23,158 research outputs found

    Australia's Carbon Tax: A Sheep in Wolf's Clothing?

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    The Australian Government has produced a CO2-equivalent tax proposal with a difference, it is a short prelude to an emission trading scheme that will allow the increasing rate of emissions to continue, while being a net cost to the Treasury. That cost extends to allowing major emitters to make guaranteed windfall profits from pollution permits. The emission trading scheme suffers numerous problems, but the issues raised show taxes can also be watered down and made ineffectual through concessions. Taxpayers will get no assets from the billions of dollars to be spent buying-off the coal generators or other polluters. The scheme hopes to stimulate private investors to create an additional 12 percent in renewable electricity generation by 2020. A serious emissions reducing alternative would be to create a nationalised electricity sector with 100 percent renewable energy within a decade. We explore the difficulties of implementing meaningful greenhouse gas taxes in Australia.greenhouse gases; taxation; emission trading; climate change; regulation; renewable energy; Australia

    Articulation of Plural Values in Deliberative Monetary Valuation: Beyond Preference Economisation and Moralisation

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    The use of deliberative methods to assess environmental values in monetary terms has been motivated by the potential for small group discussion to help with preference formation and the inclusion of non-economic values. In this review, two broad approaches are identified: preference economisation and preference moralisation. The former is analytical, concentrates upon issues of poor respondent cognition and produces a narrow conception of value linked to utilitarianism. The latter emphasises political legitimacy, appeals to community values and tends to privilege arguments made in the public interest. Both approaches are shown to embrace forms of value convergence which undermine the prospects for value pluralism. As a result exclusion and predefinition of values dominates current practice. In order to maintain democratic credentials, the importance attributed to monetary value needs to be left as an open question to be addressed as part of a process determining an ‘agreement to pay’. To this end we identify a discourse-based approach as a third way consistent with the democratic and value plural potential of deliberative monetary valuation.environmental valuation; deliberation; stated preferences; democracy; willingness to pay; value pluralism

    DLC2 modulates angiogenic responses in vascular endothelial cells by regulating cell attachment and migration.

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    Deleted in liver cancer 1 (DLC1) is a RhoGTPase activation protein-containing tumor suppressor that associates with various types of cancer. Although DLC2 shares a similar domain structure with that of DLC1, the function of DLC2 is not well characterized. Here, we describe the expression and ablation of DLC2 in mice using a reporter-knockout approach. DLC2 is expressed in several tissues and in endothelial cells (ECs) of blood vessels. Although ECs and blood vessels show no histological abnormalities and mice appear overall healthy, DLC2-mutant mice display enhanced angiogenic responses induced by matrigel and by tumor cells. Silencing of DLC2 in human ECs has reduced cell attachment, increased migration, and tube formation. These changes are rescued by silencing of RhoA, suggesting that the process is RhoA pathway dependent. These results indicate that DLC2 is not required for mouse development and normal vessel formation, but may protect mouse from unwanted angiogenesis induced by, for example, tumor cells

    A balanced homodyne detector for high-rate Gaussian-modulated coherent-state quantum key distribution

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    We discuss excess noise contributions of a practical balanced homodyne detector in Gaussian-modulated coherent-state (GMCS) quantum key distribution (QKD). We point out the key generated from the original realistic model of GMCS QKD may not be secure. In our refined realistic model, we take into account excess noise due to the finite bandwidth of the homodyne detector and the fluctuation of the local oscillator. A high speed balanced homodyne detector suitable for GMCS QKD in the telecommunication wavelength region is built and experimentally tested. The 3dB bandwidth of the balanced homodyne detector is found to be 104MHz and its electronic noise level is 13dB below the shot noise at a local oscillator level of 8.5*10^8 photon per pulse. The secure key rate of a GMCS QKD experiment with this homodyne detector is expected to reach Mbits/s over a few kilometers.Comment: 22 pages, 11 figure

    Numerical methods for analyzing electromagnetic scattering

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    Numerical methods to analyze electromagnetic scattering are presented. The dispersions and attenuations of the normal modes in a circular waveguide coated with lossy material were completely analyzed. The radar cross section (RCS) from a circular waveguide coated with lossy material was calculated. The following is observed: (1) the interior irradiation contributes to the RCS much more than does the rim diffraction; (2) at low frequency, the RCS from the circular waveguide terminated by a perfect electric conductor (PEC) can be reduced more than 13 dB down with a coating thickness less than 1% of the radius using the best lossy material available in a 6 radius-long cylinder; (3) at high frequency, a modal separation between the highly attenuated and the lowly attenuated modes is evident if the coating material is too lossy, however, a large RCS reduction can be achieved for a small incident angle with a thin layer of coating. It is found that the waveguide coated with a lossy magnetic material can be used as a substitute for a corrugated waveguide to produce a circularly polarized radiation yield

    Numerical methods for analyzing electromagnetic scattering

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    Attenuation properties of the normal modes in an overmoded waveguide coated with a lossy material were analyzed. It is found that the low-order modes, can be significantly attenuated even with a thin layer of coating if the coating material is not too lossy. A thinner layer of coating is required for large attenuation of the low-order modes if the coating material is magnetic rather than dielectric. The Radar Cross Section (RCS) from an uncoated circular guide terminated by a perfect electric conductor was calculated and compared with available experimental data. It is confirmed that the interior irradiation contributes to the RCS. The equivalent-current method based on the geometrical theory of diffraction (GTD) was chosen for the calculation of the contribution from the rim diffraction. The RCS reduction from a coated circular guide terminated by a PEC are planned schemes for the experiments are included. The waveguide coated with a lossy magnetic material is suggested as a substitute for the corrugated waveguide

    Wave attenuation and mode dispersion in a waveguide coated with lossy dielectric material

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    The modal attenuation constants in a cylindrical waveguide coated with a lossy dielectric material are studied as functions of frequency, dielectric constant, and thickness of the dielectric layer. A dielectric material best suited for a large attenuation is suggested. Using Kirchhoff's approximation, the field attenuation in a coated waveguide which is illuminated by a normally incident plane wave is also studied. For a circular guide which has a diameter of two wavelengths and is coated with a thin lossy dielectric layer (omega sub r = 9.1 - j2.3, thickness = 3% of the radius), a 3 dB attenuation is achieved within 16 diameters

    Extraction of Airways with Probabilistic State-space Models and Bayesian Smoothing

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    Segmenting tree structures is common in several image processing applications. In medical image analysis, reliable segmentations of airways, vessels, neurons and other tree structures can enable important clinical applications. We present a framework for tracking tree structures comprising of elongated branches using probabilistic state-space models and Bayesian smoothing. Unlike most existing methods that proceed with sequential tracking of branches, we present an exploratory method, that is less sensitive to local anomalies in the data due to acquisition noise and/or interfering structures. The evolution of individual branches is modelled using a process model and the observed data is incorporated into the update step of the Bayesian smoother using a measurement model that is based on a multi-scale blob detector. Bayesian smoothing is performed using the RTS (Rauch-Tung-Striebel) smoother, which provides Gaussian density estimates of branch states at each tracking step. We select likely branch seed points automatically based on the response of the blob detection and track from all such seed points using the RTS smoother. We use covariance of the marginal posterior density estimated for each branch to discriminate false positive and true positive branches. The method is evaluated on 3D chest CT scans to track airways. We show that the presented method results in additional branches compared to a baseline method based on region growing on probability images.Comment: 10 pages. Pre-print of the paper accepted at Workshop on Graphs in Biomedical Image Analysis. MICCAI 2017. Quebec Cit

    DIFFERENCES IN SEGMENTAL MOMENTUM TRANSFERS BETWEEN TWO STROKE POSTURES FOR TENNIS TWO-HANDED BACKHAND STROKE

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    Tennis stroke force depends on momentum transfer from racket to ball during ball-racket impact. Previous researchers study backhand stroke mechanics, focusing on comparison of one-handed and two-handed backhand stroke biomechanics (Reid & Elliott, 2002). This study investigated linear (LM) and angular momentum (AM) transfer from the trunk and upper extremities to the racket in open (OS) and square stances (SS) for different skill levels of players in the two-handed backhand stroke
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