title: Distribution of tetrodotoxin in the New Zealand clam, Paphies australis, established using immunohistochemistry and liquid chromatography-tandem quadrupole mass spectrometry

authors: Biessy, Laura

subjects: biotoxin

abstract: Tetrodotoxin (TTX) is one of the most potent neurotoxins known. It was originally thought to only occur in puffer fish but has now been identified in twelve different classes of freshwater and marine organisms, including bivalves. Despite being one of the world’s most studied biotoxins, its origin remains uncertain. There is contradictory evidence regarding the source of TTX and its pathway through food webs. To date, the distribution of TTX has not been examined in bivalves. In the present study, 48 Paphies australis, a TTX-containing clam species endemic to New Zealand, were collected. Thirty clams were dissected, and organs and tissues pooled into five categories (siphons, digestive gland, adductor muscles, and the ‘rest’) and analyzed for TTX using liquid chromatography-mass spectrometry (LC-MS). The micro-distribution of TTX was visualized in the remaining 18 individuals using an immunohistological technique incorporating a TTX-specific monoclonal antibody. The LC-MS analysis revealed that siphons contained the highest concentrations of TTX (mean 403.8 µg/kg). Immunohistochemistry analysis showed TTX in the outer cells of the siphons, but also in the digestive system, foot, and gill tissue. Observing TTX in organs involved in feeding provides initial evidence to support the hypothesis of an exogenous source in P. australis.

text: Distribution of tetrodotoxin in the New Zealand clam, Paphies australis, established using immunohistochemistry and liquid chromatography-tandem quadrupole mass spectrometry Tetrodotoxin (TTX) is one of the most potent neurotoxins known. It was originally thought to only occur in puffer fish but has now been identified in twelve different classes of freshwater and marine organisms, including bivalves. Despite being one of the world’s most studied biotoxins, its origin remains uncertain. There is contradictory evidence regarding the source of TTX and its pathway through food webs. To date, the distribution of TTX has not been examined in bivalves. In the present study, 48 Paphies australis, a TTX-containing clam species endemic to New Zealand, were collected. Thirty clams were dissected, and organs and tissues pooled into five categories (siphons, digestive gland, adductor muscles, and the ‘rest’) and analyzed for TTX using liquid chromatography-mass spectrometry (LC-MS). The micro-distribution of TTX was visualized in the remaining 18 individuals using an immunohistological technique incorporating a TTX-specific monoclonal antibody. The LC-MS analysis revealed that siphons contained the highest concentrations of TTX (mean 403.8 µg/kg). Immunohistochemistry analysis showed TTX in the outer cells of the siphons, but also in the digestive system, foot, and gill tissue. Observing TTX in organs involved in feeding provides initial evidence to support the hypothesis of an exogenous source in P. australis.

year: 2018

title: Factorial validity and invariance assessment of a short version of the recalled childhood gender identity/role questionnaire

authors: Veale, Jaimie

subjects: Social Sciences

abstract: Recalled childhood gender role/identity is a construct that is related to sexual orientation, abuse, and psychological health. The purpose of this study was to assess the factorial validity of a short version of Zucker et al.’s (2006) “Recalled Childhood Gender Identity/Gender Role Questionnaire” using confirmatory factor analysis and to test the stability of the factor structure across groups (measurement invariance). Six items of the questionnaire were completed online by 1929 participants from a variety of gender identity and sexual orientation groups. Models of the six items loading onto one factor had poor fit for the data. Items were removed for having a large proportion of error variance. Among birth-assigned females, a five-item model had good fit for the data, but there was evidence for differences in scale’s factor structure across gender identity, age, level of education, and country groups. Among birth-assigned males, the resulting four-item model did not account for all of the relationship between variables, and modeling for this resulted in a model that was almost saturated. This model also had evidence of measurement variance across gender identity and sexual orientation groups. The models had good reliability and factor score determinacy. These findings suggest that results of previous studies that have assessed recalled childhood gender role/identity may have been susceptible to construct bias due to measurement variance across these groups. Future studies should assess measurement invariance between groups they are comparing, and if it is not found the issue can be addressed by removing variant indicators and/or applying a partial invariance model.

text: Factorial validity and invariance assessment of a short version of the recalled childhood gender identity/role questionnaire Recalled childhood gender role/identity is a construct that is related to sexual orientation, abuse, and psychological health. The purpose of this study was to assess the factorial validity of a short version of Zucker et al.’s (2006) “Recalled Childhood Gender Identity/Gender Role Questionnaire” using confirmatory factor analysis and to test the stability of the factor structure across groups (measurement invariance). Six items of the questionnaire were completed online by 1929 participants from a variety of gender identity and sexual orientation groups. Models of the six items loading onto one factor had poor fit for the data. Items were removed for having a large proportion of error variance. Among birth-assigned females, a five-item model had good fit for the data, but there was evidence for differences in scale’s factor structure across gender identity, age, level of education, and country groups. Among birth-assigned males, the resulting four-item model did not account for all of the relationship between variables, and modeling for this resulted in a model that was almost saturated. This model also had evidence of measurement variance across gender identity and sexual orientation groups. The models had good reliability and factor score determinacy. These findings suggest that results of previous studies that have assessed recalled childhood gender role/identity may have been susceptible to construct bias due to measurement variance across these groups. Future studies should assess measurement invariance between groups they are comparing, and if it is not found the issue can be addressed by removing variant indicators and/or applying a partial invariance model.

year: 2016

title: Indigenous Language Usage in a Digital Library: He Hautoa Kia Ora Tonu Ai.

authors: Keegan, Te Taka Adrian Gregory

subjects: indigenous language

abstract: The research described in this thesis examines indigenous language usage in a digital library environment that has been accessed via the Internet.

By examining discretionary use of the Māori Niupepa and Hawaiian Nūpepa digital libraries this research investigates how indigenous languages were used in these electronic environments in 2005. The results provide encouragement and optimism to people who are striving to retain, revitalise and develop the use of indigenous languages in information technologies. The Transaction Log Analysis (TLA) methods used in this research serve as an example of how web logs can be used to provide significant information about language usage in a bilingual online information system. Combining the TLA with user feedback has provided insights into how and why clients use indigenous languages in their information retrieval activities. These insights in turn, show good practice that is relevant not only to those working with indigenous languages, indigenous peoples or multilingual environments, but to all information technology designers who strive for universal usability.
This thesis begins by describing the importance of using indigenous languages in electronic environments and suggests that digital libraries can provide an environment to support and encourage the use of such languages. TLA is explained in the context of this study and is then used to analyse aspects of te reo Māori usage in the Niupepa digital library environment in 2005. TLA also indicates that te reo Māori was used by international clients and this usage differed to te reo Māori usage by national (Aotearoa) clients. Findings further reveal that the default language setting of the Niupepa digital library had a considerable impact on te reo Māori usage. When the default language was set to te reo Māori not only were there more requests in te reo Māori but there was also a higher usage of te reo Māori in the information retrieval activities. TLA of the Hawaiian Nūpepa digital library indicated that the Hawaiian language was also used in a digital library. These results confirm that indigenous languages were used in digital library environments. 
Feedback from clients suggests reasons why indigenous languages were used in this environment. These reasons include the indigenous language content of the digital library, the indigenous language default language setting of the digital library and a stated desire by the clients to use the indigenous language. The key findings raise some interface design issues and support the claim that digital libraries can provide an environment to support the use of indigenous languages.

text: Indigenous Language Usage in a Digital Library: He Hautoa Kia Ora Tonu Ai. The research described in this thesis examines indigenous language usage in a digital library environment that has been accessed via the Internet.

By examining discretionary use of the Māori Niupepa and Hawaiian Nūpepa digital libraries this research investigates how indigenous languages were used in these electronic environments in 2005. The results provide encouragement and optimism to people who are striving to retain, revitalise and develop the use of indigenous languages in information technologies. The Transaction Log Analysis (TLA) methods used in this research serve as an example of how web logs can be used to provide significant information about language usage in a bilingual online information system. Combining the TLA with user feedback has provided insights into how and why clients use indigenous languages in their information retrieval activities. These insights in turn, show good practice that is relevant not only to those working with indigenous languages, indigenous peoples or multilingual environments, but to all information technology designers who strive for universal usability.
This thesis begins by describing the importance of using indigenous languages in electronic environments and suggests that digital libraries can provide an environment to support and encourage the use of such languages. TLA is explained in the context of this study and is then used to analyse aspects of te reo Māori usage in the Niupepa digital library environment in 2005. TLA also indicates that te reo Māori was used by international clients and this usage differed to te reo Māori usage by national (Aotearoa) clients. Findings further reveal that the default language setting of the Niupepa digital library had a considerable impact on te reo Māori usage. When the default language was set to te reo Māori not only were there more requests in te reo Māori but there was also a higher usage of te reo Māori in the information retrieval activities. TLA of the Hawaiian Nūpepa digital library indicated that the Hawaiian language was also used in a digital library. These results confirm that indigenous languages were used in digital library environments. 
Feedback from clients suggests reasons why indigenous languages were used in this environment. These reasons include the indigenous language content of the digital library, the indigenous language default language setting of the digital library and a stated desire by the clients to use the indigenous language. The key findings raise some interface design issues and support the claim that digital libraries can provide an environment to support the use of indigenous languages.

year: 2007