Showing papers by "University of Bremen published in 1977"
TL;DR: Sob-T1s of sober T1-spaces is the greatest epi-reflective subcategory of top consisting of sober spaces, moreover, Sob-T 1s is a "disconnectedness" in the sense of Preus- Arhangelskii-Wiegandt (generated by all irreducible spaces), henceSob T 1 is (extremal epi)-reflective in top as mentioned in this paper.
Abstract: A filterF on a convergence space is called irreducible, iff the set convF of convergence points ofF belongs toF. A space is sober, iff for every irreducible filterF there is a unique point x with convF=conv x. The categorySob-Conv of sober convergence spaces is a full productive, but not a reflective subcategory of the categoryConv of convergence spaces and continuous maps. For a topological space (X,t) the following are equivalent: (i) for every irreducible filterF on (X,t) there is a point x withF=x (ii) (X,t) is both sober and TD (iii) every subspace of (X,t) is sober (iv) every topological space finer than (X,t) is sober (v) whenever (Y,s) is a To-space whose latticeO(Y,s) of open sets is isomorphic toO(x,t), then (Y,s)≈(X,t). The categorySob-T1s of sober T1-spaces is the greatest epi-reflective subcategory ofTop consisting of sober spaces, moreoverSob-T1s is a “dis-connectedness” in the sense of Preus- Arhangelskii-Wiegandt (generated by all irreducible spaces), henceSob-T1 is (extremal epi)-reflective inTop. It is strictly between T1 and T2 and different from various sorts of weak Hausdorffness discussed in the literature.
29 citations
TL;DR: The existence of two chymotrypsinogen loci in the mouse genome could be demonstrated and differences in structure and function between the corresponding enzymes from the two strains were found.
14 citations
TL;DR: In this paper, the detection limits for both an XRF and a PIXE trace element analysis system were determined using empirical background parameters for typical target matrices, under standard running conditions.
14 citations
01 Jul 1977
TL;DR: In general Hg levels in organisms decreased from the limnic region to the marine environment, and some factors which may influence the heavy metal concentrations in aquatic organisms are discussed, such as: food chain, weight of organisms, and elimination via moulting products in the case of crustaceans.
Abstract: Hg concentrations in benthic invertebrates of the Elbe estuary were analyzed by atomic absorption spectrophotometry and instrumental neutron activation analysis. In general Hg levels in organisms decreased from the limnic region to the marine environment. Highest Hg levels were found inAsellus aquaticus andRadix balthica taken from the Elbe upstream of Hamburg (0.35 and 0.34 ppm wet weight). The concentrations in gammarid species decreased from 0.20 ppm (limnic region) to 0.02–0.05 ppm (brackish and marine environment). Hg levels in organisms from the brackish region proved to be 0.08–0.16 ppm(Littorina littorea), 0.04–0.09(Crangon crangon) 0.05–0.10(Corophium volutator) and 0.04–0.08 ppm (wet weight)(Nereis diversicolor). Some factors which may influence the heavy metal concentrations in aquatic organisms are discussed, such as: food chain, weight of organisms, and elimination via moulting products in the case of crustaceans.
10 citations
TL;DR: A receiver using digitally controlled AGC overcoming the difficulties of conflicting demands of time constants is described.
Abstract: A suitable Automatic Gain Control (AGC) in baseband data communication receivers is essential for a low error rate of the link. Analogue AGC suffers from conflicting demands of time constants. This paper describes a receiver using digitally controlled AGC overcoming these difficulties.
8 citations
01 Jan 1977
TL;DR: In this paper, the structure of the zoocoenosis of a 130 year old beech stand (Luzulo-Fagetum) 500 m above sealevel in the Soiling mountains (German IBP-PT research area) is described as a basis for an analysis of the role of animals in the forest ecosystem.
Abstract: The structure of the zoocoenosis of an 130 year old beech stand (Luzulo-Fagetum) 500 m above sealevel in the Soiling mountains (German IBP-PT research area) is described as a basis for an analysis of the role of animals in the forest ecosystem. Different aspects, which are interrelated but may be studied separately are distinguished: species composition, dominance and diversity (taxonomic structure), food relations (trophic structure), vertical and horizontal distribution (spatial structure), and phenology and life cycle characteristics (time structure).
7 citations
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TL;DR: In this article, a new product for topological spaces is defined by means of interior covers, which preserves paracompactness, zero-dimensionality (in the covering sense), the Lindelof property, and regular closedness.
Abstract: Examples are provided which demonstrate that in many cases topological products do not behave as they should. A new product for topological spaces is defined in a natural way by means of interior covers. In general this is no longer a topological space but can be interpreted as categorical product in a category larger than Top. For compact spaces the new product coincides with the old. There is a converse: For symmetric topological spaces X the following conditions are equivalent: (1) X is compact; (2) for each cardinal k the old and the new product Xk coincide; (3) for each compact Hausdorff space Y the old and the new product X x Y coincide. The new product preserves paracompactness, zero-dimensionality (in the covering sense), the Lindelof property, and regular-closedness. With respect to the new product, a space is N-complete iff it is zerodimensional and R-complete.
7 citations
6 citations
TL;DR: In this paper, the authors compare the concepts of monadic functors and functors with lifting and preservation properties which are essential in general algebra and in topological algebra, and show that the Linton conditions are sufficient for tripleability under milder assumptions.
Abstract: In the present paper we compare the concepts of monadic functors and functors with lifting and preservation properties which are essential in general algebra and in topological algebra. In doing this we show that the Linton conditions are sufficient for tripleability under milder assumptions as is known till yet. Using the concept of regular categories and regular functors [4] we give a complete generalization of theSet-based situation to a large class of base categories which admit certain factorizations.
5 citations
TL;DR: Using a pulsed, tunable dye laser details of the fluorescence behavior of single, intact human red blood cells have been studied and the detection of potential-dependent uptake and release of dye added to the suspension of living erythrocytes is detected.
4 citations
01 Jan 1977
TL;DR: In this paper, a measuring apparatus is introduced which can directly determine the net assimilation of macrophytic submersed aquatic vascular plants, which is possible inside the measuring cystern of acrylic glass by means of an electrode working after the CLARK-principle.
Abstract: In this paper a measuring apparatus is introduced which can directly determine the net assimilation of macrophytic submersed aquatic vascular plants. This is possible inside the measuring cystern of acrylic glass by means of an electrode working after the CLARK-prin-ciple. The measuring method is subject to comparison with others. Some examples of the accuracy and continuity of measuring are registered. The advantage of this method is that within a short period of time numerous results can be obtained. With the given distribution of the single amounts a statistical analyses thereby becomes possible. The test plants are kept in aquariums wherein the water temperature, light conditions and dissolved salts can be varied or held constant. In addition a through-passing system is introduced in which natural flowing water conditions can be simulated to the furthest possible extent.
TL;DR: Using previously published data from various authors with the authors' own, significant associations between this skin disease and genetic polymorphisms such as MN, Gc, Gm(2), red cell acid phosphatase, and red cell phosphoglucomutase were seen.
Abstract: In a sample of n=160 nonrelated male and female patients suffering from psoriasis vulgaris, blood, serum protein, and enzyme group typings have been carried out and compared with healthy controls from the same area (Rheinland-Pfalz). Marked statistically significant differences between patients and controls were found in none of the genetic blood polymorphisms considered here. However, combining previously published data from various authors with our own, significant associations between this skin disease and genetic polymorphisms such as MN, Gc, Gm(2), red cell acid phosphatase, and red cell phosphoglucomutase (PGM1) were seen. The possible reasons for these associations are discussed.
TL;DR: In this article, the results of experiments using Ta 2 O 5 and Nb O 5 as typical valve metal oxides and FeO x, MnO x, NiO x and other representative contact oxides are reviewed.
TL;DR: In this article, the synthesis and spectroscopic properties of low molecular and polymeric complexes of etioporphyrin-germaniumIV are described, and the properties of these complexes are compared.
Abstract: The synthesis and spectroscopic properties of low molecular and polymeric complexes of etioporphyrin-germaniumIV are described.
01 Jan 1977
TL;DR: To analyze signals that have been propagating in random media with rough boundaries the medium between transmitter and receiver may be considered as a time and space variant random filter, the concept of a multidimensional scattering function is presented.
Abstract: To analyze signals that have been propagating in random media with rough boundaries the medium between transmitter and receiver may be considered as a time and space variant random filter. A historical outline of the theory of random fields is given with applications to tropospheric scatter links and to underwater acoustics. To discuss the influence of the randomness of the transmitting channel on signal processing procedures, the concept of a multidimensional scattering function is presented. Its effect on the combined ambiguity-power directivity function of signals and on arrayprocessing gain are considered.
TL;DR: In this article, the trajectories of a system defined by a nonlinear functional differential equation in a real Banach space E, may be described by an ODE in appropriate state spaces.
TL;DR: In this paper, the authors discuss the recent development of training programmes in social work and social welfare in the Federa~l Republic of Germany and concentrate on the establishment of such training programmes at the university level, regarding their content and organization.
Abstract: O start off, we shall discuss a few proT blems concerning the recent development of training programmes in social work and social welfare in the Federa~l Republic of Germany. We shall then concentrate on the establishment of such training programmes at the university level, regarding their content crnd organization. As in other countries specialized training for careers in the profession of social work in Germany does not have much of a tradition. The first &dquo;Christian-Social! for Women&dquo;
TL;DR: In this paper, it was shown that the forgetful functor from the category of contiguity spaces to the class of generalized proximity spaces is topological, and that the right adjoint right inverse of this functor extends the inverse of the forgetfulness functor.
Abstract: It is shown that the forgetful functor from the category of contiguity spaces to the category of generalized proximity spaces is topological, and that the right adjoint right inverse of this functor extends the inverse of the forgetful functor from the category of totally bounded uniform spaces to the category of proximity spaces.
01 Jan 1977
TL;DR: In this article, the authors describe an Auflosungsvermogen eines Spekrometers is in erster Linie durch die physikalischen Eigenschaften des systems bedingt.
Abstract: Das Auflosungsvermogen eines Spektrometers ist in erster Linie durch die physikalischen Eigenschaften des Systems bedingt. Die Faltung des Spektrums durch die Spektrometerfunktion fuhrt dazu, das sich eng benachbarte Spektrallinien uberlagern konnen. Solche Uberlagerungen lassen sich jedoch im Prinzip mit Hilfe der bekannten Methoden der mathematischen Entfaltung auflosen, wodurch es moglich wird, die Intensitaten der Linien quantitativ zu bestimmen. Das effektive Auflosungsvermogen des Systems kann also unter Umstanden besser als die „Halbwertsbreite“ der Spektrallinien sein.
TL;DR: If the authors agree on the issue - of people having less and less children and, at the same time, tending to neglect those they have - the question is what explanation may they find in Adam Smith's main work, The Wealth of Nations.
Abstract: Unlike Marx,who looks forward to an end of the 'idiocy' of country life and to a sharpening of the wits of the working class on the anvil of history, Smith sees a growth in the idiocy of city life and the reduction of the working class to a condition in which the labourer is incapable either of comprehending (society's) interest or of understanding its connexion with his own'... Thus beneath the surface assurance that radiates from the book, a distant tragedy of vast proportions - economic decline, moral decay lurks within The Wealth of Nations. Two hundred years after its publication, one hundred after the appearance of Volume I of Capital, we may wonder whose measure o{ the future was more nearly correct that of Marx or that of Smith. 2) I. The fact that we,as social scientists from a German speaking country, investigate the problems of the quantitative and qualitative production of population is not a purely academic pastime. Instead, we are confronted with real difficulties concerning reproduction of the population in highly developed societies. The three German speaking countries of the former fascist sphere of influence, namely the Federal Republic of Germany, the German Democratic Republic, and Austria today have the lowest birth rates in the world (9.7 per mil., ]0.8 per mil., and ]2.3 per mil. respectively in 1975). Not only are their populations constantly shrinking, but in addition families among the young ore averse to having children. Moreover, we are convinced that this is not a uniquely German problem, rather i% is the pinpoint of s problem which is becoming ever more serious also in Scandinavia, in Anglo-Saxon countries, and in Eastern and Western Europe as o whole. Thus,if we agree on the issue - of people having less and less children and, at the same time, tending to neglect those they have - the question is what explanation may we find in Adam Smith's main work,The Wealth
01 Jan 1977
TL;DR: In this article, the authors discuss the history of ecology in Germany, the structure of its universities, and their idea of science, and make an attempt to give an explicit definition and to discuss it in its vast perspectives.
Abstract: The term „Ecology“is discussed in relation to its history and today’s broad spectrum. An attempt is made to give an explicit definition and to discuss it in its vast perspectives. Ecology in school should not be the pure transmission of the definition, rather, it should be part of an interdisciplinary environmental education. Some IPN-activities are referred. Ecology teaching at the university level in an ecosystem orientated manner is hampered by the history of ecology in Germany, by the structure of its universities, and by their idea of science. Some attempts are made to teach ecology as an interdisciplinary science with urgently needed applications. As an example, the outlines of the ecology part of the biology curriculum at the university of Bremen are given.