525 research outputs found
Bethe ansatz solution of the invariant spin chain
We have applied the analytical Bethe ansatz approach in order to solve the
invariant magnet. By using the Bethe ansatz equations we have
calculated the ground state energy and the low-lying dispersion relation. The
finite size properties indicate that the model has a central charge .Comment: 9 page
Integrable supersymmetric correlated electron chain with open boundaries
We construct an extended Hubbard model with open boundaries from a -matrix
based on the superalgebra. We study the reflection equation and
find two classes of diagonal solutions. The corresponding one-dimensional open
Hamiltonians are diagonalized by means of the Bethe ansatz approach.Comment: latex, 14 page
Genetic analysis of microsatellites markers in two populations of Berrenda en Negro bovine breed
The Berrenda en Negro cattle breed has been used classically in the management of the fight bull and currently is found next their extinction. To contribute to the genetic conservation programs of this breed, we are characterized a sample of 32 animals with a panel of 15 microsatellites and we are provided data that permit, in a future, to compare its variability with other cattle breeds.La raza Bovina Berrenda en Negro se ha utilizado clásicamente en el manejo del toro de lidia y actualmente se encuentra próxima a su extinción. Para contribuir a los planes de recuperación genética de esta raza, se caracteriza una muestra de 32 animales con un panel de 15 microsatélites y se proporcionan datos que permitan, en un futuro, comparar su variabilidad con otras razas bovinas
Solution of the SU(N) Vertex Model with Non-Diagonal Open Boundaries
We diagonalize the double-row transfer matrix of the SU(N) vertex model for
certain classes of non-diagonal boundary conditions. We derive explicit
expressions for the corresponding eigenvectors and eigenvalues by means of the
algebraic Bethe ansatz approach.Comment: 10 page
Exact solution and finite size properties of the vertex model
We have diagonalized the transfer matrix of the vertex
model by means of the algebraic Bethe ansatz method for a variety of grading
possibilities. This allowed us to investigate the thermodynamic limit as well
as the finite size properties of the corresponding spin chain in the massless
regime. The leading behaviour of the finite size corrections to the spectrum is
conjectured for arbitrary . For we find a critical line with central
charge whose exponents vary continuously with the -deformation
parameter. For the finite size term related to the conformal anomaly
depends on the anisotropy which indicates a multicritical behaviour typical of
loop models.Comment: 40 pages, 8 figures, late
Genetic characterisation of bovino criollo argentino cattle using microsatellites
It is characterized a sample of Bovino Criollo Argentino cattle with a panel of eight microsatellites. It is detected a number of alleles between 2 and 7. The values of Heterocigosity by locus are between 0.46 for HEL-1 and 0.72 for BM-1824 and the mean of Heterocigosity is 0.58.Se caracteriza una muestra de ganado Bovino Criollo Argentino con un panel de ocho microsatélites. Se detecta un número de alelos entre 2 y 7. Los valores de Heterocigosidad por locus están entre 0,46 para HEL-1 y 0,72 para BM-1824, la Heterocigosidad media es de 0,58
Genetic characterisation of the palmera sheep with microsatellites
It have been studied 178 animals (the whole population) of the Palmera sheep with 24 microsatellites in order to characterise this autochthonous breed from La Palma Island (Canary Islands, Spain). Ovine and bovine microsatellites recommended by FAO, ISAG (International Society of Animal Genetics) and other authors in the bibliography for ovine biodiversity studies have been used. These markers were amplified by mean of the polymerase chain reaction (PCR) technique and to get the size separation of the obtained fragments we have developed electrophoresis in polyacrylamide gel in an automatic sequencer ABI377XL. All the microsatellites have been polymorphic and between 2 (ETH10) and 15 (CSSM66) alleles have been found with an average value of 7.04. The expected heterozigosity has been 0,6039 and the observed heterozigosity 0.5504. The paternity and maternity have been checked with these microsatellites and this has been used to make a paternity panel with 10-12 markers and an a priori exclusion probability higher than 99,9 percent. This panel is useful to check paternity in this threatened breed.Se estudian 178 animales pertenecientes a la raza ovina Palmera, lo que supone la totalidad de la población, mediante 24 marcadores microsatélites con objeto de caracterizar esta raza autóctona de la Isla de la Palma (Islas Canarias, España). Se han empleado microsatélites de ovino y de bovino recomendados por la FAO, por la ISAG (International Society of Animal Genetics) y por otros autores en la bibliografía para este tipo de estudios en ovinos. Los microsatélites se han amplificado mediante la reacción en cadena de la polimerasa (PCR) y los fragmentos amplificados se han separado mediante electroforesis en un secuenciador automático ABI 377XL. Todos los microsatélites utilizados han resultado polimórficos y se han encontrado entre 2 alelos para el ETH10 y 15 para el CSSM66, con un número medio de alelos de 7,04. La heterocigosidad media esperada ha sido 0,6039 y la observada 0,5504. Se ha llevado a cabo también la comprobación de paternidades y maternidades con estos microsatélites, lo que ha servido para establecer una batería de 10-12 microsatélites con una probabilidad de exclusión a priori superior al 99,9 p.100 que puede resultar muy útil para realizar controles de filiación en esta raza ovina en serio peligro de extinción
The algebraic Bethe ansatz for rational braid-monoid lattice models
In this paper we study isotropic integrable systems based on the braid-monoid
algebra. These systems constitute a large family of rational multistate vertex
models and are realized in terms of the B_n, C_n and D_n Lie algebra and by the
superalgebra Osp(n|2m). We present a unified formulation of the quantum inverse
scattering method for many of these lattice models. The appropriate fundamental
commutation rules are found, allowing us to construct the eigenvectors and the
eigenvalues of the transfer matrix associated to the B_n, C_n, D_n,
Osp(2n-1|2), Osp(2|2n-2), Osp(2n-2|2) and Osp(1|2n) models. The corresponding
Bethe Ansatz equations can be formulated in terms of the root structure of the
underlying algebra.Comment: plain latex, 48 pages, 1 figure (under request
Bethe ansatz for the XXX-S chain with non-diagonal open boundaries
We consider the algebraic Bethe ansatz solution of the integrable and
isotropic XXX-S Heisenberg chain with non-diagonal open boundaries. We show
that the corresponding K-matrices are similar to diagonal matrices with the
help of suitable transformations independent of the spectral parameter. When
the boundary parameters satisfy certain constraints we are able to formulate
the diagonalization of the associated double-row transfer matrix by means of
the quantum inverse scattering method. This allows us to derive explicit
expressions for the eigenvalues and the corresponding Bethe ansatz equations.
We also present evidences that the eigenvectors can be build up in terms of
multiparticle states for arbitrary S.Comment: 62 page
DNA polymorphisms in Merino and Churra Lebrijana sheep breeds
The Merino and Churra Lebrijana ovine breeds are two of the most important sheeps developed in Spain. In the first case, the study of its genetic characteristics is justified by the importance it has have in the origin of other wool breeds. The Churra Lebrijana sheep breed is next the extinction therefore it is necessary to begin a conservation programme of its genetic resources.Las razas ovinas Merino y Churra son dos de las más importantes ovejas explotadas en España. En el primer caso, el estudio de sus características genéticas se justifica por la importancia que ha tenido en el origen de otras razas ovinas productoras de lana. La raza Churra Lebrijana se encuentra próxima a la extinción por lo que es necesario iniciar programas para la recuperación de sus recursos genéticos
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