Investigation of the role of neutron transfer in the fusion of 32,34S with 197Au,208Pb using quasi-elastic scattering

Excitation functions for quasi-elastic scattering have been measured at backward angles for the systems 32,34S+197Au and 32,34S+208Pb for energies spanning the Coulomb barrier. Representative distributions, sensitive to the low energy part of the fusion barrier distribution, have been extracted from the data. For the fusion reactions of 32,34S with 197Au couplings related to the nuclear structure of 197Au appear to be dominant in shaping the low energy part of the barrier distibution. For the system 32S+208Pb the barrier distribution is broader and extends further to lower energies, than in the case of 34S+208Pb. This is consistent with the interpretation that the neutron pick-up channels are energetically more favoured in the 32S induced reaction and therefore couple more strongly to the relative motion. It may also be due to the increased collectivity of 32S, when compared with 34S.Comment: 11 pages, 5 figure

Pycnogonids (Arthropoda: Pycnogonida) of Portofino, Ligurian Sea (North-Western Mediterranean Sea)

Pycnogonida collected monthly from September 2017 to August 2018 in the Portofino Marine Protected Area at 0\u20135 m depth were studied. A total of 499 specimens were collected, 457 of which were identified to species level. These were classified as belonging to 10 species: Achelia echinata*, Ascorhynchus castelli, Neotrygaeus communis*, Tanystylum conirostre*, Anoplodactylus angulatus, A. petiolatus, A. pygmaeus*, A. virescens, Callipallene phantoma and C. tiberi*. For five dominant species (those marked with an asterisk) the annual phenology was outlined. Four hundred and seventeen additional specimens, collected from the same area and depth range mainly during the 1970s and 1980s were identified to species level for completeness of information, leading to the addition of Pycnogonum pusillum and Endeis spinosa

The Regulation of Public Broadcasters' News Coverage of Political Actors in Ten European Union Countries.

Este artículo presenta los resultados de una investigación comparada realizada sobre la regulación de la cobertura de la información política en diez operadores públicos europeos. En concreto, el estudio investiga si existe regulación del pluralismo político, tanto para períodos electorales como ordinarios, aplicable a los informativos diarios. Aquí se proporcionan los resultados para cada país y las conclusiones comparadas. Los datos informan de diferentes grados de politizacion de la regulación, según el uso de criterios cualitativos o cuantitativos. La investigación también describe cuales són los sistemas de control del pluralismo político en los diez países estudiados

Damping of long-wavelength collective excitations in quasi-onedimensional Fermi liquids

The imaginary part of the exchange-correlation kernel in the longitudinal current-current response function of a quasi-onedimensional Fermi liquid is evaluated by an approximate decoupling in the equation of motion for the current density, which accounts for processes of excitation of two particle-hole pairs. The two-pair spectrum determines the intrinsic damping rate of long-wavelength collective density fluctuations, which is calculated and contrasted with a result previously obtained for a clean Luttinger liquid.Comment: 9 pages, no figures, Physica B in pres

Self-consistent Overhauser model for the pair distribution function of an electron gas at finite temperature

We present calculations of the spin-averaged pair distribution function $g(r)$ in a homogeneous gas of electrons moving in dimensionality D=3 or D=2 at finite temperature. The model involves the solution of a two-electron scattering problem via an effective potential which embodies many-body effects through a self-consistent Hartree approximation, leading to two-body wave functions to be averaged over a temperature-dependent distribution of relative momentum for electron pairs. We report illustrative numerical results for $g(r)$ in an intermediate-coupling regime and interpret them in terms of changes of short-range order with increasing temperature.Comment: 6 pages, 5 figures, submitted to Solid State Communication

Especificidad y denso-dependencia inversa en parasitoides con oviposición fuera del hospedador : el caso de Mallophora ruficauda (Diptera: Asilidae) en la Pampa Argentina

Estudiamos los fenómenos de especificidad denso-dependencia, asociados al parasitismo, en un sistema hóspedador parasitoide cuyas hembras parasitoides carecen del habitual comportamiento de búsqueda del hospedador. Para ello tomamos el sistema compuesto por los gusanos blancos del suelo (Coleoptera: carabaeidae) y el moscardón cazador de abejas Mallophora ruficauda Wiedemann 1828 (Diptera: Asilidae). El estudio se realizó en las inmediaciones de 8 apiarios ubicados en las provincias de Buenos Aires y Entre Ríos, y durante el mes de Junio de 1997. El moscardón posee un índice de referencia en la elección de su hospedador de 0.69, indicando que es ligeramente selectivo hacia Cyclocephala signaticollis (90% de parasitismo). Fenómenos de denso-dependencia inversa se manifestaron a escala pequeña, al analizar mediante regresión lineal y evaluaciones “Jackknife “, las variables abundancia de gusanos en el suelo (In) y porcentaje de parasitismo (In), indicando que el parasitoide satura sus posibilidades de parasitar más hospedadores a medida que aumenta la abundancia de los mismos en el suelo. Este fenómeno estaría vinculado a la forma que posee el parasitoide de colocar sus huevos, ya que no ovipone directamente sobre el hospedador ‘sino sobre vegetación elevada, valiéndose del viento para la dispersión de sus larvas. El encuentro hospedador parasitoide estaría ligado a la coincidencia Osimultánea en el espacio de la distribución de los hospedadores y de las larvas parasitoides en el suelo.We study the specificity and density dependence phenomena associated to the parasitism, in a host parasitoid system whose females do not have common host search behavior. We studied the system composed by the soil white worms (Coleoptera: Scarabaeidae) and the bee hunter robber fly Mallophora ruficauda Wiedemann 1828 (Diptera: Asilidae). The study was conducted in the nearness of eight apiaries located in the provinces of Buenos Aires and Entre Ríos, during the month of June of 1997. The robber fly possesses a 0.69 preference index in the election of his host, indicating that it is lightly selective toward Cyclocephala signaticollis (90% of parasitism). Phenomena of inverse density dependence were observed when analyzing at small scale the variable abundance of worms in the soil (ln) and percentage of parasitism (In) using lineal regression and “Jackknife” estimations. This result indicates that the parasitoid saturates their possibilities to parasite more hosts as the abundance of the latter increases in the soil. This phenomenon could be linked to the particular egg laying characteristics of the parasitoid. Eggs are not lay directly on the host, but on high vegetation taking advantage of the wind for the dispersion of its larvae. The host-parasitoid encounter could be bound to the simultaneous coincidence in the space of the distribution of the hosts and the larvae parasitoids in the soil

Lewis X antigen mediates adhesion of human breast carcinoma cells to activated endothelium. Possible involvement of the endothelial scavenger receptor C-Type lectin

Lewis x (Lex, CD15), also known as SSEA-1 (stage specific embryonic antigen-1), is a trisaccharide with the structure Galβ(1–4)Fucα(1–3)GlcNAc, which is expressed on glycoconjugates in human polymorphonuclear granulocytes and various tumors such as colon and breast carcinoma. We have investigated the role of Lex in the adhesion of MCF-7 human breast cancer cells and PMN to human umbilical endothelial cells (HUVEC) and the effects of two different anti-Lex mAbs (FC-2.15 and MCS-1) on this adhesion. We also analyzed the cytolysis of Lex+-cells induced by anti-Lex mAbs and complement when cells were adhered to the endothelium, and the effect of these antibodies on HUVEC. The results indicate that MCF-7 cells can bind to HUVEC, and that MCS-1 but not FC-2.15 mAb inhibit this interaction. Both mAbs can efficiently lyse MCF-7 cells bound to HUVEC in the presence of complement without damaging endothelial cells. We also found a Lex-dependent PMN interaction with HUVEC. Although both anti-Lex mAbs lysed PMN in suspension and adhered to HUVEC, PMN aggregation was only induced by mAb FC-2.15. Blotting studies revealed that the endothelial scavenger receptor C-type lectin (SRCL), which binds Lex-trisaccharide, interacts with specific glycoproteins of Mr␣∼␣28 kD and 10 kD from MCF-7 cells. The interaction between Lex+-cancer cells and vascular endothelium is a potential target for cancer treatment.Fil: Elola, Maria Teresa. Fundación Instituto Leloir; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Capurro, Mariana Isabel. University of Toronto; CanadáFil: Barrio, Maria Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación, Docencia y Prevención del Cáncer; ArgentinaFil: Coombs, Peter J.. Imperial College London; Reino UnidoFil: Taylor, Maureen E.. Imperial College London; Reino UnidoFil: Drickamer, Kurt. Imperial College London; Reino UnidoFil: Mordoh, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación, Docencia y Prevención del Cáncer; Argentin

Fate of eprinomectin in goat milk and cheeses with different ripening times following pour-on administration

The distribution of eprinomectin in goat milk and cheeses (cacioricotta, caciotta, caprilisco) with different ripening times following a pour-on administration at a single dose rate (500 microg/kg of body weight) and a double dose rate (1,000 microg/kg of body weight) to goats with naturally occurring infections of gastrointestinal nematodes was studied. Milk residues of eprinomectin reached a maximum of 0.55+/-0.18 microg/kg and 1.70+/-0.31 microg/kg at the single and double doses, respectively. The drug concentrations decreased progressively until the fifth day after treatment, when they were less than the detection limit at both dose rates. The eprinomectin levels measured in all cheese types (both treatments) were higher than those recovered in milk at all the sampling times. In caciotta cheeses, the eprinomectin residues levels were constantly higher than other cheeses. With the exception of cheeses made with milk the first day after treatment, eprinomectin concentrations were nearly constant up to the fourth day then decreased by the fifth and sixth days after treatment. In all cases, at both the single and double dosages, the maximum level of eprinomectin residues in goat milk and cheeses remained below the maximum residual level of 20 microg/liter permitted for lactating cattle

Pair densities at contact in the quantum electron gas

The value of the pair distribution function g(r) at contact (r = 0) in a quantum electron gas is determined by the scattering events between pairs of electrons with antiparallel spins. The theoretical results for g(0) as a function of the coupling strength r_s in the paramagnetic electron gas in dimensionality D=2 and 3, that have been obtained from the solution of the two-body scattering problem with a variety of effective scattering potentials embodying many-body effects, are compared with the results of many-body calculations in the ladder approximation and with quantum Monte Carlo data.Comment: 7 pages, 2 figure