202 research outputs found
Stability of Stationary Solutions of Extended Reaction-Diffusion-Convection Equations on a Finite Segment
A simple geometric criterion on the linear stability of stationary solutions of nonlinear second order parabolic equations on a finite segment is stated and proved
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
Caracterización genética preliminar del cerdo criollo cubano utilizando microsatélites
En este trabajo se pretende caracterizar genéticamente el cerdo Criollo Cubano para conocer su actual estado. Se analizaron 93 muestras de esta raza, con representación de animales entrepelados y lampiños, procedentes de varias provincias del país. Se han empleado 20 microsatélites de los recomendados por la FAO/ ISAG (International Society of Animal Genetics) para estudios de biodiversidad porcina. Todos los microsatélites utilizados han resultado polimórficos y se han encontrado entre 4 alelos para el S0227 y 12 para el S0068, con un número medio de alelos de 8,2. La heterocigosidad media esperada ha sido 0,6535 y la observada 0,6335. Los valores del PIC oscilaron entre 0,23 y 0,83 para los loci S0227 y S0068 respectivamente. Estos resultados permiten concluir que la raza manifiesta una adecuada diversidad genética
Genetic characterisation of the cuban creole pig with microsatellites
In this work the Criollo Cubano pig has been characterised to know how the breed is and to know the genetic relationships with the main varieties of the Iberian pig calculating genetic distances. It have been studied 93 animals of the Criollo Cubano pig breed belonging to the Entrepelado and Lampiño varieties. 20 microsatellites recommended by ISAG for porcine biodiversity studies. 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 4 (S0227) and 12 (S0068) alleles have been found with an average value of 8.2. The expected heterozigosity has been 0.6535 and the observed heterozigosity 0.6335. The Nei"s Ds genetic distance between the Criollo Cubano and the Iberian pig has been calculated and an UPGMA tree has been built. Finally, distances between pairs of individuals (Dsa) have been calculated and an UPGMA individual tree has been built.En este trabajo caracteriza genéticamente el cerdo Criollo Cubano para conocer el estado en que se encuentra esta raza porcina, a la vez que se establecen las relaciones genéticas del mismo con las variedades principales del cerdo Ibérico mediante el cálculo de distancias genéticas. Se han analizado 93 muestras de cerdo Criollo Cubano pertenecientes a las variedades Entrepelado y Lampiño procedentes de la provincia de Granma y de La Habana (Cuba). Se han empleado 20 microsatélites de los recomendados por la FAO/ISAG (International Society of Animal Genetics) para estudios de biodiversidad porcina. 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 tipificados han resultado polimórficos y se han encontrado entre 4 alelos para el S0227 y 12 para el S0068, con un número medio de alelos de 8,2. La heterocigosidad media esperada ha sido 0,6535 y la observada 0,6335. Se ha calculado la distancia genética DS de Nei entre el cerdo Criollo Cubano y el cerdo Ibérico y se ha construido un árbol de distancias mediante el método de UPGMA. Por último, se han calculado las distancias entre pares de individuos (DSA) y con ellas se ha construido un árbol filogenético individual basado en el algoritmo UPGMA
The Inverse Scattering Method, Lie-Backlund Transformations and Solitons for Low-energy Effective Field Equations of 5D String Theory
In the framework of the 5D low-energy effective field theory of the heterotic
string with no vector fields excited, we combine two non-linear methods in
order to construct a solitonic field configuration. We first apply the inverse
scattering method on a trivial vacuum solution and obtain an stationary
axisymmetric two-soliton configuration consisting of a massless gravitational
field coupled to a non-trivial chargeless dilaton and to an axion field endowed
with charge. The implementation of this method was done following a scheme
previously proposed by Yurova. We also show that within this scheme, is not
possible to get massive gravitational solitons at all. We then apply a
non-linear Lie-Backlund matrix transformation of Ehlers type on this massless
solution and get a massive rotating axisymmetric gravitational soliton coupled
to axion and dilaton fields endowed with charges. We study as well some
physical properties of the constructed massless and massive solitons and
discuss on the effect of the generalized solution generating technique on the
seed solution and its further generalizations.Comment: 17 pages in latex, changed title, improved text, added reference
Kinks in the Hartree approximation
The topological defects of the lambda phi^4 theory, kink and antikink, are
studied in the Hartree approximation. This allows us to discuss quantum effects
on the defects in both stationary and dynamical systems. The kink mass is
calculated for a number of parameters, and compared to classical, one loop and
Monte Carlo results known from the literature. We discuss the thermalization of
the system after a kink antikink collision. A classical result, the existence
of a critical speed, is rederived and shown for the first time in the quantum
theory. We also use kink antikink collisions as a very simple toy model for
heavy ion collisions and discuss the differences and similarities, for example
in the pressure. Finally, using the Hartree Ensemble Approximation allows us to
study kink antikink nucleation starting from a thermal (Bose Einstein)
distribution. In general our results indicate that on a qualitative level there
are few differences with the classical results, but on a quantitative level
there are some import ones.Comment: 20 pages REVTeX 4, 17 Figures. Uses amsmath.sty and subfigure.sty.
Final version, fixed typo in published versio
Plane waves with weak singularities
We study a class of time dependent solutions of the vacuum Einstein equations
which are plane waves with weak null singularities. This singularity is weak in
the sense that though the tidal forces diverge at the singularity, the rate of
divergence is such that the distortion suffered by a freely falling observer
remains finite. Among such weak singular plane waves there is a sub-class which
do not exhibit large back reaction in the presence of test scalar probes.
String propagation in these backgrounds is smooth and there is a natural way to
continue the metric beyond the singularity. This continued metric admits string
propagation without the string becoming infinitely excited. We construct a one
parameter family of smooth metrics which are at a finite distance in the space
of metrics from the extended metric and a well defined operator in the string
sigma model which resolves the singularity.Comment: 22 pages, Added references and clarifying comment
Second-order corrections to mean field evolution for weakly interacting Bosons. I
Inspired by the works of Rodnianski and Schlein and Wu, we derive a new
nonlinear Schr\"odinger equation that describes a second-order correction to
the usual tensor product (mean-field) approximation for the Hamiltonian
evolution of a many-particle system in Bose-Einstein condensation. We show that
our new equation, if it has solutions with appropriate smoothness and decay
properties, implies a new Fock space estimate. We also show that for an
interaction potential , where is
sufficiently small and , our program can be easily
implemented locally in time. We leave global in time issues, more singular
potentials and sophisticated estimates for a subsequent part (part II) of this
paper
Forage yield of Urochloa cultivars in a warm sub-humid environment
Objective: Evaluate for 10 weeks the growth of five Urochloa cultivars: Camello, Cobra, Cayman, Convert 330, Mavuno and Xaraés; during the Nortes (NS), Drought (DS) and Rainy (RS) seasons in a humid semi-warm environment.
Design/methodology/approach: Variables were crop growth rate (CGR; kg ha-1 d-1) and total dry matter yield (TDM; t ha-1); which were analyzed under a completely randomized design (Tukey; p=0.05).
Results: During NS, Mavuno and Xaraés presented, on average, the highest values ??of CGR (p<0.05), 23.7 and 19.4 kg ha-1 d-1, respectively. In DS the cultivars Xaraés, Convert 330, Mavuno and Cayman, presented the highest values, with 20.7 and 26.8 kg ha-1 d-1, in week 2 and 4, respectively. During RS, in the second and fourth week of regrowth, the Xaraés and Mavuno cultivars presented the highest CGR (p<0.05), 119.8 and 144.7 kg ha-1 d-1, on average. In the NS, the Mavuno hybrid presented the highest yields (p<0.05) of TDM, 0.886, 1.553 and 2.156 t ha-1 in week 6, 8 and 10, respectively. For RS, the cultivars Camello, Cayman, Mavuno and Xaraés presented similar yields of TDM; which, on average, were 4.652, 5.312 and 6.278 t ha-1, at 6, 8 and 10 weeks, respectively.
Findings/conclusions: The cultivars Xaraés, Mavuno and Cayman presented good forage potential in a humid semi-warm environment; mainly for showing greater growth and accumulation of total dry matter.Objective: To evaluate for 10 weeks the growth of five Urochloa cultivars: Camello,Cobra, Cayman, Convert 330, Mavuno and Xaraés; during the North Winds (NS), Dry(DS) and Rainy (RS) seasons in a warm sub-humid environment.
Design/Methodology/Approach: The variables were crop growth rate (CGR; kg ha-1 d-1 ) and total dry matter yield (TDM; t ha -1 ); which were analyzed under a completelyrandomized design (Tukey; p=0.05).
Results: During NS, Mavuno and Xaraés presented, on average, the highest values ??ofCGR (p&lt;0.05), 23.7 and 19.4 kg ha-1 d-1, respectively. In DS the cultivars Xaraés,2Convert 330, Mavuno, and Cayman presented the highest values, with 20.7 and 26.8 kgha-1 d-1 , in week 2 and 4, respectively. During RS, in the second and fourth week ofregrowth, the Xaraés and Mavuno cultivars presented the highest CGR (p&lt;0.05), 119.8and 144.7 kg ha-1 d-1 , on average. In the NS, the Mavuno hybrid presented the highestyields (p&lt;0.05) of TDM, 0.886, 1.553 and 2.156 t ha -1 in week 6, 8 and 10, respectively.For RS, the cultivars Camello, Cayman, Mavuno, and Xaraés presented similar yields ofTDM; which, on average, were 4.652, 5.312 and 6.278 t ha -1 , at 6, 8 and 10 weeks,respectively.
Findings/Conclusions: The cultivars Xaraés, Mavuno and Cayman presented goodforage potential in a warm sub-humid environment; mainly for showing greater growthand accumulation of total dry matter
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