Showing papers by "Academy of Sciences of the Czech Republic published in 1995"
TL;DR: DFT interaction energy exhibits the same basis set extension dependence as the Hartree‐Fock (HF) interaction energy, so the Boys‐Bernardi function counterpoise procedure should be employed for elimination of the DFT basis set superposition error.
Abstract: Density functional theory (DFT) methods, including nonlocal density gradient terms in the exchange and correlation energy functionals, were applied to various types of molecular clusters: H-bonded, ionic, electrostatic, and London. Reliable results on the structure and stabilization energy were obtained for the first two types of cluster as long as Becke3LYP and Becke3P86 functionals and basis sets of at least DZ + P quality were used. DFT methods with currently available functionals failed completely, however, for London-type clusters, for which no minimum was found on the potential energy surfaces. DFT interaction energy exhibits the same basis set extension dependence as the Hartree-Fock (HF) interaction energy. Therefore, the Boys-Bernardi function counterpoise procedure should be employed for elimination of the DFT basis set superposition error. © 1995 John Wiley & Sons, Inc.
499 citations
TL;DR: The construction of the first complete genetic linkage map of the laboratory rat is reported, identifying 432 markers that show polymorphisms between the SHR and BN rat strains and mapped them in a single SHR × BN F2 intercross.
Abstract: We report the construction of the first complete genetic linkage map of the laboratory rat. By testing 1171 simple sequence length polymorphisms (SSLPs), we have identified 432 markers that show polymorphisms between the SHR and BN rat strains and mapped them in a single (SHR × BN) F2 intercross. The loci define 21 large linkage groups corresponding to the 21 rat chromosomes, together with a pair of nearby markers on chromosome 9 that are not linked to the rest of the map. Because 99.5% of the markers fall into one of the 21 large linkage groups, the maps appear to cover the vast majority of the rat genome. The availability of the map should facilitate whole genome scans for genes underlying qualitative and quantitative traits relevant to mammalian physiology and pathobiology.
478 citations
TL;DR: In this paper, the modified BET isotherm was applied on adsorption data, for which it is possible to determine simultaneously the net micropore volume, the monolayer capacity and the BET parameterC.
Abstract: By application of the modified BET isotherm on adsorption data, for adsorption isotherms which are neither purely of the I or IV IUPAC type, it is possible to determine simultaneously the net micropore volume, the monolayer capacity and the BET parameterC. Specific surface obtained from the monolayer capacity represents the mesopore surface area and is not overestimated as in the case when the presence of micropores is neglected. The obtained BET parameterC can serve for choosing the appropriate master isotherm which is required for calculation of the mesopore-size distribution. The net micropore volume characterises the adsorption capacity when the adsorption mechanism is volume filling of pores.
338 citations
TL;DR: The molecular weight-dependence of tumour capture of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers was studied in vivo using subcutaneous Sarcoma 180 or B16F10 melanoma models and the ratio (accumulation index, AI) of the AUC in tumour to A UC in skeletal muscle (a typical normal tissue) increasing from six to 12 with increasing copolymer molecular weight.
327 citations
TL;DR: In this paper, a 2-dimensional Navier-Stokes equation perturbed by a sufficiently distributed white noise is considered and the existence of invariant measures is known from previous works.
Abstract: A 2-dimensional Navier-Stokes equation perturbed by a sufficiently distributed white noise is considered. Existence of invariant measures is known from previous works. The aim is to prove uniqueness of the invariant measures, strong law of large numbers, and convergence to equilibrium.
305 citations
TL;DR: The results indicated the possibility of diagnosing sex also in other heterogametic dioecious plants and the assay described here might be interesting in any area where rapid sex identification is required at an early stage of plant development.
Abstract: High-resolution flow cytometry was used to analyze nuclear DNA content in dioecious plants Melandrium album and M. rubrum. Very low coefficients of variation (0.53-0.70%) of G0/1 peaks were obtained after the analysis of nuclei isolated by chopping leaf tissues. In both species, females have lower DNA content than males due to sex chromosome heteromorphism. This made it possible to discriminate peaks belonging to female and male nuclei on the same histogram and permitted unambiguous sex identification in both species. The results indicated the possibility of diagnosing sex also in other heterogametic dioecious plants. The assay described here might be interesting in any area where rapid sex identification is required at an early stage of plant development.
270 citations
TL;DR: In this article, the authors describe a computer program REPES, which has been used in treating dynamic light scattering data for eight years but never published, and the algorithm used within it are described in detail.
Abstract: Computer program REPES, which has been used in treating dynamic light scattering data for eight years but never published, and the algorithm used within it are described in detail. A list of papers quoting REPES and a brief discussion of suitability and performance of regularizing methods in inverting Laplace transform are given.
243 citations
TL;DR: The cytotoxicity of chloropolypyridyl ruthenium complexes of structural formulas, and the cytotoxic mer-[Ru(terpy)Cl3] exhibits a significant DNA interstrand cross-linking, point to a potential new class of metal-based antitumor compounds acting by a mechanism involving DNAInterstrandCrosslinking.
Abstract: The cytotoxicity of chloropolypyridyl ruthenium complexes of structural formulas [Ru(terpy)-(bpy)Cl]Cl, cis-[Ru(bpy)2Cl2], and mer-[Ru(terpy)Cl3] (terpy = 2,2':6'2"-terpyridine, bpy = 2,2'-bipyridyl) has been studied in murine and human tumor cell lines. The results show that mer-[Ru(terpy)Cl3] exhibits a remarkably higher cytotoxicity than the other complexes. Moreover, investigations of antitumor activity in a standard tumor screen have revealed the highest efficiency for mer-[Ru(terpy)Cl3]. In a cell-free medium, the ruthenium complexes coordinate to DNA preferentially at guanine residues. The resulting adducts can terminate DNA synthesis by thermostable VentR DNA polymerase. The reactivity of the complexes to DNA, their efficiency to unwind closed, negatively supercoiled DNA, and a sequence preference of their DNA adducts (studied by means of replication mapping) do not show a correlation with biological activity. On the other hand, the cytotoxic mer-[Ru(terpy)Cl3] exhibits a significant DNA interstrand cross-linking, in contrast to the inactive complexes which exhibit no such efficacy. The results point to a potential new class of metal-based antitumor compounds acting by a mechanism involving DNA interstrand cross-linking.
227 citations
TL;DR: Cloacal swabs from wild synanthropic and exoanthropic birds of 57 species in the Czech Republic yielded 32 strains of Salmonella typhimurium, most of which were derived from black-headed gulls, which might play a role in the dispersal of pathogenic salmonellae.
Abstract: Cloacal swabs, collected from 756 wild synanthropic and exoanthropic birds of 57 species in the Czech Republic, yielded 32 strains of Salmonella typhimurium [phage types (PT) 141, 104 and 41], six isolates of S. enteritidis (PT 8, 4 and 6e), and one each of S. panama and S. anatum. Except for one S. enteritidis isolate from a grey-lag goose (Anser anser) and one S. typhimurium isolate from a coot (Fulica atra), all of the other strains were derived from black-headed gulls (Larus ridibundus), of which 24.7% were found to be infected. The black-headed gull might play a role in the dispersal of pathogenic salmonellae.
227 citations
TL;DR: In this article, the present understanding of an important and fundamental part of this relationship, namely, the structural aspects of grain boundary segregation, is reviewed and their application to materials is discussed.
Abstract: Physical and chemical properties of solid materials are strongly. influenced by the chemical composition of internal interfaces, One of the crucial parameters affecting interfacial chemistry is the atomic structure of the interface. Due to its importance. a considerable amount of work was done to elucidate the relationship between structure and chemical composition of interfaces. This article reviews the present understanding of an important and fundamental part of this relationship, namely, the structural aspects of grain boundary segregation. After a brief outline of grain boundary structure and geometry. thermodynamic approaches to describe grain boundary segregation are summarized and their application to materials is discussed. covering particular sites at a single grain boundary as well as the role of interfaces in polycrystals. Both the experimental evidence of grain boundary segregation anisotropy and the theoretical results of computer simulations of grain boundary segregation are summar...
224 citations
TL;DR: According to the data, several oligotrichous ciliate species and Cyclidium sp.
Abstract: In late summer 1993 an intensive study was carried out on protozoan grazing in the epilimnion and metalimnion of the eutrophic Rimov Reservoir in south Bohemia. On average, - 70% of bacterial production was consumed by heterotrophic flagellates and -20% by ciliates. Ciliate numbers increased from 5 to 70 cells ml l over the 5-week study period. Ciliates ~30 pm in size were numerically dominant in both layers and included Halteria grandinella and Strobilidium hexakinetum (Oligotrichida), Cyrtolophosis mucicola (Cyrtolophosida), Cinetochilum margaritaceum (Scuticociliatida), Urotricha spp., and Coleps sp. (Prostomatida). Ciliate species-specific grazing rates on bacteria and picocyanobacteria were determined. The highest individual cell grazing rates, 4,200 bacteria and 560 picocyanobacteria cell-’ h-l, were observed in Vorticella aquadulcis-complex. Oligotrichs ingested on average 360-2,130 bacteria and 76-2 10 picocyanobacteria cell ’ h - I, with H. grandinella (1,560 bacteria cell I h-l), due to its high abundance, as the most important ciliate bacterivore within the system. C. mucicola ingested on average 173 bacteria and 27 cyanobacteria cell- ’ h- l; C. margaritaceum, 57 bacteria and 7 picocyanobacteria cell-’ h--l; and prostomatids, 23-100 bacteria and 2-14 picocyanobacteria cell-’ h- I. Although there was a tight relationship between grazing rates on bacteria and picocyanobacteria (rs = 0.89, n = 12, P < 0.00 I), most of the ciliate species preferred larger picoplankton (i.e. picocyanobacteria), as indicated by their clearance rates. According to our data, several oligotrichous ciliate species and Cyclidium sp. can grow in pelagic conditions and exclusively on picoplankton food at rates of one doubling every 24-75 h.
TL;DR: The predicted hydration sites correctly reproduce the main features of hydration around the B-DNA dodecamer, including guanine and adenine, and of cytosine and thymine.
TL;DR: A necessary and sufficient condition for a linear system to be stabilizable via static output feedback is presented and makes an appeal to the linear-quadratic regulator theory.
TL;DR: In this article, a set of five equations describing vapour-liquid equilibrium properties of the ammonia-water system is presented, which are intended for use in the design of absorption processes.
Abstract: A set of five equations describing vapour-liquid equilibrium properties of the ammonia-water system is presented. They are intended for use in the design of absorption processes. Using variable dependences of technical relevance the equations make it possible to avoid iterative evaluations. The equations were constructed by fitting critically assessed experimental data using simple functional forms. They cover the region within which absorption cycles commonly used operate most often. The enthalpy of the gas phase has been calculated in the ideal mixture approximation. The results are presented in the form of an enthalpy-concentration diagram.
TL;DR: This work has analyzed the temporal regulation of light-induced c-fos gene expression in the SCN of rats maintained in long or short photoperiods and shows that the endogenous circadian rhythm of light responsiveness in theSCN is altered byPhotoperiod, with the duration of the photosensitive subjective night under the short Photoperiod 5-6 h longer than under the long photoperperiod.
Abstract: Seasonal changes of daylength (photoperiod) affect the expression of hormonal and behavioral circadian rhythms in a variety of organisms In mammals, such effects might reflect photoperiodic changes in the circadian pace-making system [located in the suprachiasmatic nucleus (SCN) of the hypothalamus] that governs these rhythms, but to date no functionally relevant, intrinsic property of the SCN has been shown to be photoperiod dependent We have analyzed the temporal regulation of light-induced c-fos gene expression in the SCN of rats maintained in long or short photoperiods Both in situ hybridization and immunohistochemical assays show that the endogenous circadian rhythm of light responsiveness in the SCN is altered by photoperiod, with the duration of the photosensitive subjective night under the short photoperiod 5-6 h longer than under the long photoperiod Our results provide evidence that a functional property of the SCN is altered by photoperiod and suggest that the nucleus is involved in photoperiodic time measurement
TL;DR: The results presented show apparent similarities in the organization of telomeric chromatin in higher plants and mammals.
Abstract: We have examined the structure and chromatin organization of telomeres in Nicotiana tabacum. In tobacco the blocks of simple telomeric repeats (TT-TAGGG)n are many times larger than in other plants, e.g., Arabidopsis thaliana or tomato. They are resolved as multiple fragments 60-160 kb in size (in most cases 90-130 kb) on pulsed-field gel electrophoresis (PFGE) of restriction endonuclease-digested DNA. The major subtelomeric repeat of the HRS60 family forms large homogeneous blocks of a basic 180 bp motif having comparable lengths. Micrococcal nuclease (MNase) cleaves tobacco telomeric chromatin into subunits with a short repeat length of 157 +/- 5 bp; the subtelomeric heterochromatin characterized by tandemly repeated sequences of the HRS60 family is cut by MNase with a 180 bp periodicity. The monomeric and dimeric particles of telomeric and subtelomeric chromatin differ in sensitivity to MNase treatment: the telomeric particles are readily digested, producing ladders with a periodicity of 7 bp, while the subtelomeric particles appear to be rather resistant to intranucleosomal cleavage. The results presented show apparent similarities in the organization of telomeric chromatin in higher plants and mammals.
TL;DR: These studies demonstrate that the HXB and BXH strains can be effectively used for genome scanning studies of complex traits and have revealed several chromosome regions that may be involved in the genetic control of blood pressure and cardiac mass in the rat.
Abstract: In the HXB and BXH recombinant inbred strains derived from the spontaneously hypertensive rat and the normotensive Brown Norway rat, we determined the strain distribution patterns of 500 genetic markers to scan the rodent genome for quantitative trait loci regulating cardiac mass and blood pressure. The markers spanned approximately 1,139 cM of the genome and were tested for correlations with left ventricular mass adjusted for body weight, and with systolic, diastolic, and mean arterial pressures. The marker for the dopamine 1A receptor (Drd1a) on chromosome 17 showed the strongest correlation with left ventricular heart weight (P = .00038, r = -0.59) and the relationship to heart weight was independent of blood pressure. The markers showing the strongest correlations with systolic, diastolic, and mean arterial pressure were D19Mit7 on chromosome 19 (P = .0012, r = .55), D2N35 on chromosome 2 (P = .0008, r = .56), and Il6 on chromosome 4 (P = .0018, r = .53), respectively. These studies demonstrate that the HXB and BXH strains can be effectively used for genome scanning studies of complex traits and have revealed several chromosome regions that may be involved in the genetic control of blood pressure and cardiac mass in the rat.
TL;DR: In this paper, a measurement of the contribution of diffractive interactions to deep-inelastic electron-proton (ep) scattering in the kinematic range 8.5 × 10−4 < Bjorken-x < 0.0133, and 3.7 × 10 −4 < χp <0.043.
TL;DR: In this article, a measurement of the proton structure function was reported for momentum transfer squared Q^2 between 4.5 GeV^2 and 1600 GeV+2 and for Bjorken x between 1.8\cdot10^{-4} and 0.13 using data collected by HERA experiment H1 in 1993.
TL;DR: It is now apparent that the binding site for most allosteric ligands is close to thebinding site for acetylcholine but that it is located at a more extracellular position.
01 Jul 1995-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the basic physical and chemical properties of YAlO 3 :Ce monocrystals are summarized and compared with existing literature, including luminescence, scintillation and absorption characteristics, the γ-ray detection capability, energy resolution in the range of 30-600 keV, light yield and radiation hardness.
Abstract: Yttrium aluminium perovskite activated by cerium (formula YAlO 3 :Ce, abbreviated YAP:Ce) is systematically investigated in view of its use as efficient scintillator for various applications. The basic physical and chemical properties of YAP:Ce monocrystals are summarized in this paper. The luminescence, scintillation and absorption characteristics, the γ-ray detection capability, energy resolution in the range of 30–600 keV, light yield and radiation hardness are presented and compared with existing literature.
TL;DR: In this paper, the authors explain the Ostwald's rule of stages in the case of aqueous solutions of citric acid, sodium hydrogen phosphate and ferrous sulphate.
Abstract: Crystallization from solutions often starts in such a way that thermodynamically unstable phases appear first followed by recrystallization to thermodynamically stable phases. This empirical observation, called as Ostwald's rule of stages, is explained here on the basis of structure changes of solutions. Experiments supporting this explanation have been carried out with aqueous solutions of citric acid, sodium hydrogen phosphate and ferrous sulphate, respectively
TL;DR: The biological activity of the pigment extracts from Monascus purpureus included their antibiotic action not only against bacteria but also against some species of yeasts and filamentous fungi, as well as embryotoxicity and teratogenicity.
Abstract: L. MART~NKOVA, P. JOZLOVA AND D. VESELV. 1995. The biological activity of the pigment extracts from Monascus purpureus included their antibiotic action not only against bacteria but also against some species of yeasts and filamentous fungi, as well as embryotoxicity and teratogenicity. These activities depended on the presence of the orange component (monascorubrin and rubropunctatin). The formation of these compounds was influenced by the composition of the culture medium and by cultivation of the fungus : when amino acids, peptides or proteins were available during cultivation, as in the case of solid-state cultivation on rice, wheat or pearl barley or submerged cultivation with an organic nitrogen source, the bioactive compounds were converted into inactive complexes and, to a lesser extent, into purple pigments (monascorubramine and rubropunctamine) which retained some biological activity. The toxicity of the orange pigments may reside in the same reaction as their detoxication, i.e. in their binding
TL;DR: In this article, the hydrogen evolution reaction was studied on electrolytically prepared amorphous smooth NiP(x) layers with a phosphorus content of 3 to 14 wt%.
TL;DR: In this article, the authors studied the general stress-strain behaviors due to the thermoelastic martensitic transformation induced by a combination of external forces of axial load and torque.
Abstract: Combined tension and torsion experiments with thin wall specimens of Cu-Al-Zn-Mn polycrystalline shape memory alloy (SMA) were performed at temperatureT =A
f
+ 25 K. The general stress-strain behaviors due to the thermoelastic martensitic transformation, induced by a combination of external forces of axial load and torque, were studied. It is shown that the progress of martensitic transformation (MT) at general stress conditions can be well considered as triggered and controlled by the supplied mechanical work (a kind of equivalent stress) in the first approximation. Pseudoelastic strains in proportional as well as nonproportional combined tension-torsion loadings were found fully reversible, provided that uniaxial strains were reversible. The axial strain can be controlled by the change of torque andvice versa due to the coupling among tension and torsion under stress, not only in forward transformation, but also in reverse transformation on unloading. The pseudoelastic strains of SMA polycrystal are path dependent but well reproducible along the same stress path. The evolution of macroscopic strain response of SMA polycrystal, subjected to the nonproportional pseudoelastic loading cycles with imposed stress path, was systematically investigated. The results bring qualitatively new information about the progress of the MT in SMA polycrystal, subjected to the general variations of external stress.
Proceedings Article•
18 Aug 1995TL;DR: In this paper, a fuzy logic of probability for which completeness results (in a probabilistic sense) are provided is proposed. But the main idea behind this approach is that probability values of crisp propositions can be understood as truth-values of some suitable fuzzy propositions associated to the crisp ones, and suggestions and examples of how to extend the formalism to cope with conditional probabilities and with other uncertainty formalisms are also provided.
Abstract: In this paper we deal with a new approach to probabilistic reasoning in a logical frame work. Nearly allmost all logics of probability that have been proposed in the literature are based on classical two-valued logic. After making clear the differences between fuzzy logic and probability theory, here we propose a fuzy logic of probability for which completeness results (in a probabilistic sense) are provided. The main idea behind this approach is that probability values of crisp propositions can be understood as truth-values of some suitable fuzzy propositions associated to the crisp ones. Moreover, suggestions and examples of how to extend the formalism to cope with conditional probabilities and with other uncertainty formalisms are also provided.
TL;DR: In this paper, the compositional dependence of the Gilbert damping parameter and the g-factor for single crystalline FexCo1−x alloy films prepared by rf sputtering was investigated.
TL;DR: In this paper, periodic Schrodinger operators for a particle on a rectangular lattice of sides were discussed, and the band spectrum of these models depends on number-theoretic properties of the parameters.
Abstract: We discuss periodic Schr\"odinger operators for a particle on a rectangular lattice of sides ${\ensuremath{\ell}}_{1},{\ensuremath{\ell}}_{2}$. In addition to the standard ( $\ensuremath{\delta}$-type) coupling with continuous wave functions at lattice nodes, we introduce two other boundary conditions which generalize naturally the one-dimensional ${\ensuremath{\delta}}^{\ensuremath{'}}$ interaction and its symmetrized version; both of them can be used as models for geometric scatterers. We show that the band spectrum of these models depends on number-theoretic properties of the parameters. In particular, the $\ensuremath{\delta}$ lattice has no gaps above the threshold if ${\ensuremath{\ell}}_{2}/{\ensuremath{\ell}}_{1}$ is badly approximable by rationals and the coupling constant is small enough.
TL;DR: In this paper, the influence of carbon dioxide on the thermal decomposition kinetics of calcium carbonate is studied and it is shown that it is possible to obtain meaningful and reliable kinetic parameters from isothermal and non-isothermal data provided that the pressure correction term is included in the kinetic equation.
TL;DR: The presence of microbial enzymes (pectinase, cellulase, xylanase, inulinase and urease) in non-fermentative segments of the digestive tract reflects the reingestion of caecal contents during coprophagy.
Abstract: Activities of twelve hydrolytic enzymes in the digestive tract of young rabbits before weaning (4 weeks old) and adult rabbits (3 months old) were measured. The principal digestive enzymes in both groups of rabbits appeared to be amylase (EC 3.2.1.1), maltase (EC 3.2.1.20), pectinase (EC 3.2.1.15) and proteinases. The stomach of young rabbits contained most of the lipolytic activity and 45.7% of the total proteolytic activity of the digestive tract. The highest specific activities (per g digesta) of amylase, maltase and proteinase in young rabbits were found in the small intestine. Total activities (per segment) of amylase and maltase in the small intestine and the caecum were similar. Activities of cellulase (EC 3.2.1.4), inulinase (EC 3.2.1.7) and beta-glucosidase (EC 3.2.1.21) were low and activity of pectinase was fairly high in all segments of the digestive tract. The highest activity of urease (EC 3.5.1.5) was found in the caecum. Enzymic profiles of the colonic chymus resembled those of the caecum. Total hydrolytic activity was lower in the colon than in the caecum. Specific activities of amylase and invertase (EC 3.2.1.26) were lower and those of inulinase and lactase (EC 3.2.1.23) higher in 4-week-old rabbits than in 3-month-old rabbits. Gastric proteinase represented almost half of the total proteolytic activity of the digestive tract, whereas lipolytic activity of gastric contents was not found in measurable quantities in adult rabbits. The caecal contents of adult rabbits contained most of the total activity of lipase (EC 3.1.1.3), cellulase, xylanase (EC 3.2.1.32), pectinase, lactase, invertase, beta-glucosidase and urease present in the digestive tract.(ABSTRACT TRUNCATED AT 250 WORDS)