title: Investigation into the Effects of Oxidative Stress on Reproductive Development.

authors: Collins, Tracey Helen

subjects: oxidative stress

abstract: Nuclear transfer (NT), or cloning, which is the transfer of a donor nucleus to a recipient enucleated oocyte, has been successfully achieved to produce viable offspring in many species.  The process is very inefficient, as reprogramming of the donor nucleus is required, and losses are high throughout development.  Placentation abnormalities are a common feature amongst cloned animals.  Incomplete nuclear reprogramming and erroneous epigenetic imprinting may contribute to aberrant protein transcription and DNA mutations, affecting mitochondrial metabolism and inducing cellular stress.  In vitro produced embryos under high oxygen culture conditions may also suffer oxidative stress, with the resulting reactive oxygen species causing mitochondrial DNA mutations and cellular stress similar to clones.

In this study, expression of oxidative stress protein markers (Hsp60, SOD2, Hsp70) in NT cotyledons were compared to artificial insemination (AI) at different time points of gestation (days 50, 100, and 150).  As a continuum of the oxidative stress investigation in cloned cotyledons, in vitro produced embryos were cultured under 20% oxygen compared to the control 7% oxygen laboratory standard culture, with oxidative stress protein markers examined between the groups at blastocyst stage (day 7) and day 15.  Embryo morphology was also observed to determine apparent physiological differences between the treatment and control embryos.  No previous studies to date have investigated the developmental effects of oxidative stress in day 15 bovine embryos.
 
The significant differences in oxidative stress proteins observed at several time points in the NT and AI groups were not repeatable, possibly due to sample freeze/thaw degradation.  Morphological differences observed between embryos cultured in 20% oxygen and control groups were visually apparent, although not quantified.  At day 15 manganese superoxide dismutase expression was significantly lower in the 20% group compared to control.  The 20% oxygen group did not show higher heat shock protein 60 expression than control, however the same results have been observed in another study at blastocyst stage.  The results of this study suggest that the effect of oxidative stress on embryonic development is evident yet inconclusive in bovine NT cotyledons, however does not appear apparent in day 15 embryos following culture in 20% oxygen.

text: Investigation into the Effects of Oxidative Stress on Reproductive Development. Nuclear transfer (NT), or cloning, which is the transfer of a donor nucleus to a recipient enucleated oocyte, has been successfully achieved to produce viable offspring in many species.  The process is very inefficient, as reprogramming of the donor nucleus is required, and losses are high throughout development.  Placentation abnormalities are a common feature amongst cloned animals.  Incomplete nuclear reprogramming and erroneous epigenetic imprinting may contribute to aberrant protein transcription and DNA mutations, affecting mitochondrial metabolism and inducing cellular stress.  In vitro produced embryos under high oxygen culture conditions may also suffer oxidative stress, with the resulting reactive oxygen species causing mitochondrial DNA mutations and cellular stress similar to clones.

In this study, expression of oxidative stress protein markers (Hsp60, SOD2, Hsp70) in NT cotyledons were compared to artificial insemination (AI) at different time points of gestation (days 50, 100, and 150).  As a continuum of the oxidative stress investigation in cloned cotyledons, in vitro produced embryos were cultured under 20% oxygen compared to the control 7% oxygen laboratory standard culture, with oxidative stress protein markers examined between the groups at blastocyst stage (day 7) and day 15.  Embryo morphology was also observed to determine apparent physiological differences between the treatment and control embryos.  No previous studies to date have investigated the developmental effects of oxidative stress in day 15 bovine embryos.
 
The significant differences in oxidative stress proteins observed at several time points in the NT and AI groups were not repeatable, possibly due to sample freeze/thaw degradation.  Morphological differences observed between embryos cultured in 20% oxygen and control groups were visually apparent, although not quantified.  At day 15 manganese superoxide dismutase expression was significantly lower in the 20% group compared to control.  The 20% oxygen group did not show higher heat shock protein 60 expression than control, however the same results have been observed in another study at blastocyst stage.  The results of this study suggest that the effect of oxidative stress on embryonic development is evident yet inconclusive in bovine NT cotyledons, however does not appear apparent in day 15 embryos following culture in 20% oxygen.

year: 2007

title: The creative potential of metaphorical writing in the literacy classroom

authors: Fraser, Deborah

subjects: creativity

abstract: Creativity is difficult to define and a universal definition remains elusive. However, common words associated with creativity affirm that it concerns novelty and originality, hallmarks of many great and enduring texts. Students can also be encouraged to surface original ideas through constructing their own creative texts. This article outlines such a project that focuses on metaphorical writing with students in the primary school setting. When teachers foster creativity in the literacy classroom, they provide openended lessons, encourage variety and innovation, and allow time to play with ideas. Engaging students in writing their own metaphorical texts is one way in which students can generate novel responses and multiple interpretations as outlined in this paper. The students’ texts reveal unique voices that range from the playful to the dramatic in their creative exploration of what it means to be human. The potential of such writing for engaging students is discussed alongside the value of metaphorical writing for encouraging emotional exploration, imagination and sheer enjoyment.

text: The creative potential of metaphorical writing in the literacy classroom Creativity is difficult to define and a universal definition remains elusive. However, common words associated with creativity affirm that it concerns novelty and originality, hallmarks of many great and enduring texts. Students can also be encouraged to surface original ideas through constructing their own creative texts. This article outlines such a project that focuses on metaphorical writing with students in the primary school setting. When teachers foster creativity in the literacy classroom, they provide openended lessons, encourage variety and innovation, and allow time to play with ideas. Engaging students in writing their own metaphorical texts is one way in which students can generate novel responses and multiple interpretations as outlined in this paper. The students’ texts reveal unique voices that range from the playful to the dramatic in their creative exploration of what it means to be human. The potential of such writing for engaging students is discussed alongside the value of metaphorical writing for encouraging emotional exploration, imagination and sheer enjoyment.

year: 2006

title: The Te Kotahitanga Observation Tool: Development, use, reliability and validity.

authors: Berryman, Mere

subjects: chool reform

abstract: Te Kotahitanga is a New Zealand school reform project aimed at improving the pedagogical contexts in mainstream classrooms in which the indigenous Māori students have traditionally been marginalised. It does this by assisting teachers to implement an Effective Teaching Profile. Part of this process uses an observation tool to monitor the degree to which participating teachers are incorporating the interactions and relationships described in the Effective Teaching Profile into their day-to-day teaching. Given the central importance of these tasks, the Te Kotahitanga team undertook to test the observation tool for measurement reliability and validity. In order to undertake this study, the team conducted synchronous observations amongst trainers (the Professional Development Coordinator and Regional Coordinators) to ascertain their level of consistency when using the tool. The team then conducted synchronous observations between trainers and 38 in-school facilitators in the 12 schools involved in Phase 3 of the project. In total 41 teachers were observed and over 200 Māori students were involved in these observations. This study suggests that the tool can produce consistent and reliable results when observers have been effectively trained.

text: The Te Kotahitanga Observation Tool: Development, use, reliability and validity. Te Kotahitanga is a New Zealand school reform project aimed at improving the pedagogical contexts in mainstream classrooms in which the indigenous Māori students have traditionally been marginalised. It does this by assisting teachers to implement an Effective Teaching Profile. Part of this process uses an observation tool to monitor the degree to which participating teachers are incorporating the interactions and relationships described in the Effective Teaching Profile into their day-to-day teaching. Given the central importance of these tasks, the Te Kotahitanga team undertook to test the observation tool for measurement reliability and validity. In order to undertake this study, the team conducted synchronous observations amongst trainers (the Professional Development Coordinator and Regional Coordinators) to ascertain their level of consistency when using the tool. The team then conducted synchronous observations between trainers and 38 in-school facilitators in the 12 schools involved in Phase 3 of the project. In total 41 teachers were observed and over 200 Māori students were involved in these observations. This study suggests that the tool can produce consistent and reliable results when observers have been effectively trained.

year: 2011