Showing papers by "University of Florence published in 1976"
TL;DR: In this article, the (infinite-dimensional) supersymmetry algebra in 1 + 1 space-time dimension is extended in order to incorporate, in a non-trivial way, an internal symmetry.
357 citations
TL;DR: In this article, the n -point amplitudes of the U(1) string model with a U (1) colour symmetry were analyzed in detail and it was shown that the critical dimension of this model is D = 2.
312 citations
TL;DR: In this article, dual string models with non-Abelian colour and flavour symmetries are investigated, and it is shown that the particles of the spectrum, which are colour singlets, are classified according to representations of a flavour group SU(2), and the model turns out to contain ghosts independently of the value of the space-time dimension.
147 citations
TL;DR: In this article, a necessary and sufficient condition for feedback stabilization of neutral functional differential equations is presented. But this condition is not applicable to the case of nonconvex functions.
Abstract: In this paper, we prove a necessary and sufficient condition for feedback stabilization of neutral functional differential equations.
98 citations
TL;DR: Even after thirteen electroshock applications, the change in the cortical acetylcholine content was similar to that observed after only one electroshock application, however, no change inThe choline acetyltransferase activity was found after repeated electroshocks.
67 citations
TL;DR: A model based on a cell-cycle dependent exposure of heparan sulphate on the cell surface with a consequent change in the potential of membrane proteins to move in the fluid lipid bilayer to explain some cellular transformations is presented.
67 citations
TL;DR: A new method for the synthesis of benzoyl phosphate was reported, which has the advantages of more rapid procedure, lower cost, and higher yield.
Abstract: A new method for the synthesis of benzoyl phosphate was reported. The advantages are: 1. more rapid procedure; 2. lower cost; 3. higher yield.
62 citations
TL;DR: In this paper, an average vertical profile of the atmospheric refractive index structure coefficient CN2 was calculated from 67 independent radiosondes (balloon) scans up to 20-25 km above sea level, from three European sites.
Abstract: With measurements of the atmospheric microthermal field obtained from 67 independent radiosondes (balloon) scans up to 20–25 km above sea level, from three European sites, we have calculated an average vertical profile of the atmospheric refractive index structure coefficient CN2.
50 citations
TL;DR: In this article, the interaction of 1,2-dichloroethane with an oxygen covered silver surface and the effect of chlorine adsorbed on silver on the oxygen chemisorption were investigated.
47 citations
43 citations
TL;DR: The 69 species found in a recent study of the benthonic algae at Sar Uanle, South of Chisimaio, in southern Somalia are listed in this paper.
Abstract: SUMMARY The 69 species found in a recent study of the benthonic algae at Sar Uanle, South of Chisimaio, in southern Somalia are listed. Many species are reported for the first time for Somalia because there have been few studies of this region of the western Indian Ocean. A considerable number of the species found are widely distributed in the Indo-Malaysian area.
01 Mar 1976
TL;DR: In this article, the collapse rate of a carboxylic acid at the W/A interphase was investigated and the authors determined the reproducibility conditions for the kinetics of substance separation from the monolayer.
Abstract: The importance of the study of the collapse phenomenon both for low molecular weight and macromolecular substances has been shown by several authors (1). I t is known and it has often been stressed that the collapse pressure and area strongly depend upon the rate and the modality of compression even for substances which are simple and very stable at the W/A interphase (2). Here we report a study on the collapse rates of a carboxylic acid at the W/A interphase, undertaken partially to ascertain the reproducibility conditions for the kinetics of substance separation from the monolayer, but chiefly to understand the mechanism and the energies of this process. Arachidic acid was selected for its great stability at the W/A interphase and also because it had previously been used by one of us in a study, at the same interphase, of its mixtures with a polypeptide (3). These components showed surface incompatibility. An understanding of the mechanism of the collapse of arachidic acid may be helpful in determining the reasons of such an incompatibility. Surface pressure measurements as a function of time were performed and ellipsometry was used mainly to obtain the thickness of the bidimensional layer at various stages of collapse. EXPERIMENTAL
TL;DR: Androstenedione, estrone, estradiol-17β, estriol and testosterone concentrations have been measured by radioimmunoassay in plasma of 17 human males affected by breast cancer.
TL;DR: It was concluded that a shortening of the interval between beats abolishes the α-mediated positive inotropic effect.
TL;DR: The use of an iridium microelectrode 0.5 mm in diameter is proposed for measuring the pH gradient in polyacrylamide gels after isoelectric focusing because the electrode exhibits a perfectly linear potential/pH relationship.
TL;DR: Neuron maturation, following cell adhesion to culture dishes, is accompanied by an increased ability of the cells to retain heparan sulfate (HS) on their surface, which is otherwise lost into the culture medium.
TL;DR: In this article, the null controllability with bounded controls of an ordinary control process in Ω(n 2 n ) was studied for the non-autonomous case, and some theorems on characteristic exponents were stated.
Abstract: We study the null controllability with bounded controls of an ordinary control process in ℝ
n
. To prove controllability conditions for the nonautonomous case, we need to generalize the definition of characteristic exponents of a linear system. Some theorems on characteristic exponents are stated.
TL;DR: The association of pharmaco-angiography with norepinephrine and transcatheter arterial embolization is a technique used to obstruct arteries invaded by renal carcinoma and its use as a complement to an operation for renal carcinomas or as definitive treatment in poor surgical candidates is recommended.
TL;DR: Testosterone has been confirmed to be the most important precursor of 5α-dihydrotestosterone in the testis as well as in the other androgen target tissues.
TL;DR: In the Bijar region (western Iran) two distinct volcanic cycles have been recognized as mentioned in this paper : the first consists of high-K cale-alkaline volcanic rocks interpreted as final products of the Tertiary phase of central Iran and the second consists of undersaturated, mainly potassic, alkaline products.
Abstract: In the Bijar region (Western Iran) two distinct volcanic cycles have been recognized. The first, of Upper Miocene age, consists of high-K cale-alkaline volcanic rocks interpreted as final products of the cale-alkaline Tertiary phase of central Iran. The second volcanic cycle, mostly of Pleistocene age (0.5–1.3 m.v.) consists of undersaturated, mainly potassic, alkaline products. As the lavas of this last phase are slightly fractionated, the chemical differences shown by these rocks have been interpreted as primitive features related to the physical conditions governing the partial melting in the mantle and/or the mantle heterogeneity. In a volcanic center (Sarajukh volcano) contemporaneous basic and acid magmas have been found, and interpreted as derived from two different and independent sources. The alkaline basic volcanism is considered as an expression of disjunctive processes that have affected the western margin of the Iranian plate after the Pliocene.
TL;DR: Modifications of the sensory function are the same as observed in subjects with a previous painful infarction, but are quite different from those observed in patients with angina pectoris.
Abstract: The sensory function of the upper limbs was examined in 18 subjects who had a myocardial infarction without a well-defined episode of chest pain. The cutaneous pain threshold was significantly higher than in normals. The ischaemia of the upper limbs induced patterns of sensations different from the normals, with onset of pain and of autonomie and coenaesthesic disturbances. These modifications of the sensory function are the same as observed in subjects with a previous painful infarction, but are quite different from those observed in patients with angina pectoris.
TL;DR: The visible spectra of solutions of cobalt(II) bovine carbonic anhydrase (carbonate hydro-lyase, EC 4.2.1.1) with increasing amounts of acetate have allowed the determination of the apparent inhibition constants and of the extrapolated limit spectRA of the completely bound enzyme.
TL;DR: The possibility that PS and PE might increase ACh output through a mechanism facilitating Ca penetration is discussed.
Abstract: In this paper an investigation into the effect of the administration of phospholipids on the spontaneous out put of acetylcholine (ACh) from the cerebral cortex in the rat is reported. The investigation was prompted by the report (Toffano and Leon, 1975) that the administration of phospholipids extracted from bovine cerebral cortex could influence brain levels of glucose and dopa mine.
TL;DR: In this paper, the infrared and Raman spectra of crystalline ethylenediamine at 200 K and 78 K have been measured from 30 cm −1 and are interpreted on the basis of the recently determined crystal structure.
TL;DR: A list of nine Decapods collected from the Sar Uanle beach includes five species described for the first time in Somalia as discussed by the authors, and the distribution, zonation, activity rhythms, biological cycle and feeding patterns of the Decapod are described.
Abstract: A list of nine Decapods collected from the Sar Uanle beach includes five species described for the first time in Somalia. The distribution, zonation, activity rhythms, biological cycle and feeding ...
TL;DR: A comparison of the geological and geophysical features of the Tyrrhenian and Pannonian basins shows that both are interarc basins; the former ensimatic and the latter ensialic as discussed by the authors.
TL;DR: In this article, methysergide and ergotamine facilitation of 5-HT activity may occur at peripheral vasomotor receptors, or centrally in the brain, which is consistent with the postulated central nature of pain in essential headache.
Abstract: SYNOPSIS
Potentiation of venospastic action of 5-HT by methysergide and ergotamine was demonstrated in man by using venomotor receptors as substrate in a venoconstriction test. 5-HT facilitation was observed only when anti-migraineous drugs were tested in concentrations similar to those expected after therapeutic administration. When ergotamine and methysergide were used in higher concentrations, the expected antagonism to 5-HT was clearly demonstrated. It is concluded that methysergide and ergotamine therapy is not antiserotonergic. These drugs act as partial agonists of 5-HT. Methysergide and ergotamine facilitation of 5-HT activity may occur at peripheral vasomotor receptors, or centrally in the brain. This latter probably is consistent with the postulated central nature of pain in essential headache.
TL;DR: In this article, the authors derived approximate expressions for the rate constant for the reaction at constant applied potential, as corrected for diffuse-layer effects only, for the case of adsorbed reactants with partial charge transfer.
TL;DR: In this paper, the electron spin relaxation of the copper ion was studied in the liquid phase in the faujasite cavities of a fully hydrated Y zeolite.
TL;DR: Observation at light and electron microscope have been carried out on the small intestine of Rats after abdominal irradiation with sublethal doses at very close intervals to try to explain the simultaneous modifications of leucineaminopeptidase (LAP) activity.
Abstract: Rats have been sacrificed after abdominal irradiation with sublethal doses at very close intervals. Observation at light and electron microscope have been carried out on the small intestine of these animals in order to try to explain the simultaneous modifications of leucineaminopeptidase (LAP) activity. In connection with the increase of LAP activity no modifications have been evidenced, at the light microscope, in the differentiated cells of the villus where the membrane digestion process takes place. In the crypt-villus junction we observe at the electron microscope a remarkable increase in the number of ribosomes since the early intervals. Also during the return phase to normal activities the cells of the crypt and of the crypt-villus junction show a temporaneous increase in the amount of ribosomes. Shortly afterwards we observe an increase of LAP activity.