Papers by Hugo Huerta Hernandez
Revista de Ingeniería Sísmica, Jul 1, 2006
Se estudia el comportamiento inelástico de puentes en arco de concreto sometidos a movimientos sí... more Se estudia el comportamiento inelástico de puentes en arco de concreto sometidos a movimientos sísmicos fuertes, mediante una serie de análisis dinámicos de un puente de gran claro usando un modelo tridimensional. El modelo corresponde a un puente con tablero superior de 600 m de longitud total y un claro principal de 400 m; se tiene en cuenta el comportamiento no lineal de los arranques del arco y de los extremos de las pilas, zonas de potenciales articulaciones plásticas. Para evaluar la respuesta se usaron 10 conjuntos de registros escalados con tres componentes cada uno. Los resultados muestran que las mayores respuestas del modelo fueron producidas por los sismos con mayores velocidades máximas del terreno; las demandas de ductilidad excedieron la capacidad rotacional en los arranques del arco para movimientos transversales. Se obtuvo que la compresión en los arranques del arco varía significativamente durante la ocurrencia de los movimientos, por lo que debe considerarse la interacción no lineal entre la compresión y el momento flexionante. Al estudiar la variabilidad espacial se encontró que las demandas rotacionales en los arranques del arco aumentaron para flexión en el plano, debido a una mayor respuesta vertical del modelo.
Revista MVZ Córdoba, 2011
RESUMENObjetivo. Conocer los hábitos de amamantamiento de becerros Chinampos (Bos taurus)en difer... more RESUMENObjetivo. Conocer los hábitos de amamantamiento de becerros Chinampos (Bos taurus)en diferentes etapas de su lactancia. Materiales y métodos. Se utilizaron 20 vacas consu cría. A partir de los 30 hasta los 180 días de la lactancia los animales fueron observadosdurante 24 horas continuas cada mes registrando la frecuencia con la que los becerrosmamaron y la duración de cada amamantamiento. Resultados. Los becerros mamaroncon mayor frecuencia entre las 06:00 y las 07:00 hr, se observaron otros picos a las 10:00y a las 19:00 hr. La frecuencia promedio de amamantamiento en 24 horas fue de 4.9±0.21utilizando un total de 66.9 ± 3.1 minutos. Los becerros de 180 días de edad mamaronmenos veces comparados con los de edades inferiores a los 150 días; la duración delamamantamiento disminuyó a los 180 días de edad (p<0.05). Las hembras mamaron conmás frecuencia que los machos (p<0.05) pero el tiempo que utilizaron para esta actividadfue similar entre sexos (p>0.05). Conclusiones...
Computacion Y Sistemas, Dec 1, 2013
The measures most commonly used in current literature to compute the roundness of digital objects... more The measures most commonly used in current literature to compute the roundness of digital objects are derivations of the form factor based on area and perimeter computations. However, these measures are highly dependent on image resolution and sensitive to shape variations. In this article, a new measure is proposed. This measure takes into consideration the dominant geometry of objects, avoiding the use of such parameters as area, perimeter and Ferret's diameter. The proposed measure is easy to compute, and since it is a distribution of probability based on the radius, it is invariant to abrupt changes in contours or to shape resolution. In order to show the performance of this measure, it is compared with three other recently proposed measures: factor shape, which is recommended by the American Standard Test Measurement, mean roundness and radius ratio.
Revista Mexicana De Micologia, Dec 1, 2012
The measures most commonly used in current literature to compute the roundness of digital objects... more The measures most commonly used in current literature to compute the roundness of digital objects are derivations of the form factor based on area and perimeter computations. However, these measures are highly dependent on image resolution and sensitive to shape variations. In this article, a new measure is proposed. This measure takes into consideration the dominant geometry of objects, avoiding the use of such parameters as area, perimeter and Ferret's diameter. The proposed measure is easy to compute, and since it is a distribution of probability based on the radius, it is invariant to abrupt changes in contours or to shape resolution. In order to show the performance of this measure, it is compared with three other recently proposed measures: factor shape, which is recommended by the American Standard Test Measurement, mean roundness and radius ratio.
Six wild strains of Agaricus bisporus were cultivated in order to determine their productivy char... more Six wild strains of Agaricus bisporus were cultivated in order to determine their productivy characteristics for a potential commercial exploitation. The spawn was prepared in sorghum seeds and mushroom productivity was determined on commercial compost samples weighing 4 kg (moistened weight) inoculated with each of the strains. Primordia began to appear on the 42 to 47th after spawning and 4 flushes were obtained between 70 to 96 days of culturing. Fruiting bodies with pileus diameters of 5 to 10 cm and cream to light brown color were mostly harvested. Biological efficiencies (BE) ranged from 40.3 to 95% and production rates (PR) from 0.47 to 1.13%. IE-747 and IE-708 strains presented the highest BEs (95 and 90.3%) and PRs (1.1 and 1.13%).
Proceedings of the 13th annual conference companion on Genetic and evolutionary computation, 2011
... However, its use in technical applications is, so far, quite limited. In this paper we implem... more ... However, its use in technical applications is, so far, quite limited. In this paper we implement the originally proposed model in sensor networks, with the aim of desynchronizing neighboring nodes as much as possible. ... Towards desynchronization of multi-hop topologies. ...
Proceedings of the 2009 workshop on Bio-inspired algorithms for distributed systems, 2009
In previous work we introduced a self-synchronized duty-cycling mechanism for mobile sensor netwo... more In previous work we introduced a self-synchronized duty-cycling mechanism for mobile sensor networks with energy harvesting capabilities, inspired by the self-synchroned sleeping patterns that can be observed in real ant colonies. The focus of our previous study was mainly on swarm intelligence aspects of the proposed system. In contrast, in this paper we propose a more realistic version of the initial system. The proposed changes concern in particular the systems&amp;#x27; asynchronous simulation. Instead of exchanging information at the same time, in our new proposal sensor nodes wake up periodically based on their own internal clock and perform an update of their internal state based on the information received by their neighbors. In addition we use a more realistic mobility model and apply the system to scenarios where weather conditions vary over the area of deployment. The simulation results show that our asynchronous system also permits adaptive duty-cycling, and that the system is able to adapt to changing weather conditions.
2011 4th Joint IFIP Wireless and Mobile Networking Conference (WMNC 2011), 2011
Graph coloring concerns the problem of assigning colors to the nodes of a graph such that adjacen... more Graph coloring concerns the problem of assigning colors to the nodes of a graph such that adjacent nodes do not share the same color. In this paper we deal with the problem of finding valid colorings of graphs in a distributed manner, while minimizing the number of used colors. This problem is at the heart of several problems arising in
Cultura - Hombre - Sociedad CUHSO, 2012
RESUMEN El presente trabajo es parte de una investigación sobre formas de reestratificación desde... more RESUMEN El presente trabajo es parte de una investigación sobre formas de reestratificación desde la sociedad civil. Aquí se observan las estrategias institucionales para el tratamiento del fenómeno de las pandillas transnacionales llevadas a cabo en El Salvador. Se observa cómo estas estrategias producen mayor violencia, sin presentar opciones organizativas orientadas a mejorar la vida de los jóvenes pandilleros, sin buscar crear formas sociales productivas en el sentido de asegurar a los jóvenes marginales instancias de resistencia a los influjos del sistema capitalista que los excluye. En estos términos, se propone observar las estrategias gubernamentales y sus efectos en la transformación de las pandillas hacia formas más violentas y jerarquizadas, debido a la acción criminalizante de las instituciones del gobierno. Así pues, se propone la observación de la reestratificación institucional de las pandillas, mediante la criminalización y su asimilación al crimen organizado, como elemento que ha producido una tendencia a la jerarquización, la clandestinidad y el aumento de la violencia. PALABRAS CLAVE Pandillas transnacionales, criminalización de la juventud, leyes de excepción, violencia juvenil.
Swarm Intelligence, 2008
Recently, the first rigorous runtime analyses of ACO algorithms appeared, covering variants of th... more Recently, the first rigorous runtime analyses of ACO algorithms appeared, covering variants of the MAX-MIN ant system and their runtime on pseudo-Boolean functions. Interestingly, a variant called 1-ANT is very sensitive to the evaporation factor while Gutjahr and Sebastiani proved partly opposite results for their variant MMAS bs. These algorithms differ in their pheromone update mechanisms and, moreover, 1-ANT accepts equally fit solutions in contrast to MMAS bs. By analyzing variants of MMAS bs , we prove that the different behavior of 1-ANT and MMAS bs results from the different pheromone update mechanisms. Building upon results by Gutjahr and Sebastiani, we extend their analyses of MMAS bs to the class of unimodal functions and show improved results for test functions using new and specialized techniques; in particular, we present new lower bounds. Finally, we compare MMAS bs with a variant that also accepts equally fit solutions as this enables the exploration of plateaus. For well-known plateau functions we prove that this drastically reduces the optimization time. Our findings are complemented by experiments that support our asymptotic analyses and yield additional insights.
Revista MVZ …, 2011
Objective. To determine the nursing habits of Chinampo calves (Bos taurus) during different stage... more Objective. To determine the nursing habits of Chinampo calves (Bos taurus) during different stages of lactation. Materials and methods. Twenty cows with their calves were used. The animals were observed from day 30 to 180 of lactation during 24 continuous hours each ...
InterSedes, 2011
Los pueblos que no se conocen han de darse prisa para conocerse, como quienes van a pelear juntos... more Los pueblos que no se conocen han de darse prisa para conocerse, como quienes van a pelear juntos. Los que enseñan los puños, como hermanos celosos, que quieren los dos la misma tierra" Nuestra América, José Martí Resumen En este trabajo se presentan cuatro migraciones que han tenido gran influencia en la actualidad: los cherokees fueron obligados a cambiar su hábitat y caminaron por un "sendero de lágrimas" que ha quedado escrito en la Historia Universal. Los chinos fueron bien recibidos en Estados Unidos y luego obligados a dejar el país. Los campesinos del centro de los Estados Unidos tuvieron que abandonar sus tierras cuando cambiaron la ecología de su región al "modernizarla". Y los mineros mexicanos de 1848 fueron discriminados y acosados en un territorio que había pertenecido a ellos.
Microbiology, 2008
In the yeast Saccharomyces cerevisiae, the first committed step of the lysine biosynthetic pathwa... more In the yeast Saccharomyces cerevisiae, the first committed step of the lysine biosynthetic pathway is catalysed by two homocitrate synthases encoded by LYS20 and LYS21. We undertook a study of the duplicate homocitrate synthases to analyse whether their retention and presumable specialization have affected the efficiency of lysine biosynthesis in yeast. Our results show that during growth on ethanol, homocitrate is mainly synthesized through Lys21p, while under fermentative metabolism, Lys20p and Lys21p play redundant roles. Furthermore, results presented in this paper indicate that, in contrast to that which had been found for Lys20p, lysine is a strong allosteric inhibitor of Lys21p (K i 0.053 mM), which, in addition, induces positive cooperativity for a-ketoglutarate (a-KG) binding. Differential lysine inhibition and modulation by a-KG of the two isozymes, and the regulation of the intracellular amount of the two isoforms, give rise to an exquisite regulatory system, which balances the rate at which a-KG is diverted to lysine biosynthesis or to other metabolic pathways. It can thus be concluded that retention and further biochemical specialization of the LYS20-and LYS21-encoded enzymes with partially overlapping roles contributed to the acquisition of facultative metabolism.
Biochemical and Biophysical Research Communications, 2011
The yeast Saccharomyces cerevisiae is able to sense the availability and quality of nitrogen sour... more The yeast Saccharomyces cerevisiae is able to sense the availability and quality of nitrogen sources and the intrinsic variation of amino acid disponibility for protein synthesis. When this yeast is provided with secondary nitrogen sources, transcription of genes encoding enzymes involved in their catabolism is elicited through the action of Gln3, which constitutes the main activator of the Nitrogen Catabolite Repression network (NCR). Activation of genes encoding enzymes involved in the amino acid biosynthetic pathways is achieved through the action of the GCN4-encoded transcriptional modulator whose transcriptional activation is induced at the translational level by limitation for any amino acid. Thus the role of each one of these activators had been secluded to either catabolic or biosynthetic pathways. However, some observations have suggested that under peculiar physiological conditions, Gln3 and Gcn4 could act simultaneously in order to contemporaneously increase expression of both sets of genes. This paper addresses the question of whether Gln3 and Gcn4 cooperatively determine expression of their target genes. Results presented herein show that induced expression of catabolic and biosynthetic genes when cells are grown under nitrogen derepressive conditions and amino acid deprivation is dependent on the concurrent action of Gln3 and Gcn4, which form part of a unique transcriptional complex. We propose that the combination of Gln3 and Gcn4 results in the constitution of a hybrid modulator which elicits a novel transcriptional response, not evoked when these modulators act in a non-combinatorial fashion.
Applicable Algebra in Engineering, Communication and Computing, 2009
Reachability, joinability and confluence properties are known to be undecidable for flat term rew... more Reachability, joinability and confluence properties are known to be undecidable for flat term rewrite systems (TRS). We give shorter and conceptually simpler proofs of these results. We also prove undecidability of weak normalization and unique normalization properties for flat TRS.
animal, 2007
We investigated whether kids were able to discriminate their own mother from an alien one in a tw... more We investigated whether kids were able to discriminate their own mother from an alien one in a two-choice test on the day of birth when they had access to acoustic, visual and olfactory cues from their mother, and whether this discrimination depended on the selective maternal behaviour of the mother (i.e. exclusive nursing of own kids). When given the choice between their own mother and an alien equivalent dam, 8-h-old kids did not show a significant preference for their dam, whereas 12- and 24-h-old kids did. When given the choice between their own and an alien mother that were both non-selective because they had been rendered peripherally anosmic by irrigation of the nostrils with zinc sulphate, 12-h-old kids did not show a significant preference for their mother. These results are similar to those reported in sheep and may suggest that the contrast of behaviour between their own and an alien mother existing in normosmic does is important for discrimination of dams by kids at this...
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Papers by Hugo Huerta Hernandez