11,523 research outputs found
The Effect of Foreign Direct Investment on International Migration: Does Education Matter?
Using migration data in 1990 and 2000, we find that inward foreign direct investment (FDI) in non-OECD countries affects the out-migration of individuals with tertiary and secondary education to OECD countries originating the investments, but has no significant effect on the out-migration of individuals with primary education. Distinguishing between linkage and home effects, our results show a dominant home effect of FDI for individuals with tertiary education, but a stronger linkage effect for those with secondary education. The existing stock of former migrants in foreign countries influences the out-migration of individuals with primary education
International Comovement of Economic Fluctuations: A Spatial Analysis
We consider the comovement of economic volatility across multiple countries. Using spatial models with data from 187 countries over the period of 1960–2007, we find a strong spatial comovement of economic volatility. More interestingly, the effect of geographical proximity on economic volatility comovement is strongest during the period of international shocks (1973–86), but almost disappears over the globalization era (1987–2007). By way of contrast, the influence of trade relations in determining the comovement of economic volatility is significant over 1987–2007
Response to ‘Protected areas and climate change Reflections from a practitioner's perspective
Cliquet et al. 1 provide a thought-provoking analysis of the challenges posed to
the EU's protected areas by climate change. This paper seeks to build on some of
the perspectives they brought to what is a highly challenging area of nature
conservation law, policy and practice. While there is much to support in their
analysis of the relationships between protected areas and climate change, there
are two key strands we seek to develop further, based on the RSPB's experience
of this area of nature conservation policy and practice: first, is the
ecological model for adapting to climate change and second, the legal framework
provided by the Birds2 and Habitats3 Directives (the Nature Directives) as it
relates to the delivery of such adaptive actions
Antennas for 20/30 GHz and beyond
Antennas of 20/30 GHz and higher frequency, due to the small wavelength, offer capabilities for many space applications. With the government-sponsored space programs (such as ACTS) in recent years, the industry has gone through the learning curve of designing and developing high-performance, multi-function antennas in this frequency range. Design and analysis tools (such as the computer modelling used in feedhorn design and reflector surface and thermal distortion analysis) are available. The components/devices (such as BFN's, weight modules, feedhorns and etc.) are space-qualified. The manufacturing procedures (such as reflector surface control) are refined to meet the stringent tolerance accompanying high frequencies. The integration and testing facilities (such as Near-Field range) also advance to facilitate precision assembling and performance verification. These capabilities, essential to the successful design and development of high-frequency spaceborne antennas, shall find more space applications (such as ESGP) than just communications
Effect of Reynolds number variation on aerodynamics of a hydrogen-fueled transport concept at Mach 6
Two separate tests have been made on the same blended wing-body hydrogen-fueled transport model at a Mach number of about 6 and a range of Reynolds number (based on theoretical body length) of 1.577 to 55.36 X 10 to the 6th power. The results of these tests, made in a conventional hypersonic blowdown tunnel and a hypersonic shock tunnel, are presented through a range of angle of attack from -1 to 8 deg, with an extended study at a constant angle of attack of 3 deg. The model boundary layer flow appeared to be predominately turbulent except for the low Reynolds number shock tunnel tests. Model wall temperatures varied considerably; the blowdown tunnel varied from about 255 F to 340 F, whereas the shock tunnel had a constant 70 F model wall temperature. The experimental normal-force coefficients were essentially independent of Reynolds number. A current theoretical computer program was used to study the effect of Reynolds number. Theoretical predictions of normal-force coefficients were good, particularly at anticipated cruise angles of attack, that is 2 to 5 deg. Axial-force coefficients were generally underestimated for the turbulent skin friction conditions, and pitching-moment coefficients could not be predicted reliably
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A heterologous expression system for bovine lens transmembrane main intrinsic protein (MIP) in Nicotiana tabacum plants
We have developed a heterologous expression system for transmembrane lens main intrinsic protein (MIP) in Nicotiana tabacum plant tissue. A native bovine MIP26 amplicon was subcloned into an expression cassette under the control of a constitutive Cauliflower Mosaic Virus promoter, also containing a neomycin phosphotransferase operon. This cassette was transformed into Agrobacterium tumefaciens by triparental mating and used to infect plant tissue grown in culture. Recombinant plants were selected by their ability to grow and root on kanamycin-containing media. The presence of MIP in the plant tissues was confirmed by PCR, RT-PCR and immunohistochemistry. A number of benefits of this system for the study of MIP will be discussed, and also its application as a tool for the study of heterologously expressed proteins in general
Two-sample Bayesian Nonparametric Hypothesis Testing
In this article we describe Bayesian nonparametric procedures for two-sample
hypothesis testing. Namely, given two sets of samples
\stackrel{\scriptscriptstyle{iid}}{\s
im} and \stackrel{\scriptscriptstyle{iid}}{\sim},
with unknown, we wish to
evaluate the evidence for the null hypothesis
versus the
alternative . Our
method is based upon a nonparametric P\'{o}lya tree prior centered either
subjectively or using an empirical procedure. We show that the P\'{o}lya tree
prior leads to an analytic expression for the marginal likelihood under the two
hypotheses and hence an explicit measure of the probability of the null
.Comment: Published at http://dx.doi.org/10.1214/14-BA914 in the Bayesian
Analysis (http://projecteuclid.org/euclid.ba) by the International Society of
Bayesian Analysis (http://bayesian.org/
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