Late Quaternary vegetational history at Navarres, Eastern Spain. A two core approach

1996

summary Percentage and concentration pollen diagrams are presented for two cores (taken 5 m apart) at an upper Pleistocene and Holocene site at Navarres (Valencia, eastern Spain). Chronological information is provided by an internally consistent radiocarbon dating series that extends from c. 20700 to 3075 yr BP. The results highlight the dangers of relying on a single core in interpreting the patterns of variation of particular taxa. Significant palynological differences, seemingly locational, are described between the two cores. The upper Pleistocene records accords well with the widely recognized European sequence of (a) upper Pleniglacial, (b) Bolling-Allerod warm period, and (c) Younger…

Optimistic, Approach‐oriented, and Avoidance Strategies in Social Situations: Three Studies on Loneliness and Peer Relationships

1996

The aim of the three studies was to examine the extent to which the cognitive and behavioural strategies young adults apply in social situations are associated with their subsequent feelings of loneliness, their peer relationships, and social behaviour. In Study 1, 303 young adults first filled in the Strategy and Attribution Questionnaire (SAQ) and, 1 year later, the revised UCLA Loneliness scale. In Study 2, 71 young adults filled in first the SAQ and, 4 months later, the UCLA Loneliness scale and a sociometric questionnaire measuring popularity and unpopularity. In Study 3, 35 young adults who had participated in Study 1 were rated by student tutors according to their social behaviour in…

Nitric oxide-mediated beta 2-adrenoceptor relaxation is impaired in mesenteric veins from portal-hypertensive rats.

1996

Abstract BACKGROUND & AIMS: beta-Adrenergic relaxation seems to be mediated by nitric oxide. The aim of this study was to evaluate changes induced by portal hypertension in beta 2-adrenergic vasorelaxation. METHODS: Isolated rat mesenteric veins were relaxed by salbutamol, and nerve- mediated vasocontractions were induced by electrical field stimulation. Responses were evaluated in the presence of NG-nitro-L-arginine methyl ester (L-NAME) or tetrodotoxin. Immunocytochemical techniques were used for localization of neuronal NO synthase. RESULTS: Salbutamol-induced relaxations were decreased in rings from portal-hypertensive animals. L- NAME reduced these relaxations, but its effects were mor…

Soil aggregate stability in three Mediterranean environments

1996

Abstract This paper considers the effect of vegetation on soil aggregate stability in three different Mediterranean landscapes in Southeast Spain. Soils on limestone, marls and clays, with two levels of vegetation cover at each north-facing slopes of the study areas, were investigated. Three aggregate stability tests (CND, TDI and UD) based on the drop impact and ultrasonic dispersion methods and the Emerson dispersion test were performed. The results of the experiments show the positive influence of vegetation on aggregate stability. However, vegetation is less important than lithology in influencing soil aggregate stability. Soil depth and moisture also affect aggregation, but the relatio…

Alternative Methods for Skin Sensitisation Testing

1996

Search for charginos and neutralinos with R-parity violation at =130 136

1996

Searches for charginos and neutralinos produced in e+e− collisions at centre-of-mass energies of 130 and 136 GeV have been performed under the assumptions that R-parity is not conserved, that the dominant R-parity violating coupling involves only leptonic fields, and that the lifetime of the lightest supersymmetric particle can be neglected. In the 5.7 pb−1 data sample collected by ALEPH, no candidate events were found. As a result, chargino and neutralino masses and couplings are constrained and the domains previously excluded at LEP1 are extended.

Noise parameters of HEMTs: analysis of their properties from a circuit model approach

1996

Noise parameters of high electron mobility transistors (HEMT) at microwave frequencies are a subject of active research since the knowledge of their performance is of key importance for the use of these devices for designing low‐noise amplifiers. Employs a simple noise model to derive the analytical expressions for the device noise parameters F0, Γ0 and N in terms of the electrical elements associated with the basic equivalent circuit of an HEMT. Analyses such expressions to establish some fundamental relationships, as well as the expected noise performance of the device when the parasitic elements representing package effects are included.

Colonic Conduit in Children

1996

Complication rates of up to 86.6% have been reported after creation of an ileal conduit. In contrast to others, we construct an antirefluxing isoperistaltic colonic for incontinent diversion in children.Between 1968 and 1989 a colonic conduit was created in 105 patients up to age 20 years for neurogenic bladder (76), bladder exstrophy (16) and other reasons (13). Long-term followup (minimum 5 years, mean 16.3 years, range 5 to 26) was possible in 84 patients (159 renal units).Early and late stenosis at the ureterocolic anastomosis, and stomal stenosis occurred in 7.6 and 15.5% of the cases, respectively. Renal calculi developed in 8.2% of the renal units. Eight kidneys without function afte…

Effects of nordihydroguaiaretic acid on murine antibody-dependent cellular cytotoxicity.

1996

The purpose of this study was to analyze the effects of nordihydroguaiaretic acid, an inhibitor of the lipoxygenase pathway of arachidonic acid, on antibody-dependent cellular cytotoxicity. Antibody-dependent cellular cytotoxicity mediated by murine spleen cells was significantly inhibited by concentrations of nordihydroguaiaretic acid from 10(-5) to 10(-4) M (1C50 = 2 x 10(-5) M). The inhibitory effect of nordihydroguaiaretic acid was also observed on antibody-dependent cellular cytotoxicity mediated by macrophage-depleted spleen cells as well as isolated macrophages. Nordihydroguaiaretic acid was highly effective when added at the beginning of the assay and was always present throughout t…

A simple method for preoperative assessment of the best fitting electrode length in single lead VDD pacing.

1996

For single lead VDD pacing, electrodes with various distances between the lead tip and the floating atrial dipole (AV distance) are available. Using different AV distances allows positioning of the atrial dipole in the mid- to high right atrium, regardless of the size of the right heart. In this position, reliable atrial sensing and rejection of ventricular far-field potentials can be expected. A simple test for the preoperative assessment of the best fitting AV distance in the individual patient was tested. We studied 24 consecutive patients prior to implantation of a VDD pacemaker. With the patient in supine position, a test electrode with an AV distance of 13 cm was taped onto the thorax…

High-Spin → Low-Spin Relaxation in [Fe(bpp)2](CF3SO3)2 H2O after LIESST and Thermal Spin-State Trapping—Dynamics of Spin Transition Versus Dynamics o…

1996

The iron(II) complex [Fe(bpp)2]-(CF3SO3)2 H2O (bpp = 2,6-bis(pyrazolyl-3-yl)pyridine) shows a thermal spin transition associated with a hysteresis of approximately 140 K width. The transition temperatures T1/2 (where the fraction of HS species γHS = 0.5) are 147 K and ≈285 K in the cooling and heating directions, respectively. The compound shows the LIESST and reverse-LIESST effects at low temperatures. The relaxation of the metastable HS states generated by LIESST was observed quantitatively at temperatures between 77.5 and 85 K by Mossbauer spectroscopy. Metastable HS states can also be generated by rapid cooling of the sample. The relaxation of the metastable HS states formed by thermal …

Dealing with negative connotations in family therapeutic treatment of an enmeshed family: A case study

1996

In psychotherapy the moments when negative connotations of diagnostic remarks become apparent are also the moments for change. To be able to use those moments for positive outcome calls for, according to this case study: 1) An inquiring approach and attitude to therapeutic work which translates to the challenging of basic hypotheses and the unambiguous meaning of diagnostic signs starting from the referral and continuing through the treatment process. 2) The integration of the nonverbal experiential technique with the verbal reflective approach, which can be conceptualized as a double description of the problem situation, and which allows reframing, or recontextualization. 3) A diagnostic c…

Scanning electron microscopy of heterochromatin in chromosome spreads of male germ cells in Schistocerca gregaria (Acrididae, Orthoptera) after tryps…

1996

Chromosome spreads, prepared from testes of the desert locust Schistocerca gregaria, were analyzed using scanning electron microscopy (SEM) after varying periods of preincubation in trypsin. The emphasis of the study was on the appearance of heterochromatin. A trypsin pretreatment of 5 sec resulted in a smooth surface on the chromatin throughout and the heterochromatin was highly electron-emissive. The facultatively heterochromatic X chromosome was clearly visible in interphase spermatogonia and in pachytene and late prophase I spermatocytes. Chromomeres of autosomal bivalents could be recognized in pachytene cells. Centromeric heterochromatin segments were very prominent in autosomes of la…

Isometric muscle contractions after double pulse stimulation. comparison of healthy subjects and patients with myotonic dystrophy.

1996

Isometric contractions of the adductor pollicis muscle were studied in healthy subjects and patients with myotonic dystrophy after single and double stimuli of the ulnar nerve using a wide range of interstimulus intervals (ISI, 0.4-180 ms). In healthy subjects, the force contributed by a second stimulus was greater than the single twitch force being maximal (mean + 140%) at 12-ms ISI. In myotonic dystrophy, the force contributed by the second stimulus was (relative to a reduced twitch amplitude) increased (mean + 204%) with a maximum at 4.8-ms ISI. An abnormal increase of force was only recorded if the single twitch force was clearly reduced. The absolute refractory period of muscle contrac…

Hypothenar hammer syndrome in sports

1996

Repetitive blunt trauma or single severe trauma to the hypothenar region may lead to traumatic thrombosis of the distal ulnar artery (hypothenar hammer syndrome, HHS). In the sports-related literature we found and analysed isolated cases attributed to injuries sustained during sporting activities such as baseball, badminton, handball, football, frisbee, softball, karate, weight-lifting and hockey. Further, we report the case of an amateur golf player with ischaemic symptoms of his left hand, where angiography revealed filling defects in the digital arteries associated with a corkscrew-like configuration of the distal ulnar artery. Magnetic resonance imaging (MRI) scan demonstrated, at the l…

The Vector QD Algorithm for Smooth Functions (f, f′)

1996

AbstractWe deal with the functionz↦(f(z), f′(z)) wheref(z)=∑i⩾0aizi, (ai∈C) with limi→∞ai+1×ai−1/(ai)2=q. We investigate the convergence of the vector QD algorithm. We give the asymptotic behaviour of the generalized Hankel determinants. A convergence result on the vector orthogonal polynomials is proved.

Temporal variation in reproductive allocation in a shield bug Elasmostethus interstinctus

1996

We investigated changes in the reproductive output and the effect of female phenotype on reproductive parameters in a shield bug Elasmostethus interstinctus (L.) (Heteroptera: Acanthosomatidae) over the whole reproductive period. At the beginning and the middle of the reproductive period eggs were smaller than at the end of the period. Clutch mass and number of eggs per clutch decreased in laying sequence, first clutches being much larger than any of the later ones. Lifetime fecundity correlated positively with female size: large females produced more eggs and lived longer than small ones. Egg size did not vary with female size. Offspring survival until adulthood increased with egg weight. …

Sequencing analysis of a 4·1 kb subtelomeric region from yeast chromosome IV identifiesHXT15, a new member of the hexose transporter family

1996

The DNA sequence of a 4·1 kb region of Saccharomyces cerevisiae chromosome IV was determined. This region contains a single open reading frame which codes for a member of the hexose transporter family. This new gene has been named HXT15 according to yeast gene data bases. The sequence has been entered in the EMBL data library under Accession Number X92891.

Extended Thomas - Fermi expansion from nuclear linear response

1996

The coefficients of the successive orders of the extended Thomas - Fermi expansion of the kinetic energy density are obtained to the leading order in the density inhomogeneities. This is done by comparing the corresponding static polarizability with the exact value in two cases: a non-interacting nuclear infinite system and symmetric nuclear matter with a Skyrme interaction.

Caracteristicas fisiologicas, eficiencia y competitividad de cepas de Bradyrhizobium japonicum, aisladas de suelos e inoculantes argentinos

1996

Adrenoceptor- and cholinoceptor-mediated mechanisms in the regulation of 5-hydroxytryptamine release from isolated tracheae of newborn rabbits

1996

Abstract 1. Isolated tracheae of newborn rabbits were incubated in vitro and the outflow of 5-hydroxytryptamine (5-HT) was determined by h.p.l.c. with electrochemical detection. Evidence has previously been provided that this 5-HT outflow derives from neuroendocrine epithelial (NEE) cells of the airway mucosa. 2. Phenylephrine (1, 10 and 30 microM) enhanced the outflow of 5-HT by 80, 290 and 205%, respectively. 5-HT outflow evoked by 10 microM phenylephrine was not affected by the presence of the neurotoxin tetrodotoxin (1 microM). 3. Rauwolscine, ARC 239 (an alpha(2B)-adrenoceptor preferring antagonist), yohimbine and prazosin antagonized the effect of 10 microM phenylephrine in a concentr…

The Heisenberg dynamics of spin systems: A quasi*‐algebras approach

1996

The problem of the existence of the thermodynamical limit of the algebraic dynamics for a class of spin systems is considered in the framework of a generalized algebraic approach in terms of a special class of quasi*-algebras, called CQ*-algebras. Physical applications to (almost) mean-field models and to bubble models are discussed. © 1996 American Institute of Physics.

Coprime action, characters and decomposition numbers

1996

Micelles formed from photochemically active amphiphiles: structural characterization by small-angle neutron scattering

1996

Abstract A novel class of photochemically active amphiphiles has been synthesized containing a ketone moiety as a biradical or radical pair precursor on the hydrophobic tail of sodium sulfate surfactants. Alteration of the molecular structure of each ketone-containing surfactant allows for the systematic and predictable manipulation of the micellar size and shape, both of which are important in determining the coupling between the unpaired electrons confined within the micelle and the intraradical dynamics. The structure of the resulting aggregates has been analyzed by small-angle neutron scattering (SANS). The results show that the amphiphiles form ellipsoidal micelles with aggregation num…

Synthesis, crystal structure and magnetic properties of the first structurally characterized 1,2-dithiocroconato-containing Cu(II) complex, [Cu(bpca)…

1996

Abstract The first crystal and molecular structure of a transition metal complex containing 1,2-dithiocroconate (1,2-dtcr, dianion of 1,2-dimercaptocylopent-1-ene-3,4,5-trione), [Cu(bpca)(H2O)]2[Cu(1,2-dtcr)2]·2H2O (where bpca is the bis(2-pyrdidylcarbonyl)amide anion), has been determined by single crystal X-ray diffraction methods. The compound crystallizesin the monoclinic syste, space group P21/c, with a = 11.661(3), b = 20.255(6), c = 8.265(3) A , s = 107.26(2)° and Z = 2. The structure is formally built of [Cu(1,2-dtcr)2]2− and [Cu(bpca)(H2O)]+ ions and water of hydration. The copper atom of the anion is situated at a crystallographic inversion centre, bonded to four sulfur atoms in a…

Functional evidence of inverse agonism in vascular smooth muscle

1996

1. In the present study, depletion of internal Ca2+ stores sensitive to noradrenaline (1 microM) in rat aorta, is the signal for the entry of extracellular Ca2+, not only to refill the stores but also, in our experimental conditions, to activate the contractile proteins. This induces an increase in the resting tone that constitutes, the first functional evidence of this Ca2+ entry. 2. The fact that methoxamine (100 microM) reproduces the same processes as noradrenaline but clonidine (1 microM) does not, indicates that alpha(1)-adrenoceptor activation is related to the increase in the resting tone observed after depletion of adrenoceptor-sensitive internal Ca2+-stores. 3. Benoxathian and WB …

Cluster growth with long-range interactions

1996

Abstract Growth models in which the morphology depends on interactions of the type V(r) = C r n are presented. The growth algorithms are generalizations of DLA. The particles diffuse on a triangular lattice and eventually either stick to the cluster or are lost. Several processes are simulated in this way: in one case only pure sticking is taken into account, in another case evaporation and rearrangement are also allowed to occur. In the former case (with attractive interactions) the clusters exhibit a highly symmetric shape (a sixfold star) whose detailed structure depends on n , C kT , and time. In the latter case (studied with repulsive dipolar interactions) the tendency to ramification …

Sodium ion distribution in the vitreous body

1996

We have studied the nuclear magnetic resonance (NMR) relaxation behavior, and thus the dynamic properties, of the sodium ion in the vitreous body at different temperatures. The 23Na NMR spectrum exhibits a resonance, the intensity of which accounts for an ion visibility of 100%. The 23Na longitudinal and transverse relaxation times, at all temperatures but the highest, present two components, suggesting that the sodium ions are present in two states of different mobility, whose populations are in slow exchange on the NMR time scale. The correlation times and quadrupole coupling constants for the two sodium pools have been derived. The faster relaxation of a fraction of the vitreal sodium ha…

Autoimmune hepatitis

1996

Autoimmune hepatitis (AIH) is a distinct form of acute and chronic inflammatory liver disease in which immune reactions against host antigens are found to be the major pathological mechanism. If left untreated it carries an unfavourable prognosis, and the diagnosis should be made as soon as possible. The diagnostic approach has been greatly facilitated by the establishment of a panel of marker autoantibodies, which do not define distinct therapeutic groups of AIH, but do allow a subgrouping based on differences in patient populations, some clinical features and prognosis. The characterization of organ-specific components of the liver cell surface as targets of cellular and humoral autoimmun…

Syntheses and Solid-State Structures of Some Dialkyltin Derivatives of ?-Methoxy- and ?-Acetoxy-phenylacetic Acids

1996

Several di-n-butyltin and diethyltin biscarboxylates and distannoxanes of α-methoxy- and α-acetoxy-phenylacetic acids were synthesized and (two of) their structures were studied by means of X-ray diffraction analysis as well as by means of IR and Mossbauer spectroscopies. It was shown for {[(n-Bu) 2 - SnOC(O)CH(OMe)Ph] 2 O} 2 that there is an interaction between the OMe group and one of the endocyclic tin atoms, resulting in a distorted pentagonal-bipyramidal geometry with the pentagonal plane defined by five O atoms and an uncommon seven coordination number for this tin atom. Spectral data indicate that biscarboxylates have trans-octahedral structures.

Multiconfigurational perturbation theory (CASPT2) applied to the study of the low-lying singlet and triplet excited states of cyclopropene

1996

The electronic spectrum of cyclopropene has been studied using multiconfigurational second-order perturbation theory (CASPT2) with extended ANO-type basis sets. The calculation comprises two valence states and the 3s, 3p, 3d members of the Rydberg series converging to the π and σ ionization limits. A total of twenty singlet and twenty triplet excited states have been analyzed. The results confirm the valence nature of the lowest energy singlet-singlet band and yield a conclusive assignment: the first dipole-allowed transition in cyclcopropene is due to absorption to a (σ → π*) state. The (π → π*) (V) state is interleaved among a number of Rydberg states in the most intense band of the syste…

Hybrid molecular materials formed by alternating layers of bimetallic oxalate complexes and tetrathiafulvalene molecules: Synthesis, structure, and m…

1996

Eosinophil Cationic Protein in Nasal Secretions and Blood Serum in Grass-Pollen Allergic Rhinitis

1996

Concentration of the Eosinophil Cationic Protein (ECP) measured in different body fluids has been demonstrated to be a good marker of eosinophilic inflammation. In allergic asthma, ECP levels in both broncho-alveolar-lavage (BAL) fluid and serum can be used to monitor disease activity. In allergic rhinitis, the value of ECP determinations in serum and nasal secretions was not directly compared, so far. In the present study, ECP levels in blood serum (Se) and nasal secretions (NS) of grass pollen allergic and healthy individuals under pollen exposure were analyzed. Forty-three grass-pollen allergic subjects and 19 healthy volunteers were included. Grass-pollen counts were measured using Bur…

Investigating the cooling rate dependence of amorphous silica: A computer simulation study

1996

We use molecular dynamics computer simulations to study the dependence of the properties of amorphous silica on the cooling rate with which the glass has been produced. In particular we show that the density, the glass transition temperature, the radial distribution function and the distribution of the size of the rings depend on the cooling rate.

Cercospora beticola toxins. Use of fluorescent cyanine dye to study their effects on tobacco cell suspensions

1996

Abstract The fluorescent dye 3,3′-diethylthiadicarbocyanine iodide [diS-C 2 -(5)] was used to observe plasmalemma transmembrane potential variations of tobacco cells treated with uncoupler (FCCP), respiratory inhibitors (azide and cyanide), and H + -ATPase inhibitors (DCCD and a carbanilate derivative). These chemicals induced an increase in fluorescence, indicating a dissipation of the transmembrane potential. The [diS-C 2 -(5)] was also used to study the effects of two Cercospora beticola toxins on tobacco cells. Changes in fluorescence of [diS-C 2 -(5)] suggested that these two toxins caused a dissipation of the transmembrane potential with a different magnitude whereas kinetics of their…

Chirality effects on 2D phase transitions

1996

Monolayers of the racemate and pure enantiomers of 1-hexadecyl-glycerol were investigated by grazing incidence X-ray diffraction (GID) at 5 and 20 °C on compression from 0 mN m−1 to pressures greater than 30 mN m−1. The racemate lattice is centred-rectangular for both temperatures at all investigated pressures. However, at both temperatures, there is a sharp phase transition from a low-pressure phase, in which the molecules are tilted towards nearest neighbours (NN) and the distortion azimuth also points towards NN, to a high-pressure phase, in which the molecules are tilted towards next-nearest neighbours (NNN) and an NNN-distorted lattice is observed. At 5 °C, the transition pressure is 1…