Abstract This paper analyses whether the level of development affects a state’s participation in the Dispute Settlement Body (DSB) of the World Trade Organization (WTO). The methodology relies on the Survival Analysis with two different tools. First, the Kaplan-Meier Curve, which indicates the survival time of an individual until the occurrence of an event, was plotted. Thereafter, the Cox Regression was used. This tool associates Survival Analysis to linear regression in order to examine the impacts of some independent variables on the time until the occurrence of the observed events. The results showed that states with higher levels of GDP and HDI, and with a larger population, have more chances of initiating a dispute and being a respondent. Likewise, the American and the European continents are more likely to experience these events. Developed and Developing countries experience the incidence of an event more easily when compared to Least Developed Countries.

Resumo Este artigo analisa se o nível de desenvolvimento de um Estado afeta sua participação no Órgão de Solução de Controvérsias (DSB) da Organização Mundial do Comércio (OMC). A metodologia se baseia na Análise de Sobrevivência com o apoio de duas ferramentas distintas. Primeiro, a Curva Kaplan-Meier, que indica o tempo de sobrevivência de um indivíduo até a ocorrência de um evento, foi traçada. Em seguida, foi utilizada a Regressão Cox. Esta ferramenta associa a Análise de Sobrevivência à regressão linear, a fim de examinar os impactos de algumas variáveis independentes no tempo até a ocorrência dos eventos observados. Os resultados mostraram que Estados com níveis mais altos de PIB e IDH, e com uma população maior, têm mais chances de iniciar uma disputa e de ser um respondente. Da mesma forma, os continentes americano e europeu são os mais propensos a experimentar tais eventos. Os países desenvolvidos e em desenvolvimento experimentam mais facilmente a incidência de um evento quando comparados aos países menos desenvolvidos.

ABSTRACT An alternative to reduce the time taken for height measurements of trees is the use of equations, usually obtained from the fitting of local hypsometric models, which require the fit of equations for each stratum that characterize the forest. Therefore, this work was developed with the objective of evaluating regional hypsometric models adjusted to clonal eucalyptus data. A total of 26 regional fixed-effect (FE) models were evaluated, adopting the following statistical criteria: lack of multicollinearity, significance in the estimation of regression coefficients, compliance with regression assumptions, graphical residual analysis and validation test with independent data adopting the mean squared of the prediction residuals, the sum of squares of the relative prediction residuals, the interquartile range between the 1st and 3rd quartiles and multiple linear correlation. After identifying the FE model that most stood out among the others, it was adjusted in the form of a mixed effect (ME) model, by including the random effect of the sampling unit. In this case, to compare with the respective FE model, in addition to the previous criteria, the following were adopted: Akaike information criterion, Bayesian information criterion and maximum likelihood ratio test. It was concluded that there is an inexorable need to consider the adjustment of models with ME, because it stands out above the respective model with FE.

RESUMO Uma alternativa para reduzir o tempo despendido com a medição da altura das árvores é o emprego de equações, geralmente, geradas a partir do ajuste de modelos hipsométricos locais, os quais exigem o ajuste de equações conforme o número de unidades amostrais e, ou, estratos que caracterizam a população inventariada. Por isso, este trabalho tem o objetivo de avaliar modelos hipsométricos regionais ajustados aos dados de eucalipto clonal. Foram avaliados um total de 26 modelos regionais de efeito fixo (EF), adotando-se os seguintes critérios estatísticos: inexistência de multicolinearidade, significância na estimativa dos coeficientes de regressão, atendimento às pressuposições de regressão, análise gráfica de resíduos e teste validação com dados independentes, adotando-se a média dos quadrados dos resíduos de predição, a soma dos quadrados dos resíduos de predição relativos, o intervalo interquartil entre o 1º e 3º quartis e correlação linear múltipla. Após identificar o modelo de EF que mais se sobressaiu dentre os demais, procedeu-se o seu ajuste na forma de modelo de efeito misto (EM), ao incluir o efeito aleatório da unidade amostral. Neste caso, para comparar com o respectivo modelo de EF, além dos critérios anteriores, adotaram-se: critério de informação de Akaike, critério de informação Bayesiano e teste da razão da máxima verossimilhança. Concluiu-se a necessidade inexorável de considerar o ajuste de modelos com EM, por este se destacar sobremaneira ao respectivo modelo com EF.

Resumen Introducción: Los inventarios son fundamentales para la gestión forestal, pero en la Amazonía la ausencia de estandarización produce pérdida de información, baja precisión y mediciones inconsistentes. Esto impide comparaciones válidas y compromete el uso de información en redes y programas. El tamaño de la unidad de muestreo es de importancia clave en el inventario de bosques nativos, particularmente en lo que respecta a la precisión y los costos. Objetivo: Identificar un tamaño de parcela que proporcione una precisión adecuada para los parámetros dendrométricos en la Amazonía. Métodos: En Cotriguaçu, Mato Grosso, Brasil, probamos cuatro tamaños de parcela con seis repeticiones cada una: 2 500, 5 000, 7 500 y 10 000 m². Medimos diámetro a la altura del pecho, densidad de población, área basal y biomasa. Se aplicaron los índices de Shannon y Jaccard; Funciones Weibull 2P y Gamma para adaptarse a la distribución diametral; y el Criterio de Información de Akaike para el mejor modelo. Resultados: Hubo una relación directamente proporcional entre el área de parcela y la similitud poblacional, pero la diversidad no indicó alteraciones significativas. El tamaño de la parcela no afectó los atributos dendrológicos y la distribución diametral. Las áreas de parcela más grandes dieron lugar a coeficientes de variación más bajos e intervalos de confianza más pequeños. La función Gamma fue el mejor modelo para representar las distribuciones de diferentes tamaños de parcela. Conclusiones: Para bosques similares, recomendamos la parcela de 2 500 m² para evaluar diámetro a la altura del pecho, densidad de población, área basal y biomasa.

Abstract Introduction: Inventories are essential for forest management, but, in the Amazon region, the absence of standardization produces information loss, low accuracy, and inconsistent measurements. This prevents valid comparisons and compromises the use of information in networks and software. Sampling unit size is of key importance in the inventory of native forests, particularly regarding accuracy and costs. Objective: To identify a plot size that provides adequate precision for dendrometric parameters in the Amazon. Methods: In Cotriguaçu, Mato Grosso, Brazil, we tested four plot sizes with six repetitions each: 2 500, 5 000, 7 500, and 10 000 m². We measured diameter at breast height, population density, basal area, and biomass. We applied Shannon and Jaccard indexes; Weibull 2P and Gamma functions to fit the diametric distribution; and the Akaike Information Criterion for the best model. Results: There was a directly proportional relationship between plot area and population similarity, but diversity did not indicate significant alterations. Plot size did not affect dendrometric attributes and diametric distribution. Larger plot areas led to lower coefficients of variation and smaller confidence intervals. The Gamma function was the best model to represent the distributions of different plot sizes. Conclusions: For similar forests, we recommend the 2 500 m² plot to evaluate diameter at breast height, population density, basal area, and biomass.

ABSTRACT The cultivation of Cotton (Gossypium hirsutum) is trending in an upward expansion at Minas Gerais state, Brazil. Due this growth, the breeding program has been demanded for the knowledge about the genetic diversity and correlation between morpho-agronomic traits, to start interesting crosses. The objective of this work was to study the genetic diversity and the correlation network between morpho-agronomic traits of cotton genotypes. Two cotton accessions and five commercial cultivars: FM993, FMT701, FM910, DP604 and DP604BG were evaluated for 16 traits. The results revealed divergence between the genotypes. Unweighted pair-group method arithmetic average (UPGMA) analysis allocated the genotypes in three clusters, with DP604 and Accession 2 being the most divergent. The correlation network helped to visualize the association between traits, presenting a negative correlation between anthracnose with plant height (-0.465), plant vigor (-0.486) and main root length (-0.437). Also, even with some genotypes presenting a higher number of reproductive branches, the correlation for this trait with number of bolls showed a high significant value (0.68). Thus, the genotypes showed wide genetic diversity for the composition of future crosses in cotton breeding programs. The correlation network allowed the visualization of a medium to high correlation pattern for the morpho-agronomic traits.

Resumo Este trabalho teve como objetivo realizar uma análise de regressão do afilamento do fuste de Corymbia citriodora. Para isso, foram cubadas 24 árvores-amostra abatidas disponibilizando os dados necessários ao ajuste de 46 modelos de afilamento de efeito fixo (EF), os quais foram avaliados por meio de uma detalhada análise de regressão baseando-se nos critérios estatísticos: análise gráfica dos resíduos, erro padrão residual, coeficiente de determinação ajustado, delineamento em blocos casualizados no esquema de parcelas subdivididas com posterior aplicação do teste Dunnett, desvio absoluto médio, Raiz quadrada do erro médio, soma dos quadrados dos resíduos relativos, desvio padrão das diferenças, critério de informação de Akaike e soma de quadrados dos resíduos. O modelo EF que mais se sobressaiu, dentre os 46 avaliados, foi ajustado incluindo-se os efeitos aleatórios da classe diamétrica e da razão H/D (CHD), resultando em uma equação de efeito misto (EM). Com isso, as equações obtidas EF e EM foram avaliadas adotando-se, também, os critérios estatísticos referentes à significância da estimativa dos coeficientes de regressão, pressuposições da regressão quanto à normalidade, homoscedasticidade e independência de resíduos e teste da razão da máxima verossimilhança. Concluiu-se por um modelo de melhor desempenho que foi do tipo expoente-forma não linear com inclusão do efeito aleatório CHD, havendo expressiva superioridade tanto na precisão quanto na acurácia da equação EM frente a de EF.

Abstract This work aimed to carry out a regression analysis of the tapering of the stem of Corymbia citriodora. For this, 24 felled sample trees were cubed, providing the necessary data for the adjustment 46 fixed-effect (FE) taper models, which were evaluated by means of a detailed regression analysis based on statistical criteria: graphical analysis of residuals, residual standard error, adjusted coefficient of determination, randomized block design in a split-plot scheme with subsequent application of the Dunnett test, mean absolute deviation, square root of mean error, sum of squares of relative residuals, standard deviation of differences, Akaike's information criterion and sum of squares of residuals. The EF model that most stood out among the 46 evaluated was adjusted by including the random effects of the diametric class and the H/D ratio (CHD), resulting in a mixed-effect equation (ME). Thus, the equations obtained FE and ME were evaluated by also adopting the statistical criteria referring to the significance of the estimation of the regression coefficients, regression assumptions regarding normality, homoscedasticity and independence of residues and maximum likelihood ratio test. It was concluded that a model with the best performance was the nonlinear exponent-form type with the inclusion of the CHD random effect, with expressive superiority in both the precision and the accuracy of the EM equation compared to the FE equation.

Resumo O estudo teve por objetivo avaliar sistema de equações utilizados na construção de diagramas de manejo de densidade. Os dados foram coletados em plantios clonais de teca na região centro-sul do estado de Mato Grosso. A idade de medição do plantio variou de um a oito anos, sendo que os dados foram coletados em parcelas circulares com área de 359 m2 a 616 m2. Das árvores que compuseram as unidades amostrais foram mensurados o diâmetro a altura do peito e a altura total. O volume foi calculado a partir da cubagem de 827 das árvores pelo método de Smalian. Dois sistemas de equações foram utilizados para a realização do estudo e a avaliação da precisão do ajuste foi realizada através das estatísticas: erro padrão residual (RMSE); erro padrão em escala percentual (RMSE%); coeficiente de determinação (R2) representado pelo coeficiente de correlação ao quadrado ( r 2 x y); resíduos em escala percentual (Resíduo (%)); e análise gráfica do perfilhamento dos parâmetros. O sistema de equações que obteve melhor resultado foi o proposto por Dean e Baldwin, com valores de 0,9942 a 0,9994, e de 2,88 a1,84, em relação ao outro sistema que apresentou 0,9558 a 0,9539, e 13,94 a 7,99 para as estatísticas do R2 e RMSE (%), respectivamente. A distribuição dos resíduos do sistema de Dean e Baldwin foram também superiores, corroborando os resultados das análises estatísticas. Os resultados deste trabalho permitem inferir que o sistema de equações proposto por Dean e Baldwin é mais preciso, e, portanto, o indicado na elaboração de diagramas de manejo da densidade populacional em povoamentos clonais de teca.

Abstract The aim objective of study was to evaluate the system of equations used at the construction of density management diagrams. The data was collected at clonal stands of teak in the southern-central region of Mato Grosso state, Brazil. The ages of the stand varied between one and eight years, where the measures were taken in circular plots. The plots had areas varying from 359 to 616 m2. The diameter at breast height and total height were measured from the trees that composed the plots. The volume was calculated in 827 trees by the Smalian’s method. Two systems of equation were used to carry this study out and the evaluation of the fit was made by the statistics: root mean square error (RMSE), percentage of root mean square error (RMSE (%)), coefficient of determination (R2) represented by the squared correlation coefficient ( r 2 x y), residuals in the percentage scale (residual (%)), and graphical analysis of the parameter fittings. The system of equation that obtain the best results was the proposed by Dean and Baldwin, with the statistic R2 between 0,9942 - 0,9994, and RMSE (%) 2,88 - 1,84, regarding the other system that presented 0,9558 - 0,9539 and 13,94 -7,99 to the statistics R2 and RMSE (%), respectively. The distribution of residues from the Dean and Baldwin system were also superior, corroborating the results of the statistical analyzes. The results of this work allow us to infer that the system of equations proposed by Dean and Baldwin is more accurate, and, therefore, the one indicated in the development of population density management diagrams in clonal teak stands.

ABSTRACT Volumetric equations is one of the main tools for quantifying forest stand production, and is the basis for sustainable management of forest plantations. This study aimed to assess the quality of the volumetric estimation of Eucalyptus spp. trees using a mixed-effects model, artificial neural network (ANN) and support-vector machine (SVM). The database was derived from a forest stand located in the municipalities of Bom Jardim de Minas, Lima Duarte and Arantina in Minas Gerais state, Brazil. The volume of 818 trees was accurately estimated using Smalian’s Formula. The Schumacher and Hall model was fitted by fixed-effects regression and by including multilevel random effects. The mixed model was fitted by adopting 14 different structures for the variance and covariance matrix. The best structure was selected based on the Akaike Information Criterion, Maximum Likelihood Ratio Test and Vuong’s Closeness Test. The SVM and ANN training process considered diameter at breast height and total tree height to be the independent variables. The techniques performed satisfactorily in modeling, with homogeneous distributions and low dispersion of residuals. The quality analysis criteria indicated the superior performance of the mixed model with a Huynh-Feldt structure of the variance and covariance matrix, which showed a decrease in mean relative error from 13.52% to 2.80%, whereas machine learning techniques had error values of 6.77% (SVM) and 5.81% (ANN). This study confirms that although fixed-effects models are widely used in the Brazilian forest sector, there are more effective methods for modeling dendrometric variables.

Resumo: O objetivo deste trabalho foi avaliar os efeitos da radiação ultravioleta (UV) e da salinidade da água sobre a nitrificação, a qualidade da água, a carga bacteriana e o crescimento de juvenis de tilápia, em sistemas de aquicultura com recirculação de água (SRAs). O período experimental foi dividido em duas fases. A primeira durou 20 dias e avaliou os efeitos da salinidade (0 e 2 g L-1) e radiação UV (com ou sem) sobre a qualidade da água, durante o período de colonização do substrato por bactérias nitrificantes. Na segunda fase, após estocagem dos juvenis de tilápia, avaliaram-se os efeitos dos mesmos fatores experimentais sobre a qualidade da água, a carga bacteriana e o desempenho dos peixes. Os SRAs empregados foram eficientes na remoção da amônia, independentemente dos tratamentos utilizados. Durante o período experimental, as concentrações de nitrito aumentaram de forma linear, com um aumento mais acentuado após o armazenamento dos peixes até 30 dias do experimento. Não houve efeitos significativos da UV, da salinidade ou da interação de ambas sobre amônia total, nitrito e alcalinidade. Os baixos níveis de salinidade (2 g L-1) e UV não afetaram o processo de nitrificação e o desempenho dos peixes. O uso da UV é eficiente na redução da carga bacteriana dos sistemas de aquicultura com recirculação de água.

Abstract: The objective of this work was to evaluate the effects of ultraviolet radiation (UV) and water salinity on nitrification, water quality, bacterial load, and juvenile tilapia growth in recirculating aquaculture systems (RASs). The experimental period was divided into two phases. The first one lasted 20 days and evaluated the effects of salinity (0 and 2 g L-1) and UV (with or without) on water quality during the period of substrate colonization by nitrifying bacteria. In the second phase, after the storage of juvenile tilapia, the effects of the same experimental factors were evaluated on water quality, bacterial load, and fish growth performance. The RASs employed were efficient for ammonia removal, regardless of the treatments used. During the experimental period, the nitrite concentrations increased linearly, with a more pronounced increase after fish storage until 30 days of the experiment. There were no significant effects of UV, salinity, or the interaction of both on total ammonia, nitrite, and alkalinity. The low levels of salinity (2 g L-1) and UV did not affect the nitrification process and fish performance. The use of UV is efficient to reduce the bacterial load of recirculating aquaculture systems.

ABSTRACT Light Detection and Ranging (LiDAR) derived individual tree crown attributes can potentially serve as a tool for ecology and forest dynamics studies and reduce field inventory costs. In this study, four methods of individual tree detection (ITD), Watershed, Silva et al. (2016), Dalponte and Coomes (2016), and Coomes et al. (2017), were evaluated in a tropical forest under sustainable forest management, situated in the State of Rondônia, Brazil. An automated tree matching procedure was developed in order to minimize the error when matching individual tree count from LiDAR and field data. In order to compare the four methods, results were expressed in recall, precision, and F score. Silva et al. (2016) outperformed the other methods, detecting 48% of trees with 46% of precision. Omission of trees was the leading source of error, caused primarily by overlapped trees in lower vegetation. However, errors of over-segmentation were relevant, caused by large and heterogeneous crowns that had multiple detections. Current canopy height model-based methods are ineffective to tropical forests, due to its complexity, which present a challenge for ITD algorithms. We believe that future studies that use complete 3D information from the point cloud, and multi-layer approaches should help to improve the accuracy of individual tree detection.

ABSTRACT Tectona grandis (teak) plantations have gained increased interest in recent decades in Brazil, bringing about the need for acquiring information regarding the growth and productive potential. The present work aims to evaluate the growth of dominant height in teak at various locations in the state of Mato Grosso, midwest Brazil. For this purpose, six stands were evaluated in distinct municipalities and the database was obtained from trunk analysis. Subsequently, the dominant height growth was estimated using nonlinear regression models, whose performance was evaluated, based on goodness-of-fit statistics and graphical analysis of residues. Tests for model identity were used to analyze the differences in growth rates between sites (municipalities). The studied teak stands displayed different dominant height growth trends, with differences reaching up to 37%.

ABSTRACT The objective of this study was to assess the prediction of partial volumes with nonlinear mixed modeling for Pinus taeda. The volume of 558 trees was measured. The four-parameter logistic model was used in its modified form for the nonlinear mixed approach and, for comparison, the 5th degree polynomial was used. In the mixed modeling, the random effects diameter, age and place were inserted. The statistical criteria used to assess the quality of the adjustment were the Akaike Information Criterion (AIC), the Bayesian Information Criterion (BIC), standard error of the estimate (Syx) and residual graphical analysis. Among the random effects analyzed, age obtained the best adjustment. However, to predict partial volumes, it was noticed that, regardless of the analyzed portion of the trunk, the 5th degree polynomial had the best estimates, with a mean standard error of 20.1% of the estimate compared to 51.8% of the logistic.

Resumo Este artigo apresenta um estudo comparativo da aplicação de um experimento de física de eletrodinâmica básica, quando realizado num Laboratório Tradicional (LT) e num Laboratório Remoto (LR) via internet. Para analisar e validar os resultados, realizamos uma análise estatística do ganho de aprendizagem, tamanho do efeito da metodologia aplicada, confiabilidade do questionário de pré-teste e pós-teste e análise da variância das respostas dos estudantes. A pesquisa foi realizada com uma amostra de 304 alunos de cinco escolas distintas de ensino médio da cidade de Guaratinguetá do estado de São Paulo – Brasil. Para manter a fidelidade do estudo, a construção do experimento de eletrodinâmica foi a mesma, tanto no formato tradicional quanto no formato remoto. Os alunos de cada uma das cinco escolas, foram separados em turmas A e B e submetidos a um pré-teste contendo 10 questões para verificação do conhecimento inicial sobre o tema. Em sequência, os alunos da turma A tiveram acesso ao LT enquanto os da turma B ao LR para realização do experimento. Ao final do processo, foi aplicado um pós-teste contendo 10 questões para verificação do conhecimento após o estudo experimental. A estatística dos resultados mostrou resultados equivalentes entre as turmas A e B no processo de aprendizagem em todas as escolas analisadas.

Abstract This paper presents a comparative study of simple electrodynamics experiment, when performed in the Traditional Laboratory (TL) and in the Remote Laboratory (RL) via the internet. Analyze and validate the results, performing an statistical analysis of the learning gain, size of the applied methodology, reliability of the pre-test and post-test questionnaire and analysis of the variance of the students' responses. The research was applied with 304 students from five high schools in the city of Guaratinguetá in the state of São Paulo - Brazil. In order to maintain the fidelity of the study, the construction of the electrodynamic remote experiment was similar the traditional format. Students from each of the five schools were separated into classes A and B prepared a pre-test containing 10 questions for the selection of initial knowledge on the topic. In sequence, students in class A had access to the TL while those in class B to the RL to perform the experiment. At the end of the process, it was submitted to a test containing 10 questions to verify the knowledge after the experimental study. Final results had show equivalente learning between classes A and B in all schools analyzed.

RESUMO O objetivo deste trabalho foi determinar a rotação econômica de plantações de eucalipto em três diferentes sítios produtivos sob condições de risco. Os dados utilizados na realização do estudo são provenientes de plantios equiâneos e monoclonais do híbrido Eucalyptus urograndis, e cedidos pela empresa Fibria Celulose. Além dos dados de produção das áreas foram também cedidas as informações de fluxo de caixa. Para a análise de risco utilizou-se o método de Monte Carlo, tendo como resultado da simulação o Valor Presente Líquido para séries Infinitas e, como variáveis de entrada e/ou fontes de incertezas, as distribuições de probabilidade referentes ao preço da terra e da madeira, o custo de colheita e transporte, a taxa de juros e além da produção de madeira. A simulação constituiu na realização 10.000 de iterações, em que foram obtidas as informações necessárias ao prosseguimento das análises. Concluiu-se que a rotação ótima para corte foi de 6, 8 e 11 anos nos sítios bom (I), médio (II) e ruim (III), respectivamente, sendo, portanto, condizente com as leis biológicas de crescimento. Conclui-se ainda que sob as mesmas condições de manejo, sítios mais produtivos geram maior retorno econômico e por consequência menor risco em cenários econômicos desfavoráveis.

ABSTRACT The objective of this study was to determine the economic cycle rotation of eucalyptus plantations in three productivity sites over hazardous conditions. The data used on this study, released by the company Fibria Celulose. Besides the timber production data, it was also given the company cash flow. It was from an even- aged stand and a monoclonal stand both of Eucalyptus urograndis. For the risk analysis, the study used Monte Carlo method, having as a result of the simulation the Net Present Value for Infinite Series, using as an input variable and/or source of uncertainty, the probability distributions of the land and wood prices, the costs of harvesting and transportation activities, the interest rate and also the timber production. The simulation consisted in carrying out 10,000 interactions, where it was obtained the necessary information for the development of the next analysis. As a conclusion the optimal rotation for cutting was 6, 8 and 11 years on the good sites (I), regular sites(II) and poor sites(III) respectively, being consistent with the biological laws of growth. Another conclusion is that even under the same management conditions, more productive sites generate greater economic returns and therefore lower risk in adverse economic scenarios.

ABSTRACT: The main purpose of this study was to assess nonlinear models generated by integrating the basal area growth rate to estimate the growth and yield of forest stands. The database was collected from permanent sample units, in Paraopeba county, in the state of Minas Gerais, Brazil. The stands were represented by Eucalyptus camaldulensis × Eucalyptus urophylla hybrid trees, with 3 × 3 meters of spacing. The data were divided into two groups: fitting and validating databases. Two nonlinear models (Strategy A and Strategy B) were developed using differential equations to estimate the basal area growth and yield of the sample units. The logistic model was fitted to estimate the volumetric yield as a function of age, site index and basal area. The efficiency of the systems generated by logistic model and models obtained by differential equations (Strategy A and Strategy B) was also compared to the efficiency of the system estimated by the Clutter model (Strategy C). The projection models used to estimate basal area obtained by differential equations were compatible with forest growth and yield, and the logistic model with covariates was compatible with volumetric growth and yield. Strategy A and Strategy B generated different thinning and harvesting options for different site indices, which is biologically consistent.

ABSTRACT Objective: The present study sought to estimate the prevalence of depression in the elderly at a Basic Health Unit (BHU) in order to identify cases of depression in the elderly patients that undergo follow-up treatment at this BHU and the use of drugs for the treatment of such disorders. Methodology: This was an exploratory and descriptive research with a quantitative approach, conducted with 241 elderly patients registered in the Family Healthcare Service (FHS) in the city of Teresina, PI, Brazil. Survey data were collected through the Geriatric Depression Scale (GDS) and analyzed using the SPSS software (version 11.0). The study was approved by the Research Ethics Committee at the UNINOVAFAPI University Center. Results: A high percentage of cases of depression in the elderly were identified. A higher prevalence was observed in females, of above 70 years of age, as well as in the widow/widower, retired, and no formal education categories. Regarding the severity of the situation, 26.6% were characterized as showing signs of mild depression, while 2.5% showed signs of probable severe depression. As for medication, most elderly people with severe depression do not use antidepressants, whereas 10.9% of the cases of elderly patients with mild depression reported only using anxiolytics. This study shows a significant rate of depression among the elderly. The analyzed variables demonstrate the need for more accurate research in the medical care provided to elderly patients in order to detect possible risk factors for depression. Conclusion: The recognition of depression in the elderly appears to be more difficult than at earlier ages, since healthcare professionals tend to attribute the onset of signs and symptoms to aging.

RESUMEN El objetivo de este estudio fue estimar la prevalencia de la depresión en adultos mayores de una Unidad Básica de Salud, identificar los casos de depresión y el uso de medicación para tratar los trastornos. Se trata de una investigación exploratorio descriptiva de enfoque cuantitativo realizada con 241 adultos mayores inscritos en la ESF de la ciudad de Teresina, PI. Los datos de la encuesta fueron recogidos a través de la Escala de Depresión Geriátrica y analizados por medio del software SPSS (versión 11.0). El estudio fue aprobado por el CEI del Centro Académico UNINOVAFAPI. Fue encontrado un alto porcentaje de casos de depresión entre dichos adultos, con mayor prevalencia en el sexo femenino, edad superior a los 70 años, viudos, jubilados y sin educación. En cuanto a su gravedad, un 26,6% tenía indicios de depresión ligera y un 2,5% probable depresión severa. Con respecto al uso de medicación, la mayoría de aquéllos con depresión severa no tomaba antidepresivos y un 10,9% de los casos de indicios de depresión ligera tomaba sólo ansiolíticos. El estudio señala un alto índice de depresión entre los adultos mayores. Las variables analizadas demuestran la pertinencia de un estudio más a fondo en la consulta de los adultos mayores con miras a detectar posibles factores de riesgo para la depresión. Reconocer la depresión en la tercera edad parece ser más difícil que en otras edades porque los profesionales atribuyen la aparición de sus señales y síntomas al envejecimiento.

RESUMO Objetivo: estimar a prevalência de depressão em idosos em uma Unidade Básica de Saúde, identificar os quadros de depressão na população de idosos que realiza acompanhamento nesta UBS e o uso de medicação para tratamento dos transtornos. Metodologia: pesquisa exploratória e descritiva com abordagem quantitativa, realizada com 241 idosos cadastrados na ESF do município de Teresina - PI. Os dados da pesquisa foram coletados com base na Escala de Depressão Geriátrica e analisados no software SPSS (versão 11.0). A pesquisa foi aprovada pelo CEP do Centro Universitário UNINOVAFAPI. Resultados: encontrou-se alta percentagem de casos de depressão nos idosos. Houve mais prevalência no sexo feminino, faixa etária maior de 70 anos, viúvos, aposentados e sem escolaridade. Em relação ao quadro de gravidade, 26,6% foram caracterizados como tendo indícios de depressão leve e 2,5% como provável depressão grave. Quanto ao uso de medicação, a maioria dos idosos com depressão grave não faz uso de antidepressivos e 10,9% dos casos de indícios de quadro depressivo leve fazem apenas uso de ansiolíticos. O estudo comprova significativo índice de depressão entre os idosos. As variáveis analisadas demonstram a relevância de uma investigação mais acurada na consulta do idoso, para detectar prováveis fatores de risco para a depressão. Conclusão: o reconhecimento da depressão no idoso parece ser mais difícil do que em idades anteriores, uma vez que os profissionais de saúde atribuem o aparecimento de sinais e sintomas ao envelhecimento.