1,390 research outputs found
Lepton masses, mixings and FCNC in a minimal S_3-invariant extension of the Standard Model
The mass matrices of the charged leptons and neutrinos, previously derived in
a minimal S_3-invariant extension of the Standard Model, were reparametrized in
terms of their eigenvalues. We obtained explicit, analytical expressions for
all entries in the neutrino mixing matrix, V_PMNS, the neutrino mixing angles
and the Majorana phases as functions of the masses of charged leptons and
neutrinos in excellent agreement with the latest experimental values. The
resulting V_PMNS matrix is very close to the tri-bimaximal form of the neutrino
mixing matrix. We also derived explicit analytical expressions for the matrices
of the Yukawa couplings and computed the branching ratios of some selected
flavour changing neutral current processes as functions of the masses of the
charged leptons and the neutral Higgs bosons. We find that the S_3 x Z_2
flavour symmetry and the strong mass hierarchy of the charged leptons strongly
suppress the FCNC processes in the leptonic sector well below the present
experimental upper bounds by many orders of magnitude.Comment: One paragraph added with comparison to tri-bimaximal mixing, two
lines changed in abstract, references added, typographical errors correcte
Magnetization vector in the reversible region of a highly anisotropic cuprate superconductor: anisotropy factor and the role of 2D vortex fluctuations
By using a high quality Tl2Ba2Ca2Cu3O10 (Tl-2223) single crystal as an
example, the magnetization vector was probed in the reversible region of highly
anisotropic cuprate superconductors. For that, we have measured its components
along and transverse to the applied magnetic field for different crystal
orientations. The analysis shows that the angular dependence of the
perpendicular component of the magnetization vector follows the one predicted
by a London-like approach which includes a contribution associated with the
thermal fluctuations of the 2D vortex positions. For the Tl-2223 crystal
studied here, a lower bound for the anisotropy factor was estimated to be about
190.Comment: 6 pages, 3 figure
Detecting cells with low RNA content colonizing artworks non-invasively: RNA-FISH
Various non-invasive RNA-FISH methodologies were tested in this
work. They seem to be good alternatives for analyzing the potential biodeteriogenic microorganisms thriving
in CH objects.This work was co- financed by FCT Fundação para a Ciência e a Tecnologia
through the project "MICROTECH-ART- Microorganisms Thriving on and Endamaging Cultural
Heritage -an Analytical Rapid Tool-" (PTDC/BBB-IMG/0046/2014) and by European Union, European
Regional Development Fund ALENTEJO 2020 through the project HIT3CH - HERCULES Interface
for Technology Transfer and Teaming in Cultural Heritage (ALT20-03-0246-FEDER-000004). Marina
González-Pérez acknowledges FCT for the economic support through the post-doctoral grant
SFRH/BPD/100754/2014
Do spiders respond to global change? A study on the phenology of ballooning spiders in Switzerland
We studied ballooning spiders captured weekly over an 11-y period using a 12.2-m- high suction trap in an agricultural landscape of western Switzerland. We analyzed population trends, changes in phenology, and species composition. Yearly trends in population size of the most abundant species were studied with nonparametric correlations. We found that these trends were markedly different for ground-living (92% of all decreasing species) and upper-strata species (75% of all increasing species). These contrasting tendencies can be explained by a stronger effect of meteorological conditions on species living at ground level and by an observed decrease in habitat availability for open-habitat species. The phenology of ballooning spiders was analyzed using mixtures of Gaussian curves fitted to the yearly capture data; this was possible for the 7 most abundant species. From these, we estimated the dates of the ballooning peaks for each species and each year (1 to 4 peaks depending on the species). We found that the dates remained mostly constant: the timing of dispersal peaks showed no annual trend for all but 1 species. Using nonparametric correlation, we analyzed the relationships between the dates of the peaks and the meteorological parameters occurring before the peak dates. In line with the absence of trend, the dates of the peaks were only weakly related to meteorological conditions. The extreme climatic event of 2003 had a strong impact by reducing populations of ground-living species. Using Canonical Correspondence Analysis and clustering methods, we identified a strong shift in the phenological structure of the ballooning spider assemblage in that year. In all, despite noticeable trends in population size during the study period, the dispersal phenology did not change, which contrasts with observations from other arthropod groups
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Intellectual structure of international new venture research: a bibliometric analysis and suggestions for a future research agenda
We examine the intellectual structure of the international new venture (INV) literature using bibliometric citation and co-citation analysis. We aim to identify the most influential papers/authors, publication outlets, and key research topics. We focus on the top 100 most-cited papers in this field published between 1994 and 2015. In the post-hoc reading, we supplement our main bibliometric techniques with the qualitative content analysis method to shed light on a number of theoretical and empirical issues. We find that the literature has grown significantly in the past two decades. However, the main factors that hinder the field are the diversity of applicable theoretical perspectives and the inconsistencies between theoretical concepts and measurements of variables in empirics. We outline a detailed future research agenda to address these inconsistencies and recommend using new lenses from international business to examine the INV phenomenon
Tear proteomic profiling with MALDI-TOF mass spectrometry coupled with magnetic-beads HIC-18 separation as a diagnostic tools in blepharitis disease
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Oral bacterial microflora associated with total acrylic dentures: implant supported vs mucus supported
Poster presented at the 1st International Congress of CiiEM - From Basic Sciences to Clinical Research. 27-28 November 2015, Egas Moniz, Caparica, Portugal
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