title: Isotopic fractionation in a large herbivorous insect, the Auckland tree weta

authors: Wehi, Priscilla M.

subjects: discrimination factor

abstract: Determining diet and trophic position of species with stable isotopes requires appropriate trophic enrichment estimates between an animal and its potential foods. These estimates are particularly important for cryptic foragers where there is little comparative dietary information. Nonetheless, many trophic enrichment estimates are based on related taxa, without confirmation of accuracy using laboratory trials. We used stable isotope analysis to investigate diet and to resolve trophic relationships in a large endemic insect, the Auckland tree weta (Hemideina thoracica White). Comparisons of isotopes in plant foods fed to captive wetas with isotope ratios in their frass provided variable results, so frass isotope values had limited usefulness as a proxy indicator of trophic level. Isotopic values varied between different tissues, with trophic depletion of 15N highest in body fat and testes. Tissue fractionation was consistent in captive and wild caught wetas, and isotopic values were not significantly different between the two groups, suggesting that this weta species is primarily herbivorous. Whole-body values in captive wetas demonstrated trophic depletion (Δδ) for δ¹⁵N of about–0.77‰ and trophic enrichment of 4.28‰ for δ¹³C. These values differ from commonly estimated trophic enrichments for both insects and herbivores and indicate the importance of laboratory trials to determine trophic enrichment. Isotopic values for femur muscles from a number of local wild weta populations did not vary consistently with body weight or size, suggesting that juveniles eat the same foods as adults. Considerable variation among individuals within and between populations suggest that isotopic values are strongly influenced by food availability and individual foraging traits.

text: Isotopic fractionation in a large herbivorous insect, the Auckland tree weta Determining diet and trophic position of species with stable isotopes requires appropriate trophic enrichment estimates between an animal and its potential foods. These estimates are particularly important for cryptic foragers where there is little comparative dietary information. Nonetheless, many trophic enrichment estimates are based on related taxa, without confirmation of accuracy using laboratory trials. We used stable isotope analysis to investigate diet and to resolve trophic relationships in a large endemic insect, the Auckland tree weta (Hemideina thoracica White). Comparisons of isotopes in plant foods fed to captive wetas with isotope ratios in their frass provided variable results, so frass isotope values had limited usefulness as a proxy indicator of trophic level. Isotopic values varied between different tissues, with trophic depletion of 15N highest in body fat and testes. Tissue fractionation was consistent in captive and wild caught wetas, and isotopic values were not significantly different between the two groups, suggesting that this weta species is primarily herbivorous. Whole-body values in captive wetas demonstrated trophic depletion (Δδ) for δ¹⁵N of about–0.77‰ and trophic enrichment of 4.28‰ for δ¹³C. These values differ from commonly estimated trophic enrichments for both insects and herbivores and indicate the importance of laboratory trials to determine trophic enrichment. Isotopic values for femur muscles from a number of local wild weta populations did not vary consistently with body weight or size, suggesting that juveniles eat the same foods as adults. Considerable variation among individuals within and between populations suggest that isotopic values are strongly influenced by food availability and individual foraging traits.

year: 2010

title: Human factors affecting the control and perception of motor vehicle dynamics

authors: Spackman, Kerry

abstract: Vehicle Dynamics Engineers (VDEs) responsible for developing passenger vehicles and Elite Race Drivers were analysed over a 5 year period using telemetry data. Investigations were undertaken in an attempt to identify the most important rate limiting factors for each profession and to develop effective training methods for them. 

In a preliminary investigation it was found that the VDEs were unable to reliably detect certain changes to a vehicle’s dynamic behaviour despite their high confidence that they were doing so. This result led to the main VDE study where the VDEs were assessed using a Rotary vestibular platform, the RAF Basic Attributes tests and telemetry analysis of their performance while they evaluated changes to a vehicle’s dynamic behaviour. It was found that there was no significant relation between either the Attributes scores or vestibular performance and the VDEs’ ability to discriminate changes to the dynamic behaviour of a vehicle, termed their Evaluation performance. 

After the VDE’s baseline Evaluation performance was established, they received individual training to improve both their performance at sensing dynamic motion (Perceptual performance) and their consistency and accuracy of controlling vehicle motion (Control performance). The VDEs were then retested to determine the effect of this training on their Evaluation performance. Whereas before training most VDEs scored in the worst Evaluation performance category, after training most scored in the highest Evaluation performance category. A new mathematical technique for analysing telemetry data was developed which allowed us to separately determine the effects of Perceptual performance and Control performance on Evaluation performance. It was found that improving the VDE’s Perceptual performance accounted for all improvements in their Evaluation performance whereas Control performance was unrelated to their Evaluation performance. This finding led to the development of a new Human Factors training program which will be instituted for all Ford’s professional VDEs from 1996 onward. 

In the Elite race driver study, a mathematical model was developed which allowed us to simulate the effect of altering a driver’s curvature control strategy, which is a key component of a driver’s style, on lap times. It was found that all drivers tested, with the notable exception of 3 times World Formula 1 Champion Jackie Stewart, had inadequate and / or faulty cognitive models for optimising curvature control when compared to our computer simulations. Training the subjects to improve their curvature control model produced substantial objective improvements in performance whereas additional unaided practice produced no improvement. For example a 19 year old N.Z. race driver was trained in one afternoon to lap faster than the current World Touring Car champion using the same vehicle.

text: Human factors affecting the control and perception of motor vehicle dynamics Vehicle Dynamics Engineers (VDEs) responsible for developing passenger vehicles and Elite Race Drivers were analysed over a 5 year period using telemetry data. Investigations were undertaken in an attempt to identify the most important rate limiting factors for each profession and to develop effective training methods for them. 

In a preliminary investigation it was found that the VDEs were unable to reliably detect certain changes to a vehicle’s dynamic behaviour despite their high confidence that they were doing so. This result led to the main VDE study where the VDEs were assessed using a Rotary vestibular platform, the RAF Basic Attributes tests and telemetry analysis of their performance while they evaluated changes to a vehicle’s dynamic behaviour. It was found that there was no significant relation between either the Attributes scores or vestibular performance and the VDEs’ ability to discriminate changes to the dynamic behaviour of a vehicle, termed their Evaluation performance. 

After the VDE’s baseline Evaluation performance was established, they received individual training to improve both their performance at sensing dynamic motion (Perceptual performance) and their consistency and accuracy of controlling vehicle motion (Control performance). The VDEs were then retested to determine the effect of this training on their Evaluation performance. Whereas before training most VDEs scored in the worst Evaluation performance category, after training most scored in the highest Evaluation performance category. A new mathematical technique for analysing telemetry data was developed which allowed us to separately determine the effects of Perceptual performance and Control performance on Evaluation performance. It was found that improving the VDE’s Perceptual performance accounted for all improvements in their Evaluation performance whereas Control performance was unrelated to their Evaluation performance. This finding led to the development of a new Human Factors training program which will be instituted for all Ford’s professional VDEs from 1996 onward. 

In the Elite race driver study, a mathematical model was developed which allowed us to simulate the effect of altering a driver’s curvature control strategy, which is a key component of a driver’s style, on lap times. It was found that all drivers tested, with the notable exception of 3 times World Formula 1 Champion Jackie Stewart, had inadequate and / or faulty cognitive models for optimising curvature control when compared to our computer simulations. Training the subjects to improve their curvature control model produced substantial objective improvements in performance whereas additional unaided practice produced no improvement. For example a 19 year old N.Z. race driver was trained in one afternoon to lap faster than the current World Touring Car champion using the same vehicle.

year: 1996

title: Taku Kuru Pounamu

authors: Pihama, Leonie

abstract: ‘Taku kuru pounamu’ (My precious adornment) is a whakataukī that speaks of a child who is loved and cherished by their whānau. It represents for us the essence of this publication, an expression of the collective wisdom and values of our ancestors, and the adoration that we have for our tamariki. A selection of whakataukī, or ancestral sayings, form the basis of this publication. Each whakataukī reflects the centrality and importance of children in the Māori world. They also give insights into practices that uplift our tamariki, mokopuna and wider whānau.
‘Taku kuru pounamu’ was born out of the research project ‘Tiakina Te Pā Harakeke’ which explores the mana of te pā harakeke, the collective values that nourish all whanau members. ‘Tiakina Te Pā Harakeke’ provided an opportunity to investigate and understand more fully our knowledge, beliefs and practices relating to whānau, and more specifically childrearing, in the Māori world. What we found was confirmation that our own tikanga, our cultural practices, are about enhancing the well-being of tamariki as taonga within our whānau, hapū and iwi.
This is a small selection of whakataukī. Many of them remind us that we need to be mindful of our actions. We must always treat each other with care and respect, especially our children. Our actions should ensure the safety and well-being of our tamariki, mokopuna, and whānau, and should never be harmful. These are critical messages passed to us by our tūpuna. These ancestral messages provide us with examples of traditional childrearing philosophies and practices.
Many valuable lessons are encoded in the language of whakataukī and in this publication we touch on but a few. In deciding which whakataukī should feature, it was important for us to acknowledge the voices of those who contributed to ‘Tiakina Te Pā Harakeke’ and to include, where possible, whakataukī shared with us by kaumātua during our interviews. A number of other whakataukī pertinent to the whānau context, have also been included as examples of how we can draw upon ancestral knowledge to support the care and nurturing of our tamariki and mokopuna today. While there is a wealth of whakataukī worthy of inclusion in this publication, many were unable to be included, due to the timeframe of the publication.
We hope that we have done justice to those whakataukī that have been included in this publication. We set out with a goal to share positive, culturally enriched and effective approaches to childrearing as defined and practiced by our tūpuna. It is our sincere hope that we have done this and that applying the cultural knowledge embodied in these whakataukī will enrich and enhance the experiences of our tamariki, mokopuna and whānau.
These are gifts of mana left to us by our tūpuna to share with present and future generations.

text: Taku Kuru Pounamu ‘Taku kuru pounamu’ (My precious adornment) is a whakataukī that speaks of a child who is loved and cherished by their whānau. It represents for us the essence of this publication, an expression of the collective wisdom and values of our ancestors, and the adoration that we have for our tamariki. A selection of whakataukī, or ancestral sayings, form the basis of this publication. Each whakataukī reflects the centrality and importance of children in the Māori world. They also give insights into practices that uplift our tamariki, mokopuna and wider whānau.
‘Taku kuru pounamu’ was born out of the research project ‘Tiakina Te Pā Harakeke’ which explores the mana of te pā harakeke, the collective values that nourish all whanau members. ‘Tiakina Te Pā Harakeke’ provided an opportunity to investigate and understand more fully our knowledge, beliefs and practices relating to whānau, and more specifically childrearing, in the Māori world. What we found was confirmation that our own tikanga, our cultural practices, are about enhancing the well-being of tamariki as taonga within our whānau, hapū and iwi.
This is a small selection of whakataukī. Many of them remind us that we need to be mindful of our actions. We must always treat each other with care and respect, especially our children. Our actions should ensure the safety and well-being of our tamariki, mokopuna, and whānau, and should never be harmful. These are critical messages passed to us by our tūpuna. These ancestral messages provide us with examples of traditional childrearing philosophies and practices.
Many valuable lessons are encoded in the language of whakataukī and in this publication we touch on but a few. In deciding which whakataukī should feature, it was important for us to acknowledge the voices of those who contributed to ‘Tiakina Te Pā Harakeke’ and to include, where possible, whakataukī shared with us by kaumātua during our interviews. A number of other whakataukī pertinent to the whānau context, have also been included as examples of how we can draw upon ancestral knowledge to support the care and nurturing of our tamariki and mokopuna today. While there is a wealth of whakataukī worthy of inclusion in this publication, many were unable to be included, due to the timeframe of the publication.
We hope that we have done justice to those whakataukī that have been included in this publication. We set out with a goal to share positive, culturally enriched and effective approaches to childrearing as defined and practiced by our tūpuna. It is our sincere hope that we have done this and that applying the cultural knowledge embodied in these whakataukī will enrich and enhance the experiences of our tamariki, mokopuna and whānau.
These are gifts of mana left to us by our tūpuna to share with present and future generations.

year: 2015