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P- and n-doped bismuth telluride (Bi2Te3) polycrystalline nanostructures were prepared on structured PECVD-oxide-layers using magnetron sputtering and a lithography independent deposition and back-etching step. The resulting polycrystalline spacer-structures have adjustable dimensions with heights of 350 to 450 nm, a widths of 200 to 220 nm and a fix length of 1240 μm and 4020 μm. This paper presents the production of Bi2Te3 structures and how annealing affects the electrical conductivity in order to improve their potential in thermoelectric applications. In addition to temperature variation and multiple annealing the influence of different atmospheres during the annealing step has been investigated. It is shown that the electrical conductivity of the p-doped material increases by a factor of 1.8, while it decreases for the n-doped material.

Thin-film thermoelectric generators (TFTEGs) can provide energy for ultra-low power devices such as microscale heaters, cooling-units, and autonomous sensors and actuators. Of particular interest are micro- and nano-structured thermoelectric materials deposited on organic substrates, which allow fabrication of ultra-fast Peltier elements, mechanically flexible TFTEGs, and integration of TFTEGs in transparent microfluidic cells. In this study we report on an integration process of bismuth telluride based cross-plane TFTEGs on polyimide as a model material for organic substrates by adapting a well-established planar technology method. The main advantage of this approach is that the length of the thermopiles is independent on the thickness of the thermoelectric materials, which allows for fabrication of TFTEGs with high aspect ratio.

In order to combine the excellent thermoelectric features of nanostructured bismuth telluride (Bi 2 Te 3 ) at room temperature without using any expensive lithography processes, the formation of Bi 2 Te 3 -thermolegs inside an in-plane thermoelectric device is executed with a lithography independent deposition- and reactive ion back-etching process. The resulting nanostructured thermolegs have a width and height in the magnitude of a few hundred nanometers and length in the millimeter regime and are finally interconnected with structures of titanium nitride. This paper presents a concept for a simple fabrication of in-plane thermoelectric devices as well as the production and electrical measurement of the first prototypes. The resulting electrical conductivity of the thermolegs are $57.782^{\ast}10^{3}\Omega^{-1}\mathrm{m}^{-1}$ for n-type and $3.579^{\ast10}10^{3} \Omega^{-1}\mathrm{m}^{-1}$ for p-type Bi 2 Te 3 .

Summary In this case study, we investigate how the use of different information derived from a seismic dataset improves the understanding of a complex gas reservoir in a development context. We are adapting a versatile imaging algorithm (the generalized radon transform) to create seismic images with enhanced S/N ratios and enhanced diffractions. These are better suited to the interpretation challenges of the reservoir. On one hand, the S/N enhanced images and gathers were used as clean and detailed input to an elastic seismic inversion. These complemented the structural interpretation and led to a better understanding of reservoir properties and connectivity in the main part of the reservoir. On the other hand, the diffraction images were incorporated in a more standard interpretation workflow as high-resolution input to seismic geomorphology in order to predict the quality at the fringe of the reservoir. This was not possible with conventional input and methods.

For an efficient execution of seismic processing algorithms on todays hardware architectures parallelization is mandatory. But the corresponding programming effort is high. General aspects like job scheduling and monitoring, data splitting and aggregation or resources management, have to be taken into account, which are inherent to a parallel execution. We present the programming framework ALOMA, a highly efficient auto-parallelization tool for a wide range of seismic processing methods. It allows to combine processing modules to complex workflows, which are executed concurrently parallelized over nodes and cores. Control and data dependencies are generated automatically. ALOMA hides the complexity of a generic parallelization framework behind a thin domain-specific interface. An easy to use plug-in architecture allows to add user-defined algorithmic modules. Existing libraries and binaries can easily be integrated without any change.

The Rotliegend saline lake periodically covered wide areas of the Southern Permian Basin in Northwest Europe during the Permian. The sedimentology, mineralogy and geochemistry of lake deposits were studied to document very high frequency lake level fluctuations and to evaluate their triggers. Increased precipitation and marine ingressions into the basin resulted in lake extension. Increased run-off is documented by intercalated fluvial deposits in low-salinity deposits of the lake. Because lake deposits reflect mainly deposition in relatively wet climate phases, they are not correlatable to halite deposits in other basin areas. Decreased precipitation is followed by shrinkage of the lake, desiccation at its margins, and higher lake salinity due to concentration of the brine. Carbonate and anhydrite contents of lake deposits increased considerably before the areas fell dry, but halite is not preserved in the study area. Falling lake level is also reflected by the occurrence of wave ripples, reflecting decreased water depth and finally by desiccation and formation of evaporite crusts. Not only the mineralogical content, but also the colour of lake claystones changes with varying salinity. Anhydrite- and carbonate-free red claystones were replaced by violet to green and grey anhydritic and calcareous claystone or marls with increasing salinity. The amount of boron adsorbed on illite also corresponds to changes in salinity and can therefore be used as a palaeosalinity indicator. Rare earth element concentrations within lake deposits do not reflect variations in salinity but different palaeogeographical settings. Marine ingressions into the lake are neither reflected by the amount of boron adsorbed onto illite nor by rare earth element contents of the lake deposits. Highly saline deposits are partly characterised by intensive deformation, which can be interpreted as seismites or dissolution breccias.

Methods permitting to test the influence of the matrix as well as of its local and temporal distribution on the plasma conditions in laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) are developed. For this purpose, the MS interface is used as plasma probe allowing to investigate the average plasma condition within the ICP zone observed in terms of temporal and spatial distribution of the matrix. Inserted matrix particles, particularly when being atomized and ionized, can cause considerable changes in both electron density and plasma temperature thus influencing the ionization equilibrium of the individual analytes. In this context, the plasma probe covers a region of the plasma for which no local thermodynamic equilibrium can be assumed. The differences in temperature, identified within the region of the plasma observed, amounted up to 3000 K. While in the central region conditions were detected that would not allow efficient atomization and ionization of the matrix, these conditions improve considerably towards the margin of the area observed. Depending on the nature as well as on the temporally and locally variable density of the matrix, this can lead to varying intensity ratios of the analytes and explain fractionation effects. By means of a derived equation it is shown that the deviation of the intensity ratio from the concentration ratio turns out to be more serious the higher the difference of the ionization potential of the analytes observed, the lower the plasma temperature and the higher the matrix concentration within the area observed.

Signal equations basing on dispersion functions describing the measured temporal intensity distribution for laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) used in scanning and drilling mode are developed. Variable ablation rates due to either varying focussing conditions typical for drilling mode and due to the changes of physical and chemical properties in inhomogeneous samples as typically investigated in scanning mode are considered for. The model accounts for intermixing of the sample aerosol within the sampling chamber, the influence of transport in a cylindrical transport channel and the fact that normally not the entire vapour generated and transported to the ICP can be observed. The absolute signal response is influenced by the actually ablated, transported and observed analyte mass. The dispersion functions describing the relative signal response depend on sample chamber volume, the volume of the transport channel, the laser shot frequency, the carrier gas flow rate and the part of observable cross-section at the MS interface compared to the entire cross-section filled by the vapour. All these parameters depend on the experimental set-up and the selected operating conditions only. Using the signal equation the influence of all mentioned parameters on signal course is shown both theoretically and experimentally. The signal equation can be used for calculation of optimal experimental conditions. On this basis, an algorithm is proposed providing the relative temporal distribution of any analyte with significantly higher temporal resolution than the measured temporal intensity distribution itself. Furthermore, usage of dispersion functions for investigation of a given transport system, for explanation of typical signal deviations, for the proof of homogeneous regions in a heterogeneous sample, for examination of changes in ablation rate and for investigation of fractionation effects is shown.

A transport model is proposed that describes the temporal intensity distribution observed in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) in single-shot mode using quantitative signal equations. Calculations aim on the deduction of the dispersion function describing the time-dependent part of the signal equation. The dispersion function depends on transport time in the centre of the transport tube, as related to carrier gas flow rate and tube volume and on the relation between carrier gas flow rate and ablation chamber volume. The equations describing the signal shape standardize signals from different systems and allow quantitative optimization of the ablation chamber, the transport tube and the detector. Application of the model to ICP-MS shows that only a part of the area filled by the transported vaporization product and thus only a part of the transported vaporization product can be observed at the detector. The model is able to quantify both fractions. As was calculated, the observed fraction of analyte is always higher than the observed fraction of the sample containing cross section and depends on the chosen transport parameters characterising the dispersion function. Thus, the determination of the signal integrals in the usual way can lead to systematic errors if the parameters influencing the dispersion function are variable. Therefore, a different method of analysis based on signal equations is proposed and demonstrated. By this method of data treatment, all important system parameters influencing the dispersion function could be calculated and matched with theoretical ones. Furthermore, a complete integral of the transient signal including its statistical variation can be generated from a limited number of measurement points. For example, this can be applied to signals detected incompletely because of detector saturation and enables the use of high-abundance elements as internal standards. Furthermore, the method can be used to monitor system performance, to identify the flow regime inside the ablation chamber, to take into account the sample volume for quantitative analysis and finally, to detect anomalous signal distributions that would lead to systematic errors. The prospects and limitations of the model are discussed for LA-ICP-MS in single shot mode.

On the basis of the three-particle Bethe-Salpeter equation we formulated a relativistic quark model for baryons. With free constituent-quark propagators and instantaneous interaction kernels a good description of the overall baryonic mass spectrum up to the highest spin states is obtained. Preliminary results on strong two-body decays of baryon resonances are discussed.

We compute electroweak form factors of the nucleon and photon transition form factors of non-strange baryon resonances up to the third resonance region in a model with instanton-induced interaction. The calculation is based on the Bethe-Salpeter equation for three light constituent quarks and is fully relativistic (U. L\"oring {\it et al.}, Eur. Phys. J. {\bf A10}, 309 (2001)). Static nucleon properties and photon resonance couplings are in good agreement with experiment and the $Q^2$-behaviour of the experimentally known form factors up to large momentum transfer is accounted for., Comment: 12 pages, 17 figures, submitted to Eur. Phys. J. A

In this paper we investigate weak decays of heavy mesons in the framework of a covariant quark model, which is based on the Bethe-Salpeter equation in instantaneous approximation. Apart from a phenomenological confinement potential, a residual interaction induced by instantons is adopted. Masses and many decay observables of light mesons have already been described successfully in this model. An appropiate extension allows a unified description of light and heavy systems. Using a set of parameters which are fixed by the mass spectra, we evaluate the form factors of semileptonic decays of charmed and bottom mesons. In the heavy quark limit these can be reduced to the Isgur-Wise function, which is calculated. Finally the form factors are used to determine the non-leptonic decay rates of B mesons in the factorization approximation.

In this contribution, the results on the spectra and semileptonic decays of light and heavy mesons in a relativistic constituent quark model incorporating a confinement potential as well as a residual interaction induced by instantons are reported.

We present new results of a relativistic quark model based on the Bethe-Salpeter equation in its instantaneous approximation. Assuming a linearly rising confinement potential with an appropriate spinorial structure in Dirac space and adopting a residual interaction based on instanton effects, we can compute masses of the light mesons up to highest observed angular momenta with a natural solution of the $U_A(1)$ problem. The calculated ground states masses and the radial excitations describe the experimental results well. In this paper, we will also discuss our results concerning numerous meson decay properties. For processes like $\pi^+/K^+\to e^+\nu_e\gamma$ and $0^-\to\gamma\gamma$ at various photon virtualities, we find a good agreement with experimental data. We will also comment on the form factors of the $K_{\ell 3}$ decay and on the decay constants of the $\pi$, $K$ and $\eta$ mesons. For the sake of completeness, we will furthermore present the electromagnetic form factors of the charged $\pi$ and $K$ mesons as well as a comparison of the radiative meson decay widths with the most recent experimental data., Comment: 30 pages including 10 tables and 16 figures; submitted to Eur. Phys. J. A; misprints corrected

Rapid sequential atomic emission spectrometry with the ‘Zig Zag’ acquisition system (ISA Jobin Yvon, France) in the case of the inductively coupled plasma is described. The ‘Zig Zag’ system is shown to enable the application of spectral stripping, as both the reproducibility of the intensities measured, for several lines of Fe, and the reproducibilty of the wavelength positioning (errors below 3 pm in the 2nd order and 5 pm in the 1st order) were found to be high. Using an integration time of only 2.5 ms/point, the precision of the intensities expressed as the relative standard deviation is below 5%. These features are shown to allow spectrum stripping from the contribution of a Zr matrix, which has a rather line-rich atomic emission spectrum. Spectrum stripping was applied in the wavelength range from 237.9 to 241.1 nm, where 10 of the most sensitive emission lines of Fe were found. For sample solutions with 500 mg/l Zr only, 10 mg/l Fe only, 500 mg/l Zr as well as 10 mg/l Fe, and for a blank solution, respectively, five spectral scans were averaged and the averaged spectral scan for a blank solution was subtracted. The spectral scan obtained for a solution containing 500 mg/l Zr only was subtracted from the one obtained for the solution containing both 500 mg/l Zr and 10 mg/l Fe. The result of spectral stripping is comparable to the experimentally obtained spectral scan for the solution containing 10 mg/l Fe only after blank subtraction. The recovery for Fe was found to be 93±2% and is therefore comparable to the one obtained by chemical separation methods using solvent extraction. When using an integration time of 50 ms per measurement point instead of 0.5 ms/point, as it is possible in the case of the ‘Zig Zag’ approach, the detection limit for Fe in the measurement solutions can be improved from 20 down to 3 μg/l, or from 40 to 6 μg/g Zr, respectively.

Amplitude-friendly imaging in complex media may also require accounting for attenuation described by a spatially varying Q-model. Here, we extend the ray-based angle migration to account for Q. Any migration with attenuation compensation needs to handle the inherent signal-to-noise ratio of the data or it may boost noise. We present both the use of a stabilization of the effect of Q in the migration and a data-driven reflection enhancement by weighting the summation in the migration to specular events. Both are important in controlling the noise.

This paper is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta, Part B (SAB). This hardcopy text, comprising the main body and an appendix, is accompanied by a disk with programs, data files and a brief manual. The main body discusses purpose, design principle and usage of the computer software for modelling the evaporation behaviour of particles in inductively coupled plasma atomic emission spectrometry (ICP-AES). Computer software has been developed in FORTRAN 77 language in order to simulate the evaporation behaviour of particles of refractory materials such as encountered in the analysis of advanced ceramic powders by slurry nebulization inductively coupled argon plasma atomic spectrometry. The program simulates the evaporation of single particles in the inductively coupled plasma and also enable it to calculate on the base of a given particle size distribution the evaporation behaviour of all the particles contained in a sample. In a so-called “intensity concept”, the intensity is calculated as a function of the observation height in order to determine recovery rates for slurries compared with aqueous solutions. This yields a quick insight whether a calibration with aqueous solutions can be used for analysis of slurries of a given powder by slurry nebulization ICP-AES and also is a help in determining the optimal parameters for analyses of powders by means of slurry nebulization ICP-AES. Applications for the evaporation of Al 2 O 3 and SiC powders document the usefulness of the model for the case of a 1.5 kW argon ICP of which the temperature at 8 mm above the load coil has been determined to be 6100 K. The model predicts the maximum particle size for SiC and Al 2 O 3 that can be transported (10–15 μm) and evaporated for a given efficiency under given experimental conditions. For both Al 2 O 3 and SiC, two ceramic powders of different grain size were investigated. The median particle sizes cover the range typical of ceramic powders. Investigations were made for SiC A 10 (median particle size 2.2 μm), SiC F1200 (4.3 μm) and Al 2 O 3 AKP 30 ( μ m) and Al 2 O 3 Cilas 715 (3.0 μm), respectively, in which particles with diameters of up to 23 μm still are found.

Rapid sequential atomic emission spectrometry with the IMAGE system (ISA Jobin Yvon, Longjumeau, France) in combination with an inductively coupled plasma is described. As analytical figures of merit the precision, limits of detection, spectral resolution and linear dynamic range are discussed in comparison with those of conventional sequential spectrometry. The IMAGE system is shown to allow a registration of the emission spectrum in the wavelength range 165–750 nm in less than 2 min (compared with several hours when applying conventional slew times and scanning at similarly high resolution) without any loss of spectral resolution. Thus, spectral interferences can easily be detected, suitable lines for quantitative determinations can be selected and standard solutions used for calibration could even be adapted ‘on-line’ to the matrix of the sample to be analyzed. However, a deterioration in the detection limits by a factor of 3–10 has to be taken into account. Results are given for several means of sample introduction. It is shown for a solution of 2 mg l–1 Fe in the presence of a 5000-fold excess of Zr that the method can be used for accurate quantitative determinations at the minor and trace element concentration level in work with solutions and slurries. For laser ablation coupled to ICP-OES of briquetted ZrO2 ceramic powders, the potential for qualitative multi-element survey analysis from a large number of laser impacts is shown.

We present a solution to allow integration of geological insight in the velocity model building, testing the impact of different geological scenarios on the resulting image. The solution consists of a seamless system of flexible model editing and fast prestack migrations. This creates an arena for the geophysicist and the geologist to work together. The enabling component is the interactivity, or the ability to work in the same time frame. This means that several complete geological scenarios, represented as velocity models, can be created and resulting image analyzed during the course of a working day.

Building a salt velocity model is usually an iterative process. Based on seismic character alone there is often a large range of alternative salt models. The iterations can often take on the form of trial-and-error in trying to understand the geologically most likely model. We present a solution to allow integration of geological insight in the velocity model building. The solution consists of a seamless system of flexible model editing and fast migrations. This creates an arena for the geophysicist and the geologist to work together. The crucial component is the interactivity, or the ability to work in the same time frame. This means that several salt models can be created and resulting images analyzed during the course of a working day.

Results on electromagnetic form factors of the nucleon and photon transition form factors of non-strange baryon resonances calculated in a relativistically covariant quark model based on the Bethe-Salpeter equation are presented. The relevance of the instanton-induced quark interaction on these properties is discussed.

We present the use of angle migration or generalized Radon transform (GRT) in 4D imaging. Illumination compensation at the imaging point allows stable imaging of 4D effects given data of equivalent coverage, but without any regularization or 4D binning in the preprocessing. The ability to fully control imaging contributions enables reducing noise contributions. Here, we show first results of using the algorithm for 4D purposes on synthetic and field data.

For several years, tracheal gland cells have been cultured from different animal species, such as the cat (1), cow (2), and ferret (3). There are dlffer ences, however, in the structure and function of the various animal airways, rendering it difficult to extrapolate to humans. In this chapter, the author describes techniques that facilitate the isolation and culture of tracheal gland cells from humans. These techniques allow high reproducibility, optimal cell isolation, and high phenotypic expression, rendering them appropriate for physiological, pharmacological, and biomedical applications.

This paper describes the East German energy sector and its fate after 1990 with particular emphasis on environmental regulation. Unification turned the enlarged Federal Republic of Germany into a rather dirty country and the world's largest producer of brown coal. While primary energy demand in the West rose by almost 10% in 1991, it fell by about 30% in the East and demand was not expected to return to its pre-Wende (U-turn) value until 2005, in spite of advancing privatization and energy price rises to Western values. In late 1991 Esso expected a permanent decline. During 1991 upheavals and uncertainty dominated life in the former German Democratic Republic; by mid-1992, bitterness described the public mood and first signs of a political separatism could be detected. Optimists had hoped that by the year 2000 at the latest, a planned economy devoted to energy self-sufficiency would have become fully integrated into the West with the achievement of similar living standards. Evidence so far supports the pessimists who observe rapid industrial decline and the relative impoverishment of large sectors of the population, possibly leading to political destabilization. The ability of market forces to transform communism is being tested, as is the ability of society to shed its socialist inheritance without psychological disintegration. The process itself is as bewildering as it is fascinating. Its outcomes surely hold lessons for developments elsewhere, especially for the role of government in transitional economies and the capacity of environmental regulation to facilitate macroeconomic change.

The true-amplitude angle migration works directly in angle/azimuth domain at the imaging point allowing complete control of imaging contributions. Limiting these contributions to specular contributions allows speed-up of migration, but more importantly it allows reduction and better control of noise. Here, we demonstrate our implementation of the algorithm on field data from a noise prone area offshore Norway. By limiting the contributions around the structural dips, hence reducing the noise, we are able with higher confidence to image the amplitude anomalies in this exploration example.

Picking in seismic traces can be combined with operations like frequency filtering and Hilbert transforming. The basic formula simply is an inner product of the vector of original data and an operation-specific interpolating function that is derived from

We are presenting results from a true-amplitude prestack depth migration in the angle/azimuth domain. The implementation is based on the generalized Radon transform. Working directly in the angle/azimuth domain means that we do not need to calculate any Beylkin-determinant, and multi-valued traveltimes, in the presence of caustics, are naturally unfolded allowing for true-amplitude results even beneath a complex overburden. Such an implementation has until recently been considered unfeasible due to the computational complexity for large 3D volume migration. Our implementation is made possible through a massively parallel implementation with fast access to large dataset.

We calculate semileptonic decays of light and heavy baryons in a relativistically covariant constituent quark model. The model is based on the Bethe-Salpeter-equation in instantaneous approximation. It generates satisfactory mass spectra for mesons and baryons up to the highest observable energies. Without introducing additional free parameters we compute on this basis helicity amplitudes of electronic and muonic semileptonic decays of baryons. We thus obtain form factor ratios and decay rates in good agreement with experiment., 8 pages, 10 figures, 2 tables, typos removed

We calculate mass spectra of charmed baryons within a relativistically covariant quark model based on the Bethe-Salpeter-equation in instantaneous approximation. Interactions are given by a linearly rising three-body confinement potential and a flavor dependent two-body force derived from QCD instanton effects. This model has already been successfully applied to the calculation of light flavor baryon spectra and is now extended to heavy baryons. Within the same framework we compare the results to those obtained with the more conventional one-gluon-exchange potential., Comment: 13 pages, 7 figures, 7 tables, typos removed

The Lorentz-covariant Bethe-Salpeter model developed by the Bonn group is used to calculate the electromagnetic form factors of the ground-state hyperons and the helicity amplitudes of the hyperon resonances. The computed magnetic moments of the ground- state hyperons agree well with the experimental values and the magnetic form factors exhibit a dipole Q2-dependence. The photo-amplitude of the Λ(1405) is badly reproduced, which hints at the special structure of this resonance.

The relativistically covariant constituent quark model developed by the Bonn group is used to compute the EM form factors of strange baryons. We present form-factor results for the ground-state and some excited hyperons. The computed magnetic moments agree well with the experimental values and the magnetic form factors follow a dipole $Q^2$ dependence., Comment: 4 pages, 1 figure, Proceedings for NSTAR '04 conference in Grenoble, France, March 24-27, 2004 (World Scientific)

For several years, tracheal gland cells have been cultured from different animal species, such as the cat (1), cow (2), and ferret (3). There are dlffer ences, however, in the structure and function of the various animal airways, rendering it difficult to extrapolate to humans. In this chapter, the author describes techniques that facilitate the isolation and culture of tracheal gland cells from humans. These techniques allow high reproducibility, optimal cell isolation, and high phenotypic expression, rendering them appropriate for physiological, pharmacological, and biomedical applications.

Predictions for the electromagnetic form factors of the Lambda$, Sigma and Xi hyperons are presented. The numerical calculations are performed within the framework of the fully relativistic constituent-quark model developed by the Bonn group. The computed magnetic moments compare favorably with the experimentally known values. Most magnetic form factors G_M(Q^2) can be parametrized in terms of a dipole with cutoff masses ranging from 0.79 to 1.14 GeV., Comment: 15 pages, 8 figures, 3 tables, submitted to Eur. Phys. J. A

In this paper, we present results on strong two-body decay widths of light $q\bar q$ mesons calculated in a covariant quark model. The model is based on the Bethe-Salpeter equation in its instantaneous approximation and has already been used for computing the complete meson mass spectrum and many electroweak decay observables. Our approach relies on the use of a phenomenological confinement potential with an appropriate spinorial Dirac structure and 't Hooft's instanton--induced interaction as a residual force for pseudoscalar and scalar mesons. The transition matrix element for the decay of one initial meson into two final mesons is evaluated in lowest order by considering conventional decays via quark loops as well as Zweig rule violating instanton--induced decays generated by the six--quark vertex of 't Hooft's interaction; the latter mechanism only contributes if all mesons in the decay have zero total angular momentum. We show that the interference of both decay mechanisms plays an important role in the description of the partial widths of scalar and pseudoscalar mesons., Comment: 35 pages, 7 figures

Weak decays of heavy mesons will be investigated in the framework of a covariant quark model, which is based on the Bethe‐Salpeter equation in instantaneous approximation. Apart from a phenomenological confinement potential, a residual interaction induced by instantons is adopted. An appropiate extension allows a unified description of light and heavy systems. In this model semileptonic and non‐leptonic decays of heavy‐light mesons are evaluated.

Within the framework of the instantaneous Bethe-Salpeter equation, we present a detailed analysis of light meson spectra with respect to various parameterizations of confinement in Dirac space. Assuming a linearly rising quark-antiquark potential, we investigate two different spinorial forms (Dirac structures), namely ${1/2}(\Id\otimes\Id - \gamma^0\otimes\gamma^0)$ as well as the $U_A(1)$-invariant combination ${1/2}(\Id\otimes\Id - \gamma^5\otimes\gamma^5 - \gamma^\mu\otimes\gamma_\mu)$, both providing a good description of the ground state Regge trajectories up to highest observed angular momenta. Whereas the first structure is slightly prefered concerning numerous meson decay properties (see \cite{pap41}), we find the $U_A(1)$-invariant force to be much more appropriate for the description of a multitude of higher mass resonances discovered in the data of the {\sc Crystal Barrel} collaboration during the last few years. Furthermore, this confinement structure has the remarkable feature to yield a linear dependence of masses on their radial excitation number. For many experimental resonances such a trajectory-like behaviour was observed by Anisovich {\it et al.} We can confirm that almost the same slope occurs for all trajectories. Adding the $U_A(1)$-breaking instanton induced 't Hooft interaction we can compute the pseudoscalar mass splittings with both Dirac structures and for the scalar mesons a natural mechanism of flavour mixing is achieved. [...], Comment: 32 pages including 19 figures and 3 tables; submitted to Eur. Phys. A

To better understand the dynamics of the cellular processes involved in early neocortical development, we studied the neuritic differentiation and synaptogenesis of dispersed neurons grown in serum-free cultures under a wide variety of culture conditions. Microtubule-associated protein (MAP2), phosphorylated neurofilament (SMI 31) and synaptophysin immunocytochemistry was complemented with time-lapse studies. During the first week in vitro dissociated cortical neurons developed from roundish cells without processes to neurons with axons and differentiated dendrites, going through five distinct phases. The sequence of these phases was unaltered in a wide range of culturing methods, but the timing of the steps varied among cultures started with different cell densities. Synaptic terminals were first observed after 3-4 days in vitro, coincident with the beginning of dendritic differentiation. Synaptogenesis progressed at least until the end of the third week in vitro, despite a decline in cell density during the second week in vitro. The process of cellular differentiation of cerebral cortical neurons in vitro resembled the development of these cells in the intact tissue, suggesting that organized cell migration is not a prerequisite for the differentiation of single cortical neurons.

The effects of ATP and UTP on intracellular Ca2+ levels and on the secretion of the bronchial inhibitor and high-molecular-weight glycoproteins were studied in cultures of human bronchotracheal gland cells. ATP, adenosine 5'-O-(3-thiotriphosphate) (ATP gamma S), and UTP increased intracellular Ca2+ levels in a manner that was partially dependent on the presence of extracellular Ca2+. Other nucleotides (ADP, alpha,beta-methylene ATP, beta,gamma-methylene ATP, and 2-methylthio ATP) and adenosine were ineffective, thus suggesting the presence of a “nucleotide” receptor specific for ATP and UTP. At concentrations similar to those that raised intracellular Ca2+ concentration, ATP, UTP, and ATP gamma S stimulate the secretion of the bronchial inhibitor. ATP and UTP also increase the production of sulfated high-molecular-weight glycoproteins. These results indicate the presence in human tracheal gland cells of a nucleotide receptor that mediates intracellular Ca2+ mobilization and controls the secretion of macromolecules.

The radiograph in Q-fever pneumonia and the course of Q-fever was reported with the help of 12 clinically examined cases. Q-fever pneumonia is not to be diffrentiated from viral pneumonia or mycoplasmal pneumonia. A chronic course with residual infiltrates which lasts as long as two or three months is, however, more frequent in Q-fever pneumonia. According to our observations, a correlation seems to exist between the severity of the clinical symptoms, the extent of the pulmonary infiltrate and the level of the titer of the complement fixation.

Longitudinal radiographic evaluation of skeletal maturation in 28 rhesus monkeys demonstrated that the majority of appendicular ossification centers were identified radiographically by 175 days of age and that physeal union was complete by 7.3 years in males and 7.2 years in females.

Vergleichsanalysen verschiedener Umweltprodukte auf ihren Gehalt an radioaktiven Nukliden zeigen, das die Ubereinstimmung zwischen den Ergebnissen zahlreicher Laboratorien in den meisten Fallen sehr zu wunschen ubrig last. Mit regelmasig durchgefuhrten derartigen Vergleichsreihen ergibt sich die Moglichkeit, nicht nur die Reproduzierbarkeit, sondern auch die Genauigkeit durch Verbesserung der Arbeitsmethoden zu erhohen. Das Vergleichsprogramm 1966 der IAEA erstreckt sich ebenfalls auf Nuklide, die bei wissenschaftlichen Untersuchungen verwendet werden und inaktive Nuklide, fur die die Anwendung der Aktivierungsanalyse interessant ist.