M. Carmen Aranda

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In this paper, an effective shape-based leaf image retrieval system is presented. A new contour descriptor is defined which reduces the number of points for the shape representation considerably. This shape representation is based on the curvature of the leaf contour and it deals with the scale factor in a novel and compact way. A two-step algorithm for(More)
´ In this paper we present a definition of a domain relational calculus for fuzzy relational databases using the GEFRED model as a starting point. It is possible to define an equivalent fuzzy tuple relational calculus and consequently we achieve the two query language levels that Codd designed for relational databases but these are extended to Ž. fuzzy(More)
MCF7 human breast cancer cells growing as multicellular spheroids were examined as a model of three-dimensional cellular organization. Estrogen-free medium inhibited spheroid formation. In medium containing estrogens, the antiestrogen hydroxytamoxifen decreased the spheroid growth rate. Analyses with the recursion formula after Gompertz fitting showed that(More)
Database management systems used in information systems for the tourism industry and based on SQL are flexible insofar as they allow queries regarding the data stored in them. However, the SQL language, in spite of its flexibility, cannot deal with the vagueness of the queries clients present to travel agencies. Questions like ''I want an inexpensive trip(More)
The present study investigated differences in the growth rate of multicellular tumour spheroids of the MCF-7 line of human breast cancer before and after their irradiation. Growth of the spheroids was analysed according to a model based on a Gompertz function. In this model, normalization to a common initial volume is achieved in a way that enables(More)
OBJECTIVE Obesity is characterized by increased levels of plasma free fatty acids (FFAs) that interfere with insulin signaling. The aim of our study was to assess the FFA profile in obese children and adolescents and to determine their relation with different degrees of insulin resistance. METHODS A transversal study was conducted of 51 children and(More)
Biogenic amines play important roles in many physiological functions, but when they are ingested in high concentrations may produce severe adverse effects. The aim of this research was to evaluate the biogenic amine content in Chilean reserve varietal wines. A high performance liquid chromatography method was optimized and validated to quantify histamine,(More)
OBJECTIVE We propose and study a new model aimed at describing the low-dose hyper-radiosensitivity phenomenon appearing in the survival curves of different cell lines. METHODS The model uses the induced repair assumption, considering that the critical dose at which this mechanism begins to act varies from cell to cell in a given population. The model(More)
A short-term method for detecting potential environmental carcinogens is described using in vitro transformation assay of human epithelial-like amniotic fluid cells. According to Styles, after a short exposition to the carcinogen, only transformed cells grow and form large colonies when cultured in semi-solid agar. In our assay addition of liver homogenate(More)
Due to the essentiality of lysine for fish, its availability is commonly used as a predictor of the protein nutritional quality of fish feed. The objective of this work was to establish a high-throughput analytical method for protein quality control in fish feed through the measurement of available lysine by planar chromatography. Sample was first incubated(More)