Complex conductivity in high-Tc single crystal superconductors

1994

The electromagnetic surface impedance of single crystal high-T c superconductors has been examined within the framework of the two-fluid model and the hypothesis that the em field modulates the partial concentrations of both normal and condensate fluids. A comparison with experimental data is reported

La ficción como elemento didáctico en la Visión deleytable de Alfonso de la Torre

1994

La Visión deleytable de Alfonso de la Torre, fue compuesta a petición del ayo del Príncipe de Viana para instruirlo en artes liberales, filosofía moral y preceptos religiosos. La génesis de la obra la encuadra directamente en la literatura de espejos de príncipes y su condición de compendio doctrinal la vincularía a las enciclopedias. A partir de estas coordenadas se estudian las técnicas narrativas y la ficción como principales factores que acrecientan el didactismo y ejemplaridad de la obra.

Stars, a myth in the age of reason

1994

The 20th century is knows as one of the periods of most desacratization in history. Myths are far back in time. Nevertheless, the star system in Hollywood and other film industries, as well as other expressions of cult in mechanical art are to be considered as a 'deteriorated' but anyway important manifestations of religious or pseudoreligious consumption. This text introduces a monographic issue of the journal Archivos de la filmoteca on the star system today.

Teoría y técnica del cuento

1994

A nuclear juvenile hormone-binding protein from larvae of Manduca sexta: a putative receptor for the metamorphic action of juvenile hormone

1994

0027-8424 (Print) Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S.; A 29-kDa nuclear juvenile hormone (JH)-binding protein from the epidermis of Manduca sexta larvae was purified by using the photoaffinity analog for JH II ([3H]epoxyhomofarnesyldiazoacetate) and partially sequenced. A 1.1-kb cDNA was isolated by using degenerate oligonucleotide primers for PCR based on these sequences. The cDNA encoded a 262-amino acid protein that showed no similarity with other known proteins, except for short stretches of the interphotoreceptor retinoid-binding protein, rhodopsin, and human nuclear protein p68. Recombinant bacu…

El sistema redox del plasmalema y el crecimiento por elongación celular

1994

2,5-Dialkoxysubstituierte Oligo- und Poly(1,4-phenylenethenylen)e

1994

2,5-Dialkoxy Substituted Oligo- and Poly(1,4-phenyleneethenylene)s O-Alkylation and regioselective Rieche formylation of 2-methylhydroquinone (1) yields the 2,5-dialkoxy-4-methylbenzaldehydes 4a–j. The corresponding azomethines 5a–j enter in a strongly alkaline medium a selfcondensation reaction leading to the title compounds 6/7a–j. These conjugated oligomers and polymers possess highly regular structures with exclusively (E)-configurated double bonds. GPC, IR, 1H-, 13C-NMR and MS-FD measurements were used for their characterization. Somewhat different results were obtained for the similarly prepared Schiff base 5l which contains chlorine substituents in the side chains. Cleavage of hydrog…

Correlation measurements in Z→τ+τ− and the τ neutrino helicity

1994

Using data collected with the ALEPH detector at LEP correlations between the decay products of the τ+ and τ- produced in the decay of the Z have been measured. The measurements performed in the decays τ-->πν and τ-->ϱν place limits on deviations from the Standard Model. These are given by the parameter ζ with ζ = -1 for the Standard Model. The measured values are ζπ = -0.95 +/- 0.11 +/- 0.05 and ζϱ = -1.03 +/- 0.11 +/- 0.05. For models which predict ζπ = ζϱ = ζ - interpreted as the average τ neutrino helicity - the measurement is ζ = -0.99 +/- 0.07 +/- 0.04.

Zvaigžņotā Debess: 1994, Pavasaris (143) - 1994/95 Ziema (146)

1994

La introducción de las Interacciones Ciencia, Técnica, Sociedad (CTS): una propuesta necesaria en la Enseñanza de las Ciencias

1994

Las investigaciones llevadas a cabo sobre las causas del desinterés de alumnos y alumnas hacia el estudio de disciplinas científicas, así como la necesidad de plantearse lo que es básico hoy en la enseñanza de las Ciencias como consecuencia de los enormes cambios sufridos en la sociedad y en ciencia y tecnología, han generado en numerosos países el desarrollo de una nueva línea de investigación en didáctica. Ésta trata de aproximar la enseñanza de las Ciencias a las necesidades de los alumnos como miembros de sociedades cada vez más desarrolladas, científica ,y tecnológicamente, y ha generado, a su vez, numerosos proyectos que pretenden la integración del aprendizaje de la ciencia en la pro…

Caracterización y activación de enzimas lipolíticas en medios no acuosos

1994

En primer lugar, en esta Tesis se ha explorado por primera vez, de una forma sistemática, el comportamiento de la fosfolipasa A2
de pancreas porcino (ppPLA2) en medios orgánicos
monofásicos con bajo contenido en agua. Se ha investigado como pueden modular las actividades tanto desacilante como acilante de la enzima un número determinado de variables, encontrándose que: (i) la ppPLA2 es severamente inhibida por moderadas concentraciones de fosfolípidos sustrato y producto, lo que tiene implicaciones importantes, particularmente concernientes a su actividad sintética; (ii) la enzima exhibe una notable alteración de su selectividad hacia la cabeza polar de los sustratos con relación a la que m…

Palabras transparentes

1994

Los cuernos figurados en cabeza de Core: nuevas propuestas en torno a su denominación, función y origen

1994

La dialéctica del amo y el esclavo en Nietzsche

1994

La filosofía de Nietzsche se desarrolla también, como no podía dejar de suceder, y entre muchas otras líneas de fuerza, a través de una permanente reflexión en torno a la esclavitud, esto es, su obra filosófica abunda en materiales sobre la famosa dialéctica del amo y del esclavo. Por lo que suele ser habitual pensar de las supuestamente antagónicas y antipódicas relaciones entre el discípulo de Dioniso y el autor de la Enciclopedia de las ciencias filosóficas, la peculiar versión de esa figura de la conciencia que aquel traza en sus escritos, incomparablemente más desconocida y secreta, puede deparar algunas reveladoras sorpresas.

Fracturas del primer metatarsiano. Valoración funcional a largo plazo

1994

Hemos revisado la evolución y resultado final de 24 fracturas del primer metatarsiano tratadas y seguidas en nuestro Hospital «La Fe» de Valencia, durante el periodo comprendido entre 1982 y 1993. Los tratamientos fueron mediante osteosíntesis con agujas de Kirschner y enyesado en 10 casos y con enyesado solamente en 14 pacientes. Las causas más frecuentes fueron los accidentes de tráfico en un 66%. Las fracturas abiertas correspondieron al 37%. Los resultados tras un seguimiento medio de 7 años fueron malos en el 86% de los tratamiento conservadores y en el 70% de los tratamientos quirúrgicos. Las secuelas más frecuentes fueron las metatarsalgias en un 4 1 % de los pacientes. We reviewed t…

Theoretical study of asymmetrically substituted poly(organosilanes)

1994

Summary form only given. Poly(organosilanes) [-SiRR'-] where R and R' represent various alkyl and aryl groups, are the subject of intense scientific and technological interest because of the interesting properties such as, intense near-UV absorption, highly efficient photoluminiscence, non-linear optical properties, these polymers present. In this contribution, we present the electronic structure of some asymmetrically substituted poly(organositanes). We have focused the study on the effect of the tacticity on the electronic structure of the polymer. We have employed ab initio methods to obtain reliable geometrical parameters. The band structure calculations have been performed using the va…

Cutting Temperatures Evaluation in Ceramic Tools: Experimental Tests, Numerical Analysis and SEM Observations

1994

The authors propose a multiple approach for the evaluation of cutting temperatures in ceramic tools. The first approach was the experimental evaluation of equitemperature lines, obtained in three-dimensional cutting by employing constant melting point powders scattered on planes parallel to rake face. In the second approach, a numerical finite element analysis was performed. At this step the determination of the percentage of total heat produced in the operation that flows into the tool was considered and, consequently, the temperature distribution within the whole volume of the insert. Finally, the examination of the crater zone with SEM microscopy confirmed the temperature levels as previ…

‘La battaglia contro il diavolo nel Salomone e Saturno I’

1994

Activation of alpha-1A adrenoceptors mobilizes calcium from the intracellular stores in myocytes from rat portal vein.

1994

International audience; Intracellular free Ca++ concentration ([Ca++]i) was monitored using the fluorescence from the dye fura-2-acetoxymethylester in single myocytes from rat portal vein. In the presence of oxodipine (a L-type Ca++ channel inhibitor), norepinephrine (10 microM) evoked transient increases in [Ca++]i which were related to release of Ca++ from intracellular stores. The alpha-1 adrenoceptors mediating intracellular Ca++ release and inositol phosphate accumulation were identified by using subtype-selective agonists and antagonists. Pretreatment with chloroethylclonidine had little effect on the norepinephrine-induced increase in [Ca++]i and inositol phosphate accumulation. In c…

Dynamical confinement in bosonized 2-dimensional QCD

1994

In the bosonized version of two dimensional theories non trivial boundary conditions (topology) play a crucial role. They are inevitable if one wants to describe non singlet states. In abelian bosonization, color is the charge of a topological current in terms of a non-linear meson field. We show that confinement appears as the dynamical collapse of the topology associated with its non trivial boundary conditions.

The Influence of Morphological Aspects in the Reaction Pathway and Superconductive Properties of Bi2223-Ca2CuO3 Ceramic Composites

1994

ABSTRACTA variation of the solid-state matrix technique has been developed as a procedure for the preparation of 2223 bismuth superconducting phases [(Bi,Pb)2Sr2Ca1-nCunO4+2n, n=3]. The adequate processing of samples of nominal compositions 2223+x 0021, obtained both by this procedure and by the polymer matrix method, has allowed the modification of the microstructure of the calcium copper excess, with no noticeable change in that of the 2223 grains. The study of the phase evolution in the processing of the samples has shown that the formation rate of the 2223 phase is faster when the particle size of the calcium cuprate is smaller. A dependence of the intergranular superconducting properti…

Anästhesiologische und notfallmedizinische Aspekte der Trendelenburgschen Lagerung

1994

Die Vielfalt des klinischen und wissenschaftlichen Wirkens Friedrich Trendelenburgs erstreckte sich, fur einen profilierten deutschen Chirurgen seiner Zeit ganz selbstverstandlich, auch auf die Problemstellungen der Anasthesie und der Erhaltung bedrohter Vitalfunktionen. Der folgende Exkurs soll daran erinnern, warum sein Name noch heute in Anasthesiologie und Notfallmedizin so gelaufig ist.

Hipertrofia pictórica y barroquismo cinematográfico en el montaje de Faust

1994

El objetivo de este artículo es analizar la concepción pictórica que se encuentra en la base del film Faust (F.W. Murnau, 1925). En este sentido, la fuerte permeación de referentes barrocos lleva a la dirección de fotografía del film a la concepción de encuadres plenos cuya máxima expresión sería la inmovilidad. Sin embargo, Murnau introduce un extraño dinamismo en el montaje que genera una dialéctica probablemente única en la historia del cine de los años veinte.

Oxygenation Status of Rhabdomyosarcoma Spheroids with Different Stages of Differentiation

1994

Multicellular tumor spheroids with regional heterogeneities of proliferation and substrate concentrations have been investigated recently to study the biological properties of small tumor nodules prior to onset of vascularization (for reviews see: Mueller-Klieser, 1987; Sutherland, 1988).

Panel Summary Perceptual Learning and Discovering

1994

The problem of learning and discovering in perception is addressed and discussed with particular reference to present machine learning paradigms. These paradigms are briefly introduced by S. Gaglio. The subsymbolic approach is addressed by S. Nolfi, and the role of symbolic learning is analysed by F. Esposito. Many of the open problems, that are evidentiated in the course of the panel, show how this is an important field of research that still needs a lot of investigation. In particular, as a result of the whole discussion, it seems that a suitable integration of different approaches must be accurately investigated. It is observed, in fact, that the weakness of the most part of the existing…

Divinyl Sulfone Cross-Linked Hyperpolymeric Human Haemoglobin as an Artificial Oxygen Carrier in Anaesthetized Spontaneously Breathing Rats

1994

Hyperpolymeric haemoglobin in concentrations necessary to transport oxygen in organism to a significant extent exhibits a negligible oncotic pressure as compared to that of plasma. This property makes hyperpolymeric haemoglobins suitable for development of an artificial oxygen transporting blood additive. With such an additive - in contrast to an oxygen transporting plasma expander - combating a chronic oxygen deficit of tissue (brain, heart, kidney, extremities or in case of anaemia) is possible. Using in these cases an isoncotic oxygen carrying plasma expander instead of an additive would be even more detrimental because of fluid load to heart, at least in case of heart injury. Chronic ox…

Co-learning of total recursive functions

1994

Premessa

1994

La categorizzazione aristotelica dei filosofi preplatonici come "fisiologi"viene messa a confronto con la categorizzazione nietzscheana ne "la filosofia nell'epoca tragica dei Greci", traendone uno spunto che fa da introduzione alla raccolta di saggi contenuta nel volume.

Philip Glass: Company; "Low" Symphony / Shostakovich: La nuova Babilonia (suite) / Nino Rota: La strada (suite dal balletto)

1994

L'articolo è stato realizzato in occasione della prima esecuzione italiana della "Low" Symphony di Philip Glass (Gibellina, 21 giugno 1994) e traccia un breve profilo del compositore, soffermandosi sulla genesi e i caratteri dell'opera.

La educación para la salud y las líneas transversales del curriculo

1994

Necesidad de concretar un currículo basado en las exigencias sociales, las motivaciones del alumnado y los conocimientos que de salud y consumo poseen. En este momento es cuando se conforman como línea transversal. El término transversal no aparece ni en la LOGSE ni en los Decretos que desarrollan los currículos de las diferentes etapas. El diseño curricular base, ya avanza en su propuesta de discusión, pero sin mencionar el término de transversal. Por ello el artículo nos explica si es necesaria la transversalidad y que clase de transversalidad debemos considerar para diseñar y desarrollar un proyecto curricular. Valencia Universidad de León. Facultad de Educación. Servicio de Biblioteca; …

La jubilación y su percepción

1994

The reaction of aromatic α,β-unsaturated ketones with 4,5-diamino-1,6- dihydropyrimidin-6-ones

1994

The reaction of 4,5-diamino-1,6-dihydropyrimidin-6-ones 1 with one equivalent of the chalcones 2 leads in an acidic medium to the formation of the 2,4-diaryl-2,3,6,7-tetrahydro-1H-pyrimido[4,5-b][1,4]diazepin-6-ones 3a-m. The structure elucidation of the products is based on detailed nmr investigations including selective 13C[1H] decoupling experiments.

Al filo del milenio: las posibilidades de un nuevo realismo

1994

La lexicografia catalana moderna a les Illes Balears

1994

The works on lexicography published in the Balearic Islands after the completion of the Diccionari Català-Valencià-Balear (1962) are described and analysed in this paper. These works are already fully inserted in the movement for the linguistic recovery undertaken the last twenty years. Especially, but not exclusively, the paper analyses the reflection on those works of the particularity of the Balearic dialect with regard to the Standard language; that is to say, the degree of vindication of the specific forms and words of the insular Catalan tacitly or explicitly accepted in the Standard frame.

Cercospora beticola toxins. VII. Fluorometric study of their interactions with biological membranes

1994

International audience

In vitro shoot organogenesis from excised immature cotyledons and microcuttings production in Stone Pine

1994

Adventitious buds were induced on isolated immature cotyledons of Pinus pinea L. in the presence of benzyladenine (BA). The response to different BA concentrations also depended upon the culture medium used (modified MS, SH and GD). A wide range of BA concentrations (5, 25 or 50 μM) can be applied to the GD and SH media, which are the media with the lower nitrogen content, without damaging effects. In the MS medium, which has the highest nitrogen concentration, the range of BA that can be applied was narrower and the highest BA concentration was lethal. The addition of indolebutyric acid (0.05, 0.25 or 0.5 μM) to the induction medium, decreased the response of cotyledons. The increase in th…