In recent years, adaptation to climate change has become a global focus; therefore, the present study was conducted in Raymond Mhlaba Local Municipality to understand the adaptation strategies employed by smallholder farmers to the adverse impact of climate change and to examine the extent to which institutional factors play a role in farmers' decisions to adapt to climate change. Using a multistage research design, data were collected from 120 smallholder farmers by administering a pre-tested questionnaire with both open- and closed-ended questions. The collected data were analysed using descriptive statistics and a binary logistic regression model. The results revealed that farmers employed crop diversification, crop rotation, calendar redefinition, resilient crop varieties, and tree planting as adaptation strategies in response to climate change. The binary logistic regression model results indicated that access to extension services, climate change information, and farmers' organisations influenced farmers' decisions to adopt climate change adaptation strategies. Policymakers should focus on enhancing rural institutional services and increasing climate change education to improve smallholder farmers' capacity in a changing climate.

Abstract Increasing the rates of drug resistant bacteria, having adverse effects and also high costs of antibiotics lead to essential oils (EOs) with antibacterial properties have gained importance. The present study was predicted to evaluate antibacterial activity of cinnamon, lavender, tea tree, lemon, coconut, oregano, mint, laurel and eucalyptus EOs alone and in combination. Chemical components of effective EOs were examined through gas chromatography/mass spectrometry (GC/MS). Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays were used to identify antibacterial effects of EOs against bacterial strains. The Fractional Inhibitory Concentration index (FICI) of the binary combinations of EOs was determined by checkerboard method. Carvacrol, linalool, linalyl acetate, 1,8-cineole, cinnamaldehyde, terpinen-4-ol and p-cymene were found main components of EOs. Oregano, cinnamon and tea tree EOs exhibited the strongest antibacterial activity with the MIC range between 0.03125-1.00% (v/v). Tea tree/lavender and cinnamon/lavender mixtures showed a synergistic effect against Streptococcus pyogenes and Streptococcus agalactiae. Oregano with tea tree and laurel exhibited a synergistic effect against Staphylococcus aureus. Oregano showed a synergistic effect when combined with cinnamon, lavender and tea tree against S.agalactiae. Our findings indicated that EOs either alone or in combination against pathogens should be preferred as potential antibacterial agents.

Abstract: Obtaining the accurate disparity of each pixel quickly is the goal of stereo matching, but it is very difficult for the 3D labels-based methods due to huge search space of 3D labels, especially for highresolution images. We present an novel two-stage optimization strategy to get the accurate disparity map for high-resolution stereo image efficiently, which includes feature points optimization and superpixel optimization. In the first stage, we construct the support points including edge points and robust points for triangulation, which is used to extract feature points and then perform spatial propagation and random refinement to get the candidate 3D label sets. In the stage of superpixel optimization, we update per pixel labels of the corresponding superpixels using the candidate label sets, and then perform spatial propagation and random refinement. In order to provide more prior information to identify weak texture and textureless areas, we design the weight combination of “intensity + gradient + binary image” for constructing an optimal minimum spanning tree (MST) to compute the aggregated matching cost, and obtain the labels of minimum aggregated matching cost. We also design local patch surrounding the corresponding superpixel to accelerate our algorithm in parallel. The experimental result shows that our method achieves a good trade-off between running time and accuracy, including KITTI and Middlebury benchmark, which are the standard benchmarks for testing the stereo matching methods.

SUMMARY: Analysis and systematization of the longitudinal dimensions of the phalanges of the index and ring fingers for the classification of morphological types of the hand using classification and regression trees (CART). X-rays of the hands of 50 men and 50 women (mean age 47.16 (10.1) years, range 23-65 years) were studied. Each hand, depending on the ratio of the length of the index and ring fingers, was classified into three types: radial (R, 2d>4d), indefinite (N, 2d=4d), ulnar (U, 2d>4d). Morphometry of radiographs included measurements of the lengths of the proximal (PP), middle (MP), and distal (DP) phalanges. The sex differences of the analyzed indicators are statistically significant. There were no significant bilateral differences between the phalanges of the II and IV fingers in length, regardless of sex (p>0.05). A set of rules for classifying the morphological types of the hand depending on the lengths of the phalanges of the index and ring fingers was created by constructing a binary decision tree. The CART method demonstrates the usefulness of this statistical procedure for developing a scientifically based prediction of the morphological type of the hand. The results of this study can be the basis of an algorithm for determining the morphological type of the hand depending on the length of the phalanges of the fingers.

RESUMEN: En este estudio se realizó un análisis y sistematización de las dimensiones longitudinales de las falanges de los dedos índice y anular para la clasificación de tipos morfológicos de la mano, mediante árboles de clasificación y regresión (CART). Se estudiaron radiografías de las manos de 50 hombres y 50 mujeres (edad media 47,16 (10,1) años, rango 23-65 años). Cada mano, según la proporción de la longitud de los dedos índice y anular, se clasificó en tres tipos: radial (R, 2d> 4d), indefinida (N, 2d = 4d), ulnar (U, 2d> 4d). La morfometría de las radiografías incluyó mediciones de las longitudes de las falanges proximal (FP), media (FM) y distal (FD). Las diferencias de sexo de los indicadores analizados fueron estadísticamente significativas. No hubo diferencias bilaterales significativas entre las falanges de los dedos II y IV en longitud, independientemente del sexo (p> 0,05). Se creó un conjunto de reglas para clasificar los tipos morfológicos de la mano en función de las longitudes de las falanges de los dedos índice y anular mediante la construcción de un árbol de decisión binario. El método CART demuestra la utilidad de este procedimiento estadístico para desarrollar una predicción con base científica del tipo morfológico de la mano. Los resultados de este estudio pueden ser la base de un algoritmo para determinar el tipo morfológico de la mano en función de la longitud de las falanges de los dedos.

Summary Objetivo The main consequences of osteoporosis are fragility fractures, associated with high morbimortality. The prediction of these fractures can help identify the most-at-risk population and implement preventive measures. The aim of this study was to assess the usefulness of multiple factors in their prevention, comparing the bone mineral density (BMD), the calculation of absolute risk of fracture using the tool FRAX® in the presence and absence of BMD, and the clinical data. Material and methods An eight-year-duration longitudinal study was conducted on a postmenopausal female population, with and without osteoporosis. All of them were taken a standardised clinical history, spinal and hip BMD, and FRAX with and without BMD. Eight years later we identified the existent fractures. In addition to a parametric and non-parametric statistic in SPSS 21.1, we used the classification and regression tree (CART) method to assess possible interactions among fracture risk factors. Results We studied 276 postmenopausal patients whose average age at the beginning of the study was 61.08±8.43 years-old and had a body mass index (BMI) of 25.67±4.04. 56.5% of the patients (n=156) were diagnosed with osteoporosis before the beginning of our study, and all of them were treated. After eight years of follow-up, 72 patients (24.6%) suffered a fracture and 17 patients (6.2%) also suffered a second one. The results of the CART analysis showed that the main risk factor to suffer an osteoporotic fracture after 8 years of following up is having preceding fractures. Having a femoral neck BMD lower than 0.67 was the main risk factor among those with a previous fracture. Conclusions The use of a binary statistical procedure (CART) on a cohort of patients allow us identify those most at risk of fractures, according to clinical parameters and simple additional tests, in order to establish more effective therapeutic measures.

Resumen Objetivo La principal consecuencia de la osteoporosis es la fractura por fragilidad asociada a elevada morbimortalidad. La predicción de la misma puede ayudar a identificar la población de mayor riesgo y establecer medidas de prevención. El objetivo de este estudio fue valorar la utilidad de diversos factores en su prevención comparando la densidad mineral ósea (DMO), el cálculo del riesgo absoluto de fractura con la herramienta FRAX® con y sin DMO, y los datos clínicos. Material y métodos Se realizó un estudio longitudinal de 8 años de duración en una población de mujeres postmenopáusicas, osteoporóticas y no osteoporóticas. A todas ellas se les realizó una historia clínica protocolizada, DMO de columna y cadera, y el FRAX con y sin DMO. A los 8 años se identificaron las fracturas existentes. Además de realizar una estadística paramétrica y no paramétrica con SPSS 21.1, se realizó un método del árbol de clasificación y regresión (CART) para evaluar las posibles interacciones entre los factores de riesgo de fractura. Resultados Se incluyeron 276 pacientes postmenopáusicas cuya edad media al inicio del estudio fue de 61,08±8,43 años y un índice de masa corporal (IMC) de 25,67±4,04. El 56,5% de las pacientes (n=156) fueron diagnosticadas de osteoporosis antes del inicio de nuestro estudio, y todas ellas fueron tratadas. Pasados los 8 años de seguimiento, 72 pacientes (24,6%) sufrieron fractura y 17 (6,2%) también sufrieron una segunda fractura. Los resultados del análisis CART nos mostraron que el principal factor de riesgo para sufrir una fractura osteoporótica tras 8 años de seguimiento fue el haber sufrido fracturas previas. Entre las pacientes que habían sufrido una fractura previa, el tener una DMO del cuello femoral menor de 0,67 fue el principal factor de riesgo. Conclusión La utilización de un procedimiento estadístico binario (CART), en una cohorte de pacientes nos permite identificar a los pacientes con mayor riesgo de fracturas en función de parámetros clínicos y de pruebas complementarias sencillas de realizar y establecer medidas terapéuticas más eficaces.

Abstract: The spatio-temporal routing in episodically connected vehicular networks es a communication pattern where the destination nodes is a set of vehicles that transit the destination región during the specified destination región. The spatio-temporal routing is well suited to support Smart City and Intelligent Transportation Systems applications (i.e. road safety, crowdsensing, entertainment). In this paper, we present Oportunistic Greedy Routing over Street-layout Graph (OGRoSG), a novel spatio-temporal routing protocol for episodically connected vehicular networks. Unlike previous works in the literature, OGRoSG takes advantage of information available in modern navigation systems, such as the streets map and the geographic position. The protocol performs greedy geographic routing, the notion of being closer to the destination área is based on the progress towards the destination región on the streets-map graph and the direction of the vehicles. In order to achieve this, the vehicles process the destination región and the street graph to generate a shortest-paths tree with an extended destination región as root. This extended destination región guarantees that it covers the entire destination región and the paths that interconnect it. We evaluate the performance of the OGRoSG protocol using simulations in NS-3, using mobility traces generated in a map based in the city of Murcia, Spain. Our results show that OGRoSG outperforms a set of Spatio-Temporal variants of the Epidemic, Spray & Wait and Binary Spray & Wait routing protocols in terms of delivery ratio and overhead induced in the network.

Resumen: El enrutamiento de tráfico con ámbito espacio-temporal para redes vehiculares episódicamente conectadas es un patrón de comunicación en el cual los nodos destino son un conjunto de vehículos que transitan en una región destino durante un intervalo de tiempo predefinido. El enrutamiento de ámbito espacio-temporal es apropiado para dar soporte a aplicaciones de Smart City y de Intelligent Tranportation System (ITS), tal como seguridad en el camino, crowdsensing, entretenimiento y negocios. En este artículo se presenta Oportunistic Greedy Routing over Street-layout Graph (OGRoSG), un novedoso protocolo de comunicación de ámbito espacio-temporal para redes vehiculares episódicamente conectadas. A diferencia de propuestas existentes en la literatura, OGRoSG aprovecha la información disponible en sistemas de navegación modernos, tal como el mapa de las calles y la posición geográfica. En el enrutamiento geográfico voraz (greedy) que realiza el protocolo, la noción de cercanía está basada en el progreso sobre el grafo vial que considera la trayectoria en la que viajan los vehículos. Con este propósito, OGRoSG procesa la región destino y el grafo de calles para crear un árbol de caminos más cortos con una región destino extendida como raíz. Esta región destino extendida garantiza que está formada de un componente conectado de que incluye a todos los nodos que representan intersecciones ubicadas dentro de la región destino. Se evaluó el desempeño de OGRoSG usando simulaciones en NS-3 usando trazas de movilidad generadas en un mapa basado en la ciudad de Murcia, España. Nuestros resultados muestran que OGRoSG supera a variantes espacio-temporales de los protocolos de enrutamiento Epidemic, Spray & Wait y Binary Spray & Wait en términos de porcentaje de entrega y sobrecarga producida en la red.

ABSTRACT Background: the coexistence of peripheral arterial disease and acute coronary syndrome is associated with a worse prognosis. The ankle-brachial index has been shown to be a marker of multisite atherosclerosis. Objective: to determine the relationship between the ankle-brachial index and coronary artery disease. Method: an analytical observational study was carried out that included all the patients discharged from the coronary care unit of the Camilo Cienfuegos Gorriarán Provincial University Hospital, of the Sancti Spíritus province, in the period from March 1, 2011 to February 30 of 2018, with a diagnosis of acute coronary syndrome, with and without ST segment elevation. Clinical data, ankle-brachial index, echocardiography and coronary angiography were collected and the prognostic implication of the index in disease was determined through a classification tree with the variables included in the binary logistic regression model. Results: multivessel disease occurred in 85.2 % patients, 81.9 % of them were men, 85.9 % of them with multivessel disease, the mean age was 59.1 years, 52.3 % presented STEACS with multivessel disease 78.8 %. The most frequent risk factors were: smoking (86.8 %), dyslipidemia (85.8 %) and arterial hypertension (84.8 %) in the group with multivessel disease and ABI = 0.9 (SD = 0.3). They received treatment with clopidogrel (86.1 %), acetylsalicylic acid (86.3 %), ACEI or ARB (85.8 %), statins (73.2 %), beta-blockers (87.5 %) and nitrates (86, 3 %). On angiography, 85.2 % had severe coronary disease. The two-predictor variables were: NSTEACS and ABI≤0.9, which showed a high positive predictive value in the prognosis of multivessel coronary artery disease. Conclusions: ankle-brachial index <0.9 showed a predictive capacity for multivessel disease that increases if it is associated with diabetes mellitus and smoking.

RESUMEN Fundamento: la coexistencia de la enfermedad arterial periférica y el síndrome coronario agudo se asocia con peor pronóstico. El índice tobillo-brazo ha demostrado ser un marcador de ateroesclerosis multisitios. Objetivo: determinar la relación entre el índice tobillo-brazo y la enfermedad arterial coronaria multivasos. Método: se realizó un estudio observacional analítico que incluyó a todos los pacientes egresados de la unidad de cuidados coronarios del Hospital Provincial Universitario Camilo Cienfuegos Gorriarán, de la provincia Sancti Spíritus, en el período comprendido entre el primero de marzo de 2011 al 30 de febrero de 2018, con diagnóstico de síndrome coronario agudo, con y sin elevación del segmento ST. Se recogieron datos clínicos, de índice tobillo-brazo, ecocardiográficos y de angiografía coronaria y se determinó la implicación pronóstica del índice en la enfermedad multivaso a través de un árbol de clasificación con las variables incluidas en el modelo de regresión logística binaria. Resultados: la enfermedad multivaso se presentó en 85,2 % pacientes, de ellos eran hombres el 81,9 %, el 85,9 % de ellos con enfermedad multivaso, la edad media fue de 59,1 años, el 52,3 % presentó SCACEST con enfermedad multivaso el 78,8 %. Los factores de riesgo más frecuentes fueron: el hábito de fumar (86,8 %), la dislipidemia (85,8 %) y la hipertensión arterial (84,8 %) en el grupo con enfermedad multivaso e ITB=0,9 (DE=0,3). Recibieron tratamiento con clopidogrel (86,1 %), ácido acetilsalicílico (86,3 %), IECA o ARA II (85,8 %), estatinas (73,2 %), betabloqueantes (87,5 %) y nitratos (86,3 %). En la angiografía, el 85,2 % presentó una enfermedad coronaria severa. Las dos variables predictoras fueron: el SCASEST y el ITB≤0,9 que mostraron un elevado valor predictivo positivo en el pronóstico de enfermedad arterial coronaria multivaso. Conclusiones: el índice tobillo-brazo<0,9 mostró una capacidad predictiva para la enfermedad multivaso que se incrementa si se asocia a la diabetes mellitus y el hábito de fumar.

ABSTRACT Introduction: Colorectal and anal cancer is a disease of high incidence and mortality, and intestinal occlusion is its most frequent complication. Objective: To identify the predictors of mortality in mechanical intestinal occlusion due to colorectal and anal cancer. Methods: An analytical observational study was carried out that included all patients with mechanical intestinal occlusion due to colorectal and anal cancer consecutively admitted to the "Camilo Cienfuegos" Hospital in Sancti Spíritus, Cuba, from January 1, 2016 to January 31, December 2018. A total of 126 patients with this diagnosis were registered. Demographic variables and associated risk factors were included. Glycemia, creatinine and arterial blood gas were determined. Surgical time, time from admission to surgery, hospital stay, and American Society of Anesthesia classification were also evaluated. For statistical analysis, a binary logistic regression and a classification tree were performed. Results: The mortality of the series studied was 27%. Age greater than or equal to 75 years, the American Society of Anesthesia classification greater than or equal to III, reoperations and complications increased the risk of dying using descriptive and inferential statistics. Conclusions: The results obtained suggest evaluating complications, advanced age, anesthetic risk and reoperations as predictors of mortality in these patients. The probability of death is low in uncomplicated patients under the age of 75 years.

RESUMEN Introducción: El cáncer colorrectal y anal es una enfermedad de elevada incidencia y mortalidad y la oclusión intestinal su complicación más frecuente. Objetivo: Identificar los factores predictores de mortalidad en la oclusión intestinal mecánica por cáncer colorrectal y anal. Métodos: Se realizó un estudio observacional analítico que incluyó todos los pacientes con oclusión intestinal mecánica por cáncer colorrectal y anal ingresados consecutivamente en el Hospital “Camilo Cienfuegos” de Sancti Spíritus, Cuba, en el período comprendido del 1ro de enero de 2016 al 31 de diciembre de 2018. Se registraron un total de 126 pacientes con este diagnóstico. Se incluyeron las variables demográficas y los factores de riesgo asociados. Se determinaron la glucemia, la creatinina y la gasometría arterial. Se evaluaron además el tiempo quirúrgico, el tiempo desde el ingreso a la cirugía, la estadía hospitalaria y la clasificación de la Sociedad Americana de Anestesia. Para el análisis estadístico se realizó una regresión logística binaria y un árbol de clasificación. Resultados: La mortalidad de la serie estudiada fue de un 27 %. La edad mayor o igual a 75 años, la clasificación de la Sociedad Americana de Anestesia mayor o igual III, las reintervenciones y las complicaciones aumentaron el riesgo de fallecer mediante la estadística descriptiva e inferencial. Conclusiones: Los resultados obtenidos sugieren evaluar las complicaciones, la edad avanzada, el riesgo anestésico y las reintervenciones como predictores de mortalidad en estos pacientes. La probabilidad de muerte es baja en pacientes no complicados con edad menor de 75 años.

Abstract We propose a generalized form for Red Black Trees. The structure, called Partitioned Binary Search Trees, tolerates finite successions of Red nodes provoking a degree of imbalance while reducing the number of maintenance operations and speeding up the updates. The tree is interesting not only because of its simple operations but also because it insures the same level of performance of Red Black Trees O(log n) and allows an even higher adaptability and efficiency rate in different fields where rebalancing is costly.

ABSTRACT INTRODUCTION Many clinical settings lack the necessary resources to complete angiographic studies, which are commonly used to predict complications and death following acute coronary syndrome. Corrected QT-interval dispersion can be useful for assessing risk of myocardial infarction recurrence. OBJECTIVE Evaluate the relationship between corrected QT-interval dispersion and recurrence of myocardial infarction in patients with ST- segment elevation. METHODS We conducted a prospective observational study of 522 patients with ST-segment elevation myocardial infarction admitted consecutively to the Camilo Cienfuegos General Provincial Hospital in Sancti Spiritus, Cuba, from January 2014 through June 2017. Of these, 476 were studied and 46 were excluded because they had other disorders. Demographic variables and classic cardiovascular risk factors were included. Blood pressure, heart rate, blood glucose, and corrected and un- corrected QT-interval duration and dispersion were measured. Patients were categorized according to the Killip-Kimball classification. Association between dispersion of the corrected QT-interval and recurrence of infarction was analyzed using a binary logistic regression model, a regression tree and receiver operator characteristic curves. RESULTS Patients with recurrent infarction (56; 11.8%) had higher average initial blood glucose values than those who did not have recurrence; the opposite occurred for systolic and diastolic blood pressure and for left ventricular ejection fraction. Dispersion of the corrected QT-interval was a good predictor of infarction recurrence according to a multivariate analysis (OR = 3.09; 95% CI = 1.105–8.641; p = 0.032). Cardiac arrest is the variable that best predicts recurrence. No recurrence of infarction occurred in 97% of patients without cardiac arrest, left ventricular ejection fraction >45% and corrected QT- interval dispersion <80 ms. CONCLUSIONS Risk of infarction recurrence is low in patients without cardiac arrest, with left ventricular ejection fraction >45% and with dispersion of corrected QT-interval <80 ms. Patients with corrected QT-interval dispersion ≥80 ms have greater risk of recurrence of infarction, which suggests that this variable could be used for stratification of risk following ST-segment elevation myocardial infarction.

Abstract: We propose a unique representation of both AVL and Red-Black trees with the same time and space complexity. We describe all the maintenance operations and also the insertion and deletion algorithms. We give the implementation of the proposed tree and the results. We then make a comparison of the three structures. The simulation results confirm the performance of the new representation relatively to AVL and Red-Black trees.

Macauba is a palm tree which provides large amount of oil. Particularly its oil from the kernel presents excellent stability to oxidation as it is mainly constituted by saturated organic chains. This stability is inherited by the biodiesel prepared with this oil. Paradoxically, contrarily to the expectation as it is mainly constituted by saturated esters, the biodiesel prepared from the macauba kernel oil presents low cold filter plugging point (CFPP). This can be understood on the basis of the high level of content of saturated esters with relatively short carbon chain. Considering these two properties of the biodiesel prepared from the macauba kernel oil, i.e., excellent oxidation stability and low CFPP, it was studied if such characteristics could be transferred to blends constituted by it and another vegetable oil. Blends with biodiesels from soy, corn, macauba pulp and fry oil were studied and it was observed that, indeed, partial transference occurs, meaning that the inconvenient characteristics of such biodiesels were favorably ameliorated, allowing the use, as fuels, of the biodiesels prepared from other oils which original properties do not attaint the quality specified by the regulatory agencies.

Abstract Energy efficient data aggregation is a key solution to enhance the lifetime of wireless sensor networks since sensor nodes are battery-powered and deployed in remote environments. This article explore a two-hop data aggregation tree construction algorithm using binary search tree to reduce the total energy consumption of sensor nodes in wireless sensor networks. An adaptive and hybrid routing algorithm for simultaneous data aggregation and exploit the data correlation between nodes using the two-hop data aggregation tree framework is proposed. Routes are chosen based on the shortest response time for the broadcasting request to minimize the total energy expended by the network. This paper also proposes a high secure asymmetric key cryptography algorithm to provide the secure data communication among the network. The data aggregation function that is used in the proposed routing algorithm enhances the lifetime of sensor network by resolving the delay, collision and security issues. Simulations results show that the binary tree based data aggregation can appreciably reduces the total energy consumption and resolves the maximum data aggregation issues in wireless sensor network.

RESUMO O fungo Microcyclus ulei é o agente causador da doença do mal das folhas em seringueira, sendo esta doença umas das mais importantes nesta cultura, visto a intensa desfolha que causa nas plantas. Varias raças deste patógeno foram descritas no Brasil, baseada em uma série de diferentes clones diferenciadores. Fundamentado nas reações de 11 clones diferenciadores já conhecidos na literatura (MDF 180, FX 3844, FX 985, FX 4098, FX 2261, FX 2804, FX 3899, IAN 6158, IAN 3087, IAN 717 e PA 31), contendo as espécies Hevea brasiliensis. Hevea benthamiana e Hevea pauciflora, realizou-se uma análise de agrupamento para os dados binários referente à virulência da doença utilizando o método de Jaccard. A análise de agrupamentos (cluster analysis) foi feita pelo método do centróide. Os resultados obtidos indicam a existência de 53 raças diferentes desse patógeno no Brasil.

ABSTRACT The fungus Microcyclus ulei is the causative agent of leaf blight in rubber trees, which is one of the most important diseases affecting this crop, since it causes intense defoliation. Several races of this pathogen have been described in Brazil based on a series of diverse differential clones. According to the reactions of 11 differential clones already reported in the literature (MDF 180, Fx 3844, Fx 985, Fx 4098, Fx 2261, Fx 2804, Fx 3899, IAN 6158, IAN 3087, IAN 717 and PA 31), containing the species Hevea brasiliensis. Hevea benthamiana and Hevea pauciflora, a cluster analysis of the binary data referring to virulence of this disease was performed by using the Jaccard method. The cluster analysis was fitted according to the centroid method. Results indicated the existence of 53 different races of this pathogen in Brazil.

ResumenEl éxito de anidación ha sido un indicador para evaluar los cambios ambientales que afectan el éxito reproductivo de aves, ya que permite analizar cambios que ocurren en la natalidad. En el presente estudio analizamos el éxito de anidación de Turdus grayi en el Centro Ecológico Recreativo “El Zapotal”, Chiapas. Durante la temporada reproductiva del 2015, evaluamos las características del hábitat, presentes en los sitios de anidación a través de la búsqueda intensiva de nidos. Localizamos 56 nidos de los cuales, 27 (48.2 %) fueron exitosos y 29 (51.7 %) fueron fallidos. La mayoría de los nidos no exitosos (19) fueron depredados mientras que 8 (27.6 %) fueron abandonados y 2 (6.9 %) parasitados. El éxito de anidación fue de 46 %. La depredación fue el principal factor del fallo de los nidos. La incubación fue la etapa más susceptible a la depredación.Identificamos que las variables del sitio de anidación operaron a dos escalas espaciales: local y parche del nido. A través del análisis de regresión logística binaria se obtuvo un modelo para cada escala, el cual predijo qué variables incrementaron la probabilidad de éxito de anidación. Además realizamos un análisis de regresión logística multivariante para descartar posibles interacciones entre las variables. A escala local encontramos que la altura del nido a un intervalo de 4.2-5.1 m de altura incrementó el éxito del nido, mientras a escala parche del nido, la probabilidad de éxito de anidación fue mayor en los sitios con una densidad ≥ 12 árboles. Los análisis indicaron que la probabilidad de éxito de anidación no presentó una relación entre la escala local y parche del nido. Lo que sugiere un desacoplamiento de escalas y mecanismos. Por lo cual los cambios que ocurren en las variables que intervienen a escala local parecen no interferir en la escala de parche del nido. Los resultados obtenidos mostraron que la variación en las características de los sitios de anidación podría influir en la depredación además de que la depredación podría haberse presentado de manera aleatoria ya que los nidos que presentaron probabilidades medias y altas de ser exitosos fallaron por esta causa. De este modo, con el fin de comprender los factores, mecanismos y características de historia de vida que influyen en el éxito de anidación, sugerimos que además de las variables ambientales, los estudios futuros deberán considerar el comportamiento de las aves anidantes.

AbstractNesting success has been a surrogate to assess environmental changes that affect the reproductive success of birds, and to analyze changes that influence natality. We analyzed the nesting success of Turdus grayi at “El Zapotal” Recreational Ecological Preserve, Central Chiapas. During the 2015 breeding season, we intensively searched for active nests and evaluated habitat characteristics. We located a total of 56 nests of which 27 (48.2 %) were successful and 29 (51.7 %) were unsuccessful. Most unsuccessful nests (19) were depredated, while 8 (27.6 %) were abandoned and 2 (6.9 %) parasitized. Nesting success was 46 %. Depredation was the main mechanism of nest failure, mostly during incubation. We identified operating variables at site and patch scales. Through analysis of binary logistic regression models for each scale, we predicted which variables increased the probability of nesting success. We also performed a multivariate logistic regression analysis to rule out possible interactions among variables. At nest scale we found that nest height, ranging 4.2 - 5.1 m had increased nesting success, while at patch scale, the probability of nest success was greater at sites with a tree density ≥ 12. Our results indicated that the probability of nesting success did not show a relationship between scales. We suggest a decoupling between scales and mechanism. Thus, habitat changes occurring at local scale did not seem to interfere with the patch scale. Also, our results showed that variation in characteristics at nest scale could also influence depredation, when depredation had been presented at random, since nests with medium and high probability of being successful, failed also for this reason. Thus, in order to understand the factors, mechanisms and life history characteristics influencing nesting success, we suggest that in addition to the environmental variables, future studies should also consider the bird nesting behaviour. Rev. Biol. Trop. 65 (3): 925-938. Epub 2017 September 01.