981 research outputs found
RSVP in orbit: Identification of single and dual targets in motion
Three experiments using rapid serial visual presentation (RSVP) tested participants' ability to detect targets in streams that are in motion. These experiments compared the ability to identify moving versus stationary RSVP targets and examined the attentional blink with pairs of targets that were moving or stationary. One condition presented RSVP streams in the center of the screen; a second condition used an RSVP that was orbiting in a circle, with participants instructed to follow the stream with their eyes; and a third condition had participants fixate in the middle while observing a circling RSVP stream. Relative to performance in stationary RSVP streams, participants were not markedly impaired in detecting single targets in RSVP streams that were moving, either with or without instructions to pursue the motion. In streams with two targets, a normal attentional blink effect was observed when participants were instructed to pursue the moving stream. When participants had to maintain central fixation as the RSVP stream moved, the attentional blink was nearly absent even when a trailing mask was added. We suggest that the reduction of the attentional blink for moving RSVP streams may reflect a reduced ability to perceive the temporal boundaries of the individual items
A role for coaching to support leadership development? The experiences of female Arab leaders: An interpretative phenomenological analysis
Objectives: This study aimed to explore how eight female leaders from four Arab countries experienced their leadership journey, and to consider a potential role for coaching in that developmental journey.Design and Method: A qualitative design was applied to explore the participants’ experiences. Data collection was through semi-structured interviews, and interpretative phenomenological analysis (IPA) was used to analyse the data.Results: Four themes emerged:(1) Acontinuous, exhausting struggle; (2) Fulfilment and pride in achievements;(3) Adoption of coping strategies;(4) Engagementin personal and professional development.Conclusion: The findings suggest that coaching could be an appropriate intervention to increase the individual leadership potential of females in the Arab world
Constraints to liberty of movement and attachment styles significantly account for well-being in three Palestinian samples
Background: Political violence and constraints on liberty of movement can have consequences for health and well-being but affect individuals differently.
Objective: In three Palestinian samples, we sought to examine the relationship between key environmental and psychological factors and general and mental health, including the previously unexplored roles of constraints to liberty of movement and attachment orientation.
Method: Participants (n=519) in the Occupied Palestinian Territories and Jordan completed questionnaires on constraints to liberty of movement (4-item scale devised by the authors for the purpose of the current study), attachment insecurity (Experiences in Close Relationships Scale – Short Form, Wei et al., 2007), resource loss (Conservation of Resources Evaluation scale, Hobfoll & Lilly, 1993), experience of political violence (Experience and fear of political violence, Hobfoll et al., 2011), demographics, general health (adapted from DeSalvo et al, 2006) and mental health (PHQ4 for depression, and Ballenger et al.’s, (2001) 2 item screener for anxiety). All measures were translated from English to Arabic and back-translated into English.
Results: Findings from regression and mediation analyses indicated that (i) differences in general and mental health among Palestinians in the Occupied Palestinian Territories and the diaspora in Jordan, can be explained by the assessed constructs; (ii) constraints to liberty of movement, attachment avoidance, and resource loss significantly accounted for poor general health; (iii) constraints to liberty of movement, attachment anxiety, and resource loss significantly explained general anxiety symptoms; and (iv) attachment anxiety, resource loss, and experience of political violence significantly explained depression symptoms.
Conclusion: Findings have theory-building implications for psychological models of human flourishing and suffering, suggesting that they are incomplete without consideration of liberty as a context, as well as implications for policymakers and champions of global health initiatives, as they highlight the psychological effects of constraints to liberty of movement on health
Off-Shore wind potential estimation along the coast of Chile by using scatterometer and Reanalysis data
Revista oficial de la Asociación Española de Teledetección[EN] This work presents the first offshore wind potential estimation over the coast of Chile using long term data series from “QuikSCAT (V04) wind vectors” and ERA-interim’s wind product between 1999-2009 and 1979-2012, respectively. Weibull and Rayleigh’s distribution were used to adjust the data series from the study period to find the probability density function, mean wind speed, maximum and minimum from each data series adjusted per pixel. Power generation and a capacity factor were estimated for the whole scene using three wind turbine models corresponding to 3.6, 5.0 and 8.0 MW. The images obtained from the data processing were grouped into three different wind power zones named (A) located up north, (B) in the center and (C) down south-center. The mean capacity factors are higher than 20%, moreover B and C areas have an average of 36%. This work shows the high wind power potential to generate electricity by using wind off-shore technologies along the coast of Chile.[ES] En este trabajo se presenta la primera estimación del potencial eólico offshore de Chile a partir de información de viento proveniente del producto “QuikSCAT (V04) wind vectors” y datos de velocidad del viento del reanalysis ERA-interim para el periodo 1999-2009 y 1979-2012 respectivamente. Ambos conjuntos de datos fueron ajustados a las distribuciones de Weibull y Rayleigh para encontrar la probabilidad de ocurrencia y las medias, mínimas y máximas de cada serie de tiempo ajustada por pixel. Para toda la escena se estimaron los valores de generación eléctrica y factor de planta usando tres turbinas aerogeneradores de 3,6, 5,0 y 8,0 MW. Las imágenes resultantes fueron agrupadas en tres diferentes zonas de potencial a lo largo de Chile, denominadas (A) en el extremo norte, (B) en el centro y (C) en el centro-sur. Los factores de planta promedio son superiores al 20%, siendo un 36% para las zonas B y C. Esto demuestra el alto potencial para la generación de energía eléctrica a base de turbinas eólicas frente a las costas de Chile.Esta publicación ha sido en parte financiada por el Programa U-INICIA Concurso de Reforzamiento de Inserción Productiva de Nuevos Académicos VID 2012; código U-INICIA 4/0612 Universidad de Chile. Programa U-Viajes, VID-UChile, Beca
Santander Universidad de Chile 2013 para jóvenes investigadores. Los autores agradecen a NASA Ocean Vector Winds Science Team y a ERA-interim Reanalysis por lo datos entregados.Mattar, C.; Villar-Poblete, N. (2014). Estimación del potencial eólico off-shore en las costas de Chile utilizando datos de escaterómetro y Reanalysis. Revista de Teledetección. (41):49-58. https://doi.org/10.4995/raet.2014.2787SWORD495841Yaniktepe, B., Koroglu, T., & Savrun, M. M. (2013). Investigation of wind characteristics and wind energy potential in Osmaniye, Turkey. Renewable and Sustainable Energy Reviews, 21, 703-711. doi:10.1016/j.rser.2013.01.00
Estimation of vegetation biophysical parameters in grasslands and crops in Chile through hemispheric digital photography by a GoPro camera
Revista oficial de la Asociación Española de Teledetección[EN] The estimation of the biophysical parameters of vegetation such as LAI (Leaf Area Index), FAPAR (Fraction of Absorbed Photosynthetically Active Radiation) and FCOVER (Fraction of Green Vegetation) have many climatic, hydrologic, ecosystem and silvo-agricultural applications. Despite the various satellite products that estimate these parameters continuously and globally, it’s necessary to continue generating in situ estimations to validate these remote data. It’s in this context where Digital Hemispheric Photography (DHP) technique stands out as being one of the most accurate an adaptable to operate continuously with diverse photographic equipment and field scenarios. The objective of this paper is to estimate effective LAI (LAIeff), true LAI (LAItrue), FAPAR and FCOVER through the DHP method on several agricultural land covers in Chile, between the years 2015 and 2016 using a GoPro camera and the CAN-EYE software to process hemispheric photographs. The results obtained were initially compared with those provided by a CANON EOS 6D camera mounted together with a SIGMA 8mm F3.5-EX DG fisheye lens and subsequently with satellite products provided by the Copernicus Global Land service, derived from PROBA-V mission at 333 m2 spatial resolution. The comparison between the CANON and GoPro shows similar values and R2 over 0,72 for all parameters. The comparison with PROBA-V resulted in values over 0,52 of R2 for the parameters, and similar multitemporal patterns. It’s concluded that it’s possible to estimates LAIeff, FAPAR and FCOVER like other fish eyes cameras. Concerning PROBA-V, except for FAPAR, the estimates with the GoPro do not show much correlation. In both campaigns significant discrepancies were observed in the LAItrue, which could be related to the calculation of CAN-EYE canopy clumping with the characteristics of the camera itself.[ES] La estimación de los parámetros biofísicos de la vegetación como el LAI (Leaf Area Index, FAPAR (Fraction of Absorbed Photosynthetically Active Radiation) y FCOVER (Fraction of Green Vegetation) tienen una gran cantidad de aplicaciones climáticas, hidrológicas, ecosistémicas y en sistemas silvoagropecuarios. A pesar de los diversos productos satelitales que estiman estos parámetros de forma continua y global, es necesario seguir generando estimaciones in situ para validar estos datos remotos. Es en este escenario en donde la técnica de Fotografía Digital Hemisférica (DHP) destaca por ser una de las más precisas y adaptables para funcionar de forma continua en diversos equipos fotográficos y escenarios de campo. El objetivo de este estudio es estimar el LAI efectivo (LAIeff), LAI verdadero (LAItrue), FAPAR y FCOVER a través del método DHP sobre diversas cubiertas agrícolas de Chile, entre los años 2015 y 2016 utilizando la cámara fotográfica GoPro y el software CAN-EYE para procesar las fotografías hemisféricas. Los resultados obtenidos se compararon inicialmente con los suministrados por una cámara CANON EOS 6D montada junto a un lente ojo de pez SIGMA 8mm F3.5-EX DG y posteriormente con productos satelitales proporcionados por el servicio Copernicus Global Land, derivado de la misión PROBA-V a 333 m2 de resolución espacial. La comparación entre las cámaras CANON y GoPro muestra estimaciones similares y valores de R2 sobre 0,72 para todos los parámetros. La comparación con PROBA-V dio lugar a valores sobre 0,52 de R2 para los parámetros y estimaciones multitemporales con patrones similares. Se concluye que con la cámara GoPro, es posible generar estimaciones de LAIeff, FAPAR y FCOVER de forma similar a otras cámaras ojos de pez. Respecto a PROBA-V, a excepción de FAPAR, las estimaciones con la GoPro no muestran mucha correlación. En ambas campañas se observaron discrepancias significativas del LAItrue lo que se podría relacionar al cálculo del agrupamiento de la canopia de CAN-EYE sobre las características propia cámara.Los autores agradecen el financiamiento parcial del proyecto Conicyt – Fondecyt Iniciación 11130359 “Estimating the Surface soil moisture at regional scale by using a synergic optical-passive microwave approach and remote sensing data”. Al Earth Observation Laboratory (EOLAB) y al proyecto IMAGINES, junto con la libre entrega de datos PROBA-V CopernicusUribe, D.; Mattar, C.; Camacho, F. (2018). Estimación de parámetros biofísicos de la vegetación en praderas y cultivos en Chile mediante fotografía digital hemisférica obtenidas por una cámara GoPro. Revista de Teledetección. (52):1-15. https://doi.org/10.4995/raet.2018.9315SWORD11552Baret, F., Camacho, F., Cernicharo, J., Lacaze, R., Weiss, M. 2013. GEOV1: LAI, FAPAR essential climate variables and FCOVER global time series capitalizing over existing products. Part1: Principles of development and production. Remote Sensing of Environment, 137, 310-329. https://doi.org/10.1016/j.rse.2012.12.027Baret, F., Hagolle, O., Geiger, B., Bicheron, P., Miras, B., Huc, M., Berthelot, B., Niño, F.,Weiss, M., Samain, O., Roujean, J.L., Leroy, M. 2007. LAI, fAPAR and fCover CYCLOPES global products derived from VEGETATION. Part 1: Principles of the algorithm. Remote Sensing of Environment, 110(3), 275-286. https://doi.org/10.1016/j.rse.2007.02.018Baret, F., Weiss, M. 2018. 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Viticanopy: A free computer app to estimate canopy vigor and porosity for grapevine. Sensors, 16(4). https://doi.org/10.3390/s16040585Demarez, V., Duthoit, S., Baret, F., Weiss, M., Dedieu, G. 2008. Estimation of leaf area and clumping indexes of crops with hemispherical photographs. Agricultural and Forest Meteorology, 148(4), 644-655. https://doi.org/10.1016/j.agrformet.2007.11.015Fang, H., Liang, S., Hoogenboom, G. 2011. Integration of MODIS LAI and vegetation index products with the CSM-CERES-Maize model for corn yield estimation. International Journal of Remote Sensing, 32(4), 1039-1065. https://doi.org/10.1080/01431160903505310Fournier, R.A., Landry, R., August, N.M., Fedosejevs, G., Gauthier, R.P. 1996. Modelling light obstruction in three conifer forests using hemispherical photography and fine tree architecture. Agricultural and Forest Meteorology, 82(1-4), 47-72. https://doi.org/10.1016/0168-1923(96)02345-3Garrigues, S., Shabanov, N. V, Swanson, K., Morisette, J.T., Baret, F., Myneni, R.B. 2008. Intercomparison and sensitivity analysis of Leaf Area Index retrievals from LAI-2000, AccuPAR, and digital hemispherical photography over croplands. Agricultural and Forest Meteorology, 148(8-9), 1193-1209. https://doi.org/10.1016/j.agrformet.2008.02.014Gower, S.T., Kucharik, C.J., Norman, J.M. 1999. Direct and indirect estimation of leaf area index, fAPAR, and net primary production of terrestrial ecosystems. Remote Sensing of Environment, 70(1), 29-51. https://doi.org/10.1016/S0034-4257(99)00056-5Jonckheere, I., Fleck, S., Nackaerts, K., Muys, B., Coppin, P., Weiss, M., Baret, F. 2004. Review of methods for in situ leaf area index determination Part I. Theories, sensors and hemispherical photography. Agricultural and Forest Meteorology, 121(1-2), 19- 35. https://doi.org/10.1016/j.agrformet.2003.08.027Kross, A., McNairn, H., Lapen, D., Sunohara, M., Champagne, C. 2015. Assessment of RapidEye vegetation indices for estimation of leaf area index and biomass in corn and soybean crops. International Journal of Applied Earth Observation and Geoinformation, 34(1), 235-248. https://doi.org/10.1016/j.jag.2014.08.002Lang, M., Kuusk, A., Mõttus, M., Rautiainen, M., Nilson, T. 2010. Canopy gap fraction estimation from digital hemispherical images using sky radiance models and a linear conversion method. Agricultural and Forest Meteorology, 150(1), 20-29. https://doi.org/10.1016/j.agrformet.2009.08.001Latorre, C., Camacho, F., Mattar, C., Santamaría-Artigas, A., Leiva-Büchi, N., Lacaze, R. 2016. Obtención de mapas verdad-terreno de LAI, FAPAR y cobertura vegetal a partir de imágenes del satélite chileno FASat-C y medidas in-situ en la zona agrícola de Chimbarongo, Chile, para la validación de productos de satélite. 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Validation of PROBA-V GEOV1 and MODIS C5 & C6 fAPAR Products in a Deciduous Beech Forest Site in Italy. Remote Sensing, 9(2), 126. https://doi.org/10.3390/rs9020126Olivera-Guerra, L., Mattar, C., Galleguillos, M. 2014. Estimation of real evapotranspiration and its variation in Mediterranean landscapes of central-southern Chile. International Journal of Applied Earth Observation and Geoinformation, 28(1), 160-169. https://doi.org/10.1016/j.jag.2013.11.012Olivera-Guerra, L., Merlin, O., Mattar, C., Duran-Alarcon, C., Santamaria-Artigas, A., Stefan, V. 2015. Combining meteorological and lysimeter data to evaluate energy and water fluxes over a row crop for remote sensing applications. International Geoscience and Remote Sensing Symposium (IGARSS), 2015-Novem, 4649- 4651. https://doi.org/10.1109/IGARSS.2015.7326865Paul M. Rich, 1990. Characterizing Plant Canopies with Hemispherical Photograph s. 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Remote Sensing of Environment, 112(2), 535-549. https://doi.org/10.1016/j.rse.2007.05.008Verger, A., Baret, F., Camacho, F. 2011. Optimal modalities for radiative transfer-neural network estimation of canopy biophysical characteristics: Evaluation over an agricultural area with CHRIS/PROBA observations. Remote Sensing of Environment, 115(2), 415-426. https://doi.org/10.1016/j.rse.2010.09.012Weiss, M., Baret, F. 2016. Can Eye User Manual.Weiss, M., Baret, F., Smith, G.J., Jonckheere, I., Coppin, P. 2004. Review of methods for in situ leaf area index (LAI) determination Part II. Estimation of LAI, errors and sampling. Agricultural and Forest Meteorology, 121(1-2), 37-53. https://doi.org/10.1016/j.agrformet.2003.08.001Zheng, G., Moskal, L.MX009. Retrieving Leaf Area Index (LAI) Using Remote Sensing: Theories, Methods and Sensors. Sensors, 9(4), 2719-2745. https://doi.org/10.3390/s9040271
Genotype × environment interaction for long-yearling weight in Canchim cattle quantified by reaction norm analysis.
The objective of this study was to investigate the presence of genotype × environment interactions (G×E) for long-yearling weight in Canchim cattle (5/8 Charolais + 3/8 zebu) in Brazil using reaction norms (RN). The hierarchical RN model included the fixed effect of age of the animal (linear coefficient) and random effects of contemporary groups and additive animal genetic intercept and slope of the RN and contemporary group effects as random effects. Contemporary groups as the most elemental representation of management conditions in beef cattle were chosen to represent the environmental covariate of the RN. The deviance information criteria demonstrated that a homoskedastic residual RN model provided a better data fit compared with a heteroskedastic counterpart and with a traditional animal model, which had the worst fit. The environmental gradient for long-yearling weight based on contemporary group effects ranged from ?105 to 150 kg. The additive direct variance and heritability estimates increased with increasing environmental gradient from 74.33 ± 22.32 to 1,922.59 ± 258.99 kg2 and from 0.08 ± 0.02 to 0.68 ± 0.03, respectively. The high genetic correlation (0.90 ± 0.03) between the intercept and the slope of the RN shows that animals with the greatest breeding values best responded to environmental improvement, characterizing scale effect as the source of G×E for long-yearling weight. The phenotypic plasticity demonstrated by the slope of the RN of the animal indicates the possibility to change genotype expression along the environmental gradient through selection. The results demonstrate the importance of accounting for G×E in the genetic evaluation of this population
Interação genótipo-ambiente para peso ao sobreano em alguns estados brasileiros e em clusters de municípios do estado de São Paulo em bovinos da raça Canchim.
Foram analisados dados de rebanhos Canchim pertencentes a alguns estados do Brasil (IGA1) e clusters de municípios paulistas (IGA2) para a investigação da presença de interação genótipo-ambiente (IGA) para a característica peso ao sobreano (PS). Duas investigações distintas foram realizadas para os diferentes ambientes (IGA1 e IGA2) por meio da comparação de dois modelos sugeridos em cada ambiente, um com o efeito aleatório de touro-ambiente e o outro sem este efeito. Para o estudo no ambiente IGA1 foi constatada a presença da IGA, indicando alteração significativa no desempenho de PS dos animais conforme a região em que foram avaliados. No estudo no ambiente IGA2 não foi encontrada diferença significativa entre os desempenhos de PS nos clusters paulistas, sugerindo não haver IGA entre os municípios analisados. No entanto, no estudo de IGA2 houve variação entre os modelos das estimativas das variâncias genéticas, de ambiente e fenotípicas, o que não permitiu descartar a possibilidade da presença da IGA
Caracterización espectral de Quillaja saponaria (Mol.)
Revista oficial de la Asociación Española de Teledetección[EN] This paper presents a spectral reflectance characterization of the specie Quillaja saponaria (Mol.), endemic tree of Chile and valued by society due to its provision of several ecosystem services that gives to society and also for its high concentration of saponins in cortex widely used in the pharmacological industry. For spectral characterization a foliar spectral signatures protocol was designed which included standardized instrumental and environmental parameters. The spectral response of different individuals was measured to evaluate the spectral behaviour and degree of variability within species in the visible and near infrared ranges (VNIR; 400-990 nm) with two hyperspectral sensors (ASD HH and camera PDF-65-V10E). The resulting spectral signatures obtained with ASD HH showed a variation less than 5% of reflectance in VNIR and lesser than that in the transition zone from red to near infrared (red-edge; 680-730 nm). Additionally, two distinctive spectral features were detected for the specie, the first is related to a fast increase of reflectance in bands 450-480 nm and the second, to a marked decrease in the 920-970 nm range associated with water absorption features. At branch level, these distinctive features are maintained but with a smaller magnitude of reflectance, which could indicate that they are useful characteristic spectral patterns that can eventually be used for monitoring the physical health state of the specie using remote sensing. On the other hand, we used a PDF-65 camera for study the plant vigour from different health states (healthy, ill, died) with spectral vegetation index. The Plant Senescence Reflectance Index detected stress on leaves, and Triangular Vegetation Index allows for a gradually characterization of every state. This work provides the first spectral reference for one of the most important sclerophyll species of Chile.[ES] En este trabajo se presenta una caracterización de la reflectancia espectral de Quillaja saponaria (Mol.), especie endémica de Chile y principalmente valorada por los servicios ecosistémicos que brinda a la sociedad así como su elevada concentración de saponinas en la corteza, utilizada como insumo en la industria farmacéutica. Para la caracterización espectral se diseñó un protocolo de adquisición de firmas espectrales foliares, controlando pará-metros instrumentales y ambientales. Se evaluó el comportamiento espectral y el grado de variabilidad de la especie en el rango del visible e infrarrojo cercano (VNIR; 400-990 nm) con dos sensores hiperespectrales (ASD HH y cámara PDF-65-V10E). Las firmas espectrales obtenidas con el ASD HH mostraron una variación inferior al 5% de reflectancia en el VNIR y en menor medida en la zona de transición del visible al infrarrojo cercano (red-edge; 680-730 nm). Además, se detectaron dos rasgos espectrales distintivos de la especie, el primero se relaciona con un incremento rápido de la reflectancia en los 450-480 nm y el segundo, un decrecimiento entre los 920-970 nm relacionado con las bandas de absorción de agua. De hecho, al medir la reflectancia de un conjunto de ramas apiladas, éstos rasgos perduran pero con una menor magnitud, indicando un patrón espectral característico y eventualmente utilizable en campañas de monitoreo del estado físico y sanitario de la especie mediante teledetección. Usando la cámara PDF-65 se estudió el vigor de las hojas bajo diferentes condiciones sanitarias (sana, enferma, muerta) a través de los índices espectrales de vegetación. Entre los resultados, el índice PSRI (Plant Senescence Reflectance Index) detecta sectores de bajo vigor fotosintético y el TVI (Triangular Vegetation Index) permite una caracterización gradual de cada condición. Este trabajo presenta la primera referencia espectral para una de las especies de bosque esclerófilo más importante de Chile.Este trabajo fue financiado por el proyecto Fondecyt 1140319 “Vegetation Knowledge-based Indicators for Urban Sustainable Planning” de CONICYT Chile. Los autores también agradecen a AGSEN y a SPECIM por contribuir con
la imagen obtenida con la cámara hiperespectral PDF-65-V10E.Acuña, T.; Mattar, C.; Hernández, HJ. (2016). Spectral characterization of Quillaja saponaria (Mol.). Revista de Teledetección. (47):65-73. https://doi.org/10.4995/raet.2016.6488SWORD65734
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