João Carlos Campos - Academia.edu (original) (raw)
Papers by João Carlos Campos
Revista Arvore, 2005
The main objective of this study was to evaluate the estimates generated by a diametric distribut... more The main objective of this study was to evaluate the estimates generated by a diametric distribution model, under the biologic point of view. Another objective was to evaluate the efficiency of the percentage of entries method to determine the technical age for the first and second thinning in eucalypt stands. The qualitative evaluation of the model was carried out through the evaluation of the results obtained by the percentage of entries method, the behavior of the diametric distributions projected for the future, and the behavior of the remaining distributions after some thinning simulations, theoretically, logically and biologically speaking. According to the results it was concluded that the diametric distribution model proposed is biologically correct and consistent. Growth stagnation is stimulated after thinning. It also was concluded that the percentage of entries method is suitable to determine the technical age for the first and second thinning. The model evaluated allows the simulation of various situations, generating consistent estimates and it can be used without restrictions, that is, situations can be simulated with or without the conditions observed in the field.
Revista Arvore, 2009
The objective of this work was to develop and propose a procedure to quantify the volume of trees... more The objective of this work was to develop and propose a procedure to quantify the volume of trees in non-thinned Eucalypt clone plantings. To quantify the volume of the trees, data pertaining to 2036 commercial trees of eucalypt clones owned by CAF, Santa Barbara were used, with their volume equations being adjusted for each group, determined by clone and region. For each tree, a taper model was adjusted. For each tree, a taper model was adjusted, followed by the cut of three trees from new clones without specific volume equation, i.e., a "small" tree, an "average" tree, and "a large" tree, in terms of dap and total height. With the three trees cubed, the taper model was adjusted, considering the three trees. Based on the estimates of the parameters, a measure of similarity was calculated for the tape equation parameters adjusted for the 2,036 commercial clone trees and the equation parameter of the new clone. The commercial clone tree presenting the lesser Euclidean distance value when compared with the new clone was considered the most similar; thus, the volume equation of this commercial clone was used estimated the volume of the new clone trees, with this procedure being termed profile similarity method. This method can be used to estimate the tree volume of clones without specific equations, generating similar estimates when comparing observed and estimated, both for individual trees and total stand.
RESUMO -O presente estudo teve como objetivo avaliar a aplicabilidade do modelo de Clutter em pov... more RESUMO -O presente estudo teve como objetivo avaliar a aplicabilidade do modelo de Clutter em povoamentos desbastados de eucalipto. Esta pesquisa foi desenvolvida com dados da empresa Copener Florestal Ltda., atualmente Bahia Pulp, no Município de Alagoinhas, BA. Os dados utilizados fazem parte de um experimento de desbaste implantado em povoamentos de eucalipto, empregando-se o esquema de blocos casualizados constituídos de quatro tratamentos e repetidos em três locais diferentes, perfazendo 48 parcelas com área média de 2.600 m 2 cada uma. As parcelas foram medidas aos 27, 40, 50, 58, 61 e 76 meses de idade, e aos 58 meses realizouse o desbaste. Para ajuste do modelo, foi empregado o sistema de equações simultâneas, que utiliza informações do povoamento referentes a área basal, volume, idade e índice de local. A partir do ajuste do modelo, elaborouse uma tabela de produção de densidade variável e determinou-se a idade técnica de corte em diferentes capacidades produtivas. Realizaram-se simulações na tabela de produção de regimes de desbaste. Concluiu-se que o modelo de Clutter foi eficiente para predizer a produção atual e futura dos povoamentos desbastados de eucalipto, mostrando-se útil na análise de alternativas de manejo, como a determinação da idade técnica de desbaste, de diferentes índices de local e regimes de desbaste.
Revista Arvore, 2007
This study was carried to evaluate the efficiency of the Bitterlich method in growth and yield mo... more This study was carried to evaluate the efficiency of the Bitterlich method in growth and yield modeling of the even-aged Eucalyptus stands. 25 plots were setup in Eucalyptus grandis cropped under a high bole system in the Central Western Region of Minas Gerais, Brazil. The sampling points were setup in the center of each plot. The data of four annual mesurements were colleted and used to adjust the three model types using the age, the site index and the basal area as independent variables. The growths models were fitted for volume and mass of trees. The efficiency of the Bitterlich method was confirmed for generating the data for growth and yield modeling.
RESUMO: O objetivo deste trabalho foi avaliar e propor alguns refinamentos necessários no Método ... more RESUMO: O objetivo deste trabalho foi avaliar e propor alguns refinamentos necessários no Método dos Ingressos Percentuais (MIP), proposto por Garcia e . Este método, permite determinar a idade técnica do primeiro desbaste, bem como o intervalo de tempo entre os desbastes sucessivos, com base na dinâmica de crescimento e no ingresso de árvores em sucessivas classes de diâmetro. No presente estudo, foram implementados alguns refinamentos nesse método, visando a determinação do momento de realização do primeiro desbaste, quando se conta com apenas três medições anuais de parcelas permanentes. Para esta finalidade utilizou-se um modelo de distribuição diamétrica. Os resultados indicaram, para um povoamento de eucalipto localizado na Região Nordeste do Estado da Bahia, a idade de 69 meses para realização do primeiro desbaste. Pode-se comprovar que o MIP permite reduzir o custo de experimentação sobre desbastes e, ainda, determinar a época de iniciar a aplicação de tratamentos de desbaste, pelo menos um ano antes da idade técnica de desbaste. Isto considerando que para eucalipto, o primeiro desbaste, em geral, ocorre em idades maiores ou igual a 4,5 anos.
Revista Arvore, 2006
The objective of this study was to evaluate, under the biological point of view, a diametric dist... more The objective of this study was to evaluate, under the biological point of view, a diametric distribution model. Another objective was to evaluate the efficiency of the percentage of entries method to determine the technical age for the first and second thinning in teak (Tectona grandis L. f.) stands. This evaluation was carried out by comparing the technical thinning ages obtained by the percentage of entries method, the diametric distributions projected for future ages and the behavior of the remaining distribution, after some thinning simulations, with the expected logical tendency. It was be concluded that the proposed diametric distribution model generates estimates which follow a logical tendency, biologically speaking and that the percentage of entries method is suitable to determine the technical age of the first and second thinning.
RESUMO -O principal objetivo deste estudo foi avaliar as estimativas geradas por um modelo de dis... more RESUMO -O principal objetivo deste estudo foi avaliar as estimativas geradas por um modelo de distribuição diamétrica, do ponto de vista biológico. Também foi objetivo avaliar a eficiência do método dos ingressos porcentuais para determinação da idade técnica do primeiro e do segundo desbaste em plantação de eucalipto. A análise qualitativa do modelo consistiu em avaliar os resultados obtidos pelo método dos ingressos porcentuais, o comportamento das distribuições diamétricas projetadas para idades futuras e o comportamento das distribuições diamétricas remanescentes, após algumas simulações de desbaste, do ponto de vista da teoria, da lógica e do realismo biológico. Pôde-se inferir que o modelo de distribuição diamétrica proposto é biologicamente correto e consistente. A estagnação do crescimento é mais rápida após o desbaste. Concluiu-se, ainda, que o método dos ingressos porcentuais é adequado para determinar a idade técnica do primeiro e do segundo desbaste. O modelo avaliado permite simular diferentes cenários, gerando estimativas consistentes, podendo ser aplicado sem restrições, ou seja, podem ser simulados cenários que contemplem, ou não, as condições observadas no campo.
Revista Arvore, 2006
A model to manage even-aged stands was developed using a modification of the Buckman model. Data ... more A model to manage even-aged stands was developed using a modification of the Buckman model. Data from Eucalyptus urophylla and Eucalyptus cloeziana stands located in the Northern region of Minas Gerais State, Brazil were used in the formulation of the system. The proposed model generated precise and unbiased estimates in non-thinned stands. Keywords: Buckman model, growth and yield, basal area growth.
Revista Arvore, 2005
The objective of the present study was to evaluate the applicability of the Clutter model in thin... more The objective of the present study was to evaluate the applicability of the Clutter model in thinned eucalypt stands. The study was developed with data from the Copener Florestal, Bahia Pulp Enterprise, located in the municipality of Alagoinhas, Bahia, Brazil. Data came from a thinning experiment established in eucalypt stands using a randomized block design with four treatments and three repetitions, each one in a different place, totaling 48 plots with a mean area of 2,600 m2 each. The plots were measured at 27, 40, 50, 58, 61 and 76 months of age, and the thinning was carried out at 58 months. For model adjustment, a system of simultaneous equations was used with stand information such as basal area, volume, age and site index. From the model adjustment, a yield table with variable density was built, and the technical cutting age was determined for various thinning intensities. Simulations were carried out with the yield table. It was concluded that the Clutter model was efficient to predict the present and future yields of the thinned eucalypt stands, showing its usefulness in the analysis of alternative managements, such as the technical cutting age determination for various site indexes and thinning intensities.
Revista Arvore, 2008
The objective of this study was to evaluate the growth tendencies of the stand variables and eval... more The objective of this study was to evaluate the growth tendencies of the stand variables and evaluate alternatives to construct site index curves for teak (Tectona grandis) in stands located in the Tangará da Serra, Mato Grosso state. For this purpose, data from 50 permanent plots with a minimum of four successive measurements were used. The tendencies of growth in height, diameter, basal area and volume were analyzed by means of the regression method, using the Chapman-Richards model. Two methods of construction of site index curves, with different models, were evaluated. The results of the analysis showed that Chapman-Richards model adjusted well to the observed data, describing the growth tendencies of the stand variables. The best alternative for the construction of site index curves was the guide-curve method, using the Chapman-Richards model.
Revista Arvore, 2009
The objective of this work was to develop and propose a procedure for modeling growth and yield o... more The objective of this work was to develop and propose a procedure for modeling growth and yield of nonthinned eucalyptus clone plantations. The data used were obtained from 37 clones distributed in 4325 permanent plots from continuous forest inventories. Each clone contained at least three annual measurements. Five alternatives were studied for prognosis evaluation of clones with more than three permanent plot measurements. For the volumetric stock prognosis, the study showed that the model adjusted by modeling stratum was more efficient than the Clutter model. It could be concluded that growth and yield estimations for clones with less than three measurements can be performed using specific models per stratum or a general model. Such decision must, however, be evaluated by the modeling agent and the user, and a strong interaction between them is necessary.
Journal of The Neurological Sciences, 2009
Brainstem gliomas constitute 10% of brain tumors in children and less than 2% in adults. Since th... more Brainstem gliomas constitute 10% of brain tumors in children and less than 2% in adults. Since therapeutic options are limited and brainstem gliomas are associated with a high morbidity and mortality, we sought to analyze the prognostic factors associated with a better outcome. We reviewed the records of 86 patients with brainstem gliomas treated between 1996 and 2006. We recorded demographic and clinical variables as well as radiological findings and survival. Patients were divided in two groups regarding overall survival: late progressors (survival >or=12 months) or early progressors (survival<12 months). Of 86 patients with brainstem gliomas, 55.8% were females. The mean age at diagnosis was 14.2 years (range 1 to 52 years). Twenty-four (27.9%) patients were adults. Lesions were located at pons in 75.6% of patients, midbrain in 15.1% and medulla in 9.3%. There was no difference between early and late progressors concerning gender, age at onset, location at pons, presence of necrosis or contrast enhancement observed at MRI or surgical resection. In both univariate and multivariate analysis, only a short duration of symptoms before diagnosis (<3 months) was associated with a worst prognosis (odds ratio 5.59, 95% CI 1.94 to 16, p=0.0014). A short duration of symptoms, which may imply a more aggressive tumor, was associated with a worst prognosis in patients with brainstem gliomas. This information may be useful in the selection of patients for future therapeutic trials.
Revista Arvore, 2006
... Helio Garcia Leite2 , Gilciano Saraiva Nogueira3, João Carlos Chagas Campos2, Fausto Hissashi... more ... Helio Garcia Leite2 , Gilciano Saraiva Nogueira3, João Carlos Chagas Campos2, Fausto Hissashi Takizawa4 e Flávio Lopes Rodrigues5 ... provenientes de uma rede de parcelas permanentes instaladas em povoamentos de teca, no Estado do Mato Grosso, de propriedade da ...
Revista Arvore, 2005
RESUMOOs dados utilizados neste estudo foram obtidos de um experimento sobre desbaste, instalado... more RESUMOOs dados utilizados neste estudo foram obtidos de um experimento sobre desbaste, instalado em povoamentos de eucalipto da Copener Florestal Ltda., na região nordeste do Estado da Bahia. Os dados foram coletados em 48 parcelas permanentes ...
Pediatric Neurology, 2005
Hydromyelia is frequently associated with dissociated sensory loss, scoliosis, and upper limb wea... more Hydromyelia is frequently associated with dissociated sensory loss, scoliosis, and upper limb weakness. This report describes the case of a 9-year old male with an extensive hydromyelia associated with a spinal cord tumor and an oligosymptomatic clinical presentation.
Revista Arvore, 2008
The objective of this study was to adjust and evaluate growth and yield models for young stands o... more The objective of this study was to adjust and evaluate growth and yield models for young stands of Tectona grandis (aged less than 6 years), located in Tangará da Serra, Mato Grosso, Brazil. Thus, 50 permanent plots with at least five successive measurements were used. After the analysis, it was verified that the alternative model is more precise than the Clutter´s model.
Arquivos De Neuro-psiquiatria, 2007
The purpose of this article is to highlight an uncommon combination of supranuclear downward gaze... more The purpose of this article is to highlight an uncommon combination of supranuclear downward gaze paralysis with bilateral eyelid ptosis in a 53-year-old man with a radiation induced midbrain tumor and to discuss the aspects regarding the centers and pathways that mediate supranuclear vertical gaze movements.
Geoderma, 2002
Little is known about the soil distribution on quartzitic uplands of Brazil. The Diamantina Plate... more Little is known about the soil distribution on quartzitic uplands of Brazil. The Diamantina Plateau, where deeply weathered oxisols (latosols) and shallow sandy soils occur side by side, represents part of the higher and oldest planation on the quartzitic uplands of Minas Gerais State. We studied representative soils from the Diamantina Plateau to help understand the pedogenesis and landscape evolution of this part of Minas Gerais. We found evidence of a lithological and tectonic control on the distribution of soils in the landscape. Polygenetic oxisols (Acrustox) occur at the top of the landscape at altitudes of 1300 m or more, resting uncomformably on quartzitic saprocks (Xanthic types) or mafic rocks (Rhodic types). They change downslope to in situ Quartzpsamments and Haplorthods. In the B horizon of the Xanthic Acrustox, quartz grains smaller than 0.3 mm are surrounded by gibbsitic plasma, forming subspherical microaggregates. Microaggregates in the Bw horizon of all upland oxisols display inherited features of intense biological activity regardless of the parent material or texture. The nutrient-poor catena of Xanthic Acrustox -Ustic Quartzpsamments -Oxyaquic Haplorthods represents a sequence of increasing hydromorphic conditions downwards, in which clay minerals are destroyed in low pH and ferrolysis. In the poorly drained soils downslope, low pH and eH induce the movement of reduced Fe 2+ and organic matter (OM)-bound Al and Fe both per descendum and through lateral flow downslope. In the bottom, micromorphological features and the chemistry of organic matter indicated that some Bsh horizons represent buried A horizons subjected to 0016-7061/02/$ -see front matter D 2002 Elsevier Science B.V. All rights reserved. PII: S 0 0 1 6 -7 0 6 1 ( 0 1 ) 0 0 1 5 1 -3 * Corresponding Geoderma 107 post-burial podzolization, corroborating morphological field data. This indicates the pertinence of the study of humic fractions in defining the Bhs (spodic) horizons of Brazilian spodosols. D
Pediatric Neurology, 2008
Meningiomas are central nervous system neoplasms derived from arachnoid cap cells. They are the s... more Meningiomas are central nervous system neoplasms derived from arachnoid cap cells. They are the second most common brain tumors after gliomas, but are rare in children. Furthermore, meningiomas exhibit different behavior in this age group. From 1997From -2007 children with brain meningiomas were treated at the Department of Neurosurgery, Brazilian National Cancer Institute, Rio de Janeiro, Brazil. They represented 2.7% of all brain meningiomas, and 2.1% of all brain tumors, in children followed during this period at our institution. There were 4 boys, and the mean age at diagnosis was 7.3 years. Headaches, seizures, and motor deficits were the most frequent signs at presentation. All patients underwent surgery, and total resection was achieved in 6 of 7 patients. Most lesions were World Health Organization class I meningiomas. There were no deaths, and patients were asymptomatic or demonstrated mild motor or sensory signs at follow-up. In conclusion, meningiomas are rare in the pediatric population. Most of the lesions are low-grade, and the prognosis in this setting is good. Ó
Revista Arvore, 2005
The main objective of this study was to evaluate the estimates generated by a diametric distribut... more The main objective of this study was to evaluate the estimates generated by a diametric distribution model, under the biologic point of view. Another objective was to evaluate the efficiency of the percentage of entries method to determine the technical age for the first and second thinning in eucalypt stands. The qualitative evaluation of the model was carried out through the evaluation of the results obtained by the percentage of entries method, the behavior of the diametric distributions projected for the future, and the behavior of the remaining distributions after some thinning simulations, theoretically, logically and biologically speaking. According to the results it was concluded that the diametric distribution model proposed is biologically correct and consistent. Growth stagnation is stimulated after thinning. It also was concluded that the percentage of entries method is suitable to determine the technical age for the first and second thinning. The model evaluated allows the simulation of various situations, generating consistent estimates and it can be used without restrictions, that is, situations can be simulated with or without the conditions observed in the field.
Revista Arvore, 2009
The objective of this work was to develop and propose a procedure to quantify the volume of trees... more The objective of this work was to develop and propose a procedure to quantify the volume of trees in non-thinned Eucalypt clone plantings. To quantify the volume of the trees, data pertaining to 2036 commercial trees of eucalypt clones owned by CAF, Santa Barbara were used, with their volume equations being adjusted for each group, determined by clone and region. For each tree, a taper model was adjusted. For each tree, a taper model was adjusted, followed by the cut of three trees from new clones without specific volume equation, i.e., a "small" tree, an "average" tree, and "a large" tree, in terms of dap and total height. With the three trees cubed, the taper model was adjusted, considering the three trees. Based on the estimates of the parameters, a measure of similarity was calculated for the tape equation parameters adjusted for the 2,036 commercial clone trees and the equation parameter of the new clone. The commercial clone tree presenting the lesser Euclidean distance value when compared with the new clone was considered the most similar; thus, the volume equation of this commercial clone was used estimated the volume of the new clone trees, with this procedure being termed profile similarity method. This method can be used to estimate the tree volume of clones without specific equations, generating similar estimates when comparing observed and estimated, both for individual trees and total stand.
RESUMO -O presente estudo teve como objetivo avaliar a aplicabilidade do modelo de Clutter em pov... more RESUMO -O presente estudo teve como objetivo avaliar a aplicabilidade do modelo de Clutter em povoamentos desbastados de eucalipto. Esta pesquisa foi desenvolvida com dados da empresa Copener Florestal Ltda., atualmente Bahia Pulp, no Município de Alagoinhas, BA. Os dados utilizados fazem parte de um experimento de desbaste implantado em povoamentos de eucalipto, empregando-se o esquema de blocos casualizados constituídos de quatro tratamentos e repetidos em três locais diferentes, perfazendo 48 parcelas com área média de 2.600 m 2 cada uma. As parcelas foram medidas aos 27, 40, 50, 58, 61 e 76 meses de idade, e aos 58 meses realizouse o desbaste. Para ajuste do modelo, foi empregado o sistema de equações simultâneas, que utiliza informações do povoamento referentes a área basal, volume, idade e índice de local. A partir do ajuste do modelo, elaborouse uma tabela de produção de densidade variável e determinou-se a idade técnica de corte em diferentes capacidades produtivas. Realizaram-se simulações na tabela de produção de regimes de desbaste. Concluiu-se que o modelo de Clutter foi eficiente para predizer a produção atual e futura dos povoamentos desbastados de eucalipto, mostrando-se útil na análise de alternativas de manejo, como a determinação da idade técnica de desbaste, de diferentes índices de local e regimes de desbaste.
Revista Arvore, 2007
This study was carried to evaluate the efficiency of the Bitterlich method in growth and yield mo... more This study was carried to evaluate the efficiency of the Bitterlich method in growth and yield modeling of the even-aged Eucalyptus stands. 25 plots were setup in Eucalyptus grandis cropped under a high bole system in the Central Western Region of Minas Gerais, Brazil. The sampling points were setup in the center of each plot. The data of four annual mesurements were colleted and used to adjust the three model types using the age, the site index and the basal area as independent variables. The growths models were fitted for volume and mass of trees. The efficiency of the Bitterlich method was confirmed for generating the data for growth and yield modeling.
RESUMO: O objetivo deste trabalho foi avaliar e propor alguns refinamentos necessários no Método ... more RESUMO: O objetivo deste trabalho foi avaliar e propor alguns refinamentos necessários no Método dos Ingressos Percentuais (MIP), proposto por Garcia e . Este método, permite determinar a idade técnica do primeiro desbaste, bem como o intervalo de tempo entre os desbastes sucessivos, com base na dinâmica de crescimento e no ingresso de árvores em sucessivas classes de diâmetro. No presente estudo, foram implementados alguns refinamentos nesse método, visando a determinação do momento de realização do primeiro desbaste, quando se conta com apenas três medições anuais de parcelas permanentes. Para esta finalidade utilizou-se um modelo de distribuição diamétrica. Os resultados indicaram, para um povoamento de eucalipto localizado na Região Nordeste do Estado da Bahia, a idade de 69 meses para realização do primeiro desbaste. Pode-se comprovar que o MIP permite reduzir o custo de experimentação sobre desbastes e, ainda, determinar a época de iniciar a aplicação de tratamentos de desbaste, pelo menos um ano antes da idade técnica de desbaste. Isto considerando que para eucalipto, o primeiro desbaste, em geral, ocorre em idades maiores ou igual a 4,5 anos.
Revista Arvore, 2006
The objective of this study was to evaluate, under the biological point of view, a diametric dist... more The objective of this study was to evaluate, under the biological point of view, a diametric distribution model. Another objective was to evaluate the efficiency of the percentage of entries method to determine the technical age for the first and second thinning in teak (Tectona grandis L. f.) stands. This evaluation was carried out by comparing the technical thinning ages obtained by the percentage of entries method, the diametric distributions projected for future ages and the behavior of the remaining distribution, after some thinning simulations, with the expected logical tendency. It was be concluded that the proposed diametric distribution model generates estimates which follow a logical tendency, biologically speaking and that the percentage of entries method is suitable to determine the technical age of the first and second thinning.
RESUMO -O principal objetivo deste estudo foi avaliar as estimativas geradas por um modelo de dis... more RESUMO -O principal objetivo deste estudo foi avaliar as estimativas geradas por um modelo de distribuição diamétrica, do ponto de vista biológico. Também foi objetivo avaliar a eficiência do método dos ingressos porcentuais para determinação da idade técnica do primeiro e do segundo desbaste em plantação de eucalipto. A análise qualitativa do modelo consistiu em avaliar os resultados obtidos pelo método dos ingressos porcentuais, o comportamento das distribuições diamétricas projetadas para idades futuras e o comportamento das distribuições diamétricas remanescentes, após algumas simulações de desbaste, do ponto de vista da teoria, da lógica e do realismo biológico. Pôde-se inferir que o modelo de distribuição diamétrica proposto é biologicamente correto e consistente. A estagnação do crescimento é mais rápida após o desbaste. Concluiu-se, ainda, que o método dos ingressos porcentuais é adequado para determinar a idade técnica do primeiro e do segundo desbaste. O modelo avaliado permite simular diferentes cenários, gerando estimativas consistentes, podendo ser aplicado sem restrições, ou seja, podem ser simulados cenários que contemplem, ou não, as condições observadas no campo.
Revista Arvore, 2006
A model to manage even-aged stands was developed using a modification of the Buckman model. Data ... more A model to manage even-aged stands was developed using a modification of the Buckman model. Data from Eucalyptus urophylla and Eucalyptus cloeziana stands located in the Northern region of Minas Gerais State, Brazil were used in the formulation of the system. The proposed model generated precise and unbiased estimates in non-thinned stands. Keywords: Buckman model, growth and yield, basal area growth.
Revista Arvore, 2005
The objective of the present study was to evaluate the applicability of the Clutter model in thin... more The objective of the present study was to evaluate the applicability of the Clutter model in thinned eucalypt stands. The study was developed with data from the Copener Florestal, Bahia Pulp Enterprise, located in the municipality of Alagoinhas, Bahia, Brazil. Data came from a thinning experiment established in eucalypt stands using a randomized block design with four treatments and three repetitions, each one in a different place, totaling 48 plots with a mean area of 2,600 m2 each. The plots were measured at 27, 40, 50, 58, 61 and 76 months of age, and the thinning was carried out at 58 months. For model adjustment, a system of simultaneous equations was used with stand information such as basal area, volume, age and site index. From the model adjustment, a yield table with variable density was built, and the technical cutting age was determined for various thinning intensities. Simulations were carried out with the yield table. It was concluded that the Clutter model was efficient to predict the present and future yields of the thinned eucalypt stands, showing its usefulness in the analysis of alternative managements, such as the technical cutting age determination for various site indexes and thinning intensities.
Revista Arvore, 2008
The objective of this study was to evaluate the growth tendencies of the stand variables and eval... more The objective of this study was to evaluate the growth tendencies of the stand variables and evaluate alternatives to construct site index curves for teak (Tectona grandis) in stands located in the Tangará da Serra, Mato Grosso state. For this purpose, data from 50 permanent plots with a minimum of four successive measurements were used. The tendencies of growth in height, diameter, basal area and volume were analyzed by means of the regression method, using the Chapman-Richards model. Two methods of construction of site index curves, with different models, were evaluated. The results of the analysis showed that Chapman-Richards model adjusted well to the observed data, describing the growth tendencies of the stand variables. The best alternative for the construction of site index curves was the guide-curve method, using the Chapman-Richards model.
Revista Arvore, 2009
The objective of this work was to develop and propose a procedure for modeling growth and yield o... more The objective of this work was to develop and propose a procedure for modeling growth and yield of nonthinned eucalyptus clone plantations. The data used were obtained from 37 clones distributed in 4325 permanent plots from continuous forest inventories. Each clone contained at least three annual measurements. Five alternatives were studied for prognosis evaluation of clones with more than three permanent plot measurements. For the volumetric stock prognosis, the study showed that the model adjusted by modeling stratum was more efficient than the Clutter model. It could be concluded that growth and yield estimations for clones with less than three measurements can be performed using specific models per stratum or a general model. Such decision must, however, be evaluated by the modeling agent and the user, and a strong interaction between them is necessary.
Journal of The Neurological Sciences, 2009
Brainstem gliomas constitute 10% of brain tumors in children and less than 2% in adults. Since th... more Brainstem gliomas constitute 10% of brain tumors in children and less than 2% in adults. Since therapeutic options are limited and brainstem gliomas are associated with a high morbidity and mortality, we sought to analyze the prognostic factors associated with a better outcome. We reviewed the records of 86 patients with brainstem gliomas treated between 1996 and 2006. We recorded demographic and clinical variables as well as radiological findings and survival. Patients were divided in two groups regarding overall survival: late progressors (survival >or=12 months) or early progressors (survival<12 months). Of 86 patients with brainstem gliomas, 55.8% were females. The mean age at diagnosis was 14.2 years (range 1 to 52 years). Twenty-four (27.9%) patients were adults. Lesions were located at pons in 75.6% of patients, midbrain in 15.1% and medulla in 9.3%. There was no difference between early and late progressors concerning gender, age at onset, location at pons, presence of necrosis or contrast enhancement observed at MRI or surgical resection. In both univariate and multivariate analysis, only a short duration of symptoms before diagnosis (<3 months) was associated with a worst prognosis (odds ratio 5.59, 95% CI 1.94 to 16, p=0.0014). A short duration of symptoms, which may imply a more aggressive tumor, was associated with a worst prognosis in patients with brainstem gliomas. This information may be useful in the selection of patients for future therapeutic trials.
Revista Arvore, 2006
... Helio Garcia Leite2 , Gilciano Saraiva Nogueira3, João Carlos Chagas Campos2, Fausto Hissashi... more ... Helio Garcia Leite2 , Gilciano Saraiva Nogueira3, João Carlos Chagas Campos2, Fausto Hissashi Takizawa4 e Flávio Lopes Rodrigues5 ... provenientes de uma rede de parcelas permanentes instaladas em povoamentos de teca, no Estado do Mato Grosso, de propriedade da ...
Revista Arvore, 2005
RESUMOOs dados utilizados neste estudo foram obtidos de um experimento sobre desbaste, instalado... more RESUMOOs dados utilizados neste estudo foram obtidos de um experimento sobre desbaste, instalado em povoamentos de eucalipto da Copener Florestal Ltda., na região nordeste do Estado da Bahia. Os dados foram coletados em 48 parcelas permanentes ...
Pediatric Neurology, 2005
Hydromyelia is frequently associated with dissociated sensory loss, scoliosis, and upper limb wea... more Hydromyelia is frequently associated with dissociated sensory loss, scoliosis, and upper limb weakness. This report describes the case of a 9-year old male with an extensive hydromyelia associated with a spinal cord tumor and an oligosymptomatic clinical presentation.
Revista Arvore, 2008
The objective of this study was to adjust and evaluate growth and yield models for young stands o... more The objective of this study was to adjust and evaluate growth and yield models for young stands of Tectona grandis (aged less than 6 years), located in Tangará da Serra, Mato Grosso, Brazil. Thus, 50 permanent plots with at least five successive measurements were used. After the analysis, it was verified that the alternative model is more precise than the Clutter´s model.
Arquivos De Neuro-psiquiatria, 2007
The purpose of this article is to highlight an uncommon combination of supranuclear downward gaze... more The purpose of this article is to highlight an uncommon combination of supranuclear downward gaze paralysis with bilateral eyelid ptosis in a 53-year-old man with a radiation induced midbrain tumor and to discuss the aspects regarding the centers and pathways that mediate supranuclear vertical gaze movements.
Geoderma, 2002
Little is known about the soil distribution on quartzitic uplands of Brazil. The Diamantina Plate... more Little is known about the soil distribution on quartzitic uplands of Brazil. The Diamantina Plateau, where deeply weathered oxisols (latosols) and shallow sandy soils occur side by side, represents part of the higher and oldest planation on the quartzitic uplands of Minas Gerais State. We studied representative soils from the Diamantina Plateau to help understand the pedogenesis and landscape evolution of this part of Minas Gerais. We found evidence of a lithological and tectonic control on the distribution of soils in the landscape. Polygenetic oxisols (Acrustox) occur at the top of the landscape at altitudes of 1300 m or more, resting uncomformably on quartzitic saprocks (Xanthic types) or mafic rocks (Rhodic types). They change downslope to in situ Quartzpsamments and Haplorthods. In the B horizon of the Xanthic Acrustox, quartz grains smaller than 0.3 mm are surrounded by gibbsitic plasma, forming subspherical microaggregates. Microaggregates in the Bw horizon of all upland oxisols display inherited features of intense biological activity regardless of the parent material or texture. The nutrient-poor catena of Xanthic Acrustox -Ustic Quartzpsamments -Oxyaquic Haplorthods represents a sequence of increasing hydromorphic conditions downwards, in which clay minerals are destroyed in low pH and ferrolysis. In the poorly drained soils downslope, low pH and eH induce the movement of reduced Fe 2+ and organic matter (OM)-bound Al and Fe both per descendum and through lateral flow downslope. In the bottom, micromorphological features and the chemistry of organic matter indicated that some Bsh horizons represent buried A horizons subjected to 0016-7061/02/$ -see front matter D 2002 Elsevier Science B.V. All rights reserved. PII: S 0 0 1 6 -7 0 6 1 ( 0 1 ) 0 0 1 5 1 -3 * Corresponding Geoderma 107 post-burial podzolization, corroborating morphological field data. This indicates the pertinence of the study of humic fractions in defining the Bhs (spodic) horizons of Brazilian spodosols. D
Pediatric Neurology, 2008
Meningiomas are central nervous system neoplasms derived from arachnoid cap cells. They are the s... more Meningiomas are central nervous system neoplasms derived from arachnoid cap cells. They are the second most common brain tumors after gliomas, but are rare in children. Furthermore, meningiomas exhibit different behavior in this age group. From 1997From -2007 children with brain meningiomas were treated at the Department of Neurosurgery, Brazilian National Cancer Institute, Rio de Janeiro, Brazil. They represented 2.7% of all brain meningiomas, and 2.1% of all brain tumors, in children followed during this period at our institution. There were 4 boys, and the mean age at diagnosis was 7.3 years. Headaches, seizures, and motor deficits were the most frequent signs at presentation. All patients underwent surgery, and total resection was achieved in 6 of 7 patients. Most lesions were World Health Organization class I meningiomas. There were no deaths, and patients were asymptomatic or demonstrated mild motor or sensory signs at follow-up. In conclusion, meningiomas are rare in the pediatric population. Most of the lesions are low-grade, and the prognosis in this setting is good. Ó