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Registros recuperados: 31
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A new method for estimating the leaf area index of cucumber and tomato plants Horticultura Brasileira
Blanco,Flávio Favaro; Folegatti,Marcos Vinícius.
Non-destructive methods of leaf area measurement are useful for small plant populations, such as experiments with potted plants, and allow the measurement of the same plant several times during the growing period. A methodology was developed to estimate the leaf area index (LAI) of cucumber and tomato plants through the evaluation of the leaf area distribution pattern (LADP) of the plants and the relative height of the leaves in the plants. Plant and leaf height, as well as the length and width of all leaves were measured and the area of some leaves was determined by a digital area meter. The obtained regression equations were used to estimate the leaf area for all relative heights along the plant. The LADP adjusted to a quadratic model for both crops and...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Cucumis sativus L.; Esculentum Mill.; Greenhouse; Leaf area index.
Ano: 2003 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362003000400019
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Almacenamiento de carbono en bosques manejados de pinus patula: Estimación mediante percepción remota Colegio de Postgraduados
Aguirre Salado, Carlos Arturo.
Se presenta la metodología y los resultados obtenidos sobre estimación de almacenamiento de carbono mediante técnicas de percepción remota en bosques manejados de Pinus patula en Zacualtipán, Hidalgo, México; la cual surge como una necesidad de monitoreo de los recursos forestales a partir de los compromisos adquiridos por México en el Protocolo de Kyoto para aminorar el inminente cambio climático causado por los denominados gases invernadero (CO2). En esta tesis se estudia principalmente el carbono (CHA) (Mg/ha) aunque preliminarmente resulta necesaria la cuantificación de biomasa (BHA) (Mg/ha). De manera paralela también se estudian algunos parámetros forestales de densidad como índice de área foliar (IAF) (m2/ m2), cobertura arbórea (COB) (%), área...
Palavras-chave: Carbono; Índice de área foliar; Cobertura arbórea; Regresión lineal; K-nn; Percepción remota; SPOT 5; Fotografía hemisferica; Bosque de Pinus patula. Carbon; Leaf area index; Canopy closure; Linear regression; K-nn; Remote sensing; SPOT 5; Hemispherical photography; Pinus patula forest..
Ano: 2012 URL: http://hdl.handle.net/10521/789
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Almacenamiento de carbono en bosques manejados de pinus patula: Estimación mediante percepción remota Colegio de Postgraduados
Aguirre Salado, Carlos Arturo.
Se presenta la metodología y los resultados obtenidos sobre estimación de almacenamiento de carbono mediante técnicas de percepción remota en bosques manejados de Pinus patula en Zacualtipán, Hidalgo, México; la cual surge como una necesidad de monitoreo de los recursos forestales a partir de los compromisos adquiridos por México en el Protocolo de Kyoto para aminorar el inminente cambio climático causado por los denominados gases invernadero (CO2). En esta tesis se estudia principalmente el carbono (CHA) (Mg/ha) aunque preliminarmente resulta necesaria la cuantificación de biomasa (BHA) (Mg/ha). De manera paralela también se estudian algunos parámetros forestales de densidad como índice de área foliar (IAF) (m2/ m2), cobertura arbórea (COB) (%), área...
Tipo: Tesis Palavras-chave: Carbono; Índice de área foliar; Cobertura arbórea; Regresión lineal; K-nn; Percepción remota; SPOT 5; Fotografía hemisferica; Bosque de Pinus patula.; Carbon; Leaf area index; Canopy closure; Linear regression; K-nn; Remote sensing; SPOT 5; Hemispherical photography; Pinus patula forest..
Ano: 2007 URL: http://hdl.handle.net/10521/1172
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Almacenamiento de carbono en bosques manejados de pinus patula: Estimación mediante percepción remota Colegio de Postgraduados
Aguirre Salado, Carlos Arturo.
Se presenta la metodología y los resultados obtenidos sobre estimación de almacenamiento de carbono mediante técnicas de percepción remota en bosques manejados de Pinus patula en Zacualtipán, Hidalgo, México; la cual surge como una necesidad de monitoreo de los recursos forestales a partir de los compromisos adquiridos por México en el Protocolo de Kyoto para aminorar el inminente cambio climático causado por los denominados gases invernadero (CO2). En esta tesis se estudia principalmente el carbono (CHA) (Mg/ha) aunque preliminarmente resulta necesaria la cuantificación de biomasa (BHA) (Mg/ha). De manera paralela también se estudian algunos parámetros forestales de densidad como índice de área foliar (IAF) (m2/ m2), cobertura arbórea (COB) (%), área...
Palavras-chave: Carbono; Índice de área foliar; Cobertura arbórea; Regresión lineal; K-nn; Percepción remota; SPOT 5; Fotografía hemisferica; Bosque de Pinus patula. Carbon; Leaf area index; Canopy closure; Linear regression; K-nn; Remote sensing; SPOT 5; Hemispherical photography; Pinus patula forest..
Ano: 2012 URL: http://hdl.handle.net/10521/849
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Biometric Responses of Soybean to Different Potassium Fertilization Management Practices in Years with High and Low Precipitation Rev. Bras. Ciênc. Solo
Esper Neto,Michel; Minato,Evandro Antonio; Besen,Marcos Renan; Inoue,Tadeu Takeyoshi; Batista,Marcelo Augusto.
ABSTRACT Brazilian soybean producers commonly apply maintenance potassium (K) fertilization during cultivation to restore the K taken up by plants; however, this measure can modify the morphophysiological plant characteristics, since the functions of K are closely related with plant growth and development. This study assessed the morphological changes in soybean plants in response to K rates, sowing fertilization, and the application periods of K fertilization in a Latossolo Vermelho eutroférrico (Oxisol) under a no-tillage system, located in the municipality of Floresta, Paraná. A randomized block design was used in the experiment with four replications in a fully crossed factorial design (5 × 2 × 2). The experiment was carried out in two growing seasons...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Leaf area index; Correlation; Yield; Drought.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100525
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Combined effects of water status and iron deficiency chlorosis on grape composition in non-irrigated vineyards Scientia Agricola
González,María-Rosa; Hailemichael,Girma; Catalina,Álvaro; Martín,Pedro.
ABSTRACT: Although water deficit and iron deficiency chlorosis are common environmental stresses in the Mediterranean area, few data are reported in the literature on their effects on vineyards, when acting simultaneously. The main objective of this research was to study the combined effects of iron deficiency and water status on vigor, yield and fruit composition in rainfed vineyards. Moreover, the investigation aimed to evaluate the feasibility of using foliar chlorophyll content (Chl) and predawn leaf water potential (LWP), measured at veraison, to assess potential quality of grapes in the framework of precision viticulture. For this, 24 non-irrigated ‘Tempranillo’ vineyard subzones were monitored in Ribera del Duero (North-Central Spain) during three...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Vitis vinifera L.; Chlorophyll; Drought; Leaf area index; Stress.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162019001600473
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Commercial Digital Camera to Estimate Postharvest Leaf Area Index in Vitis vinifera L. cv. Cabernet Sauvignon on a Vertical Trellis Chilean J. Agric. Res.
Espinosa L.,Miguel; Acuña C.,Eduardo; Espinosa B.,Miguel; Barrera B.,Juan.
The leaf area index (LAI) of a vineyard (Vitis vinifera L.) cv. Cabernet Sauvignon located in the commune of Cauquenes, Maule Region in Chile, was estimated from digital images obtained with a commercial camera using two indirect methods: Leaf Area Gap and Brightness (LAGB) and -Photogrammetric Leaf Area Quantification System (PLAQS). The latter requires deleafing of the grapevine. In a normalized difference vegetation index (NDVI) map, three points of vine vigor were selected: high, medium, and low for which horizontal and vertical images were obtained. Images were filtered with the Arc View GIS 3.1 program to provide only leaf images and corresponding pixel numbers. Image area and square meters per linear meter were calculated. The best models were...
Tipo: Journal article Palavras-chave: Vitis vinifera; Leaf area index; Digital image; Photographic camera.
Ano: 2010 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000200015
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Dynamic of dominance, growth and bromatology of Eragrostis plana Nees in secondary vegetation area Rev. Ciênc. Agron.
Scheffer-Basso,Simone Meredith; Cecchin,Kalinca; Favaretto,Adriana.
ABSTRACT The objective of this work was to evaluate the dominance, growth and bromatology of tough lovegrass or 'annoni' grass (Eragrostis plana) in secondary vegetation area. The evaluations were carried out at 23, 45, 64, 86, 111, 132, 153, and 174 days of growth after a mowing. The tough lovegrass was the dominant species on the area, accounting for 76 to 90% of biomass. There was a linear increase for leaf (9.8 kg DM ha-1 day-1) and total dry mass (16.9 kg DM ha-1 day-1) of the tough lovegrass. During the 111 days of the vegetative stage, the biomass was composed only of leaves, and the flowering started at 132 days. At 174 days, the tough lovegrass accumulated about 4,000 kg DM ha-1, 650 kg DM ha-1 of which was composed of inflorescences. The growth...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Crude Protein; Dry matter; Fiber; Leaf area index; Leaf area ratio.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902016000300582
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Effect of dates of planting, plant geometry and number of seedlings on growth and yield of hybrid rice (Oryza sativa L.) Open Agri
V.K..
Palavras-chave: Hybrids; Grain; Heterosis; Planting date; Dry matter; Spacing; Yields; Field experimentation; Plant population; Leaf area index.
Ano: 2008 URL: http://agropedia.iitk.ac.in/openaccess/?q=node/4676
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Environmental control on water vapour and energy exchanges over grasslands in semiarid region of Brazil AGRIAMBI
Gondim,Patrícia S. de S.; Lima,José R. de S.; Antonino,Antonio C. D.; Hammecker,Claude; Silva,Renan A. B. da; Gomes,Clarissa A..
A micrometeorological experiment was conducted over grasslands in a semi-arid region of north-eastern Brazil (São João, Pernambuco) from January to December 2011, using the Bowen ratio energy balance method, to improve the current understanding of energy partitioning and water vapour exchange over this ecosystem in this region. The objectives of the present study were to quantify the seasonal and diurnal variations in energy and water vapour exchanges over grasslands and understand the biotic and abiotic factors controlling the energy partitioning of this ecosystem. In the dry period, the low stored soil water limited the grass production and leaf area index, and as a consequence of these conditions, most of the annual net radiation (58%) was consumed in...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Evapotranspiration; Soil water content; Leaf area index.
Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662015000100003
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Evaluación cuantitativa de diez variedades de alfalfa (Medicago sativa L.). Colegio de Postgraduados
Álvarez Vázquez, Perpetuo.
En México, la alfalfa es la leguminosa más utilizada en la alimentación del ganado lechero, debido a su alto rendimiento y valor nutritivo. El objetivo del presente estudio fue evaluar las variables que determinan el crecimiento y rendimiento de diez variedades de alfalfa a intervalos de corte definidos estacionalmente. El estudio se realizó de septiembre de 2011 a septiembre de 2012 en el Colegio de Postgraduados, Campus Montecillo, Texcoco, México. Las variedades de alfalfa estudiadas fueron: Vía Láctea, Chipilo, Atlixco, Oaxaca, San Miguelito, Cuf-101, Milenia, Aragón, Valenciana y Júpiter, distribuidas aleatoriamente en un diseño experimental completamente al azar con cuatro repeticiones. El mayor rendimiento (14,510 kg MS ha-1), tasa de crecimiento...
Palavras-chave: Medicago sativa L.; Rendimiento; Radiación interceptada; Indice de área foliar; Densidad de plantas; Herbage yield; Intercepted radiation; Leaf area index; Plant density; Ganadería; Maestría.
Ano: 2013 URL: http://hdl.handle.net/10521/2031
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Evaluation of mathematical equations for estimating leaf area in rapeseed Rev. Ciênc. Agron.
Dalmago,Genei Antonio; Bianchi,Cleusa Adriane Menegassi; Kovaleski,Samuel; Fochesatto,Elizandro.
ABSTRACT The aim of this study was to evaluate estimations of leaf area in rapeseed (Brassica napus L.) and the potential for application to different genotypes, environmental conditions and types of crop management. In experiments conducted during 2013, 2014, 2016 and 2017, three genotypes of rapeseed, five doses of nitrogen and three sowing dates were used. Leaves were randomly collected from different plants and positions on the plants. The leaf area (LA), and maximum width (W) and length (L) were determined for each leaf, and the product of L and W (LxW) was calculated. Fifty-six equations for estimating LA in rapeseed, where the independent variables were W, L or LxW, were compiled from the bibliography and evaluated in this work. The evaluation was...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Brassica napus; Colza; Modelling; Leaf area index.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902019000300420
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Forage mass and structure of piatã grass deferred at different heights and variable periods R. Bras. Zootec.
Vilela,Hélio Henrique; Sousa,Braulio Maia de Lana; Santos,Manoel Eduardo Rozalino; Santos,Andreza Luzia; Assis,Camila Zimmer de; Rocha,Gabriel de Oliveira; Faria,Bruno Damaceno; Nascimento Júnior,Domicio do.
The objective of this study was to determine the deferment period and the most adequate initial sward height of Brachiaria brizantha cv. Piatã for deferment in the region of Viçosa, Minas Gerais. For so, the following characteristics were evaluated: masses and bulk density of forage and its morphological components, light interception by the sward, leaf area index, leaf angle, sward and extended tiller height and falling index of the deferred piatã grass. The three deferment periods assessed (65, 85 and 105 days) were randomized to the plots and the three sward heights (20, 30 and 40 cm), randomized in the subplots. The experimental design was of completely randomized blocks, with three replicates, in a subdivided plots arrangement. Masses of forage, green...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Brachiaria brizantha; Forage bulk density; Leaf area index; Light interception; Pasture management.
Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982012000700010
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Growth and yield of rice cultivars sowed on different dates under tropical conditions Ciencia e Investigación Agraria
Garcés-Varon,Gabriel; Restrepo-Díaz,Hermann.
Rice plants are susceptible to low light or high temperature conditions during the reproductive and maturity stages. Two rice cultivars, Fedearroz 50 ('F50') and Fedearroz 733 ('F733'), were planted on three planting dates, January 1st (PD1), February 15th (PD2) and April 1st (PD3), to expose them to different climatic conditions during the different stages of rice development. The experiment was a factorial arrangement. Of the various weather parameters, solar radiation fluctuated the most among the three different planting dates, with PD1 having the highest number of days with values ≥ 450 cal·cm-2·d-1. The yield components were influenced by the planting time. PD3 showed the lowest number of tillers per unit of area and the highest percentage...
Tipo: Journal article Palavras-chave: Grain yield; Leaf area index; Planting date; Rice; Solar radiation; Tillers; Unfilled Spikelet percentage.
Ano: 2015 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202015000200008
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Growth indices ans productivity in sugarcane Scientia Agricola
Simões,Maurício dos Santos; Rocha,Jansle Vieira; Lamparelli,Rubens Augusto Camargo.
A knowledge about the temporal development of agronomic variables in sugarcane is a very important aspect for the development of crop yield prediction models using remote sensing, and further studies are still needed. This paper describes the temporal evolution of sugarcane biophysical parameters, such as total biomass, leaf area index, number of plants per meter, and productivity. During two seasons, a commercial field in Araras/SP, planted with variety SP80-1842, on the 4th and 5th cuts, was monitored on eight different dates, and data were obtained for 2 m of sugarcane in three crop rows at 18 sampling points. Linear and multiple regression analyses were used to study growth analysis and to correlate agronomic variables (leaf area index and number of...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Biomass; Leaf area index; Crop temporal evolution.
Ano: 2005 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162005000100005
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Heliotropic responses of soybean cultivars at three phenological stages and under two water regimes PAB
Rakocevic,Miroslava; Neumaier,Norman; Oliveira,Gustavo Migliorini de; Nepomuceno,Alexandre Lima; Farias,José Renato Bouças.
The objectives of this work were to determine the heliotropic movements of the upper trifoliates for two soybean cultivars, BR 16 and Embrapa 48, during a daily cycle, in three phenological stages and two water regimes, and to estimate the impact of irrigation and daily leaflet movements on agronomic characteristics and grain yield. Heliotropic movements were studied in three phenological stages: V4-V6, V7-V10, and R5 in irrigated and non-irrigated plots. For each stage, the leaflet elevation and azimuth were measured hourly. Under a low (V4-V6 stage) and mid (V7-V10 stage) leaf area index (LAI) the diaheliotropism was slightly more frequent and intensive in non-irrigated than in irrigated plants, only at early morning and late afternoon hours. At R5 stage...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Glycine max; Diaheliotropism; Irrigation; Leaf area index; Paraheliotropism.
Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2010000700005
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Hemispherical photography to estimate biophysical variables of cotton AGRIAMBI
Brandão,Ziany N.; Zonta,João H..
ABSTRACT The Leaf Area Index (LAI) is a key parameter to evaluate the vegetation spectral response, estimating plant nutrition and water requirements. However, in large fields is difficult to obtain accurate data to LAI determination. Therefore, the objective of this study was the estimation of LAI, biomass and yield of irrigated cotton through digital hemispherical photography. The treatments consisted of four nitrogen doses (0, 90, 180 and 270 kg ha-1) and four phosphorus doses (0, 120, 240 and 360 kg ha-1). Digital hemispherical photographs were collected under similar sky brightness conditions at 60 and 75 days after emergence (DAE), performed by the Digital Plant Canopy Imager - CI-110® of CID Inc. Biomass and LAI measurements were made on the same...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Leaf area index; Cotton biomass; Plant Canopy Imager CI-110.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000900789
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Identification of cowpea genotypes for drought tolerance Rev. Ciênc. Agron.
Bastos,Edson Alves; Nascimento,Sebastião Pereira do; Silva,Everaldo Moreira da; Freire Filho,Francisco Rodrigues; Gomide,Reinaldo Lúcio.
The genotypes selection for drought tolerance is very important for world food production, principally in arid regions or sites with irregular rain distribution. The objective of this work was to identify cowpea genotypes with drought tolerance and water stress sensitivity characteristics. Two experiments were carried out with 20 treatments and four replications, one under water deficit during reproductive phase and another one under full irrigation. The water deficit was obtained applying half the water depth required by cowpea. The leaf area index, chlorophyll content, grain components and grain yield were evaluated. The water deficit reduced 20% the leaf area index, 16% the chlorophyll content, 175% the pod number per plant and 60% the grain yield. The...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Vigna unguiculata; Leaf area index; Chlorophyll content.
Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902011000100013
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Impact of Nitrogen Levels on Associated Weeds, Fodder Ability and Grain Protein Content of Dual-Purpose Wheat Planta Daninha
NAVEED,K.; BALOCH,M.S.; QAYYUM,A.; MEHMOOD,A.; HUSSAIN,I.; ALI,N..
ABSTRACT: Studies were carried out to see the response of dual-purpose wheat to different nitrogen levels i.e. 0, 50, 100, 150 and 200 kg N ha-1 in cut (for forage and grain purpose) vs. uncut (for grain only) treatments at the Agriculture Research Institute, Dera Ismail Khan, Pakistan during the years 2009-10 and 2010-11. The results revealed that maximum number of days to heading (123.5 and 124.5), plant height (117.7 and 116.6 cm), grain protein content (11.59 and 12.47%), fresh forage yield (2,646 and 2,956 kg ha-1) and grain yield (4,631 and 4,489 kg ha-1) were recorded in plots that received either 150 or 200 kg ha-1 nitrogen respectively and vice-versa. The data indicated higher values for number of days to heading in cut (124.9) as compared to...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Crop growth rate; Leaf area index; Nitrogen levels; Crop production.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100309
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Influence of data acquisition geometry on soybean spectral response simulated by the prosail model REA
Breunig,Fábio M.; Galvão,Lênio S.; Formaggio,Antonio R.; Epiphanio,José C. N..
View angle and directional effects significantly affect reflectance and vegetation indices, especially when daily images collected by large field-of-view (FOV) sensors like the Moderate Resolution Imaging Spectroradiometer (MODIS) are used. In this study, the PROSAIL radiative transfer model was chosen to evaluate the impact of the geometry of data acquisition on soybean reflectance and two vegetation indices (Normalized Difference Vegetation Index - NDVI and Enhanced Vegetation Index -EVI) by varying biochemical and biophysical parameters of the crop. Input values for PROSAIL simulation were based on the literature and were adjusted by the comparison between simulated and real satellite soybean spectra acquired by the MODIS/Terra and hyperspectral...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Leaf area index; NDVI; EVI; Reflectance; MODIS; Remote sensing.
Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000100018
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