Resumne Introducción. Los bioestimulantes son productos orgánicos que mejoran la absorción de nutrientes de las plantas, entre ellos sustancias húmicas, aminoácidos, extractos de algas y bacterias promotoras del crecimiento de las plantas; y se han identificado numerosos mecanismos y de selectividad de bioestimulantes para nutrientes específicos. Objetivo. Determinar el efecto de la aplicación de bioestimulantes en la producción de pepino y melón en invernadero. Materiales y métodos. Se evaluaron los bioestimulantes BioRemedy 2,0 g L-1, Grand Sill 2,0 g L-1, Fossil 5,0 g L-1, L-Amino 2,0 mL L-3 y un Testigo (con aplicación de solo agua), en tres estadios de desarrollo de los cultivos. El experimento fue establecido bajo un diseño experimental completamente aleatorio desbalanceado con 10 tratamientos. Cada unidad experimental estuvo constituida por tres hileras. Las variables de respuestas fueron: altura de planta, grosor de tallo, número de frutos, tamaño del fruto, volumen del fruto y peso de frutos (rendimiento). Resultados. Los bioestimulantes tuvieron mejor efecto en la altura de planta, diámetro de tallo, volumen de fruto en el pepino. En melón los bioestimulantes tuvieron mayor efecto en el volumen de fruto y peso. Se encontró que Fossil mostró mejor efecto para la altura de planta en ambas especies y el BioRemedy resulto ser el mejor para el diámetro de tallo, volumen de fruto, peso de fruto y número de frutos. Conclusión. El BioRemedy fue el mejor bioestimulante para el diámetro de tallo, el volumen y peso de fruto para el cultivo de pepino y melón. El L-amino tuvo mejor respuesta para diámetro de tallo en melón.

Abstract Biostimulants are organic products that improve plant nutrient absorption, for instance humic substances, amino acids, algae extracts and plant growth-promoting bacteria; and numerous mechanisms and selectivity of specific biostimulants for specific nutrients have been identified. Objetive. Determine the effect of the application of biostimulants on the production of cucumber and melon in the greenhouse. Materials and methods. The biostimulants BioRemedy 2.0 g L-1, Grand Sill 2.0 g L-1, Fossil 5.0 g L-1, L-Amino 2.0 mL L-3 and a Control with application of only water were evaluated in three stages of crop development. The experiment was established as a completely randomized unbalanced experimental design with 10 treatments. Each experimental unit consisted of three rows. The response variables were: plant height, stem thickness, number of fruits, fruit size, fruit volume and fruit weight (yield). Results. The biostimulants had a better effect on plant height, stem diameter, and fruit volume for cucumber. For the melon, fruit volume and weight were affected by biostimulants. It was found that Fossil showed the best effect for plant height in both species and BioRemedy turned out to be the best for stem diameter, fruit volume, fruit weight and number of fruits. Conclusion. BioRemedy was the best biostimulant for stem diameter, volume and fruit weight for cucumber and melon cultivation. L-amino had the best response for stem diameter in melon.

Zusammenfassung: Ziel dieser quantitativen Studie ist es, die Korrelation zwischen den L2-Lernstrategien von Deutschlernenden und der Beherrschung der Nebensatzsyntax bei deutschen Verben festzustellen. Zur Messung der Lernstrategien wurde die Version 7 des Oxford SILL (Oxford, 2003) verwendet. Die Forced-Choice-Tests von Catasso (2004) wurden verwendet, um die Kenntnisse der Nebensatzsyntax zu beurteilen. Die Probanden an dieser Studie waren 55 Schüler einer deutschen Schule Chiles. Die mit R durchgeführte Analyse zeigt, dass die am häufigsten verwendete Lernstrategie die Kompensationsstrategien waren. Die Daten zeigten, dass keine statistisch signifikante positive Korrelation zwischen häufiger Lernstrategieanwendung und besserer Beherrschung der Verbstellung besteht. Es besteht jedoch eine statistisch signifikante negative Korrelation zwischen dem Einsatz metakognitiver Strategien und der Beherrschung der Nebensatzsyntax bei männlichen Lernenden. Die persönlichen Variablen beim Sprachenlernen könnten positive Auswirkungen haben. In Zukunft wäre es sinnvoll, diese Art von Korrelationsstudien auf andere Aspekte des deutschen Spracherwerbs wie die Deklination auszuweiten. Zusammenfassung L2Lernstrategien LLernstrategien L2 L festzustellen Oxford, (Oxford 2003 verwendet ForcedChoiceTests Forced Choice Tests 2004 (2004 beurteilen 5 Chiles zeigt zeigten Lernenden haben sinnvoll auszuweiten 200 (200 20 (20 2 (2 (

Abstract: The aim of this quantitative study is to determine the correlation between German learners' L2 learning strategies and their mastery of German verb subordinate clause syntax. To measure learning strategies, version 7 of the Oxford SILL (Oxford, 2003) was used. Catasso's (2004) forced-choice tests were used to assess knowledge of subordinate clause syntax. The subjects in this study were 55 students from a German school in Chile. The analysis carried out with R shows that the most frequently used learning strategy was the compensatory strategies. The data showed that there is no statistically significant positive correlation between frequent learning strategy use and better mastery of verb position. However, there is a statistically significant negative correlation between the use of metacognitive strategies and the mastery of subordinate clause syntax in male learners. Personal variables in language learning could have positive effects. In the future, it would be useful to extend this type of correlational study to other aspects of German language acquisition such as declension. Abstract learners L Oxford, (Oxford 2003 Catassos Catasso s 2004 (2004 forcedchoice forced choice 5 Chile position However effects future declension 200 (200 20 (20 2 (2 (

Resumen Se llevó a cabo un estudio de la variación espacio-temporal del valor b de la relación frecuencia-magnitud de sismos ocurridos en el Volcán Cerro Machín (VCM), Colombia, para el período 20072020. Se pudo establecer que el valor b presenta variaciones espaciales caracterizadas por valores altos (1,1-1,3) en la parte superficial del volcán, debajo del domo principal y hasta una profundidad de 1 km. Entre 1 y 6 km de profundidad, se observaron valores normales a bajos (0,8-0,6). Bajo el domo Tapias, entre 8 y 13 km de profundidad, se observaron valores altos de b (1,1-1,3). Estos valores anómalos indicarían zonas de circulación de fluidos hidrotermales en la parte superficial y posibles reservorios de magma en la parte más profunda del VCM. Adicionalmente, se observaron variaciones temporales del valor b; se destacan tres cambios importantes, relacionados con variaciones en la actividad del VCM: el primero, ocurrido en noviembre 2008, se asoció con un enjambre al NE y E del domo principal (3-5 km de profundidad); el segundo, ocurrido en agosto-diciembre 2010, se asoció con la presencia de sismicidad profunda (12-18 km) a unos 8 km al SE del domo principal, y el tercero, ocurrido en febrero de 2018, se asoció con un enjambre sísmico (3-5 km de profundidad) al SW del domo principal. Estos tres cambios se interpretan como posibles intrusiones de pulsos de magma, asociadas a un dique o silo superficial (<4 km de profundidad) y a una entrada de magma a mayores profundidades (>15 km). Algunos de estos cambios en el valor b estuvieron asociados con cambios geoquímicos o de deformación de la superficie. Los resultados de este estudio muestran que el cálculo rutinario del valor b sirve como herramienta de monitoreo volcánico para el VCM.

Abstract A study of the spatiotemporal variation of b-value for earthquakes that occurred at Cerro Machin Volcano (CMV), Colombia was carried out for the period 2007-2020. b-value showed spatial variations, with high values (1.1-1.3) at the shallow portion of the volcano, beneath the main dome up to 1 km depth from the top of the volcano. Normal to low b-values (0.8-0.6) were observed between 1 and 6 km depth all around the volcano, while high b-values (1.1-1.3) were observed beneath the Tapias dome between 8 and 13 km depth. These b-values could indicate circulation of hydrothermal fluids at shallow depths, and a possible magma reservoir at deeper portions beneath the CMV. In addition, temporal variations of the b-value were observed during the study period. Three remarkable episodes of increase in b-value were detected related to changes in CMV activity. The first, which occurred in November 2008, related to a strong earthquake swarm (3-5 km depth) located to the NE and E of the main dome. The second, occurred between August and December 2010 related to deep seismicity (12-18 km depth), 8 km southeast of the main dome. The third occurred in February 2018 related to a strong earthquake swarm (3-5 km depth) located to the SW of the main dome. These three episodes are interpreted as pulses of magma at the volcanic system of CMV, associated with a dike or sill intrusion (<4 km depth) and input of magma to a deeper reservoir of CMV (>15 km depth). Some of these changes in the b-value were correlated to changes in geochemistry and ground deformation. The results of the study confirm the idea of the routine task of b-value calculation as a volcano monitoring tool for CMV activity.

Resumo Em áreas tropicais quentes, para evitar o estresse térmico, é comum a prática de que os edifícios escolares dependam do uso de sistemas de climatização mecânicos. A utilização de estratégias passivas de projeto, nessas regiões, em busca do conforto térmico com um baixo gasto energético, é de suma importância. Nesse sentido, as aberturas da edificação desempenham um importante papel, pois interferem na quantidade da radiação solar recebida e no padrão de distribuição do fluxo do ar interno. O objetivo desta pesquisa foi avaliar o desempenho térmico em uma sala de aula sob diferentes configurações de modelos de janelas e portas em Vitória, ES, e Belém, PA. A metodologia utilizou simulações de desempenho térmico e de dinâmica dos fluidos computacional para análise da intensidade de desconforto térmico e do consumo energético. Os resultados mostram que a adição do peitoril ventilado aumenta a velocidade do ar na entrada da abertura e melhora significativamente o desempenho térmico na sala de aula. O uso de brise-soleil reduz em até 50% e 13% o consumo energético no ambiente, em Belém e Vitória, respectivamente. O estudo contribui para a seleção de aberturas mais eficientes, adaptadas às condições climáticas de cada região.

Abstract In school buildings located in hot tropical areas, it is a common practice to use mechanical climate control systems to avoid heat stress. The use of passive design strategies is of paramount importance for the achievement of thermal comfort with low energy consumption. Hence, buildings’ openings play an important role, as they have an impact on the amount of solar radiation received and on the internal air flow distribution pattern. The objective of this study was to evaluate the thermal performance in classrooms with different window and door model configurations in Vitória/ES and Belém/PA, Brazil. Simulations of thermal performance were conducted to analyse the intensity of thermal discomfort and energy consumption, while the aid of Computational Fluid Dynamics tools enabled the verification of details of the air velocity and temperature fields. The results show that the addition of a ventilated sill increases air velocity at the inlet opening and significantly improves thermal performance in the classroom. The use of brise-soleil reduces energy consumption in the classrooms in Belém and Vitória by up to 50% and 13%, respectively. The study helps in the selection of more efficient openings, adapted to the climatic conditions of each region.

This study investigated the effectiveness of bed sills in reducing the scour depth with time at rectangular piers in a laboratory. Experiments were conducted just below the threshold of sediment motion (U/Uc = 0.95) for round-nosed piers with the length-to-width ratios of L/b = 1, 2, 3 and 4. Accordingly, a 1 cm thick PVC section as wide as the channel was used as the bed sill, which was flush with the bed and located at various distances, D, in the downstream of the piers, i.e. D/b = 0, 1, 2 and 3. It was found that the efficiency of the bed sill for a rectangular pier was significantly less than that for the circular one; there was a decrease in efficiency and scour depth with an increase of the pier length. The maximum efficiency obtained for the round-nosed piers with L/b = 1, 2, 3 and 4 was 32.5%, 21.3%, 14.4% and 5.7%, respectively. The application of a bed sill to reduce the local scour in round-nosed rectangular piers, when the length-to-width ratio exceeds 2, is therefore not recommended. Furthermore, the efficiency of the bed sill is the best when it is attached to the downstream end of the pier; its efficiency is decreased when increasing its distance from the pier.

Resumen Introducción: Los ecosistemas costeros alrededor del mundo están bajo la influencia de tensores locales, regionales y globales, como la contaminación, la eutroficación y el cambio climático. El Golfo Dulce es un profundo ecosistema tropical relativamente inalterado y accesible, que provee oportunidades para la investigación comparativa y colaborativa. Objetivo: Resumir los informes publicados sobre investigaciones pasadas realizadas en el ecosistema, identificar tópicos para estudios futuros y sugerir nuevas áreas de investigación. Métodos: Se hizo una búsqueda en la red de informes basados en investigaciones hechas en Golfo Dulce y publicadas en revistas científicas. Fueron incluidos aquellos informes sobre parámetros ambientales y la biota. Resultados: Un total de 123 estudios que incluyen datos sobre Golfo Dulce son citados. Los cuatro tópicos citados con más frecuencia fueron: Los resultados de la expedición del R/V Victor Hensen (1993-1994) y estudios de seguimiento sobre microbiología, informes sobre parámetros acuáticos, investigaciones sobre vertebrados y estudios sobre zooplancton. Los informes sobre perfiles de oxígeno y temperatura son presentados con mayor detalle, seguidos por aquellos sobre la biota. Conclusiones: Golfo Dulce tiene bajas concentraciones de oxígeno por debajo de 50 m y es usualmente anóxico a 200 m en el fondo, con formación ocasional de H2S. Sin embargo, el ecosistema contiene una diversidad de organismos identificados relativamente alta, desde bacterias hasta ballenas. De relevancia particular para futuros estudios es, entre otros, la conducción, de muestreos multidisciplinarios orientados a obtener datos sobre productividad primaria, la diversidad y biomasa de los principales grupos de organismos planctónicos, demersales y bénticos, así como la frecuencia y magnitud del flujo de agua oceánica hacia el interior. Estos datos, así como los obtenidos en el pasado, son esenciales para actualizar el modelo trófico desarrollado hace más de 25 años, o en apoyo de nuevos modelos predictivos de funcionamiento del ecosistema.

Abstract Introduction: Coastal ecosystems worldwide are under the influence of local, regional and global stressors, such as pollution, eutrophication and climate change. Golfo Dulce is a relatively pristine and accessible deep tropical ecosystem that provides opportunities for comparative and collaborative research. Objective: To summarize published reports on past research conducted in this ecosystem, identify topics for further study, and suggest new research issues. Methods: A search was made on the web for reports based on research conducted in Golfo Dulce and published in scientific journals. Reports focusing on environmental parameters and on the biota were included. Results: A total of 123 studies that include data from Golfo Dulce are cited. The four topics more frequently addressed were reports based on the results of the R/V Victor Hensen expedition (1993-1994) and follow-up work on microbiology, studies on water parameters, research on vertebrates, and zooplankton studies. The reports focusing on vertical profiles of oxygen and temperature are discussed in detail, followed by those on the biota. Conclusions: Golfo Dulce has low oxygen concentrations below 50 m and is frequently anoxic at the 200 m deep basin with occasional formation of H2S. However, the ecosystem contains a relatively high diversity of identified organisms, from bacteria to whales. Of particular relevance for future studies are multidisciplinary surveys aiming at obtaining data on primary productivity, the diversity and biomass of the main groups of planktonic, demersal and benthic organisms, and the frequency and magnitude of the influx of deep offshore waters over the sill into the basin. These data, as well as the information gathered in the past, are essential for updating the trophic model developed more than 25 years ago and in support of new predictive models on the functioning of the ecosystem.

Abstract: Knowing the effects of natural aging on wood properties is important both for the conservation of historical wooden material and for reuse of aged wood. The aim of this study was to investigate the wood properties of old wooden elements not impregnated with any protective chemicals and taken from different parts of Zeytinlik houses in Giresun, Turkey. Test samples were prepared from old wooden elements and freshly cut chestnut timber. The anatomical, chemical, physical and mechanical properties were determined according to standard procedure, and the results were compared with those of recent wood specimen. As a result of the anatomical identification, it was determined that the wooden elements used in traditional Zeytinlik houses belong to species of Anatolian chestnut (Castanea sativa), and after an average service life of 88, 113 and 120 years, there was no change in the anatomical structure of the old wooden elements. Fourier transform infrared band characterization of old wood specimens revealed that hemicelluloses degraded and lignin structure changed on the surface of almost all specimens. Especially, the wood density values of the facade elements were smaller than that of recent wood specimen. Except for the modulus of rupture of window sill and rafter, all mechanical properties were significantly greater compared with those of recent wood specimen. The results of this research showed that old wood not damaged by fungi and insects could be evaluated for reuse.

Abstract Orthogneisses associated with metavolcanosedimentary successions related to the 1000 - 920 Ma Cariris Velhos event occur mainly in a ca. 700 km-long sigmoidal-shaped belt that crosscuts the Transversal Zone of the Borborema Province and extends to the fold belts located in its southern or external zone (part of the Riacho do Pontal and Sergipano orogens). Despite its importance, the tectonic setting and the role of those rocks in the geological evolution of the Borborema Province are contentious and not yet well understood. New zircon U-Pb SHRIMP data on an augen-gneiss sill of the Afeição Suite intruding mica-schists mapped as part of the Santa Filomena Complex yielded a Concordia Age of 974 ± 11 Ma, indicating that at least part of the metasedimentary rocks in the internal zone of the Riacho do Pontal Orogen are Tonian or older and possibly related to the Cariris Velhos event. Hf-in-zircon isotope data are presented for the first time for Cariris Velhos-related ortho-derived rocks of the Afeição Suite. Analyzed samples yielded εHf(t) in a narrow range between -1.51 and +2.41, with associated TDMHf of 1.6-1.4 Ga, similar to previously obtained Nd isotope data with εNd(t) = -1.0 to +3.1 and TDMNd of 1.5-1.2 Ga. A possible scenario to explain both the geochemical features and the moderately juvenile to slightly evolved, near-chondritic Hf and Nd isotope signatures is a continental arc setting, where fractionated melts produced in the supra-subduction zone mantle wedge carrying a Tonian juvenile signature became contaminated with discrete amounts of Archean-Paleoproterozoic continental crust during ascent, producing Mesoproterozoic model ages which represent the mixture of those two end-members.

In this study, temporal variation of local scour occurring at the downstream part of the stepped channel were investigated experimentally. The experimental tests were carried out in a stepped flume with a height of 2.4 m. The width of the rectangular flume was 0.10 m and the length of the stilling basin was 2.12 m. Bed material was placed in a sediment box with a height of 24 cm and length of 2.48 m, without any compaction. Experiments were carried out by using bed material of 4 different grain size distributions, 2 different sill heights and 6 different flow rates. Two empirical equations which include Shields parameter (θ) and densimetric Froude particle number (Fd) were proposed by using the experimental findings to predict the temporal variation of the scour depth. The R² (coefficient of determination) values were computed for both proposed equations as 0.866 and 0.865. The scatter index (SI) values were also determined and computed as 8.73% and 8.25%. The fit of the equations was also determined by means of Fisher's test.

RESUMO Em viveiros de mudas de cafeeiro (Coffea arabica) ocorrem condições favoráveis para a ocorrência de epidemias da mancha aureolada (Pseudomonas syringae pv. garcae). Estudar a distribuição espacial de plantas doentes pode auxiliar na adoção de estratégias de manejo. Nesse sentido, a geoestatística tem sido aplicada para modelar a distribuição espacial e estudar aspectos epidemiológicos de doenças de plantas. Assim, este estudo foi desenvolvido para caracterizar o padrão de distribuição espacial da mancha aureolada em viveiro de mudas de cafeeiro. Para isso, o progresso da doença foi monitorido ao longo do tempo em 704 mudas organizadas em linhas e colunas em viveiro. Considerando o diâmetro médio dos recipientes utilizados para produção das mudas, foi realizado o georreferencimento das mudas no viveiro em sistema de coordenadas plano-cartesiano. Os dados de incidência da doença foram submetidos a uma análise exploratória não espacial e à análise geoestatística. O semivariograma isotrópico esférico foi ajustado aos dados e a interpolação dos dados foi realizada por krigagem ordinária para visualizar a distribuição espacial de mudas sintomáticas. Epidemia da doença foi detectada em viveiro durante o período experimental, havendo variabilidade e dependência espacial em relação à distribuição das mudas doentes. Com o decorrer da epidemia, houve aumento da população de plantas doença, número e tamanho dos focos e coalescência desses. Além disso, houve aumento do valor do alcance, patamar e do efeito pepita. Os mapas de krigagem mostraram o progresso da doença e sua variação. A epidemia da mancha aureolada do cafeeiro iniciou com padrão aleatório de distribuição espacial, progredindo para padrão agregado.

ABSTRACT In nurseries of coffee tree seedlings (Coffea arabica), there are favorable conditions for bacterial blight epidemics (Pseudomonas syringae pv. garcae). Studying the spatial distribution of diseased plants can help in the adoption of management strategies. Likewise, geostatistics has been applied to shape the spatial distribution and study epidemiological aspects of plant diseases. Thus, this study was developed to characterize the spatial distribution pattern of bacterial blight in a nursery of coffee tree seedlings. The disease progress was monitored over time in 704 seedlings organized in lines and columns in a nursery. Considering the mean diameter of the pots used for producing seedlings, georeferencing was carried out in Cartesian coordinate system for the seedlings in the nursery. The disease incidence data were subjected to non-spatial exploratory analysis and geostatistical analysis. The spherical isotropic semivariogram model was adjusted to the data and data interpolation was performed by ordinary kriging to visualize the spatial distribution of symptomatic seedlings. Bacterial blight epidemic was detected in the nursery during the experimental period, and there was variability and spatial dependence in relation to the distribution of diseased seedlings. As the epidemic progressed, the population of diseased plants increased, as well as the number and the size of the foci and their coalescence. Besides, there was an increase in the range value, sill and nugget effect. The kriging maps showed the disease progress and its variance. The bacterial blight epidemic of coffee tree started with a random spatial distribution pattern, progressing to an aggregate pattern.

RESUMO: O objetivo deste artigo foi avaliar o comportamento e o relacionamento do alcance e dos componentes do IDE (Índice de Dependência Espacial) em geral e em função de fatores de campo, tais como tipos de solo, tipo de atributo e profundidades de solo. Esta avaliação foi baseada em dados reais coletados em periódicos nacionais. Foi observado que o parâmetro alcance, em geral, e para diferentes fatores de campo, apresentou comportamento de assimetria positiva. Os componentes do IDE apresentaram comportamento aproximadamente simétrico. O IDE consegue captar, de forma mais intensa, o comportamento do alcance (o comportamento da variabilidade espacial no sentido horizontal do semivariograma), e, de forma menos intensa, o comportamento dos parâmetros contribuição e patamar (o comportamento da dependência espacial no sentido vertical do semivariograma). Assim, o IDE descreve o comportamento de dependência espacial de toda a gama de aspectos do semivariograma.

ABSTRACT: The main purpose of this article was to evaluate the behavior and relationship of the range and components of SDI (Spatial Dependence Index) in general and in function of field factors such as soil types, type of attribute and soil layers. This evaluation was based on real data collected in national journals. It was noticed that the parameter range, in general and for different field factors, presented asymmetric positive behavior. The components of the SDI showed approximately symmetrical behavior. The SDI can capture the range behavior more intensely (the spatial variability behavior in the horizontal direction of the semivariogram), and, in a less intense way, the behavior of the contribution and sill parameters (the spatial dependence behavior in the vertical direction of the semivariogram). Thus, the SDI describes the behavior of spatial dependence of the total set of aspects of the semivariogram.

RESUMO Assumindo a existência de uma relação entre a heterogeneidade da paisagem e medidas de dependência espacial obtidas de dados de sensoriamento remoto, o objetivo deste estudo foi avaliar o potencial dos parâmetros do semivariograma derivados de imagens de satélite com diferentes resoluções espaciais, para caracterizar áreas cobertas por floresta e áreas sob ação antrópica. Para isso, o NDVI (Índice de Vegetação da Diferença Normalizada) de cada umas das imagens (SPOT 6, Landsat 8 e MODIS Terra) foi gerado em uma área de floresta tropical Amazônica (1.000 km²), onde foram selecionadas amostras (1 x 1 km) de áreas florestadas e áreas antrópicas. A partir destes dados, foram gerados os semivariogramas e extraídos os parâmetros patamar (σ²-variabilidade espacial total) e alcance (φ-distância dentro da qual as amostras apresentam-se estruturadas espacialmente). A análise revelou que a resolução espacial das imagens influencia os parâmetros σ² e φ, apresentando significativo aumento das áreas de florestas para as áreas sob ação antrópica. A maior variação entre estas classes foi obtida com as imagens Landsat 8, indicando estas imagens, com resolução espacial de 30 metros, a mais apropriada para a obtenção dos parâmetros do semivariograma objetivando a caracterização da heterogeneidade espacial da paisagem. Combinando o sensoriamento remoto e técnicas geostatisticas, demonstrou-se que os parâmetros do semivariograma derivados de imagens NDVI podem ser utilizados como um simples indicador de heterogeneidade da paisagem, gerando mapas que permitem aos pesquisadores delinearem com maior eficácia o regime de amostragem. Outras aplicações combinando estas duas técnicas devem ser investigadas, como por exemplo a detecção de mudanças na cobertura do solo e a classificação de imagens utilizando análises orientada a objetos (OBIA).

ABSTRACT Assuming a relationship between landscape heterogeneity and measures of spatial dependence by using remotely sensed data, the aim of this work was to evaluate the potential of semivariogram parameters, derived from satellite images with different spatial resolutions, to characterize landscape spatial heterogeneity of forested and human modified areas. The NDVI (Normalized Difference Vegetation Index) was generated in an area of Brazilian amazon tropical forest (1,000 km²). We selected samples (1 x 1 km) from forested and human modified areas distributed throughout the study area, to generate the semivariogram and extract the sill (σ²-overall spatial variability of the surface property) and range (φ-the length scale of the spatial structures of objects) parameters. The analysis revealed that image spatial resolution influenced the sill and range parameters. The average sill and range values increase from forested to human modified areas and the greatest between-class variation was found for LANDSAT 8 imagery, indicating that this image spatial resolution is the most appropriate for deriving sill and range parameters with the intention of describing landscape spatial heterogeneity. By combining remote sensing and geostatistical techniques, we have shown that the sill and range parameters of semivariograms derived from NDVI images are a simple indicator of landscape heterogeneity and can be used to provide landscape heterogeneity maps to enable researchers to design appropriate sampling regimes. In the future, more applications combining remote sensing and geostatistical features should be further investigated and developed, such as change detection and image classification using object-based image analysis (OBIA) approaches.

Abstract: This study aimed at investigating the self-reported language learning strategy use among university learners of English as a foreign language and the variation of this use according to the level of English proficiency. A translated version (into Spanish) of the SILL (Strategy Inventory for Language Learning) (Oxford, 1990) was administered to obtain data about perceived strategy use and English proficiency was measured by means of the Oxford Placement Test (Allan, 2004). The data were analysed using descriptive (mean, standard deviation, frequency and percentage) and inferential statistics (ANOVA followed by a post hoc Scheffé’s test). The results show that the participants were medium strategy users overall, with affective strategies showing the most frequent use, followed by compensation strategies and metacognitive strategies. Regarding variation in perceived strategy use according to English proficiency, the study concludes that the higher the proficiency level, the more frequent the declared strategy use. The findings suggest that factors, such as cultural and socio-educational origin, and proficiency level affect both strategy choice and frequency of strategy use.

Resumen: Este artículo presenta un estudio orientado a investigar el uso percibido de estrategias de aprendizaje de una lengua entre aprendientes universitarios de inglés como lengua extranjera y la variación de este uso en función del nivel de competencia en esta lengua. Como herramienta de obtención de datos se empleó el Strategy Inventory for Language Learning (en español, el Inventario de Estrategias para el Aprendizaje de una Lengua) (Oxford, 1990). El nivel de competencia de los participantes, por su parte, se midió a través del Oxford Placement Test (Allan, 2004). Los datos fueron sometidos a análisis estadístico de tipo descriptivo (media, moda, desviación estándar, frecuencia y porcentaje) e inferencial (ANOVA seguido de la prueba post hoc de Scheffé). Los resultados indican que los participantes, en su conjunto, se declaran usuarios de estrategias de un nivel intermedio, siendo las estrategias afectivas las que manifiestan emplear con mayor asiduidad, seguidas por las estrategias de compensación y las de naturaleza metacognitiva. En cuanto a la variación en el uso percibido de estrategias derivada del nivel de competencia en inglés, el estudio concluye que cuanto más elevado es el nivel de competencia, más frecuente es el uso declarado de estrategias. Los hallazgos apuntan a que factores como el origen cultural y socioeducativo de los informantes y su nivel de competencia inciden tanto en la elección de estrategias, como en la frecuencia de su uso.

Resumo: Em geoestatística, a utilização de medidas que descrevam a dependência espacial do atributo é de grande importância, porém apenas alguns modelos (que possuem estacionariedade de segunda ordem) são contemplados com tais medidas. Assim, este trabalho tem como objetivo propor medidas para avaliação do grau de dependência espacial em fenômenos com ajuste de modelo potência. A partir de uma premissa que considera o patamar-equivalente como o valor de semivariância que coincide com o ponto em que as curvas ajustadas do modelo potência se interceptam, pode-se construir dois índices para avaliação de tal dependência. O primeiro, DE * , é obtido a partir da relação entre a contribuição-equivalente (α) e o patamar-equivalente (C * = C 0 + α), e varia de 0 a 100% (baseado no cálculo de áreas de dependência espacial). O segundo, IDE * , além da relação anterior, considera um fator de modelo equivalente (FM * ), que depende do expoente β, o qual descreve a força da dependência espacial no modelo potência (baseado em áreas de correlação espacial). O IDE * , para β próximo de 2, assume sua maior escala, variando de 0 a 66.67%. Ambos os índices possuem distribuição simétrica, e permitem a classificação da dependência espacial em fraca, moderada e forte.

Abstract: In Geostatistics, the use of measurement to describe the spatial dependence of the attribute is of great importance, but only some models (which have second-order stationarity) are considered with such measurement. Thus, this paper aims to propose measurements to assess the degree of spatial dependence in power model adjustment phenomena. From a premise that considers the equivalent sill as the estimated semivariance value that matches the point where the adjusted power model curves intersect, it is possible to build two indexes to evaluate such dependence. The first one, SPD * , is obtained from the relation between the equivalent contribution (α) and the equivalent sill (C * = C 0 + α), and varies from 0 to 100% (based on the calculation of spatial dependence areas). The second one, SDI * , beyond the previous relation, considers the equivalent factor of model (FM * ), which depends on the exponent β that describes the force of spatial dependence in the power model (based on spatial correlation areas). The SDI * ,for β close to 2, assumes its larger scale, varying from 0 to 66.67%. Both indexes have symmetrical distribution, and allow the classification of spatial dependence in weak, moderate and strong.

Time series of currents speed from 3 current meters moored at the mouth of Aysén Fjord, between October and November 1996, were analyze to estimate residual circulation and to relate surface flow to variations in salinity, wind and Aysén River runoff. Residual circulation and salinity at 6 m were determined by events of strong river discharge and relaxing of local wind. Periods of strong outflow and evident drop of salinity at the mouth of the fjord were preceded by a weakening of wind and in some cases were accompanied by an increase of Aysén river discharge. Moreover, the results confirm the 3-layer structure proposed for Aysén fjord, since seaward average currents were observed at 6 and 110 m depth, whereas weak transition average currents were observed at 50 m depth, representing a transition between an intermediate landward flow and the seaward bottom layer.

Se analizaron las series de tiempo de velocidad de la corriente en un anclaje de 3 correntómetros instalados en la boca del fiordo Aysén, entre octubre y noviembre de 1996, obteniendo la circulación residual y relacionando el flujo superficial con la variación de la salinidad, el viento y el caudal del río Aysén. Se observó que la circulación residual y la salinidad a 6 m, estuvieron determinadas por eventos de fuerte descarga del río y relajamiento del viento local. Periodos de fuerte flujo y un acentuado descenso de salinidad en la boca del fiordo estuvieron precedidos por una disminución del viento y en algunos casos estuvieron acompañados de aumentos en el caudal del río Aysén. Por otra parte, los resultados obtenidos confirman la estructura de 3 capas propuesta para el fiordo Aysén, ya que a 6 y 110 m de profundidad se observaron velocidades promedio de salida, mientras que a 50 m se registraron débiles corrientes con un flujo promedio también de salida y que correspondería a la transición entre una capa intermedia de ingreso hacia el fiordo y la capa profunda de salida.