showing 36 of ~574560 from 574555 documents
Gastos y costes de la ensenanza
1991
International audience
Causes of a Growing Judicial Litigation: Empirical Analysis of a Case
1991
In Spain, judicial litigation has grown considerably since 1959 to 1987, both in absolute and relative dimensions. This trend is especially accentuated in the criminal and in the contentious-administrative jurisdictional areas. By applying an interdisciplinary (economic, juridical, sociological political …) approach, the characteristics of this phenomenon are summarized in this paper, and their numerous and complex causes are analysed. Some of these causes can be considered socially positive, as they seem connected with a greater economic and social development in the country that allows citizens to appeal more frequently and directly to justice courts; but others show a worsening in the s…
Comparative imaging of structure and metabolites in tumours.
1991
A novel technique for metabolic imaging using quantitative bioluminescence and single photon imaging was used to measure the distribution of ATP and lactate in two types of human melanoma xenografts with different radiobiologically hypoxic cell fractions (MF: 45 +/- 17% and EE: 6 +/- 3%; mean +/- SD). The tumours were s.c. grown in nude mice and were used for measurement at volumes of 153-3072 mm3. For metabolic imaging the rapidly frozen tumours were serially sectioned, and each cryosection was brought into contact with a frozen bioluminescent enzyme cocktail using a specially designed glass sandwich system. After thawing section and cocktail the luminescence was started, and light was emi…
Circulating diphtheria antitoxin levels in children aged 11-14 years in relation to the vaccinal history.
1991
Diphtheria antitoxin level in serum samples obtained from 204 healthy children aged 11-14 years was determined by means of an indirect haemagglutination technique and related to the vaccinal history of the subjects. Irrespective of the time since the last toxoid inoculation, the mean antitoxin titre per ml of serum in the individuals who had received incomplete/irregular anti-diphtheria vaccination in childhood was significantly higher when the number of toxoid doses was higher (from two to more than four doses); the same was not observed for individuals given primary vaccination (three toxoid doses) according to the schedule for childhood vaccination in Italy (regular vaccinees) and one or…
LC-Polymers with Axial Chirality
1991
Abstract Liquid crystalline polymers with axial chirality are prepared. These polymers are chiral, not due to a single asymmetric carbon atom, but due to a larger molecular fragment, which is chiral as a whole. They exhibit cholesteric and chiral smectic C* phases. Dielectric spectroscopy proves strong ferroelectric properties in the chiral smectic C* phases of these polymers.
Conditional measures and their applications to fuzzy sets
1991
Abstract Given a ⊥-decomposable measure with respect to a continuous t-conorm, as introduced by the author in an earlier paper (see Section 1), we can construct ⊥-conditional measures as implications. These fulfil a ‘generalized product law’ replacing the product in the classical law by any other strict t-norm ⊥ and turn out to be decomposable with respect to an operation ⊥ V depending on ⊥, ⊥ and the condition set V (Section 2). More general, conditional measures are introduced axiomatically and are shown to be ⊥-conditional measures with respect to some ⊥-decomposable measure (Section 3). ‘Bayesian-like’ models are given which are alternatives to that presented by the author in a recent p…
Theory of quadrupole detection fourier transform-ion cyclotron resonance
1991
Abstract The theoretical basis of the recently introduced quadrupole detection Fourier transform-ion cyclotron resonance technique is developed by use of the concept of image charges induced in the detection electrodes. The appearance of resonances at frequencies 2ω+, 2ω−, (ω+ + ω−) and (ω+ − ω−) is explained. The new method is compared with the standard (dipole) detection scheme. Techniques are suggested allowing the simultaneous determination of all resonance frequencies ω+ (perturbed, or reduced, cyclotron frequency), ω− (magnetron frequency) and ωz (trapping frequency).
Autonomic and cortical responses during anticipation of a sensory task and of feedback from task results
1991
Systemic Treatment with Interferon-α2B: An Effective Method to Prevent Sterility after Bilateral Mumps Orchitis
1991
In men orchitis represents the most common complication of mumps infection and occurs in 5 to 37% of this population. Bilateral manifestation is observed in 16 to 65% of the patients. The most important danger is the risk of testicular atrophy which results in sterility. Four patients with bilateral mumps orchitis received systemic treatment with interferon-alpha 2B (3 x 10(6) IU per day) for 7 days. All acute symptoms of mumps orchitis disappeared within 2 to 4 days of hospitalization. During 6 to 15 months of followup no incidence of testicular atrophy was observed. In 3 of 4 patients pre-treatment examination revealed subfertility (oligoasthenospermia), while 2 to 4 months after interfer…
The quantum relativistic harmonic oscillator: generalized Hermite polynomials
1991
A relativistic generalisation of the algebra of quantum operators for the harmonic oscillator is proposed. The wave functions are worked out explicitly in configuration space. Both the operator algebra and the wave functions have the appropriate c→∞ limit. This quantum dynamics involves an extra quantization condition mc2/ωℏ = 1, 32, 2, … of a topological character.
Fibrinolytic parameters in normotensive pregnancy with intrauterine fetal growth retardation and in severe preeclampsia
1991
In pregnancy a decrease in fibrinolytic activity, which is due to an increase in plasminogen activator inhibitor activity and plasminogen activator inhibitor type 1 and type 2, has been described. Because the placenta is a source of both type 1 and type 2 plasminogen activator inhibitor, we have studied them and other fibrinolytic parameters in a group of normotensive pregnant women with intrauterine fetal growth retardation and in two groups of women with preeclampsia, with or without intrauterine growth retardation. A significant increase in plasminogen activator inhibitor type 1 antigen and plasminogen activator inhibitor activity was observed in preeclampsia, with or without intrauterin…
On the influence of the physico-chemical properties of aerosols on the life cycle of radiation fogs
1991
A one-dimensional model of radiation fog with detailed microphysics is presented. Aerosols and cloud droplets are treated in a joint two-dimensional size distribution. Radiative fluxes are calculated as functions of the radiative properties of the time-dependent particle spectra. The droplet growth equation is solved by considering radiative effects. Turbulence is treated by means of a higher order closure model. The interaction between the atmosphere and the earth's surface is explicitly simulated. Three numerical sensitivity studies are performed to investigate the impact of the different physico-chemical properties of urban, rural and maritime aerosols on fog formation. Numerical results…
Calculation of the neutrinoless ββ decay of 76Ge using a quark model with harmonic confinement
1991
Abstract The half-life of the neutrinoless double beta decay of 76Ge into the ground state of 76Se is calculated in a relativistic quark confinement model. The proton-neutron quasi-particle random-phase approximation is used to evaluate the s- and p-wave nuclear matrix elements contained in the decay amplitude. We avoid the closure approximation and calculate the effective vector and axial-vector coupling constants of the hadronic currents using our quark model. In our formulation the recoil matrix element arises from the quark recoil in the decaying neutrons. The recoil and the p-wave effect are discussed and compared with other calculations. From the experimental lower bound for the decay…
Immunohistochemical evaluation of bone marrow lymphoid nodules in chronic myeloproliferative disorders
1991
One hundred and seventy bone marrow biopsies from patients with chronic myeloproliferative disorders (CMPDs) were evaluated for the presence of lymphoid nodules (LNs) and were immunostained using a panel of monoclonal antibodies (UCHL1, 4KB5 and L26) recognizing different lymphocyte antigens. LNs were found in 35% of cases of idiopathic thrombocythaemia, 24.6% of myelofibrosis/osteomyelosclerosis, 18.2% of polycythaemia vera 12.1% of chronic myeloid leukaemia and 19.2% of borderline cases. Varying degrees of immunohistochemical positivity for the three antibodies tested were found. LNs were always made up of variable proportions of both T- and B-lymphocytes with a prevalence of T-cells. Thi…
High-spin states in 121Ba and deformation-dependent alignments
1991
The high-spin structure of 121Ba has been investigated by in-beam gamma-ray spectroscopic techniques. Rotational bands based on the h11/2, g7/2 and tentatively d5/2 quasineutron configurations have ...
The Jervell and Lange-Nielsen syndrome.
1991
Deafness and electrocardiographic changes (prolongation of the Q-T interval and inversion of the T wave) with a clinical picture of syncopal attacks and sudden death, were described as a distinct syndrome by Jervell and Lange-Nielsen in 1957. The syndrome is inherited as an autosomal recessive trait. In this study, all the cases reported since 1957 and their proposed prevalence are reviewed. The authors describe the 4 cases they have studied, all of which presented congenital sensorineural hearing loss and electrocardiographic changes characteristic of the syndrome. The relatively high number of cases they have encountered casts doubt on literature that states that the syndrome occurs more …
Infantile neuroaxonal dystrophy: Diagnosis by skin biopsy
1991
A child who shows progressive motor and mental deterioration after the first year of life, who has pyramidal signs, marked muscle hypotonia, but no seizures, suggests to have infantile neuroaxonal dystrophy (INAD). Beyond the age of two years, the EEG also entails characteristic findings. Diagnosis may be obtained by an ultrastructural examination of biopsied skin. The respective clinical and morphological findings are recorded and illustrated from four patients in this report.
Extrapyramidal Symptoms and their Relationship to Clinical Efficacy under Perphenazine Treatment*
1991
In order to verify the hypothesis of a strict relationship between clinical improvement and extrapyramidal side-effects, especially micrographia, twenty-two acutely ill schizophrenics were treated with perphenazine in a controlled prospective 28-day trial. During the study period, psychopathometric data, prolactin plasma levels, and handwriting samples were collected. According to the remission criteria fixed before the study began (both BPRS ≤ 25 and GAS ≥ 80 points), 45.5% (10/22) of the total patient sample were classified as treatment responders. Handwriting tests were quantified in 21 patients. "Positive" handwriting results, i. e., a reduction of at least 13% in the overall area of 50…
Kinetic studies on protoporphyrinogen oxidase inhibition by diphenyl ether herbicides
1991
Diphenyl ethers (DPEs) and related herbicides are powerful inhibitors of protoporphyrinogen oxidase, an enzyme involved in the biosynthesis of haems and chlorophylls. The inhibition kinetics of protoporphyrinogen oxidase of various origins by four DPEs, (methyl)-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (acifluorfen and its methyl ester, acifluorfen-methyl), methyl-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-chlorobenzoate (LS 820340) and methyl-5-[2-chloro-5-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (RH 5348), were studied. The inhibitions of the enzymes from maize (Zea mays) mitochondrial and etiochloroplastic membranes and mouse liver mitochondrial membranes were com…
Ah receptor mediating induction of cytochrome P450IA1 in a novel continuous human liver cell line (Mz-Hep-1)
1991
Abstract The Ah receptor regulates induction of cytochrome P450IA1 and mediates certain toxicities of polyhalogenated aromatics such as 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD). It has been characterized previously in continuous cell lines, notably the mouse hepatoma line Hepa 1, the human squamous cell carcinoma line A431, and the human liver cell line Hep G2. The present work extends our knowledge of the Ah receptor in continuous human liver cell lines. Ah receptor can be detected in Mz-Hep-1, a hepatitis B virus-negative cell line derived from a Thorotrast-induced hepatocellular carcinoma. The mean concentration of Ah receptor in Mz-Hep-1 cells was 341 ± 22 fmol/mg cytosol protein (m…
GABA, receptor mediated fast synaptic inhibition in the rabbit brain-stem respiratory system
1991
The involvement of GABA mediated neurotransmission in the central control of respiration was investigated by administration of the specific GABAA receptor agonist muscimol and the specific GABAA receptor antagonist biculline into the fourth cerebral ventricle of the rabbit. Cycle-triggered averaging of the phrenic nerve activity (PNA) was used to quantify drug-induced changes of the central respiratory pattern. Muscimol reduced the peak amplitude of PNA and increased the duration of the respiratory phases. High amounts of muscimol led to a long-lasting but reversible central apnea. Bicuculline very effectively blocked the effects of externally applied muscimol. Blockade of intrinsically act…
Selection of biological and chemical parameters indicating or affecting the vitality of Norway spruce
1991
Abstract Thirty-two young and old Norway spruce trees ( Picea abies (L.) Karst.) showing different degrees of damage were investigated in a forest stand in the Taunus Mountains (FRG). The old trees showed visual symptoms of damage such as discolouration of the needles and needle loss. Over 70 biometric, physiological and chemical parameters were determined for needle and soil samples. Interrelationships between these variables were described by correlation analysis. The most discriminant variables between different groups of trees were found by Fisher weighing. This reduced data set was used for principal component analysis and for the classification of various parameters according to diffe…
The duodenum in liver cirrhosis: endoscopic, morphological and clinical findings.
1991
Endoscopic studies were performed to determine whether changes occurred in the duodenum related to portal hypertension in patients with liver cirrhosis. The total of 271 patients studied were subdivided into three groups: 83 patients with liver cirrhosis and portal hypertension, 53 with liver cirrhosis but no portal hypertension, and 135 controls. In the duodenum of cirrhotic patients with portal hypertension several changes were observed on endoscopy that were also present in the other two groups. Atrophy and vascular malformations, however, were present only in the duodenum of cirrhotic patients with portal hypertension, although in only a few patients and with statistical significance on…
La escuela com unidad de produccion
1991
International audience
Nonlinear Critical Layers in Barotropic Stability
1991
Abstract Applying the method of matched asymptotic expansions (MAE) to the shallow water equations on a rotating sphere, the structure of critical layers that occur in the linear and inviscid analysis of neutral disturbances of barotropic zonal flows is investigated, assuming that the critical layers are controlled by nonlinearity rather than viscosity or nonparallel flow effects. It turns out that nonlinearity is insufficient to resolve the critical layer singularity completely. It suffices however to connect linear and nondissipative solutions across critical latitudes.
Photon absorption by aqueous TiO2 dispersion contained in a stirred photoreactor
1991
We present a simple experimental method which allows the evaluation of the absorbed photon flow. The method is based on measurements of transmitted photon rates (by means of standard actinometer solutions) for different reactor thicknesses and/or catalyst concentrations. The method was applied to phenol degradation reaction carried out in a stirred batch phtotoreactor containing aqueous TiO 2 (anatase) dispersion, directly irradied by a 1,500 W Xe lamp
LC n Compacta are n -Improved
1991
Ion-exchange high-performance liquid chromatography of nucleotides and polypeptides on new types of ion-exchange sorbents, based on polystyrene-coate…
1991
A novel type of ion exchanger was prepared by multipoint covalent binding of polystyrene chains onto the surface of porous silica followed by polymer-analogous modification of the bonded layer. Both anion and cation exchangers were synthesized and examined in the separation of nucleotides and proteins. Rapid and efficient separation of basic polypeptides on strong anion exchangers and that of acidic polypeptides on strong cation exchangers could be achieved. For the separation of complete mixtures of polypeptides the application of zwitter-ionic ion exchangers can be recommended.
Myristylation is involved in intracellular retention of hepatitis B virus envelope proteins
1991
The envelope of hepatitis B virus contains three related proteins, one of which is myristylated. The nonmyristylated small and middle protein are assembled into empty envelope particles which are secreted from cells, whereas the myristylated large envelope protein is mainly found in complete virions and is not secreted in the absence of the nucleocapsid. The block to secretion can be partially overcome by mutation or deletion of the myristylation site. Creation of a myristyl attachment site in the small protein impairs the secretion of empty envelope particles but not their intracellular assembly. Myristylation may therefore play a crucial role in hepatitis B virus replication by channeling…
N-acetyl-L-glutamate in brain: assay, levels, and regional and subcellular distribution.
1991
N-Acetyl-L-glutamate (NAG), the activator of mitochondrial carbamoyl phosphate synthetase (CPS), is demonstrated by several methods, including a new HPLC assay, in the brain of mammals and of chicken. The brain levels of NAG are 200-300 times lower than the levels of N-acetyl-L-aspartate (NAA), and are similar to the levels of NAG in rat liver. The NAG levels in chicken liver are very low. Although NAG is mitochondrial in the liver, it is cytosolic in brain. Using enzyme activity and immuno assays we did not detect CPS in brain (detection limit, 12.5 micrograms/g brain), excluding that brain NAG is involved in citrullinogenesis. The regional distribution of brain NAG differs from that of NA…
Complexes hétéronucléaires Cp2MM′(Cp)(CO)3 (M Nb, Ta; M′ Mo, W) avec groupes carbonyles pontants et semi-pontants: synthèse et comportement dynam…
1991
Abstract Heteronuclear structures Cp 2 MM′(Cp)(CO) 3 (M Nb, Ta; M′ Mo, W) are obtained by heating Cp 2 MH 3 (M Nb, Ta) with Cp 2 M′ 2 (CO) 6 (M′ Mo, W) or starting from Cp 2 M(CO)H and Cp 2 M′ 2 (CO) 4 . These heterobimetallic complexes show three CO coordination modes: terminal, semi-bridging and bridging. The two cyclopentadienyl groups of the Cp 2 M moiety are anisochronous owing to molecular rigidity; rotation barriers around the MM′ bond have been estimated and are greatest with tantalum derivatives.
Phylogeny of viroids, viroidlike satellite RNAs, and the viroidlike domain of hepatitis delta virus RNA.
1991
We report a phylogenetic study of viroids, some plant satellite RNAs, and the viroidlike domain of human hepatitis delta virus RNA. Our results support a monophyletic origin of these RNAs and are consistent with the hypothesis that they may be "living fossils" of a precellular RNA world. Moreover, the viroidlike domain of human hepatitis delta virus RNA appears closely related to the viroidlike satellite RNAs of plants, with which it shares some structural and functional properties. On the basis of our phylogenetic analysis, we propose a taxonomic classification of these RNAs.
Mismatch negativity — Factors affecting its variation
1991
Independent and cumulative yields of very neutron-rich nuclei in 20 MeVp- and 18–41 MeVd-induced fission ofU238
1991
Independent and cumulative yields in nearly symmetric fission have been measured for the first time by bombarding $^{238}\mathrm{U}$ with 20-MeV protons and with 18-, 25-, and 41-MeV deuterons. Isobaric charge dispersion has been determined in the A=110, A=112, and A=114 mass chains and, from asymmetric fission, in the A=80 mass chain. The average isobaric charges in the p+U reaction were 44.01\ifmmode\pm\else\textpm\fi{}0.20 (A=110), 45.15\ifmmode\pm\else\textpm\fi{}0.15 (A=112), and 45.74\ifmmode\pm\else\textpm\fi{}0.15 (A=114). The widths (standard deviations) of the charge dispersion curves were 0.82\ifmmode\pm\else\textpm\fi{}0.08 (A=112) and 0.54\ifmmode\pm\else\textpm\fi{}0.08 (A=114…
Age-related accumulation of congophilic fibrillar inclusions in endocrine cells
1991
Intracellular fibrillar congophilic inclusions are well known as neurofibrillary tangles in neurons and as Biondi bodies in choroid plexus epithelial cells. Recently similar amyloid-like inclusions in adrenal cortical cells were described (Eriksson and Westermark 1990). This study on 150 adrenal glands confirms these observations. In our material the age-related accumulation of congophilic inclusions starts earlier (in the sixth decade) and reaches a higher incidence (42.7%). We found similar intracellular inclusions in other endocrine organs, for example in the anterior lobe of the pituitary, in the cells of parathyroid glands and in Sertoli cells. The age-related incidence of these fibril…
Characterization of prejunctional muscarinic autoreceptors in the guinea-pig trachea
1991
1. The effects of ten muscarinic antagonists on electrically evoked [3H]-acetylcholine release and muscle contraction were compared in an epithelium-free preparation of the guinea-pig trachea that had been preincubated with [3H]-choline. 2. The M3-selective antagonists UH-AH 37, 4-diphenyl-acetoxy-N-piperidine methobromide and para-fluorohexahydrosiladiphenidol were more potent in reducing the contractile response than in facilitating the evoked [3H]-acetylcholine release. Hexahydrosiladiphenidol did not discriminate between pre- and postjunctional effects. The rank order of the postjunctional potencies of the ten antagonists as well as the postjunctional pA2 values obtained for hexahydrosi…