72 resultados para Seleção dependente de frequência
Resumo:
Marmosets, Callithrix jacchus, are strictly diurnal animals. The motor activity rhythmicity is generated by the circadian timing system and is modulated by environmental factors, mainly by photic stimuli that compose the light-dark cycle. Photic stimuli can reset the biological oscilators changing activity motor pattern, by a mechanism called entrainment. Otherwise, light can act directly on expressed rhythm, without act on the biological oscillators, promoting the masking. Thus, photic stimuli can synchronize the circadian activity rhythm (CAR) by two distinct mechanisms, acting isolated or at a combined way. Among the elements that can influence photic synchronization, the duration and time of photic exposure is pointed out. If in the natural environment the marmoset can choose places of different intensity illumination and is synchronized to light-dark cycle (LD), how the photic synchronization mechanism can be evaluated in laboratory by light self-selection? With objective to response this question, four adult male marmosets were studied at two conditions: with and without sleeping box. The animals were submitted to a LD cycle (12:12/ 350:2 lx) and constant light (LL: 350 lx) conditions in individual cages with an opaque sleeping box, that permitted the light self-selection. At the room, the temperature was 25.6 ºC (± 0.3 ºC) and humidity was 78.7 (± 5%). The motor activity was recorded at 5 min bins by infrared movement sensors installed at the top of the cages. The motor activity profile was distinct at the two conditions: without the sleeping box protection against light, the activity frequency was higher at CT 11-12 (ANOVA; F(3.23) = 62.27; p < 0.01). Also, the duration of the active phase (α) was prolonged of about 1 h (t test, p < 0.05) and the animals showed a significant delay on the activity onset and offset (t test, p < 0.05) and at the acrophase (confidence intervals of 5%) of CAR. In LL, the light continuous exposure prolonged the active phase and influenced the endogenous expression of the circadian activity rhythm period. From the result analysis, it is concluded that the light self-selection can modify several parameters of CAR in marmosets, allowing the study of the synchronization mechanism using the burrow model. Thus, without sleeping box there was a phase delay between the CAR and LD (entrainment) and an increase of activity near lights off (positive masking). Furthermore, in LL, the light continuous exposure modifies α and the endogenous expression of CAR. It is suggested that the light self-selection might be take into account at investigations that evaluate the biological rhythmicity in marmosets
Resumo:
While providing physical and psychological benefits, excessive exercise could be or cause a compulsive behavior, making the individual dependent on it. In a parallel discussion, computerized psychological instruments, for a hand, reflects the development of information technology and your applicability to other areas, but also shows little advance for Psychological Assessment. In this perspective, this study aims to adapt the Exercise Dependence Scale (EDS-R) in two formats (paper-and-pencil and computerized) and evaluate evidence of factorial and convergent validity, and reliability of each version and compare them with each other. It is also proposed to observe the relationship of some bio-demographic (Sex, age, frequency, duration and intensity of practice exercise) and the exercise dependence (DEF). For this purpose, 709 regular physical activity practitioners, selected by procedures non-probabilistic sampling, responded a adapted version of EDS-R, Muscle Appearance Satisfaction Scale (MASS), Body Modification Scale (BMS) and a demographic questionnaire, analyzed through Exploratory Factor Analysis, Cronbach's Alpha and not parametric tests. Both the traditional version and the computer showed a seven factors structure, explaining 57 and 62% of the variance, respectively, and Cronbach's alphas of 0.83 and 0.89. Factors were: (1) intentionality, (2) continuity, (3) tolerance, (4) reduction of other activities, (5) lack of control, (6) abstinence and (7) time spent on exercise. Relationships were observed between the Exercise Dependence and the variables: age, diets, consumption of food supplements and medicines for weight change, desire to do plastic surgery and body satisfaction. We observed also a positive correlation between the DEF and the frequency, duration and intensity of exercise, and the factor "Dependence on exercising" from MASS, indicating convergent validity of the EDS-R. Finally, comparisons between the two formats were equivalent, with few changes: computerized version achieved higher DEF scores. Based on these results, it can be concluded that the EDS-R has factorial and convergent validity, reliability, to measure exerceise dependence on traditional e computerized formats. DEF is related to actions used to body modification and behaviors toward exercise. Finally, it was found equivalence between the formats, especially in psychometric parameters, thus suggesting feasibility of a computerized assessment. However, it was observed that the computerized data has sample recruiting strategies more limited
Resumo:
The aim of this study was to evaluate the potential of near-infrared reflectance spectroscopy (NIRS) as a rapid and non-destructive method to determine the soluble solid content (SSC), pH and titratable acidity of intact plums. Samples of plum with a total solids content ranging from 5.7 to 15%, pH from 2.72 to 3.84 and titratable acidity from 0.88 a 3.6% were collected from supermarkets in Natal-Brazil, and NIR spectra were acquired in the 714 2500 nm range. A comparison of several multivariate calibration techniques with respect to several pre-processing data and variable selection algorithms, such as interval Partial Least Squares (iPLS), genetic algorithm (GA), successive projections algorithm (SPA) and ordered predictors selection (OPS), was performed. Validation models for SSC, pH and titratable acidity had a coefficient of correlation (R) of 0.95 0.90 and 0.80, as well as a root mean square error of prediction (RMSEP) of 0.45ºBrix, 0.07 and 0.40%, respectively. From these results, it can be concluded that NIR spectroscopy can be used as a non-destructive alternative for measuring the SSC, pH and titratable acidity in plums
Resumo:
The International Labor Organization (OIT) estimates that there are around 118 million children subjected to child labor around the world. In Brazil, there are 3.5 million workers aged between 5 and 17. This exploitation practice constitutes a serious social problem, including of Public Health, since these workers are exposed to a wide range of risks, such as those related to health, physical integrity and even to life, which may cause them to become sick adults and/or interrupt their lives prematurely. Therefore, this research aims to investigate the relationship between the frequency of child labor in the age group of 10 to 13 years and some socio-economic indicators. It is a quantitative research in an ecological study whose levels of analysis are the Brazilian municipalities grouped in 161 regions, defined from socioeconomic criteria. The dependent variable of this study was the prevalence of child labor in the age group of 10 to 13 years. The independent variables were selected after a correlation between the 2010 Census of child labor in the age group of 10 to 13 years and secondary data had been conducted, adopting two main independent variables: funds from the Family Allowance Program (PBF) per 1,000 inhabitants and Funds from the Child Labor Eradication Program (PETI) per a thousand inhabitants. Initially, it was conducted a descriptive analysis of the variables of the study, then, a bivariate analysis, and the correlation matrix was built. At last, the Multiple Linear Regression stratified analysis was performed. The results of this survey indicate that public policies , like the Bolsa Familia Program Features per 1000 inhabitants and Resources Program for the Eradication of Child Labour to be allocated to municipalities with HDI < 0.697 represent a decrease in the rate of child labor ; These programs have the resources to be invested in municipalities with HDI > = 0.697 have no effect on the rate of child labor. Other adjustment variables showed significance, among these the municipal Human Development Index (IDH), years of schooling at 18 years of age, illiteracy at 15 years of age or more, employees without employment contract at 18 years of age and the Gini Index. It is understood that the child labor issue is complex. The problem is associated, although not restricted to, poverty, the social exclusion and inequality that exist in Brazil, but other factors of cultural and economic nature, as well as of organization of production, also account for its aggravation. Fighting child labor involves a wide intersectoral articulation, shared and integrated with several public policies, among them health, sports, culture, agriculture, labor and human rights, with a view to guaranteeing the integrality of the rights of children and adolescents in situation of labor and of their respective families
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Traditional applications of feature selection in areas such as data mining, machine learning and pattern recognition aim to improve the accuracy and to reduce the computational cost of the model. It is done through the removal of redundant, irrelevant or noisy data, finding a representative subset of data that reduces its dimensionality without loss of performance. With the development of research in ensemble of classifiers and the verification that this type of model has better performance than the individual models, if the base classifiers are diverse, comes a new field of application to the research of feature selection. In this new field, it is desired to find diverse subsets of features for the construction of base classifiers for the ensemble systems. This work proposes an approach that maximizes the diversity of the ensembles by selecting subsets of features using a model independent of the learning algorithm and with low computational cost. This is done using bio-inspired metaheuristics with evaluation filter-based criteria
Resumo:
The process for choosing the best components to build systems has become increasingly complex. It becomes more critical if it was need to consider many combinations of components in the context of an architectural configuration. These circumstances occur, mainly, when we have to deal with systems involving critical requirements, such as the timing constraints in distributed multimedia systems, the network bandwidth in mobile applications or even the reliability in real-time systems. This work proposes a process of dynamic selection of architectural configurations based on non-functional requirements criteria of the system, which can be used during a dynamic adaptation. This proposal uses the MAUT theory (Multi-Attribute Utility Theory) for decision making from a finite set of possibilities, which involve multiple criteria to be analyzed. Additionally, it was proposed a metamodel which can be used to describe the application s requirements in terms of the non-functional requirements criteria and their expected values, to express them in order to make the selection of the desired configuration. As a proof of concept, it was implemented a module that performs the dynamic choice of configurations, the MoSAC. This module was implemented using a component-based development approach (CBD), performing a selection of architectural configurations based on the proposed selection process involving multiple criteria. This work also presents a case study where an application was developed in the context of Digital TV to evaluate the time spent on the module to return a valid configuration to be used in a middleware with autoadaptative features, the middleware AdaptTV
Resumo:
Classifier ensembles are systems composed of a set of individual classifiers and a combination module, which is responsible for providing the final output of the system. In the design of these systems, diversity is considered as one of the main aspects to be taken into account since there is no gain in combining identical classification methods. The ideal situation is a set of individual classifiers with uncorrelated errors. In other words, the individual classifiers should be diverse among themselves. One way of increasing diversity is to provide different datasets (patterns and/or attributes) for the individual classifiers. The diversity is increased because the individual classifiers will perform the same task (classification of the same input patterns) but they will be built using different subsets of patterns and/or attributes. The majority of the papers using feature selection for ensembles address the homogenous structures of ensemble, i.e., ensembles composed only of the same type of classifiers. In this investigation, two approaches of genetic algorithms (single and multi-objective) will be used to guide the distribution of the features among the classifiers in the context of homogenous and heterogeneous ensembles. The experiments will be divided into two phases that use a filter approach of feature selection guided by genetic algorithm
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The main goal of Regression Test (RT) is to reuse the test suite of the latest version of a software in its current version, in order to maximize the value of the tests already developed and ensure that old features continue working after the new changes. Even with reuse, it is common that not all tests need to be executed again. Because of that, it is encouraged to use Regression Tests Selection (RTS) techniques, which aims to select from all tests, only those that reveal faults, this reduces costs and makes this an interesting practice for the testing teams. Several recent research works evaluate the quality of the selections performed by RTS techniques, identifying which one presents the best results, measured by metrics such as inclusion and precision. The RTS techniques should seek in the System Under Test (SUT) for tests that reveal faults. However, because this is a problem without a viable solution, they alternatively seek for tests that reveal changes, where faults may occur. Nevertheless, these changes may modify the execution flow of the algorithm itself, leading some tests no longer exercise the same stretch. In this context, this dissertation investigates whether changes performed in a SUT would affect the quality of the selection of tests performed by an RTS, if so, which features the changes present which cause errors, leading the RTS to include or exclude tests wrongly. For this purpose, a tool was developed using the Java language to automate the measurement of inclusion and precision averages achieved by a regression test selection technique for a particular feature of change. In order to validate this tool, an empirical study was conducted to evaluate the RTS technique Pythia, based on textual differencing, on a large web information system, analyzing the feature of types of tasks performed to evolve the SUT
Resumo:
Software product line engineering promotes large software reuse by developing a system family that shares a set of developed core features, and enables the selection and customization of a set of variabilities that distinguish each software product family from the others. In order to address the time-to-market, the software industry has been using the clone-and-own technique to create and manage new software products or product lines. Despite its advantages, the clone-and-own approach brings several difficulties for the evolution and reconciliation of the software product lines, especially because of the code conflicts generated by the simultaneous evolution of the original software product line, called Source, and its cloned products, called Target. This thesis proposes an approach to evolve and reconcile cloned products based on mining software repositories and code conflict analysis techniques. The approach provides support to the identification of different kinds of code conflicts – lexical, structural and semantics – that can occur during development task integration – bug correction, enhancements and new use cases – from the original evolved software product line to the cloned product line. We have also conducted an empirical study of characterization of the code conflicts produced during the evolution and merging of two large-scale web information system product lines. The results of our study demonstrate the approach potential to automatically or semi-automatically solve several existing code conflicts thus contributing to reduce the complexity and costs of the reconciliation of cloned software product lines.
Resumo:
Despite the advances in the cure rate for acute myeloid leukemia, a considerable number of patients die from their disease due to the occurrence of multidrug resistance (MDR). Overexpression of the transporter proteins P-glycoprotein (Pgp) and multidrug resistance-associated protein (MRP) confer resistance to the treatment these leukemias. OBJECTIVE: To analyze the expression of the Gpp and MRP1 in patients with AML by flow cytometry (FC) and to determine the correlation between expression and demographic and also clinical and laboratorial variables. METHODS: Bone marrow and peripheral blood samples from 346 patients with a diagnosis of AML were assessed for the expression of Pgp and MRP1 by FC. RESULTS: The expression of Pgp and MRP1 was found in 111 (32.1%) and 133 (38.4%) patients, respectively, with greater prevalence in older patients and lower in adolescents, observing also a high incidence in patients with refractory disease, recurrence and secondary in comparison with the cases of de novo AML. Regarding the laboratory findings, we observed a higher correlation statistically significant between the expression of Pgp and MRP1 in AML CD34+ and FAB AML M7, M5A and M2 and lower the M3 subtype, not observed statistically significant correlation between the phenotype MDR and other laboratory data such with hemoglobin, leukocyte count, platelet count, aberrant expression of lymphoid antigens (CD2, CD7 and CD19) and clinical signs related to the disease. CONCLUSIONS: The results showed that the detection of MDR phenotype by flow cytometry can be a molecular marker for prognosis independent patients diagnosed with AML.
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Background & Aims: HFE-associated Hereditary Hemochromatosis (HH) is one of the most frequent autosomal recessive disease in the caucasian population, caused by the high absorption and deposition of iron in several organs. This accumulation results in several clinical complications such as cirrhosis, arthritis, cardiopathies, diabetes, sexual disorders and skin darkening. Although most of the cases are homozygous individuals for the C282Y mutation, another two mutations, H63D and S65C, have been reported to be associated with milder forms of the disease. The objective is to avaluate the distribution of C282Y, H63D and S65C mutations in the HFE gene in patients with suspected HH in the state of Rio Grande do Norte, Brazil. Methods: Samples of peripheral blood were taken from 335 patients originating from Natal-RN, a city in northeastern Brazil with suspected of HH and which were screened for the HFE gene C282Y, H63D and S65C mutations, using molecular genetics assays (Polymerase Chain Reaction- Restriction Fragments Length Polymorphism). The main criterion for including such patients in the study was the increasing of persistent serum ferritin in individuals aged between 18 and 70 or older, both males and females. As to the exclusion criteria, individuals holding hemolytical anemia, talassemy and previously report of blood transfusion did not take part of the study. Results: Out of the 335 patients studied, 143 patients showed absence of mutation and 195 showed some kind of mutation in the HFE gene: 07/335 (2,08%) were homozigous C282Y, 25/335 heterozygous C282Y, 25/335 (7,46%) were homozigous H63D, 115/335 (34,32%) heterozygous H63D, 5/335 (1,48%) heterozygous S65D, 11/ 335 (3,28%) and were double heterozygous (H63D/C282Y). None patients were Homozygous S65D and S65D heterozygous (S65D/H63D and S65D/C282Y). Conclusions. The distribution of the HFE gene C282Y, H63D and S65C mutations found in our group matches the tendencies observed in other European countries. Due to the high prevalence of hemochromatosis, its seriousness and easy treatment, the genetic diagnosis of HH has become a dream, especially in the high risk group.
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Macrobrachium rosenbergii is a freshwater prawn which presents agonistic behavior and heterogeneous growth. It is known that captive conditions can intensify agonism causing injuries and decreased survival, generating a condition of poor welfare. Based on this, we aim to investigate the behavior of M. rosenbergii in the juvenile phase according to different types of shelter and frequencies of feed offer, emphasizing their agonistic behavior. For this, juveniles were observed in the laboratory in three steps. At step I we characterized the behavioral profile; prawns were kept in eight aquariums (27 prawns/m2 ), identified and observed four times along both phases of 24 h light cycle. At step II (2 experiments), we evaluated the use of shelters (brick or polyethylene rolls) and their influence on agonism by the animals. For classification of animals in dominance rank, the method used was David's Score. At step III (3 experiments), we evaluated different frequencies of feed offer on the behavior of individuals, in particular agonism. Results showed that juveniles do not present a pattern activity/inactivity between the phases of the light cycle. We identified a dominance hierarchy among individuals taking advantage of access to food by the dominant, which showed greater weight gain although the frequency of intake did not differ between individuals. The type of shelter influenced the behavior of animals. Brick shelter generated a higher frequency of permanence and a reduction in the frequency of agonistic interactions. The distribution of food more frequently throughout the day, decreased the motivation of animals for food, as well as to fight. Prawns fed four times showed lower frequency of feed intake and agonistic interactions. Thus, we conclude the shelters which reduce animal’s detection by coespecifics and offer the food four times along the day reduce agonistic behavior. This result causes na improvement in life quality of the prawns and also in its quality as final product.
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Frequency Selective surfaces are increasingly common structures in telecommunication systems due to their geometric and electromagnetic advantages. As a matter of fact, the frequency selective surfaces with fractal geometry type would allow an even bigger reduction of the electrical length which provided greater flexibility in the design of these structures. In this work, we investigated the use of multifractal geometry in frequency selective surfaces. Three structures with different multifractal geometries have been proposed and analyzed. The first structure allowed the design of multiband structures with greater flexibility in controlling the resonant frequencies and bandwidth. The second structure provided a bandwidth increase even with the rising of the fractal level. The third structure showed response with angle stability, dual polarization and provided room for a bandwidth increase with the rising of the structural multifractality. Furthermore, the proposed structures increased the degree of freedom in the multiband designs because they have multiple resonant frequencies ratios between adjacent bands and are easy to deploy. The validation of the proposed structures was initially verified through simulations in Ansoft Designer software and then the structures were constructed and the experimental results obtained
Resumo:
Introduction: Transcranial Direct Current Stimulation (tDCS) has been used in studies for the treatment of chronic pain, but their effects on the autonomic nervous system (ANS) are non-existent. Therefore, the need for studies is of fundamental importance, as these individuals have autonomic imbalance and the intensity of this is dependent on the degree and level of injury. Objective: We investigated the effect of tDCS on the ANS in people with spinal cord injury (SCI) with different degrees and levels of injury. Methods: Randomized, placebo-controlled, double-blind, applied anodal tDCS or sham on the primary motor cortex (M1), bilaterally. The subjects (lower incomplete injury, n = 7; lower complete injury, n = 9; and high complete thoracic injury, n = 3) visited the laboratory three times and received active or sham tDCS for 13min. The heart rate variability (HRV) was measured before, during and after stimulation and analyzed the variables LF, HF and LF / HF. Results: The tDCS modulated the ANS in different ways among the groups. In individuals with SCI high complete thoracic the tDCS did not change the HRV. However, for individuals with SCI low incomplete, tDCS changed the HRV in order to increase sympathetic (LF, p = 0.046) and reduced parasympathetic (HF, p = 0.046). For individuals SCI low complete to tDCS changed the HRV reduction sympathetic (LF, p = 0.017) and increased parasympathetic (HF, p = 0.017). Conclusions: The present study suggests that anodal tDCS applied on the motor cortex bilaterally could modulate the ANS balance in people with spinal cord injury and that this effect is dependent on the degree and level of injury.
Resumo:
Considering the fact that, the use of wireless communication systems has grown too fast, investigations concerning absorbers of electromagnetic waves has called closer attention of researchers. It is applicable from indoor systems to military applications. Paralleling with this growth, some extremely relevant investigations through Frequency Selective Surfaces (FSS) allows its filter property to be applicable in several systems, for example: reflector antennas, band-pass radomes, and absorbers, which are the main objective of this work. Therefore, the main goal of this work concerns to design micro-waves absorbers through FSS. Thus, the methodology consists basically in two steps: the first step concerns a theoretical and numerical analysis of the structures involved in the process of absorption, the second step, the analysis of the cascaded structures. In order to carry out the analysis, the Equivalent Circuit Method will be used. This method provides characteristics of transmission from the structure, for a plane wave incidence and it requires an extremely limited computing resource in relation if compared to full wave analyses method. Hence, it is useful to allow fast predictions of the development of the structures. Furthermore, a spreading matrix will be used in order to cascade the conductive FSS and the resistive FSS achieving absorption characteristics in the designed band. The experimental results used for the analysis are found in the literature due to the difficulty of building soon, given that it is not a simple construction technique. To conclude, a mathematical development through the Equivalent Circuit Method of a FSS modeling with cross-dipole geometry and a resistive FSS will be presented, as well as the cascading involving the two structures. The same setting is used with a square loop geometry. Besides it, the next steps will be discussed in the conclusion.