389 research outputs found
Z_4 flavor model in Randall-Sundrum model 1
Randall Sundrum models provide a possible explanation of (gauge-gravity)
hierarchy, whereas discrete symmetry flavor groups yield a possible description
of the texture of Standard Model fermion masses. We use both these ingredients
to propose a five-dimensional extension of the Standard Model where the mass
hierarchy of the four-dimensional effective field theory is obtained only using
localizations parameters of order 1. We consider a bulk custodial gauge
symmetry group together with an Abelian group: the model turns out to
yield a rather minimal extension of the SM as it only requires two brane Higgs
fields to provide the desired Yukawa interactions and the required spontaneous
symmetry breaking pattern. In fact, the presence of an extra-dimension allows
the use of the Scherk-Schwarz mechanism to contribute to the breaking of the
bulk custodial group down to the SM gauge symmetry. Moreover, no right-handed
neutrinos are present and neutrino masses are generated radiatively with the
help of a bulk charged scalar field that provides the Lepton-number violation.
Using experimental inputs from the Global Neutrino Analysis and recent Daya Bay
results, a numerical analysis is performed and allowed parameter regions are
displayed.Comment: 23 pages, 3 figures. A brief discussion on contribution from higher
order operators has been added, a few typos corrected and references added.
Version to appear in Phys. Rev.
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Effects of wind power spectrum analysis over resource assessment
Based on the Van der Hoven's seminal work, wind power industry has adopted the 10 minutes mean time as the proper sampling to estimate resource assessment. However, research within the literature questions the generalization of the 10 minutes as a standard measure of minima dispersion due to the particular geographic characteristics where the measurements took place. In this work the power spectrum of a high-frequency wind speed time series is analyzed and its influence over the resource assessment in the region of
La Ventosa, Oaxaca, Mexico. Power spectrum analysis from a monthly, seasonal, and annual time series results show a defined synoptic-scale, diurnal, and semi-diurnal variations, which changes in amplitude throughout the year.To study the influence of power spectrum in wind resource assessment were
estimated and compared the capacity factors of a typical 2MW wind turbine against measured wind speed with 1, 5, 10, 60, and 360 minutes mean times, we found that a maximum difference of 1.4 %. Resource assessment was also estimated using reanalysis data and WRF results, finding similar to high-resolution estimations, highlighting bias-corrected WRF performance, offering reliable results to model power performance after a statistical correction
Helmholtz theorem and the v-gauge in the problem of superluminal and instantaneous signals in classical electrodynamics
In this work we substantiate the applying of the Helmholtz vector
decomposition theorem (H-theorem) to vector fields in classical
electrodynamics. Using the H-theorem, within the framework of the two-parameter
Lorentz-like gauge (so called v-gauge), we show that two kinds of magnetic
vector potentials exist: one of them (solenoidal) can act exclusively with the
velocity of light c and the other one (irrotational) with an arbitrary finite
velocity (including a velocity more than c . We show also that the
irrotational component of the electric field has a physical meaning and can
propagate exclusively instantaneously.Comment: This variant has been accepted for publication in Found. Phys.
Letter
Spatial optical solitons in nonlinear photonic crystals
We study spatial optical solitons in a one-dimensional nonlinear photonic
crystal created by an array of thin-film nonlinear waveguides, the so-called
Dirac-comb nonlinear lattice. We analyze modulational instability of the
extended Bloch-wave modes and also investigate the existence and stability of
bright, dark, and ``twisted'' spatially localized modes in such periodic
structures. Additionally, we discuss both similarities and differences of our
general results with the simplified models of nonlinear periodic media
described by the discrete nonlinear Schrodinger equation, derived in the
tight-binding approximation, and the coupled-mode theory, valid for shallow
periodic modulations of the optical refractive index.Comment: 15 pages, 21 figure
Response to early generation genomic selection for yield in wheat
We investigated increasing genetic gain for grain yield using early generation genomic selection (GS). A training set of 1,334 elite wheat breeding lines tested over three field seasons was used to generate Genomic Estimated Breeding Values (GEBVs) for grain yield under irrigated conditions applying markers and three different prediction methods: (1) Genomic Best Linear Unbiased Predictor (GBLUP), (2) GBLUP with the imputation of missing genotypic data by Ridge Regression BLUP (rrGBLUP_imp), and (3) Reproducing Kernel Hilbert Space (RKHS) a.k.a. Gaussian Kernel (GK). F2 GEBVs were generated for 1,924 individuals from 38 biparental cross populations between 21 parents selected from the training set. Results showed that F2 GEBVs from the different methods were not correlated. Experiment 1 consisted of selecting F2s with the highest average GEBVs and advancing them to form genomically selected bulks and make intercross populations aiming to combine favorable alleles for yield. F4:6 lines were derived from genomically selected bulks, intercrosses, and conventional breeding methods with similar numbers from each. Results of field-testing for Experiment 1 did not find any difference in yield with genomic compared to conventional selection. Experiment 2 compared the predictive ability of the different GEBV calculation methods in F2 using a set of single plant-derived F2:4 lines from randomly selected F2 plants. Grain yield results from Experiment 2 showed a significant positive correlation between observed yields of F2:4 lines and predicted yield GEBVs of F2 single plants from GK (the predictive ability of 0.248, P < 0.001) and GBLUP (0.195, P < 0.01) but no correlation with rrGBLUP_imp. Results demonstrate the potential for the application of GS in early generations of wheat breeding and the importance of using the appropriate statistical model for GEBV calculation, which may not be the same as the best model for inbreds
Risks of dengue secondary infective biting associated with aedes aegypti in home environments in Monterrey, Mexico
Abstract. Secondary dengue virus infections are a major risk for developing dengue hemorrhagic fever. Recent exposure to infectious bites of Aedes aegypti (L.) females in previously diagnosed dengue cases fulfills the epidemiological model of dengue hemorrhagic fever. A study was comprised of 357 (89.2%) dengue and 43 (10.8%) dengue hemorrhagic fever cases confirmed by laboratory tests and clinical manifestations. An entomological survey was done in homes and backyards. Concurrently, a questionnaire was used to assess the impact of healthpromotion campaigns through knowledge of the vector and its epidemiological role. Seventy-six (28.4%) of the 268 (67.0%) total wet or dry oviposition sites were
positive for the presence of larvae or pupae, while adult Ae. aegypti were found in 32 (8.0%). One hundred thirty-two (33%) householders who formerly had dengue fever or dengue hemorrhagic fever had knowledge of either larval or adult dengue vector stages. According to gender distribution, 145 (36.2%) and 14 (3.5%) of the males confirmed with cases of dengue and dengue hemorrhagic fever lived in houses with 17.9 and 2% of the Ae. aegypti larval and pupal habitats. Houses with females who had dengue and dengue hemorrhagic fever were 212 (53%) and 29
(7.3%), with containers with immature Ae. aegypti in 19.4 and 7%, respectively. Lack of sustainability of government-targeted health education campaigns is the
major problem for involving communities in prevention and control of dengu
Persistent infection of rhesus monkeys with ‘Helicobacter macacae’ and its isolation from an animal with intestinal adenocarcinoma
A novel helicobacter, ‘Helicobacter macacae’, was previously isolated from a colony of rhesus and cynomolgus monkeys in which diarrhoea from chronic idiopathic colitis was enzootic. A survey performed in a second colony of rhesus monkeys without a history of chronic diarrhoea determined that 57 % were faecal-culture positive for Helicobacter species. Ten years after the survey, one of the animals from which ‘H. macacae’ had been isolated, a 23-year-old, intact male rhesus monkey (Macaca mulatta), presented with partial inappetence and progressive weight loss. Subsequent evaluation of the monkey revealed anaemia, hypoproteinaemia, hypoalbuminaemia and a palpable abdominal mass. Contrast radiography suggested partial intestinal obstruction. The animal was euthanized and a diagnosis was made of intestinal adenocarcinoma of the ileocaecocolic junction with metastasis to regional lymph nodes and liver. Microaerobic culture of caecal tissue yielded a helicobacter organism identified as ‘H. macacae’ by 16S rRNA gene sequencing – the same species of bacteria isolated 10 years previously. The liver, small intestine and colon were also positive by PCR for Helicobacter species. Intestinal adenocarcinoma is the most common malignancy of aged macaques. Faeces or caecal tissue from five out of five monkeys that remained from the original cohort and that were colonized with ‘H. macacae’ in the initial survey were positive for the organism. The apparent persistence of ‘H. macacae’ in these animals, the isolation of the bacterium from animals with colitis and the recognition of the importance of inflammation in carcinogenesis raise the possibility of an aetiological role in the genesis of intestinal adenocarcinoma in aged rhesus monkeys
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