Showing papers by "Universidade de Pernambuco published in 2009"

A Survey on Internet Traffic Identification

Abstract: The area of Internet traffic measurement has advanced enormously over the last couple of years. This was mostly due to the increase in network access speeds, due to the appearance of bandwidth-hungry applications, due to the ISPs' increased interest in precise user traffic profile information and also a response to the enormous growth in the number of connected users. These changes greatly affected the work of Internet service providers and network administrators, which have to deal with increasing resource demands and abrupt traffic changes brought by new applications. This survey explains the main techniques and problems known in the field of IP traffic analysis and focuses on application detection. First, it separates traffic analysis into packet-based and flow-based categories and details the advantages and problems for each approach. Second, this work cites the techniques for traffic analysis accessible in the literature, along with the analysis performed by the authors. Relevant techniques include signature-matching, sampling and inference. Third, this work shows the trends in application classification analysis and presents important and recent references in the subject. Lastly, this survey draws the readers' interest to open research topics in the area of traffic analysis and application detection and makes some final remarks.

Silver Diamine Fluoride: A Caries “Silver-Fluoride Bullet”

Abstract: The antimicrobial use of silver compounds pivots on the 100-year-old application of silver nitrate, silver foil, and silver sutures for the prevention and treatment of ocular, surgical, and dental infections. Ag+ kills pathogenic organisms at concentrations of < 50 ppm, and current/potential anti-infective applications include: acute burn coverings, catheter linings, water purification systems, hospital gowns, and caries prevention. To distill the current best evidence relative to caries, this systematic review asked: Will silver diamine fluoride (SDF) more effectively prevent caries than fluoride varnish? A five-database search, reference review, and hand search identified 99 human clinical trials in three languages published between 1966 and 2006. Dual review for controlled clinical trials with the patient as the unit of observation, and excluding cross-sectional, animal, in vitro studies, and opinions, identified 2 studies meeting the inclusion criteria. The trials indicated that SDF’s lowest prevented...

Fairness in Distributive Justice by 3- and 5-Year-Olds Across Seven Cultures

Abstract: This research investigates 3- and 5-year-olds' relative fairness in distributing small collections of even or odd numbers of more or less desirable candies, either with an adult experimenter or between two dolls. The authors compare more than 200 children from around the world, growing up in seven highly contrasted cultural and economic contexts, from rich and poor urban areas, to small-scale traditional and rural communities. Across cultures, young children tend to optimize their own gain, not showing many signs of self-sacrifice or generosity. Already by 3 years of age, self-optimizing in distributive justice is based on perspective taking and rudiments of mind reading. By 5 years, overall, children tend to show more fairness in sharing. What varies across cultures is the magnitude of young children's self-interest. More fairness (less self-interest) in distributive justice is evident by children growing up in small-scale urban and traditional societies thought to promote more collective values.

Diagnosis and treatment of dentinal hypersensitivity

Abstract: This bibliographic review provides a general view of the etiology, characteristics and treatment of dentinal hypersensitivity, so that professionals can use this information in the therapeutic management of this clinical condition. For this purpose, the authors have analyzed whole texts of relevant articles on the subject. This study showed that the predisposing factors associated with the causes of dentinal hypersensitivity must be controlled or eliminated, by educating the patient regarding the excessive intake of acidic food, as well as providing guidance on the proper tooth brushing technique and analysis of occlusion. Effective treatment must be preceded by a proper diagnosis, established after the exclusion of any other possible causes of the pain. These cases must be managed efficiently, quickly and permanently. The availability of a wide variety of treatment could be an indicator that there is still no effective desensitizing agent to completely resolve the patient's discomfort, or that it is difficult to treat, irrespective of the available treatment options. Even with the large number of published studies, it has not been possible to reach a consensus about the product that represents the gold standard in the treatment of dentinal hypersensitivity. (J Oral Sci 51, 323-332, 2009)

[Health risk behaviors among adolescents in the south of Brazil: prevalence and associated factors].

Abstract: OBJETIVO:Determinar a prevalencia de comportamentos de risco a saude e analisar fatores associados a exposicao a esses comportamentos em adolescentes do Estado de Santa Catarina, Brasil METODO: Adolescentes escolares de 240 turmas do ensino medio da rede publica estadual responderam a um questionario para a coleta de informacoes demograficas (sexo, idade, regiao de residencia e periodo de estudo), socioeconomicas (trabalho e renda familiar mensal) e de comportamentos de risco a saude (niveis insuficientes de atividade fisica, baixo consumo de frutas/verduras, tabagismo, consumo abusivo de bebidas alcoolicas, consumo de drogas ilicitas, envolvimento em brigas e nao utilizar preservativos regularmente nas relacoes sexuais) RESULTADOS: Foram considerados validos os questionarios de 5 028 adolescentes (2 984 do sexo feminino e 2 044 do sexo masculino), com idade entre 15 e 19 anos (media = 17,0; desvio padrao = 1,12) Os comportamentos de risco mais prevalentes na amostra foram niveis insuficientes de atividade fisica (36,5%), baixo consumo de frutas/verduras (46,5%) e nao utilizar preservativos regularmente nas relacoes sexuais (38,3%) Aproximadamente sete em cada 10 adolescentes (64,7%) estavam expostos a dois ou mais comportamentos de risco de forma simultânea Os seguintes subgrupos de risco foram identificados: adolescentes do sexo masculino, adolescentes de 18 a 19 anos de idade, que residem em area urbana, que estudam no periodo noturno e que tem maior renda familiar CONCLUSOES: A proporcao de adolescentes expostos a comportamentos de risco a saude foi elevada, principalmente ao se considerar a exposicao simultânea a diferentes comportamentos Os resultados encontrados podem contribuir para o desenvolvimento de programas de promocao da saude no ambiente escolar, direcionados principalmente aos subgrupos de risco

A Method for Extracting the Fundamental-Frequency Positive-Sequence Voltage Vector Based on Simple Mathematical Transformations

Abstract: In this paper, a novel scheme for obtaining the fundamental-frequency positive-sequence grid voltage is proposed. The method is based on four simple mathematical transformations; two of them are in the stationary reference frame, which are able to eliminate odd harmonics from the original signals. The other two transformations are implemented in a synchronously rotating reference frame in order to eliminate even harmonics. The output of the last transformation block is the input to a synchronous reference-frame phase-locked loop for detecting the frequency and position of the positive-sequence voltage vector. The proposed algorithm was verified through simulations and experiments by applying distorted and unbalanced signals, containing positive and negative-sequence components. The results are in agreement with those theoretically predicted and indicate that the proposed scheme has a great potential for use in grid-connected converter synchronization algorithms.

Text Line Segmentation Based on Morphology and Histogram Projection

Abstract: Text extraction is an important phase in document recognition systems. In order to segment text from a page document it is necessary to detect all the possible manuscript text regions. In this article we propose an efficient algorithm to segment handwritten text lines. The text line algorithm uses a morphological operator to obtain the features of the images. Following, a sequence of histogram projection and recovery is proposed to obtain the line segmented region of the text. First, an Y histogram projection is performed which results in the text lines positions. To divide the lines in different regions a threshold is applied. After that, another threshold is used to eliminate false lines. These procedures, however, cause some loss on the text line area. So, a recovery method is proposed to minimize this effect. In order to detect the extreme positions of the text in the horizontal direction, an X histogram projection is applied. Then, as in the Y direction, another threshold is used to eliminate false words. Finally, in order to optimize the area of the manuscript text line, a text selection is carried out. Experimental results using the IAM-database showed that this new approach is robust, fast and produces very good score rates.

A Methodology for Mapping SysML Activity Diagram to Time Petri Net for Requirement Validation of Embedded Real-Time Systems with Energy Constraints

Abstract: In this paper we use the Activity diagram of the System Modeling Language (SysML) in combination with the new UML profile for Modeling and Analysis of Real-Time and Embedded systems (MARTE) in order to validate functional, timing and low power requirements in early phases of the embedded system development life-cycle. However, SysML lacks a formal semantics and hence it is not possible to apply, directly, mathematical techniques on SysML models for system validation. Thus, a novel approach for automatic translation of SysML Activity diagram into Time Petri Net with Energy constraints (ETPN) is proposed. In order to depict the practical usability of the proposed method, a case study is presented, namely, pulse-oximeter. Besides, the estimates obtained (execution time and energy consumption) from the model are 95% close to the respective measures obtained from the real hardware platform.

OSNR model to consider physical layer impairments in transparent optical networks

Abstract: We propose a model that considers several physical impairments in all-optical networks based on optical signal-to-noise degradation. Our model considers the gain saturation effect and amplified spontaneous emission depletion in optical amplifiers, coherent crosstalk in optical switches, and four-wave mixing in transmission fibers. We apply our model to investigate the impact of different physical impairments on the performance of all-optical networks. The simulation results show the impact of each impairment on network performance in terms of blocking probability as a function of device parameters. We also apply the model as a metric for impairment-constraint routing in all-optical networks. We show that our proposed routing and wavelength assignment algorithm outperforms two common approaches.

Development of secondary dental care: a study on specialized dental clinics in Pernambuco State, Brazil

Abstract: This exploratory study aimed to evaluate the Specialized Dental Care Centers in Pernambuco State, Brazil, based on secondary outpatient treatment data from 2006 and standards and criteria adopted to implement these services The study describes the overall achievement of targets by these specialized dental clinics and variables for characterization of the dental services and municipalities (counties) The methodology included descriptive analysis and non-parametric correlation analysis (Spearman coefficient), with significance set at 5% Of the 22 specialized dental clinics, 409% showed good performance, and 818% met the target for basic dental care, as compared to 136% that met the target for minor oral surgery Among the independent variables, only population size and Municipal Human Development Index (MHDI) were correlated with the performance of the specialized dental clinics: the smaller the city (r = 0678; p < 0001) and the lower the MHDI (r = 0599; p < 0001), the worse the performance The findings suggest that standardization of the implementation and functioning of specialized dental clinics should be monitored and evaluated in order to ensure better quality of services for the population

Prevalence of dental trauma in deciduous teeth of Brazilian children

Abstract: The aim of this study was to assess the prevalence of dental trauma as compared to the prevalence of dental caries in children aged 3-59 months. A cross-sectional study was carried out during the National Immunization Day for Polio in Recife, northeast Brazil. The sample comprised 3489 children under the age of 5. The clinical examination was performed by 123 previously trained dental students. The inter-examiner agreement for crown fracture was 90.32% and for tooth discoloration it was 83.87%. The prevalence of dental caries was assessed using the dmf-t index. The statistical methods included descriptive analysis and the chi-square test with a margin of error of 5%. A total of 56 142 teeth were examined and the prevalence of dental trauma was 14.9%. Dental fracture was the most prevalent injury observed in 516 teeth (0.9%), followed by discoloration in 191 (0.9%), intrusion in 12 (0.02%) and extrusion in five (0.008%). The most affected teeth were the upper central incisors. The prevalence of dental trauma increased significantly with age and family income (P Language: en

Is it better to be rich in a poor area or poor in a rich area? A multilevel analysis of a case–control study of social determinants of tuberculosis

Abstract: Background Tuberculosis is known to have socio-economic determinants at individual and at area levels, but it is not known whether they are independent, whether they interact and their relative contributions to the burden of tuberculosis. Methods A case–control study was conducted in Recife, Brazil, to investigate individual and area social determinants of tuberculosis, to explore the relationship between determinants at the two levels and to calculate their relative contribution to the burden of tuberculosis. It included 1452 cases of tuberculosis diagnosed by the tuberculosis services and 5808 controls selected at random from questionnaires completed for the demographic census. Exhaustive information on social factors was collected from cases, using the questionnaire used in the census. Socio-economic information for areas was downloaded from the census. Multilevel logistic regression investigated individual and area effects. Results There was a marked and independent influence of social variables on the risk of tuberculosis, both at individual and area levels. At individual level, being aged ≥20, being male, being illiterate, not working in the previous 7 days and possessing few goods, all increased the risk of tuberculosis. At area level, living in an area with many illiterate people and where few households own a computer also increased this risk; individual and area levels did not appear to interact. Twice as many cases were attributable to social variables at individual level than at area level. Conclusions Although individual characteristics are the main contributor to the risk of tuberculosis, contextual characteristics make a substantial independent contribution.

Eating disorders in patients with obsessive-compulsive disorder: prevalence and clinical correlates.

Abstract: Institute of Psychiatry University of Sao Paulo Medical School, R. Dr. Ovidio Pires de Campos, 785, 05403-010 SaoPaulo, Sao Paulo

Relationship between oral health, nutrient intake and nutritional status in a sample of Brazilian elderly people

Abstract: Objective: To evaluate the relationship between the oral health condition, the nutrient intake and the body mass index (BMI) in elderly people. Background: Impaired dentition has been associated with an inadequate consumption of key nutrients and with changes in nutritional status in elderly people. Materials and methods: The sample comprised 887 elderly people, aged 60 and over, of whom 816 underwent a clinical oral examination and were allocated into groups according to the numbers of teeth and number of posterior occluding pairs of natural teeth. Nutritional status was determined using the BMI. Dietary intake was assessed by a 24-h diet recall interview and the data from these records were converted to nutritional intake using DietPro software. Differences between means were evaluated using anova, together with the Tukey test or Dunnet test, according to the normality of the data. Associations between categorical variables were tested using chi-square analysis. Results: Ages ranged from 60 to 96 years (mean, 71.46 years), with 47% of the respondents in the 60-to 69-year-old group. A high DMFT index (mean, 27.81) was observed with the missing component accounting for 88.8% of the index. Significant differences were observed between the mean intake of nutrients and the number of posterior occluding pairs of natural teeth (p < 0.05). No significant differences were found between the number of teeth and BMI. Conclusion: Nutrient intake is associated with the oral health status as defined by clinical measures.

Fatores de risco para mortalidade neonatal em crianças com baixo peso ao nascer

Abstract: OBJETIVO: Analisar os fatores de risco associados aos obitos neonatais em criancas com baixo peso ao nascer. METODOS: Realizou-se um estudo de coorte, composto pelos nascidos vivos com peso entre 500 g e 2.499 g, residentes no Recife (PE), entre 2001 e 2003, produtos de gestacao unica e sem anencefalia. Os dados sobre os 5.687 nascidos vivos e 499 obitos neonatais, provenientes do Sistema de Informacoes sobre Nascidos Vivos e do Sistema de Informacoes sobre Mortalidade, foram integrados pela tecnica de linkage. Em modelo hierarquizado, as variaveis dos niveis distal (fatores socioeconomicos), intermediario (fatores de atencao a saude) e proximal (fatores biologicos) foram submetidas a analise univariada e regressao logistica multivariada. RESULTADOS: Com o ajuste das variaveis na regressao logistica multivariada, as variaveis do nivel distal que permaneceram significantemente associadas com o obito neonatal foram: a coabitacao dos pais, numero de filhos vivos e tipo de hospital de nascimento; no nivel intermediario: numero de consultas no pre-natal, complexidade do hospital de nascimento e tipo de parto; e no nivel proximal: sexo, idade gestacional, peso ao nascer, indice de Apgar e presenca de malformacao congenita. CONCLUSOES: Os principais fatores associados a mortalidade neonatal nos nascidos vivos com baixo peso estao relacionados com a atencao a gestante e ao recem-nascido, redutiveis pela atuacao do setor saude.

[Prevalence of high blood pressure and associated factors in students from public schools in Greater Metropolitan Recife, Pernambuco State, Brazil, 2006].

Abstract: The aim of this study was to identify the prevalence of systemic arterial hypertension (high blood pressure) and associated health factors in adolescents, using a cross-sectional, population-based, epidemiological design from April to September 2006, within a stratified sample according to school size and shift. Using the Portuguese version of the Global School-Based Student Health Survey questionnaire, 1,878 students from 29 public schools in Greater Metropolitan Recife, Pernambuco State, Brazil, were analyzed for: age, gender, body mass index, fruit, vegetable, alcohol, and tobacco consumption, as well as blood pressure, adopting the 1996 Task Force Report on High Blood Pressure in Children and Adolescents and Centers for Disease Control and Prevention parameters for nutritional status. Prevalence rates for high blood pressure, overweight, and obesity were 17.3%, 6.9%, and 3.7%, respectively. Factors associated with high blood pressure were: male gender, obesity, overweight, and lack of physical activity. Knowledge of factors associated with arterial hypertension in adolescents can help support health education campaigns.

Condutas de saúde entre universitários: diferenças entre gêneros

Abstract: Este estudo investigou diferencas entre os generos nas condutas de saude de universitarios em final de curso. A amostra foi composta de 382 estudantes de universidades publicas do Estado de Pernambuco, Brasil, com idade entre 20 e 29 anos. Os dados foram coletados mediante a aplicacao do questionario National College Health Risk Behavior Survey, validado previamente para o portugues. Foram utilizadas tecnicas de estatistica descritiva e inferencial. Para analise de associacao foram utilizados teste qui-quadrado ou exato de Fisher. Os resultados foram considerados significantes para p < 0,05. Verificou-se que, de modo geral, os estudantes do genero feminino apresentaram frequencias menores de condutas de risco para a saude como: consumo de alcool (p = 0,005), tabagismo (p = 0,002), experimentacao de maconha (p = 0,002), consumo de inalantes (p < 0,001), uso de esteroides (p = 0,003), porte de arma (p = 0,001) e envolvimento em briga fisica (p = 0,014). Os estudantes, no entanto, relataram maior preocupacao em perder ou manter o peso, apesar de a pratica de atividade fisica ter sido menos frequente neste grupo. Pode-se concluir que ha diferencas significativas com relacao as condutas de saude entre os generos, devendo haver abordagens diferenciadas para os dois grupos.

The relationship between dental anxiety and dental pain in children aged 18 to 59 months: a study in Recife, Pernambuco State, Brazil

Abstract: The aim of this study was to evaluate anxiety and pain related to dental treatment in children under the age of five years. This cross sectional study was carried out with 2,735 children of both sexes. Socioeconomic data, dental anxiety and dental pain experience, as well as the assessment of the child's oral health status, were obtained through a questionnaire answered by the child's parent or guardian. Dental anxiety was measured using the Dental Anxiety Question (DAQ). The prevalence of dental anxiety was 34.7% and that of dental pain was 9.1%. There was an association between these two variables (p < 0.0001). There was also an association between dental pain, age, family income and assessment of oral health status. The poorest rating of the child's oral health and the lowest family income were correlated with the highest percentages of a history of dental pain. Dental anxiety was related to a history of dental pain in children under the age of five years.

Integrated health care networks in Latin America: toward a conceptual framework for analysis

Abstract: Las inequidades e ineficiencias de los sistemas de salud de America Latina motivaron algunas reformas, concentradas en las ultimas dos decadas, particularmente en el financiamiento y el suministro de la atencion sanitaria. Este trabajo se enfoca en la introduccion de redes integradas de atencion sanitaria (RIAS) en varios paises de America Latina y los ubica en el contexto internacional. La descripcion y el analisis de las RIAS, ya fueran regionales o de afiliacion, resaltan el debate actual sobre sus posibles beneficios y riesgos. El impacto de las RIAS -en terminos del mejoramiento del acceso a la atencion sanitaria o de la promocion de la eficiencia y la equidad en los sistemas de salud- se ha evaluado en muy pocas oportunidades. Para contribuir al tema, se propone un marco conceptual abarcador para el analisis del desempeno de las RIAS, que trata el proceso interno y los factores externos considerados criticos para alcanzar sus objetivos intermedios y finales.

Work-related musculoskeletal disorders among Brazilian dental students.

Abstract: The aim of this analytical cross-sectional study was to evaluate the presence of work-related musculoskeletal disorders (WMSD) among dental students in two Brazilian dental schools. The sample included 227 randomized subjects from fifth to ninth semesters who were developing clinical activities. Each student signed an informed consent form. A self-reporting questionnaire was used to obtain data on the practice of physical exercise, the presence of pain during or soon after treating patients, and the adoption of preventive measures related to clinical activities. Results were analyzed using the Statistical Package for Social Sciences 13.0. The χ 2 test was used to identify associations between variables. The presence of pain during or after clinical work was reported by 173 participants (76.2 percent). Statistically significant differences were found between gender and the occurrence of pain. Pain was present during clinical activities (p=0.006) and imposed limitations on the work routine (p=0.011). Among those who practiced physical exercise, eighty-eight (74.6 percent) reported pain. The high percentage of pain reported by dental students suggests the value of reviewing work conditions in dental practices in order to minimize the exposure of all workers to WMSD.

Fish School Search

Abstract: Real world problems are packed with complex issues often hard to be computed. Searching for parameters or candidate solutions is frequently associated with these complexities. The reason for that is chiefly related to the large dimensionalities of some search spaces. In general, problems involving large search spaces use traditional computer intensive methods that are, quite often, expensive (i.e. resource consuming). Nature-inspired algorithms, on the other hand, are able to deal reasonably well with the abovementioned difficulties. In this chapter, we provide an overview of a novel approach for searching in high-dimensional spaces based on the behaviors of fish schools. As any other intelligent technique based on population, Fish School Search (FSS) greatly benefits from the collective emerging behavior that increases mutual survivability. Broadly speaking, FSS is composed of operators that can be grouped in the following categories: feeding, swimming and breeding. Together, these operators provide computing behavior such as: (i) high-dimensional search ability, (ii) automatic selection between exploration and exploitation, and (iii) self-adaptable guidance towards sought solutions. This chapter seeks to explain the main ideas behind FSS to researchers and practitioners. In addition, we include examples and simulations aimed at clarifying the simplicity and potentials of FSS.

Chronic treatment with sildenafil stimulates Leydig cell and testosterone secretion

Abstract: The phosphodiesterase type 5 (PDE5) inhibitor, Sildenafil, is a novel, oral treatment approach for pulmonary hypertension. As Leydig cells present PDE5, this study was conducted to investigate the effects of the chronic treatment with Sildenafil (25 mg/kg) on male Swiss Webster mice steroidogenesis. After a 4-week long experimental design, Leydig cells were analysed by morphological and immunocytochemical procedures. Serum testosterone was assayed by radioimmunoassay. Leydig cells presented noteworthy ultrastructural alterations, such as a vesicular smooth endoplasmic reticulum, large vacuoles scattered through the cytoplasm, enlarged mitochondria with discontinue cristaes and whorle membranes with vesicles at the periphery, which are typical characteristics of an activated steroid-secreting cell. Important immunocytochemical labelling for steroidogenic acute regulatory protein, cytochrome P450 side-chain cleavage enzyme and testosterone were detected in isolated Leydig cells. In addition, Sildenafil-treated mice showed significant increased levels of total testosterone. The results obtained in the present study are consistent with the hypothesis that the accumulation of cyclic guanosine monophosphate by PDE5 inhibition could be involved in the androgen biosynthesis stimulation. Important clinical implications of hormonal disorders should be taken into account for patients with pulmonary hypertension.

Prevalence of overweight and obesity and associated factors among public high school students in Pernambuco State, Brazil

Abstract: This study aims to analyze the association between demographic, socioeconomic, school-related, and behavioral factors and overweight and obesity in adolescents. The sample included 4,210 public high school students (14-19 years old) in Pernambuco State, Brazil, selected by two-stage cluster sampling. Obesity and overweight were assessed using anthropometric measurements, and the Global School-Based Health Survey was used to collect personal and behavioral data. The cutoff points for defining overweight and obesity were those recommended by the International Obesity Task Force. Prevalence rates for overweight and obesity were 11.5% (95%CI: 10.7-12.8) and 2.4% (95%CI: 1.9-2.9), respectively. Overweight and obesity were more common in males who reported residing in urban areas and were not enrolled in physical education classes. Watching television 3+ hours/day was associated with obesity in females. Reducing TV time and encouraging enrollment in physical education could be effective measures to counteract the growing obesity trends.

A Modulation Technique to Reduce Switching Losses in Matrix Converters

Abstract: This paper presents a modulation technique based on the generalized pulsewidth-modulation strategy for matrix converters. The proposed technique uses a discontinuous modulation to clamp each output leg of the converter during 120deg of the output voltage period, achieving a reduced number of switchings compared with the traditional modulation techniques. Aside from that, the major attraction of the proposed technique is an additional algorithm that lags the clamping of each output leg of the converter to synchronize it with the peak of the corresponding output current (load current), avoiding high switching losses (switching at high currents). Therefore, this technique reduces the number of switchings as well as guarantees only medium and low current switchings. Simulation and experimental results show the efficiency of the proposed technique.

An Age-Based Inspection and Replacement Policy for Heterogeneous Components

Abstract: This paper considers a hybrid maintenance policy for a single component from a heterogeneous population. The component is placed in a socket, and the component and socket together comprise the system. The s-population of components consists of two sub-populations with different failure characteristics. By supposing that a component may be in a defective but operating state, so that there exists a delay time between defect arrival and component failure, we consider a novel maintenance policy that is a hybrid of inspection and replacement policies. There are similarities in this approach with the concept of ldquoburn-inrdquo maintenance. The policies are investigated in the context of traction motor bearing failures. Under certain circumstances, particularly when the mixture parameter is large, and the distribution of lifetimes for the two component types are well separated, the hybrid policy has significant cost savings over the standard age-based replacement policy, and over the pure inspection policy. In addition to the cost metric, the mean time between operational failures of the system under the hybrid policy can be used to guide decision-making. This maintenance policy metric is calculated using simulation, and using an approximation which assumes that operational failures occur according to a Poisson process with a rate that can be calculated in a straightforward way. The simulation results show good agreement with the approximation.

Atualização sobre hemoglobina glicada (HbA1C) para avaliação do controle glicêmico e para o diagnóstico do diabetes: aspectos clínicos e laboratoriais

Abstract: Universidade Federal de Sao Paulo (UNIFESP) Hospital do Rim e Hipertensao Centro Integrado de Hipertensao e Metabologia Cardiovascular

Therapeutic effect of two fluoride varnishes on white spot lesions: a randomized clinical trial

Abstract: The aim of this randomized clinical trial study was to evaluate the therapeutic effect of two varnish formulations (G1 = 5% NaF, G2 = 6% NaF + 6% CaF(2)) on the remineralization of white spot lesions (WSL). The sample was composed of 15 (7- to 12-year-old) children with 45 active WSL in anterior permanent teeth. The children were randomly divided into two groups providing 22 lesions for G1 and 23 for G2. The children were submitted to weekly varnish applications 4 times. The WSL were evaluated twice: baseline and on week 4. Maximum lesion dimensions (mesiodistal and incisogingival) were measured in millimeters and classified in four grades of size. WSL were also assessed regarding lesion activity by one calibrated examiner. The Pearson chi-square and Fisher's exact tests were used (P 0.01). It was concluded that after 4 applications the two varnish formulations tested produced similar clinical effects, indicating the reduction and the control of carious activity in most WSL.