347 research outputs found

    tecnologías de información y comunicación para la enseñanza de la biotecnología

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    This study is framed in an investigation of descriptive field, the same was to describe the use of ITC for teaching biotechnology. This research is focused on the constructivist theory supported on technological theory .The subjects of this study were composed of thirty (30) teachers who teach the subject of Biology. . The phase of the study was conducted primarily by the diagnosis is performed by applying an instrument with its evaluation by experts in the subject proposed. In other reliability was performed by calculating the  Alpha Cronbach coefficient to determine that the instrument is homogeneous, uniform, consistent and reliable. The analysis results indicate that there is very high need for incorporating ITC for teaching biotechnology.El presente estudio está enmarcado en una  investigación de campo de tipo descriptiva, el mismo tuvo el fin de describir el uso del tic para la enseñanza de la Biotecnología. Esta investigación está enfocada en la teoría constructivista  apoyada en la teoría tecnológica. Los sujetos del presente estudio estuvieron conformados por treinta (30) docentes que imparten la asignatura de Biología. La fase del estudio se desarrolló principalmente por el diagnosticó esta se realizó mediante la aplicación de un instrumento con su respectiva evaluación por expertos en la temática planteada. A demás la confiabilidad se realizó a través del cálculo del coeficiente Alpha Cronbach permite determinar que el instrumento es homogéneo, uniforme, consistente y confiable. El análisis de los resultados indica que existe muy alta necesidad de incorporar las TIC para la enseñanza de la Biotecnología

    Phosphorus restriction does not prevent the increase in fibroblast growth factor 23 elicited by high fat diet

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    This study was designed to evaluate the influence of phosphorus (P) restriction on the dele- terious effects of high fat diets on mineral metabolism. Twenty-four rats were allotted to 3 groups (n = 8 each) that were fed different diets for 7 months. Rats in group 1 were fed nor- mal fat-normal P (0.6%) diet (NF-NP), rats in group 2 were fed high fat- normal P diet (HF- NP) and rats in group 3 were fed high fat-low P (0.2%) diet (HF-LP). Blood, urine and tissues were collected at the end of the experiments. When compared with the control group (NF- NP), rats fed HF diets showed increases in body weight, and in plasma concentrations of tri- glycerides and leptin, and decreased plasma calcitriol concentrations. In rats fed HF-NP plasma fibroblast growth factor 23 (FGF23) was higher (279.6 ± 39.4 pg/ml vs 160.6 ± 25.0 pg/ml, p = 0.018) and renal klotho (ratio klotho/GAPDH) was lower (0.75 ± 0.06 vs 1.06 ± 0.08, p < 0.01) than in rats fed NF-NP. Phosphorus restriction did not normalize plasma FGF23 or renal klotho; in fact, rats fed HF-LP, that only ingested an average of 22.9 mg/day of P, had higher FGF23 (214.7 ± 32.4 pg/ml) concentratio ns than rats fed NF-NP (160.6 ± 25. 0 pg/ml), that ingested and average of 74.4 mg/day of P over a 7 month period. In conclusion, our results demonstrate that severe P restriction over a prolonged period of time (7 months) does not normalize the increase in circulating FGF23 induced by HF diets. These data indi- cate that the deleterious effects of high fat diet on the FGF23/klotho axis are not eliminated by reduced P intake

    Evaluación de sistemas de producción y alimentación bovina (Quindío-Colombia).

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    Se realizó una encuesta en 50 explotaciones ganaderas en el departamento de Quindio (Colombia) cubriendo aspectos: físicos (altura m.s.n.m.), socio-económicos (precio de leche, uso de mano de obra), manejo de forrajes (area de pastos mejorados), manejo animal (sistemas de crianza de terneros), alimentación (uso de concentrados, pasto de corte), parámetros de productividad (producción por vaca, carga animal). Los objetivos básicos del trabajo, fueron describir y caracterizar los sistemas de producción y evaluar técnicamente las formas de alimentación tradicional utilizadas. Para el primer objetivo se emplearon las técnicas para análisis multivariante de datos: análisis factorial y análisis de conglomerados ((cluster), de la cual se obtuvo la tipificación de los productores en 4 grupos de fincas con caractersticas productivas y socio-agroenonómicas diferentes. Para cada grupo se obtuvo un modelo esquemático del sistema de producción respectivo. La evaluación alimentaria se realizó con modelos sencillos para el cálculo de raciones en vacas en producción, vacas secas, novillas y terneros, empleando en el modelo dietas típicas utilizadas en los diferentes sistemas de producción. Al analizar las dietas se encontraton tendencias dentro de la muestra en estudio tales como: deficiencias de energía en el aporte nutricional de las dietas para las vacas en producción, bajos niveles de producción de leche/vaca y bajas ganancias de peso para animales en crecimiento. También se encontró en la zona de estudio costosos sistemas de crianza para terneros, manejo irracional del componente forrajero: praderas - pasto de corte y utilización ineficiente de subproductos y recursos no convencionales de alta disponibilidad para la alimentación de bovinos.;A partir del análisis integrado de los aspectos estudiados, se proponen recomendaciones prácticas dirigidas al asistente técnico e instituciones tendientes a solucionar los problemas encontrados y con el criterio de reducir costos de producción y aumentar productividad/ha en las finca

    Klotho/FGF23 and Wnt Signaling as Important Players in the Comorbidities Associated with Chronic Kidney Disease

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    Fibroblast Growth Factor 23 (FGF23) and Klotho play an essential role in the regulation of mineral metabolism, and both are altered as a consequence of renal failure. FGF23 increases to augment phosphaturia, which prevents phosphate accumulation at the early stages of chronic kidney disease (CKD). This effect of FGF23 requires the presence of Klotho in the renal tubules. However, Klotho expression is reduced as soon as renal function is starting to fail to generate a state of FGF23 resistance. Changes in these proteins directly affect to other mineral metabolism parameters; they may affect renal function and can produce damage in other organs such as bone, heart, or vessels. Some of the mechanisms responsible for the changes in FGF23 and Klotho levels are related to modifications in the Wnt signaling. This review examines the link between FGF23/Klotho and Wnt/β-catenin in different organs: kidney, heart, and bone. Activation of the canonical Wnt signaling produces changes in FGF23 and Klotho and vice versa; therefore, this pathway emerges as a potential therapeutic target that may help to prevent CKD-associated complications

    Energy-dense diets increase FGF23, lead to phosphorus retention and promote vascular calcifications in rats

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    Rats with normal renal function (Experiment 1, n = 12) and uninephrectomized (1/2Nx) rats (Experiment 2, n = 12) were fed diets with normal P (NP) and either normal (NF) or high fat (HF). Rats with intact renal function (Experiment 3, n = 12) were also fed NF or HF diets with high P (HP). Additionally, uremic (5/6Nx) rats (n = 16) were fed HP diets with NF or HF. Feeding the HF diets resulted in significant elevation of plasma FGF23 vs rats fed NF diets: Experiment 1, 593 ± 126 vs 157 ± 28 pg/ ml (p < 0.01); Experiment 2, 538 ± 105 vs 250 ± 18 pg/ml (p < 0.05); Experiment 3, 971 ± 118 vs 534 ± 40 pg/ml (p < 0.01). Rats fed HF diets showed P retention and decreased renal klotho (ratio klotho/actin) vs rats fed NF diets: Experiment 1, 0.75 ± 0.06 vs 0.97 ± 0.02 (p < 0.01); Experiment 2, 0.69 ± 0.07 vs 1.12 ± 0.08 (p < 0.01); Experiment 3, 0.57 ± 0.19 vs 1.16 ± 0.15 (p < 0.05). Uremic rats fed HF diet showed more severe vascular calcification (VC) than rats fed NF diet (aortic Ca = 6.3 ± 1.4 vs 1.4 ± 0.1 mg/g tissue, p < 0.001). In conclusion, energy-rich diets increased plasma levels of FGF23, a known risk factor of cardiovascular morbidity and mortality. Even though FGF23 has major phosphaturic actions, feeding HF diets resulted in P retention, likely secondary to decreased renal klotho, and aggravated uremic V

    Oral Acid Load Down-Regulates Fibroblast Growth Factor 23

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    Increased dietary acid load has a negative impact on health, particularly when renal function is compromised. Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that is elevated during renal failure. The relationship between metabolic acidosis and FGF23 remains unclear. To investigate the effect of dietary acid load on circulating levels of FGF23, rats with normal renal function and with a graded reduction in renal mass (1/2 Nx and 5/6 Nx) received oral NH4Cl for 1 month. Acid intake resulted in a consistent decrease of plasma FGF23 concentrations in all study groups when compared with their non-acidotic control: 239.3 ± 13.5 vs. 295.0 ± 15.8 pg/mL (intact), 346.4 ± 19.7 vs. 522.6 ± 29.3 pg/mL (1/2 Nx) and 988.0 ± 125.5 vs. 2549.4 ± 469.7 pg/mL (5/6 Nx). Acidosis also decreased plasma PTH in all groups, 96.5 ± 22.3 vs. 107.3 ± 19.1 pg/mL, 113.1 ± 17.3 vs. 185.8 ± 22.2 pg/mL and 504.9 ± 75.7 vs. 1255.4 ± 181.1 pg/mL. FGF23 showed a strong positive correlation with PTH (r = 0.877, p < 0.0001) and further studies demonstrated that acidosis did not influence plasma FGF23 concentrations in parathyroidectomized rats, 190.0 ± 31.6 vs. 215 ± 25.6 pg/mL. In conclusion, plasma concentrations of FGF23 are consistently decreased in rats with metabolic acidosis secondary to increased acid intake, both in animals with intact renal function and with decreased renal function. The in vivo effect of metabolic acidosis on FGF23 appears to be related to the simultaneous decrease in PTH

    Modelación numérica hidrodinámico-hidrológica en zonas de inundación con presencia de infraestructura

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    Se presenta la modelación numérica computacional de la hidrodinámica superficial e hidrológica de la zona de estudio donde se pretende construir infraestructura para la exploración de hidrocarburos en las márgenes del río Grijalva, México; para ello se muestra el análisis de la información meteorológica, determinando los valores de intensidad de precipitación, temperaturas, evaporación y una estimación de los gastos, correspondiente al año 2014; las zonas de inundación se estimaron con el uso de programas desarrollados en Fortran y Matlab, que resuelven las ecuaciones de Navier-Stokes-Reynolds para flujos a superficie libre y la intensidad de precipitación con la distribución de Gumbel, con parámetros estimados mediante el método de Momentos Ponderados con Probabilidad (MPP), con los cuales, mediante una malla numérica de la topografía, en conjunto con los valores meteorológicos, como condiciones iniciales y forzantes, se determina la magnitud de la inundación del área de estudio, así como la obtención de gastos, velocidades y el funcionamiento hidráulico de las obras de mitigación propuestas para preservar el balance hidrológico del sistema

    Procaine Inhibits Osteo/Odontogenesis through Wnt/β-Catenin Inactivation

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    Introduction Periodontitis is a complex pathology characterized by the loss of alveolar bone. The causes and the mechanisms that promote this bone resorption still remain unknown. The knowledge of the critical regulators involved in the alteration of alveolar bone homeostasis is of great importance for developing molecular therapies. Procaine is an anesthetic drug with demethylant properties, mainly used by dentists in oral surgeries. The inhibitor role of Wnt signaling of procaine was described in vitro in colon cancer cells. Methods In this work we evaluated the role of procaine (1 uM) in osteo/odontogenesis of rat bone marrow mesenchymal stem cells. Similarly, the mechanisms whereby procaine achieves these effects were also studied. Results Procaine administration led to a drastic decrease of calcium content, alkaline phosphatase activity, alizarin red staining and an increase in the expression of Matrix Gla Protein. With respect to osteo/odontogenic markers, procaine decreased early and mature osteo/odontogenic markers. In parallel, procaine inhibited canonical Wnt/β-catenin pathway, observing a loss of nuclear β-catenin, a decrease in Lrp5 and Frizzled 3, a significant increase of sclerostin and Gsk3β and an increase of phosphorylated β-catenin. The combination of osteo/ odontogenic stimuli and Lithium Chloride decreased mRNA expression of Gsk3β, recovered by Procaine. Furthermore it was proved that Procaine alone dose dependently increases the expression of Gsk3β and β-catenin phosphorylation. These effects of procaine were also observed on mature osteoblast. Interestingly, at this concentration of procaine no demethylant effects were observed. PLO
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