Showing papers by "Vrije Universiteit Brussel published in 1974"
TL;DR: Thiamineless mutants of Arabidopsis were corrected by treating the seeds with DNA preparations from various bacteria, and possible mechanisms for this are discussed.
Abstract: Avery’s [1] classical experiments showed that it was possible to influence cell function in procaryotes by the addition of exogenous genetic information. Analysis demonstrated that bacteria can take up DNA and integrate it into their genome by genetic recombination (see A. Tomasz, this book).
102 citations
TL;DR: In this article, it was shown that the core of a convex game behaves nicely, and a characterization of the extreme points of a finite game with infinite players was given, using a different method.
76 citations
01 Jan 1974
TL;DR: The life history of Polydora ciliata has been studied in the Bassin de Chasse, Ostende as mentioned in this paper, where three or even four generations succeed one another during the period from April to September.
Abstract: The life-history of Polydora ciliata has been studied in the Bassin de Chasse, Ostende.
Three or even four generations succeed one another during the period from April to September. Their planktonic larvae can be found throughout the year, they have a life of 12 to 14 days. Larvae from 3 to 9 segments are growing 2 segments a day, larvae from 10 to 16 segments 1 segment a day. During the first period they feed on nannoplankton or detrital particles, during the second period they are carnivorous, but also detritiphagous and phytophagous.
After 3 weeks of sedentary life egg-laying takes place. When one or two broods have been produced most animals die. The eggs hatch after 1 week. The worms are detritiphagous and scrape the food directly on the substrate with their palps.
The settling on the substrate is followed by the accumulation and active fixation of mud during May-June. The following generations do not produce a heavy settlement due to interspecific competition and heavy mortality of the larvae.
The density of settled Polydora may amount to 1 million individuals per m2. This causes the destruction and death of the remaining fauna. Its prolific occurrence responsible for the silting up of rocky intertidal shores, is related to the mud suspensed in the water. Being typically euryoecious Polydora can withstand diverse pollutions longer than many other organisms.
75 citations
64 citations
TL;DR: In this article, a bacterial activity involving mineralization of methylmercury was found in bottom sediments of the river Sambre (Belgium), in a zone highly polluted with inorganic mercury.
51 citations
49 citations
TL;DR: In this study, copper and zinc have been determined in 11 different brain areas, obtained at autopsy from cases in which no disorders of the nervous system had been reported.
42 citations
01 Jan 1974
TL;DR: In this article, the authors describe the colonisation of a biotope d'eau saumâtre by a set of artificiels that deviennent planctoniques pendant quelques jours by Harpacticides "benthiques".
Abstract: [Des substrats artificiels, sans contact avec le fond dans un biotope d'eau saumâtre sont colonises apres quelques jours par un nombre d'Harpacticides "benthiques". Vu que la distance entre le fond et les substrats est 1 metre environ, ces animaux doivent nager une distance de plus que 1.000 fois leur taille pour occuper ces nouveaux biotopes. Des experiences pour decrire ce comportement ont montre que la colonisation a lieu pendant la nuit. Ce sont les adultes et copepodites qui deviennent planctoniques pendant cette periode. Les nauplii nes sur les substrats restent benthiques pendant les stades nauplii. Ce comportement peut etre important pour comprendre la speciation du groupe., Des substrats artificiels, sans contact avec le fond dans un biotope d'eau saumâtre sont colonises apres quelques jours par un nombre d'Harpacticides "benthiques". Vu que la distance entre le fond et les substrats est 1 metre environ, ces animaux doivent nager une distance de plus que 1.000 fois leur taille pour occuper ces nouveaux biotopes. Des experiences pour decrire ce comportement ont montre que la colonisation a lieu pendant la nuit. Ce sont les adultes et copepodites qui deviennent planctoniques pendant cette periode. Les nauplii nes sur les substrats restent benthiques pendant les stades nauplii. Ce comportement peut etre important pour comprendre la speciation du groupe.]
42 citations
TL;DR: An “illegitimate” crossing-over between the two arms of a replication fork is envisioned as a possible mode of formation to protect the evolutionary interest of duplicated genes which have escaped their normal regulation.
Abstract: Duplications of arg genes selected as suppressors of polar effects occur in recA strains. Some of them are tandem duplications of short chromosomal segments. An “illegitimate” crossing-over between the two arms of a replication fork is envisioned as a possible mode of formation. The evolutionary interest of duplicated genes which have escaped their normal regulation is stressed.
33 citations
TL;DR: DNA-RNA hybridization experiments performed with separated strands of a φ80 transducing bacteriophage carrying the argECBH cluster from Escherichia coli show that the transcription of the latter is bidirectional and under repression control by arginine.
33 citations
01 Jan 1974
TL;DR: In this paper, the authors used the analogy of calculation and comparison of the resistance of ship models to find the effective choice of form parameters for water resistance on human beings, and concluded that, in the research of water resistance, one also must strive toward an effective choice for form parameters.
Abstract: Using the analogy of calculation and comparison of the resistance of ship models, it appears that, in the research of water resistance on human beings, one also must strive toward an effective choice of form parameters.
TL;DR: Une nouvelle méthode de routine pour le dosage par spectrophotofluorométrie de la sérotonine dans 1 ml de sang est décrite.
Abstract: Une nouvelle methode de routine pour le dosage par spectrophotofluorometrie de la serotonine dans 1 ml de sang est decrite. Grâce a l'emploi d'un antioxydant et a une congelation immediate, le taux de serotonine reste constant pendant au moins une semaine.
TL;DR: In this article, photoionization-and-dissociation efficiency curves for N 2 O + and NO + are presented and discussed, and a potential surface diagram is given on the basis of the results and of their comparison with the literature data.
TL;DR: In this article, an amino acidopathy by overflow of α-amino adipic acid was described in a 6-year-old mentally retarded and hypotonie child, who suffered from epilepsy.
TL;DR: Evidence is reported that the ‘acetylornithinase’ activity present in yeast is no artefactual side-reaction of ornithine acetyltransferase, and its presence may be regarded as paradoxical unless the enzyme involved is shown to bear no relationship to its E. coli counterpart.
TL;DR: The mass spectra of some N-methylpyridinium, quinolinium, isoquinolinium and phenanthridinium salts (R+X−)1 are analyzed (X− = I− or ClO4−).
Abstract: The mass spectra of some N-methylpyridinium, quinolinium, isoquinolinium and phenanthridinium salts (R+X−)1 are analyzed (X− = I− or ClO4−). For X− = I−, thermal decomposition gives rise mainly to the superimposed spectra of CH3I and the free base. Hence, iodide salts cannot be determined specifically by their mass spectra. When an α-methyl group is present, e.g. 2-methylpyridinium methiodide, elimination of HI becomes an important thermal process. For X− = ClO4−, the same pattern is observed, but in addition a generally important peak at [R + 15] is present. This peak is due to the oxidation, mainly α to the nitrogen of the organic moiety by the ClO4− ion, giving rise to the corresponding amide. In some cases, chlorination of the organic moiety has been observed as well as double oxidation. The thermal processes for the perchlorate salts are characteristic and are useful in the elucidation of the quaternary structure.
TL;DR: A total of 26 recombination defective mutants of Bacillus subtilis have been tested for their linkage relationships by the recombination index method, and the previously known recA and recB loci could be distinguished.
Abstract: A total of 26 recombination defective mutants of Bacillus subtilis have been tested for their linkage relationships by the recombination index method. In addition to the previously known recA and recB loci, four further linkage groups (recE, recE, recF, recG) could be distinguished. The recD and recF loci map between ade-16 and cysA14 by PBS1 transduction.
TL;DR: The sluice-dock of Ostend, a shallow (1,5 m) marine biotope of 86 ha stays closed during some 6-7 months of the year and is not influenced by the tides as discussed by the authors.
Abstract: The sluice-dock of Ostend, a shallow (1,5 m) marine biotope of 86 ha stays closed during some 6–7 months of the year and is not influenced by the tides
TL;DR: In this paper, the addition of propene to cyclohexa-1,3-diene has been studied between 512 and 638°K at pressures between 70 and 640 torr.
Abstract: The addition of propene to cyclohexa-1,3-diene has been studied between 512 and 638°K at pressures between 70 and 640 torr. The products are endo- and exo-5-methylbicyclo [2.2.2] oct-2-ene, and their formations are second order. The rate constants (in 1./mole-sec) are given by
The results are discussed in terms of a biradical mechanism.
01 Jan 1974
TL;DR: Recently, cinematographic equipment has been simplified considerably, and film material has become less expensive, and the result is that the student or expert will use the camera for research in most motion studies.
Abstract: From the beginning, cinematographic techniques always have been popular with researchers investigating a variety of human movements. Recently, cinematographic equipment has been simplified considerably, and film material has become less expensive. The result is that the student or expert will use the camera for research in most motion studies. This may be the reason for the increased interest in the use of analytical film techniques in sports during the last few years.
01 Jan 1974
TL;DR: The study of man and movement is a complex task and as Alexis Carrel once remarked, “The authors do not apprehend man as a whole but know him as composed of distinct parts.”
Abstract: The study of man and movement is a complex task. As Alexis Carrel once remarked, “We do not apprehend man as a whole. We know him as composed of distinct parts. And even these are created by our methods.”
TL;DR: The authors analyzes annual revisions of figures for G.N.P. and 8 of its components in 40 countries and concludes that first estimates are very often significantly biased downwards, especially Private Consumption, Fixed Investment, G.D., and G.P., and also successive revisions are sometimes correlated (negatively in most cases).
Abstract: The paper analyzes annual revisions of figures for G.N.P. and 8 of its components in 40 countries. It arrives at the conclusion that first estimates are very often significantly biased downwards, especially Private Consumption, Fixed Investment, G.D.P. and G.N.P. Also successive revisions are sometimes correlated (negatively in most cases). The distribution of revisions differ as between developed and developing countries.
TL;DR: The present data support the existence of a mechanism of joint effusion which is common to several etiologies, and a general increase in the absolute amount of plasma proteins in these synovial fluids, while serum values are close to normal levels.
TL;DR: In this article, the synthesis of a D/E cis isomer of the title compound is described, and the configuration and conformation of the isomers are determined on the basis of their 1H NMR spectra.
Abstract: The synthesis of a D/E cis isomer of the title compound is described. In an attempt to obtain the other D/E cis isomer, epimerisation reactions were studied. The configuration and conformation of the isomers are determined on the basis of their 1H NMR spectra. The shift of the 16b proton on N-9 protonation indicates the quinolizidine conformation. At 270 MHz, the ABCD system of the C-10 and C-11 methylenes can be analysed. The 2J(C-10H2), together with the multiplicity of H-8a, allows an unequivocal assignment of a cis-anti-cis structure to the only D/E cis isomer obtained.
TL;DR: Mutants representing four loci specifying recombination-repair functions in Bacillus subtilis have been characterized in terms of their response in transformation, to transfection by SPP1 or SP50 phage DNA and their sensitivity to X-irradiation.
Abstract: Mutants representing four loci (recB, recD, recE, recF) specifying recombination-repair functions in Bacillus subtilis have been characterized in terms of their response in transformation, to transfection by SPP1 or SP50 phage DNA and their sensitivity to X-irradiation. Each of the four mutants is more sensitive to X-rays than wild type and shows a reduced ability to transform as measured by the uptake and expression of 3H-labelled DNA. Transfection is reduced in recB and recF strains but the recD and recE mutants appear to retain a high level of transfectability for SP50 phage DNA. The recB and recE mutants retain some capacity for repair of X-ray induced single-strand breaks as judged by alkaline sucrose density gradient analysis. The recF and recD strains show no apparent ability to repair single-strand breaks after irradiation.
TL;DR: In this article, it was shown that the ambiguity in the transformation laws of some thermodynamic quantities is not a consequence of special relativity, and that it is not due to any special relativity.