1,569 research outputs found
Structure and Dynamics of Trade in a Small Economy in Transition before the EU Accession: The Case of Czech Exports and Imports
The basic objective of this paper is to design an appropriate structural model based on economic behavioral foundations and test it on data representing the determining factors of Czech trade specialization and growth. Policy recommendations based on the functioning of some policy instruments relevant to monetary policy decisions are also a part of the study.
In the empirical part of the analysis, we use alternative specifications of export and import functions estimated as panels for the EU and non-EU countries, disaggregated into 29 industries for 1993-2001. It is evident from our tests that the future of the Czech trade balance and GDP growth will hinge on ow the Czech economy substitutes its present comparative advantage in labor by building up its capital endowments, most notably its human capital endowments.
Although our tests confirm that the balance of trade was fundamentally influenced by the exchange rate, aggregate demand and tariff changes, the underlying fundamental factors relevant for a sustainable trade balance and an equilibrium exchange rate rest on supply-side capacities (such as changes in factor endowments, inflows of foreign direct investment (FDI), developments in productivity and wage rates, pricing policy of enterprises and the nature of competitiveness of domestic production), which are extremely closely related to export and import performance.
It seems evident that industrial policies (such as support for FDI, capital availability, the building-up of human capital or labor mobility and the promotion of domestic import substitution) can lead to significant changes in the nature of Czech exports and international competitiveness.
We can induce from our analysis that the fundamental restructuring of Czech enterprises in the period 1993 -2001 was driven by openness to trade, especially with the EU. While exports offered growth and employment, accelerating import penetration required the downsizing of many industries, which burdened the whole Czech economy with high adjustment costs. Now, in a period of economic structural stabilization and EU accession, the prospects for accelerated economic growth are much higher.
The seemingly low or even reversed response of trade intensities to real exchange rate appreciation can be explained by supply-side gains in the quality of products, productivity improvements, the buildup of human capital associated with FDI and the fast dynamics of intra-industrial trade, which had a low sensitivity to exchange rate fluctuations. Relative to the unwieldy performance of the state sector or the domestic production of the non-traded commodities, Czech export sector made a tremendous progress in competitiveness during 1993- 2001, showing high dynamics of growth, intensive level of structural adjustments and an accelerated seed of integration with the EU
Enhanced low-energy -decay strength of Ni and its robustness within the shell model
Neutron-capture reactions on very neutron-rich nuclei are essential for
heavy-element nucleosynthesis through the rapid neutron-capture process, now
shown to take place in neutron-star merger events. For these exotic nuclei,
radiative neutron capture is extremely sensitive to their -emission
probability at very low energies. In this work, we present
measurements of the -decay strength of Ni over the wide range
MeV. A significant enhancement is found in the
-decay strength for transitions with MeV. At present,
this is the most neutron-rich nucleus displaying this feature, proving that
this phenomenon is not restricted to stable nuclei. We have performed
-strength calculations within the quasiparticle time-blocking
approximation, which describe our data above MeV very well.
Moreover, large-scale shell-model calculations indicate an nature of the
low-energy strength. This turns out to be remarkably robust with
respect to the choice of interaction, truncation and model space, and we
predict its presence in the whole isotopic chain, in particular the
neutron-rich .Comment: 9 pages, 9 figure
Study of the island morphology at the early stages of Fe/Mo(110) MBE growth
We present theoretical study of morphology of Fe islands grown at Mo(110)
surface in sub-monolayer MBE mode. We utilize atomistic SOS model with bond
counting, and interactions of Fe adatom up to third nearest neighbors. We
performed KMC simulations for different values of adatom interactions and
varying temperatures. We have found that, while for the low temperature islands
are fat fractals, for the temperature 500K islands have faceted rhombic-like
shape. For the higher temperature, islands acquire a rounded shape. In order to
evaluated qualitatively morphological changes, we measured averaged aspect
ration of islands. We calculated dependence of the average aspect ratio on the
temperature, and on the strength of interactions of an adatom with neighbors.Comment: 6 pages, 6 figures. Proceedings of 11-th Symposium on Surface
Physics, Prague 200
Future of management of recreational gill, haul, and cast netting in Western Australia and summary of submissions to the netting review
The results of a major review into recreational gill and haul netting in Western Australia were announced by the Minister for Fisheries, Hon. Monty House MLA on 24 December 1993. This document presents the findings of the recreational netting review and the process which resulted in the announced changed to management practices
Theoretical analysis of neutron scattering results for quasi-two dimensional ferromagnets
A theoretical study has been carried out to analyse the available results
from the inelastic neutron scattering experiment performed on a quasi-two
dimensional spin-1/2 ferromagnetic material . Our formalism is based
on a conventional semi-classical like treatment involving a model of an ideal
gas of vortices/anti-vortices corresponding to an anisotropic XY Heisenberg
ferromagnet on a square lattice. The results for dynamical structure functions
for our model corresponding to spin-1/2, show occurrence of negative values in
a large range of energy transfer even encompassing the experimental range, when
convoluted with a realistic spectral window function. This result indicates
failure of the conventional theoretical framework to be applicable to the
experimental situation corresponding to low spin systems. A full quantum
formalism seems essential for treating such systems.Comment: 16 pages, 6 figures, 1 Table Submitted for publicatio
A statistical approach to quantitative data validation focused on the assessment of students' perceptions about biotechnology
Student awareness levels are frequently used to evaluate the effectiveness of educational policies to promote scientific literacy. Over the last years several studies have been developed to assess students' perceptions towards science and technology, which usually rely on quantitative methods to achieve broad characterizations, and obtain quantifiable and comparable data. Although the usefulness of this information depends on its validity and reliability, validation is frequently neglected by researchers with limited background in statistics. In this context, we propose a guideline to implement a statistical approach to questionnaire validation, combining exploratory factor analysis and reliability analysis. The work focuses on the psychometric analysis of data provided by a questionnaire assessing 1196 elementary and high school students' perceptions about biotechnology. Procedural guidelines to enhance the efficiency of quantitative inquiry surveys are given, by discussing essential methodological aspects and relevant criteria to integrate theory into practice.The authors are grateful to all the participant teachers and students that contributed to gather the data presented and to Catarina L. Santos for useful comments and suggestions on the manuscript. Maria Joao Fonseca was supported by the FCT fellowship SFRH/BD/37389/2007 and this work was sponsored by a research grant (PTDC/AGR-PRO/111857/2009) from Fundacao para a Ciencia e Tecnologia (FCT, Portugal)
The Glial Regenerative Response to Central Nervous System Injury Is Enabled by Pros-Notch and Pros-NFκB Feedback
Organisms are structurally robust, as cells accommodate changes preserving structural integrity and function. The molecular mechanisms underlying structural robustness and plasticity are poorly understood, but can be investigated by probing how cells respond to injury. Injury to the CNS induces proliferation of enwrapping glia, leading to axonal re-enwrapment and partial functional recovery. This glial regenerative response is found across species, and may reflect a common underlying genetic mechanism. Here, we show that injury to the Drosophila larval CNS induces glial proliferation, and we uncover a gene network controlling this response. It consists of the mutual maintenance between the cell cycle inhibitor Prospero (Pros) and the cell cycle activators Notch and NFκB. Together they maintain glia in the brink of dividing, they enable glial proliferation following injury, and subsequently they exert negative feedback on cell division restoring cell cycle arrest. Pros also promotes glial differentiation, resolving vacuolization, enabling debris clearance and axonal enwrapment. Disruption of this gene network prevents repair and induces tumourigenesis. Using wound area measurements across genotypes and time-lapse recordings we show that when glial proliferation and glial differentiation are abolished, both the size of the glial wound and neuropile vacuolization increase. When glial proliferation and differentiation are enabled, glial wound size decreases and injury-induced apoptosis and vacuolization are prevented. The uncovered gene network promotes regeneration of the glial lesion and neuropile repair. In the unharmed animal, it is most likely a homeostatic mechanism for structural robustness. This gene network may be of relevance to mammalian glia to promote repair upon CNS injury or disease
Long-Term Characterization of 6H-SiC Transistor Integrated Circuit Technology Operating at 500 C
NASA has been developing very high temperature semiconductor integrated circuits for use in the hot sections of aircraft engines and for Venus exploration. This paper reports on long-term 500 C electrical operation of prototype 6H-SiC integrated circuits based on epitaxial 6H-SiC junction field effect transistors (JFETs). As of this writing, some devices have surpassed 4000 hours of continuous 500 C electrical operation in oxidizing air atmosphere with minimal change in relevant electrical parameters
Improved methodical approach for quantitative BRET analysis of G protein coupled receptor dimerization
G Protein Coupled Receptors (GPCR) can form dimers or higher ordered oligomers, the process of which can remarkably influence the physiological and pharmacological function of these receptors. Quantitative Bioluminescence Resonance Energy Transfer (qBRET) measurements are the gold standards to prove the direct physical interaction between the protomers of presumed GPCR dimers. For the correct interpretation of these experiments, the expression of the energy donor Renilla luciferase labeled receptor has to be maintained constant, which is hard to achieve in expression systems. To analyze the effects of non-constant donor expression on qBRET curves, we performed Monte Carlo simulations. Our results show that the decrease of donor expression can lead to saturation qBRET curves even if the interaction between donor and acceptor labeled receptors is non-specific leading to false interpretation of the dimerization state. We suggest here a new approach to the analysis of qBRET data, when the BRET ratio is plotted as a function of the acceptor labeled receptor expression at various donor receptor expression levels. With this method, we were able to distinguish between dimerization and non-specific interaction when the results of classical qBRET experiments were ambiguous. The simulation results were confirmed experimentally using rapamycin inducible heterodimerization system. We used this new method to investigate the dimerization of various GPCRs, and our data have confirmed the homodimerization of V2 vasopressin and CaSR calcium sensing receptors, whereas our data argue against the heterodimerization of these receptors with other studied GPCRs, including type I and II angiotensin, β2 adrenergic and CB1 cannabinoid receptors
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