4,476 research outputs found
Urbanism as a way of life? Räumliche Variationen der Lebensführung in Deutschland
In his classic article, Wirth (1938) asserted that urban ways of life would eventually spread into rural areas through enhanced mobility and communicative interconnectedness. This view is shared by many contemporary urban sociologists who claim that disparities in prosperity and shrinking regions have replaced the rural-urban continuum as the primary dimension of spatial inequality in Germany. According to Fischer's (1975) subcultural theory of urbanism, however, large cities will continue to produce and attract unconventional, nontraditional lifestyles due to a critical mass of like-minded people. In this paper, we test these hypotheses against rural-urban as well as regional variations in lifestyles using survey data randomly sampled from resident registration lists of rural and urban municipalities in four German states. As a measurement instrument we use Otte's (2004) lifestyle typology conceptualized along two dimensions: a level of living and a modernity/biographical perspective. Replicating it supra-regionally for the first time, we provide evidence of its reliability and construct validity, albeit with some reservations for East Germany. In essence, inhabitants of large cities prove to be more modern, biographically open, and unconventional; East Germans tend to have a reduced level of living – even when differences in social structural composition are controlled for
Recommended from our members
Noble gases from the interstellar medium trapped on the MIR space station and analyzed by in vacuo etching
Introduction: The composition of the present interstellar medium (ISM) provides an important benchmark in cosmochemistry. It serves as a reference for galactic chemical evolution (GCE) models, solar mixing predictions and provides information for understanding Big Bang nucleosynthesis. The present-day ISM 3He abundance allows, combined with the protosolar 3He, deduced from the Jovian atmosphere or meteorites [1,2], tracing the GCE over the past 4.56 Ga. 3He/4He = (2.5 0.6) x 10-4 has been determined for the local ISM [3]. However, the uncertainty is too large to better constrain GCE models and - in combination with the present-day solar wind value - the protosolar D/H [4]
Multiphonon Giant Resonances
A new class of giant resonances in nuclei is discussed, i.e., giant
resonances built on other giant resonances. These resonances are observed with
very large cross sections in relativistic heavy ion collisions. A great
experimental and theoretical effort is underway to understand the reaction
mechanism which leads to the excitation of these states in nuclei, as well as
the better microscopic understanding of their properties, e.g., strength,
energy centroids, widths, and anharmonicities.Comment: Postscript file with text and 11 embedded figure
Theory of the Normal/Superfluid interface in population imbalanced Fermi gases
We present a series of theoretical studies of the boundary between a
superfluid and normal region in a partially polarized gas of strongly
interacting fermions. We present mean-field estimates of the surface energy in
this boundary as a function of temperature and scattering length. We discuss
the structure of the domain wall, and use a previously introduced
phenomonological model to study its influence on experimental observables.
Our microscopic mean-field calculations are not consistent with the magnitude
of the surface tension found from our phenomonological modelling of data from
the Rice experiments. We conclude that one must search for novel mechanisms to
explain the experiments.Comment: 15 pages, 9 figures (13 subfigures) -- v2: minor change
Structure of the Coulomb and unitarity corrections to the cross section of pair production in ultra-relativistic nuclear collisions
We analyze the structure of the Coulomb and unitarity corrections to the
single pair production as well as the cross section for the multiple pair
production. In the external field approximation we consider the probability of
pair production at fixed impact parameter between colliding
ultra-relativistic heavy nuclei. We obtain the analytical result for this
probability at large as compared to the electron Compton wavelength. We
estimate also the unitary corrections to the total cross section of the
process.Comment: 10 pages, 2 figures, RevTeX, references correcte
Photon-Photon Luminosities in Relativistic Heavy Ion Collisions at LHC Energies
Effective photon-photon luminosities are calculated for various realistic
hadron collider scenarios. The main characteristics of photon-photon processes
at relativistic heavy-ion colliders are established and compared to the
corresponding photon-photon luminosities at electron-positron and future Photon
Linear Colliders (PLC). Higher order corrections as well as inelastic processes
are discussed. It is concluded that feasible high luminosity Ca-Ca collisions
at the Large Hadron Collider (LHC) are an interesting option for photon-photon
physics up to about 100 GeV photon-photon CM energy.Comment: REVTeX, 13 pages, 10 figures (uuencoded,compressed postscript
interference in the Coulomb dissociation of B
We investigate the effects arising out of the interference in the
Coulomb dissociation of B at beam energies below and around 50 MeV/nucleon.
The theory has been formulated within a first order semiclassical scheme of
Coulomb excitation, in which both the ground state and the continuum state wave
functions of B enter as inputs. We find that the magnitude of the
interference could be large in some cases. However, there are some specific
observables which are free from the effects of the interference,
which is independent of the models used to describe the structure of B.
This will be useful for the analysis of the breakup data in relation to the
extraction of the astrophysical factor .Comment: Revised version to appear in Physical Review
Coherent Vector Meson Photoproduction with Nuclear Breakup in Relativistic Heavy Ion Collisions
Relativistic heavy ions are copious sources of virtual photons. The large
photon flux gives rise to a substantial photonuclear interaction probability at
impact parameters where no hadronic interactions can occur. Multiple
photonuclear interactions in a single collision are possible. In this letter,
we use mutual Coulomb excitation of both nuclei as a tag for moderate impact
parameter collisions. We calculate the cross section for coherent vector meson
production accompanied by mutual excitation, and show that the median impact
parameter is much smaller than for untagged production. The vector meson
rapidity and transverse momentum distribution are very different from untagged
exclusive vector meson production.Comment: 14 pages, including 4 figure
Stable Calculations for Unstable Particles: Restoring Gauge Invariance
We discuss theoretical and phenomenological aspects of the use of boson
propagators with energy-dependent widths in predictions for high-energy
scattering processes. In general, gauge invariance is violated in such
calculations. We discuss several approaches to restore gauge invariance,
necessary for a reliable result. The most promising method is the addition of
the relevant parts of the fermionic corrections, which fulfills all Ward
identities. The numerical difference between this and other approaches is
studied. A number of recommendations are given for LEP2 computations.Comment: 13 pages LaTeX inc 1 figure, uses epsf, axodraw. The ps file is
available as ftp://rulgm4.leidenuniv.nl/pub/preprints/stable.ps or on
http://rulgm4.leidenuniv.nl/ under preprints. Added two reference
Fully Automatic and Real-Time Catheter Segmentation in X-Ray Fluoroscopy
Augmenting X-ray imaging with 3D roadmap to improve guidance is a common
strategy. Such approaches benefit from automated analysis of the X-ray images,
such as the automatic detection and tracking of instruments. In this paper, we
propose a real-time method to segment the catheter and guidewire in 2D X-ray
fluoroscopic sequences. The method is based on deep convolutional neural
networks. The network takes as input the current image and the three previous
ones, and segments the catheter and guidewire in the current image.
Subsequently, a centerline model of the catheter is constructed from the
segmented image. A small set of annotated data combined with data augmentation
is used to train the network. We trained the method on images from 182 X-ray
sequences from 23 different interventions. On a testing set with images of 55
X-ray sequences from 5 other interventions, a median centerline distance error
of 0.2 mm and a median tip distance error of 0.9 mm was obtained. The
segmentation of the instruments in 2D X-ray sequences is performed in a
real-time fully-automatic manner.Comment: Accepted to MICCAI 201
- …