Característica de Euler-Poincaré aplicada para identificar baixa densidade óssea a partir de imagens tomográficas de vértebras

Roque, Waldir L.; Souza, Ândrea Celestino de; Barbieri, Denis Xavier

doi:10.1590/s0482-50042009000200006

Cited by 23 publications

(5 citation statements)

References 11 publications

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“…In such case, it was called unclassified pore (UN). The pore network tortuosity (t) and connectivity were analyzed using a computer program called OsteoImage (Arcaro, 2013;Roque et al, 2009). t was computed assuming the geodesic reconstruction algorithm implemented by Roque et al (2012a,b):…”

Section: Micromorphological Analysis (Mct)mentioning

confidence: 99%

“…Once estimated the EPC for each disector of a sample, the sum of EPC values gives an estimate of the connection of the sample; however, it is more convenient to obtain the EPC per sample volume (Roque et al, 2012b). According to the EPC, highly connected structures present small and negative values (Chappard et al, 1999) while low connected structures present high positive values (Roque et al, 2009).…”

Section: Micromorphological Analysis (Mct)mentioning

confidence: 99%

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Soil structure changes induced by tillage systems

Pires

Borges

Rosa³

et al. 2017

Soil and Tillage Research

Self Cite

218

104

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Structure represents one of the main soil physical attributes indicators. The soil porous system (SPS) is directly linked to the soil structure. Water retention, movement, root development, gas diffusion and the conditions for all soil biota are related to the SPS. Studies about the influence of tillage systems in the soil structure are important to evaluate their impact in the soil quality. This paper deals with a detailed analysis of changes in the soil structure induced by conventional (CT) and no-tillage (NT) systems. Three different soil depths were studied (0-10, 10-20 and 20-30 cm). Data of the soil water retention curve (SWRC), micromorphologic (impregnated blocks) (2D) and microtomographic (mCT) (3D) analyses were utilized to characterize the SPS. Such analyses enabled the investigation of porous system attributes such as: porosity, pore number and shape, pore size distribution, tortuosity and connectivity. Results from this study show a tri-modal pore size distribution (PSD) at depths 0-10 and 10-20 cm for the soil under CT and a bi-modal PSD for the lower layer (20-30 cm). Regarding the soil under NT, tri-modal PSDs were found at the three depths analyzed. Results based on the micromorphologic analysis (2D) showed that the greatest contribution to areal porosity (AP) is given by pores of round (R) shape for CT (52%: 0-10 cm; 50%: 10-20 cm; 67%: 20-30 cm). Contrary to the results observed for CT, the soil under NT system gave the greatest contribution to AP, for the upper (0-10 cm) and intermediate (10-20 cm) layers, due to the large complex (C) pore types. For the mCT analysis, several types of pores were identified for each soil tillage system. Small differences in the macroporosity (MAP) were observed for the 0-10 and 20-30 cm between CT and NT. A better pore connectivity was found for the 0-10 cm layer under NT. 2016 Elsevier B.V. All rights reserved.

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Section: Micromorphological Analysis (Mct)mentioning

confidence: 99%

Section: Micromorphological Analysis (Mct)mentioning

confidence: 99%

Soil structure changes induced by tillage systems

Pires

Borges

Rosa³

et al. 2017

Soil and Tillage Research

Self Cite

218

104

View full text Add to dashboard Cite

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“…The soil pores were also classified according to their shape using the terminology suggested by Bullock et al 35 , described in detail in Galdos et al 36 . The network tortuosity (τ) of the pores and connectivity was calculated using Osteoimage 37,38 . Tortuosity was determined through the geodesic reconstruction algorithm implemented by Roque et al 39,40 .…”

Section: X-ray Computed Tomography (Ct)mentioning

confidence: 99%

“…This parameter for a 3D structure is related to the number of isolated parts minus the connectivity of an object 41 . The EPC number is an indicator of how connected a pore is: the smaller (more negative) it is, the greater the pore connectivity 38,42 .…”

Section: X-ray Computed Tomography (Ct)mentioning

confidence: 99%

Brachiaria species influence nitrate transport in soil by modifying soil structure with their root system

Galdos

Brown

Rosolem

et al. 2020

Sci Rep

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Leaching of nitrate from fertilisers diminishes nitrogen use efficiency (the portion of nitrogen used by a plant) and is a major source of agricultural pollution. To improve nitrogen capture, grasses such as brachiaria are increasingly used, especially in South America and Africa, as a cover crop, either via intercropping or in rotation. However, the complex interactions between soil structure, nitrogen and the root systems of maize and different species of forage grasses remain poorly understood. This study explored how soil structure modification by the roots of maize (Zea maize), palisade grass (Brachiaria brizantha cv. Marandu) and ruzigrass (Brachiaria ruziziensis) affected nitrate leaching and retention, measured via chemical breakthrough curves. All plants were found to increase the rate of nitrate transport suggesting root systems increase the tendency for preferential flow. The greater density of fine roots produced by palisade grass, subtly decreased nitrate leaching potential through increased complexity of the soil pore network assessed with X-ray Computed Tomography. A dominance of larger roots in ruzigrass and maize increased nitrate loss through enhanced solute flow bypassing the soil matrix. These results suggest palisade grass could be a more efficient nitrate catch crop than ruzigrass (the most extensively used currently in countries such as Brazil) due to retardation in solute flow associated with the fine root system and the complex pore network.

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“…Vogel e Kretzshmar (1996) apresentam a técnica aqui utilizada e implementada em (Roque et al, 2009), para a contagem de #I, #B e #H automaticamente em um volume de um meio poroso a partir das imagens binárias do disector. Quanto mais conectada se apresenta a estrutura, menores e negativos são os valores da CEP (Chappard et al, 1999).…”

Section: Conectividadeunclassified

Tortuosidade e conectividade da rede trabecular do rádio distal a partir de imagens microtomográficas

2012

RBEB

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Resumo A osteoporose é uma doença que causa perda de massa óssea e deterioração da estrutura trabecular. A rede formada pelo osso trabecular é muito importante para estabelecer a competência mecânica do esqueleto. Estudos mostram que a microarquitetura trabecular pode elevar a predição do risco de fratura para cerca de 90%, por isso a sua investigação é de grande interesse da comunidade científica. Vários parâmetros estão relacionados à competência mecânica da estrutura óssea, entretanto, a tortuosidade trabecular ainda não foi seriamente levada em consideração e sua contribuição é desconhecida. Neste trabalho, o enfoque está direcionado à estimativa da tortuosidade trabecular e sua correlação com a conectividade, através da característica de Euler-Poincaré, para amostras do osso rádio distal in vitro, a partir de imagens de microtomografia computadorizada. Um método para estimar a tortuosidade do volume trabecular é apresentado e a tortuosidade é computada para os dois sentidos das três direções do volume. Os resultados apresentam valores distintos da tortuosidade dependendo da qualidade da rede trabecular e uma correlação positiva (r = 0,64) com a característica de Euler-Poincaré; além disso, observa-se que a tortuosidade busca alinhar-se nas direções de maiores tensões e compressões imprimidas à rede trabecular. Tais resultados evidenciam a importância da tortuosidade como parâmetro estrutural da rede trabecular. Palavras-chave

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Característica de Euler-Poincaré aplicada para identificar baixa densidade óssea a partir de imagens tomográficas de vértebras

Cited by 23 publications

References 11 publications

Soil structure changes induced by tillage systems

Soil structure changes induced by tillage systems

Brachiaria species influence nitrate transport in soil by modifying soil structure with their root system

Tortuosidade e conectividade da rede trabecular do rádio distal a partir de imagens microtomográficas

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