1,031 research outputs found

    An Empirical Analysis of the Effects of Plant Variety Protection Legislation on Innovation and Transferability

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    Under the TRIPs Agreement, all member-countries of the World Trade Organization are required to provide an "effective" system of plant variety protection within a specific time frame. In many developing countries this has led to a divisive debate about the fundamental desirability of extending intellectual property rights to agriculture. But empirical studies on the economic impacts of PVP, especially its ability to generate large private sector investments in plant breeding and facilitate the transfer of technology, have been very limited. This paper examines two aspects of the international experience of PVP legislation thus far (i) The relationship between legislation, R&D expenditures and PVP grants, i.e., the innovation effect, and (ii) The role of PVP in facilitating the flow of varieties across countries, i.e., the transferability effect.Plant variety protection, biotechnology, technology transfer, Crop Production/Industries,

    Electron Detectors for Electron-Beam Testing of Ultra Large Scale Integrated Circuits

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    The increasing density of components in integrated circuits imposes severe constraints on conventional electron beam testers. The use of electron detectors consisting of combined electrostatic and magnetic fields has demonstrated improved performance over conventional electrostatic detectors. Such detectors also ease many of the practical difficulties associated with electron beam testing of Ultra Large Scale Integration (ULSI) circuits. A detector using a single pole magnetic lens will be described and compared to detectors which use only electrostatic fields. The single pole lens detector has demonstrated superior performance to the electrostatic detector in terms of local field error and imaging resolution, allowing accurate measurements to be made on sub-micron structures

    The Magnitude-Size Relation of Galaxies out to z ~ 1

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    As part of the Deep Extragalactic Evolutionary Probe (DEEP) survey, a sample of 190 field galaxies (I_{814} <= 23.5) in the ``Groth Survey Strip'' has been used to analyze the magnitude-size relation over the range 0.1 < z < 1.1. The survey is statistically complete to this magnitude limit. All galaxies have photometric structural parameters, including bulge fractions (B/T), from Hubble Space Telescope images, and spectroscopic redshifts from the Keck Telescope. The analysis includes a determination of the survey selection function in the magnitude-size plane as a function of redshift, which mainly drops faint galaxies at large distances. Our results suggest that selection effects play a very important role. A first analysis treats disk-dominated galaxies with B/T < 0.5. If selection effects are ignored, the mean disk surface brightness (averaged over all galaxies) increases by ~1.3 mag from z = 0.1 to 0.9. However, most of this change is plausibly due to comparing low luminosity galaxies in nearby redshift bins to high luminosity galaxies in distant bins. If this effect is allowed for, no discernible evolution remains in the disk surface brightness of bright (M_B < -19) disk-dominated galaxies. A second analysis treats all galaxies by substituting half-light radius for disk scale length, with similar conclusions. Indeed, at all redshifts, the bulk of galaxies is consistent with the magnitude-size envelope of local galaxies, i.e., with little or no evolution in surface brightness. In the two highest redshift bins (z > 0.7), a handful of luminous, high surface brightness galaxies appears that occupies a region of the magnitude-size plane rarely populated by local galaxies. Their wide range of colors and bulge fractions points to a variety of possible origins.Comment: 19 pages, 12 figures. Accepted for publication in the Astrophysical Journa

    Are rates of school suspension higher in socially disadvantaged neighbourhoods? An Australian study

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    Issue addressed: Health promotion with adolescents spans many contexts including schools. Income and its distribution, education and social exclusion are key social determinants of health. Exclusionary school policies such as school suspension contribute to exclusion, increase the likelihood of school dropout (reducing educational and subsequent employment opportunities), and negatively impact on student wellbeing. Often excluded students are from socio-economically disadvantaged areas. This paper examines associations between area level socio-economic status (SES) and school suspension in Australian students. Methods: Students (8,028) in years 6 (n = 4393) and 8 (n = 3635) completed a comprehensive social development survey administered in schools in 30 socio-economically stratified communities in 2006.Results: Associations between area level SES and school suspension were found. Relative to students in the lowest SES quartile communities, students in mid level and high SES had lower suspension rates. These effects remained after controlling for antisocial behaviour, gender, age and the established risk factors of poor family management, interaction with antisocial peers and academic failure. Conclusions: Students living in low SES areas are exposed to higher rates of school suspension, at similar levels of adjustment problems. Assisting schools, particularly those with disadvantaged students, to foster school engagement is essential for schools committed to health promotion

    The Detection of a Red Sequence of Massive Field Galaxies at z~2.3 and its Evolution to z~0

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    The existence of massive galaxies with strongly suppressed star formation at z~2.3, identified in a previous paper, suggests that a red sequence may already be in place beyond z=2. In order to test this hypothesis, we study the rest-frame U-B color distribution of massive galaxies at 2<z<3. The sample is drawn from our near-infrared spectroscopic survey for massive galaxies. The color distribution shows a statistically significant (>3 sigma) red sequence, which hosts ~60% of the stellar mass at the high-mass end. The red-sequence galaxies have little or no ongoing star formation, as inferred from both emission-line diagnostics and stellar continuum shapes. Their strong Balmer breaks and their location in the rest-frame U-B, B-V plane indicate that they are in a post-starburst phase, with typical ages of ~0.5-1.0 Gyr. In order to study the evolution of the red sequence, we compare our sample with spectroscopic massive galaxy samples at 0.02<z<0.045 and 0.6<z<1.0. The rest-frame U-B color reddens by ~0.25 mag from z~2.3 to the present at a given mass. Over the same redshift interval, the number and stellar mass density on the high-mass end (>10^11 Msol) of the red sequence grow by factors of ~8 and ~6, respectively. We explore simple models to explain the observed evolution. Passive evolution models predict too strong d(U-B), and produce z~0 galaxies that are too red. More complicated models that include aging, galaxy transformations, and red mergers can explain both the number density and color evolution of the massive end of the red sequence between z~2.3 and the present.Comment: Accepted for publication in the Astrophysical Journa
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