70 research outputs found
Miscellaneous bean viruses
Bean crops are attacked by several viruses transmitted by insects among which are: (1) the alfalfa mosaic virus (aphids); susceptibility is correlated with plant age; (2) curly top (Circulifer tenellus); the best control measure is the utitilization of resistant var.; (3) bean summer death (Orosius argentatus); (4) tomato spotted wilt virus, which is transmitted mechanically and by various types of thrips; (5) red node, which is transmitted mechanically and in the seed. Insect vectors have not been reported; it can be controlled using resistant var. (CIAT)El cultivo del frijol es atacado por varios virus transmitidos por insectos, entre los cuales estan: 1) el virus del mosaico de la alfalfa (afidos); la susceptibilidad esta correlacionada con la edad de la planta; 2) el virus del apice rizado (Circulifer tenellus); la mejor medida de control es el uso de var. resistentes; 3) la muerte de verano del frijol (Orosius argentatus); 4) virus del marchitamiento manchado del tomate, el cual se transmite mecanicamente y por varias clases de trips; 5) el nudo rojo, el cual se transmite mecanicamente y por medio de la semilla. No se han observado insectos vectores; se puede controlar usando var. resistentes. (CIAT
Complicaciones de los osteocondromas
Los osteocondromas o exostosis cartilaginosas son los tumores óseos más frecuentes, representando
el 10-15 % de la totalidad. Parece ser más bien una alteración del desarrollo óseo más que un tumor verdadero. Suele
tener una imagen radiográfica patognomónica. Los osteocondromas pueden ser solitarios o múltiples, estos últimos
forman parte del síndrome de exostosis múltiples hereditarias, de transmisión autosómica dominante. Las complicaciones
que pueden presentar, pueden ser óseas; deformidad del hueso donde asientan o fracturas del mismo, o de los
tejidos que lo rodean, pudiendo provocar trastornos neurológicos, vasculares, bursitis, y la peor complicación, que es
su malignización. Existen variantes de los osteocondromas como la exostosis subungueal, la displasia epifisaria hemimielica,
y las exostosis en torreta y por tracción. Es importante conocer la apariencia radiológica de todos los tipos
de exostosis, para diferenciarlas de sus posibles complicaciones.Osteochondroma, also termed osteocartlaginous exostoses represents the most common bone tumors
and is a developmental lesion rather than a true neoplasm. It constitutes 10-15 % of all bone tumors. Its radiologic
features are often pathognomonic. Osteochondromas may be solitary or multiple, the latter being associated with the
autosomal dominant syndrome, hereditary multiple exostoses. Complications associated with osteochondroma include
deformity, fracture, vascular compromise, neurologic sequelae, overlying bursa formation, and malignant transformation.
Variant of osteochondroma include subungueal exostosis, dysplasia epiphysealis hemimelica, turret and
traction exostoses. Recognition of the radiologic spectrum of appearances of osteochondroma and its variants allow
prospective diagnosis and differentiation of the numerous potential complications
Virus miscelaneos del frijol
Bean crops are attacked by several viruses transmitted by insects among which are: (1) the alfalfa mosaic virus (aphids); susceptibility is correlated with plant age; (2) curly top (Circulifer tenellus); the best control measure is the utitilization of resistant var.; (3) bean summer death (Orosius argentatus); (4) tomato spotted wilt virus, which is transmitted mechanically and by various types of thrips; (5) red node, which is transmitted mechanically and in the seed. Insect vectors have not been reported; it can be controlled using resistant var. (CIAT)El cultivo del frijol es atacado por varios virus transmitidos por insectos, entre los cuales estan: 1) el virus del mosaico de la alfalfa (afidos); la susceptibilidad esta correlacionada con la edad de la planta; 2) el virus del apice rizado (Circulifer tenellus); la mejor medida de control es el uso de var. resistentes; 3) la muerte de verano del frijol (Orosius argentatus); 4) virus del marchitamiento manchado del tomate, el cual se transmite mecanicamente y por varias clases de trips; 5) el nudo rojo, el cual se transmite mecanicamente y por medio de la semilla. No se han observado insectos vectores; se puede controlar usando var. resistentes. (CIAT
Importancia del ablandamiento térmico en simulaciones de impactos en placas de acero a altas temperaturas
En el presente trabajo se presenta un estudio experimental y numérico de impactos balísticos sobre placas de acero inoxidable martensítico a altas temperaturas (400ºC y 700ºC), que pone de manifiesto la importancia del ablandamiento térmico en simulaciones de impactos a altas temperaturas. Mediante un estudio metalográfico de la zona de impacto, se ha observado la aparición de bandas adiabáticas de cortante formadas por el aumento brusco de la temperatura debido a la acumulación del trabajo plástico en el interior del material. La correcta predicción en la formación de estas bandas durante el proceso de penetración es crítica a la hora de obtener resultados representativos de los experimentos realizados. Basándose en datos experimentales de ensayos previamente realizados, se ha calibrado un modelo de material de Johnson-Cook (JC) para su uso con simulaciones numéricas en el código no lineal de elementos finitos LSDYNA. Mediante estas simulaciones numéricas se demuestra la importancia del ablandamiento térmico en el proceso de perforación de placas, al igual que la incapacidad que un modelo tipo JC tiene para representar el dicho ablandamiento para material estudiado. Esta investigación presenta, finalmente, una modificación a un modelo tipo JC programado como subrutina de material de usuario para LS-DYNA que permite simular correctamente estos procesos de impacto a alta temperatur
Application of molecular topology to the prediction of inhibition of Trypanosoma cruzi Hexokinase by bisphosphonates
Se ha desarrollado un modelo topológico-matemático para la búsqueda de nuevos derivados bisfosfonatos activos
frente a la hexokinasa de Trypanosoma cruzi. Utilizando el análisis lineal discriminante se ha seleccionado una función
con cuatro variables capaz de predecir adecuadamente la CI50 para cada compuesto de las series de entrenamiento
y test. El modelo propuesto se ha aplicado a una librería molecular y se han propuesto nuevas estructuras potencialmente activas frente a T. cruzi.A topological-mathematical model has been arranged to search for new derivatives of bisphosphonate compounds acting
as inhibitors against Trypanosoma cruzi hexokinase. By using linear discriminant analysis, a four-variable function was
achieved allowing an accurate prediction of the IC50 for each compound of the training and test series. After carrying
out a virtual screening based upon such a model, new structures potentially actives against T. cruzi are proposed.Este trabajo ha sido posible gracias al Fondo de Investigación Sanitaria, Ministerio de Sanidad, España (proyecto SAF2005-PIO52128) y al Máster Internacional en Enfermedades Parasitarias Tropicales, Universidad de Valencia
An embedded cohesive crack model for finite element analysis of quasi-brittle materials
This paper presents a numerical implementation of the cohesive crack model for the anal-ysis of quasibrittle materials based on the strong discontinuity approach in the framework of the finite element method. A simple central force model is used for the stress versus crack opening curve. The additional degrees of freedom defining the crack opening are determined at the crack level, thus avoiding the need for performing a static condensation at the element level. The need for a tracking algorithm is avoided by using a consistent pro-cedure for the selection of the separated nodes. Such a model is then implemented into a commercial program by means of a user subroutine, consequently being contrasted with the experimental results. The model takes into account the anisotropy of the material. Numerical simulations of well-known experiments are presented to show the ability of the proposed model to simulate the fracture of quasibrittle materials such as mortar, concrete and masonry
Effect of single layer centrifugation using Androcoll-E-Large on the sperm quality parameters of cooled-stored donkey semen doses
The aim of this study was to determine the effect of single layer centrifugation (SLC) using Androcoll-E-Large on donkey sperm
quality parameters after 24 h of cool-storage. Ejaculates were collected from Andalusian donkeys and then cooled at 5°C. SLC was
carried out after 24 h of cool-storage using Androcoll-E-Large. In the first experiment, all sperm parameters assessed (total and
progressive sperm motility, viability, sperm morphology and sperm kinematics VCL, VSL, VAP, LIN, STR, WOB, ALH and BCF) were
statistically compared between semen samples processed or not with Androcoll-E-Large. Significant differences ( P<0.05) were
found between SLC-selected and unselected semen samples for all parameters assessed, obtaining better results after SLC. In the
second experiment, semen samples were classified in two groups according to their sperm progressive motility (PM) before SLC.
Then, the increments obtained in semen quality parameters after SLC were compared between groups. No significant differences
were found between groups, indicating that SLC improved the sperm quality parameters of entire set of semen samples processed
with independence to their original PM. In conclusion, SLC with Androcoll-E-Large can be used in donkeys, increasing the sperm
quality of cooled-stored donkey semen doses after 24 h of cool storag
An embedded cohesive crack model for finite element analysis of brickwork masonry fracture
This paper presents a numerical procedure for fracture of brickwork masonry based on the strong discontinuity approach. The model is an extension of the cohesive model prepared by the authors for concrete, and takes into account the anisotropy of the material. A simple central-force model is used for the stress versus crack opening curve. The additional degrees of freedom defining the crack opening are determined at the crack level, thus avoiding the need of performing a static condensation at the element level. The need for a tracking algorithm is avoided by using a consistent procedure for the selection of the separated nodes. Such a model is then implemented into a commercial code by means of a user subroutine, consequently being contrasted with experimental results. Fracture properties of masonry are independently measured for two directions on the composed masonry, and then input in the numerical model. This numerical procedure accurately predicts the experimental mixed-mode fracture records for different orientations of the brick layers on masonry panels
Profiling of antioxidant potential and phytoconstituents of Plantago coronopus
The halophyte species Plantago coronopus has several described ethnomedicinal uses, but few reported biological activities. This work carried out for the first time a comparative analysis of P. coronopus organs in terms of phenolic composition and antioxidant activity of organic and water extracts from roots, leaves and flowers. The leaves contents in selected nutrients, namely amino acids and minerals, are also described. Roots (ethyl acetate and methanol extracts) had the highest radical scavenging activity (RSA) towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, while leaves (hexane extract) had higher RSA on nitric oxide radical and iron chelating ability. High performance liquid chromatography (HPLC) analysis identified eighteen phenolics from which salicylic acid and epicatechin are here firstly described in Plantago species. Leaves had mineral levels similar to those of most vegetables, proving to be a good source for elements like calcium, sodium, iron and magnesium, and also for several of the essential amino acids justifying it use as food. Our results, especially those regarding the phenolics composition, can explain the main traditional uses given to this plantain and, altogether, emphasize the potential of P. coronopus as a source of bioactive molecules particularly useful for the prevention of oxidative stress-related diseases
- …