title: Managing an invasive predator pre-adapted to a pulsed resource: a model of stoat (Mustela erminea) irruptions in New Zealand beech forests

authors: King, Carolyn M.

subjects: Nothofagus

abstract: The stoat (Mustela erminea) is a specialist predator that evolved to exploit the unstable populations of northern voles and lemmings. It was introduced to New Zealand, where it is pre-adapted to respond with a population irruption to the resource pulses that follow a heavy seedfall of southern beech (Nothofagus spp.). Culling stoats during an irruption is necessary to reduce damaging predation on nesting endemic birds. Culling might not reduce the stoat population long term, however, if high natural mortality exceeds culling mortality in peak years. During other phases of the beech-mast cycle, culling might have a greater effect on a smaller stoat population, whether or not damage prevention is critical. We developed a 4-matrix model to predict the effects of culling on k, the annual rate of change in the size of the stoat population, through the four annual phases of an average masting cycle, explicitly distinguishing between apparent and real culling. In the Post-seedfall phase of the cycle, large numbers of stoats are killed, but little of this extra mortality is additive; in other phases, culling removes larger proportions of smaller total numbers of stoats that would otherwise have lived. Culling throughout all phases is most effective at reducing stoat populations, but is also the most expensive option. Culling in Postseedfall plus Seed or Crash years is somewhat less effective but better than culling in one phase only. Culling has different short-term effects on stoat age distribution depending on the phase of the cycle when culling begins.

text: Managing an invasive predator pre-adapted to a pulsed resource: a model of stoat (Mustela erminea) irruptions in New Zealand beech forests The stoat (Mustela erminea) is a specialist predator that evolved to exploit the unstable populations of northern voles and lemmings. It was introduced to New Zealand, where it is pre-adapted to respond with a population irruption to the resource pulses that follow a heavy seedfall of southern beech (Nothofagus spp.). Culling stoats during an irruption is necessary to reduce damaging predation on nesting endemic birds. Culling might not reduce the stoat population long term, however, if high natural mortality exceeds culling mortality in peak years. During other phases of the beech-mast cycle, culling might have a greater effect on a smaller stoat population, whether or not damage prevention is critical. We developed a 4-matrix model to predict the effects of culling on k, the annual rate of change in the size of the stoat population, through the four annual phases of an average masting cycle, explicitly distinguishing between apparent and real culling. In the Post-seedfall phase of the cycle, large numbers of stoats are killed, but little of this extra mortality is additive; in other phases, culling removes larger proportions of smaller total numbers of stoats that would otherwise have lived. Culling throughout all phases is most effective at reducing stoat populations, but is also the most expensive option. Culling in Postseedfall plus Seed or Crash years is somewhat less effective but better than culling in one phase only. Culling has different short-term effects on stoat age distribution depending on the phase of the cycle when culling begins.

year: 2011

title: Kinetic and isotherm studies on adsorption of arsenic using silica based catalytic media

authors: Aremu, James Oyediji

abstract: This study investigates the removal of arsenic (both As (III) and As (V)) from drinking water using a silica based catalytic media (DMI-65). In this study, BET, FTIR, XRD, SEM and XRF were used to characterize the adsorbent before and after contact with As (III) and As (V). Batch experiments were performed to evaluate the adsorption kinetics at different pH (5, 6, 7 and 8.5). The kinetic study showed that a contact time of 6 h was needed to reach equilibrium and the experimental data were best fitted to the pseudo second-order kinetic model for both As (III) and As (V). Several batch tests were conducted with different concentration of arsenic at different pH conditions (5, 6, 7 and 8.5). During the adsorption test, the maximum adsorption of As (III) occurred at pH 5, while As (V) adsorption reached its maximum at pH 8.5. The adsorption data showed a good fit to Langmuir isotherm models and the maximum adsorption capacity of the silica based catalytic media for As (III) and As (V) were estimated to be 0.318 mg/g and 0.237 mg/g respectively.

text: Kinetic and isotherm studies on adsorption of arsenic using silica based catalytic media This study investigates the removal of arsenic (both As (III) and As (V)) from drinking water using a silica based catalytic media (DMI-65). In this study, BET, FTIR, XRD, SEM and XRF were used to characterize the adsorbent before and after contact with As (III) and As (V). Batch experiments were performed to evaluate the adsorption kinetics at different pH (5, 6, 7 and 8.5). The kinetic study showed that a contact time of 6 h was needed to reach equilibrium and the experimental data were best fitted to the pseudo second-order kinetic model for both As (III) and As (V). Several batch tests were conducted with different concentration of arsenic at different pH conditions (5, 6, 7 and 8.5). During the adsorption test, the maximum adsorption of As (III) occurred at pH 5, while As (V) adsorption reached its maximum at pH 8.5. The adsorption data showed a good fit to Langmuir isotherm models and the maximum adsorption capacity of the silica based catalytic media for As (III) and As (V) were estimated to be 0.318 mg/g and 0.237 mg/g respectively.

year: 2019

title: He reo amiorangi

authors: Roa, Tom

subjects: Māori language

abstract: This paper discusses a project involving the translation of a learning management system (LMS), Modular Object-Oriented Dynamic Learning Environment (Moodle), into te reo Māori so that users of this LMS, learners, teachers and administrators who have a high level of competence in the language, can work within a fully Māori environment. Aspects of the project referred to here include adaptation of the style guide created by Te Taura Whiri for the Microsoft project, use of the Microsoft translation guidelines, the philosophy guiding the translation and the translation process itself (with examples). The process by which the project was evaluated is also discussed.

text: He reo amiorangi This paper discusses a project involving the translation of a learning management system (LMS), Modular Object-Oriented Dynamic Learning Environment (Moodle), into te reo Māori so that users of this LMS, learners, teachers and administrators who have a high level of competence in the language, can work within a fully Māori environment. Aspects of the project referred to here include adaptation of the style guide created by Te Taura Whiri for the Microsoft project, use of the Microsoft translation guidelines, the philosophy guiding the translation and the translation process itself (with examples). The process by which the project was evaluated is also discussed.

year: 2006