Triton calculations with the new Nijmegen potentials

1993

Triton properties are calculated using new nucleon-nucleon potentials, which were fit to the world nucleon-nucleon data. All potentials are charge dependent and explicitly incorporate the mass difference between the charged and neutral pions. Three of these models have a nearly optimal chi**2 per degree of freedom and can therefore be considered as alternative partial wave analyses, which in quality can almost compete with the Nijmegen partial-wave analysis. The triton binding energy obtained with three local models (Nijm II, Reid93, AV18) can be summarized as 7.62 +_ 0.01 MeV, which is nearly 900 keV lower than experiment. The non-local model Nijm I binds by 7.72 MeV.

Abelian current algebra and the Virasoro algebra on the lattice

1993

We describe how a natural lattice analogue of the abelian current algebra combined with free discrete time dynamics gives rise to the lattice Virasoro algebra and corresponding hierarchy of conservation laws.

Mapping of the high molecular weight kininogen binding site of prekallikrein. Evidence for a discontinuous epitope formed by distinct segments of the…

1993

Prekallikrein, a glycoprotein involved in contact phase activation, circulates in plasma in the form of a binary complex with high molecular weight kininogen (H-kininogen). The binding to H-kininogen is mediated by the prekallikrein heavy chain consisting of four repetitive domains, A1-A4. To define more precisely the region(s) involved in kininogen binding, we have employed an affinity cross-linking strategy with a synthetic peptide of 31 residues which mimics the prekallikrein binding site of H-kininogen. Cross-linking of the radiolabeled peptide to (pre)kallikrein revealed a binding segment in the NH2-terminal portion of the prekallikrein heavy chain; another binding segment was located …

A taxonomical study of the subtribe leontodontinae based on the distribution of phenolic compounds

1993

Abstract Evaluation of the phenolic constituents of five species belonging to the subtribe Leontodontinae (family Asteraceae) allowed the identification of ten flavonoid and eight phenolic acids by means of HPLC and other standard methods. The role of these compounds in relation to the morphological characteristics in the systematics of the subtribe is discussed.

Method of Discrimination of Surface Fractality

1993

Abstract A simple method for the discrimination of surface fractality is proposed. This method is based on the comparison of the nitrogen adsorption isotherm on a given sample with the "standard" isotherm on a smooth surface. The proposed comparative method makes it possible to determine the lower limit of the scale range of surface fractality. A thermodynamic method is recommended as a complement to fractal analysis in the scale range of about 10-1000 A. The results of the investigation of surface roughness are presented with examples of typical samples of silica gels, porous glasses, apatite, and coal.

Study of vacancy defects in PbSe and Pb1-xSnxSe by positron annihilation

1993

Abstract Positron lifetime measurements have been performed to study vacancy defects in vapour-liquid-solid (VLS) grown PbSe and Pb 1- x Sn x Se ( x = 0.07, 0.1, 0.3). Post-growth annealing under various vapour pressure conditions has been used to change the number of Pb vacancies, resulting in the determination of the specific positron trapping rate μ Pb v = (1.0±0.1)×10 14 s -1 . The sensitivity range of the positron annihilation method to the Pb vacancies was found to be 10 17 Pb ] 20 cm -3 . Positron lifetimes in perfect PbTe, PbSe and PbS crystals have been calculated. Moreover, we have predicted lifetimes of positrons trapped by vacancies. The calculated lifetimes in bulk and defects …

Relativistic corrections and unitary equivalence in elastic electron deuteron scattering.

1993

The role of unitary equivalence of relativistic corrections in elastic electron deutron scattering is studied, starting from a class of approximately, unitarily equivalent Hamiltonians and using consistent charge density operators. The connection of various formal approaches for deriving the relativistic corrections to wave functions and operators are discussed in detail. For reasons of simplicity, we have chosen a pure one-pion-exchange model and calculated the charge and quadrupole form factors of the deuteron. The numerical results show that the unitary equivalence holds at small momentum transfers, but breaks down rather soon with increasing momentum transfers (\ensuremath{\lesssim}5 ${…

A thermodynamic analysis on the coincidence of extrema conditions in the sorption equilibrium for ternary polymer systems

1993

Flory-Huggins theory of polymer solutions has been used to express the condition of extrema values in the total sorption, as well as the inversion point in the preferential adsorption parameters for termary polymer systems. Two approaches have been followed, the first considers the binary and ternary interaction parameters independent of polymer concentration and solvent composition. In the second one, this dependence has been introduced. Our attention is focused on the volume fraction of solvent mixture dependence of the above parameters, in order to confirm or not the coincidence between the extrema values and the inversion point. Several cosolvent and cononsolvent ternary polymer systems…

Why a scalar explanation of the L3 events is implausible

1993

We investigate the question of whether an additional light neutral scalar can explain the $l^+ l^- \gamma \gamma$ events with high invariant mass photon pairs recently observed by the L3 collaboration. We parameterize the low energy effects of the unknown dynamics in terms of higher dimensional effective operators. We show that operators which allow for the scalar to be produced and decay into photon pairs will allow other observable processes that should have been seen in current experiments.

MIXED OLIGOPOLY WITH HOMOGENEOUS GOODS

1993

A Kinetic Model of Short- and Long-Term Potentiation

1993

We present a kinetic model that can account for several experimental findings on short- and long-term potentiation (STP and LTP) and their pharmacological modulation. The model, which is consistent with Hebb's postulate, uses the hypothesis that part of the origin of LTP may be a consequence of an increased release of neurotransmitter due to a retrograde signal. The operation of the model is expressed by a set of irreversible reactions, each of which should be thought of as equivalent to a set of more complex reactions. We show that a retrograde signal alone is not sufficient to maintain LTP unless long-term change of the rate constant of some of the reactions is caused by high-frequency s…

The mean field to Ising crossover in the critical behavior of polymer mixtures : a finite size scaling analysis of Monte Carlo simulations

1993

Monte Carlo simulations of the bond fluctuation model of symmetrical polymer mixtures (chain lengths N A =N B =N) are analyzed near the critical temperature T c (N) of their unmixing transition. Two choices of interaction range are studied, using a square-well potential with effective coordination number z eff ≃ 14 or z eff ≃ 5, respectively, at a volume fraction O= 0.5 of occupied lattice sites, and chain lengths in the range 8≤ N≤ 512. A linear relation between N and T c (N) is established, T c (N)= AN+B, where the correction term B is positive for z eff = 14 but negative for z eff = 5. The critical behavior of the models is analyzed via finite size scaling techniques, paying attention to…

Synthesis of optically pure alkynols

1993

Abstract (R,S)-1-alkylprop-2-yn-1-ols have been separated by a 2-step procedure, esterification with N-p-tosyl-(L)-phenylalanine (or valine), recrystallisation of the diastereomeric esters from ethanol/hexane and saponification of the optically pure esters.

De l'inégalité sociale devant la santé au dualisme sanitaire : le RMI, une réponse adéquate aux besoins de santé des plus défavorisés ?

1993

Literature on household medical expenditure according to socio economiccategories indicates that that disparities in access to health care are no longer a major obstacle to social equality. Nevertheless these surveys do not take into account the dualistic structure of society and therefore do not recognise the changing issues in health and social policy. As regards health policy the issues are set in terms of the exclusion of those individuals who since they live on the fringes of economic activity no longer qualify for Social Security benefits. To give a complete picture of social inequalities it is essential to study this exclusion from health care. By studying the people who are on "RMI"…

The Karsikko and Cross-Tree Tradition of Finland The Origins, Change and End of the Custom

1993

According to an East -Finnish custom that came to an end around the beginning of the 20th century, the karsikko (conifer shorn of branches) and the cross-tree were prepared when the deceased was taken for burial. The Roman-Catholic Church and the Reformation introduced into folk beliefs the idea that the deceased did not journey all the way to the community of the dead. Restoring the social order of the community that had been disturbed by death then required that the dead be placed in the intermediary stage dictated by the tripartite division of the rite of passage in status. It was also necessary to establish a boundary between the living and the dead as a precaution against the undesired…

Impaired muscle strength in female adolescents and young adults surviving leukemia in childhood

1993

Background. With the improving cure rate in childhood malignancies, increasing interest has been focused on long-term survivors. To evaluate late sequelae of childhood leukemia, the muscle strength of 43 young female survivors was investigated and compared with that of 69 healthy age-matched women. The patients had been off therapy for 1 to 19 years. Methods. The anthropometric characteristics measured were height and weight, and body mass index was calculated. The maximal isometric strengths for elbow flexion, knee extension, and hand grip were measured on a special dynamometer chair. Dynamic muscular endurance was measured by pushup and situp tests. Results. The mean height of the patient…

Optic Nerve Decompression Improves Hemodynamic Parameters in Papilledema

1993

Purpose: The purpose of this study is to examine changes in color Doppler imaging parameters before and after optic nerve sheath decompression (ONSD) for chronic papilledema caused by pseudotumor cerebri (PTC). Methods: Color Doppler imaging was performed within 48 hours before surgery and within 48 hours after the procedure using a color Doppler unit with a 7.5-MHz phased linear transducer. Pulsed Doppler spectrum analyses were recorded digitally on videotape from the ophthalmic, central retinal, and short posterior ciliary arteries, using a 0.4 × 0.6-mm sample volume. Results: Blood flow velocities in the ophthalmic, short posterior ciliary, and central retinal arteries of 24 eyes were si…

Cerebrospinal fluid choline levels in Parkinson's disease

1993

Comparative multinuclear magnetic resonance spectroscopic study of transition metal (Cr, W and Mn) mesitylene tricarbonyls and transition metal (Ru a…

1993

Abstract Three mononuclear 1,3,5-trimethylbenzene (mesitylene) carbonyl transition metal complexes, mesitylene tricarbonyl chromium, (CH 3 ) 3 C 6 H 3 Cr(CO) 3 ( 1 ), mesitylene tricarbonyl tungsten, (CH 3 ) 3 C 6 H 3 W(CO) 3 ( 2 ), mesitylene tricarbonyl manganese tetra-fluoroborate, [(CH 3 ) 3 C 6 H 3 Mn(CO) 3 ]BF 4 ( 3 ); and three clusters, mesitylene nonacarbonyl tetracobalt, (CH 3 ) 3 C 6 H 3 Co 4 (CO) 9 ( 4 ), mesitylene carbido tetradecacarbonyl hexaruthenium, (CH 3 ) 3 C 6 H 3 Ru 6 C(CO) 14 ( 5 ) and carbido heptadecacarbonyl hexaruthenium, Ru 6 C(CO) 17 ( 6 ), have been studied by means of 1 H, 13 C and natural abundance 17 O NMR spectroscopy. Generally, the 1 H and 13 C NMR chemi…

Alternierende ferro- und antiferromagnetische Austauschwechselwirkungen in einem kettenförmigen CuII-Koordinationspolymer

1993

Self-assembly by co-ordination and strong hydrogen bonding. X-ray crystal structures of a dimeric trisodium complex of a new acidic complexing ligand…

1993

Abstract The new acidic complexing ligand triethanolamine-O,O,O-triacetic acid, 3, is synthesized by reaction of triethanolamine with chloroacetic acid in the presence of sodium tert-butoxide. The resulting Na complex, 4, and its dihydrate, 5, contain two ligand molecules, both with one Na+ ion interaction and both co-ordinated to a third, central, Na+ ion. In addition the acidic ligands are hydrogen bonded to each other, like carboxylic acids, and in 4, by three crystallographically symmetric hydrogen bonds, while in 5, due to the breakdown of symmetry, two normal and one crystallographically symmetrical hydrogen bond. Inside this extraordinary dimeric assembly (a pseudo-cryptate) are the …

Synthesis and spectroscopic characterization of R3SnIV derivatives ofN-acetyldipeptides

1993

Triorganotin(IV) derivatives of N-acetyldipeptides R3SnAcDip; RMe, Et, n-Bu, n-Oct, Cy or Ph (HAcDipN-acetylglycylglycine and N-acetylglycylvaline; RMe, n-Bu, Cy, HAcDipN-acetylglycylalanine) were obtained by neutralization of R3SnOH and HAcDip. The complexes were studied by means of 119Sn Mossbauer, IR and 1H, 13C and 119Sn NMR spectroscopy. The CSnC bond angles have been inferred by rationalization of Mossbauer nuclear quadrupole splittings as well as from NMR coupling constants. Correlations of Mossbauer isomer shifts with partial atomic charges on tin atoms have been determined: Polymeric trigonal bipyramidal structures, with near-planar R3Sn units and axial carboxylate (unidentate) and…

New complexes of nickel and nickel/cobalt with tetrahydrofuran-2,3,4,5-tetracarboxylic acid, THF(COOH)4. Crystal structures of Ni[THF(COOH)2(COOH)2](…

1993

Abstract The reaction of NiCl2·6H2O with tetrahydrofuran-2,3,4,5-tetracarboxylic acid, THF(COOH)4, partially deprotonated by Na2CO3 (1 : 1 metal/ligand molar ratio), yielded Ni[THF(COOH)2(COO)2](H2O)3 (1). The molecular structure of 1 was determined by X-ray diffraction on the monocrystal. The structure consists of a mononuclear neutral unit with the nickel atom coordinated by a [THF(COOH)2(COO)2]2− ligand, which acts as a tridentate ligand, and three water molecules. Direct interaction of NiCl2·6H2O and CoCl2·6H2O (1 : 1 molar ratio) with THF(COOH)4 previously deprotonated by Na2CO3 (1 : 1 metal/ligand molar ratio) gave, by slow evaporation of the solution obtained, green crystals of the n…

A Rapid Method for Amplification of Plastome DNA-Fragments from Spinacia oleracea by PCR

1993

Summary Polymerase Chain Reaction (PCR) was used as a very powerful technique to amplify DNA-fragments. Isolated chloroplasts and a crude suspension of small leaf pieces of Spinacia oleracea were osmotically shocked and subsequently heated. Aliquots of the resulting homogenate including the organelle DNA were directly added to basic reaction mixtures to carry out PCR without additional isolation- or purification steps. A 180 by DNA-fragment from the psbA-gene was amplified in both cases. In parallel, plasmid-DNA (pHT1) bearing the psbA-gene was subjected to PCR retaining unchanged reaction conditions. Identical DNA-fragments were obtained, as the following sequencing revealed. With the meth…

Bioproduction of an extract from Penicillium funiculosum Thom with activity against Ceratitis capitata and Tetranychus urticae

1993

The bioproduction conditions of a crude extract from a strain of Penicillium funiculosum Thom, which shows activity against Ceratitis capitata and Tetranychus urticae, have been optimized. The efficacy degree was 95% (C. capitata) and 100% (T. urticae), according to Abbot. This is the first report on the pesticide activity of an extract from P. funiculosum against these species. The best yields were obtained when P. funiculosum was grown in Raulin-Thom medium at pH 6.5 with sucrose candy as the carbon source and ammonium sulphate and phosphate as the nitrogen source. Other favourable conditions were static cultures, at 28 degrees C, and in the dark.

Search for high mass photon pairs in (f= e, μ, τ, v, q) at LEP

1993

Abstract The result of a search for high mass photon pairs from the processes e + e − → f f γγ (f = e, μ, τ, v and q) with the ALEPH detector is reported. The result for f = e , μ and τ is to be compared with the observation of 4 events by the L3 Collaboration with invariant masses, M γγ , of the two photons near 60 GeV. From a data sample approximately twice as large taken from 1990 to 1992, 6 events are found with M γγ distributed between 50 GeV and 72 GeV, while 4.9 events are expected from a QED calculation. There is no evidence for a mass peak; only one event ( μ + μ − γγ ) at M γγ = 59.4 ± 0.2 GeV is compatible with the L3 observation. In addition, for M γγ > 50 GeV, no event is found…

The efficient bovine insulin presentation capacity of bone marrow-derived macrophages activated by granulocyte-macrophage colony-stimulating factor c…

1993

Bone marrow-derived macrophages (BMM phi) were shown before to function as antigen-presenting cells. We show here, that the antigen presentation capacity of BMM phi depends on the nature of the antigen and is differently regulated by the lymphokines interferon-gamma (IFN-gamma) and granulocyte/macrophage-colony-stimulating factor (GM-CSF). When bovine insulin (BI) was employed as antigen, only BMM phi treated with GM-CSF (GM-CSF-M phi) were efficient presenters, but when presentation of the antigens ovalbumin and conalbumin was tested, IFN-gamma-pulsed BMM phi (IFN-gamma-M phi) proved superior to GM-CSF-M phi. The lack of efficient BI presentation function of IFN-gamma-M phi was only obviou…

Bioaccumulation of dioxins, coplanar PCBs, PCDEs, HxCNs, R-PCNs, R-PCPHs and R-PCBBs in fish from a pulp-mill recipient watercourse

1993

Abstract Pike, perch and lake bream from the river Kymijoki were analyzed by gas chromatography/mass spectrometry (GC/MS) for toxic polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), hexachlorinated naphthalenes (HxCNs), non-ortho substituted polychlorinated biphenyls (coplanar PCBs) and alkylchloroaromatics of pulp mill origin. In most fish, the only congener of PCDD/PCDFs found was 2,3,7,8-TeCDF (

Regioselective synthesis of calixcrowns derived from p-tert-butylcalix[5]arene

1993

Abstract Alkylation of p-tert-butylcalix[5]arene with oligoethylene glycol-ditosylates in the presence of CsF affords the 1,3-bridged calix[5]crowns 1a–c in 51 to 72% yield. In the case of hexaethylene glycol the isomeric 1,2-bridged calix[5]crown-7 2c was obtained additionally. The calixcrowns were further modified by alkylation of the remaining hydroxyl groups.

Environmental analysis of chlorinated aromatic thioethers, sulphoxides and sulphones

1993

Abstract Chlorinated aromatic thioethers discussed here are polychlorinated dibenzothiophenes, thianthrenes and diphenylsulphides. Relatively little is known about their occurrence, behaviour and fate in the environment. Polychlorinated dibenzothiophenes and diphenylsulphides have recently been found to be formed in waste combustion and analysed in pulp mill effluents. Chlorinated sulphoxides and sulphones are usually metabolites or oxidation products of different chlorinated aromatic compounds. Different gas chromatographic-mass spectrometric techniques are used in the analysis of the chlorinated thioethers. The sulphoxides and sulphones, because of their higher polarity, can be isolated f…

Modulation of accessory cell function of immortalized bone marrow-derived macrophages by granulocyte/macrophage colony-stimulating factor.

1993

To generate cloned macrophage populations with sensitivity towards granulocyte/macrophage colony-stimulating factor (GM-CSF), bone marrow-derived macrophages (BMM phi) were immortalized by transformation with SV40. A panel of transformed clones was established. The majority of clones represented independently derived transformants, as evidenced by restriction fragment length polymorphism using genomic DNA digested with EcoRI and TaqI and the 5.2 kb SV40 DNA for hybridization analysis. The cells belong to the macrophage lineage according to several criteria, e.g. the presence of nonspecific esterase, their phagocytic capacity and their morphology. Many clones were potent antigen-presenting c…

IMMUNOGENICITY OF AN ACELLULAR PERTUSSIS VACCINE COMPOSED OF GENETICALLY INACTIVATED PERTUSSIS TOXIN COMBINED WITH FILAMENTOUS HEMAGGLUTININ AND PERT…

1993

We studied the immunogenicity of an acellular pertussis vaccine composed of genetically detoxified pertussis toxin (PT-9K/129G), filamentous haemagglutinin, and a 69-kilodalton protein, pertactin, in 30 children aged 12 to 24 months and in 80 infants aged 2 to 4 months. A significant increase of the neutralizing titer and of the titers against pertussis toxin, filamentous hemagglutinin, and pertactin, as determined by enzyme-linked immunosorbent assay, was achieved after three doses of vaccine in all the children; a significant increase of these antibody titers was obtained in 100%, 96.1%, 93.5%, and 98.7% of the infants, respectively.

The apparent loss of tissue culture competence during leaf differentiation in yams (Dioscorea bulbifera L.)

1993

Explants taken from the leaves of yams (Dioscorea bulbifera L.) at different stages of development were cultured in vitro on a checkerboard using various combinations and/or concentrations of auxin (2,4-d) and cytokinin (6-BAP). An addition of cytokinin to the culture media was not essential for callus induction from explants derived from young leaves in the very early stages of expansion. When the leaves expanded further they required cytokinin and the requirement increased considerably during expansion. Explants taken from fully expanded leaves were no longer able to proliferate, even when extremely high concentrations of cytokinins were applied. Callus grown from highly immature leaves w…

Application of 252Cf plasma desorption mass spectrometry in dental research

1993

Abstract Topically applied fluorides introduced in dental hygiene products elevate the concentration levels of fluoride in oral fluids and thus also affect chemical reactions of enamel de- and remineralisation. The chemical reactions on the surface of tooth enamel still are a subject of controversy. Here 252 Cf-plasma desorption mass spectrometry and argon ion etching are used to analyse the molecular structure of the upper layes of enamel. The mass spectrum of untreated enamel is characterised by a series of cluster ions containing phosphate. It is evident that under certain conditions the molecular structure of the surface enamel is completely transformed by treatment with fluorides. The …

Orthometallation reaction in dirhodium(II) compounds. Selective formation of doubly-metallated compounds with head-to-head structure

1993

Abstract The reaction of the mono-metallated compound Rh 2 (O 2 CCH 3 ) 3 [(C 6 H 4 )P(CH 3 ) (C 6 H 5 )]·2(HO 2 CCH 3 ) with PPh 3 (1:1 molar ratio) has been studied by 31 P NMR spectroscopy. The reaction yields the doubly-metallated compound Rh 2 (O 2 CCH 3 ) 2 [(C 6 H 4 ) P(CH 3 )(C 6 H 5 )]p(C 6 H 4 )P(C 6 H 5 ) 2 ]·2(HO 2 CCH 3 ) with a head-to-head (H-H) configuration. An intermediate reaction compound, not previously observed, has been spectroscopically detected in solution. Analogous intermediate compounds have been detected using P( p -CH 3 C 6 H 4 ) 3 and P( p -ClC 6 H 4 ) 3 instead of triphenylphosphine.

Vestibular Decruitment

1993

Torok studied the ratio obtained between the responses to two different heat stimulation intensities of the same temperature. A decrease in response to the strong stimulus (i.e., a diminished ratio) was called "vestibular decruitment," and was regarded as a topodiagnostic indicator of central vestibular lesion, reflecting "adaptation" or "fatigue." The authors studied the reliability of vestibular decruitment obtained by Torok's technique in the indication of central vestibular pathology. Twenty-eight normal individuals and 30 patients previously diagnosed by other methods with diffuse pathology of the central nervous system were evaluated. The results obtained show that the two stimuli use…