Spontaneous mass generation and the small dimensions of the Standard Model gauge groups U(1), SU(2) and SU(3)

The gauge symmetry of the Standard Model is SU(3)_c x SU(2)_L x U(1)_Y for unknown reasons. One aspect that can be addressed is the low dimensionality of all its subgroups. Why not much larger groups like SU(7), or for that matter, SP(38) or E7? We observe that fermions charged under large groups acquire much bigger dynamical masses, all things being equal at a high e.g. GUT scale, than ordinary quarks. Should such multicharged fermions exist, they are too heavy to be observed today and have either decayed early on (if they couple to the rest of the Standard Model) or become reliquial dark matter (if they don't). The result follows from strong antiscreening of the running coupling for those larger groups (with an appropriately small number of flavors) together with scaling properties of the Dyson-Schwinger equation for the fermion mass.Comment: 15 pages, 17 plots. This version incorporates community as well as referee comments. Accepted for publication in Nuclear Physics

Numerical test of the Cardy-Jacobsen conjecture in the site-diluted Potts model in three dimensions

We present a microcanonical Monte Carlo simulation of the site-diluted Potts model in three dimensions with eight internal states, partly carried out in the citizen supercomputer Ibercivis. Upon dilution, the pure model's first-order transition becomes of the second-order at a tricritical point. We compute accurately the critical exponents at the tricritical point. As expected from the Cardy-Jacobsen conjecture, they are compatible with their Random Field Ising Model counterpart. The conclusion is further reinforced by comparison with older data for the Potts model with four states.Comment: Final version. 9 pages, 9 figure

Systematics and diversity of Neotropical ants.

With a long history of more than 100 million years and about 14,000 described living species, ants are one of the most important and well-known groups of insects in the world. Ants are key elements in the structure and dynamics of terrestrial systems, especially in the tropics, as well as models in studies of evolution, ecology, and monitoring of disturbed ecosystems. For all this, it is essential to know their history and phylogeny, in order among other things, to have a solid base for their systematics and taxonomy. Within Aculeata ants appear to be the sister group of Apoidea, and the ancestor of the Formicidae may have inhabited the northern hemisphere during the early Cretaceous. Since then, and especially since the Eocene, ants have spread throughout the planet, occupying almost all environments from forests to deserts. The Neotropical region has 137 genera and around 3,100 species of ants. The Neotropics seem to have been the “cradle” and “museum” of the groups of ants, which would explain their great diversity and a high degree of endemisms. This review describes the current state of knowledge of ants in the Neotropical region from a systematic point of view, with a synopsis of all supraspecific taxa described to date. Critical genera, problems to be solved, and perspectives for the study of these insects are also presented

Microcanonical finite-size scaling in specific heat diverging 2nd order phase transitions

A Microcanonical Finite Site Ansatz in terms of quantities measurable in a Finite Lattice allows to extend phenomenological renormalization (the so called quotients method) to the microcanonical ensemble. The Ansatz is tested numerically in two models where the canonical specific-heat diverges at criticality, thus implying Fisher-renormalization of the critical exponents: the 3D ferromagnetic Ising model and the 2D four-states Potts model (where large logarithmic corrections are known to occur in the canonical ensemble). A recently proposed microcanonical cluster method allows to simulate systems as large as L=1024 (Potts) or L=128 (Ising). The quotients method provides extremely accurate determinations of the anomalous dimension and of the (Fisher-renormalized) thermal $\nu$ exponent. While in the Ising model the numerical agreement with our theoretical expectations is impressive, in the Potts case we need to carefully incorporate logarithmic corrections to the microcanonical Ansatz in order to rationalize our data.Comment: 13 pages, 8 figure

Leveraging on Digital Signage Networks to Bring Connectivity IOT Devices

The number of Internet-connected devices exceeds the world’s population by more than three times and this figure is expected to be doubled within the next five years. The Internet of Things is a concept that describes this trend and outlines certain aspects of design and functionality that new devices should incorporate for a successful integration into the Internet. In this respect, Digital Signage networks traditionally used for audiovisual media, accomplish many of the characteristics of the Internet of Things devices: interoperability, mobility, scalability and ubiquity, both in terms of access and control of devices and regarding the information they generate. This paper raises the power to employ a proposed Digital Signage network as a substrate to connect other types of devices that can benefit from the advantages of this kind of networks. For that aim, the main problems for this integration are discussed, mainly those related to the bidirectional tunneling scheme used in the proposed Digital Signage solution. The effects of this tunneling approach are analyzed in scenarios with bandwidth constraints, and different solutions are proposed. Tunneling performance in mobility is improved, to increase the amount of Internet of Things devices and applications that can benefit from this type of network. El número de dispositivos conectados a Internet supera actualmente a la población mundial por más de tres veces y se espera que esta cifra se duplique en los próximos cinco años. El Internet de las Cosas es un concepto que describe esta tendencia y perfila ciertos aspectos de diseño y funcionalidad que los nuevos dispositivos deben incorporar para lograr una integración exitosa en Internet. En este sentido, las redes digital signage utilizadas tradicionalmente para los medios de comunicación audiovisual cumplen muchas de las características requeridas en el contexto del Internet de las Cosas: interoperabilidad, movilidad, escalabilidad y ubicuidad; relativas tanto al acceso y control de dispositivos como a la información que estos generan. En este trabajo se plantea el poder de emplear la red digital signage propuesta como sustrato para poder conectar otros tipos de dispositivos para que así puedan aprovechar las ventajas de estas redes. Para ese fin, se discuten los principales problemas existentes en esta integración, prestando especial atención al esquema de túnel bidireccional utilizado en la solución digital signage propuesta. Los efectos de este enfoque de tunelación se analizan en escenarios con limitaciones de ancho de banda y se proponen diferentes soluciones. Con ello se consigue mejorar el rendimiento del túnel en movilidad, facilitando la integración de más dispositivos al Internet de las Cosas al permitir que puedan integrarse en este tipo de redes

HSF1: Primary Factor in Molecular Chaperone Expression and a Major Contributor to Cancer Morbidity

Heat shock factor 1 (HSF1) is the primary component for initiation of the powerful heat shock response (HSR) in eukaryotes. The HSR is an evolutionarily conserved mechanism for responding to proteotoxic stress and involves the rapid expression of heat shock protein (HSP) molecular chaperones that promote cell viability by facilitating proteostasis. HSF1 activity is amplified in many tumor contexts in a manner that resembles a chronic state of stress, characterized by high levels of HSP gene expression as well as HSF1-mediated non-HSP gene regulation. HSF1 and its gene targets are essential for tumorigenesis across several experimental tumor models, and facilitate metastatic and resistant properties within cancer cells. Recent studies have suggested the significant potential of HSF1 as a therapeutic target and have motivated research efforts to understand the mechanisms of HSF1 regulation and develop methods for pharmacological intervention. We review what is currently known regarding the contribution of HSF1 activity to cancer pathology, its regulation and expression across human cancers, and strategies to target HSF1 for cancer therapy.Fil: Prince, Thomas L.. Geisinger Clinic. Department of Molecular Functional Genomics; Estados UnidosFil: Lang, Benjamin J.. Harvard Medical School; Estados UnidosFil: Guerrero Gimenez, Martin Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Fernandez Muñoz, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Ackerman, Andrew. Geisinger Clinic. Department of Molecular Functional Genomics; Estados UnidosFil: Calderwood, Stuart K.. Harvard Medical School; Estados Unido