A source analysis of the conficker outbreak from a network telescope.
- Authors: Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429742 , vital:72636 , 10.23919/SAIEE.2013.8531865
- Description: This paper discusses a dataset of some 16 million packets targeting port 445/tcp collected by a network telescope utilising a /24 netblock in South African IP address space. An initial overview of the collected data is provided. This is followed by a detailed analysis of the packet characteristics observed, including size and TTL. The peculiarities of the observed target selection and the results of the flaw in the Conficker worm's propagation algorithm are presented. An analysis of the 4 million observed source hosts is reported, grouped by both packet counts and the number of distinct hosts per network address block. Address blocks of size /8, 16 and 24 are used for groupings. The localisation, by geographic region and numerical proximity, of high ranking aggregate netblocks is highlighted. The observed shift in geopolitical origins observed during the evolution of the Conficker worm is also discussed. The paper concludes with some overall analyses, and consideration of the application of network telescopes to the monitoring of such outbreaks in the future.
- Full Text:
- Authors: Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429742 , vital:72636 , 10.23919/SAIEE.2013.8531865
- Description: This paper discusses a dataset of some 16 million packets targeting port 445/tcp collected by a network telescope utilising a /24 netblock in South African IP address space. An initial overview of the collected data is provided. This is followed by a detailed analysis of the packet characteristics observed, including size and TTL. The peculiarities of the observed target selection and the results of the flaw in the Conficker worm's propagation algorithm are presented. An analysis of the 4 million observed source hosts is reported, grouped by both packet counts and the number of distinct hosts per network address block. Address blocks of size /8, 16 and 24 are used for groupings. The localisation, by geographic region and numerical proximity, of high ranking aggregate netblocks is highlighted. The observed shift in geopolitical origins observed during the evolution of the Conficker worm is also discussed. The paper concludes with some overall analyses, and consideration of the application of network telescopes to the monitoring of such outbreaks in the future.
- Full Text:
An invader within an altered landscape: one catfish, two rivers and an inter-basin water transfer scheme
- Kadye, Wilbert T, Booth, Anthony J
- Authors: Kadye, Wilbert T , Booth, Anthony J
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123776 , vital:35494 , https://doi.10.1002/rra.2599
- Description: African sharptooth catfish Clarias gariepinus has become established as a non-native invasive species in Eastern Cape, South Africa, where it was translocated primarily through an inter-basin water transfer scheme into the Great Fish and Sundays rivers. This study examined the patterns in catfish distribution and abundance, and compared trophic niches in relation to the ichthyofauna of the two rivers. Correspondence analysis revealed upstream to downstream gradients associated with the spatial distribution in species richness for most species within the mainstream and mainstream to tributary gradients that were associated mostly with the spatial distribution of native minnows in both rivers. Catfish was predicted to occur widely within the mainstream habitats and to decrease progressively from mainstreams to tributaries. Based on classification and regression trees, the physico-chemical environment was found to be a good proxy for predicting the occurrence and abundance of catfish. Although non-significant relationships were observed between catfish and other native fish species abundances, the study suggests potential impact due to predation and interference in habitats where the invader co-occurs with other fishes. Comparisons of trophic niches indicated higher trophic diversity for the mainstream ichthyofauna than the tributary communities in both rivers, suggesting an upstream to downstream continuum in community structure and resource availability. Catfish within the invaded mainstream had comparable trophic niches and similar dispersion patterns among individuals for both rivers, but indicated differences in shapes of scatter. This suggests that the catfish exhibited a differential response, probably in relation to resource availability, that may be indicative of its dietary plasticity. The study suggests the proliferation of catfish and its probable impact within the mainstream flow-altered habitats where invasion resistance was possibly reduced. Comparisons of trophic niches provided information on its probable impact at different scales and the potential risk of invasion of tributaries inhabited by native minnow species.
- Full Text:
- Authors: Kadye, Wilbert T , Booth, Anthony J
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123776 , vital:35494 , https://doi.10.1002/rra.2599
- Description: African sharptooth catfish Clarias gariepinus has become established as a non-native invasive species in Eastern Cape, South Africa, where it was translocated primarily through an inter-basin water transfer scheme into the Great Fish and Sundays rivers. This study examined the patterns in catfish distribution and abundance, and compared trophic niches in relation to the ichthyofauna of the two rivers. Correspondence analysis revealed upstream to downstream gradients associated with the spatial distribution in species richness for most species within the mainstream and mainstream to tributary gradients that were associated mostly with the spatial distribution of native minnows in both rivers. Catfish was predicted to occur widely within the mainstream habitats and to decrease progressively from mainstreams to tributaries. Based on classification and regression trees, the physico-chemical environment was found to be a good proxy for predicting the occurrence and abundance of catfish. Although non-significant relationships were observed between catfish and other native fish species abundances, the study suggests potential impact due to predation and interference in habitats where the invader co-occurs with other fishes. Comparisons of trophic niches indicated higher trophic diversity for the mainstream ichthyofauna than the tributary communities in both rivers, suggesting an upstream to downstream continuum in community structure and resource availability. Catfish within the invaded mainstream had comparable trophic niches and similar dispersion patterns among individuals for both rivers, but indicated differences in shapes of scatter. This suggests that the catfish exhibited a differential response, probably in relation to resource availability, that may be indicative of its dietary plasticity. The study suggests the proliferation of catfish and its probable impact within the mainstream flow-altered habitats where invasion resistance was possibly reduced. Comparisons of trophic niches provided information on its probable impact at different scales and the potential risk of invasion of tributaries inhabited by native minnow species.
- Full Text:
Biogeographical boundaries, functional group structure and diversity of rocky shore communities along the Argentinean coast
- Wieters, Evie A, McQuaid, Christopher D, Palomo, Gabriela, Pappalardo, Paula
- Authors: Wieters, Evie A , McQuaid, Christopher D , Palomo, Gabriela , Pappalardo, Paula
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6835 , http://hdl.handle.net/10962/d1010956
- Description: We investigate the extent to which functional structure and spatial variability of intertidal communities coincide with major biogeographical boundaries, areas where extensive compositional changes in the biota are observed over a limited geographic extension. We then investigate whether spatial variation in the biomass of functional groups, over geographic (10′s km) and local (10′s m) scales, could be associated to species diversity within and among these groups. Functional community structure expressed as abundance (density, cover and biomass) and composition of major functional groups was quantified through field surveys at 20 rocky intertidal shores spanning six degrees of latitude along the southwest Atlantic coast of Argentina and extending across the boundaries between the Argentinean and Magellanic Provinces. Patterns of abundance of individual functional groups were not uniformly matched with biogeographical regions. Only ephemeral algae showed an abrupt geographical discontinuity coincident with changes in biogeographic boundaries, and this was limited to the mid intertidal zone. We identified 3–4 main ‘groups’ of sites in terms of the total and relative abundance of the major functional groups, but these did not coincide with biogeographical boundaries, nor did they follow latitudinal arrangement. Thus, processes that determine the functional structure of these intertidal communities are insensitive to biogeographical boundaries. Over both geographical and local spatial scales, and for most functional groups and tidal levels, increases in species richness within the functional group was significantly associated to increased total biomass and reduced spatial variability of the group. These results suggest that species belonging to the same functional group are sufficiently uncorrelated over space (i.e. metres and site-to-site ) to stabilize patterns of biomass variability and, in this manner, provide a buffer, or “insurance”, against spatial variability in environmental conditions.
- Full Text:
- Authors: Wieters, Evie A , McQuaid, Christopher D , Palomo, Gabriela , Pappalardo, Paula
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6835 , http://hdl.handle.net/10962/d1010956
- Description: We investigate the extent to which functional structure and spatial variability of intertidal communities coincide with major biogeographical boundaries, areas where extensive compositional changes in the biota are observed over a limited geographic extension. We then investigate whether spatial variation in the biomass of functional groups, over geographic (10′s km) and local (10′s m) scales, could be associated to species diversity within and among these groups. Functional community structure expressed as abundance (density, cover and biomass) and composition of major functional groups was quantified through field surveys at 20 rocky intertidal shores spanning six degrees of latitude along the southwest Atlantic coast of Argentina and extending across the boundaries between the Argentinean and Magellanic Provinces. Patterns of abundance of individual functional groups were not uniformly matched with biogeographical regions. Only ephemeral algae showed an abrupt geographical discontinuity coincident with changes in biogeographic boundaries, and this was limited to the mid intertidal zone. We identified 3–4 main ‘groups’ of sites in terms of the total and relative abundance of the major functional groups, but these did not coincide with biogeographical boundaries, nor did they follow latitudinal arrangement. Thus, processes that determine the functional structure of these intertidal communities are insensitive to biogeographical boundaries. Over both geographical and local spatial scales, and for most functional groups and tidal levels, increases in species richness within the functional group was significantly associated to increased total biomass and reduced spatial variability of the group. These results suggest that species belonging to the same functional group are sufficiently uncorrelated over space (i.e. metres and site-to-site ) to stabilize patterns of biomass variability and, in this manner, provide a buffer, or “insurance”, against spatial variability in environmental conditions.
- Full Text:
Place of Knowledge
- Rhodes University Development & Alumni Relations Division
- Authors: Rhodes University Development & Alumni Relations Division
- Date: 2013
- Language: English
- Type: text
- Identifier: vital:7950 , http://hdl.handle.net/10962/d1013054
- Description: [From Introduction] How it all began. The dream of the new library began with the late Margaret Kenyon. Initially joining the library staff in 1982 as a cataloguer. she was appointed to the position of University Librarian in April 2001. It was through her initiative as Head of Cataloguing that Rhodes became the first library in South Africa to create hyperlinks on OPAC records to material also available in electronic format. She was an initiator of the Rhodes eResearch Repository (ReRR) which was among the first open access institutional repositories in South Africa. She also started the LibQUAL survey and while the old library scored well on service and information, it failed dismally on place. The pattern of student use had changed and there was no space for discussion areas to accommodate peer learning and group work. With student numbers having grown to 6200 and academic staff to 300, the library could only seat 10 percent of its users. It was Mrs Kenyon who contacted Geoff de Wet, Architect and Director of the Physical Planning Unit at UCT, and arranged for him to visit the Rhodes Library. It was a great tragedy that she did not see the seed that she had planted come to fruition. The ever changing demands for versatile workspaces that are responsive to evolving patterns of teaching, learning and research require a completely new approach to university libraries. We are thrilled to have seen the Rhodes University Library evolve from humble beginnings in a single room in the old Drostdy building into its grand position as a highly technological facility today. , Indawo Yolwazi (place of knowledge) in pursuit of excellence in teaching, research and community engagement.
- Full Text:
- Authors: Rhodes University Development & Alumni Relations Division
- Date: 2013
- Language: English
- Type: text
- Identifier: vital:7950 , http://hdl.handle.net/10962/d1013054
- Description: [From Introduction] How it all began. The dream of the new library began with the late Margaret Kenyon. Initially joining the library staff in 1982 as a cataloguer. she was appointed to the position of University Librarian in April 2001. It was through her initiative as Head of Cataloguing that Rhodes became the first library in South Africa to create hyperlinks on OPAC records to material also available in electronic format. She was an initiator of the Rhodes eResearch Repository (ReRR) which was among the first open access institutional repositories in South Africa. She also started the LibQUAL survey and while the old library scored well on service and information, it failed dismally on place. The pattern of student use had changed and there was no space for discussion areas to accommodate peer learning and group work. With student numbers having grown to 6200 and academic staff to 300, the library could only seat 10 percent of its users. It was Mrs Kenyon who contacted Geoff de Wet, Architect and Director of the Physical Planning Unit at UCT, and arranged for him to visit the Rhodes Library. It was a great tragedy that she did not see the seed that she had planted come to fruition. The ever changing demands for versatile workspaces that are responsive to evolving patterns of teaching, learning and research require a completely new approach to university libraries. We are thrilled to have seen the Rhodes University Library evolve from humble beginnings in a single room in the old Drostdy building into its grand position as a highly technological facility today. , Indawo Yolwazi (place of knowledge) in pursuit of excellence in teaching, research and community engagement.
- Full Text:
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