875 results for Journal article, 1990

  • Late Miocene paleo-geomorphology of the Bakony-Balaton Highland Volcanic Field (Hungary) using physical volcanology data

    Nemeth, Karoly; Martin, Ulrike (1999-01-01)

    Journal article
    Massey University

    A new view is presented of the Bakony-Balaton Highland Volcanic Field (BBHVF), Hungary, active in late Miocene and built up of ca. 100 mostly alkaline basaltic eruptive centers, scoria cones, tuff rings, maar volcanic complexes and shield volcanoes. A detailed map shows the physical volcanology of the monogenetic volcanic field. In areas where thick Pannonian Sandstone beds build up the pre-volcanic strata normal maar volcanic centers have formed with usually thick late magmatic infill in the maar basins. In areas, where relatively thin Pannonian Sandstone beds resting on thick Mesozoic or Paleozoic fracture-controlled, karsrwater-bearing aquifer, large unusual maar volcanic sequences appear (Tihany type maar volcanoes). In the northern pare of the field large former scoria cones and shield volcanoes give evidence for a smaller impact of the ground and surface water causing phreatomagmatic explosive activity. The Tihany type maar volcanic centers are usually filled by thick maar lake deposits, building up Gilbert type gravelly, scoria rich deltas in the northern side of the maar basins, suggesting a mostly north to south fluvial system in the pre-volcanic surface. Calculating paleosurface elevation for the eruptive centers, two paleo-geomorphology maps are drawn for a younger (4-2.8 Ma) and an older (7.54-4 Ma) scenario. The erosion rate of the volcanic field is estimated to vary between 96 m/Ma and 18 m/Ma. In the western site of BBHVF the erosion rate is higher (more than 60 m/Ma, Tapolca Basin), and an average 50 m/Ma in the center and eastern side.

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  • Large hydrovolcanic field in the Pannonian Basin: general characteristics of the Bakony- Balaton Highland Volcanic Field, Hungary.

    Nemeth, Karoly; Martin, Ulrike (1999-01-01)

    Journal article
    Massey University

    No abstract available

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  • Subaqueous volcanism and their depositional processes, their relationship to subaerial volcanism: review

    Nemeth, Karoly (1999-01-01)

    Journal article
    Massey University

    A vizalatti vulkanizmus jelenségei és üledékképződési folyamatai, kapcsolatai a szárazföldi vulkáni folyamatokkal: attekintes (Subaqueous volcanism and their depositional processes, their relationship to subaerial volcanism: review)

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  • Eroded porous-media aquifer controlled hydrovolcanic centers in the South Lake Balaton Region, Hungary: The Boglár Volcano

    Nemeth, Karoly; Martin, Ulrike; Philippe, Marc (1999-01-01)

    Journal article
    Massey University

    No abstract available

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  • The value of the world's ecosystem services and natural capital

    Costanza, R; d'Arge, R; de Groot, R; Faber, S; Grasso, M; Hannon, B; Limburg, K; Naeem, S; O'Neill, RV; Paruelo, J; Raskin, RG; Sutton, P; van den Belt, M (1997-05-15)

    Journal article
    Massey University

    The services of ecological systems and the natural capital stocks that produce them are critical to the functioning of the Earth’s life-support system. They contribute to human welfare, both directly and indirectly, and therefore represent part of the total economic value of the planet. We have estimated the current economic value of 17 ecosystem services for 16 biomes, based on published studies and a few original calculations. For the entire biosphere, the value (most of which is outside the market) is estimated to be in the range of US$16–54 trillion (1012) per year, with an average of US$33 trillion per year. Because of the nature of the uncertainties, this must be considered a minimum estimate. Global gross national product total is around US$18 trillion per year.

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  • Sustaining the physical and social dimensions of wilderness tourism: the perceptual approach to wilderness management in New Zealand

    Higham, James E S (1998)

    Journal article
    University of Otago

    Full text available only via related link.

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  • Poverty, Dependence and ‘Women’: Reading Autobiography and Social Policy from 1930s New Zealand

    Cooper, Annabel; Molloy, Maureen (1997)

    Journal article
    University of Otago

    This essay explores the construction of ‘women’ in New Zealand during the 1930s, when the social legislation of the First Labour Government was being formulated and enacted. It examines the documentation produced by the legislative process in relation to the autobiographical texts of John A. Lee and Mary Isabella Lee, arguing that there are parallel conflicts in each set of texts. There is a series of double movements: the offer of the state’s protection to women is at the same moment a gesture of defence; ‘women’ are simultaneously constructed as ‘helpless’ and—not so overtly—as needing to be controlled.

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  • Textual territories: Gendered cultural politics and Australian representations of the war of 1914–1918

    Cooper, Annabel (1993)

    Journal article
    University of Otago

    If, having passed through the long courtyard where the walls are inscribed with the names of thousands of Australian war dead, you enter the inner sanctum of the Australian War Memorial, the Hall of Memory (quietly, as you have been asked to preserve the hush appropriate to a chapel), you will see first the towering six- metre bronze infantryman occupying the place of the altar. If you have read Ken Inglis on the subject of memorials, you may observe this figure critically, because you know that his position was once to have been occupied by a personified Australia in female form. Turning, and looking up and around, you see the three large stained-glass windows with their fifteen panels, each representing a figure in a uniform of the 1914-1918 war, and each typifying, to quote the booklet you may have bought at the War Memorial shop, 'what were judged to be the marked qualities of Australian service men and women'. 'And women': the central figure of the southern and central panel is indeed a woman, a nurse, although she is the only woman represented in the windows. Dressed in her nurse's uniform with red cape and white cap and collar, she stands out against the dominant greys and blues in the uniforms of the fourteen soldiers, airmen and sailors to either side of her. Above her are the Red Cross and a symbol, to quote the booklet again, 'of charity': 'the pelican feeding her young from her bleeding breast'. This central window represents 'personal qualities', and the four soldiers who flank the nurse embody 'Resource', 'Candour', 'Curiosity', and 'Independence'. Her attribute, however, is 'Devotion', the other-directedness of the label interrogating her central position in the window. While never entirely central (because that is the place of the bronze infantryman, towards whom she gazes), the nurse is accorded nevertheless both a nominal centrality (as the middle figure of the fifteen panels) and a defining marginality (as 'Devotion'). Her emblem, the pelican, identifying her with motherhood, places her again in both positions, as the sacrificial focus, and as the mother whose life is subordinated to those of her children.

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  • A pepstatin-insensitive aspartic proteinase from a thermophilic Bacillus sp.

    Toogood, H.S.; Prescott, Mark; Daniel, Roy M. (1995)

    Journal article
    University of Waikato

    Bacillus sp. strain Wp22.A1 produced a cell-associated aspartic proteinase which was purified to homogeneity using phenyl-Sepharose (hydrophobic and affinity chromatography) and Mono Q. The proteinase has a molecular mass of 45 kDa by SDS/PAGE and a pI of 3.8. It is insensitive to pepstatin, but is sensitive to the other aspartic proteinase-specific inhibitors diazoacetyl-DL-norleucine methyl ester (DAN) and 1,2-epoxy-3-(p-nitrophenoxy)propane. Inactivation by DAN was only partial, suggesting that it had non-specifically modified an aspartate residue at a site other than the active site. The enzyme was not inhibited by any of the serine or cysteine proteinase inhibitors tested. Maximum proteolytic activity was observed at pH 3.5. The proteinase had a higher activity with haemoglobin, but was more specific (Vmax./Km) for cytochrome c. Substrate inhibition was observed with both these substrates. The cleavage of oxidized insulin B chain tended to occur at sites where the P1 amino acid was bulky and non-polar, and the P1' amino acid was bulky and polar, such as its primary cleavage site of Val2-Asn3. The proteinase was stable in the pH range 2.5-5.5. Thermostability was increased in the presence of Ca2+, although to a lesser extent at higher temperatures. The thermostabilities at 60, 70, 80 and 90 degrees C were 45 h, 102, 21 and 3 min respectively in the presence of Ca2+.

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  • Cellulolytic and hemicellulolytic enzymes functional above 100℃

    Ruttersmith, L.D.; Daniel, Roy M.; Simpson, H.D. (1992)

    Journal article
    University of Waikato

    Cellulases and hemicellulases have a variety of potential industrial applications, including the production of fermentable sugars from biomass and enzyme-assisted pulp bleaching. There are several advantages, in industrial terms, to be gained from employing thermostable enzymes in processes operating at elevated temperatures. For example, the lignin component of hemicellulose, which often blocks enzyme access, softens and melts over the temperature range 90-180°C.

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  • An extremely thermostable xylanase from the thermophilic eubacterium Thermotoga.

    Simpson, H.D.; Haufler, U.R.; Daniel, Roy M. (1991)

    Journal article
    University of Waikato

    Endo-1,4-beta-xylanase (EC 3.2.1.8) was isolated from the culture supernatant of Thermotoga sp. strain FjSS3-B.1, an extremely thermophilic anaerobic eubacterium which grows optimally at 80 degrees C. Activity was purified 165-fold by anion-exchange and hydroxyapatite chromatography. The enzyme has an Mr of 31,000 as determined by SDS/PAGE and 35,000 by analytical gel filtration. The optima for activity and stability for purified xylanase were between pH 5.0 and 5.5. At pH 5.5, which is the optimum pH for thermostability, t1/2 (95 degrees C) is 90 min. The thermostability was improved by immobilization of the xylanase on to porous glass beads; t1/2 (105 degrees C) is 10 min. Several additives, such as sorbitol and xylan, were also found to increase the thermostability. At 130 degrees C, the half-life of immobilized xylanase in the presence of 90% sorbitol was 1.3 min. At 130 degrees C in molten sorbitol half of the enzyme denatured rapidly, but the remainder appeared to have a half-life of about 60 min.

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  • Modern life at high temperatures

    Daniel, Roy M. (1992)

    Journal article
    University of Waikato

    A variety of micro-organisms are now known which grow optimally above 65°C, and are defined as extreme thermophiles. As might be expected they are found in both natural and artificial hot environments. Until comparatively recently the upper optimum temperature for the growth of any living organism was about 85°C. Then in 1982 Stetter described an organism, isolated from the hot sea floor of a submarine solfatara field, which grew optimally at 105°C. Since then several other organisms have been found with optimum growth temperatures at 100"C or above and a few are capable of growth at 110*C (e.g. Huber et al., 1987; Fiala and Stetter, 1986; Zillig et al., 1987; Stetter et al., 1990).

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  • Cellulolytic properties of an extremely thermophilic anaerobe

    Hudson, J. Andrew; Morgan, Hugh W.; Daniel, Roy M. (1990)

    Journal article
    University of Waikato

    An extremely thermophilic anaerobe was isolated from a New Zealand hot spring by incubating bacterial mat strands in a medium containing xylan. The Gramreaction-negative organism that was subsequently purified had a temperature optimum of 70° C and a pH optimum of 7.0. The isolate, designated strain H173, grew on a restricted range of carbon sources. In batch culture H173 could degrade Avicel completely when supplied at 5 or 10 g l⁻¹. There was an initial growth phase, during which a cellulase complex was produced and carbohydrates fermented to form acetic and lactic acids, followed by a phase where cells were not metabolising but the cellulase complex actively converted cellulose to glucose. When co-cultured with strain Rt8.B1, an ethanologenic extreme thermophile, glucose was fermented to ethanol and acetate, and no reducing sugars accumulated in the medium. In pH controlled batch culture H173 produced an increased amount of lactate and acetate but there was again a phase when reducing sugars accumulated in the medium, and these were converted to ethanol by co-culture with Rt8.B1.

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  • Purification and characterization of a pepstatin-insensitive, thermostable, extracellular acid proteinase from a bacterium

    Prescott, Mark; Peek, Keith; Prendergast, Elizabeth; Daniel, Roy M. (1992)

    Journal article
    University of Waikato

    Aspartate proteinases (also referred to as acid or carboxyl) represent one of the four major classes of proteinase. Work on members of this group has centered largely around those enzymes isolated from mammalian, fungal, or plant sources. Some of these have proven to be of great economic importance, for example, the renneting enzyme, chymosin.

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  • Self-assembly of a columnar polymeric calcium phosphinate derived from camphene

    Henderson, William; Leach, Meto T.; Nicholson, Brian K.; Sabat, Michal (1995)

    Journal article
    University of Waikato

    (2,2-Dimethylbicyclo[2.2.1] hept-3-ylmethyl)phosphinic acid (RPO₂H₂), readily prepared from camphene and hypophosphorous acid, formed a polymeric calcium salt [{Ca(RPO₂H) ₂ (RPO₂H₂)(H₂O)}n], with both terminal and triply bridging phosphinate groups, and an overall columnar structure with an inorganic core and a pseudo-close-packed sheath of terpene moieties.

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  • Book Review: To Circumjack MacDiarmid: The Poetry and Prose of Hugh MacDiarmid by W. N. Herbert

    Riach, Alan (1995)

    Journal article
    University of Waikato

    This article reviews the book: “To Circumjack MacDiarmid: The Poetry and Prose of Hugh MacDiarmid”, by W. N. Herbert.

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  • Cementation scenarios for New Zealand Cenozoic nontropical limestones

    Hood, Steven D.; Nelson, Campbell S. (1996)

    Journal article
    University of Waikato

    Cenozoic limestones are widely distributed in New Zealand, especially in the Oligocene-earliest Miocene in both islands, and the Pliocene-Pleistocene in North Island. A spectrum of limestone types exists, but all are skeletal-dominated (>70%), with usually <10% siliciclasts, and they have facies attributes typical of nontropical carbonates. The range of diagenetic features identified within the limestones is the basis for assigning them to a small number of “end-member” cementation classes that are inferred to be associated with four, broad, diagenetic settings.

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  • Did primitive microorganisms use nonhem iron proteins in place of NAD/P?

    Daniel, Roy M.; Danson, Michael J. (1995)

    Journal article
    University of Waikato

    Nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) are of universal occurrence in living organisms and play a central role in coupling oxidative with reductive reactions. However, the evidence that the origin and early evolution of life occurred at high temperatures (>95°C) is now strong, and at these temperatures some modern metabolites, including both the reduced and oxidized forms of these coenzymes, are unstable. We believe there is good evidence that indicates that in the most primitive organisms nonhem iron proteins carried out many or all of the functions of NAD/P(H). This has important implications for the way in which investigations of archaebacterial metabolism are conducted.

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  • Characterization of a chelator-resistant proteinase from Thermus strain Rt4A2

    Freeman, S.A.; Peek, Keith; Prescott, Mark; Daniel, Roy M. (1993)

    Journal article
    University of Waikato

    The Thermus isolate Rt4A2 was found to produce an extracellular chelator-resistant proteinase. The proteinase was purified to homogeneity by (NH4)2SO4 precipitation, cation-exchange chromatography, gel-filtration chromatography, and weak anion-exchange chromatography. The Rt4A2 proteinase was found to have properties typical of an alkaline serine proteinase. It had a pH optimum of 9.0 and was specifically inhibited by phenylmethanesulphonyl fluoride. Its isoelectric point was greater than 10.25. Its molecular-mass was 31.6 kDa as determined by SDS/PAGE. N-terminal sequencing has shown it to have high sequence similarity with other serine proteinases from Thermus species. The proteinase hydrolysed a number of substrates including fibrin, casein, haemoglobin, collagen, albumin and the synthetic chromogenic peptide substrate Suc-Ala-Ala-Pro-Phe-NH-Np. The specific activity of the purified proteinase using azocasein as substrate was 313 units/mg. Substrate inhibition was observed above an azocasein concentration of 0.05% (w/v). Esterase activity was directed mainly towards those substrates containing the aliphatic or aromatic residues of alanine, glycine, tryptophan, tyrosine and phenylalanine. Thermostability half-lives of greater than 7 days at 70 degrees C, 43 h at 80 degrees C and 90 min at 90 degrees C were found in the presence of 5 mM CaCl2. At 90 degrees C increasing the CaCl2 concentration 100-fold (0.5 mM to 50 mM) caused a 4.3-fold increase in the half-life of the enzyme from 30 to 130 min. Half-lives of 19.4 min at 100 degrees C and 4.4 min at 105 degrees C were found in the presence of 50 mM CaCl2. The metal chelators EGTA and EDTA reduced the stability at higher temperatures but had no effect on the activity of the proteinase. Activity was not stimulated by common metal activators such as Ca2+, Mg2+ and Zn2+.

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  • Purification of a Thermostable DNA Polymerase from a Thermotoga Species

    Simpson, H.D.; Coolbear, Tim; Daniel, Roy M. (1990)

    Journal article
    University of Waikato

    Most of the initial studies on the fundamental cellular process of biosynthesis and repair of deoxyribonucleic acid (DNA) have been carried out on the bacterium Escherichia coli.¹When a single-stranded DNA template is provided with a primer, the 5’ - 3’ polymerase copies the template in the presence of deoxyribonucleotide triphosphates and a divalent cation, for example, Mg²⁺.

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