Rudimentos de uma inspeção topográfica aplicados à Passacaglia para orquestra, opus 1, de Anton Webern

SILVA, Alexandre Reche e. Rudimentos de uma inspeção topográfica aplicados à Passacaglia para orquestra, opus 1, de Anton Webern. Ictus - Periódico do PPGMUS/UFBA, Salvador, v. 7, p.189-208, 2010

Rudimentos de uma inspeção topográfica aplicados à Passacaglia para orquestra, opus 1, de Anton Webern

SILVA, Alexandre Reche e. Rudimentos de uma inspeção topográfica aplicados à Passacaglia para orquestra, opus 1, de Anton Webern. Ictus - Periódico do PPGMUS/UFBA, Salvador, v. 7, p.189-208, 2010

A doença de criar passarinhos: a lírica humanizadora de João Cabral de Melo Neto

João Cabral de Melo Neto n a jamais aimé les vers sentimentaux et prolixes venus de la tradition romantique. C est pour ça que son uvre a un discours objectif, rigoureusement elaboré e elle comporte certaines influences concretistes ça explique pourquoi l auteur est connu comme l ingénieur de la langage. En verité, le poète même dissait qu il était un homme froid et rationnel. La critique a assidument analysé la matière logique et le rigeuer formel de l uvre de Cabral de Melo. Pourtant, dans ce travail nous analysons les poèmes dont le sentiments humaines sont la mtière principal de l élaboration de l experiènce esthétique. La poèsie de João Cabral n est pas simple verbalisme formel, ni un uvre sens vie, car les objects concrètes et la langage objectif n empêchent pas qui le sujet décrit avec émotion les scènes presents dans les poèmes. Nous travaillons avec la hypothèse de que le poète a une attitude trop humaine quand il parle de l experience culturel et de l experience de la vie dans le Nord-est brésilien. Les unités témathiques de ce travail, pourtant, montrent la représentation du Nord-est dans la poèsie de João Cabral et examinent aussi le sentiment qu il sent par la memoire culturel de sa région. Parmi les aspects qui composent sa lyrique humaine nous citons la personification constant de les paysages du Nord-est le poète ne veux pas faire une décrition tophographique de la région parce que les places ont un valeuer sentimentel pour lui; au moyen d un discours erotique, Cabral represente les desirs et les intints humaines de sa terre; ensuite, il semble que le poète est enchanté et enveloppé avec certains elemets culturels de sa région, come l hamac, la littérature oral et la musique régional; la preoccupation avec la population explorée et la denonciation de la condition miserable dans le Nord-est brésilien confirment aussi la humanité présent dans son uvre; finalment, la récordation de l enfance et la nostalgie du temps passé sont, pour le poète, un possibilité qui peut aider dans la formation humaine de la population

Análise dos fatores responsáveis pela alta salinidade do aqüífero fissural da microbacia da Riacho do Feijão - Pedro Avelino/RN

The fissures aquifer northeast semi-arid Brazilian, present high text frequently of leave, with of low a hídric availability. The research has as objective main to analyze the components that inside influence in the salinity of the waterbearing fissures of an evaluation physicist-chemistry of the water, leading in consideration the physical interventions of the environment. One used techniques of interpretation of image of Landsat satellite -1999 and delimitation of the micro basin through the topographical map SUDENE. One identified waters of the NaCl type with Ca++ and Mg++ in secondary concentrations. The analyzed wells (15), had presented an average salinity of 5.147 mg/L of STD and a well only supplies drinking waters with 319 mg/L of STD. The recharge of the aquifer one if carries through for infiltration in the open fracture of ortognaisse it migmatization. The type and directions of the fracture do not control the STD. Relations between salinity and out let do not exist. The quality of the well of low salinity is identical the superficial waters (aquifer dam and alluvial). The studies of the meteoric erosion processes had evidenced that in the transformations of the rock in ground, the Ca++ and Na+ are taken for superficial waters. The treatment of the data chemical showed that the grade of Na+, Ca++, Mg++ and Cl-are controlled for the evaporation process, from only water that would have the qualities of superficial waters or the well of low salinity. Already the HCO3-grade is controlled for the precipitation of the dolomite. The STD of this aquifer one would be consequence of the high tax of evaporation of dams constructed in regions of plain topography. You leave them precipitated in deep argillaceous ones dry dams are led for the aquifer in first rains. The research suggests some recommendations for the use and exploitation of the water salinity in piscicultura, carcinicultura, culture of the grass-salt (Atriplex sp), among others

Aspectos anatômicos do olho e neuroquímicos da retina do mocó (Kerodon rupestris)

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

A história do intemperismo na Província Borborema Oriental, Nordeste do Brasil: implicações paleoclimáticas e tectônicas

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

Dois testes de imageamento com GPR em problemas de controle ambiental em regiões tropicais: migração de dunas e localização de dutos de óleo enterrados

Because the penetration depth of Ground Penetrating Radar (GPR) signals is very limited in high conductive soils, the usefullness of this method in tropical regions is not yet completly known. The main objective of this researh is to test the usefullness of the method in Brazil. Two typical problems where GPR has been used in Europe and North American were choosed for this test: the first one is to characterize the internal structures of a sand body and the second problem is the localization of old buried pipes lines. The first test was done near the city of São Bento do Norte, in the northern coast of Rio Grande do Norte state, NE Brazil. In this region, there is a sand dune that is migrating very fast in the direction of adjacent settling areas. To characterize the internal structure of the dune and its relationship to the prevailing wind direction, as a preliminary step to understand the dune migration, GPR profiles using the 400 MHz frequency were performed in E-W, N-S, NE-SW, and SE-NW directions over the sand dune intersecting at the top of the dune. The practical resolution of the GPR data is around 30 cm; this was sufficient to distinguish individual foresets inside the dune. After applying the elevation correction to the data, we identified that dips of bedding structures are smallest for the N-S profile, which is perpendicular to the dominant wind direction, largest for the E-W profile, and intermediate for the SW-NE and SE-NW profiles. Foresets in the E-W profile dip with angles varying from 2 to 6 degrees. In the E-W profile, the water table and a horizontal truncation interface separating two generations of dunes were identified, as well as an abrupt directional change in the foreset patterns associated to a lateral contact between two dune generations, the older one extending to the west. The used high frequency of 400 Mhz does not allow a penetration deep enough to map completely these internal contacts. The second test was done near Estreito, a small town near Carnaúbais city, also in Rio Grande do Norte state. In this locality, there are several old pipe lines buried in area covered by plantations where digging should be minimized. Several GPR profiles using the 400 and 200 MHz frequency were performed trying to intercept perpendicularly the possible pipe lines. Because of the high conductivity of the soil, the raw original data can hardly be use to identify the pipe lines. However, after an adequate processing over the 200 MHz profiles, six pipe lines were identified. As a global result of the tests, GPR can be very usefull if the conductivity of the ground is low or, in the case of medium conductivities of the soils, if adequate processing is performed

Sistemas de dunas do parque das Dunas e Barreiras do Inferno/Natal (RN: levantamento geológico /geofísico, elaboração do modelo deterministico e avaliação da vulnerabilidade/suscetibilidade

The current work was developed on the dune systems of the Parque das Dunas and Barreira do Inferno. These places are located in the cities of Natal and Parnamirim (RN, Brazil), respectively. This project has the purpose of developing the deterministic model on a specific blowout at Parque das Dunas, based in the geophysical interpretations of the lines gotten with the Ground Penetration Radar and the planialtimetric acquisitions of the topographical surface of the land. Also analyses of the vulnerability/susceptibility of these dune systems had been done in relation to the human pressures. To develop its deterministic model, it is necessary to acquire inner and outer geometries of the cited blowout. In order to depict inner geometries underneath the surface are used the GPR observing the altimetric control for topographical correction of the GPR lines. As for the outer geometries, the geodesic GPS gives us the planialtimetric points (x, y and z points) with milimetric precision, resulting in high-resolution surfaces. Using interpolation methods of the planialtimetric points was possible create Digital Elevations Models (DEM´s) of these surfaces. As a result, 1,161.4 meters of GPR lines were acquired on the blowout at the Parque das Dunas and 3,735.27 meters on the blowout at the Barreira do Inferno. These lines had been acquired with a 200 MHz antenna, except the 7 and 8 lines, for which we had been used a 100 MHz antenna. The gotten data had been processed and interpreted, being possible to identify boundary surfaces of first, second and third order. The first order boundary surface is related with the contact of the rocks of the Barreiras Group with the aeolian deposits. These deposits had been divided in two groups (Group 1 and Group 2) which are related with the geometry of stratum and the dip of its stratifications. Group 1 presented stratum of sigmoidal and irregular geometries and involved bodies where the reflectors had presented dips that had varied of 20 to the 28 degrees for the Parque das Dunas blowout and of 22 to the 29 degrees for the Barreira do Inferno blowout. Usually, it was limited in the base for the first order surface and in the top for the second order surface. Group 2 presented stratum of trough, wedge or lens geometries, limited in the base for the second order vi surface, where the corresponding deposits had more shown smoothed reflectors or with dips of low angle. The Deterministic and Digital Elevation Models had been developed from the integration and interpretation of the 2D data with the GOCAD® program. In Digital Elevations Models it was possible to see, for the localities, corridor or trough-shaped blowouts. In Deterministic Model it was possible to see first and second order boundary surfaces. For the vulnerability/susceptibility of the dune systems it was applied the methodology proposal by Boderè al (1991); however the same one did not show adequate because it evaluates actual coastal dunes. Actual coastal dunes are dunes that are presented in balance with the current environmental conditions. Therefore, a new methodology was proposal which characterizes the supplying and activity sedimentary, as well as the human pressures. For the methodology developed in this work, both the localities had presented a good management. The Parque das Dunas was characterized as a relic dune system and the Barreira do Inferno was characterized as a palimpsestic dune system. Also two Thematic Maps had been elaborated for the environmental characterization of the studied dune systems, with software ArcGis 8.3, and its respective data bases

Correlação entre contexto morfoestrutural e sismicidade nas regiões de João Câmara e São Rafael (RN)

This MSc thesis describes brittle deformation in two seismic zones located in north-eastern Brazil: João Câmara and São Rafael, Rio Grande do Norte State. Both areas show seismogenic faults, Samambaia and São Rafael, indicated by narrow zones of epicentres with a strike of 040o, a lenght of 30 km and 4 km, and a depth of 1-12 and 0,5-4 km, respectively. The first seismological and geological studies suggested blind faults or faults that were still in the beginning of the nucleation process. The region is under E-W-oriented compression and is underlain by Precambrian terrains, deformed by one or more orogenic cycles, which generated shear zones generally marked by strong pervasive foliation and sigmoidal shapes. The crystalline basement is capped by the Cretaceous Potiguar basin, which is also locally capped by Pliocene continental siliciclastic deposits (Barreiras Formation), and Quaternary alluvium. The main aim of this study was to map epicentral areas and find whether there are any surface geological or morphotectonic expression related to the seismogenic faults. A detailed geological map was carried out in both seismic areas in order to identify brittle structures and fault-related drainage/topographic features. Geological and morphotectonic evidence indicate that both seismogenic faults take place along dormant structures. They either cut Cenozoic rocks or show topographic expression, i.e., are related to topographic heights or depressions and straight river channels. Faults rocks in the Samambaia and São Rafael faults are cataclasite, fault breccia, fault gouge, pseudotachylyte, and quartz veins, which point to reactivation processes in different crustal levels. The age of the first Samambaia and the São Rafael faulting movement possibly ranges from late Precambrian to late Cretaceous. Both fault cut across Precambrian fabric. They also show evidence of brittle processes which took place between 4 and 12 km deep, which probably have not occurred in Cenozoic times. The findings are of great importance for regional seismic hazard. They indicate that fault zones are longer than previously suggested by seismogenic studies. According to the results, the methodology used during this thesis may also be useful in other neotectonic investigation in intraplate areas

Fragilidade ambiental da bacia hidrográfica do Rio Seridó (RN/PB Brasil)

There are many applications coming from geomorphological studies and their different constitutive and inter related elements, to the implementation of public politics of planning and environmental management. This search presents an analysis of the environmental fragility of the watershed of Seridó River, situated between the states of Paraíba and Rio Grande do Norte (Brazil), including the identification of possible unstable areas. It is based on the methodological approach of Ecodynamics of the French researcher J. Tricart (1977) and on the operalisation proposal advocated by the Brazilian J. Ross (1994), related to the Potential and Emerging Ecodynamic Units, grounded in the Relief s Dissection Index or the topographic roughness, soil, rainfall and land use/vegetal cover. Under a quantitative perspective, the results obtained from the analysis of the watershed can be divided into classes of potential fragility: around 2.613,0 km² of low intensity, 5.188,4 km² of medium intensity and 2.585,5 km² of high intensity. Concerning the emerging fragility, the results are close to 2.212,0 km² of low intensity, 6.191,23 km² of medium intensity and 2.062,34 km² of high intensity. In the case of the watershed in question, the environmental degradation is particularly effective in the areas more dissected, where the ecological conditions, in synergy the environmental degradation, prevent the regeneration of vegetation when arises an opportunity for the (re)establishment of its equilibrium tenuous. The collected data is relevant for the territorial and environmental planning of the watershed, once we can still verify a close association of the cities on the central area of desertification with the areas of high environmental instability/fragility. This is an important tool to the understanding of the potential susceptibility of the natural and anthropic environments related to the advance and/or intensification of the erosion process, rock falls, mass movements, among other phenomena inside the potential unstable areas. From this perspective, the continuity of this research becomes extremely important to the understanding and arrangement of the process, together with the engendering and sustainability of the system in its totality; in narrow correlation because their potentialities, constraints and alternatives on Seridó River watershed, and in all the semi-arid region with similar characteristics