OPUS 4 | Universitätspublikationen

Protein C preserves microcirculation in a model of neonatal septic shock (2005)

Doris Fischer Marcel Friedrich Nold Claudia A. Nold-Petry Antonio Furlan Alex Veldman

Objectives: Sepsis remains a disease with a high mortality in neonates. Microcirculatory impairment plays a pivotal role in the development of multiorgan failure in septic newborns. The hemodynamic effects of recombinant activated protein C (rhAPC) were tested in an animal model of neonatal septic shock focusing on intestinal microcirculation. Materials and methods: Endotoxic shock was triggered by intravenous application of Escherichia coli lipopolysaccarides in newborn piglets. Thereafter, five animals received a continuous infusion of 24 µg/kg/h rhAPC, and five received vehicle for control. Over the course of three hours, intestinal microcirculation was assessed by intravital microscopy every 30 min. Macrocirculation and blood counts were monitored simultaneously. Results: After a short hypotensive period in all animals, the arterial blood pressure returned to baseline in the rhAPC-treated piglets, whereas the hypotension became increasingly severe in the controls. By 90 min, mean blood pressure in the controls was significantly lower than in the treatment group. Similar observations were made regaring microcirculation. After an early impairment in all study animals, functional capillary density and intestinal microcirculatory red blood cell velocity and red blood cell flow recovered in the rhAPC group, but deteriorated further in the control piglets. Conclusion: Recombinant activated protein C protects macro- and microcirculation from endotoxic shock.

The QCD phase diagram at zero and small baryon density (2005)

Owe Philipsen

I review recent developments in determining the QCD phase diagram by means of lattice simulations. Since the invention of methods to side-step the sign problem a few years ago, a number of additional variants have been proposed, and progress has been made towards understanding some of the systematics involved. All available techniques agree on the transition temperature as a function of density in the regime mq/T <~1. There are by now four calculations with signals for a critical point, two of them at similar parameter values and with consistent results. However, it also emerges that the location of the critical point is exceedingly quark mass sensitive. At the same time sizeable finite volume, cut-off and step size effects have been uncovered, demanding additional investigations with exact algorithms on larger and finer lattices before quantitative conclusions can be drawn. Depending on the sign of these corrections, there is ample room for the eventual phase diagram to look as expected or also quite different, with no critical point at all.

The pseudoparticle approach for solving path integrals in gauge theories (2005)

Marc Wagner Frieder Lenz

We present a numerical technique for calculating path integrals in non-compact U(1) and SU(2) gauge theories. The gauge fields are represented by a superposition of pseudoparticles of various types with their amplitudes and color orientations as degrees of freedom. Applied to Maxwell theory this technique results in a potential which is in excellent agreement with the Coulomb potential. For SU(2) Yang-Mills theory the same technique yields clear evidence of confinement. Varying the coupling constant exhibits the same scaling behavior for the string tension, the topological susceptibility and the critical temperature while their dimensionless ratios are similar to those obtained in lattice calculations.

Observations of meteoritic material and implications for aerosol nucleation in the winter Arctic lower stratosphere derived from in situ particle measurements (2005)

Joachim Curtius Ralf Weigel Hermann-Josef Vössing Heini Wernli Anja Sabine Werner C.-Michael Volk Paul Konopka Michael Krebsbach Cornelius Schiller Anke Roiger Hans Schlager Volker Dreiling Stephan Borrmann

Number concentrations of total and non-volatile aerosol particles with size diameters >0.01 µm as well as particle size distributions (0.4–23 µm diameter) were measured in situ in the Arctic lower stratosphere (10–20.5 km altitude). The measurements were obtained during the campaigns European Polar Stratospheric Cloud and Lee Wave Experiment (EUPLEX) and Envisat-Arctic-Validation (EAV). The campaigns were based in Kiruna, Sweden, and took place from January to March 2003. Measurements were conducted onboard the Russian high-altitude research aircraft Geophysica using the low-pressure Condensation Nucleus Counter COPAS (COndensation PArticle Counter System) and a modified FSSP 300 (Forward Scattering Spectrometer Probe). Around 18–20 km altitude typical total particle number concentrations nt range at 10–20 cm−3 (ambient conditions). Correlations with the trace gases nitrous oxide (N2O) and trichlorofluoromethane (CFC-11) are discussed. Inside the polar vortex the total number of particles >0.01 µm increases with potential temperature while N2O is decreasing which indicates a source of particles in the above polar stratosphere or mesosphere. A separate channel of the COPAS instrument measures the fraction of aerosol particles non-volatile at 250°C. Inside the polar vortex a much higher fraction of particles contained non-volatile residues than outside the vortex (~24% outside vortex). This is most likely due to a strongly increased fraction of meteoritic material in the particles which is transported downward from the mesosphere inside the polar vortex. The high fraction of non-volatile residual particles gives therefore experimental evidence for downward transport of mesospheric air inside the polar vortex. It is also shown that the fraction of non-volatile residual particles serves directly as a suitable experimental vortex tracer. Nanometer-sized meteoritic smoke particles may also serve as nuclei for the condensation of gaseous sulfuric acid and water in the polar vortex and these additional particles may be responsible for the increase in the observed particle concentration at low N2O. The number concentrations of particles >0.4 µm measured with the FSSP decrease markedly inside the polar vortex with increasing potential temperature, also a consequence of subsidence of air from higher altitudes inside the vortex. Another focus of the analysis was put on the particle measurements in the lowermost stratosphere. For the total particle density relatively high number concentrations of several hundred particles per cm3 at altitudes below ~14 km were observed in several flights. To investigate the origin of these high number concentrations we conducted air mass trajectory calculations and compared the particle measurements with other trace gas observations. The high number concentrations of total particles in the lowermost stratosphere are probably caused by transport of originally tropospheric air from lower latitudes and are potentially influenced by recent particle nucleation.

On the observation of mesospheric air inside the arctic stratospheric polar vortex in early 2003 (2005)

Andreas Engel Tanja Möbius Hans-Peter Haase Harald Bönisch Thomas Wetter Ulrich Schmidt Ingeborg Levin Thomas Reddmann Hermann Oelhaf Gerald Wetzel Katja Grunow Nathalie Huret Michel Pirre

During several balloon flights inside the Arctic polar vortex in early 2003, unusual trace gas distributions were observed, which indicate a strong influence of mesospheric air in the stratosphere. The tuneable diode laser (TDL) instrument SPIRALE (Spectroscopie InFrarouge par Absorption de Lasers Embarqués) measured unusually high CO values (up to 600 ppb) on 27 January at about 30 km altitude. The cryosampler BONBON sampled air masses with very high molecular Hydrogen, extremely low SF6 and enhanced CO values on 6 March at about 25 km altitude. Finally, the MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) Fourier Transform Infra-Red (FTIR) spectrometer showed NOy values which are significantly higher than NOy* (the NOy derived from a correlation between N2O and NOy under undisturbed conditions), on 21 and 22 March in a layer centred at 22 km altitude. Thus, the mesospheric air seems to have been present in a layer descending from about 30 km in late January to 25 km altitude in early March and about 22 km altitude on 20 March. We present corroborating evidence from a model study using the KASIMA (KArlsruhe Simulation model of the Middle Atmosphere) model that also shows a layer of mesospheric air, which descended into the stratosphere in November and early December 2002, before the minor warming which occurred in late December 2002 lead to a descent of upper stratospheric air, cutting of a layer in which mesospheric air is present. This layer then descended inside the vortex over the course of the winter. The same feature is found in trajectory calculations, based on a large number of trajectories started in the vicinity of the observations on 6 March. Based on the difference between the mean age derived from SF6 (which has an irreversible mesospheric loss) and from CO2 (whose mesospheric loss is much smaller and reversible) we estimate that the fraction of mesospheric air in the layer observed on 6 March, must have been somewhere between 35% and 100%.

Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles (2005)

Marcel Dorf Hartmut Bösch Andre Butz Claude C. Camy-Peyret Martyn P. Chipperfield Andreas Engel Florence Goutail Katja Grunow François Hendrick Serhiy Hrechanyy Barbara Naujokat Jean-Pierre Pommereau Michel van Roozendael Christopher E. Sioris Fred Stroh Frank Weidner Klaus Pfeilsticker

For the first time, results of all four existing stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM). Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) satellite instrument. The balloon observations include (a) balloon-borne in situ resonance fluorescence detection of BrO, (b) balloon-borne solar occultation DOAS measurements (Differential Optical Absorption Spectroscopy) of BrO in the UV, and (c) BrO profiling from the solar occultation SAOZ (Systeme d'Analyse par Observation Zenithale) balloon instrument. Since stratospheric BrO is subject to considerable diurnal variation and none of the measurements are performed close enough in time and space for a direct comparison, all balloon observations are considered with reference to outputs from the 3-D CTM. The referencing is performed by forward and backward air mass trajectory calculations to match the balloon with the satellite observations. The diurnal variation of BrO is considered by 1-D photochemical model calculation along the trajectories. The 1-D photochemical model is initialised with output data of the 3-D model with additional constraints on the vertical transport, the total amount and photochemistry of stratospheric bromine as given by the various balloon observations. Total [Bry]=(20.1±2.8)pptv obtained from DOAS BrO observations at mid-latitudes in 2003, serves as an upper limit of the comparison. Most of the balloon observations agree with the photochemical model predictions within their given error estimates. First retrieval exercises of BrO limb profiling from the SCIAMACHY satellite instrument agree to <±50% with the photochemically-corrected balloon observations, and tend to show less agreement below 20 km.

Highly resolved observations of trace gases in the lowermost stratosphere and upper troposphere from the Spurt project: an overview (2005)

Andreas Engel Harald Bönisch Dominik Brunner Herbert Fischer Harald Franke Gebhard Günther Christian Thomas Gurk Michaela I. Hegglin Peter Hoor Rainer Königstedt Michael Krebsbach Rolf Maser Uwe Parchatka Thomas Peter Dieter Schell Cornelius Schiller Ulrich Schmidt Nicole Spelten T. Szabo Uwe Weers Heini Wernli Thomas Wetter Volkmar Wirth

During SPURT (Spurenstofftransport in der Tropopausenregion, trace gas transport in the tropopause region) we performed measurements of a wide range of trace gases with different lifetimes and sink/source characteristics in the northern hemispheric upper troposphere (UT) and lowermost stratosphere (LMS). A large number of in-situ instruments were deployed on board a Learjet 35A, flying at altitudes up to 13.7 km, at times reaching to nearly 380 K potential temperature. Eight measurement campaigns (consisting of a total of 36 flights), distributed over all seasons and typically covering latitudes between 35° N and 75° N in the European longitude sector (10° W–20° E), were performed. Here we present an overview of the project, describing the instrumentation, the encountered meteorological situations during the campaigns and the data set available from SPURT. Measurements were obtained for N2O, CH4, CO, CO2, CFC12, H2, SF6, NO, NOy, O3 and H2O. We illustrate the strength of this new data set by showing mean distributions of the mixing ratios of selected trace gases, using a potential temperature – equivalent latitude coordinate system. The observations reveal that the LMS is most stratospheric in character during spring, with the highest mixing ratios of O3 and NOy and the lowest mixing ratios of N2O and SF6. The lowest mixing ratios of NOy and O3 are observed during autumn, together with the highest mixing ratios of N2O and SF6 indicating a strong tropospheric influence. For H2O, however, the maximum concentrations in the LMS are found during summer, suggesting unique (temperature- and convection-controlled) conditions for this molecule during transport across the tropopause. The SPURT data set is presently the most accurate and complete data set for many trace species in the LMS, and its main value is the simultaneous measurement of a suite of trace gases having different lifetimes and physical-chemical histories. It is thus very well suited for studies of atmospheric transport, for model validation, and for investigations of seasonal changes in the UT/LMS, as demonstrated in accompanying and elsewhere published studies.

Generation and secularisation in Germany : the succession of generations up to the youngest adult generation and the advancing process of secularisation (2005)

Manuel Franzmann

When one considers the results of social scientific surveys, secularisation in Germany seems to be a more or less linear process of erosion of what is traditionally named religiosity. The percentage of citizens who affirm that they are “religious”, believe in God or otherworldly beings, hope for life after death or participate regularly in the praxis of a religious community has been – by and large – steadily declining for decades. This decline has occurred over the succeeding generations: The younger the generation, the fewer “religious” people in it. But the process of secularisation is apparent not only in this persistent quantitative shrinkage from generation to generation. Above all it also manifests itself – this is the thesis of the article – in the transformation of the habitus formations and contents of faith of the generations. The essence of ongoing secularisation naturally is reflected most clearly in its contemporary state of development which is represented in the youngest adult generation. Therefore the analysis of this generation is particularly interesting for the sociology of religion. But the article does not confine to analyze this generation. After indicating some basic premises of the sociology of generations and the notion of secularisation presupposed in this paper, the succession of generations in Germany is outlined hypothetically, from the so-called generation of ´68 to the youngest adult generation, concluding with some remarks about the progress of secularisation.

Unity of Buddhism and Hinduism : in experience and teachings of the Dalai Lama (2005)

Edmund Weber

The Dalai Lama, in exile since 1959 in Hindu majority India, has continuously been taking a firm stand on giving importance to an inter-religious dialogue and interaction. He has made it absolutely clear that Buddhism represents just one of the many religious ways open for mankind. Nonetheless, he has always referred to the bond shared between Buddhism and Hinduism as a very special one and has experienced it as a religious tie. Both these religious streams belong to what is known as Bharatiya or Indo-genous Dharma. The Dalai Lama does not restrict his care for nurturing this common bond to a mere academic talk. In fact he has been taking active part in promoting this kind of inter-religious dialogue and has been showing a fiery political commitment as well. He thus took active part in the second World Hindu Congress organized by the Vishwa Hindu Parishad held in Prayag-Allahabad in the year 1979. According to official reports, the organizers in their welcome speech for the Dalai Lama were frank enough to admit that 2500 years ago, the Kashi Pandits (Kashi also known as Varanasi) had stopped Siddharta Gautama Buddha from entering the Vishwanath temple. It was also mentioned that for all these years, there has never been any letup in the conflict between Sanatani Hindus and Bauddhas, despite the fact that later on Shakya Muni was rewarded the status of avatara by Hindus. The fact that these very Kashi Pandits had invite one of the highest religious authorities of Buddhism - the Dalai Lama- to this congress should be seen as "a positive step towards reconciliation." The Dalai Lama was thus pleasantly surprised to see that the highest rung of the religious body of Hindus publicly acknowledged the divine status of Siddharta Gautama Buddha and recognized the presence of the Dalai Lama as a valuable contribution towards the reconciliation between the two religious streams. ...

A modern Hindu concept of inter-religious dialogue (2005)

Ashok Chowgule

Dialogue has become a fashionable word in the theological circles for quite some time now. However, there is a need to review what has been achieved so far. If it is significant, we should then review how much religious tension has been reduced so far. If it is not much, why has there been no progress. In this note I will deal with the issues relating to Hindu-Christian dialogue. I am using Christianity only as a reference point, and the issues raised do have a wider context as well. As far as Hindu-Christian dialogue is concerned, I am of the opinion that there has been hardly any progress all these years. Many academics and theologians have been involved in the exercise so far. The whole literature, over a long period of time, seems to follow a familiar pattern – a discussion on the theory of the dialogue, what should be included in a dialogue, who should and should not be involved in a dialogue, and ends with a lament that there is so very little progress. The problem, according to me, is that the dialogue does not even consider a need to discuss what is the basic difference between Hinduism and Christianity, and an inquiry into whether these come in the way of communal harmony. A dialogue is really not necessary if we are to discuss only what is similar between the two systems. ...

Universitätspublikationen

Refine

Author

Year of publication

Document Type

Language

Has Fulltext

Keywords

Institute

270 search hits