Role of dynamic pairing correlations in fission dynamics. II. Fermium and nobelium isotopes

The competition between the quenching of pairing due to the repulsive Coulomb interaction and dynamic pairing correlations added by particle number symmetry restoration has been studied in a selected set of Fermium and Nobelium isotopes by using a hierarchy of Hartree-Fock-Bogoliubov-based approximations and a restricted variation after particle number projection, all of them based on the D1M∗ parametrization of the Gogny force. It is found that Coulomb antipairing is partially compensated by beyond-mean-field pairing correlations. However, the compensation is not perfect and a modulation of the spontaneous fission half-lives, as functions of the neutron number, indicates that the combined effect on fission dynamics of Coulomb antipairing and restricted particle number symmetry restoration cannot be overlooked. Neither can it be accounted for by the Coulomb Slater approximatio

Small scale fracture behaviour of multilayer TiN/CrN systems: Assessment of bilayer thickness effects by means of ex-situ tests on FIB-milled micro-cantilevers

TiN/CrN multilayered PVD coatings are known to exhibit outstanding micromechanical properties and wear resistance. On the other hand, information on their small scale fracture behaviour is rather scarce. The present work aims to address it by testing to failure FIB-milled microbeams of multilayer TiN/CrN systems with different bilayer periods (8, 19 and 25 nm). In doing so, these micrometric specimens are first FIB notched, and thus deflected by means of a nanoindentation system. It is found that multilayer architecture translates into a beneficial synergic effect regarding critical load for reaching unstable failure; and thus, on energy absorption at fracture. Such behaviour is associated with small scale crack deflection as main toughening mechanism.Peer ReviewedPostprint (author's final draft

Quadrupole-octupole coupling and the evolution of collectivity in neutron-deficient Xe, Ba, Ce, and Nd isotopes

The evolution of quadrupole and octupole collectivity in neutron-deficient Xe, Ba, Ce, and Nd nuclei near the "octupole magic" neutron number N=56 is investigated within the mapped sdf-IBM framework. Microscopic input is obtained via quadrupole and octupole constrained Hartree-Fock-Bogoliubov calculations, based on the parametrization D1M of the Gogny energy density functional. Octupole-deformed mean-field ground states are predicted for Ba and Ce isotopes near N=56. Excitation energies of positive- and negative-parity states as well as electric transition rates are computed with wave functions resulting from the diagonalization of the mapped IBM Hamiltonian. The parameters of the Hamiltonian are determined via the mapping of the mean-field potential energy surfaces onto the expectation value of the Hamiltonian in the condensate state of the s, d, and f bosons. Enhanced octupolarity is predicted for Xe, Ba, and Ce isotopes near N=56. The shape/phase transition from octupole-deformed to strongly quadrupole-deformed near N=60 is analyzed in detai

Homocysteine treatment alters redox capacity of both endothelial and tumor cells

Homocysteine is a non-proteinogenic amino acid playing key roles in two interconnected metabolic pathways, namely, the activated methyl cycle and the linear trans-sulfuration pathway that allows the conversion of methionine to cysteine. A dysregulation of intracellular homocysteine metabolism could yield an increased export of this amino acid, leading to hyperhomocysteinemia, which has been associated with an increased risk of cardiovascular diseases. In spite of decades of experimental effort, there is no definitive consensus on what could be the molecular mechanisms whereby hyperhomocysteinemia could contribute to cardiovascular disease. The redox active nature of homocysteine has favored the idea of an induction of oxidative stress as the underlying mechanism of homocysteine toxicity. In contrast, homocysteine can also behave as an anti-oxidant. The present work is aimed to further analyze the capacity of homocysteine to modulate the redox capacity of both endothelial and tumor cells. [Our experimental work is supported by grants BIO2014-56092-R (MINECO and FEDER) and P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain)].Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Multiple Sources toward the High-mass Young Star S140 IRS1

S140 IRS1 is a remarkable source where the radio source at the center of the main bipolar molecular outflow in the region is elongated perpendicular to the axis of the outflow, an orientation opposite to that expected if the radio source is a thermal jet exciting the outflow. We present results of 1.3 cm continuum and H2O maser emission observations made with the VLA in its A configuration toward this region. In addition, we also present results of continuum observations at 7 mm and re-analyse observations at 2, 3.5 and 6 cm (previously published). IRS 1A is detected at all wavelengths, showing an elongated structure. Three water maser spots are detected along the major axis of the radio source IRS 1A. We have also detected a new continuum source at 3.5 cm (IRS 1C) located ~0.6'' northeast of IRS 1A. The presence of these two YSOs (IRS 1A and 1C) could explain the existence of the two bipolar molecular outflows observed in the region. In addition, we have also detected three continuum clumps (IRS 1B, 1D and 1E) located along the major axis of IRS 1A. We discuss two possible models to explain the nature of IRS 1A: a thermal jet and an equatorial wind.Comment: 17 pages, 4 figures, to be published in A

On metaphors in thinking about preparing mathematics for teaching

This paper explores how different schools of thought in mathematics education think and speak about preparing mathematics for teaching by introducing and proposing certain metaphors. Among the metaphors under consideration here are the unpacking metaphor, which finds its origin in the Anglo-American school of thought of pedagogical reduction of mathematics; the elementarization metaphor, which has its origin in the German school of thought of didactic reconstruction of mathematics; and the recontextualization metaphor, which originates in the French school of thought of didactic transposition. The metaphorical language used in these schools of thought is based on different theoretical positions, orientations, and images of preparing mathematics for teaching. Although these metaphors are powerful and allow for different ways of thinking and speaking about preparing mathematics for teaching, they suggest that preparing mathematics for teaching is largely a one-sided process in the sense of an adaptation of the knowledge in question. To promote a more holistic understanding, an alternative metaphor is offered: preparing mathematics for teaching as ecological engineering. By using the ecological engineering metaphor, the preparation of mathematics for teaching is presented as a two-sided process that involves both the adaptation of knowledge and the modification of its environment

Precise OBS location at the sea bottom in active seismic profiles using the air gun shot records

The Norcaribe campaign, in November – December 2013, funded by Spanish Ministry of Innovation and Science (Norcaribe Project CGL2010-17715), was performed on board of the Spanish research vessel “Sarmiento de Gamboa” around the Hispaniola island, also with the participation of the Dominic Republic Navy patrol vessels and several Haiti and Dominic Republic institutions. During the campaign, a 200 km long, wide-amgle refraction seismic profile was carried out crossing the Beata ridge. The air gun signal (5100 ci) was recorded by 15 OBSs deployed along the seismic line in water depths between 2.300 meters and 4.320 meters. To obtain the section records, the OBS position is needed, usually the deployment location is used, but the OBS can drift while is sinking due to the deep oceanic currents. The recovery locations at surface could provide information about the drift, assuming a constant sea current since the deployment to the recovery, but it is imprecise. In this work we show a method to obtain a precise location of the OBS at the sea bottom using a high-resolution bathymetry and the OBS record of the closest air gun shots of the profile. Also, the preliminary results for the Norcaribe campaign (Beata ridge profile) are shown.Peer Reviewe

CCR5Δ32 variant and cardiovascular disease in patients with rheumatoid arthritis: a cohort study

Introduction The aim of our study was to analyze the influence of the CCR5Δ32 polymorphism in the risk of cardiovascular (CV) events and subclinical atherosclerosis among patients with rheumatoid arthritis (RA). Methods A total of 645 patients fulfilling the American Rheumatism Association 1987 revised classification criteria for RA were studied. Patients were genotyped for the CCR5 rs333 polymorphism using predesigned TaqMan assays. Also, HLA DRB1 genotyping was performed using molecular-based methods. Carotid intima-media thickness, flow-mediated endothelium-dependent dilatation (FMD) and endothelium-independent vasodilatation, which were used as surrogate markers of subclinical atherosclerosis, were measured in a subgroup of patients with no clinical CV disease. Results A lower frequency of carriers of the CCR5Δ32 allele among patients with CV events (3.4% versus 11.3%, P = 0.025, odds ratio 0.28, 95% confidence interval (95% CI) 0.06 to 0.89) was observed. However, after adjusting for gender, age at time of RA diagnosis, and the presence of shared epitope, rheumatoid factor and classic CV risk factors in the Cox regression analysis, this reduction of CV events in CCR5Δ32 allele carriers was slightly outside the range of significance (P = 0.097; hazard ratio 0.37 (95% CI 0.12 to 1.19)). Carriers of the CCR5Δ32 deletion also showed higher FMD values than the remaining patients (CCR5/CCR5Δ32 patients: 7.03% ± 6.61% versus CCR5/CCR5 patients: 5.51% ± 4.66%). This difference was statistically significant when analysis of covariance was performed (P = 0.024). Conclusions Our results show a potential influence of the CCR5Δ32 deletion on the risk of CV disease among patients with RA. This may be due to a protective effect of this allelic variant against the development of vascular endothelial dysfunction

Continuous‑wavelet‑transform analysis of the multifocal ERG waveform in glaucoma diagnosis

The vast majority of multifocal electroretinogram (mfERG) signal analyses to detect glaucoma study the signals’ amplitudes and latencies. The purpose of this paper is to investigate application of wavelet analysis of mfERG signals in diagnosis of glaucoma. This analysis method applies the continuous wavelet transform (CWT) to the signals, using the real Morlet wavelet. CWT coefficients resulting from the scale of maximum correlation are used as inputs to a neural network, which acts as a classifier. mfERG recordings are taken from the eyes of 47 subjects diagnosed with chronic open-angle glaucoma and from those of 24 healthy subjects. The high sensitivity in the classification (0.894) provides reliable detection of glaucomatous sectors, while the specificity achieved (0.844) reflects accurate detection of healthy sectors. The results obtained in this paper improve on the previous findings reported by the authors using the same visual stimuli and database.Ministerio de Ciencia e Innovació

CRISPR elements provide a new framework for the genealogy of the citrus canker pathogen Xanthomonas citri pv. citri

Background: Xanthomonads are an important clade of Gram-negative bacteria infecting a plethora of economically important host plants, including citrus. Knowledge about the pathogen's diversity and population structure are prerequisite for epidemiological surveillance and efficient disease management. Rapidly evolving genetic loci, such as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), are of special interest to develop new molecular typing tools. Results: We analyzed CRISPR loci of 56 Xanthomonas citri pv. citri strains of world-wide origin, a regulated pathogen causing Asiatic citrus canker in several regions of the world. With one exception, 23 unique sequences built up the repertoire of spacers, suggesting that this set of strains originated from a common ancestor that already harbored these 23 spacers. One isolate originating from Pakistan contained a string of 14 additional, probably more recently acquired spacers indicating that this genetic lineage has or had until recently the capacity to acquire new spacers. Comparison of CRISPR arrays with previously obtained molecular typing data, such as amplified fragment length polymorphisms (AFLP), variable-number of tandem-repeats (VNTR) and genome-wide single-nucleotide polymorphisms (SNP), demonstrated that these methods reveal similar evolutionary trajectories. Notably, genome analyses allowed to generate a model for CRISPR array evolution in X. citri pv. citri, which provides a new framework for the genealogy of the citrus canker pathogen. Conclusions: CRISPR-based typing will further improve the accuracy of the genetic identification of X. citri pv. citri outbreak strains in molecular epidemiology analyses, especially when used concomitantly with another genotyping method