5,446 research outputs found
Moving beyond the ‘crisis’: Recommendations for the European Commission’s communication on migration. EPC Discussion Paper, 9 DECEMBER 2019
The year 2015 marked the arrival of an unprecedented number of migrants and refugees in the EU. Soon politicians, policymakers and the press dubbed these events a ‘migration crisis’. With the steep increase in public attention putting migration at the very top of the political agenda, right-wing populist parties saw their chance to capitalise on voters’ concerns in a vast majority of EU member states
Intriguing sets of partial quadrangles
The point-line geometry known as a \textit{partial quadrangle} (introduced by
Cameron in 1975) has the property that for every point/line non-incident pair
, there is at most one line through concurrent with . So in
particular, the well-studied objects known as \textit{generalised quadrangles}
are each partial quadrangles. An \textit{intriguing set} of a generalised
quadrangle is a set of points which induces an equitable partition of size two
of the underlying strongly regular graph. We extend the theory of intriguing
sets of generalised quadrangles by Bamberg, Law and Penttila to partial
quadrangles, which surprisingly gives insight into the structure of hemisystems
and other intriguing sets of generalised quadrangles
Anomalous transport resolved in space and time by fluorescence correlation spectroscopy
A ubiquitous observation in crowded cell membranes is that molecular
transport does not follow Fickian diffusion but exhibits subdiffusion. The
microscopic origin of such a behaviour is not understood and highly debated.
Here we discuss the spatio-temporal dynamics for two models of subdiffusion:
fractional Brownian motion and hindered motion due to immobile obstacles. We
show that the different microscopic mechanisms can be distinguished using
fluorescence correlation spectroscopy (FCS) by systematic variation of the
confocal detection area. We provide a theoretical framework for space-resolved
FCS by generalising FCS theory beyond the common assumption of spatially
Gaussian transport. We derive a master formula for the FCS autocorrelation
function, from which it is evident that the beam waist of an FCS experiment is
a similarly important parameter as the wavenumber of scattering experiments.
These results lead to scaling properties of the FCS correlation for both
models, which are tested by in silico experiments. Further, our scaling
prediction is compatible with the FCS half-value times reported by Wawrezinieck
et al. [Biophys. J. 89, 4029 (2005)] for in vivo experiments on a transmembrane
protein.Comment: accepted for publication in Soft Matte
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