Showing papers by "University of Bonn published in 1976"

Intersection numbers of curves on Hilbert modular surfaces and modular forms of Nebentypus

Abstract: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 57 Chapter 1 : The Intersection Behaviour of the Curves T N . . . . . . 60 1.1. Special Points . . . . . . . . . . . . . . . . . . . . . 60 1.2. Modules in Imaginary Quadratic Fields . . . . . . . . . . 68 1.3. The Transversal Intersections of the Curves T N . . . . . . . 74 1.4. Contributions from the Cusps . . . . . . . . . . . . . . 78 1.5. Self-Intersections . . . . . . . . . . . . . . . . . . . . 82 Chapter 2: Modular Forms Whose Fourier Coefficients Involve Class Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . 87 2.1. The Modular Form ~oo(z ) . . . . . . . . . . . . . . . . 88 2.2. The Eisenstein Series of Weight 3 . . . . . . . . . . . . . 91 2.3. A Theta-Series Attached to an Indefinite Quadratic Form . . 96 2.4. Proof of Theorem 1 . . . . . . . . . . . . . . . . . . . I00 Chapter 3: Modular Forms with Intersection Numbers as Fourier Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . 103 3.1. Modular Forms of Nebentypus and the Homology of the Hilbert Modular Surface . . . . . . . . . . . . . . . . . . . . t03 3.2. The Relationship to the Doi-Naganuma Mapping . . . . . 108 References . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Physiological disposition of verapamil in man.

Abstract: 14C-D,L-verapamil was administered intravenously (10 mg) and orally (80 mg) to five volunteer patients. Plasma concentrations of verapamil, which were determined by mass fragmentography, declined bi-exponentially with half-lives of the chi-phase ranging from 18 to 35 min and of the beta-phase from 170 to 440 min. The apparent volume of distribution ranged from 270 to 460 litre and plasma clearance from 730 to 1980 ml/min. Following oral administration absorption was almost complete as judged from the area under the curve (AUC) of 14C-activity and cumulative urinary excretion of 14C. After intravenous infusion of verapamil about 80% of the radioactivity administered could be recovered in urine and faeces within 5 d. Despite its almost complete absorption after oral administration verapamil was shown to undergo extensive first pass metabolism as the bioavailability was only 10 to 22%. Rapid biotransformation had occurred as only a small percentage of AUC of 14C was seen to correspond to unchanged verapamil after both intravenous and oral administration.

Cytoplasmic actomyosin fibrils in tissue culture cells: direct proof of contractility by visualization of ATP-induced contraction in fibrils isolated by laser micro-beam dissection.

Abstract: A special cell line derived from a rat mammary adenocarcinoma (RMCD cells) displays a distinct pattern of actomyosin fibrils (AM fibrils) visible with phase contrast, Nomarski interference and polarized light optics. It was shown that the cytoplasmic AM fibrils are arranged as bundles of highly parallel F-actin filaments. The chemical nature of the filaments was identified by incubation with heavy meromyosin from rabbit skeletal muscle. These cytoplasmic actomyosin fibrils actively contract under isotonic conditions. This was shown by contraction experiments under polarized light optics, by cinematographic analysis and by direct proof of the contractility of AM fibrils isolated by laser micro-dissection. Thus, cytoplasmic AM fibrils can be assumed to represent structures essential for motive force generation in contraction processes in non-muscle cells.

Sterility in tsetse flies (Glossina morsitans Westwood) caused by loss of symbionts

Abstract: Tsetse flies fed on blood containing oxytetracycline, sulphaquinoxaline or lysozyme do not reproduce. It could be proved that primarily the symbionts in flies are damaged, which secondarily leads to sterility.

Cell surgery by laser micro-dissection: a preparative method

Abstract: A new UV-laser device is introduced as a micro-manipulator and micro-dissection apparatus for experimental cell research. High energy irradiation is produced by a quasi-continuous N2-laser. The laser micro-beam can be focused to a minimal diameter of 0-75 mum. The micro-laser can be used for cutting and, hence, as a micro-surgical instrument at the level of cellular organelles. Cytoplasmic actomyosin fibrils (AM fibrils) from tissue culture cells (RMCD-cells) are isolated from the surrounding ground cytoplasm. It is shown that the contractile proteins are not damaged by the laser dissection method to an extent that would prevent their normal function, e.g. contraction.

Ligandstruktur und Komplexierung, V. Neue Kronenäther und ihre Alkalimetallion‐Komplexe

Abstract: Neue cyclische, neutrale Liganden unterschiedlicher Ringgrose und Flexibilitat mit Kronenather-Struktur werden synthetisiert. Auser 5 Sauerstoffatomen dient eine variierte intraanulare Gruppe (Pyridinstickstoff, Pyridin-N-oxid-Sauerstoff, OCH3 NO2, SOCH3, F) als Donorzentrum. Chirale Kronenather entstehen durch Einbau von Sulfoxidfunktionen oder von Biphenyleinheiten. Das Komplexierungs-und Phasentransfer-Verhalten der neuen Liganden werden nach verschiedenen Methoden gepruft und die Ergebnisse in Abhangigkeit von der Ligandenstruktur (Stereochemie)diskutiert. Kristalline, stochiometrisch zusammengesetzte Komplexe mit einer Reihe von Salzen mit Alkali-, NH4 und Erdalkalimetallionen sowie Ni2+, CO2+Ag+, Hg2+, Cu2+, Cu2+, Fe2+ und Pr3+, Nd3+ werden isoliert. Die Anderung der spektroskopischen Eigenschaften durch die Komplexbildung wird untersucht. Bei der Bildung des NaSCN-Komplexes der Biphenylverbindung 6 beobachtet man im 1H-NMR-Spektrum eine Aufspaltung der Benzylprotonen zum AB-System. Einige neue schwefel-und stickstoffhaltige Kronenather verschiedener Ringgrose werden zu Vergleichen herangezogen.

Zero-field hyperfine structure measurements of the metastable states 3 d 2 4 s 4 F 3/2, 9/2 of 45 Sc using laser-fluorescence atomic-beam-magnetic-resonance technique

Abstract: In an atomic beam experiment we measured the hyperfine structure (hfs) of the metastable states 3d 2 4s 4 F 3/2,9/2 of Scandium, which were populated by electron impact. A single mode cw dye laser was used to create a population difference between neighbouring hfs states by optical pumping. Rf transitions between these states, equalizing the population numbers, could then be detected by repeating the optical pumping experiment and looking for the laser induced fluorescent light. The following constants of the magnetic dipole and electric quadrupole interactions have been obtained by this method:A 3/2=−158.513(3)MHzB 3/2=−5.19(2)MHzA 9/2=285.967(9)MHzB 9/2=−15.46(70)MHz From these constants and the corresponding values forJ=5/2, 7/2, as measured by [1], the following parameters can be calculated: 〈r −3〉 01 =0.911(4)a 0 −3 〈r −3〉 12 =2.395 (62)a 0 −3 and:α=〈r −3〉 01 /〈r −3〉 12 =0.38(1).

Transformation of cytoplasmic actin. Importance for the organization of the contractile gel reticulum and the contraction--relasation cycle of cytoplasmic actomyosin.

Abstract: (1) Within the low viscous flowing endoplasm of Physarum polycephalum a considerable amount of actin is in the non-filamentous state. This can be demonstrated by applying poly-L-lysin to surface spreads of native protoplasm. (2) It has been shown that in protoplasmic drops the endoplasm-ectoplasm transformation is accompanied by an actin polymerization from the non-filamentous state to F-actin. (3) The actual state of the labile G-F-actin equilibrium determines the varying consistency (viscosity) of the cytoplasm. (4) Increasing viscosity can be interpreted as being brought about by a) shifting of the G-F-actin equilibrium to the filamentous side, and (b) increased myosin-mediated binding sites between actin filaments. (5) Polymerization and depolymerization processes are involved in the rhythmically occurring contraction-relaxation cycle of cytoplasmic actomyosin in Physarum. (6) Cytoplasmic actin and myosin represent the architectural proteins of the contractile gel reticulum in eukaryotic cells. (7) The importance of the regulation of actin polymerization as a basic control mechanism of the eukaryotic cell is discussed.

Drug Protein Binding and the Nephrotic Syndrome

Abstract: A reduction in plasma albumin concentration, as seen in patients with the nephrotic syndrome, is usually associated with a decrease in plasma protein binding of highly bound drugs. Therefore, the fraction of the unbound drug increases, but the absolute free concentration remains essentially unchanged due to a compensatory reduction in the steady state total plasma concentration. With phenytoin, protein binding and plasma albumin concentration are closely related, so that the degree of binding can be estimated without specific binding techniques. To be able to correctly interprete plasma levels the degree of protein binding should be known, since a reduced total concentration may be fully effective, if the free drug fraction is increased in hypoalbuminaemic patients. Although the mean steady state plasma concentration of highly bound drugs is not affected in the nephrotic syndrome, a greater fluctuation of the unbound level is observed between doses, offering a possible explanation for the increased incidence of toxicity in hypoalbuminaemic patients. As a consequence, shorter dosing intervals of these drugs seems to be advisable, rather than a reduction in the total daily dose. Reduced protein binding is accompanied by an increase in the total plasma clearance which is a function of the elimination rate constant and the volume of distribution.

Drug metabolism in thyroid disease

Abstract: Thyroid dysfunction can influence the physiological disposition of drugs. Depending on the pharmacokinetic properties of the individual drug, changes in the rate of metabolism ranging from profound to moderate or negligible have been observed. Since renal function is also influenced by thyroid disease, changes in renal elimination of drugs which are excreted in the urine mainly as unchanged drugs have to be considered as another reason for altered drugs disposition in thyroid disease. In patients with thyrotoxicosis lower, and in patients with myxoedema, higher, digitalis plasma levels have been observed. The altered disposition of cardiac glycosides in thyroid dysfunction can be attributed to changes in renal elimination and metabolism. These findings may be the kinetic correlate for the clinical observation that larger than the usual dose of digitalis is required in thyrotoxic patients and lower in hypothyroid patients. Antipyrene half-lives are very much shortened during hyperthyroidism and prolonged appreciably during hypothyroidism. The alterations in the disposition of these drugs seen during thyroid dysfunction can be ascribed to changes in its rate of metabolism which is controlled by the levels of circulating thyroid hormones. N-demethylation of aminopyrine is depressed both in hyper- and hypothyroid patients as compared with euthyroid subjects. Changes in the half-life of this drug were observed only during hypothyroidism. The physiological disposition of the antithyroid drug propylthiouracil is not changed during thyrotoxicosis. A decrease in plasma half-life of methimazole is however, observed during hyperthyroidism, whereas in hypothyroid patients half-life is increased. The few data available so far do not allow general prediction of how thyroid disease could alter drug metabolism in man.

Der Umsatz von Pflanzenwurzeln im Laufe der Vegetationsperiode und dessen Beitrag zur „Bodenatmung”︁

Abstract: The Turnover of Plant Roots during the Growth Period and its Influence on “Soll Respiration” Mustard and wheat plants were grown under 14CO2, their roots being tightly separated from the shoot sphere. Root formation, root respiration, and root decomposition could thus be followed during the plant development by radiometric methods. The total quantity of organic root matter in soil at harvest time turned out to be 20–50% larger than the amount of root residues as determined by ordinary washing procedures. Depending on the plant and duration of the experiment, an additional amount of up to three times more than this remaining root carbon was already mineralized during the vegetation period. Only one fifth of this 14CO2-production could be attributed to the respiration of living root tissue, all the remainder seemed to be due to the microbial decomposition of dead roots, root residues and root excretions. Root respiration and root decomposition together produced almost four fifths of the total evolving CO2-quantity, whilst the contribution from soil organic matter breakdown did not exceed one fourth of it. According to these data, the total rhizo-deposition amounts to 3–4 times as much organic substance than what can be found as root residues at harvest time. This rich supply of readily decomposable organic matter leads to a most intensive turnover in the rhizosphere, which should be of considerable influence on the dynamic processes in soil.

Marine sponges as habitats of anaerobic phototrophic bacteria.

Abstract: Enrichment cultures were prepared with different media for phototrophic bacteria from four species of marine sponges, collected from oxic coastal waters near Split (Yugoslavia). We obtained pure cultures of six strains ofChromatiaceae and two strains ofRhodospirillaceae by agar shake dilution. TheRhodospirillaceae were identified asRhodopseudomonas sulfidophila and a marine form ofRhodopseudomonas palustris. TheChromatiaceae were identified asChromatium vinosum, Chromatium gracile, Chromatium minutissimum. Ectothiorhodospira mobilis, and a Chromatium species, which in some respects resemblesChromatium minus. The occurrence of strictly anaerobic phototrophic bacteria in aerobic sponges is discussed with respect to nutrition and possible syntrophism.

Ab initio configuration interaction calculations for the electronic spectrum of hydrogen sulfide

Abstract: A series of ab initio SCF and CI calculations using a moderately large AO basis including various polarization and Rydberg-type functions is carried out to investigate the ground and excited electronic states of hydrogen sulfide The first rather broad feature found in the 40 000 to 60 000 cm −1 region of the H 2 S spectrum is thereby assigned as a strong Rydberg 2b 1 →4s transition (calculated Δ E is 613 eV, very close to the experimental band maximum) overlapping with a much more valence-like 2b 1 →3d xz system (where 3d xz is the component lying in the H 2 S plane with the same symmetry as an out-of-phase combination of H 1s AOs) The higher-lying 2b 1 →4p Rydberg transitions are assigned to the extremely sharp ,(and possibly ) absorption systems (Herzberg notation) respectively, in agreement with Robin's interpretation; theband is shown to arise from 2b 1 →3da 1 transitions while theandspecies are believed to involve the corresponding (2b 1 , 4d) excitations The discrepancies between calculation and experiment for the locations of the various absorption peaks are generally less than 02 eV The first transition involving the 5a 1 MO is to the 3d xz valence-like MO (triplet coupling), but the first such allowed excitation is Rydberg in origin (4s at 939 eV); the 1 B 2 (5a 1 , 3d xz ) counterpart is found at 1069 eV with a quite large f value (023 vs 011 for the 5a 1 →4s species and 006 for the 2b 1 →4s transition) It is suggested that such 5a 1 -type excitations should produce a relatively broad-banded structure because of the significant geometrical changes expected to result from depopulating the 5a 1 MO (in contrast to the behavior for 2b 1 ) and hence it is argued that these transitions are at least partially responsible for the rather high level of background radiation found to underly the 2b 1 →4p and higher-lying Rydberg lines in the region of the H 2 S spectrum beyond 80 eV

Reaktionen im Zweikomponentensystem Triphenylphosphin/Tetrachlormethan1)

Abstract: Die Umsetzung zwischen Triphenylphosphin und Tetrachlormethan wird erneut studiert und in ihrem Verlauf aufgeklart. Als erstes isolierbares Zwischenprodukt kann das (Trichlormethyl)-phosphoniumchlorid 4 nachgewiesen werden. Es reagiert mit noch nicht umgesetztem Phosphin sehr rasch uber die Stufe des in diesem System nur als kurzlebige Zwischenverbindung anzusehenden (Dichlormethylen)phosphorans 5 und des Dichlorphosphorans 6 zum stabilen [Chlor(triphenylphosphoranyliden)methyl]triphenylphosphoniumchlorid (10). Die Bedeutung dieses Reaktionsablaufs fur die Reaktionen des Zweikomponentensystems mit dritten Komponenten wird diskutiert. Reactions in the System Triphenylphosphine/Carbon Tetrachloride1) In a renewed study the course of the reaction between triphenylphosphine and carbon tetrachloride has been elucidated. The first isolable intermediate product shown to exist is the (trichloromethyl)-phosphonium chloride 4. It reacts with remaining phosphine very fast to give via the short-lived intermediates (dichloromethylene)phosphorane 5 and dichlorophosphorane 6 the stable [chloro-(triphenylphosphoranylidene)methyl]triphenylphosphonium chloride (10). The importance of this reaction course for reactions of this two-component system with a third component is discussed.

Zur L~-Konvergenz linearer finiter Elemente beim Dirichlet-Problem

Abstract: For piecewise linear Ritz approximation of second order elliptic Dirichlet problemsAu=f over domainsΩ⊂ℝ n globalL ∞ error boundsO(h 2|lnh|v) are obtained under the assumptionfeL ∞(Ω). The proof rests on interpolation ofH 2(Ω)-functions with second derivatives in the space of John and Nirenberg by piecewise linear splines and a technique of Nitsche [7] using weighted Sobolev norms.

Cycling aggregation patterns of cytoplasmic F-actin coordinated with oscillating tension force generation.

Abstract: Isometric contracting protoplasmic veins of Physarum polycephalum show cycling patterns of cytoplasmic F-actin, dependent on their oscillating contraction behaviour (minute rhythms). The process of fibrillogenesis represents a parallel arrangement of F-actin chains (“plasma filaments, microfilaments”) during the isometric contraction phase. A part of the results of the present work corroborates previous results on stretch-activated veins which showed that the fibrillar form of F-actin reflects the isometric contracted state. During isometric relaxation phase, a disaggregation of the fibrillar pattern takes place and is accompanied by a deparallelisation of F-actin chains. Therefore, the isometric relaxed state of cytoplasmic actomyosin is non-fibrillar in nature. Thus, the morphologically detectable fibrillar form of cytoplasmic actomyosin, according to physiological interpretation, is solely representative of the isometric contracted state. The question whether assembly-disassembly processes, e.g. G⇌F-actin-transformation, play a role in the contraction-relaxation cycle is discussed.

Labelling of DNA and differential sister chromatid staining after BrdU treatment in vivo.

Abstract: A method of labelling DNA in vivo with 5-bromodeoxyuridine (BrdU) is described. After 6 h permanent subcutaneous infusion of BrdU in rodents (adult Microtus agrestis, pregnant NMRI-mice), cell nuclei which have undergone DNA synthesis during the BrdU treatment can be differentiated from the nuclei of other cycle stages by means of their altered staining behaviour after Giemsa. 24 h after the BrdU treatment, mitoses from both bone marrow of the adult animals and tissues from the fetuses showed a differential sister chromatid staining. In male M. agrestis, sister chromatid exchanges were most frequently found in the euchromatic part of the X and in the constitutive heterochromatin of both sex chromosomes.