title: Gossypol's effects on ingestive behaviour in mice: The first step in a systematic process to define gossypol's suitability for use in murine pest management

authors: Churchill, Geoff

subjects: Gossypol

abstract: Gossypol, synthesised by the cotton plant, Gossypium, causes physiological and behavioural changes in mammals, suggesting it may be suitable for murine pest management. One of the most under-studied responses to gossypol, especially in the house mouse, Mus musculus, is its effect on ingestive behaviour, with some authors reporting anorexia and others observing no effect on energy metabolism. Importantly, there has been no systematic analysis of gossypol’s effect on food intake in mice. Therefore, the goal of this thesis was to provide the initial step in defining gossypol’s effect on feeding behaviour in mice by observing their responses after exposure to precise doses of gossypol delivered via injection. Mice underwent two injection intraperitoneal (IP) paradigms; acute and chronic (11 daily injections) exposures to 0 (vehicle), 10, 30, 100 and 300 mg/kg b.wt., and 0 (vehicle) and 100 mg/kg b.wt. respectively. The intakes of bland (chow) and palatable tastants were measured during the acute exposure. An increase in chow intake was observed at 1 and 3 hr post-exposure with 300 mg/kg b.wt. dose. An increase in glucose intake was also observed in mice injected with 100 mg/kg b.wt. at 1 and 12 hr post-exposure. Neither of these hyperphagia responses showed a complementary increase in body weight. During the chronic exposure, body weight and chow intake were measured throughout the injection period and on select days of the 40 day post-exposure period. While there was no difference in food intake and body weight during the gossypol exposure, on day 10 post-exposure, food intake had increased by 50% and was still elevated on day 40, but no differences in body weight were noted. To examine whether this increase in food intake was an effect of a long-term anxiogenic response associated with a likely post-exposure malaise, several anxiety assessment tests were performed, showing no change. This thesis shows that gossypol affects feeding behaviour in mice. Interestingly, no anorexigenic effect was observed, but in fact moderate hyperphagia without changes in body weight was shown in both acute and chronic paradigms. The data from this thesis can be built upon with future studies using oral administration to develop the understanding of this important aspect of gossypol and to more precisely determine gossypol’s suitability for enhancing murine pest management.

text: Gossypol's effects on ingestive behaviour in mice: The first step in a systematic process to define gossypol's suitability for use in murine pest management Gossypol, synthesised by the cotton plant, Gossypium, causes physiological and behavioural changes in mammals, suggesting it may be suitable for murine pest management. One of the most under-studied responses to gossypol, especially in the house mouse, Mus musculus, is its effect on ingestive behaviour, with some authors reporting anorexia and others observing no effect on energy metabolism. Importantly, there has been no systematic analysis of gossypol’s effect on food intake in mice. Therefore, the goal of this thesis was to provide the initial step in defining gossypol’s effect on feeding behaviour in mice by observing their responses after exposure to precise doses of gossypol delivered via injection. Mice underwent two injection intraperitoneal (IP) paradigms; acute and chronic (11 daily injections) exposures to 0 (vehicle), 10, 30, 100 and 300 mg/kg b.wt., and 0 (vehicle) and 100 mg/kg b.wt. respectively. The intakes of bland (chow) and palatable tastants were measured during the acute exposure. An increase in chow intake was observed at 1 and 3 hr post-exposure with 300 mg/kg b.wt. dose. An increase in glucose intake was also observed in mice injected with 100 mg/kg b.wt. at 1 and 12 hr post-exposure. Neither of these hyperphagia responses showed a complementary increase in body weight. During the chronic exposure, body weight and chow intake were measured throughout the injection period and on select days of the 40 day post-exposure period. While there was no difference in food intake and body weight during the gossypol exposure, on day 10 post-exposure, food intake had increased by 50% and was still elevated on day 40, but no differences in body weight were noted. To examine whether this increase in food intake was an effect of a long-term anxiogenic response associated with a likely post-exposure malaise, several anxiety assessment tests were performed, showing no change. This thesis shows that gossypol affects feeding behaviour in mice. Interestingly, no anorexigenic effect was observed, but in fact moderate hyperphagia without changes in body weight was shown in both acute and chronic paradigms. The data from this thesis can be built upon with future studies using oral administration to develop the understanding of this important aspect of gossypol and to more precisely determine gossypol’s suitability for enhancing murine pest management.

year: 2014

title: Acoustic tamper detection sensor with very low false alarm rate

authors: Muijlwijk, Lawrence

subjects: false alarms

abstract: We describe a device designed to detect interference (vandalism or tampering) by acoustic means. The design employs both a piezoelectric vibration transducer and a common microphone in a novel mechanical arrangement. In contrast to conventional acoustic sensors that simply respond to vibrations above a threshold, this design analyses the outputs of the two to trigger an alarm. The method confers a near-zero susceptibility to triggering by external loud noises. No complex calculations are required so that only a low-cost, embedded microcontroller is required and the whole sensor can be very cheap. Extreme sensitivity can be achieved with little risk of false alarms.

text: Acoustic tamper detection sensor with very low false alarm rate We describe a device designed to detect interference (vandalism or tampering) by acoustic means. The design employs both a piezoelectric vibration transducer and a common microphone in a novel mechanical arrangement. In contrast to conventional acoustic sensors that simply respond to vibrations above a threshold, this design analyses the outputs of the two to trigger an alarm. The method confers a near-zero susceptibility to triggering by external loud noises. No complex calculations are required so that only a low-cost, embedded microcontroller is required and the whole sensor can be very cheap. Extreme sensitivity can be achieved with little risk of false alarms.

year: 2008

title: An indigenous model of career satisfaction: Exploring the role of workplace cultural wellbeing

authors: Haar, Jarrod M.

subjects: career satisfaction

abstract: Despite career satisfaction models being well established, little is understood about the career satisfaction of indigenous employees. Using a sample of 172 Maori employees, the indigenous people of New Zealand, we tested a career satisfaction model with a cultural wellbeing factor over and above established factors of human capital, sociodemographic, individual differences and organizational sponsorship. This new measure workplace cultural wellbeing was found to significantly relate to career satisfaction, accounting for twenty-three percent of the variance over and above the established factors which highlights its importance for indigenous workers. Furthermore, due to collectivistic orientations amongst Maori, collectivism was tested as a potential moderator and found to significantly interact with workplace cultural wellbeing, showing that Maori respondents reported the greatest career satisfaction when workplace cultural wellbeing was high, irrespective of collectivism orientation. This paper offers an extended model for exploring career satisfaction of indigenous workers.

text: An indigenous model of career satisfaction: Exploring the role of workplace cultural wellbeing Despite career satisfaction models being well established, little is understood about the career satisfaction of indigenous employees. Using a sample of 172 Maori employees, the indigenous people of New Zealand, we tested a career satisfaction model with a cultural wellbeing factor over and above established factors of human capital, sociodemographic, individual differences and organizational sponsorship. This new measure workplace cultural wellbeing was found to significantly relate to career satisfaction, accounting for twenty-three percent of the variance over and above the established factors which highlights its importance for indigenous workers. Furthermore, due to collectivistic orientations amongst Maori, collectivism was tested as a potential moderator and found to significantly interact with workplace cultural wellbeing, showing that Maori respondents reported the greatest career satisfaction when workplace cultural wellbeing was high, irrespective of collectivism orientation. This paper offers an extended model for exploring career satisfaction of indigenous workers.

year: 2013