76 research outputs found
Hard photon production rate of a quark-gluon plasma at finite quark chemical potential
We compute the photon production rate of a quark-gluon plasma (QGP) at finite
quark chemical potential using the Braaten-Pisarski method, thus
continuing the work of Kapusta, Lichard, and Seibert who did the calculation
for .Comment: 9 pages, revtex, no figures, error in soft part corrected, figures
available at ftp://theorie.physik.uni-giessen.de/usr/users/ftp/photon
Using Different Data Sources for New Findings in Visualization of Highly Detailed Urban Data
Measurement of infrastructure has highly evolved in the last years. Scanning systems became more precise
and many methods were found to add and improve content created for the analysis of buildings and
landscapes. Therefore the pure amount of data increased significantly and new algorithms had to be found to
visualize these data for further exploration. Additionally many data types and formats originate from
different sources, such as Dibits hybrid scanning systems delivering laser-scanned point clouds and
photogrammetric texture images. These are usually analyzed separately. Combinations of different types of
data are not widely used but might lead to new findings and improved data exploration.
In our work we use different data formats like meshes, unprocessed point clouds and polylines in tunnel
visualization to give experts a tool to explore existing datasets in depth with a wide variety of possibilities.
The diverse creation of datasets leads to new challenges for preprocessing, out-of-core rendering and
efficient fusion of this varying information. Interactive analysis of different formats of data also has to have
several approaches and is usually difficult to merge into one application.
In this paper we describe the challenges and advantages of the combination of different data sources in
tunnel visualization. Large meshes with high resolution textures are merged with dense point clouds and
additional measurements. Interactive analysis can also create additional information, which has to be
integrated precisely to prevent errors and misinterpretation. We present the basic algorithms used for
heterogeneous data formats, how we combined them and what advantages are created by our methods.
Several datasets evolve over time. This dynamic is also considered in our visualization and analysis methods
to enable change detection. For tunnel monitoring this allows to investigate the entire history of the
construction project and helps to make better informed decisions in the preceding construction phases or for
repairs.
Several methods are merged like the data they are based on enabling new ways of data exploration. In
analyzing this new approach to look at heterogeneous datasets we come to the conclusion that the
combination of different sources leads to a better solution than the sum of its parts
Virtual Exploration of Urban Spatial Changes due to Regional Tramway Line Construction
For most large infrastructure projects, it is mandatory to assess their impact on the urban and rural
environment before they are started. Many shareholders want to involve the public or even are obliged to do
so due to legal provisions. For interactive exploration, a 3D viewer is needed that supports very complex
scenes. They should be realistically rendered for sufficient credibility. Applied research on this topic (in
close cooperation with industrial partners) resulted in GEARViewer, a geospatial rendering framework. It
supports huge geospatial scenes consisting of large-scale terrain models, buildings, roads, tramways,
railways, tunnels, vegetation and a skylight model. Everything is georeferenced. It can import GIS data and
turn this into 3D objects. In the future, it will also support Building Information Modeling (BIM) standards.
Furthermore, it also simulates traffic in a simplified way including cars, trams, trains and pedestrians. It was
used for many planned projects in Austria and Germany.
In this paper, we describe one of the projects for the city centre of Innsbruck, created with the GEARViewer.
It supported several stages of the segment wise planning and realization of a new regional tramway line over
multiple years. Depending on progress, the project visualization incorporated varying levels of details into
the existing city model, from graphic planning concepts during route optimization to detailed depictions of
stops and road design shortly before constructional implementation. In this way, shareholders and citizens
can experience the geospatial transformation and changes of the street network and traffic flow in the
affected regions of the city. The system allows the regular creation of videos, screenshots, interactive online
panorama tours and live demonstrations for publications and citizen information events. In order to fit the
current state of planning, the system and model were constantly extended and updated. It supported the
project progress and associated votes and discussions by supplying the display of variants, flexible
viewpoints and realistic visualization
Does Posterior Tibial Slope Influence Knee Kinematics in Medial Stabilized TKA?
Background: During total knee arthroplasty (TKA), one of the key alignment factors to pay attention to is the posterior tibial slope (PTS). The PTS clearly influences the kinematics of the knee joint but must be adapted to the coupling degree of the specific TKA design. So far, there is hardly any literature including clear recommendations for how surgeons should choose the PTS in a medial stabilized (MS) TKA. The aim of the present study is to investigate the effects of different degrees of PTS on femorotibial kinematics in MS TKA. Materials and Methods: An MS TKA was performed in seven fresh-frozen human specimens successively with 0 degrees, 3 degrees, and 6 degrees of PTS. After each modification, weight-bearing deep knee flexion (30-130 degrees) was performed, and femorotibial kinematics were analyzed. Results: A lateral femoral rollback was observed for all three PTS modifications. With an increasing PTS, the tibia was shifted more anteriorly on the lateral side (0 degrees PTS anterior tibial translation -9.09 (+/- 9.19) mm, 3 degrees PTS anterior tibial translation -11.03 (+/- 6.72) mm, 6 degrees PTS anterior tibial translation 11.86 (+/- 9.35) mm). No difference in the tibial rotation was found for the different PTS variants. All PTS variants resulted in internal rotation of the tibia during flexion. With a 3 degrees PTS, the design-specific medial rotation point was achieved more accurately. Conclusions: According to our findings, we recommend a PTS of 3 degrees when implanting the MS prosthesis used in this study
Damping Rate of a Scalar Particle in Hot Scalar QED
In contrast to the damping of partons in a quark-gluon plasma, the damping of
a scalar particle in a hot scalar QED plasma can be calculated to leading order
for the whole momentum range using the Braaten-Pisarski method. In this way the
evolution of the logarithmic infrared singularity caused by the exchange of a
transverse photon from soft to hard momenta can be studied.Comment: 10 pages, uuencoded postscript file with 6 figure
Stromal Expression of Heat-Shock Protein 27 Is Associated with Worse Clinical Outcome in Patients with Colorectal Cancer Lung Metastases
Pulmonary metastases are common in patients with primary colorectal cancer (CRC). Heat-
shock protein 27 (Hsp27) is upregulated in activated fibroblasts during wound healing and
systemically elevated in various diseases. Cancer-associated fibroblasts (CAFs) are also
thought to play a role as prognostic and predictive markers in various malignancies includ-
ing CRC. Surprisingly, the expression of Hsp27 has never been assessed in CAFs. There-
fore we aimed to investigate the expression level of Hsp27 in CAFs and its clinical
implications in patients with CRC lung metastases
Clinical Relevance of Elevated Soluble ST2, HSP27 and 20S Proteasome at Hospital Admission in Patients with COVID-19
Although, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) represents one of the biggest challenges in the world today, the exact immunopathogenic mechanism that leads to severe or critical Coronavirus Disease 2019 (COVID-19) has remained incompletely understood. Several studies have indicated that high systemic plasma levels of inflammatory cytokines result in the so-called “cytokine storm”, with subsequent development of microthrombosis, disseminated intravascular coagulation, and multiorgan-failure. Therefore, we reasoned those elevated inflammatory molecules might act as prognostic factors. Here, we analyzed 245 serum samples of patients with COVID-19, collected at hospital admission. We assessed the levels of heat shock protein 27 (HSP27), soluble suppressor of tumorigenicity-2 (sST2) and 20S proteasome at hospital admission and explored their associations with overall-, 30-, 60-, 90-day- and in-hospital mortality. Moreover, we investigated their association with the risk of ventilation. We demonstrated that increased serum sST2 was uni- and multivariably associated with all endpoints. Furthermore, we also identified 20S proteasome as independent prognostic factor for in-hospital mortality (sST2, AUC = 0.73; HSP27, AUC = 0.59; 20S proteasome = 0.67). Elevated sST2, HSP27, and 20S proteasome levels at hospital admission were univariably associated with higher risk of invasive ventilation (OR = 1.8; p < 0.001; OR = 1.1; p = 0.04; OR = 1.03, p = 0.03, respectively). These findings could help to identify high-risk patients early in the course of COVID-19
Photon Emission from a Parton Gas at Chemical Non-Equilibrium
We compute the hard photon production rate of a chemically non-equilibrated
quark-gluon plasma. We assume that the plasma is already thermally
equilibrated, i.~e. describable by a temperature, but with a phase-space
distribution that deviates from the Fermi/Bose distribution by a time dependent
factor (fugacity). The photon spectrum is obtained by integrating the photon
rate over the space-time evolution of the quark-gluon plasma. Some consequences
for ultrarelativistic heavy ion collisions are discussed.Comment: 17 pages, uuencoded Postscript file, figures include
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