Methane and carbon monoxide infrared emissions observed at the Canada-France-Hawaii Telescope during the collision of comet SL-9 with Jupiter

1995

Observations with the Fourier Transform Spectrometer were conducted in spectral ranges from 1.6 to 4.7 µm from July 17 to 21 (UT) on the hot plumes appearing on the limb as well as hours or days after the impacts. We present here an analysis of the methane emission observed at 3.3 µm some 10 min after the C impact, indicating the presence of a very small (less than 100 km wide) hot region with temperatures in the 750–1500 K range within the 0.1- to 0.01-mbar region. We also report the detection of CO emission at 4.7 µm 4.5 hrs after the L impact, indicative of a temperature of 274±10 K at the ∼1016 CO molec cm−2 level. The observations suggest that the stratospheric temperature decreases wi…

A Lattice Construction of Chiral Gauge Theories

1995

We formulate chiral gauge theories non-perturbatively, using two different cuttoffs for the fermions and gauge bosons. We use a lattice with spacing $b$ to regulate the gauge fields in standard fashion, while computing the chiral fermion determinant on a finer lattice with spacing $f << b$. This determinant is computed in the background of $f$-lattice gauge fields, obtained by gauge-covariantly interpolating $b$-lattice gauge fields. The notorious doublers that plague lattice theories containing fermions are decoupled by the addition of a Wilson term. In chiral theories such a term breaks gauge invariance explicitly. However, the advantage of the two-cutoff regulator is that gauge inv…

Searching for $B_c$ mesons in the ATLAS experiment at LHC

1995

We discuss the feasibility of the observation of the signal from $B_c$ mesons in the ATLAS experiment at the LHC. In particular, we address the decay mode $B_c{\rightarrow}J/\psi \pi$ followed by the leptonic decay $J/\psi{\rightarrow}\mu^+\mu^-$, which should permit an accurate measurement of the $B_c$ mass. We performed a Monte Carlo study of the signal and background concluding that a precision of $\approx$ 1 MeV for the $B_c$ mass could be achieved after one year of running at $\lq\lq$low" luminosity. The semileptonic decay $B_c{\rightarrow}J/\psi\ {\mu}^+{\nu}_{\mu}$ is also considered for a possible extraction of ${\mid}V_{cb}{\mid}$.

The Enterotoxin from Clostridium difficile (ToxA) Monoglucosylates the Rho Proteins

1995

The enterotoxin from Clostridium difficile (ToxA) is one of the causative agents of the antibiotic-associated pseudomembranous colitis. In cultured monolayer cells ToxA exhibits cytotoxic activity to induce disassembly of the actin cytoskeleton, which is accompanied by morphological changes. ToxA-induced depolymerization of actin filaments is correlated with a decrease in the ADP-ribosylation of the low molecular mass GTP-binding Rho proteins (Just, I., Selzer, J., von Eichel-Streiber, C., and Aktories, K. (1995) J. Clin. Invest. 95, 1026-1031). Here we report on the identification of the ToxA-induced modification of Rho. Applying electrospray mass spectrometry, the mass of the modification…

Glucosylation of Rho proteins by Clostridium difficile toxin B.

1995

TOXIN A and B, the major virulence factors of Clostridium difficile, are the causative agents of antibiotic-associated pseudomembran-ous colitis. In cultured cell lines their potent cytotoxicity results from their ability to induce disaggregation of the microfilament cytoskeleton1,2. Toxin B acts on the low-molecular-mass GTPase Rho A3,4, which is involved in the regulation of the actin cytoskeleton. We report here that toxin B catalyses the incorporation of up to one mole of glucose per mole of RhoA at the amino acid thre-onine at position 37. The modification was identified and localized by tandem electrospray mass spectrometry. UDP-glucose selectively serves as cosubstrate for the monogl…

Noninvasive Visualization of an Apparent Patent Intracoronary Stent by Transesophageal Echocardiography

1995

In the area of increasing interventional techniques there is a need for noninvasive imaging modalities to provide postinterventional follow-up. We were able to visualize the apparent patency and measure the dimensions of an intracoronary Palmaz-Schatz stent in the left circumflex coronary artery using transesophageal two-dimensional echocardiography. This report indicates the potential of echocardiography to directly assess coronary stents.

THE PARTON DISTRIBUTIONS IN NUCLEONS: A QUARK MODEL ANALYSIS

1995

We use a laboratory frame description based on quark model wave functions to study the parton distributions in the nucleon. The present approach incorporates two major improvements, namely, it has the correct support and the renormalization group evolution is carried out to next-to-leading order. We obtain initially the parton distributions arising from the Isgur-Karl wave function. The failure of the latter to reproduce, even approximately, the data motivates us to analyze different scenarios, i.e. additional high momentum components and nonvanishing gluon distributions at the initial scale. We conclude that in order to understand data at various scales complex models simultaneously, it i…

VLBI Observations of a Complete Sample of Radio Galaxies V. 3C346 and 4C31.04: two Unusual CSS Sources

1995

We present observations at 1.7 and 8.4 GHz of two Compact Steep Spectrum (CSS) sources from a complete sample of low-intermediate power radio galaxies. 3C346 shows an asymmetric structure with a one-sided ``jet'' and ``hot spot''. Present observations suggest that the classification of this source as a CSS is inappropriate, and that it is a common radio galaxy at a small angle to the line of sight. Its properties are in agreement with the predictions of unified schemes models. 4C31.04 shows more complex structure with the possibility of a centrally located flat spectrum core in between two close lobes. We suggest that this source could be a low redshift Compact Symmetric Object.

Pigment variant of neuronal ceroid-lipofuscinosis

1995

A 6-year-old girl had progressive ataxia, and visual disturbances resulting in blindness. She died in her sleep at age 22 years. She shared with her sister and paternal relatives bilateral pes cavus deformities and impaired deep-tendon reflexes which suggested Charcot-Marie-Tooth disease. Her sister, who also had both polyneuropathy and a progressive central nervous system (CNS) disease, did not have pigmentary retinopathy. At autopsy, the patient was found to have neuronal ceroid-lipofuscinosis (NCL) marked by intraneuronal accumulation of autofluorescent granular lipopigments in ballooned perikarya and conspicuous extraneuronal pigmentation of subcortical grey matter, but without axonal s…

Immunelectronmicroscopic characterization of T4 and T8 lymphocytes and natural killer cells in neuronal ceroid-lipofuscinosis.

1995

CD4+, CD8+, and CD56+ cells were isolated with the immunomagnetic separation technique from peripheral blood mononuclear cells (PBMC) of 3 patients with neuronal ceroid-lipofuscinosis : one patient each with infantile (INCL), late infantile (LINCL), and juvenile (JNCL) neuronal ceroid-lipofuscinoses, all studied by light (LM) and electron (EM) microscopy. To compare the pathology of these cells with affected cells in other types of lysosomal diseases, the separation was also performed with PBMC of 1 patient with mucolipidosis (ML) type II, 2 patients with mucopolysaccharidosis (MPS) type I, and 4 patients with MPS type III. Disease-specific lysosomal inclusions were identified in CD4+, CD8+…

Significance of lipopigments with fingerprint profiles in eccrine sweat gland epithelial cells.

1995

Lipopigments with fingerprint profiles in eccrine sweat gland epithelial cells are regular findings in childhood NCL. They have also been described in adult NCL (ANCL) a few times, but not consistently. However, they have been considered nonspecific when not matched by similar abnormal profiles in noneccrine sweat gland epithelial cells. These conflicting reports may pose a diagnostic dilemma as outlined in the following 2 examples. Patient 1 is a 20-year-old man who developed severe tetraparesis and dementia over 2 years. Electroencephalogram was abnormal with epileptiform discharges. The patient died at age 21 years without autopsy ; no other relatives are known to have a similar disease.…

La formation de la morphologie urbaine

1995

International audience

Phosphorylation of the Goodpasture antigen by type A protein kinases.

1995

Collagen IV is the major component of basement membranes. The human alpha 3 chain of collagen IV contains an antigenic domain called the Goodpasture antigen that is the target for the circulating immunopathogenic antibodies present in patients with Goodpasture syndrome. Characteristically, the gene region encoding the Goodpasture antigen generates multiple alternative products that retain the antigen amino-terminal region with a five-residue motif (KRGDS). The serine therein appears to be the major in vitro cAMP-dependent protein kinase phosphorylation site in the isolated antigen and can be phosphorylated in vitro by two protein kinases of approximately 50 and 41 kDa associated with human …

Cellular expression of α4 subunit mRNA of the nicotinic acetylcholine receptor in the developing rat telencephalon

1995

By contrast to adult brain, little is known on the development of nicotinic acetylcholine receptor (nAChR) expression. Using a digoxigenin-labeled riboprobe for in situ hybridization, alpha 4 nAChR subunit mRNA expression was studied in embryonic and postnatal rat neocortex and hippocampus where it was transiently increased in neuronal subpopulations and preceded cholinergic fiber ingrowth. alpha 4 expression was increased in neocortical layer VIb between E20 and P2 and, about birth, in dentate gyrus granule cells subsequently decreasing to adult levels. nAChR mRNA expression is increased at the developing neuromuscular endplate preceding cholinergic innervation which triggers changes in no…

Book Review: Mechanistic Heyday: The Adventure Playground of Mechanisms and Novel Reactions. (Series: Profiles, Pathways, and Dreams. Series editor: …

1995

Mechanism of anionic polymerization of methyl methacrylate in the presence of aluminium alkyls

1995

Methyl methacrylate was polymerized with tert-butyl lithium in the presence of triethylaluminium or triisobutylaluminium at 78°C in toluene. As indicated by GPC and MALDI-TOF mass spectrometry, the polymerization is accompanied by side reactions. The lower oligomers were fractionated by distillation and characterised by NMR, FT-IR, UV and electron impact (EI) mass spectrometry. All these data show that part of the polymer chains are carrying exactly one tert-butyl isoprenyl ketone unit. In order to avoid the formation of tert-butyl isoprenyl ketone a molar ratio of Al/Li>2 is necessary.

Influence of some aromatic and aliphatic compounds on the rate of photodegradation of phenol in aqueous suspensions of TiO2

1995

Abstract The influence of 3-nitrophenol, 4-nitrophenol, pentachlorophenol, ethanol, 2-propanol, ethanoic acid and ethanedioic acid on the photodegradation rate of phenol in an aqueous suspension of TiO2 (anatase) irradiated in the near-UV region was investigated. Binary mixtures of organic compound and phenol in molar ratios of 1:1 and 10:1 were used for the photoreactivity experiments performed in a batch reactor. The mineralization rate of all the mixtures was also monitored by measuring the total organic carbon (TOC) concentration. The reactivity results indicate that the photodegradation rate of phenol is mainly determined by the total amount of aromatic substrates present in the reacti…

Heredity and obesity-associated hypertension: impact of hormonal characteristics and left ventricular mass.

1995

Objectives : To investigate the influence of heredity on obesity-associated hypertension, we evaluated casual and 24-h blood pressure, left ventricular mass and some metabolic and hormonal measurements in normotensive obese subjects. Design : Healthy, normotensive obese subjects (n = 81) with positive or negative family history of hypertension were studied. Both groups were also subdivided according to a positive or a negative family history of obesity. Accordingly, 45 obese subjects had a positive family history of hypertension, 25 of these having a positive (subgroup A) and 20 having a negative family history of obesity (subgroup B). The other 36 obese subjects had a negative family histo…

Enhancement by TNF-alpha of reactivation and replication of latent herpes simplex virus from trigeminal ganglia of mice.

1995

The influence of tumor-necrosis-factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukine-1 (IL-1) and IL-3 on the in vitro reactivation frequency and replication rate of trigeminal ganglia of mice latently infected with herpes simplex virus (HSV) strain KOS was studied. It could be demonstrated that TNF-alpha and possibility GM-CSF, but not IL-1 and IL-3, enhanced the reactivation frequency and replication of HSV. Interferon alpha/beta (IFN alpha/beta) prevented reactivation and replication.

Evaluation of the acute toxicity, analgesic and CNS activities of different species ofTeucrium genus

1995

Methanol and dichloromethanol extracts of the leaves and stems of four Teucrium species (T. cartaginenses, T. flavum, T. pumillum and T. buxifolium) have been tested for their toxicity, analgesic and central depressor effects. The intraperitoneal administration of the different extracts showed a CNS depressant activity in mice, but they lacked anticonvulsive effects. When tested for analgesic activity none of the extracts increased the threshold of pain thermal stimulus. However, the methanol and dichloromethanol extracts of T. cartaginenses and T. buxifolium species showed a significant analgesic effect in models of pain induced by chemical or mechanical stimulation.

N-ACETYL-ASPARTATE ABNORMALITIES IN INTERNAL-TEMPORAL EPILEPTICUS FOCUS USING PROTON MAGNETIC-RESONANCE SPECTROSCOPY

1995

International audience; Abstract: The aim of this study was to characterize the neurochemical abnormalities related to N-acetyl-aspartate which is a neuronal marker, within an epilepticus focus located in the internal-temporal area, using proton magnetic resonance spectroscopy, Eleven patients,with a mono-hippocampal epilepticus focus on clinical and per-critical electroencephalographical criteria, were matched with II controls by age, sex and laterality. Proton spectroscopy of a volume of 8 cm(3) was performed within the ipsilateral and the contralateral internal-temporal area and within the 2 hippocampus of controls. Volumetry of the ipsilateral and the contralateral hippocampus and of th…

Double pion photoproduction on the nucleon: study of the isospin channels

1995

A model for the gamma p ----> pion+ pion- p reaction developed earlier is extended to account for all isospin channels. The model includes N, Delta(1232), N^*(1440) and N^*(1520) as intermediate baryonic states and the rho-meson as an intermediate two pion resonance. Although many terms contribute to the cross section, some channels exhibit particular sensitivity to certain mechanisms of resonance excitation or decay and the reactions provide novel information on such mechanisms. In particular the gamma N ----> N^*(1520) ----> Delta(1232) pion process affects all the channels and is a key ingredient in the interpretation of the data. Comparison is made with all available data and t…

Ab initio molecular orbital study of SenS4−nN4 (n = 0−4)

1995

Abstract We report an ab initio study of Se n S 4− n N 4 ( n = 0−4). The full geometry optimization for each molecule was performed at the Hartree-Fock level of theory involving the MIDI-4 ∗ basis sets for atomic orbitals. The correction for electron correlation was carried out for optimized geometries by utilizing the second-order Moller-Plesset (MP2) perturbation theory. The fundamental vibrations calculated for all molecular species verified that all molecules lie at the local minima. All molecules showed cage structures similar to those observed experimentally for S 4 N 4 and Se 4 N 4 . The calculated bond parameters of S 4 N 4 and Se 4 N 4 were in good agreement with the experimental v…

Breccias of the Adnet Formation: indicators of a Mid-Liassic tectonic event in the Northern Calcareous Alps (Salzburg/Austria)

1995

Stratigraphy, lithology and depositional structures of Liassic red limestone-breccias of the Adnet Formation, including the ‘Adnet Scheck’, were studied at several outcrops of the Northern Calcareous Alps (NCA) south-east of Salzburg. A four-fold lithostratigraphic division is proposed for the Adnet Formation of the Osterhorn Mountains: the hemipelagic Schmiedwirt (Sinemurian) and Kehlbach (Carixian) members are separated from the pelagic Saubach Member (Toarcian) by a layer of amalgamated breccias (Scheck Member, probably Domerian to early Toarcian). Several other breccia beds occur locally from the base of the Kehlbach Member up to the lower Saubach Member. Although the sediments overlyin…

Antibodies anti HTLV-I/II in Sicilian residents, in drug addicts, and in African immigrants

1995

Změny příhraničních oblastí sousedících se státy Evropské unie

1995

International audience; Tématem druhého kulatého stolu jsou proměny regionů hraničících s Evropskou unií. Nejprve se Michel Foucher (Université Lumière Lyon II) zabývá neustále obnovovanou problematikou vnitřních a vnějších hranic Evropské unie, pak se Gilles Lepesant (Centre Français de Recherches en Sciences sociales) soustředí na obchod a spolupráci podél východních hranic Spolkové republiky Německo. Jiří Patočka (AV ČR) následně referuje o některých aspektech vývoje euroregionů v České republice, zatímco František Zich (AV ČR) se zajímá o vývoj vztahů mezi obyvateli česko-německých pohraničních regionů. Následují zpráva Giorgia Ficarelliho (Evropská komise) o zásazích Evropské unie na p…

New contributions to supersymmetric mechanism of neutrinoless double beta decay

1995

The neutrinoless double beta ($\znbb$) decay is analyzed within the Minimal Supersymmetric Standard Model with explicit R-parity violation (\rp MSSM). We have found new supersymmetric contributions to this process and give the complete set of relevant Feynman diagrams. Operators describing $0^+ \longrightarrow 0^+$ nuclear transitions induced by the supersymmetric interactions of the \rp MSSM are derived. These operators can be used for calculating the $\znbb$ decay rate applying any specific nuclear model wave functions.

HEMT for low-noise microwaves: CAD-oriented performance evaluation

1995

This paper shows how a graphic processing of low-noise HEMT's small signal parameters, allows evaluating and comparing the actual performance obtainable in front-end applications. HEMT's tradeoff charts which solve tradeoffs among the basic low-noise amplifier performance are reported. Figures of merit for microwave low-noise HEMT which represent a fast way of evaluating HEMT in actual working conditions and of selecting the proper transistor, are defined. As an example, the tradeoff charts and the figures of merit of two HEMT's (Fujitsu FHR02FH, Sony 2SK677) and a pseudomorphic-HEMT (Celeritek CFB001-03) are reported and compared with the data sheets. © 1995, IEEE. All rights reserved.

Renal and nonrenal clearances of ceftriaxone at the steady-state and its relation to plasma protein binding

1995

Abstract The effect of the saturable plasma protein binding of ceftriaxone on the elimination of this drug was studied under steady-state conditions in the rat. A concentration-dependent increase in the total, renal and nonrenal clearances of total drug (bound + unbound) was observed, and it was related to the increase in the ex vivo unbound fraction of ceftriaxone as the plasma concentration increased. The nonrenal clearance of the unbound ceftriaxone showed a statistically significant decrease as the plasma concentration of the unbound drug at the steady state increased, which indicates that the nonrenal elimination of the drug (mainly by biliary excretion) is a saturable process. Renal c…

First lattice calculation of the B-meson binding and kinetic energies

1995

We present the first lattice calculation of the B-meson binding energy $\labar$ and of the kinetic energy $-\lambda_1/2 m_Q$ of the heavy-quark inside the pseudoscalar B-meson. This calculation has required the non-perturbative subtraction of the power divergences present in matrix elements of the Lagrangian operator $\bar h D_4 h$ and of the kinetic energy operator $\bar h \vec D^2 h$. The non-perturbative renormalisation of the relevant operators has been implemented by imposing suitable renormalisation conditions on quark matrix elements, in the Landau gauge. Our numerical results have been obtained from several independent numerical simulations at $\beta=6.0$ and $6.2$, and using, for t…

Change, Reliability, and Stability in Self-perceptions in Early Adolescence: A Four-year Follow-up Study

1995

Changes in self-perceptions of fitness, appearance, and self-esteem among adolescents were assessed in a 4-year follow-up study. Both the changes in the mean levels across time (profile analysis), and the changes in the reliability and stability of individual differences (i.e. covariance stability as test-retest correlations) were examined. The subjects (64 boys, 49 girls) were 11 years old at the first annual measurement. Self-esteem was assessed using the Rosenberg Self-Esteem Scale, as well as self-assessment questionnaires specifically designed for this study to assess Perceived Fitness and Perceived Appearance. MANOVA-and Simplex-models were used in the analysis. Our results among the…

Polymer-induced shape changes and capping in giant liposomes

1995

We studied the coupling of a polymeric amphiphile undergoing a transition from an expanded to a collapsed state of the hydrophilic polymer chain upon heating above 29°C with free and solid supported lipid bilayers. Lateral diffusion measurements and studies of vesicle shape-changes confirmed previous calorimetric studies, suggesting that the amphiphile remains incorporated in the giant vesicles and the supported bilayer during the transition. The two-dimensional hydrodynamic radii of the amphiphile in the expanded and collapsed state was measured by making use of the strong quadratic dependence of the diffusion coefficient on the radius of the diffusant (D ∞ r−2) due to the frictional coupl…

Few-neutron removal from238U at relativistic energies

1995

As part of a comprehensive study of uranium fragmentation at relativistic energies at the GSI projectile fragment separator, FRS, inclusive neutron-removal cross sections have been measured for severalxn channels at projectile energies of 600 and 950A MeV using targets of Al, Cu and Pb. The variation of the experimental cross sections with target nuclear charge is used to disentangle nuclear and electromagnetic contributions. The electromagnetic cross sections agree surprisingly well with a simple harmonic oscillator calculation of giant dipole resonances based on measured photonuclear cross sections and do not require an extra enhancement of the two-phonon giant dipole excitation as conclu…

Spatial Interaction between Neighbouring Counties: Cancer Mortality Data in Valencia (Spain)

1995

The statistical analysis of geographical mortality data has usually been approached via regression models that include appropriate covariates. These models assume stochastic independence of mortality counts for neighbouring sites, a questionable assumption that spatial automodels (Besag, 1974, Journal of the Royal Statistical Society, Series B 36, 192-236) make unnecessary. This paper presents the use of the autopoisson distribution in order to detect spatial interaction between neighbouring sites. If this interaction results in being nonsignificant, the auto-Poisson distribution reduces to a usual Poisson regression model, a particular case of generalized linear models (McCullagh and Nelde…

The contribution of ozone to forest decline

1995

More than 10 years of intensive research into forest decline in Germany has ascertained that the full extent of the visible damage cannot be explained by just one of the current hypotheses on forest decline. One of the prominent hypotheses is that chronic exposure of forest trees to ozone is probably one of the primary causes of forest decline. The aim of this paper is the critical review of a number of recent results dealing with the ozone hypothesis from a plant physiological point of view. The synopsis focusses on the effects of ozone on conifers because the most extensive data are available for coniferous trees, especially for spruce (Picea sp.) and pine (Pinus sp.) trees.

Biophysical Models as an Approach To Study Passive Absorption in Drug Development: 6-Fluoroquinolones

1995

A preliminary study attempting to assess and explain the intestinal absorption of a series of antibacterial 7-piperazinyl-6-fluoroquinolones is presented. The synthesis, n-octanol partition coefficients, intrinsic rat gut in situ absorption rate constants, and in vitro antibacterial activity data found for these homologous compounds are described. A fluorimetric, reverse-phase HPLC method was performed for the quantification of the quinolones in absorption and partition samples. Equations based on two classic biophysical absorption models are given for predicting the intrinsic absorption features of the series according to the partition data or merely single structural parameters. In situ a…