title: The metabolic response of huhu larvae, prionoplus reticularis (coleopteran : cerambycidae) to stress from elevated temperature and reduced oxygen

authors: Rogers, David John

abstract: Huhu, Prionoplus reticularis White (Coleoptera: Cerambycidae), are native New Zealand borers of quarantine importance. Huhu do not attack living trees, although their eggs can be laid on freshly-felled timber and larvae may be found in older export timber. To control insect pests, many logs from New Zealand are currently fumigated with methyl bromide (MBr), which has led to research to find alternatives for this ozone-depleting chemical. Treatments using heat and controlled atmospheres require a large amount of insect mortality data, often collected on a trial and error basis, which is time consuming and expensive. Insect physiological responses to treatment stress may complement mortality studies. These physiological studies on huhu sought to determine how huhu larvae respond to stresses caused by elevated temperature and low oxygen atmospheres. The purpose was to identify metabolic responses in huhu that could assist with development of commodity, insect disinfestation strategies. 
An artificial diet for huhu larvae was developed and tested for rearing uniform insects for physiological studies. Larvae were reared at 20 and 25°C and two day-lengths to identify suitable rearing conditions. The artificial diet was suitable for rearing huhu larvae at 20°C with either day-length. Rearing at 25°C shortened development time initially, but ultimately, larval weight decreased and many died. 
Huhu larvae had standard and active metabolic rates at 20°C of 1.66 and 4.42 μmol.kg⁻¹.s⁻¹, respectively as measured by manometric compensatory respirometry. Larval metabolic rate increased 1.72 times in response to a 10°C increase in temperature, over the range of 20 to 42°C. At temperatures greater than 35°C, larval movement ceased, consistent with stress responses reported for other insects. 
An automated gas analysis system was constructed and calibrated, which redirected the focus of planned research using the manometric system. SMR for huhu at 20- 40°C was lower than predicted values, but within the range of non-flying adult coleopterans and had a mass exponent between 0.62 and 0.67. The respiratory quotient (RQ) increased with temperature, suggesting a shift from metabolising fat to include other substrates. Activity increased larval metabolism but RQ was independent of activity at 20°C. Temperature sensitivity was similar when measured by gas analysis or manometrically. 
Huhu oxygen consumption ( ṀO₂ ) and carbon dioxide production ( ṀCO₂ ) were measured with the automated gas analysis system. .When larvae were exposed to extreme constant temperatures, 35-45°C, larval ṀO₂ increased until a critical temperature (42/43°C) resulted in falling ṀO₂ , which was exacerbated by time. ṀCO₂ reached a thermal maximum, suggesting the elimination of carbon dioxide may be a limiting factor. These changes in metabolism were consistent with mortality studies on huhu exposed to heat. Larval ṀCO₂ was reduced in 1.8% oxygen and movement ceased, suggesting huhu use metabolic depression to survive hypoxia. Recovery from anoxia increased ṀO₂ as larvae repaid an oxygen debt. 
Huhu haemolymph pH and lactate levels were measured after exposure to stress. Extreme temperature, reduced oxygen atmospheres and their combinations increased anaerobiosis, indicated by increased haemolymph acidosis and lactate. The metabolic response depended on the severity of the atmosphere-temperature treatment and exposure time. 
This study has successfully measured the metabolism of a larval cerambycid, and added valuable knowledge to the relative paucity of studies in this subject area. In response to stress, huhu larvae can utilise anaerobic pathways leading to severe acidosis with large amounts of lactate, in contrast to much of the published literature. The respiratory responses and increased anaerobic respiration found in this study, when an insect is exposed to stress, will assist the development of commodity disinfestation protocols and will contribute to a reduction the use of MBr.

text: The metabolic response of huhu larvae, prionoplus reticularis (coleopteran : cerambycidae) to stress from elevated temperature and reduced oxygen Huhu, Prionoplus reticularis White (Coleoptera: Cerambycidae), are native New Zealand borers of quarantine importance. Huhu do not attack living trees, although their eggs can be laid on freshly-felled timber and larvae may be found in older export timber. To control insect pests, many logs from New Zealand are currently fumigated with methyl bromide (MBr), which has led to research to find alternatives for this ozone-depleting chemical. Treatments using heat and controlled atmospheres require a large amount of insect mortality data, often collected on a trial and error basis, which is time consuming and expensive. Insect physiological responses to treatment stress may complement mortality studies. These physiological studies on huhu sought to determine how huhu larvae respond to stresses caused by elevated temperature and low oxygen atmospheres. The purpose was to identify metabolic responses in huhu that could assist with development of commodity, insect disinfestation strategies. 
An artificial diet for huhu larvae was developed and tested for rearing uniform insects for physiological studies. Larvae were reared at 20 and 25°C and two day-lengths to identify suitable rearing conditions. The artificial diet was suitable for rearing huhu larvae at 20°C with either day-length. Rearing at 25°C shortened development time initially, but ultimately, larval weight decreased and many died. 
Huhu larvae had standard and active metabolic rates at 20°C of 1.66 and 4.42 μmol.kg⁻¹.s⁻¹, respectively as measured by manometric compensatory respirometry. Larval metabolic rate increased 1.72 times in response to a 10°C increase in temperature, over the range of 20 to 42°C. At temperatures greater than 35°C, larval movement ceased, consistent with stress responses reported for other insects. 
An automated gas analysis system was constructed and calibrated, which redirected the focus of planned research using the manometric system. SMR for huhu at 20- 40°C was lower than predicted values, but within the range of non-flying adult coleopterans and had a mass exponent between 0.62 and 0.67. The respiratory quotient (RQ) increased with temperature, suggesting a shift from metabolising fat to include other substrates. Activity increased larval metabolism but RQ was independent of activity at 20°C. Temperature sensitivity was similar when measured by gas analysis or manometrically. 
Huhu oxygen consumption ( ṀO₂ ) and carbon dioxide production ( ṀCO₂ ) were measured with the automated gas analysis system. .When larvae were exposed to extreme constant temperatures, 35-45°C, larval ṀO₂ increased until a critical temperature (42/43°C) resulted in falling ṀO₂ , which was exacerbated by time. ṀCO₂ reached a thermal maximum, suggesting the elimination of carbon dioxide may be a limiting factor. These changes in metabolism were consistent with mortality studies on huhu exposed to heat. Larval ṀCO₂ was reduced in 1.8% oxygen and movement ceased, suggesting huhu use metabolic depression to survive hypoxia. Recovery from anoxia increased ṀO₂ as larvae repaid an oxygen debt. 
Huhu haemolymph pH and lactate levels were measured after exposure to stress. Extreme temperature, reduced oxygen atmospheres and their combinations increased anaerobiosis, indicated by increased haemolymph acidosis and lactate. The metabolic response depended on the severity of the atmosphere-temperature treatment and exposure time. 
This study has successfully measured the metabolism of a larval cerambycid, and added valuable knowledge to the relative paucity of studies in this subject area. In response to stress, huhu larvae can utilise anaerobic pathways leading to severe acidosis with large amounts of lactate, in contrast to much of the published literature. The respiratory responses and increased anaerobic respiration found in this study, when an insect is exposed to stress, will assist the development of commodity disinfestation protocols and will contribute to a reduction the use of MBr.

year: 2005

title: Probability calibration trees

authors: Leathart, Tim

subjects: computer science

abstract: Obtaining accurate and well calibrated probability estimates from classifiers is useful in many applications, for example, when minimising the expected cost of classifications. Existing methods of calibrating probability estimates are applied globally, ignoring the potential for improvements by applying a more fine-grained model. We propose probability calibration trees, a modification of logistic model trees that identifies regions of the input space in which different probability calibration models are learned to improve performance. We compare probability calibration trees to two widely used calibration methods—isotonic regression and Platt scaling—and show that our method results in lower root mean squared error on average than both methods, for estimates produced by a variety of base learners.

text: Probability calibration trees Obtaining accurate and well calibrated probability estimates from classifiers is useful in many applications, for example, when minimising the expected cost of classifications. Existing methods of calibrating probability estimates are applied globally, ignoring the potential for improvements by applying a more fine-grained model. We propose probability calibration trees, a modification of logistic model trees that identifies regions of the input space in which different probability calibration models are learned to improve performance. We compare probability calibration trees to two widely used calibration methods—isotonic regression and Platt scaling—and show that our method results in lower root mean squared error on average than both methods, for estimates produced by a variety of base learners.

year: 2017

title: An evaluation of Te Rau Puawai workforce 100: Perspectives of Te Rau Puawai bursars

authors: Nikora, Linda Waimarie

subjects: Maori students

abstract: The Te Rau Puawai programme is an attempt to change the nature of the Maori
mental health workforce. To do this, Maori with aspirations to work, or to continue to
work in the mental health workforce, are supported, financially and academically, to
complete a tertiary qualification relevant to the field.
To evaluate the Te Rau Puawai programme, the Ministry of Health commissioned the
Maori and Psychology Research Unit of the University of Waikato in July 2001. The
overall aim of the evaluation was to provide the Ministry with a clearer understanding
of the programme including: the perceived critical success factors, the barriers if any
regarding Te Rau Puawai, the impact of the programme, the extent to which the
programme may be transferable, gaps in the programme, and suggested
improvements.
The evaluation team set out to gather the experiences and perspectives of recipients of
Te Rau Puawai services by asking all bursars to complete a questionnaire and
volunteer for follow up interviews or focus groups. Sixty two bursars responded to
our questionnaire, and we complete focus group or individual follow up interviews
with 19 bursars.

text: An evaluation of Te Rau Puawai workforce 100: Perspectives of Te Rau Puawai bursars The Te Rau Puawai programme is an attempt to change the nature of the Maori
mental health workforce. To do this, Maori with aspirations to work, or to continue to
work in the mental health workforce, are supported, financially and academically, to
complete a tertiary qualification relevant to the field.
To evaluate the Te Rau Puawai programme, the Ministry of Health commissioned the
Maori and Psychology Research Unit of the University of Waikato in July 2001. The
overall aim of the evaluation was to provide the Ministry with a clearer understanding
of the programme including: the perceived critical success factors, the barriers if any
regarding Te Rau Puawai, the impact of the programme, the extent to which the
programme may be transferable, gaps in the programme, and suggested
improvements.
The evaluation team set out to gather the experiences and perspectives of recipients of
Te Rau Puawai services by asking all bursars to complete a questionnaire and
volunteer for follow up interviews or focus groups. Sixty two bursars responded to
our questionnaire, and we complete focus group or individual follow up interviews
with 19 bursars.

year: 2002-05-01