Showing papers by "University of Florence published in 1980"

Existence of the displacements field for an elasto-plastic body subject to Hencky's law and Von Mises yield condition

Abstract: We give “necessary” and sufficient conditions on body and traction forces for the existence of the displacements field for an elasto-plastic body subject to Hencky's law and Von Mises yield condition.

First return map and invariant measures

Abstract: We give sufficient conditions for the existence of absolutely continuous invariant measures, finite or σ-finite, for maps on the interval. We givea priori bound for the number of different ergodic measures. The results are obtained via the first return map.

Endogenous Opioids in Cerebrospinal Fluid and Blood in Idiopathic Headache Sufferers

Abstract: SYNOPSIS Endogenous opioids and 5-hydroxytryptamine are the main neurotransmitters that regulate nociception, hedonia and autonomia. These functions are simultaneously impaired in idiopathic headaches. Enkephalins, beta-endorphin, and tryptophan (5-HT precursor) were evaluated in CSF and plasma of migraine and cluster headache sufferers. The following results were obtained:(a) decreased levels of CSF enkephalins in migraine attack and cluster headache,(b) increased CSF Tryptophan (TP) in migraine,(c) increased free plasma TP in migraine attack,(d) increased serum beta-endorphin-like-immunore-activity at the end of attack.A possible link between these findings and the impairment of nociception, hedonia and vegetative balance in headache sufferers is here discussed.

Controllability and stabilization for linear systems of algebraic and differential equations

Abstract: In this paper, we study several reachability and controllability definitions for linear, autonomous systems of degenerate ordinary differential equations. We try to identify the most interesting among them; we prove the connections with stabilizability and full stabilizability properties of the systems, which are also studied. In particular, we show the connection of the stabilizability property with the existence of special solutions of a suitable version of the Riccati equation.

Measurement of the Cosmic-Background Large-Scale Anisotropy in the Millimetric Region

Abstract: Dipole anisotropy in the cosmic background radiation in the 500-3000-\ensuremath{\mu}m wavelength region has been measured in a balloon-borne experiment. A dipole amplitude was found with ${T}_{D}=({2.9}_{\ensuremath{-}0.6}^{+1.3})$ mK, at R. A. = 11h 24m\ifmmode\pm\else\textpm\fi{}0h 40m, $\ensuremath{\delta}=3\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}10\ifmmode^\circ\else\textdegree\fi{}$, the errors arising essentially from detector and magnetometer calibrations. This Letter also reports the existence of a second harmonic ${T}_{Q}=({0.9}_{\ensuremath{-}0.2}^{+0.4})$ mK.

The enlightenment and the sciences of man

Abstract: That the human and the social sciences, or at least a certain number of them, were born during the eighteenth century is a thesis which seems at present largely accepted, and which has been confirmed by some recent, valuable works.! They developed through a rather complex historical process, full of theoretical detours and ambiguities. An adequate illustration of this itinerary would comand a much longer analysis than that which is possible here. Tackling the problem at the level of the history of ideasand thereby passing over all the extra-cultural factors which favoured the growth of the sciences de l'homme during the Enlightenment-it is undeniable that this growth took place in the eighteenth century, above all by way of a critical confrontation with the episteme of the preceding century. It is not by chance that, while tracing the programmes and procedures of the new-born human sciences, many savants andphilosophes of the Age of Reason constantly took as their point of reference precisely the character and content of that episteme. Yet, the result of this confrontation was not uniform. On the one hand, the Enlightenment expressed the highest admiration for the age of Rationalism and the Scientific Revolution. On the other, it strove for self-emancipation from a theoretical perspective which was felt to hinder the birth and growth of certain sciences--or, to recall the notion dear to Imre Lakatos, of certain research programmes. This helps explain the energy with which the eighteenth century criticized some philosophical principles of the age of Descartes, and worked out new cognitive principles and new anthropological views which were considered necessary for the elaboration of the sciences de l'homme. In the course of this paper it is my aim not so much to examine analytically the inquiries and debates through which the Enlightenment founded the human and social sciences, but rather to specify and comment briefly on the main theoretical conditions which permitted the opening of a new perspective for some of those sciences.

Anaphylactic shock from mustard after ingestion of pizza

Abstract: A 27-year-old nurse came to us because of itching and the appearance of wheals on her forearms when she prepared injections containing analgesics (unspecified). In the past, from the age of 12 until her first pregnancy at age 23, she had taken analgesics containing phenazonic compounds regularly during her periods. At age 26 she took an unspecified analgesic for back pain and had an immediate reaction of diffuse itching. Approximately 1 year later a tablet of Nisidina® produced anaphylactic shock. Nisidina is a mixture of two antispastic drugs, adiphedrine and ethyl-N-diphenylaminoacetate, an antihistamine, diphenydramine, and the analgesic methamizole (4-methylamino-1.5dimethyl-2-phenyl-3-pyrazolone sodium methanesulfonate) which is sold in Italy under the name Novalgina®. Patch tests with 10 % aminophenazone gave negative immediate and delayed reactions. The prick test with aminophenazone (10 %) and an intradermal test with a 1 % concentration both provoked an immediate wheal reaction. A patch test with Nisidina (saturated solution) also provoked an immediate wheal reaction, but patch tests with the individual ingredients (10 % pet.) were all negative except for methamizole which gave an immediate wheal reaction. Prick tests with methamizole in concentrations of 1, 5, 25, and 50% all provoked immediate reactions. The structural formulas of methamizole and aminophenazone are: Methamizole (Novalgina)

Transient Fluctuations in the Decay of an Unstable State

Abstract: The decay of an unstable state by the stochastic time of intersection of a given threshold is described. This stochastic parameter is characterized by closed moment equations exactly soluble, whereas previous approaches, in terms of stochastic amplitudes sampled at a fixed time, led to an open hierarchy of equations requiring approximate solutions. The relevance of this new description is shown by the fit with the experimental transient fluctuations of an unstable system.

Researches on the coast of somalia. the shore and the dune of sar uanle

Abstract: SUMMARY A list of Terrestrial Isopoda collected in the area of Sar Uanle (Southern Somalia) is given. Twelve species are mentioned of which six are new species: Tylos africanus, Buchnerillo oceanicus, Alloniscus rohustus, Armadilloniscus mirabilis, Tura candida, Periscyphis rubroantennatus.

Immediate sensitization to methamizole verified by patch tests

Abstract: A 27-year-old nurse came to us because of itching and the appearance of wheals on her forearms when she prepared injections containing analgesics (unspecified). In the past, from the age of 12 until her first pregnancy at age 23, she had taken analgesics containing phenazonic compounds regularly during her periods. At age 26 she took an unspecified analgesic for back pain and had an immediate reaction of diffuse itching. Approximately 1 year later a tablet of Nisidina® produced anaphylactic shock. Nisidina is a mixture of two antispastic drugs, adiphedrine and ethyl-N-diphenylaminoacetate, an antihistamine, diphenydramine, and the analgesic methamizole (4-methylamino-1.5dimethyl-2-phenyl-3-pyrazolone sodium methanesulfonate) which is sold in Italy under the name Novalgina®. Patch tests with 10 % aminophenazone gave negative immediate and delayed reactions. The prick test with aminophenazone (10 %) and an intradermal test with a 1 % concentration both provoked an immediate wheal reaction. A patch test with Nisidina (saturated solution) also provoked an immediate wheal reaction, but patch tests with the individual ingredients (10 % pet.) were all negative except for methamizole which gave an immediate wheal reaction. Prick tests with methamizole in concentrations of 1, 5, 25, and 50% all provoked immediate reactions. The structural formulas of methamizole and aminophenazone are: Methamizole (Novalgina)

Paleobiogeographic Perspectives on the Origin of the Platyrrhini

Abstract: This chapter will explore the various hypotheses and scenarios that have been advanced concerning the paleobiogeographic source of origin of the Platyrrhini. The specific questions to be addressed include: (1) From what geographical region or regions were the immediate ancestors of the New World monkeys derived? (2) When and by what means did these first platyrrhines reach the island continent of South America? (3) What influence did continental drift have on the geographic source of origin and mode of dispersal of the Platyrrhini? Nearly all of the preceding chapters in this volume have attempted to specifically answer one or more of these questions. It is our purpose herein to provide a background for the discussion of all these paleobiogeographic proposals and then to present a consensus-oriented maximum-parsimony model of platyrrhine origins and dispersal.

Hyperresponsiveness of migraine patients to the hypotensive action of bromocriptine.

Abstract: SYNOPSIS Migraine frequently induces hypotension, which has a large postural component. Since pain and other symptoms of the migraine syndrome have been suggested to be central in nature, an involvement of the dopaminergic pathways within the central nervous system that mediate hypotensive responses, might be postulated in migraine patients. In the study, a test dose (2.5 mg) of bromocriptine, a brain dopamine agonist, induced an intense hypotensive reaction in migraineurs, but not in controls. During bromocriptine-induced hypotension, serum dopamine β-hydroxylase activity did not change. The fall of blood pressure, due to bromocriptine, in migraine patients could be considered as an indirect expression of brain dopamine receptor supersensitivity caused by a deficiency of dopamine and or endogenous morphine-like substances. This mechanism is compatible with the hypothesis which considers migraine as a clinical condition of chronic natural opioid abstinence.

α‐SYMPATHOMIMETIC AMINES AND CALCIUM‐MEDIATED ACTION POTENTIALS IN GUINEA‐PIG VENTRICULAR MUSCLE

Abstract: 1 The ability of amines, having alpha- or alpha- and beta-adrenoceptor stimulating activity, to restore excitability and contractility in heart preparations partially depolarized by potassium, was investigated in guinea-pig ventricular muscle in order to elucidate the mechanism of the positive inotropic effect mediated via alpha-adrenoceptors. 2 In preparations in which fast sodium channels were inactivated by K+-rich medium (22 mM) slow electrical responses as well as contractions were consistently induced by high concentrations of phenylephrine (10(-4) to 3 X 10(-4) M) and synephrine (3 X 10(-4) M). 3 The restorative effective effects of both phenylephrine and synephrine were unaffected by phentolamine (10(-5) M) but were readily abolished by practolol (10(-5) M) or sotalol (10(-5) M). 4 Methoxamine induced a dose-dependent positive inotropic effect in ventricular strips paced at 0.5 Hz in normal Tyrode solution; the maximum increase in contractile tension was obtained with methoxamine 10(-4) M. However, at the same concentration, the amine did not induce slow electrical responses in potassium-depolarized preparations. 5 It is concluded that the induction of slow responses by phenylephrine and synephrine is due to beta-adrenoceptor stimulation, and that the increase in cardiac contractility caused by alpha-adrenoceptor stimulation does not involve an increase in slow inward calcium current.

The Timing of Monetary and Price Changes and the International Transmission of Inflation

Abstract: This paper presents a theoretical and empirical investigation into timing relationships between variables within and across industrialized countries. In the analysis we highlight the two polar cases of completely closed and open economies and draw some implications for timing between monetary expansion and inflation, inter-country comparisons of inflation rates and interest rates, and comparisons of central bank behavior. The Granger-causality test is applied in a bivariate fashion to these groups of variables. The main empirical results of our analysis are: (1) Domestic monetary expansion appears to lead inflation in the sense that money Granger-causes prices without feedback, contradicting an implication of the monetary approach to the balance of payments. (2) Hardly any significant timing relationship exists between domestic and foreign rates of inflation during the fixed exchange rate period, providing no evidence for a generalized "law of one price." (3) Some sterilization of official reserve inflows was successfully performed by the non-reserve central banks, except for Canada. (4) U.S. interest rates Granger-cause foreign rates, providing evidence of some international transmission via asset markets.