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1.
Environ Monit Assess ; 195(9): 1119, 2023 Aug 31.
Article de Anglais | MEDLINE | ID: mdl-37648931

RÉSUMÉ

Environmental vulnerability is an important tool to understand the natural and anthropogenic impacts associated with the susceptibility to environmental damage. This study aims to assess the environmental vulnerability of the Doce River basin in Brazil through Multicriteria Decision Analysis based on Geographic Information Systems (GIS-MCDA). Natural factors (slope, elevation, relief dissection, rainfall, pedology, and geology) and anthropogenic factors (distance from urban centers, roads, mining dams, and land use) were used to determine the environmental vulnerability index (EVI). The EVI was classified into five classes, identifying associated land uses. Vulnerability was verified in water resource management units (UGRHs) and municipalities using hot spot analysis. The study employed the water quality index (WQI) to assess the EVI and global sensitivity analysis (GSA) to evaluate the model input parameters that most influence the basin's environmental vulnerability. The results showed that the regions near the middle Doce River were considered environmentally more vulnerable, especially the UGRHs Guandu, Manhuaçu, and Caratinga; and 35.9% of the basin has high and very high vulnerabilities. Hot spot analysis identified regions with low EVI values (cold spot) in the north and northwest, while areas with high values (hot spot) were concentrated mainly in the middle Doce region. Water monitoring stations with the worst WQI values were found in the most environmentally vulnerable areas. The GSA determined that land use and slope were the primary factors influencing the model's response. The results of this study provide valuable information for supporting environmental planning in the Doce River basin.


Sujet(s)
Surveillance de l'environnement , Rivières , Brésil , Effets anthropiques , Systèmes d'information géographique
2.
Behav Processes ; 197: 104608, 2022 Apr.
Article de Anglais | MEDLINE | ID: mdl-35219753

RÉSUMÉ

Environmental enrichment effectively reduces anxiety-like indicators in animals, a potential co-treatment for diseases that generate variations in basal anxiety, such as alcoholism. Here we present an experimental design that allows investigating the effect of enrichment on anxiety-related behaviors using contextual aversive conditioning in zebrafish (Danio rerio). It was first observed whether animals conditioned with an aversive stimulus (electroshock paired with checked background tank) exhibited behavioral variations when previously held in barren (BE) or enriched (EE) environment. Enrichment reduced anxiety-like behaviors. Then, fish was exposed to four alcohol concentrations (0.00%, 0.10%, 0.50%, and 1.00%) after being held in BE or EE, and contextual fear conditioning was tested again. Fish showed dose-dependent and enrichment-related variation in anxiety-like behavior. Together, these results indicate that the experimental design in question is efficient in measuring behavior related to BE and EE, and that enrichment seems to impair the acquisition of dose-dependent effects of alcohol. Our results show that EE can alleviate deleterious effects caused by traumatic events, but it should also consider some effects of enrichment and alcohol exposure interaction.


Sujet(s)
Comportement animal , Danio zébré , Animaux , Conditionnement psychologique , Éthanol/pharmacologie , Peur
3.
Semina Ci. agr. ; 41(05, supl. 01): 1909-1922, 2020. mapas, tab, graf
Article de Anglais | VETINDEX | ID: vti-764773

RÉSUMÉ

Understanding the hydrologic regime, and monitoring runoff at the micro-basin scale is critical for understanding water availability, and for managing water resources in strategic biomes such as the cerrado. The objective of this research is to evaluate morphometric characteristics and the hydrologic regime and determine their relationships with soil characteristics and typical land-use in the cerrado biome. To reach this objective morphometric characterization, runoff and precipitation monitoring, and determination of the water retention curve were conducted in three micro-basins in the municipality of Campo Verde, Mato Grosso. These micro-basins each have a different, but regionally typical land use and were selected strategically to represent this area of cerrado: agriculture, pasture and native vegetation. The results obtained allow for the analysis of the hydrologic regime throughout the period measured. Micro-basins with native vegetation and pasture, with greater altimetric range and more sandy soils, show greater erosion. Despite this, the micro-basin with pasture cover showed greater regulation of runoff. The micro-basin with agriculture showed less regularization of water flux due to the physical characteristics of the local soils.(AU)


O conhecimento e monitoramento da vazão, assim como o entendimento do regime hidrológico a nível de microbacias tem sido relevante para se determinar a disponibilidade hídrica, assim como promover o gerenciamento dos recursos hídricos em biomas considerados estratégicos como o cerrado. Este trabalho foi desenvolvido com o objetivo de avaliar as características morfométricas e o regime hidrológico e sua relação com as características do solo bem como do seu uso em três microbacias no bioma cerrado. Para alcançar o objetivo proposto, fez-se a caracterização morfométrica, o monitoramento da vazão e da precipitação diária e elaboração da curva de permanência de três microbacias hidrográficas localizadas no município de Campo Verde-MT contemplando os seguintes usos: agricultura, pastagem e vegetação nativa. Essas bacias foram selecionadas estrategicamente por serem representativas dos principais sistemas de uso do solo na região de cerrado. Os resultados obtidos permitem ponderar que há diferença no regime hidrológico das microbacias hidrográficas ao longo do período analisado. As microbacias com vegetação nativa e com pastagem, por terem maior amplitude altimétrica, além de apresentarem solos de textura arenosa, são mais propensas à erosão hídrica. A microbacia com pastagem apresentou maior regularidade na vazão e, a microbacia com agricultura uma menor regularização do fluxo hidrológico em função das características físicas dos solos que compõe a microbacia.(AU)


Sujet(s)
Analyse du Sol , Caractéristiques du Sol , Humidité du Sol , Bassins Hydrographiques/analyse , Prairie , Pluie , Coefficient D'écoulement/analyse
4.
Semina ciênc. agrar ; 41(05, supl. 01): 1909-1922, 2020. map, tab, graf
Article de Anglais | VETINDEX | ID: biblio-1501607

RÉSUMÉ

Understanding the hydrologic regime, and monitoring runoff at the micro-basin scale is critical for understanding water availability, and for managing water resources in strategic biomes such as the cerrado. The objective of this research is to evaluate morphometric characteristics and the hydrologic regime and determine their relationships with soil characteristics and typical land-use in the cerrado biome. To reach this objective morphometric characterization, runoff and precipitation monitoring, and determination of the water retention curve were conducted in three micro-basins in the municipality of Campo Verde, Mato Grosso. These micro-basins each have a different, but regionally typical land use and were selected strategically to represent this area of cerrado: agriculture, pasture and native vegetation. The results obtained allow for the analysis of the hydrologic regime throughout the period measured. Micro-basins with native vegetation and pasture, with greater altimetric range and more sandy soils, show greater erosion. Despite this, the micro-basin with pasture cover showed greater regulation of runoff. The micro-basin with agriculture showed less regularization of water flux due to the physical characteristics of the local soils.


O conhecimento e monitoramento da vazão, assim como o entendimento do regime hidrológico a nível de microbacias tem sido relevante para se determinar a disponibilidade hídrica, assim como promover o gerenciamento dos recursos hídricos em biomas considerados estratégicos como o cerrado. Este trabalho foi desenvolvido com o objetivo de avaliar as características morfométricas e o regime hidrológico e sua relação com as características do solo bem como do seu uso em três microbacias no bioma cerrado. Para alcançar o objetivo proposto, fez-se a caracterização morfométrica, o monitoramento da vazão e da precipitação diária e elaboração da curva de permanência de três microbacias hidrográficas localizadas no município de Campo Verde-MT contemplando os seguintes usos: agricultura, pastagem e vegetação nativa. Essas bacias foram selecionadas estrategicamente por serem representativas dos principais sistemas de uso do solo na região de cerrado. Os resultados obtidos permitem ponderar que há diferença no regime hidrológico das microbacias hidrográficas ao longo do período analisado. As microbacias com vegetação nativa e com pastagem, por terem maior amplitude altimétrica, além de apresentarem solos de textura arenosa, são mais propensas à erosão hídrica. A microbacia com pastagem apresentou maior regularidade na vazão e, a microbacia com agricultura uma menor regularização do fluxo hidrológico em função das características físicas dos solos que compõe a microbacia.


Sujet(s)
Analyse du Sol , Bassins Hydrographiques/analyse , Caractéristiques du Sol , Pluie , Coefficient D'écoulement/analyse , Prairie , Humidité du Sol
5.
Semina Ci. agr. ; 40(6): 2705-2718, Nov.-Dec. 2019. graf, tab
Article de Anglais | VETINDEX | ID: vti-28629

RÉSUMÉ

The goal was to determine the ideal cutting age of elephant grass BRS Canará for forage production in the dry and rainy seasons. The experimental design comprised randomized blocks, with five treatments (42, 56, 70, 84, and 98 days in the dry season and 42, 60, 76, 91, and 105 days of regrowth in the rainy season) and four replications each. Agronomic, morphological, and chemical characteristics were evaluated. In the dry season, there was a significant quadratic response for plant height and leaf blade length. For the other characteristics, a significant linear response was observed, except stem diameter. In the rainy season, a quadratic response for the leaf blade length, leaf blade width, and leaf:stem ratio was observed. For the other characteristics, there was a significant linear effect, except for the percentage of dead material. In the dry season, a verified linear response was observed for the chemical characteristics, except neutral detergent insoluble protein. In the rainy season, a linear response was verified for all evaluated characteristics, except acid detergent insoluble protein. Elephant grass BRS Canará for forage production should be cut between 70 and 85 days in the dry season and between 60 and 70 days of regrowth in the rainy season.(AU)


Objetivou-se determinar a idade de corte ideal do capim-elefante BRS Canará para produção de forragem no período da seca e das águas. O delineamento experimental foi em blocos casualizados, com cinco tratamentos (42, 56, 70, 84 e 98 dias no período da seca e 42, 60, 76, 91 e 105 dias no período das águas) e quatro repetições cada. Foram avaliadas características agronômicas, morfológicas e químicas. No período da seca verificou-se resposta quadrática significativa para altura de planta e comprimento de lâmina foliar. Para as demais características constatou-se resposta linear significativa, com exceção de diâmetro de colmo. No período das águas verificou-se resposta quadrática para comprimento de lâmina foliar, largura de lâmina foliar e relação folha: colmo. Para as demais características verificaram-se efeito linear significativo, com exceção de porcentagem de material senescente. Na seca verificou-se resposta linear das características químicas, exceto para proteína insolúvel em detergente neutro (% MS). No período das águas, verificou-se resposta linear para todas as características avaliadas, exceto para proteína insolúvel em detergente ácido (% PB). O capim-elefante BRS Canará para produção de forragem deve ser cortado entre 70 e 85 dias no período da seca e entre 60 e 70 dias no período das águas.(AU)


Sujet(s)
Pennisetum/composition chimique , Pennisetum/croissance et développement , Valeur nutritive , Aliment pour animaux , Produits agricoles
6.
Semina ciênc. agrar ; 40(6): 2705-2718, Nov.-Dec. 2019. graf, tab
Article de Anglais | VETINDEX | ID: biblio-1501534

RÉSUMÉ

The goal was to determine the ideal cutting age of elephant grass BRS Canará for forage production in the dry and rainy seasons. The experimental design comprised randomized blocks, with five treatments (42, 56, 70, 84, and 98 days in the dry season and 42, 60, 76, 91, and 105 days of regrowth in the rainy season) and four replications each. Agronomic, morphological, and chemical characteristics were evaluated. In the dry season, there was a significant quadratic response for plant height and leaf blade length. For the other characteristics, a significant linear response was observed, except stem diameter. In the rainy season, a quadratic response for the leaf blade length, leaf blade width, and leaf:stem ratio was observed. For the other characteristics, there was a significant linear effect, except for the percentage of dead material. In the dry season, a verified linear response was observed for the chemical characteristics, except neutral detergent insoluble protein. In the rainy season, a linear response was verified for all evaluated characteristics, except acid detergent insoluble protein. Elephant grass BRS Canará for forage production should be cut between 70 and 85 days in the dry season and between 60 and 70 days of regrowth in the rainy season.


Objetivou-se determinar a idade de corte ideal do capim-elefante BRS Canará para produção de forragem no período da seca e das águas. O delineamento experimental foi em blocos casualizados, com cinco tratamentos (42, 56, 70, 84 e 98 dias no período da seca e 42, 60, 76, 91 e 105 dias no período das águas) e quatro repetições cada. Foram avaliadas características agronômicas, morfológicas e químicas. No período da seca verificou-se resposta quadrática significativa para altura de planta e comprimento de lâmina foliar. Para as demais características constatou-se resposta linear significativa, com exceção de diâmetro de colmo. No período das águas verificou-se resposta quadrática para comprimento de lâmina foliar, largura de lâmina foliar e relação folha: colmo. Para as demais características verificaram-se efeito linear significativo, com exceção de porcentagem de material senescente. Na seca verificou-se resposta linear das características químicas, exceto para proteína insolúvel em detergente neutro (% MS). No período das águas, verificou-se resposta linear para todas as características avaliadas, exceto para proteína insolúvel em detergente ácido (% PB). O capim-elefante BRS Canará para produção de forragem deve ser cortado entre 70 e 85 dias no período da seca e entre 60 e 70 dias no período das águas.


Sujet(s)
Pennisetum/croissance et développement , Pennisetum/composition chimique , Valeur nutritive , Produits agricoles , Aliment pour animaux
7.
Sci Total Environ ; 635: 259-274, 2018 Sep 01.
Article de Anglais | MEDLINE | ID: mdl-29665544

RÉSUMÉ

Studies on the impacts of land-use and land-cover change on stream hydrochemistry in active deforestation zones of the Amazon agricultural frontier are limited and have often used low-temporal-resolution datasets. Moreover, these impacts are not concurrently assessed in well-established agricultural areas and new deforestations hotspots. We aimed to identify these impacts using an experimental setup to collect high-temporal-resolution hydrological and hydrochemical data in two pairs of low-order streams in catchments under contrasting land use and land cover (native vegetation vs. pasture) in the Amazon and Cerrado biomes. Our results indicate that the conversion of natural landscapes to pastures increases carbon and nutrient fluxes via streamflow in both biomes. These changes were the greatest in total inorganic carbon in the Amazon and in potassium in the Cerrado, representing a 5.0- and 5.5-fold increase in the fluxes of each biome, respectively. We found that stormflow, which is often neglected in studies on stream hydrochemistry in the tropics, plays a substantial role in the carbon and nutrient fluxes, especially in the Amazon biome, as its contributions to hydrochemical fluxes are mostly greater than the volumetric contribution to the total streamflow. These findings demonstrate that assessments of the impacts of deforestation in the Amazon and Cerrado biomes should also take into account rapid hydrological pathways; however, this can only be achieved through collection of high-temporal-resolution data.


Sujet(s)
Écosystème , Surveillance de l'environnement/méthodes , Rivières/composition chimique , Agriculture , Brésil , Conservation des ressources naturelles , Forêts , Hydrologie
8.
Zebrafish ; 14(5): 430-437, 2017 10.
Article de Anglais | MEDLINE | ID: mdl-28714785

RÉSUMÉ

The zebrafish (Danio rerio) can be used in studies addressing the effects of drugs on learning, memory, and anxiety. In the present study, we investigated the effect of different alcohol treatments (chronic and acute) on the learning and anxiety response of zebrafish in an inhibitory avoidance paradigm. Zebrafish were initially exposed to different alcohol treatments and submitted to an inhibitory avoidance protocol, where an electroshock was applied to the fish as they swam from the white to the black side of a shuttle box tank (naturally preferred environment of zebrafish). Animals from the control and 0.5% acute alcohol groups exhibited high latency to enter the black side of the tank after the first exposure to electroshock, in addition to higher freezing and a shorter distance from the bottom of the tank, suggesting acute alcohol exposure did not affect aversive learning in zebrafish. However, chronic exposure and alcohol withdrawal impaired the fish's capacity to properly respond to the aversive stimulus. Overall, our results show the harmful effects of chronic alcohol exposure, both continued intake and its cessation, but avoidance behavior persisted and anxiety increased following acute alcohol exposure.


Sujet(s)
Apprentissage par évitement/effets des médicaments et des substances chimiques , Comportement animal/effets des médicaments et des substances chimiques , Dépresseurs du système nerveux central/administration et posologie , Éthanol/administration et posologie , Danio zébré/physiologie , Animaux , Électrochoc
9.
PLoS One ; 12(6): e0179414, 2017.
Article de Anglais | MEDLINE | ID: mdl-28609462

RÉSUMÉ

Understanding the impacts of land-use change on landscape-hydrological dynamics is one of the main challenges in the Northern Brazilian Cerrado biome, where the Amazon agricultural frontier is located. Motivated by the gap in literature assessing these impacts, we characterized the soil hydro-physical properties and quantified surface water fluxes from catchments under contrasting land-use in this region. We used data from field measurements in two headwater micro-catchments with similar physical characteristics and different land use, i.e. cerrado sensu stricto vegetation and pasture for extensive cattle ranching. We determined hydraulic and physical properties of the soils, applied ground-based remote sensing techniques to estimate evapotranspiration, and monitored streamflow from October 2012 to September 2014. Our results show significant differences in soil hydro-physical properties between the catchments, with greater bulk density and smaller total porosity in the pasture catchment. We found that evapotranspiration is smaller in the pasture (639 ± 31% mm yr-1) than in the cerrado catchment (1,004 ± 24% mm yr-1), and that streamflow from the pasture catchment is greater with runoff coefficients of 0.40 for the pasture and 0.27 for the cerrado catchment. Overall, our results confirm that conversion of cerrado vegetation to pasture causes soil hydro-physical properties deterioration, reduction in evapotranspiration reduction, and increased streamflow.


Sujet(s)
Agriculture/méthodes , Plantes/métabolisme , Sol/composition chimique , Eau/métabolisme , Agriculture/tendances , Algorithmes , Animaux , Brésil , Bovins , Écosystème , Géographie , Hydrodynamique , Modèles théoriques , Transpiration des plantes , Rivières , Facteurs temps , Mouvements de l'eau
10.
Arq Neuropsiquiatr ; 74(12): 1031-1034, 2016 Dec.
Article de Anglais | MEDLINE | ID: mdl-27992003

RÉSUMÉ

Epilepsy is a potentially devastating brain disorder characterized by a predisposition to spontaneous epileptic seizures. In patients with medically refractory epilepsy, new non-pharmacological therapeutic approaches may be considered. In this scenario, palliative surgery such as vagus nerve stimulation (VNS) or deep brain stimulation (DBS) may be indicated in a subset of patients. In this paper we make recommendations for the use of VNS and DBS in patients in Brazil with refractory epilepsy.


Sujet(s)
Stimulation cérébrale profonde/normes , Épilepsie/thérapie , Stimulation du nerf vague/normes , Brésil , Résistance aux substances , Humains
11.
Arq. neuropsiquiatr ; Arq. neuropsiquiatr;74(12): 1031-1034, Dec. 2016.
Article de Anglais | LILACS | ID: biblio-828007

RÉSUMÉ

ABSTRACT Epilepsy is a potentially devastating brain disorder characterized by a predisposition to spontaneous epileptic seizures. In patients with medically refractory epilepsy, new non-pharmacological therapeutic approaches may be considered. In this scenario, palliative surgery such as vagus nerve stimulation (VNS) or deep brain stimulation (DBS) may be indicated in a subset of patients. In this paper we make recommendations for the use of VNS and DBS in patients in Brazil with refractory epilepsy.


RESUMO Epilepsia é uma doença cerebral potencialmente devastadora caracterizada por predisposição em gerar crises epilépticas espontâneas. Em pacientes com epilepsia refratária novas abordagens terapêuticas, não farmacológicas, podem ser consideradas. Neste cenário, cirurgias paliativas, como a estimulação do nervo vago (VNS) ou estimulação cerebral profunda (DBS) podem ser indicadas em um subgrupo de pacientes. Neste trabalho sugerimos recomendações sobre as indicações de uso do VNS e do DBS em pacientes com epilepsia refratária no Brasil.


Sujet(s)
Humains , Stimulation cérébrale profonde/normes , Épilepsie/thérapie , Stimulation du nerf vague/normes , Brésil , Résistance aux substances
12.
PLoS One ; 8(6): e64874, 2013.
Article de Anglais | MEDLINE | ID: mdl-23762259

RÉSUMÉ

The Pantanal is a biodiversity hotspot comprised of a mosaic of landforms that differ in vegetative assemblages and flooding dynamics. Tree islands provide refuge for terrestrial fauna during the flooding period and are particularly important to the regional ecosystem structure. Little soil CO2 research has been conducted in this region. We evaluated soil CO2 dynamics in relation to primary controlling environmental parameters (soil temperature and soil water). Soil respiration was computed using the gradient method using in situ infrared gas analyzers to directly measure CO2 concentration within the soil profile. Due to the cost of the sensors and associated equipment, this study was unreplicated. Rather, we focus on the temporal relationships between soil CO2 efflux and related environmental parameters. Soil CO2 efflux during the study averaged 3.53 µmol CO2 m⁻² s⁻¹, and was equivalent to an annual soil respiration of 1220 g C m⁻² y⁻¹. This efflux value, integrated over a year, is comparable to soil C stocks for 0-20 cm. Soil water potential was the measured parameter most strongly associated with soil CO2 concentrations, with high CO2 values observed only once soil water potential at the 10 cm depth approached zero. This relationship was exhibited across a spectrum of timescales and was found to be significant at a daily timescale across all seasons using conditional nonparametric spectral Granger causality analysis. Hydrology plays a significant role in controlling CO2 efflux from the tree island soil, with soil CO2 dynamics differing by wetting mechanism. During the wet-up period, direct precipitation infiltrates soil from above and results in pulses of CO2 efflux from soil. The annual flood arrives later, and saturates soil from below. While CO2 concentrations in soil grew very high under both wetting mechanisms, the change in soil CO2 efflux was only significant when soils were wet from above.


Sujet(s)
Dioxyde de carbone/métabolisme , Changement climatique , Sol/composition chimique , Arbres , Eau/métabolisme , Brésil , Simulation numérique , Environnement , Iles , Température , Eau/composition chimique , Zones humides
13.
Arq Neuropsiquiatr ; 71(11): 902-6, 2013 Nov.
Article de Anglais | MEDLINE | ID: mdl-24394879

RÉSUMÉ

Epilepsy comprises a set of neurologic and systemic disorders characterized by recurrent spontaneous seizures, and is the most frequent chronic neurologic disorder. In patients with medically refractory epilepsy, therapeutic options are limited to ablative brain surgery, trials of experimental antiepileptic drugs, or palliative surgery. Vagal nerve stimulation is an available palliative procedure of which the mechanism of action is not understood, but with established efficacy for medically refractory epilepsy and low incidence of side-effects. In this paper we discuss the recommendations for VNS use as suggested by the Brazilian League of Epilepsy and the Scientific Department of Epilepsy of the Brazilian Academy of Neurology Committee of Neuromodulation.


Sujet(s)
Épilepsie/thérapie , Soins palliatifs/normes , Stimulation du nerf vague/normes , Brésil , Humains , Sociétés médicales , Stimulation du nerf vague/effets indésirables
14.
Campo digit. ; 8(1)2013.
Article de Portugais | VETINDEX | ID: vti-714979

RÉSUMÉ

Este estudo teve por objetivo investigar a utilização de técnicas geoestatísticas no estudo da variabilidade espacial de dados pluviométricos para Estado de Alagoas, mediante análise da dependência espacial, variograma, técnica de krigagem ordinária e da validação cruzada. Para tanto, nesta pesquisa utilizou-se o total anual médio da precipitação de 63 estações pluviométricas no período de 1965 a 1980. A utilização da geoestatística mostrou que as características estruturais da precipitação estão correlacionadas e apresentaram forte dependência espacial. A distribuição espacial da precipitação apresentou variabilidade espacial, com totais pluviométricos que variaram de 500 mm/ano na região do sertão e 2.000 mm/ano no litoral. Palavras chaves: geoestatística, krigagem, validação cruzada, variograma.

15.
Campo digit ; 8(1)2013.
Article de Portugais | LILACS-Express | VETINDEX | ID: biblio-1471735

RÉSUMÉ

Este estudo teve por objetivo investigar a utilização de técnicas geoestatísticas no estudo da variabilidade espacial de dados pluviométricos para Estado de Alagoas, mediante análise da dependência espacial, variograma, técnica de krigagem ordinária e da validação cruzada. Para tanto, nesta pesquisa utilizou-se o total anual médio da precipitação de 63 estações pluviométricas no período de 1965 a 1980. A utilização da geoestatística mostrou que as características estruturais da precipitação estão correlacionadas e apresentaram forte dependência espacial. A distribuição espacial da precipitação apresentou variabilidade espacial, com totais pluviométricos que variaram de 500 mm/ano na região do sertão e 2.000 mm/ano no litoral. Palavras chaves: geoestatística, krigagem, validação cruzada, variograma.

16.
São Paulo; Cortez; 2009. 206 p. mapas, tab, graf.(Atlas da nova estratificação social no Brasil, 3).
Monographie de Portugais | LILACS | ID: lil-620649

RÉSUMÉ

Desde o nascimento do país, a concentração da propriedade distorceu os caminhos da república e da cidadania. Este livro revela a capacidade dos grandes proprietários de manter-se, subordinando, mais uma vez, o país e o Estado aos seus interesses.


Sujet(s)
Humains , Cartographie géographique , Revenu , Facteurs socioéconomiques/économie , Propriété , Classe sociale , Brésil , Cartes comme sujet
17.
Phys Rev Lett ; 101(8): 081602, 2008 Aug 22.
Article de Anglais | MEDLINE | ID: mdl-18764601

RÉSUMÉ

Some consequences of promoting the object of noncommutativity theta(ij) to an operator in Hilbert space are explored. Its canonical conjugate momentum is also introduced. Consequently, a consistent algebra involving the enlarged set of canonical operators is obtained, which permits us to construct theories that are dynamically invariant under the action of the rotation group. In this framework it is also possible to give dynamics to the noncommutativity operator sector, resulting in new features.

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