title: Properties of single fibers in global extraocular muscle of the cane toad, Bufo marinus

authors: Halsey, Elizabeth Hope

abstract: Very limited information exists on the contractile physiology of the specialized muscle fibers that make up vertebrate extraocular muscle (EOM). This study was undertaken to measure some contractile properties of fibers in the global region of EOM using the cane toad, Bufo marinus, and in particular the tonic or multiply-innervated fibers (MIFs). Fiber types were characterized using a number of methods.

Tonic and twitch fibers were identified in EOM using transmission electron microscopy. Tonic fibers lacked an M-line, had sparse sarcoplasmic reticulum (SR), few mitochondria and a thick Z-line. Some twitch fibers showed the presence of lipid stores and abundant mitochondria, whereas others were distinguished more by well developed SR. In transverse section, tonic fibers showed a felderstruktur pattern of fused myofibrils and the twitch fibers displayed a fibrillenstruktur pattern of well-delineated myofibrils.

The distribution and diameter of tonic and twitch fibers in the global region were characterized using histochemistry. Transverse sections stained for mATPase, α-GPDH and NADH-TR activity revealed the presence of at least three different fiber types in global EOM of Bufo marinus. Tonic fibers showed little or no activity for all three enzymes and were distributed randomly within the global region where they made up about 20% of the fibers. Tonic fibers always occurred at lower frequencies than twitch fibers at all diameter ranges analysed. Two further types of fiber were characterized by their histochemical appearance as twitch light and twitch dark.

Force-pCa relationships were determined for chemically skinned single fibers by recording peak isometric force at maximal and submaximal calcium activation. Fibers were found to differ in their force response to initial and maximal calcium activation. Force-pCa data were fitted to Hill plots and Hill coefficients, n₁ and n₂, obtained for responses at high and low calcium concentrations, respectively. This information together with diameter and appearance (clear versus dark) also allowed fibers to be divided into three groups. Tonic fibers developed tension slowly and had significantly lower maximum normalized tension and n₂ values than twitch light fibers. Twitch dark and twitch light fibers developed tension rapidly in response to initial and maximal calcium activation and had similar n₂ values. However, twitch dark fibers had a significantly lower maximum normalized tension than twitch light fibers. The pCa₅₀ values did not differ between the three groups of fibers. Fiber classifications were corroborated by single fiber transmission electron microscopy (TEM). SDS-PAGE followed by silver staining was used to resolve the MLC components of single fibers for which force-pCa relationships were known. Both twitch light and twitch dark fibers had three myosin light chains, each having the same electrophoretic mobility as the light chains from the fast-twitch rabbit psoas muscle. The tonic fibers were found to lack the low molecular weight light chain, myosin light chain three (MLC3), and the regulatory light chain (MLC2) of these fibers showed reduced mobility compared to that of the twitch fibers.

The finding that tonic fibers responded in a different manner to initial and maximal calcium activation from twitch fibers can be used by others to aid in their identification. The significantly different responses of twitch and tonic fibers to maximal and submaximal calcium activation highlight the extent to which these fiber types differ. Additional work using single fibers will undoubtedly reveal further differences in the composition and functioning of contractile proteins in EOM fibers.

text: Properties of single fibers in global extraocular muscle of the cane toad, Bufo marinus Very limited information exists on the contractile physiology of the specialized muscle fibers that make up vertebrate extraocular muscle (EOM). This study was undertaken to measure some contractile properties of fibers in the global region of EOM using the cane toad, Bufo marinus, and in particular the tonic or multiply-innervated fibers (MIFs). Fiber types were characterized using a number of methods.

Tonic and twitch fibers were identified in EOM using transmission electron microscopy. Tonic fibers lacked an M-line, had sparse sarcoplasmic reticulum (SR), few mitochondria and a thick Z-line. Some twitch fibers showed the presence of lipid stores and abundant mitochondria, whereas others were distinguished more by well developed SR. In transverse section, tonic fibers showed a felderstruktur pattern of fused myofibrils and the twitch fibers displayed a fibrillenstruktur pattern of well-delineated myofibrils.

The distribution and diameter of tonic and twitch fibers in the global region were characterized using histochemistry. Transverse sections stained for mATPase, α-GPDH and NADH-TR activity revealed the presence of at least three different fiber types in global EOM of Bufo marinus. Tonic fibers showed little or no activity for all three enzymes and were distributed randomly within the global region where they made up about 20% of the fibers. Tonic fibers always occurred at lower frequencies than twitch fibers at all diameter ranges analysed. Two further types of fiber were characterized by their histochemical appearance as twitch light and twitch dark.

Force-pCa relationships were determined for chemically skinned single fibers by recording peak isometric force at maximal and submaximal calcium activation. Fibers were found to differ in their force response to initial and maximal calcium activation. Force-pCa data were fitted to Hill plots and Hill coefficients, n₁ and n₂, obtained for responses at high and low calcium concentrations, respectively. This information together with diameter and appearance (clear versus dark) also allowed fibers to be divided into three groups. Tonic fibers developed tension slowly and had significantly lower maximum normalized tension and n₂ values than twitch light fibers. Twitch dark and twitch light fibers developed tension rapidly in response to initial and maximal calcium activation and had similar n₂ values. However, twitch dark fibers had a significantly lower maximum normalized tension than twitch light fibers. The pCa₅₀ values did not differ between the three groups of fibers. Fiber classifications were corroborated by single fiber transmission electron microscopy (TEM). SDS-PAGE followed by silver staining was used to resolve the MLC components of single fibers for which force-pCa relationships were known. Both twitch light and twitch dark fibers had three myosin light chains, each having the same electrophoretic mobility as the light chains from the fast-twitch rabbit psoas muscle. The tonic fibers were found to lack the low molecular weight light chain, myosin light chain three (MLC3), and the regulatory light chain (MLC2) of these fibers showed reduced mobility compared to that of the twitch fibers.

The finding that tonic fibers responded in a different manner to initial and maximal calcium activation from twitch fibers can be used by others to aid in their identification. The significantly different responses of twitch and tonic fibers to maximal and submaximal calcium activation highlight the extent to which these fiber types differ. Additional work using single fibers will undoubtedly reveal further differences in the composition and functioning of contractile proteins in EOM fibers.

year: 1999

title: The drink problem in the Te Aroha district

authors: Hart, Philip

abstract: This paper deals with the downside of drinking alcohol, not with its pleasures experienced by those indulging. Public drunkenness was always deplored, in part because it led to accidents and to criminal behaviour, in particular violence. Details of who became drunkards is given, with examples of some notable drunkards, one of them a leading businessman, and also of how women were affected by having drunken husbands. And two female drunkards are included.
To control drunkards, prohibition orders were sometimes issued, but the thirsty had various ways of evading these. Sly grog seems to have been a minor problem, perhaps because there were so many hotels. Details are given of these and how they were conducted, along with accounts of the lives of several prominent publicans, some of whom became a prey to intemperance, an occupational hazard with significant consequences for their health.
Because polite members of society and those suffering from drunkards wasting their family’s money were appalled by the behaviour described here, a strong temperance movement developed in response.

text: The drink problem in the Te Aroha district This paper deals with the downside of drinking alcohol, not with its pleasures experienced by those indulging. Public drunkenness was always deplored, in part because it led to accidents and to criminal behaviour, in particular violence. Details of who became drunkards is given, with examples of some notable drunkards, one of them a leading businessman, and also of how women were affected by having drunken husbands. And two female drunkards are included.
To control drunkards, prohibition orders were sometimes issued, but the thirsty had various ways of evading these. Sly grog seems to have been a minor problem, perhaps because there were so many hotels. Details are given of these and how they were conducted, along with accounts of the lives of several prominent publicans, some of whom became a prey to intemperance, an occupational hazard with significant consequences for their health.
Because polite members of society and those suffering from drunkards wasting their family’s money were appalled by the behaviour described here, a strong temperance movement developed in response.

year: 2016

title: Educational leadership and Māori communities’ involvement in their children’s schooling

authors: McMillan, Hoana

subjects: Educational leadership

abstract: The leadership of state primary schools in New Zealand is made up of Board of Trustees (BoT) members and the principal who together, play an important role in addressing take Māori – Māori issues, to enable better outcomes for Māori achievement and empowering relationships with Māori communities.  However not all schools have met their professional responsibilities to provide a learning environment that promotes the success of their Māori students (Education Review Office, 2010) therefore an important question for Māori communities to contemplate is whether they need to take up a more active role in ensuring accountability from these parties, as well as actively contributing to efforts to ensure better outcomes for their children.
The case studies presented in this thesis examine two successful mainstream primary schools identified as doing well in terms of Māori achievement and empowering relationships with their Māori communities.  It explores the knowledge of Māori Board of Trustees Members (MBTMS) and also their perceptions of what Māori communities know regarding school leadership and policies and procedures relating to Māori achievement and Māori communities.  It also explores the knowledge of their school leadership in terms of leadership that works well with Māori communities, and how Māori communities might work alongside school leadership effectively.  The case studies were conducted in a kaupapa Māori framework where the collection and analysis of qualitative data included school documents, observations of Boards of Trustees (BoT) meetings, information about professional development relating to Māori achievement and or Māori communities, and semi-structured interviews with the MBTMS and principals.
The literature review highlighted the relationship between the role of principals and their knowledge of Māori perspectives toward meeting outcomes for Māori achievement and empowering relationships with Māori communities. It also highlighted the role of the BoT and the implications of ethnicity and of legislation toward meeting these outcomes.  Lastly it highlighted the evolution of whānau roles within education, and the ability of whānau to challenge school leadership towards meeting these outcomes.
The findings from the case studies indicate that the knowledge of MBTMS with regards to the roles of school leadership and policies and procedures relating to Māori achievement and Māori communities were consistent with the structure of partnerships within their school leadership.  The knowledge of school leadership across the case studies regarding leadership that works well with Māori communities is consistent with traditional whānau roles within education where there is emphasis on the well-being of Māori, creating the following conditions of school culture and climate within their schools – Whakamana Tangata – Acknowledging People, Whakamana Whānau – Acknowledging Family, Whakamana Tikanga, Acknowledging Protocol, Whakamana Reo – Acknowledging Language, Matauranga Māori – Knowledge of Māori worldviews, Pono – Trust, and Manaaki – Care.
The study suggests further research examining what Māori community members, beyond MTBMS, know about the role of school leadership and of policies and procedures relating to Māori achievement and Māori communities, and how Māori communities might envisage working alongside school leadership.  However, this study does offer a useful point of reflection and discussion for school leadership interested in improving their practice toward better outcomes for Māori.

text: Educational leadership and Māori communities’ involvement in their children’s schooling The leadership of state primary schools in New Zealand is made up of Board of Trustees (BoT) members and the principal who together, play an important role in addressing take Māori – Māori issues, to enable better outcomes for Māori achievement and empowering relationships with Māori communities.  However not all schools have met their professional responsibilities to provide a learning environment that promotes the success of their Māori students (Education Review Office, 2010) therefore an important question for Māori communities to contemplate is whether they need to take up a more active role in ensuring accountability from these parties, as well as actively contributing to efforts to ensure better outcomes for their children.
The case studies presented in this thesis examine two successful mainstream primary schools identified as doing well in terms of Māori achievement and empowering relationships with their Māori communities.  It explores the knowledge of Māori Board of Trustees Members (MBTMS) and also their perceptions of what Māori communities know regarding school leadership and policies and procedures relating to Māori achievement and Māori communities.  It also explores the knowledge of their school leadership in terms of leadership that works well with Māori communities, and how Māori communities might work alongside school leadership effectively.  The case studies were conducted in a kaupapa Māori framework where the collection and analysis of qualitative data included school documents, observations of Boards of Trustees (BoT) meetings, information about professional development relating to Māori achievement and or Māori communities, and semi-structured interviews with the MBTMS and principals.
The literature review highlighted the relationship between the role of principals and their knowledge of Māori perspectives toward meeting outcomes for Māori achievement and empowering relationships with Māori communities. It also highlighted the role of the BoT and the implications of ethnicity and of legislation toward meeting these outcomes.  Lastly it highlighted the evolution of whānau roles within education, and the ability of whānau to challenge school leadership towards meeting these outcomes.
The findings from the case studies indicate that the knowledge of MBTMS with regards to the roles of school leadership and policies and procedures relating to Māori achievement and Māori communities were consistent with the structure of partnerships within their school leadership.  The knowledge of school leadership across the case studies regarding leadership that works well with Māori communities is consistent with traditional whānau roles within education where there is emphasis on the well-being of Māori, creating the following conditions of school culture and climate within their schools – Whakamana Tangata – Acknowledging People, Whakamana Whānau – Acknowledging Family, Whakamana Tikanga, Acknowledging Protocol, Whakamana Reo – Acknowledging Language, Matauranga Māori – Knowledge of Māori worldviews, Pono – Trust, and Manaaki – Care.
The study suggests further research examining what Māori community members, beyond MTBMS, know about the role of school leadership and of policies and procedures relating to Māori achievement and Māori communities, and how Māori communities might envisage working alongside school leadership.  However, this study does offer a useful point of reflection and discussion for school leadership interested in improving their practice toward better outcomes for Māori.

year: 2012