Determination of trace elements in water by metal chelate capillary gas chromatography

1981

Discrimination between stationary objects by the blind cave fishAnoptichthys jordani (Characidae)

1981

Blind Mexican cave fish were trained to discriminate between grids of vertical bars placed at various distances from each other. Discrimination was possible only if the freely swimming fish was allowed to glide past the grids in close proximity.

The non-isothermal rheological behaviour of molten polymers: Shear and elongational stress growth of polyisobutylene under heating

1981

Data of stress growth under both shear and elongational kinematics have been taken in presence of heating temperature ramps on a commerical polyisobutylene.

The effects of electrodermal lability and stimulus intensity on skin conductance habituation: A preliminary report

1981

A between-subjects design (N=60) was used to investigate the effects of electrodermal lability and auditory stimulus intensity on habituation of the skin conductance response (SCR). Subjects were subdivided into “labile” and “stabile” groups on the basis of frequency of nonspecific electrodermal responses during the prestimulation period. They received 20 presentations of a 1,000-Hz tone of 15, 35, 55, 75, 95, or 110 dB. There were significant effects of stimulus intensity on all three habituation measures (number of trials to habituation, reciprocal of SCR frequency to the first 10 stimuli, slope of the regression of SCR amplitude on log stimulus number). Additionally, significant effects …

Leukodiapedesis and leukocyte migration in the leptomeninges and in the subarachnoid space.

1981

Pleocytosis in cerebrospinal fluid and infiltration of the leptomeningeal tissue have been studied after injection of ferritin into the subarachnoid space (SAS) of cats. The most important source of granulocytes in the leptomeninges are the relatively large veins of the pia mater, which have very thin walls. Passing between the lining cells of the pia mater the granulocytes leave the connective tissue space of the pia mater and reach the SAS. Leukodiapedesis has also been observed in veins crossing the SAS. During this process, gaps between the lining cells of the perivascular leptomeningeal sheath may develop. There are two possible ways for the granulocytes to pass from the vascular pia m…

A Common Characterization of Finite Projective Spaces and Affine Planes

1981

Let S be a finite linear space for which there is a non-negative integer s such that for any two disjoint lines L, L' of S and any point p outside L and L' there are exactly s lines through p intersecting the two lines L and L'. We prove that one of the following possibilities occurs: (i) S is a generalized projective space, and if the dimension of S is at least 4, then any line of S has exactly two points. (ii) S is an affine plane, an affine plane with one improper point, or a punctured projective plane. (iii) S is the Fano-quasi -plane.

Molecular orbital studies on the mechanism of catalytic isomerization of xylenes II. The photochemical process

1981

Abstract The feasibility of an intermediate step in the mechanism of photochemical isomerization of xylenes in acidic media is explored by using CNDO molecular orbital methods. Along the reaction path from 2,6-dimethylbenzenium ion to dimethylbicyclo[3.1.0]hexenyl cation, the energy surfaces for this intermediate step have been drawn both for the first singlet S1 and triplet T1 excited states. The energies of these excited states have been calculated by adding to the ground-state energy calculated by CNDO/2 method the excitation energy calculated by CNDO/S-CI method. An optimization of the saddle point energy is achieved by introducing the angle between methyl groups and the ring plane as a…

The Multi-Fibre Arrangement—A hydra of protectionism?

1981

Talks are at present in progress in Geneva among 51 industrialised and developing countries on a renewal of the Multi-Fibre Arrangement (MFA) which expires at the end of 1981. The preliminaries of the negotiations have already revealed the existence of massive conflicts of interest not only between the industrialised countries on the one hand and the developing countries on the other but also within the two groups. The talks are moreover overshadowed by threats from individual industrialised countries to resort to unilateral protectionist measures unless a result satisfactory to them is achieved. This situation is the more explosive as the outcome of the negotiations is regarded worldwide a…

Structure and phase transitions of a liquid crystalline polymer

1981

The structures, textures as well as thermodynamic properties of a side chain polymer exhibiting a liquid crystalline phase in addition to a partially crystalline state and the isotropic fluid state were investigated. Furthermore the kinetics of phase transitions between these states were analyzed. It was found that the properties of this polymer are intermediate between that of low molecular weight liquid crystals and common polymers. In particular it was observed that the relation between the liquid crystalline texture and the structure is different from that of low molecular weight liquid crystals and that the properties of the crystalline and liquid crystalline state depend strongly on t…

Microtubules and microfilaments in HSV-Infected rabbit-kidney cells.

1981

In rabbit kidney cells infected with strains of Herpes simplex virus producing either cell-rounding or polycaryocytosis. Vinblastine induced paracrystals. This could be shown by phase-contrast- and electron-microscopy. Infections were done under one-step-growth conditions or at low MOI. 90 per cent noninfected cells contained stress fibers as detected by Servablue R250-staining. Shortly after recruitment into polycaryocytes, stress fibres of normal length appearing in criss-cross arrangement can be seen in the periphery of these cells. Later they polymerize to very long fibers and finally they are partially destroyed. The time of destruction depends on the MOI employed. By using Actinomycin…

The 235 ns 9+ isomer in 63 148 Eu85

1981

From (p, xn) in-beamγ-ray and electron measurements aT1/2=235(14) ns isomer at 720 keV was identified in63148Eu85 and the levels populated in its decay have been characterized. The results determineIπ=9+ for the isomeric state, and we assign it as the (πh11/2j0−2ν f72/3)9+ shell model state, analogous to the configuration of the 235 μs isomer in63146Eu83.

The effects of sex hormones, prolactin, and chorionic gonadotropin on pineal electrical activity in guinea pigs.

1981

Microelectrophoretic application of sex hormones onto pineal cells in guinea pigs has shown different responses in pregnant females as compared to males. In pregnant females estrone caused excitation in 74% of the cells tested, while progesterone and testosterone, prolactin, and HCG were inhibitory in a majority of the cells tested, while progesterone and testosterone, prolactin, and HCG were inhibitory in a majority of the cells. In contrast, in males estrone caused excitation of only 19% but inhibition of 37%. A smaller percentage of cells was inhibited by progesterone, while the predominant response to testosterone was excitation. These results suggest that the pineal gland may be under …

Effects of severe arterial hypocapnia on regional blood flow regulation, tissuePO2 and metabolism in the brain cortex of cats

1981

The effect of a stepwise decrease in PaCO2 from 3.9-1.6 kPa on rCBF, rCMRO2, tissue PO2 and concentrations of glucose, lactate, pyruvate, ATP, ADP, AMP and phosphocreatine in the brain cortex was studied in cats lightly anaesthetized with sodium pentobarbital. 1. Moderate lowering of PaCO2 to 2.5 kPa induced in all animals a homogeneous decrease of rCBF in corresponding areas of the right and left hemisphere. Mean rCBF fell from 129.2 to 103.1 ml X 100 g-1 X min-1, while rCMRO2 remained unchanged (12.7-12.9 ml X 100 g-1 X min-1). The tissue PO2 frequency histograms showed a shift to lower values without indicating the presence of brain tissue hypoxia. 2. Severe arterial hypocapnia (PaCO2 = …

Invarianten unipotenter Gruppen

1981

Antivirale wirkstoffe, XIX [1] N-(2-adamantyl)-N′-(fluoraryl)harnstoffe und -thioharnstoffe

1981

Zusammenfassung Auf dem Wege der nucleophilen Addition von 2-Aminoadamantan an die entsprechenden Isothiocyanate sind die folgenden N-(2-Adamantyl)thioharnstoffe dargestellt worden: N-(2-Adamantyl)-N′-(2-naphthyl)-, N-(2-Adamantyl)-N′-(3-fluorphenyl)- und N-(2-Adamantyl)-N′-(4-fluorphenyl)thioharnstoff. In analoger Weise hat die Addition von 2-Aminoadamantan an 2-Fluorphenylisocyanat zu N-(2-Adamantyl)-N′-(2-fluorphenyl)harnstoff gefuhrt. N-(2-Adamantyl)-N′-(3-fluorphenyl)- und N-(2-Adamantyl)-N′-(4-fluorphenyl)thioharnstoff weisen antivirale Wirksamkeit auf.

Ultrastructural observations on the central innervation of the guinea-pig pineal gland.

1981

In the present study the central innervation of the guinea-pig pineal gland was investigated. The habenulae and the pineal stalk contain myelinated and non-myelinated nerve fibres with few dense-cored and electron-lucent vesicles. Some myelinated fibres leave the main nerve fibre bundles, lose their myelin-sheaths and terminate in the pineal gland. Although direct proof is lacking, the non-myelinated fibres appear to end near the site where the bulk of the myelinated fibres are located. Here a neuropil area exists where synapses between non-myelinated fibre elements are abundant. Neurosecretory fibres were also seen. The results support the concept of functional interrelationships between h…

Fits of the baryon magnetic moments

1981

Static dielectric constant, viscosity, and structure of pure isomeric pentanols

1981

Static dielectric constants, viscosities, densitites and refractive indices of 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 2-methyl-2-butanol were measured at 15, 25, 35 and 45°C. These results together with the previous data on n-pentanol have been analyzed in terms of the Kirkwood correlation factor g k and of the energy of activiation for viscous flow. With the exception of 2-methyl-2-butanol, g k was found to be greater than unity. These results show that the monomeric units of isomeric pentanols interact by means of hydrogen bonding to form dynamic structures essentially of two types: linear chains where co-association raises the total polarizability and cyclic d…

Holomorphic approximation of ultradifferentiable functions

1981

Introduct ion Let S be a closed subset of some open set in Cn and denote by dT(S) the space of germs of holomorphic functions on (a neighborhood of) S. For a space F(S) of tEvalued (continuous, differentiable etc.) functions on S [containing t~(S)] the problem of holomorphic approximation consists of finding conditions to ensure that the natural mapping Q : e)(S)-~F(S) has dense range with respect to a given topology on F(S). Positive solutions for F = C r, 0_ l . For Q:tP(/3)~O(D)c~C(/3), DCIE n strongly pseudoconvex, proofs were given independently by Henkin [17], Kerzman [21], and Lieb [27], for the case e : (9(/3)~(9(D)c~C~(/3) cf. also [30] and for Sobolev spaces see Bell [3, Sect. 6].…

A mixed finite element method for the heat flow problem

1981

A semidiscrete finite element scheme for the approximation of the spatial temperature change field is presented. The method yields a better order of convergence than the conventional use of linear elements.

Genesis and evolution of the fumaroles of vulcano (Aeolian Islands, Italy): a geochemical model

1981

A geochemical model explaining the presence of fumaroles having different gas composition and temperature at the top of the crater and along the northeastern coast of Vulcano island is proposed. A pressurized biphase (liquid-vapor) reservoir at the depth of about 2 km is hypothesized. Energy and mass balance sheets controlP-T conditions in the system.P-T must vary along a boiling curve of brine as liquid is present. The CO2 content in the steam is governed by the thermodynamic properties of the fluids in the H2-NaCl-CO2 system. On the assumption that oxygen fugacity in the system is between the HM-FMQ oxygen buffers, observed SO2/H2S, CO2/CO, CO/CH4 ratios in the fumarolic gases at the Foss…

A topological obstruction to the geodesibility of a foliation of odd dimension

1981

Let M be a compact Riemannian manifold of dimension n, and let ℱ be a smooth foliation on M. A topological obstruction is obtained, similar to results of R. Bott and J. Pasternack, to the existence of a metric on M for which ℱ is totally geodesic. In this case, necessarily that portion of the Pontryagin algebra of the subbundle ℱ must vanish in degree n if ℱ is odd-dimensional. Using the same methods simple proofs of the theorems of Bott and Pasternack are given.

Dispersive approach to the nuclear compton amplitude and exchange effects

1981

We discuss the limitation of the standard approach to exchange current effects from photonuclear sum rules. We propose to look for an energy-independent contribution to the real part of the forward Compton-scattering amplitude below pion threshold. Experimental data on photonuclear cross-sections are used to calculate the real part of the amplitude, by means of an once-subtracted dispersion relation. The analysis is made for2H,7Li and9Be at energies varying between 50 and 150 MeV. A remarkably stable value ofK=0.60 is extracted for deuterium. For 1p shell nuclei, the main uncertainty is due to the lack of data above 300 MeV.

Students services: rationale, costs and utilization

1981

Référence interne : 81007; The purpose of this paper is to explore student services from an economist's perspective and to clarify why universities become involved in providing these services, at which costs, and for the benefit of whom. Definition and classification of student services have to be offered and an explicit statement about the various reasons of their development has to be attempted. Then, the main task is to identify the costs of student services and to investigate how the burden of costs is shared by the various constituencies in the university. The patterns of finance varies a lot from one institution is a mix of the sources of funding, and no strict allocation of monies to…

Traits Associated with Men and Women

1981

The association of certain psychological traits with men and others with women was studied among 4285- and 8-year-old children in 5 European countries. Subjects were read 32 stories, each representing a particular trait (e.g., aggressive, emotional), and following each story they selected between male and female silhouettes as being "the person the story is about." The findings indicated substantial cross-national similarity in the traits ascribed to men and women. Some evidence of differences between countries was found, with the children's responses in Germany and France being relatively most discrepant. The results were discussed in relation to the findings from studies of adults in Eur…

A rotating wheel system for the detection of spontaneously fissioning nuclides from heavy ion reactions

1981

Abstract A rotating wheel system for the detection of spontaneously fissioning reaction products from heavy ion reactions was developed. In this system products recoiling from a rotating target wheel are stopped in a catcher foil stack which can be rotated at various velocities up to 80 rotations per second. All products emitted within a wide emission cone are stopped in the catcher foils and are rotated into shielded positions with stationary fission-track detectors positioned on both sides of each rotating foil. This technique allows a sensitive detection of spontaneously fissioning nuclides over a broad range of half-lives from 1 ms to about 1 d. By post-bombardment exposure of the catch…

Importancia del ginecólogo en el diagnóstico precoz del cáncer de mama y su participación en los "Screening" de grandes masas de población

1981

Se analizaron el peso y la talla de 217 embarazadas de alto riesgo que consultaron al Departamento de Obstetricia y Ginecología durante el primer semestre del presente año. El peso promedio de las madres fue de 62 kilos 500 gramos y el de los recién nacidos de 3.100 gramos. La D.S. del peso materno fue de 10.30 kilos y la de los niños de 396.15 gramos.Al analizar el coeficiente de correlación (r= 0.3368) se encontró positivo en- tre el peso de la madre y el del recién nacido p. 0.001, por lo tanto, es de esperar, que entre más pese la madre mayor será el peso del niño. En el análisis de la talla materna se encontró que el promedio fue de 152 centímetros y el de los recién naci…

Azomethin-imine durch Umsetzung von Diphenylketen mit Azodicarbonsäureestern

1981

Die Umsetzung von Diphenylketen mit Azodicarbonsaureester fuhrt zu den Azomethin-iminen 4, die 1,3-dipolare Reaktivitat zeigen: Addition von Diphenylketen liefert das Addukt 8, von Phenylisocyanat ergibt 7 und Dimerisierung fuhrt zu 5. Azomethine Imines by Reaction of Diphenylketene with Azodicarboxylates1) The reaction of diphenylketene with azodicarboxylates yields azomethine imines 4 which show 1,3-dipolaric reactivity: addition of diphenylketene yields the 2:1-adduct 8, addition of phenyl-isocyanate produces 7, and dimerization leads to 5.

Growth stimulation of apple trees by VA mycorrhiza inoculation in unsterilized soil under field conditions

1981

International audience

The influence of different endomycorrhizal fungi on the growth of oat, strawberry, leek and apple tree cultivated in the greenhouse

1981

International audience

The effect of VA mycorrhizal fungus (Glomus epigaeus) on the growth of two apple tree clones propagated in vitro

1981

International audience

Effects of VA status on the growth of various plant species in natural and fumigated soil

1981

International audience

Electron Angular Distribution in Laser-Assisted X-ray Photoeffect

1981

Calculations are reported of the differential cross section of the laser-assisted X-ray photoeffect from K shells showing that drastic changes occur in the shape of the ejected-electron angular distribution when laser photons are exchanged during the ionisation. This process appears well suited to the study of laser effects and multiphoton exchanges in laser-assisted atomic collisions.

Kinetic properties of a nucleoside phosphotransferase of chick embryo

1981

1. A nonspecific nucleoside phosphotransferase (nucleotide : 3'-deoxynucleotide 5'-phosphotransferase, EC 2.7.1.77), purified from chick embryos, catalyzes the transfer of phosphate ester from a nucleotide donor to a nucleoside acceptor. 2. The enzyme exhibits sigmoidal kinetics with respect to nucleoside monophosphate donors, but with respect to nucleoside di- or triphosphate donors and nucleoside acceptors hyperbolic kinetics were obtained. 3. The nucleoside phosphotransferase of chick embryo is unstable to heat and is protected from inactivation by a large number of nucleosides. 4. Nucleoside di- and triphosphates lower both the concentration of nucleoside monophosphates required for hal…

LARGE DEFORMATION CREEP BEHAVIOR OF A SOLID POLYMER.

1981

Abstract The effect of loading rate and strain on the creep behavior after sample yielding has been studied in previous communications (14–15) for Mylar in tension and for Lexan in compression. In this work the creep behavior of Lexan samples previously elongated is considered both in tension and in compression. A procedure which collects all the data independently of both loading rate and initial creep strain is proposed.

ELEKTROREDUKTIVE DIREKTDARSTELLUNG VON Ni(O)-, Pd(O)- UND Rh(O)-PHOSPHIN-KOMPLEXEN1

1981

Abstract 1. Der Ni(O)-Komplex [Ni(PC2P)2] 1 mit zwei Ethylen-1,2-bis (diphenylphosphin)-Partnern (PC2P) als Ligand wird elektroreduktiv erhalten: (a) aus [Ni(PC2P)2Br2]; (b) aus [Ni(PC2P)Br2] + PC2P; (c) aus NiBr2 · 3H2O + 2PC2P. Die Ausbeuten liegen uber 90%. Nach Verfahren (b) entstehen auch Komplexe mit zwei unterschiedlichen Liganden, z.B. [Ni(PC2P) (PPh3)2] 4 [Ni(PC2P)(PC3P)] 5, [Ni(PC2P)(AsPh3)2], wenn man an Stelle von PC2P. PPh3. PC3P und AsPh3 einsetzt. (PC3P entspricht Trismethylen-1.3-bis (diphenylphosphin). Nach dem Direktverfahren, (c) ist Tetrakis(triphenylphosphinnickel(O) [Ni(PPh3)4] 6 in einer Ausbeute von 77% zuganglich. 2. [PD(PC2P)2] 7 entsteht elektroreduktiv nach Verfa…