8,087 research outputs found

    Coordination chemistry in fused-salt solutions

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    Spectrophotometric work on structural determinations with fused-salt solutions is reviewed. Constraints placed on the method, as well as interpretation of the spectra, are discussed with parallels drawn to aqueous spectrophotometric curves of the same materials

    CAN PROMOTING CULTURAL DIVERSITY BACKFIRE? A LOOK AT THE IMPLICIT EFFECTS OF PSYCHOLOGICAL REACTANCE

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    Psychological reactance occurs when an individual's freedom to engage in a particular behavior is compromised, resulting in a greater urge to engage in that behavior (Brehm, 1966). The current study examined the role of reactance in the divergence between implicit and explicit attitudes, and considered the possibility that reactance itself may be experienced either implicitly or explicitly. Participants (N = 162) watched a cultural sensitivity video or control video in a study administered by a White or Black experimenter. It was found that the cultural sensitivity video elicited implicit reactance, but only for participants whose motivation to appear non-prejudiced was internal. Participants whose motivation to appear non-prejudiced was external had the highest levels of implicit racism with the White experimenter and the control video. Finally, participants showed higher scores on the Modern Racism Scale when they had the White experimenter than when they had the Black experimenter. This study suggests that there are circumstances in which cultural sensitivity videos may backfire, and that the distinction between people who are internally versus externally motivated to appear non-prejudiced is an important one, with regard to the effects of such videos

    Selection biases in empirical p(z) methods for weak lensing

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    To measure the mass of foreground objects with weak gravitational lensing, one needs to estimate the redshift distribution of lensed background sources. This is commonly done in an empirical fashion, i.e. with a reference sample of galaxies of known spectroscopic redshift, matched to the source population. In this work, we develop a simple decision tree framework that, under the ideal conditions of a large, purely magnitude-limited reference sample, allows an unbiased recovery of the source redshift probability density function p(z), as a function of magnitude and color. We use this framework to quantify biases in empirically estimated p(z) caused by selection effects present in realistic reference and weak lensing source catalogs, namely (1) complex selection of reference objects by the targeting strategy and success rate of existing spectroscopic surveys and (2) selection of background sources by the success of object detection and shape measurement at low signal-to-noise. For intermediate-to-high redshift clusters, and for depths and filter combinations appropriate for ongoing lensing surveys, we find that (1) spectroscopic selection can cause biases above the 10 per cent level, which can be reduced to 5 per cent by optimal lensing weighting, while (2) selection effects in the shape catalog bias mass estimates at or below the 2 per cent level. This illustrates the importance of completeness of the reference catalogs for empirical redshift estimation.Comment: matches published version in MNRA

    Resampling images in Fourier domain

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    When simulating sky images, one often takes a galaxy image F(x)F(x) defined by a set of pixelized samples and an interpolation kernel, and then wants to produce a new sampled image representing this galaxy as it would appear with a different point-spread function, a rotation, shearing, or magnification, and/or a different pixel scale. These operations are sometimes only possible, or most efficiently executed, as resamplings of the Fourier transform F~(u)\tilde F(u) of the image onto a uu-space grid that differs from the one produced by a discrete Fourier transform (DFT) of the samples. In some applications it is essential that the resampled image be accurate to better than 1 part in 10310^3, so in this paper we first use standard Fourier techniques to show that Fourier-domain interpolation with a wrapped sinc function yields the exact value of F~(u)\tilde F(u) in terms of the input samples and kernel. This operation scales with image dimension as N4N^4 and can be prohibitively slow, so we next investigate the errors accrued from approximating the sinc function with a compact kernel. We show that these approximations produce a multiplicative error plus a pair of ghost images (in each dimension) in the simulated image. Standard Lanczos or cubic interpolators, when applied in Fourier domain, produce unacceptable artifacts. We find that errors <1<1 part in 10310^3 can be obtained by (1) 4-fold zero-padding of the original image before executing the xux\rightarrow u DFT, followed by (2) resampling to the desired uu grid using a 6-point, piecewise-quintic interpolant that we design expressly to minimize the ghosts, then (3) executing the DFT back to xx domain.Comment: Typographical and one algebraic correction, to appear in PASP March 201

    Open research data: Report to the Australian National Data Service (ANDS)

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    Main points Research data are an asset we have been building for decades, through billions of dollars of public investment in research annually. The information and communication technology (ICT) revolution presents an unprecedented opportunity to ‘leverage’ that asset. Given this, there is increasing awareness around the world that there are benefits to be gained from curating and openly sharing research data (Kvalheim and Kvamme 2014). Conservatively, we estimate that the value of data in Australia’s public research to be at least 1.9billionandpossiblyupto1.9 billion and possibly up to 6 billion a year at current levels of expenditure and activity. Research data curation and sharing might be worth at least 1.8billionandpossiblyupto1.8 billion and possibly up to 5.5 billion a year, of which perhaps 1.4billionto1.4 billion to 4.9 billion annually is yet to be realized. Hence, any policy around publicly-funded research data should aim to realise as much of this unrealised value as practicable. Aims and scope This study offers conservative estimates of the value and benefits to Australia of making publicly-funded research data freely available, and examines the role and contribution of data repositories and associated infrastructure. It also explores the policy settings required to optimise research data sharing, and thereby increase the return on public investment in research. The study’s focus is Australia’s Commonwealth-funded research and agencies. It includes research commissioned or funded by Commonwealth bodies as well as in-house research within research-oriented agencies wholly or largely funded by the Commonwealth. Government data or public sector information is a separate category of publicly-funded data – although there is some overlap at the margins (e.g. Commonwealth Government funding for Geoscience Australia). Main findings For the purposes of estimation, we explore a range of research funding and expenditure from total Australian Government funding support for research to the sum of government and higher education expenditure on research by sector of execution. The lower bound estimates are based on the labour-cost share of research funding and expenditure (4.3billionto4.3 billion to 6.4 billion per annum), and upper bound estimates on total research funding and expenditure (8.9billionto8.9 billion to 13.3 billion per annum)

    Has transition improved well-being? An analysis based on income, inequality-adjusted income, nonincome, and subjective well-being measures

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    In this paper we examine trends in economic well-being in transition countries from 1988-2002. To do this, we examine economic performance, inequality-adjusted well-being measures, subjective well-being measures, and non-income dimensions of well-being. While for some of the transition countries in Central Europe, the level of well-being is now higher than prior to transition, it is far below those levels in most other transition countries. The only indicator which has shown consistent improvements are measures of political and civil liberties.

    Excepting the future

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    This report makes the economic case for flexible copyright exceptions and extended safe harbour provisions. Copyright can strengthen the incentive to create by affording rights holders exclusive rights to exploit their work. This can bring into existence work that would not otherwise exist, generating economic benefits. A content owner’s exclusive rights are subject to limitations and exceptions.Excepting the Future makes the the economic case for flexible copyright exceptions and extended safe harbour provisions. These mediate the respective rights of the myriad participants in the copyright eco-system, where intellectual property (IP) outputs are, to an increasing extent, developed from IP inputs, where creators are also users, users are creators and copyright material cannot be distributed digitally without copies being made. A companion report, Exceptional Industries, reveals the economic contribution to Australia and other countries made by industries relying on such limitations and exceptions to copyright. In Australia in 2010 this includes: Contributing 14% of Australia’s annual Gross Domestic Product (GDP), or 182 billion;  Employing 21% of our paid workforce, almost 2.4 million people;  Paying wages and salaries of 116 billion. &nbsp; This report was prepared for the Australian Digital Alliance by John Houghton and Nicholas Gruen, Lateral Economics

    New class of compounds have very low vapor pressures

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    Magnesium hexahydrate tetrachlorometallates are 50-volume-percent water, have a high melting point and possess a low vapor pressure. These new compounds are relatively noncorrosive, thermally stable, and water soluble but not hygroscopic. They may have potential applications as cooling fluids
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