Modelling of bulk density as related to aggregate size distribution in clayey Ferralsols

Among microaggregated soils, there are Ferralsols that show little or no distinct horizonation. Their macrostructure is weak to moderate and they have typically a strong microstructure. In most Brazilian clayey Ferralsols, physical properties are closely related to the development of microstructure that consists of subrounded microaggregates 50 to 500 µm in diameter

Mass Proportion of Microaggregates and Bulk Density in a Brazilian Clayey Oxisol.

The physical properties of Brazilian Oxisols are closely related to the development of their microstructure, which typically consists of stable microaggregates smaller than 1 mm. There is no model available to predict changes in microstructure in Oxisols. The objective of this work was to relate the proportion of microaggregates to the bulk density (Db) in the soil studied. Five sites of a typic Haplustox under native vegetation (two sites) and pasture (three sites) were sampled. Soil bulk density, sand, silt, and clay content and aggregate size distribution were measured from the surface to 1.6 m deep in increments of 0.1 m. Thin sections were prepared from undisturbed samples collected in duplicate from 0-0.1 m, 0.3-0.4 m, 0.8-0.9 m and 1.5-1.6 m depth, and backscattered electron scanning images (BESI) were generated. Clay content ranged from 672 to 798 g kg-1 and bulk density between 0.87 and 1.18 g cm-3 among the 80 samples studied. Db was poorly correlated with clay content (R² = 0.358) and at any depth was not significantly smaller under native vegetation than under pasture. Visual assessment of BESI revealed that soil material corresponded to either microaggregates (< 0.1 mm) in loose arrangement or to much larger aggregates. Quantification of BESI from the deepest sampling depth of all soils showed that 96.2 and 95.7 % of microaggregates were < 0.8 mm with 73.2 and 95.7 % between 0.1 and 0.5 mm under native vegetation and pasture, respectively. The mass proportion of microaggregates can be estimated using the < 0.84 mm soil material that is obtained by dry sieving (&<0.84). Finally, our results showed that &<0.84 varied with Db. Linear regression coefficients were calculated for the relationship between &<0.84 and the reciprocal of bulk density (1/ Db) (&<0.84 = 1.97 (1/ Db) – 1.52, R² = 0.82), assuming no interaction between microaggregates and macroaggregates, the porosity of these two structural types was estimated as 0.71 and 0.51, respectively

Ion concentrations in the solution of an Oxisol under different management systems

O objetivo deste trabalho foi avaliar as concentrações de íons na solução de um Latossolo Vermelho, em diferentes sistemas de manejo. Foram avaliados os sistemas de lavoura e pastagem contínua, assim como os rotacionados em integração lavoura-pecuária. O experimento foi iniciado em 1991, e as coletas das soluções foram realizadas em 2005 e 2006. Cápsulas porosas foram instaladas às profundidades de 20 e 150 cm, e as soluções foram extraídas em seis épocas de cada ano. As concentrações de Cl-, SO4(2-), NO3-, H2PO4-, K+, Mg2+ e Ca2+ foram determinadas. Independentemente das profundidades e dos sistemas de manejo, a concentração de íons nas soluções, em ordem decrescente de grandeza, foi: NO3- >Cl- >SO4(2-) >H2PO4- e Ca2+ >K+ >Mg2+. Entre os sistemas de cultivo, a concentração dos íons na solução decresceu e foi maior em lavoura contínua sob preparo convencional, seguida de lavoura contínua sob plantio direto e, finalmente, pelo sistema de integração lavoura-pecuária e pela pastagem contínua. À profundidade de 150 cm, as concentrações dos íons na solução do solo sob pastagem contínua e integração lavoura-pecuária foram sempre baixas, o que indica baixo risco de lixiviação.The objective of this work was to evaluate ion concentrations in an Oxisol solution, in plots subjected to different management systems. Continuous crop and pasture, and the integrated crop-livestock management system were evaluated. The experiment started in 1991, and the soil solutions were collected in 2005 and 2006. Ceramic cups were installed at 20 and 150 cm soil depths, and the solutions were extracted six times each year. The concentrations of Cl-, SO4(2-), NO3-, H2PO4-, K+, Mg2+, and Ca2+ were determined. Irrespective of the depths and cropping systems considered, the concentrations of ions into the soil solutions, in decreasing order, were: NO3- >Cl- >SO4(2-) >H2PO4- and Ca2+ >K+ >Mg2+. Among the cropping systems, the ion concentrations in the soil solution was higher in the continuous crop under conventional tillage, followed by the continuous crop under no-tillage, and finally by the integrated crop-livestock system and the continuous pasture. At 150 cm depth, the ion concentrations in soil solutions under continuous pasture and integrated crop-livestock system were always low, which indicates a low leaching risk

Concentração de íons na solução de um Latossolo Vermelho sob diferentes sistemas de manejo

The objective of this work was to evaluate ion concentrations in an Oxisol solution, in plots subjected to different management systems. Continuous crop and pasture, and the integrated crop-livestock management system were evaluated. The experiment started in 1991, and the soil solutions were collected in 2005 and 2006. Ceramic cups were installed at 20 and 150 cm soil depths, and the solutions were extracted six times each year. The concentrations of Cl-, SO42-, NO3-, H2PO4-, K+, Mg2+, and Ca2+ were determined. Irrespective of the depths and cropping systems considered, the concentrations of ions into the soil solutions, in decreasing order, were: NO3- >Cl- >SO42- >H2PO4- and Ca2+ >K+ >Mg2+. Among the cropping systems, the ion concentrations in the soil solution was higher in the continuous crop under conventional tillage, followed by the continuous crop under no‑tillage, and finally by the integrated crop‑livestock system and the continuous pasture. At 150 cm depth, the ion concentrations in soil solutions under continuous pasture and integrated crop-livestock system were always low, which indicates a low leaching risk.O objetivo deste trabalho foi avaliar as concentrações de íons na solução de um Latossolo Vermelho, em diferentes sistemas de manejo. Foram avaliados os sistemas de lavoura e pastagem contínua, assim como os rotacionados em integração lavoura-pecuária. O experimento foi iniciado em 1991, e as coletas das soluções foram realizadas em 2005 e 2006. Cápsulas porosas foram instaladas às profundidades de 20 e 150 cm, e as soluções foram extraídas em seis épocas de cada ano. As concentrações de Cl-, SO42-, NO3-, H2PO4-, K+, Mg2+ e Ca2+ foram determinadas. Independentemente das profundidades e dos sistemas de manejo, a concentração de íons nas soluções, em ordem decrescente de grandeza, foi: NO3->Cl- >SO42->H2PO4- e Ca2+ >K+ >Mg2+. Entre os sistemas de cultivo, a concentração dos íons na solução decresceu e foi maior em lavoura contínua sob preparo convencional, seguida de lavoura contínua sob plantio direto e, finalmente, pelo sistema de integração lavoura-pecuária e pela pastagem contínua. À profundidade de 150 cm, as concentrações dos íons na solução do solo sob pastagem contínua e integração lavoura-pecuária foram sempre baixas, o que indica baixo risco de lixiviação

EDUCAÇÃO BÁSICA EM FOCO: REPRODUÇÃO E EMANCIPAÇÃO SOB A PERSPECTIVA SOCIOLÓGICA DE PIERRE BOURDIEU

Este estudo tem por objetivo discutir aspectos em torno dos conceitos de reprodução e emancipação no campo educacional a luz da teoria bourdieusiana.  Iniciaremos a partir da conceituação de democracia passando para o resgate histórico do sistema educacional brasileiro para compreender o surgimento das teorias criticas do currículo onde se destacam os estudos de Pierre Bourdieu e a teoria da reprodução que fundamenta o presente trabalho, explicitando alguns conceitos chaves do autor que  suscitam e embasam reflexões importantes sobre a função da escola e seus dilemas contemporâneos, dentre eles o conflito entre reprodução e emancipação na educação básica, apoiados por uma revisão bibliográfica de estudos recentes encontrado no banco de teses e dissertações da UNESP compreendendo o período de 2014-2019

Modelling Bulk Density According to Structure Development: Toward an Indicator of Microstructure Development in Ferralsols.

Ferralsols have a ferralic horizon at some depth between 30 and 200 cm that results from long and intense weathering. Their clay fraction is usually mainly low-activity clay consisting of kaolinite with hematite, goethite and gibbsite in different proportions. Ferralsols show little or no horizonation, and their macrostructure is absent to moderate. On the other hand, they have typically a strong microstructure consisting of microaggregates < 1 mm in size. Because of the lack or small development of macrostructure, porosity of Ferralsols is closely related to the development of microstructure and the assemblage of elementary particles within the microaggregates with a small contribution of large pores resulting from root development and macrofaunal activity. Their physical properties are then closely related to the development of this microstructure. However, there is still no model in the literature that predicts changes of microstructure of these soils using easily accessible soil properties when land-use is modified. The objective of this work was to relate microstructure development to the bulk density (Db) in Ferralsols and then to make possible the use of Db as an indicator of microstructure development

Fatores associados aos óbitos por acidentes de trânsito nas rodovias federais da Bahia

Objetivo identificar fatores associados aos óbitos em decorrência dos acidentes de trânsito ocorridos de 2010 a 2019 nas rodovias federais sob circunscrição da Polícia Rodoviária Federal na Bahia. Trata-se de um estudo epidemiológico de corte transversal com dados secundários. O coeficiente de letalidade geral de 3,90%, maior incidência em mulheres (IL% = 4,29%, IC95% = 0,98-1,10), pedestres (IL% = 30,99%, IC95% = 9,17-10,38), sexta a domingo (IL% = 4,83%, IC95% = 1,33-1,46), mal subido (IL% = 11,52%, IC95% = 2,80-4,50), atropelamento (IL% = 11,45%, IC95% = 2,79-3,14), veículos com tempo de uso superior a 10 anos (IL% = 4,79%, IC95% = 1,33-3,92), bicicleta (IL% = 14,50%, IC95% = 4,09-5,40), nevoeiro/neblina (IL% = 6,31%, IC95% = 1,28-1,80), pista simples (IL% = 4,82%, IC95% = 2,47-3,84), desvio temporário (IL% = 7,29 %, IC95% = 1,45-2,34). A análise confere panorama importante, proporcionando informações aos usuários das vias além de subsidiar o debate e ações preventivas

Agronomy Maringá, v. 33, n. 1, p

ABSTRACT. This study aimed to determine the number of termite epigeal nests and estimate the soil turning capacity of termites in cultivated pasture environments and in a native vegetation area. Surveys were conducted in four areas: three pasture areas and a Cerrado area, measuring 5 ha each. For each nest, the height, the perimeter and diameter at the base were measured. The volume of each mound was calculated. Turned soil was determined by randomly sampling 30 termite mounds in a pasture area for bulk density determinations. The mean number of termite mounds per ha was 408; the highest number of termite nests (672 per ha) was found in the 10-year-old pasture. In terms of termite mound density, there was no difference between the Cerrado, 3-year-old pasture, and 3-year-old intercropped pasture treatments. The total area occupied by termite nests ranged from 0.4 to 1.0%. The mean bulk density of the nest materials was 1.05 g c

Correlations between speech disorders, mouth breathing, dentition and occlusion

PURPOSE: to check the correlations among speech disorders and mouth breathing symptoms with the type of dentition and occlusion, using video recordings. METHODS: a retrospective study with 397 patients, by studying the shooting script - ROF. Types of speech disorders and mouth breathing symptoms were assessed by Orofacial Motricity Specialist Speech and Language Pathologists and compared with the occlusal types proposed by Angle and with the dentition parameters, both evaluated by an Orthodontist. For the statistical analysis we used the program SPSS (Statistical Package for Social Sciences), version 13.0. For analyzing Spearman correlation, all assessment data were matched and analyzed. The adopted significance level was 5%. RESULTS: Considering speech disorders and dentition and occlusion data, we noted parallelism between distortion and crossbite, imprecision and bone deviation of lower midline line, locking and overjet, locking and overbite, frontal lisp and Angle Class III malocclusion, frontal lisp and malocclusion, frontal lisp and open bite, frontal lisp and crossbite; and frontal lisp and lower midline deviation. We also noted correlated opposition between locking and openbite, locking and bone deviation of lower bone midline, frontal lisp and Angle Class II-1 malocclusion, frontal lisp and overjet; and frontal lisp and overbite. Considering mouth breathing symptoms and dentition and occlusion data, we noted a symptom of parallelism between the protrusion of lower lip and overjet, accumulation of saliva on the labial commissures and crossbite, accumulation of saliva on the labial commissures and lack of intra-oral room; Half-opened lips at rest and Angle Class II-1 malocclusion. Dark eye circle and Angle Class II-1 malocclusion, protrusion of lower lip and Class II-1 malocclusion; and shortened upper lip and overbite show correlated opposition. CONCLUSIONS: the anterior lisp is correlated to dentition disorders and Angle Class III malocclusion; dark eye circle, protrusion of lower lip and half-opened lips in rest are adaptations found in Angle Class II-1 malocclusion, not characterizing oral breathing in this group; the accumulation of saliva on the labial commisures was a symptom of mouth breathing that was correlated with the disorders in dentition.OBJETIVO: verificar as correlações entre alterações de fala e sinais de respiração oral ao tipo de dentição e oclusão, utilizando-se registros em vídeo. MÉTODOS: estudo retrospectivo, de 397 pacientes, por meio de levantamento do roteiro de filmagem ROF. Tipos de alterações de fala e de sinais de respiração oral foram avaliados por Fonoaudiólogos Especialistas em Motricidade Orofacial e comparados com os tipos oclusais propostos por Angle e com parâmetros da dentição, ambos avaliados por Ortodontista. Para a análise estatística foi utilizado o programa SPSS (Statistical Package for Social Sciences), em sua versão 13.0. Para a análise de correlação de Spearman, todos os dados da avaliação foram pareados e analisados. Foi adotado o nível de significância de 5%. RESULTADOS: Considerando alterações de fala e dados de dentição e oclusão, observou-se paralelismo entre distorção e mordida cruzada, imprecisão e desvio ósseo de linha média inferior, travamento e sobressaliência, travamento e sobremordida, ceceio anterior e Classe III de Angle, ceceio anterior e mordida aberta, ceceio anterior e mordida cruzada; e ceceio anterior e desvio de linha média inferior. Observou-se ainda correlação de oposição entre travamento e mordida aberta, travamento e desvio ósseo de linha média inferior, ceceio anterior e Classe II-1 de Angle, ceceio anterior e sobressaliência; e ceceio anterior e sobremordida. Considerando os sinais de respiração oral e dados de dentição e oclusão, observou-se sinal de paralelismo entre eversão de lábio inferior e sobressaliência, acúmulo de saliva nas comissuras labiais e mordida cruzada, acúmulo de saliva nas comissuras labiais e falta de espaço intra-oral; e lábios entreabertos no repouso e Classe II-1 de Angle. Olheira e classe II-1 de Angle, eversão de lábio inferior e Classe II-1 de Angle; e lábio superior encurtado e sobremordida apresentaram correlação de oposição. CONCLUSÕES: o ceceio anterior está correlacionado a alterações de dentição e à Classe III de Angle; olheira, eversão do lábio inferior e lábios entreabertos no repouso são adaptações presentes na Classe II-1, não caracterizando respiração oral neste grupo; o acúmulo de saliva nas comissuras labiais foi o sinal de respiração oral que se correlacionou às alterações de dentição.172