OBJECTIVE: to compare two surgical approaches for fractures of the tibial pilon: open reduction and internal fixation with plate and screws versus closed reduction and external fixation with the Ilizarov circular external fixator, constituting a study with a level of evidence level 4 and seeking to determine which patients benefit most from each surgical approach. METHODS: The research involved 19 patients with fractures of the tibial pilon, divided into two groups according to their respective medical records and evaluated considering the quality of joint reduction, acute complications in relation to these two methods and associated injuries and comorbidities due to a minimum outpatient follow-up of four months. RESULTS: there was no difference in terms of reduction quality, whereas in terms of acute complications and the need for surgical re-approaches, the group of patients undergoing open reduction and internal fixation with plate and screws showed worse results. CONCLUSION: the choice between the methods must be individualized, considering the specific injuries and comorbidities of each patient.

OBJETIVO: comparar duas abordagens cirúrgicas para fraturas do pilão tibial: redução aberta e fixação interna com placa e parafusos versus redução fechada e fixação externa com o fixador externo circular de Ilizarov, constituindo um estudo prospectivo randomizado e busca determinar quais pacientes se beneficiam mais com cada abordagem cirúrgica. MÉTODOS: A pesquisa envolveu 19 pacientes com fraturas do pilão tibial, divididos em dois grupos de acordo com seus respectivos números de prontuário e foram avaliados considerando a qualidade da redução articular, complicações agudas em relação a esses dois métodos e com lesões associadas e comorbidades por um seguimento ambulatorial mínimo de quatro meses. RESULTADOS: não houve diferença quanto a qualidade de redução, já em relação a complicações agudas e necessidade de reabordagens o grupo de pacientes submetido a redução aberta e fixação interna com placa e parafusos apresentou piores resultados. CONCLUSÃO: a escolha entre os métodos deve ser individualizada, considerando as lesões e comorbidades específicas de cada paciente.

Abstract The Leaf Area Index (LAI) is one of the main physiological parameters of the plant related to transpiration, productivity and rainfall interception. Among the methods to determine the LAI, the use of remote sensing that estimates the LAI through image processing techniques stands out. Thus, the objective of this work was to estimate the LAI for industrial tomatoes from orbital remote sensing images and validate the results with the LAI obtained by the destructive method. The study was carried out in an area irrigated by a central pivot in the municipality of Vila Propício of Goiás. The leaf area was determined from georeferenced sampling in a regular grid of 60x60m, to calculate the SAVI and IAF vegetation index, 4 images obtained through the Sentinel satellite were used in the period from 07/01/2018 to 07/31/2018 where the culture is in the second phase of the vegetative cycle. The LAI estimated by the orbital remote sensing showed good results compared to the LAI obtained through the destructive method. The estimated leaf area index was not completely homogeneous, as part of the pivot showed better results, with a growth in the vegetative development phase and a decrease in the maturation phase of the crop. The values of the statistical analysis of the real LAI compared to the estimated LAI were very close, but the coefficient of variation showed a greater difference between them, indicating that there may be a greater variation in the estimate.

Abstract Objective This study assesses risk factors for periprosthetic joint infection after elective primary total knee or hip arthroplasty. Methods The study included 706 medical records of patients undergoing elective primary total hip or knee arthroplasty from January to December 2018. We used a multivariate analysis of infection predictors through a logistic regression model. The R software performed all statistical analysis. Results The prevalence of infection in the sample was 2.0% (14 cases). Most patients were women (79.6%), with an afflicted right side (50.6%), and underwent a total knee arthroplasty (61.3%). Significant risk factors (p< 0.05) for infection included surgical time greater than 120 minutes (p= 0.009) and a history of diabetes (p= 0.025). Conclusion The risk of infection after elective primary total knee or hip arthroplasty is higher when the surgical procedure is lengthy (over 120 minutes), or the patient has a history of diabetes mellitus. Level of EvidenceIIIB, retrospective, case-control study.

Resumo Objetivo Avaliar os fatores de risco para infecção articular periprotética após procedimento cirúrgico eletivo de artroplastia primária total de joelho ou quadril. Métodos Incluem-se no estudo 706 prontuários de pacientes que foram submetidos a artroplastia total primária eletiva de quadril ou joelho entre os meses de janeiro e dezembro de 2018. Utilizou-se a análise multivariada dos fatores preditores de infecção por meio de um modelo de regressão logística. Toda a análise estatística foi realizada no software R. Resultados A prevalência de infecção de toda a amostra foi de 2,0% (14 casos). A amostra contou com a maioria do gênero feminino (79,6%), com o lado direito afetado (50,6%) e predomínio da artroplastia total de joelho (61,3%). Os fatores de risco significativos (p< 0,05) para a infecção foram: tempo cirúrgico maior do que 120 minutos (p= 0,009) e diagnóstico prévio de diabetes (p= 0,025). Conclusão Artroplastias totais primárias eletivas de joelho ou quadril possuem maior risco de infecção quando ocorre um tempo prolongado do procedimento cirúrgico (acima de 120 minutos) e quando o paciente possui diagnóstico prévio de diabetes mellitus. Nível de EvidênciaIIIB, estudo retrospectivo caso-controle.

Resumen En un libre mercado, el bienestar se alcanza protegiendo la competencia. Los carteles entorpecen o eliminan la competencia y la reemplazan por cooperación, fijando ilegalmente condiciones de comercio. El Derecho de Competencia los combate mediante herramientas de disuasión, detección y sanción. Estos mecanismos forman parte de un régimen de lucha contra los carteles, y son eficaces cuando son interpretados técnicamente y aplicados. Sin embargo, en la práctica administrativa y judicial ecuatoriana existen interpretaciones antitécnicas de las normas de competencia, especialmente en lo que se refiere a la lucha contra los carteles. Este debilitamiento del régimen se da, al menos, en las reglas de anticompetitividad por efecto y objeto; en el estándar de prueba para las prácticas concertadas; y, en la configuración de carteles en contratación pública. Estas interpretaciones antitécnicas han derivado en un estructuralmente debilitado mecanismo de lucha contra los carteles en Ecuador.

Abstract Economic social welfare in free market is achieved by protecting competition. Despite this fact, cartels obstruct or replace it with illegal cooperation setting market conditions. Competition Law fights against them through tools of deterrence, detection and sanction. These mechanisms are part of a regime for the persecution of cartels and are effective when they are technically interpreted and applied. However, in the Ecuadorian administrative and judicial practice there are erroneous interpretations of the competition regulation, especially in what corresponds to cartel enforcement. This weakening of the regime occurs, at least, when enforcing restriction by object and by effect rules; about the test for concerted practices; and, on the possibility of cartels in public procurement. These erroneous interpretations have generated a structurally weakened fighting mechanism against cartels in Ecuador.

Resumen En la región norte de Mato Grosso (Brasil) la distribución de la precipitación afecta principalmente la actividad económica. La deficiencia de lluvias limita la producción agrícola y su exceso, el flujo de productos por vías secundarias. Estos obstáculos imponen la necesidad de un mayor conocimiento de la distribución de lluvias en regiones distantes del Estado, como Paranorte, en Juara-MT. Este estudio tuvo como objetivo identificar el comienzo y el final de la temporada de lluvias, así como la frecuencia e intensidad del verano, e investigar los eventos causales de estas temporadas y sus relaciones con los fenómenos ENOS (El Niño de Oscilación Sur). Para ello, se adoptaron métodos basados en la cantidad y la continuidad de las lluvias. Los resultados mostraron que en Paranorte la precipitación anual acumulada varía entre 2322 y 2720 mm. Los meses del año se dividen en un período seco (entre julio y agosto), dos meses de baja precipitación (mayo y septiembre - ≈ 80 mm) y dos más extensos con altas precipitaciones (entre enero y abril y entre octubre y diciembre, con 214 a 464 mm). Las sequías prolongadas ocurren con mayor frecuencia al comienzo (septiembre) y al final (mayo) de la temporada de lluvias. A su vez, los fenómenos ENOS influyen en la lluvia solo en primavera.

Abstract Rainfall predominantly influences economic activity in northern of Mato Grosso. The scarcity of rainfall limits agricultural production, and its excess hinders the flow of production on back roads. These obstacles impose the need for greater knowledge of rainfall in distant regions of the state, such as Paranorte, in Juara-MT. This study aimed to identify the beginning and end of the rainy season, as well as the frequency and duration of dry days, besides to investigate causal relationships of rainfall with ENSO (El Niño de Oscillation Sul) phenomena. Methods based on rainfall quantity and continuity were adopted. The results showed that in Paranorte, the accumulated annual precipitation varies between 2322 and 2720 mm. The months of the year are divided into a dry period (June, July and August), a period of low rainfall (May and September - ≈ 80 mm) and a period of high rainfall (October, November, December, January, February, March and April, with 214 to 464 mm). Prolonged droughts occur most often at the beginning (September) and end (May) of the rainy season. In turn, ENSO phenomena influence rainfall only in spring.

Resumen: Se evaluó el efecto de los taninos condensados (TC) en la pastura (Lotus uliginosus cv. E-Tanin) y/o extractos de quebracho y castaño en la calidad de la canal y carne de corderos. Se realizaron dos experimentos en años consecutivos con 60 corderos cruza cada año. Los animales fueron estratificados por peso vivo (PV) y asignados al azar a los tratamientos: pastoreo de trébol blanco (TB); pastoreo de TB más ración (TB + R); pastoreo de trébol blanco más ración y extracto de quebracho y castaño (TB + R + TC); pastoreo de Lotus uliginosus (E-Tanin); pastoreo de E-Tanin más ración (E-Tanin+R); pastoreo de E-Tanin más ración y extracto de quebracho y castaño (E-Tanin + R + TC), cada uno con dos repeticiones cada año. La pastura afectó el peso del bife, que fue mayor (P < 0,05) en los animales que pastorearon TB respecto a aquellos sobre E-Tanin. La intensidad de rojo (a*) del color de la carne fue mayor (P < 0,05) en los tratamientos suplementados con R (con y sin TC) respecto a aquellos exclusivamente pastoriles. El contenido de grasa intramuscular no fue afectado (P > 0,05) por el tipo de pastura, suplementación, o año. Los corderos que pastorearon E-Tanin presentaron una mayor (P < 0,05) proporción del ácido dihomo-gamma-linolénico (C20:3-n6) que aquellos sobre TB. La suplementación afectó (P < 0,05) las proporciones de ácidos grasos saturados (AGS) y monoinsaturados (AGM), y la relación omega 6:omega 3. Estimaciones del consumo en condiciones de pastoreo permitirían conocer mejor el efecto de los TC en la calidad de la canal y la carne.

Summary: The effect of condensed tannins (CT) in the pasture (Lotus uliginosus cv. E-Tanin) and/or quebracho and chestnut extracts on lamb carcass and meat quality was evaluated. Two experiments were conducted in consecutive years with 60 crossbreed lambs each year. The animals were stratified by live weight (LW) and randomly assigned to the treatments: white clover grazing (WC); WC plus concentrate supplementation (WC + C); WC plus concentrate supplementation and quebracho and chestnut extract (WC + C + CT); Lotus uliginosus grazing (E-Tanin); E-Tanin plus concentrate supplementation (E-Tanin + C); E-Tanin plus concentrate supplementation plus quebracho and chestnut extract (E-Tanin + C + CT); with two repetitions each year. Pasture type affected loin weight, which was greater (P < 0.05) in lambs grazing WC than E-Tanin. Meat color redness (a*) was greater (P < 0.05) in supplemented treatments with C (with or without CT) than those exclusively grazing. Intramuscular fat content was not affected (P > 0.05) by the pasture, the supplementation, or the year. The proportion of dihomo-gamma-linolenic acid (C20:3-n6) was greater (P < 0.05) in lambs grazing E-Tanin compared to WC. Supplementation affected (P < 0.05) the saturated (SFA) and monounsaturated fatty acids (MUFA) proportions, and the omega 6:omega 3 ratio. Estimation of dry matter intake under grazing conditions would allow a better understanding of the effect of CT on carcass and meat quality.

ABSTRACT This study evaluated lairage time effects on carcass and meat quality traits of Hereford steers. Thirty Hereford steers fed on pasture were assigned to two treatments according to lairage time: 3 h (n = 15) and 12 h (n = 15). Individual temperament was assessed using crush score and flight speed. pH decline, glycogen content, meat color, and shear force were measured. pH was not different between treatments at any time point, showing a normal decline rate. Meat color and shear force did not differ between treatments, but muscle glycogen was lower in treatment with 3 h, not enough to affect quality but suggesting a higher level of stress in 3 h lairage time. Temperament did not have any impact on carcass and meat quality traits. No differences were found in pH, color, and tenderness between treatments, but the lower muscle glycogen concentrations for the shorter lairage suggest a higher risk regarding meat quality.

ABSTRACT This study focuses on the subwatershed "V Aniversario", belonging to Cuyaguateje River Basin, Pinar del Río Province. Its latitudinal position leads to the development of a greater volume of runoff, higher than other karstic regions in the country, then numerous damages related mainly with floods are done. Therefore, the objective of this work is to forecast the runoff in advance at the subwatershed, on annual and monthly scales, through linear stochastic modeling. In order to comply with the above, White Noise, AR (p), MA (q) and ARMA (p, q) models for the annual runoff series were implemented in R software, being the White Noise model the best adjusted to it. However, the monthly runoff series must be modeled by SARIMA, because it presented a seasonal behavior. It is interesting to note that the latter had a better memory and linear correlation compared to the annual series.

RESUMEN Este estudio se enfoca en la subcuenca “V Aniversario”, perteneciente a la cuenca del Río Cuyaguateje, provincia de Pinar del Río. Su posición latitudinal favorece el desarrollo de un volumen de escurrimiento superior a otras corrientes en zonas cársicas del país, por lo que se producen numerosos daños relacionados fundamentalmente con las inundaciones. Por tanto, el objetivo de este trabajo es pronosticar con antelación el escurrimiento en esta subcuenca, a escalas anual y mensual, a través de la modelación lineal estocástica. Para dar cumplimiento a lo anterior, se implementaron en el software R los modelos: Ruido Blanco, AR(p), MA(q) y ARMA(p,q) para la serie de escurrimiento anual, ajustándose mejor a la misma el Ruido Blanco. Sin embargo, la serie de escurrimiento mensual debe ser modelada mediante un SARIMA, pues presentó un comportamiento estacional. Es de interés destacar, que esta última tuvo mejor memoria y correlación lineal en comparación con la serie anual.

RESUMO Objetivou-se avaliar três tipos de silagem de grão úmido de sorgo (alto tanino, baixo tanino e branco), na forma de silagem de grão úmido, combinados com duas formas de fornecimento da ração (volumoso e concentrado fornecidos de forma separada ou misturada), sobre o consumo de matéria seca, evolução do peso vivo, ganho de peso médio diário, conversão alimentar e principais características de carcaça (área de olho de lombo, espessura de gordura subcutânea e marmorização in vivo e post mortem) e carne (cor, maciez e pH) de novilhos cruzados Hereford-Angus. Foram utilizados 48 bovinos machos, castrados, cruzados Hereford-Angus, com idade média de 20 meses, divididos em blocos casualizados, em fatorial 3 × 2. A regressão do ganho de peso de cada tratamento foi comparada utilizando-se contrastes ortogonais. Para consumo de matéria seca relativo, houve efeito do tipo de sorgo (P=0,002) e forma de fornecimento da ração (P=0,0005). A forma de fornecimento da ração pode interferir sobre o consumo de matéria seca absoluto e peso vivo médio (P=0,0001). Para a conversão alimentar foi observado efeito do tipo de sorgo (P=0,04. Observou-se efeito da forma de fornecimento da ração para a marmorização (P=0,04) post mortem. Não houve efeito do tipo de sorgo e da forma de fornecimento da ração sobre as características de carcaça e pesos dos cortes cárneos. O fornecimento do volumoso separado do concentrado na alimentação de bovinos confinados é viável do ponto de vista operacional e nutricional.

SUMMARY This work aimed to evaluate three varieties of sorghum as wet grain silage (high, low and white tannin), combined with two form of food supply (concentrated with roughage separated or mixed) on dry matter intake, body weight evolution, average daily growth, feed conversion, main meat and carcass traits (rib eye area, fat thickness and marbling in vivo and post mortem) in Hereford-Angus crossbred steers. Forty eight males castrated with 20 months of age were used, divided into randomized blocks, arranged in a 3 × 2 factorial. The regression coefficients for the weight gain of each treatment was compared using orthogonal contrasts. Dry matter intake was affected by the type of sorghum (P=0.002) and the form of food supply (P=0.0005). The form of food supply can interfere with the dry matter intake (P=0.0001) and weight (P=0.0001). Feed conversion and marbling, was affected by the type of sorghum (P=0.04). Meat marbling measured at deboning was affected by the form of food supply (P=0.04). The type of sorghum and form of food supply did not influence carcass characteristics and weights of meat cuts. The concentrated with roughage separated supply is nutritionally and operationally preferable.

The objective of this study is to show a case study application of the blue print methodology for probabilistic prediction of discharge and sediment yield under extreme events, which was published in previous volumes of this Journal. The study focus on “V Aniversario” basin, which is located in the Cuyaguateje River Basin, Pinar del Río Province, west of Cuba. Using site-based rainfall, discharge and sediment series, and landuse and soil information the KINEROS (K2) model was calibrated and validated. The extreme maxima in the area fitted a theoretical probability distribution EV type II - Fréchet. Results of the hydrological response predictions for a 50-year return event are also shown in this paper

El objetivo de este estudio es mostrar un ejemplo de aplicación de la metodología para la predicción probabilística del escurrimiento y la pérdida de sedimento bajo condiciones extremas, la cual fue publicada en volumen anterior de esta revista. El estudio se enfoca en la subcuenca “V Aniversario”, perteneciente a la cuenca del Río Cuyaguateje, provincia de Pinar del Río. Usando series de lluvia, escurrimiento y sedimentos en río, e información de suelo y uso de la tierra, el modelo KINEROS (K2) fue calibrado y validado. Los máximos en la subcuenca se ajustan a una distribución teórica de probabilidades tipo II - Fréchet. En el estudio se muestran los resultados de predicciones de la respuesta hidrológica para un evento de 50 años de periodo de retorno

This paper intends to introduce a blueprint methodology for predicting discharges and sediment yield under extreme conditions using a process-based hydrologic system model. In a next paper, part II, a case study application of this methodology will be presented. The methodology is organized in: 1) model setup (calibration and validation for extremes), 2) extreme value analysis, 3) stochastic rainfall disaggregation and 4) probability predictions and interpretation of the KINEROS2 (recommended physically-based model) outputs. This methodology introduces a study of the random component under rainfall-runoff process and allows predicting capabilities of unseen extreme events

Este artículo pretende introducir una metodología para la predicción del escurrimiento superficial y la concentración de sedimentos en sistemas fluviales, bajo condiciones extremas, y mediante el uso de un modelo de base física. En el siguiente artículo, Parte II, se publicará la aplicación de la metodología a un caso de estudio específico. Esta metodología está organizada en: 1) ajustes del modelo (calibración y validación para extremos), 2) análisis de valores extremos, 3) desagregación estocástica de precipitaciones y 4) predicción probabilística e interpretación de las salidas del modelo (KINEROS2 - recomendado). Este estudio introduce en la modelación la aleatoriedad del proceso lluvia-escurrimiento y provee capacidades predictivas de eventos extremos no observados

In Cuba, one of the prioritized regions in terms of water erosion is “Cuyaguateje” river basin, where more than 85 % of its soil shows a high erosion risk subjected to intensive farming practices. High pluviometric values registered together with the non-uniform topography necessitate spatially characterised rain erosivity in this area, as it constitutes an essential factor of soil erosion. The objectives of this paper were: (a) to compare expressions that predict kinetic energy from rainfall intensity in our basin of interest, (b) to develop and validate the relationship between cumulative rainfall and R factor from RUSLE (Revised Universal Soil Loss Equation) (EI30), (c) to compare results and trends between R and the Modified Fournier Index MFI, as well as with Lal’s index AIm (EI7.5), (d) to present rainfall erosivity maps, according to each index calculated. Data from two pluviographic stations were used to calculate R (by Brown and Foster’s also Kinnell’s kinetic energy equations) and AIm, besides data from 26 pluviometric stations located along the basin of interest. Thus, R values ranged between 8284 and 22044 MJ mm ha-1 h-1yr-1 through both kinetic energy equations, with the highest erosivity values at the top or mountainous part and the lowest values at the basin bottom. Around 96 % of the basin area is affected by rainfall with high erosive potential. Correlations between R factor from RUSLE and the other indexes calculated (MFI and AIm) were higher than 0,9

En Cuba, una de las regiones priorizadas en términos de erosión hídrica es la cuenca del río Cuyaguateje, donde más del 85 % de su suelo presenta alto riesgo de erosión por estar bajo intensas prácticas de laboreo. Los altos acumulados de precipitaciones registrados junto a la no uniformidad de la topografía hacen necesaria una caracterización espacial de la erosividad de las lluvias en el área, ya que constituye un factor fundamental de la erosión. Los objetivos de este trabajo fueron: (a) comparar expresiones que estiman la energía cinética, desde la intensidad de las precipitaciones en la cuenca bajo estudio; (b) desarrollar y validar la relación entre los acumulados de precipitación y el factor R del Modelo RUSLE (Ecuación de Perdidas de Suelo Universal Revisada) (EI30); (c) comparar resultados y tendencias entre R y el Índice Modificado de Fournier MFI así como con el Índice de Lal, AIm (EI7.5); (d) presentar los mapas de erosividad de las precipitaciones, según cada índice calculado. Fueron utilizados datos de dos estaciones pluviográficas de la cuenca para calcular R (usando las ecuaciones de energía cinética de Brown y Foster y la de Kinnell) y AIm y datos de 26 estaciones pluviométricas a lo largo de toda la cuenca. Como resultado se obtuvo valores de R entre 8284 y 22044 MJ mm ha-1 h-1yr-1 mediante las dos ecuaciones de energía cinética, con los valores más elevados de erosividad en la parte alta o montañosa y los valores más bajos en la parte baja de la cuenca. Alrededor del 96 % del área de la cuenca está afectada por las precipitaciones con alto potencial erosivo. Las correlaciones entre el factor R de RUSLE y el resto de los índices calculados (MFI y AIm) fueron altas, más de 0,9

O objetivo deste trabalho foi a purificação e organofilização em escala piloto de dois tipos de argila bentonita (cinza e verde) com tensoativo não iônico e a aplicação destas argilas em nanocompósitos com matriz de Polipropileno (PP). As argilas foram purificadas e em seguida organicamente modificadas com tensoativo não iônico tornando-se organofílicas, sendo denominadas de CPO e VPO respectivamente, e caracterizadas por Análise Granulométrica por Difração a Laser (AG), análise química por Fluorescência de Raios X (EDX), Difração de Raios X (DRX) e espectroscopia no infravermelho (IV). Os resultados de AG e EDX mostraram redução significativa do teor de areia e da sílica livre na forma de quartzo confirmando que houve a purificação da argila. Os resultados de DRX e IV mostraram que a organofilização em escala piloto das argilas foi realizada com sucesso. Os compósitos contendo 3pcr de argila foram caracterizados por DRX, Calorimetria exploratória diferencial (DSC), Termogravimetria (TG) e propriedades mecânicas. As análises por DRX indicaram formação de um nanocompósito com estrutura intercalada para o sistema PP/E-GMA/CPO, enquanto para o sistema PP/E-GMA/VPO formou-se um micro-compósito. Os resultados de DSC indicaram que as argilas não influenciaram na temperatura de fusão do PP. Os resultados de TG indicaram que as argilas CPO e VPO melhoraram a estabilidade térmica do PP. O sistema PP/E-GMA/CPO foi o que apresentou maior estabilidade térmica e maior módulo. As resistências à tração e ao impacto dos compósitos não apresentaram melhora significativa em relação ao PP puro. Mesmo assim, este comportamento é importante uma vez que as propriedades mecânicas do PP não foram deterioradas.

The aim of this work was the purification and organophilization on a pilot scale of two types of bentonite clay (green and grey) with nonionic surfactant, and their application in nanocomposites with a Polypropylene (PP) matrix. The bentonitic clays were purified and then organically modified with a non-ionic surfactant to become organophilic, being referred to as CPO and VPO respectively, and characterized by Particle Size Analysis by Laser Diffraction (AG), chemical analysis by X-Ray Fluorescence (EDX), X-ray diffraction (XRD) and infrared spectroscopy (IR). The results of AG and EDX showed significant reduction in the amount of sand and free silica in the form of quartz confirming that the clay was purified. The results of XRD and IR showed that the organophilization on pilot scale of the clays was successful. The composites containing 3phr of clay were characterized by XRD, differential scanning calorimetry (DSC), thermogravimetry (TG) and mechanical properties. XRD results indicated that for the PP/E-GMA/CPO system a nanocomposite with an intercalated structure was formed. As for the PP/E-GMA/VPO system, a micro-composite was obtained. DSC results indicated that CPO and VPO clays did not affect the melting temperature of PP. TG results indicated that the CPO and VPO clays improved the thermal stability of PP. PP/E-GMA/CPO system showed the highest thermal stability. The mechanical properties of PP were not significantly improved with the addition of clay and compatibilizer. However they were not deteriorated.

Este trabalho foi desenvolvido com o objetivo de estudar a evolução das características de crescimento e carcaça em função da idade em bovinos da raça Hereford, utilizando modelos não-lineares. Foram utilizados dados de 240 bovinos machos (castrados) da raça Hereford, pertencentes à fazenda Experimental "La Estanzuela" do INIA, Colonia, Uruguai. As características começaram a ser mensuradas a partir da desmama de animais com aproximadamente seis meses de idade, até o abate (dois anos de idade). As medições de peso foram realizadas a cada 15±3 dias durante todo o período e sem jejum prévio. As mensurações de área de olho de lombo, obtidas por ultrassom, e altura dos animais foram obtidas a cada 90 dias, sendo que as medidas de ultrassom foram tomadas entre a 12ª e 13ª costelas. Os modelos não-lineares utilizados foram os modelos de Brody, Gompertz, Logístico e Von Bertalanffy. Para as características peso, altura e área de olho de lombo, todos os modelos avaliados atingiram a convergência. Para descrever a evolução dos dados de peso e área de olho de lombo em função da idade, o modelo de Von Bertalanffy foi o mais indicado, e os modelos de Brody e Logístico mostraram o pior ajuste, respectivamente. A evolução da altura dos animais desde o desmame até os dois anos de idade pode ser modelada através de qualquer um dos modelos não-lineares considerados neste estudo.

The objective of this research was to study the evolution of growth and carcass traits as a function of age in Hereford cattle using nonlinear models. Records from 240 Hereford steers (castrated), belonging to the experimental station "La Estanzuela" of INIA Uruguay, were utilized. The animals were measured from weaning, approximately at 6 months of age, to slaughter (two years of age). The animals were weighed, without fasting, every 15±3 days throughout the period. The measurements of ribeye loin area (between the 12th and 13th rib) were obtained by ultrasound every 90 days. The height of the animals was obtained every 90 days. The Brody, Gompertz, Logistic and Von Bertalanffy nonlinear models were applied to describe the trajectory of weight, height and ribeye loin area along the age. For height, weight and ribeye loin area, all the models reached the convergence. To describe the evolution of weight and ribeye loin area, the Von Bertalanffy nonlinear model was the most suitable. For weight and ribeye loin area, the Brody and Logistic nonlinear models have shown the worst fit, respectively. The height trajectory from weaning until two years of age can be modeled by any of the nonlinear models considered in this research.