Understanding the complexity of human language requires an appropriate analysis of the statistical distribution of words in texts. We consider the information retrieval problem of detecting and ranking the relevant words of a text by means of statistical information referring to the spatial use of the words. Shannon's entropy of information is used as a tool for automatic keyword extraction. By using The Origin of Species by Charles Darwin as a representative text sample, we show the performance of our detector and compare it with another proposals in the literature. The random shuffled text receives special attention as a tool for calibrating the ranking indices. PACS. -89.70.+c Information theory and communication theory -05.45.Tp Time series analysis -89.75.-k Complex systems

Near-infrared (NIR) spectroscopy has become a very popular technique for the non-invasive assessment of intact fruit. This work presents an application of a low-cost commercially available NIR spectrometer for the estimation of ripeness of Chilean wine grapes. Two configurations for the spectra acquisition were used (diffuse transmittance and interactance), using a custom-designed contact probe. Samples of Chardonnay, Carménère and Cabernet Sauvignon, collected over the 2002 harvest and pre-harvest seasons, were analysed for total soluble solids content ( • Brix). Partial least squares calibration models, obtained from several preprocessing techniques (smoothing, multiplicative signal correction, standard normal variate, etc), were compared. Also, two spectral regions were used, one without the red part of the visible spectrum (just the short-wave (SW-NIR) region) and the other including it. Performance of different models was assessed in terms of root mean square of cross-validation, root mean square of prediction (RMSEP) and R 2 for a validation set of samples. RMSEPs of 1.06 with R 2 = 0.942 indicate that it is possible to estimate wine grape ripeness ( • Brix value), by using a CCD portable spectrometer. The red grape models performed better than the white grape models.

The proximate and amino acid compositions of the leaves and pods of Prosopis chilensis and P tamarugo and the leaves of P alba have been assessed. The biological activity of the leaves and pods of the ®rst two species as well as the leaves and exudate of P alba has been determined for free radical scavenging activity, xanthine oxidase inhibition and DNA binding. The best protein source among the forage trees was the leaves of P chilensis; P alba and P tamarugo leaves showed higher crude protein, fat and nitrogen-free extract values than reported in previous studies. According to their amino acid pro®les, all species surveyed are de®cient in essential amino acids. The alkaloids b-phenethylamine and tryptamine were isolated from P chilensis, and phenethylamine was detected in P tamarugo. At 0.50 mg ml À1, both compounds showed DNA binding activity, with values of 18.5 and 11% respectively. The exudate of P alba showed a strong free radical scavenging effect. The activity was related with the total phenolics content, consisting mainly of catechin.

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Contextualización: Los rumiantes tienen una ventaja comparativa con relación a otras especies, gracias a la capacidad de digerir las fracciones de la fibra presente en los forrajes.    Vacío de conocimiento: En regiones tropicales, debido a las condiciones medioambientales cambiantes, se hace más difícil la producción de pasturas de alta calidad nutricional, derivando así en una estacionalidad forrajera.  Esto conlleva a que sea necesaria la suplementación con alimentos comerciales para los animales, lo que incrementa los costos de producción. Propósito del estudio: Evaluar el efecto de la suplementación con forraje verde hidropónico (FVH) y forraje verde organopónico (FVO) de maíz sobre el rendimiento productivo de ovinos en fase de levante, en el piedemonte amazónico del Departamento del Putumayo.    Metodología: Se utilizaron 12 corderos Dorper enteros con edad de 90 días y peso 14.62 kg, los cuales se distribuyeron para la aplicación de tres tratamientos consistentes en: T0: dieta base (DB), T1: forraje verde hidropónico (FVH) y T2: forraje verde organopónico (FVO). Se evaluó la ganancia de peso total (GPT), ganancia diaria de peso (GDP), consumo total de alimento (CTA), conversión alimenticia (CA) y eficiencia alimenticia (EA) durante un periodo de suplementación de 45 días. Se utilizó un diseño completamente al azar. Los datos se analizaron mediante análisis de varianza y las medias fueron separadas mediante la prueba de Tukey con un nivel de significancia de (p < 0.05).    Resultados y conclusiones: Se encontraron diferencias (p < 0.05) en la GPT 3.66 kg (T1), 3.61 kg (T2) y 2.35 kg (T0); de igual manera para la GDP 81.39 g (T1), 80.30 g (T2) y 52.22 g (T0); para el CTA 1.33 kg (T1), 1.27 kg (T2) y 1.05 kg (T0); la CA se estimó para el T1 en 3.23, 3.27 en T2 y 5.13 en T0; y la EA fue de 0.063 (T1), 0.061 (T2) y 0.050 (T0), evidenciando la influencia del tipo de dieta utilizada. La implementación de FVH y FVO se convierte en una alternativa viable de suplementación en los sistemas de producción de ovinos, en los que las condiciones medioambientales hacen difícil el cultivo de forrajes para pastoreo. Se concluye que la inclusión del 30 % de FVH de maíz en la dieta de ovinos en crecimiento mejora su rendimiento productivo.