title: Tetrodotoxin Concentrations in Pleurobranchaea maculata: Temporal, Spatial and Individual Variability from New Zealand Populations

authors: Wood, Susanna A.

subjects: tetrodotoxin

abstract: Tetrodotoxin (TTX) is a potent neurotoxin that has been identified in a range of phylogenetically unrelated marine and terrestrial organisms. Tetrodotoxin was recently detected in New Zealand in Pleurobranchaea maculata (the grey side-gilled sea slug). From June 2010 to June 2011 wild specimens were collected from 10 locations around New Zealand. At one site (Narrow Neck Beach, Auckland) up to 10 individuals were collected monthly for 6 months. Attempts were also made to rear P. maculata in captivity. Tetrodotoxin was detected in samples from eight of the ten sites. The highest average (368.7 mg kg⁻¹) and maximum (1414.0 mg kg⁻¹) concentrations were measured in samples from Illiomama Rock (Auckland). Of the toxic populations tested there was significant variability in TTX concentrations among individuals, with the highest difference (62 fold) measured at Illiomama Rock. Tetrodotoxin concentrations in samples from Narrow Neck Beach varied temporally, ranging from an average of 184 mg kg⁻¹ in June 2010 to 17.5 mg kg⁻¹ by December 2010. There was no correlation between TTX levels and mass. The highest levels correspond with the egg laying season (June–August) and this, in concert with the detection of high levels of TTX in eggs and early larval stages, suggests that TTX may have a defensive function in P. maculata. Only one larva was successfully reared to full maturation and no TTX was detected.

text: Tetrodotoxin Concentrations in Pleurobranchaea maculata: Temporal, Spatial and Individual Variability from New Zealand Populations Tetrodotoxin (TTX) is a potent neurotoxin that has been identified in a range of phylogenetically unrelated marine and terrestrial organisms. Tetrodotoxin was recently detected in New Zealand in Pleurobranchaea maculata (the grey side-gilled sea slug). From June 2010 to June 2011 wild specimens were collected from 10 locations around New Zealand. At one site (Narrow Neck Beach, Auckland) up to 10 individuals were collected monthly for 6 months. Attempts were also made to rear P. maculata in captivity. Tetrodotoxin was detected in samples from eight of the ten sites. The highest average (368.7 mg kg⁻¹) and maximum (1414.0 mg kg⁻¹) concentrations were measured in samples from Illiomama Rock (Auckland). Of the toxic populations tested there was significant variability in TTX concentrations among individuals, with the highest difference (62 fold) measured at Illiomama Rock. Tetrodotoxin concentrations in samples from Narrow Neck Beach varied temporally, ranging from an average of 184 mg kg⁻¹ in June 2010 to 17.5 mg kg⁻¹ by December 2010. There was no correlation between TTX levels and mass. The highest levels correspond with the egg laying season (June–August) and this, in concert with the detection of high levels of TTX in eggs and early larval stages, suggests that TTX may have a defensive function in P. maculata. Only one larva was successfully reared to full maturation and no TTX was detected.

year: 2012

title: Traceroute probe method and forward IP path inference

authors: Luckie, Matthew John

subjects: computer science

abstract: Several traceroute probe methods exist, each designed to perform better in a scenario where another fails. This paper examines the effects that the choice of probe method has on the inferred forward IP path by comparing the paths inferred with UDP, ICMP, and TCP-based traceroute methods to (1) a list of routable IP addresses, (2) a list of known routers, and (3) a list of well-known websites. We further compare methods by examining seven months of macroscopic Internet topology data collected by CAIDA's Archipelago infrastructure.
We found significant differences in the topology observed using different probe methods. In particular, we found that ICMP-based traceroute methods tend to successfully reach more destinations, as well as collect evidence of a greater number of AS links. UDP-based methods infer the greatest number of IP links, despite reaching the fewest destinations. We hypothesise that some per-flow load balancers implement different forwarding policies for TCP and UDP, and run a specific experiment to confirm this hypothesis.

text: Traceroute probe method and forward IP path inference Several traceroute probe methods exist, each designed to perform better in a scenario where another fails. This paper examines the effects that the choice of probe method has on the inferred forward IP path by comparing the paths inferred with UDP, ICMP, and TCP-based traceroute methods to (1) a list of routable IP addresses, (2) a list of known routers, and (3) a list of well-known websites. We further compare methods by examining seven months of macroscopic Internet topology data collected by CAIDA's Archipelago infrastructure.
We found significant differences in the topology observed using different probe methods. In particular, we found that ICMP-based traceroute methods tend to successfully reach more destinations, as well as collect evidence of a greater number of AS links. UDP-based methods infer the greatest number of IP links, despite reaching the fewest destinations. We hypothesise that some per-flow load balancers implement different forwarding policies for TCP and UDP, and run a specific experiment to confirm this hypothesis.

year: 2008

title: An analysis of typical errors of young learners of te reo Maori

authors: Houia, Waldo

subjects: te reo Maori

abstract: In 1999, the New Zealand Ministry of Education commissioned the development of a draft proficiency test for learners of Māori in bilingual and immersion settings in Year 5 of schooling (aged 8 - 10). That test was, along with a range of survey materials, produced and piloted in a very short time - 13 weeks. Although it provided a starting point for further development of a proficiency battery, it did not prove sufficiently robust in itself to retain. What it did do, however, was provide a range of useful samples of the speaking and writing of Year 5 students (70 samples were collected from five different schools). These samples revealed a number of common errors, errors which were analysed and are discussed here.

text: An analysis of typical errors of young learners of te reo Maori In 1999, the New Zealand Ministry of Education commissioned the development of a draft proficiency test for learners of Māori in bilingual and immersion settings in Year 5 of schooling (aged 8 - 10). That test was, along with a range of survey materials, produced and piloted in a very short time - 13 weeks. Although it provided a starting point for further development of a proficiency battery, it did not prove sufficiently robust in itself to retain. What it did do, however, was provide a range of useful samples of the speaking and writing of Year 5 students (70 samples were collected from five different schools). These samples revealed a number of common errors, errors which were analysed and are discussed here.

year: 2002-02