44,621 research outputs found
Courts of Good and Ill Repute: Garoupa and Ginsburg’s Judicial Reputation: A Comparative Theory
Nuno Garoupa and Tom Ginsburg have published an ambitious book that seeks to account for the great diversity of judicial systems based, in part, on how courts are designed to marshal the power of a high public opinion of the judiciary. Judges, the book posits, care deeply about their reputations both inside and outside the courts. Courts are designed to capitalize on judges’ desire to maximize their reputation, and judges’ existing stock of reputation can affect the design of the courts which they serve. We find much to like in this book, ranging from its intriguing and ambitious positive claims to its masterful use of comparative case studies from around the globe. However, we also have questions about the ability of the theory to hang together in a unified manner and to do the work assigned to it
Mass generation and the dynamical role of the Katoptron Group
Heavy mirror fermions along with a new strong gauge interaction capable of
breaking the electroweak gauge symmetry dynamically were recently introduced
under the name of katoptrons. Their main function is to provide a viable
alternative to the Standard-Model Higgs sector. In such a framework, ordinary
fermions acquire masses after the breaking of the strong katoptron group which
allows mixing with their katoptron partners. The purpose of this paper is to
study the elementary-scalars-free mechanism responsible for this breaking and
its implications for the fermion mass hierarchies.Comment: 15 LaTeX pages, some comments added, version published in Modern
Physics Letters
The culture of corruption: A nonparametric analysis
By using a sample of 77 countries the analysis applies several nonparametric techniques in order to reveal the link between national culture and corruption. Based on Hofstede΄s cultural dimensions and the corruption perception index, the results reveal that countries with higher levels of corruption tend to have higher power distance and collectivism values in their society.Nonparametric methods,Corruption perception index, National culture
Method for comparing finite temperature field theory results with lattice data
The values of the presently available truncated perturbative expressions for
the pressure of the quark-gluon plasma at finite temperatures and finite
chemical potential are trustworthy only at very large energies. When used down
to temperatures close to the critical one Tc, they suffer from large
uncertainties due to the renormalization scale freedom. In order to reduce
these uncertainties, we perform resummations of the pressure by applying
Pade-related approximants to the available perturbation series for the
short-distance and for the long-distance contributions. In the two
contributions, we use two different renormalization scales which reflect
different energy regions contributing to the different parts. Application of
the obtained expressions at low temperatures is made possible by replacing the
usual four-loop barMS beta function for alpha_s by its Borel-Pade resummation,
eliminating thus the unphysical Landau singularities of alpha_s. The obtained
results are remarkably insensitive to the chosen renormalization scale and can
be compared with lattice results -- for the pressure (p), the chemical
potential contribution (delta p) to the pressure, and various susceptibilities.
A good qualitative agreement with the lattice results is revealed down to
temperatures close to Tc.Comment: 24 pages, 17 figures, revtex4; Ref.[25] is new; the ordering of the
references and grammatic and stylistic errors are corrected - version as it
appears in PR
The zipper mechanism in phagocytosis: energetic requirements and variability in phagocytic cup shape
Phagocytosis is the fundamental cellular process by which eukaryotic cells
bind and engulf particles by their cell membrane. Particle engulfment involves
particle recognition by cell-surface receptors, signaling and remodeling of the
actin cytoskeleton to guide the membrane around the particle in a zipper-like
fashion. Despite the signaling complexity, phagocytosis also depends strongly
on biophysical parameters, such as particle shape, and the need for
actin-driven force generation remains poorly understood. Here, we propose a
novel, three-dimensional and stochastic biophysical model of phagocytosis, and
study the engulfment of particles of various sizes and shapes, including spiral
and rod-shaped particles reminiscent of bacteria. Highly curved shapes are not
taken up, in line with recent experimental results. Furthermore, we
surprisingly find that even without actin-driven force generation, engulfment
proceeds in a large regime of parameter values, albeit more slowly and with
highly variable phagocytic cups. We experimentally confirm these predictions
using fibroblasts, transfected with immunoreceptor FcyRIIa for engulfment of
immunoglobulin G-opsonized particles. Specifically, we compare the wild-type
receptor with a mutant receptor, unable to signal to the actin cytoskeleton.
Based on the reconstruction of phagocytic cups from imaging data, we indeed
show that cells are able to engulf small particles even without support from
biological actin-driven processes. This suggests that biochemical pathways
render the evolutionary ancient process of phagocytic highly robust, allowing
cells to engulf even very large particles. The particle-shape dependence of
phagocytosis makes a systematic investigation of host-pathogen interactions and
an efficient design of a vehicle for drug delivery possible.Comment: Accepted for publication in BMC Systems Biology. 17 pages, 6 Figures,
+ supplementary informatio
A Method for Distinguishing Between Transiently Accreting Neutron Stars and Black Holes, in Quiescence
We fit hydrogen atmosphere models to the X-ray data for four neutron stars
(three from a previous paper, plus 4U 2129+47) and six black hole candidates
(A0620-00, GS 2000+25, GS 1124-68, GS 2023+33, GRO J1655-40, and GRO J0422+32).
While the neutron stars are similar in their intrinsic X-ray spectra (similar
effective temperatures and emission area radii ~10 km), the spectra of two
black hole candidates are significantly different, and the spectra of the
remaining four are consistent with a very large parameter space that includes
the neutron stars. The spectral differences between the neutron stars and black
hole candidates favors the interpretation that the quiescent neutron star
emission is predominantly thermal emission from the neutron star surface. Our
work suggests that an X-ray spectral comparison in quiescence provides an
additional means for distinguishing between neutron stars and black holes. The
faint X-ray sources in globular clusters are also a class of objects which can
be investigated in this manner.Comment: 33 pages, including 3 ps figures, LaTeX. To appear in Ap
An application of statistical interference in DEA models: An analysis of public owned university departments' efficiency
This paper uses Data Envelopment Analysis (DEA) model formulations in order to determine the performance levels of 16 departments of the University of Thessaly. Particularly, the constant returns to scale (CRS) and variable returns to scale (VRS) models have been applied alongside with bootstrap techniques in order to determine accurate performance measurements of the 16 departments. The study illustrates how the recent developments in efficiency analysis and statistical inference can be applied when evaluating institutional performance issues. The paper provides the efficient departments and the target values which need to be adopted from the inefficient departments in order to operate in the most productive scale size (MPSS). Moreover it provides bias corrected estimates alongside with their confidence intervals. The analysis indicates that there are strong inefficiencies among the departments, emphasizing the misallocation of resources or/and inefficient application of departments policy developments.University efficiency; DEA; Bootstrap techniques; Kernel density estimation, Economic research; Europe; University rankings.
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