Amplification and cloning of cDNAS of cytochrome P4501A1 and metallothionein genes from Sparus aurata Linnaeus, 1758 and Liza aurata (Risso, 1810) by Race-PCR

The biotransformation of xenobiotics found in marine ecosystems is catalysed by inducible systems, a property that makes them useful as early-warning biomarkers of environmental pollution. We have focused our study on cytochrome P4501A1 (CYP 1A1) as a phase I response against organic aromatic xenobiotics, and metallothionein (MT), which reflects pollution by transition metals. The high homology existing between the sequences of both genes, already cloned in different fish species, enabled us to design degenerate oligos to amplify by RT-PCR specific sequences of CYP 1A1 and MT genes in two teleost fish species of the Spanish South Atlantic littoral, the gilthead seabream, Sparus aurata Linnaeus, 1758, and the grey mullet, Liza aurata (Risso 1810). To this end, the expression of both genes was previously induced by intraperitoneal injection with Aroclor 1254 (CYP 1A1) and CdCl2 (MT). The specific sequences for both genes amplified by RT-PCR with degenerate oligos were subsequently used to design new, specific oligos to obtain by Race-PCR (Rapid Amplification of cDNA Ends) the complete cDNAs coding for both genes in both fish species, which were subsequently cloned and sequenced. The coding sequences and the corresponding proteins were compared with those already obtained in other fish species. We are currently developing homologous probes for mRNA quantification using molecular biology techniques in both fish species, to be employed as molecular biomarkers of pollution in the Spanish South Atlantic littoral.La biotransformación de xenobióticos presentes en ecosistemas marinos está catalizada por varios sistemas inducibles, lo que permite su uso como biomarcadores de alerta temprana de contaminación ambiental. Este estudio se ha centrado en el citocromo P4501A1 (CYP 1A1), como respuesta de fase I contra xenobióticos orgánicos aromáticos, y la metalotioneína (MT), que refleja la contaminación por metales de transición. La alta homología existente entre las secuencias de ambos genes previamente clonados en diferentes especies de peces permitió diseñar oligos degenerados para amplificar por RT-PCR secuencias específicas de los genes CYP 1A1 y MT en dos especies de peces teleósteos del litoral suratlántico español, la dorada Sparus aurata Linnaeus, 1758 y la lisa Liza aurata (Risso, 1810). Para ello, la expresión de ambos genes se indujo por inyección intraperitoneal con Aroclor 1254 (CYP 1A1) y CdCl2 (MT). Las secuencias específicas de ambos genes, amplificadas por RT-PCR con tales oligos, se usaron posteriormente para diseñar nuevos oligos específicos; éstos se usaron para amplificar por Race-PCR (Rapid Amplification of cDNA Ends) los cDNAs completos que codifican tales genes en ambas especies de peces, que fueron posteriormente clonados y secuenciados. Las secuencias codificantes y las proteínas correspondientes se han comparado con las obtenidas en otras especies de peces. Actualmente se desarrollan sondas homólogas para cuantificar por métodos de biología molecular los mRNAs específicos en ambos peces, para su uso como biomarcadores moleculares de contaminación en el litoral suratlántico español.Instituto Español de Oceanografí

Boson-conserving one-nucleon transfer operator in the interacting boson model

The boson-conserving one-nucleon transfer operator in the interacting boson model (IBA) is reanalyzed. Extra terms are added to the usual form used for that operator. These new terms change generalized seniority by one unit, as the ones considered up to now. The results obtained using the new form for the transfer operator are compared with those obtained with the traditional form in a simple case involving the pseudo-spin Bose-Fermi symmetry $U^{B}(6) \otimes U^F(12)$ in its $U^{BF}(5) \otimes U^F(2)$ limit. Sizeable differences are found. These results are of relevance in the study of transfer reactions to check nuclear supersymmetry and in the description of (\beta)-decay within IBA.Comment: 13 pages, 1 table, 0 figures. To be published in Phys. Rev.

Garvey-Kelson Relations for Nuclear Charge Radii

The Garvey-Kelson relations (GKRs) are algebraic expressions originally developed to predict nuclear masses. In this letter we show that the GKRs provide a fruitful framework for the prediction of other physical observables that also display a slowly-varying dynamics. Based on this concept, we extend the GKRs to the study of nuclear charge radii. The GKRs are tested on 455 out of the approximately 800 nuclei whose charge radius is experimentally known. We find a rms deviation between the GK predictions and the experimental values of only 0.01 fm. This should be contrasted against some of the most successful microscopic models that yield rms deviations almost three times as large. Predictions - with reliable uncertainties - are provided for 116 nuclei whose charge radius is presently unknown.Comment: 4 pages and 3 figure

New supersymmetric quartet of nuclei in the A=190 mass region

We present evidence for a new supersymmetric quartet in the A=190 region of the nuclear mass table. New experimental information on transfer and neutron capture reactions to the odd-odd nucleaus 194 Ir strongly suggests the existence of a new supersymmetric quartet, consisting of the 192,193 Os and 193,194 Ir nuclei. We make explicit predictions for the odd-neutron nucleus 193 Os, and suggest that its spectroscopic properties be measured in dedicated experiments.Comment: 5 pages, 4 figures, updated figures and revised text, Physical Review C, Rapid Communication, in pres

Relationship between X(5)-models and the interacting boson model

The connections between the X(5)-models (the original X(5) using an infinite square well, X(5)-$\beta^8$, X(5)-$\beta^6$, X(5)-$\beta^4$, and X(5)-$\beta^2$), based on particular solutions of the geometrical Bohr Hamiltonian with harmonic potential in the $\gamma$ degree of freedom, and the interacting boson model (IBM) are explored. This work is the natural extension of the work presented in [1] for the E(5)-models. For that purpose, a quite general one- and two-body IBM Hamiltonian is used and a numerical fit to the different X(5)-models energies is performed, later on the obtained wave functions are used to calculate B(E2) transition rates. It is shown that within the IBM one can reproduce well the results for energies and B(E2) transition rates obtained with all these X(5)-models, although the agreement is not so impressive as for the E(5)-models. From the fitted IBM parameters the corresponding energy surface can be extracted and it is obtained that, surprisingly, only the X(5) case corresponds in the moderate large N limit to an energy surface very close to the one expected for a critical point, while the rest of models seat a little farther.Comment: Accepted in Physical Review

Influence of Dust in Solar Cells Used for Measuring Solar Radiation

Permiso obtenido por la institución para subir este documentoThe photovoltaic cells (PV) are commonly used as global radiation measurement device, even though when it has been proved that there are significant differences with respect to using pyranometers. The dirt deposited on the surface of the PV is one of the most influential factors in the measurement of the solar radiation. In this work we have made experimental measurements with four identical cells, two cleans and two dirties with different soil density (0.2 g/m2, 0.4 g/m2, 0.8 g/m2, 1.2 g/m2 and 1.5 g/m2) and different size particles (< 125 μm) comparing the results and obtaining a correlation between the density of the dust and the difference between the measured irradiance for clean and dirty cells for each particle size

New supersymmetric quartet of nuclei in the A=190 mass region

We present evidence for a new supersymmetric quartet in the A=190 region of the nuclear mass table. New experimental information on transfer and neutron capture reactions to the odd-odd nucleaus 194 Ir strongly suggests the existence of a new supersymmetric quartet, consisting of the 192,193 Os and 193,194 Ir nuclei. We make explicit predictions for the odd-neutron nucleus 193 Os, and suggest that its spectroscopic properties be measured in dedicated experiments.Comment: 5 pages, 4 figures, updated figures and revised text, Physical Review C, Rapid Communication, in pres

Cystathionine beta synthase deficiency and brain edema associated with methionine excess under betaine supplementation: Four new cases and a review of the evidence.

CBS deficient individuals undergoing betaine supplementation without sufficient dietary methionine restriction can develop severe hypermethioninemia and brain edema. Brain edema has also been observed in individuals with severe hypermethioninemia without concomitant betaine supplementation. We systematically evaluated reports from 11 published and 4 unpublished patients with CBS deficiency and from additional four cases of encephalopathy in association with elevated methionine. We conclude that, while betaine supplementation does greatly exacerbate methionine accumulation, the primary agent causing brain edema is methionine rather than betaine. Clinical signs of increased intracranial pressure have not been seen in patients with plasma methionine levels below 559 μmol/L but occurred in one patient whose levels did not knowingly exceed 972 μmol/L at the time of manifestation. While levels below 500 μmol/L can be deemed safe it appears that brain edema can develop with plasma methionine levels close to 1000 μmol/L. Patients with CBS deficiency on betaine supplementation need to be regularly monitored for concordance with their dietary plan and for plasma methionine concentrations. Recurrent methionine levels above 500 μmol/L should alert clinicians to check for clinical signs and symptoms of brain edema and review dietary methionine intake. Levels approaching 1000 μmol/L do increase the risk of complications and levels exceeding 1000 μmol/L, despite best dietetic efforts, should be acutely addressed by reducing the prescribed betaine dose

Q-Value and Half-Lives for the Double-Beta-Decay Nuclide 110Pd

The 110Pd double-beta decay Q-value was measured with the Penning-trap mass spectrometer ISOLTRAP to be Q = 2017.85(64) keV. This value shifted by 14 keV compared to the literature value and is 17 times more precise, resulting in new phase-space factors for the two-neutrino and neutrinoless decay modes. In addition a new set of the relevant matrix elements has been calculated. The expected half-life of the two-neutrino mode was reevaluated as 1.5(6) E20 yr. With its high natural abundance, the new results reveal 110Pd to be an excellent candidate for double-beta decay studies

Millisecond radiative recombination in poly(phenylene vinylene)-based light-emitting diodes from transient electroluminescence

The current and electroluminescence transient responses of standard poly(phenylene vinylene)-based light-emitting devices have been investigated. The electroluminescence time response is longer (milliseconds scale) than the current switch-off time by more than one order of magnitude, in the case of small area devices (<0.1 cm2). For large area devices ( ∼ 6 cm2) the electroluminescence decay time decreases from 1.45 ms to  ∼ 100 μs with increasing bias voltage. The fast current decay limits the electroluminescence decay at higher voltages. Several approaches are discussed to interpret the observed slow decrease of electroluminescence after turning off the bias. One relies upon the Langevin-type bimolecular recombination kinetics which is governed by the minority carriers (electrons), and another focuses on the slow release of trapped electrons as possible explanations. Additionally, we show that the device current density is mainly determined by the transport of the fastest carriers (holes)[email protected]