Showing papers by "University of Zurich published in 1971"
TL;DR: Two ways of implementing the algorithm are considered: multitape Turing machines and logical nets (with step=binary logical element.)
Abstract: Es wird ein Algorithmus zur Berechnung des Produktes von zweiN-stelligen Dualzahlen angegeben. Zwei Arten der Realisierung werden betrachtet: Turingmaschinen mit mehreren Bandern und logische Netze (aus zweistelligen logischen Elementen aufgebaut).
976 citations
TL;DR: Thxe appears to be a critical intensity for these initial struciural changes, which only partly can be explained on the basis of a purely mechanical effect.
Abstract: 32 guinea pigs were exposed to 100-138 dB wide band noise for 1 min to 1 hour and sacrificed immediately afterwards or after short survival times. In light and electron microscopic examinations the initial structural changes proved to be: distortion of outer hair cells, buckling of sensory hairs, swelling of the dendrites to the inner hair cells, and increase of density in efferent nerve endings at the outer hair cells, followed by disintegration of hair cells and rupture of dendrites with incipient retrograde nerve degeneration at higher exposures. Thxe appears to be a critical intensity for these initial struciural changes, which only partly can be explained on the basis of a purely mechanical effect. Swelling of dendrites seems to be reversible to a certain extent, whereas the buckling of sensory hairs of the inner hair cells remains even after longer survival times.
310 citations
TL;DR: In this article, the authors discuss proposals for testing the presence of phase relations and for extracting them quantitatively by means of numerical bispectrum analysis, and derive their statistical properties and compare their relative merits.
Abstract: Harmonically related peaks in the spectrum of a stationary stochastic process may indicate the presence or wave components that are not sine-shaped, i.e., whose Fourier expansions contain phase-locked higher order terms. But the spectrum itself suppresses phase relations, and more refined methods are needed to decide such questions. Moreover, phase relations might also exist outside of the peaks. We discuss proposals for testing the presence of phase relations and for extracting them quantitatively by means of numerical bispectrum analysis, and we derive their statistical properties and compare their relative merits. Applications of these methods to EEG signals will be presented.
206 citations
178 citations
TL;DR: Reptilase®‐R, a purified thrombin‐like snake‐venom enzyme from Bothrops atrox, has been tested for its usefulness as a substitute forThrombin in two coagulation assay systems.
Abstract: Summary. Reptilase®-R, a purified thrombin-like snake-venom enzyme from Bothrops atrox, has been tested for its usefulness as a substitute for thrombin in two coagulation assay systems. Reptilase was found to be more stable than thrombin and not to be inhibited by heparin and hirudin.
Performance of the Reptilase time allows the rapid exclusion of heparin contamination in plasma samples with prolonged thrombin times. In the presence of fibrinogen/fibrin split products, the Reptilase time is less prolonged than the thrombin time, whereas in patients with prolonged thrombin times because of congenital dysfibrinogenaemia the inverse is found. Thus, performance of both Reptilase time and thrombin time allows the rapid identification of three major causes for a prolongation of the thrombin time. In patients on heparin therapy because of a defibrination syndrome, the Reptilase time may replace the thrombin time as a guide for the degree of coagulation inhibition by FDP, although our results show that it is somewhat less sensitive.
Reptilase can also be substituted for thrombin in the rapid chronometric fibrinogen assay. Unfortunately the advantages of reagent stability and insensitivity to heparin are balanced by a lesser reproducibility, especially in the presence of FDP.
121 citations
TL;DR: The bispectrum allows a detailed analysis of the third central moment, which is influenced either by interrelations between frequency components or by non-stationarity of the signal, and may therefore display important additional information about the properties of a stochastic signal like the EEG.
109 citations
TL;DR: Detailed examination showed that silver grains were predominatly located over the axolemma and agranular endoplasmic reticulum in axons, and over mitochondria and synaptic vesicles in neuronal endings, which support the proposition that synaptic proteins migrate rapidly in the axon.
Abstract: Electro microscopic autoradiography was used to study the distribution of labeled proteins in the pigeon optic tectum, 12 hours after intraocular injection of 3H-1-leucine. More than 65% of the grains were detected over synaptic endings, in the fifth layer which is rich in retino-tectal axon terminals. In the first layer which contains retino-tectal fibers 70% of the grains were over axons. These data support the proposition that synaptic proteins migrate rapidly in the axon. Detailed examination showed that silver grains were predominatly located over the axolemma and agranular endoplasmic reticulum in axons, and over mitochondria and synaptic vesicles in neuronal endings.
107 citations
TL;DR: Endoxan and Trenimon, the alkylating agents tested, are potent cytostatic drugs, therapeutically acting through their mutagenic effects, and to demonstrate their chromosome breaking effects in bone marrow, higher than the usual therapeutic doses in man had to be applied.
Abstract: 1.
Endoxan and Trenimon, the alkylating agents tested, are potent cytostatic drugs, therapeutically acting through their mutagenic effects. To demonstrate their chromosome breaking effects in bone marrow, higher than the usual therapeutic doses in man had to be applied. Starting from these practical threshold doses the dose-response curves were, however, rising very steeply.
2.
The extent of chromsome damage in individual cells was dose-dependent: after treatments in the lower dose range only metaphases with one or few chromatid aberrations were observed in a small percentage of the mitotic figures. With increasing doses the number of aberrations per cell steadily rose to the point of complete pulverization of the chromosome complement.
3.
After the last application of the test substances the cell population with visible chromosome damage diminuishes soon. The maximum incidence of aberrations was observed after 6–8 hrs.
4.
The effect was several times higher after two applications spaced by 24 hrs than after a single application. With Endoxan given per os the incidence of affected cells was 8 times higher, with Trenimon i.p. 2–3 times. A longer oral treatment is less effective due to the radiomimetic damage to the intestinal mucosa thereby reducing further resorption of the mutagenic compound. Only a relatively small increase in effect is gained with more than two intraperitoneal applications; if there is a severe mutagenic effect, the animals begin to succumb to the treatment after 4 days.
5.
A prolonged treatment with low doses of Endoxan (8 mg/kg daily for 7 weeks) produced no increase in the very low aberration incidence.
101 citations
TL;DR: While both vesicles and SR tubules are confined to separate areas of the axonal growth cone it was found that a common affinity to the ZIO staining agent exists, the neurofilaments and microtubular components as well as the growth cone vacuoles remain consistently ZIO negative.
Abstract: The ultrastructure of axonal and dendritic growth cones has been examined in the cerebellar cortex of 7 days old rats and 12 days old cats. The unique feature is a bulge of the perikaryon surface or a varicosity of the growing tip of nerve processes. These cone-like areas contain large amounts of tubular smooth surfaced endoplasmic reticulum (SR) and large vacuoles. They are further characterized by filopodia (Tennyson, 1970) with a fibrillary matrix. Early cell contacts with synaptic membrane specializations are described between filopodia of mossy fiber endings and dendritic growth cones of granular cells. Synaptic vesicles appear early in synaptogenesis. While both vesicles and SR tubules are confined to separate areas of the axonal growth cone it was found that a common affinity to the ZIO staining agent exists. In contrast, the neurofilaments and microtubular components as well as the growth cone vacuoles remain consistently ZIO negative.
88 citations
TL;DR: The three genetic groups are identified unequivocally and without any overlapping, as demonstrated in 140 tests of 125 normal controls, 10 tests of 7 hemizygous mothers and 17 tests of 11 affected patients.
Abstract: . A new modification of the nitroblue-tetrazolium (NBT) test for the detection of chronic granulomatous disease is described. Phagocytosis is initiated by particles of killed Candida albicans which are easily seen and counted. The three genetic groups are identified unequivocally and without any overlapping, as demonstrated in 140 tests of 125 normal controls, 10 tests of 7 hemizygous mothers and 17 tests of 11 affected patients. The accurate working procedures are fully described.
81 citations
TL;DR: Donor rat peritoneal macrophages, activated by peptone injection or by infection with the nematode Nippostrongylus brasilien sis, can inhibit the growth of Walker carcinosarcoma cells in rats.
TL;DR: A ribosome bound to Qβ RNA prevents Qβ replicase from completing synthesis of a minus strand and a mechanism is proposed to explain how replic enzyme acts to free Q β RNA of ribosomes prior to using it as template.
Abstract: A ribosome bound to Qβ RNA prevents Qβ replicase from completing synthesis of a minus strand. A mechanism is proposed to explain how replicase acts to free Qβ RNA of ribosomes prior to using it as template.
TL;DR: The ability to generalize visual stimuli enabling the bees to recognize distinct stimulus characteristics, even when other stimulus properties of a special pattern are changing during time is demonstrated in arthropods for the first time.
TL;DR: In this paper, the formation of aminophenyl carbene complexes Cr(CO)5C(NHR)C6H5 (II) follows the fourth-order rate law d[(II)]/dt = KA·[(I)]·[RNH2]·[HX]·
TL;DR: Methylation and acetylation experiments support the notion that the high contrast of synaptic membrane complexes as demonstrated by the BIUL method may be related to the presence of high concentrations of anionic as well as cationic groups.
TL;DR: In each of 11 patients with sporadic acute hepatitis, whose first serum-sample was positive for S.H. (Australia) antigen, S. H. antigen was found in the faeces or sera of these patients irrespective of history of needle contact, and β 1 A, an antigen related to the third component of complement (C3), showed a characteristic fluctuation.
TL;DR: The results show that the perikaryon supplies newly synthesized proteins to its terminals, specifically for subcellular fractions of the retina and optic lobes and for the optic tracts.
Abstract: — The protein supply of the synaptic ending by its nerve cell body has been studied in the retino-tectal system of the pigeon. [3H]Leucine was injected into the vitreous humor of one eye and the protein specific activity was determined for subcellular fractions of the retina and optic lobes and for the optic tracts. The results show that the perikaryon supplies newly synthesized proteins to its terminals. Two main waves of labelled macromolecules could be distinguished: one, migrating at a speed of 40 mm/day or more, is directly destined for the synaptic ending while the other, progressing at a rate of 1 mm/day, distributes along the entire axon.
TL;DR: The dissociation of synaptic contacts has successfully been performed in solutions of high ionic strength and supports the hypothesis of polyionic binding as the mechanism of connectivity between preand postsynaptic membranes.
TL;DR: The distribution of chromatid aberrations induced by mitomycin C among the individual chromosomes of female and male Chinese hamster cells in vitro was studied and it was found to be non-randomly distributed.
Abstract: The distribution of chromatid aberrations induced by mitomycin C among the individual chromosomes of female and male Chinese hamster cells in vitro was studied. The aberrations were found to be non-randomly distributed. Among the autosomes, the chromosomes possessing constitutive heterochromatin were more often involved in aberrations as well as in homologous exchanges. The inactivated X chromosomes in the female cells offer a situation where the short arm is facultatively heterochromatic and the long arm constitutively heterochromatic, thus enabling an analysis of their response for aberration formation. The short arm was seldom found to be involved in the aberration. The long arm of the inactivated X was more often affected (5 to 10 times) than the long arm of the functional X though both are constitutively heterochromatic. The possible role of (a) structure of heterochromatin, (b) the chromocenter formation and their association, (c) allocycly, and (d) the qualitative differences in the DNA of different types of heterochromatin are discussed in relation to the formation of chromatid aberrations.
TL;DR: The infrared spectrum of zinc hydroxide nitrate, Zn5(OH)8(NO3)2·2H2O, is measured between 4000 and 200 cm−1.
TL;DR: Electrolytical lesion or reversible cooling of the rostral part of the supraoptic decussation induced a significant decrease of ipsilaterally evoked potential amplitudes; these procedures had no effect on contralateral evoked responses.
Abstract: Evoked potentials and single unit discharges in the wulst of the pigeon were observed in response to contralateral and ipsilatcral eye stimulation. Mean latencies of the first component of the ipsilateral evoked responses following electrical stimulation of the optic nerve papilla were 14.3 msec; those from contralateral eye were 10.1 msec. Photically evoked responses showed similarly longer latencies to stimulation of the ipsilateral eye. Electrolytical lesion or reversible cooling of the rostral part of the supraoptic decussation (DSO) induced a significant decrease of ipsilaterally evoked potential amplitudes; these procedures had no effect on contralateral evoked responses. 125 wulst units activated by electrical stimulation of the optic nerve papilla were studied. 52 % of the wulst neurones responded to contralateral stimulation with first spike latencies of 7-39 msec; these were localized dorsally in the wulst. Units responding exclusively to ipsilateral stimulation (26.4%) were located ventrally an...
TL;DR: Theodorakopoulos et al. as mentioned in this paper orientiert sich die WustenameiseCataglyphis bicolor vorweigend anemomenotaktisch.
Abstract: Nachts orientiert sich die WustenameiseCataglyphis bicolor vorweigend anemomenotaktisch. Einerseits kann jedoch in Mondnachten bei Lichtintensitaten 350 Lux (ca. 30 min vor Sonnenauf-und nach Sonnenuntergang) die astromenotaktische Orientierung nach dem Polarisationsmuster uber die Anemomentoaxis. Wegen der Spiegelsymmetrie des Polarisationsmusters bei horizontnahem Stand der Sonne treten in diesem Zeitintervall bimodale Laufverteilungen auf, die jedoch bei Sonnensicht sofort in unimodale ubergehen.
TL;DR: It was concluded that the functional part of cell-associated receptors might be structurally similar to the variable portion of an immunoglobulin.
Abstract: The possibility that a rat alloantiserum DA anti-Lewis possesses similar recognition structures for Lewis transplantation antigens, as do DA immunocompetent cells, was investigated by raising an antiserum against this alloantiserum in (Lewis x DA)F(1) hosts. This antiserum, as well as one provoked by injecting DA lymphoid cells, was active against recognition structures for Lewis antigens of DA immunocompetent cells. The anti-(DA anti-Lewis) antiserum displayed the same degree of specificity as was found previously for anti-recognition structure sera prepared by injecting parental strain lymphoid cells into F(1) hosts. Since the activities of antisera raised against cell-bound receptors or against the antigen-binding region of an immunoglobulin were indistinguishable, it was concluded that the functional part of cell-associated receptors might be structurally similar to the variable portion of an immunoglobulin.
TL;DR: In this article, a series of aromatic amines, their Noxides and the corresponding protonated species are analysed in terms of differential chemical shifts of the N-oxide with respect to the corresponding amine or to the hydrocarbon.
Abstract: The proton NMR. spectra of a series of aromatic amines, their N-oxides and the corresponding protonated species are analysed. The results for different protons are expressed in terms of differential chemical shifts of the N-oxide with respect to the corresponding amine or to the hydrocarbon. These data are compared with calculated shielding values obtained according to the theories of McConnell & Buckingham using published data for the magnetic susceptibilities and electric dipoles of the functional groups. The major part of the shielding by the N-oxide group originates from the electric dipole. If one considers resonance structures for the aromatic N-oxides the single bond structure and the double bond structure for the NO bond are of approximately equal importance.
TL;DR: RNA phages such as R17, MS2 and f2 (group I of Watanabe1) consist of a single-stranded RNA, about 180 molecules of coat protein and one of A (or maturation) protein, a component required for the functional integrity of the viral particle, possibly for its adsorption to the host.
Abstract: RNA phages such as R17, MS2 and f2 (group I of Watanabe1) consist of a single-stranded RNA, about 180 molecules of coat protein and one of A (or maturation) protein, a component required for the functional integrity of the viral particle, possibly for its adsorption to the host2–4. The phage genome comprises three cistrons, accounting for the two proteins mentioned above as well as for a component of the viral RNA replicase5,6.
TL;DR: The RNA of phage Qβ consists of three known cistrons coding for maturation protein, coat protein and the β subunit of the viral replicase and when ribosomes are bound to intact Qβ RNA they attach predominantly to one binding site, namely that at the beginning of the coat cistron.
Abstract: THE RNA of phage Qβ consists of about 3,500 nucleotides1 and comprises three known cistrons coding for maturation protein (a structural component of the viral particle also designated as A or A2 protein), coat protein and the β subunit of the viral replicase2. When ribosomes are bound to intact Qβ RNA they attach predominantly to one binding site, namely that at the beginning of the coat cistron3. This binding site is located at about the 1,400th nucleotide from the 5′ end1.
TL;DR: The enlargement of synaptic vesicles in degenerating terminals which has recently been demonstrated in the pigeon retino‐tectal fibers as an early sign of secondary degeneration, is confirmed in the rat cortico‐caudate system.
Abstract: The enlargement of synaptic vesicles in degenerating terminals which has recently been demonstrated in the pigeon retino-tectal fibers as an early sign of secondary degeneration, is confirmed in the rat cortico-caudate system. Enlarged synaptic vesicles appear already five hours postoperatively in endings which subsequently undergo the classical changes of Wallerian degeneration. Three categories of terminals, SS−, SL− and F-terminals, are defined on the basis of shape and size of synaptic vesicles in the normal rat caudate nucleus. Only the first category is involved after cortical ablation, while the others remain unchanged.
TL;DR: Evidence was found that proteins synthesized in the ganglion cell perikarya migrate in the axoplasm, and some data suggested that two separate molecular waves reached regions rich in synaptic endings in the early phase after injection.
Abstract: The distribution of labeled protein along the pigeon retino-tectal pathway was studied with light microscopic autoradiography after intraocular injection of 3H-l-leucine. Evidence was found that proteins synthesized in the ganglion cell perikarya migrate in the axoplasm. Some data suggested that two separate molecular waves reached regions rich in synaptic endings in the early phase after injection. Their respective speed of migration would be 100–500 mm/day and 20–60 mm/day. The most heavily labeled wave, advancing at a speed of 1–2 mm/day, was detected during the late phase after injection.
TL;DR: The growth of Walker sarcoma was entirely suppressed or greatly enhanced in Nippostrongylus brasiliensis infected rats depending on the timing of the tumour-cell inoculum in relation to the parasitic infection, suggesting that the tumor and parasite share antigens.
TL;DR: It is proposed that the thymic dysplasia in these three sons of consanguineous parents may have developed as a consequence of a stem cell anomaly.