title: Experimental evidence for radiative attachment in astrochemistry from electron attachment to NCCCCN

authors: Graupner, K.

subjects: astrochemistry

abstract: Electron attachment to NCCCCN, dicyanoacetylene (2-butynedinitrile), has been observed. Metastable parent anions, NCCCCN_∗, with microsecond or longer lifetimes are formed close to 0 eV electron energy with a cross section of ≥0.25 2. The stability of NCCCCN suggests that radiative attachment to NCCCCN and similar _∗ °A linear carbon chain molecules may be an important mechanism for the formation of negatively charged molecular ions in astrophysical environments. CCCN_ and CN_ fragment anions are formed at ∼3 and ∼6 eV.

text: Experimental evidence for radiative attachment in astrochemistry from electron attachment to NCCCCN Electron attachment to NCCCCN, dicyanoacetylene (2-butynedinitrile), has been observed. Metastable parent anions, NCCCCN_∗, with microsecond or longer lifetimes are formed close to 0 eV electron energy with a cross section of ≥0.25 2. The stability of NCCCCN suggests that radiative attachment to NCCCCN and similar _∗ °A linear carbon chain molecules may be an important mechanism for the formation of negatively charged molecular ions in astrophysical environments. CCCN_ and CN_ fragment anions are formed at ∼3 and ∼6 eV.

year: 2006

title: Contribution of seagrass (Zostera muelleri) to estuarine food webs revealed by carbon and nitrogen stable isotope analysis

authors: Hailes, Sarah

subjects: Seagrasses

abstract: Seagrass is a conspicuous marine angiosperm that forms extensive beds in coastal and intertidal estuarine areas. In many regions worldwide seagrass is in decline and there is a pressing need to understand the function and importance of seagrasses to coastal ecosystems. To assess the importance of seagrass (Zostera muelleri) to secondary production, a dual carbon and nitrogen stable isotope study was conducted using potential food sources (seagrass live blades and detritus, phytoplankton and microphytobenthos) and selected macro-invertebrate consumers at four study sites in three estuaries (Raglan, Tauranga and Whangapoua Harbours). Sampling focused on bivalves, gastropods, crustaceans and annelid polychaetes, representing a range of functional feedings groups (suspension- and deposit-feeders) that were found in seagrass beds and adjacent non-vegetated sediment. In addition, macro-invertebrate community analysis determined the abundances of species selected for isotope analysis and their relative importance to the macro-invertebrate communities.

Macro-invertebrate species analysed for stable isotope analysis accounted for between 26 - 63% and 37 - 95% of the macro-invertebrate abundance within seagrass and nonvegetated sediment, respectively. The distinctive δ¹³ C and δ¹⁵N isotope signatures of Z. muelleri (δ¹³C = -10 and δ¹⁵N = 6%₀), phytoplankton (-23 and 7%₀) and microphytobenthos (-20 and 5%₀) allowed these potential food sources to be traced through the food webs studied. The herbivorous gastropods Diloma subrostrata and Zeacumantus lutulentus had similar δ¹³C values to seagrass (mean δ¹³C = -10%₀) and the δ¹³C values of the deposit feeding bivalve Macomona liliana, crustacean Helice crassa and annelid polychaete species Orbinia papillosa and Aquilaspio aucklandica were generally intermediate between microphytobenthos and Z. muelleri. Austrovenus stutchburyi (suspension feeding bivalve) was depleted in ¹³C and had a mean δ¹³C value similar to microphytobenthos. Polychaetes Aglaophamus macroura, Aonides oxycephala and Glycera americana consistently recorded δ¹³ C values similar to the other consumers (excluding A. stutchburyi) but had δ¹⁵N values characteristic of a higher trophic level and a predatory existence. Differences in the isotopic ratios of macro-invertebrate species between sampling locations within seagrass beds and adjacent non-vegetated sediment were not significant, indicating that seagrass contributes to the food chain in nearby (< 20 m) non-vegetated sediment. Significant differences in isotopic signatures existed between east and west coast sites, with food sources and benthic consumers consistently displaying enriched δ¹⁵N and depleted δ¹³C values at Raglan on the west coast suggesting differences in the inorganic nutrient inputs fuelling primary production.

Results suggest that secondary production was fuelled by benthic (seagrass and microphytobenthos) rather than pelagic organic matter (phytoplankton). Z. muelleri was an exclusive food source for gastropods D. subrostrata and Z lutulentus and also contributed to the diets of M. liliana, H. crassa, O. papillosa and A. aucklandica. Spatial differences occurred between study sites but not between sampling locations. This study confirms that Z. muelleri plays a role in the production of benthic macro-invertebrate communities and its loss from estuarine ecosystems will impact negatively on secondary production.

text: Contribution of seagrass (Zostera muelleri) to estuarine food webs revealed by carbon and nitrogen stable isotope analysis Seagrass is a conspicuous marine angiosperm that forms extensive beds in coastal and intertidal estuarine areas. In many regions worldwide seagrass is in decline and there is a pressing need to understand the function and importance of seagrasses to coastal ecosystems. To assess the importance of seagrass (Zostera muelleri) to secondary production, a dual carbon and nitrogen stable isotope study was conducted using potential food sources (seagrass live blades and detritus, phytoplankton and microphytobenthos) and selected macro-invertebrate consumers at four study sites in three estuaries (Raglan, Tauranga and Whangapoua Harbours). Sampling focused on bivalves, gastropods, crustaceans and annelid polychaetes, representing a range of functional feedings groups (suspension- and deposit-feeders) that were found in seagrass beds and adjacent non-vegetated sediment. In addition, macro-invertebrate community analysis determined the abundances of species selected for isotope analysis and their relative importance to the macro-invertebrate communities.

Macro-invertebrate species analysed for stable isotope analysis accounted for between 26 - 63% and 37 - 95% of the macro-invertebrate abundance within seagrass and nonvegetated sediment, respectively. The distinctive δ¹³ C and δ¹⁵N isotope signatures of Z. muelleri (δ¹³C = -10 and δ¹⁵N = 6%₀), phytoplankton (-23 and 7%₀) and microphytobenthos (-20 and 5%₀) allowed these potential food sources to be traced through the food webs studied. The herbivorous gastropods Diloma subrostrata and Zeacumantus lutulentus had similar δ¹³C values to seagrass (mean δ¹³C = -10%₀) and the δ¹³C values of the deposit feeding bivalve Macomona liliana, crustacean Helice crassa and annelid polychaete species Orbinia papillosa and Aquilaspio aucklandica were generally intermediate between microphytobenthos and Z. muelleri. Austrovenus stutchburyi (suspension feeding bivalve) was depleted in ¹³C and had a mean δ¹³C value similar to microphytobenthos. Polychaetes Aglaophamus macroura, Aonides oxycephala and Glycera americana consistently recorded δ¹³ C values similar to the other consumers (excluding A. stutchburyi) but had δ¹⁵N values characteristic of a higher trophic level and a predatory existence. Differences in the isotopic ratios of macro-invertebrate species between sampling locations within seagrass beds and adjacent non-vegetated sediment were not significant, indicating that seagrass contributes to the food chain in nearby (< 20 m) non-vegetated sediment. Significant differences in isotopic signatures existed between east and west coast sites, with food sources and benthic consumers consistently displaying enriched δ¹⁵N and depleted δ¹³C values at Raglan on the west coast suggesting differences in the inorganic nutrient inputs fuelling primary production.

Results suggest that secondary production was fuelled by benthic (seagrass and microphytobenthos) rather than pelagic organic matter (phytoplankton). Z. muelleri was an exclusive food source for gastropods D. subrostrata and Z lutulentus and also contributed to the diets of M. liliana, H. crassa, O. papillosa and A. aucklandica. Spatial differences occurred between study sites but not between sampling locations. This study confirms that Z. muelleri plays a role in the production of benthic macro-invertebrate communities and its loss from estuarine ecosystems will impact negatively on secondary production.

year: 2006

title: 'Entitled to a History': The World of Alice Tawhai's Short Stories and the Maori Literary Tradition

authors: Modlik, Kimberley

subjects: Alice Tawhai

abstract: New Zealand short story writer Alice Tawhai is one of the latest additions to the Maori literary tradition. Her three collections of short stories, Festival of Miracles, Luminous and Dark Jelly, deal with issues not entirely unique to New Zealand – from gang life, to domestic violence, to drug and alcohol abuse – and take as their primary subject an alienated, marginalized and disenfranchised underclass. This means she is likely to be read as speaking solely for the Maori experience.  This thesis will revise this misconception, which in effect ghettoizes or marginalizes Tawhai’s work.

Influential women writers of the Maori literary tradition, such as J. C. Sturm, Patricia Grace and Keri Hulme, have taken a particular interest in the long legacy of colonialism in New Zealand, especially of the impact of that legacy on Maori women. This thesis demonstrates that while Tawhai’s work engages with these familiar notions, her gaze is not limited to these issues. This thesis therefore places Tawhai’s work within that tradition and matrilineal genealogy before going on to show how she moves the paradigm beyond the usual grievances of biculturalism and colonialism, orienting her work instead around the increasingly multicultural experience of contemporary life in New Zealand.

The first section of this thesis will establish a platform for reading Tawhai in regards to her literary legacy and in the context of contemporary thinking, drawing on cultural theorist Stuart Hall and his theory on identity formation and identity politics as well as indigenous writings experts Patrick Evans and Chadwick Allen. This thesis will then move into its second section, which is an analysis of some of the overarching themes that can be found in the short stories of Tawhai’s literary foremothers, Sturm, Grace and Hulme. These include, for example, racism and discrimination, loss of ancestral lands, problems to do with urbanization and family violence.

The third and final section of this thesis will then consider Tawhai’s representation of contemporary experience, taking a particular interest in her portrayals of contemporary multicultural ethnic identities as well as the flexible and provisional nature of gendered and sexual identities today. The final subsection will then analyze her representations of the new family and social structures that may have replaced the traditional family model.

Through a close reading of her short stories and an appreciation of the legacy that she bears, this thesis will show how Tawhai’s work is a larger lens of contemporary New Zealand society as well as a significant addition to the Maori literary tradition.

text: 'Entitled to a History': The World of Alice Tawhai's Short Stories and the Maori Literary Tradition New Zealand short story writer Alice Tawhai is one of the latest additions to the Maori literary tradition. Her three collections of short stories, Festival of Miracles, Luminous and Dark Jelly, deal with issues not entirely unique to New Zealand – from gang life, to domestic violence, to drug and alcohol abuse – and take as their primary subject an alienated, marginalized and disenfranchised underclass. This means she is likely to be read as speaking solely for the Maori experience.  This thesis will revise this misconception, which in effect ghettoizes or marginalizes Tawhai’s work.

Influential women writers of the Maori literary tradition, such as J. C. Sturm, Patricia Grace and Keri Hulme, have taken a particular interest in the long legacy of colonialism in New Zealand, especially of the impact of that legacy on Maori women. This thesis demonstrates that while Tawhai’s work engages with these familiar notions, her gaze is not limited to these issues. This thesis therefore places Tawhai’s work within that tradition and matrilineal genealogy before going on to show how she moves the paradigm beyond the usual grievances of biculturalism and colonialism, orienting her work instead around the increasingly multicultural experience of contemporary life in New Zealand.

The first section of this thesis will establish a platform for reading Tawhai in regards to her literary legacy and in the context of contemporary thinking, drawing on cultural theorist Stuart Hall and his theory on identity formation and identity politics as well as indigenous writings experts Patrick Evans and Chadwick Allen. This thesis will then move into its second section, which is an analysis of some of the overarching themes that can be found in the short stories of Tawhai’s literary foremothers, Sturm, Grace and Hulme. These include, for example, racism and discrimination, loss of ancestral lands, problems to do with urbanization and family violence.

The third and final section of this thesis will then consider Tawhai’s representation of contemporary experience, taking a particular interest in her portrayals of contemporary multicultural ethnic identities as well as the flexible and provisional nature of gendered and sexual identities today. The final subsection will then analyze her representations of the new family and social structures that may have replaced the traditional family model.

Through a close reading of her short stories and an appreciation of the legacy that she bears, this thesis will show how Tawhai’s work is a larger lens of contemporary New Zealand society as well as a significant addition to the Maori literary tradition.

year: 2014