Showing papers by "University of Barcelona published in 1973"
TL;DR: Rodríguez et al. as mentioned in this paper investigated crystal formation by soil bacteria cultured on solid media and found that they can form aragonite (a form of CaCO3) crystals in cultures of Pseudomonas.
Abstract: CERTAIN bacteria form crystals from the solutes in their aqueous environment, and some authors have associated this activity with the extensive deposits of CaCO3 in such places as the Grand Bahama, in spite of the belief that physicochemical effects, such as rapid changes in pH, salinity and temperature, are responsible1–4. Drew5 isolated a denitrifying bacterium able to form CaCO3 crystals in liquid media and named it “Bacterium calcis” (later named Pseudomonas calcis6). Greenfield7 obtained aragonite (another form of CaCO3) crystals in cultures of Pseudomonas in an artificial seawater medium containing Na2CO3 or (NH4)2CO3. Buck and Greenfield reported the same result with marine yeast, and claimed that calcium crystals resulted from the accumulation of calcium deposits on the surface of the cells8. McCallum and Guhathakurta9 observed calcium carbonate deposition by marine bacteria isolated from Bahama Island sediments, and when these were cultured in different media aragonite crystals formed. Shinano10 described many marine bacteria able to form crystals in liquid media. Ramos-Cormenzana11 has also reported crystal formation by soil bacteria in solid media. This, together with the knowledge that previous research concerned only marine bacteria in liquid media, stimulated us to investigate crystal formation by soil bacteria cultured on solid media.
545 citations
Journal Article•
57 citations
TL;DR: Hematological values of six species of galliformes have been determined and the values shown are homogeneous.
48 citations
TL;DR: In this article, a detailed description of the Hipparion fauna from European localities is given, and a list of other fossil mammals from the quarries referred to here will be also given.
32 citations
01 Aug 1973
TL;DR: Both lack of food and high population density increased the numbers of anemones that disappeared, and it was noted that these artificial conditions probably do not occur in the natural habitat.
Abstract: In the artificial habitat of an aquarium specimens of hermit crabs carrying commensal sea anemones gradually lose their anemones, surprisingly because the crabs frequently damage or eat them. On the Mediterranean association Dardanus arrosor and Calliactis parasitica, the influence of feeding, of population density, or the activity of Dardanus towards Calliactis, and the presence or absence of a predator, were investigated as possible factors responsible for the disappearance of the anemone and the anomalous behavior of the crabs. Both lack of food and high population density increased the numbers of anemones that disappeared. It was noted that these artificial conditions probably do not occur in the natural habitat. All freshly collected Dardanus (both sexes), and presumably all Dardanus in their natural habitat, are active in acquiring Calliactis but during 4–5 months in the aquarium most of this activity is lost. In the presence of a probable predator, the octopus Eledone, these inactive crabs become a...
21 citations
TL;DR: In this paper, a possible correlation between the logarithm of the absorption rate constants of closely chemically related drugs consistent with the pH-partition theory and their Rm values in partition chromatograms is reported.
Abstract: A possible correlation between the logarithm of the absorption rate constants (kaof closely chemically related drugs consistent with the pH-partition theory and their Rm values in partition chromatograms is reported. The theoretical basis for the existence of this relationship is briefly outlined. On the basis of the data reported in the available literature for gastric absorption rate constants of several barbiturates and their Rm values in seven paper Chromatographic partition systems, correlations ranging from good to excellent were found.
16 citations
01 Jan 1973
TL;DR: The authors compare des moments dipolaires experimentaux dans le benzene a 25°C du v-triazole and de ses deux derives N-methyles permet de calculer that le tautomere symetrique du vtriazoles represente 83 % du melange Une deuxieme mesure a 45 °C permis de determiner les parametres thermodynamiques de l'equilibre
Abstract: La comparaison des moments dipolaires dans le benzene a 25°C du v-triazole et de ses deux derives N-methyles permet de calculer que le tautomere symetrique du v-triazole represente 83 % du melange Une deuxieme mesure a 45 °C a permis de determiner les parametres thermodynamiques de l'equilibre On compare egalement les moments dipolaires experimentaux avec ceux prevus par des methodes semi-empiriques de la chimie theorique
12 citations
TL;DR: Low, though significant, genotype-temperature interaction exists among the isogenic strains, but not among the F(1) nor F(2) hybrid progenies, and there is no evidence of heterosis and some evidence of dominance.
Abstract: The effect of genotype-temperature interactions on body weight has been studied in a natural population of Drosophila melanogaster using four isogenic strains derived from it, and their hybrid F 1 and F 2 progenies. Measurements were made at four constant temperatures–25°, 21°, 17° and 13°C—and at a temperature oscillating between 17° and 25°C.—Low, though significant, genotype-temperature interaction exists among the isogenic strains, but not among the F 1 nor F 2 hybrid progenies. These low interaction values may be due to the fact that all isogenic strains have a common origin and therefore presumably little genic divergence exists among them. F 1 and F 2 hybrid progenies generally exhibit higher homeostasis than the isogenic strains, although one isogenic line has better homeostasis than the majority of the hybrids.—There is no evidence of heterosis and some evidence of dominance. These results are consistent with the hypothesis that body weight is regulated mainly by additive genetic factors and is subject to stabilizing selection.
5 citations
[...]
TL;DR: The introduction of Copernican ideas into Spain, has, until now, been the subject of a brief article by Father Antonio Romana Pujo S. as discussed by the authors, which is based on the remains of the expurgatory Indices of the Inquisition.
Abstract: The introduction of Copernican ideas into Spain, has, until now, been the subject of a brief article by Father Antonio Romana Pujo S. J.1 (noted in the Bibliografia Kopernikowska 1509–1955 2 ) in which the author follows Ernst Zinner3 in his basic ideas. Previously, Jose Gavira4 and A. Frederico Gredilla in their Biografia de Jose Celestino Mutis con relation de su viaje y estudios practicados en el Nuevo Reino de Granada 5 had dealt with this topic fairly extensively — not to mention the continuous allusions, rather more rhetorical than scientific, to be found throughout all polemics on the subject of Spanish science6. Subsequently, after the date of the completion of the Bibliografia Kopernikowska, Vicente Peset Llorca7 has published a first--class document which basically contains the study in Latin carried out by Gregorio de Mayans y Siscar (1699–1781)8 in 1773 at the request of the Polish Samuel Luther Geret, of Torun. This monograph, now two hundred years old, is based on the remains of the expurgatory Indices of the Inquisition. It will be duly appreciated in the lines to follow. Complementary materials can be found in the different works of J. M. Lopez Pinero9, which will be referred to at the appropriate place.
4 citations
TL;DR: In this article, the second-class axial currents were considered and the best fit was obtained forMA2=0.71 (GeV)2, where MA2 = 0.
Abstract: In this paper a calculation of the reactionνμ+d → p+p+μ− has been carried out using the impulse approximation and taking into account the relativistic corrections. The influence of second-class axial currents is considered. The obtained results are compared with the existing experimental data and using a dipolar parametrization for the axial form factor the best fit is obtained forMA2=0.71 (GeV)2.
4 citations
TL;DR: In this article, a kinetic equation for dense gases is proposed which does not diverge in the kinetic stage and allows us to establish some conclusions about the analyticity of the reduced n-particle distribution function and about the evaluation of transport coefficients.
TL;DR: In this article, the partial radiative capture rates of pions from the 1s and 2p states by /sup 6/Li were calculated using the impulse approximation and the possible configuration mixing of the iritial and firal nuclear wave functions as well as the distortion of the pion wave function due to the finite size of nucleus and the strong interaction between the pions and the nucleons were taken into account.
TL;DR: A thin-layer chromatographic method suitable for the determination of the two epimeric corticosteroids dexameth asone and betamethasone in mixtures is described, finding up to 5% of each epimer in the presence of the other can be accurately determined.
TL;DR: In this article, the enregistrements de la radioemission de Jupiter, which ont ete obtenus pour la premiere fois a Barcelone, sont, en principe, coherents avec la periode du Systeme III (1967.0), and trouve satisfaisante, aussi, l'oscillation que l'on observe, des radiosources A and B, autour de leurs longitudes moyennes respectives.
TL;DR: In this paper, the energy loss spectra of protons in the reaction 12C(p, 2p)11X, where 11X can be B(3/2), B(1/2, Be(3 2 ), and Be(1 2 ), were studied in the framework of Glauber's theory.
Abstract: The energy loss spectra of protons in the reaction12C(p, 2p)11X, where11X can be B(3/2), B(1/2), Be(3/2) and Be(1/2), are studied in the framework of Glauber’s theory. A possible reaction mechanism is discussed.