5,159 research outputs found
-Flavour Violation at the LHC
We study the conditions required for
decays to yield observable tau flavour violation at the LHC, for cosmologically
interesting values of the neutralino relic density. These condition can be
achieved in the framework of a SU(5) model with a see-saw mechanism that allows
a possible coexistence of a LHC signal a low prediction for radiative LFV
decays.Comment: 7 pages, 5 figures, Prepared for the proceedings of the workshop:
"LC09: Physics at the TeV Scale and the Dark Matter Connection",
21-24 September 2009, Perugia, Ital
Assessing Insect Flight Behavior in the Laboratory: A Primer on Flight Mill Methodology and What Can Be Learned
Dispersal is a key component in the population ecology and dynamics of insects and remains one of the most difficult and intractable ecological processes to study in the field. As a consequence, many researchers have looked to laboratory methods for investigating the myriad factors that govern and impact an insect’s ability to move within its environment. A key tool in this effort since at least the early 1950s has been the insect flight mill. Nearly 260 studies have been published using flight mills covering 214 species in 61 families and 9 orders. This review explores the methodology and technology of tethered flight in insects using flight mills. The goal is to provide the reader with a historical context of the approach, an understanding of the available tools and technology, background on how best to apply these tools through a comparative lens, and to summarize the wide breadth of factors that have been explored to further our knowledge of insect flight behavior. Overall, it is hoped that the interested reader will understand the limits and benefits of flight mills and will know where to find the resources, and perhaps collaborators, to pursue this line of study
Bailouts in Costa Rica as a Result of Government Centralization and Discretionary Transfers
This paper investigates the inter-relation between the central government and the municipalities in Costa Rica. It examines episodes in which the central government has bailed out the local governments from their obligations. We employ empirical and descriptive methods to show how discretionary grants relate to the degree of fiscal discipline of the municipality to produce hidden bailouts. Political, demographic, and economic variables explain the allocation of these discretionary transfers. We illustrate the effects of the high concentration of decision-making of the central government on the fiscal performance of the municipalities. The municipalities play a limited role and its functioning largely depends upon the central government. We argue that the national administration would face a high political cost if it did not bail out the local government in several of the episodes studied. Using panel data from 1982-1997 on 81 cantones, we find that the fiscal effort of the local government is reduced by the presence of discretionary grants. The local governments finance local expenses with these discretionary transfers according to our empirical results. As expected from the centralization issue, political variables such as the affiliation of the local administration have significant effects on the resources received by the municipalities.
Diseño y Optimización del tamaño de grano triturado para alimentación avícola para criaderos y suministro de balanceado/Design and Optimization of crushed grain size for poultry feed for hatcheries and supply of balanced
En la investigación se diseñó, modeló y mejoró un molino de martillo económico y accesible aplicando métodos lógicos deductivos, la máquina provee un tamaño de grano ideal, que sirve como alimentación directa para aves, o también se puede utilizar como un componente para balanceado en la producción avícola, acorde a los requerimientos de las distintas pymes ya sea para consumo cárnico, producción de huevos, entre otros. Por esta razón es necesario definir distintos parámetros como el tamaño adecuado del tamiz teniendo una variedad desde los 2mm hasta los 5 mm, cuchillas, selección adecuada del motor dependiendo de la cantidad de horas por día, para esto se realizó un análisis mecánico y dinámico de los distintos elementos de la máquina mediante simulación en el software Solidworks free students, luego de tener el dimensionamiento óptimo bajo parámetros ingenieriles de cada una de las partes de la máquina, se realizó una cotización de los materiales bajo consideración económica en el que fue necesario realizar una correcta selección de los mismo elementos basados en catálogos nacionales para que la maquina sea rentable y accesible a los micro productores así como a los mayoristas, una vez considerado todo el procedimiento se construyó la máquina con un costo final de 355,39 dólares americanos, siendo esta de fácil desmontaje, mantenimiento y aplicación para la sociedad, el cual permite la reducción de costos, tiempos de producción y aumenta la eficiencia en la obtención grano triturado para el consumo el sector avícola.
In the research an economical and accessible hammer mill was designed, modeled and improved by applying deductive logical methods, the machine provides an ideal grain size, which serves as direct feed for birds, or it can also be used as a component for balanced in the poultry production, according to the requirements of the different SMEs, whether for meat consumption, egg production, among others. For this reason, it is necessary to define different parameters such as the appropriate size of the sieve having a variety from 2mm to 5 mm, blades, suitable engine selection depending on the number of hours per day, for this a mechanical and dynamic analysis of the different elements of the machine by means of simulation in the software Solidworks free students, after having the optimal dimensioning under engineering parameters of each one of the parts of the machine, a quotation of the materials was made under economic consideration in which it was necessary to carry out a correct selection of the same elements based on national catalogs so that the machine is profitable and accessible to the micro producers as well as to the wholesalers. Once the entire procedure was considered, the machine was built with a final cost of US $ 355.39. being this easy to disassembly, maintenance and application for society, which allows the reduction of costs, production times and increases the efficiency in obtaining crushed grain for consumption in the poultry sector.
Palabras clave: diseño, producción avícola, grano, balanceado, molino, grano triturado.
Keywords: design, poultry production, grain, balanced, mill, crushed grain
Aislamiento e identificación de hongos de la región del Parque Nacional de Iguazú - Paraná
Anais do V Encontro de Iniciação Científica e I Encontro Anual de Iniciação ao Desenvolvimento Tecnológico e Inovação – EICTI 2016 - 05 e 07 de outubro de 2016 – Sessão BiológicasA pesar que los hongos desempeñan un rol esencial en el reciclaje de materia orgánica,
dentro de los procesos ecosistémicos, según estimativas mundiales de cada 15 especies
fúngicas apenas una ha sido descrita (Rodrígues et al., 2010). Consecuentemente, existe una
gran necesidad de estudiar la diversidad fúngica en ambientes naturales (Rodrígues et al.,
2010); aún más en los ambientes mínimamente impactados como el Parque Nacional de
Iguazú (PNI), la mayor área remanente del Bosque Atlántico Estacional Semidecíduo del sur
de Brasil, donde la microbiota es prácticamente desconocida.
En ese sentido, el objetivo del presente proyecto es evaluar la diversidad de hongos del
PNI – Paraná e identificar el impacto del estado de conservación del ambiente frente a
diversidad microbiana. El foco de esta investigación son los hongos de suelo, mineralizadores
de las macromoléculas provenientes de residuos orgánicos. Su actividad se ve afectada por
innumerables factores bióticos y abióticos, tal como la gran proporción de hierro del suelo del
PNI. Dicha variable, al funcionar como recurso o condición, podría ser clave para albergar
una diversidad fúngica diferenciada en este ambiente, al afectar la producción de metabolitos
secundarios esenciales en su sobrevivencia, una situación poco evaluada hasta ahora. Los
resultados obtenidos abrirán espacios para futuras investigaciones en diferentes áreas
microbiológicas, biotecnológicas y ecológicas
Aislamiento, identificación y potencial enzimático de hongos de la región del Parque Nacional de Iguazú - Paraná
Anais do VI Encontro de Iniciação Científica e II Encontro Anual de Iniciação ao Desenvolvimento Tecnológico e Inovação – EICTI 2017 - 04 a 06 de outubro de 2017 - temática OutrosEl Parque Nacional Iguazú (PNI), el mayor remanente forestal del Bosque
Atlántico, está básicamente formado por suelos arcillosos con alto contenido de
hierro (Schobbenhaus et al, 2002). Esta variable ambiental puede haber
propiciado la adaptación de microorganismos que puedan proporcionar
ventajas biotecnológicas en relación a otros ya descritos; no obstante, la
incalculable diversidad fúngica es prácticamente desconocida en el PNI. Por
otro lado, la acelerada degradación de los ambientes naturales y la notable
eficiencia de la bioprospección a partir de microbiota han intensificado el
estudio de esta última en diversos hábitats, a nivel morfológico, molecular y
funcional. Las enzimas fúngicas, de hecho, son de interés por su potencial uso
en aplicaciones biotecnológicos e industriales; por ejemplo, las lacasas, un tipo
de ligninasas, son las principales catalizadoras de la lignina y de una amplia
gama de sustratos problemáticos para el medio ambiente. En ese sentido, el
presente trabajo tiene como objetivo evaluar la diversidad estructural, funcional
y biotecnológica de los hongos de la región del PNI. Los resultados obtenidos
servirán de base para futuras investigaciones biotecnológicasUniversidade Federal da Integração Latino-Americana (Unila); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação Araucária; Parque Tecnológico Itaipu (PTI) e Companhia de Saneamento do Paraná (SANEPAR
On the dimension of Voisin sets in the moduli space of abelian varieties
We study the subsets of a complex abelian variety consisting in
the collection of points such that the zero-cycle is
-nilpotent with respect to the Pontryagin product in the Chow group. These
sets were introduced recently by Voisin and she showed that and is countable for a very general abelian variety of dimension
at least .
We study in particular the locus in the moduli space of
abelian varieties of dimension with a fixed polarization, where is
positive dimensional. We prove that an irreducible subvariety , , such that for a very general there is a curve in generating satisfies The hyperelliptic locus shows that this bound is sharp.Comment: Final version to appear in Mathematische Annale
Late Quaternary monogenetic volcanoes along Río Salado, Sothwest Mendoza Province, Argentina
On the eastem flank of the Andes, to the north of Río Salado in southwest Mendoza Province (35º07'S-35º10'S), there are 4 monogenetic cones with blocky lava flows. A western group of small volcanoes, Hoyada, Lagunita and Loma Negra, with a total volume of -0.2 km3, are composed of amphibole-bearing basaltic andesite, and the eastem, more voluminous Hoyo Colorado volcano, with 0.44 km3 is composed of olivine (+ oxidised amphibole) basaltic andesite. Although data indicate they were emitted through successive, strombolian eruptions, they are overall coeval and the youngest Late Pleistocene volcanoes located in an "extra-Andean" setting, -70 km east of the main volcanic front. The magmas of the westem group of monogenetic cones show petrographic and geochemical characteristics that support processes of crustal interaction during ascent. In contrast, the magmas of the Hoyo Colorado volcano had a more direct ascent. Structural characteristics of the basement rocks to the volcanoes and the current seismotectonic activity of the Andes at this latitude indicate that the monogenetic cones of Río Salado were emplaced in a dominantly compressive tectonic regime
A phase of liposomes with entangled tubular vesicles
An equilibrium phase belonging to the family of bilayer liposomes in ternary mixtures of dimyristoylphosphatidylcholine (DMPC), water, and geraniol (a biological alcohol derived from oil-soluble vitamins that acts as a cosurfactant) has been identified. Electron and optical microscopy reveal the phase, labeled Ltv, to be composed of highly entangled tubular vesicles. In situ x-ray diffraction confirms that the tubule walls are multilamellar with the lipids in the chain-melted state. Macroscopic observations show that the Ltv phase coexists with the well-known L4 phase of spherical vesicles and a bulk L alpha phase. However, the defining characteristic of the Ltv phase is the Weissenberg rod climbing effect under shear, which results from its polymer-like entangled microstructure
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