title: Structural complexity in isoprenoid glycerol dialkyl glycerol tetraether lipid cores of Sulfolobus and other archaea revealed by liquid chromatography–tandem mass spectrometry

authors: Knappy, Chris S.

subjects: archaea

abstract: Liquid chromatography-tandem mass spectrometry of membrane lipid cores from Sulfolobus species reveals isomeric forms of ring-containing isoprenoid glycerol dialkyl glycerol tetraether components not previously recognised via the use of NMR and liquid chromatography-mass spectrometry techniques. Equivalent isomerism was confirmed for the components in other hyperthermophilic genera and in sediments which contain the lipids of mesophilic archaea. The recognition of the isomeric structures in distinct archaeal clades suggests that profiles of tetraether lipids reported previously may have oversimplified the true lipid complexity in archaeal cultures and natural environments. Accordingly, the extent of variation in tetraether structures revealed by the work should direct more informative interpretations of lipid profiles in the future. Moreover, the results emphasise that tandem mass spectrometry provides a unique capability for assigning the structures of intact tetraether lipid cores for co-eluting species during chromatographic separation.

text: Structural complexity in isoprenoid glycerol dialkyl glycerol tetraether lipid cores of Sulfolobus and other archaea revealed by liquid chromatography–tandem mass spectrometry Liquid chromatography-tandem mass spectrometry of membrane lipid cores from Sulfolobus species reveals isomeric forms of ring-containing isoprenoid glycerol dialkyl glycerol tetraether components not previously recognised via the use of NMR and liquid chromatography-mass spectrometry techniques. Equivalent isomerism was confirmed for the components in other hyperthermophilic genera and in sediments which contain the lipids of mesophilic archaea. The recognition of the isomeric structures in distinct archaeal clades suggests that profiles of tetraether lipids reported previously may have oversimplified the true lipid complexity in archaeal cultures and natural environments. Accordingly, the extent of variation in tetraether structures revealed by the work should direct more informative interpretations of lipid profiles in the future. Moreover, the results emphasise that tandem mass spectrometry provides a unique capability for assigning the structures of intact tetraether lipid cores for co-eluting species during chromatographic separation.

year: 2012

title: Oxytocin and Vasopressin Neuronal Activity In Response to Novel Versus Familiar Object Exposure In Mice

authors: Gerring, Crystal

subjects: oxytocin

abstract: Oxytocin (OT) and vasopressin (AVP), peptides synthesised in the hypothalamic supraoptic and paraventricular nuclei, are released during the introduction to a familiar or novel stimulus in low-stress social and environmental scenarios. Importantly, it is unknown whether the activity of neurons synthesising OT and AVP differs when animals are exposed to novel versus familiar objects.  Therefore, mice were subjected to a short-term presence of a novel or familiar, small and distinctively shaped plastic object in a pre-exposed arena.  Immunohistochemical analysis following exposure to a novel versus familiar object showed significantly greater activation of OT and AVP neurons in the paraventricular nucleus of the hypothalamus when exposed to a familiar stimulus versus a novel stimulus. Furthermore, immunohistochemical analysis showed an increasing, but not significant, trend in the number of active OT and AVP neurons in the supraoptic nucleus in response to a novel stimulus versus a familiar stimulus.  Mice who received intraperitoneal injections of OT receptor antagonist L-368,899 prior to being exposed to a familiar versus a novel object showed a significant increase in the amount of time spent with a familiar object and a decrease of time spent with a novel object.  We conclude that introduction to novelty results in a decrease in OT neuronal activity as well as changes in AVP neuronal activity in the paraventricular nucleus of the hypothalamus.

text: Oxytocin and Vasopressin Neuronal Activity In Response to Novel Versus Familiar Object Exposure In Mice Oxytocin (OT) and vasopressin (AVP), peptides synthesised in the hypothalamic supraoptic and paraventricular nuclei, are released during the introduction to a familiar or novel stimulus in low-stress social and environmental scenarios. Importantly, it is unknown whether the activity of neurons synthesising OT and AVP differs when animals are exposed to novel versus familiar objects.  Therefore, mice were subjected to a short-term presence of a novel or familiar, small and distinctively shaped plastic object in a pre-exposed arena.  Immunohistochemical analysis following exposure to a novel versus familiar object showed significantly greater activation of OT and AVP neurons in the paraventricular nucleus of the hypothalamus when exposed to a familiar stimulus versus a novel stimulus. Furthermore, immunohistochemical analysis showed an increasing, but not significant, trend in the number of active OT and AVP neurons in the supraoptic nucleus in response to a novel stimulus versus a familiar stimulus.  Mice who received intraperitoneal injections of OT receptor antagonist L-368,899 prior to being exposed to a familiar versus a novel object showed a significant increase in the amount of time spent with a familiar object and a decrease of time spent with a novel object.  We conclude that introduction to novelty results in a decrease in OT neuronal activity as well as changes in AVP neuronal activity in the paraventricular nucleus of the hypothalamus.

year: 2016

title: Ngā Tuituinga o te Pōtae: Rangatahi perspectives of leadership within Ngāti Maniapoto

authors: Moss, Luke

subjects: Rangatahi

abstract: Research on youth leadership development is often saturated by adult perceptions and thus the literature often lacks youth voice and youth perspective on what integral areas are needed for successful youth leadership development. This research focuses on the rangatahi of Ngāti Maniapoto and their perspectives of leadership within the iwi to aid the gap in academic literature relating to youth perception of leadership development.

Maniapoto has an abundance of leadership examples from the plethora of tūpuna that have developed the iwi to the leaders of contemporary Maniapoto pushing the iwi forward. The purpose of this research is to delve into the perspectives of rangatahi Maniapoto that pertain to good leadership qualities, their perception of leadership, unique leadership styles within Maniapoto, rangatahi leadership skills and perspectives of youth development within the iwi. By interviewing rangatahi with strong connection to Maniapoto this information of their perspectives revealed four integral areas of rangatahi leadership development were collated into a model for dissemination and use within the iwi for youth development practices. This model is named Ngā Tuituinga o te Pōtae and has four areas, education, collective, communication and vision. Education was identified by rangatahi as they found that learning Maniapoto reo and tikanga was integral for a Maniapoto leader, in addition they saw an opportunity to establish a wānanga to future proof our Maniapototanga. A collective approach to leadership was highlighted as the rangatahi perceive that Maniapoto leaders need to be well known in the community and have good relationships with iwi members to be successful. Rangatahi reported that communication was an important attribute for leaders to have, not just speech but communicating by doing was essential for a Maniapoto leader. Finally, rangatahi explained that leaders need to have a vision for the taiao and a vision for our people to be a successful leader, and be able to take the iwi to a place they have not been to before.

This study adds to the scarce literature on youth perceptions on youth leadership development and definitively answers the question on how rangatahi of Maniapoto perceive leadership and how rangatahi of Maniapoto would develop leadership within Te Nehenehenui. The key findings presented in this thesis indicate that rangatahi from Maniapoto engage and identify leadership in many ways, however they do agree that leadership development is necessary for Maniapoto to flourish in the future. Applying this model and research within the iwi will create new foundations for leadership to grow within Maniapoto, and fill the gap of leadership for the iwi that rangatahi have identified.

text: Ngā Tuituinga o te Pōtae: Rangatahi perspectives of leadership within Ngāti Maniapoto Research on youth leadership development is often saturated by adult perceptions and thus the literature often lacks youth voice and youth perspective on what integral areas are needed for successful youth leadership development. This research focuses on the rangatahi of Ngāti Maniapoto and their perspectives of leadership within the iwi to aid the gap in academic literature relating to youth perception of leadership development.

Maniapoto has an abundance of leadership examples from the plethora of tūpuna that have developed the iwi to the leaders of contemporary Maniapoto pushing the iwi forward. The purpose of this research is to delve into the perspectives of rangatahi Maniapoto that pertain to good leadership qualities, their perception of leadership, unique leadership styles within Maniapoto, rangatahi leadership skills and perspectives of youth development within the iwi. By interviewing rangatahi with strong connection to Maniapoto this information of their perspectives revealed four integral areas of rangatahi leadership development were collated into a model for dissemination and use within the iwi for youth development practices. This model is named Ngā Tuituinga o te Pōtae and has four areas, education, collective, communication and vision. Education was identified by rangatahi as they found that learning Maniapoto reo and tikanga was integral for a Maniapoto leader, in addition they saw an opportunity to establish a wānanga to future proof our Maniapototanga. A collective approach to leadership was highlighted as the rangatahi perceive that Maniapoto leaders need to be well known in the community and have good relationships with iwi members to be successful. Rangatahi reported that communication was an important attribute for leaders to have, not just speech but communicating by doing was essential for a Maniapoto leader. Finally, rangatahi explained that leaders need to have a vision for the taiao and a vision for our people to be a successful leader, and be able to take the iwi to a place they have not been to before.

This study adds to the scarce literature on youth perceptions on youth leadership development and definitively answers the question on how rangatahi of Maniapoto perceive leadership and how rangatahi of Maniapoto would develop leadership within Te Nehenehenui. The key findings presented in this thesis indicate that rangatahi from Maniapoto engage and identify leadership in many ways, however they do agree that leadership development is necessary for Maniapoto to flourish in the future. Applying this model and research within the iwi will create new foundations for leadership to grow within Maniapoto, and fill the gap of leadership for the iwi that rangatahi have identified.

year: 2021