4,646 research outputs found
Who Wins the Olympic Games: Economic Development and Medal Totals
This paper examines determinants of Olympic success at the country level. Does the U.S. win its fair share of Olympic medals? Why does China win 6% of the medals even though it has 1/5 of the world's population? We consider the role of population and economic development in determining medal totals from 1960-1996. We also provide out of sample predictions for the 2000 Olympics in Sydney.
l. suis medication of piglets with Baycoxo 5% against coccidiose and for stabilisation of the microflora against intestinal infections and reducing the application of antibiotica and vaccines against diarrhoea with E.coli and Clostridia
After the oral treatment of all p1glets 3 - 5 days after birth with Baycox 5% we found a better intestine health in the suckling and in the flatdeck period. ln this study there was a reduced diarrhoea dunng suckling and in the flatdeck.With the Baycox• therapeutic the vaccination program against E. coli and Clostridium perfringens Typ C and the application of antibiotica to the weaners could be decreased for nearly 40 % during the breeding period. AII pigs got better health status with higher weight gain and uniformity
Diffusion and dispersion of passive tracers: Navier-Stokes versus MHD turbulence
A comparison of turbulent diffusion and pair-dispersion in homogeneous,
macroscopically isotropic Navier-Stokes (NS) and nonhelical magnetohydrodynamic
(MHD) turbulence based on high-resolution direct numerical simulations is
presented. Significant differences between MHD and NS systems are observed in
the pair-dispersion properties, in particular a strong reduction of the
separation velocity in MHD turbulence as compared to the NS case. It is shown
that in MHD turbulence the average pair-dispersion is slowed down for
, being
the Kolmogorov time, due to the alignment of the relative Lagrangian tracer
velocity with the local magnetic field. Significant differences in turbulent
single-particle diffusion in NS and MHD turbulence are not detected. The fluid
particle trajectories in the vicinity of the smallest dissipative structures
are found to be characterisically different although these comparably rare
events have a negligible influence on the statistics investigated in this work.Comment: Europhysics Letters, in prin
Sources of dynamic variability in NF-κB signal transduction: a mechanistic model
The transcription factor NF-{kappa}B (p65/p50) plays a central role in the coordination of cellular responses by activating the transcription of numerous target genes. The precise role of the dynamics of NF-{kappa}B signalling in regulating gene expression is still an open question. Here, we show that besides external stimulation intracellular parameters can influence the dynamics of NF-{kappa}B. By applying mathematical modelling and bifurcation analyses, we show that NF-{kappa}B is capable of exhibiting different types of dynamics in response to the same stimulus. We identified the total NF-{kappa}B concentration and the I{kappa}B{alpha} transcription rate constant as two critical parameters that modulate the dynamics and the fold change of NF-{kappa}B. Both parameters might vary as a result of cell-to-cell variability. The regulation of the IκBα transcription rate constant, e.g. by co-factors, provides the possibility of regulating the NF-{kappa}B dynamics by crosstalk
Hysteresis phenomenon in turbulent convection
Coherent large-scale circulations of turbulent thermal convection in air have
been studied experimentally in a rectangular box heated from below and cooled
from above using Particle Image Velocimetry. The hysteresis phenomenon in
turbulent convection was found by varying the temperature difference between
the bottom and the top walls of the chamber (the Rayleigh number was changed
within the range of ). The hysteresis loop comprises the one-cell
and two-cells flow patterns while the aspect ratio is kept constant (). We found that the change of the sign of the degree of the anisotropy of
turbulence was accompanied by the change of the flow pattern. The developed
theory of coherent structures in turbulent convection (Elperin et al. 2002;
2005) is in agreement with the experimental observations. The observed coherent
structures are superimposed on a small-scale turbulent convection. The
redistribution of the turbulent heat flux plays a crucial role in the formation
of coherent large-scale circulations in turbulent convection.Comment: 10 pages, 9 figures, REVTEX4, Experiments in Fluids, 2006, in pres
A New Framework for Innovation-Based Regional Development
To foster sustainable regional development, many regions rely on innovations.
To safeguard the generation of innovations and their market introduction,
companies have increasingly used technology roadmapping and open innovation.
The project INNOrural (Innovations for sustainable rural development) expanded
these concepts by applying them to regions. This led to the rise of the
“Regional Open Innovation Roadmapping” framework for innovation-based regional
development (ROIR). This framework was tested by conducting two innovation
roadmapping processes in the model region of Märkisch-Oderland (MOL), Germany:
the certification of regional wood fuel and the establishment of a competence
center for precision farming technology. Both innovation ideas were selected
during the roadmapping process by applying a sustainability assessment. After
12 months, two complete roadmaps were ready for implementation. Key principles
of ROIR were identified, including the use of a clear and replicable
sustainability assessment method, the involvement of all relevant stakeholder
groups in the early process and the cooperation between regional and subject
experts. Generally, the broader adaptation of ROIR for additional regions will
be useful. Nevertheless, the ROIR processes need to be evaluated in depth to
develop a better understanding and to provide evidence of the benefits and
limitations of this approach
The extostosin family: Proteins with many functions
Heparan sulfates are complex sulfated molecules found in abundance at cell surfaces and in the extracellular matrix. They bind to and influence the activity of a variety of molecules like growth factors, proteases and morphogens and are thus involved in various cell–cell and cell–matrix interactions. The mammalian EXT proteins have glycosyltransferase activities relevant for HS chain polymerization, however their exact role in this process is still confusing. In this review, we summarize current knowledge about the biochemical activities and some proposed functions of the members of the EXT protein family and their roles in human disease.publishedVersio
Nonlinear Competition Between Small and Large Hexagonal Patterns
Recent experiments by Kudrolli, Pier and Gollub on surface waves,
parametrically excited by two-frequency forcing, show a transition from a small
hexagonal standing wave pattern to a triangular ``superlattice'' pattern. We
show that generically the hexagons and the superlattice wave patterns bifurcate
simultaneously from the flat surface state as the forcing amplitude is
increased, and that the experimentally-observed transition can be described by
considering a low-dimensional bifurcation problem. A number of predictions come
out of this general analysis.Comment: 4 pages, RevTex, revised, to appear in Phys. Rev. Let
Defect Chaos of Oscillating Hexagons in Rotating Convection
Using coupled Ginzburg-Landau equations, the dynamics of hexagonal patterns
with broken chiral symmetry are investigated, as they appear in rotating
non-Boussinesq or surface-tension-driven convection. We find that close to the
secondary Hopf bifurcation to oscillating hexagons the dynamics are well
described by a single complex Ginzburg-Landau equation (CGLE) coupled to the
phases of the hexagonal pattern. At the bandcenter these equations reduce to
the usual CGLE and the system exhibits defect chaos. Away from the bandcenter a
transition to a frozen vortex state is found.Comment: 4 pages, 6 figures. Fig. 3a with lower resolution no
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