Showing papers by "Hungarian Academy of Sciences published in 1979"
TL;DR: A coding theorem for the discrete memoryless broadcast channel is proved for the case where no common message is to he transmitted and the result is tight for broadcast channels having one deterministic component.
Abstract: A coding theorem for the discrete memoryless broadcast channel is proved for the case where no common message is to he transmitted. The theorem is a generalization of the results of Cover and van der Meulen on this problem. The result is tight for broadcast channels having one deterministic component
739 citations
TL;DR: In this article, the authors studied the limit behavior as N→∞ and showed that the norming constants tend to infinity more rapidly than the usual norming sequence when the correlation function r(n) tends slowly to 0, and generalized the results to the case when the parameter set is multi-dimensional.
Abstract: Let a stationary Gaussian sequence X
n
, n=... −1,0,1, ... and a real function H(x) be given. We define the sequences
$$Y_n^N = \frac{1}{{A_N }} \cdot \sum\limits_{j = \left( {n - 1} \right)N}^{nN - 1} {H\left( {X_j } \right)}$$
,n=... −1,0,1...; N=1,2, ... where A
N
are appropriate norming constants. We are interested in the limit behaviour as N→∞. The case when the correlation function r(n)=EX
0
X
n
tends slowly to 0 is investigated. In this situation the norming constants A>
N
tend to infinity more rapidly than the usual norming sequence A>
N
=√N. Also the limit may be a non-Gaussian process. The results are generalized to the case when the parameter-set is multi-dimensional.
580 citations
TL;DR: If the sequences are the outputs of two correlated memoryless binary sources, then in some cases the rate of this information may be substantially less than the joint entropy of the two sources.
Abstract: How much separate information about two random binary sequences is needed in order to tell with small probability of error in which positions the two sequences differ? If the sequences are the outputs of two correlated memoryless binary sources, then in some cases the rate of this information may be substantially less than the joint entropy of the two sources. This result is implied by the solution of the source coding problem with two separately encoded side information sources for a special class of source distributions.
413 citations
TL;DR: Evidence indicates that the structural phosphate resides in a protease-sensitive region of the native enzyme, which is not the same as the enzyme-bound phosphate that is derived from ATP during the lyase reaction.
145 citations
TL;DR: In this article, the authors demonstrate that the crystalline quality of Si layers grown on sapphire substrate (SOS) by the CVD method can be greatly improved through the use of implantation of Si ions and subsequent thermal annealing at relatively low temperatures.
Abstract: We demonstrate that the crystalline quality of Si layers grown on sapphire substrate (SOS) by the CVD method can be greatly improved through the use of implantation of Si ions and subsequent thermal annealing at relatively low temperatures (∼550 °C). This method utilizes an amorphous layer created by ion implantation near the sapphire/Si interface. Subsequent regrowth of this amorphous layer starting from the relatively perfect Si surface region leads to a much improved Si crystalline layer, as evidenced by MeV 4He+ channeling and TEM measurements. When the implantation‐formed amorphous layer is located at the outer portion of the Si layer, thermal annealing leads to only a small reduction in the amount of defects in the regrown layer as compared to the unimplanted sample. In these layers, epitaxial regrowth occurs with the same rate and activation energy observed in self‐ion‐implanted 〈100〉 Si.
123 citations
TL;DR: Asymptotically coincident upper and lower bounds on the exponent of the largest possible probability of the correct decoding of block codes are given for all rates above capacity.
Abstract: Asymptotically coincident upper and lower bounds on the exponent of the largest possible probability of the correct decoding of block codes are given for all rates above capacity. The lower bound sharpens Omura's bound. The upper bound is proved by a new and simple combinatorial argument.
117 citations
TL;DR: D dopamine's low concentration relative to norepinephrine (below 15%) suggests that in the cortical areas studied dopamine is present as the precursor of norpinephrine.
99 citations
TL;DR: The results suggest that phage lambda daroE152 carries a "hybrid" rRNA gene which was probably formed by recombination between two different chromosomal rRNA genes.
Abstract: Escherichia coli DNA was digested with restriction endonucleases BamHI, PstI, EcoRI, SalI, HindIII, XhoI, BglII, SmaI, HpaI and with selected double and triple combinations of the same enzymes. The digests were electrophoresed and hybridized with 32P-labelled ribosomal RNA by using the Southern blotting technique. The resulting bands could be arranged into seven groups, and it was possible to construct a unique physical map of the seven rRNA genes (operons) of the bacterial chromosome. Mapping information obtained on several transducing phages and recombinant plasmids carrying rRNA genes, and mapping data published in the literature helped to determine the final map. The results suggest that phage lambda daroE152 carries a "hybrid" rRNA gene which was probably formed by recombination between two different chromosomal rRNA genes.
90 citations
TL;DR: Intergeneric gene transfer by fusion of protoplasts from dividing and mitotically inactive somatic cells is discussed as a possible method in genetic manipulation of higher plants.
89 citations
TL;DR: All mutants tested were effective in symbiotic plant tests and had normal nitrogenase activity, indicating that nitrogenase and nitrate reductase do not share the same molybdenum cofactor.
Abstract: Twenty-five mutants unable to utilize nitrate as sole nitrogen source were isolated from Rhizobium meliloti 41. These mutations mapped at four different sites, narA, narB, narC and narD; narB, C and D were located between trp-15 and ade-15 on the chromosome. NarA mutants were affected in assimilatory nitrate reduction but not in‘respiratory’ nitrate reduction and had methyl viologen-coupled nitrate reductase activity. NarB mutants were affected in both assimilatory and ‘respiratory’ nitrate reduction and lacked methyl viologen-coupled nitrate reductase activity. NarC and narD mutants were impaired not only in assimilatory and ‘respiratory’ nitrate reduction but lacked xanthine dehydrogenase activity as well. Acid-treated crude extracts of these two mutant classes were unable to restore NADPH-coupled nitrate reductase activity to the nit-1 mutant of Neurospora crassa, indicating the lack of active molybdenum cofactor. All mutants tested were effective in symbiotic plant tests and had normal nitrogenase activity, indicating that nitrogenase and nitrate reductase do not share the same molybdenum cofactor.
86 citations
TL;DR: Ability to adapt membrane fluidity to the temperature might be important for survival at low temperatures.
Abstract: 1. 1. Fats of freshwater crustaceans overwintering in an active form are richer in long chain polyunsaturated fatty acids (50%) than of those spending the winter in form of resting eggs (10%). 2. 2. The former species (Cyclops vicinus, Eudiaptomus gracilis) increase the level of docosahexaenoic acid from about 10 to 25% in their phospholipids with decreasing environmental temperature. 3. 3. Exposing warm-adapted Cyclops vicinus and Eudiaptomus gracilis to 5°C in laboratory brought about an increase in the phospholipid docosahexaenoic acid level from 10 to 24%. 4. 4. Ability to adapt membrane fluidity to the temperature might be important for survival at low temperatures.
TL;DR: In this paper, the molecular structure of p -xylene in the gas phase has been determined by electron diffraction analysis, and the most appreciable distortion from the D 6h symmetry of unsubstituted benzene is a reduction from 120° of the internal angle at the ipso carbon.
TL;DR: A series of concentrated ferric chloride solutions, both neutral and acidic, as well as the hydrated melt FeCl3⋅6H2O have been studied by x-ray diffraction as discussed by the authors, and the changes in the radial distribution curves by varying iron concentration or Cl−/Fe3+ ratio and least squares fitting of the structure functions for various solute models lead to an unambiguous conclusion with respect to the dominant species which are present in the solutions.
Abstract: A series of concentrated ferric chloride solutions, both neutral and acidic, as well as the hydrated melt FeCl3⋅6H2O have been studied by x‐ray diffraction. The changes in the radial distribution curves by varying iron concentration or Cl−/Fe3+ ratio and least squares fitting of the structure functions for various solute models lead to an unambiguous conclusion with respect to the dominant species which are present in the solutions. The existence of monochloro, dichloro, trichloro, and tetrachloro complexes, predicted by literature information in dilute solutions, has been established in the different solutions investigated. Octahedral complexes, mainly Fe(H2O)4Cl+2 and Fe(H2O)3Cl3, are the principal species occurring in neutral and acidic solutions while in the hydrated melt tetrahedral FeCl−4 predominates. Species of the type FeCl5(H2O)2− or FeCl3−6 as well as polymeric network are excluded. Hydration water molecules around Cl− anions has been found for both free chloride and chloride ions bonded to iron atoms. Second order interactions around Fe3+ ions are strongly suggested by the presence of a large peak at about 4.2 A in the distribution curves.
TL;DR: In this article, a model is presented in which an ion of a given crystallographic radius is surrounded by a series of concentric spherical layers, each with a different relative permittivity, immersed in the bulk liquid.
Abstract: For the calculation of the electrostatic free energy (and also the entropy) of solvation of an ion, a model is set up in which an ion of given crystallographic radius is surrounded by a series of concentric spherical layers, each with a different relative permittivity, immersed in the bulk liquid. A complete general solution is given for any number of such layers, both for the electrostatic free energy of solvation and the corresponding entropy term. The dielectric saturation effect is taken into account through the different relative permittivities of the layers. The first layer, next to the ion, is considered to have a special role and to have a relative permittivity e=n2, independent of the dielectric saturation effect of the ion.
TL;DR: Terminal degeneration within the hypothalamus was studied by electron microscopy 1 or 2 days after carefully placed microlesion in the arcuate, anterior periventricular, ventromedial, premammillary and posterior hypothalamic nuclei and after microlesions placed in the hypothalamic deafferented 3 weeks earlier.
Abstract: Terminal degeneration within the hypothalamus was studied by electron microscopy 1 or 2 days (1) after carefully placed microlesions in the arcuate, anterior periventricular, ventromedial, premammillary and posterior hypothalamic nuclei and (2) after microlesions placed in the hypothalamus deafferented 3 weeks earlier.
TL;DR: In this article, the authors interpreted X-ray diffraction data of two aqueous solutions of AlCl3 using a model in which the Cl− ions have a coordination number of six and the Al(H2O)3+6 ions interact with twelve water molecules through short and linear H bonds, the water molecules nearest neighbor to the Al3+ ions having a trigonal orientation.
Abstract: X‐ray diffraction data of two aqueous solutions of AlCl3 are interpreted using a model in which the Cl− ions have a coordination number of six and the Al(H2O)3+6 ions interact with twelve water molecules through short and linear H bonds, the water molecules nearest neighbor to the Al3+ ions having a trigonal orientation. Moreover, evidence is given that such a hydration structure tends to persist even when the total amount of water present in the system is rather small.
TL;DR: The inability to induce mutations in the 87C 1 heat-shock puff locus is consistent with the current interpretation of a duplication of coding sequences at the 87A7 and 87C1 heat- shock puffs.
Abstract: Ethyl methanesulphonate (EMS) was used to induce 39 lethal and 13 karmoisin mutations within Df(3R)kar(3J), a nine-band deficiency extending from 87C1 to 87C9 (inclusive). Five complementation groups (four lethal and one visible) were identified and cytologically mapped between 87C4-5 and 87C9, one complementation group per band, with the exception of complementation group A, which is localized to 87C4-5. These positions were determined using a set of overlapping deficiencies, each having at least one breakpoint in the 87C1-9 region. Mutations within a single complementation group have similar lethal phases or subvital phenotypes, consistent with the notion that each complementation group represents a single functional locus. No mutations localized to 87C1-C3. The inability to induce mutations in the 87C1 heat-shock puff locus is consistent with the current interpretation of a duplication of coding sequences at the 87A7 and 87C1 heat-shock puffs.
TL;DR: Root formation was induced by 10-6M benzylaminopurine inPrunus myrobalan, Prunus avium, Prinus persica × PrunUS amygdalus and Cydonia oblonga shoot cultures maintained without exogenous auxin.
TL;DR: Questions arise: (1) Whether the hardening plants can, in some way, compensate for the effects of senescence; (2) To what extent these opposing trends in membrane fluidity affect the survival of such plants at reduced temperatures.
TL;DR: The study demonstrates pharmacologically the possible existence of an opiate receptor mechanism and the pharmacological effect on dopamine and cyclic nucleotide levels were blocked by prior treatments of the cerebral ganglia with naloxone.
TL;DR: In this paper, the formation of inhomogeneous structures and hillocks is explained using the results of structural properties and formation of Al thin films on the basis of literature, the phenomena of crystal growth taking place in vacuum deposited Al films are discussed.
Abstract: After reviewing the structural properties and formation of Al thin films on the basis of literature, the phenomena of crystal growth taking place in vacuum deposited Al films are discussed. The presence of oxygen in the residual gases affects the layer growth of the individual crystallites directly. The adsorbed oxygen accumulates at the growth steps continuously and in consequence of this, oxide precipitates and two-dimensional oxide films can develop along the steps, hindering the growth of layers. These phenomena depend on the orientation of crystallites and influence both the coalescence of contacting crystallites and their recrystallization in continuous films. The formation of inhomogeneous structures and hillocks is explained using these results.
Anschliesend an einen Uberblick uber die Bildung und die strukturellen Eigenschaften von dunnen Aluminiumschichten werden die Wachstumsphanomene beschrieben, die in dunnen Aluminium-Aufdampfschichten auftreten. Das Schichtwachstum der einzelnen Kristallite wird direkt durch Sauerstoff aus dem Restgas des Vakuums beeinflust. Als Folge einer kontinuierlichen Anreicherung des adsorbierten Sauerstoffs an den Stufen konnen sich Oxidausscheidungen und zweidimensionale Oxidschichten langs der Stufen bilden, die das Schichtwachstum behindern. Diese Phanomene hangen von der Orientierung der Kristallite ab und beeinflussen sowohl die Koaleszenz benachbarter Kristallite als auch die Rekristallisation kontinuierlicher Filme. Auf der Grundlage dieser Resultate wird die Bildung von Hugeln und inhomogenen Strukturen erklart.
TL;DR: Germanium dichloride was produced by reaction of Ge + GeCl 4 at 660°C in a combined electron diffraction/quadrupole mass-spectrometric experiment as discussed by the authors.
TL;DR: Preliminary studies, using a procedure that allows for measurement of enzyme activity starting 1 min after beginning the extraction of lyase from hepatocytes, have shown no difference in lyase activity when hepatocytes are treated with or without glucagon.
TL;DR: In this article, four platinum catalysts, Pt-black, PtC, PtSiO2, and PtAl2O3, have been compared in skeletal reactions of 3-methylpentane (3MP) and methylcyclopentane (MCP), in the presence of various partial pressures of hydrogen.
TL;DR: In this article, the authors consider some unconventional partition problems in which the parts of the partition are restricted by divisibility conditions, for example, partitions where the partition is restricted by partitions
Abstract: We consider some unconventional partition problems in which the parts of the partition are restricted by divisibility conditions, for example, partitions
TL;DR: The Fechner-Benham color phenomenon is a percep tual effect in which color is generated by intermittent presentations of patterned white light, and the colors seen were the complements of those normally seen at those postions.
TL;DR: The mitochondrial matrix subfractions from rat liver, kidney cortex, brain, heart, and skeletal muscle were isolated and their protein components were resolved by two-dimensional polyacrylamide gel electrophoresis, increasing the number of mitochondrial matrix proteins observed 3-fold over one-dimensional systems.
TL;DR: The enantioselectivity of catalysts obtained in situ from [Rh(nbd)Cl] 2, (+)-DIOP and triethyl amine for the hydrogenation of aryl ketones is significantly increased if benzene is used as a solvent.
TL;DR: A cytophotometric study of DNA content in Purkinje cells of the cerebellum of rats, cats, chicken and humans (Feulgen staining) revealed that in a certain number of cells the amount of DNA ranged between the diploid and tetraploid level (H2C cells).
Abstract: A cytophotometric study of DNA content in Purkinje cells of the cerebellum of rats, cats, chicken and humans (Feulgen staining) revealed that in a certain number of cells the amount of DNA ranged between the diploid and tetraploid level (H2C cells). The incidence of H2C Purkinje cells varied among the species studied. In rats, which were studied most thoroughly, these cells amounted on average to 3%. In some rats, as well as in some cats and chickens H2C Purkinje cells were entirely absent. In the group of animals possesing H2C Purkinje cells, great interindividual differences were observed. In rats for instance, the incidence of these cells varied from 1 to 23 per cent. Topographic analyses carried out in rat and human cerebellum revealed that H2C Purkinje cells occurred more frequently in the hemispheres than in the vermis. No significant differences were found in the number of H2C Purkinje cells in healthy and Kilham-DNA-virus infected rats. Densitometric analysis of the distribution of nuclear chromatin showed that H2C Purkinje cells were richer in condensed chromatin, especially in the region of the nucleolus, which apparently contains the hyperploid surplus of DNA. It is proposed that the phenomenon of DNA hyperdiploidy arises as a result of either incomplete S-phase in some immature Purkinje cell precursors or the amplification of some DNA sequences particularly those localized in the nucleolar region.