Change of surface critical current in the surface superconductivity and mixed states of superconducting Niobium

A systematic study of irreversible magnetization was performed in bulk Niobium after different surface treatments. Starting with smooth surfaces and abrading them, a strong increase of the critical current is observed up an apparent limiting value. An impressive change of the critical current is also observed in the surface superconductivity (SSC) state, reaching values of the same order of magnitude as in the mixed state. We explain also the observation of strong SSC for magnetic field perpendicular to larges facets in terms of nucleation of SC along bumps of a corrugated surface.Comment: Accepted for publication in Superconducing Science and Technolog

Phylogeography and historical demography of the Lusitanian snail Elona quimperiana reveal survival in unexpected separate glacial refugia

<p>Abstract</p> <p>Background</p> <p>Present day distributions of Palearctic taxa in northern latitudes mainly result from populations having survived in local patches during the Late Pleistocene and/or from recolonizing populations from southern temperate refugia. If well-studied Mediterranean and eastern European refugia are widely accepted, some recent biogeographical assumptions still remain unclear, such as the occurrence of multiple glacial refugia in Iberia and cryptic refugia in northern Europe during the last glaciations. The Lusitanian snail <it>Elona quimperiana </it>has a remarkably disjunct distribution, limited to northwestern France (Brittany), northwestern Spain and the Basque Country. By describing the phylogeographical structure of this species across its entire range, the present study attempts to identify refugia and subsequent recolonization routes.</p> <p>Results</p> <p>Results based on 16S and COI gene sequences showed that the low genetic diversity observed in the Brittany populations should be associated with a recent demographic expansion. By contrast, populations from Spain exhibit several differentiated lineages and are characterized by demographic equilibrium, while the Basque populations are the only ones harboring typical distinct haplotypes. The center of the star-like networks of both gene sequences is occupied by a common ancestral-like haplotype found in Brittany and Spain, which might have originated from the middle of Northern Spain (i.e. Asturias, eastern Lugo and western Cantabria). Estimates of the divergence time between the Spain-Brittany and Basque lineages strongly suggest that <it>E. quimperiana </it>survived the Pleistocene glaciations in distinct refugia on the Iberian Peninsula, one of which is situated in Picos de Europa, and the other in the Basque Country. The occurrence of a northern refugium in France cannot be rejected as of yet.</p> <p>Conclusion</p> <p>Present results confirm the Iberian origin of the land snail <it>E. quimperian</it>a and strongly support the emerging phylogeographic hypothesis of multiple refugia in Iberia during the last glaciations. The scenario of a spatial expansion of <it>E. quimperiana </it>from an Iberian refuge located in Asturias to northern areas provides the most probable explanation for the present distribution of this land snail. By harboring distinct haplotypes, the Basque Country populations appear to be of great importance in terms of potential adaptation, long term persistence and hence, the conservation of <it>E. quimperiana</it>.</p

Bounds on CDM and neutrino isocurvature perturbations from CMB and LSS data

Generic models for the origin of structure predict a spectrum of initial fluctuations with a mixture of adiabatic and isocurvature perturbations. Using the observed anisotropies of the cosmic microwave backgound, the matter power spectra from large scale structure surveys and the luminosity distance vs redshift relation from supernovae of type Ia, we obtain strong bounds on the possible cold dark matter/baryon as well as neutrino isocurvature contributions to the primordial fluctations in the Universe. Neglecting the possible effects of spatial curvature and tensor perturbations, we perform a Bayesian likelihood analysis with thirteen free parameters, including independent spectral indexes for each of the modes and for their cross-correlation angle. We find that around a pivot wavenumber of k=0.05 h/Mpc the amplitude of the correlated isocurvature component cannot be larger than about 60% for the cold dark matter mode, 40% for the neutrino density mode, and 30% for the neutrino velocity mode, at 2 sigma. In the first case, our bound is larger than the WMAP first-year result, presumably because we prefer not to include any data from Lyman-alpha forests, but then obtain large blue spectral indexes for the non-adiabatic contributions. We also translate our bounds in terms of constraints on double inflation models with two uncoupled massive fields.Comment: 12 pages, 5 figure

Lexical properties: Trademarks, dictionaries, and the sense of the generic

The third edition of Webster’s International Dictionary, first published in 1961, represented a novel approach to lexicography. It recorded the English language used in everyday life, incorporating colloquial terms that previous grammarians would have considered unfit for any responsible dictionary. Many were scandalized by the new lexicography. Trademark lawyers were not the most prominent of these critics, but the concerns they expressed are significant because they touched on the core structure of the trademark as a form of property in language. In the course of eavesdropping on everyday usage, Merriam-Webster’s lexicographers picked up on the use of trademarks as common nouns: “thermos” as a generic noun for any vacuum flask, “cellophane” as a term for transparent wrapping, and so on. If Webster’s Third were to be taken as sound evidence of the meaning of words, then the danger was that some of the most familiar marks in the USA would be judged “generic” in the legal sense, and would thereby cease to be proprietary. In this article, we explore the implications of this encounter between law and lexicographic technique

Direct correlation between strengthening mechanisms and electrical noise in strained copper wires

We have measured the resistance noise of copper metallic wires during a tensile stress. The time variation of the main resistance is continuous up to the wire breakdown, but its fluctuations reveal the intermittent and heterogeneous character of plastic flow. We show in particular direct correlations between strengthening mechanisms and noise spectra characteristics.Comment: accepted in Phys Rev

Los comprobantes de pago electrónicos y su relación con la evasión tributaria del IGV (impuesto General a las ventas) en la empresa Dynatest Perú S.A.C. Del distrito de San Isidro, Lima 2020

La presente tesis titulada: “Comprobantes de pago electrónicos y la evasión tributaria del IGV (Impuesto General a las Ventas) en la empresa Dynatest Perú S.A.C., Distrito de San Isidro; Lima 2020”; se plantea como problemática la falta de control en la emisión de los comprobantes de pago; cuya finalidad fue determinar el nivel de relación existente entre los comprobantes de pago electrónicos y la evasión tributaria del IGV. La metodología de investigación utilizada fue de un estudio de enfoque cuantitativo, de tipo básico, de nivel descriptivo correlacional, de diseño no experimental, de corte transversal, de método inductivo deductivo; cuya muestra estuvo conformada por de 22 empleados; asimismo, para la recolección de datos se utilizó a la técnica de la encuesta y como instrumento a la cédula de cuestionario; siendo procesados dichos datos fueron analizados mediante la estadística descriptiva, logrando obtener un resultado de 0,917 para la validez de los ítems del instrumento por el Coeficiente Alfa de Cronbach; también, para la confiabilidad se utilizó a la prueba de hipótesis mediante el Coeficiente Rho de Spearman; cuyos resultados de la correlación de la variable independiente Comprobantes de pago electrónicos con la variable dependiente Evasión tributaria del IGV fue de 0,748 grados de correlación; para la primera dimensión Sistema de emisión electrónica se obtuvo un resultados igual a 0,704 grados, medido como muy alto, positivo y significativo; para la segunda dimensión Obligaciones formales de hacer o no hacer el resultado fue igual a 0,547 grados de correlación y para la tercera dimensión Obligaciones sustanciales de dar o no dar el resultado fue igual a 0,708 considerado como muy alto positivo y significativo; concluyendo que se acepta la hipótesis alterna y se rechaza la hipótesis nula y que debe implementarse la emisión electrónica de los comprobantes de pago para disminuir y evitar la evasión tributaria del impuesto indicado.The present thesis entitled: “Electronic payment receipts and tax evasion of the IGV General Sales Tax) in the company Dynatest Peru S.A.C., District of San Isidro; Lima 2020”; The lack of control in the issuance of payment vouchers is considered problematic; whose general objective was to establish the relationship between electronic payment vouchers and VAT tax evasion. The research methodology used was a quantitative approach, applied type, descriptive correlational level, non-experimental design, cross-sectional, inductive deductive method; whose sample population was 22 workers; Likewise, for data collection, the survey technique and the questionnaire card were used as an instrument; said data being processed by descriptive statistics, obtaining a result of 0.917 for the validity of the instrument items by Cronbach's Alpha Coefficient; Also, for reliability, the hypothesis test was used using Spearman's Rho Coefficient; The results of the correlation of the independent variable Electronic payment receipts with the dependent variable VAT tax evasion was 0.748 degrees of correlation; For the first dimension Electronic emission system, a result equal to 0.704 degrees was obtained, measured as very high, positive and significant; for the second dimension Formal obligations to do or not to do the result was equal to 0.547 degrees of correlation and for the third dimension Substantial obligations to give or not give the result was equal to 0.708 considered as very high positive and significant; concluding that the alternative hypothesis is accepted and the null hypothesis is rejected and that the electronic issuance of payment vouchers should be implemented to reduce and avoid VAT tax evasion; to improve the commercial image of the investigated company

Disease-causing mutations in BEST1 gene are associated with altered sorting of bestrophin-1 protein

Doumanov, Jordan A. et al.Mutations in BEST1 gene, encoding the bestrophin-1 (Best1) protein are associated with macular dystrophies. Best1 is predominantly expressed in the retinal pigment epithelium (RPE), and is inserted in its basolateral membrane. We investigated the cellular localization in polarized MDCKII cells of disease-associated Best1 mutant proteins to study specific sorting motifs of Best1. Real-time PCR and western blots for endogenous expression of BEST1 in MDCK cells were performed. Best1 mutant constructs were generated using site-directed mutagenesis and transfected in MDCK cells. For protein sorting, confocal microscopy studies, biotinylation assays and statistical methods for quantification of mislocalization were used. Analysis of endogenous expression of BEST1 in MDCK cells revealed the presence of BEST1 transcript but no protein. Confocal microscopy and quantitative analyses indicate that transfected normal human Best1 displays a basolateral localization in MDCK cells, while cell sorting of several Best1 mutants (Y85H, Q96R, L100R, Y227N, Y227E) was altered. In contrast to constitutively active Y227E, constitutively inactive Y227F Best1 mutant localized basolaterally similar to the normal Best1 protein. Our data suggest that at least three basolateral sorting motifs might be implicated in proper Best1 basolateral localization. In addition, non-phosphorylated tyrosine 227 could play a role for basolateral delivery. © 2013 by the authors; licensee MDPI, Basel, Switzerland.This work was supported by Agence Nationale de la Recherche (Chaire d’Excellence to Shomi S. Bhattacharya), Fondation Voir et Entendre (Young Investigator Grants to Christina Zeitz and Emeline F. Nandrot), Centre National de la Recherche Scientifique (CNRS) and Fondation Bettencourt Schueller (to Emeline F. Nandrot), Université Pierre et Marie Curie-Paris6 (Bonus Qualité Recherche to Christina Zeitz), Foundation Fighting Blindness (grant number CD-CL-0808-0466-CHNO to Isabelle Audo), Centre d’Investigation Clinique 503 recognized as a Foundation Fighting Blindness Center (grant number C-CMM-0907-0428-INSERM04), Fundacion Progreso y Salud (to Shomi S. Bhattacharya, Maria Luz Bellido Diaz, Abhay Krishna and Paloma Dominguez Gimenez), Instituto de Salud Carlos III (grant number CM06/00183 to Maria Luz Bellido Diaz) and Bulgarian National Science Fund (grant number DDVU 02/10). Additionally, the Institut de la Vision is funded by Institut National de la Santé et de la Recherche Médicale, Université Pierre et Marie Curie-Paris 6, Centre National de la Recherche Scientifique and Départment de Paris.Peer Reviewe

Ascl1 (Mash1) Defines Cells with Long-Term Neurogenic Potential in Subgranular and Subventricular Zones in Adult Mouse Brain

Ascl1 (Mash1) is a bHLH transcription factor essential for neural differentiation during embryogenesis but its role in adult neurogenesis is less clear. Here we show that in the adult brain Ascl1 is dynamically expressed during neurogenesis in the dentate gyrus subgranular zone (SGZ) and more rostral subventricular zone (SVZ). Specifically, we find Ascl1 levels low in SGZ Type-1 cells and SVZ B cells but increasing as the cells transition to intermediate progenitor stages. In vivo genetic lineage tracing with a tamoxifen (TAM) inducible Ascl1CreERT2 knock-in mouse strain shows that Ascl1 lineage cells continuously generate new neurons over extended periods of time. There is a regionally-specific difference in neuron generation, with mice given TAM at postnatal day 50 showing new dentate gyrus neurons through 30 days post-TAM, but showing new olfactory bulb neurons even 180 days post-TAM. These results show that Ascl1 is not restricted to transit amplifying populations but is also found in a subset of neural stem cells with long-term neurogenic potential in the adult brain

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO