110 research outputs found
The Mannheim Enterprise Panel (MUP) and firm statistics for Germany
The Mannheim Enterprise Panel (Mannheimer Unternehmenspanel – MUP) of the Centre for
European Economic Research (ZEW) is the most comprehensive micro database of companies in
Germany outside the official business register (which is not accessible to the public). The MUP is
based on the firm data pool of Creditreform e.V., which is the largest credit rating agency in
Germany. At the end of 2013, the MUP contained information on 7.7 Mio firms, of which about
3.2 Mio were still active. Comparisons of the active stock of firms in the MUP with the Business
Register of the Federal Statistical Office indicate that the MUP gives by and large a
representative picture of the corporate landscape in Germany. The MUP is a valuable database
for analyzing the number of start‐ups and firm closures on a yearly basis for Germany. Further,
the MUP is the sampling frame for the ZEW firm surveys and it is used for analyzing the
development of firms over time
Identification of geographically distributed sub-populations of Leishmania (Leishmania) major by microsatellite analysis
<p>Abstract</p> <p>Background</p> <p><it>Leishmania </it>(<it>Leishmania</it>) <it>major</it>, one of the agents causing cutaneous leishmaniasis (CL) in humans, is widely distributed in the Old World where different species of wild rodent and phlebotomine sand fly serve as animal reservoir hosts and vectors, respectively. Despite this, strains of <it>L. (L.) major </it>isolated from many different sources over many years have proved to be relatively uniform. To investigate the population structure of the species highly polymorphic microsatellite markers were employed for greater discrimination among it's otherwise closely related strains, an approach applied successfully to other species of <it>Leishmania</it>.</p> <p>Results</p> <p>Multilocus Microsatellite Typing (MLMT) based on 10 different microsatellite markers was applied to 106 strains of <it>L. (L.) major </it>from different regions where it is endemic. On applying a Bayesian model-based approach, three main populations were identified, corresponding to three separate geographical regions: Central Asia (CA); the Middle East (ME); and Africa (AF). This was congruent with phylogenetic reconstructions based on genetic distances. Re-analysis separated each of the populations into two sub-populations. The two African sub-populations did not correlate well with strains' geographical origin. Strains falling into the sub-populations CA and ME did mostly group according to their place of isolation although some anomalies were seen, probably, owing to human migration.</p> <p>Conclusion</p> <p>The model- and distance-based analyses of the microsatellite data exposed three main populations of <it>L. (L.) major</it>, Central Asia, the Middle East and Africa, each of which separated into two sub-populations. This probably correlates with the different species of rodent host.</p
The influence of different footprint preparation techniques on tissue regeneration in rotator cuff repair in an animal model
Introduction: Rotator cuff tears are common diseases of the upper extremity. There are no recommendations to the surgeon on how to prepare the footprint to ensure optimal tendon-to-bone healing. However, biologic augmentation using stem cells and growth factors is considered to encourage the healing process of the tendon. The aim of the study was to investigate the biomechanical and histological outcome of different footprint preparations in rotator cuff repair. Material and methods: One hundred and eighty-nine Sprague-Dawley rats were randomly assigned to either spongialization, radiofrequency ablation or an untreated control group. Rats were killed after 1 or 7 weeks for histological evaluation or after 7 weeks for biomechanical testing. Results: Histological evaluation showed better tissue organization in the control and spongialization group compared to the radiofrequency ablation group. The highest collagen I to collagen III quotient was found in the control group, followed closely by the spongialization group. Measured quotients showed a decrease in the values after 1 week compared to the values after 7 weeks, except in the radiofrequency ablation group, where an increase was detected. A significant difference was found in the load to failure test comparing the radiofrequency ablation group to the spongialization group (p = 0.0409) and control group (p = 0.014), but not comparing the spongialization group to the control group (p = 0.2456). Conclusions: The results of this study suggest that spongialization of the footprint before attaching the torn supraspinatus tendon can lead to better structural properties and higher quality of tendon-to-bone restoration at the insertion area when compared with radiofrequency ablation
Most discriminative stimuli for functional cell type clustering
Identifying cell types and understanding their functional properties is
crucial for unraveling the mechanisms underlying perception and cognition. In
the retina, functional types can be identified by carefully selected stimuli,
but this requires expert domain knowledge and biases the procedure towards
previously known cell types. In the visual cortex, it is still unknown what
functional types exist and how to identify them. Thus, for unbiased
identification of the functional cell types in retina and visual cortex, new
approaches are needed. Here we propose an optimization-based clustering
approach using deep predictive models to obtain functional clusters of neurons
using Most Discriminative Stimuli (MDS). Our approach alternates between
stimulus optimization with cluster reassignment akin to an
expectation-maximization algorithm. The algorithm recovers functional clusters
in mouse retina, marmoset retina and macaque visual area V4. This demonstrates
that our approach can successfully find discriminative stimuli across species,
stages of the visual system and recording techniques. The resulting most
discriminative stimuli can be used to assign functional cell types fast and on
the fly, without the need to train complex predictive models or show a large
natural scene dataset, paving the way for experiments that were previously
limited by experimental time. Crucially, MDS are interpretable: they visualize
the distinctive stimulus patterns that most unambiguously identify a specific
type of neuron
Upper limits on the strength of periodic gravitational waves from PSR J1939+2134
The first science run of the LIGO and GEO gravitational wave detectors
presented the opportunity to test methods of searching for gravitational waves
from known pulsars. Here we present new direct upper limits on the strength of
waves from the pulsar PSR J1939+2134 using two independent analysis methods,
one in the frequency domain using frequentist statistics and one in the time
domain using Bayesian inference. Both methods show that the strain amplitude at
Earth from this pulsar is less than a few times .Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo
Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July
200
Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers
We study frequency dependent (FD) input-output schemes for signal-recycling
interferometers, the baseline design of Advanced LIGO and the current
configuration of GEO 600. Complementary to a recent proposal by Harms et al. to
use FD input squeezing and ordinary homodyne detection, we explore a scheme
which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are
sub-optimal among all possible input-output schemes, provide a global noise
suppression by the power squeeze factor, while being realizable by using
detuned Fabry-Perot cavities as input/output filters. At high frequencies, the
two schemes are shown to be equivalent, while at low frequencies our scheme
gives better performance than that of Harms et al., and is nearly fully
optimal. We then study the sensitivity improvement achievable by these schemes
in Advanced LIGO era (with 30-m filter cavities and current estimates of
filter-mirror losses and thermal noise), for neutron star binary inspirals, and
for narrowband GW sources such as low-mass X-ray binaries and known radio
pulsars. Optical losses are shown to be a major obstacle for the actual
implementation of these techniques in Advanced LIGO. On time scales of
third-generation interferometers, like EURO/LIGO-III (~2012), with
kilometer-scale filter cavities, a signal-recycling interferometer with the FD
readout scheme explored in this paper can have performances comparable to
existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi
Searching for a Stochastic Background of Gravitational Waves with LIGO
The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed
the fourth science run, S4, with significantly improved interferometer
sensitivities with respect to previous runs. Using data acquired during this
science run, we place a limit on the amplitude of a stochastic background of
gravitational waves. For a frequency independent spectrum, the new limit is
. This is currently the most sensitive
result in the frequency range 51-150 Hz, with a factor of 13 improvement over
the previous LIGO result. We discuss complementarity of the new result with
other constraints on a stochastic background of gravitational waves, and we
investigate implications of the new result for different models of this
background.Comment: 37 pages, 16 figure
Search for gravitational wave bursts in LIGO's third science run
We report on a search for gravitational wave bursts in data from the three
LIGO interferometric detectors during their third science run. The search
targets subsecond bursts in the frequency range 100-1100 Hz for which no
waveform model is assumed, and has a sensitivity in terms of the
root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No
gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published
in Classical and Quantum Gravit
The Delphi Delirium Management Algorithms. A practical tool for clinicians, the result of a modified Delphi expert consensus approach
Delirium is common in hospitalised patients, and there is currently no specific treatment. Identifying and treating underlying somatic causes of delirium is the first priority once delirium is diagnosed. Several international guidelines provide clinicians with an evidence-based approach to screening, diagnosis and symptomatic treatment. However, current guidelines do not offer a structured approach to identification of underlying causes. A panel of 37 internationally recognised delirium experts from diverse medical backgrounds worked together in a modified Delphi approach via an online platform. Consensus was reached after five voting rounds. The final product of this project is a set of three delirium management algorithms (the Delirium Delphi Algorithms), one for ward patients, one for patients after cardiac surgery and one for patients in the intensive care unit.</p
Immature and Maturation-Resistant Human Dendritic Cells Generated from Bone Marrow Require Two Stimulations to Induce T Cell Anergy In Vitro
Immature dendritic cells (DC) represent potential clinical tools for tolerogenic cellular immunotherapy in both transplantation and autoimmunity. A major drawback in vivo is their potential to mature during infections or inflammation, which would convert their tolerogenicity into immunogenicity. The generation of immature DC from human bone marrow (BM) by low doses of GM-CSF (lowGM) in the absence of IL-4 under GMP conditions create DC resistant to maturation, detected by surface marker expression and primary stimulation by allogeneic T cells. This resistence could not be observed for BM-derived DC generated with high doses of GM-CSF plus IL-4 (highGM/4), although both DC types induced primary allogeneic T cell anergy in vitro. The estabishment of the anergic state requires two subsequent stimulations by immature DC. Anergy induction was more profound with lowGM-DC due to their maturation resistance. Together, we show the generation of immature, maturation-resistant lowGM-DC for potential clinical use in transplant rejection and propose a two-step-model of T cell anergy induction by immature DC
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