Constraints on additionalZ′gauge bosons from a precise measurement of theZmass

1990

We analyze the constraints on the mass and mixing of superstring-inspired E{sub 6} {ital Z}{prime} neutral gauge boson that follow from the recent precise {ital Z} mass measurements and show that they depend very sensitively on the assumed value of the {ital W} mass and also, to a lesser extent, on the top-quark mass.

Muon capture revisited

1990

Abstract The problem of inclusive muon capture in nuclei is studied by calculating the capture rate in asymmetric infinite nuclear matter and using the local density approximation to evaluate the capture rates in nuclei. It is shown that the method is rather reliable and allows one to improve on approximations used in the past. The need for a strong nuclear renormalization is shown, reducing the capture rates by about a factor two in medium and heavy nuclei. By using standard effective interactions in the spin-isospin channel one can account for this renormalization and one finds a remarkable overall agreement with the measured capture rates for a large list of nuclei through the periodic t…

An abdominal aortic aneurysm (AAA) in combination with duplication of the inferior vena cava (IVC), the right renal artery (RRA) and the right renal …

1990

Intra-abdominal abnormality of vessels may sometimes lead to complications. A case of the rare combination of an abdominal aortic aneurysm (AAA) at the origin of the inferior mesenteric a. with duplications of the inferior vena cava (IVC), the right renal a. (RRA) and the right renal v. (RRV) as well as absence of the left common iliac v. is reported.

(e,e'f) Coincidence experiments on 235U and 238U

1990

Abstract Coincidence experiments for (e, e'f) on the actinide nuclei 235 U and 238 U have been performed at the Mainz Microtron (MAMI A) concentrating on three subjects: multipole strength distributions and form factors for the lowest multipolarities, the mass split in the fission decay of various giant multipole resonances, and the separation of near barrier fission channels. Data were taken at four values of momentum transfer ( q eff ≈ 0.20, 0.28, 0.53, and 0.71 fm −1 for 238 U, q eff ≈ 0.20, 0.44, 0.57, and 0.71 fm −1 for 235 U) for excitation energies ω = 4–22 MeV. The fission fragments have been detected using the Giessen PPAC-Ball. A model-independent multipole analysis yields both fo…

Acanthocephala in fish from the Bothnian Bay, Finland

1990

A sample of 7266 fish from 31 species was obtained from the north-eastern Bothnian Bay, Baltic Sea, from 1975 to 1982. Twenty-six fish species were found to be infected with seven acanthocephalan species identified as Echinorhynchus salmonis, E. bothniensis, E. borealis, E. gadi, Acanthocephalus anguillae, A. lucii and Neoechinorhynchus rutili. Acanthocephalus lucii was the only acanthocephalan not to attain sexual maturity M at least one species of fish. Fourteen new host records were found for E. bothniensis. A total of 1576 acanthocephalan infections was found; in most cases these were single species infections, but in 108 cases infections of two, and in two cases of three species were o…

Il caso Diigalu Tiiti. Strutture sociali e processi produttivi presso i Borana dell'Etiopia

1990

This paper concerns the social elements which are relevant in relation with some important productive features of the Borana of Southern Ethiopia. Recent field-data seem to indicate that the structure provided by descent is particularly significant with regard both to economical mutual assistance and to management of wells, the crucial natural resources. Cet article concerne les éléments sociaux importants par rapport à des procédés de production des Borana du sud de l'Ethiopie. Le système de parenté semble particulièrement significatif aussi bien en ce qui concerne l'assistance réciproque que pour la gestion des puits, la ressource naturelle cruciale.

A characterization of the line set of an odd-dimensional Baer subspace

1990

Generalizing a theorem of Beutelspacher and Seeger, we consider line sets\(\mathcal{L}\) inP=PG(2t + 1,q),t ∈ IN, with the following properties: (1) any (t + 1)-dimensional subspace ofP contains at least one line of\(\mathcal{L}\), (2) if a pointx ofP is incident with at least two lines of\(\mathcal{L}\) then the points in the factor geometryP/x which are induced by the lines of\(\mathcal{L}\) throughx form a blocking set of type (t, 1) inP/x, (3) any line of\(\mathcal{L}\) is coplanar with at least one further line of\(\mathcal{L}\). We will show that the examples of minimal cardinality are exactly the line sets of Baer subspaces ofP.

Symptomatische Verkalkungen beim Neugeborenen

1990

Stippled epiphyses occur in the new-born and young infant in the different hereditary forms of chondrodysplasia punctata. Symptomatic stippling has been described also in association with chromosomal anomalies, gangliosidosis and drug induced embryopathies. We present patients with Cumarin-embryopathy (2), fetal alcohol syndrome (1), Zellweger-syndrome (2) and chromosomal anomaly 16 (1) and discuss the typical roentgenographic features, distribution and differential diagnosis of epiphyseal stippling.

ElectromagneticN→N*(1535)transition in the relativistic constituent-quark model

1990

We study a light-cone model of the nucleon and the ${S}_{11}(1535)$ resonance which provides a relativistic generalization of the constituent-quark model in the nonperturbative low-${Q}^{2}$ regime. The two parameters of the model, namely, the size parameter $\ensuremath{\alpha}$ and the constituent-quark mass ${m}_{q}\ensuremath{\approx}300$ MeV, are fixed by the axial form factor. We find good agreement for the electromagnetic form factors of the nucleon up to ${Q}^{2}\ensuremath{\approx}1\ensuremath{-}2$ Ge${\mathrm{V}}^{2}$. All static properties of the nucleon, except for the neutron charge radius, are reproduced within 10%. In addition, we show that the electromagnetic current of the …

Synaptic ribbons of the rat pineal gland: responses to in-vivo and in-vitro treatment with inhibitors of protein synthesis.

1990

To elucidate the role of protein synthesis in the nocturnal increase of synaptic ribbons in the rat pineal gland, actinomycin-D, which inhibits transcription, and cycloheximide, an inhibitor of translation, were used. To assure that the drugs were effective and to relate morphological changes to pineal biosynthetic phenomena, the activity of N-acetyltransferase and levels of pineal indoleamine were measured. Results of in-vivo, short-term and long-term treatment with either drug suggest that transcription of proteins related to synaptic ribbon formation occurs during the first half of the light phase, whereas translation takes place during the first few hours of the dark phase. In contrast,…

Effects of scintillation light collection on the time resolution of a time-of-flight detector for annihilation quanta

1990

Monte Carlo methods were used to simulate the production and collection of scintillation light in a BaF/sub 2/ crystal. The calculated results were compared to measured values for detectors with different heights. Based on this simulation, a TOF (time-of-flight) detector consisting of two conical BaF/sub 2/ crystals (base radius 18 mm, top radius 15 mm, height 25 mm) was assembled. The total time resolution of this system was (210+or-5) ps FWHM (full width at half maximum) for 511-keV annihilation quanta and was found to be independent of the source position between the detectors. Since the time resolution of the TOF detector system consisting of two conical BaF/sub 2/ crystals is sufficien…

Studies on the Content of Free Amino Acids in Needles of Undamaged and Damaged Spruce Trees at a Natural Habitat

1990

Summary Measurements of the amino acids in needles of undamaged and damaged 90-year-old spruce trees ( Picea abies ) showed different patterns. During the summer months a reduction in total amino acid content of about 60 % was found. In autumn the content of total amino acids rose again. The courses of the single amino acids behave similarly to that of the total amino acids. Quantitatively, the main amino acids were GLU, ASP and GLN with about 37 %, 21 % and 10 %, respectively, followed by PRO, ALA and SER with about 3–4 % each. In the needles of healthy trees large variations in ARG content could be observed. These variations correlate neither with the damage degree of the trees nor with t…

The problem of welfare: Is there a welfare civilization?

1990

Abstract Welfare policy is at present increasingly tied both to market forces and to primary social networks. This process splits society into two camps. One‐fifth of the population is segregated from the rest in its dependence on the welfare system, which is in turn dependent on a diminishing portion of the economy and required to rationalize itself in terms of market forces. Meanwhile, the welfare system is making an effort to minimize its social cost by decentralization and by utilizing community ties and lifestyles rather than relying on the professional welfare bureaucracy. This process tends to combine modern forms of production with the meanings and values of traditional society. It …

Adducts of tin(IV) and organotin(IV) derivatives with 2,2′-azopyridine II. Crystal and molecular structure of SnMe2Br2AZP and further mössbauer and p…

1990

Abstract A series of adducts of tin(IV) derivatives with 2,2′-azopyridine, AZP, has been studied by Mossbauer and X-ray photoelectronic spectroscopies and the crystal and molecular structure of SnMe2Br2- AZP has been determined. The linear correlation of the Mossbauer parameter isomer shift with partial atomic charge on tin suggests the occurrence of a single homologous series of isostructural adducts. The correlation of the Mossbauer parameter quadrupole splitting and C-Sn-C bond angle permits their calculation in SnMe2X2AZP adducts (X = Cl, Br). The N1s binding energies, obtained by XPS data, pointed out two slightly different values for both pyridinic and azo-group nitrogens. The crystal…

Effect of phosphinothricin (glufosinate) on photosynthesis and photorespiration of C3 and C 4 plants.

1990

Phosphinothricin (glufosinate), an irreversible inhibitor of glutamine synthetase, causes an inhibition of photosynthesis in C3 (Sinapis alba) and C4 (Zea mays) plants under atmospheric conditions (400 ppm CO2, 21% O2). This photosynthesis inhibition is proceeding slower in C4 leaves. Under non-photorespiratory conditions (1000 ppm CO2, 2% O2) there is no inhibition of photosynthesis. The inhibition of glutamine synthetase by phosphinothricin results in an accumulation of NH4 (+). The NH4 (+)-accumulation is lower in C4 plants than in C3 plants. The inhibition of glutamine synthetase through phosphinothricin in mustard leaves results in a decrease in glutamine, glutamate, aspartate, asparag…

Relationship between electrical and mechanical properties of motor units.

1990

In six healthy volunteers, the size of the motor unit action potential (MUAP) was related to its contractile behaviour. Electrical activity was determined by measuring amplitude and area of the potential, using the macro electromyography (EMG) technique. The mechanical response was characterised by contraction time, twitch force and relaxation time, recorded with the spike triggered averaging technique. With increasing tension of the whole muscle corresponding to an increasing threshold, the force of single units enlarged exponentially compared to their EMG. There was only a weak relationship between contraction time and electrical activity and none between EMG and relaxation time.

Decay modes of sigma and lambda hypernuclei

1990

Abstract A review is presented of the problem of Σ and Λ decay in nuclei. By means of handy, yet reliable approximations, an approach to Σ decay is developed which allows a clear insight into the different aspects of the problem. The role of nuclear polarization, due to the spin-isospin ΣN → ΛN interaction, in the reduction of the Σ widths is discussed. Many experimentally observable Σ hypernuclei are predicted by showing that their widths are narrower than the separation energies between levels. The mesonic and non-mesonic decays of Λ hypernuclei are analyzed. The non-mesonic width is fairly well reproduced by simplified models for the ΛN → NN weak transition, but quantities like the ratio…

Abstracts of scientific papers second international symposium on central nervous system monitoring

1990

Differential effects of calcium channel antagonists (omega-conotoxin GVIA, nifedipine, verapamil) on the electrically-evoked release of [3H]acetylcho…

1990

Electrically-evoked release of [3H]acetylcholine from autonomic neurons (myenteric plexus), motoneurons (phrenic nerve) and the central nervous system (neocortex) was investigated in the presence and absence of the calcium channel antagonists omega-conotoxin GVIA, nifedipine and verapamil, whereby the same species (rat) was used in all experiments. Release of [3H]acetylcholine was measured after incubation of the tissue with [3H]choline. omega-Conotoxin GVIA markedly reduced (70%) the evoked release of [3H]acetylcholine from the myenteric plexus of the small intestine (IC50: 0.7 nmol/l) with a similar potency at 3 and 10 Hz stimulation. An increase in the extracellular calcium concentration…

An International Proficiency Study with the Tumor Marker CA 125

1990

A strict and adequate quality assurance program is the only real guarantee of the reliability of laboratory test results. Such proficiency testing was carried out for the CA 125 test system in five university laboratories over a period of three years (1984 - 1987) using five different reference materials (BIOREF, FRG). A concentration-dependent performance profile could thus be established evaluating a total of 301 assays. Intra-assay precision of the test ranged between 4.8 and 11.5%, and interassay precision between 13.6 and 19.1%. Laboratory specific average values of the individual reference materials ranged between 26 and 32 U/ml for reference 1, 51 and 59 U/ml for reference 2, 109 an…

The Galactose-Specific Lectin from the Sponge Chondrilla Nucula Displays Anti-Human Immunodeficiency Virus Activity in vitro via Stimulation of the (…

1990

A new lectin has been isolated from the sponge Chondrilla nucula. The purified CN lectin is a protein composed of four polypeptide chains with a molecular weight (MW) of 15600. The isoelectric point is 4.5 and the amino acid composition is rich in aspartic and glutamic acid. The lectin precipitates erythrocytes from humans (A, B, O) with a titre between 25 and 210. The CN lectin is d-galactose-specific and displays a moderate mitogenic effect on spleen lymphocytes from mice and on CD4-positive human H9 cells. An interesting feature of this lectin is its ability to stimulate the (2′-5′)oligoriboadenylate [(2′-5′)A] metabolic pathway in non-infected and human immunodeficiency virus (HIV-1)-i…

Anaemia during pregnancy as a risk factor for infant iron deficiency: report from the Valencia Infant Anaemia Cohort (VIAC) study.

1990

A prospective cohort study with a 1-year follow-up of 156 neonates was carried out specifically designed to test the hypothesis that there is a positive relationship between iron deficiency during pregnancy and the development of the same disease in newborn infants. Exposure was defined as being born of a mother with ferropenic anaemia at delivery, and cases as the infants who developed iron deficiency during their first year of life. A statistically significant positive association was detected with an odds ratio of 6.57 (95% confidence limits 1.81-25.97). A stratified analysis was also performed to control the effect of potential confounders such as socio-economic variables, feeding pract…

Combined complete C5 and partial C4 deficiency in humans: clinical consequences and complement-mediated functions in vitro.

1990

A family is described with two siblings who suffered at different times from a single episode of meningococcal meningitis by Neisseria meningitidis groups B and C, respectively. In the two subjects, hemolytically active fifth component of complement (C5) was not detectable and antigenic C5 was less than 0.05% and less than 0.7% of normal, respectively. Repletion of sera by purified human C5 (70 micrograms/ml) restored total complement hemolytic activities. The asymptomatic first degree family members had C5 levels compatible with a heterozygous state of C5 deficiency. C4 allotyping revealed an inherited partial deficiency (Q0) of C4A and C4B in the family with a combined C4AQ0 and C4BQ0 het…

Thermodynamics of electrokinetic processes—I. Formulations

1990

Abstract The phenomenological equations of electrokinetic processes are studied according to five different formulations. Transformation matrices with Haase's formulation are given. A study of the measurable character of fluxes, forces and phenomenological coefficients in those formulations is also made. The extrinsic character, if so, of the formulations is examined and a general definition of formulations established only for binary solutions is given. Finally, a review of the literature is included, aiming to clarify the possible misunderstandings arising from the application of these five formulations.

A breakdown in macromolecular synthesis preceding differentiation in Streptomyces coelicolor A3(2)

1990

Summary: A transitory cessation of growth was recorded in Streptomyces coelicolor A3(2) at the end of vegetative mycelium formation on solid medium. In the same phase a striking reduction in protein and nucleic acid synthesis was detected. Growth and macromolecular synthesis resumed, nearly reaching the original values, when morphological differentiation occurred. It is concluded that a physiological stress occurs within the bacterial population just before the onset of the morphological differentiation.

Organische Chemie. Ein kurzes Lehrbuch. Von H. Hart. Übersetzt und ergänzt von J. Lehmann. VCH Verlagsgesellschaft, Weinheim 1989. XVI, 458 S., Brosc…

1990

Neuromuscular adaptations and serum hormones in females during prolonged power training.

1990

Training-induced adaptations in the neuromuscular and endocrine systems were investigated in seven females during prolonged power type strength training. Great (p less than 0.05) changes occurred primarily during the earlier weeks of the 16-week training especially in the time of force production (from 161 +/- 107 to 93 +/- 65 ms to produce a 500 N force) and, correspondingly, in the average forces in the earlier positions of the (absolute) force-time curve of the leg extensor muscles. These changes were accompanied by significant (p less than 0.05) increases in the neural activation of the trained muscles in the earliest positions of the IEMG-time curve. Hypertrophic changes, as judged fro…

Ureterosigmoidostomy: an outdated approach to bladder exstrophy?

1990

Long-term results among 46 children with ureterosigmoidostomy are presented. The indication for ureterosigmoidostomy had been bladder exstrophy in 40 patients, incontinent epispadias in 5 and neurogenic bladder dysfunction in 1. Of the 40 patients with bladder exstrophy 8 had undergone ureterosigmoidostomy after failure of other types of urinary tract reconstruction (6 had upper tract dilatation before ureterosigmoidostomy). Three patients with previously damaged upper urinary tracts required early postoperative conversion because of severely increasing kidney dilatation. Three other patients required conversion after a mean of 10 years to preserve kidney function. One patient died after 16…

Autoantibodies to human asialoglycoprotein receptor in autoimmune-type chronic hepatitis.

1990

Autoantibodies to the human asialoglycoprotein receptor (anti-h-ASGPR) were studied with a solid-phase ELISA in the sera of 421 patients with inflammatory liver diseases, 288 patients with various other disorders and 31 controls. Anti-h-ASGPR were found predominantly in autoimmune chronic active hepatitis (44 of 88, 50%) and were closely related to inflammatory activity. In a subpopulation of these patients with untreated, biopsy-proven active disease or relapse, 15 of 17 were positive (88%). In contrast, only 11 of 204 patients (5.3%) with viral hepatitis were anti-h-ASGPR receptors-positive (chi 2 analysis; p less than 0.001). We also compared the occurrence of anti-h-ASGPR with antibodie…

Different muscarinic receptors mediate autoinhibition of acetylcholine release and vagally-induced vasoconstriction in the rat isolated perfused heart

1990

Experiments were carried out on rat isolated perfused hearts with both vagus nerves attached. The acetylcholine stores were labelled with [14C]-choline. The effects of muscarinic receptor antagonists on the [14C]-overflow and increase in perfusion pressure evoked by vagus nerve stimulation (10 Hz, 4-10 mA) were studied in order to determine the muscarinic receptor type involved in autoinhibition of acetylcholine release and vagally-induced vasoconstriction in the rat heart. Stimulation of the vagus nerves (1200 pulses) caused an increase in [14C]-overflow and in perfusion pressure which was significantly reduced by hexamethonium 500 mumol/l and abolished by tetrodotoxin 0.3 mumol/l or perfu…

Genetic location and biochemical characterization of eye-colour mutants from natural populations of Drosophila melanogaster

1990

From six captures of Drosophila melanogaster carried out in three different habitats (cellar, vineyard, and pinewood) in two different seasons of the year (spring and autumn), 60 eye-colour mutations were isolated, which were reduced to 29 loci by means of allelism tests within and between populations. Forty-five of these mutations were analyzed genetically and biochemically; of these 33 turned out to be previously described mutants and mapped to a total of 17 loci. Twelve new mutants were discovered and they mapped to 12 new loci, distributed on chromosomes X, II, and III. The eye-colour mutants show large effects on the red and brown pigments. The high variability of the eye-colour loci …

Zinc acexamate inhibits gastric acid and pepsinogen secretion in the rat.

1990

Abstract Pretreatment with zinc acexamate (25–100 mg kg−1 i.p.) inhibited acid and pepsinogen secretion in the pylorus-ligated rat. Zinc acexamate (5–50 mg kg−1 p.o.) also inhibited the increases in acid secretion induced by carbachol (10 μg kg−1) and 2-deoxy-D-glucose (200 mg kg−1) in the perfused stomach of the anaesthetized rat. A delayed antisecretory effect was observed with this drug on histamine induced responses. High concentrations of zinc acexamate (10−5-10−2 M) did not modify the in-vitro activity of pepsin. Administration of zinc acexamate resulted in an increase in the presence of pepsinogen at the mucosal level. A morphological examination of the gastric mucosa confirmed an ac…

Histone variants from pea (Pisum sativum): Their differential presence in fractions obtained by DNase I digestion of nuclei

1990

The variants of the core histones of Pisum sativum L. cv. Lincoln have been resolved by two dimensional polyacrylamide gel electrophoresis. Acetic acid, 8 M urea, 7.2 mM Triton X-100 was used in the first dimension. The second dimension was run in the presence of either anionic (sodium dodecylsulphate) or cationic (cetyltrimethyl-aminonium bromide) detergents. Four putative variants were found for the H2B histone class, 4 for H3 and 3 for H2A. Peptide mapping with (Staphylococcus aureus V8 protease was used, together with other criteria, to characterize the variants. The pattern of histone variants is not organ specific and, in an attempt to determine whether the diversity of histone varian…

Nucleotide sequence of Clostridium difficile toxin A.

1990

A rapid and simple method for the preparation of yeast mitochondrial DNA

1990

Zone plates with cells apodized by Legendre profiles

1990

By apodizing the cells of a zone plate and changing the opening ratio, it is possible to shape the relative power spectrum of its foci. We describe a novel procedure that leads to an analytical formula for shaping the focus power spectrum by using apodizers expressible as the Legendre series; these act on cells of arbitrary opening ratio. Our general result is used to design zone plates that have missing foci and to discuss a synthesis procedure using apodizers with various opening ratios. Our applications can also be used for shaping the power spectrum of 1-D gratings.