title: Full field image ranger hardware

authors: Payne, Andrew D.

subjects: imaging

abstract: We describe the hardware designed to implement a full field heterodyning imaging system. Comprising three key components - a light source, high speed shutter and a signal generator - the system is expected to be capable of simultaneous range measurements to millimetre precision over the entire field of view. Current modulated laser diodes provide the required illumination, with a bandwidth of 100 MHz and peak output power exceeding 600 mW. The high speed shutter action is performed by gating the cathode of an image intensifier, driven by a 50 Vpp waveform with 3.5 ns rise and fall times. A direct digital synthesiser, with multiple synchronised channels, provides high stability between its outputs, 160 MHz bandwidth and tuning of 0.1 Hz.

text: Full field image ranger hardware We describe the hardware designed to implement a full field heterodyning imaging system. Comprising three key components - a light source, high speed shutter and a signal generator - the system is expected to be capable of simultaneous range measurements to millimetre precision over the entire field of view. Current modulated laser diodes provide the required illumination, with a bandwidth of 100 MHz and peak output power exceeding 600 mW. The high speed shutter action is performed by gating the cathode of an image intensifier, driven by a 50 Vpp waveform with 3.5 ns rise and fall times. A direct digital synthesiser, with multiple synchronised channels, provides high stability between its outputs, 160 MHz bandwidth and tuning of 0.1 Hz.

year: 2006

title: Diet selectivity in a terrestrial forest invertebrate, the Auckland tree wētā, across three habitat zones.

authors: Brown, Matthew

subjects: feeding behaviour

abstract: Insects are important but overlooked components of forest ecosystems of New Zealand. For many invertebrate species, information on foraging patterns and trophic relationships is lacking. We examined diet composition and selectivity in a large bodied invertebrate, the Auckland tree wētā, in three habitat zones in a lowland New Zealand forest. We asked if Hemideina thoracica selectively forage from available plant food sources, and if these choices were lipid-rich compared to non-preferred available plants. We also identified the proportion of invertebrates in their frass as a proxy for omnivory. From reconnaissance plot sampling, together with faecal fragment analysis, we report that more than 93% of individual wētā had eaten other invertebrates before capture. Wētā in the highest elevation hillslope habitat consumed significantly fewer plants on average than wētā on either the low elevation terrace or mid-slope habitat. Hillslope wētā also had the highest average number of invertebrate fragments in their frass, significantly more than wētā in the low elevation terrace habitat. Wētā showed high variability in the consumption of fruit and seeds across all habitats. Generally, we did not observe diet differences between the sexes (although it appears that male wētā in the mid hillslope habitat ate fruits and seeds more voraciously than females), suggesting that the sexes have similar niche breadths and display similar degrees of omnivorous behaviour. Extraction of leaf lipids demonstrated a range of lipid content values in available plants, and Ivlev’s electivity index indicated that plant species which demonstrated high electivity, tended to have higher concentrations of lipids in their leaves. Our findings indicate that H. thoracica forage omnivorously and selectively, and hence play multiple roles in native ecosystems and food webs.

text: Diet selectivity in a terrestrial forest invertebrate, the Auckland tree wētā, across three habitat zones. Insects are important but overlooked components of forest ecosystems of New Zealand. For many invertebrate species, information on foraging patterns and trophic relationships is lacking. We examined diet composition and selectivity in a large bodied invertebrate, the Auckland tree wētā, in three habitat zones in a lowland New Zealand forest. We asked if Hemideina thoracica selectively forage from available plant food sources, and if these choices were lipid-rich compared to non-preferred available plants. We also identified the proportion of invertebrates in their frass as a proxy for omnivory. From reconnaissance plot sampling, together with faecal fragment analysis, we report that more than 93% of individual wētā had eaten other invertebrates before capture. Wētā in the highest elevation hillslope habitat consumed significantly fewer plants on average than wētā on either the low elevation terrace or mid-slope habitat. Hillslope wētā also had the highest average number of invertebrate fragments in their frass, significantly more than wētā in the low elevation terrace habitat. Wētā showed high variability in the consumption of fruit and seeds across all habitats. Generally, we did not observe diet differences between the sexes (although it appears that male wētā in the mid hillslope habitat ate fruits and seeds more voraciously than females), suggesting that the sexes have similar niche breadths and display similar degrees of omnivorous behaviour. Extraction of leaf lipids demonstrated a range of lipid content values in available plants, and Ivlev’s electivity index indicated that plant species which demonstrated high electivity, tended to have higher concentrations of lipids in their leaves. Our findings indicate that H. thoracica forage omnivorously and selectively, and hence play multiple roles in native ecosystems and food webs.

year: 2018

title: Matariki, commodity culture, and multiple identities

authors: Hardy, Ann

subjects: Matariki

abstract: The event known as Matariki, the rising of the Pleiades in winter, which Māori take as the mark of the beginning of a new year, was not a strong feature of the wider public sphere for most of the 20th century. Since 2001, however, when Te Taura Whiri, the Māori Language Commission, published an explanatory booklet with the aim of reviving interest in Matariki as an aide to the maintenance of te reo, it has been promoted by several quasi-governmental institutions, especially the national museum, Te Papa, as a winter festival for all New Zealanders. Its main public presence to date has been through media products: posters, banners, websites, television programmes, newspaper features, calendars, some theatrical performances and physical commemoration ceremonies.

The larger project, of which this paper represents an initial descriptive and positioning phase, is a continuation of the researcher's long-standing interest in the intersections of religiosity, culture, and media as they are active in the environment of Aotearoa New Zealand. It assumes, building on theorists such as Bellah and Lundby that the creation of such festivals is an act of 'civil religiosity' that attempts to create and strengthen national community around a set of numinous symbols.
However, the development of an enterprise such as Matariki is pursued in a complex political field, where broad agreement across various factions is needed before the festival can take on an enduring material and symbolic existence. In investigating the factors that will determine the future of Matariki it is relevant to consider the interaction of three factors in particular: the ethno-political history of New Zealand; the characteristics of contemporary reflexive spirituality, which are intertwined with commodificatory tendencies and thirdly, the impacts of increasing globalisation on the parameters of identity-formation for citizens in late-modern societies.

text: Matariki, commodity culture, and multiple identities The event known as Matariki, the rising of the Pleiades in winter, which Māori take as the mark of the beginning of a new year, was not a strong feature of the wider public sphere for most of the 20th century. Since 2001, however, when Te Taura Whiri, the Māori Language Commission, published an explanatory booklet with the aim of reviving interest in Matariki as an aide to the maintenance of te reo, it has been promoted by several quasi-governmental institutions, especially the national museum, Te Papa, as a winter festival for all New Zealanders. Its main public presence to date has been through media products: posters, banners, websites, television programmes, newspaper features, calendars, some theatrical performances and physical commemoration ceremonies.

The larger project, of which this paper represents an initial descriptive and positioning phase, is a continuation of the researcher's long-standing interest in the intersections of religiosity, culture, and media as they are active in the environment of Aotearoa New Zealand. It assumes, building on theorists such as Bellah and Lundby that the creation of such festivals is an act of 'civil religiosity' that attempts to create and strengthen national community around a set of numinous symbols.
However, the development of an enterprise such as Matariki is pursued in a complex political field, where broad agreement across various factions is needed before the festival can take on an enduring material and symbolic existence. In investigating the factors that will determine the future of Matariki it is relevant to consider the interaction of three factors in particular: the ethno-political history of New Zealand; the characteristics of contemporary reflexive spirituality, which are intertwined with commodificatory tendencies and thirdly, the impacts of increasing globalisation on the parameters of identity-formation for citizens in late-modern societies.

year: 2011