The myth of the nation: Historiography of New Zealand architecture since 1907

This paper considers the relationship between the recent historiography (of the last quarter century) of “New Zealand architecture” and the historical notion of “New Zealand-ness” invoked in contemporary architecture. It argues that a more recent programmatic uptake of post-War discussions on national identity and regional specificity has fed the tendencies of practicing architects to defer to history in rhetorical defences of their work: the beach-side mansion as a contemporary expression of the 1950s bach; a formal modernism divorced from the social discourse adherent to the historical moment that it “restates”; and so on. The paper will consider instances in the historiography of New Zealand architecture where historians have compounded, consciously or accidentally, a problem that is systemic to the uses made by architects of historical knowledge (in the most general examples), identifying the difficulties of relying upon the tentative conclusions of an under-studied field in developing principles of contemporary architectural practice under the banners of New Zealand-ness, regionalism, or localism, or with reference to icons of New Zealand architectural history. At the heart of this paper is a reflection on historiographical responsibility in presenting knowledge of a national past to an audience that is eager to transform that knowledge into principles of contemporary production. What, the paper asks, is the historical basis for speaking of a New Zealand architecture? Can we speak of a national history of architecture distinct from a regional history, or from an international history of architecture?

A novel, open access, elliptical cross-section magnet for paediatric MRI

Almost all clinical magnetic resonance imaging systems are based on circular cross-section magnets. Recent advances in elliptical cross-section RF probe and gradient coil hardware raise the question of the possibility of using elliptical cross-section magnet systems, This paper presents a methodology for calculating rapidly the magnetic fields generated by a multi-turn coil of elliptical cross-section and incorporates this in a stochastic optimization method for magnet design, An open magnet system of elliptical cross-section is designed that both reduces the claustrophobia for the patients and allows ready access by attending physicians, The magnet system is optimized for paediatric use, The coil geometry produced by the optimization method has several novel features.

Integrable open-boundary conditions for the q-deformed supersymmetric U model of strongly correlated electrons

A general graded reflection equation algebra is proposed and the corresponding boundary quantum inverse scattering method is formulated. The formalism is applicable to all boundary lattice systems where an invertible R-matrix exists. As an application, the integrable open-boundary conditions for the q-deformed supersymmetric U model of strongly correlated electrons are investigated. The diagonal boundary K-matrices are found and a class of integrable boundary terms are determined. The boundary system is solved by means of the coordinate space Bethe ansatz technique and the Bethe ansatz equations are derived. As a sideline, it is shown that all R-matrices associated with a quantum affine superalgebra enjoy the crossing-unitarity property. (C) 1998 Elsevier Science B.V.

An open-boundary integrable model of three coupled XY spin chains

The integrable open-boundary conditions for the model of three coupled one-dimensional XY spin chains are considered in the framework of the quantum inverse scattering method. The diagonal boundary K-matrices are found and a class of integrable boundary terms is determined. The boundary model Hamiltonian is solved by using the coordinate space Bethe ansatz technique and Bethe ansatz equations are derived. (C) 1998 Elsevier Science B.V.

Changes in three-dimensional architecture of microfilaments in cultured vascular smooth muscle cells during phenotypic modulation

To investigate changes in the three-dimensional microfilament architecture of vascular smooth muscle cells (SMC) during the process of phenotypic modulation, rabbit aortic SMCs cultured under different conditions and at different time points were either labelled with fluorescein-conjugated probes to cytoskeletal and contractile proteins for observation by confocal laser scanning microscopy, or extracted with Triton X-100 for scanning electron microscopy. Densely seeded SMCs in primary culture, which maintain a contractile phenotype, display prominent linear myofilament bundles (stress fibres) that are present throughout the cytoplasm with alpha-actin filaments predominant in the central part and beta-actin filaments in the periphery of the cell. Intermediate filaments form a meshed network interconnecting the stress fibres and linking directly to the nucleus. Moderately and sparsely seeded SMCs, which modulate toward the synthetic phenotype during the first 5 days of culture, undergo a gradual redistribution of intermediate filaments from the perinuclear region toward the peripheral cytoplasm and a partial disassembly of stress fibres in the central part of the upper cortex of the cytoplasm, with an obvious decrease in alpha-actin and myosin staining. These changes are reversed in moderately seeded SMCs by day 8 of culture when they have reached confluence. The results reveal two changes in microfilament architecture in SMCs as they undergo a change in phenotype: the redistribution of intermediate filaments probably due to an increase in synthetic organelles in the perinuclear area, and the partial disassembly of stress fibres which may reflect a degradation of contractile components.

Architecture and morphogenesis of grain sorghum, Sorghum bicolor (L.) Moench

Plant architecture has been neglected in most studies of biomass allocation in crops. To help redress this situation for grain sorghum (Sorghum bicolor (L.) Moench), we used a 3D digitiser to measure the dimensions and orientations of vegetative and reproductive structures and derived thermal time-based functions for architectural changes during morphogenesis. Our plants, which were grown in a greenhouse, controlled environment cabinets and the field, covered a large, three-fold, size range when mature. This allowed us to detect some general architectural relationships and to fit morphogenetic functions common across the size range we observed. For example, the relationship between the lengths of successive fully-expanded leaves within a plant was nearly constant for all plants. The lengths of existing leaf blades were accurate predictors of the lengths of up to six subsequently-formed blades in our plants. Similar constant relationships were detected for internode lengths in the panicle and for heights above ground of the collars of successive leaves, even though these traits varied a lot between growth conditions. We suggest that such architectural relationships may be used to link the effect of previous growth conditions to future growth potential, and in that way to predict future partitioning. Our results provide the basis for a preliminary model of sorghum morphogenesis which could eventually become useful in conjunction with crop models by allowing resource acquisition to be related to changes in plant architecture during development. (C) 1999 Elsevier Science B.V. All rights reserved.

Quantum open-systems approach to current noise in resonant tunneling junctions

A quantum Markovian master equation is derived to describe the current noise in resonant tunneling devices. This equation includes both incoherent and coherent quantum tunneling processes. We show how to obtain the population master equation by adiabatic elimination of quantum coherences in the presence of elastic scattering. We calculate the noise spectrum for a double well device and predict subshot noise statistics for strong tunneling between the wells. The method is an alternative to Green's function methods and population master equations for very small coherently coupled quantum dots.

Thylakoid membrane architecture

Confocal scanning laser microscopic observations were made on live chloroplasts in intact cells and on mechanically isolated, intact chloroplasts. Chlorophyll fluorescence was imaged to observe thylakoid membrane architecture. C-3 plant species studied included Spinacia oleracea L., Spathiphyllum sp. Schott, cv. 'Mauna Loa', and Pisum sativum L. C-4 plants were also investigated: Saccharum officinarum L., Sorghum bicolor L. Moench, Zea mays L. and Panicum miliaceum L. Some Spinacia chloroplasts were treated with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) to enhance or sodium dithionite (SD) to reduce the photosystem II fluorescence signal. Confocal microscopy images of C-3 chloroplasts differed from electron microscopy pictures because they showed discrete spots of bright fluorescence with black regions between them. There was no evidence of fluorescence from stroma thylakoids. The thylakoid membrane system at times appeared to be string-like, with brightly fluorescing grana lined up like beads. C-4 bundle sheath chloroplasts were imaged from three different types of C-4 plants. Saccharum and Sorghum bundle sheath chloroplasts showed homogeneous fluorescence and were much dimmer than mesophyll chloroplasts. Zea had rudimentary grana, and dim, homogeneous intergrana fluorescence was visualised. Panicum contained thylakoids similar in appearance and string-like arrangement to mesophyll chloroplasts. Isolated Pisum chloroplasts, treated with a drop of 5 mM MgCl2 showed a thylakoid membrane system which appeared to be unravelling. Spongy mesophyll chloroplasts of Spinacia treated with 5 mM sodium dithionite showed a granal thylakoid system with distinct regions of no fluorescence. A time-series experiment provided evidence of dynamic membrane rearrangements over a period of half an hour.

Algebraic Bethe ansatz for integrable one-dimensional extended Hubbard models with open boundary conditions

Nine classes of integrable open boundary conditions, further extending the one-dimensional U-q (gl (212)) extended Hubbard model, have been constructed previously by means of the boundary Z(2)-graded quantum inverse scattering method. The boundary systems are now solved by using the algebraic Bethe ansatz method, and the Bethe ansatz equations are obtained for all nine cases.

Interaction of RTD-1, a cyclic antimicrobial defensin from Rhesus macaque leukocytes, and its open chain analogue with membrane mimics

In contrast to other mammalian defensins, rhesus theta defensin-1 (RTD-1) is composed of just 18 amino acids with the backbone cyclized through peptide bonds. Antibacterial activities of both the native cyclic peptide and a linear form were examined, showing that the cyclic form was 3-fold more active than the open chain analogue, oRTD-1, although both peptides adopt very similar structures in water. It was suggested that the additional charges at the termini of oRTD-1 are the cause for its lower antimicrobial activity. Therefore, we studied the interaction of both peptides with membrane mimics composed of zwitterionic (PC) and negatively charged (PG) phospholipids, major lipid components of erythrocyte and bacterial cell membranes, respectively. Microcalorimetry showed that RTD-1 and oRTD-1 did not affect the phase behavior of PC liposomes, while in PG liposomes both peptides induced new phase transitions above the chain melting transition of the lipid. The shape and fraction differed between both peptides, depending also on their concentration, which will be discussed in terms of their antimicrobial activity.