884 resultados para Biometric authentication


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Ciência e Tecnologia Animal - FEIS

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The use of gastropod shells by hermit crabs is determined by the availability of shells in the environment or through selection for size and volume. This study analyzed patterns in the use of shells by Dardanus insignis (Saussure, 1858). From January 1998 to December 1999, 386 individuals were collected from two islands at Ubatuba, Sao Paulo. The crabs were measured for cephalothoracic shield length (CSL) and wet weight (CWW). The gastropod shells occupied by hermit crabs were identified, and the shell aperture width (SAW), dry weight (SDW) and internal volume (STY) were measured. The relationships between the dimensions of the gastropod shell and the hermit crabs were evaluated by linear regression analysis. Among the 11 species of gastropod shells used by D. insignis, the most often used was Olivancillaria urceus (31%), followed by Strombus pugilis (22%) and Siratus tenuivaricosus (18%). The shell of O. urceus was used most probably due to its high availability on Couves and Mar Virado islands. The most significant biometric parameter was shell aperture width (F=18.231; p<0.0001), highlighting the importance of this variable for the shell choice by D. insignis at both sites.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Experimental models composed by human and animal cell lines are simplified and informative, allowing them to be widely used for biomedical research. Most laboratories that use in vitro cultivated cells maintain a variation of cell lines stored and cultivated. Therefore, misidentification and cross-contamination events can happen during cell lines handling. This problem can generate a repertoire of dubious results and papers, which may prejudice biomedical research. Recently it was created the International Cell Line Authentication Committee (ICLAC), which aims to spread knowledge about cross-contamination and misidentification of in vitro cell lines. Despite of the efforts spent trying to aware scientific community about the importance of the correct identification of cells, the number of papers based on misidentified cell lines it´s still worrying, compromising the reliability of out coming results and conclusions regarding them. The present study aims to analyze and discuss the main advantages and limitations of eukaryote in vitro cell lines use, characterizing the cell lines authentication problems. Therefore, compilation and critical analyses of literature data was realized, aiming to improve the understanding about this subject. Based on information about 445 cell lines with issues published by ICLAC it´s clear that contamination in human cell lines represented 89,2 % of mentioned problems. HeLa cell line was the responsible for most contamination, especially in 92 normal tissue cell lines, representing 44,6% of the contamination. These results reinforce the importance of periodic maintenance of cell lines cultures by labs and implementation of authentication methods as polymorphic STRs, besides obtaining cell lines from reliable sources and cell banks

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The biometric characteristics have been used increasingly as a way to identify an individual, mainly for security reasons. Among them, the fingerprint is the most used biometric characteristic around the world, because it is relatively simple and very efficient. In this scene, there was a significant increase in the size of databases containing information on fingerprints, necessary to perform the recognition of a person. The task of classifying them beforehand has become extremely important as it reduces dramatically the size of the problem during a search, because it is not necessary to go through the whole database. Considering its importance, in the last thirty years, many techniques have been developed to try to increase the efficiency of the classification process. This project followed the rules-based approach and the Software Development Kit (SDK) VeriFinger 6.1 was used to assist in the detection of cores and deltas. Additionally, the classification was also implemented by means of directional map and the Poincar´e index. To make the experiments, the number four database from the National Institute of Standards and Technology (NIST) was used, which is a standard in this area

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The use of physical characteristics for human identification is known as biometrics. Among the many biometrics traits available, the fingerprint is the most widely used. The fingerprint identification is based on the impression patterns, as the pattern of ridges and minutiae, characteristics of first and second levels respectively. The current identification systems use these two levels of fingerprint features due to the low cost of the sensors. However, the recent advances in sensor technology, became possible to use third level features present within the ridges, such as the perspiration pores. Recent studies show that the use of third-level features can increase security and fraud protection in biometric systems, since they are difficult to reproduce. In addition, recent researches have also focused on multibiometrics recognition due to its many advantages. The goal of this research project was to apply fusion techniques for fingerprint recognition in order to combine minutia, ridges and pore-based methods and, thus, provide more robust biometrics recognition systems, and also to develop an automated fingerprint identification system using these three methods of recognition. We evaluated isotropic-based and adaptive-based automatic pore extraction methods, and the fusion of pore-based method with the identification methods based on minutiae and ridges. The experiments were performed on the public database PolyUHRF and showed a reduction of approximately 16% in the EER compared to the best results obtained by the methods individually

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Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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The aim of this study was to determine the best pre-germination treatments for seeds and the best size container for seedlings growing of coral tree Erythrina mulungu (Mart. ex. Benth). Among the treatments applied to seeds, scarification with sulfuric acid during 10 minutes and cutting stylus in the region opposite to hilum resulted, respectively, in highest values of germination percentage (82.8% and 82.1%) and rates of germination speed (1.15 and 1.71). The biometric variables indicated no effect of container size on leaf area and dry mass plants. At 63 days after sowing, although with Dickson quality score statistically similar (mean 0.26), only plants grown in small and large bags reached the diameter collect close to 5 mm, minimum recommended for field planting. According to the results, for initial development of coral tree, it is recommended pre-seed treatment with sulfuric acid commercial, sowing in plastic bags of 17 x 20 cm, and wait 63 days before planting in the field.

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The species Pimelodus maculatus is one of the most abundant fish in many artificial reservoirs. Shows feeding plasticity and exploits all trophic levels in aquatic ecosystems. This study aimed to analyze and compare aspects of the diet of P. maculatus in two important tributaries (Taquari and Veados rivers) in the upper Paranapanema River system, and also investigate possible differences in the condition factor using its feeding habit as reference. Samplings were carried out every three months during 2011 and 2012 in two tributaries of Jurumirim's dam. After biometric analysis, fish were dissected to remove the stomachs that were fixed in formaldehyde 10% and conserved in alcohol 70%. The stomach content was analyzed under stereomicroscope and the food items were identified until the least possible taxonomic level. The diet was characterized based on the Alimentary Index (IAi). Feeding strategy and aspects of species autoecology were evaluated by the relation between abundance of prey-specific (Pi) and occurrence frequency (Fo) of the prey, and also was calculated the niche width of Levin (B). The condition factor was also established and values obtained in samples of both rivers were compared, correlating them with diet of the species

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Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA