Showing papers by "Université libre de Bruxelles published in 1973"
TL;DR: This paper is an attempt to formalize in Boolean terms genetic situations, from simple concepts like recessitivity and cis-dominance, to models describing complex control circuits, to describe in compact and unambiguous way, systems which become more and more difficult to describe as their complexity is being unravelled.
986 citations
TL;DR: In this article, the evolution of the variable along the most probable path and fluctuation properties around the path are considered from a general point of view with an emphasis on the relation of nonlinearity of evolution and the associated fluctuation.
Abstract: Assuming that a macrovariable follows a Markovian process, the extensive property of its probability distribution is proved to propagate. This is a generalization of the Gaussian properties of the equilibrium distribution to nonequilibrium nonstationary processes. It is basically a WKB-like asymptotic evaluation in the inverse of the size of the macrosystem. Evolution of the variable along the most probable path and fluctuation properties around the path are considered from a general point of view with an emphasis on the relation of nonlinearity of evolution and the associated fluctuation. Anomalous behavior of the fluctuation is discussed in connection with unstable, critical, or marginal states. A general treatment is given for the asymptotic properties of relaxation eigenmodes.
621 citations
TL;DR: A new determination of the binding energy of light hypernuclei (A ⩽ 15) is reported in this paper, based on the analysis of some 27 000 π − mesonically-decaying hypernucus produced by stopping K − mesons in nuclear emulsion.
271 citations
TL;DR: In this article, the authors investigated the compression yield behavior of PMMA over a wide range of experimental conditions which cannot be reached in tensile tests owing to the brittle nature of the material.
Abstract: The compression yield behaviour of PMMA has been investigated, here, over a wide range of experimental conditions which cannot be reached in tensile tests owing to the brittle nature of the material. The plot of the ratio of the compression yield stress to absolute temperature, as a function of the logarithm of the strain-rate, gives a set of parallel curves which can be accurately superimposed by shifting along a slanting straight line. A master curve is built from which the yield behaviour may be predicted for any state of stress, or value of temperature and strain-rate in the glassy range, using Bauwens' yield criterion.
219 citations
165 citations
TL;DR: The surface tension of aqueous solutions of higher alcohols is measured as a function of temperature at constant pressure and mole fraction, and the heat of reversible extension of the surface area vanishes at this minimum as mentioned in this paper.
157 citations
TL;DR: The reliability of a simplified procedure based on isotopic dilution of the labelled estradiol, to be used with very small tumor tissue samples, was studied and compared quite well with the other one except in case of very low concentrations of receptor.
103 citations
TL;DR: In this article, the Bourke lectures of the Faraday Division of the Chemical Society were used as a basis for a paper based on the 1972 Bourke lecture, "The Bourke Lecture".
Abstract: This article is based on the 1972 Bourke lectures of the Faraday Division of the Chemical Society.
90 citations
TL;DR: In 68 patients with disseminated cancer, favorable results were observed in 13 out of 23 (57%), 11 out of 22 (50%), and 19 out of23 (83%) of the patients, respectively, and these results correlated well with the higher antibacterial activity found in sera of patients who received the combination of gentamicin and carbenicillin as compared to seras of patients treated with carbeniillin or Gentamicin alone.
Abstract: Gentamicin, carbenicillin, and the combination of gentamicin and carbenicillin were used at random to treat severe bacteriologically proven infections caused by gram‐negative bacilli. In 68 patients with disseminated cancer, favorable results were observed in 13 out of 23 (57%), 11 out of 22 (50%), and 19 out of 23 (83%) of the patients, respectively. These results correlated well with the higher antibacterial activity found in sera of patients who received the combination of gentamicin and carbenicillin as compared to sera of patients treated with carbenicillin or gentamicin alone. Gentamicin was used in this series at doses ranging from 6 to 8.5 mg/kg/day without the development of serious ototoxicity, or renal toxicity. Copyright © 1973 American Cancer Society
85 citations
TL;DR: The morphologic changes induced by the various experimental procedures suggest that newly formed platelets are larger than platelets of a normal population; some large platelets may be released by macromegakaryocytes; other large thrombocytes probably represent fragments of granular megakaryocyte; and large young platelet are preferentially retained in vivo on glass beads.
79 citations
TL;DR: Mass spectrometric examination of fatty acids synthesized in the presence of high concentrations of D2O provides direct information concerning the extents to which a fatty acid is formed by de novo synthesis and by chain elongation of other fatty acids.
Abstract: Fatty acid synthesis has been studied in livers of rats perfused with 10% D2O and with >90% D2O. The number of deuterium atoms incorporated in 100% D2O is 22.3 and 24.9 per molecule of newly synthesized palmitate and stearate respectively. The result for palmitate agrees with the result obtained by Jungas with rat adipose tissue under quite different conditions ((1968), Biochemistry 10, 3717). Mass spectrometric measurements of deuterium content were used to measure the rate of fatty acid synthesis. The results so obtained agree well with results obtained by measuring tritium incorporation from 3H2O. Mass spectrometric examination of fatty acids synthesized in the presence of high concentrations of D2O provides direct information concerning the extents to which a fatty acid is formed by de novo synthesis and by chain elongation of other fatty acids. Stearate is synthesized at about 40% the rate of palmitate. Of the stearate formed about 97% is made by de novo synthesis. (An alternative interpretation of the last result is that the chain elongation mechanism uses only palmitate synthesized de novo and little or no preexisting palmitate.).
01 Jan 1973
TL;DR: In this paper, the authors give examples of the variety of corrosion phenomena, traces historical developments, describes the economic significance, and presents the results of illustrative experiments, and gives examples of different types of corrosion.
Abstract: The word corrosion means the destruction of a material under the chemical or electrochemical action of the surrounding environment. For this reason corrosion is a subject of technical and economic interest as well as of scientific interest. This chapter gives examples of the variety of corrosion phenomena, traces historical developments, describes the economic significance, and presents the results of illustrative experiments.
TL;DR: In this paper, the authors introduced the concept of subdynamics to study the behavior of large systems, and formulated the usual thermodynamic description of such systems can be formulated in a subspace οП of the Liouville space.
TL;DR: In this paper, two mechanisms of action of these mutations have to be considered, namely a modification of the process of induction (such as removal of inducer exclusion) and a suppression of nitrogen catabolite repression.
TL;DR: The storage form of insulin in beta cells is the beta granule that resembles a microcrystal of zinc insulin, which contains an actin-like substance.
Abstract: Publisher Summary This chapter presents the concept of the involvement of the microtubular-microfilamentous system in the intracellular transport of beta granules and the mechanism by which insulin is released from the beta cell. Glucose stimulates both the release and the synthesis of insulin in beta cells. Insulin release occurs within a few seconds after stimulation with glucose. The sequence of events in the formation of insulin are as follows: (1) proinsulin is formed within the endoplasmic reticulum and is transferred by an energy-requiring process to the Golgi complex, (2) distinct beta granules form within the Golgi complex and are pinched off into the cytoplasm, (3) the C peptide of proinsulin is removed in the Golgi area, and (4) zinc binds with the insulin in the mature beta granules, resulting in the formation of a crystalline matrix. Thus, the storage form of insulin in beta cells is the beta granule that resembles a microcrystal of zinc insulin. The beta granule is surrounded by a smooth membranous sac with a space between the granule and the encompassing membrane. Biochemical studies on microtubular protein isolated from the brain indicate that these structures contain an actin-like substance.
TL;DR: In this paper, the ages of three precambrian orogenic cycles have been defined hy means of U/Ph, Rb/Sr and K/Ar determinations carried out on igneous and metamorphic rocks of southeast Brazil.
Abstract: The ages of three precambrian orogenic cycles have been defined hy means of U/Ph, Rb/Sr and K/Ar determinations carried out on igneous and metamorphic rocks of southeast Brazil. This work confirms the preliminary results obtained by the same authors on the granitoid rocks of Serra dos Orgaos (which belong to the Brazilian orogenic cycle, about 620 m.y.), and on the granulitic gneisses of the Paraiba do Sul Formation (Trans-Amazonian orogenic cycle, about 2070 m.y.). For the Mantiqueira gneisses, considered, by field relationships, to be the oldest rocks of the region, new results establish an age of about 2800 m.y. (λ Rb 87 = 1,47 X 10 - 11 years -1 ). The Juiz de Fora Formation has the same petrologic characteristics as the Paraiba do Sul Formation, and it is supposed to be discordant over the Mantiqueira gneisses. However, the geochronological results seem to demonstrate that it is, at least in part, as old as the latter formation. In addition, this work demonstrates a practically complete redistribution of Sr isotopes among the minerals of all rocks of the region, including the oldest ones, during the late precambrian Brazilian orogeny.
TL;DR: Arguments for a role of plasma FFA in the control of insulin secretion and of insulin sensitivity in man are provided.
Abstract: The aim of the present work was to study the effects of experimental changes in plasma free fatty acid (FFA) levels on basal insulin (IRI) concentration and onβ cell response to IV glucose, tolbutamide or glucagon in man. Each of the 53 subjects tested was studied on two separate occasions: i) in the basal state; ii) after an experimental decrease or increase in plasma FFA levels induced, respectively, by administration of nicotinic acid or the combination of a fat meal and heparin. The lowering of plasma FFA resulted in a small but significant fall in basal insulin concentration and in a 30% decrease in. IRI response whatever the insulinotropic agent used. On the other hand, experimental elevation of plasma FFA enhanced pancreatic response to glucose (+178%) and tolbutamide (+58%), but did not alter significantly the IRI response to glucagon. Both the increase and the decrease in FFA concentration resulted in a reduction in the rate of glucose assimilation. — These results provide arguments for a role of plasma FFA in the control of insulin secretion and of insulin sensitivity in man.
TL;DR: This note tries to improve and clarify the interpretation of the only existing method for constructing quarterly data using related series such that consistency with annual figures is ensured.
Abstract: SUMMARY Several methods have been devised to deal with the problem of constructing quarterly data (a) either when related series are available or (b) when only annual totals exist. Methods (a) lead to quarterly figures inconsistent with annual totals. Method (b) adds nothing to the economic interpretation of the quarterly phenomenon. Very little has been done to construct quarterly data using related series such that consistency with annual figures is ensured. This note tries to improve and clarify the interpretation of the only existing method we know of.
TL;DR: The histological changes of the gonads of Asterias rubens during the annual reproductive cycle are described and an inverse relation exists between the pyloric caecum weight and gonad weight.
TL;DR: Three pairs of simultaneous consonant–vowel syllables were presented over two loudspeakers, and the subject attempted total recall, and results are discussed in terms of the interpretations which have been proposed for right ear superiority in dichotic listening to verbal material.
Abstract: Three pairs of simultaneous consonant vowel syllables were presented over two loudspeakers, and the subject attempted total recall. With the loudspeakers situated to the left and to the right of the subject, the message from the right is better recalled. With one loudspeaker in front of the subject and the other on one side, the message from the middle is better recalled. These results are discussed in terms of the interpretations which have been proposed for right ear superiority in dichotic listening to verbal material.
TL;DR: Some aspects of oxygen equilibrium are reported for both types of hemoglobin obtained from several species, namely oxygen affinity in the absence or presence of inositolhexaphosphate, the Bohr effect and the heme-heme interaction.
01 Jan 1973
TL;DR: In this article, the first experimental investigations of generalized hydrodynamics behavior in simple liquids were performed, which showed that the frequency dependence of transport coefficients is not negligible and should introduced observable effects into the propagation of hyper-sound.
Abstract: Generalized hydrodynamics suggests that at high frequencies, there should be significant departire from classical hydrodynamics behavior in simple fluids. In particular, the frequency dependence of transport coefficients is not negligible and should introduced observable effects into the propagation of hyper-sound. This work which analyzes rayleigh-Brillouin spectra measured in liquid Argon and Neon reports one of the first experimental investigations of generalized hydrodynamic behavior in simple liquids
TL;DR: In this article, les glandes surrenaliennes disposant de a synthese de cholesterol endogene importante (boeuf) ne contiennent que des quantites reduites de cholesterol esterifie et de triglycerides; le nombre de liposomes est petit.
TL;DR: In this article, an order-of-magnitude criterion for the initiation of damage-induced surface topography on clean and well-polished metal single crystals is proposed based on a model of preferential erosion of parts from the sample surface due to a local increase of sputtering yield above "extensive defects".
Abstract: A first approach to the establishment of an “order-of-magnitude” criterion for the initiation of damage-induced surface topography on clean and well-polished metal single crystals is proposed. It is based on a model proposing a mechanism of preferential erosion of parts from the sample surface due to a local increase of sputtering yield above “extensive defects”. These “extensive defects”, resulting of the migration of the point-defects, created during the collision-cascade started by the incoming ions, can indeed influence the sputtering yield if they are located close under the surface, i.e. when the surface has regressed, due to sputtering, to the level where these “extensive defects” have been formed. The condition implies that the formation of “extensive defects” must have taken place before the surface reaches them. The condition is written in terms of the irradiation parameters and quantities characteristic for the migration of point-defects due to the presence of a potential gradient rela...
TL;DR: This method gives results in agreement with data already published by other authors and the same conditions can be used for the analysis of hydrolysates and physiological fluids on a regular amino acid analyzer in a quick and simple way.
TL;DR: The glands of Myrmica rubra aggregate around a source of one of their secretions, which can be called ‘alarm pheromone’, and also around workers of Lasius flavus, and the mechanism of these aggregations differ.
TL;DR: The data indicate that the effects of nicotinic acid on glucose metabolism may be partly mediated through changes in plasma FFA concentration and are consistent with the idea that the “glucose-fatty acid cycle” plays a significant role in the control of glucose metabolism in man.
Abstract: The effects of antilipolysis induced by nicotinic acid on the rates of turnover and oxidation of plasma glucose were studied in normal overnight fasted, obese overnight fasted, and obese starved subjects, using a 14 C-glucose infusion technique. Changes induced by nicotinic acid were similar whatever the nutritional state of the subjects. Plasma FFA levels and blood concentrations of glycerol and ketones decreased by about 60%; glycemia remained essentially unchanged but both the removal rate of plasma glucose and the hepatic glucose output increased by about 25%. Moreover, the fraction of glucose taken up by tissues and promptly oxidized and the fraction of expired CO 2 derived from plasma glucose increased, respectively, by 18% and 33%. This enhancement of glucose utilization occurred despite a small but significant decrease in plasma IRI concentration, indicating that nicotinic acid increased sensitivity to insulin. The above-mentioned results were obtained in 8 of the 10 patients studied. The remaining two subjects did not respond to the administration of nicotinic acid by any significant decrease in FFA nor in glycerol concentrations and showed no change in the rates of glucose turnover and oxidation. These data indicate that the effects of nicotinic acid on glucose metabolism may be partly mediated through changes in plasma FFA concentration and are consistent with the idea that the “glucose-fatty acid cycle” plays a significant role in the control of glucose metabolism in man.
TL;DR: Fever was attributed to the cancer itself in 18 patients: 5 had acute leukemia in relapse, 6 had extensive lymphomas, 7 presented widespread metastatic carcinomas, and, in 6 of them, large liver metastases were present.
TL;DR: In non-ruminant mammals pyruvate derived from carbohydrate, and fatty acids derived from fat, are converted to acetyl-CoA by intramitochondrial enzyme systems, which is an obligatory step in the de novo synthesis of fatty acids.
TL;DR: It is concluded that one of the effects of progesterone might be a repression of RNA synthesis, and repeated treatments with cycloheximide and actinomycin D failed to induce maturation, but often produced ‘pseudomaturation’ in X. laevis.