Informātika: Ekonomikas informātika

1991

Rakstu krājumā apkopoti pētījumu rezultāti par ekonomikas informātikas teorētiskām un praktiskām problēmām - datu apstrādes projektēšanu, modelēšanu, organizāciju un ekonomisko analīzi, izmantojot dažāda līmeņa datorus.

El maltrato infantil : un análisis ecológico de los factores de riesgo

1991

Analysis of Educational Frequency Data from a Complex Sample Survey

1991

Abstract Some recent methods are presented for analyzing categorial data from complex surveys involving clustering familiar in educational research where e.g. teaching groups are used as sample clusters. The methods are introduced through a discussion of the test of independence on a two‐way table and the analysis of a two‐way table using logistic regression models. The analyses are illustrated using data from the First National Assessment of the Finnish Comprehensive School 1979. The primary focus of the paper is on the methods that provide first‐order corrections to standard multinomial‐based chi‐square tests by taking account of survey design effects. Both first‐ and second‐order correct…

The Coexistence of Three Species of Daphnia in the Klostersee: iii. The Simulation Model Coda

1991

The population dynamics of three coexisting Daphnia species are described by means of a discrete event simulation model. The model is formulated in the algorithmic language SIMULA which allows very convenient object-oriented programming. Different compartments of a lake are simulated at different levels of integration, each represented by a PROCESS CLASS in SIMULA: The properties of the lake are deposited in a set of meteorological data which were measured in the field. Fish are simulated as a population with properties which are derived from field observations and Daphnia are represented as individuals. The model shows that hypotheses about the stabilizing mechanisms (seasonal change of en…

Nicotinic acetylcholine receptors have ligand-specific attachment point patterns.

1991

Employing a panel of synthetic peptides as representative structural elements of the nicotinic acetylcholine receptor from Torpedo electric organ, we recently identified three sequence regions of the receptor (alpha 55-74, alpha 134-153 and alpha 181-200) serving as subsites for the binding of high molecular weight antagonists of acetylcholine (Conti-Tronconi et al. 1990). The relative binding affinities to these subsites of alpha-bungarotoxin and three competitive antibodies varied in a ligand-specific fashion. Employing a set of homologous synthetic peptides differing from alpha 181-200 by the exchange of single amino acid residues along the sequence, we now find that ligand binding cruci…

Funkcja indolowa tryptofanu w syntezie peptdów

1991

Caracterización y datación de una unidad carbonática de edad noriense (fm zamoranos) en el trías de la zona subbética

1991

Ana.Marquez@uv.es; leopoldo.marquez@uv.es Dentro del Trias de facies germánica que aflora en la Zona Subbética de la Cordillera Bética, denominado Trias Sudibérico, se estudia una unidad carbonática de edad Noriense que hasta ahora había sido considerada como perteneciente a las facies Muschelkalk y de edad Ladiniense. Esta Unidad, que se define de manera formal en este trabajo como Formación Zamoranos, está constituída por tres miembros diferentes que de abajo a arriba son: Miembro Calizas carniolares (0,25 a 1,75 m de espesor), Miembro Detrítico ferruginoso (1 m de potencia media), Miembro Calizas y Dolomías laminadas (20 a 40 m de potencia). El Miembro Detrítico ferruginoso es el más dis…

Indicaciones Límite de las Fracturas de Húmero con Clavo Endomedular Cerrojado

1991

El tratamiento de las fracturas diafisarias del húmero ha entrado en controversia en los últimos años, como lo refleja la literatura internacional. La problemática aumenta cuando se trata de fracturas diafisarias límites que alcanzan la zona metafisaria superior e inferior. En un intento de mejora terapéutica este grupo de autores ha testado un clavo cerrojado para el húmero diseñado por Seidel. El promedio de seguimiento ha sido de 12 meses con un mínimo de 6 meses. El número de casos evaluados ha sido 6. Siguiendo la cotación de Stewart, 4 de los seis pacientes obtuvieron resultados buenos o excelentes. Todos los pacientes consolidaron sus fracturas en un período de tiempo normal, entre 3…

Towards a Better Understanding of the Functioning of School Systems for Better Decision Making : The Case of Primary Schools in Togo

1991

International audience

La retòrica i la lingüística, 1775-1990

1991

It is a well known fact that school manuals' of the 18th and 19th centuries centred on the teaching of Rhetoric are closely linked with those geared towards the study of language in general and of Grammar in particular. The article, based on the work by Marcet-Solà, shows the relevance of this especial relationship and offers illustrative material from these manuals, restricted, like the work referred to, to the Catalan speaking area.

Société, cultures et genres de vie dans la France moderne (16e, 17e, 18e siècles)

1991

Nucleotomía Percutánea Automatizada: nuestra Experiencia

1991

Ante las diferentes técnicas quirúrgicas en la patología del disco lumbar, los autores presentan su experiencia personal con la nucleotomía percutánea automatizada utilizando el nucleotomo de Surgical Dynamics. Sobre un total de 50 pacientes intervenidos se expone la técnica utilizada, con algunas variantes sobre la inicial de Onik, tal como la posición en sedestación del enfermo. Se puntualizan las indicaciones y contraindicaciones y se analizan los resultados obtenidos tras un mínimo de 6 meses de seguimiento. Se considera como una técnica útil, adecuada, relativamente inócua y que no sustituye sino que complementa a los procedimientos quirúrgicos convencionales. Faced with the different …

A chromatin-associated histone deacetylase from pea (Pisum sativum)

1991

Abstract A histone deacetylase activity has been found in preparation of chromatin from pea (Pisum sativum) embryonic axes. This activity readily deacetylates free histones and is somewhat specific for H2A and H2B; this property and its chromatographic behaviour allowed us to identify the enzyme with the previously described histone deacetylase HD2 (Sendra et al., Plant Mol. Biol., 11 (1988) 857). HD2 is only loosely associated to chromatin but the enzymatic activity is enhanced when chromatin adopts a folded conformation. Polyamines and divalent cations activate the enzyme, probably due to their effect on chromatin folding.

Centre archéologique européen du Mont-Beuvray

1991

Le corps du délit: spot publicitaire et mythe technologique

1991

Ce texte passe en revue l'imagerie publicitaire lorsqu'elle a affaire avec la technologie moderne. La limpidité des formes et les métaphores astrales suggèrent un space incontaminé proche au mythe.

Un évolutionniste bernardien à l'Institut Pasteur? Morphologie des Ciliés et évolution physiologique dans l'œuvre d'André Lwoff

1991

Reliability of Restriction Enzyme Digestions of Genomic DNA for the Generation of DNA Fingerprints

1991

Since minisatellite DNA probes are used for the detection of hypervariable loci in eucaryotic genomes [1] the application of so called DNA fingerprints and DNA technology itself in paternity testing and forensic casework is critically discussed ([3]; Brinkmann et al., this volume). A particular problem is the possibility of obtaining partially digested genomic DNA in casework after treatment with restriction enzymes leading to inconclusive or even false results. This is even more important when multilocus DNA probes are used, since the total number of fragments in a given person is not known in advance. But also with single locus probes, where only two allelic fragments are usually detected…

Natural Convection Heat Transfer in a Partially- or Completely-Partitioned Vertical Rectangular Enclosure

1991

Recursive estimators 2

1991

In this paper the techniques for recursive estimation of linear model are extended to non-spherical disturbances. First we present the recursive formulae of generalized least squares. The recurrence relation for the residual sum of squares are derived. We show in the second part of the paper a recursive formulae of generalized instrumental variables.

El llemosinisme valencià a la darreria del segle XIX

1991

As this paper tries to show, the association between the terms Catalan and llemosí, traditionally used in an indiscriminate way when mainly referring to Catalan, was clearly revised and corrected by the middle of the 19th century both in Catalonia and the Balearic Islands, but not so in Valencia, where its persistence can be seen as the clear expression of an outstanding form of local particularism vis à vis the raising linguistic Catalanism.

Per una nuova organizzazione dei Comuni in Sicilia

1991

Organizzazione dei Comuni in Sicilia

Structural and Mechanical Characteristics of the Heart of the Icefish Chionodraco hamatus (Lönnberg)

1991

The absence of haemoglobin from the blood of icefish, antarctic teleosts of the family Chaenichthydae, has stimulated important physiological mechanisms which serve to compensate for the absence of the respiratory pigment. In view of the central role played by the circulation in meeting the oxygen demands of the tissues, it is not surprising to find that the cardiocirculatory system has been extensively remodelled in icefish. These adaptations include: (1) increases in blood volume, from two to four times larger than that in many teleosts (Hemmingsen and Douglas 1970; Holeton 1970); (2) increases in blood flow associated with lowered oxygen demands (Hemmingsen and Douglas 1970; Holeton 1970…

Spin Physics at MAMI

1991

Flavonoid constituents of Stachys aegyptiaca

1991

International audience

A linear approach for the nonlinear distributed parameter identification problem

1991

In identifying the nonlinear distributed parameters we propose an approach, which enables us to identify the nonlinear distributed parameters by just solving linear problems. In this approach we just need to identify linear parameters and then recover the nonlinear parameters from the identified linear parameters. An error estimate for the finite element approximation is derived. Numerical tests are also presented.

Lacunary bifurcation for operator equations and nonlinear boundary value problems on ℝN

1991

SynopsisWe consider nonlinear eigenvalue problems of the form Lu + F(u) = λu in a real Hilbert space, where L is a positive self-adjoint linear operator and F is a nonlinearity vanishing to higher order at u = 0. We suppose that there are gaps in the essential spectrum of L and use critical point theory for strongly indefinite functionals to derive conditions for the existence of non-zero solutions for λ belonging to such a gap, and for the bifurcation of such solutions from the line of trivial solutions at the boundary points of a gap. The abstract results are applied to the L2-theory of semilinear elliptic partial differential equations on ℝN. We obtain existence results for the general c…

Pharmacokinetics of Droloxifene and Its Metabolites in Breast Cancer Patients

1991

Pharmacokinetics and metabolism of droloxifene, a new antiestrogenic drug, have been investigated by single- and multiple-dose studies in postmenopausal patients with advanced breast cancer. Short terminal elimination half-life, low accumulation, and improved drug tolerability are the most striking features of this safe and effective new antiestrogen. Bioequivalence of film-coated tablet, tablet, and standard solution of droloxifene has been shown. The concentrations of droloxifene and its metabolites have been determined by a highly selective HPLC method.

Las perturbaciones mentales en el corpus hippocraticum. El concepto "manía"

1991

LA MEDICINA HIPOCRATICA MUESTRA GRAN INTERES POR LOS ESTADOS PATOLOGICOS DE LA MENTE. EL CORPUS HIPPOCRATICUM UTILIZA UNA AMPLIA GAMA DE LOCUCIONES PARA EXPRESAR LOS TRASTORNOS MENTALES, TANTO LOS DE CARACTER TRANSITORIO COMO LOS PERMANENTES O CRONICOS. EN GENERAL, LOS AUTORES CONTINUAN APLICANDO TERMINOS USADOS YA EN LA TRAGEDIA GRIEGA, AUNQUE APORTAN LA ORIGINALIDAD DE LA CREACION DE ALGUNOS NEOLOGISMOS, COMO EL TERMINO "FRENITIS", CON UN SENTIDO ESPECIFICO MEDICO. ENTRE LOS TERMINOS EMPLEADOS DESTACAN LAS LOCUCIONES QUE SE RELACIONAN CON LA RAIZ INDOEUROPEA MEN-, "PENSAR", TALES COMO MANIA Y MAINOMAI. EL SENTIDO DE MANIA ES EL QUE YA APARECE A PARTIR DEL SIGLO V A.C. EN LA TRAGEDIA GRIEG…

Finite-Size Scaling Study of the Simple Cubic Three-State Potts Glass

1991

During the last few years the Potts glass model has attracted more and more attention. It is considered as a first step towards modelling the phase transition of structural and orientational glasses. A mean-field approach /1/ predicts a low temperature behavior completely different from what is known from Ising spin glasses /2/. But short range models differ markedly from mean-field-predictions. So it is natural to ask, how the short range Potts glass behaves. Especially the question of the lower critical dimension d l is important, below which a finite temperature transition ceases to occur. We tried to answer this by combining Monte-Carlo simulations with a finite-size scaling analysis. T…

Quantum Solitons on Quantum Chaos: Coherent Structures, Anyons, and Statistical Mechanics

1991

This paper is concerned with the exact evaluation of functional integrals for the partition function Z (free energy F = -β -1 ln Z, β -1 = temperature) for integrable models like the quantum and classical sine-Gordon (s-G) models in 1+1 dimensions.1–12 These models have wide applications in physics and are generic (and important) in that sense. The classical s-G model in 1+1 dimensions $${\phi _{xx}} - {\phi _{tt}} = {m^2}\sin \phi$$ (1) (m > 0 is a “mass”) has soliton (kink, anti-kink and breather) solutions. In Refs 1–12 we have reported a general theory of ‘soliton statistical mechanics’ (soliton SM) in which the particle description can be seen in terms of ‘solitons’ and ‘phonons’. The …

CEMS/XPS study of iron stearate Langmuir-Blodgett layers

1991

Langmuir-Blodgett mono- and multilayers of ferric stearate have been formed on oxidized silicon wafers. Thermodesorption of these layers was investigated by conversion electron Mossbauer and photoelectron spectroscopy and some complementary methods. Heating of samples in air up to 523 K leads to a desorption of the fatty acid chains, while the ferric ions are left on the substrate surface. These ions do not cluster laterally like it was found for Cd ions. They form a rather homogeneous, closed oxidic layer. This well defined layer may be used afterwards for further studies of surface reactions as well as interface and intra-layer interactions. The surface iron ions were found to exhibit a r…

An experimental method for the determination of the photon flow reflected and absorbed by aqueous dispersions containing polycrystalline solids in he…

1991

An experimental method for the evaluation of the photon flow reflected and absorbed by aqueous dispersions containing polycrystalline solids is proposed. The method is based on actinometric measurements. It is shown that the values obtained are independent of the particle sizes and of the concentration of the solids at least in the experimental conditions and in the range used in the present study (particle size range: 40–500 μm; solids concentration: 0.1–2 g liter−1). The results suggest that the values obtained should be attributed to the interfaces formed between the surface of the solids and the medium. The method is applied to a photocatalytic reaction, namely to the photodegradation o…

Determination of lead on the airborne particulates of urban Valencia city

1991

A method for the determination of lead in airborne particulates by graphite furnace atomic absorption spectrometry after extraction with HCl-HNO3 (120–150°C) is described. Particulate lead levels in the atmosphere have been measured in samples collected throughout a year, sampling has been made at eleven sites within the city of Valencia. The results obtained in this study show that annual means of lead levels are within the range of 0.526 to 7.033 μg/m3 depending upon the sampling site. Lead levels are higher in winter and autumn. Lead and nitrogen oxide levels are well correlated.

Non-Stationary Probabilistic Response of Linear Systems Under Non-Gaussian Input

1991

The probabilistic characterization of the response of linear systems subjected to non-normal input requires the evaluation of higher order moments than two. In order to obtain the equations governing these moments, in this paper the extension of the Ito’s differential rule for linear systems excited by non-normal delta correlated processes is presented. As an application the case of the delta correlated compound Poisson input process is treated.

Invertebrate lectins: new aspects in retrospects

1991

Invertebrate lectins may be regarded as a special group of lectins, as there are several reasons for this: (a) their role in different defense mechanisms and in nutrition, (b) their specificity, for instance their anti-neuraminyl reactivity (and no mannose-specific lectins) and (c) their distribution in the haemolymph and in organ cells or defense-commited haemocytes.

Ein neues Konzept zur Behandlung von Beckenwandrezidiven gynäkologischer Malignome

1991

Beckenwandrezidive gynakologischer Krebserkrankungen haben eine sehr schlechte Prognose, obwohl etwa die Halfte der Patientinnen geheilt werden konnte, wenn eine lokale Sanierung erreicht wurde. Aus tumor- und strahlenbiologischen Uberlegungen haben wir fur Patientinnen mit unilateralen Beckenwandrezidiven ein neues kombiniertes operatives und strahlentherapeutisches (CORT) Behandlungskonzept entwickelt, das seit 1989 in unserer Klinik angewandt wird. Die Grundlagen und Aspekte der Durchfuhrung des CORT-Konzep-tes haben wir kurzlich veroffentlicht (Hockel et al. 1989).