Evaluation and monitoring of the water quality of an Argentinian urban river applying multivariate statistics.

In this work, we present the water quality assessment of an urban river, the San Luis River, located in San Luis Province, Argentina. The San Luis River flows through two developing cities; hence, urban anthropic activities affect its water quality. The river was sampled spatially and temporally, evaluating ten physicochemical variables on each water sample. These data were used to calculate a Simplified Index of Water Quality in order to estimate river water quality and infer possible contamination sources. Data were statistically analyzed with the opensource software R, 4.1.0 version. Principal component analysis, cluster analysis, correlation matrices, and heatmap analysis were performed. Results indicated that water quality decreases in areas where anthropogenic activities take place. Robust inferential statistical analysis was performed, employing an alternative of multivariate analysis of variance (MANOVA), MANOVA.wide function. The most statistically relevant physicochemical variables associated with water quality decrease were used to develop a multiple linear regression model to estimate organic matter, reducing the variables necessary for continuous monitoring of the river and, hence, reducing costs. Given the limited information available in the region about the characteristics and recovery of this specific river category, the model developed is of vital importance since it can quickly detect anthropic alterations and contribute to the environmental management of the rivers. This model was also used to estimate organic matter at sites located in other similar rivers, obtaining satisfactory results.

Exploring the effect of the structural model of active aging on the self-assessment of quality of life among older people: A cross-sectional and analytical study

ABSTRACT BACKGROUND: Although studies have examined the relationship between variables associated with active aging and quality of life (QoL), no studies have been identified to have investigated the effect of a structural model of active aging on QoL in a representative sample of older people in the community. OBJECTIVE: To measure the domains and facets of QoL in older people and identify the effect of the structural model of active aging on the self-assessment of QoL. DESIGN AND SETTING: This cross-sectional analytical study included 957 older people living in urban areas. Data were collected from households using validated instruments between March and June 2018. Descriptive, confirmatory factor, and structural equation modeling analyses were performed. RESULTS: Most older people self-rated their QoL as good (58.7%), and the highest mean scores were for the social relationships domain (70.12 ± 15.4) and the death and dying facet (75.43 ± 26.7). In contrast, the lowest mean scores were for the physical domains (64.41 ± 17.1) and social participation (67.20 ± 16.2) facets. It was found that active aging explained 50% of the variation in self-assessed QoL and directly and positively affected this outcome (λ = 0.70; P < 0.001). CONCLUSION: Active aging had a direct and positive effect on the self-assessment of QoL, indicating that the more individuals actively aged, the better the self-assessment of QoL.

Modelos de variables latentes en patrones de alimentación y actividad física en niños/adolescentes: una revisión sistemática / Models of latent variables used for eating and physical activity patterns in children/ adolescents: a systematic review

Introducción. Debido a la poca evidencia sobre el modelamiento de los patrones de alimentación y actividad física (AF), basado en variables latentes, el presente estudio de revisión pretende describir las técnicas estadísticas aplicadas para modelar estos patrones en niños y adolescentes y valorar su calidad metodológica. Materiales y métodos. La búsqueda se realizó en bases de datos electrónicas (Science Direct, PubMed, SCOPUS, Web of science y Cochrane) con las palabras "diet", 'physical activity', children y 'latent variable'. Se incluyeron artículos que utilizaron modelos estadísticos basados en variables latentes para analizar patrones de alimentación y AF en niños y adolescentes sanos, publicados entre 2014­2019, en inglés o español. Resultados. Entre los 27 artículos seleccionados, el Modelo de Ecuaciones Estructurales (MEE) fue el más utilizado (77,78%); seguido del Modelo de Perfil Latente (7,41%), mientras, el restante, 14,81% aplican el Modelo del Factor Común, Modelo Ecológico y el Modelo de Regresión Logística Multinivel. El MEE fue aplicado a 12 de los 16 artículos con enfoque de AF, y en 7 de los 9 artículos con enfoque de Alimentación. El 48,15% de los estudios sí justificaba el uso del modelo, y el 37,04% poseen una calidad "Excelente" (cumplen el 85% o más de los ítems de STROBE). Conclusiones. El MEE fue el más utilizado para abstraer los patrones de AF y alimentación en niños y adolescentes, sin embargo, solo la mitad de los artículos justifica su pertinencia. Las guías de reporte de estudios deberían evaluar la calidad metodológica de los modelos estadísticos aplicados(AU)

Introduction. Due to the limited evidence on the modeling of eating and physical activity (PA) patterns based on latent variables, the present review study aims to describe the statistical techniques applied to model these patterns in children and adolescents and to assess their methodological quality. Materials and methods. The search was performed in electronic databases (Science Direct, PubMed, SCOPUS, Web of science and Cochrane) with the words 'diet', 'physical activity', children and 'latent variable'. We included articles that used statistical models based on latent variables to analyze diet and PA patterns in healthy children and adolescents, published between 2014-2019, in English or Spanish. Results. Among the 27 selected articles, the Structural Equation Model (SEM) was the most used (77.78%); followed by the Latent Profile Model (7.41%), while, the remaining 14.81% applied the Common Factor Model, Ecological Model and Multilevel Logistic Regression Model. The SEM was applied to 12 of the 16 articles with PA approach, and in 7 of the 9 articles with eating approach. The 48.15% of studies did justify the use of the model, and 37.04% were classified as "Excellent" quality (meet 85% or more of the STROBE items). Conclusions. The SEM was the most commonly used to model the PA and eating patterns in children and adolescents, however, only half of the articles justify their relevance. Study reporting guidelines should evaluate the methodological quality of the statistical models applied(AU)

Global Distribution of Aedes aegypti and Aedes albopictus in a Climate Change Scenario of Regional Rivalry.

Arboviral mosquito vectors are key targets for the surveillance and control of vector-borne diseases worldwide. In recent years, changes to the global distributions of these species have been a major research focus, aimed at predicting outbreaks of arboviral diseases. In this study, we analyzed a global scenario of climate change under regional rivalry to predict changes to these species' distributions over the next century. Using occurrence data from VectorMap and environmental variables (temperature and precipitation) from WorldClim v. 2.1, we first built fundamental niche models for both species with the boosted regression tree modelling approach. A scenario of climate change on their fundamental niche was then analyzed. The shared socioeconomic pathway scenario 3 (regional rivalry) and the global climate model Geophysical Fluid Dynamics Laboratory Earth System Model v. 4.1 (GFDL-ESM4.1; gfdl.noaa.gov) were utilized for all analyses, in the following time periods: 2021-2040, 2041-2060, 2061-2080, and 2081-2100. Outcomes from these analyses showed that future climate change will affect Ae. aegypti and Ae. albopictus distributions in different ways across the globe. The Northern Hemisphere will have extended Ae. aegypti and Ae. albopictus distributions in future climate change scenarios, whereas the Southern Hemisphere will have the opposite outcomes. Europe will become more suitable for both species and their related vector-borne diseases. Loss of suitability in the Brazilian Amazon region further indicated that this tropical rainforest biome will have lower levels of precipitation to support these species in the future. Our models provide possible future scenarios to help identify locations for resource allocation and surveillance efforts before a significant threat to human health emerges.

Factors Associated with a Prolonged Hospital Length of Stay in a Population of Patients with Exacerbation of Chronic Obstructive Pulmonary Disease in a Reference Hospital in Northeastern Colombia / Factores asociados a estancia prolongada en una población de pacientes con exacerbación de Enfermedad Pulmonar Obstructiva Crónica en un hospital de referencia del Nororiente Colombiano

A prolonged hospital length of stay during an episode of exacerbation of chronic obstructive pulmonary disease is a condition that increases the risk of suffering associated medical complications. Objective: The objective of this study was to determine the factors associated with a prolonged hospital length of stay in exacerbations of chronic obstructive pulmonary disease through a prediction model. Materials and Methods: In a cross-sectional study we gathered the data of the medical records of a hospital located in the Eastern region of Colombia, between years 2012 and 2014. We carried out a descriptive, bivariate and multivariate analysis. Results: A total of 212 patients were included in this study. 61.32% showed a prolonged hospital length of stay. We found a significant statistical association between the prolonged hospital stay and the independent variables of the bivariate analysis: dyspnea (OR [Odds Ratio]: 2.87 p = 0.04), fever (OR: 2; p = 0.02), inpatient oxygen (OR: 2.34, p = 0.003), inpatient anticholinergics (OR: 2.91, p = 0.002), inpatient antibiotic (OR: 2.25, p= 0.004), segs (OR: 1.02, p= 0.01) and lymphocytes (OR: 0.95, p = 0.003). The predictive model had a p value of 0.4950 in the analysis of goodness (Pearson Test) and a p value of 0.2689 in the goodness of fit test (Hosmer-Lemeshow Test), indicating an adequate fit. Also, the model showed an area under the curve of 0.6588. Conclusions: Our prediction model included the following variables: age, anticholinergics and segs, for their significant association. It has an adequate fit and a good pattern of prediction.

Determination of factors affecting dairy cattle: a case study of Ardahan province using data mining algorithms

This study was conducted to compare predictive performances of different data-mining algorithms for determining factors influencing the average daily milk yield at dairy cattle enterprises of Ardahan province, located in the Eastern Anatolia region of Turkey. The algorithms employed in the present study were Classification and Regression Tree (CART), Chi-Square Automatic Interaction Detector (CHAID), Exhaustive Chi-Square Automatic Interaction Detector (Exhaustive CHAID), Multivariate Adaptive Regression Splines (MARS), and Multilayer Perceptron (MLP). The MARS algorithm outperformed the other algorithms in the study. Visual results of CART revealed that the culture-breed cows with a lactation length greater than 237.500 days had the highest milk yield (10.64 kg/day). Culture-breed cows calving earlier than the 4th month gave the highest yield of approximately 10 kg/day in the regression tree of CHAID. The Exhaustive CHAID results were almost the same as the structure of the CHAID. The use of MARS may provide an opportunity to detect factors affecting milk production (breed, feed supply, type of milking, mastitis control, cow year group, and lactation length) and their interactions. Moreover, the MARS algorithm may be useful in making an accurate decision about increasing milk yield per cow.(AU)

Modelagem estatística: perguntas que você sempre quis fazer, mas nunca teve coragem / Statistical modeling: questions you have always wanted to ask but never had the courage to

Dando continuidade aos artigos da série "Perguntas que você sempre quis fazer, mas nunca teve coragem", que tem como objetivo responder e sugerir referências para o melhor entendimento das principais dúvidas dos pesquisadores do Hospital de Clínicas de Porto Alegre sobre estatística, este quarto artigo se propõe a responder às principais dúvidas levantadas sobre modelagem estatística. São discutidas questões referentes à classificação de variáveis em independentes e dependentes, diferenças entre correlação, associação e regressão, os principais tipos de regressão e quais etapas são necessárias na construção de modelos. Os conceitos são abordados numa linguagem acessível ao público leigo e diversas referências são sugeridas para os curiosos em relação ao tema. (AU)

Continuing the series of articles "Questions you have always wanted to ask but never had the courage to," which aims to answer the most common questions of researchers at Hospital de Clínicas de Porto Alegre regarding statistics and to suggest references for a better understanding, this forth article addresses the topic of statistical modeling. Questions about classification of variables as dependent or independent, differences between correlation, association and regression, types of regression and steps for statistical modeling are discussed. The concepts are explained in plain language for lay readers and several references are suggested for those curious about the topic. (AU)

Social determinants of tuberculosis via a zero-inflated model in small areas of a city in Southeastern Brazil

Abstract INTRODUCTION: This study aimed to analyze social factors involved in the spatial distribution and under-reporting of tuberculosis (TB) in the city of Vitória, Espírito Santo State, Brazil. METHODS: This was an ecological study of the reported cases of TB between 2009 and 2011, according to census tracts. The outcome was TB incidence for the study period and the variables of exposure were proportions of literacy, inhabitants with an income of up to half the minimum monthly wage (MMW), and inhabitants associated with sewer mains or with access to safe drinking water. We used a zero-inflated process, zero-inflated negative binomial regression (ZINB), and selected an explanatory model based on the Akaike Information Criterion (AIC). RESULTS: A total of 588 cases of tuberculosis were reported in Vitória during the study period, distributed among 223 census tracts (38.6%), with 354 (61.4%) tracts presenting zero cases. In the ZINB model, the mean value of p i was 0.93, indicating that there is a 93% chance that an observed false zero could be due to sub-notification. CONCLUSIONS: It is important to prioritize areas exhibiting determinants that influence the occurrence of TB in the municipality of Vitória. The zero-inflated model can be useful to the public health sector since it identifies the percentage of false zeros, generating an estimate of the real epidemiological condition of TB in Vitória.

Hypothesized diprotomeric enzyme complex supported by stochastic modelling of palytoxin-induced Na/K pump channels.

The sodium-potassium pump (Na+/K+ pump) is crucial for cell physiology. Despite great advances in the understanding of this ionic pumping system, its mechanism is not completely understood. We propose the use of a statistical model checker to investigate palytoxin (PTX)-induced Na+/K+ pump channels. We modelled a system of reactions representing transitions between the conformational substates of the channel with parameters, concentrations of the substates and reaction rates extracted from simulations reported in the literature, based on electrophysiological recordings in a whole-cell configuration. The model was implemented using the UPPAAL-SMC platform. Comparing simulations and probabilistic queries from stochastic system semantics with experimental data, it was possible to propose additional reactions to reproduce the single-channel dynamic. The probabilistic analyses and simulations suggest that the PTX-induced Na+/K+ pump channel functions as a diprotomeric complex in which protein-protein interactions increase the affinity of the Na+/K+ pump for PTX.

Fast projection/backprojection and incremental methods applied to synchrotron light tomographic reconstruction.

Iterative methods for tomographic image reconstruction have the computational cost of each iteration dominated by the computation of the (back)projection operator, which take roughly O(N3) floating point operations (flops) for N × N pixels images. Furthermore, classical iterative algorithms may take too many iterations in order to achieve acceptable images, thereby making the use of these techniques unpractical for high-resolution images. Techniques have been developed in the literature in order to reduce the computational cost of the (back)projection operator to O(N2logN) flops. Also, incremental algorithms have been devised that reduce by an order of magnitude the number of iterations required to achieve acceptable images. The present paper introduces an incremental algorithm with a cost of O(N2logN) flops per iteration and applies it to the reconstruction of very large tomographic images obtained from synchrotron light illuminated data.

Analysis of growth curves in different lineages of Caipira broiler type / Análise de curvas de crescimento em diferentes linhagens de frangos de corte tipo Caipira

The objective of this work was to identify, by means of different statistical criteria the idealnonlinear regression model to describe the growth curve of three lineages of caipira broiler for meatproduction. A total of 90 birds were used, being 30 birds from each of the following lineages: Pescoço Pelado,Carijó and Pesadão Vermelho. The individual body weight of broilers (1, 7, 14, 21,28, 35, 42, 49, 56, 63, 70,77, 84 and 91 days of age) was collected weekly for determination of growth curves by means of Modelsvon Bertalanffy, Gompertz, Logistic, Richards and Brody. The parameters of Brody model did notconverge to the weight of strains. The model that better adjusted to the data was Logistic.

Objetivou-se com este trabalho identificar, por meio de diferentes critérios estatísticos, omodelo de regressão não linear mais adequado para descrever a curva de crescimento de três linhagens defrangos caipira para produção de carne. Utilizaram-se 90 aves caipiras, sendo 30 aves de cada uma dasseguintes linhagens: Pescoço Pelado, Carijó e Pesadão Vermelho. Foi coletado semanalmente o pesocorporal individual dos frangos (1, 7, 14, 21,28, 35, 42, 49, 56, 63, 70, 77, 84 e 91 dias de idade) paradeterminação das curvas de crescimento por meio dos modelos Von Bertalanffy, Gompertz, Logístico,Richards e Brody. Os parâmetros do modelo Brody não convergiram, sendo então não adequado paradescrever o peso dessas linhagens. O modelo que melhor se ajustou aos dados foi o Logístico.

Analysis of growth curves in different lineages of Caipira broiler type / Análise de curvas de crescimento em diferentes linhagens de frangos de corte tipo Caipira

The objective of this work was to identify, by means of different statistical criteria the idealnonlinear regression model to describe the growth curve of three lineages of caipira broiler for meatproduction. A total of 90 birds were used, being 30 birds from each of the following lineages: Pescoço Pelado,Carijó and Pesadão Vermelho. The individual body weight of broilers (1, 7, 14, 21,28, 35, 42, 49, 56, 63, 70,77, 84 and 91 days of age) was collected weekly for determination of growth curves by means of Modelsvon Bertalanffy, Gompertz, Logistic, Richards and Brody. The parameters of Brody model did notconverge to the weight of strains. The model that better adjusted to the data was Logistic.(AU)

Objetivou-se com este trabalho identificar, por meio de diferentes critérios estatísticos, omodelo de regressão não linear mais adequado para descrever a curva de crescimento de três linhagens defrangos caipira para produção de carne. Utilizaram-se 90 aves caipiras, sendo 30 aves de cada uma dasseguintes linhagens: Pescoço Pelado, Carijó e Pesadão Vermelho. Foi coletado semanalmente o pesocorporal individual dos frangos (1, 7, 14, 21,28, 35, 42, 49, 56, 63, 70, 77, 84 e 91 dias de idade) paradeterminação das curvas de crescimento por meio dos modelos Von Bertalanffy, Gompertz, Logístico,Richards e Brody. Os parâmetros do modelo Brody não convergiram, sendo então não adequado paradescrever o peso dessas linhagens. O modelo que melhor se ajustou aos dados foi o Logístico.(AU)

Modeling Optimal Cutoffs for the Brazilian Household Food Insecurity Measurement Scale in a Nationwide Representative Sample.

Background: This is the second part of a model-based approach to examine the suitability of the current cutoffs applied to the raw score of the Brazilian Household Food Insecurity Measurement Scale [Escala Brasileira de Insegurança Alimentar (EBIA)]. The approach allows identification of homogeneous groups who correspond to severity levels of food insecurity (FI) and, by extension, discriminant cutoffs able to accurately distinguish these groups.Objective: This study aims to examine whether the model-based approach for identifying optimal cutoffs first implemented in a local sample is replicated in a countrywide representative sample.Methods: Data were derived from the Brazilian National Household Sample Survey of 2013 (n = 116,543 households). Latent class factor analysis (LCFA) models from 2 to 5 classes were applied to the scale's items to identify the number of underlying FI latent classes. Next, identification of optimal cutoffs on the overall raw score was ascertained from these identified classes. Analyses were conducted in the aggregate data and by macroregions. Finally, model-based classifications (latent classes and groupings identified thereafter) were contrasted to the traditionally used classification.Results: LCFA identified 4 homogeneous groups with a very high degree of class separation (entropy = 0.934-0.975). The following cutoffs were identified in the aggregate data: between 1 and 2 (1/2), 5 and 6 (5/6), and 10 and 11 (10/11) in households with children and/or adolescents <18 y of age (score range: 0-14), and 1/2, between 4 and 5 (4/5), and between 6 and 7 (6/7) in adult-only households (range: 0-8). With minor variations, the same cutoffs were also identified in the macroregions. Although our findings confirm, in general, the classification currently used, the limit of 1/2 (compared with 0/1) for separating the milder from the baseline category emerged consistently in all analyses.Conclusions: Nationwide findings corroborate previous local evidence that households with an overall score of 1 are more akin to those scoring negative on all items. These results may contribute to guide experts' and policymakers' decisions on the most appropriate EBIA cutoffs.

A Model-Based Approach to Identify Classes and Respective Cutoffs of the Brazilian Household Food Insecurity Measurement Scale.

BACKGROUND: The Brazilian Household Food Insecurity Measurement Scale (EBIA) is the main tool for assessing household food insecurity (FI) in Brazil, assisting in monitoring and improving national public policies to promote food security. Based on the sum of item scores, households have been classified into 4 levels of FI, with the use of cutoffs arising from expert discussions informed by psychometric analyses and policy considerations. OBJECTIVES: This study aimed to identify homogeneous latent groups corresponding to levels of FI, examine whether such subgroups could be defined from discriminant cutoffs applied to the overall EBIA raw score, and compare these cutoffs against those currently used. METHODS: A cross-sectional population-based study with a representative sample of 1105 households from a low-income metropolitan area of Rio de Janeiro was conducted. Latent class factor analysis (LCFA) models were applied to the answers to EBIA's items to identify homogeneous groups, obtaining the number of latent classes for FI measured by the scale. Based on this and a thorough classification agreement evaluation, optimal cutoffs for discriminating between different severity levels of FI were ascertained. Model-based grouping and the official EBIA classification cutoffs were also contrasted. RESULTS: LCFA identified 4 homogeneous groups with a very high degree of class separation (entropy = 0.906), endorsing the classification of EBIA as a 4-level measure of FI. Two sets of cutoffs were identified to separate such groups according to household type: 1/2, 5/6, and 10/11 in households with children and adolescents (score range: 0-14); and 1/2, 3/4, and 5/6 in adult-only households (score range: 0-7). CONCLUSION: Although roughly classifying EBIA as in previous studies, the current approach suggests that, in terms of raw score, households endorsing only one item of the scale would be better classified by being placed in the same stratum as those remaining negative on all items.

Non-destructive linear model for leaf area estimation in Vernonia ferruginea Less / Modelo linear não-destrutivo para estimativa de área foliar de Vernonia ferruginea Less

Leaf area estimation is an important biometrical trait for evaluating leaf development and plant growth in field and pot experiments. We developed a non-destructive model to estimate the leaf area (LA) of Vernonia ferruginea using the length (L) and width (W) leaf dimensions. Different combinations of linear equations were obtained from L, L2, W, W2, LW and L2W2. The linear regressions using the product of LW dimensions were more efficient to estimate the LA of V. ferruginea than models based on a single dimension (L, W, L2 or W2). Therefore, the linear regression “LA=0.463+0.676WL” provided the most accurate estimate of V. ferruginea leaf area. Validation of the selected model showed that the correlation between real measured leaf area and estimated leaf area was very high.

A estimativa de área foliar é um importante traço biométrico para avaliação do desenvolvimento foliar e do crescimento vegetal em experimentos de campo e casa-de-vegetação. Foi desenvolvido um modelo linear não destrutivo capaz de estimar a área foliar (AF) de Vernonia ferruginea usando o comprimento (C) e a largura (L) foliar. Diferentes combinações de equações lineares foram obtidas a partir de C, C2, L, L2, CL e C2L2. As regressões lineares usando o produto de dimensões CL foram mais eficientes para estimar a AF de V. ferruginea do que os modelos baseados em uma única dimensão (C, L, C2 ou L2). O modelo linear "AF = 0,463+0,676 CL" forneceu com maior precisão a AF de V. ferruginea em relação aos demais modelos testados. A validação do modelo selecionado revelou elevada correlação entre a área foliar real e a área foliar estimada pelo modelo.

Non-destructive linear model for leaf area estimation in Vernonia ferruginea Less / Modelo linear não-destrutivo para estimativa de área foliar de Vernonia ferruginea Less

Leaf area estimation is an important biometrical trait for evaluating leaf development and plant growth in field and pot experiments. We developed a non-destructive model to estimate the leaf area (LA) of Vernonia ferruginea using the length (L) and width (W) leaf dimensions. Different combinations of linear equations were obtained from L, L2, W, W2, LW and L2W2. The linear regressions using the product of LW dimensions were more efficient to estimate the LA of V. ferruginea than models based on a single dimension (L, W, L2 or W2). Therefore, the linear regression “LA=0.463+0.676WL” provided the most accurate estimate of V. ferruginea leaf area. Validation of the selected model showed that the correlation between real measured leaf area and estimated leaf area was very high.(AU)

A estimativa de área foliar é um importante traço biométrico para avaliação do desenvolvimento foliar e do crescimento vegetal em experimentos de campo e casa-de-vegetação. Foi desenvolvido um modelo linear não destrutivo capaz de estimar a área foliar (AF) de Vernonia ferruginea usando o comprimento (C) e a largura (L) foliar. Diferentes combinações de equações lineares foram obtidas a partir de C, C2, L, L2, CL e C2L2. As regressões lineares usando o produto de dimensões CL foram mais eficientes para estimar a AF de V. ferruginea do que os modelos baseados em uma única dimensão (C, L, C2 ou L2). O modelo linear "AF = 0,463+0,676 CL" forneceu com maior precisão a AF de V. ferruginea em relação aos demais modelos testados. A validação do modelo selecionado revelou elevada correlação entre a área foliar real e a área foliar estimada pelo modelo.(AU)

Use of discriminant analysis based on echocardiography for classification of congestive heart failure in dogs with myxomatous mitral valve disease / Utilização da análise discriminante baseada na ecocardiografia para classificação de insuficiência cardíaca congestiva em cães com degeneração mixomatosa da valva mitral

Mixomatous mitral valve disease (MMVD) is one of the most common cardiac abnormalities in dogs and humans that can lead to cardiac heart failure (CHF). Its diagnosis remains based on echocardiography and clinical signs. However, the early diagnose of MMVD can contribute to a better prognosis and avoid CHF. The aim of this study was to evaluate the clinical, radiographic and echocardiographic presence of CHF in dogs with MMVD in combination with a statistical model as a mathematical tool. For this purpose, dogs were divided into three groups (healthy; MMVD without CHF; and MMVD with CHF), according the clinical, radiographic and echocardiographic evaluation findings. Thus, linear discriminant functions were obtained by analyzing the variables weight, body surface area, aortic diameter, the ratio of the left atrium/aortic diameter, the ratio between the mitral regurgitation jet area and the left atrial area, vena contracta diameter and mitral valve proximal isovelocity surface area. Then, mathematical equations were established for each group of dogs. Statistical functions obtained in this study enabled to classify the dogs, regarding the presence of CHF with a probability of correct classification of 90.4%. Thus the statistical model demonstrated that it could be used as an auxiliary method for identifying CHF in dogs with MMVD.(AU)

A doença mixomatosa da valva mitral (DMVM) é uma das alterações cardíacas mais comuns em cães e humanos, a qual pode levar à insuficiência cardíaca congestiva (ICC). O diagnóstico dessa alteração ocorre com base principalmente no exame ecocardiográfico e na presença de sinais clínicos. No entanto, o diagnóstico precoce da DMVM pode contribuir para um melhor prognóstico e evitar o desenvolvimento de ICC. Assim, o objetivo do presente estudo foi avaliar a presença de ICC em cães com DMVM, por meio de exames clínico, radiográfico e ecocardiográfico em combinação com um modelo estatístico. Para este propósito, os cães foram divididos em três grupos (sadios; DMVM sem ICC; e DMVM com ICC), de acordo com os achados dos exames realizados. Então, as funções lineares discriminantes foram obtidas por meio da análise das variáveis peso; superfície de área corporal; diâmetro aórtico; relação entre o diâmetro do átrio esquerdo e aórtico; relação entre a área do jato regurgitante mitral e a área do átrio esquerdo; diâmetro da vena contracta e área da isovelocidade proximal mitral (PISA). As equações matemáticas foram estabelecidas para cada grupo de cães e demonstraram ser possível classificar os animais de acordo com a presença de ICC, com uma probabilidade de classificação correta de 90,4%. Diante disso, o modelo estatístico poderia ser uma ferramenta auxiliar para a identificação de ICC em cães com DMVM.(AU)

Use of discriminant analysis based on echocardiography for classification of congestive heart failure in dogs with myxomatous mitral valve disease / Utilização da análise discriminante baseada na ecocardiografia para classificação de insuficiência cardíaca congestiva em cães com degeneração mixomatosa da valva mitral

Mixomatous mitral valve disease (MMVD) is one of the most common cardiac abnormalities in dogs and humans that can lead to cardiac heart failure (CHF). Its diagnosis remains based on echocardiography and clinical signs. However, the early diagnose of MMVD can contribute to a better prognosis and avoid CHF. The aim of this study was to evaluate the clinical, radiographic and echocardiographic presence of CHF in dogs with MMVD in combination with a statistical model as a mathematical tool. For this purpose, dogs were divided into three groups (healthy; MMVD without CHF; and MMVD with CHF), according the clinical, radiographic and echocardiographic evaluation findings. Thus, linear discriminant functions were obtained by analyzing the variables weight, body surface area, aortic diameter, the ratio of the left atrium/aortic diameter, the ratio between the mitral regurgitation jet area and the left atrial area, vena contracta diameter and mitral valve proximal isovelocity surface area. Then, mathematical equations were established for each group of dogs. Statistical functions obtained in this study enabled to classify the dogs, regarding the presence of CHF with a probability of correct classification of 90.4%. Thus the statistical model demonstrated that it could be used as an auxiliary method for identifying CHF in dogs with MMVD...

A doença mixomatosa da valva mitral (DMVM) é uma das alterações cardíacas mais comuns em cães e humanos, a qual pode levar à insuficiência cardíaca congestiva (ICC). O diagnóstico dessa alteração ocorre com base principalmente no exame ecocardiográfico e na presença de sinais clínicos. No entanto, o diagnóstico precoce da DMVM pode contribuir para um melhor prognóstico e evitar o desenvolvimento de ICC. Assim, o objetivo do presente estudo foi avaliar a presença de ICC em cães com DMVM, por meio de exames clínico, radiográfico e ecocardiográfico em combinação com um modelo estatístico. Para este propósito, os cães foram divididos em três grupos (sadios; DMVM sem ICC; e DMVM com ICC), de acordo com os achados dos exames realizados. Então, as funções lineares discriminantes foram obtidas por meio da análise das variáveis peso; superfície de área corporal; diâmetro aórtico; relação entre o diâmetro do átrio esquerdo e aórtico; relação entre a área do jato regurgitante mitral e a área do átrio esquerdo; diâmetro da vena contracta e área da isovelocidade proximal mitral (PISA). As equações matemáticas foram estabelecidas para cada grupo de cães e demonstraram ser possível classificar os animais de acordo com a presença de ICC, com uma probabilidade de classificação correta de 90,4%. Diante disso, o modelo estatístico poderia ser uma ferramenta auxiliar para a identificação de ICC em cães com DMVM...

Use of discriminant analysis based on echocardiography for classification of congestive heart failure in dogs with myxomatous mitral valve disease / Utilização da análise discriminante baseada na ecocardiografia para classificação de insuficiência cardíaca congestiva em cães com degeneração mixomatosa da valva mitral

Mixomatous mitral valve disease (MMVD) is one of the most common cardiac abnormalities in dogs and humans that can lead to cardiac heart failure (CHF). Its diagnosis remains based on echocardiography and clinical signs. However, the early diagnose of MMVD can contribute to a better prognosis and avoid CHF. The aim of this study was to evaluate the clinical, radiographic and echocardiographic presence of CHF in dogs with MMVD in combination with a statistical model as a mathematical tool. For this purpose, dogs were divided into three groups (healthy; MMVD without CHF; and MMVD with CHF), according the clinical, radiographic and echocardiographic evaluation findings. Thus, linear discriminant functions were obtained by analyzing the variables weight, body surface area, aortic diameter, the ratio of the left atrium/aortic diameter, the ratio between the mitral regurgitation jet area and the left atrial area, vena contracta diameter and mitral valve proximal isovelocity surface area. Then, mathematical equations were established for each group of dogs. Statistical functions obtained in this study enabled to classify the dogs, regarding the presence of CHF with a probability of correct classification of 90.4%. Thus the statistical model demonstrated that it could be used as an auxiliary method for identifying CHF in dogs with MMVD.

A doença mixomatosa da valva mitral (DMVM) é uma das alterações cardíacas mais comuns em cães e humanos, a qual pode levar à insuficiência cardíaca congestiva (ICC). O diagnóstico dessa alteração ocorre com base principalmente no exame ecocardiográfico e na presença de sinais clínicos. No entanto, o diagnóstico precoce da DMVM pode contribuir para um melhor prognóstico e evitar o desenvolvimento de ICC. Assim, o objetivo do presente estudo foi avaliar a presença de ICC em cães com DMVM, por meio de exames clínico, radiográfico e ecocardiográfico em combinação com um modelo estatístico. Para este propósito, os cães foram divididos em três grupos (sadios; DMVM sem ICC; e DMVM com ICC), de acordo com os achados dos exames realizados. Então, as funções lineares discriminantes foram obtidas por meio da análise das variáveis peso; superfície de área corporal; diâmetro aórtico; relação entre o diâmetro do átrio esquerdo e aórtico; relação entre a área do jato regurgitante mitral e a área do átrio esquerdo; diâmetro da vena contracta e área da isovelocidade proximal mitral (PISA). As equações matemáticas foram estabelecidas para cada grupo de cães e demonstraram ser possível classificar os animais de acordo com a presença de ICC, com uma probabilidade de classificação correta de 90,4%. Diante disso, o modelo estatístico poderia ser uma ferramenta auxiliar para a identificação de ICC em cães com DMVM.

Caracterización de la lactancia materna y factores asociados en Puerto Carreño, Colombia / Characterizing breastfeeding and associated factors in Puerto Carreño, Colombia

Objetivo Caracterizar el uso de la lactancia materna en Puerto Carreño e identificar los factores asociados a brindar leche materna al recién nacido, lactancia exclusiva y lactancia materna total. Métodos Estudio transversal descriptivo por medio de encuestas estructuradas e individuales no aleatorias a 609 madres. El análisis incluyó métodos univariados, bivariados, curvas de supervivencia y modelos de regresión de logística binaria y riesgos proporcionales de Cox. Resultados La duración de la lactancia materna exclusiva y total es superior a los tiempos reportados a nivel nacional y regional en la mayoría de los casos. Los principales factores asociados a la lactancia se relacionan con la ocupación, el entorno familiar, la condición indígena, experiencias maternas anteriores y el acceso a los servicios de salud. Conclusiones La lactancia exclusiva es influida en mayor medida por el oficio de la madre, mientras que la duración total de la lactancia es influenciada por la red de apoyo familiar en el hogar. Los resultados obtenidos son importantes en la planificación de medidas de intervención direccionados a mejorar los hábitos de lactancia en el municipio.(AU)

Objective Characterizing breastfeeding in Puerto Carreño and identifying factors associated with providing breast-milk for the newborn, exclusive breastfeeding and total breastfeeding. Methods This descriptive, cross-sectional study, using structured individual and non-random surveys, involved 609 mothers. The statistical analysis methods included univariate and bivariate analysis, survival curves, binary logistic regression and Cox proportional hazard models. Results The duration of total and exclusive breastfeeding was higher than reported times at national and regional level in most cases. The main factors associated with breastfeeding were related to occupation, family background, Indigenous status, previous maternal experience and access to healthcare services. Conclusions Exclusive breastfeeding was influenced more by the mother’s occupation, while the total duration of breastfeeding was influenced by home-based family support network. The results are significant regarding planning intervention measures addressed towards improving breastfeeding habits in the target municipality.(AU)