961 research outputs found

    El uso del ajuste lineal en los espectros de tamaño de biomasa para diseñar indicadores ecosistémicos

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    Biomass size spectra describe the structure of aquatic communities ataxonomically. The slope (b) of the normalized biomass size spectrum (NBSS) is often used as an indicator of the impact of perturbations, such as pollution or overfishing. The NBSS intercept (a), has generally been ignored on the basis of a correlation between the NBSS slope and intercept, although this correlation has not been shown to be universal. We assessed whether the NBSS parameters are correlated using: (i) theoretical analysis, (ii) virtual communities randomly generated based only on statistical considerations, and (iii) virtual food webs changing over time following a dynamic bioenergetic model. We also analyzed whether the parameters of the Pareto distribution are correlated or not, using approaches (i) and (ii). We found that when communities change over time there is no single relationship between the two NBSS parameters, due to a dependence on the variation in total community abundance (N). We conclude that to characterize any aquatic system at least two parameters are necessary from the NBSS triad N, a, b. In the case of the Pareto distribution, both NPareto and bPareto are necessary.Los espectros de tamaño de biomasa son un método ataxonómico para describir la estructura de comunidades acuáticas. La pendiente (b) del espectro de tamaños de biomasa normalizado (ETBN) se usa como un indicador del impacto de perturbaciones tales como polución y sobrepesca. El intercepto del ETBN (a) ha sido normalmente ignorado debido a una correlación observada entre la pendiente y el intercepto del ETBN, aunque no se ha demostrado la recurrencia de esta correlación. Se evaluó esta correlación entre los parámetros usando: (i) análisis teórico, (ii) comunidades virtuales generadas aleatoriamente basado en consideraciones estadísticas, y (iii) redes tróficas virtuales cambiando en el tiempo siguiendo un modelo bioenergético dinámico. Además, se analizó si los parámetros de la distribución de Pareto estaban o no correlacionados usando los enfoques (i) y (ii). Cuando las comunidades cambian en el tiempo no existe una única correlación entre los parámetros del ETBN, debido a una dependencia en la variación de la abundancia comunitaria (N). Para caracterizar cualquier sistema acuático se necesitan al menos dos coeficientes del ETBN de la triada N, a, b. En la distribución de Pareto los dos parámetros, NPareto y bPareto, son necesarios

    Neural correlates of phonological, orthographic and semantic reading processing in dyslexia

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    Developmental dyslexia is one of the most prevalent learning disabilities, thought to be associated with dysfunction in the neural systems underlying typical reading acquisition. Neuroimaging research has shown that readers with dyslexia exhibit regional hypoactivation in left hemisphere reading nodes, relative to control counterparts. This evidence, however, comes from studies that have focused only on isolated aspects of reading. The present study aims to characterize left hemisphere regional hypoactivation in readers with dyslexia for the main processes involved in successful reading: phonological, orthographic and semantic. Forty-one participants performed a demanding reading task during MRI scanning. Results showed that readers with dyslexia exhibited hypoactivation associated with phonological processing in parietal regions; with orthographic processing in parietal regions, Broca's area, ventral occipitotemporal cortex and thalamus; and with semantic processing in angular gyrus and hippocampus. Stronger functional connectivity was observed for readers with dyslexia than for control readers 1) between the thalamus and the inferior parietal cortex/ventral occipitotemporal cortex during pseudoword reading; and, 2) between the hippocampus and the pars opercularis during word reading. These findings constitute the strongest evidence to date for the interplay between regional hypoactivation and functional connectivity in the main processes supporting reading in dyslexia. Keywords: Dyslexia, Reading, Hypoactivation, Functional connectivity, Thalamus, Hippocampu

    Efecto del extracto de ajo como compensador de frio en la brotación del manzano red delicious en la región de nuevo ideal durango México

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    The research evaluated the effects of organic and chemical cold compensators on flowering, fruit quality and productivity. The experimental design was random blocks with 4 treatments and 5 repetitions. T0 = control; T1 = garlic (5 kg / 1000 l + glycerin 2 l / 1000 l); T2 = Erger ® (Organic nitrogen (1%), inorganic nitrogen (5% nitric and 5% ammoniacal) and 50% organic carbon + calcium nitrate 5 kg / 1000 L; T3 = Revent ® (Thidiazuron 200 ml / 1000l + winter mineral oil 10 l / 100) Five similar branches were identified and marked, 4 according to the cardinal points and one central.The number of flowers was evaluated, in fruits the equatorial and polar diameter with a vernier, the weight was determined with precision balance and percentage of coloration, to measure the hardness of a penetrometer, the soluble solids with a refractometer The analysis of variance and the comparison test of means (Tukey; α = 0.05) between the response variables, was performed with the statistical package of Dr. Olivares of FAUANL There were significant differences in the flowering of the treatments T1 = 178, T2 = 171, T3 = 208 with respect to the control T0 = 91. The polar and equatorial diameter of the fruit T2 was different from the rest (19.7%). The concentration of soluble solids and the hardness of the pulp did not present differences, contrary to the coloration the T1 was different to the other treatments (74.78%). In conclusion, garlic can function as a cold compensator in the Red deliciuos apple tree, however, it is less productive compared to the chemical treatments used.La investigación evaluó los efectos de compensadores de frio orgánicos y químicos en la floración, calidad de fruto y productividad. El diseño experimental fue bloques al azar con 4 tratamientos y 5 repeticiones. T0=control; T1=ajo (5 kg 1000 L-1 + glicerina 2 L 1000 L-1); T2=Erger ® (Nitrógeno orgánico (1%), nitrógeno inorgánico (nítrico 5% y amoniacal 5%) y 50% de carbono orgánico + nitrato de calcio 5 kg 1000 L-1; T3=Revent ® (Thidiazuron 200 ml 1000 L-1 + aceite mineral invernal 10 L/100). Se identificaron y marcaron 5 ramas similares, 4 de acuerdo a los puntos cardinales y una central. Se evaluó el número de flores, en frutos el diámetro ecuatorial y polar con un vernier, el peso se determinó con balanza de precisión y porcentaje de coloración, para medir la dureza un penetrómetro, los sólidos solubles con un refractómetro. El análisis de varianza y la prueba de comparación de medias (Tukey; α=0.05) entre las variables respuesta, se realizó con el paquete estadístico del Dr. Olivares de FAUANL. Hubo diferencias significativas en la floración de los tratamientos T1=178, T2=171, T3=208 respecto al control T0=91. El diámetro polar y ecuatorial del fruto el T2 fue diferente a los demás (19.7%). La concentración de sólidos solubles y la dureza de la pulpa no presentaron diferencias, contrario a la coloración el T1 fue diferente a los otros tratamientos (74.78%). En conclusión, el ajo puede funcionar como compensador de frio en el manzano Red deliciuos, sin embargo, es menos productivo en comparación con los tratamientos químicos utilizados

    Is fetal gender associated with adverse perinatal outcome in intrauterine growth restriction (IUGR)?

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    OBJECTIVE: The purpose of this study was to determine if there is a difference in perinatal outcome by gender among growth-restricted fetuses. STUDY DESIGN: This was a retrospective cohort study of intrauterine growth restriction (IUGR) singleton pregnancies over a 5-year period. Clinical outcomes compared by gender included preterm delivery, perinatal mortality (PNM), respiratory distress syndrome (RDS), grade 3 or 4 intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), and periventricular leukomalacia (PVL). Statistical analysis included bivariate and multivariable techniques. RESULTS: Seven hundred and twenty-seven singleton pregnancies with IUGR were identified. Three hundred and forty-six (47.6%) were males. Birth weight was similar between the groups. After adjusting for maternal demographics, medical history, gestational age, mode of delivery, and antenatal corticosteroids, adverse perinatal outcomes were similar between the groups. Severity of outcomes was also similar between males and females (P = .66). CONCLUSION: Male fetuses with IUGR have similar outcomes when compared with female IUGR fetuses. Gender does not play a role in perinatal outcome in the setting of fetal growth restriction

    La indagación científica como enfoque pedagógico: estudio sobre las prácticas innovadoras de docentes de ciencia en EM (Región de Valparaíso)

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    RESUMEN: El presente trabajo refiere los resultados de un estudio cualitativo cuyo objetivo fue describir y comprender las prácticas de seis docentes de ciencia en Educación Secundaria que han logrado transformar su enseñanza, aproximándose a un enfoque indagatorio. El enfoque metodológico empleado fue Grounded Theory, el cual se aplicó a la observación de 54 horas (cr.) de clase. El estudio aporta con información descriptiva y comprensiva sobre las características de las prácticas observadas, así como las condiciones que las permiten y las consecuencias que conllevan. Se finaliza discutiendo el impacto que este estudio tiene sobre la formación inicial y continua de docentes de ciencia de Educación Secundaria. ABSTRACT: This research refers the results of a qualitative study which purpose was to describe and understand the teaching practices of six secondary science teachers who have transformed their teaching practice by applying an inquiry approach. The method used was Grounded Theory applied to the observation of 54 class hours (cr.). This research contributes with descriptive and comprehensive information about characteristics of the observed practices, as well as the conditions that allow them and their consequences. Finally, we discuss the implications that this study has on pre-service and in-service secondary science teacher education

    Características coligadas al estilo de vida en pacientes adultos mayores en un Centro de Salud de los Andes en el Perú: Characteristics related to lifestyle in elderly patients in a Health Center of the Andes in Peru

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    Introduction: A correct lifestyle is vital in older adults to reduce their risk of diseases and loss of functionality. Objective: To determine the lifestyles of elderly patients in a Health Center in the Peruvian Andes. Method: Observational, descriptive study with elderly patients from a health center. We worked with a previously collected database. Descriptive statistics were used. The study was approved by the institutional ethics committee. Results: Of the 74 patients evaluated, the mean age was 75.4 years and 52% were females. The mean BMI was 24.8 kg / m2 and that of the abdominal circumference was 86.8 cm. 32.7% had a visual acuity of 70 in the right eye and 36.4% of 50 in the left eye. Glucose (mg / dL), hemoglobin (g / dL) and uric acid (mg / dL) had a median of 97, 15.4 and 7; respectively. Triglycerides and cholesterol had a mean of 182.2 mg / dL and 189.9 mg / dL; respectively. 5.4% of men had reactive PSA. 4% had diabetes, 21.6% hypertension, and 22.2% anemia; while 70.3% consumed alcohol, 6.8% smoked and 89.2% consumed soda. Conclusions: Some indicators of poor lifestyle were found, such as the consumption of alcohol and soft drinks, as well as indicators of conditions related to a poor lifestyle such as an average BMI close to being overweight, high triglycerides and cholesterol.Introducción: Un correcto estilo de vida es vital en los adultos mayores para reducir su riesgo de enfermedades y de perder funcionalidad. Objetivo: Determinar las características coligadas al estilo de vida en pacientes adultos mayores en un Centro de Salud de los andes peruanos. Método: Estudio observacional, descriptivo con pacientes adultos mayores de un centro de salud. Se trabajó con una base de datos previamente recolectada. Se usó estadística descriptiva. El estudio fue aprobado por el comité de ética institucional. Resultados: De los 74 pacientes evaluados, la media de edad fue de 75,4 años y el 52% fue de sexo femenino. La media del IMC fue de 24,8 Kg/m2 y la del perímetro abdominal de 86,8 cm. 32,7% tuvieron una agudeza visual de 70 en el ojo derecho y 36,4% de 50 en el ojo izquierdo. La glucosa (mg/dL), hemoglobina (g/dL) y el ácido úrico (mg/dL) tuvieron una mediana de 97, 15,4 y 7; respectivamente. Los triglicéridos y el colesterol tuvieron una media de 182,2 mg/dL y 189,9 mg/dL; respectivamente. Un 5,4% de hombres tuvieron PSA reactivo. 4% tuvieron diabetes, 21,6% hipertensión arterial y 22,2% anemia; mientras que 70,3% consumía alcohol, 6,8% tenía tabaquismo y 89,2% consumía bebidas gaseosas. Conclusiones: Se encontraron algunos indicadores de mal estilo de vida, como el consumo de alcohol y bebidas gaseosas, así como indicadores de condiciones relacionadas a un mal estilo de vida como una media del IMC cercano al sobrepeso, de triglicéridos y colesterol elevados

    Three Trocars Laparoscopic Resection of Angiomyolipoma of the Liver

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    Angiomyolipoma of the liver (AML) is an infrequent neoplasm composed of three tissues (adipose, muscle and vessels). In spite of advances in radiology, preoperative correct diagnosis is difficult. Clasically, a conservative management strategy was adopted in patients with asymptomatic tumors less than 5 cm with undoubtful diagnosis. But after publishing some few cases of malignant angiomyolipoma a more radical has been advocated. Laparoscopic resection of liver tumors is becoming a excellent approach for operating on benign liver tumors. Usually is performed using five trocars but in some cases a less invasive technique with three trocars could be used. We present a laparoscopic resection of liver angiomyolipoma in a 65 year-old male using only three trocars and also discuss the optimal management of AML and technical tips of three-trocar technique
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