One-dimensional error-diffusion technique adapted for binarization of rotationally symmetric pupil filters

1995

Abstract Two novel algorithms for the binarization of continuous rotationally symmetric real and positive pupil filters are presented. Both algorithms are based on the one-dimensional error diffusion concept. In our numerical experiment an original gray-tone apodizer is substituted by a set of transparent and opaque concentric annular zones. Depending on the algorithm the resulting binary mask consists of either equal width or equal area zones. The diffractive behavior of binary filters is evaluated. It is shown that the filter with equal width zones gives Fraunhofer diffraction pattern more similar to that of the original gray-tone apodizer than that with equal area zones, assuming in both…

Beta-decay studies of far from stability nuclei near N = 28

1995

Abstract Beta-decay half-lives and β-delayed neutron-emission probabilities of the very neutron-rich nuclei 43 P, 42,44,45 S and 44–46 Cl, 47 Ar, which lie at or close to the N=28 magic shell, have been recently measured through β or β-n time correlation measurement. The results are compared to recent model predictions and indicate a rapid weakening of the N=28 shell effect below 48 Ca. The nuclear structure effects reflected in the decay properties of the exotic S and Cl isotopes may be the clue for the astrophysical understanding of the unusual 48 Ca 46 Ca abundance ratio measured in the solar system.

Usefulness of omp1 restriction mapping for avian Chlamydia psittaci isolate differentiation

1995

Abstract Sixty-five avian Chlamydia psittaci isolates collected worldwide, including 27 previously characterized reference strains, were analysed by restriction mapping of the major outer membrane protein gene ( omp1 ) obtained after DMA amplification by PCR. They were compared to 2 ruminant isolates, a feline pneumonitis and a guinea pig inclusion conjunctivitis (GPIC) isolate. According to their omp1 restriction patterns, avian strains were heterogeneous in that they exhibited 6 and 4 distinct patterns using Alu I and Mbo II restriction enzymes, respectively, thus defining 7 groups. However, 84% of the studied strains belonged to groups 1 to 4, which share a specific fragment triplet of 4…

Mono-, bi- and polynuclear complexes of dimethyldiphenylsilane, diphenylether and biphenyl with Cr, Co and Ru. Synthesis and 1H, 13C, 17O and 29Si NM…

1995

Abstract Mono- and bimetallic transition metal carbonyls of dimethyldiphenylsilane, Ph 2 Si(CH 3 ) 2 (L1), diphenylether, Ph 2 O (L2) and biphenyl, Ph 2 (L3): Ph 2 Si(CH 3 ) 2 Cr(CO) 3 ( 1 ), Ph 2 Si(CH 3 ) 2 [Cr(CO) 3 ] 2 ( 2 ), Ph 2 Si(CH 3 ) 2 Co 4 (CO) 9 ( 3 ), Ph 2 Si(CH 3 ) 2 [Co 4 (CO) 9 ] 2 ( 4 ), Ph 2 Si(CH 3 ) 2 Cr(CO) 3 Co 4 (CO) 9 ( 5 ), Ph 2 OCr(CO) 3 ( 6 ), Ph 2 OCo 4 (CO) 9 ( 7 ), Ph 2 ORu 6 C(CO) 14 ( 8 ), Ph 2 OCr(CO) 3 Co 4 (CO) 9 ( 9 ) and Ph 2 Ru 6 C(CO) 14 ( 10 ) have been prepared and characterized by means of 1 H, 13 C, 17 O and 29 Si NMR spectroscopy. The same order of the shielding effects induced by the transition metal (Co 1 H NMR chemical shifts of the η 6 -coord…

Monolayers of dipalmitoylphosphatidylcholine at the oil-water interface

1995

Abstract Monolayers of dipalmitoylphosphatidylcholine at the interfaces waterbicylohexyl, waterdodecane and waterhexadecane were studied by fluorescence microscopy and thermodynamic measurements. The experiments show that the oil also partitions in the liquid condensed (LC) monolayer phase with concentration depending on the type of oil and the lateral pressure. In contrast to monolayers of dipalmitoylphosphatidylethanolamine the larger molecular area per head group enables oil partitioning in the LC phase even if there is a mismatch between the aliphatic tails of liquid and alkane.

Orbital varices: a tricky diagnosis in MRI

1995

Orbital varix (OV) is a rare condition causing intermittent positional exophthalmos. Because of low venous pressure, OVs tend to collapse, being frequently undetectable in routine CT or MRI examinations. We describe one case of giant intraorbital varix studied with CT and MRI techniques.

Differential localization of two acid proteinases in germinating barley (Hordeum vulgare) seed

1995

A cathepsin D-like aspartic proteinase (EC 3.4.23) is abundant in ungerminated barley (Hordeum vulgare) seed while a 30 kDa cysteine endoproteinase (EC 3.4.22) is one of the proteinases synthesized de novo in the germinating seed. In this work, the localization of these two acid proteinases was studied at both the tissue and subcellular levels by immunomicroscopy. The results confirm that they have completely different functions. The aspartic proteinase was present in the ungerminated seed and, during germination, it appeared in all the living tissues of the grain, including the shoot and root. Contrary to previous suggestions, it was not observed in the starchy endosperm. By immunoblotting…

Inhibition of thromboxane biosynthesis and platelet function by simvastatin in type IIa hypercholesterolemia

1995

Abstract Thromboxane A 2 (TXA 2 ) biosynthesis is enhanced in the majority of patients with type IIa hypercholesterolemia. Because simvastatin (a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor) was previously shown to reduce platelet aggregation and TXB 2 production ex vivo, we investigated TXA 2 biosynthesis and platelet function in 24 patients with type IIa hypercholesterolemia randomized to receive in a double-blind fashion simvastatin (20 mg/d) or placebo for 3 months. The urinary excretion of 11-dehydro-TXB 2 , largely a reflection of platelet TXA 2 production in vivo, was measured by a previously validated radioimmunoassay technique. Blood lipid levels and urinary 11-dehyd…

Production of interleukin-6, tumor necrosis factor α and interleukin-10 in vitro correlates with the clinical immune defect in chronic hemodialysis p…

1995

Production of interleukin-6, tumor necrosis factor α and interleukin-10 in vitro correlates with the clinical immune defect in chronic hemodialysis patients. In patients with chronic renal failure alterations in monokine production are a common feature. Their clinical relevance has not yet been proven. We show here a correlation between an overproduction of interleukin-(IL)-6 and tumor necrosis factor alpha (TNFα) upon stimulation with LPS by mononuclear cells in vitro and the clinical grade of immunodeficiency found in these patients. Higher levels of IL-6 and TNFα were correlated with an immunocompromized state, that is, non-responsiveness to hepatitis B vaccination, whereas patients with…

Expression of synapsin I gene in primary cultures of differentiating rat cortical neurons

1995

Synapsin I is a neuron-specific protein which is present in two isoforms, Ia and Ib. In the last few years this protein has been demonstrated to play a central role in the regulation of neurotransmitter release and synaptic plasticity. In this paper the developmental expression of this protein has been investigated in primary neuronal cultures from fetal rat brain cortices. The presence of thyroid hormone in the culture medium stimulates an early expression of the protein without exerting any effect at the level of mRNA transcription and accumulation. These observations implicate a T3-dependent regulation of this neuron-specific gene at the level of mRNA translation. © 1995 Plenum Publishin…

Silver ion chromatography and gas chromatography-mass spectrometry in the structural analysis of cyclic dienoic acids formed in frying oils

1995

The nature of the cyclic monoenoic fatty acids formed from linoleic acid in sunflower oil heated to 275°C has been determined by gas chromatography-mass spectrometry of the picolinyl ester derivatives, before and after hydrogenation and deuteration, and following simplification by silver ion high-performance liquid chromatography. In addition, they were examined by gas chromatography-Fourier transform infrared spectroscopy. Cyclopentene fatty acids (50% of the total monoenes) were formed from C-8 to C-12 and C-10 to C-14 of the original chain in equal amounts with unique stereochemistry. In some isomers the double bond appeared to remain in its original position, and in others it migrated t…

Changes of protein gene product 9.5 (PGP 9.5) immunoreactive nerves in inflamed appendix.

1995

The existence of chronic appendicitis is controversial. In this prospective study, we investigated possible changes in the innervation of the appendix under different pathological conditions and correlated histological findings with clinical observation. Thirty appendectomy specimens and 14 appendices obtained from organ donors or patients who underwent right hemicolectomy were immediately fixed in Bouin's solution and processed for immunocytochemistry using an antiserum directed against the panneuronal marker protein gene product 9.5 (PGP 9.5). The density of PGP 9.5 immunostaining was evaluated by digitized morphometry. Significant differences in the density of the PGP 9.5-immunoreactive …

Thermogravimetric behavior of black liquors and their organic constituents

1995

The slow thermal degradation of various black liquors and their organic components (lignin, aliphatic carboxylic acids, extractives and polysaccharides) was investigated by thermogravimetry in the temperature range 25–700 °C under an inert nitrogen atmosphere and at a heating rate of 20 °C/min. Oven-dried samples of pine and birch black liquors from kraft and soda-anthraquinone pulping were tested. Similar tests with black liquor components were carried out both in the absence and in the presence of alkali. In all cases, the mass loss occurred primarily in the temperature range 250–500 °C. The thermograms of the various black liquors were very similar even though there were significant diff…

Enzymatic Biosynthesis of Vomilenine, a Key Intermediate of the Ajmaline Pathway, Catalyzed by a Novel Cytochrome P 450-Dependent Enzyme from Plant C…

1995

Abstract Microsomal preparations from Rauwolfia serpentina Benth. cell suspension cultures cata­lyze a key step in the biosynthesis of ajmaline -the enzymatic hydroxylation of the indole alkaloid vinorine at the allylic C-21 resulting in vomilenine. Vomilenine is an important branch-point intermediate, leading not only to ajmaline but also to several side reactions of the biosynthetic pathway to ajmaline. The investigation of the taxonomical distribution of the enzyme indicated that vinorine hydroxylase is exclusively present in ajmaline-producing plant cells. The novel enzyme is strictly dependent on NADPH2 and O2 and can be inhibited by typical cytochrome P450 inhibitors such as cytochrom…

Anaerobic respiration of Bacillus macerans with fumarate, TMAO, nitrate and nitrite and regulation of the pathways by oxygen and nitrate

1995

In Bacillus macerans, anaerobic respiratory pathways and the regulation of facultatively anaerobic catabolism by electron acceptors were analysed. In addition to fermentative growth, B. macerans was able to grow anaerobically by fumarate, trimethylamine N-oxide, nitrate, and nitrite respiration with glycerol as donor. During growth by fumarate respiration, a membrane-bound fumarate reductase was present that was different from succinate dehydrogenase. The end product of nitrate and nitrite respiration was ammonia. No N2 or NO and only traces of N2O could be detected. O2 repressed the activity of nitrate and fumarate reductases and the fermentation of glucose, presumably at the transcription…

<title>Spectral/spatial integration effects on information extraction from multispectral data: multiresolution approaches</title>

1995

New techniques for information extraction from multispectral data require physical modeling to understand the energy transfer at the atmosphere/surface interface and to develop appropriate inversion procedures, in combination with advanced processing techniques. A multi-step procedure is proposed in this work: the first step implies a binary decision about the second step to be applied in each case. If the pixel is considered as being a `pure' pixel, through a spectral/spatial classification procedure based on multiresolution techniques, then numerical inversion techniques, based on a multiple-scattering reflectance model, are used to extract parameters representing specific surface propert…

Investigation of bloodstains: false negative results of the benzidine test

1995

Since the discovery of the Benzidine Test, this method has been considered absolutely reliable for the generic diagnosis of bloodstains. The authors reviewed support the existence of false positive results, as the subtract in the coloration reaction the peroxidases may be found in numerous natural products [ 11. There is also general agreement with the false negative results: a negative result provided by the Benzidine Test indicates that the stain is not blood [2]. Given the strong certainty offered by most works of forensic medicine and criminology, most countries Spain included use this technique as a screening method in the investigation of bloodstains: when the result is negative the i…

Ulnar ray defect in an infant with a 6q21;7q31.2 translocation: Further evidence for the existence of a limb defect gene in 6q21

1995

Ectrodactyly is a developmental defect of the distal limbs characterized by marked clinical variability and genetic heterogeneity, also reflected in the observation of different chromosome abnormalities non randomly associated with longitudinal postaxial limb deficiencies. The one most frequently found in patients with split hand-split foot (SHSF) involves chromosome band 7q22. Recently, structural anomalies of chromosome 6q21 have been reported in 2 unrelated patients with SHSF, suggesting that this region may also contain genes responsible for limb development [Braverman et al., 1993. Am J Hum Genet, suppl 53: 410; Viljoen and Smart, 1993. Clin Dysmorph 2: 274-277]. We report on a third p…

Constitutive expression and inducibility of O6-methylguanine-DNA methyltransferase and N-methylpurine-DNA glycosylase in rat liver cells exhibiting d…

1995

AbstractWe have analyzed the expression of the DNA repair genes O6-methylguanine-DNA methyltransferase (MGMT) and N-methylpurine-DNA glycosylase (MPG) at RNA and protein activity level in primary rat hepatocytes in vitro and various rat hepatoma cell lines exhibiting different status of differentiation. The basal level of MGMT mRNA and activity correlated well with the degree of differentiation, as measured by tyrosine aminotransferase (TAT) mRNA expression. Induction of MGMT mRNA and protein activity by X-ray and Nmethyl-N′-nitro-N-nitrosoguanidine (MNNG) treatment was most pronounced in the well-differentiated hepatocytes and in various differentiated hepatoma cell lines (up to 6-fold). T…

Meson exchange currents in pion double charge exchange at high energies

1995

In this letter we study the high energy behavior of the forward differential cross section for the $^{18}O(\pi^+,\pi^-)^{18}Ne$ double charge exchange reaction. We have evaluated the sequential and the meson exchange current mechanisms. The meson exchange current contribution shows a very weak energy dependence and becomes relevant at incident pion kinetic energies above 600 MeV.

A New Analysis of the Tippe Top: Asymptotic States and Liapunov Stability

1995

Asymptotic behaviour of a tippe top, under the action of gliding friction. Liapunov stability analysis of the asymptotics of states with arbitrary initial conditions.

Spurenbestimmung der Radionuclide90Sr und89Sr in Umweltproben I: Laser-Massenspektrometrie

1995

Novel transmembrane topology of the hepatitis B virus envelope proteins.

1995

Abstract The small (S), middle (M) and large (L) envelope proteins of the hepatitis B virus (HBV) are initially synthesized as multispanning membrane proteins of the endoplasmic reticulum membrane. We now demonstrate that all envelope proteins synthesized in transfected cells or in a cell-free system adopt more than one transmembrane orientation. The L protein disposes its N-terminal preS domain both to the cytoplasmic and the luminal side of the membrane. This unusual topology does not depend on interaction with the viral nucleocapsid, but is preserved in secreted empty envelope particles. Pulse-chase analysis suggests a novel process of post-translational translocation leading to the non-…

Structure Determination from Powder X-Ray Diffraction Data of a Hydrogen-Bonded Molecular Solid with Competing Ferromagnetic and Antiferromagnetic In…

1995

Connection between the pinch technique and the background field method

1995

The connection between the pinch technique and the background field method is further explored. We show by explicit calculations that the application of the pinch technique in the framework of the background field method gives rise to exactly the same results as in the linear renormalizable gauges. The general method for extending the pinch technique to the case of Green's functions with off-shell fermions as incoming particles is presented. As an example, the one-loop gauge independent quark self-energy is constructed. We briefly discuss the possibility that the gluonic Green's functions, obtained by either method, correspond to physical quantities.

Evaluation of an automated chromogenic substrate assay for the rapid determination of hirudin in plasma.

1995

Abstract A fully mechanized chromogenic substrate assay method for the rapid and specific determination of recombinant hirudin (r-hirudin) in citrated plasma on clinical chemistry analyzers (Hitachi 911 and Cobas Mira) is described. In a first step, 12 μl sample volume is mixed with the chromogenic substrate. Due to the almost immediate action of hirudin the inhibitory reaction and the cleavage of the substrate is started simultaneously when bovine thrombin is added in excess. This excludes interferences by antithrombin III or heparin cofactor II. The change in absorbance/min is recorded at 405 nm. The measuring range is about 0.2 – 4.0 mg/l r-hirudin on both analyzers. Precision is charact…

Una aproximación empírica a través de las relaciones Ciencia-Tecnología- Sociedad (CTS, en estudiantes de secundaria y universitarios valencianos

1995

Resumen basado en el de la publicación Resumen en inglés Se revelan las perspectivas sobre la Ciencia-Tecnología-Sociedad (STS) de estudiantes de secundaria y estudiantes universitarios. El inventario VOSTS (Aikenhead et al., 1989) se utilizó para reflejar las creencias, posiciones y alfabetización de CTS. Llos resultados apuntan a la necesidad de introducir nuevos conceptos y actitudes, enfatizando la epistemología,la información y la cognición. ESP

Tipología de los errores en el cálculo mental : un estudio en el contexto educativo

1995

Resumen basado en el de la publicación Resumen en inglés Se aborda una tipología de errores y dificultades de los estudiantes españoles de un Colegio de Formación de Profesores cuando aplican métodos históricos de cálculo mental (métodos tomados de la tradición escrita que se encuentra en la aritmética) de los libros de texto para resolver problemas con números naturales y con números decimales. ESP

Effects of the insect growth regulator cyromazine on the fecundity, fertility and offspring development of Mediterranean fruit fly,Ceratitis capitata…

1995

Addition of cyromazine to adult diet affected negatively the development of Ceratitis capitata Wied. (Dipt., Tephritidae) offspring. Five concentrations of cyromazine (0.00001 mg/ml, 0.01 mg/ml, 0.1 mg/ml, 1 mg/ml and 10 mg/ml) have been tested. A reduction of Mediterranean fruit fly populations has been found mainly due to the effects of fertility and larval development. At these concentrations, cyromazine does not affect Ceratitis capitata fecundity.

Etude de la morphologie de l'interface reactive de dissolution en utilisant le concept de géométrie fractale

1995

National audience

Short range correlations in the pion s-wave self-energy of pionic atoms

1995

We evaluate the contribution of second order terms to the pion-nucleus s-wave optical potential of pionic atoms generated by short range nuclear correlation. The corrections are sizeable because they involve the isoscalar s-wave $\pi N$ amplitude for half off-shell situations where the amplitude is considerably larger than the on-shell one. In addition, the s-wave optical potential is reanalyzed by looking at all the different conventional contributions together lowest order, Pauli corrected rescattering term, second order absorptive effects, terms from the interaction of pions with the virtual pion cloud (chiral corrections) and correlation effects. Different off-shell extrapolations for t…

Synthesis and assembly of virus-like particles of human papillomaviruses type 6 and type 16 in fission yeast Schizosaccharomyces pombe.

1995

AbstractWe have synthesized capsid proteins of human papillomavirus types 6 (HPV 6) and 16 (HPV 16) in fission yeast Schizosaccharomyces pombe and produced virus-like particles (VLP). The capsid proteins were localized in the nucleus by indirect immunofluorescence and cell fractionation analyses. The VLP were produced in both yeast clones synthesizing L1 alone and L1/L2 and purified by sulfato-cellulofine chromatography. Electron microscopic examination showed that these VLP were similar in structure to native HPV particles. Two HPV 16 L1 variants (16 B27L1 and 16 T3L1), isolated from benign cervical samples, produced many more (68- and 14-fold) VLP than the prototype L1 (16 PL1) derived fr…

Left-right symmetry and Neutrino Stability

1995

We consider a left-right symmetric model in which neutrinos acquire mass due to the spontaneous violation of both the gauged $B-L$ and a global $U(1)$ symmetry broken by the vacuum expectation value (VEV) of a gauge singlet scalar boson $\VEV{\sigma}$. For suitable choices of $\VEV{\sigma}$ consistent with all laboratory and astrophysical observations neutrinos will be unstable against majoron emission. All neutrino masses in the keV to MeV range are possible, since the expected neutrino decay lifetimes can be short enough to dilute their relic density below the cosmologically required level. A wide variety of possible new phenomena, associated to the presence of left-right symmetry and/or …

Multibondic cluster algorithm for Monte Carlo simulations of first-order phase transitions.

1995

Inspired by the multicanonical approach to simulations of first-order phase transitions we propose for $q$-state Potts models a combination of cluster updates with reweighting of the bond configurations in the Fortuin-Kastelein-Swendsen-Wang representation of this model. Numerical tests for the two-dimensional models with $q=7, 10$ and $20$ show that the autocorrelation times of this algorithm grow with the system size $V$ as $\tau \propto V^\alpha$, where the exponent takes the optimal random walk value of $\alpha \approx 1$.

Character of the Phase Transition in Thin Ising Films with Competing Walls

1995

By extensive Monte Carlo simulations of a lattice gas model we have studied the controversial nature of the gas-liquid transition of a fluid confined between two parallel plates that exert competing surface fields. We find that the transition is shifted to a temperature just below the wetting transition of a semi-infinite fluid but belongs to the two-dimensional Ising universality class. In between this new type of critical point and bulk criticality, a response function ${x}_{\mathrm{nn}}^{max}$ varying exponentially with $D$ is observed, $\frac{2 \mathrm{ln}{\ensuremath{\chi}}_{\mathrm{nn}}^{max}}{D}={\ensuremath{\ell}}^{\ensuremath{-}1}$, where $\ensuremath{\ell}$ is a new length charact…

A Paradox in Compatibilist Accounts of Free Will and Moral Responsibility

1995

In this paper, it is argued that Frankfurt¿s sophisticated, ¿hierarchical¿ version of compatibilism faces the following paradox: a person with a highly disintegrated and incoherent value system will enjoy more freedom of the will than a person whose value system is more integrated and coherent. The reason is that the more (contrary) values a person embraces, the more likely will it be that s/he identifies with his or her first-order desires. The paradox, however, might also be extended to other versions of compatibilism.// En este artículo sostenemos que la versión refinada, ¿jerárquica¿ del compatibilismo, defendida por Harry Frankfurt se enfrenta a la siguiente paradoja: una persona con u…