Showing papers by "Hungarian Academy of Sciences published in 1975"

Analysis of the Linear Methods for Determining Copolymerization Reactivity Ratios. I. A New Improved Linear Graphic Method

Abstract: A new graphically-evaluable linear method is suggested for the determination of the reactivity ratios of copolymerization. The proposed new equation is very well adaptable for visual determination of the applicability of the copolymer composition equation. If the experimental data are adequate to the composition equation, the procedure offers a simple and reliable method for the graphical determination of copolymerization constants.

An Approximation of Partial Sums of Independent RV's, and the Sample DF. II

Abstract: Let S n =X 1+X 2+⋯+X n be the sum of i.i.d.r.v.-s, EX 1=0, EX 1 2 =1, and let T n = Y 1+Y 2+⋯+Y n be the sum of independent standard normal variables. Strassen proved in [14] that if X 1 has a finite fourth moment, then there are appropriate versions of S n and T n (which, of course, are far from being independent) such that ¦S n -T n ¦=O(n 1/4(log n)1/1(log log n)1/4) with probability one. A theorem of Bartfai [1] indicates that even if X 1 has a finite moment generating function, the best possible bound for any version of S n , T n is O(log n). In this paper we introduce a new construction for the pair S n , T n , and prove that if X 1 has a finite moment generating function, and satisfies condition i) or ii) of Theorem 1, then ¦S n -T n ¦=O(log n) with probability one for the constructed S n , T n . Our method will be applicable for the approximation of sample DF., too.

Source coding with side information and a converse for degraded broadcast channels

Abstract: Let \{(X_i, Y_i,)\}_{i=1}^{\infty} be a memoryless correlated source with finite alphabets, and let us imagine that one person, encoder 1, observes only X^n = X_1,\cdots,X_n and another person, encoder 2, observes only Y^n = Y_1,\cdots,Y_n . The encoders can produce encoding functions f_n(X^n) and g_n(Y^n) respectively, which are made available to the decoder. We determine the rate region in case the decoder is interested only in knowing Y^n = Y_1,\cdots,Y_n (with small error probability). In Section H of the paper we give a characterization of the capacity region for degraded broadcast channels (DBC's), which was conjectured by Bergmans [11] and is somewhat sharper than the one obtained by Gallager [12].

Functional and fine structural characteristics of the sensory neuron blocking effect of capsaicin.

Abstract: In the eye of rats the long-lasting specific desensitization induced by local or systemic capsaicin treatment is characterized by three phases: 1. complete insensitivity, 2. decreased sensitivity and a tendency to rapid adaptation, 3. normal initial sensitivity with a tendency to rapid adaptation to chemical pain stimuli. A low density of microvesicles and swollen mitochondria were found after local capsaicin treatment in certain nerve endings of the cornea of rats, but no signs of axonal degeneration or alteration in fine structure of non-neural elements were seen. Systemic capsaicin desensitization induced selective mitochondrial swelling in B type of neurons of the trigeminal ganglion which was demonstrable even 60 days after the pretreatment. Actinomycin-D, 8-azaguanine, 6-azauracil, aminopterin, mannomustin or cycloheximide in high doses did not alter the desensitizing effect of systemic capsaicin treatment. However, pretreatment of rats with colchicine or vinblastine prolonged the desensitizing effect of local capsaicin application, probably by inhibiting the axonal flow. It is concluded that capsaicin is a specific sensory neuron blocking agent having a practically irreversible effect in rats and guineapigs.

Non-Mendelian streptomycin-resistant tobacco mutant with altered chloroplasts and mitochondria

Abstract: THE possibility of producing mutant plants of economic value by tissue culture techniques has attracted considerable interest and discussion1–6, and was confirmed by the regeneration of plants from mutant cell lines1. The isolation of cytoplasmic mutants (all of those studied so far have carried Mendelian traits1,2) can be of practical importance; for example, male sterile ones in maize may be used for producing hybrid seeds. We report here, however, properties of a non-Mendelian, cytoplasmic mutant.

Quantitative studies on the supraoptic nucleus in the rat. I. Synaptic organization

Abstract: Four types of synapses: axo-axonic, axo-dendritic, axon-spine, and axo-somatic were distinguished in the supraoptic nucleus in the rat. The density of synaptic terminals (boutons) in this nucleus is 35.17·106/mm3 hence there are over 5 million boutons on each side, and on the average 596 per neuron. Only about one third of the axon terminals in this nucleus originate outside the nucleus and its immediate neighbourhood. Two thirds appear to be of intranuclear or otherwise of local origin. This could be explained by assuming either numerous intranuclear axon collaterals or interneurons having richly arborizing axons, or possibly both.

Analysis of the linear methods for determining copolymerization reactivity ratios. II. A critical reexamination of cationic monomer reactivity ratios

Abstract: A thorough examination of some cationic copolymerization systems by a new method has shown that many published r values have to be corrected significantly and that some are erroneous and meaningless, because for these systems the conventional copolymer compositions equation does not hold. Available information in regard of cationic copolymerizations has been treated in terms of three classes: (a) Systems in which the conventional copolymer composition equation adequately describes the copolymerization mechanism and previous authors justifiably used the two parameter model to calculate reactivity ratios. Our results show that the discrepancy between published r values and the more precise values obtained in this work is about ±23%. (b) Systems in which the approximations implicit in the conventional copolymer composition equation do not hold and the calculated r values are erroneous and misleading. Monomer pairs comprising monomers of significantly different reactivities belong to this class indicating that in copolymerizations in general and in cationic copolymerizations in particular a strong cast system exists, i.e., copolymerization can readily occur within the cast (between monomers of similar reactivities); however, only with difficulty if at all between casts (between monomers of differing reactivities). (c) Systems in which the use of the copolymer composition equation is completely unjustified, the calculated r values are meaningless and in some cases the existence of true copolymers is questioned.

A new method to prove strassen type laws of invariance principle. 1

Abstract: A new method is developed to produce strong laws of invariance principle without making use of the Skorohod representation. As an example, it will be proved that $${{\mathop {\lim }\limits_{n \to \infty } \left( {S_n - W(n)} \right)} \mathord{\left/ {\vphantom {{\mathop {\lim }\limits_{n \to \infty } \left( {S_n - W(n)} \right)} {n^{{1 \mathord{\left/ {\vphantom {1 {6 + \varepsilon }}} \right. \kern- ulldelimiterspace} {6 + \varepsilon }}} }}} \right. \kern- ulldelimiterspace} {n^{{1 \mathord{\left/ {\vphantom {1 {6 + \varepsilon }}} \right. \kern- ulldelimiterspace} {6 + \varepsilon }}} }} = 0$$ with probability 1, for any g3>0, where S n =X 1 + ... +X n , X i is a sequence of i.i.d.r.v.'s with P(X i

Quantitative studies on the supraoptic nucleus in the rat. II. Afferent fiber connections.

Abstract: A quantitative electron microscopic study of synaptic terminal degeneration was performed in the supraoptic nucleus (NSO) after a variety of major transections or ablations, destroying or interrupting in different combinations the afferent pathways known from earlier and own light microscopic degeneration studies. Solutions of a set of equations, expressing the percentage degenerations in synaptic profiles after different combinations in which the several pathways are interrupted by the various interferences, enabled the authors to give the following percentage numbers for afferent synapses from different sources. 32.7% of supraoptic afferents originate from the brain stem probably representing the monoaminergic innervation of this nucleus. The medial basal hypothalamus (21.0%), amygdala (13.5%), septum (13.5%), hippocampus (8.5%) and olfactory tubercle and further rostral cortical region (17.0%) are the other main sites of origin of supraoptic nucleus afferents. There are no supraoptic afferents from the optic nerve, superior cervical ganglion or fimbria hippocampi.

Ramsey theorems for multiple copies of graphs

Abstract: If G and H are graphs, define the Ramsey number r(G, H) to be the least number p such that if the edges of the complete graph Kp are colored red and blue (say), either the red graph contains G as a subgraph or the blue graph contains H. Let mG denote the union of m disjoint copies of G . The following result is proved : Let G and H have k and I points respectively and have point independence numbers of i and j respectively. Then N 1 5 r(mG, nH) < N + C, where N = km + In min(mi, ml) and where C is an effectively computable function of G and H. The method used permits exact evaluation of r(mG, nH) for various choices of G and H, especially when m = n or G = H. In particular, r(mK3 , nK 3 ) = 3m + 2n when m _> n, m 3 2 . 1 . Introduction . Let G and H be graphs without isolated points . Following Chvátal and Harary [11, define the Ramsey number r(G, H) to be the least integer n such that if the edges of Kn (the complete graph on n points) are two-colored, say red and blue, either the red graph contains G as a subgraph or the blue graph containsH. Note that r(Kk, KI) is the \"ordinary\" Ramsey number r(k, 1) for which an extensive literature exists . The evaluation of r(G, H) has received attention from several authors in recent years. An extensive survey is given in [2] . In this paper we will generally follow the notation of Harary [3] . In particular, let nG denote the union of n vertex-disjoint copies of G . In §2 we obtain surprisingly sharp and general upper and lower bounds for r(nG, nH) for G and H fixed and n sufficiently large. In §3 we extend these results to r(mG, nH), in §4 to k-graphs . In §5 we consider a related problem of J . W. Moon concerning the decomposition of a complete graph into complete monochromatic subgraphs of prescribed size . Finally, in §6 we give exact values for various cases . 2. The Ramsey numbers r(nG, IIH). Again following [3], let p(G) denote the number of points of G and let 9,(G) denote the number of points in a maximal independent set in G . As a special notation, let [X] 2 denote the complete graph on X and XY denote the complete bipartite graph on X and Y. Also, let r(G) = r(G, G) ; these we call the diagonal Ramsey numbers . Presented to the Society, January 16, 1974 ; received by the editors January 14, 1974 . AMS (MOS) subject classifications (1970) . Primary 05C35 ; Secondary 05C15 . ( 1 ) Supported under U .S. Office of Naval Research Contract N00014-67-A-0202-0063 . Copyright © 1975 . American Mathematical Society

Extremal Problems for Hypergraphs

Abstract: By a hypergraph we mean a pair (V,A), where V is a finite set, and A = {A1,…,Am} is a family of its different subsets. |V| means the number 1 m of elements of V; this is usually denoted simply by n. Similarly, |A| =m. The elements of V are called vertices, the elements of A are the edges.

Connectednesses and disconnectednesses in topology

Abstract: The development of a general theory for connectednesses and disconnectednesses of topological spaces was started in Preuss' Ph.D. thesis [8], in [4], [9], [10] and [11]. Preuss' investigations exhibited the until then hidden, but conjectured relationship between separation axioms and not-connectedness of topological spaces. Our present paper clarifies the fact that the theory of connectednesses and disconnectednesses of topological spaces corresponds to the radical—semisimple theory of rings and to the torsion—torsionfree theory of abelian categories (cf. Theorems 2.1, and 3.1). It is the purpose of this paper to study and characterize disconnectednesses and connectednesses of topological spaces. Disconnectednesses will be characterized as hereditary, productive and upwards-closed classes and connectednesses will be classified as continuously closed, second additive and q-reversible classes of topological spaces. It turns out that the class of totally disconnected spaces is the smallest non-trivial disconnectedness; the largest and second largest non-trivial disconnectedness is the class of T0-and T1-spaces, respectively. It is shown that there are infinitely many disconnectednesses and they do not form a chain. Finally some questions concerning the theory of connectednesses and disconnectednesses are stated.

Ion-pair formation as a source of enhanced reactivity of the essential thiol group of D-glyceraldehyde-3-phosphate dehydrogenase.

Abstract: The reactivity and the mode of activation of the essential – SH group (Cys-149) of d-glyceral-dehyde-3-phosphate dehydrogenase have been studied by means of a spectrophotometric method [Polgar, L., FEBS Lett. 38, 187–190 (1974)], capable of detecting the dissociated form of the thiol group in proteins. Alkylations of Cys-149 of NAD-free d-glyceraldehyde-3-phosphate dehydrogenase with iodoacetamide and iodoacetate were investigated. The corrected absorbance change on alkylation at 250 nm (which is a direct parameter of the dissociation of the thiol group) and the alkylation rate were determined as a function of pH. The pH profiles of both dissociation and alkylation rate of Cys-149 conform to doubly sigmoid curves. All these curves implicate two ionizing groups (pK1= 5.5, pK2= 8.2). It is concluded that there are two reactive forms of the –SH group in the apoenzyme between pH 5 and 10. One reactive form corresponds to the free mercaptide ion. The other can be identified with an ion-pair composed of a mercaptide ion and some base, possibly the imidazolium group of His-176. The ion-pair has lower molar absorption coefficient and nucleophilicity than the free mercaptide ion. The two reactive forms are transformed into each other with pK2= 8.2. The ion-pair decomposes to a nondissociated thiol group and a protonated base with pK1= 5.5. In the presence of NAD, only the pH-rate profile of alkylation of d-glyceraldehyde-3-phosphate dehydrogenase was measured (at 370 nm). Using iodoacetamide as alkylating agent we also obtained a doubly sigmoid curve. A slight downward shift on pK1 and an upward shift in pK2 indicate that the ion-pair exists in a somewhat wider pH-range in the enzyme-coenzyme complex. An increase in the ionic strength of the reaction mixture from 0.09 to 0.45 M does not abolish the doubly sigmoid character of the curves determined either in the presence or in the absence of NAD.

Distribution-free exponential error bound for nearest neighbor pattern classification

Abstract: The rate of convergence of the nearest neighbor (NN) rule is investigated when independent identically distributed samples take values in a d -dimensional Euclidean space. The common distribution of the sample points need not be absolutely continuous. An upper bound consisting of two exponential terms is given for the probability of large deviations of error probability from the asymptotic error found by Cover and Hart. The asymptotically dominant first term of this bound is distribution-free, and its negative exponent goes to infinity approximately as fast as the square root of the number of preclassified samples. The second term depends on the underlying distributions, but its exponent is proportional to the sample size. The main term is explicitly given and depends very weakly on the dimension of the space.

A simplified and fast version of the Hueckel operator for finding optimal edges in pictures

Abstract: A simplified version of the Hueckel operator was worked out to preserve all the advantages of the original one with a running time considerably shorter. Its concept is based on there interpretation of the Hueckel operator as a template matching method. This reinterpretation renders some theoretical and computational simplifications possible. As a result, an optimal edge-shaped template is constructed by linear combination of two suitably chosen original ones. The parameters of this optimal template characterize the edge segment found in a picture area.

Problems and results on diophantine approximations (II)

Abstract: In a previous paper (referred to as (I)) I discussed several problems. First of all I will report on any progress made on these questions and at the end of the paper I will state a few new questions. I will try to make the references as complete as possible, but I have not done much work on this subject recently and I hope the reader (and writer) will forgive me if I omitted any reference. P. Erdős, \"Problems and results on diophantine approximations\", Put n 2sikx. A k = n lim. E e j=1 I conjectured that lim sup A k = m and expected the proof to be k=m simple. Indeed, not much later I obtained a simple proof. Clunie proved a much stronger result, he showed that for infinitely many k JAkl > c A Perhaps lA k l > ck holds for infinitely many values of k. Clunie gives an example for which JA k l < k for all k. (1967). 2. Following van der Corput, define the discrepancy D(x l BLOCKINxn) of x i ,. .. t x n (the x i are all in (0,1)) as follows : D(x , BLOCKINx) = sup IN (a,b)-(b-a)n~ 1 n 0

Thermostability of Newcastle disease virus strains of different virulence.

Abstract: The thermal inactivation rate constant for infectivity of a total of 24 Newcastle disease virus (NDV) strains was determined at 50° and 56° C. The greater part of the examined NDV strains were found, irrespective of virulence properties, to be thermostable, since the loss of infectivity titre did not exceed 2 logarithmic orders after exposure at 50° C for 60 minutes. Thermostable (I+) and thermolabile (I−) strains with respect to infectivity were uniformly encountered among the 12 avirulent (lentogenic) and 10 fully virulent (velogenic) strains studied. Strains with both heat stable (Ha+) and heat labile (Ha−) haemagglutinin were found in the lentogenic group, whereas haemagglutinins of all examined velogenic strains were heat stable. On the basis of I/Ha character,i.e. combination of thermosensitivity of infectivity and haemagglutinin, all examined strains could be classified into one of three categories: I−Ha− (8 lentogenic strains), I+Ha+ (4 lentogenic and 7 velogenic strains) and I−Ha+ (2 mesogenic and 3 velogenic strains). The possible fourth combination, I+Ha−, was not encountered among the strains studied. Determination of the I/Ha character may be helpful in clarifying the origin of a lentogenic NDV strain.

Crystal orientation dependence of residual disorder in As-implanted Si

Abstract: MeV 4He+ channeling effect measurements combined with transmission electron microscopy (TEM) and Hall effect measurements were employed to study the orientation dependence of the amount of damage remaining after anneal of 200−keV As−implanted Si. The residual disorder after high−temperature annealing was found to depend upon the crystal orientation. For 〈111〉−oriented Si, anomalously high residual disorder was found in the dose region of 1015/cm2 by both the TEM and channeling measurements. Significantly less disorder was found in 〈100〉− and 〈110〉−oriented Si, the latter exhibiting essentially no residual disorder. The electrical activity of the implanted layer was consistent with the orientation dependence observed.

Set Mappings, Partitions, and Chromatic Numbers

Abstract: Publisher Summary This chapter discusses some aspects of combinatorial set theory related to recent results The chapter presents results in their simplest forms so that their proofs reflect the main ideas and difficulties to be found in the proofs of analogous but more comprehensive results The chapter also discusses chromatic numbers of a certain kind of graphs

Light-dependent absorption and selective scattering changes at 518 nm in chloroplast thylakoid membranes.

Abstract: The light-induced absorbance change at 518 nm of isolated chloroplasts consists of a rapid phase, and a slow phase which is complete in about 20 sec The slow component of the 518 nm absorbance change correlates with the light-induced change in 90 degrees light scattering at 518 nm Both show a similar time course, similar pH dependence with a maximum at pH 60, and similar sensitivity to inhibitors and to treatment of the chloroplasts with a low concentration of glutaraldehyde Their light minus dark difference spectra are similar with maxima at about 520 nm It is concluded that they are manifestations of the same phenomenon, and the slow absorbance increase at 518 nm is due to enhanced scattering It is proposed that the light-induced changes in scattering at 518 nm reflect alterations in selective dispersion, due to proton uptake and conformational changes in the chloroplast thylakoid membrane

Evaluation of high conversion copolymerization data by a linear graphical method

Abstract: A method is presented by which experimental data for copolymerization can be treated also at high conversions to allow determination of copolymerization para meters by a simple, graphically evaluable linear equation.

Autoradiographic localization of 3H-gamma-aminobutyric acid in the medial hypothalamus.

Abstract: Tritium labelled gamma-aminobutyric acid (3H-GABA) was infused into the third ventricle of rats with normal or deafferented hypothalamus and the distribution of the label was studied by light and electron microscopic autoradiography.