title: Shoreline Variation and Beach Rotation of Pauanui Beach

authors: Foster, Renee Abigail

abstract: Shoreline variation over short, medium and long term time scales is well studied and documented. Rotation studies however have only focused on the phenomenon occurring on embayed beaches. This type morphological change is known to be caused by variations in wave climate such as wave approach direction and energy flux.  Rotation studies on other beach classifications are limited, specifically on the potential of harbour adjacent beaches to rotate. Given the highly variable nature of estuaries and their impact on sediment supply to these flanking beaches, rotation could be exacerbated and aggravate existing localised erosion as a result.  This thesis uses a video imagery shoreline dataset to determine the shoreline variation and beach rotation of Pauanui Beach, a harbour adjacent beach. Comparisons are then made to neighbouring Tairua Beach, an embayed beach.

The shoreline over 2002, 2003 and 2004 displayed variation at short, medium and long term scales. Large wave events exceeding 4 m in significant wave height eroded beach profiles until accretion occurred during lull periods. Alongshore uniformity of this erosion pattern was not consistent throughout the timeseries at both beaches indicating the phenomenon of beach rotation. Pauanui transects moved in unison with each other, while an out of phase relationship existed between the Tairua transects.  Seasonal changes in wave climate also influenced shoreline change however consistent cycles were not evident at both Pauanui and Tairua until 2004 where summer accretion and winter erosion dominated.    The effects of ENSO were also observable in the long term where the shoreline gradually accreted with the long term negative ENSO index. Pauanui accretion quantity was much larger than Tairua over the same period. Rotation phenomenon at Pauanui was caused by a strong variation in cross shore shoreline position while Tairua demonstrated a strong out of phase behaviour at either end of the beach. Wave models were generated to determine the effect of islands inshore of the generating conditions. Shadowing effects were highly noticeable on the wave climate projected onto the beach, affecting the rotation and mean shoreline position. Alongshore currents were generated which affected the sediment transport to these rotated areas of beach. 

Based on these results, the two beaches responded similarly during erosion, accretion and rotation events.  Alongshore uniformity does not exist alongshore of the two beaches as wave climate variations are created by the offshore island.

text: Shoreline Variation and Beach Rotation of Pauanui Beach Shoreline variation over short, medium and long term time scales is well studied and documented. Rotation studies however have only focused on the phenomenon occurring on embayed beaches. This type morphological change is known to be caused by variations in wave climate such as wave approach direction and energy flux.  Rotation studies on other beach classifications are limited, specifically on the potential of harbour adjacent beaches to rotate. Given the highly variable nature of estuaries and their impact on sediment supply to these flanking beaches, rotation could be exacerbated and aggravate existing localised erosion as a result.  This thesis uses a video imagery shoreline dataset to determine the shoreline variation and beach rotation of Pauanui Beach, a harbour adjacent beach. Comparisons are then made to neighbouring Tairua Beach, an embayed beach.

The shoreline over 2002, 2003 and 2004 displayed variation at short, medium and long term scales. Large wave events exceeding 4 m in significant wave height eroded beach profiles until accretion occurred during lull periods. Alongshore uniformity of this erosion pattern was not consistent throughout the timeseries at both beaches indicating the phenomenon of beach rotation. Pauanui transects moved in unison with each other, while an out of phase relationship existed between the Tairua transects.  Seasonal changes in wave climate also influenced shoreline change however consistent cycles were not evident at both Pauanui and Tairua until 2004 where summer accretion and winter erosion dominated.    The effects of ENSO were also observable in the long term where the shoreline gradually accreted with the long term negative ENSO index. Pauanui accretion quantity was much larger than Tairua over the same period. Rotation phenomenon at Pauanui was caused by a strong variation in cross shore shoreline position while Tairua demonstrated a strong out of phase behaviour at either end of the beach. Wave models were generated to determine the effect of islands inshore of the generating conditions. Shadowing effects were highly noticeable on the wave climate projected onto the beach, affecting the rotation and mean shoreline position. Alongshore currents were generated which affected the sediment transport to these rotated areas of beach. 

Based on these results, the two beaches responded similarly during erosion, accretion and rotation events.  Alongshore uniformity does not exist alongshore of the two beaches as wave climate variations are created by the offshore island.

year: 2012

title: Quiescence induces epigenetic changes in bovine fibroblasts and improves their reprogramming into cloned embryos

authors: Kallingappa, Prasanna Kumar

subjects: Quiescence, Epigenetics, Reprogramming, Somatic cell nuclear transfer (SCNT), Histone Methylation, Histone Acetylation, Histone varients, DNA methylation, Polycomb group (PcG) proteins

abstract: Cloning by somatic cell nuclear transfer (SCNT) forces cells to lose their lineage-specific epigenetic marks and become totipotent again. This reprogramming process often results in epigenetic and transcriptional aberrations that compromise development. Development rates after SCNT can thus serve as a functional assay for genome-wide epigenetic reprogramming. Dolly the sheep, the first mammalian SCNT clone, was derived from a donor cell that was induced into quiescence by serum starvation. We hypothesized that quiescence alters the epigenetic status of donor cells and elevates their reprogrammability. In order to test this idea, we compared chromatin composition and cloning efficiency of serum-starved, quiescent (G₀), bovine fibroblasts vs non-starved, diploid G₁ controls. Mechanically synchronized G₁ cells were generated by mitotic shake-off and harvested within 3 h post-mitosis. Based on morphological assessment and EdU incorporation during continuous labeling, >93% of cells were captured in G₁.
Using quantitative confocal immunofluorescence microscopy and fluorometric ELISA, we show that G₀ fibroblasts were significantly hypomethylated at lysines (K) of histone 3 (H3), specifically H3K4me3, H3K9me2, H3K9me3 and H3K27me3, but not H3K9me1. Histone acetylation was reduced at H3K9 and H4K5, increased at H3K12 and remained unchanged at H3K16. G₀ cells also significantly reduced DNAme. In addition, they significantly down-regulated the nuclear abundance of RNA polymerase II, histone variant H2A.Z, as well as Polycomb group (PcG) proteins EED, SUZ12, PHC1 and RING2. Histone variant H3.3, PcG proteins EZH2 and histone deacetylase HDAC1 did not change compared to the G₁ controls. Following NT into metaphase-arrested oocytes, G₀ DNA condensed slower than that of G₁ cells, indicating a more relaxed chromatin configuration. After seven days of in vitro culture, H3K9me3, but not H3K4me3, H3K27me3, SUZ12 and RING2, remained hypomethylated in G₀- vs G₁-derived NT blastocysts, both in the inner cell mass and trophectoderm. Furthermore, G₀ donors significantly improved development into cloned blastocysts. In conclusion, quiescence induced long-term epigenetic changes, specifically H3K9me3 hypomethylation, that correlated with increased donor cell reprogrammability.

text: Quiescence induces epigenetic changes in bovine fibroblasts and improves their reprogramming into cloned embryos Cloning by somatic cell nuclear transfer (SCNT) forces cells to lose their lineage-specific epigenetic marks and become totipotent again. This reprogramming process often results in epigenetic and transcriptional aberrations that compromise development. Development rates after SCNT can thus serve as a functional assay for genome-wide epigenetic reprogramming. Dolly the sheep, the first mammalian SCNT clone, was derived from a donor cell that was induced into quiescence by serum starvation. We hypothesized that quiescence alters the epigenetic status of donor cells and elevates their reprogrammability. In order to test this idea, we compared chromatin composition and cloning efficiency of serum-starved, quiescent (G₀), bovine fibroblasts vs non-starved, diploid G₁ controls. Mechanically synchronized G₁ cells were generated by mitotic shake-off and harvested within 3 h post-mitosis. Based on morphological assessment and EdU incorporation during continuous labeling, >93% of cells were captured in G₁.
Using quantitative confocal immunofluorescence microscopy and fluorometric ELISA, we show that G₀ fibroblasts were significantly hypomethylated at lysines (K) of histone 3 (H3), specifically H3K4me3, H3K9me2, H3K9me3 and H3K27me3, but not H3K9me1. Histone acetylation was reduced at H3K9 and H4K5, increased at H3K12 and remained unchanged at H3K16. G₀ cells also significantly reduced DNAme. In addition, they significantly down-regulated the nuclear abundance of RNA polymerase II, histone variant H2A.Z, as well as Polycomb group (PcG) proteins EED, SUZ12, PHC1 and RING2. Histone variant H3.3, PcG proteins EZH2 and histone deacetylase HDAC1 did not change compared to the G₁ controls. Following NT into metaphase-arrested oocytes, G₀ DNA condensed slower than that of G₁ cells, indicating a more relaxed chromatin configuration. After seven days of in vitro culture, H3K9me3, but not H3K4me3, H3K27me3, SUZ12 and RING2, remained hypomethylated in G₀- vs G₁-derived NT blastocysts, both in the inner cell mass and trophectoderm. Furthermore, G₀ donors significantly improved development into cloned blastocysts. In conclusion, quiescence induced long-term epigenetic changes, specifically H3K9me3 hypomethylation, that correlated with increased donor cell reprogrammability.

year: 2013

title: Mentoring and teaching in academic settings:  Professional and cultural identities from one Pākehā’s perspective

authors: Middleton, Sue

subjects: biculturalism

abstract: When invited to respond to the paper on “Mentoring Māori in a Pākehā framework” by Hook, Waaka and Raumati (2007), I hesitated. Mentoring was not a term I had previously used in my professional thinking or academic writing: unlike Barbara Grant (Ratima & Grant, 2007), I had not been involved in formal mentoring programmes or immersed myself in the mentoring literature. As a Pākehā, I was not qualified to evaluate the authors’ definition of a Māori framework. At first glance, the target paper’s focus seemed to be on mentoring in commercial, rather than academic workplaces. My experience had been as a teacher, the last 30 years having been in a university School of Education. I was persuaded to undertake this commentary on the grounds that academic work involves nurturing, advising and supporting younger or less experienced colleagues, as well as students – tasks identified as mentoring in the Hook et al. paper. The following comments are informed by my everyday practices as teacher, thesis supervisor and researcher, and by my former management roles as an assistant dean of graduate studies and head of department. My angle of vision and conceptual resources are those of a (Pākehā and feminist) sociologist of education.

text: Mentoring and teaching in academic settings:  Professional and cultural identities from one Pākehā’s perspective When invited to respond to the paper on “Mentoring Māori in a Pākehā framework” by Hook, Waaka and Raumati (2007), I hesitated. Mentoring was not a term I had previously used in my professional thinking or academic writing: unlike Barbara Grant (Ratima & Grant, 2007), I had not been involved in formal mentoring programmes or immersed myself in the mentoring literature. As a Pākehā, I was not qualified to evaluate the authors’ definition of a Māori framework. At first glance, the target paper’s focus seemed to be on mentoring in commercial, rather than academic workplaces. My experience had been as a teacher, the last 30 years having been in a university School of Education. I was persuaded to undertake this commentary on the grounds that academic work involves nurturing, advising and supporting younger or less experienced colleagues, as well as students – tasks identified as mentoring in the Hook et al. paper. The following comments are informed by my everyday practices as teacher, thesis supervisor and researcher, and by my former management roles as an assistant dean of graduate studies and head of department. My angle of vision and conceptual resources are those of a (Pākehā and feminist) sociologist of education.

year: 2007-12