sister underwent cardiac arrest as well.Family workup revealed asymptomatic parents and siblings, of which one had a positive stress test with multifocal premature ventricular contractions (PVCs).Gly3118Arg missense mutation was found in RYR2 with typical recessive segregation: The affected members are homozygous for the mutation whereas the non-affected parents and siblings are heterozygous (figure).This variant was only once described, and classified as variant of uncertain significance.It was not found in 60,000 sequenced genomes from unrelated individuals' database and is located in an area which is conserved in evolution.In the RYR2 protein the mutation is located in the cytosolic component of the RYR2 outside the areas with frequent cluster mutations.The three affected members underwent ICD implantation and have been receiving metoprolol therapy.During nine years of follow up the female had an episode of multiple ventricular fibrillation episodes and shocks (figure).The Metoprolol dose was increased and no further episodes occurred.Conclusion: This is a first report of an RYR2 variant and autosomal recessive CPVT1.It suggests different or a less severe mechanism for the disruption of RYR2 function.

The phase diagram of the double perovskites of the type Sr_2-x La_x Fe Mo O_6 is analyzed, with and without disorder due to antisites. In addition to an homogeneous half metallic ferrimagnetic phase in the absence of doping and disorder, we find antiferromagnetic phases at large dopings, and other ferrimagnetic phases with lower saturation magnetization, in the presence of disorder.

A Curie temperature enhancement in heterogeneous nanostructured materials with two Curie temperatures has been found. Two kinds of systems have been studied: nanocrystalline materials, consisting of α-Fe nanocrystals and an amorphous interphase, and multilayers composed of two different ferromagnetic metals. In FeBNbCu nanocrystalline alloy it has been observed that the Curie temperature of the intergranular amorphous region is greatly enhanced with respect to that of amorphous ribbons of the same composition, reaching this increase a value of 125 °C. Multilayers of NiCo and NiAg have been grown because of its simpler geometry. The Curie temperature of the Ni layers experiments a maximum increase of 75 °C, when Ni is located between Co layers. The effect depends mainly on the average separation between higher Curie temperature phases. A compositional gradient has been suggested to explain this temperature behaviour. The authors agree with its influence but consider it insufficient to account for such large temperature differences. We propose as a possible explanation a slight penetration of the exchange field of the higher Curie temperature phase. The great area occupied by ferromagnetic interfaces favours the induction of magnetization into the amorphous matrix or into the Ni layers, even above their Curie temperature.

Extraordinary magnetoresistance factors are reported in Co/Ni sputtered multilayers. Magnetic softness, large anisotropic magnetoresistance and a special contacts configuration give rise to magnetoresistance factors as large as 120% at room temperature and under an applied field of 40 Oe.

Anisotropic magnetoresistance in Ni is found to increase abruptly when Co impurity layers are inserted. Some experiments carried out in different Ni/Co multilayers indicate that interfaces are responsible for the magnetoresistance enhancement.

We study the relation between the Roma and Zaragoza proposals for chiral fermions on the lattice. The fermion action in the Roma approach is shown to be equivalent to one of the Zaragoza type. This result is used to perform a mean-field study of the phase diagram for chiral Yukawa models based on the Roma action. The phase diagram is compared with the one based on the Zaragoza model with the most local choice for the fermion interactions.

We study the relation between the Roma and Zaragoza proposals for chiral fermions on the lattice. The fermion action in the Roma approach is shown to be equivalent to one of the Zaragoza type. This result is used to perform a mean-field study of the phase diagram for chiral Yukawa models based on the Roma action. The phase diagram is compared with the one based on the Zaragoza model with the most local choice for the fermion interactions.

The Roma and Zaragoza actions for chiral fermions on the lattice are shown to be essentially equivalent. The auxiliary fermion fields in the Roma model can be integrated out, and the resulting action is a special case of the Zaragoza approach.We use this result to perform a mean-field study of the phase diagram of chiral Yukawa models in the Roma formulation.

Extraordinary magnetoresistance effect has been found in Ni/Co sputtered multilayers. Magnetoresistance values higher than 130% are achieved at room temperature with a saturation magnetic field of 35 Oe, using a particular arrangement of contacts. The large anisotropic magnetoresistance and the low coercivity of these samples are the origin of such an outstanding property. The results reported here seem to have promising applications in magnetoresistive devices.

We study the relation between the Roma and Zaragoza proposals for chiral fermions on the lattice. The fermion action in the Roma approach is shown to be equivalent to the one of the Zaragoza type. This result is used to perform a mean-field study of the phase diagram for chiral Yukawa models based on the Roma action. The phase diagram is compared with the one based on the Zaragoza model with the most local choice for the fermion interactions.

We present a calculation of the phase diagram of a SU(2) × SU(2) chiral Yukawa model with massless decoupled doublers, using a saddle point approach, both for small and large Yukawa coupling. Some preliminary MonteCarlo results are also known.

Using the Zaragoza proposal for lattice chiral gauge fermions, the S, U and DELTArho parameters have been calculated at one loop. It is shown that the continuum values for these quantities can be reproduced without requiring explicit fine tuning of counterterms. Furthermore, fermion fields doubling is not necessary. To the best of our knowledge, the Zaragoza proposal is the only scheme which has these properties.

We simulate the U(1)-Higgs lattice model with fixed Higgs modulus, in the region where the transition between the Higgs and Confining phases disappears. We find a first order transition line that ends in a second order point. Thermodynamic magnitudes and their associated critical exponents are introduced. The measured data allow us to fit the critical exponents finding values in agreement with the mean field prediction. The location of the critical point and the slope of the first order line are accurately given.

We study SU(2) lattice gauge theory in small volumes and with twist m = (1, 1, 1). We investigate the presence of the periodic instantons of Q = 12 and determine their free energy and their contribution to the splitting of energy flux sectors E(e = (1, 1, 1)) − E(e = (0, 0, 0)).

We study numerically the critical properties of the U(1)-Higgs lattice model, with fixed Higgs modulus, in the region of small gauge coupling where the Higgs and confining phases merge. We find evidence for a first-order transition line that ends in a second-order point. By means of a rotation in parameter space we introduce thermodynamic magnitudes and critical exponents in close resemblance with simple models that show analogous critical behaviour. The measured data allow us to fit the critical exponents finding values in agreement with the mean-field prediction. The location of the critical point and the slope of the first-order line are accurately measured.

We simulate the compact U(1)-Higgs model in a four-dimensional lattice. We present a numerical study for the behaviour around the region where the transition between the confining and Higgs phases disappears. The transition line is found to be first order and to end in a second-order point. We measure the critical exponents of the endpoint obtaining the mean field ones within errors.