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| Registros recuperados: 23 | |
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| PÉLLICO NETTO,SYLVIO; SANQUETTA,CARLOS R.; CARON,BRAULIO O.; BEHLING,ALEXANDRE; SIMON,AUGUSTO A.; CORTE,ANA PAULA D.; BAMBERG,ROGÉRIO. |
| ABSTRACTThe objective is to study the dynamics of photosynthetic radiation reaching the soil surface in stands of Acacia mearnsii De Wild and its influence on height growth in stands. This fact gives rise to the formulation of the following hypothesis for this study: "The reduction of the incidence of light inside the stand of black wattle will cause the inflection point in its height growth when this reaches 4 to 5 m in height, i.e. when the stand is between 2 and 3 years of age". The study was conducted in stands in the state of Rio Grande do Sul, Brazil, where diameters at breast height, total height and photosynthetically active radiation available at ground level were measured. The frequency tended to be more intense when the age of the stands... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Burr function; Light intensity; Probabilistic models; Temporal variation. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652015000401833 |
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| Dias,Jaqueline; Pimenta,José Antonio; Medri,Moacyr Eurípedes; Boeger,Maria Regina Torres; Freitas,Claudinei Toledo de. |
| The aim of this work was to compare the physiological parameters of sun and shade leaves of a specimen of L. molleoides. The higher-positional leaves, classified as sun leaves, presented similar photosynthetic rate, lower chlorophyill contents (a, b and total), same a chlorophyll /b chlrorophyll rate, lower transpiratory rate, same stomatal conductance and intercellular concentration of CO2 as the lower-positional leaves, classified as shade leaves. Nutrient concentration, except for Ca and Mg, was the same for both sun and shade leaves.The physiological parameter responses indicated that although receiving lower light intensity, the shade leaves had the same capacity to grow and develop as the sun leaves. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photosynthesis; Sun leaves; Shade leaves; Light intensity; Chlorophyll; Lithraea molleoides. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000100011 |
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| Cerqueira,Vinicius Ronzani; Brügger,André Macedo. |
| Different light intensities were tested during the larval rearing of fat snook (Centropomus parallelus) to evaluate its influence on survival and functional swim bladder rate. Newly-hatched larvae were obtained by stripping of hormonally induced broodstock, and were stocked in 32-liter tanks at densities from 30 to 50 L-1. Four experiments were carried out testing six light intensities: 50, 100, 200, 500, 1500, and 2500 lx, and total darkness as a control. Mean survival ranged from 0.06 to 16.0% and were significantly influenced by light intensity. Complete darkness resulted in 100% mortality after one week, larvae appeared to have starved since they had empty stomachs. The species has the characteristics of a visual-feeder. Survival was the highest at 200... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fat snook; Larva; Centropomus parallelus; Light intensity; First-feeding. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132001000400004 |
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| Danesi,Eliane Dalva Godoy; Rangel-Yagui,Carlota Oliveira; Sato,Sunao; Carvalho,João Carlos Monteiro de. |
| The effects of light intensity and temperature in S. platensis cultivation with potassium nitrate or urea as nitrogen source were investigated, as well as the biomass chlorophyll contents of this cyanobacteria, through the Response Surface Methodology. Experiments were performed at temperatures from 25 to 34.5ºC and light intensities from 15 to 69 µmol photons m-2 s-1, in mineral medium. In cultivations with both sources of nitrogen, KNO3 and urea, statistic evaluation through multiple regression, no interactions of such independent variables were detected in the results of the dependent variables maximum cell concentration, chlorophyll biomass contents, cell and chlorophyll productivities, as well as in the nitrogen-cell conversion factor. In cultivation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Spirulina platensis; Light intensity; Temperature; Nitrogen sources; Chlorophyll. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000100046 |
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| Curkovic,Tomislav; Ferrera,Catalina. |
| Callisphyris apicicornis is a fruit pest of increasing concern in Chile. To aid in the identification of its sex pheromone for use in the management of this insect, "calling" (pheromone release) of females and "orientation and searching" behaviors of males to calling females were video recorded. Light intensity, wind speed, temperature, time of the day, and the frequency of individuals performing each step within both behavioral sequences were recorded as well. Drawings of the behavioral steps and ethograms (routes and returns) are also provided, including transition frequencies between behavioral steps. The calling behavior of females included diagnostic movements of the abdomen, legs, elytra, and wings, showing similarities to the descriptions of other... |
| Tipo: Journal article |
Palavras-chave: Cerambycidae; Insect age; Light intensity; Pheromone; Sexual behavior. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202012000100012 |
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| Yongzhong,Lu; Zhang,Xuecheng. |
| In cyanobacteria, few details are known of the mechanisms through which the expression of the light-harvesting pigment c-phycocyanin is regulated. In the present study, a 419 bp upstream sequence of the phycocyanin b subunit (cpcB) gene from Arthrospira platensis FACHB341 was fused with green fluorescent protein (gfp) gene, and a heterologous reporting system was built up to investigate the influence of light intensity on the expression of gfp gene, and the regulation function of different region of the upstream sequence of cpcB gene. Results showed that the upstream sequence of cpcB gene could drive the expression of gfp gene in Synechococcus sp. strain PCC7942, and the expression was influenced by light intensity, the lower the light intensity, the... |
| Tipo: Journal article |
Palavras-chave: CpcB gene; Deletion analysis; Light intensity; Synechococcus; Transformation. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000100010 |
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| Henschel,Juliane M; Resende,Juliano TV; Giloni-Lima,Patrícia C; Zeist,André R; Lima Filho,Renato B; Santos,Matheus H. |
| ABSTRACT Strawberry is a crop of great economic and social importance. Its fruits are appreciated both for their flavor and nutraceutical potential. Some studies confirm that light quality influences plant physiology. Thus, the aim of this study was to investigate if changes in light spectrum, provided by low tunnels, can improve vegetative traits, as well as, production and fruit quality of strawberry. The authors used six tunnel covers (red, yellow, blue, green, transparent and opaque and one control, without cover), and two cultivars: a short photoperiod cultivar (Camarosa) and a neutral photoperiod cultivar (Albion). Experiment was evaluated in two seasons: production and plant development first; and then, post-harvest quality. Overall, Camarosa showed... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fragaria ananassa; Light spectrum; Light intensity; Colored films; Photomorphogenesis; Photoperiod.. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362017000300364 |
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| Heydarizadeh, Parisa; Veidi, Brigitte; Huang, Bing; Lukomska, Ewa; Wielgosz-collin, Gaetane; Couzinet-mossion, Aurélie; Bougaran, Gael; Marchand, Justine; Schoefs, Benoit. |
| Diatoms adapt to changing environmental conditions in very efficient ways. Among the mechanisms that can be activated, the reorientation of carbon metabolism is crucial because it allows the storage of energy into energy-dense molecules, typically lipids. Beside their roles in physiology, lipids are commercially interesting compounds. Therefore studies dealing with this topic are relevant for both basic and applied science. Although the molecular mechanisms involved in the reorientation of carbon metabolism as a response to a deficiency in nutrients such as nitrogen or phosphorus has been partially elucidated, the impacts of carbon availability on the implementation of the reorientation mechanisms remain unclear. Indeed, it has not been determined if the... |
| Tipo: Text |
Palavras-chave: Diatom; Carbon deficiency; Carbon metabolism; Stress; Light intensity; Regulation; Biotechnology; Phosphoenolpyruvate. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00489/60058/63338.pdf |
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| Coulombier, Noémie; Nicolau, Elodie; Le Déan, Loic; Antheaume, Cyril; Jauffrais, Thierry; Lebouvier, Nicolas. |
| Twelve microalgae species isolated in tropical lagoons of New Caledonia were screened as a new source of antioxidants. Microalgae were cultivated at two light intensities to investigate their influence on antioxidant capacity. To assess antioxidant property of microalgae extracts, four assays with different modes of action were used: 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azinobis (3-éthylbenzothiazoline-6-sulphonique) (ABTS), oxygen radical absorbance capacity (ORAC), and thiobabituric acid reactive substances (TBARS). This screening was coupled to pigment analysis to link antioxidant activity and carotenoid content. The results showed that none of the microalgae studied can scavenge DPPH and ABTS radicals, but Chaetoceros sp., Nephroselmis sp., and... |
| Tipo: Text |
Palavras-chave: Nephroselmis; Light intensity; In vitro antioxidant activity; Siphonaxanthin; Carotenoid; Bioactive compounds. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00609/72152/70900.pdf |
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| Guo,YL; Ma,SM; Du,JJ; Chen,JL. |
| ABSTRACT An experiment was conducted to investigate the effects of light intensity on growth, anti-stress ability, and immune function of yellow feathered broilers. A total of 480 one-day-old male Lingnan yellow feathered broilers were randomly allocated to 4 treatments based on light intensity (1, 5, 20 and 80 lx) with 8 replicates of 15 chicks each. The experiment lasted for 63 days. Compared with those under high light intensity, broilers exposed to low light intensity had higher (p<0.05) total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), a-Naphthylacetate esterase (ANAE+), antibody titer, but lower (p<0.05) malonaldehyde (MDA) levels and heterophil/lymphocyte ratio (H/L). There was a linear effect for T-AOC(p=0.002),... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anti-stress ability; Growth; Immune function; Light intensity; Yellow feathered broilers.. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2018000100079 |
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| Ramão,IB; Nunes,RV; Bruno,LDG; Tsutsumi,CY; Silva,WTM; Pozza,MSS. |
| The aim of this study was to determine the effects of different levels of light intensity (0, 5 or 20 lx) and different pre-slaughter feed fasting duration (3, 6, 9, 12 and 15 hours) on the parameters body weight loss, carcass yield, commercial cuts yield, water carcass retention, bacterial counts and breast meat pH. A number of 72 broiler chickens at 45 days of age (Cobb 500 strain) was distributed in three chambers, in a total of 24 broilers per chamber. The results showed that feed fasting significantly influenced (p<0.05) body weight losswhen broilers were submitted to 9 hours of fasting. Broilers kept in the chamber with 0 lx presented higher body weight loss compared with other light intensities. The results showed an increase in carcass yield... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bacterial counts; Carcass yield; Feed fasting; Light intensity. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2011000400003 |
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| Guevara,BDM; Pech,PS; Zamora,BR; Navarrete,SLF; Magaña,SHF. |
| ABSTRACT The purpose of this study was to evaluate the effect of green monochromatic light emitting diodes (LED) or white fluorescent lamps on the growth performance of broilers reared in open houses. Two hundred broilers (Ross 308) were sexed and divided into four treatments, according to sex and supplemental light source: T1, males under green LED; T2, males under fluorescent lamps; T3, females under green LED; and T4, females under fluorescent lamps, totaling 50 birds per treatment with five replicates each (n=10). Broilers of both sexes received natural light during the day and supplemental lighting (fluorescent or LED) during the night, according to age. Individual body weight, mortality, and feed intake were recorded weekly per replicate. Feed... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Light Emitting Diode; Light intensity; Photoperiod; Light wavelength; Broiler. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2015000400553 |
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| Registros recuperados: 23 | |
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