showing 36 of ~574560 from 574555 documents
Epidemic dissemination of Salmonella enterica spp. enterica serovar Bovismorbificans in southern Italy in the years 1989-1991.
1994
Epidemic strains of Salmonella enterica subsp. enterica serovar Bovismorbificans isolated in southern Italy during the years 1989-1991 were submitted to a molecular epidemiological study in comparison with isolates identified in the years 1980-1988 in the same geographic area. Genomic DNA fragments obtained by digestion with BglI or Eco RI hybridized with Escherichia coli rRNA to produce three distinct, but highly related patterns. Ribotype 1, which had never been identified before 1989, was found to characterize most of the strains identified between 1989 and 1991. Such a finding supports the hypothesis of emergence and spread of a new bacterial clone associated with the increased number o…
Poisson-Nijenhuis structures and the Vinogradov bracket
1994
We express the compatibility conditions that a Poisson bivector and a Nijenhuis tensor must fulfil in order to be a Poisson-Nijenhuis structure by means of a graded Lie bracket. This bracket is a generalization of Schouten and Frolicher-Nijenhuis graded Lie brackets defined on multivector fields and on vector valued differential forms respectively.
Photocatalytic oxidation of phenol on TiO2 powders. A Fourier transform infrared study
1994
Abstract In the present paper a detailed investigation of a well known photoreaction, i.e. phenol photodegradation in the presence of TiO2, has been carried out. The Fourier transform infrared (FT-IR) technique has been used to characterize the catalyst surface and to follow the photoprocess by “in situ” measurements in a gas—solid regime, simulating the aqueous liquid—solid regime in which this photodegradation reaction has been usually carried out. The influence on the photoprocess of the surface hydroxylation of the catalyst has been investigated and the presence of some reaction intermediates has been revealed by FT-IR. The experimental results have demonstrated that the chosen gas—soli…
Ectoparasites, nest site choice and breeding success in the pied flycatcher
1994
It has recently been suggested that nest box studies might bias the measurement of behavioural and life-history traits, because the removal of old nests may reduce the load of ectoparasites. This experimental artefact may have notable effects on nest site choice and breeding success in cavity-breeding birds. We tested (i) if pied flycatchers Ficedula hypoleuca prefer clean nest boxes and (ii) if old nest material affects the number of parasites and the breeding success of pied flycatchers. In the first experiment we offered birds one cleaned nest box and one nest box with old nest material from the previous year. The two nest boxes were placed in very similar sites near each other. In this …
Une nouvelle méthode d'analyse des réseaux
1994
International audience
Physisorption Instabilities during Dynamic Langmuir Wetting
1994
Continuous dynamic Langmuir wetting of lipid monolayers can create regular stripe patterns on the solid substrate surface. Monolayers doped with minor amounts of fluorescence dye may be deposited in stripes of alternating high and low dye concentration. In case of pure monolayers stripes are observed with AFM. The striations run normal to the dipping direction and have widths of typically several micrometres and distances varying from 1 to ≈ 100 μm. The stripe widths, distances, and fluorescence contrast depend on deposition speed, surface pressure, substrate surface preparation, and dye concentration. The patterns probably result from physisorption (meniscus) instabilities caused by a feed…
Koexistenz mobiler und lokalisierter Elektronen in Salzen des Bis(ethylen)dithiotetrathiafulvalen-Radikals (BEDT-TTF) mit paramagnetischen Polyoxomet…
1994
Deceptive pollination of Dactylorhiza incarnata: an experimental test of the magnet species hypothesis
1994
Floral deception, which mainly appears in highly evolved families such as Orchidaceae, was studied in Central Finland. In nectarless Dactylorhiza incarnata, the deceptive pollination system has been considered to function best in remote habitats such as marshes, where flowering plants attractive to pollinators are rare (remote habitats hypothesis). In contrast, the magnet-species theory predicts that a nectarless plant benefits from growing in the vicinity of nectarcontaining species. We tested these hypotheses by adding attractive, nectar-containg violets (Viola x wittrockiana) to orchid populations. The percentage of fruit set in D. incarnata was adversely affected by the violets, probabl…
Modelisation des echanges d'energie et de masse d'un couvert vegetal, dans le but de relier la transpiration et la photosynthese aux mesures de refle…
1994
National audience
General Relativistic Dynamics of Irrotational Dust: Cosmological Implications
1994
The non--linear dynamics of cosmological perturbations of an irrotational collisionless fluid is analyzed within General Relativity. Relativistic and Newtonian solutions are compared, stressing the different role of boundary conditions in the two theories. Cosmological implications of relativistic effects, already present at second order in perturbation theory, are studied and the dynamical role of the magnetic part of the Weyl tensor is elucidated.
Elementary presentation of self‐consistent intermediate Hamiltonians and proposal of two totally dressed singles and doubles configuration interactio…
1994
Intermediate Hamiltonians are effective Hamiltonians which are defined on an N‐dimensional model space but which only provide n<N exact eigenvalues and the projections of the corresponding eigenvectors onto the model space. For a single root research, the intermediate Hamiltonian may be obtained from the restriction of the Hamiltonian to the model space by an appropriate, uniquely defined dressing of the diagonal energies or of the first column. Approximate self‐consistent dressings may be proposed. The simplest perturbative form gives the same result as the original 2nd order intermediate Hamiltonian or the ‘‘shifted Bk’’ technique but it is of easier implementation. Self‐consistent inclus…
Differential Regularization of a Non-relativistic Anyon Model
1994
Differential regularization is applied to a field theory of a non-relativistic charged boson field $\phi$ with $\lambda (\phi {}^{*} \phi)^2$ self-interaction and coupling to a statistics-changing $U(1)$ Chern-Simons gauge field. Renormalized configuration-space amplitudes for all diagrams contributing to the $\phi {}^{*} \phi {}^{*} \phi \phi$ 4-point function, which is the only primitively divergent Green's function, are obtained up to 3-loop order. The renormalization group equations are explicitly checked, and the scheme dependence of the $\beta$-function is investigated. If the renormalization scheme is fixed to agree with a previous 1-loop calculation, the 2- and 3-loop contributions …
Attrition and Use of Proxy Respondents and Auxiliary Information in the Sicilian Neuroepidemiologic Study
1994
Two-phase prevalence surveys with screening (phase 1) and examination (phase 2) are useful for some chronic diseases. Attrition, which may bias estimates, occurs in either phase because some eligible subjects die before contact, some refuse to cooperate, some are incapacitated, and some are unreachable. This investigation relates to a survey of neurologic diseases conducted in three municipalities of Sicily (prevalence date, November 1, 1987) and considers the attrition experienced and the use of proxy respondents in phase 1 and auxiliary information in phase 2 to offset, in part, this attrition. Regarding case finding, the salvage effort was more productive for decreased and incapacitated …
Digital assessment of MRI for lumbar disc desiccation. A comparison of digital versus subjective assessments and digital intensity profiles versus di…
1994
During magnetic resonance imaging, a vast amount of digital data on anatomic structures is translated into images, which are then assessed subjectively. The development of an objective, sensitive method to directly assess the digital data would have clear benefits, particularly for clinical research on disc degeneration. The study goals were to develop a method of digital assessment of disc desiccation and to compare digital signal intensity profiles with discographic patterns and macroanatomic findings. Proton density-weighted MRIs were obtained from 45 males (9-77 years) and digital analysis was done with a freely selectable region of interest facility. The adjacent cerebrospinal fluid (C…
Column-switching techniques for screening of diuretics and probenecid in urine samples
1994
A method based on high-performance liquid chromatography using column-switching is described for the screening of diuretics and probenecid in urine samples. The system uses a 20- x 2.1-mm i.d. precolumn, packed with a Hypersil ODS-C18, 30-microns stationary phase, for the on-line sample cleanup and enrichment. Untreated urine samples are directly injected, and the precolumn is flushed for 1 min with water to eliminate polar matrix components. The retained analytes are then back-flushed by means of a six-port switching valve onto a Hypersil ODS-C18 analytical column (5 microns, 250- x 4-mm i.d.), where they are separated using an acetonitrile/phosphate buffer (pH = 3) gradient elution. Under…
High-performance liquid chromatographic study of the regulation of phospholipid metabolism in cultured adrenocortical cells
1994
Abstract A rapid high-performance liquid chromatographic (HPLC) method for the separation of phospholipids was developed for minute samples of total lipids (ca. 200 μg). The method was applied to the study of the phospholipid metabolism in adrenocortical cell cultures. A complete separation of the different cellular phospholipid classes was achieved in 40 min. Good resolution of the phospholipid peaks was obtained, which allowed the collection of each individual class of phospholipids for further analysis of radioactivity and fatty acid composition by gas chromatography. When cells were incubated with [U-14C]glycerol or [U-14C]palmitate the bulk of the radioactivity was found in cellular ph…
A new method for computing one-loop integrals
1994
We present a new program package for calculating one-loop Feynman integrals, based on a new method avoiding Feynman parametrization and the contraction due to Passarino and Veltman. The package is calculating one-, two- and three-point functions both algebraically and numerically to all tensor cases. This program is written as a package for Maple. An additional Mathematica version is planned later.
Laser-stimulated two-step recombination of highly charged ions and electrons in a storage ring
1994
Two-step resonant laser-stimulated recombination of highly charged ions was performed for the first time. Nd:YAG laser pulses overlapped with an Ar[sup 18+] beam in the electron cooler of the ESR storage ring at GSI induced transitions from the continuum to the [ital n]=81 state of hydrogenlike Ar[sup 17+]. To avoid reionization in the bending magnet before reaching the detector, the [ital n]=81 population was transferred to a state well below the reionization threshold by a Ti:sapphire laser. Tuning of this laser yielded the [ital n]=81 to 36 and 37 transition-line profiles. The two-step method provides access to detailed Rydberg spectroscopy in an electron beam environment.
La disciplina della formazione professionale avanzata nella regione siciliana
1994
Il libro illustra la disciplina regionale della formazione professionale avanzata alla luce della disciplina legislativa regionale e della normativa comunitaria
The nicardipine-isoprenaline interaction in human and guinea-pig isolated airways
1994
Summary— The effects of the dihydropyridine calcium antagonist nicardipine on the concentration-response curves of relaxant compounds acting through the adenylate-cyclase/cAMP system (isoprenaline, forskolin, adenosine and theophylline) or by the cGMP pathway (sodium nitroprusside) were studied on human isolated bronchus and guinea-pig isolated trachea. These effects were compared with those of nifedipine (a dihydropyridine derivative) and theophylline (a non-selective phosphodiesterase inhibitor). Nicardipine, in the range of 0.01 to 1 μM, significantly potentiated the relaxant effects of isoprenaline, forskolin, adenosine and theophylline, whereas the effects of sodium nitroprusside were …
Lexicografia i correcció: la funció dels diccionaris en la revisió de textos
1994
The aim of this paper is an attempt to revise the role of dictionaries in professional text supervising processes. Under the frame of text linguistics, we first explain how correction tasks are conditioned by text typology. Next, we study the macro structure of dictionaries (in order to consider what kind of lexicographical works are closer to the corrector needs) and then we study their micro structure (in order to set up what kind of information might be relevant for correction tasks). In conclusion, we finally State some lacks of current dictionaries for correction purposes, and we settle some aspects of text revision which are not expected to be solved with dictionary consultation.
La liquidació de la Generalitat en el segle XVIII
1994
La nécropole monumentale Cerny de Passy (Yonne) : description d'ensemble et problèmes d'interprétation
1994
International audience; D'abord repérée d'avion, puis fouillée sur l'emprise d'une gravière, la nécropole néolithique de Passy couvre plus de 20 hectares. Elle se compose d'une trentaine de grands monuments allongés, orientés à l'Est, et construits de terre et de bois. Les défunts, déposés sur le dos dans de probable coffres, reposaient dans des fosses profondes creusées dans l'axe des monuments. Les dépôts funéraires, qui comprennent des objets anthropomorphes, permettent d'attribuer ces sépultures au groupe de Cerny. La diversité des architectures et les phases de réfection constatées suggèrent une certaine dure d'utilisation.En rupture avec les traditions antérieure, ces pratiques funéra…
Los límites de la interpretación
1994
Caracterización molecular y análisis poblacional de la variabilidad del DNA mitocondrial del áfido Rhopalosiphum padi (Homoptera: Aphidiade)
1994
Tentative Recommendation on Terminology and Definitions in Respiratory Physiology: Résumé of the Isott Consensus Session 1992
1994
1 The use of small letters for the symbols “p” (partial pressure), “s” (saturation) and “c” (concentration) (e.g. pO2, sO2, cO2) follows recommendations of the IFCC and IUPAC [4]. This supports the use of contemporary word processing systems and mostly eliminates the need to use subscripts (except for chemical valencies: e.g. O2, CO2, H2CO3 etc.). The potential risk of misinterpretations and double meanings is reduced also (e.g. “cO2” [oxygen concentration] v.s. “CO2” [carbon dioxide] and “sO2” [oxygen saturation] v.s. “sO2” [sulfur dioxide]). 2 The symbol shall include the site of measurement or description, e.g. paO2 (arterial O2 partial pressure), svO2 (mixed venous oxygen saturation), o…
D.P14 In vitro cytotoxic activity against erythrocytes by ascidians hemocytes: Target/effector interactions
1994
The cell-mediated, calcium-dependent cytotoxic activity against mammalian erythrocytes by the hemocytes of the ascidians Ciona intestinalis and Stye/a plicata was investigated by in vitro cytotoxic assay (HCA). Hemocytes/erythrocytes mixtures were performed in artificial sea water or TBS enriched with 10 mM CaC12, at 25° or 3rC, and the released haemoglobin was estimated by reading the absorbance at 541 nm (Parrinello et al., D.C.I., 17:19, 1993). With the aim to examine the cytotoxic mechanism involved, inhibition experiments with lipidic components of the erythrocyte membrane have been carried out in TBS-Ca. Among the phospholipids tested sphingomyelin is an inhibitor of the Ciona intesti…
In Vitro Cytokine Production by HLA-B8, DR3 Positive Subjects
1994
It is well known that healthy subjects carrying the HLA-B8,DR3 haplotype may show an impairment of immune system, the T cells being the most affected. To gain insight into the mechanism(s) of the impairment displayed by these subjects, efforts have been centered on the study of in vitro cytokine production because of the pivotal role played by these mediators in the activation and control of several immune functions. The available results indicate that the ability to several immune functions. The available results indicate that the ability to produce interleukin-1 (IL-1), IL-2 and the soluble form of its receptor (sIL-2R) is impaired in HLA-B8,DR3 positive healthy subjects. To better charac…
Cerámicas ibéricas con decoración impresa de Arse (Sagunt, Valencia)
1994
Arroyada superficial en terrazas de cultivo abandonadas: El caso del País Valencià
1994
Se comparan los resultados de experimentos realizados con lluvia simulada realizados en tres terrazas de cultivo abandonadas en el País Valenciano. En los tres casos están situadas en el fondo del valle y el último cultivo fueron olivos, aunque la edad de abandono, el clima y especialmente la litología son diferentes. Los resultados demuestran que los suelos sobre margas son los que presentan mayores tasas de escorrentía y erosión, frente a las terrazas sobre arcillas del Keuper y calizas en las cuales la pérdida de agua y suelos son insignificantes, incluso nulas en el caso de las últimas. Estos resultados están directamente relacionados con las características de los suelos, básicamente c…
Otto Wilhelm Kuusinen (1881-1964) : un itinéraire militant de la Finlande à l'URSS
1994
Evaluación del área trabecular por digitalización de imágenes en el callo de fractura: estudio experimental
1994
Se presenta un método de evaluación del área trabecular por medio de digitalización de imágenes de microscopía óptica. Se estudia la evolución de 20 callos de fractura en ratas de cepa Wistar, obteniendo un incremento progresivo del área trabecular desde los 14 a los 49 días, correlacionando ésta directamente con la actividad neoformativa. Se concluye proponiendo el uso de este método por su uniformidad, objetividad y reproductibilidad en todo el estudio, permitiendo la independencia del anatomopatológico. We present a method for assessment of the bone trabecular area by using optic microscope digitalized imaging. We studied 20 fracture callus performed at the tibia in Wistar rats. The bone…
Dimethoxy Aromatic Compounds. VIII. Degenerate Dealkylation-Realkylation Reaction of 1-Bis(2,4-dimethoxyphenyl)-2-methylpropane.
1994
The condensation reaction under acid condition of the benzylic alcohols 1, 2 and 3 with the hexadeutero dimethoxybenzenes 4, 5 and 6 leads to the expected hexadeutero bis(dimethoxyphenyl)-2-methylpropanes 7, 8 and 9, respectively. However, the presence of both dodecadeutero and unlabelled 1-bis(2, 4-dimethoxyphenyl)-2-methylpropanes 10 and 11 indicates that 9 undergoes a rapid degenerate dealkylation-alkylation reaction.
Enumerable classes of total recursive functions: Complexity of inductive inference
1994
This paper includes some results on complexity of inductive inference for enumerable classes of total recursive functions, where enumeration is considered in more general meaning than usual recursive enumeration. The complexity is measured as the worst-case mindchange (error) number for the first n functions of the given class. Three generalizations are considered.
De la justa expulsión de los moriscos de España
1994
Les bovins sont-ils une source significative de Escherichia coli 0157:H7 ?
1994
no. spécial