Showing papers by "Free University of Berlin published in 1978"
TL;DR: In this article, a system of equations which must be satisfied by multiparticle matrix elements of any local operator in field theories with soliton behaviour is derived, and the form factors of various operators of interest are calculated exactly by means of the known exact S-matrices in the sine-Gordon, massive Thirring, nonlinear σ−, and Gross-Neveu models.
436 citations
TL;DR: In this paper, a reduction method for edge-connectivity in graphs is introduced, where the set of edges between the vertices x and y of a multigraph G is denoted by [ x, y ] G, sometimes without the index G.
Abstract: Publisher Summary This chapter introduces a reduction method for edge-connectivity in graphs. Let V ( G ) be the vertices and E ( G ) the edges of the multigraph G = ( V ( G ) E , ( G )).In a multigraph, parallel edges are allowed, but not loops. The set of edges are denoted between the vertices x and y of G by [ x , y ] G , sometimes without the index G . Let λ ( x , y ; G ) be the maximal number of edge-disjoint paths between x and y in G . If z is a nonseparating vertex of degree at least 4 in the multigraph G then there exists an admissible lifting of G at z . A theorem stating that every finite multigraph possesses an admissible orientation is presented. The chapter presents several definitions and symbols, which can be used analogously for directed multigraphs. It also discusses an immediate consequence of Menger's theorem.
297 citations
TL;DR: In this paper, S-matrices describing the scattering of solitons belonging to the fundamental representation of U(n) are classified, and the scattering properties of these matrices are investigated.
152 citations
TL;DR: It was found that immersion to the diaphragm of a standing subject produces the same changes as assumption of the supine posture and the preferential increase in blood volume of the apical regions is striking.
Abstract: The present experiments have been conducted to study the immediate effects of graded immersion on the central circulation. When taking heart volume as an indicator, it was found that immersion to the diaphragm of a standing subject produces the same changes as assumption of the supine posture. Heart volume increases by approximately 130ml. When the water level is raised to the neck, an extra pressure corresponding to a water column extending from the diaphragm to the surface of the water of approximately 25 cm H2O forces blood into the thorax. The heart becomes distended by an additional 120ml. Correspondingly the central venous pressure at the height of the right atrium increases from 2.5 to 12.8 mm Hg when the water level rises from the diaphragm to the neck. The greater filling of the pulmonary circulation is accompanied by a decrease in vital capacity and visualized by scintigrams. The preferential increase in blood volume of the apical regions is striking. When raising the water level from the symphysis to the xiphoid heart rate falls by about 15%.
138 citations
TL;DR: In this paper, a general quantum field theory of collective excitations is presented for many-body systems, where Lagrangians involving fundamental particles are transformed to collective fields exactly via Feynman path integrals.
Abstract: A general quantum field theory of collective excitations is presented for many-body systems. Lagrangians involving fundamental particles are transformed to collective fields exactly via Feynman path integrals. Graphically, this amounts to a complete resummation of the perturbation series without the danger of double counting. Plasma and pairing effects provide special examples corresponding to mutually complementary transformations. Bose and Fermi systems can be treated on equal footing. The methods are illustrated by giving the exact collective Lagrangian for the BCS model and approximate ones for type II superconductors and 3He.
137 citations
125 citations
TL;DR: Lymphocyte chromosomes from 20 heavy smokers were analyzed from 48-h whole blood cultures for the frequency of dicentric chromosomes, ring chromosomes, and chromatid translocations.
Abstract: Lymphocyte chromosomes from 20 heavy smokers were analyzed from 48-h whole blood cultures for the frequency of dicentric chromosomes, ring chromosomes, and chromatid translocations. Compared to controls, these exchange type aberrations occurred more frequently in the smokers.
114 citations
TL;DR: In this article, it was shown that the sin/cos functions of the axial potential of the free massive Dirac field appropriately describe the correlation functions of two independent superimposed Ising systems taken in the continuum limit.
108 citations
TL;DR: It is concluded that aldosterone induces an amiloride-sensitive Na+-pathway only in rectum, but not in colon, and that colon and rectum differ basically in their transport properties, quantitatively as well as qualitatively, as do the kidney distal convoluted tubule and the cortical collecting duct.
Abstract: Functionally isolated segments of rat colon and rectum were perfused in situ in a closed loop system. Rectum was defined as the lower 25–35% of the length of large intestine (cecum excluded). Perfusion conditions were optimized at 0.5 ml·min−1 and 3 cm H2O luminal pressure.
97 citations
TL;DR: An outbreak of neuropathies among Berlin solvent sniffers was closely related to the denaturation by methyl-ethyl-ketone (MEK) of the mixture used, which suggests that commercial solvent mixtures containing MEK/n-hexane should be avoided.
Abstract: An outbreak of neuropathies among Berlin solvent sniffers was closely related to the denaturation by methyl-ethyl-ketone (MEK) of the mixture used The solvent was composed of n-hexane, toluene and ethyl-acetate Nervous system responses to chronic repeated exposure to 10,000 ppm pure n-hexane, 10,000 ppm MEK/n-hexane (ratio 1:9) and 6000 ppm pure MEK were investigated in rats Motor neuropathy of the dying back type with giant swelling of axons in the peripheral and central nervous system developed in animals exposed to MEK/n-hexane and n-hexane Severe potentiation of n-hexane neurotoxicity and shortened onset of morphological and clinical signs were demonstrated in animals exposed to MEK/n-hexane MEK alone did not produce neuropathy under these conditions The findings suggest that commercial solvent mixtures containing MEK/n-hexane should be avoided
91 citations
TL;DR: The results suggest a transport of valproate into and out of CSF, probably by the monocarboxylic acid system, and diffusion should only play a minor role.
TL;DR: In this paper, the authors deal with a periodic review inventory system and present methods for determining the reorder point s of an (s, S) order policy when a certain service level is required.
Abstract: This paper deals with a periodic review inventory system. Methods are discussed for determining the re-order point s of an (s, S) order policy, when a certain service level is required. The results differ from those presented for a (Q, s) model which is usually considered in literature and implemented in practice. Methods are discussed for determining the re-order point of an (s, S) policy when demand is normal or gamma distributed. A numerical investigation demonstrates the applicability of the described methods. In particular, it is shown that these methods are superior to a formula that is implemented in many inventory control systems.
TL;DR: In this article, the authors discuss Hamiltonians in arbitrary C ∞ external electromagnetic fields and with positive potentials and prove convergence to the classical limit when ħ → 0 as well as for the expectation values of some local observables.
TL;DR: In this paper, a space-time spectral analysis is applied to the daily 500 mb geopotential field (gridded along 50° N) of five winter seasons (1972-77).
Abstract: A space-time spectral analysis is applied to the daily 500 mb geopotential field (gridded along 50° N) of five winter seasons (1972–77). The results are displayed in the wavenumber-frequency domain as two-sided frequency spectra of meridional geostrophic wind and one-sided spectra of geopotential. They show three isolated spectral peaks: stationary ultralong waves (k = 1–4, p ≈ 25 days), and eastward propagating long (k = 5–6, p ≈ 10 days, c ≈ 6 m s−1) and short waves (k = 7–8, p = 4–6 days, c ≈ 10 m s−1). In the wave-number-frequency domain only the magnitudes of the peaks vary from one season to the other.
TL;DR: The data suggest the presence of an abnormal extrathyroidal T4 metabolism as well as a pituitary defect in euthyroid patients with severe diabetic ketoacidosis, and caution is recommended in the interpretation of thyroid‐function tests during and several days after the treatment of diabetic ketOacidosis.
Abstract: The pituitary-thyroid axis was investigated in nineteen euthyroid patients with severe diabetic ketoacidosis. A 'low T3 syndrome' was found, with the following characteristics: lowered serum concentrations of triiodothyronine (T3), increased reverse triiodothyronine (rT3), slightly low thyroxine (T4), normal thyrotrophin (TSH), slightly increased triiodothyronine uptake (RT3U) values, and a blunted TSH response to thyrotrophin-releasing hormone (TRH). These disturbances in thyroid-function tests required several days good control of the diabetes to be corrected, at least partially. The data suggest the presence of an abnormal extrathyroidal T4 metabolism as well as a pituitary defect. Caution is recommended in the interpretation of thyroid-function tests during and several days after the treatment of diabetic ketoacidosis.
TL;DR: Single cell recordings in the mushroom body area of the bee revealed that the majority of cells responds to more than one modality, and some neurons showed increasing sensitivity for a scent after a number of olfactory conditionings.
Abstract: . Single cell recordings in the mushroom body area of the bee revealed that the majority of cells responds to more than one modality. Five different modalities were tested: light, scent, sugar-water applied to the antennae or the proboscis, and mechanical stimuli of the antennae (air puffs). The background discharge (spontaneous) frequency of the neurons was correlated with the recording site, being low in the calyx area and high in the area of the β-lobes. No correlation between the reaction spectra of neurons and the recording location was found. A simple classification of single cells into different classes is not possible. Some units change their response pattern during recording; this is interpreted as an indication of other inputs which were not controllable in the experiments. After-effects, lasting some seconds to minutes, were found with scent, light and sugar-water stimuli. The olfactory and gustatory inputs obviously play an important role in activating multimodal units. Some neurons showed increasing sensitivity for a scent after a number of olfactory conditionings. An increase of sensitivity in these units is correlated with an increase of the spontaneous discharge frequency.
TL;DR: In this article, the extremum conditions for general nonlinear optimization problems in ordered topological vector spaces were proved and the variational derivatives of higher order were defined and proper variations introduced.
Abstract: We prove necessary extremum conditions for general nonlinear optimization problems in ordered topological vector spaces. For that reason, we define variational derivatives of higher order and introduce proper variations. Especially assuming certain weak hypotheses, we establish maximum principles of higher order.
TL;DR: The data cannot prove the hypothesis that only humoral antibodies are responsible for the thyroid stimulation in Graves' disease, but of course they cannot exclude it; furthermore, they suggest the existence of antibodies which bind to the human thyroid cell membrane without necessarily stimulating thyroid cellular activity.
Abstract: The prevalence of TSI in Graves' disease was investigated with a radioligand receptor assay using human thyroid membranes and highly purified labeled porcine TSH or bovine TSH in 110 patients before treatment and in 39 patients after successful treatment with antithyroid drugs In 11 patients, the assay was performed before, during, and after therapy The results in the radioligand receptor assay were compared to thyroid function tests (TRH test, free T4 index, serum T3 level, and thyroid suppression test) Normal IgG inhibits nonspecifically, but dose dependently, the binding of [125I]TSH to thyroid membranes IgG samples from patients were only considered to be positive if they reduced the binding of the labeled hormone below the mean value minus 2 SD of the controls TSI activity was found in 50% of the patients with untreated diffuse toxic goiter, in 3 out of 27 cases who regained suppressible thyroid function, and in 5 out of 12 cases who were off therapy for more than 6 weeks and showed normal TRH t
TL;DR: In this article, the electrochemical properties of sulfur adsorbed on gold electrodes were studied in 10−5 M solutions of S2− in 1 M NaOH, and the double layer capacity decreases during adsorption of sulfur indicating the formation of an insulating sulfur layer with a dielectric constant of about 2.
TL;DR: The number of days per lunar month determined using fossil shells has increased dramatically during the last 420 Myr, indicating that during this period the Moon revolved more rapidly and was much closer to the Earth than has previously been expected.
Abstract: Daily growth lines and lunar monthly septa are formed in Nautilus pompilius Linnaeus shells. The number of days per lunar month determined using fossil shells has increased dramatically during the last 420 Myr, indicating that during this period the Moon revolved more rapidly and was much closer to the Earth than has previously been expected.
TL;DR: In this paper, a nonlinear and time-dependent climate model is formulated as a gradient system of a potential and can be analyzed without explicit time integration, which includes many of the results which are also exhibited by one-dimensional energy balance models.
Abstract: An ‘almost trivial’ climate system of geometrical dimension zero is analysed, the complexity of which has been reduced to a minimum. It can be simply described as the globally averaged energy flux balance between infrared emission and solar heat input, expanded by a linear albedo-temperature feedback. This nonlinear and time-dependent climate model is formulated as a gradient system of a potential and can be analysed without explicit time integration. It includes many of the results which are also exhibited by one-dimensional energy balance models. Two equilibrium solutions appear. The stable one is characterized by the interglacial, whereas the unstable equilibrium defines a lower bound for temperature (state variable) changes which the system can absorb. Beyond a threshold of an external parameter combination (fold catastrophe) no equilibria exist so that the system attains a ‘deep freeze’ climate situation. A −2 power law describes the linear response of the (internally stable) system to weather fluctuations.
TL;DR: The in vivo binding of IgA by hepatocytes is probably a physiological phenomenon which in part may explain the normal clearance of polymeric IgA from serum.
Abstract: IgA bound in vivo was shown by immunofluorescence on the plasma membrane of isolated hepatocytes from subjects with normal liver and patients with liver cirrhosis, chronic active hepatitis or fatty liver. IgA in sera with elevated IgA concentrations, especially from cases with alcoholic cirrhosis, was bound in vitro to isolated hepatocytes from rabbit and mouse. This was not due to the high IgA concentration per se. Moreover, polyclonal polymeric serum-type and secretory IgA, and three of ten polymeric monoclonal IgA preparations, showed similar binding properties. Conversely, purified polyclonal and monoclonal monemeric IgA did not show affinity for the hepatocytes. The binding of polymeric IgA did not seem to depend on the proportion of dimers and larger polymers, kappa- or lambda-type light chains, heavy-chain subclasses, content of J chain or affinity for secetory component. The in vivo binding of IgA by hepatocytes is probably a physiological phenomenon which in part may explain the normal clearance of polymeric IgA from serum.
TL;DR: The time courses of changes in brain content of γ-aminobutyric acid (GABA) and sensitivity to convulsions were studied in mice after administration of AOAA and there was a good correlation of increase in GABA content with elevation of the thresholds for the electroconvulsion as well as for the pentetrazole convulsion.
TL;DR: Injection of normal mice with CY results in manifestation of autoreactive T lymphocytes followed by the appearance of suppressor cells counteracting autoreactivity, which is consistent with the existence of CY-sensitive suppressionor cells.
Abstract: THERE is increasing evidence of potentially autoreactive cells in normal animals1,2. Expression of autoimmunity, however, may not arise as a primary effector cell abnormality but more possibly as the consequence of a defect in a thymus-dependent control mechanism3–5. Cyclophosphamide (CY) enhances the capacity of mice to give T cell-dependent responses, such as delayed type hypersensitivity (DTH) induced by sheep red blood cells6. It was suggested that B cells were the targets of CY action7 and that the enhanced DTH reaction was due to inhibition of antibody production and consequently to lack of the antigen–antibody complexes responsible for inhibition of DTH. Askenase et al.8 presented evidence for an alternative explanation for enhancement of DTH by CY. They demonstrated augmented DTH to sheep red blood cells with doses of CY which did not influence antibody responses, suggesting the existence of CY-sensitive suppressor cells. Similar conclusions have been drawn by Roellinghoff et al.9, who observed induction of cytotoxic lymphocytes in mice to hapten-conjugated syngeneic cells after treatment with CY. We report here that injection of normal mice with CY results in manifestation of autoreactive T lymphocytes followed by the appearance of suppressor cells counteracting autoreactivity.
TL;DR: In this paper, the dispersion of plasmons at the surface of a metal and at the interface between two metals is derived by a proper combination of electrodynamics with the hydrodynamic approximation.
Abstract: The dispersion of plasmons at the surface of a metal and at the interface between two metals is derived by a proper combination of electrodynamics with the hydrodynamic approximation. With a two-step model we discuss the effect of a transition region at the surface of a metal and we so explain recent measurements by Krane and Raether for aluminum.
TL;DR: Tetrahydronorharmane (tryptoline), the condensation product of tryptamine and formaldehyde, inhibits the high‐affinity uptake of serotonin and to a smaller extent that of noradrenaline into a synaptosome‐rich fraction from the hippocampus and hypothalamus respectively of rats.
Abstract: — Tetrahydronorharmane (tryptoline), the condensation product of tryptamine and formaldehyde, inhibits the high-affinity uptake of serotonin and to a smaller extent that of noradrenaline into a synaptosome-rich fraction from the hippocampus and hypothalamus respectively of rats. The uptake mechanisms of dopaminergic neurones of the hypothalamus, cholinergic neurones of the hippocampus, and GABA-ergic neurones of the cerebral cortex are affected to a much lesser degree. Substitution of tetrahydronorharmane by fluor-, chlor-, methyl-, hydroxy-, methoxy-, and catechol-groups alters the inhibition. Drugs with substituents which attract electrons are relatively good inhibitors of the uptake of serotonin. The indole-ring contributes to the binding of the molecule probably by forming a charge transfer complex with the uptake molecule. Pyrido (3,4-b)-indoles (harmala alkaloids) are weak inhibitors of the serotonin-uptake compared with respective piperidoindoles (tetrahydro-β-carbolines).
The potency of the drugs to inhibit uptake is different for each uptake system. The order among the drugs with respect to their affinity for the uptake site varies, too.
TL;DR: In this article, the exact S-matrix of the soliton model is proposed and it is shown to be consistent with the semiclassical spectrum and with the scattering amplitudes in leading order of the 1N expansion.
TL;DR: The organic acid excretion in a patient with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency is described and 3-Methylcrotonic acid and possibly one of its isomers was found to be formed artificially from 3- methylglutaconic acid.
TL;DR: In this article, an infinite class of new gravitational instantons for the axial anomaly is found, consisting entirely of algebraic spin- manifolds, and the possible relation of this to the gauge theory of weak and electromagnetic interactions is explored.
01 Mar 1978
TL;DR: The inverse problem for quantal potential scattering at fixed energy is solved exactly for a scattering function which has the form of a product of a complex rational function of angular momentum times the scattering function of a given reference potential.
Abstract: The inverse problem for quantal potential scattering at fixed energy is solved exactly for a scattering function which has the form of a product of a complex rational function of angular momentum times the scattering function of a given reference potential. Schematic numerical studies indicate the viability of the method in realistic applications.