Foraminíferos, ostracodes e microfauna associada da plataforma continental equatorial norte-rio-grandense, NE Brasil: área Porto do Mangue a Galinhos

This study was conducted in the adjacent Brazilian equatorial inner shelf to Rio Grande do Norte, between the region of Porto do Mangue and Galinhos. The main objective is the characterization of biogenic sediments, especially foraminifera and ostracod collected on the surface of the seafloor. The methodology involved standard procedures including literature, surveys, processing of samples in the laboratory and identification of foraminifera and ostracods by genera or species under stereo microscopy and scanning electron microscopy (SEM). Multivariate statistical analyzes and study of ecological indexes were also applied to the study of foraminifera. Three transects, from inner shelf to slope were sampled: profile 01 (east, near Galos), profile 02 (center, near the city of Macau) and profile 03 (west, near Ponta do Mel). Results indicated the predominance of benthic foraminifera and little plankton occurrence. Benthic foraminifera genera observed in abundance were Quinqueloculina, Textularia, Globigerina and Pyrgo, Quinqueloculina, Textularia, Pyrgo, Ammonia, Elphidium, Pseudononion, Peneroplis, Bolivina and Poroeponides, occurred more frequently. Less frequently been described Amphistegina, Archaias, Bigenerina, Cibicides, Cassidulina, Amphicorina, Cornuspira, Paterina, Hopkunsina, Oolina, Uvigerina, Fusenkoina, Nonionella, Amphisorus, Wiesrella, Reussella, Reophax, Nodosaria, Marginulina and Cyclogyra. Six genera of ostracods were also identified: Puriana variabilis / P. convoluted?, Loxoconcha sp, Bairdiidae, Xestoleberis sp, Hemicytheridae and Ruggiericythere sp. Groups of organisms found in the studied shelf presented chemical composition of Ca, C, O, Na, Cl, Al, Mg, and Si. The proportions of chemical elements may vary according to the type of biogenic sediment, with the highest values identified as Ca, C, Cl, Na and O. The absolute dating by carbon 14 method indicated sediments of different colors (light and dark), correspond to a single age from 3000 to 6000 years BP, related to the Quaternary. These data intend to complement information about biogenic sediments in the Brazilian continental shelf, especially in the Northeast, where there is a lack of such studies.

História da matemática na formação de professores: sistemas de numeração antigos

This essay aims to present and describe a proposal of insertion of Mathematics History into teachers undergraduation. Such addition proposal is expected to take place as curricular component to be taught on initial undergraduation for mathematics teachers. The selection of contents for the proposal has been based on the national Curriculum Guidelines (DCN, 2001, acronym in portugueses) for bachelor’s degree in Mathematics; the National Curricular Guidelines for Elementary School (PCNEF, 1998, acronym in Portuguese); and the National Curricular Guidelines for High School (PCNEM, 1999, acronym in Portuguese). The curricular component now presented is supposed to take a 60 hour workload, and includes the following topics: History of Ancient Numbering Systems, History of Trigonometriy and History of fuctions. For the sake of exemplification, the topic History of Ancient Numbering Systems is discussed and analysed in detail as practice for the new curricular component.

Análise do discurso sobre o "bom" professor de História no Brasil contemporâneo: uma questão de cidadania...

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

O papel do turismo nos conflitos urbanos da cidade do Natal/RN: a história que ninguém quer contar

La présente étude a comme objectif comprendre la relation entre l implantation et le développement du Tourisme à Natal et les conflits urbains établits entre 2006 et 2010 et publiés par les médias imprimés, élaborant ses impacts dans le quotidien des résidents. Tandis qu une relecture partielle de la méthode régressive-progressive développée par le philosophe français Henri Lefebvre, cherche à recouper du présent, des contradictions qui promeuvent des réactions dans le quotidien de la ville; ainsi qu identifier des moments du passé qui puissent contribuer à sa compréhension. Aujourd hui, nous avons les médias, comme principale source pour observer la perception locale des problèmes causés par l espace conçu, à partir des actions de l État référentes à l activité. Par rapport au passé, ces situations sont recherchées dans des sources secondaires, mettant en évidence le dialogue avec le Relatório Conflitos Urbanos (Rapport Conflits Urbains) à Natal-1976-1986 (ANDRADE et al.,1986), qui présente les conflits existants à des moments qui ont précédé ou ont acompagné le début du développement de l activité au RN, spécialement à Natal. Alors que dans la contribution à la compréhension du rôle du Tourisme dans l apparition de conflits urbains de la ville sont aussi inclues nos coupures vécues, des actions de l État par rapport à la consolidation, ainsi comme pour les conflits qui se sont plus demarqués ou qui ont conduit à la réaction de la population de la ville pendant les périodes analysées. Au final, on cherche à démontrer les limites de la responsabilité de l activité touristique dans l urgence des principaux conflits urbains dans la ville. L analyse des données de la recherche, avec l identification des conflits urbains de Natal et sa relation avec le Tourisme; la présentation des conflits par rapport à la localisation, fréquence et son encadrement dans les catégories de l analyse adoptée; l identification des agents intéressés et la relation entre eux; ont amené à la confirmation de l hypothèse proposée. De cette façon, en prenant en compte les coupures temporelles et spatiales, la source de recherche et la méthodologie adoptées, nous arrivons à la conclusion que l activité touristique à Natal n est pas directement responsable de l apparition des conflits urbains de la ville

Hidrocarbonetos policíclicos aromáticos em sedimentos de fundo do estuário do rio Potengi, região da grande Natal (RN): implicações ambientais

Estuaries are environments prone to the input of chemical pollutants of various kinds and origins, including polycyclic aromatic hydrocarbons (PAHs). Anthropogenic PAHs may have two possible sources: pyrolytic (with four or more aromatic rings and low degree of alkylation) and petrogenic (with two and three aromatic rings and high degree of alkylation). This study aimed to evaluate the levels, distribution and possible sources of polycyclic aromatic hydrocarbons in the estuary of the Potengi river, Natal, Brazil. Samples of bottom sediments were collected in the final 12 km of the estuary until its mouth to the sea, where the urbanization of the Great Natal is more concentrated. Sampling was performed on 12 cross sections, with three stations each, totaling 36 samples, identified as T1 to T36. The non alkylated and alkylated PAHs were analyzed by gas chromatography coupled to mass spectrometry (GC / MS). PAHs were detected in all 36 stations with total concentration on each varying 174-109407 ng g-1. These values are comparable to those of several estuarine regions worldwide with high anthropogenic influence, suggesting the record of diffuse contamination installed in the estuary. PAHs profiles were similar for most stations. In 32 of the 36 stations, low molecular weight PAHs (with 2 and 3 ring: naphthalene, phenanthrene and their alkylated homologues) prevailed, which ranged from 54% to 100% of the total PAH, indicating that leaks, spills and combustion fuels are the dominant source of PAH pollution in the estuary. The level of contamination by PAHs in most stations suggests that there is potential risk of occasional adverse biological effects, but in some stations adverse impacts on the biota may occur frequently. The diagnostic ratios could differentiate sources of PAHs in sediments of the estuary, which were divided into three groups: petrogenic, pyrolytic and mixing of sources. The urban concentration of the Great Natal and the various industrial activities associated with it can be blamed as potential sources of PAHs in bottom sediments of the estuary studied. The data presented highlight the need to control the causes of existing pollution in the estuary

Hidrocarbonetos alifáticos em sedimentos de fundo do estuário do Rio Potengi, grande Natal (RN): implicações ambientais

The Potengi river estuary is located in the region of Natal (RN, Brazil), comprising a population of approximately 1,000,000 inhabitants. Besides the dominant urban presence, the estuary has fragments of mangrove forest. The objective of this study is to determine the aliphatic hydrocarbons found in the bottom sediments of this estuary, identifying their levels, distribution and their possible origins through the diagnostic rates, indexes and results comparisons with the local anthropic and natural characteristics. The samples were obtained according to a plan that allowed sampling of the estuary up to 12 km upstream from it as mounth. 36 stations were selected, grouped into 12 cross sections through the course of the river and spaced on average by 1 km. Each section consisted of three stations: the right margin, the deepest point and the left margin. The hydrocarbon n-alkanes from C10 to C36, the isoprenoids pristane and phytane, the unresolved complex mixture (UCM) and the total resolved hydrocarbons were analyzed by gas chromatography. N-alkanes, pristane, phytane and UCM were detected only at some stations. In the other, the concentration was below the detection limit defined by the analytical method (0.1 mg / kg), preventing them from being analyzed to determine the origin of the material found. By using different parameters, the results show that the estuary receives both the input of petrogenic hydrocarbons, but also of biogenic hydrocarbons, featuring a mixture of sources and relatively impacted portions. Based on the characteristics and activities found in the region, it is possible to affirm that petrogenic sources related to oil products enter the estuary via urban runoff or boats traffic, boat washing and fueling. Turning to the biogenic source, the predominant origin was terrestrial, characterized by vascular plants, indicating contribution of mangrove vegetation. It was evident the presence of, at specific points in the estuary, hydrocarbon pollution, and, therefore is recommended the adoption of actions aimed at interrupting or, at least, mitigating the sources potentially capable of damp petrogenic hydrocarbons in the estuary studied.