El gasto público: una reducción bien difícil

Así como a otros sectores de la economía se les suele medir su importancia económica a través de ciertos índices, lo mismo se puede realizar con el sector público. En efecto, con el fin de ofrecer una visión sintética y general del peso que tienen las finanzas públicas en el conjunto de la economía nacional, así como para efectos de comparaciones internacionales, se han elaborado varios indicadores de medición del sector público

A general approach for vitrification of fish sperm

The goal of this project was to develop streamlined protocols that could be integrated into a standardized approach for vitrification of germplasm for all aquatic species. Vitrification (freezing by formation of “glass” rather than crystalline ice) is simple, fast, inexpensive, can be potentially used to preserve samples in the field, and offers new options for germplasm management especially appropriate for small fishes. Sperm were studied from freshwater fish (channel catfish Ictalurus punctatus), viviparous freshwater fish (green swordtail Xiphophorus hellerii), and marine fishes (spotted seatrout Cynoscion nebulosus, red snapper Lutjanus campechanus, red drum Sciaenops ocellatus, and southern flounder Paralichthys lethostigma). To reduce toxicity, combinations of cryoprotectants at reduced concentrations with incorporation of trehalose and polymers were used to enhance glass formation. For freezing, samples were suspended on 10-µL polystyrene loops and plunged into liquid nitrogen. Thawing was done at 24ºC using Hanks’ balanced salt solution at 300 mOsmol/kg for freshwater species, and seawater at 1,020 mOsmol/kg for marine species. Quality after vitrification was evaluated by sperm motility, membrane integrity and when possible fertility. Post-thaw motility of sperm in marine fishes was higher (as high as 70%) than in freshwater fishes (as high as 20%). The percentage of membrane-intact sperm for marine fishes was ~20% except for southern flounder (11%). For freshwater fishes, the percentage of membrane-intact sperm for swordtail was low (\u3c12%) compared to channel catfish (~50%). Adaptations by marine fish to high osmotic pressures could explain the survival in the high cryoprotectant concentrations (40 – 60%) required for vitrification. This research yielded the first successful vitrification of sperm in these fishes and production of offspring from vitrified sperm in channel catfish, green swordtail, and southern flounder. Sperm vitrification offers an alternative approach to conventional cryopreservation for conservation of valuable genetic lineages, such as endangered species, model strains used in research, and improved farmed strains. Furthermore, sperm vitrification could be used to transport cryopreserved sperm from the field to the laboratory to expand genetic resources available for germplasm repositories. This technique could be utilized to reconstitute genetic lines, and as a new option for conservation biology in imperiled aquatic species

Notas sobre provincialismos

(En abril de este año se cumplió el centenario del nacimiento del General Rafael Uribe Uribe, ilustre colombiano que no sólo se destacó como conductor político y hombre de estado, sino que espigó también con éxito en la lingüística. La Revista para honrar la memoria del eminente caudillo ha recogido, seleccionándolas, algunas de las Notas que incluyó al final de su obra "Diccionario Abreviado de Galicismos, Provincialismos y Correcciones del Lenguaje", que se publicó en 1887 y no ha sido reimpreso, notas que son un decidido aporte lexicográfico para el idioma)

El gasto público: una reducción bien difícil

Así como a otros sectores de la economía se les suele medir su importancia económica a través de ciertos índices, lo mismo se puede realizar con el sector público. En efecto, con el fin de ofrecer una visión sintética y general del peso que tienen las finanzas públicas en el conjunto de la economía nacional, así como para efectos de comparaciones internacionales, se han elaborado varios indicadores de medición del sector público

Spin Weyl Topological Insulators

The quantum nature of electron spin is crucial for establishing topological invariants in real materials. Since the spin does not in general commute with the Hamiltonian, some of the topological features of the material can be extracted from its study. In insulating materials, the spin operator induces a projected operator on valence states called the spin valence operator. Its spectrum contains information with regard to the different phases of the spin Chern class. If the spin valence spectrum is gapped, the spin Chern numbers are constant along parallel planes thus defining spin Chern insulating materials. If the spin valence spectrum is not gapped, the changes in the spin Chern numbers occur whenever this spectrum is zero. Materials whose spin valence spectrum are gapless will be denoted spin Weyl topological insulators and its definition together with some of their properties will be presented in this work. The classification of materials from the properties of the spin valence operator provides a new characterization which complements the existing list of topological invariants.Comment: 12 pages, 6 figure

Antecedentes del Cabildo Abierto de 1810

Se trata de una sección del discurso pronunciado por el General Rafael Uribe Uribe ante la Academia de Historia. El discurso fue publicado en el número 14 del Registro Municipal del 31 de julio de 1933. p. 433-438. El texto usa las reglas ortográficas y gramaticales usadas en la época

Uniwap

WAPEATECH LTDA es una empresa que se dedica a la venta, desarrollo y mantenimiento de plataformas Wap, donde se busca optimizar los procesos que realizan los usuarios con el uso de herramientas tecnológicas que permiten la obtención de información y resultados en tiempo real. La empresa WAPEATECH LTDA. Se ubicará exactamente en el departamento de Risaralda en la ciudad de Pereira, entre las carreras 6 y 9 con calles 19 y 24, el lugar de trabajo constará de una oficina de 10 m x 12 m aproximadamente, El proyecto Uniwap de la empresa WAPEATECH, más que una herramienta tecnológica es una forma innovadora de acceder a los recursos que las universidades brindan a la comunidad, donde se puede visualizar datos de primera mano sobre consulta de notas, descarga de horarios, consulta de eventos, etc, desde cualquier lugar solo con la ayuda de un celular, sin necesidad de tener un equipo de computo a la mano. para tener un marco de cómo se encuentra nuestro mercado potencial, se realizó un estudio de aceptación en las tres universidades mas importantes de la ciudad de Pereira (Universidad Tecnológica de Pereira, Universidad Católica Popular de Risaralda y Universidad Libre Seccional Pereira), dando como resultado importantes datos que nos insinúan que la diferentes comunidades universitarias estarían de acuerdo en los servicios que WAPEATECH con su proyecto Uniwap prestarían, además es de resaltar que aunque muchos de las personas encuestadas no conocían esta tecnología vieron en ella una solución drástica a muchos de los problemas que a diario viven, lo que nos concluye que el proyecto Uniwap es viable. Cabe resaltar que nuestro proyecto en un principio está solamente dirigido a las universidades de la ciudad de Pereira, que serian en si nuestro mercado objetivo, pero con el pasar del tiempo y de los resultados, el proyecto es totalmente adaptable a otros entes de la sociedad, como lo serian entidades educativas de diferentes niveles de educación

Beyond Conus: Phylogenetic relationships of Conidae based on complete mitochondrial genomes

Understanding how the extraordinary taxonomic and ecological diversity of cone snails (Caenogastropoda: Conidae) evolved requires a statistically robust phylogenetic framework, which thus far is not available. While recent molecular phylogenies have been able to distinguish several deep lineages within the family Conidae, including the genera Profundiconus, Californiconus, Conasprella, and Conus (and within this one, several subgenera), phylogenetic relationships among these genera remain elusive. Moreover, the possibility that additional deep lineages may exist within the family is open. Here, we reconstructed with probabilistic methods a molecular phylogeny of Conidae using the newly sequenced complete or nearly complete mitochondrial (mt) genomes of the following nine species that represent all main Conidae lineages and potentially new ones: Profundiconus teramachii, Californiconus californicus, Conasprella wakayamaensis, Lilliconus sagei, Pseudolilliconus traillii, Conus (Kalloconus) venulatus, Conus (Lautoconus) ventricosus, Conus (Lautoconus) hybridus, and Conus (Eugeniconus) nobilis. To test the monophyly of the family, we also sequenced the nearly complete mt genomes of the following three species representing closely related conoidean families: Benthomangelia sp. (Mangeliidae), Tomopleura sp. (Borsoniidae), and Glyphostoma sp. (Clathurellidae). All newly sequenced conoidean mt genomes shared a relatively constant gene order with rearrangements limited to tRNA genes. The reconstructed phylogeny recovered with high statistical support the monophyly of Conidae and phylogenetic relationships within the family. The genus Profundiconus was placed as sister to the remaining genera. Within these, a clade including Californiconus and Lilliconus + Pseudolilliconus was the sister group of Conasprella to the exclusion of Conus. The phylogeny included a new lineage whose relative phylogenetic position was unknown (Lilliconus) and uncovered thus far hidden diversity within the family (Pseudolilliconus). Moreover, reconstructed phylogenetic relationships allowed inferring that the peculiar diet of Californiconus based on worms, mollusks, crustaceans and fish is derived, and reinforce the hypothesis that the ancestor of Conidae was a worm hunter. A chronogram was reconstructed under an uncorrelated relaxed molecular clock, which dated the origin of the family shortly after the Cretaceous-Tertiary boundary (about 59 million years ago) and the divergence among main lineages during the Paleocene and the Eocene (56–30 million years ago).This work was supported by the Spanish Ministry of Science and Innovation – Spain (CGL2010-18216 and CGL2013-45211-C2-2-P to RZ; BES-2011-051469 to JEU),Peer Reviewe

On quasi-nodal spheres and the spin Hall effect: the case of YH3 and CaTe

Band inversion is a known feature in a wide range of topological insulators characterized by a change of orbital type around a high-symmetry point close to the Fermi level. In some cases of band inversion in topological insulators, the existence of quasinodal spheres has been detected, and the change of orbital type is shown to be concentrated along these spheres in momentum space. To understand this phenomenon, we develop a local effective fourfold Hamiltonian that models the band inversion and reproduces the quasinodal sphere. This model shows that the signal of the spin Hall conductivity, as well as the change of orbital type, are both localized on the quasinodal sphere, and moreover, that these two indicators characterize the topological nature of the material. Using K-theoretical methods, we show that the change of orbital type parametrized by an odd clutching function is equivalent to the strong Fu-Kane-Mele invariant. We corroborate these results with ab initio calculations for the materials YH3 and CaTe, where in both cases the signal of the spin Hall conductivity is localized on the quasinodal spheres in momentum space. We conclude that a nontrivial spin Hall conductivity localized on the points of change of orbital type is a good indicator for topological insulation.Comment: 10 pages, 5 figure