title: Depuration of tetrodotoxin and changes in bacterial communities in Pleurobranchea maculata adults and egg masses maintained in captivity

authors: Wood, Susanna A.

subjects: chemical defense

abstract: Depuration of tetrodotoxin (TTX) was investigated in adult grey side-gilled sea slugs, Pleurobranchaea maculata, maintained in captivity on a TTX-free diet. Three adults were harvested every 21 days for 126 days, and TTX concentrations were measured in organs/tissues and egg masses. Automated rRNA intergenic spacer analysis (ARISA) was used to investigate bacterial community structure in selected samples. Linear modeling of adult data demonstrated a decline (P < 0.001) in average total TTX concentrations over time. Temporal data obtained from a wild population showed similar depuration rates, indicating that once adults reach a certain size, or sexual maturity, TTX is no longer produced or acquired substantially. Depuration rates differed among organs, with concentrations in the heart declining the fastest. The gonads had the slowest and least significant depuration rate indicating, at most, weak depuration of this tissue. There was a strong correlation (R (2) = 0.66) between TTX concentrations in the first-laid egg masses and total TTX in the corresponding adult. These data suggest that adult P. maculata transfer TTX to their offspring, and presumably that functions as a chemical defense. ARISA data showed a shift in bacterial community structure within 3 weeks of introduction to captivity. Based on the combined data, the exact origin of TTX in P. maculata is unclear, with evidence both in favor and against a dietary source, and endogenous or bacterial production.

text: Depuration of tetrodotoxin and changes in bacterial communities in Pleurobranchea maculata adults and egg masses maintained in captivity Depuration of tetrodotoxin (TTX) was investigated in adult grey side-gilled sea slugs, Pleurobranchaea maculata, maintained in captivity on a TTX-free diet. Three adults were harvested every 21 days for 126 days, and TTX concentrations were measured in organs/tissues and egg masses. Automated rRNA intergenic spacer analysis (ARISA) was used to investigate bacterial community structure in selected samples. Linear modeling of adult data demonstrated a decline (P < 0.001) in average total TTX concentrations over time. Temporal data obtained from a wild population showed similar depuration rates, indicating that once adults reach a certain size, or sexual maturity, TTX is no longer produced or acquired substantially. Depuration rates differed among organs, with concentrations in the heart declining the fastest. The gonads had the slowest and least significant depuration rate indicating, at most, weak depuration of this tissue. There was a strong correlation (R (2) = 0.66) between TTX concentrations in the first-laid egg masses and total TTX in the corresponding adult. These data suggest that adult P. maculata transfer TTX to their offspring, and presumably that functions as a chemical defense. ARISA data showed a shift in bacterial community structure within 3 weeks of introduction to captivity. Based on the combined data, the exact origin of TTX in P. maculata is unclear, with evidence both in favor and against a dietary source, and endogenous or bacterial production.

year: 2012

title: Accessing child sexual abuse material: Pathways to offending and online behaviour

authors: Wortley, Richard

subjects: CSAM

abstract: Background: Most research examining the consumption of online child sexual abuse material (CSAM) has focused on offenders' demographic and psychological characteristics. While such research may assist in the development of therapeutic interventions with known offenders, it has little to offer the development of interventions for the vast majority of offenders who are never caught. Objective: To learn more about the offending strategies of CSAM offenders, in order to inform prevention efforts to deter, disrupt, and divert individuals from their pursuit of CSAM. Participants & setting: Seventy-five male CSAM offenders, who were living in the community and were voluntarily participating in a treatment programme. Methods: Participants completed a detailed self-report questionnaire focussing on their pathways to offending and their online behaviour. Results: Most participants reported that they did not initially seek out CSAM but that they first encountered it inadvertently or became curious after viewing legal pornography. Their involvement in CSAM subsequently progressed over time and their offending generally became more serious. The most notable feature of participants' online behaviour was the relative lack of sophisticated technical expertise. Opportunity and other situational factors emerged as mediators of offending frequency. Offending patterns were affected by participants' psychological states (e.g., depression, anger, stress), offline relationships and commitments (e.g., arguments with spouse, loss of job), and online experiences (e.g., blocked sites, viruses, warning messages). Conclusions: Findings suggest that many offenders are receptive to change and may be potentially diverted from their offending pathway.

text: Accessing child sexual abuse material: Pathways to offending and online behaviour Background: Most research examining the consumption of online child sexual abuse material (CSAM) has focused on offenders' demographic and psychological characteristics. While such research may assist in the development of therapeutic interventions with known offenders, it has little to offer the development of interventions for the vast majority of offenders who are never caught. Objective: To learn more about the offending strategies of CSAM offenders, in order to inform prevention efforts to deter, disrupt, and divert individuals from their pursuit of CSAM. Participants & setting: Seventy-five male CSAM offenders, who were living in the community and were voluntarily participating in a treatment programme. Methods: Participants completed a detailed self-report questionnaire focussing on their pathways to offending and their online behaviour. Results: Most participants reported that they did not initially seek out CSAM but that they first encountered it inadvertently or became curious after viewing legal pornography. Their involvement in CSAM subsequently progressed over time and their offending generally became more serious. The most notable feature of participants' online behaviour was the relative lack of sophisticated technical expertise. Opportunity and other situational factors emerged as mediators of offending frequency. Offending patterns were affected by participants' psychological states (e.g., depression, anger, stress), offline relationships and commitments (e.g., arguments with spouse, loss of job), and online experiences (e.g., blocked sites, viruses, warning messages). Conclusions: Findings suggest that many offenders are receptive to change and may be potentially diverted from their offending pathway.

year: 2024

title: Tīhei Mauri Ora: Negotiating primary school teachers' personal and professional identities as Māori

authors: Gilgen, Renée

subjects: Professional Learning and Development for teachers

abstract: Colonial attitudes that positioned Māori language, knowledge and pedagogy as inferior and deficient continue to impact on 21st century primary school contexts in Aotearoa/New Zealand. They continue to impact particularly on the personal and professional identities and experiences of Māori teachers in contemporary English-medium schools. Just as, historically, Māori students were expected to leave their language and culture at the 19th century colonial school gates, so too are many contemporary Māori teachers in mainstream schools expected to set aside their language and culture and engage with the curriculum and pedagogy of the school where they work. Ironically, at the same time, these teachers are often expected to guide and assist their school to meet its requirements under Te Tiriti o Waitangi/Treaty of Waitangi to ensure that its Māori students will succeed as Māori.

This thesis sought to understand how a small cohort of experienced Māori teachers, positioned within 21st century English-medium primary schools, perceived and negotiated the challenges to their personal and professional identities as Māori, and as Māori teachers. The thesis employed a qualitative participant narrative methodology, framed with kaupapa Māori theory. The teachers participated in individual interviews and in a series of hui kōrero (focused conversations) that assisted them to reflect critically on sociohistorical and educational factors that influenced the formation and maintenance of their identities as Māori.

The teachers’ narratives that emerged from individual and collaborative hui kōrero revealed that (1) being raised within urban environments and being themselves educated in monocultural schools during the 1960s and 1970s strongly impacted on how their Māori identities were shaped and, (2) their teaching experiences within English-medium primary schools and classrooms were culturally isolating and destructive, and largely unsupportive of the diverse realities that exists for some Māori teachers.

I offer two key strategic responses to these findings. Firstly, I offer a self-identity continuum that seeks to respect and affirm Māori identity by taking into account the different levels and contexts of experience some Māori teachers may have with Māori cultural concepts and practices. Secondly, I assert the need for a culturally located and relational space within English-medium school contexts for Māori teachers to engage with, and draw on the support of other Māori teachers in order to affirm their varying personal and professional identities as Māori. Meeting this need is understood as a Tiriti o Waitangi/Treaty-honouring response, required of all schools.

text: Tīhei Mauri Ora: Negotiating primary school teachers' personal and professional identities as Māori Colonial attitudes that positioned Māori language, knowledge and pedagogy as inferior and deficient continue to impact on 21st century primary school contexts in Aotearoa/New Zealand. They continue to impact particularly on the personal and professional identities and experiences of Māori teachers in contemporary English-medium schools. Just as, historically, Māori students were expected to leave their language and culture at the 19th century colonial school gates, so too are many contemporary Māori teachers in mainstream schools expected to set aside their language and culture and engage with the curriculum and pedagogy of the school where they work. Ironically, at the same time, these teachers are often expected to guide and assist their school to meet its requirements under Te Tiriti o Waitangi/Treaty of Waitangi to ensure that its Māori students will succeed as Māori.

This thesis sought to understand how a small cohort of experienced Māori teachers, positioned within 21st century English-medium primary schools, perceived and negotiated the challenges to their personal and professional identities as Māori, and as Māori teachers. The thesis employed a qualitative participant narrative methodology, framed with kaupapa Māori theory. The teachers participated in individual interviews and in a series of hui kōrero (focused conversations) that assisted them to reflect critically on sociohistorical and educational factors that influenced the formation and maintenance of their identities as Māori.

The teachers’ narratives that emerged from individual and collaborative hui kōrero revealed that (1) being raised within urban environments and being themselves educated in monocultural schools during the 1960s and 1970s strongly impacted on how their Māori identities were shaped and, (2) their teaching experiences within English-medium primary schools and classrooms were culturally isolating and destructive, and largely unsupportive of the diverse realities that exists for some Māori teachers.

I offer two key strategic responses to these findings. Firstly, I offer a self-identity continuum that seeks to respect and affirm Māori identity by taking into account the different levels and contexts of experience some Māori teachers may have with Māori cultural concepts and practices. Secondly, I assert the need for a culturally located and relational space within English-medium school contexts for Māori teachers to engage with, and draw on the support of other Māori teachers in order to affirm their varying personal and professional identities as Māori. Meeting this need is understood as a Tiriti o Waitangi/Treaty-honouring response, required of all schools.

year: 2016