632 research outputs found
Antennal Phenotype of Triatoma dimidiata Populations and Its Relationship with Species of phyllosoma and protracta Complexes
Triatoma dimidiata (Latreille 1811) Reduviidae Triatominae is the main vector of Chagas disease in several countries of Latin America. As for other vector species, the characterization of T. dimidiata subpopulations within particular geographical regions or occupying different habitats could help in better planning of vector control actions. A Þrst objective in this study was to evaluate the antennal phenotype as a phenetic marker to characterize populations of T. dimidiata collected in different geographic areas and domestic and sylvatic habitats. A second objective was to evaluate the phenetic relationships of T. dimidiata with other species of the phyllosoma complex: longipennis, pallidipennis, and phyllosoma. The antennal sensilla of T. dimidiata specimens collected in Mexico, Central America, and Colombia were analyzed and compared with the antennal sensilla of T. longipennis, T. pallidipennis, and T. phyllosoma. T. barberi was used as an outgroup in the analysis. For each specimen, the ventral side of the three distal segments of the antennae was drawn, identifying and counting four types of sensilla. In T. dimidiata, univariate and multivariate analysis showed differences between sexes, among populations collected in different habitats within the same region, and among populations collected in different geographic regions. Two types of antennal sensilla showed a latitudinal variation. Domestic specimens showed intermediate characteristics of the antennal phenotype, between sylvatic cave- and sylvatic forest-collected specimens. The antennal phenotypes show high similarities among T. pallidipennis, T. phyllosoma, and T. longipennis, with a better differentiation of T. pallidipennis. T. dimidiata is separated from the other members of the complex by a similar distance to T. barberi, of the protracta complex.Fil: Catala, Silvia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Sachetto, C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Moreno, Mariana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Rosales, R.. Universidad de San Carlos; GuatemalaFil: Salazar Schettino, P. M.. Universidad Nacional Autónoma de México; MéxicoFil: Gorla, David Eladio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; Argentin
UCP2 and ANT differently modulate proton-leak in brain mitochondria of long-term hyperglycemic and recurrent hypoglycemic rats
A growing body of evidence suggests that mitochondrial
proton-leak functions as a regulator of reactive
oxygen species production and its modulation may limit
oxidative injury to tissues. The main purpose of this work
was to characterize the proton-leak of brain cortical mitochondria
from long-term hyperglycemic and insulininduced
recurrent hypoglycemic rats through the modulation
of the uncoupling protein 2 (UCP2) and adenine nucleotide
translocator (ANT). Streptozotocin-induced diabetic
rats were treated subcutaneously with twice-daily insulin
injections during 2 weeks to induce the hypoglycemic episodes.
No differences in the basal proton-leak, UCP2 and
ANT protein levels were observed between the experimental
groups. Mitochondria from recurrent hypoglycemic rats
presented a decrease in proton-leak in the presence of
GDP, a specific UCP2 inhibitor, while an increase in
proton-leak was observed in the presence of linoleic acid,
a proton-leak activator, this effect being reverted by the
simultaneous addition of GDP. Mitochondria from longterm
hyperglycemic rats showed an enhanced susceptibility
to ANT modulation as demonstrated by the complete inhibition
of basal and linoleic acid-induced proton-leak caused
by the ANT specific inhibitor carboxyatractyloside. Our
results show that recurrent-hypoglycemia renders mitochondria
more susceptible to UCPs modulation while the protonleak
of long-term hyperglycemic rats is mainly modulated
by ANT, which suggest that brain cortical mitochondria
have distinct adaptation mechanisms in face of different
metabolic insults.The authors’ work is supported by the Fundação
para a Ciência e a Tecnologia (FCT) (PTDC/SAU-NEU/103325/2008)
co-funded by Fundo Europeu de Desenvolvimento Regional (FEDER)
via Programa Operacional Factores de Competitividade (COMPETE).
Susana Cardoso has a PhD fellowship from the Portuguese Foundation
for Science and Technology (SFRH/BD/43968/2008)
Parameter estimation of an empirical kinetic model for CO preferential oxidation
In this work the application of genetic algorithms (GA) for solving the parameter estimation problem in a nonlinear empirical kinetic model for CO preferential oxidation is reported. Kinetic models with nonlinear rate equations often suffer of considerable parameter uncertainty which can lead to inaccurate predictions. Here, after the parameter vector is obtained, a statistical study is performed in order to show how accurate the parameter estimations are determined. The unknown model parameters are obtained by fitting the model predictions against our laboratory observations measured under a range of experimental conditions using a novel Au/TiO2 catalyst.Sociedad Argentina de Informática e Investigación Operativa (SADIO
Parameter estimation of an empirical kinetic model for CO preferential oxidation
In this work the application of genetic algorithms (GA) for solving the parameter estimation problem in a nonlinear empirical kinetic model for CO preferential oxidation is reported. Kinetic models with nonlinear rate equations often suffer of considerable parameter uncertainty which can lead to inaccurate predictions. Here, after the parameter vector is obtained, a statistical study is performed in order to show how accurate the parameter estimations are determined. The unknown model parameters are obtained by fitting the model predictions against our laboratory observations measured under a range of experimental conditions using a novel Au/TiO2 catalyst.Sociedad Argentina de Informática e Investigación Operativa (SADIO
Optimización No Lineal Basada en “Enjambre de Partículas”
La optimización basada en “enjambre de partículas” (particle swarm optimization) es una estrategia de programación estocástica que ha cobrado gran popularidad en los últimos años debido a sus buenas propiedades de convergencia a óptimos globales y sencillez de implementación. Sin embargo, al igual que otras técnicas de naturaleza evolutiva, su mayor debilidad radica en el tratamiento de las restricciones. En esta contribución se propone una metodología para manipular en forma eficiente las restricciones del problema de optimización que se encuentran habitualmente en problemas típicos de la ingeniería de procesos.Sociedad Argentina de Informática e Investigación Operativ
Optimal Production Planning of Concentrated Apple and Pear Juice Plants
This paper presents a mathematical model aimed at optimizing the yearly profit of a concentrated apple and pear juice plant through the appropriate design of its production plan. This study assumes a business scenario where the products are devoted to the international market and therefore the production schedule is dictated by a fluctuating prices scenario due to the worldwide supply/demand tradeoff. Moreover, raw fruit is available only during the relatively short harvest season and suffers juice yield reduction during storage. In this context, decisions related to the manufacturing of each juice variety to exploit favorable prices, while minimizing juice yield loss due to fruit aging are not intuitive. Scenario studies, together with sensitivity analysis on some model parameters are developed to illustrate the performance of the proposed approach.Sociedad Argentina de Informática e Investigación Operativ
Optimal Production Planning of Concentrated Apple and Pear Juice Plants
This paper presents a mathematical model aimed at optimizing the yearly profit of a concentrated apple and pear juice plant through the appropriate design of its production plan. This study assumes a business scenario where the products are devoted to the international market and therefore the production schedule is dictated by a fluctuating prices scenario due to the worldwide supply/demand tradeoff. Moreover, raw fruit is available only during the relatively short harvest season and suffers juice yield reduction during storage. In this context, decisions related to the manufacturing of each juice variety to exploit favorable prices, while minimizing juice yield loss due to fruit aging are not intuitive. Scenario studies, together with sensitivity analysis on some model parameters are developed to illustrate the performance of the proposed approach.Sociedad Argentina de Informática e Investigación Operativ
Mentha aquatica L. extract effects on mitochondrial bioenergetics
Mentha aquatica (water mint) extracts are regularly used in food flavoring and pharmacology. In the present study, the possible effects of an ethanolic extract from leaves of M. aquatica L. on rat liver mitochondria bioenergetics were evaluated.
The plant extract (25 μg·mg protein−1) but not the vehicle, inhibited the mitochondrial oxidative system, as seen by a depression
of respiration (state 3, respiratory control ratio (RCR), FCCP stimulated respiration) and lower generation of the transmembrane
electric potential using glutamate+malate and succinate as respiratory substrates. The depressing effects in oxidative phosphorylation can probably be related with the polyphenolic composition of the extract
(mainly eriodictyol-7-O-rutinoside, luteolin-7-O-rutinoside, naringenin-
7-O-rutinoside, hesperitin-7-O-rutinoside and rosmarinic acid) that can interact with membrane and change the inner mitochondrial membrane lipidic moiety. Despite decreasing the RCR, the presence of M. aquatica extract did not affect the mitochondrial phosphorylative capacity, as estimated by the ADP/O ratio. No significant increase in inner mitochondrial membrane permeability was observed and induction of mitochondrial permeability transition pore was not altered in the range of concentrations tested (up to 25 μg·mg protein−1) either. For the highest concentrations tested (25 μg·mg protein−1 or higher) the inhibition observed on the mitochondrial respiratory chain, as reflected
by FCCP-stimulated respiration, revealed that M. aquatica ethanolic extract is toxic for mitochondrial bioenergetics. In conclusion, the presente study suggests that a high daily consumption of an ethanolic extract of M. aquatica leaves should be regarded as hazardous
Effects of increasing levels of pea hulls in the diet on productive performance, development of the gastrointestinal tract, and nutrient retention of broilers from one to eighteeen days of age
The effects of inclusion of pea hulls (PH) in the diet on growth performance, development of the gastrointestinal tract and nutrient retention were studied in broilers from 1 to 18d of age. There were a control diet based on low fibre ingredients (69.3 total dietary fibre (16.1g crude fibre/kg)) and three additional diets that resulted from the dilution of the basal diet with 25, 50 and 75g PH/kg (81.2, 93.2, and 105.1g total dietary fibre/kg diet, respectively). Each treatment was replicated six times and the experimental unit was a cage with 12 chicks. Growth performance, development of the gastrointestinal tract and the coefficients of total tract apparent retention (CTTAR) of nutrients were recorded at 6, 12 and 18d of age. In addition, jejunal morphology was measured at 12 and 18d and the coefficients of apparent ileal digestibility (CAID) of nutrients at 18d of age. Pea hulls inclusion affected all the parameters studied. The inclusion of 25 and 50g PH/kg diet improved growth performance as compared to the control diet. The relative weight (g/kg body weight) of proventriculus (P≤0.01), gizzard (P≤0.001) and ceca (P≤0.05) increased linearly as the level of PH in the diet increased. The inclusion of PH affected quadratically (P≤0.01) villus height:crypt depth ratio with the highest value shown at 25g PH/kg. In general, the CTTAR and CAID of nutrients increased linearly and quadratically (P≤0.05) with increasing levels of PH, showing maximum values with PH level between 25 and 50g/kg diet. We conclude that the size of the digestive organs increases with increasing levels of PH in the diet. In general, the best performance and nutrient digestibility values were observed with levels of PH within the range of 25 and 50g/kg. Therefore, young broilers have a requirement for a minimum amount of dietary fibre. When pea hulls are used as a source of fibre, the level of total dietary fibre required for optimal performance is within the range of 81.2–93.2g/kg diet (25.6–35.0g crude fibre/kg diet). An excess of total dietary fibre (above 93.2g/kg diet) might reduce nutrient digestibility and growth performance to values similar to those observed with the control diet
Modelo resiliente y sostenible para optimizar la trazabilidad en la cadena de suministro de la carne
En este trabajo se optimiza la trazabilidad en la cadena de suministro de la carne (CSC) considerando no solo aspectos económicos y ambientales sinotambién estrategias de resiliencia para reducir su vulnerabilidad en un contexto incierto. El problema se formula como un modelo multiobjetivo de programación mixta entera lineal (MOMILP) que busca optimizar simultáneamente la dispersión total de lotes, los beneficios totales y las emisiones de CO2 considerando disrupciones en la cadena e incertidumbre en la demanda de productos. Para resolver el modelo propuesto se emplea el método de Programación por Metas (PPM), obteniéndose un conjunto reducido de soluciones entre las cuales el encargado de la toma de decisión seleccionará la que mejor se adapte a sus preferencias. La formulación permite realizar el seguimiento de lotes generados a lo largo de la CSC identificando los lotes de animal que forman parte de cada lote de producto elaborado y seleccionar alternativas frente a diferentes eventos isruptivospara satisfacer la demanda de los minoristas.Sociedad Argentina de Informática e Investigación Operativ
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