showing 36 of ~574560 from 574555 documents
Pascal, entre Descartes y el pirronismo
1994
En la epistemología moderna, fuertemente condicionada por el modelo axiomático de la matemática, cobra singular relevancia el problema de la fundamentación del conocimiento, que llega a convertirse en uno de los ejes principales de la polémica entre el escepticismo filosófico y sus detractores. El propósito de este trabajo es definir la posición de Pascal en un tema central de dicha polémica: el conocimiento de los primeros principios. Partiendo de su doctrina de la incapacidad de la razón, tanto para justificar teóricamente dicho conocimiento, como para destruir nuestra confianza en el mismo, trataré de mostrar que la crítica de Pascal al escepticismo extremo representa una alternativa a l…
D'une bibliothèque privée à une bibliothèque publique : "l'Affaire Andreu" et la naissance de la bibliothèque de Remiremont
1994
National audience
Synthesis and characterization of amphiphilic comb-polymers via ring-opening metathesis polymerization of exo,exo-5,6-bis(alkoxymethyl)-7-oxabicyclo[…
1994
A number of exo,exo-5,6-bis(alkoxymethyl)-7-oxabicyclo[2.2.1]hept-2-enes (exo,exo-5,6-bis(alkoxymethyl)-7-oxanorbornenes) with long alkyl chains were prepared by reduction of the Diels-Alder adduct of furan and maleic anhydride, followed by alkylation with a series of different n-alkylbromides. These monomers were polymerized via ring-opening metathesis polymerization (ROMP) catalyzed by ruthenium trichloride in ethanolic solution. Contrary to a helical conformation as it was predicted by a previous molecular model study the poly(7-oxanorbornenes) adopt a coil conformation in solution. In bulk the materials show side chain crystallization.
Optimal Pre-Oxygenation: The Nasoral-System
1994
The human body’s intra-and extrapulmonary O2 reserves, i.e. the oxygen stores of the functional residual capacity (FRC) and the blood, will be rapidly depleted during any kind of respiratory arrest (apnea). Application of oxygen prior to iatrogenic apnea (e.g. for endotracheal intubation procedures), therefore, commonly is discussed [e.g. Miller, 1990] as the proposed measure designed to achieve an increase in the human body’s oxygen stores sufficient to avoid hypoxemia. This prophylactic application of oxygen simply has become to be termed “pre-oxygenation”, regardless of the amount of increase in the O2 stores actually achieved. A myriad of different techniques and procedures are practica…
Synthesis and structures of some diorganotin bis(hydroxamate)s
1994
Analysis of literature data on the antitumor activity of organotin compounds reveals that R2SnX2 and their complexes containing SnO, SnN or SnS bonds often exhibit biological activity, especially if such bonds are formed by means of intramolecular coordination. Furthermore, a wide range of biological activities, from fungicidal, bactericidal and antiseptic to psychotropic and antitumor, is found to be characteristic for some organic hydroxamic acids (N-acylhydroxylamines). From this point of view the diorgantion bis-hydroxamates in this paper are of particular interest as potential biologically active antitumor drugs. Di-n-butyltin bis(N-methyl-N-p-bromobenzoylhydroxylamine) is being screen…
Visual Tools in Virtual Reality: Complex Environment
1994
In this paper, we analyse an integrated system able to merge graphical and vision technique in order to improve virtual space environment. Virtual space is characterized by Dynamic Visual Icons and Virtual Reality for arising a hererogeneous environment. Essentially, we propose a fusion technique between visual icon and virtual space, where their integration is supported by Visual lcon Grammar (VIG) working on Dynamic lcon and Visual World. VIG allows to test the actions of the Dynamic Icon on the active Visual Word metaphor at the lime "t", and the different rage of transactions between user and VW(visual query, view and brows of under-world,... ). Moreover, user can define, modify and rem…
La gestion et la mobilisation des personnels enseignants : des perspectives difficiles mais exaltantes pour le DAE TMS
1994
International audience
Una institución valenciana en el umbral de la modernidad: la Diputación del General durante el primer cuarto del siglo XVI
1994
Vascular atherosclerotic disease: Evaluation of white blood cell rheology and metabolism after acute intravenous administration of defibrotide
1994
Defibrotide is a single-strand polydeoxyribonucleotide, obtained by controlled depolymerization of DNA extracted from mammalian organs. It stimulates vascular prostacyclin production and secretion (1-3) and enhances fibrinolysis (1, 4-6). Several clinical trials have evidentiated that defibrotide is effective in the prophylaxis of deep vein thrombosis and in the treatment of peripheral obliterative arterial disease (for a review see ref. 7). There are several reports concerning, in vitro and in vivo, the dose-dependent activity of defibrotide on the polymorphonuclear leucocytes (PMN). From these results, the molecule influences the PMN adhesivity (8, 9) and especially PMN activation, with s…
I progetti finalizzati
1994
Il saggio esamina le caratteristiche e la funzione dei progetti finalizzati del CNR.
GERM CELL TUMOURS IN CHILDREN- A Report of 84 Cases
1994
In January 1991 a Protocol for diagnosis and treatment of Germ Cell Tumours (GCT) in children was activated in 15 Italian Paediatric Centres.
Obesity and cardiovascular diseases.
1994
Obesity and overweight have great clinical and social significance and are associated with a number of medical and surgical complications. We attempt here to summarize current knowledge on the subject and describe the research we are presently carrying out in this field. After a brief introduction, definition, and discussion of etiopathogenesis, the indexes of ponderal excess and epidemiology are illustrated. The cardiovascular adjustments and the relationships between obesity and hypertension, ischemic heart disease and congestive heart failure are then treated. One aim of our investigation was to study the modifications of an entire set of biological and clinical parameters which could co…
Archéologie et image de synthèse
1994
Determinantes del consumo privado en la economía española
1994
Arte valenciano. Puntualizaciones historiográficas (I). Las colonizaciones
1994
Langue et Politique: À Quoi Sert la Dialecte dans la Cyrénaïque Romaine?
1994
En Cyrénaïque, comme dans le reste des contrées de la Méditerranée orientale passées sous le contrôle romain, le grec reste la langue écrite prédominante. Des inscriptions latines y apparaissent aussi, en nombre limité; elles sont l'objet de la communication de G. Paci. On a enfin retrouvé quelques bilingues, mais c'est surtout en grec que, pour longtemps, on grave ce qui doit être porté À la connaissance du public.Or, dira-t-on, en quelle forme de grec sont rédigées ces inscriptions? On sait que dans les siècles précédents existe un concurrence entre le dialecte local, seul présent aux VIe et Ve siècles et une forme de langue plus internationalement répandue À partir du IVe siècle, que l'o…
Coding with traces
1994
We prove that the existence of a coding between two trace monoids is decidable for some families of trace monoids. Decidability heavily depends on the structure of the dependence graphs. The concept of coding is based on the new notion of strong morphism between trace monoids.
Probleme?
1994
Polskie wydawnictwa na Śląsku Opolskim po podziale regionu
1994
Arheoloģija un etnogrāfija, 17
1994
El Atlas anatómico de Crisóstomo Martínez como ejemplo de 'vanitas'
1994
El Atlas anatómico de Crisóstomo Martínez como ejemplo de 'vanitas'.
E. F. Schumacher : un precursor de la socioeconomía.
1994
Mercedes.Gomis@uv.es Jose.Perez@uv.es
Una biblioteca "modélica". La formación libresca de Teodoro Ardemans (I)
1994
SE REALIZA UN ESTUDIO DE LA BIBLIOTECA DEL ARQUITECTO TEODORO ARDEMANS A TRAVES DE DOS INVENTARIOS: EL HASTA AHORA INEDITO DE 1726, INMEDIATO A SU MUERTE, Y EL YA CONOCIDO DE 1733, REALIZADO CUANDO SE IBA A REPARTIR LA HERENCIA. EL ANALISIS INCIDE EN LAS INQUIETUDES INTELECTUALES DEL ARQUITECTO Y SEÑALA COMO LA FORMACION DE SU BIBLIOTECA CORRIO PARALELA A SU ASCENSO PROFESIONAL. DE HECHO, SU ORIGEN HUMILDE CONDICIONO QUE NO POSEYERA FONDOS LIBRARIOS CONSIDERABLES, Y HASTA 1697 NO ADQUIRIO LA MAYOR PARTE DE SU BIBLIOTECA EN LA ALMONEDA DE BIENES DE JOSE DE ARROYO. EL INVENTARIO POSTUMO DE ARDEMANS MUESTRA, NO OBSTANTE, QUE FORMO UNA LIBRERIA MUY DISTINTA Y DISTANTE. METODICA Y DISCIPLINADA Q…
Compte rendu de "The Cambridge History of American Literature, Volume I: 1590-1820," ed. Sacvan Bercovitch. Revue Française d’Etudes Américaines 62 (…
1994
Compte rendu
Statistical Modeling for the Flow of Short Fibers Composites
1994
Numerical results are given for the flow of fiber composites modelled as suspensions of non spherical particles. In this framework, because the many particles rotate, their state of orientation is described with a statistical approach. We used these methods to compute coupled solutions in which the orientation of the particles is affected by the flow and the flow itself depends on the orientation of the particles. The computation methods involve an augmented lagrangian approach and a streamline upwind petrov galerkin formulation to solve the convective orientation equation.
Algunas reflexiones sobre la percepción del cambio climático en una muestra de población adulta de nivel cultural medio
1994
El cambio climático es uno de los aspectos del Medio Ambiente que mayor eco social ha alcanzado en los últimos años. El tema ha trascendido de los centros de investigación a la opinión pública de manera distorsionada, debido, en gran parte, a medios de comunicación poco rigurosos. Este trabajo reflexiona sobre la percepción del fenómeno por parte de una muestra de población adulta de nivel cultural medio, que da por sentado un cambio climático importante, producido en los últimos años por el hombre y que ha originado la mayor parte de catástrofes naturales de tipo hidrometeorológico. Esta imagen catastrofista contrasta con la indeterminación que muestra la comunidad científica, que pone de …
Osteoma osteoide de rodilla Dos casos de difícil diagnóstico
1994
Presentamos dos casos de osteoma osteoide yuxtacortical de localización infrecuente en la rodilla y de difícil diagnóstico. La gammagrafía reveló la localización de la lesión y la tomografía axial computerizada (TAC) en cortes finos indicó el lugar exacto, facilitando así la planificación del abordaje quirúrgico de la zona. La resonancia magnética no aportó datos de interés. Tras la cirugía, la sintomatología previa remitió completamente en ambos casos. We present two cases of osteoid osteoma affecting the knee, a very infrequent localization and therefore of difficult diagnosis. The scintigraphy was found to be of valuable assitance in revealing the presence of this lesion at the knee and …
Ursprung und Entwicklung des modernen Menschen (Homo sapiens)
1994
Das gegenwartig wohl umstrittenste Thema menschlicher Stammesgeschichte ist die Evolution von H. sapiens (Ubersicht in Wolpoff 1980, 1992; F. Smith u. F. Spencer 1984; Henke 1988; F. Smith et al. 1989; Mellars u. Stringer 1989; Stringer 1989a, b; Trinkaus 1989a; Hublin u. Tillier 1991; Cavalli-Sforza 1992; A. Wilson u. Cann 1992; Thorne u. Wolpoff 1992; Brauer u. F. Smith 1992). Anlas fur das grose aktuelle Interesse an den Fragen des Ursprungs und der Entwicklung des modernen Menschen sind — sehr ungewohnlich fur die Palaoanthropologie — nicht neue Fossilfunde, sondern vielmehr Impulse aus Nachbardisziplinen. So fuhrten neue archaometrische Verfahren (vgl. Kap. 2.4.2) zur Revision der Dati…
Internal ion impact ionization for Fourier-transform ion cyclotron resonance
1994
A general scheme for ionization and fragmentation of ions in Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICRMS) is introduced. The technique is based upon excitation of high-frequency (i.e. lowmass) primary ions (e.g. N, Al+, H2O+·) which may be generated by standard ionization methods (e.g. electron ionization or laser desorption) inside the trap. Generation of the primary ions is followed by excitation of their cyclotron motion to high translational energy to serve as projectile ions. The projectiles serve two functions: to ionize neutral gas atoms and/or molecules (secondary ions) within the trap internal ion impact ionization (IIII), and to collisionally activate the…
Histometric investigations of placental villi in cases of unexpected fetal acidosis.
1994
It is not unusual that, after an apparently uneventful pregnancy and birth, postpartal analysis of fetal blood unexpectedly reveals the presence of peripartal acidosis, a finding that is inexplicable on the basis of routine observation of the placenta. Using computer-assisted histometric procedures, it is possible to make a quantitative assessment with respect to the maturity and differentiation of villi, thus casting light on the functional anatomy of these structures. 89 single-birth pregnancies were grouped in accordance to the pH of blood in the umbilical artery (pre-acidosis, acidosis, non acidotic). In acidotic newborns, there is an absolute reduction in the surface area of the placen…
The Wiener test and potential estimates for quasilinear elliptic equations
1994
Multiple positive solutions of some elliptic problems via the Morse theory and the domain topology
1994
We use Morse theory to estimate the number of positive solutions of an elliptic problem in an open bounded setΩ ∉ ℝN. The number of solutions depends on the topology ofΩ, actually onP t (Ω), the Poincare polynomial ofΩ. More precisely, we obtain the following Morse relations: $$\sum\limits_{u \in K} {t^{\mu \left( u \right)} } = tP_t \left( \Omega \right) + t^2 [P_t \left( \Omega \right) - 1] + t\left( {1 + t} \right)\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\thicksim}$}}{O} \left( t \right)$$ , where $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\thicksim}$}}{O} \left( t \right)$$ is a polynomial with non-negative integer coefficients,K is the set of positive solutions …
Le Moyen âge dans l'enseigneument secondaire Français et sa perception per l'éléve: entre memoire scolaire et memoire "buissonniere" (Continuació)
1994
Émergence, développement et contacts de la société Cerny en bassin d'Yonne - Point des connaissances et voies de recherche
1994
International audience
Quantum-chemistry calculations of surface complex and orbital control in para/ortho toluene alkylation catalyzed by big pore zeolites
1994
Summary By means of MNDO-PM3 semiempirical quantum-chemistry calculations, the mechanism for alkylation of toluene by methanol on two zeolite clusters with Al and Ga as T III has been studied. The process variables controlled through the hypersurface of the reaction were: the distances of methyl group to the cluster of zeolite and to the toluene molecule; and the distances of the hydrogen atom of the toluene to be transfered to the zeolite cluster and to the toluene. The energetic factor associated with the electronic interaction between the molecular orbitals (LUMO of the zeolite-methoxy and HOMO of toluene) have been calculated by a PMO analysis for two geometries: the transition state an…