53 resultados para Taxa de detecção

em Universidade Federal do Rio Grande do Norte(UFRN)


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Among placental mammals, primates are the only ones to present trichromatic color vision. However, the distribution of trichromacy among primates is not homogeneous: Old World primates shows an uniform trichromacy (with all individuals being trichromats) and New World primates exhibit a color vision polymorphism (with dichromatic males and dichromatic or trichromatic females). Visual ecology studies have investigated which selective pressures may have been responsible for the evolution of trichromacy in primates, diverging from the dichromat standard found in other mammals. Cues associated with foraging and the socio-reproductive status were analyzed, indicating a trichromatic advantage for the rapid detection of visually conspicuous objects against a green background. However, dichromats are characterized by an efficient capture of cryptic and camouflaged stimuli. These advantages regarding phenotype may be responsible for the maintenance of the visual polymorphism in New World primates and for the high incidence of color blindness in humans (standing around 8% in Caucasian men). An important factor that has not yet been experimentally taken into account is the predation risk and its effect on the evolution of trichromacy in primates. To answer this question, we prepared and edited pictures of animals with different coats: oncillas (Leopardus spp.), puma (Puma concolor) and ferret (Galictis cuja). The specimens were taxidermized and the photographs were taken in three different vegetation scenarios (dense forest, cerrado and grassland). The images of the predators were manipulated so that they fit into two categories of stimulus size (small or large). After color calibration and photo editing, these were presented to 40 humans (20 dichromats and 20 trichromats) by a computer program, which presented a set of four photos at a time (one picture containing the taxidermized animal amid the background vegetation and three depicting only the background vegetation) and recorded the response latency and success rate of the subjects. The results show a trichromatic advantage in detecting potential predators. The predator detection was influenced by the background, the predator species, the dimension of the stimulus and the observer s visual phenotype. As humans have a high rate of dyschromatopsias, when compared to wild Catarrhini or human tribal populations, it is possible that the increased rate of dichromats is a result of reduced pressure for rapid predator detection. Since our species came to live in more cohesive groups and resistant to attack by predators, with the advent of agriculture and the formation of villages, it is possible that the lower risk of predation has reduced the selection in favor of trichromats

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This thesis is part of research on new materials for catalysis and gas sensors more active, sensitive, selective. The aim of this thesis was to develop and characterize cobalt ferrite in different morphologies, in order to study their influence on the electrical response and the catalytic activity, and to hierarchize these grains for greater diffusivity of gas in the material. The powders were produced via hydrothermal and solvothermal, and were characterized by thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, transmission electron microscopy (electron diffraction, highresolution simulations), and energy dispersive spectroscopy. The catalytic and electrical properties were tested in the presence of CO and NO2 gases, the latter in different concentrations (1-100 ppm) and at different temperatures (room temperature to 350 ° C). Nanooctahedra with an average size of 20 nm were obtained by hydrothermal route. It has been determined that the shape of the grains is mainly linked to the nature of the precipitating agent and the presence of OH ions in the reaction medium. By solvothermal method CoFe2O4 spherical powders were prepared with grain size of 8 and 20 nm. CoFe2O4 powders exhibit a strong response to small amounts of NO2 (10 ppm to 200 ° C). The nanooctahedra have greater sensitivity than the spherical grains of the same size, and have smaller response time and shorter recovery times. These results were confirmed by modeling the kinetics of response and recovery of the sensor. Initial tests of catalytic activity in the oxidation of CO between temperatures of 100 °C and 350 °C show that the size effect is predominant in relation the effect of the form with respect to the conversion of the reaction. The morphology of the grains influence the rate of reaction. A higher reaction rate is obtained in the presence of nanooctahedra. In order to improve the detection and catalytic properties of the material, we have developed a methodology for hierarchizing grains which involves the use of carbonbased templates.

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Shrimp farming is one of the activities that contribute most to the growth of global aquaculture. However, this business has undergone significant economic losses due to the onset of viral diseases such as Infectious Myonecrosis (IMN). The IMN is already widespread throughout Northeastern Brazil and affects other countries such as Indonesia, Thailand and China. The main symptom of disease is myonecrosis, which consists of necrosis of striated muscles of the abdomen and cephalothorax of shrimp. The IMN is caused by infectious myonecrosis virus (IMNV), a non-enveloped virus which has protrusions along its capsid. The viral genome consists of a single molecule of double-stranded RNA and has two Open Reading Frames (ORFs). The ORF1 encodes the major capsid protein (MCP) and a potential RNA binding protein (RBP). ORF2 encodes a probable RNA-dependent RNA polymerase (RdRp) and classifies IMNV in Totiviridae family. Thus, the objective of this research was study the IMNV complete genome and encoded proteins in order to develop a system differentiate virus isolates based on polymorphisms presence. The phylogenetic relationship among some totivirus was investigated and showed a new group to IMNV within Totiviridae family. Two new genomes were sequenced, analyzed and compared to two other genomes already deposited in GenBank. The new genomes were more similar to each other than those already described. Conserved and variable regions of the genome were identified through similarity graphs and alignments using the four IMNV sequences. This analyze allowed mapping of polymorphic sites and revealed that the most variable region of the genome is in the first half of ORF1, which coincides with the regions that possibly encode the viral protrusion, while the most stable regions of the genome were found in conserved domains of proteins that interact with RNA. Moreover, secondary structures were predicted for all proteins using various softwares and protein structural models were calculated using threading and ab initio modeling approaches. From these analyses was possible to observe that the IMNV proteins have motifs and shapes similar to proteins of other totiviruses and new possible protein functions have been proposed. The genome and proteins study was essential for development of a PCR-based detection system able to discriminate the four IMNV isolates based on the presence of polymorphic sites

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This master dissertation presents the study and implementation of inteligent algorithms to monitor the measurement of sensors involved in natural gas custody transfer processes. To create these algoritmhs Artificial Neural Networks are investigated because they have some particular properties, such as: learning, adaptation, prediction. A neural predictor is developed to reproduce the sensor output dynamic behavior, in such a way that its output is compared to the real sensor output. A recurrent neural network is used for this purpose, because of its ability to deal with dynamic information. The real sensor output and the estimated predictor output work as the basis for the creation of possible sensor fault detection and diagnosis strategies. Two competitive neural network architectures are investigated and their capabilities are used to classify different kinds of faults. The prediction algorithm and the fault detection classification strategies, as well as the obtained results, are presented

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The transport of fluids through pipes is used in the oil industry, being the pipelines an important link in the logistics flow of fluids. However, the pipelines suffer deterioration in their walls caused by several factors which may cause loss of fluids to the environment, justifying the investment in techniques and methods of leak detection to minimize fluid loss and environmental damage. This work presents the development of a supervisory module in order to inform to the operator the leakage in the pipeline monitored in the shortest time possible, in order that the operator log procedure that entails the end of the leak. This module is a component of a system designed to detect leaks in oil pipelines using sonic technology, wavelets and neural networks. The plant used in the development and testing of the module presented here was the system of tanks of LAMP, and its LAN, as monitoring network. The proposal consists of, basically, two stages. Initially, assess the performance of the communication infrastructure of the supervisory module. Later, simulate leaks so that the DSP sends information to the supervisory performs the calculation of the location of leaks and indicate to which sensor the leak is closer, and using the system of tanks of LAMP, capture the pressure in the pipeline monitored by piezoresistive sensors, this information being processed by the DSP and sent to the supervisory to be presented to the user in real time

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This work presents a proposal to detect interface in atmospheric oil tanks by installing a differential pressure level transmitter to infer the oil-water interface. The main goal of this project is to maximize the quantity of free water that is delivered to the drainage line by controlling the interface. A Fuzzy Controller has been implemented by using the interface transmitter as the Process Variable. Two ladder routine was generated to perform the control. One routine was developed to calculate the error and error variation. The other was generate to develop the fuzzy controller itself. By using rules, the fuzzy controller uses these variables to set the output. The output is the position variation of the drainage valve. Although the ladder routine was implemented into an Allen Bradley PLC, Control Logix family it can be implemented into any brand of PLCs

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In the artificial lift method by Electrical Submersible Pump (ESP), the energy is transmitted for the well´s deep through a flat electric handle, where it is converted into mechanical energy through an engine of sub-surface, which is connected to a centrifugal pump. This transmits energy to the fluid under the pressure form, bringing it to the surface In this method the subsurface equipment is basically divided into: pump, seal and motor. The main function of the seal is the protect the motor, avoiding the motor´s oil be contaminated by oil production and the consequent burning of it. Over time, the seal will be wearing and initiates a contamination of motor oil, causing it to lose its insulating characteristics. This work presents a design of a magnetic sensor capable of detecting contamination of insulating oil used in the artificial lift method of oil-type Electrical Submersible Pump (ESP). The objective of this sensor is to generate alarm signal just the moment when the contamination in the isolated oil is present, enabling the implementation of a predictive maintenance. The prototype was designed to work in harsh conditions to reach a depth of 2000m and temperatures up to 150°C. It was used a simulator software to defined the mechanical and electromagnetic variables. Results of field experiments were performed to validate the prototype. The final results performed in an ESP system with a 62HP motor showed a good reliability and fast response of the prototype.

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This study assessed the level of knowledge, attitude and practice of Pap smear and human papillomavirus (HPV), in addition to analyzing the prevalence of genital HPV infection, Herpes Simplex Type 2 (HSV-2) and Chlamydia trachomatis in teenagers. The study consisted of two approaches, one based only on interviews conducted with adolescents enrolled in public schools or in public health facilities in the city of Natal. The other approach involved only a group of 132 adolescents enrolled among those admitted to two health units in Natal-RN. This second group of participants two specimens were collected for laboratory analysis: one was directed to prepare the blade for the Pap test, and other processed for DNA extraction for molecular analysis, focusing on the detection of HPV, HSV-2 and C . trachomatis. The presence of DNA of the three pathogens was investigated by the technique of polymerase chain reaction (PCR). The presence of each of the three pathogens was analyzed in terms of socio-demographic characteristics, as well as sexual and reproductive activity to identify risk factors for infection and development of lesions of the uterine cervix. The results show that the adolescents in this study had levels of knowledge and attitude very low, both in relation to cytology to HPV as though they have made a reasonable percentage of adequate practice exam and prevention of HPV infection. The overall prevalence of HPV infection was 54.5% and 48.2% in adolescents with normal cytology and 86.4% in those with abnormal cytology. We observed a higher proportion of cases of infection in the age group of 18 to 21. The prevalence of HPV infection was slightly higher among pregnant teenagers. The overall prevalence of HSV-2 infection was 13.6% and 11.8% in women with normal cytology and 22.7% in those with abnormal cytology. A higher proportion of cases of infection was found in the age group from 14 to 17, with a slightly higher prevalence among pregnant women. The C. trachomatis was found with an overall prevalence of 19.7% and 21.8% in adolescents with normal cytology and 9.1% in those with abnormal cytology. The prevailing rate was highest in the age group 18 to 21 years and in nonpregnant

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Genital infection with Chlamydia trachomatis is now recognized as one of the most prevalent sexually transmitted infections (STDs). Despite major advances in laboratory diagnosis techniques, primarily the character of asymptomatic chlamydial infection in both men and in women constitutes the basis for the formation of reservoirs that perpetuate transmission and acquisition of this and other STDs. The asymptomatic in women favors the rise of infection to the upper genital tract, causing injuries that can result in infertility. An examination of population screening for early detection and treatment of asymptomatic infections is the key step in combating this major public health problem. The present study aimed to evaluate the prevalence of infection by C. trachomatis in sexually active women attended the screening program for cervical cancer of the uterus in health facilities in municipalities in different regions of the State of Rio Grande do Norte, and identify factors that may contribute to the spread of this pathogen and its relationship with the lesions of the uterine cervix. It is a cross-sectional study aimed at detecting the presence of genital tract infection by C. trachomatis either in isolated form or in association with human papilloma virus (HPV) infection in asymptomatic women. Were included in this study, a total sample of 1,134 women aged 13-76, mean 34.4 years, from March 2008 to September 2012. Specimens containing exfoliated cells of the epithelium of the uterine cervix were analyzed by examining Pap cytology for the detection of possible injuries, and the polymerase chain reaction (PCR) for detection of plasmid DNA from C. trachomatis and HPV. Infection with C. trachomatis was detected with overall prevalence rate of 8.1% in the isolated form and 2.8% in co-infection with HPV. The infection was detected in 7.4% of women with normal cytology 11.5% of those with atypical cells of undetermined significance (ASC-US) and 16.7% of those with low-grade squamous intraepithelial lesion (LSIL). We observed an association between C. trachomatis and incidence of low-grade squamous intraepithelial lesion (LSIL). The genital tract infection by C. trachomatis alone was associated with education level, ethnicity and parity, revealing that women with higher education, those of non-white ethnicity and those who had three or more pregnancies were more likely to acquire infection. Levels very close to statistical significance were observed for chronological age, age at first sexual intercourse and first pregnancy. There was no association with marital status, number of sexual partners. Co-infection with C. trachomatis and HPV was detected in 2.3% of women with normal cytology, who had 5.1% in ASC-US and 10.4% in those with LSIL. No association was found between infection C. trachomatis and increased risk of HPV infection, but women with simultaneous infection by both pathogens showed greater risk for LSIL. Co-infection was more prevalent among single women, who had in the first sexual intercourse under 18 years and those who had two or more sexual partners over a lifetime

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Visceral leishmaniasis hás adapted in the past 20 years to periurban and urban areas, and in Natal, Rio Grande do Norte, it became endemic. Thid study aimed to evaluate the environmental and social aspectsof Leishmania chagasi infection and its epidemiologic transmission chain in an urban, periurban and rural area of Parnamirim-RN. A study with three sections was conducted: Section 1: Sectional study of the human and canine infection by L. chagasi and its environmental and social determinants. Section 2: Observational longitudinal cohort to evaluate the dynamics of the canine infection. Section 3: Longitudinal study to evaluate the behavior of Lu. Longipalpis vector and the seasonal factors related to its dynamics. To include in the study the hauses were randomly selected and georreferenciated. Montenegro skin test was done in the human population and blood samples were collected for anti-Leishmania antibody detection. The canine population was examinated for L. chagasi infection by RIFI, ELISA and ELISA for rK39. An entomologic surveillance was monthly done with CDC light trapsin 10 houses of each locality. Quantitative and qualitative analyses was done using STATISC 6.0. Probality and prediction maps were done using ArcGis 9.0 model. In the human population L. chagasi infection was associated with the area of the hause, age, sex, population densyti, vegetation, kind of the floor of thr hause, water and resides destiny. In the canine population L. chagasi infection was associated with the breed, size, time of living in the hause, presence of dogs in the neighborhood, presence of horses and donkeys in the neighborhood, vegetation, kind of the floor and walls of the hause. The human infection was associated with canine infction only when analyzed taking into account the locality. In the prospective study, serum conversion and antibody lost observed in 30,8% and 22% of the animals examined, respectively. The human infection rate by L. chagasi was 24,6%, by the presence of anti-Leishmania antibody and 38,6% by the Montenegro skin test. The canine infection rate 32,5% by the presence of anti-Leishmania antibody. The vector Lu longipalpis showed an atypical behavior. These results indicate that environmental and social factors are important variables associated with L. chagasi infection in humans and canines, with punctual association of thr last two. Control measures of the infection on the studied points are necessary, in the aim to reduce the endemic focus of the disease in the study area. This research was carried out in a multidisciplinary involving the categories of: doctor, biologist, veterinarian, statistical, pharmaceutical and biochemical

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Cyanobacterial blooms are common in eutrophic reservoirs in Brazilian northeastern semi-arid. Given this reality, the present study aimed to analyze the effect of potentially toxic cyanobacterial blooms in Gargalheiras reservoir (semi-arid) on the cladocerans Ceriodaphnia dubia and Daphnia gessneri. In vitro chronic bioassays were performed with reservoir water dilutions from August/2011 to May/2012 and the following effects were evaluated on: intrinsic rate of population growth (r), reproductive parameters (age of first reproduction and fecundity per capita) and cladocerans movements. Phytoplankton was dominated by Cylindrospermopsis raciborskii and Planktothrix agardhii and saxitoxin and microcystin were detected in reservoir water. In most months C. dubia showed differences in r between control (absence of cyanobacteria) and treatments, and has shown negative effects on reproductive parameters. In all months paralysis of swimming movements was observed in C. dubia when both C. raciborskii and saxitoxin (cyanotoxin neurotoxic) were present in water. While C. dubia was sensitive to the reservoir water containing cyanobacteria, D. gessneri showed less intense negative effects in r and reproductive parameters. Furthermore, D. gessneri showed no paralysis of swimming movements. These results support the hypothesis in the literature that D. gessneri is resistant to the Cylindrospermopsis effects. The clone‟s life history may be a key to understand the results. The C. dubia clone, isolated from eutrophicated environment, is in the lab for ten years and it is an exotic species in Brazil. D. gessneri is a common species in the country and this clone was isolated from the Gargalheiras reservoir (where there are constant blooms of potentially toxic cyanobacteria) a year ago. Perhaps the recent contact with cyanobacteria explain the higher resistance presented by this D. gessneri clone. In conclusion, the cladocerans studied have different levels of sensitivity to cyanobacteria, characterizing species-specific responses

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Hansen´s disease is considered a serious public health problem. In 2006, the Ministry of Health reported that worldwide, Brazil ranked 2nd in the number of cases of the disease, surpassed only by India. The North region is the geographical area in Brazil that presents the most cases. In the state of Rio Grande do Norte, the disease is considered to be eliminated because its prevalence has been identified as 1 per 10.000 inhabitants, criteria established by the State Elimination Letter of 2005. Training programs have been offered by the Coordination for the Control of Hansen´s Disease Program of Rio Grande do Norte, PCH-RN since 1997, with the support of the English governmental agency Leprosy Relief Association, LRA, with no evaluation having been conducted. The objective of this study was to evaluate the training programs in clinical diagnosis of Hansen´s disease and their contribution to the detection of the disease in the state of Rio Grande do Norte. The study was conducted in seven municipalities that are known as Regional Public Health Units (URSAPs): São José de Mipibu URSAP I, Mossoró URSAP II, João Câmara URSAP III, Caicó URSAP IV, Santa Cruz URSAP V, Pau dos Ferros URSAP VI and Natal, capital city of the State, in the Metropolitan Region. Physicians and nurses of the Family Health Program PSF were interviewed as to their perceptions of the implementation of the training program in clinica diagnosis of Hansen´s Disease conducted by the PCH-RN. They evaluated their own practice and the training program. These professionals presented a positive evaluation of the program and gave suggestions for future courses. The results of this study suggest the need for permanent education. Data of the disease obtained from the official records of the Secretariat of Health and from the interviews indicate that health education is the means to control Hansen´s disease effectively

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The objective of this exploratory descriptive quantitative study was to analyze the behaviors in the detection, treatment and followup of the pregnant woman with syphilis, by health professionals that conduct the pre-natal consultation in the Family Health Strategy, as to the adherence to the recommendations of the Ministry of Health. The study was conducted in nine municipalites of the Trairi region in the state of Rio Grande do Norte. Data were collected during the months of July through September 2007, by means of a questionnaire with a population of 53 health professionals, 30 nurses and 23 physicians. Data were analyzed by descriptive statistics. The results were organized in three major items: knowledge of the health professionals about the symptomatology of syphilis and their actions in the detection of the disease; actions in the treatment of the pregnant woman with syphilis; and the actions of followup of the desease. We identified that 81,2% of the professionals have knowledge about the symptomatology of syphilis in the pregnant woman;79,2% request the VDRL exam in the adequate intervals and approximately 50% conduct the treatment in conformity with the recommendations of the Ministry of Health. For the followup care of the infected woman, 79,2% request a monthly VDRL examination, 69,8% explain the disease to the pregnant woman, and 20,7% affirm that they conduct a proper reception to the woman.We conclude that the majority of the health professionals have knowledge of the detection, treatment and followup of the pregnant woman with syphilis. However, the actions of some professionals diverge from the conduct procedures recommended by the Ministry of Health, as to the requesting of the examinations, medication prescription and notification of the iesease. This indicates the need for improved

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This study is an exploratory descriptive study with a quantitative approach. The objective was to identify the actions for the early detection of breast cancer conducted by the health professionals of the Family Health Strategy in the Trairi region of the State of Rio Grande do Norte, Brazil. The research was conducted in nine municipalities of the region. Data were collected by means of a questionnaire with 52 Family Health Strategy professionals, 30 nurses and 22 physicians, that work in the region. Analysis was conducted using descriptive statistics. The results were organized and discussed in three areas: Knowledge about the early detection of breast cancer; Actions for early detection detection of breast cancer, and Difficulties experienced in the screening actions for breast cancer. The results indicate that these professionals (100%) have knowledge of the signs and symptoms of breast cancer and that the majority (96,2%) conduct screening actions in accordance with the recommendations of the Ministry of Health. However, a considerable number (55,8%) of these professionals encounters difficulties while conducting the screening procedures in his work setting. The difficulties varied from those of a personal nature to those of access to the procedure, such as the unavailability of sufficient quotas of screening exams. We conclude that the majority of health professionals execute the screening actions for breast cancer in their work settings according to the recommendations of the Ministry of Health, even though they encounter difficulties in the conclusion of the mammography and ultrasound exams, essential procedures in the early detection of breast cancer. We understand that these professionals demonstrate knowledge of secondary prevention even though they do not execute all the actions necessary for early detection primarily because they are impeded by the blockage of access to exam quotas. We conclude that, in spite of the difficulties experienced, the procedures for the early detection of breast cancer are being executed by the majority of the Family Health Strategy professionals in the Trairí region, specifically the clinical examination of the breast, orientation of breast self examination, requests for mammography and ultra sound examinations. Measures are needed that can mediate the difficulties, that will permit the realization of secondary prevention procedures with the population at risk in the region. We suggest training and actualization courses on the complete screening process that includes a wide discussion of the new legislation that provides the mammography exam for women over 40 years. We believe that the acquisition of such a work perspective for the early detection of breast cancer, along with knowledge of health vigilance and of breast cancer, will enhance integral health care of women that constitutes an aim of the nurse and the family health team

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Telecommunication is one of the most dynamic and strategic areas in the world. Many technological innovations has modified the way information is exchanged. Information and knowledge are now shared in networks. Broadband Internet is the new way of sharing contents and information. This dissertation deals with performance indicators related to maintenance services of telecommunications networks and uses models of multivariate regression to estimate churn, which is the loss of customers to other companies. In a competitive environment, telecommunications companies have devised strategies to minimize the loss of customers. Loosing customers presents a higher cost than obtaining new ones. Corporations have plenty of data stored in a diversity of databases. Usually the data are not explored properly. This work uses the Knowledge Discovery in Databases (KDD) to establish rules and new models to explain how churn, as a dependent variable, are related to a diversity of service indicators, such as time to deploy the service (in hours), time to repair (in hours), and so on. Extraction of meaningful knowledge is, in many cases, a challenge. Models were tested and statistically analyzed. The work also shows results that allows the analysis and identification of which quality services indicators influence the churn. Actions are also proposed to solve, at least in part, this problem