1,713 research outputs found

    Adaptation of Australian houses and households to future heat waves

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    Climate change predictions indicate more extremes in weather conditions in the coming decades with more frequent and severe heat waves in certain locations including Australia. It is likely that the more vulnerable members of the community will be at risk during heat waves in the future from both health and financial perspectives. The trend towards fully air conditioned larger homes has already seen very large peaks in electricity demand during past heat waves with associated system failures. The impact of increased periods of hot weather, electricity price rises and system failure can be addressed in part through household behaviour; however it is concurrently exacerbated by housing designs which limit occupant choice. This paper employs outputs from the thermal analysis of typical Australian housing types to discuss this relationship between behaviour and design in future heat wave scenarios. Particular attention is given to populated regions forecast to experience a significant increase in heat waves in the future. Alterations to existing buildings and modifications of typical new house designs are utilised to demonstrate methods of reducing risks associated with extended periods of hot weather. In conclusion, a summary of the positive environmental and comfort implications of the modified designs is presented.Jasmine Palmer, Helen Bennetts, Stephen Pullen, Jian Zuo, Tony Ma, Nicholas Chilesh

    Changes in the expression of the type 2 diabetes-associated gene VPS13C in the β cell are associated with glucose intolerance in humans and mice

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    Single nucleotide polymorphisms (SNPs) close to the VPS13C, C2CD4A and C2CD4B genes on chromosome 15q are associated with impaired fasting glucose and increased risk of type 2 diabetes. eQTL analysis revealed an association between possession of risk (C) alleles at a previously implicated causal SNP, rs7163757, and lowered VPS13C and C2CD4A levels in islets from female (n = 40, P < 0.041) but not from male subjects. Explored using promoter-reporter assays in β-cells and other cell lines, the risk variant at rs7163757 lowered enhancer activity. Mice deleted for Vps13c selectively in the β-cell were generated by crossing animals bearing a floxed allele at exon 1 to mice expressing Cre recombinase under Ins1 promoter control (Ins1Cre). Whereas Vps13cfl/fl:Ins1Cre (βVps13cKO) mice displayed normal weight gain compared with control littermates, deletion of Vps13c had little effect on glucose tolerance. Pancreatic histology revealed no significant change in β-cell mass in KO mice vs. controls, and glucose-stimulated insulin secretion from isolated islets was not altered in vitro between control and βVps13cKO mice. However, a tendency was observed in female null mice for lower insulin levels and β-cell function (HOMA-B) in vivo. Furthermore, glucose-stimulated increases in intracellular free Ca2+ were significantly increased in islets from female KO mice, suggesting impaired Ca2+ sensitivity of the secretory machinery. The present data thus provide evidence for a limited role for changes in VPS13C expression in conferring altered disease risk at this locus, particularly in females, and suggest that C2CD4A may also be involved

    Prenatal maternal effects appear to be insensitive to experimental or natural environmental variation:Environmental effects on egg traits

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    In many birds, hatching asynchrony is a common phenomenon, primarily driven by patterns of incubation behaviour. However, experimental results in blue tits (Cyanistes caeruleus) have shown that asynchrony is reduced by intrinsic properties of later eggs that accelerate prenatal development. These intrinsic differences between early and late eggs could be driven by changes in resource availability to females, which are then passively passed onto the egg. Alternatively, it may be due to an anticipatory maternal effect, wherein some signal or resource is actively placed within the egg, which is beneficial to those eggs laid late within the clutch. In order to distinguish between these hypotheses we designed a supplementary feeding experiment, wherein females were provided with food at certain times during the laying phase. This had no discernible effect on development rate, or other egg characteristics, consistent with anticipatory maternal effects. Using a larger dataset we also tested whether natural environmental variation (weather) during egg formation affected maternal investment in eggs. Similarly, egg characteristics were found to be relatively insensitive to the environmental variation, supporting the experimental results.</p

    Identification of dynamical Lie algebras for finite-level quantum control systems

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    The problem of identifying the dynamical Lie algebras of finite-level quantum systems subject to external control is considered, with special emphasis on systems that are not completely controllable. In particular, it is shown that the dynamical Lie algebra for an N-level system with equally spaced energy levels and uniform transition dipole moments, is a subalgebra for so(N)so(N) if N=2ℓ+1N=2\ell+1, and a subalgebra of sp(ℓ)sp(\ell) if N=2ℓN=2\ell. General conditions for obtaining either so(2ℓ+1)so(2\ell+1) or sp(ℓ)sp(\ell) are established.Comment: IoP LaTeX, ca. 14 page

    The Partition Function and Level Density for Yang-Mills-Higgs Quantum Mechanics

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    We calculate the partition function Z(t)Z(t) and the asymptotic integrated level density N(E)N(E) for Yang-Mills-Higgs Quantum Mechanics for two and three dimensions (n=2,3n = 2, 3). Due to the infinite volume of the phase space Γ\Gamma on energy shell for n=2n= 2, it is not possible to disentangle completely the coupled oscillators (x2y2x^2 y^2-model) from the Higgs sector. The situation is different for n=3n = 3 for which Γ\Gamma is finite. The transition from order to chaos in these systems is expressed by the corresponding transitions in Z(t)Z(t) and N(E)N(E), analogous to the transitions in adjacent level spacing distribution from Poisson distribution to Wigner-Dyson distribution. We also discuss a related system with quartic coupled oscillators and two dimensional quartic free oscillators for which, contrary to YMHQM, both coupling constants are dimensionless.Comment: 10 pages, LaTeX; minor changes; version accepted for publication as a Letter in J. Phys.

    Economies of visibility as a moderator of feminism: ‘Never mind Brexit. Who won Legs‐it!’

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    This article utilizes economies of visibility to interpret how two UK women political leaders’ bodies are constructed in the press, online and by audience responses across several media platforms via a multimodal analysis. We contribute politicizing economies of visibility, lying at the intersection of politics of visibility and economies of visibility, as a possible new modality of feminist politics. We suggest this offers a space where feminism can be progressed. Analysis illustrates how economies of visibility moderate feminism and tie women leaders in various ways to their bodies; commodities constantly scrutinized. The study surfaces how media insist upon femininity through appearance from women leaders, serving to moderate power and feminist potential. We consider complexities attached to public consumption of powerful women's constructions, set up in opposition, where sexism is visible and visceral. This simultaneously fortifies moderate feminism and provokes feminism. The insistence on femininity nevertheless disrupts, through an arousal of audible and commanding feminist voices, to reconnect with the political project of women's equality

    Experimental ionization of atomic hydrogen with few-cycle pulses

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    We present the first experimental data on strong-field ionization of atomic hydrogen by few-cycle laser pulses. We obtain quantitative agreement at the 10% level between the data and an {\it ab initio} simulation over a wide range of laser intensities and electron energies

    An organic fluorophore-nanodiamond hybrid sensor for photostable imaging and orthogonal, on-demand biosensing

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    Organic fluorescent probes are widely used to detect key biomolecules; however, they often lack the photostability required for extended intracellular imaging. Here we report a new hybrid nanomaterial (peroxynanosensor, PNS), consisting of an organic fluorescent probe bound to a nanodiamond, that overcomes this limitation to allow concurrent and extended cell-based imaging of the nanodiamond and ratiometric detection of hydrogen peroxide. Far-red fluorescence of the nanodiamond offers continuous monitoring without photobleaching, while the green fluorescence of the organic fluorescent probe attached to the nanodiamond surface detects hydrogen peroxide on demand. PNS detects basal production of hydrogen peroxide within M1 polarised macrophages and does not affect macrophage growth during prolonged co-incubation. This nanosensor can be used for extended bio-imaging not previously possible with an organic fluorescent probe, and is spectrally compatible with both Hoechst 33342 and MitoTracker Orange stains for hyperspectral imaging.Malcolm S. Purdey, Patrick K. Capon, Benjamin J. Pullen, Philipp Reineck, Nisha Schwarz, Peter J. Psaltis, Stephen J. Nicholls, Brant C. Gibson and Andrew D. Abel

    Adventures of the Coupled Yang-Mills Oscillators: II. YM-Higgs Quantum Mechanics

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    We continue our study of the quantum mechanical motion in the x2y2x^2y^2 potentials for n=2,3n=2,3, which arise in the spatially homogeneous limit of the Yang-Mills (YM) equations. In the present paper, we develop a new approach to the calculation of the partition function Z(t)Z(t) beyond the Thomas-Fermi (TF) approximation by adding a harmonic (Higgs) potential and taking the limit v→0v\to 0, where vv is the vacuum expectation value of the Higgs field. Using the Wigner-Kirkwood method to calculate higher-order corrections in ℏ\hbar, we show that the limit v→0v\to 0 leads to power-like singularities of the type v−nv^{-n}, which reflect the possibility of escape of the particle along the channels in the classical limit. We show how these singularities can be eliminated by taking into account the quantum fluctuations dictated by the form of the potential
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