Showing papers by "University of Hamburg published in 1977"

Classification of the types of androgenetic alopecia (common baldness) occurring in the female sex

Abstract: Androgenetic alopecia in the female occurs much more frequently than is generally believed. The condition is still considered infrequent, for it differs, in its clinical picture and in the sequence of events leading to it, from common baldness in men. To facilitate an early diagnosis (desirable in view of the therapeutic possibilities by means of antiandrogens) a classification of the stages of the common form (female type) of androgenetic alopecia in women is presented. The exceptionally observed male type of androgenetic alopecia can be classified according to Hamilton or to the modification of this classification proposed by Ebling & Rook.

All unitary ray representations of the conformal group SU(2,2) with positive energy

Abstract: We find all those unitary irreducible representations of the ∞-sheeted covering group\(\tilde G\) of the conformal group SU(2,2)/ℤ4 which have positive energyP0≧0. They are all finite component field representations and are labelled by dimensiond and a finite dimensional irreducible representation (j1,j2) of the Lorentz group SL(2ℂ). They all decompose into a finite number of unitary irreducible representations of the Poincare subgroup with dilations.

Construction of a selfadjoint, strictly positive transfer matrix for euclidean lattice gauge theories

Abstract: It is shown that physical positivity holds in Wilson's lattice gauge theories, i.e. transition probabilities between gauge invariant states are non-negative and the quantum mechanical Hamiltonian has real eigenvalues only.

Convergence of operator product expansions on the vacuum in conformal invariant quantum field theory

Abstract: In a conformal invariant quantum field theory (in 4 space time dimensions) Wilson operator product expansions converge on the vacuum, because they are closely related to conformal partial wave expansions.

Phase space cell expansion and borel summability for the Euclidean φ{ 3 / 4 } theory

Abstract: The stability of the free energy is proved for complex values of the coupling constant by the way of a convergent expansion. As a consequence, one obtains the Borel summability of the perturbation series.

Extension of KMS states and chemical potential

Abstract: We present an algebraic description of the concept of chemical potential for a general compact gauge groupG, as a first step in the classification of thermodynamical equilibrium states of a given temperature. Adopting first the usual setting of a field algebra ℱ containing the observable algebra\(\mathfrak{A}\) as its gauge invariant part, we establish the following results (i) the existence and uniqueness, up to gauge, of τ-weakly clustering states ф of ℱ extending a given such state ω of\(\mathfrak{A}\) (τ an asymptotically abelian automorphism group of ℱ commuting withG) (ii) in the case of an ω faithful and β-KMS for a time evolution commuting with τ, and of a time-invariant ф, the fact that ф is β-KMS for a one-parameter group of time and gauge whose gauge part lies in the center of the stabilizerGφ of ф. (iii) a description of the general case where ф is neither time invariant nor faithful: ф is then in general vacuum-like in directions of the gauge space governed by an “asymmetry subgroup”. We further analyze the representations and von Neumann algebras determined by ω, ф and the gauge average\(\bar \omega \) of ф. The covariant representation generated by\(\bar \omega \) is shown to be obtained by inducing up fromGφ toG the representation generated by ф. Finally we present, for the case whereG is ann-dimensional torus, an intrinsic description of the chemical potential in terms of cocycle Radon-Nicodym derivatives of the state ω w.r.t. its (quasi equivalent) transforms by localized automorphisms of\(\mathfrak{A}\). Our main result (ii) is established using two independant techniques, the first making systematic use of clustering properties, the second relying on the analysis of representations. Both proofs are basically concerned with Tannaka duality—the second with a version thereof formulated in Robert's theory of Hilbert spaces in a von Neumann algebra.

Collision theory for massless bosons

Abstract: We present a complete solution of the collision problem for massless Bosons in four space-time dimensions.

Some high-level language constructs for data of type relation

Abstract: For the extension of high-level languages by data types of mode relation, three language constructs are proposed and discussed:- a repetition statement controlled by relations- predicates as a generalisation of boolean expressions- a constructor for relations using predicates.The language constructs are developed step by step starting with a set of elementary operations on relations. They are designed to fit into PASCAL without introducing too many additional concepts.

Separating non-stationary from stationary scene components in a sequence of real world TV-images

Abstract: Results are presented for a new method to identify images of moving objects in a sequence of scene images, e.g. from a TV-camera observing a street intersection. The reported approach exploits the assumption that systematic greyvalue differences - based on second order statistics - between consecutive frames are due to images of moving objects. No knowledge is assumed about size, shape, or texture for images of stationary or non-stationary scene components.

Quantitative estimates of the meiofauna from the deep sea off North Carolina, USA

Abstract: In 1974 the authors collected, sorted and enumerated meiofauna from 400, 800 and 4000 m off North Carolina, USA. Samples were replicated respectively with 4 boxcores and 21 subsamples, 2 boxcores and 7 subsamples and 2 boxcores and 8 subsamples. Total meiofaunal numbers were highest in fine silt sediment at 800 m (\(\bar x\)=891.9 10 cm−2) and lowest in very fine silt at 4000 m (\(\bar x\)=73.5 10 cm−2). Fine sand at 400 m yielded a mean of 442.4 10 cm−2. At all depths, most fauna were located in the upper 3 cm of sediment (\(\bar x\) depth distribution=2.2 cm), and typically only nematodes and foraminiferans were found below 4 cm. Total community abundances significantly differed with depth; however, there were no differences among replicate boxcores at particular depths. Since most (85.7%) of the variance was associated with subsamples from a boxcore, it appears that meiofauna densities are homomeneous within large areas at particular depths, and that patchiness is a smallscale phenomenon at the level of the 10 cm2 subsampler. Comparisons of sorting efficiencies of live and preserved samples indicated that to accurately enumerate formainiferans, samples must first be fixed and stained, while turbellarians and oligochaetes must be sorted live.

Histopathological features in mixed types of chronic aggressive hepatitis and primary biliary cirrhosis. Correlations of liver histology with mitochondrial antibodies of different specificity.

Abstract: A histopathological study was carried out on 27 patients with chronic inflammatory liver disease and clinical and/or biochemical evidence of cholestasis who had either mitochondrial antibodies against mitochondrial antigen fractions of 1.19 density (“PBC antigen”; 14 cases) or of 1.13 density (“CAH-PBC mixed-type antigen”; 13 cases). For comparison, the liver biopsies of 17 patients with chronic-aggressive hepatitis (CAH) and antinuclear and/or anti-smooth muscle antibodies but without cholestasis and mitochondrial antibodies, were evaluated. The 14 patients with mitochondrial antibodies against the PBC antigen showed the typical histological features of primary biliary cirrhosis (PBC). The 13 patients with mitochondrial antibodies against the CAH-PBC mixed-type antigen had heterogenous liver alterations. In 11 cases highly active CAH and/or active postnecrotic cirrhosis (AC) were found both with augmented ductular proliferation. Some of these cases showed distinct criteria of PBC as early bile duct lesions or absence of regular bile ducts. The liver histology of one case corresponded to classical PBC; another case to chronic persistent hepatitis. The CAH-patients without cholestasis and mitochondrial antibodies only occasionally showed bile duct proliferation. In conclusion, a high correlation was found between mitochondrial antibodies against the CAH-PBC mixed-type antigen and highly active CAH or early AC with augmented ductular proliferation. This represents an overlapping of CAH and PBC. In contrast, the cases with antibodies reacting to the PBC antigen showed the slowly progressive liver changes of typical PBC.

Manifest sadomasochism of males: results of an empirical study.

Abstract: Two hundred forty-five manifestly sadomasochistic West German men completed an anonymous questionnaire concerning their sexual behavior and psychosocial problems. They were reached as placers of sadomasochistic contact advertisements or as members of sadomasochistic clubs. Thirty percent were exclusively heterosexually oriented, 31% bisexually oriented, and 38% homosexually oriented. Results are described with respect to the invisibility of deviant behavior, seeking of partners, participation in the subculture, realization of the deviant desires, self-acceptance, preferences for sadomasochistic roles and practices, masturbation, and coming out. The possibilities for realization of the deviance are poorer for heterosexual sadomasochists than for the other groups. However, subcultural groups exist among heterosexual sadomasochists.

Radiocarbon dating of soils, a review

Abstract: Radiocarbon-Datierung von Boden - ein Uberblick Die Verwendung der Radiokohlenstoff-Datierungsmethode fur bodenkundliche Zwecke wird in chronologischer Abfolge der Hauptzielrichtungen zusammenfassend dargestellt. Die dabei erkennbaren Hauptphasen und Schwerpunkte dienen als Gliederung. Am Anfang stand die Datierung von Holzkohle und begrabenen Palaoboden sowie der Versuch, einige wenige rezente Bodenbildungen auf der Basis extrahierter Huminsauren anzugehen. Die folgende Kontroverse in bezug auf die Moglichkeiten und Grenzen der Datierung von Bodenkohlenstoff aus dem Bereich der rezenten intakten Biodynamik loste eine intensive Suche aus nach der gunstigsten C-Fraktion, gegebenenfalls nach dem Vorhandensein biologisch inerten Kohlenstoffs innerhalb des organischen C-Pools. Heranziehung der 14C-Datierungsmethode fur bodengenetische Aufgaben fuhrte zu Profildatierungen und zur Ermittlung der Alters-Tiefen-Interdependenz. Δ13C/12C-Messungen erlaubten Herkunftsbestimmungen des Kohlenstoffs aus verschiedenen photosynthetischen Mechanismen, aus lithogenen oder biogenen C-Reservoiren. Die schwierige Aufgabe der Erarbeitung von Systemen zur Korrektur der Verjungung in rezenten Boden stost auf die Notwendigkeit der Verwendung von Simulationsmodellen.

The villous stroma of the human placenta. I. The ultrastructure of fixed connective tissue cells.

Abstract: In human placental villi the connective tissue is constructed by mesenchymal cells, small and large reticulum cells and fibroblasts. During early pregnancy mesenchymal cells dominate; starting with the third month of gestation the reticulum cells are in the majority within the terminal villi, the fibroblasts within the stem villi. Ultrastructurally intermediary types of cells can be differentiated. Together with reticular and collagenous fibres the reticulum cells form the basic architecture of the villous stroma during the first 2/3 of gestation: the “reticular type of stroma”. This consists of a network of cells and fibres with fetal vessels fitted in between. The remaining interspaces form a fluid system of compartments in which Hofbauer cells are suspended. They are called stromal channels. During the last trimester these channels and the Hofbauer cells as well are progressively replaced either by voluminous masses of fibres (“fibrous type of stroma”, mainly in the stem villi) or by sinusoidal enlargements of fetal capillaries (“sinusoidal type of stroma”, mainly in the terminal villi).

Uranium anomaly in Black Sea sediments

Abstract: The upper 90 cm of Black Sea basin sediment with an aereal extension of 2.96 × 105 km2 has an U3O8 content of 6.7 × 106 tonnes. Plankton is the prime agent for uranium fixation. Reducing conditions at depth permit uranium to accumulate over the past 5,000 yr. Energetically self-sufficient burning of the top 1-m strata will lead to U3O8 concentrations in the order of 100 g per tonne ash.

Residual circulation in the North Sea due to the M2-tide and mean annual wind stress

Abstract: In a high resolving (mean grid size 11 km) barotropic numerical model of the North Sea tides the M2-tide is computed. Nonlinearities of the Navier-Stokesequation yield, in connection with an annual mean wind stress, a residual circulation fitting well to observational data. Some effects of this circulation are discussed in connection with pollution problems.

Wave-Vector Dependence of the Electron Energy Losses of Boron Nitride and Graphite

Abstract: Wave-vector (q)-dependent energy loss functions, Im [−ϵ⟂(ω, q⟂)]−1, and dielectric functions, ϵ2⟂(ω, q⟂), of hexagonal boron nitride and graphite up to q⟂-values of almost one third of the Brillouin zone and up to energies of 40 eV were derived from electron energy loss measurements. The results are discussed in terms of non-vertical interband transitions of two-dimensional band structures. Aus Elektron-Energieverlustmessungen wurden die vom Wellenvektor abhangigen Energieverlustfunktionen Im [−ϵ⟂(ω, q⟂)]−1 und dielektrischen Funktionen ϵ2⟂(ω, q⟂) von hexagonalem Bornitrid und Graphit bis hin zu q⟂ -Werten von ungefahr einem Drittel der Brillouinzone und bis hin zu Energieverlusten von 40 eV bestimmt. Die Ergebnisse werden in der Form nichtsenkrechter Interbandubergange fur zweidimensionale Bandstrukturen diskutiert.

Copepod carcasses in the upwelling region south of cap blanc, N.W. Africa

Abstract: High numbers of copepod carcasses were found in zooplankton samples taken in the upwelling system off N.W. Africa. The validity of the measurements is discussed. It is suggested that rapid changes in the environment, caused by the pulsation of violent mesoscale upwelling at the shelf edge, result in an increased mortality in zooplankton. Considerations are made on the role of copepod detritus in the upwelling region.

e + e − annihilation into baryon-antibaryon pairs

Abstract: Using generalized-vector-dominance-model-type form factors we calculate the ${e}^{+}\ensuremath{-}{e}^{\ensuremath{-}}$ production cross sections for the reactions ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{B}_{{\frac{1}{2}}^{+}} {\overline{B}}_{{\frac{1}{2}}^{\ifmmode\pm\else\textpm\fi{}}}$, ${B}_{{\frac{1}{2}}^{+}}{\overline{B}}_{{\frac{3}{2}}^{\ifmmode\pm\else\textpm\fi{}}}$, ${B}_{{\frac{1}{2}}^{+}}{\overline{B}}_{{\frac{5}{2}}^{+}}$, and ${B}_{{\frac{3}{2}}^{+}}{\overline{B}}_{{\frac{3}{2}}^{+}}$ including all prominent baryon resonances at energies of present and planned ${e}^{+}\ensuremath{-}{e}^{\ensuremath{-}}$ storage-ring machines. The calculated cross sections indicate that the interference of direct and one-photon decay of the $\ensuremath{\psi}$ particles into baryon pairs is small.