The genomes and history of domestic animals

This paper reviews how mammalian genomes are utilized in modern genetics for the detection of genes and polymorphisms (mutations) within domesticated animal (mostly livestock) genomes that are related to traits of economic importance to humans. Examples are given of how genetic analysis allows to determine key genes associated with the quality and quantity of milk in cattle and key genes for meat production. Various questions are reviewed, such as how contemporary methods of genome sequencing allow to maximise the effective detection of coding and regulatory DNA polymorphisms within the genomes of major domesticated mammals (cattle, sheep and pigs) and the history of their formation from the standpoint of genetics

Search for conformal invariance in compressible two-dimensional turbulence

We present a search for conformal invariance in vorticity isolines of two-dimensional compressible turbulence. The vorticity is measured by tracking the motion of particles that float at the surface of a turbulent tank of water. The three-dimensional turbulence in the tank has a Taylor microscale $Re_\lambda \simeq 160$. The conformal invariance theory being tested here is related to the behavior of equilibrium systems near a critical point. This theory is associated with the work of L\"owner, Schramm and others and is usually referred to as Schramm-L\"owner Evolution (SLE). The system was exposed to several tests of SLE. The results of these tests suggest that zero-vorticity isolines exhibit noticeable departures from this type of conformal invariance

Localization and Interaction Effects in Strongly Underdoped La2-xSrxCuO4

The in-plane magnetoresistance (MR) in La2-xSrxCuO4 films with 0.03 < x < 0.05 has been studied in the temperature range 1.6 K to 100 K, and in magnetic fields up to 14 T, parallel and perpendicular to the CuO2 planes. The behavior of the MR is consistent with a predominant influence of interaction effects at high temperatures, switching gradually to a regime dominated by spin scattering at low T. Weak localization effects are absent. A positive orbital MR appears close to the boundary between the antiferromagnetic and the spin-glass phase, suggesting the onset of Maki-Thompson superconducting fluctuations deep inside the insulating phase.Comment: 4 pages, 3 figures, to appear in Phys. Rev. Letter

Nonlinear conduction of sliding electronic crystals: Charge and Spin Density Waves

A model of local metastable states due to the pinning induces plastic deformations allows to describe the nonlinear I-V curves in sliding density waves -DW. With increasing the DW velocity v, the metastable states of decreasing lifetimes ~1/v are accessed. The characteristic second threshold field is reached when configurations of shortest life time are accessed by the fast moving DW. Thus the DW works as a kind of a ``linear accelerator'' testing virtual states.Comment: To be published in Proceedings of ECRYS-99, J. de Physique, Coll., December 1999, http://ipnweb.in2p3.fr/~lptms/membres/brazov

Phase Separation in Bose-Fermi-Fermi Mixtures as a Probe of Fermi Superfluidity

We study the phase diagram of a mixture of Bose-Einstein condensate and a two-component Fermi gas. In particular, we identify the regime where the homogeneous system becomes unstable against phase separation. We show that, under proper conditions, the phase separation phenomenon can be exploited as a robust probe of Fermi superfluid

Disorder-induced superconductivity in ropes of carbon nanotubes

We study the interplay between disorder and superconductivity in a rope of metallic carbon nanotubes. Based on the time dependent Ginzburg Landau theory, we derive the superconducting transition temperature T$_c$ taking into account the critical superconducting fluctuations which are expected to be substantially strong in such low dimensional systems. Our results indicate that, contrary to what is expected, T$_c$ increases by increasing the amount of disorder. We argue that this behavior is due to the dynamics of the tubes which reduces the drastic effect of the local disorder on superconductivity by enhancing the intertube Josephson tunneling. We also found that T$_c$ is enhanced as the effective dimensionality of the rope increases by increasing the number N of the tubes forming the rope. However, T$_c$ tends to saturate for large values of N, expressing the establishment of a bulk three dimensional (3D) superconducting order.Comment: 9 pages, 4 figur

Controlling the Sign of Magnetoconductance in Andreev Quantum Dots

We construct a theory of coherent transport through a ballistic quantum dot coupled to a superconductor. We show that the leading-order quantum correction to the two-terminal conductance of these Andreev quantum dots may change sign depending on (i) the number of channels carried by the normal leads or (ii) the magnetic flux threading the dot. In contrast, spin-orbit interaction may affect the magnitude of the correction, but not always its sign. Experimental signatures of the effect include a non-monotonic magnetoconductance curve and a transition from an insulator-like to a metal-like temperature dependence of the conductance. Our results are applicable to ballistic or disordered dots.Comment: Final version (4pages 3figs)- improved presentation and fig 3, and updated reference

Criticality in inhomogeneous magnetic systems: Application to quantum ferromagnets

We consider a $\phi^4$-theory with a position-dependent distance from the critical point. One realization of this model is a classical ferromagnet subject to non-uniform mechanical stress. We find a sharp phase transition where the envelope of the local magnetization vanishes uniformly. The first-order transition in a quantum ferromagnet also remains sharp. The universal mechanism leading to a tricritical point in an itinerant quantum ferromagnet is suppressed, and in principle one can recover a quantum critical point with mean-field exponents. Observable consequences of these results are discussed.Comment: 4pp, 4 eps figs, contains additional information compared to PRL version. PRl, in pres