Showing papers by "University of Hamburg published in 1978"
TL;DR: In this paper, parity violating asymmetries in the inelastic scattering of longitudinally polarized electrons from deuterium and hydrogen were measured, and the asymmetry is (−9.5 × 10−5)Q2 with statistical and systematic uncertainties each about 10%.
455 citations
TL;DR: In this article, a formulation of gauge theories with an extended supersymmetry for N = 2 is given in terms of superfields and component fields as well as the Lagrangian.
373 citations
TL;DR: In this article, a second order theoretical approximation of the dispersion relation of surface plasma oscillations (SPO's) at coated silver surfaces was developed, showing that the influence of thin coatings on the SPO properties is explained by the change of the field distribution of the surface contamination.
352 citations
TL;DR: In this article, it was shown that finite energy solutions of the field equations of the non-linear σ-model decay asymptotically into massless lumps.
318 citations
TL;DR: In this article, a review of known and unknown aspects of wet and dry fluxes of atmospheric trace constituents past the air-sea interface is presented, and a resistance model for dry deposition illustrates that the rate-limiting stage of dry removal can occur in different layers depending on atmospheric and oceanic conditions and on properties of the pollutants.
283 citations
TL;DR: In this article, the SU(4) supersymmetric gauge theory with central charges was studied and it was shown that the theory has a larger SU (4) invariance once the equations of motion are used.
239 citations
TL;DR: In this paper, the authors investigated the applicability of the two-frequency microwave technique at slant incidence for the measurement of ocean wave spectra, first proposed by Rucket et al. (1972), with respect to its applicability in aircraft and space vehicles.
Abstract: The two-frequency microwave technique at slanting incidence for the measurement of ocean wave spectra, first proposed by Rucket al. (1972), is investigated in more detail with respect to its applicability in aircraft and space vehicles. It is shown that by carrying out signal processing in the frequency domain the system-inherent signal-to-noise ratio can be increased considerably, making the operation of the system from air- and space-borne platforms feasible.
237 citations
TL;DR: In this paper, the Bianchi identities for gauge theories in an extended flat superspace are evaluated, and they permit better understanding of possible constraint equations, and can serve as a starting point for further constructions of gauge theories with extended supersymmetry.
202 citations
TL;DR: The early neurogenesis of rat neocortex was analysed by means of light and electron microscopic autoradiography and found that the very first preneurons originate probably as early as ED 11, confirming the hypothesis of a dual origin of the mammalian neocortex.
Abstract: The early neurogenesis of rat neocortex was analysed by means of light and electron microscopic autoradiography. It was found that the very first preneurons originate probably as early as ED 11. They are the horizontal cells of Cajal-Retzius. The peak of their formation is on ED 13 (surface index estimated on ED 17 after injection of 3H-thymidine on ED 13:21, after injection on ED 12:4, after injection on ED 15:5), whereas no Cajal-Retzius cells could be found to have originated after ED 15. These cells are the developmentally most advanced of the neocortex. The cells second in date of origin and maturation are preneurons which presumably correspond to the presumptive neurons of Layer VII (VI b), and begin to originate on ED 12. The end of their formation could not be defined owing to a lack of ultrastructural differences to other, younger preneurons in later gestational stages. These two cell types are the first cellular components of the primordial plexiform layer (Marin-Padilla, 1978) or pallial anlage (Rickmann, 1977), demonstrating an outside-in gradient within this layer, and are separated by the formation of the cortical plate. This could be proven by their simultaneous labelling above and below the cortical plate after administration of 3H-thymidine before ED 15. These results confirm the hypothesis of a dual origin of the mammalian neocortex (Marin-Padilla, 1978).
188 citations
17 Jul 1978
TL;DR: A self-modifying net is a Petri net, which is able to modify its own firing rules, which has been used to simulate national economic systems /Fu/.
Abstract: In this paper we study a natural extension of Petri nets and discuss the usefullness of this approach. Like ordinary Petri nets self-modifying nets are defined as multigraphs having edges of the form O q >I and I q >O " Circles denote places and bars represent transitions. But in opposition to ordinary Petri nets q may be either the number I or an arbitrary place p of the net. If q = I, as in the case of a Petri net, firing the transition means~ that one token has to be moved from or to the place. But if q is a place p, then the number of tokens to be moved equals the actual number of tokens in p and thus depends on the actual marking. If for an actual marking M we define n := IF qEP THEN M(q) ELSE q and substitute q by n, we obtain a Petri net and the firing rule for that marking is defined as usually. Therefore a self-modifying net is a Petri net, which is able to modify its own firing rules. Bounded models of such nets have been used to simulate national economic systems /Fu/.
181 citations
TL;DR: The 2,2′-bicinchoninate reagent described previously for sugar detection in liquid chromatography with ethanol as eluent was adapted to an automated borate complex ion-exchange chromatographic system, in which orcinol-sulphuric acid was used for detection as mentioned in this paper.
TL;DR: In this article, a deep seismic soundings performed in Greece in the years 1971-1974 revealed that the area of Greece consists of continental crust of variable thickness, and that the crust of the west Hellenic chains is 46 km thick and covered by sediments which locally exceed 10 km.
TL;DR: In this article, an experiment using the PLUTO detector has observed the formation of a narrow, high mass, resonance in e+e− annihilations at the DORIS storage ring.
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TL;DR: In this paper, the authors describe the analysis of current and temperature cross spectra from the trimoored internal wave experiment Iwex and present a spectral model for the fluctuations in the internal wave range.
Abstract: We describe the analysis of current and temperature cross spectra from the trimoored internal wave experiment Iwex and present a spectral model for the fluctuations in the internal wave range. The model consists of internal waves contaminated by temperature and current fine structure and by current noise. Except for the inertial and tidal frequencies the distribution of wave energy is vertically symmetric and horizontally isotropic. The wave number spectrum is characterized by a bandwidth of about 20–10 equivalent modes (decreasing with frequency), by a power law at high wave numbers, and by a sharp peak at low wave numbers. The general features of this spectrum agree fairly well with the one proposed by Garrett and Munk (1975). The contaminations increase with frequency. Contamination by temperature fine structure is confirmed by independent measurements. The Iwex spectral model provides a consistent description of all observed cross spectra.
TL;DR: Das Addukt Phenyllithium wurde dargestellt und seine Kristallstruktur rontgenographisch ermittelt (R = 0.066, 1595 signifikante Reflexe) as mentioned in this paper.
Abstract: Das Addukt Phenyllithium · N, N, N′, N′-Tetramethylethylendiamin wurde dargestellt und seine Kristallstruktur rontgenographisch ermittelt (R = 0.066, 1595 signifikante Reflexe). Die monokline Elementarzelle (Raumgruppe C2/c) enthalt 4 Molekule eines Dimeren. Ahnlich wie im dimeren Triphenylaluminium sind in jedem Molekul zwei Li-Atome durch zwei Phenyl-Gruppen verbruckt. Durch die Anlagerung eines Diamin-Liganden erreicht jedes Li-Atom vierfache Koordination.
TL;DR: It is suggested that scarring of the exocrine pancreas affects islet composition, probably by impairment of the local circulation and of glucose diffusion, thus leading to reduction of the number and glucose sensitivity of B cells.
Abstract: The endocrine pancreatic tissue from patients with severe primary chronic pancreatitis (n=6), secondary chronic pancreatitis due to duct obstruction by carcinoma (n=6) and non-diabetic, non-pancreatitic controls (n=4) was studied qualitatively and quantitatively using specific immunocytochemistry and electron microscopy. Grouping of variously sized islets in the sclerotic tissue (sclerosis islets), islet neoformation by ductuloinsular proliferation, and intrainsular fibrosis were the main qualitative findings. Immunocytochemical quantitation of the distribution of insulin (B), glucagon (A), somatostatin (D) and pancreatic polypeptide (PP) producing cells revealed a significant relative increase in the number of A cells and a decrease in the number of B cells of the sclerosis islets in primary chronic pancreatitis (B-44.1±9.3%:A-38.3±2.4%:D-8.6±5.1%:PP-4.6±4.1%) as well as in secondary chronic pancreatitis (B-38.0±14.3%:A-38.4±19.0%:D-9.1±5.8%:PP-14.5±23.4%) compared with controls (B-71.1±8.1%:A-24.3±5.5%:D-8.0±2.8%:PP-0.5±0.4%). The number of PP cells was significantly increased in primary chronic pancreatitis only. It is suggested that scarring of the exocrine pancreas affects islet composition, probably by impairment of the local circulation and of glucose diffusion, thus leading to reduction of the number and glucose sensitivity of B cells. The hyperplasia of A and PP cells appears to be a secondary phenomenon due to the loss of B cells.
TL;DR: In this paper, the authors describe the deblocking reactions of the saccharides in the presence of silver perchlorate under mildest conditions, forming predominantly α-glycosides in good yields.
Abstract: 1,6;2,3-Dianhydro-4-O-benzyl-β-D-mannopyranose (1) wird mit Natriumazid zum Derivat 3 der 2-Azido-2-desoxy-D-glucopyranose (11) geoffnet. Die durch saure Acetolyse erhaltliche 1,6-Di-O-acetyl-3,4-di-O-benzyl-Verbindung 10 ist in das α-Bromid 13 uberfuhrbar, das mit Tetraethylammoniumchlorid unter kontrollierten Bedingungen zum β-Chlorid 14 invertiert werden kann. Das Chlorid 14 ist fur selektive α-Glycosid-Synthesen bestens geeingnet. Mit entsprechend blockierten Sacchariden last sich 14 unter mildesten Bedingungen bei Gegenwart von Silberperchlorat in guten Ausbeuten zu Oligosacchariden mit hohen Anteilen an α-Glycosid umsetzen. So liefert 14 mit 17 das Disaccharid 19, mit 20 das Trisaccharid 26 und mit 27 das Tetrasaccharid 34. Die Entblockierung der Saccharide wird beschrieben.
Building Units for Oligosaccharides, IX: Stereoselective Synthesis of α-Glycosidically Linked Di- and Oligosaccharides of 2-Amino-2-deoxy-D-glucopyranose
1,6;2,3-Dianhydro-4-O-benzyl-β-D-mannopyranose (1) reacts with sodium azide to give the derivative 3 of 2-azido-2-deoxy-D-glucopyranose (11). Acid acetolysis of 11 yields the 1,6-di-O-acetyl-3,4-di-O-benzyl derivative 10. This is transformed to the α-bromide 13 which can be inverted under controlled conditions into the β-chloride 14. Compound 14 is most suitable for selective syntheses of α-glycosides. It reacts with partially blocked saccharides in the presence of silver perchlorate under mildest conditions, forming predominantly α-glycosides in good yields. For example, 14 gives with 17 the disaccharide 19, with 20 the trisaccharide 26, and with 27 the tetrasaccharide 34. The deblocking reactions of the saccharides are described.
TL;DR: In this article, the synthesis of 2-azido-2-deoxy- D -gluco- and -D -galactopyranosyl halides is described.
TL;DR: In this paper, an analysis of data taken with the detector PLUTO and the DORIS storage rings was performed to obtain evidence for jet structure in e + e − annihilation with hadrons.
TL;DR: A single-crystal X-ray diffraction study (tetragonal space group 42/n) reveals that the methyllithium tetramers persist and are linked through Li-tmeda-Li bridges as discussed by the authors.
TL;DR: In this article, the initial stages of Al single crystals are studied by soft X-ray photoemission spectroscopy at photon energies hv = 30 eV and 111.13 eV using synchroton radiation.
TL;DR: In this paper, the synthesis of α-Glycosidically linked Di- and Oligosaccharides of 2-Amino-2-deoxy-D-galactopyranose is discussed.
Abstract: Durch Epoxidoffnung von 1,6;2,3-Dianhydro-β-D-talopyranose (1) mit Natriumazid ist das Derivat 3 der 2-Azido-2-desoxy-D-galactose zuganglich, das uber 6 und 9 + 10 in das α-Bromid 13 umgewandelt werden kann. Inversion von 13 mit Tetraethylammoniumchlorid fuhrt zum β-Chlorid 14, das direkt zur selektiven α-Glycosidsynthese geeignet ist: Mit 5 bildet 14 das Disaccharid 15, mit 25 das Disaccharid 26. Beide Verbindungen liefern nach Entblockierung die α-13-verknupften Aminozucker-Disaccharide 20 bzw. 31. Aus 16 + 17 ist das α-Bromid 21 zu gewinnen, das als reaktiver Disaccharid-Synthesebaustein an andere Saccharide anknupfbar ist.
Building Units for Oligosaccharides, XI: Synthesis of α-Glycosidically Linked Di- and Oligosaccharides of 2-Amino-2-deoxy-D-galactopyranose
The reaction of 1,6;2,3-dianhydro-β-D-talopyranose (1) with sodium azide gives the derivative 3 of 2-azido-2-deoxy-D-galactose which can be transformed via6 and 9 + 10 to the α-bromide 13. Inversion of 13 with tetraethylammonium chloride leads to the β-chloride 14 which is suitable for selective syntheses of α-glycosides. Condensation of 14 with 5 gives the disaccharide 15, and with 25 the disaccharide 26 is obtained. Deblocking of these conjugates yields the α-13 linked amino sugar disaccharides 20 and 31, respectively. From 16 + 17 the α-bromide 21 is obtained. This reactive building unit can be linked with other saccharides.
TL;DR: A specific androgen receptor protein was demonstrated in the heart muscle cytosol which was physicochemically identical to the receptor protein described by us for various androgenic target organs.
Abstract: Binding, metabolism, and tissue levels of [3H]5α-androgens were investigated in rat heart muscle. [3H]Testosterone (T) and [3H]5α-dihydrotestosterone (5α-DHT) binding was analyzed in the 100,000 × g cytosol by agargel electrophoresis. In vitro metabolism at 0C of T, 5α-DHT, and 5α-androstane-3α,17β-diol (3α-diol) was investigated in the heart and skeletal muscle by thin layer chromatography. Endogenous T, 5α-DHT, and 3α-diol were extracted from the heart muscle, skeletal muscle, prostate, and plasma and quantified by RIA. The primary findings were the following. 1 A specific androgen receptor protein was demonstrated in the heart muscle cytosol which was physicochemically identical to the receptor protein described by us for various androgenic target organs. 2) The T binding displayed a dissociation constant (Kd) of 1.1 nM, and the maximal binding sites amounted to 2.0 fmol/mg cytosol protein. 3) The heart cytosol of prepuberal rats had the highest and the heart cytosol of uncastrated adult males had the ...
TL;DR: NAD-dependent acetaldehyde dehydrogenase of human tissues was investigated by electrophoresis and enzyme assay and the distribution of various phenotypes of ALDH isozyme sets is presented.
Abstract: NAD-dependent acetaldehyde dehydrogenase (ALDH) of human tissues was investigated by electrophoresis and enzyme assay. ALDH is located mainly in the liver and kidney. The isozymes consist of at least six different components. Five different phenotypes were found in a total of 68 human liver and kidney specimens. It is likely that three isozyme sets are concerned in determining ALDH types. The distribution of various phenotypes of ALDH isozyme sets is presented.
TL;DR: In this paper, a model of non-linear quantum mechanics in which the wave equation satisfies the homogeneity condition (2.1) is discussed, and it is argued that in this model the set of (mixed) states is a simplex.
Abstract: We discuss a model of non linear quantum mechanics in which the wave equation satisfies the homogeneity condition (2.1). It is argued that in this model the set of (mixed) states is a simplex.
TL;DR: The human rete testis was examined with regard to the number and distribution of entrances of seminiferous tubules, the light microscopic topography and details of the passages as revealed by scanning and transmission electron microscopy to be interpreted as a highly complex myoelastic sponge.
Abstract: The human rete testis was examined with regard to 1) the number and distribution of entrances of seminiferous tubules, 2) the light microscopic topography and 3) details of the passages as revealed by scanning and transmission electron microscopy. In a newborn 1474 entrances were counted, approximately 50 % entering from the right and 50 % from the left of the central long axis. Three major subdivisions of the rete were distinguished and described: a septal (or interlobular) part represented by tubuli recti, a tunical (or mediastinal) part which is a true network of channels, and an extratesticular part characterized by dilatations (up to 3 mm wide) which we have called bullae retis. In SEM, cylindrical strands running from wall to wall in the tunical and extratesticular rete spaces are a prominent feature. We have called these chordae retis. They are covered by epithelium and are 5–40 μm wide and 15 to more than 100 μm long. They contain a peculiar tissue consisting of central myoid cells in a fibroelastic matrix. The smaller chordae are avascular. In the light of these findings the rete is interpreted as a highly complex myoelastic sponge. Its function is discussed.
TL;DR: The need for a less generally cytotoxic serotonin neurotoxin was thus clearly evident, and in 1972 Baumgarten and Lachenmayer described the effects of intraventricular administration of 5,7dihydroxytryptamine (5,7-DHT) on central 5-HT neurons by use of the conventional Falck-Hillarp method.
Abstract: The first description of the rather selective reduction in regional brain 5-hydroxytryptamine (5-HT) content after injection of 25-75 pg of 5,6-dihydroxytryptamine (5,6-DHT) into the lateral ventricle of the adult rat was provided by Baumgarten et a1.l in 1971. These results were soon confirmed by two one of which pointed to serious limitations in the applicability of 5,6-DHT as a tool for selective degeneration of serotonin (5-HT) neurons by demonstrating that there was a partial atrophy of the septum and caudate on the injection side.* Electron microscopic findings of Baumgarten et al.4 revealed that, in addition to injuring nonmyelinated presumptive monoaminergic axons and terminals, 5,6-DHT also lesioned glial cells and myelinated fibers in the head of the caudate and the septum on the injection side. The potential of 5,6-DHT to nonselectively damage both catecholamine-containing and serotonin-containing neurons was substantiated by four findings: the reduction of striatal dopamine (DA) and forebrain noradrenaline (NA) content after a high intraventricular dose of 5,6-DHT,2 the destruction of peripheral sympathetic noradrenergic fibers by 5,6-DHT, particularly after prior depletion of NA by reserpine and subsequent inhibition of monoamine oxidase (MAO) ,5 the destruction of subependymally located DA terminals in the head of the left caudate nucleus after left lateral ventricular injections of low to high doses of 5,6-DHT (25-75 pg),s and the destruction of DA-containing axons by small intracerebral injections of 5,6-DHT.7v * The need for a less generally cytotoxic serotonin neurotoxin was thus clearly evident, and in 1972 Baumgarten and Lachenmayer described the effects of intraventricular administration of 5,7dihydroxytryptamine (5,7-DHT) on central 5-HT neurons by use of the conventional Falck-Hillarp method. This dihydroxyindoleamine appears to have
TL;DR: The total cross section for e + e − annihilation into hadronic final states between 3.6 and 5.2 GeV was measured by the nonmagnetic inner detector of DASP, which has similar trigger and detection efficiencies for photons and charged particles as discussed by the authors.
TL;DR: In this paper, the Auger multiplet structure is shifted to higher kinetic energies at the resonance line and new lines appear which can be assigned to shake-up processes in the ionization process.
Abstract: The ${N}_{4,5}{O}_{2,3}{O}_{2,3}$ Auger spectra from Xe and the ${M}_{4,5}{N}_{2,3}{N}_{2,3}$ Auger spectra from Kr are investigated for different photon energies around threshold ionization. When exciting at the resonance line ($4{d}^{9}5{s}^{2}5{p}^{6}6p$ for Xe and $3{d}^{9}4{s}^{2}4{p}^{6}5p$ for Kr) we observe the usual Auger multiplet structure to be shifted to higher kinetic energies. Additionally, new lines appear which can be assigned to shake-up processes in the ${\mathrm{Xe}}^{+}$ and ${\mathrm{Kr}}^{+}$ ions.