99 resultados para Tipos de conhecimento


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Some studies reported in the literature that emotional factors and quality of life may be involved both in aetiology, as in the progression of Temporomandibular disorders (TMD). Proposition: The purpose of this study is to observe a possible association between different forms of anxiety, quality of life and general health of patients diagnosed as carriers of various types and levels of Temporomandibular Dysfunction. Methodology: The sample consisted of 60 patients diagnosed as carriers of TMJD origin of muscle, joint, or both, with different levels of severity (mild TMD, moderate and severe). The patients were diagnosed with TMD-RDC (Research Diagnostic Criteria) to assess the type of dysfunction (muscle or joint) and by the Protocol of Fonseca to verify the degree of dysfunction (mild, moderate or severe). To evaluate the psychosocial aspects were used three self-applied, with the purpose of obtaining information about the general health (General Health Questionnaire - GHQ), the type of anxiety (Trait Anxiety Inventory-State - STAI) and quality of life (World Health Organization Quality Of Life Short WHOQOL-brief). Results: There was a correlation between all indicators studied in several forms of TMD with varying degrees of commitment. Quality of life appeared linked to the type and the level of TMD: Muscular and Articular TMD (p = 0,037), Disk Displacement With Reduction (p = 0.01) and Mild TMD (p = 0.042). The General Health showed association with the level of TMD, with the exception of the stress factor (p = 0.78). For the analysis of the types and levels to Severe Muscular TMD had a statistically significant indicator of the quality of life (p = 0049). The anxiety only showed association with the level of TMD (p = 0,047 for anxiety-trait). Conclusion: Besides the limitations of the study, it was concluded that anxiety, quality of life and general health are important psychosocial indicators, which are linked to several forms of TMD in different levels of severity

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Oral squamous cell carcinoma (OSCC) is the most prevalent malignancy in the oral cavity and reach a large number of individuals, has become an important public health problem. Studies have demonstrated changes in pathway components BMP in various types of cancers as prostate, colon, breast, gastric and OSCCs. Is the current knowledge that these proteins may exert pro-tumor effect in more advanced stages of neoplastic development coming to favor progression and invasion tumor. The inhibition of the signaling pathway BMP-2 through its antagonists, have shown positive results of antitumor activity and use of Noggin may be a novel therapeutic target for cancer. Given this evidence and the few studies with BMP-2, Noggin and OSCC, the objective of this research was to evaluate the effect of BMP-2 and its antagonist Noggin on proliferation and migration cell in line of cell cultures of human tongue squamous cell carcinoma (SCC25). The study was divided in three groups, a control group, where SCC25 cells suffered no treatment, a BMP-2 group, in which cells were treated with 100ng/ml of BMP-2 and a group of cells that were treated with 100ng/ml of Noggin. For the proliferation assay and cell cycle were established three time intervals (24, 48 and 72 hours). Proliferative activity was investigated by trypan blue and cell cycle analysis by staining with propidium iodide flow cytometry. The potential for migration / invasion of SCC25 cells was performing by a cell invasion assay using Matrigel in a 48-hour interval. The proliferation curve showed a higher proliferation in cells treated with BMP-2 in 72 hours (p < 0.05), and lower overgrowth and cell viability in Noggin group. Recombinant proteins favored a greater percentage of cells in cell cycle phase Go/G1 with a statistically significant difference in the interval of 24 hours (p < 0.05). BMP- 2 produced a greater invasion of cells studied as well as its antagonist Noggin inhibits invasion of cells (p < 0.05). Thus, these results indicate that BMP-2 promotes malignant phenotype, dues stimulates proliferation and invasion of SCC25 cells and, its antagonist Noggin may be an alternative treatment, due to inhibit the tumor progression

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The visual system is an important link between the animal and the environment, com profound influences on the habits and lifestyle in various habitats. Adaptive mechanismsto the temporal niche are present in the visual system of many vertebrates, involving changins in ocular dimensios and design, retinal cell distribution and organization of neurochemical circuits related to the retinal resolution or sensitivity. The sensory system of the eye is represented by the retina, whose organization is responsible by receipty, initial analysis, and transmission of the information to the brain. The knowledge of the position of the eyes in the head and the distribution of retinal cells allow to identify adaptive aspects of each species to its visual field, which is characteristic to the ecological niche it occupies. In this research, we study eye anatomical characteristics and retina neurochemical features of the rock cavy (Kerodon rupestris), a tipical Brazilian rodent from the suborder Hystricomorpha, family Caviidae. The rock cavy has lateral eyes well constitute bony orbit and well differentiated extrinsic muscle. The study of the descriptive and morphometric anatomy of the showed mean values of axial diameter 10.7±0,5mm and equatorial diameter 11.6±0.7mm. The pupil is slit shaped and the lens has mean axial diameter 5.4±0.03 mm, corresponding to ~45% of the axial diameter of the eye. The posterior nodal distance and the retinal magnification factor were estimated at 6.74 mm e 118 μm/grau, respectively. Flat mounts were processed for Nissl stain, and the topographic distribution of ganglion cells showed a moderate visual band, just below the optic disc, with higher density in the ventral retina. Retinal vertical sections and flat mounts were processed for immunohistochemistry to visualize tyrosine hydroxilase (TH) and thus two types of TH+ cells were detected. Type 1 cells had strong TH-immunoreactivity, the body cell varied from 120.047 to 269.373 μm2 stratifying in the sublamina 1 of the IPL. Type 2 cells were weakly TH-imunoreactive, had cell body located mostly in the IPL, varying from 54.848 to 177.142 μm2, constituting ~10% of the TH+ cells. Both cell types exhibited similar topographic distribution with higher density found in a horizontal band along of the naso-temporal axis in the dorsal retina. The total population of dopaminergic cells was 2,156±469,4 cells, occupying an average area of 198,164 μm2. The presence of cones and rods was detected by immunohistochemistry in vertical sections and flat mounts. S cones density is around 10 times smaller than L cones, with different degree of spatial organization. Other retinal neuronal populations of the rock cavy were also detected in vertical sections with specific markers. Comparative analysis of the anatomical characteristics of the rock cavy eye 12 suggest that it was designed to acquire higher sensitivity to light, at expense of image sharpness, compatible with a vision at mesopic conditions. Additionally, the distribution of the 2 subtypes of dopaminergic cells in a naso-temporal band in the dorsal retina seems suitable to a gain in sensitivity, coherent with an animal with predominantly crepuscular activity pattern

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Understanding the behavioral activities of freshwater shrimp in captivity is of paramount importance for the appropriate management of the species. In Brazil, the shrimp Macrobrachium rosenbergii is currently the most widely used species in the freshwater shrimp culture due to its high potential for cultivation and good market acceptance. Thus, the present study aimed to describe and characterize the behavioral activities of M. rosenbergii in monosex and in mixed (male and female) (manuscript 1, 2 and 3) populations and the growth performance of this species in restrictive feeding conditions and in different feeding management (manuscript 4 and 5, respectively) . Juvenile and adult shrimps were collected from ponds of the Aquaculture Station - Unidade Especializada em Ciências Agrárias - Universidade Federal do Rio Grande do Norte (UFRN), Macaíba/RN and then transferred to the Laboratório de Estudos do Comportamento do Camarão LECC (Laboratory for Shrimp Behavioral Studies) of the Universidade Federal do Rio Grande do Norte (UFRN). For each treatment , eight aquaria of 250 L (50 cm x 50 cm x 100 cm) were used in a closed recirculating water system with artificial lighting, constant aeration , continuous filtration through a biochemical and biological filter (canister filter), and fine sand as substrate . The water quality was monitored daily. The lab consisted of two rooms with artificial lighting system , controlled by a timer with dark / light cycle of 12:12 h . In manuscript 1, the behavioral categories of the species were presented through an ethogram, which described 31 behaviors, subdivided into general and agonistic behaviors. Manuscript 2 compared the behavioral profile of shrimps in male and in female monosex and mixed populations over 24 hours in laboratory. In three types (mixed, male monosex and female monosex) of populations during the light and dark phases of the 24 hour cycle, the shrimps showed higher occurrence of cleaning behavior. Manuscript 3 examined the influence of the color of the shelter on the frequency of its use and behavioral activities of shrimp in mixed, in male monosex and in female monosex populations over 24 hours. We observed that the shrimp M. rosenbergii burrow more frequently during the light phase in male monosex and mixed populations; they also tend to choose the black shelters. Female monosex populations tend to use red and orange shelters. In manuscript 4, we evaluated in laboratory the behavioral activities and growth performance of juvenile shrimps under food restriction. We observed that a mild food restriction may be used since there is no loss concerning the growth of the animals; feeding management on alternate days , compared to daily management can be financially productive both reducing labor costs and reducing the amount of feed used . Manuscript 5 evaluated the behavior of shrimps in monosex and in mixed populations, as well as the latency of reach the food according to feed offer (tray or food dispersal) . Our results indicate that animals adjust to both types of feed offer food dispersal as much as tray, but they spend more time to reach the feed when it is offered in trays (feeders). Comparing culture types (mixed, male monosex and female monosex), the latency to reach the food was lower for female monosex population. The data obtained in this study demonstrate the importance of identifying different pressures and environmental stimuli on the behavioral responses of this species. This knowledge would support management improvement to optimize the levels of animals‟ welfare, resulting in a better zootecnical performance

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The exposure to stressors produces physiological changes of the organism in order to adapt the individual to the environment. Depending on the type, intensity and duration, stress can affect some cognitive functions, particularly processes of learning and memory. Several studies have also proposed that some level of anxiety would be necessary for memory formation. In this context, memories of previously aversive experiences may determine the manner and intensity with which are expressed fear responses, which explains the great interest in analyzing both anxiety and memory in animals. In addition, males and females demonstrate different reactions in relation to stressful stimuli, showing different levels of anxiety and differences in processing of the acquisition, retention and recall of information. Based on this information, the present study aimed to verify the effect of stress on learning, memory and anxiety behavioral parameters in rats exposed at different types of stressors of long duration (seven consecutive days): restraint (4h/day), overcrowding (18h/day) and social isolation (18h/day) in the different phases of the estrous cycle. Our results showed that the stress induced by restraint and social isolation did not cause changes in the acquisition process, but impaired the recall of memory in rats. Furthermore, it is suggested a protective effect of sex hormones on retrieval of aversive memory, since female rats in proestrus or estrus phase, characterized by high estrogen concentrations, showed no aversive memory deficits. Furthermore, despite the increased plasma levels of corticosterone observed in female rats subjected to restraint stress and social isolation, anxiety levels were unaltered, compared to those various stress conditions. Animal models based on psychological and social stress have been extensively discussed in the literature. Correlate behavioral responses, physiological and psychological have contributed in increasing the understanding of stress-induced psychophysiological disorders

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Currently, several psychological and non-psychological tests can be found in publishes without standardization on procedures set in different psychological areas, like intelligence, emotional states, attitudes, social skills, vocation, preferences and others. The computerized psychological testing is a extension of traditional testing psychological practices. However, it has own psychometrics qualities, either by its matching in a computerized environment or by the extension that can be developed in it. The current research, developed from a necessity to study process of validity and reliability on a computerized test, drew a methodological structure to provide parallel applications in numerous kinds of operational groups, evaluating the influences of the time and approach in the computerization process. This validity refers to normative values groups, reproducibility in computerized applications process and data processing. Not every psychological test can be computerized. Therefore, our need to find a good test, with quality and plausible properties to transform in computerized application, leaded us to use The Millon Personality Inventory, created by Theodore Millon. This Inventory assesses personality according to 12 bipolarities distributed in 24 factors, distributed in categories motivational styles, cognitive targets and interpersonal relations. This instrument doesn t diagnose pathological features, but test normal and non adaptive aspects in human personality, comparing with Theodore Millon theory of personality. In oder to support this research in a Brazilian context in psychological testing, we discuss the theme, evaluating the advantages and disadvantages of such practices. Also we discuss the current forms in computerization of psychological testing and the main specific criteria in this psychometric specialized area of knowledge. The test was on-line, hosted in the site http://www.planetapsi.com, during the years of 2007 and 2008, which was available a questionnaire to describe social characteristics before test. A report was generated from the data entry of each user. An application of this test was conducted in a linear way through a national coverage in all Brazil regions, getting 1508 applications. Were organized nine groups, reaching 180 applications in test and retest subject, where three periods of time and three forms of retests for studies of on-line tests were separated. Parallel to this, we organized multi-application session offline group, 20 subjects who received tests by email. The subjects of this study were generally distributed by the five Brazilian regions, and were noticed about the test via the Internet. The performance application in traditional and on-line tested groups subsidies us to conclude that on-line application provides significantly consistency in all criteria for validity studied and justifies its use. The on-line test results were related not only among themselves but were similar to those data of tests done on pencil and paper (0,82). The retests results demonstrated correlation, between 0,92 and, 1 while multisessions had a good correlation in these comparisons. Moreover, were assessed the adequacy of operational criteria used, such as security, the performance of users, the environmental characteristics, the organization of the database, operational costs and limitations in this on-line inventory. In all these five items, there were excellent performances, concluding, also, that it s possible a self-applied psychometric test. The results of this work are a guide to question and establish of methodologies studies for computerization psychological testing software in the country

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Poverty is a main theme in Brazil: according to official data, poverty reachs 70 million Brazilian people, and, between them, 20 million are unable to provide their basic needs. Psychology, as a welfare profession, and given its historical concerns with social actions, could not be away from this theme. Based on this, we ask: Which answers Psychology can provide, toward both the production of knowledge and the practice about social reality? The purpose of this paper is to investigate the psychological scientific production on poverty and the propositions, limits and impacts of psychological actions. We carried out a three stages documental based study analyzing Brazilian psychological literature: (1) online databases survey (312 papers identified); (2) 109 scientific abstracts accessed and coded; (3) selected 47 scientific papers read and analyzed. Results are presented in three sections: general description of the selected scientific production; characterization of the role of poverty in psychological literature; and themes presented at the papers. The academic production about the main theme (poverty) is dispersed, heterogeneous, and related to other fields of knowledge. Poverty is presented at these studies in many ways, such as: a criterium for sample design and the assessment of its psychological impacts; reports on professional experience with poor population; descriptions of this population group; relationship between poverty and others social themes; developmental and learning problems of poor children. In general, it appears that Psychology has improved the scientific production and experiences with poor population. However, it is necessary to build up theories and technical innovations and also to understand structural boundaries for professional practice with this population group

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In the world we are constantly performing everyday actions. Two of these actions are frequent and of great importance: classify (sort by classes) and take decision. When we encounter problems with a relatively high degree of complexity, we tend to seek other opinions, usually from people who have some knowledge or even to the extent possible, are experts in the problem domain in question in order to help us in the decision-making process. Both the classification process as the process of decision making, we are guided by consideration of the characteristics involved in the specific problem. The characterization of a set of objects is part of the decision making process in general. In Machine Learning this classification happens through a learning algorithm and the characterization is applied to databases. The classification algorithms can be employed individually or by machine committees. The choice of the best methods to be used in the construction of a committee is a very arduous task. In this work, it will be investigated meta-learning techniques in selecting the best configuration parameters of homogeneous committees for applications in various classification problems. These parameters are: the base classifier, the architecture and the size of this architecture. We investigated nine types of inductors candidates for based classifier, two methods of generation of architecture and nine medium-sized groups for architecture. Dimensionality reduction techniques have been applied to metabases looking for improvement. Five classifiers methods are investigated as meta-learners in the process of choosing the best parameters of a homogeneous committee.

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A colaboração na pesquisa é uma das tarefas centrais da área acadêmica. Atualmente, muitos pesquisadores estão utilizando meios modernos de troca de arquivos digitais através de ferramentas assíncronas e também com o uso de ferramentas mais sofisticadas, do tipo síncronas. Juntamente com o fato da crescente quantidade de artigos sendo gerados, mais complexos, diversificados e aumentando de forma desorganizada, o que trás ao pesquisador uma tarefa difícil para organizá-los de forma a se extrair o melhor conteúdo destes, isto ocorre porque uma subárea da Engenharia de Software (ES) ainda é bastante mal aproveitada, a Engenharia de Software Experimental (ESE). Utilizando-se de um dos tipos de experimentos que a ESE oferece, as revisões sistemáticas entram como uma solução bastante robusta, na qual o pesquisador pode identificar o conhecimento existente em uma área e planejar devidamente sua pesquisa, evitando a repetição de erros em pesquisas já efetivadas por outros pesquisadores no passado. Contudo, estas duas abordagens, a colaboração virtual de pesquisadores e a utilização de revisões sistemáticas, contem problemas: na primeira, sistemas colaborativos são geralmente difíceis de configurar e usar; na segunda, apesar da robustez da metodologia de revisões sistemáticas, ainda se torna necessário uma rigorosa revisão na literatura para se conseguir um resultado satisfatório. Assim, com o foco de unir estas duas abordagens, este trabalho propõe uma maneira de produzir revisões sistemáticas de forma organizada e com a possibilidade de interação entre usuários, com o desenvolvimento de um sistema interativo, no qual as revisões sistemáticas possam ser geradas por usuários em colaboração com outros e também ser avaliadas seguindo a orientação de um profissional da área, tornando o seu conteúdo mais consistente e de melhor qualidade. O sistema não possui níveis de acesso, ou seja, qualquer pessoa pode se cadastrar e usufruir de seus recursos, seja na área acadêmica ou mesmo na área profissional

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The process of development of any area is closely linked to teaching and research, and in Tourism it is not different. Thus, in this area in which service is one of the factors intrinsically related to its success , it is observed the need for people with deep and critical training in the various aspects of this activity acting in this sector. However, we can see the existence of some differences between what is offered by the academy from what is required by the market. Therefore, the objective of this research is to verify the relationship between higher education in Tourism and labor market through the perception of the bachelor in this area, graduated in Natal-RN, since it is the tourismologist who makes the link between this two fields. To know the perception of these tourismologists, it was necessary to apply a questionnaire to those ones graduated in the years 2009 and 2010. In accordance with the aim of this study, this research was exploratory-descriptive. Related to the technical procedures, it was a documentary, literature and field research. To have it analyzed, some qualitative and quantitative techniques were applied according to our specific objectives and the types of data collected, such as: content analysis, factorial analysis to synthesize the information and identify the basic dimensions that represent the different variables studied, the standard deviation to verify the variation of the responses in some items and the correlation technique that allows the analysis of the relationship between two variables. In response to the objectives proposed here, we could finally conclude that: the syllabuses of these courses are too general and the graduates themselves consider them so. It was diagnosed that the graduates 1) are mostly female, 2) a very small part of them is working in the area that they are graduated in, and 3) not all of them receive satisfactory wages which contributes to having a negative view of their degree course. Moreover, the educational institution where they studied was not a decisive factor to get a job. It was still diagnosed that most part of them do not have positive perceptions when thinking about the future of their careers as bachelors in Tourism. Many of them, including, if it was possible to change something in their careers so far, they could have chosen another college degree. It was found that, although there is a negative perception about their professional future, almost half of them believe that the course met the needs of the market. However, those ones that are not working have a more positive point of view related to the applicability of higher education. On the other hand, the other ones who already worked in this area have a more negative perception about it and do not believe that the course meets the market's needs. In summary, this study allowed the understanding of the existence of some gaps that exist between higher education in Tourism and the market needs, professionally speaking, thus contributing to the spreading of ideas on that subject for teachers, researchers and the current and future students of the area.

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During the dry and rainy periods, in the Piranhas-Assu river hydrographic basin, variations in bacterioplankton and trophic state indexes were studied in the lotic and lentic environments. The means of total bacterial density wavered in the order of 107 organisms. mL-1 and they were higher in the rainy period. Cocci bacteria were numerically predominant in all sampling points, influencing the total abundance of bacterioplankton. Total bacterial biomass varied from 659 to 1997,3 µgC.L-1 due to the high values of filaments cellular volume. Total phosphorus amounted 108 µg.L-1 and it had a positive correlation with chlorophyll a (r = 0,94; p < 0,05) during dry period, when these variables presented higher concentrations. There wasn t a high spatial variation. The low transparency of water and the phosphorus and chlorophyll concentrations indicated eutrophic or hipereutrophic levels in studied points of reservoir. These variables, associated with high density and biomass values found, alert to the necessity of a constant monitoring of the semi-arid aquatic ecosystems, where the quality of water is affected by dry occurrence

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The need for sustainability in the exploitation of natural resources in coastal areas has been out in recent years, as well as the social and cultural sustainability of traditional communities in these regions. Coastal and estuarine wild areas are influenced directly or indirectly by a set of human activities such as artisanal fishing. Therefore, there is a demand for an integrated design of these areas and according to the landing values, a pattern of unsustainable development of national marine fishing activity. The study was conducted in the coastal community of Praia da Pipa, Tibau do Sul municipality, RN, between june 2009 and june 2010 and aimed to characterize the fishery performed, its socio-economic strategies and fishing areas, as well as to identify ichthyofauna, to assess the sustainability of the major resources and to identify cultural traits related to artisanal fisheries, their problems and prospects; linking tradition and the present fishing activity carried out in the community. For this study, a total of 67 structured interviews were collected, including qualitative and quantitative data. A total of 133 fish landings and direct observations were performed. Informants were identified according to one of the following categories: fishermen, vessel masters and members of the local population with offspring. Applications SPSS 10.0, Paint.Ink and Microsoft Office Excel 2007 were used for tabulation and analysis of results. Local fishermen are, on average, 25 years fishing, have 40 years old and the average monthly income is up to 03 minimum wages. The local fleet consists of 20 vessels, that uses different line sizes and types of networks, operating in 21 fishing grounds and showing a reduction in the vessel numbers by 66% in the last decade. We recorded 76 species of fish, captured by the local fleet and the top 5 were quantitatively analyzed serra spanish mackarel (Scomberomorus brasiliensis), little tunny (Euthynnus alleteratus), yellowtail snapper (Ocyurus chrysurus), red snapper (Lutjanus analis) and common snook (Centropomus undecimalis), accounting for 46,5% of production in the period. The capture of these species was composed mostly of adults. Data analysis showed a significant decrease of the local fishing activity over the last decade due to the weakness displayed by the political-social category, the devaluation of local knowledge and the emergence of new sources of income through increased tourism. The characteristics of the fishing community suggest it to pass through significant changes as the appreciation of their cultural and traditional aspects. We identified a tendency to sustainability of main species caught, suggesting that public policies to be adopted locally comply with the current characteristics of fishing undertaken in the community and knowledge of fishermen related to the environment, allowing environmental, as well as social and cultural sustainability of the community involved.

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O texto trata-se de um recorte de uma pesquisa de mestrado realizada no Programa de Pós-Graduação em Educação da UFRN. Para tanto, consideraremos a relação entre os significados do corpo e da beleza identificados nas produções analisadas e os modelos de beleza na Educação Física. Essa pesquisa é de natureza qualitativa, tendo a Análise de Conteúdo para tratamento dos dados. O corpus de análise foi composto por 8 dissertações da área de Educação Física, publicadas no Banco de Teses da Capes no período de 2004 a 2008, selecionados a partir da temática corpo e beleza. Foi possível observar que a compreensão do corpo e da beleza na área vem sendo ressignificada, ao tratar de outras concepções estéticas, que consideram as singularidades expressas no corpo humano e na cultura da qual o indivíduo faz parte

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Until some years ago, weathering geochronology was primarily based on the K-Ar and 40Ar/39Ar dating of supergene minerals. Recent advances in the analysis of supergene goethite by the (U-Th)/He method expanded the number of suitable minerals for such purpose, as well as the time of application for weathering geochronology. This study represents the first systematic approach in Brazil, combining both the 40Ar/39Ar e (U-Th)/He methodologies to improve the knowledge on the weathering and the age of nonfossiliferous sediments. Supported by geologic and geomorphologic correlations, we identified different types of weathering profiles occurring in the interior and coastal areas of northeastern Brazil. These profiles were correlated to main regional geomorphological domains: the Borborema Plateau , the Sertaneja Depression , and the Coastal Cuestas and Plains, and respective planation surfaces, which study is fundamental to understand the landscape evolution of the northern portion of the eastern Borborema Province. The depth and stratigraphic organization of the weathering profiles in each of the geomorphological domains permitted to establish that: (i) the profiles on the highlands that cap the Borborema Surface are deeper (up to 100 m) and can be considered as typical lateritic profiles; (ii) on the lowlands that form the Sertaneja Surface , the weathering profiles are shallow and poorly developed (2-5 m deep); (iii) the profiles along the coastal area are moderately developed (up to 25 m deep), and are characterized by thick saprolites and mottle zones. Aiming to establish the timing of the evolution of northeastern Brazil, we studied 29 weathering profiles representing distinct topographic levels of the Borborema Province, from the highlands to the coast, through the analysis of 248 grains of supergene manganese oxides using laser step-heating 40Ar/39Ar geochronology. Additionally, we applied the (U-Th)/He method in 20 weathering profiles, by dating 171 grains of supergene iron oxides and hydroxides. Geochronological results for 248 grains of manganese oxides analyzed by the 40Ar/39Ar method indicate that the weathering profiles in the study area record the history of weathering from the Oligocene to the Pleistocene, with ages in the order of 31.4 ± 1.0 Ma to 0.8 ± 0.4 Ma. Dating of 171 grains of goethite by the (U-Th)/He method yielded ages ranging from 43.2 ± 4.3 Ma to 0.8 ± 0.1 Ma, suggesting the weathering processes last from the Eocene to the Pleistocene. The precipitation of supergene goethite in this interval confirms the age of the weathering processes identified from the manganese oxides record. 105 goethite grains from 8 different occurrences of the Barreiras Formation were dated by the (U-Th)/He method. Five grains collected from the cement in the Barreiras Formation sandstones, in the Lagoa Salgada and Rio do Fogo coastal cuestas, yielded ages of 17.6 ± 1.8 Ma, 17.3 ± 1.7 Ma, 16.3 ± 1.6 Ma, 16.2 ± 1.6 Ma and 13.6 ± 1.4 Ma. Results of 69 goethite grains from authigenic pisoliths collected in 7 different localities also yielded concordant ages, varying from 17.8 ± 1.8 to 7.5 ± 0.8 Ma. Results obtained from 31 detrital grains are concordant in 3 distinct localities (Lagoa Salgada, Praia da Garças e Ponta Grossa); they vary in the range of 43.2 ± 4.3 to 21.6 ± 2.2 Ma, and indicate that the maximum age for the Barreiras Formation deposition is around 22 Ma. 40Ar/39Ar results for 15 manganese oxides grains associated with the Barreiras Formation weathering profiles, in 3 different localities, vary from 13.1 ± 0.9 to 7.7 ± 0.4 Ma, in the same range of ages obtained by the (U-Th)/He method. The systematic application of the 40Ar/39Ar and (U-Th)/He methods, respectively for manganese oxides and goethites, show that the Barreiras Formation sediments were already deposited since ca. 17 Ma, and that the weathering processes were active until ca. 7 Ma ago. The ages obtained from manganese oxides collected in the Cenozoic basalts (Macau Formation) also reveal a weathering history between 19 and 7 Ma, pointing to hot and humid conditions during most of the Miocene. 40Ar/39Ar ages yielded by manganese oxides associated with the Serra do Martins Formation vary from 14.1 ± 0.4 to 10.5 ± 0.3 Ma. On the other hand, (U-Th)/He ages from iron oxides/hydroxides collected in the Serra do Martins Formation mesas vary from 20.0 ± 2.0 to 5.5 ± 0.6 Ma, indicating that those sediments are older than 20 Ma. 40Ar/39Ar and (U-Th)/He results produced in this study are in agreement with paleoclimatic interpretations based on stable isotopes and clay index values measured in the Atlantic Ocean sediments, validating the use of weathering geochronology to investigate paleoclimatic variations. The direct dating of the Barreiras Formation permitted, for the first time, confident inferences on the age of the brittle deformation recorded by this sedimentary unit in the Rio Grande do Norte and Ceará states. The first event, syn-deposition, occurred during the early Miocene; an younger event, related to the post-depositional deformation of the Barreiras Formation, is associated with tectonic activity from the very early Miocene to the Holocene. In agreement with data from other areas, results obtained in this study reveal that the depth and complexity of the weathering profiles reflect the time of exposition of such areas to the weathering agents close to the surface. However, there is no clear relationship between ages vs. altitude. The depth and the stratigraphic organization of weathering profiles in northeastern Brazil, contrary to the southeastern Brazil pattern, do not vary toward the coast. In our study area, field observations reveal the presence of ancient, thick and complex lateritic profiles preserved in the sedimentary mesas on the Borborema Plateau, as younger, narrow and incipient ones occur in the dissected areas. Geochronological results obtained for these profiles yielded older ages on the high altitudes, and younger ages in the lowlands, suggesting the scarp retreatment is the most reliable model to explain the regional landscape evolution. However, in the coastal lowlands, the relatively older ages obtained indicate that more complexes processes were involved in the modeling of the local relief

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OBJETIVO: As doenças osteomusculares são as afecções ocupacionais mais prevalentes em cirurgiões-dentistas. Nosso propósito: 1) investigar os conhecimentos, aplicabilidades clínicas dos princípios ergonômicos em discentes e docentes em atividades clínicas de uma universidade pública 2) pesquisar a incidência de sintomatologias dolorosas no pescoço, ombros, parte superior e inferior das costas, cotovelos, quadris, coxas, joelhos, tornozelos e pés no universo de alunos em estágios clínicos. 3) incitar discussões de normas e diretrizes ergonômicas na universidade. MÉTODOS: Esse estudo investigou o universo de alunos matriculados em disciplinas clínicas (148) e respectivos professores (30) do curso de odontologia da Universidade Federal do Rio Grande do Norte, Natal-RN a respeito dos princípios ergonômicos utilizados na rotina clínica. Paralelamente foi pesquisada a incidência de sintomatologia dolorosa nos alunos por intermédio do questionário nórdico e a partir dos resultados foi mensurado o índice de severidade dos sintomas em alunos. The Nordic Musculoskeletal Questionnaire (NMQ) é um instrumento de diagnóstico, proposto para padronizar a mensuração de relatos de sintomas osteomusculares. A análise dos dados foi através do programa SPSS-Statistical Package for the Social Sciences, versão 17.0 realizada analítica e descritivamente, com determinação das médias (x), desvio-padrão para variáveis quantitativas, freqüências simples e relativas para as variáveis categóricas, além da estatística de associação entre grupos (teste t) e a análise de associação do quiquadrado com nível de significância 5% entre as variáveis (Person). As respostas das questões abertas foram codificadas e transformadas em freqüências, descritas posteriormente. RESULTADOS: A aplicabilidade de medidas ergonômicas nas clínicas universitárias não foi evidenciada pelo universo de discentes e docentes. Quanto ao relato de sintomas osteomusculares o sexo feminino foi o mais acometido qualquer que seja o nível acadêmico cursado. As regiões anatômicas de maior grau de severidade de relatos dos sintomas foram: pescoço, parte inferior das costas, punhos, mãos e ombros, com significância etatística p<0,001. CONCLUSÃO: Em função dos achados os autores apresentam um protocolo de intervenção clínica baseado nos determinantes ergonômicos da Associação internacional de ergonomia (EAI) como medida de prevenção da saúde ocupacional dos futuros cirurgiões-dentistas ainda em processo de formação nas clínicas odontológicas das universidades.