Does reservoir trophic status influence the feeding and growth of the sharptooth catfish, Clarias gariepinus (Teleostei: Clariidae)?
- Authors: Potts, Warren M , Hecht, Thomas , Andrew, Timothy G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124309 , vital:35591 , https://doi.org/10.2989/A JAS.2008.33.2.6.503
- Description: The diet and growth of sharptooth catfish, Clarias gariepinus, in an oligotrophic system (Kat River Reservoir, Eastern Cape, South Africa) were compared to those in a eutrophic system (Laing Reservoir, Eastern Cape) to determine if the trophic status of a waterbody had an effect on the growth rate of the species. In order of importance, the diet of catfish in Kat River Reservoir consisted of fish, insects, zooplankton, plant material and other items, while the diet of catfish in Laing Reservoir consisted of fish, plant material, zooplankton, other vertebrates and insects. The diets of catfish in the two reservoirs had a similarity index of 68.1% and there was no significant difference in their nutritional value. Fish prey was the most important dietary component in both reservoirs. Temperature regime and zooplankton and zoobenthos density were similar in both systems. However, fish prey density was significantly higher in the eutrophic Laing Reservoir and catfish grew significantly faster in that system. The slower growth rate in Kat River Reservoir was attributed to the higher energy costs associated with the capture of fish prey, which was less abundant than in Laing Reservoir. Trophic status therefore had an indirect effect on catfish growth by influencing the availability of fish prey.
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- Date Issued: 2010
A Grid-Based Approach to the Remote Control and Recall of the Properties of IEEE1394 Audio Devices
- Authors: Foss, Richard , Foulkes, Phillip
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427212 , vital:72422 , https://www.aes.org/e-lib/browse.cfm?elib=14453
- Description: Typically, the configuration of audio hardware and software is not integrated. This paper discusses a software system that has been developed to remotely control and recall the properties of IEEE1394 (FireWire) audio devices via a series of graphical routing matrices. The software presents sound engineers with a graphical routing matrix that shows, along its axes, the available FireWire audio devices on a FireWire network. Inter device connection management may be performed by selecting the cross points on the grid, and intra device control may be performed via device editors that are displayed via the axes of the matrix. The software application may be hosted by a compatible Digital Audio Workstation (DAW) application to allow for the storing and recalling of the various properties associated with the devices.
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- Date Issued: 2008
Enhancing end-user capabilities in high speed audio networks
- Authors: Chigwamba, Nyasha , Foss, Richard
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427279 , vital:72427 , https://www.aes.org/e-lib/browse.cfm?elib=14266
- Description: Firewire is a digital network technology that can be used to interconnect professional audio equipment, PCs and electronic devices. The Plural Node Architecture splits connection management of firewire audio devices between two nodes, namely an Enabler and a Transporter. The Audio Engineering Society’s SC-02-12-G Task Group has produced an Open Generic Transporter guideline document which describes a generic interface between the Enabler and Transporter. A client-server implementation above the Plural Node Architecture allows connection management of firewire audio devices via TCP/IP. This paper describes enhancements made to connection management applications as a result of additional capabilities revealed by the Open Generic Transporter document.
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- Date Issued: 2008