48 resultados para Rádio Frequência


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Conselho Nacional de Desenvolvimento Científico e Tecnológico

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Epilepsies are neurological disorders characterized by recurrent and spontaneous seizures due to an abnormal electric activity in a brain network. The mesial temporal lobe epilepsy (MTLE) is the most prevalent type of epilepsy in adulthood, and it occurs frequently in association with hippocampal sclerosis. Unfortunately, not all patients benefit from pharmacological treatment (drug-resistant patients), and therefore become candidates for surgery, a procedure of high complexity and cost. Nowadays, the most common surgery is the anterior temporal lobectomy with selective amygdalohippocampectomy, a procedure standardized by anatomical markers. However, part of patients still present seizure after the procedure. Then, to increase the efficiency of this kind of procedure, it is fundamental to know the epileptic human brain in order to create new tools for auxiliary an individualized surgery procedure. The aim of this work was to identify and quantify the occurrence of epilepticform activity -such as interictal spikes (IS) and high frequency oscillations (HFO) - in electrocorticographic (ECoG) signals acutely recorded during the surgery procedure in drug-resistant patients with MTLE. The ECoG recording (32 channels at sample rate of 1 kHz) was performed in the surface of temporal lobe in three moments: without any cortical resection, after anterior temporal lobectomy and after amygdalohippocampectomy (mean duration of each record: 10 min; N = 17 patients; ethic approval #1038/03 in Research Ethic Committee of Federal University of São Paulo). The occurrence of IS and HFO was quantified automatically by MATLAB routines and validated manually. The events rate (number of events/channels) in each recording time was correlated with seizure control outcome. In 8 hours and 40 minutes of record, we identified 36,858 IS and 1.756 HFO. We observed that seizure-free outcome patients had more HFO rate before the resection than non-seizure free, however do not differentiate in relation of frequency, morphology and distribution of IS. The HFO rate in the first record was better than IS rate on prediction of seizure-free patients (IS: AUC = 57%, Sens = 70%, Spec = 71% vs HFO: AUC = 77%, Sens = 100%, Spec = 70%). We observed the same for the difference of the rate of pre and post-resection (IS: AUC = 54%, Sens = 60%, Spec = 71%; vs HFO: AUC = 84%, Sens = 100%, Spec = 80%). In this case, the algorithm identifies all seizure-free patients (N = 7) with two false positives. To conclude, we observed that the IS and HFO can be found in intra-operative ECoG record, despite the anesthesia and the short time of record. The possibility to classify the patients before any cortical resection suggest that ECoG can be important to decide the use of adjuvant pharmacological treatment or to change for tailored resection procedure. The mechanism responsible for this effect is still unknown, thus more studies are necessary to clarify the processes related to it

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The aerial activities, leaps and slaps with parts of the body in the surface of water, are part of the behavioral repertoire of several species of cetaceans. Among them, the spinner dolphin, Stenella longirostris, shows greater diversity in such behavior. For the spinner dolphins of Fernando de Noronha, the aerial activities are classified as vertical and horizontal, with eight patterns to be noted (tail slap, head slap, motor boating, partial leap, leap, spin, tail over head and tail over head with spin) discriminated between these categories. Such behaviors can be used as a parameter to identify behavioral changes, as well as patterns of daily and seasonal activity. In this manner, this study aimed to characterize the frequency in performance of such activity while the dolphins were within the Dolphin Bay of Fernando de Noronha, and verify possible daily and seasonal hourly fluctuations on such behaviors. The data analyzed in this study was acquired during the period of January 2006 through December 2010, totaling 1431 days of observation from land set point, with 113027 aerial activities registered, daily average of 72,27 (SD=96,10). During 5478h and 54 min of observation the horizontal aerial activity was the most observed and rotation was the most executed pattern. Greater frequency of execution of aerial activity was observed in adults, but for both adults and calves, was observed a predominance of horizontal activities, with spin being the pattern most executed. Positive correlation was observed between the amount of aerial activity performed and the number of animals inside the Bay. Hourly daily fluctuation was observed in the expression of aerial activities by spinner dolphins, and was observed a peak of activity between 8h and 8h59min for the overall frequency relative of aerial activities, as well as for the categories and patterns. Seasonal differences were observed between the rainy and dry season with the greater amount of activity being observed during the rainy season. Nevertheless, the same profile of frequency relative of aerial activity was observed in both seasons with the peak amount being during the same period. When discriminated the aerial activities in categories and patterns, for both seasons, there was a similar pattern of hourly fluctuation; for most of parameters, higher frequency relative of execution of aerial activity remain between 8h and 8h59min

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This research analyzes the discursive construction of Educommunication, from a training course of educommunicators, with teachers and students of school Profº Francisco Ivo Cavalcanti, state public school, geographically located in the city of Natal / RN, studying the constitution of the meanings that educommunication practice in School Radio acquires for trainers and course participants (teachers and students). The socio-historical context in which this research is based corresponds to the new social reality, mediated by information and communication Technologies. These technologies drive the educational institution to train students in the use of different languages that permeate society. But to do so, you must have also enabled teachers to work Communication technology to meet the aspirations of young people and adults who are part of the educational community. The objectives are to identify the conditions of discursive production around the educommunication practice in Radio School, examine the discursive construction of instructors and course participants in Educommunication and its dialogical brands, and see how the course participants relate to their educommunicative practice in the educational contexts, attributing meaning to the place of teachers and students. Therefore, this research uses ethnography applied to the school context as a methodological option, Pecheuxtian Discourse Analysis, the principles of Educommunication, the reflections of Paulo Freire and the concepts of Dialogism in Bakhtin as theoretical contributions. We adopted three areas of knowledge: Language, Communication and Education, in order to produce an analysis committed to the aspects that involve the use of radio in the school environment to promote an educommunicative practice. With this research we have built a web of meanings about the school that we are forming or we want to form in the XXI century, because we used the discourses of teachers and students immersed in new knowledge and practices in order to propel them to be subjects of communication in educational environment for a qualitative transformation of being and doing in school.

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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

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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.

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The past years have seen a great interest in the use of frequency selective surfaces (FSS), as spatial filters, in many microwave applications. Among these, we highlight applications in telecommunication systems (such as satellite communications and radar), high gain antennas (combined with planar antennas) and (home and industrial) microwave ovens. The FSS is usually composed of two-dimensional periodic arrays, with equally spaced elements, which may be metallic patches (printed on dielectric substrates) or aperture (holes in thin metal surfaces). Using periodic arrays, the FSS have been able to meet the demands of the telecommunications industry. However, new demands are finding technological limitations. In this context, adverse filtering requirements have forced designers to use FSS optimization methods to find specific formats of FSS elements. Another alternative that has been used to increase the selectivity of the FSS is the cascaded FSS, a simple technique that has as main drawback the increased dimensions of the structure, as well as its weight. This work proposes the development of a new class of selective surfaces frequency (FSS) composed of quasi-periodic (or non-periodic) arrangements. The proposed FSS have no array periodicity, in relation with the spatial position of their elements. The frequency responses of these structures were simulated using commercial softwares that implement full-wave methods. For the purpose of validation of this study, FSS prototypes were built and measured, being possible to observe a good agreement between simulated and measured results. The main conclusions of this work are presented, as well as suggestions for future works.

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The constant necessity for new sources of renewable energy is increasingly promoting the increase of investments in this area. Among other sources, the wind power has been becoming prominent. It is important to promote the search for the improvement of the technologies involved in the topologies of the wind turbines, seeking for alternatives which enhance the gotten performance, despite the irregularity of the wind speed. This study presents a new system for speed control, in this case applied to the wind turbines - the Electromagnetic Frequency Regulator (EFR). One of the most used devices in some topologies is the mechanical gearboxes which, along with a short service life, often represent sources of noise and defects. The EFR does not need these transmission boxes, representing a technological advancement, using for that an adapted induction machine, in which the stator becomes mobile, supportive to the axis of the turbine. In the topology used in this study, the EFR also allows us to leave out the usage of the eletronic converters to establish the coupling between the generator and the electrical grid. It also the reason why it provides the possibility of obtaining the generation in alternating current, with constant voltage and frequency, where there is no electrical grid. Responsable for the mechanical speed control of the generator, the EFR can be useful in other transmission systems in which the mechanical speed control output is the objective. In addition, the EFR operates through the combination of two inputs, a mechanical and other electrical. It multiplies the possibilities of application because it is able to synergistic coupling between different arrays of energy, and, for such reasons, it enables the various sources of energy involved to be uncoupled from the network, being the synchronous generator responsible for the system connection with the electrical grid, simplifying the control strategies on the power injected in it. Experimental and simulation results are presented through this study, about a wind turbine, validating the proposal related to the efficience in the speed control of the system for different wind conditions.

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This work aims to investigate the behavior of fractal and helical elements structures in planar microstrip. In particular, the frequency selective surfaces (FSSs) had changed its conventional elements to fractal and helical formats. The dielectric substrate used was fiberglass (FR-4) and has a thickness of 1.5 mm, a relative permittivity 4.4 and tangent loss equal to 0.02. For FSSs, was adopting the Dürer’s fractal geometry and helical geometry. To make the measurements, we used two antennas horns in direct line of sight, connected by coaxial cable to the vector network analyzer. Some prototypes were select for built and measured. From preliminary results, it was aimed to find practical applications for structures from the cascading between them. For FSSs with Dürer’s fractal elements was observed behavior provided by the multiband fractal geometry, while the bandwidth has become narrow as the level of iteration fractal increased, making it a more selective frequency with a higher quality factor. A parametric analysis allowed the analysis of the variation of the air layer between them. The cascading between fractal elements structure were considered, presented a tri-band behavior for certain values of the layer of air between them, and find applications in the licensed 2.5GHz band (2.3-2.7) and 3.5GHz band (3.3-3.8). For FSSs with helical elements, six structures were considered, namely H0, H1, H2, H3, H4 and H5. The electromagnetic behavior of them was analyzed separately and cascaded. From preliminary results obtained from the separate analysis of structures, including the cascade, the higher the bandwidth, in that the thickness of the air layer increases. In order to find practical applications for helical structures cascaded, the helical elements structure has been cascaded find applications in the X-band (8.0-12.0) and unlicensed band (5.25-5.85). For numerical and experimental characterization of the structures discussed was used, respectively, the commercial software Ansoft Designer and a vector network analyzer, Agilent N5230A model.

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This thesis aims to investigate the space of radio reporting and production conditions in radio newscasts in commercial stations operating in modulated frequency (FM) in the city of Natal, Rio Grande do Norte. Through preliminary empirical observation, it was observed that this journalistic style (radio reportage) is hardly present in the schedule of local commercial radio stations, with a lack of in-depth news coverage. The research is based on the content broadcast in four daily radio news programs transmitted by commercial stations. It raises the hypothesis that the crisis that cuts across journalistic companies could be justified by the lack of financial funding in in-depth news reporting. The starting point for the case study (Yin, 2005) was a bibliographical research, for building a theoretical model of reference for the studied style, based on Prado (1989), Bespalhok (2006), Meditsch (2007), Lopes (2013) and Ferraretto (2014). The methodology also included listening to content broadcast during a week in the four analyzed news programs, participant observation and interviews with professionals who produce these programs. There were eight events with similar characteristics to radio reporting, all broadcast in just one of the analyzed programs. According to the interviewees, the format is rarely used because it would generate high businesses costs, which are prohibitively high for the stations. The research also inferred that besides the lack of entrepreneurial vision, there is accommodation of the professionals who could produce news stories even with little structure available. Finally, this work points out the need to invest more on local radio journalism to improve the quality of the information provided on commercial broadcasters in Natal and the training of journalism students to use radio's potential to maximum use.

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The growth of the elderly population is a global phenomenon and, in Brazil, this transformation is happening in a very rapid rhythm. With the current population aging, this emerging age group will need more health care and attention. One of the characteristics of the population aging is the progressive accumulation of disabilities, which makes it more vulnerable to falls. This study was developed with the purpose of knowing the episode falls in the scope of an elderly population treated at a Family Health Unit. It is a research with cross-sectional nature, and its sample was composed by 121 elderly. The research was approved by the Ethics Committee of HUOL, with Opinion nº 816.022. We applied a questionnaire to the participants, and the results were statistically analyzed by using Chi-square test and Fisher’s exact test to verify the association between variables. In order to perform a multivariate analysis, we used the method of the Binomial Logistic Regression. For both tests, we accepted significance p<0,05 and CI of 95%. The results prove that the majority belongs to the female gender (76,9%); the age group of elderly reaches 88,4% and 11,6% is over-aged; regarding the marital status, 35,3% are married and 29,4% widowed; 92,1% with family income between one and two minimum wages; and 91,8% live with their partners and/or children. Regarding the frequency of falls, we found that 61,2% of the surveyed elderly suffered one or more falls in 2014. As associated factors, it became clear that 73,8% were due to extrinsic factors, 6,4% to intrinsic factors and 21,4% to both factors. As a consequence of the fall, we found that 89,2% have fear of falling again, 37,3% showed anxiety and 13,3% had their ambulation affected. Concerning the exposure to the risk factors, the most prevalent places were: street/avenue (31,0%), pavement (19,0%), living room (14,3%) and courtyard/backyard (10,7%). The study has proven a statistically significant association among female gender (p=0,001), rubble/objects in the backyard (p=0,015) and furniture that may cause accidents (p=0,005). It was evident among the elderly people surveyed, 72.7% receive little information about falls, being a risk factor for falls. We conclude that there is a high frequency of falls in the surveyed elderly, thereby constituting a worrisome data because this event in the elderly population is a serious matter, which raises the need to ensure them a safe environment in their homes and, above all, outside them. The information provided by the Family Health Strategy team are important to avoid these occurrences, which reinforces the need for developing health education activities together with the population as a way to prevent and reduce the occurrence of falls, thereby improving the quality of life of elderly.

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Agriculture is an essential activity to the human development, the tendency is that their need to increase according to the increase in world population. It is very important to take the maximum performance that is possible of each land without degrading it, a frequently monitoring is essential for the best performance. The purpose of this work is, nondestructively, to monitor the surface electrical conductivity of the soil in a demarcated area, as on a plantation, using low frequency radio waves. The conductivity is directly linked to the amount of water in the area and nutrients, therefore a periodic or even permanent monitoring increases significantly the efficient of the use of the soil. They will be used long-wave radio transmission or medium whose main characteristic to spread over the surface of the earth. It is possible to choose an AM radio with location, frequency and power of the transmission known or generate the signal. The studied method computes the conductivity of the ground in a straight line between two measured points, so it can be used in smaller or larger size fields. Measurements were carried out using an electromagnetic field strength analyzer. The data obtained in the measurements are processed by a numerical calculation program, in our case Matlab. It is concluded that the recommendations of the ITU (International Telecommunication Union) on the conductivity of soil in Brazil is far from reality, on some routes the recommendations indicate the use of the electrical conductivity of the soil 1 mS/m, while the measurements was found 19 mS/m. With the method described a precision farmer, once initial research for about a year, can monitor the humidity and salinity of the land, with the ability to predict the area and the most suitable time for irrigation and fertilization, making management more efficient and less expensive, while optimizing water use, natural resource increasingly precious.