119 research outputs found
Genetic characterization of the mexican hair-less pig by means of molecular markers
Long time ago the Mexican Hair-less pig has been considered as a not improved and not valuable ecotype, nevertheless there are few information about the genetics of their populations. In this work we are determining the genetic variability that could exist in the population of Hair-less pigs existing in the rural areas of the Mexican state of Yucatan, as well as in the population of animals, belonging to the center of genetic conservation of the Agricultural Technological Institute N.2. The experiment was divided in two phases, one on the field and another in the laboratory. On one hand, 102 samples were obtained (69 of blood and 33 of hair) from both populations. In the laboratory the DNA was extracted and was amplified by means of the Polimerase Chain Reaction to study 26 microsatellites recommended by the FAO/ISAG for studies of genetic diversity. The alleles number was analyzed, the frequencies alleles, the hetererozygosity (Genepop version programs 3,1c) and the content of polymorphic information (PIC). We observe as in the population coming from the state of Yucatan all the loci were polymorphic, with an average of 7,07 alleles. We also observe that the loci S0355, S0227 are homozygotic. In the population of animals coming from the rescue center most of the loci were polymorphic with the exception of the S0355 and S0215 that were homozygotic, with an alleles average of 3,65. The PIC also reflect the polymorphism detected in most of the locus in both populations. These results are similar to those obtained with different varieties of Iberian pig. According to this, we can consider that the population of hair-less pigs in the state of Yucatan represents a source of genetic variability that could be of utility in the future.Desde tiempos atrás al Cerdo Pelón Mexicano se le ha considerado como un biotipo no mejorado y sin atributos comerciales, no obstante se carece de información sobre la genética de sus poblaciones. En este trabajo se pretende determinar la variabilidad genética que existe en la población de cerdos del biotipo Pelón que se encuentra en las áreas rurales del estado Mexicano de Yucatán, así como en la población perteneciente al centro de conservación genética que se tiene para este biotipo en el Instituto Tecnológico Agropecuario Nº 2. En la fase de campo se obtuvieron 102 muestras (69 de sangre y 33 de pelo) en ambas poblaciones. En la fase de laboratorio se extrajo el ADN de cada una de las muestras por la técnica del Chelex y fueron amplificadas por medio de la reacción en cadena de la polimerasa para estudiar 26 microsatélites recomendados por la FAO/ISAG para estudios de diversidad genética en porcinos. Se analizó el número de alelos, las frecuencias alélicas, las heterocigosidad (Genepop versión 3,1c) y el contenido de información polimórfica (PIC). Se observó que en los animales procedentes del estado de Yucatán todos los loci fueron polimórficos, con un promedio de 7,07, también que existen 2 alelos que son homocigotos para dos locis diferentes (S0355, S0227). En la población de animales procedentes del centro de rescate la mayoría de los loci fueron polimórficos a excepción del S0355 y S0215 que resultaron homocigotos, con un promedio de 3,65 alelos. Así mismo la heterocigosidad y el PIC reflejan el polimorfismo detectado en la mayoría de los locus en ambas poblaciones. Estos resultados son similares a los de otros autores en diferentes variedades de cerdo Ibérico. La población de cerdos pelones del estado de Yucatán son una fuente importante de variabilidad genética que puede ser de utilidad en un futuro inmediato
Bounds on the dipole moments of the tau-neutrino via the process in a 331 model
We obtain limits on the anomalous magnetic and electric dipole moments of the
through the reaction
and in the framework of a 331 model. We consider initial-state radiation, and
neglect and photon exchange diagrams. The results are based on the data
reported by the L3 Collaboration at LEP, and compare favorably with the limits
obtained in other models, complementing previous studies on the dipole moments.Comment: 13 pages, 4 figures, to be published in The European Physical J C.
arXiv admin note: substantial text overlap with arXiv:hep-ph/060527
Large Extra Dimensions and Decaying KK Recurrences
We suggest the possibility that in ADD type brane-world scenarios, the higher
KK excitations of the graviton may decay to lower ones owing to a breakdown of
the conservation of extra dimensional ``momenta'' and study its implications
for astrophysics and cosmology. We give an explicit realization of this idea
with a bulk scalar field , whose nonzero KK modes acquire vacuum
expectation values. This scenario helps to avoid constraints on large extra
dimensions that come from gamma ray flux bounds in the direction of nearby
supernovae as well as those coming from diffuse cosmological gamma ray
background. It also relaxes the very stringent limits on reheat temperature of
the universe in ADD models.Comment: 16 pages, late
Left-right symmetry in 5D and neutrino mass in TeV scale gravity models
We construct a left-right symmetric model based on the gauge group
in five dimensions where both the
gauge bosons and fermions reside in all five dimensions. The orbifold boundary
conditions are used not only to break the gauge symmetry down to but also to ``project'' the right handed neutrino out
of the zero mode part of the spectrum, providing a new way to understand the
small neutrino masses without adding (singlet) bulk neutrinos. This formulation
of the left-right model has also two new features: (i) it avoids most existing
phenomenological bounds on the scale of the right handed boson allowing
for the possibility that the right handed gauge bosons could have masses under
a TeV, and (ii) it predicts a stable lepton with mass of order of the inverse
radius of the fifth dimension.Comment: 20 pages; some new materials and references adde
Dynamics of a large extra dimension inspired hybrid inflation model
In low scale quantum gravity scenarios the fundamental scale of nature can be
as low as TeV, in order to address the naturalness of the electroweak scale. A
number of difficulties arise in constructing specific models; stabilisation of
the radius of the extra dimensions, avoidance of overproduction of Kaluza Klein
modes, achieving successful baryogenesis and production of a close to
scale-invariant spectrum of density perturbations with the correct amplitude.
We examine in detail the dynamics, including radion stabilisation, of a hybrid
inflation model that has been proposed in order to address these difficulties,
where the inflaton is a gauge singlet residing in the bulk. We find that for a
low fundamental scale the phase transition, which in standard four dimensional
hybrid models usually ends inflation, is slow and there is second phase of
inflation lasting for a large number of e-foldings. The density perturbations
on cosmologically interesting scales exit the Hubble radius during this second
phase of inflation, and we find that their amplitude is far smaller than is
required. We find that the duration of the second phase of inflation can be
short, so that cosmologically interesting scales exit the Hubble radius prior
to the phase transition, and the density perturbations have the correct
amplitude, only if the fundamental scale takes an intermediate value. Finally
we comment briefly on the implications of an intermediate fundamental scale for
the production of primordial black holes and baryogenesis.Comment: 9 pages, 2 figures version to appear in Phys. Rev. D, additional
references and minor changes to discussio
Charge disproportionation in YNiO : ESR and susceptibility study
We present a study of the magnetic properties of YNiO in the
paramagnetic range, above and below the metal-insulator (MI) transition. The dc
susceptibility, (measured up to 1000 K) is a decreasing function of
T for 150 K (the N\'{e}el temperature) and we observe two different
Curie-Weiss regimes corresponding to the metallic and insulator phases. In the
metallic phase, this behaviour seems to be associated with the small ionic
radius of Y% . The value of the Curie constant for T T allows
us to discard the possibility of Ni localization. An electron spin
resonance (ESR) spectrum is visible in the insulator phase and only a fraction
of the Ni ions contributes to this resonance. We explain the ESR and behaviour for T T in terms of charge disproportionation of
the type 2Ni Ni+Ni that is compatible with the
previously observed structural transition across T.Comment: 10 pages, 4 figures, submitted to Phys. Rev.
A Comparative Study of Conventional and Microwave‐Assisted Synthesis of Quinoxaline 1,4‐di‐N‐oxide N‐acylhydrazones Derivatives Designed as Antitubercular Drug Candidates
Quinoxaline 1,4‐di‐N‐oxide (QdNO) and N‐acylhydrazone subunit are considered privileged scaffolds in medicinal chemistry because of its wide spectrum of biological activities, such as antibacterial, antitubercular, antiviral, anticancer, and antifungal. Beirut's reaction is the mostly commonly employed synthetic method to obtain QdNO; however, extended time, low yields, and byproduct formation are common features observed during the synthesis. Microwave‐assisted organic synthesis (MW) has gained popularity as an effective way to speed up chemical reactions, increasing yields and selectivity of a variety of reactions. Therefore, in an effort to synthesize compounds with potential to tuberculosis treatment, we reported herein the use of MW as a tool to obtain new QdNO derivatives containing the N‐acylhydrazone subunit. Four different synthetic routes were evaluated by using different benzofuroxan derivatives in the Beirut's reaction. The synthetic route D, which employed a dioxolan‐benzofuroxan derivative, has shown to be the best condition to obtain the desired hybrid quinoxaline. MW drastically reduces the reaction time to obtain all compounds compared to conventional heating. For compound 13, for example, the use of MW instead of conventional heating was able to reduce the reaction time in 192‐fold. In conclusion, the use of a benzofuroxan derivative without additional electrophilic sites besides N‐oxide nitrogen and the employment of the microwave‐assisted synthesis have proved to be the optimum condition to obtain quinoxaline 1,4‐di‐N‐oxide N‐acylhydrazone derivatives
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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