Spontaneous symmetry breaking as a resource for noncritically squeezed light

In the last years we have proposed the use of the mechanism of spontaneous symmetry breaking with the purpose of generating perfect quadrature squeezing. Here we review previous work dealing with spatial (translational and rotational) symmetries, both on optical parametric oscillators and four-wave mixing cavities, as well as present new results. We then extend the phenomenon to the polarization state of the signal field, hence introducing spontaneous polarization symmetry breaking. Finally we propose a Jaynes-Cummings model in which the phenomenon can be investigated at the single-photon-pair level in a non-dissipative case, with the purpose of understanding it from a most fundamental point of view.Comment: Review for the proceedings of SPIE Photonics Europe. 11 pages, 5 figures

Domain wall dynamics in an optical Kerr cavity

An anisotropic (dichroic) optical cavity containing a self-focusing Kerr medium is shown to display a bifurcation between static --Ising-- and moving --Bloch-- domain walls, the so-called nonequilibrium Ising-Bloch transition (NIB). Bloch walls can show regular or irregular temporal behaviour, in particular, bursting and spiking. These phenomena are interpreted in terms of the spatio-temporal dynamics of the extended patterns connected by the wall, which display complex dynamical behaviour as well. Domain wall interaction, including the formation of bound states is also addressed.Comment: 15 pages Tex file with 11 postscript figures. Resubmitted to Phys. Rev.

Targeted DNA demethylation in human cells by fusion of a plant 5-methylcytosineDNA glycosylase to a sequence-specific DNA binding domain

DNA methylation is a crucial epigenetic mark associated to gene silencing, and its targeted removal is amajor goal of epigenetic editing. In animal cells, DNA demethylation involves iterative 5mC oxidation byTET enzymes followed by replication-dependent dilution and/or replication-independent DNA repair of itsoxidized derivatives. In contrast, plants use specific DNA glycosylases that directly excise 5mC and initiateits substitution for unmethylated C in a base excision repair process. In this work, we have fused thecatalytic domain ofArabidopsisROS1 5mC DNA glycosylase (ROS1_CD) to the DNA binding domain ofyeast GAL4 (GBD). We show that the resultant GBD-ROS1_CD fusion protein binds specifically a GBD-targeted DNA sequencein vitro. We also found that transientin vivoexpression of GBD-ROS1_CD inhuman cells specifically reactivates transcription of a methylation-silenced reporter gene, and that suchreactivation requires both ROS1_CD catalytic activity and GBD binding capacity. Finally, we show thatreactivation induced by GBD-ROS1_CD is accompanied by decreased methylation levels at several CpGsites of the targeted promoter. All together, these results show that plant 5mC DNA glycosylases can beused for targeted active DNA demethylation in human cells

DISEÑO DE ESTRATEGIAS QUE PERMITAN DETERMINAR LA EXCELENCIA DEL SERVICIO AL CLIENTE PRESTADO POR PARTE DE LOS COLABORADORES DEL BANCO CAJA SOCIAL OFICINA SOLEDAD, DURANTE EL I SEMESTRE DEL AÑO 2013

The project entitled "Design strategies to determine the excellence of customer service provided by the staff of Banco Caja Social Soledad office, during the first half of 2013", was established due to the need to know whether customers office above, are satisfied with the care or service provided by the partners of this entity, if the products offered fill all your financial expectations. That is why the project is designed to determine if customers find a high degree of satisfaction with the service and the product that is being offered and whether Bank employees are complying with the rules and policies established in the state, aimed at providing excellent customer service. Databases will take to implement the CRM customer assets, and inactive users, generate a high level of brand recall among people who visit, in order to attract more customers and increasing our customer base office, to generate much more uptake and profitability. This project will benefit both customers and employees the Bank as to the extent that employees provide excellent customer service and meet their financial needs more investment and business opportunities, getting mutual benefit.El proyecto titulado ― Diseño de estrategias que permitan determinar la excelencia del Servicio al Cliente prestado por parte de los colaboradores del Banco Caja Social oficina Soledad, durante el I semestre del año 2013‖, se estableció debido a la necesidad de conocer si los clientes de la oficina antes mencionada, se encuentran satisfechos con la atención o el servicio prestado por parte de los colaboradores de esta entidad, si los productos ofrecidos llenan todas sus expectativas financieras. Por ello es que el proyecto va encaminado a determinar si los clientes encuentran un alto grado de satisfacción en el servicio y el producto que se le está ofreciendo y si los colaboradores del Banco están cumpliendo con las normas y políticas establecidas en la entidad, encaminada a brindar un excelente Servicio al Cliente. Tomaremos bases de datos para implementar el CRM de los clientes activos, inactivos y usuarios, generar un alto nivel de recordación de la marca entre las personas que lo visitan, con el fin de atraer la mayor cantidad de clientes y aumentando los clientes Base de nuestra oficina, con el fin de generar mucha más captación y rentabilidad. 5 Con este proyecto se beneficiaran tanto clientes como los empleados el Banco, ya que en la medida en que los colaboradores presten un excelente servicio y los clientes satisfagan sus necesidades financieras aumentaran las inversiones y oportunidades de negocio, recibiendo un mutuo beneficio

Active DNA demethylation in plants

Methylation of cytosine (5-meC) is a critical epigenetic modification in many eukaryotes, and genomic DNA methylation landscapes are dynamically regulated by opposed methylation and demethylation processes. Plants are unique in possessing a mechanism for active DNA demethylation involving DNA glycosylases that excise 5-meC and initiate its replacement with unmodified C through a base excision repair (BER) pathway. Plant BER-mediated DNA demethylation is a complex process involving numerous proteins, as well as additional regulatory factors that avoid accumulation of potentially harmful intermediates and coordinate demethylation and methylation to maintain balanced yet flexible DNA methylation patterns. Active DNA demethylation counteracts excessive methylation at transposable elements (TEs), mainly in euchromatic regions, and one of its major functions is to avoid methylation spreading to nearby genes. It is also involved in transcriptional activation of TEs and TE-derived sequences in companion cells of male and female gametophytes, which reinforces transposon silencing in gametes and also contributes to gene imprinting in the endosperm. Plant 5-meC DNA glycosylases are additionally involved in many other physiological processes, including seed development and germination, fruit ripening, and plant responses to a variety of biotic and abiotic environmental stimuli