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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

The role of colour and odour in fruit selection by diurnal, endemic skinks (Oligosoma) in Aotearoa / New Zealand

Marshall, Jane Elizabeth, n/a January 2006 (has links)
The flora of Aotearoa/ New Zealand has evolved in association with birds and lizards as the dominant frugivores and seed dispersers. There is a wide range of ripe fruit colours within the native fleshy-fruited plants spanning the visible light spectrum from red to violet, with the notable exception of green. The evolution of fleshy-fruit and fruiting related trait, may be a result of the selection pressures exerted by different frugivore guilds. This study was conducted to ascertain if endemic diurnal lizards, Oligosoma species (Scincidae: Lacertilia), display features associated with visual based foraging, colour sensitivity and colour preferences, which are necessary conditions to infer a co-evolutionary mutualism between fleshy-fruited plant species and lizards as seed dispersers, which may have influenced the evolution of fruit colour. Many lizards have exceptional colour vision, with the ability to see a wide range of the visual light spectrum from short wave ultra violet to long wave red. They are able to discriminate all aspects of colour: hue, brightness and saturation. Fruit colour within Coprosma (Rubiaceae), is extremely variable, between and within species. The study of fruit colour preferences within this genus and particularly within species with polymorphic fruit colour provides a valuable comparison of frugivore preference to fruit with little inter and intraspecific variation, therefore minimising potentially confounding factors due to phylogeny. Fruit-colour choice experiments were conducted offering fruit from two colour categories based on postulated frugivore preferences; red and red orange fruit has been associated with avian frugivores whilst white and pale fruit has been associated with lizard frugivory in New Zealand. Experiments were conducted both ex-situ, in environmentally controlled laboratories and in-situ at Macraes Flat, Otago. Pilot trials indicated that the background colour on which fruit were presented was important in fruit choice and consequentially, all fruit were offered on a background which provided contrast to both fruit colour categories. The laboratory trials showed some weak evidence for a preference of white and pale blue fruit however, in-situ trials showed a strong preference for white over red fruit. Field studies were conducted to ascertain the composition of fleshy-fruit in the diets of lizards and the results were consistent with those expected for a generalist omnivore; many of the small fruits available to lizards were consumed however, the results indicated that plant abundance does not adequately explain fruit consumption at this field site. A preference index showed that white and pale fruited plants, Melicytus alpinus and Coprosma spp., were preferred over more abundant orange and red fruited plants. Fruit odour was investigated to determine if fruit choice was mediated primarily by visual cues as opposed to odour cues. Fruit choice trials with the fruit concealed from view indicated that fruit choice was based primarily on visual cues in Oligosoma skinks. It is concluded that lizards demonstrate the necessary conditions to infer that as frugivores, they may have influenced the evolution of fruit colour and that within the open habitats of Aotearoa/ New Zealand, the shrubs, particularly the divaricate shrubs may have provided sufficient environmental conditions to establish a mutualism between plants and lizards resulting in the evolution of small, white and other low chroma fruits.
412

Gender, family responsibilities and career success in the New Zealand accountancy profession

Whiting, Rosalind Heather, n/a January 2007 (has links)
This study contributes to an understanding of the causes, consequences and complexities of gender inequity in career success (high levels of status and salary) in the New Zealand accounting profession. Sixty-nine (twenty-seven male and forty-two female) experienced Chartered Accountants were interviewed about their career histories. A feminist, interpretative and qualitative approach was followed and NVIVO was used for analysis. The first significant contribution of the study was the identification of five work/family strategies based on levels of family and work involvement (Traditional Men, Traditional Women, Family Balancers, Stepping Stone Men and Work First Women). Secondly, the level of family responsibilities explained career success much better than gender alone, although these two factors were commonly (but not always) directly related. The third contribution was the revision of the three-pronged model previously offered by Whiting & Wright (2001) to explain gender inequities in salary and status in the New Zealand accounting profession. Because the original model was derived from quantitative data, using qualitative data to revise the model constituted a sequential mixed method (pragmatic) approach. In the revised model, gender centrality and the three explanatory categories (Attributes, Structure and Attitudes) were removed. Career success was enhanced by high career aspirations (related to perceptions of stress, managerial and responsibility requirements and remuneration), long working hours and availability to clients, hard work, high technical competence and skills (enhanced by overseas experience), networking (less attractive to women), self-confidence (enhanced by mentoring for the least self-confident), flexibility to relocate if required (decreased by family and lifestyle ties) and large size and growth of the employing organisation. Most influential were career aspirations and a long hours/available work ethic. This demonstrated the pervasiveness of the male linear career model (derived from the male breadwinner-female carer family structure), that rewarded (in terms of progression) unilateral allegiance to the firm. Career aspirations, desire for responsibility, perceived ability to handle pressure, long hours, availability to clients, networking and possibly technical skills (if there were periods of extended leave) were all influenced by the Chartered Accountant�s level of family responsibilities. Those with the least family responsibilities (childless, Traditional Men and Work First Women) demonstrated unswerving commitment to the firm and were equally the most successful career wise. The impact of family responsibilities on career progression could be ameliorated by organisational cultural change. There were some indications of cultural change, being most prevalent in public sector and educational organisations. Enhancing conditions included a culture of flexibility and a concurrent atmosphere of trust, a less competitive work culture, absence of constant overtime demands and on-call work, encouraging top management who worked positively to retain and foster top performers over a longer period, and high level part-time positions supported by well-trained subordinate teams. To achieve these conditions provides an imminent challenge to organisations which employ Chartered Accountants, because the profession is increasing its proportion of females, has a younger generation more interested in work-life balance, and is losing many of its members overseas.
413

Oral delivery of bioactive compounds to the common brushtail possum (Trichosurus vulpecula)

McDowell, Arlene, n/a January 2005 (has links)
The common brushtail possum (Trichosurus vulpecula) is the most significant vertebrate pest in New Zealand as an ecological threat to the indigenous biodiversity and an economic threat as a vector for bovine tuberculosis. Biological control is considered to be the most accepted management strategy to reduce the population, specifically by impairing fertility. Successful development of a biocontrol agent (most likely a protein or peptide macromolecule) requires identification of a compound that is species-specific and potent. The challenge is also to deliver the bioactive to this free-ranging, widespread, feral animal and ensure sufficient bioavailability. Macromolecules have low oral bioavailability, thus new formulation strategies are required to enhance stability and absorption in the gastrointestinal tract (GIT) of T. vulpecula. Oral administration of the bioactive contained within a non-toxic bait is the most practical delivery strategy. Essential to designing an oral delivery system is to quantify the transit time of different sized delivery systems. The gastrointestinal transit in T. vulpecula was investigated (n = 72) by gamma scintigraphy. Technetium-labelled (99mTc) anion exchange resin particles (75 - 125 (mu)m or 500 - 700 (mu)m) or solution (99mTc-DTPA) was administered orally. After 3, 6, 12, 24 or 32 h, distribution of radioactivity in excised GITs was determined. Transit profiles were similar for each formulation. For delivery to the hindgut, bioactives need protection for 12 h though the upper GIT. Particulate formulations may be retained in the caecum for up to 32 h. Transit time was not different between animals dosed in the evening or the morning. Furthermore, GIT morphology is different between specimens in this study from southern New Zealand and Australian specimens. This may reflect improved diet quality in New Zealand. A model protein (insulin) was incorporated into poly(ethyl 2-cyanoacrylate) (PECA) nanoparticles prepared by interfacial polymerisation of water-in-oil microemulsions. The mean size of nanoparticles was 220 nm with a mean entrapment efficiency of 78%, determined using reverse phase HPLC. In vitro release of insulin from PECA nanoparticles in phosphate buffer (0.067 M, pH 7.4) at 37°C was triphasic and not all entrapped insulin was released. Following in vitro incubation of nanoparticles with enzyme solutions prepared from the GIT of T. vulpecula, lumen enzymes were more aggressive towards insulin compared to mucosal enzymes and the hindgut lumen was the GIT region with the lowest degradation. For the first time in a marsupial species, the in vivo pharmacokinetics of insulin-loaded, PECA nanoparticles were investigated following i.v. and intra-caecal administration and measured by radioimmunoassay. The low cross reactivity of human and endogenous brushtail possum insulin means that T. vulpecula is a suitable non-diabetic model to study pharmacokinetics of insulin. The i.v. pharmacokinetics of insulin solution and insulin-loaded nanoparticles were similar. On intracaecal dosing, co-administration of a permeation enhancer (EDTA) resulted in a small increase in plasma insulin concentration compared to insulin-loaded nanoparticles alone. In conclusion, transit time to the caecum of T. vulpecula following oral delivery was 12 h for fluid and particulate formulations < 1 mm diameter and was independent of the time of day the dose was given. T. vulpecula is a potential non-diabetic model for the study of insulin pharmacokinetics. This thesis demonstrates the potential application of oral peptide and protein delivery technology in the area of wildlife management.
414

Larval dispersal and population genetic structure of brachiopods in the New Zealand fiords

Ostrow, D. Gigi, n/a January 2007 (has links)
New Zealand�s fourteen deep-water fiords have complex physical and hydrographic features as well as strong environmental gradients, all of which may influence the population structure of organisms that inhabit the fiords. I examined the population structure of the brachiopod Terebratella sanguinea over ecological and evolutionary time scales in relation to physical and hydrographic features of the fiords. To further explore the role of larval dispersal in this system, comparisons between population genetic structure of T. sanguinea and a brachiopod with a contrasting larval dispersal strategy (Liothyrella neozelanica) were made. Aspects of the life history of the articulate brachiopod Terebratella sanguinea were measured. I measured density and size throughout Doubtful Sound and growth at outer (5 km from outer coast) and inner fiord sites (13.5 km from outer coast). Additionally, reproductive periodicity was measured at a single site within Doubtful Sound. Terebratella sanguinea occurred at significantly lower densities and was significantly smaller at the outer fiord site (p < 0.05), however growth rates between an inner and outer fiord site did not differ significantly. Terebratella sanguinea was found to have separate sexes and synchronous maturation of oocytes with spawning occurring in the austral winter. These results indicated that, on an ecological time scale, the environmental gradient of the fiords influences aspects of T. sanguinea population structure. In order to determine the influence of the fiord environment on genetic population structure, patterns among T. sanguinea from across Fiordland were assessed using two genetic markers, and these data were compared to hydrodynamic variables. Ten sites (322 individuals) were included in a preliminary allozyme analysis, and 20 sites (358 individuals) were used for the amplified fragment length polymorphism (AFLP) analysis. Patchy genetic differentiation was revealed with both markers, and a break between Long Sound and the other Fiordland sites was detected with AFLP markers. My results suggest hydrodynamic features of this region may isolate organisms that can disperse only during a planktonic larval phase, however this isolation is visible in genetic patterns only at the most extreme values of the hydrodynamic variables. To better understand how the fiord environment influences population structure of organisms that disperse via planktonic larvae, I compared population genetic structure of two sympatric brachiopod species that differ in planktonic larval duration. Genetic analysis using the AFLP technique revealed population structuring corresponding to the contrasting modes of larval dispersal. AMOVA analysis indicated Liothyrella neozelanica, a brachiopod that broods its larvae, had more limited exchange among sites within a fiord than did T. sanguinea, a brachiopod that does not brood its larvae. In general, the fiord hydrographic conditions may be creating opportunities for local genetic differentiation (for example Long Sound) in organisms capable of longer distance dispersal, but organisms with lower potential for dispersal are more strongly influenced by ontogeny than by hydrography. Understanding the population structure of some of the marine fauna of Fiordland is an important cornerstone for the developing management plan for the area. Conservation of the underwater resources of this World Heritage Area can be successful if the structure of the system and the mechanisms driving this structure are taken into account.
415

An investigation into the antimicrobial repertoire of Streptococcus uberis

Wirawan, Ruth E., n/a January 2007 (has links)
Streptococcus uberis, an environmental organism also associated with dairy animals, is a common and persistent cause of bovine mastitis. New approaches to control these infections need to be identified. One such strategy may be the application of bacteriocins; proteinaceous antimicrobials elaborated by bacteria that typically inhibit the growth of strains closely related to the producer organism. The well-characterized lactococcal bacteriocin nisin is the active ingredient in two commercial products currently in use for the prevention of mastitis. However, reports of resistance development have prompted the investigation of alternative bacteriocins to be used in conjunction with nisin in 'bacteriocin cocktails' designed to have more comprehensive inhibitory activity against mastitis pathogens. The bacteriocins of gram-positive bacteria have been divided into four distinct classes: (I) lantibiotics, (II) non-lantibiotic peptides, (III) large proteins, and (IV) circular peptides. Although it has been known for more than twenty years that S. uberis commonly produce bacteriocin-like inhibitory substances (BLIS), none had been characterised prior to the present study. The first step in the current investigation was a survey of the BLIS activities of a set of fifteen S. uberis and S. bovis strains against a set of standard indicators as well as common gram-positive mastitis pathogens. Additional tests using a deferred antagonism agar plate-based assay showed that some of the BLIS activities were heat-sensitive and their production was influenced by the presence of either blood or a fermentable carbohydrate source in the test medium. On the basis of the results obtained from these tests it became apparent that S. uberis and S. bovis may commonly produce more than a single inhibitory agent. S. uberis 42 became the focus of this study because (a) it had broad inhibitory activity against mastitis-associated bacteria, (b) it did not display cross-resistance to nisin, and (c) from the preliminary screening results it appeared to produce both heat-stable and heat-labile inhibitory agents. Acid extracts of S. uberis 42 cells yielded inhibitory activity that, when fractionated by reversed-phase HPLC, yielded a peptide of 3029 Da. Although this peptide was blocked to Edman degradation at position 2, following propanethiol-modification a 20-amino acid sequence was obtained. Degenerate primers to lantibiotic biosynthesis gene homologs were used to initiate inverse PCR and primer walking, ultimately yielding a 15-kb contiguous sequence encompassing 11 genes typical of those involved in lantibiotic synthesis, regulation and immunity. Due to the close similarities to nisin of the S. uberis 42 lantibiotic precursor (78%), and the organisation and composition of the locus, this inhibitor was named nisin U. Nucleotide sequences homologous to insertion sequences were detected in the vicinity of the nisin U locus, and indicate a possible mechanism of acquisition of this locus by S. uberis. The locus was detected in ten other S. uberis, and also in two S. agalactiae and two S. thoraltensis strains, and in one S. porcinus and one S. pluranimalium strain. The amino acid sequences of some of these differed in one or two amino acids, and these variants were named nisin U2 and nisin U3 accordingly. Nisin U, the two nisin U variants, and nisin A exhibited cross-immunity (i.e. all of the producer strains were insensitive to each form of nisin) and cross-inducibility (i.e. all of the producer strains displayed enhanced production when exposed to each form of nisin). Nisin U did not contribute to the entire spectrum of inhibitory activity of S. uberis 42. Freeze thaw extracts of S. uberis 42 agar cultures yielded heat-labile inhibitory activity that was inhibitory to L. lactis A5, a producer of nisin Z. Subsequent purification by cation-exchange chromatography, gel filtration, and reversed-phase HPLC yielded a peptide of mass 7048 Da, which was resistant to Edman degradation. Digestion with chymotrypsin released an 819 Da peptide fragment of sequence NH₂-KAQAVIW-COOH. Tn916 mutagenesis of S. uberis 42 enabled the identification of the genetic locus of the inhibitor, comprising six genes potentially involved in its biosynthesis and immunity. The detection of a pair of flanking 159-bp direct repeats indicates possible acquisition of the locus by 'long target duplication'. The inhibitor was inferred to be a circular peptide, on the basis of its behaviour to Edman degradation, and by comparison of its locus with that of other circular bacteriocins. On the basis that the purified peptide appears to induce lysis in sensitive bacteria, although by an as-yet unidentified mechanism, the inhibitor was named uberolysin. The uberolysin structural gene was detected in eight other strains of S. uberis, however not all of these appeared to be producing active inhibitor. No bacteriocins closely resembling the two reported in this thesis have been demonstrated previously to be produced by members of the genus Streptococcus. The remarkable diversity in the structures, activity spectra and basic modes of action of these two bacteriocins produced by a single strain of S. uberis, combined with the observation of apparent greater heterogeneity in properties of a preliminary sampling of BLIS-producing strains, indicates that these bacteria may be an important source of novel antimicrobials of potential value for the treatment of mixed bacterial infections and for minimising potential resistance development.
416

Population dynamics, spawning and movement of brown trout in Taieri River tributary streams

Kristensen, Esben Astrup, n/a January 2007 (has links)
The aim of this study was to investigate population densities and dynamics of brown trout along multiple tributaries of the Taieri River, a large New Zealand river. Relationships between juvenile brown trout population dynamics and food availability, discharge and water temperature were examined in the same lowland stream. Downstream movements of juvenile brown trout were also examined. Trace element analyses of eggs aimed to identify the source of fish spawning in tributary streams. An experimental study of juvenile brown trout collected from downstream and upstream reaches compared patterns of agonistic behaviour amongst trout that were considered to be dominated by either migratory (downstream) or resident (upstream) fish. Longitudinal surveys of juvenile trout abundance were expanded across four additional streams to determine whether there were consistent patterns in population dynamics of brown trout. Large spatial and temporal variation in population dynamics of juvenile brown trout was found in Silverstream with an upstream site having significantly less temporal variation in densities than a downstream site. No effect of food availability on population dynamics was found. Discharge and temperature affected population densities of juvenile brown trout in some years, but could not solely explain the general pattern in spatial variation in population dynamics. Downstream movement was found to be a behavioural strategy used by juvenile brown trout and appeared to contribute to variation in juvenile density. Analysis of trace element signatures in brown trout eggs indicated that upstream spawning migration by anadromous females was restricted by the presence of a steep gorge along the middle reaches of the Taieri River. Patterns of spawning by migratory and resident fish along tributary streams appeared to vary. In Silverstream, spawning by anadromous fish dominated the lower reaches, whereas considerable overlap between anadromous and resident fish was observed in Big Stream. In Cap Burn distinct trace element signatures were observed for redds spawned along upstream and downstream reaches. However, it was not possible to confidently ascribe the source of the redds to main river migrants or Cap Burn resident fish. Behavioural observations of juvenile brown trout collected from upstream (resident) and downstream (migratory) reaches of Silverstream revealed differences in aggression level, with migratory fish being more aggressive. No difference in growth rates was found between fish from the two areas. Furthermore, the social organisation of resident fish was based on the formation of dominance hierarchies, whereas the competitive status of migratory fish was more even. Patterns in spatial and temporal variation in the longitudinal population dynamics and patterns of abundance of juvenile trout were repeated across the five tributaries. Populations in upstream reaches consisted of fish from multiple age classes and exhibited relatively limited variation in densities, whereas juvenile fish dominated populations along downstream reaches and densities varied greatly over an annual cycle. Taken together, these results suggest a general pattern of spatial and temporal variation in the population dynamics of brown trout sub-populations along tributaries of a large New Zealand river. Whilst various environmental factors may contribute to some of the variation, longitudinal separation into resident and migratory populations also appeared to be important. These finding are important for the management of brown trout in both main river channels and tributaries in New Zealand.
417

Lagarosiphon major : an introduced macrophyte and its ecological role in the littoral of Lake Dunstan, New Zealand

Bickel, Tobias O., n/a January 2007 (has links)
The littoral of Lake Dunstan, Central Otago, New Zealand, is dominated by the introduced submersed macrophyte Lagarosiphon major (hereafter Lagarosiphon) which effectively excludes native macrophytes from most of the littoral. Lake Dunstan is a large hydro lake that was - after reaching its operational water level in 1993 - rapidly colonized by Lagarosiphon from upstream sources. Because of its extensive biomass and growth, it is believed the macrophyte plays an important part in the lake ecosystem but also that it requires frequent management to allow for recreational activities, to restore aesthetic values of beaches and especially to prevent further spread into unaffected waterways. To assess the integration of Lagarosiphon into the lake ecosystem and possible impacts of extensive macrophyte removal a 3 year study was initiated focusing on invertebrate and fish distribution and diet in relation to Lagarosiphon. A stable isotope analysis was used to reconstruct carbon flows and trophic structure within the littoral of Lake Dunstan. Additionally, a small scale weed management experiment was carried out to assess possible impacts of macrophyte removal on invertebrates and fish. Lagarosiphon harboured a high density and diversity of macroinvertebrates. The invertebrate community was dominated by mollusc species in terms of biomass and abundance. There was little temporal and spatial variation in invertebrate distribution and communities on a large scale (lake-wide variation), but there were differences in invertebrate biomass on a smaller scale in relation to the location of samples within the macrophyte belt. Invertebrate biomass was lowest at the bottom of the dense macrophyte beds. The positive association of common bully (Gobiomorphus cotidianus: Eleotridae) with the dense Lagarosiphon stands and a diet - mainly consisting of invertebrates common on Lagarosiphon - suggested the important role of this macrophyte as a provider of food and shelter for small fish species. Brown and rainbow trout (Salmo trutta, Oncorhynchus mykiss: Salmonidae) diet was dominated by invertebrate species common on this macrophyte as well. Results of the stable isotope analysis suggested a secondary role of Lagarosiphon in the lake food web as a surface provider for the growth of epiphytic algae that appeared to be a major primary producer in the littoral of Lake Dunstan. Detritus (FPOM), assumed to consist partly of decaying Lagarosiphon, played a less important role as a base for the food chain. The main carbon flow pathway was from the primary producers (epiphyton - FPOM) through primary consumers (Mollusca, Chironomidae, Trichoptera) through to the top predators (tertiary consumers: trout and bullies) in the system. A small scale experiment on the influence of macrophyte harvest, i.e. the cutting of channels into dense macrophyte beds, showed that a partial removal of macrophyte biomass could help achieve several management goals: it not only reduced macrophyte biomass to enable recreational activities but also had no negative impacts on invertebrate biomass and diversity. The channels even increased invertebrate abundance and biomass in the treated compared to the untreated control plots along the cut edges. Regrowth of Lagarosiphon was rapid, with the cut channels being completely overgrown within 4 months. All these results taken together suggested a major role of Lagarosiphon in the littoral of Lake Dunstan. Lagarosiphon supported a species rich invertebrate community and was the main provider of food and shelter for fish in this lake. A partial removal of macrophyte biomass might be a more suitable management option than large scale eradication to avoid negative impacts on the lake ecosystem. The most important aspect in management of this weed remains the prevention of further spread into pristine waters.
418

Structural controls on gold - quartz vein mineralisation in the Otago schist, New Zealand

Scott, John G., n/a January 2006 (has links)
Hydrothermal fluid flow is spatially and genetically associated with deformation in the earth�s crust. In the Otago Schist, New Zealand, the circulation of hydrothermal fluids in the Cretaceous formed numerous mesothermal gold-quartz vein deposits. Otago schist rocks are largely L-S tectonites in which the penetrative fabric is the product of more than one deformation phase/transposition cycle. Regional correlation of deformation events allowed mineralised deposits to be related to the structural evolution of the Otago Schist. Compilation of a detailed tectonostratigraphy of New Zealand basement rocks reveals that extensional mineralisation correlates with the onset of localised terrestrial fanglomerate deposition, thermal perturbation and granitic intrusion that mark the beginning of New Zealand rifting from the Antarctic portion of Gondwana. Laminated and breccia textures in mineralised veins suggest that host structures have experienced repeated episodes of incremental slip and hydrothermal fluid flow. However, analysis of vein orientation data in terms of fault reactivation theory (Amontons Law) shows that most deposits contain veins that are unfavourably oriented for frictional reactivation. Repeated movement on unfavourably oriented structures may involve dynamic processes of strain refraction due to competency contrasts, the effect of anisotropy in the schist, or localised stress field rotation. Deposits have been classified on the basis of host structure kinematics at the time of mineralisation into low angle thrust faults, and high angle extensional fault - fracture arrays. Low angle deposits have a mapped internal geometry that is very different from conventional imbricate thrust systems. This study applied ⁴⁰Ar/�⁹Ar geochronology to selected deposits and has identified at least three distinct mineralisation events have occurred within the central axial belt during the Cretaceous. Relationships between radiometric apparent age and inferred crustal depth reveal that after metamorphism, the onset of cooling and rapid exhumation of the schist belt coincides temporally and spatially with the age of mineralisation and structural position of a regional scale low angle shear zone in Otago.
419

The geology of central southern Fiordland : with emphasis on the cause of polybaric Cretaceous metamorphism in western New Zealand

Powell, Nicholas Garth, n/a January 2007 (has links)
Central southern Fiordland, New Zealand, is underlain extensively by metasediments and associated metavolcanics. These are mapped in three lithostratigraphic units, from west to east Edgecumbe Group, Cameron Group and Cumbrae Supergroup. Lower Cameron Group units lithocorrelate with Central Fiordland Belt lithological associations and with those of Fraser Complex, Westland. Eastern Fiordland Belt metavolcanics and lacustrine metasediments are tectonostratigraphically unrelated to Cameron Group, from which they are separated by the Grebe Fault. They instead have affiliations with the Loch Burn Formation, Largs Volcanics, Drumduan Group and Paterson Group. These units (collectively, "Cumbrae Supergroup") represent remnants of a Triassic-Jurassic calc-alkaline arc. Six deformational episodes are identified in central southern Fiordland. The earliest, D₁, is obliterated by D₂ and M₂ metamorphism. D₃ is restricted to the Southwest Fiordland Block. D₄ occupied a brief interval of M₃ time. D₄ of the Central and Western Fiordland Belts corresponds to earliest deformation in Eastern Fiordland Belt metavolcanics. The Grebe Fault is a left-lateral reverse D₄ fault; now vertical, it previously dipped eastward. The Dusky Fault, a reactivated D₅ left-lateral transfer structure, accommodated the dip-slip component of displacement at low-angle normal faults during mid-Cretaceous extension. Open folds represent D₆. Post-glacial scarps mark the post-D₆ Kilcoy and Vincent Faults. Their merged northward continuation is intersected by the tailrace tunnel of the Manapouri Hydroelectric Power Station. Southwest Fiordland Block pelites were metamorphosed at 665 �C, c. 3 kbar during M₂. Early M₃ is of contact metamorphic aspect. Late M₃ is distinctively polybaric: Central Fiordland Belt kyanite-garnet pelites recrystallised at c. 8.5 kbar after metamorphism in the sillimanite field at c. 3.5 kbar. Western Fiordland Orthogneiss 12 kbar granulite assemblages formed during late M₃. South of the Dusky Fault, late M₃ is almost asymptomatic. The M₃ field gradient is continuous across the Grebe Fault: in the Eastern Fiordland Belt, late M₃ staurolite and garnet supersede chloritoid in lacustrine (meta-)sapropel-silts. The Grebe Fault is an important tectonostratigraphic break; it may separate New Zealand�s Western and Eastern Provinces. Its relationship to any "Median Tectonic Zone" is unclear, as no such zone has been found in southeastern Fiordland. Cumbrae Supergroup rocks within the "Median Tectonic Zone" represent the arc that nourished the Eastern Province�s Barretts Formation, Murihiku Supergroup and Stephens Subgroup. The Cumbrae arc was �obducted� westwards during Early Cretaceous continent-arc collision. This event simultaneously halted Eastern Province volcanogenic sedimentation and tectonically buried Fiordland, imposing late M₃ pressure increments. Drumduan Group lawsonite is coeval. Cretaceous collision induced glaciation. Late Cretaceous climatic deterioration and extensional tectonism caused icecap development. The Otago "Peneplain" is a Late Cretaceous subglacial floor. Accumulation of voluminous perennial Cretaceous ice on Earth has hitherto not been inferred. Facultative psychrophily in New Zealand�s ancient endemics and their preference for dark conditions reflect passage through a hitherto-unsuspected evolutionary bottleneck: prolonged winter darkness and harsh climate of near-polar Late Cretaceous New Zealand exerted extraordinary evolutive pressures on ancestral forms after biotic links with Gondwana were severed. New Zealand�s ancient endemics are the evolutionary derivatives of a Late Cretaceous near-polar fauna.
420

Food security in New Zealand

Parnell, Winsome R., n/a January 2005 (has links)
There was growing concern in New Zealand in the 1990�s that Food Security: access by all people at all times to enough food for an active healthy life, was not being achieved, despite an abundant food supply. A study of a convenience sample of 40 families with children (58 adults and 92 children) whose sole income was a government welfare benefit was undertaken. Two-thirds of these households regularly relied on a limited variety of food; one-half did not have a sufficient amount of food because of lack of money and outstanding debts. Over the previous year two-thirds had sourced food from a food bank and one-third had been gifted food from friends or relatives. Women�s intakes were compromised regularly but not children�s. All of the women experienced worry about feeding their household. One-fifth were overweight and over 40% obese despite low reported daily energy intakes (median (SE) 5.7 (0.5) MJ) compared to national data. Six repeated 24-hour diet recalls collected randomly over a two-week period enabled calculation of usual daily intake and the prevalence of inadequate intake for eight micronutrients which were disturbingly high. The children�s growth patterns compared favourably with US population percentiles. The National Nutrition Survey (NNS97) allowed the adaption of eight questions--developed by Reid using qualitative methods--to eight indicator statements about food security to be addressed by each participant on behalf of them or their household. Prevalence was significantly higher (p<0.05) for females compared to males for the majority of indicator statements among New Zealand European and Others (NZEO) and Maori. NZEO reported the most food security; Pacific people reported the least and Maori fell between the two. There was a significant increasing linear trend of food security with age (p<0.001) after adjusting for gender. Rasch analysis was performed on 1868 households where participants reported some food insecurity. The responses were ranked according to the proportion and ordering of their positive responses to eight indices of food security, achieving reliability (Cronbach�s Alpha) close to the conventionally accepted level of 0.7. The eight indices were ranked on the same scale; the minimum score -1.66 was achieved by the index �use special food grants/banks� (the index least reported and most severe) and the maximum score 1.86 was achieved by the index �variety of foods eaten limited� (the index most reported and least severe). Categories of food security were assigned using scale cut points: �fully/almost fully food secure�; �moderate food security�; �low food security�. Category status was associated with consumption of recommended number of daily serves of fruit, vegetables, fruits and vegetables, consumption of leaner meats, fatty meats and daily serves of bread. By ANOVA and controlling for sex, ethnicity, Index of Deprivation, urban/rural location, age, level of education, income, and household size, category of household food security was associated with the level of daily intake of total fat, saturated, monounsaturated and polyunsaturated fat, cholesterol, glucose, fructose, lactose, vitamin B6, vitamin B12, and vitamin C. Dietary data were from the primary 24-hour diet recall of respondents. Participants in the fully/almost fully food secure category of households had a mean BMI of 28.7 compared to those moderately secure (29.2) and of low food security (29.5) (p=0.015 for difference among categories). In the Children�s Nutrition Survey 2002 (CNS02) data set, the same eight indices were used and food insecurity was experienced significantly more often by children in the largest households, those in the most deprived areas of residence (NZDep01 Quintile) and those of Pacific and Maori ethnicity compared to NZEO children. Rasch analysis was performed on responses for 1561 households with children which reported some food insecurity. Subject reliability was close to 0.7 (the conventionally acceptable level). The distribution of the eight indices on the Rasch scale was similar to that observed among the NNS97 households and almost identical to the sub-set of households with children, from that dataset. Categories of food security status were assigned as in the NN5S97 and they predicted daily nutrient intake levels of children: total sugars, lactose, vitamm A, β-carotene, vitamin B12 and calcium. A more rigorous assigning of categories at the low/moderate scale cut-off, resulted in a further association with level of intake of glucose, fructose and folate. Mean BMI across categories of food security did not differ. Collectively these data provide unequivocal evidence that food insecurity exists in New Zealand, that it can be quantified and associated with nutrition outcomes. It has a negative impact on the nutrient intakes of both adults and children and a negative impact on the body weight status of adults. These data have implications for nutrition and health professionals and policy makers in New Zealand. They also add to the world-wide body of knowledge of the experience of, and the measurement and predictive potential of food security in populations where the food supply appears plentiful.

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