784 research outputs found
Mathematical modeling of nonlinear blood glucose-insulin dynamics with beta cells effect
We consider mathematical modeling of blood glucose-insulin regulatory system with the additional effect of the secreted insulin by the pancreatic beta cells and in the presence of an external energy input to such system. Such modeling system is investigated to determine the time-dependent nonlinear dynamics that take place by the quantities, which represent the glucose and insulin concentrations in the blood, insulin action as well as in the absence or presence of secreted insulin due to the pancreatic beta cells. Using both analytical and numerical procedures, we determine such quantities versus time for both diabetes patients and normal human and for different values of the parameters. We find that the nonlinear effect of the dynamics of the investigated regulatory system increases the values of the insulin action and the glucose and insulin concentrations. In the absence of the beta cells effects, which can correspond to the case of severe type 1 diabetes, the plasma glucose is higher and the insulin action and the insulin concentration are less active than the corresponding ones for the case in the presence of beta cells, which is relevant for type 2 diabetes or moderate type 1 diabetes patients. For the present system, smaller values of the parameters of the model, which represent kinetics of the glucose and insulin action, insulin sensitivity, insulin secretion enhancement and the plasma insulin decay rate, can lead to notably lower values of the glucose concentration. In the presence of the secreted insulin by the pancreatic beta cells the insulin action and the insulin concentration are more effective to reduce the blood glucose, which can help to improve the diabetes patient’s health
Selección y reproducción en ganado lechero: el uso de registros en los hatos.
Ganado de leche-GanaderÃa lech
Efecto de la suplementación de la vitamina A y del complejo vitamÃnico A, D, E, sobre la producción lechera y la reproducción de vacas Holstein.
Experimento con 54 vacas Holstein distribuidas en 9 tratamientos, que evalúa 2 épocas: 1, post-parto y 2, pre-parto; se aplican complejo vitamÃnico A, D, E y vitamina A; para cada clase de vitamina se utilizan 2 dosis: 1 millón y 2 millones de vitamina A por vÃa parenteral. Los objetivos son determinar los efectos de la suplementación de cada clase de vitamina, aplicadas 30 dÃas antes del parto, 30 dÃas después del parto, en el parto, puerperio, aparición de calores y servicios por concepción. Se evalúa su efecto en producción de leche durante los primeros 150 dÃas de lactancia. Se determinan las variedades de peso corporal en 3 estados: próximas al parto, el dÃa del parto y vacÃa iniciando lactancia. Se analizan 162 muestras de sangre. Los resultados indican que el nivel de vitamina A es independiente del de beta-caroteno en sangre; el beta-caroteno desciende fuertemente 60 dÃas post-parto; la vitamina A post-parto mantiene su nivel en suero sanguÃneo. Para la época 1, el nivel de vitamina A al parto aumenta levemente, lo cual indica efecto de la aplicación de vitamina A 30 dÃas post-parto. Se encuentra relación directa entre mayor producción lechera y mayor número de dÃas al primer calor post-parto. Se sugiere continuar este tipo de trabajos por la tendencia que se encuentra en algunos tratamientos a una mayor producción lechera y una mejor eficiencia reproductiva, en vacas tratadas pre y post-parto con vitamina A y complejo vitamÃnico A, D, EGanado de leche-GanaderÃa lecheMaestrÃa en CienciasMaestrÃ
Resumen del informe de progreso 1982 : programa de ganado de leche
Instituto Colombiano Agropecuario - ICAGanado de leche-GanaderÃa lech
Organización de las unidades de investigación (UNI) de los CRECED con el apoyo de los centros de investigación y estaciones experimentales.
Medical equipment replacement prioritisation: A comparison between linear and fuzzy system models
In hospital management, health technology assessment techniques are being increasingly developed. This paper presents a comparison of the results obtained using two models for replacement priority value calculation applied to the Galliera hospital in Genoa (Italy). One the models was developed at the Galliera Hospital along the lines of the model by Fennigkoh and addresses four primary replacement issues: equipment service and support, equipment function, cost benefits and clinical efficacy, by a "yes-no" scheme. This model is compared with a model based on fuzzy logic. The comparison between the two models shows a conservative behaviour by the Galliera model, according to which 77.4% of the analysed instrumentation is maintained, whereas the classification by the fuzzy model allows for a better discrimination among the devices
Advanced oxidation processes with Uv-H2O2 for nitrification and decolorization of dyehouse wastewater
In this work, a UV/H2O2 system was evaluated using an experimental design 2 level I-optimal response surface design to analyze the effect of temperature, pH, UV lamp power (W), and H2O2 concentration on dye load removal and nitrification from industrial cleaning wastewater. Results showed that the optimum conditions were 80 °C, pH 4, PW-UV 60 W, and H2O2 3.1 Mol*L-1. Removal percentages of 45% for COD, 47.5% color, 87% Fe, 82% Cr and 91% ammonium oxidation to nitrate were achieved. It can be concluded that the effluents treated by this process could be promising for reuse and exploitation in biotechnological tools through microalgae and cyanobacteria
Biochemical characterization of the initial steps of the Kennedy pathway in Trypanosoma brucei:the ethanolamine and choline kinases
Note related output below contains correction of this paper.Ethanolamine and choline are major components of the trypanosome membrane phospholipids, in the form of GPEtn (glycero-phosphoethanolamine) and GPCho (glycerophosphocholine). Ethanolamine is also found as an integral component of the GPI (glycosylpliosphatidylinositol) anchor that is required for membrane attachment of cell-surface proteins, most notably the variant-surface glycoproteins. The de novo synthesis of GPEtn and GPCho starts with the generation of phosphoethanolamine and phosphocholine by ethanolamine and choline kinases via the Kennedy pathway. Database mining revealed two putative C/EKs (choline/ethanolamine kinases) in the Trypanosoma brucei genome, which were cloned, overexpressed, purified and characterized. TbEK 1 (T brucei ethanolamine kinase 1) was shown to be catalytically active as an ethanolamine-specific kinase, i.e. it had no choline kinase activity. The K values for ethanolamine and ATP were found to be 18.4 +/- 0.9 and 219 29 mu M respectively. TbC/EK2 (T brucei choline/ethanolamine kinase 2), on the other hand, was found to be able to phosphorylate both ethanolamine and choline, even though choline was the preferred substrate, with a K-m 80 times lower than that of ethanolamine. The K. values for choline, ethanolamine and ATP were 31.4 +/- 2.6 mu M, 2.56 +/- 0.31 mu M and 20.6 +/- 1.96 mu M respectively. Further substrate specificity analysis revealed that both TbEK1 and TbC/EK2 were able to tolerate various modifications at the amino group, with the exception of a quaternary amine for TbEK1 (choline) and a primary amine for TbC/EK2 (ethanolamine). Both enzymes recognized analogues with substituents oil C-2, but substitutions oil C-1 and elongations of the carbon chain were not well tolerated.Publisher PDFPeer reviewe
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