as the world geared up for the 15th Conference of the Parties (COP 15) in Copenhagen, where it was expected that the largest ever gathering of world leaders would sign binding agreements to reduce carbon emissions to keep global temperatures from rising by more than 2⁰C. As we make the final contributions to the refinement of this editorial, late in December 2009, it is concerning to note that this did not happen, that civil society voices were marginalised at the COP 15 and that there has been little progress on a socially just and ecologically sound global climate change deal. The stark reality remains that developing countries – southern African countries in particular – remain most vulnerable to the risks associated with global climate change. Havnevik (2007) stated a while ago that: The ways in which poverty, consumption and climate change are addressed, tend to blur historical, structural and power features underlying global inequalities. This makes possible the focus on market forces, such as carbon trading, to resolve the problems. However, these market solutions will not suffice, and may only delay a real solution, which will then have to be developed in a situation of more acute global social injustice and possibly deeper conflicts … Issues related to inequality, energy and climate are of a global character: there is no longer one solution for the South and one for the North. (18,19) So where does the current state of climate change and the political failures surrounding responses to climate change leave education research in developing and developed nations? What are the implications for environmental education researchers in southern Africa and elsewhere? These are some of the questions pondered in this edition of the Southern African Journal of Environmental Education (SAJEE). As one of us (Kronlid) reflects in a Think Piece in this journal: ‘the world is one and many and … the complexities associated with climate change means that we have a shared global systematic problem manifested in a myriad different concrete ways in people’s everyday life throughout the globe. We need many different kinds and modes of climate change education research’ (Kronlid, this edition).
- Full Text:
- Date Issued: 2009
- Authors: Lotz-Sisitka, Heila , Kronlid, David O
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67356 , vital:29080 , https://www.ajol.info/index.php/sajee/article/view/122784
- Description: publisher version , Introduction: This year there has literally been a cacophony surrounding the implications of climate change, as the world geared up for the 15th Conference of the Parties (COP 15) in Copenhagen, where it was expected that the largest ever gathering of world leaders would sign binding agreements to reduce carbon emissions to keep global temperatures from rising by more than 2⁰C. As we make the final contributions to the refinement of this editorial, late in December 2009, it is concerning to note that this did not happen, that civil society voices were marginalised at the COP 15 and that there has been little progress on a socially just and ecologically sound global climate change deal. The stark reality remains that developing countries – southern African countries in particular – remain most vulnerable to the risks associated with global climate change. Havnevik (2007) stated a while ago that: The ways in which poverty, consumption and climate change are addressed, tend to blur historical, structural and power features underlying global inequalities. This makes possible the focus on market forces, such as carbon trading, to resolve the problems. However, these market solutions will not suffice, and may only delay a real solution, which will then have to be developed in a situation of more acute global social injustice and possibly deeper conflicts … Issues related to inequality, energy and climate are of a global character: there is no longer one solution for the South and one for the North. (18,19) So where does the current state of climate change and the political failures surrounding responses to climate change leave education research in developing and developed nations? What are the implications for environmental education researchers in southern Africa and elsewhere? These are some of the questions pondered in this edition of the Southern African Journal of Environmental Education (SAJEE). As one of us (Kronlid) reflects in a Think Piece in this journal: ‘the world is one and many and … the complexities associated with climate change means that we have a shared global systematic problem manifested in a myriad different concrete ways in people’s everyday life throughout the globe. We need many different kinds and modes of climate change education research’ (Kronlid, this edition).
- Full Text:
- Date Issued: 2009
Sigtuna Think Piece 8: Piecing together conceptual framings for climate change education research in southern African contexts
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67378 , vital:29082 , https://www.ajol.info/index.php/sajee/article/view/122808
- Description: publisher version , This think piece considers a range of theoretical and conceptual tools that may assist with the emergence of a research agenda for climate change in education. It considers the conditions that are created by climate change in and for southern African contexts, and then deliberates which contextually related theoretical tools may be useful to frame research questions for climate change education. I consider the educational research implications of adaptation practices, reflexive justice and agency, reflexivity and capability, noting that a climate change education research agenda, not different to a wider reflexive environmental education research agenda dealing with transformative praxis in southern Africa, is essentially a sociologically and historically emergent ‘researching with’ agenda, and is in effect a social learning process. In putting together these conceptual framings for a climate change research agenda in southern Africa, I am interested in exploring how participatory social learning research may strengthen agency and reflexivity (development of capabilities) in response to socio-ecological conditions.
- Full Text:
- Date Issued: 2009
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67378 , vital:29082 , https://www.ajol.info/index.php/sajee/article/view/122808
- Description: publisher version , This think piece considers a range of theoretical and conceptual tools that may assist with the emergence of a research agenda for climate change in education. It considers the conditions that are created by climate change in and for southern African contexts, and then deliberates which contextually related theoretical tools may be useful to frame research questions for climate change education. I consider the educational research implications of adaptation practices, reflexive justice and agency, reflexivity and capability, noting that a climate change education research agenda, not different to a wider reflexive environmental education research agenda dealing with transformative praxis in southern Africa, is essentially a sociologically and historically emergent ‘researching with’ agenda, and is in effect a social learning process. In putting together these conceptual framings for a climate change research agenda in southern Africa, I am interested in exploring how participatory social learning research may strengthen agency and reflexivity (development of capabilities) in response to socio-ecological conditions.
- Full Text:
- Date Issued: 2009
SDF-1 and PDGF enhance αvβ5-mediated ERK activation and adhesion-independent growth of human pre-B cell lines:
- Acharya, Mridu, Edkins, Adrienne L, Ozanne, B, Cushley, W
- Authors: Acharya, Mridu , Edkins, Adrienne L , Ozanne, B , Cushley, W
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165044 , vital:41204 , DOI: 10.1038/leu.2009.126
- Description: CD23 acts through the αvβ5 integrin to promote growth of human pre-B cell lines in an adhesion-independent manner. αvβ5 is expressed on normal B-cell precursors in the bone marrow. Soluble CD23 (sCD23), short CD23-derived peptides containing the arg-lys-cys (RKC) motif recognized by αvβ5 and anti-αvβ5 monoclonal antibodies (MAbs) all sustain growth of pre-B cell lines. The chemokine stromal cell-derived factor-1 (SDF-1) regulates key processes during B-cell development. SDF-1 enhanced the growth-sustaining effect driven by ligation of αvβ5 with anti-αvβ5 MAb 15F-11, sCD23 or CD23-derived RKC-containing peptides. This effect was restricted to B-cell precursors and was specific to SDF-1.
- Full Text:
- Date Issued: 2009
- Authors: Acharya, Mridu , Edkins, Adrienne L , Ozanne, B , Cushley, W
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165044 , vital:41204 , DOI: 10.1038/leu.2009.126
- Description: CD23 acts through the αvβ5 integrin to promote growth of human pre-B cell lines in an adhesion-independent manner. αvβ5 is expressed on normal B-cell precursors in the bone marrow. Soluble CD23 (sCD23), short CD23-derived peptides containing the arg-lys-cys (RKC) motif recognized by αvβ5 and anti-αvβ5 monoclonal antibodies (MAbs) all sustain growth of pre-B cell lines. The chemokine stromal cell-derived factor-1 (SDF-1) regulates key processes during B-cell development. SDF-1 enhanced the growth-sustaining effect driven by ligation of αvβ5 with anti-αvβ5 MAb 15F-11, sCD23 or CD23-derived RKC-containing peptides. This effect was restricted to B-cell precursors and was specific to SDF-1.
- Full Text:
- Date Issued: 2009
Hydrology, sediment transport dynamics and geomorphology of a variable flow river : the Mfolozi River, South Africa
- Grenfell, Suzanne E, Ellery, William F N
- Authors: Grenfell, Suzanne E , Ellery, William F N
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6632 , http://hdl.handle.net/10962/d1006826
- Description: The co-efficient of variation for inter-annual streamflow of the Mfolozi River is extremely high at 79%. An analysis of flow frequency indicated that streamflow is skewed towards low-flow values, with a number of extremely large flood events occurring as outliers on the histogram. Streamflow variability in the Mfolozi River may be linked to multiple factors including a large catchment size, a seasonal climate of a dry winter and wet summer, evergreen vegetation in the catchment, variable precipitation and the occurrence of regionally pervasive climatic oscillations. This research aimed to address how streamflow variability impacted upon sediment transport and thus, geomorphology. It was found that sediment transport variability occurred at the intra-and inter-annual scale. Analysis of mean monthly sediment concentration and discharge showed a hysteresis effect, such that sediment concentration peaked prior to discharge in the early wet season. During the late wet season, peak discharges often had unexpectedly low sediment concentrations. Furthermore, data suggested the existence of long-term hysteresis that may be related to decadal-scale climatic oscillations that alter sediment availability and stream capacity, resulting in discharge peaking in 2000 and sediment concentration in 2005. However, more data are required to confirm this relationship. Variability in streamflow appears to share a causal relationship with sediment transport variability, as both are linked to variation in precipitation and the resultant impacts on vegetation growth and evapotranspiration rates. The variability of streamflow and sediment transport has implications for stream and floodplain geomorphology, and the hydrology of variable rivers should be considered when interpreting their geomorphology.
- Full Text:
- Date Issued: 2009
- Authors: Grenfell, Suzanne E , Ellery, William F N
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6632 , http://hdl.handle.net/10962/d1006826
- Description: The co-efficient of variation for inter-annual streamflow of the Mfolozi River is extremely high at 79%. An analysis of flow frequency indicated that streamflow is skewed towards low-flow values, with a number of extremely large flood events occurring as outliers on the histogram. Streamflow variability in the Mfolozi River may be linked to multiple factors including a large catchment size, a seasonal climate of a dry winter and wet summer, evergreen vegetation in the catchment, variable precipitation and the occurrence of regionally pervasive climatic oscillations. This research aimed to address how streamflow variability impacted upon sediment transport and thus, geomorphology. It was found that sediment transport variability occurred at the intra-and inter-annual scale. Analysis of mean monthly sediment concentration and discharge showed a hysteresis effect, such that sediment concentration peaked prior to discharge in the early wet season. During the late wet season, peak discharges often had unexpectedly low sediment concentrations. Furthermore, data suggested the existence of long-term hysteresis that may be related to decadal-scale climatic oscillations that alter sediment availability and stream capacity, resulting in discharge peaking in 2000 and sediment concentration in 2005. However, more data are required to confirm this relationship. Variability in streamflow appears to share a causal relationship with sediment transport variability, as both are linked to variation in precipitation and the resultant impacts on vegetation growth and evapotranspiration rates. The variability of streamflow and sediment transport has implications for stream and floodplain geomorphology, and the hydrology of variable rivers should be considered when interpreting their geomorphology.
- Full Text:
- Date Issued: 2009
Aes white paper: Best practices in network audio
- Bouillot, Nicolas, Cohen, Elizabeth, Cooperstock, Jeremy R, Floros, Andreas, Fonseca, Nuno, Foss, Richard, Goodman, Michael, Grant, John, Gross, Kevin, Harris, Steven, Harshbarger, Brent, Heyraud, Joffrey, Jonsson, Lars, Narus, John, Page, Michael, Snook, Tom, Tanaka, Atau, Trieger, Justin, Zanghieri, Umberto
- Authors: Bouillot, Nicolas , Cohen, Elizabeth , Cooperstock, Jeremy R , Floros, Andreas , Fonseca, Nuno , Foss, Richard , Goodman, Michael , Grant, John , Gross, Kevin , Harris, Steven , Harshbarger, Brent , Heyraud, Joffrey , Jonsson, Lars , Narus, John , Page, Michael , Snook, Tom , Tanaka, Atau , Trieger, Justin , Zanghieri, Umberto
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427181 , vital:72420 , https://www.aes.org/e-lib/browse.cfm?elib=14839
- Description: Analog audio needs a separate physical circuit for each channel. Each microphone in a studio or on a stage, for example, must have its own circuit back to the mixer. Routing of the signals is inflexible. Digital audio is frequently wired in a similar way to analog. Although several channels can share a single physical circuit ( e. g., up to 64 with AES10 ), thus reducing the number of cores needed in a cable. Routing of signals is still inflexible and any change to the equipment in a location is liable to require new cabling. Networks allow much more flexibility. Any piece of equipment plugged into the network is able to communicate with any other. However, installers of audio networks need to be aware of a number of issues that affect audio signals but are not important for data networks and are not addressed by current IT networking technologies such as IP. This white paper examines these issues and provides guidance to installers and users that can help them build successful networked systems.
- Full Text:
- Date Issued: 2009
- Authors: Bouillot, Nicolas , Cohen, Elizabeth , Cooperstock, Jeremy R , Floros, Andreas , Fonseca, Nuno , Foss, Richard , Goodman, Michael , Grant, John , Gross, Kevin , Harris, Steven , Harshbarger, Brent , Heyraud, Joffrey , Jonsson, Lars , Narus, John , Page, Michael , Snook, Tom , Tanaka, Atau , Trieger, Justin , Zanghieri, Umberto
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427181 , vital:72420 , https://www.aes.org/e-lib/browse.cfm?elib=14839
- Description: Analog audio needs a separate physical circuit for each channel. Each microphone in a studio or on a stage, for example, must have its own circuit back to the mixer. Routing of the signals is inflexible. Digital audio is frequently wired in a similar way to analog. Although several channels can share a single physical circuit ( e. g., up to 64 with AES10 ), thus reducing the number of cores needed in a cable. Routing of signals is still inflexible and any change to the equipment in a location is liable to require new cabling. Networks allow much more flexibility. Any piece of equipment plugged into the network is able to communicate with any other. However, installers of audio networks need to be aware of a number of issues that affect audio signals but are not important for data networks and are not addressed by current IT networking technologies such as IP. This white paper examines these issues and provides guidance to installers and users that can help them build successful networked systems.
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- Date Issued: 2009
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