Consulta: subjectFacets:"Light"
Registros recuperados: 68
Data/hora: 01/06/2024 00:57:19

Temperatura, humedad relativa y luz para almacenamiento de tallos florales de Heliconia psittacorum L. f. cv. Trópica.
Provedor de dados: 32
Autores: Bañuelos Hernández, Karina Patricia.
La especie Heliconia psittacorum L. f. cv. Trópica se ha identificado en los últimos años como una  ornamental tropical con gran demanda debido a su belleza y a  su vida postcosecha prolongada, que puede superar los 15 días; sin embargo, se desconoce el manejo postcosecha adecuado durante su comercialización. El objetivo de este estudio fue identificar las condiciones adecuadas para el almacenamiento postcosecha de tallos florales de H. psittacorum L. f. cv. Trópica. Se postula que la combinación adecuada de temperatura, H.R. y luz contribuirían a conservar la calidad de las inflorescencias durante la comercialización. Los tallos florales evaluados se obtuvieron de una plantación comercial en Campo Chico, municipio de Iztaczoquitlán, Veracruz. Inicialmente...
Palavras-chave: Almacenamiento; Heliconia; Trópica; Humedad relativa; Luz; Temperatura; Light; Relative humidity; Storage; Temperature; Botánica; Maestría.
Ano: 2012
URL: http://hdl.handle.net/10521/1745

LED TUBS ARTIFICIAL LIGHTING SYSTEM IN BROILER PRODUCTION
Provedor de dados: 70
Autores: Seber,Rogério; Moura,Daniella; Lima,Nilsa; Massari,Juliana.
ABSTRACT Light is important for the physiology and zootechnical development of broilers and is characterized by the type of source defined by the spectral emission and geometry of the lamp, as well as the intensity and spatial distribution of the illuminance. The aim of this study was to verify the influence of an artificial lighting system based on tubular Light Emitting Diode (LED) lamps on the productive performance of broilers. The study was carried out in two broiler houses located in Londrina-PR. The lighting system for one of the broiler houses was composed of 52 tubular LED bulbs of 18 W powers, and the control broiler house consisted of 75 incandescent bulbs with 60 W powers. This research was divided into two parts; the first phase was evaluated...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Broiler; Light; Tubular light emitting diode.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000300319

CHEMICAL AGENTS AND SHADING LEVELS FOR THE PRODUCTION OF PEPPER SEEDLINGS
Provedor de dados: 70
Autores: Binotti,Eliana D. C.; Costa,Edilson; Binotti,Flávio F. da S.; Batista,Thiago B.
ABSTRACT The aim of this study was to evaluate protected cultivation environments with different levels of shading and application of foliar chemical agents, on growth, photosynthetic pigments and seedling quality of Capsicum frutensens L. The experiment was developed at the State University of Mato Grosso do Sul, University Unit of Cassilândia, with chili pepper. Three cultivation environments (screen of 18, 35 and 50% of shading) and six leaf chemical agents were used [(1) control – without application; (2) Nitrogen (N) 1%; (3) Paclobutrazol 50 mg L-1 + N 1%; (4) Auxin 0.05 g L-1 + N 1%; (5) Gibberellin 0.05 g L-1 + N 1%; and (6) Auxin 0.05 g L-1 + Gibberellin 0.05 g L-1 + N 1%]. Each environment was considered an experiment in which the completely...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Auxin; Capsicum frutensens L; Gibberellin; Light; Nitrogen; Paclobutrazol.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000400450

Growth, assimilate partition and yield of melon charenthais under different shading screens
Provedor de dados: 75
Autores: Pereira,FHF; Puiatti,M; Finger,FL; Cecon,PR.
In this experiment we evaluated the growth, partition of assimilates and yield of melons type hybrid Charenthais 'Fleuron' under different shading nets. The experiment was conducted at Federal University of Viçosa, from November 24, 2003 to March 11, 2004. The treatments consisted of four growth environmental conditions, as follows: control (full sun), and under Aluminet® 30%-O, Cromatinet® 30%-O, Sombrite® 30%, with reduction of photosynthetic active radiation (PAR) of 30.85%, 35.9% and 32.0%, respectively. The experiment was arranged in a complete random design with four replicates. For the periodically evaluated characteristics we used a sub divided parcel 4 x 7 with the growing conditions in the parcel and the evaluations on the sub parcel (0, 14, 28,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cucumis melo; Light; Leaf area; Dry weight; Yield.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362011000100015

Evaluation of photosynthetic photon flux in lettuce cultivation at different shading levels
Provedor de dados: 75
Autores: Cometti,Nilton Nélio; Silva,Josimar V da; Zonta,Everaldo; Cessa,Raphael MA.
ABSTRACT Protected cultivation has grown in Brazil. Generally, greenhouses are covered with transparent plastic film and shading screen. The plastic, over time, loses its transparency due to pollution residues, dust and other debris. The loss of transparency reduces lightness, photosynthesis and leads to losses of productivity and product quality. The losses are not always detectable by the farmer. Additionally, internal shading screens are used to reduce heating transmission to the ground. The objective of this study was to evaluate the impact of shading on lettuce crop productivity and to determine the optimum shading to reach the highest productivity. Plots were set up inside and outside the greenhouse, with four shading levels with black screens (0,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Lactuca sativa; Plastic film; Crop protection; Light.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362020000100065

Phytoplankton carbon to chlorophyll a ratio:  response to light, temperature and nutrient
Provedor de dados: 13
Autores: Finenko, Z. Z.; Hoepffner, N.; Williams, R.; Piontkovski, S. A.
Выполнено обобщение литературных и собственных экспериментальных данных по действию света, темпе-ратуры и биогенных элементов на отношение углерод-хлорофилл а в клетках 36 видов водорослей из 7 так-сономических групп. При одинаковых условиях средние значения С:Хл. отношения для отдельных таксоно-мических групп увеличиваются в следующем порядке: Chlorophyceae &lt; Bacillariophyceae, Prochlorococcus &lt; Prymnesiophyceae &lt; Cyanophyceae &lt; Dinophyceae. При постоянной температуре С:Хл. отношение повышается линейно с увеличением света и уменьшается экспоненциально с ростом температуры при одинаковой интен-сивности света. Комбинированное действие света и температуры на С:Хл. отношение у всех исследованных водорослей описано одним уравнением с 3...
Tipo: Journal Contribution
Palavras-chave: Углерод: хлорофилл а отношение; Свет; Температура; Биогенное лимитирование; Фотоадаптация; Микроводоросли; Carbon:chlorophyll a ratio; Light; Temperature; Nutrient-limitation; Photoacclimation; Microalgae Temperature Light Light Temperature http://aims.fao.org/aos/agrovoc/c_4322 http://aims.fao.org/aos/agrovoc/c_7657.
Ano: 2003
URL: http://repository.ibss.org.ua/dspace/handle/99011/38

Photosynthetic characteristics of phytoplankton in the western Black Sea during the autumn bloom.
Provedor de dados: 13
Autores: Finenko, Z. Z.; Churilova, T. Ya.; Parkhomenko, A. V.; Tugrul, S.
In the autumn of 2005 photosynthetic characteristics of phytoplankton were studied along transects from a coast to deep-waters in the western and southern Black Sea. Efficiency of photosynthesis (αB) varied from 0.012 to 0.068 mg C (mg Chl)-1h-1(μE m-2 s-1)-1. Light – saturated rate of chlorophyll a-normalized photosynthesis (P) ranged from 5 mg C (mg Chl)-1 h-1 in the deep-waters to 12 mg C (mg Chl)-1 h-1 in the shelf waters. In the shelf area P and αB varied by a factor of 3. Variability of these parameters was as lower as that of the chlorophyll concentration. The mean αB and P values at the shelf were higher than those of the deep-water region. The phodoadaptive strategy of phytoplankton was characterized by increasing of αB at lower light levels....
Tipo: Journal Contribution
Palavras-chave: Phytoplankton; Photosynthesis; Light; Primary production; Black Sea; Фитопланктон; Фотосинтез; Свет; Первичная продукция; Чёрное море; Фітопланктон; Світло; Первинна продукція; Чорне море.
Ano: 2008
URL: http://repository.ibss.org.ua/dspace/handle/99011/834

Региональная модель для расчёта первичной продукции Чёрного моря с использованием данных спутникового сканера цвета SeaWiFS.
Provedor de dados: 13
Autores: Финенко, З. З.; Суслин, В. В.; Чурилова, Т. Я.
Разработана и применена малопараметрическая региональная модель для оценки первичной продукции Чёрного моря с использованием данных спутникового сканера цвета (SeaWiFS) за 1998 – 2004 гг. В модели использованы результаты исследований фотосинтетических характеристик черноморского фитопланктона и вертикального распределения хлорофилла, послужившие основой для обоснования и создания регионального алгоритма. Использованная  параметризация учитывает совместное действие плотности светового потока, температуры и концентрации хлорофилла  в поверхностном слое на фотосинтетические параметры кривой фотосинтез–свет и их изменение с глубиной. Полученные закономерности соединены с данными спутниковых измерений для оценки пространственно-временной вариабельности...
Tipo: Journal Contribution
Palavras-chave: Чёрное море; Модель; Спутник; Первичная продукция; Хлорофилл; Свет; Фитопланктон; Black Sea; Model; Satellite; Primary production; Chlorophyll; Light; Phytoplankton; Чорне море; Модель; Супутник; Первинна продукція; Хлорофіл; Світло; Фітопланктон.
Ano: 2009
URL: http://repository.ibss.org.ua/dspace/handle/99011/844

Влияние освещённости на физиолого-биохимические характеристики зелёной микроводоросли Haemotococcus pluvialis Flotow (Chlamydomonales)
Provedor de dados: 13
Autores: Терентьева, Н. В.; Дробецкая, И. В.; Чубчикова, И. Н.; Минюк, Г. С.
Приведены экспериментальные данные, характеризующие влияние освещённости на скорость роста и химический состав вегетативных клеток и апланоспор зелёной микроводоросли Haematococcus pluvialis (штамм IBSS-16) в условиях двухстадийной накопительной культуры.
Tipo: Journal Contribution
Palavras-chave: Haematococcus pluvialis; Astaxanthine; Light; Productivity; Nitrogen and phosphorus uptake; Total carotenoid yield.
Ano: 2008
URL: http://repository.ibss.org.ua/dspace/handle/99011/646

Сезонная изменчивость отношения органического углерода к хлорофиллу «а» и  факторы, ее определяющие в фитопланктоне прибрежных вод Черного моря
Provedor de dados: 13
Autores: Стельмах, Л. В.; Бабич, И. И.
На основе данных, полученных на пяти станциях в прибрежных поверхностных водах Черного моря (в районе Севастополя) в 2002 – 2003 гг., представлена сезонная динамика отношения С:хл “a” в нано- и микрофитопланктоне. В течение года этот показатель изменялся приблизительно на порядок. Наибольшие значения отношения (400 – 500) были получены в летний период (в июле), когда интенсивность солнечной радиации достигала максимума, а концентрация нитратов снижалась до аналитического ноля. Наименьшие величины (30 – 50) отмечены зимой при минимальных интенсивностях солнечной радиации и  относительно высоких (4 – 25 мкМ) концентрациях нитратов. Представлены регрессионные зависимости, отражающие комбинированное действие света, температуры, биогенных веществ и видового...
Tipo: Journal Contribution
Palavras-chave: Хлорофилл "a"; Органический углерод; Фитопланктон; Свет; Биогенные вещества; Черное море; Сhlorophyll "a"; Phytoplankton; Organic carbon; Light; Nutrients; Black Sea Phytoplankton Organic carbon Light Nutrients (mineral) Light Phytoplankton http://aims.fao.org/aos/agrovoc/c_4322 http://aims.fao.org/aos/agrovoc/c_13344.
Ano: 2006
URL: http://repository.ibss.org.ua/dspace/handle/99011/315

Diversity and Variability of the Cорероd Behaviour in Environmental Gradients: an Overview
Provedor de dados: 13
Autores: Seregin, S. A.; Piontkovski, S. A.
The overview is based on results of long-term experimental studies оf the authors and literature data, and applies to copepod species from plankton of the Black Sea, the Mediterranean Sea and the Atlantic Ocean. The work has incorporated the analysis of diversity and variability of the locomotory acts under the impact of abiotic factors: light, temperature, salinity, and the turbulent diffusion. Variability of locomotory activity depending on intensity, orientation (for the scalar factors), from a various combination of the environmental factors is shown. One of the mechanisms of a preferred conditions selection and phenomenon of a polymodality of copepod distribution in gradient conditions of environment is analyzed on an example of Acartia clausi...
Tipo: Journal Contribution
Palavras-chave: Diversity; Copepod behaviour; Light; Temperature; Salinity; Turbulent diffusion; Pазнообразие; Поведение копепод; Свет; Температура; Соленость; Турбулентная диффузия Light Temperature Salinity Turbulent diffusion Light Temperature Salinity http://aims.fao.org/aos/agrovoc/c_4322 http://aims.fao.org/aos/agrovoc/c_7657 http://aims.fao.org/aos/agrovoc/c_6751.
Ano: 2003
URL: http://repository.ibss.org.ua/dspace/handle/99011/148

Dial behavioral responses of Metamysidopsis elongata atlantica (Crustacea, Mysida) to gradients of salinity and temperature
Provedor de dados: 76
Autores: Gama,Andréa M. da S; Calazans,Danilo; Fontoura,Nelson F.
Metamysidopsis atlantica elongata (Bascescu, 1968) is a common mysid in the surf zone of sandy beaches from the state of Rio Grande do Sul, Brazil, where it is frequently recorded forming dense aggregations. Trough laboratory trials, behavioral responses to salinity (10, 20, 25, 28, 30, 40 e 45), temperature (10, 15, 20, 30±1ºC) and light (yes/no) were tested using adult males, adult females and juveniles. Although there was no response to temperature, the species showed clear response to salinity and light. In the presence of light, organisms remained in the bottom of the aquaria, but moved to surface when bottom salinities were increased. In the absence of light, adults moved to the surface. However, juveniles moved down to or remained on the bottom,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mysids; Behavior; Light; Predation.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212011000100014

Temperatura e luz na germinação de sementes de juta.
Provedor de dados: 14
Autores: FIGUEIREDO, F. J. C.; CARVALHO, J. E. U. de; OLIVEIRA, R. P. de; FRAZÃO, D. A. C.
bitstream/item/28802/1/CPATU-BP4.pdf
Tipo: Séries anteriores (INFOTECA-E)
Palavras-chave: Cultivar roxa; Luz; Alenquer; Pará; Brasil; Seed; Variety.; Corchorus Capsularis; Germinação; Juta; Semente; Temperatura.; Amazonia; Germination; Jute; Light; Temperature.
Ano: 1980
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/375878

Crescimento de freijó (Cordia goeldiana Huber) em plantios experimentais.
Provedor de dados: 14
Autores: CARPANEZZI, A. A.; YARED, J. A. G.
bitstream/item/30794/1/CPATU-BP26.pdf
Tipo: Séries anteriores (INFOTECA-E)
Palavras-chave: Freijo; Recru; Linha; Luz; Efeito; Floresta Nacional do Tapajos; Belterra; Santarém; Pará; Brasil; Brazilian walnut; Growth; Effect; Plantation; Line.; Crescimento; Cordia Goeldiana; Plantio; Química; Solo.; Amazonia; Chemistry; Light; Soil.
Ano: 1981
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/379784

Seasonal Variation of Lipids and Fatty Acids of the Microalgae Nannochloropsis oculata Grown in Outdoor Large-Scale Photobioreactors
Provedor de dados: 5
Autores: Olofsson, Martin; Lamela, Teresa; Nilsson, Emmelie; Berge, Jean-pascal; Del Pino, Victoria; Uronen, Pauliina; Legrand, Catherine.
While focus in oil-producing microalgae is normally on nutrient deficiency, we addressed the seasonal variations of lipid content and composition in large-scale cultivation. Lipid content, fatty acid profiles and mono- di- and triglycerides (MAGs, DAGs, and TAGs) were analyzed during May 2007-May 2009 in Nannochloropsis oculata grown outdoors in closed vertical flat panels photobioreactors. Total lipids (TL) ranged from 11% of dry weight (DW) in winter to 30% of DW in autumn. 50% of the variation in TL could be explained by light and temperature. As the highest lipid content was recorded during autumn indicating an optimal, non-linear, response to light and temperature we hypothesize that enhanced thylakoid stacking under reduced light conditions resulted...
Tipo: Text
Palavras-chave: Biodiesel; Microalgae; Seasonal variation; Nannochloropsis oculata; Large-scale; Lipids; Fatty acids; Light; Temperature.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00085/19582/17206.pdf

Etude expérimentale et modélisation des effets de la lumière et des sels nutritifs azotés sur la croissance d'une algue unicellulaire servant de fourrage en aquaculture intensive
Provedor de dados: 5
Autores: Frecon, Pierre.
INTRODUCTION For several years, intensive aquaculture has been aiming at experimentally building shortened food chain allowing commercial farming of one mollusk or fish specie. Therefore, CNEXO (IFREMER) developed several branches in its laboratories, each one starting with the growing of one or several unicellular algae which primary production was utilised to feed, either an intermediary herbivore crustacean, or directly larvae or juvenile mollusks (abalone, scallops...). A first step consisted in setting up then trivialize in vitro algal production. Now that we can benefit from routine farming, it seems interesting to move on to a second step, a more analytical one, in order to possibly optimize this type of production. The object of this DEA internship...
Tipo: Text
Palavras-chave: Nitrogenized nutritive salts; Light; Growth; Unicellular seaweed; Intensive aquiculture; Sels nutritifs azotés; Lumière; Croissance; Algue unicellulaire; Aquaculture intensive.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/rapport-1654.pdf

Influence of Environmental Factors on the Paralytic Shellfish Toxin Content and Profile of Alexandrium catenella (Dinophyceae) Isolated from the Mediterranean Sea
Provedor de dados: 5
Autores: Laabir, Mohamed; Collos, Yves; Masseret, Estelle; Grzebyk, Daniel; Abadie, Eric; Savar, Veronique; Sibat, Manoella; Amzil, Zouher.
Laboratory experiments were designed to study the toxin content and profile of the Alexandrium catenella strain ACT03 (isolated from Thau Lagoon, French Mediterranean) in response to abiotic environmental factors under nutrient-replete conditions. This dinoflagellate can produce various paralytic shellfish toxins with concentrations ranging from 2.9 to 50.3 fmol/cell. The toxin profile was characterized by carbamate toxins (GTX3, GTX4 and GTX5) and N-sulfocarbamoyl toxins (C1, C2, C3 and C4). C2 dominated at 12-18 degrees C, but only for salinities ranging from 10 to 25 psu, whereas GTX5 became dominant at temperatures ranging from 21 to 30 degrees C at almost all salinities. There was no significant variation in the cellular toxin amount from 18 degrees C...
Tipo: Text
Palavras-chave: Alexandrium catenella; PSP toxins; Temperature; Salinity; Light.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00148/25969/24056.pdf

The effects of growth phase and light intensity on toxin production by Dinophysis acuminata from the northeastern United States
Provedor de dados: 5
Autores: Tong, Mengmeng; Kulis, David M.; Fux, Elie; Smith, Juliette L.; Hess, Philipp; Zhou, Qixing; Anderson, Donald M.
For many years, the study of toxic Dinophysis species was primarily restricted to field populations until it was recently demonstrated that some of these organisms can be mixotrophically cultured in the laboratory with the ciliate prey, Myrionecta rubra. which had previously been fed with cryptophytes of the genus Teleaulax and Geminigera. Here we investigated the influence of growth phase and light intensity on the production of diarrhetic shellfish poisoning (DSP) toxins and pectenotoxins (PTXs) in cultures of Dinophysis acuminata from the northeastern United States. The cell toxin content of okadaic acid (OA), dinophysistoxin-1 (DTX1), pectenotoxin-2 (PTX2), and the okadaic acid diol ester (OA-D8) varied significantly with growth phase under all light...
Tipo: Text
Palavras-chave: Diarrhetic shellfish poisoning (DSP); Dinophysis acuminata; Dinophysistoxin (DTX); Growth phase; Light; Okadaic acid (OA); Pectenotoxins (PTXs).
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00037/14827/12195.pdf

Fonctionnement des marais maritimes atlantiques: échanges d'énergie et effets des flux aquacoles diffus
Provedor de dados: 5
Autores: Bel Hassen, Malika.
French estuaries, from the Atlantic coast to the English channel, have been characterized by a poor phytoplankton biomass. The turbidity has always been considered as the limiting factor for phytoplankton. Estuarine ecosystems are situated at the boundary between the land and the sea. Consequently, they are subject to an enrichment by nutrient loadings from upland ecosystems. Although it has been demonstrated that a part of the nutrient loadings support an important benthic production. The part, which escapes to the estuarine benthic and planktonic food web and is exported to adjacent estuarine ecosystems, still remains undetermined. Quantifying the nu trient and particulate matter exchange between a macrotidal Bay, the Fier d'Ars, and the adjacent ocean...
Tipo: Text
Palavras-chave: Aquaculture; Exportation; Matière dissoute; Fiers d'Ars; Systèmes d'Information Géographique; Importation; Usages; Lumière; Micorphytobenthos; Modélisation; Nutriments; Matière organique; Matière particulaire; Phytoplancton; Sédimentation; Aquaculture; Export; Dissolved matter; Fier d'Ars Bay; Geographic Information Systems; Import; Land use; Light; Microphytobenthos; Modelling; Nutrients; Organic matter; Particulate matter; Phytoplankton; Sedimentation.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00450/56185/57738.pdf

L'élevage larvaire intensif du loup Dicentrarchus labrax. Influence de la lumière, de la densité en proies et de la température sur l'aluminium, sur le transit digestif et sur les performances zootechniques
Provedor de dados: 5
Autores: Ronzani Cerqueira, Vinicius.
Several sea bass-rearing experiments were performed from hatching trough metamorphosis. The rearing units employed were 500 1 polyester tanks, where flow rate and temperature of seawater, light and suitable food (rotifer and artemia) were controlled. Stock density ranged between 50 and 100 larvae per liter.  Individuals held in tanks with internal black walls developed faster and had a greater survival rate than those in white tanks. This suggests that a better contrast between preys and background assists the larvae to see food organisms more clearly.  The sea bass larvae search for food is based only in vision and not trought mechanoreceptors or chemoreceptors. It was very difficult to evaluate the light intensity (50-5000 lux) influence on feeding,...
Tipo: Text
Palavras-chave: Food; Prey; Light; Zootechnical; Digestive transit; Temperature; Dicentrarchus labrax; Intensive rearing; Sea bass.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/1986/these-1676.pdf

Environmental factors controlling biomass development of seagrass meadows of Zostera noltei after a drastic decline (Arcachon Bay, France)
Provedor de dados: 5
Autores: Cognat, Mathis; Ganthy, Florian; Auby, Isabelle; Barraquand, Frederic; Rigouin, Loic; Sottolichio, Aldo.
The relative impact of light, depth, hydrology, hydrodynamics, sediment and nutrients on growth of the seagrass Zostera noltei was investigated in Arcachon Bay, where the extent of seagrass beds has been decreasing for 20 years. A comprehensive multi-parameter survey of 9 sites was conducted monthly over one year. A three-parameter logistic growth model was fitted to biomass data to unravel the relative contributions of environmental factors on seagrass growth. The present study highlights the fact that, in addition to the dominant positive effect of light on plant growth, the hydrological and hydrodynamic parameters were important drivers for Z. noltei growth at the scale of the whole Bay. At the scale of individual sites, other factors such as macroalgal...
Tipo: Text
Palavras-chave: Physical parameters; Light; Hydrodynamics; Adaptation; Statistical growth model.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00451/56229/57789.pdf

Étude et modélisation des populations de macrophytes dans la lagune de Thau (Hérault, France)
Provedor de dados: 5
Autores: Plus, Martin.
The works carried out can be divided in three main lines : design and management of experimental studies on primary production processes, macrophyte spatial distribution study and development of macrophyte and seagrass numerical models.  In situ and in vitro experiments have been performed with the aim of studying the processes and the parameters involved in the photosynthesis-respiration system, as well as to establish the main biotic (self-shading effect, physiology of the photosynthesis, carbon, nitrogen and chlorophyll tissu contents) and abiotic (temperature, light and nutrients) factors controlling macrobenthic primary production. A seagrass ecosystem model based on nitrogen and oxygen fluxes has been developped. Model calibration and validation have...
Tipo: Text
Palavras-chave: Primary production; Light; Nitrogen; Nutrients; Mathematical model; Thau lagoon; Seagrass; Macrophytes; Production primaire; Lumière; Azote; Nutriments; Model mathématique; Thau; Phanérogames; Macrophytes.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/these-6518.pdf

La Reproduction naturelle et contrôlée des bivalves cultivés en France. -Rapport de Groupe de Travail- IFREMER/Nantes/France, 14 et 15 novembre 1995
Provedor de dados: 5
Autores: Devauchelle, Nicole; Barret, Jean; Salaun, Gilles.
This report compiles 17 short and illustrated syntheses concerning the natural strategies of reproduction and the artificial control of the reproductive process for the flat oyster, Ostrea edulis, the japanese oyster, Crassostrea gigas, the mussels, Mytilus edulis and My ti/us galloprovincialis, the scallop, Pecten maximus. An additional syntheses is presented, as a comparison within molluscs, which are the main research topics at IFREMER concerning the artificial control of the reproductive processes in Marine Fish. Three main subjects are documented :  1. the ecophysiology of the natural period of reproduction in the wild,  2. the methods developed in the hatcheries for the artificial control of the reproductive periods, the gametes collection and the...
Tipo: Text
Palavras-chave: Bivalves; Stratégie de reproduction; Contrôle artificiel; Gonades; Gamètes; Coquille St Jacques; Moules; Huîtres; Nourriture; Photopériode; Température; Biologie; Physiologie; Biochimie.; Bivalves; Reproductive strategy; Artificial induction of reproduction; Gonads; Gametes; Scallop; Mussels; Oysters; Food; Light; Temperature; Biology; Physiology; Biochemistry.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00043/15441/12811.pdf

Short time scale changes in underwater irradiance in a wind-exposed lagoon (Vaccares lagoon, France): efficiency of infrequent field measurements of water turbidity or weather data to predict irradiance in the water column
Provedor de dados: 5
Autores: Banas, D; Grillas, P; Auby, Isabelle; Lescuyer, F; Coulet, E; Moreteau, J; Millet, B.
High frequency water sampling in the wind-exposed Vaccares lagoon revealed frequent and rapid changes in suspended solid (SS) concentrations in the water column. SS concentrations, sometimes higher than 800 mg l(-1), were significantly correlated with antecedent wind conditions. Mean wind velocity during the 5-33 h before water sampling or maximal wind velocity during the previous 8.5-22 h were good predictors of SS concentrations in the water column. Underwater irradiance at canopy level was modeled (r(2) = 0.66, n = 7584) using the SS calculated from the relationship between SS and antecedent mean wind velocity and the surface irradiance data measured at the weather station close to the study site. On the other hand, we have shown that in this...
Tipo: Text
Palavras-chave: Shallow lagoon; Submerged macrophyte; Wind; Light.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-3690.pdf

The evolution of light and vertical mixing across a phytoplankton ice-edge bloom
Provedor de dados: 5
Autores: Randelhoff, Achim; Ozierm, Laurent; Massicotte, Philippe; Becu, Guislain; Gali, Marti; Lacour, Leo; Dumont, Dany; Vladoiu, Anda; Marec, Claudie; Bruyant, Flavienne; Houssais, Marie-noelle; Tremblay, Jean-eric; Deslongchamps, Gabriele; Babin, Marcel.
During summer, phytoplankton can bloom in the Arctic Ocean, both in open water and under ice, often strongly linked to the retreating ice edge. There, the surface ocean responds to steep lateral gradients in ice melt, mixing, and light input, shaping the Arctic ecosystem in unique ways not found in other regions of the world ocean. In 2016, we sampled a high-resolution grid of 135 hydrographic stations in Baffin Bay as part of the Green Edge project to study the ice-edge bloom, including turbulent vertical mixing, the under-ice light field, concentrations of inorganic nutrients, and phytoplankton biomass. We found pronounced differences between an Atlantic sector dominated by the warm West Greenland Current and an Arctic sector with surface waters...
Tipo: Text
Palavras-chave: Arctic; Phytoplankton; Ice edge; Spring bloom; Light; Turbulence.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00504/61530/65391.pdf

Natural and semi-natural grasslands in Japan with special reference to Sasa dwarf bamboo grasslands
Provedor de dados: 19
Autores: Konno, Yasuo; 紺野, 康夫.
2003年8月28日とかちプラザで開催､日本ユネスコ国内委員会主催の帯広農村開発教育国際セミナー(OASERD)国際連合ユネスコアジア太平洋地域教育開発計画事業(APEID)シンポジウム「地球にやさしい農業をめざして : 緑地回復と持続的農業」講演資料
Palavras-chave: Competition; Regulation of leaf production; Light; Water content of soil.
Ano: 2003
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/1907

A model of nematode dynamics in the Westerschelde Estuary
Provedor de dados: 27
Autores: Li, J.; Vincx, M.; Herman, P.M.J.
We developed a time dynamic model to investigate the temporal dynamics of nematode community in the brackish zone of the Westerschelde Estuary. The biomass of four nematode feeding groups observed from March 1991 to February 1992 is used to calibrate the model. Using environmental data as the input, the model predicts the temporal modification and interrelation of four nematode feeding groups. Nematodes achieve a dominant position in the community because of their lower loss rate (in respiration, excretion and natural death). Predators which are deposit-feeding macrobenthos control the variations of dominant nematodes, such as omnivores and non-selective deposit feeders. Food availability causes modification only for rare nematodes such as epigrowth...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diatoms; Ecology; Food; Light; Marine nematodes; Meiobenthos; Population dynamics; Predation; Respiration; Temperature; Nematoda [Nematodes].
Ano: 1996
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7284

Leaf gas exchange differences between males and females of yerba-mate
Provedor de dados: 190
Autores: Rakocevic, Miroslava; Medrado, Moacir José Sales; Lavoranti, Osmir José.
A preliminary study was developed on leaf gas exchange properties of males and females in yerbamate (Ilex paraguariensis St. Hil.), planted in open growth conditions. The photosynthesic photon flux density (PPFD) on leaf level, stomatal conductance (gs), net photosynthesis (A), transpiration (E), and leaf temperature (Tl) was measured during the biennial production period: in the summer during the fruit ripening when there is a pause in its growth (January, February), spring  sprouting (November) and autumn sprouting (March, Jun). The measurements have been taken in different tree crown positions (inside, exterior and tips). First indications of sex physiological  dimorphism in yerba-mate have been shown.  Conductance was superior on female plants, with...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Light; Photosynthesis; Stomatal conductance; Temperature; Transpiration Condutância estomática; Fotossíntese; Luz; Temperatura; Transpiração.
Ano: 2010
URL: http://pfb.cnpf.embrapa.br/pfb/index.php/pfb/article/view/127

Yield and performance of sugarcane in on-farm interface with rubber in Brazil
Provedor de dados: 86
Autores: Pinto,Luís Fernando Guedes; Bernardes,Marcos Silveira; Pereira,Antônio Roberto.
Agroforestry systems are indicated as an alternative for sugarcane (Saccharum officinarum) cultivation in Piracicaba, SP, Brazil, however there are not many field experiments on plant performance under these conditions in the world. The objective of this work was to assess crop yield and partitioning in a sugarcane-rubber (Hevea brasiliensis) interface in on-farm conditions. The availability of irradiance for the crop along the interface was simulated and its effe ct over sugarcane dry matter production was tested. Crop yield was negatively affected by distance of the trees, but development and sucrose were not affected. Above ground dry matter increased from 16.6 to 51.5 t ha-1 from trees. Partitioning did not have a defined standard, as harvest index...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Saccharum officinarum; Hevea brasiliensis; Agroforestry systems; Light; Partitioning.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2006000200009

Light and temperature effects on seed germination of four native species of Mediterranean high mountains(Spain)
Provedor de dados: 85
Autores: Serrano-Bernardo,F; Rosúa,JL; Díaz-Miguel,M.
The Mediterranean region is considered one of the most important zones worldwide in terms of plant diversity. Sierra Nevada (S Spain) is a unique mountain massif within the high-mountain systems of the Mediterranean. It is of great floristic importance and very rich in endemic species. However, it requires numerous tasks for restoring plant cover due to the constant anthropic degradation, especially because of the ski station located near the second-highest peak of the mountain. One of the restoration efforts consists of trying to reproduce, in the laboratory, the ideal conditions to pre-germinate seeds of some of the species most threatened by these perturbations. This is to transplant the seedlings afterwards in the mountain, thereby contributing to the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Germination; Plant-cover restoration; Mediterranean high mountains; Sierra Nevada; Light; Temperature.
Ano: 2007
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1851-56572007000100003

Modeling light interception and distribution in mixed canopy of common cocklebur (Xanthium stramarium) in competition with corn
Provedor de dados: 87
Autores: Vazin,F.; Hassanzadeh,M.; Madani,A.; Nassiri-Mahallati,M.; Nasri,M.
The aim of this study was to model light interception and distribution in the mixed canopy of Common cocklebur (Xanthium stramarium) with corn. An experiment was conducted in factorial arrangement on the basis of randomized complete blocks design with three replications in Gonabad in 2006-2007 and 2007-2008 seasons. The factors used in this experiment include corn density of 7.5, 8.5 and 9.5 plants per meter of row and density of Common cocklebur of zero, 2, 4, 6 and 8 plants per meter of row. INTERCOM model was used through replacing parabolic function with triangular function of leaf area density. Vertical distribution of the species' leaf area showed that corn has concentrated the most leaf area in layer of 80 to 100 cm while Common cocklebur has...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Competition; Common cocklebur; Corn; Light.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582010000300001

Germination and emergence of Stachytarpheta cayennensis and Ipomoea asarifolia
Provedor de dados: 87
Autores: Dias Filho,M.B.
Understanding how weed seed germination and emergence respond to environmental factors is critical to determining their adaptive capabilities and potential for infestations, and could also aid in the development of effective control practices. Germination of Ipomoea asarifolia (Desr.) Roem. &amp;amp; Schultz and Stachytarpheta cayennensis (Rich) Vahl. decreased linearly with decreasing osmotic potentials. Also, increasing osmotic stress delayed germination of Ipomoea more than that of Stachytarpheta. Ipomoea germination was insensitive to light, while Stachytarpheta showed a positive photoblastic behavior. Nitrate had a negative effect on germination of Ipomoea seed under both light and dark conditions but stimulated dark germination of Stachytarpheta....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrate; Light; Osmotic stress; Depth of planting.
Ano: 1996
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83581996000200005

Effects of Environmental Factors on Seed Germination and Emergence of Velvetleaf (Abutilon theophrasti)
Provedor de dados: 87
Autores: XIONG,RC.; MA,Y.; WU,HW.; JIANG,WL.; MA,XY.
ABSTRACT: Velvetleaf, an annual broadleaf weed, is a common and troublesome weed of cropping systems worldwide. Laboratory and field experiments were conducted to determine the effects of environmental factors on germination and emergence of velvetleaf. Seeds germinated over a range of constant temperatures from 10 to 40 oC regardless of light conditions, but no germination occurred at temperature below 5 oC and beyond 50 oC. Seeds germinated at alternating temperature regimes of 15/5 to 40/30 oC, with maximum germination (&gt;90%) at alternating temperatures of 40/30 oC. Germination was sensitive to water stress, and only 0.4% of the seeds germinated at the osmotic potential of -0.4 MPa. There was no germination at ? 0.6 MPa. Moreover, germination was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Burial depth; Light; Osmotic potential; Saline and alkaline stress; Temperature.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100321

Germination and emergence of trumpet flower (tecoma stans) under different environmental conditions
Provedor de dados: 87
Autores: Reis,F.C.; Medina Sotomayor,J.F.; Garcia,D.B.; Barroso,A.A.M.; Albrecht,A.J.P.; Filho,R.V.
The aim of this work was to analyze the effect of temperature and light intensity on trumpet flower seed germination, as well as the effect of seeding depth on its emergence. To study the influence of temperature, nine temperature intervals were evaluated, ranging from 15.0 to 40.0 ºC. A randomized block design experiment was used with five replications and 20 seeds per replication, and performed twice. To evaluate light intensity on seed germination, a randomized experimental design was used with eight replications and 25 seeds per replication. The treatments applied were: photoperiod with temperature alternation; photoperiod with constant temperature; darkness with temperature alternation; and darkness with constant temperature. The photoperiod consisted...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Temperature; Light; Photoperiod; Photoblastism.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582014000200005

Germination Ecology of Lathyrus aphaca, a Problematic Weed of Wheat Crop under Semi-Arid Conditions of Pakistan
Provedor de dados: 87
Autores: AAMIR,M.; KHAN,E.A.; BALOCH,M.S.; ASLAM,M.
ABSTRACT: Lathyrus aphaca is an aggressive dicotyledonous weed. The effect of different agroecological components/factors on the germination ecology of this weed was explored under a glasshouse and laboratory condition in 2014. The germination response of L. aphaca was lower at high temperature while maximum seed germination was found at 15/12 oC (day/night). Light significantly stimulated L. aphaca germination; nevertheless, substantial germination occurred under dark conditions. More than 86-90% of L. aphaca seeds germinated at pH level of 6.2-7.5. A significant quantity of seed germinated at 250 mM NaCl. There was no germination at -1 MPa. When the temperature was lower than 20/15 oC (day/night) initiation time of germination and germination index (GI)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Osmotic stress; Weed seeds; Salt stress; Temperature; PH; Light.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100253

Germination Ecology of Two Troublesome Weeds of Arid Chickpea: Euphorbia dracunculoides and Astragalus Species
Provedor de dados: 87
Autores: IKRAM,R.M.; TANVEER,A.; ALI,H.H.; SAFDAR,M.E.; JAVAID,M.M.; ABBAS,T.; HASHIM,S.; CHAUHAN,B.S.
ABSTRACT: The species Euphorbia dracunculoides and Astragalus are problematic weeds of arid chickpea in the chickpea mono-cropping system in Pakistan. The influence of various ecological factors on germination and seedling emergence characteristics of these weeds was determined under laboratory conditions. The results suggested that seed germination of both species was 50% at 15 oC under light conditions, and germination decreased when the temperature was increased. The increase in drought stress from 2.5 to 15% significantly decreased germination of E. dracunculoides and Astragalus spp. Both species failed to germinate at the osmotic potential of -3.02 MPa. The increase in field capacity from 25 to 100% increased emergence percentage and emergence index...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Temperature; Burial depth; Light; Management; Emergence; Salinity.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100247

Environmental and physiological factors that affect the efficacy of herbicides that inhibit the enzyme protoporphyrinogen oxidase: a literature review
Provedor de dados: 87
Autores: Matzenbacher,F.O.; Vidal,R.A.; Merotto Jr.,A; Trezzi,M.M.
Herbicides that inhibit the enzyme protoporphyrinogen oxidase (PROTOX) are usually effective to control dicotyledonous weeds and their agronomic efficacy is affected by environmental and physiological factors. The objective of this review is to summarize the knowledge of those factors available in the scientific literature in the last decade. Environmental factors that influence PROTOX inhibitors include temperature, irradiance and relative humidity. The most relevant physiological factors are the activity of enzymes that can detoxify herbicides and also of enzymes that mitigate the effects of oxidative stress in plants. The study also suggests some possible management strategies that could optimize the activity of PROTOX-inhibiting herbicides.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Temperature; Light; Relative humidity; Enzymes.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582014000200024

Abiotic Factors Affecting Seed Germination and Early Seedling Emergence of Large Crabgrass (Digitaria sanguinalis)
Provedor de dados: 87
Autores: WANG,Y.H.; MA,Y.L.; FENG,G.J.; LI,H.H.
ABSTRACT:  Large crabgrass is one of the worst exotic weed in tropical, subtropical, and temperate regions of the world. In this study, the abiotic factors affecting seed germination and early seedling emergence of large crabgrass were investigated under laboratory conditions. The optimum temperatures of germination occurred at the range from 25 to 35 oC under 12 h light/12 h dark condition. Some seeds could germinate in the dark, but light exposure significantly stimulated the germination. Large crabgrass seed was tolerant to salinity level range of 0 to 160 and low water potential (11% germination at -0.8 MPa). Medium pH had no significant effect on seed germination and more than 90% seeds germination was obtained over a broad pH range from 4.0 to 10.0....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Temperature; Light; Osmotic potential; Heat-shock; Burial depth.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100268

Interference of Brassicaceae and Poaceae on Canola Hybrids
Provedor de dados: 87
Autores: SILVA,D.R.O.; AGUIAR,A.C.M.; GHELLER,D.P.; NOVELLO,B.D.; BASSO,C.J.
ABSTRACT: The objective of this study was to evaluate the initial competitive ability of canola hybrids against Brassicaceae and Poaceae species in terms of root and shoot resources. Two experiments were conducted in greenhouse, in a completely randomized design with four replications. The treatments consisted of interference conditions by root + shoot interference (root+shoot) and shoot interference (Light); and Brassicaceae and Poaceae weeds competing with hybrid of canola (Hyola 61 and Diamond) with different traits for competitiveness. The plant height, root length, dry matter of shoot and root, number of leaves and leaf area were evaluated. Data were compared using orthogonal contrasts. The turnip and volunteer canola reduced root development of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Root interaction; Raphanus sativus; Avena strigosa; Lolium multiflorum; Brassica napus; Light.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100282

Germination of Solanum nigrum L. (Black Nightshade) in Response to Different Abiotic Factors
Provedor de dados: 87
Autores: DONG,H.; MA,Y.; WU,H.; JIANG,W.; MA,X.
ABSTRACT: Solanum nigrum L. (black nightshade), an annual to short-lived perennial weed, has become a problem weed in farming systems in central China. Laboratory and greenhouse experiments were conducted to examine the influence of various abiotic factors on seed germination of black nightshade to develop effective weed control programs. Seeds germinated at a range of constant temperatures from 15 to 30 oC, but no germination occurred at temperatures below 10 oC or above 35 oC. Seeds also germinated at alternating temperature regimes from 15/5 to 40/30 oC, with maximum germination (&gt; 93.5%) at the alternating temperatures of 25/15 and 30/20 oC. Germination decreased as osmotic potential became more negative, and no germination was observed at ≤ -0.8...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Burial depth; Light; Osmotic potential; Saline and alkaline stress; Seed biology; Temperature.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582020000100245

Ocorrência de plantas aquáticas nos reservatórios da Light-RJ
Provedor de dados: 87
Autores: Martins,D.; Velini,E.D.; Piteli,R.A.; Tomazella,M, S.; Negrisoli,E.
O objetivo do presente trabalho foi caracterizar as comunidades infestantes de plantas aquáticas presentes nos reservatórios da Light-Sistema de Eletricidade S.A., localizada no município de Piraí-RJ. Os levantamentos foram realizados no período de julho a setembro de 1998. Os reservatórios analisados foram: Vigário, Pereira Passos e Lajes, sendo as quantidades de pontos amostrados de 19, 9 e 15, respectivamente. Em cada ponto amostrado fez-se a marcação das coordenadas geográficas e avaliou-se a porcentagem de ocupação do corpo d'água pelas espécies de plantas aquáticas presentes. Depois da identificação das plantas, pôde-se verificar quais eram as espécies mais freqüentes e a sua distribuição dentro do sistema de geração de energia. As espécies...
Tipo: Info:eu-repo/semantics/report
Palavras-chave: Planta aquática; Levantamento; Light.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582003000400016

Growth of red and green strains of the tropical agarophyte Gracilaria cornea J. Agardh (Gracilariales, Rhodophyta) in laboratory
Provedor de dados: 88
Autores: Ferreira,Luciana B.; Barufi,José B.; Plastino,Estela M.
Gracilaria cornea J. Agardh is an important agarophyte occurring in the western Atlantic Ocean. Green colour individuals of G. cornea were found in a natural population, growing next to red individuals, which were more common. Due to the importance of colour strains in genetic and intraspecific variability studies, this work aimed to characterize the red and green strains evaluating different nutritional and light conditions. Red and green gametophytes were cultivated at 14:10 light: dark cycle, with alternating aeration periods of 30 min. Two different enriched solutions were tested: von Stosch (VSS) at concentrations reduced to 12.5% and 25%; and Provasoli (PES) at concentrations reduced to 25% and 50%, and 100%. Red and green gametophytes were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agarophyte; Colour strain; Gracilaria cornea; Growth; Light.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042006000100017

Light and storage on the germination of spores of Dicksonia sellowiana (Presl.) Hook., Dicksoniaceae
Provedor de dados: 88
Autores: FIILIPPINI,ELAINE CRISTINA DE PAULA; DUZ,SONIA REGINA; RANDI,ÁUREA MARIA.
Spores of Dicksonia sellowiana are positively photoblastic and reach the maximum percentage of germination at 23 ± 2°C in white light after seven days of imbibition. The pre-induction phase for spores induced by white or red light for 24 hours was 72 hours. Gametophytes grown in white light were plane and bidimensional, while those grown under red light were filamentous. The higher the number of hours of light applied per day during 10 days, the higher the percentage of germination. Germination was higher for long white light treatments applied on a daily basis. The effect of different light intensities on germination was also investigated here. The lower percentages of germination were observed for spores kept under 43% and 2% of full sunlight, while...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fern germination; Gametophytes; Light; Storage.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84041999000100004

Germinação de sementes de Matelea maritima (Jack.) Woods (Asclepiadaceae)
Provedor de dados: 88
Autores: CUZZUOL,GERALDO ROGÉRIO FAUSTINI; LUCAS,NEIDE M. C.
Sementes de M. maritima germinam na temperatura ótima de 25°C com valores máximos na luz, sendo o processo otimizado em temperatura alternada de 25/30°C. Escarificação mecânica promove a germinação. Em sementes nuas, a germinação é promovida e acelerada tanto na luz quanto no escuro. Temperatura de armazenamento e tempo de estocagem alteram a fotossensibilidade das sementes: sementes estocadas à temperatura ambiente por 90 dias perdem o fotoblastismo positivo enquanto que nas estocadas sob baixa temperatura (10°C) este efeito permanece. O teste do tetrazólio demonstra que aos 180 dias de estocagem 46% das sementes permaneceram viáveis. Análises topoquímicas indicam que a principal fonte de reserva destas sementes, localizada nos cotilédones, é proteica.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: M. maritima; Propagation; Restingas; Storage; Light; Scarification.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84041999000100001

Physiological, morphological and biochemical characteristics of the sexual propagation of Piper aduncum (Piperaceae)
Provedor de dados: 88
Autores: Dousseau,Sara; Alvarenga,Amauri Alves de; Alves,Eduardo; Chaves,Izabel de Souza; Souza,Elma dos Santos; Alves,Juliana da Silva.
In this work we attempted to characterize the diaspores and the germination process of Piper aduncum L., as well as to verify the influence of the interaction between presence and absence of light (photoperiod of 12 hours and dark) and temperature (25 °C, 30 °C and 20-30 °C) and also of gibberellin (0, 50, 100, 200 and 400 mg L-1) on the root protrusion and normal seedlings formation. The diaspores are very small with a thousand seed weight of 0.3645 g, 13% moisture and protein reserve. Diaspores are strict positively photoblastic in the tested temperature range and the optimum temperature for root protrusion was 30 °C, while for normal seedlings was 25 °C. The previous permanence in the dark led to an increase in the speed of root protrusion and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Germination; Gibberellin; Light; Post-germination; Temperature.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042011000300005

Comportamento de plântulas de Sclerolobium paniculatum Vog. var. rubiginosum (Tul.) Benth. sob diferentes níveis de sombreamento, em viveiro
Provedor de dados: 88
Autores: FELFILI,JEANINE MARIA; HILGBERT,LUÍS FERNANDO; FRANCO,AUGUSTO CÉSAR; SOUSA-SILVA,JOSÉ CARLOS; RESENDE,ALBA VALÉRIA; NOGUEIRA,MARIA VALDENETE PEREIRA.
As perturbações por desmatamentos, queimadas e mineração nas matas de galeria estão se avolumando em função do desenvolvimento econômico, gerando desequilíbrio ecológico e tornando necessários estudos que possibilitem a recuperação deste ecossistema. O objetivo deste trabalho foi o de avaliar, em viveiro, a resposta da espécie Sclerolobium paniculatum submetida a quatro níveis de sombreamento. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos e quinze repetições. Cada tratamento representou uma fase da sucessão em floresta natural: pleno sol, simulando uma condição de área degradada; condição de clareira, com aproximadamente 50% de sombreamento; dossel da mata, em fase de fechamento, com sombreamento médio de 70%; dossel...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gallery forests; Light; Shading; Brazil.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84041999000500011

Note on the germination of Vochysia tucanorum seeds treated with growth regulators
Provedor de dados: 88
Autores: Pereira,Bruno F.; Simão,Edson; Terra Filho,João B.; Cardoso,Jean C.; Cardoso,Victor J. M.
(Note on the germination of Vochysia tucanorum seeds treated with growth regulators). The aim of this work was to evaluate the germination response of Vochysia tucanorum Mart. seeds treated with GA3 and CEPA and germinated under white light or darkness. Newly collected seeds from a Cerrado area were stored for 14 days at two temperatures (25 °C ± 2 and 7 °C ± 1). After the storage period the seeds were pre-treated with distilled water (control), gibberellic acid (GA3), 2-chloroethylphosphonic acid (CEPA) and a mixture of GA3 + CEPA. Following this, the seeds were sown in Petri dishes on filter paper moistened with distilled water and germinated in either darkness or white light. The results suggest that seeds are non-photoblastic and non-dormant, however a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: CEPA; Ethylene; Gibberellin; Light; Temperature.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042011000200010

Behavior of Layers under Different Light Sources
Provedor de dados: 89
Autores: Tavares,BO; Pereira,DF; Bueno,LGF; Silva,GF.
ABSTRACT Light is an important factor in the management of laying poultry. The ideal lamp spectrum that provides the best welfare conditions still needs to be determined. Wavelength and light intensity influence poultry behavior and their welfare. This study evaluated the influence of four lamps types with different light spectra on the behavior of seventy 52-week laying hens. Incandescent, fluorescent, and sodium and mercury vapor lamps were set in a different poultry house each and supplied similar light intensities. Layer behavior was video-recorded three times weekly using video cameras installed on the ceiling. The effects of different wavelengths emitted by the light sources on layer behavior were evaluated by the Kruskal-Wallis median test. Results...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Animal behavior; Light; Animal precision.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2015000400511

Effect of Environmental Enrichment on the Body Weight in Broiler Chickens
Provedor de dados: 89
Autores: Jacob,FG; Salgado,DA; Nää,IA; Baracho,MS.
ABSTRACT The present study had the objective of analysing the impact of the use of environmental enrichment (music and light stimuli), broiler sex, and age in broiler chickens’ weight during growth. The observational study was carried out on a commercial farm. The environmental enrichment consisted of broilers’ stimulation by sound and light, and a house was kept without stimulus (control). The music stimuli consisted of different music styles and was played during the experiment to promote motivation for the birds. The light stimuli came from a coloured (red and green) LED strobe projector. Both stimuli were applied once a day for about 6 minutes, for five weeks. The broilers were weighed at the end of each week of growth. Throughout the growth period,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Broiler production broiler welfare; Music; Light.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2020000200303

Influence of light regimes on respiration, activity of alternative respiratory pathway and carbohydrates content in mature leaves of Ajuga reptans L.
Provedor de dados: 93
Autores: PYSTINA,NATALIA V.; DANILOV,ROMAN A.
Influence of different light regimes (plants grown in shade and in the sun) on respiration, activity of alternative respiratory pathway and carbohydrates content in mature leaves of Ajuga reptans L. was investigated. All experiments were carried out under natural conditions. Sun plants had higher respiration, activity of the alternative pathway and carbohydrates content compared to the shade plants. Additional experiments were performed in order to study effects of darkening as well as evolution of respiration and carbohydrates concentrations in leaves of A. reptans during the day. Darkening led to a decline in total respiration in all types of plants investigated. Activity of the alternative pathway remained unchanged by 20 % in the leaves of the shade...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alternative respiratory pathway; Respiration; Alternative oxidase; Leaves; Light; Carbohydrates.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000300004

STABILITY OF ANTHOCYANINS FROM AGROINDUSTRIAL RESIDUE OF ISABEL GRAPE GROWN IN SÃO FRANCISCO VALLEY, BRAZIL
Provedor de dados: 94
Autores: BASTOS,RAFAELLA DA SILVA; OLIVEIRA,KARLLA KARINNE GOMES DE; MELO,ENAYDE DE ALMEIDA; LIMA,VERA LÚCIA ARROXELAS GALVÃO DE.
ABSTRACT  Grape by-products are promising and sustainable sources of anthocyanins. Considering the factors related to degradation of those pigments, spectrophotometric and kinetic analyzes were carried out with the aim to evaluate the light and heat stability of anthocyanins from Isabel grape residue. We found that the exposure to luminosity (80W; 2500 lux) and high temperature (= 70ºC) significantly affected the absorption and content of those compounds (p &lt;0.05), whose the most stable condition was obtained at 50°C (t1/2: 37.7h; k: 1.84 x 10-2 h-1) and protected from light (t1/2: 3,320.6h; k: 2.09 x 10-4 h-1). Therefore, the anthocyanins from the agroindustrial residue of Isabel grape are an alternative of natural colorants for food that can be...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Vitis labrusca; Kinetics; Thermal degradation; Light.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452017000100903

Feed training of juvenile giant trahira under different light intensities
Provedor de dados: 96
Autores: Salaro,Ana Lúcia; Tavares,Mateus Moraes; Chaves,William; Campelo,Daniel Abreu Vasconcelos; Zuanon,Jener Alexandre Sampaio; Luz,Ronald Kennedy.
The aim of this study was to evaluate the influence of light intensity on the feed training of juvenile giant trahiras (Hoplias lacerdae). A completely randomized design with four light treatments and three replicates was used, and the following light intensities were tested: 204.9; 177.58; 54.64 and 0.00 lux. Juvenile giant trahiras (length = 3.0 ± 0.4 cm and weight = 0.5 ± 0.05 g) were stocked at 6 fish L-1 in 12 rectangular tanks (24 × 20 × 14 cm) containing six liters of water, and subjected to feed training to accept dry diets. At the end of the experiment (21 days), weight gain, length gain, survival, cannibalism, and mortality rates were evaluated. Data were subjected to regression analysis at 5% probability. Different light intensities did not...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cannibalism; Carnivorous fish; Feed training; Hoplias lacerdae; Light.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011001100002

Ecophysiology of seed germination in Digitaria insularis ((L.) Fedde)
Provedor de dados: 124
Autores: Mendonça,Giovana Soares de; Martins,Cibele Chalita; Martins,Dagoberto; Costa,Neumárcio Vilanova da.
The invasive behaviour of sourgrass (Digitaria insularis) in cultivated areas is due to its strategy of aggressive regeneration, which is based on seed germination. Knowledge of the physiological ecology of this species can contribute to the development of management and control strategies. The aim of this research was to understand the effects of provenance, temperature and light on the germination of sourgrass seeds collected in the Brazilian state of São Paulo in the cities of Americana, Botucatu and São José do Rio Preto and in the state of Paraná in the city of São Miguel do Iguaçu. The seeds were left to germinate at temperatures of 15, 25, 35 and 45 °C, both with and without light. The number of normal seedlings was recorded daily from seven to 60...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sourgrass; Plant physiology; Provenance; Light; Temperature.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902014000400021

Leaf anatomical traits of non-arboreal savanna species along a gradient of tree encroachment
Provedor de dados: 39
Autores: Pinheiro,Luiz Felipe Souza; Kolb,Rosana Marta; Rossatto,Davi Rodrigo.
ABSTRACT In the Brazilian savanna (Cerrado of Brazil), fire suppression has transformed typical savanna formations (TS) into forested savanna (FS) due to the phenomenon of encroachment. Under encroachment, non-arboreal plants begin to receive less light due to greater tree density and canopy closure. Here we aim to evaluate if leaf anatomical traits of non-arboreal species differ according to the degree of tree encroachment at the Assis Ecological Station - São Paulo, Brazil. To this end, we evaluated leaf tissue thickness and specific leaf area (SLA) in representative non-arboreal species occurring along a gradient of tree encroachment. Leaves of TS species showed a trend towards xeromorphism, with traits reported to facilitate survival under high...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Canopy closure; Cerrado; Fire suppression; Light; Specific leaf area.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062018000100028

Effect of some environmental factors on seed germination of Eryngium caeruleum M. Bieb. populations
Provedor de dados: 39
Autores: Rezvani,Mohammad; Zaefarian,Faezeh.
ABSTRACT The effects of alternating and constant temperatures and light regimes, osmotic and salt stress and pH were tested on seed germination in four populations of Eryngium caeruleum. Laboratory experiments revealed that the four populations exhibited different responses to alternating temperature and light conditions. Alternating temperature and photoperiod had a greater positive effect on seed germination compared to complete darkness. The optimal constant temperature within 10 ºC to 15 ºC for seed germination of each population was determined in a light/dark photoperiod. Seed germination severely decreased under water stress and was completely inhibited at -0.8 MPa osmotic potential. Saline stress sharply decreased germination percentage. Germination...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alternating and constant temperatures; Germination; Light; PH; Salt and osmotic stress.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062017000200220

Effects of chemical treatments and environmental factors on seed dormancy and germination of shepherd's purse (Capsella bursa-pastoris (L.) Medic.)
Provedor de dados: 39
Autores: Rezvani,Mohammad; Zaefarian,Faezeh; Amini,Vajihe.
Shepherd's purse (Capsella bursa-pastoris) is a problematic weed in citrus orchards and crop fields in northern Iran. In a series of laboratory and greenhouse experiments, we evaluated the effects that treatment with gibberellic acid (GA3) and potassium nitrate (KNO3), as well as environmental factors, including temperature, the duration of pre-chilling (wet and dry), drought stress, salt stress, pH, and sowing depth, have on seed dormancy breaking and germination in C. bursa-pastoris. Treatment with GA3 strongly stimulated germination of C. bursa-pastoris in conditions of light/dark and continuous darkness. The germination rate was highest (40.08%) for seeds treated with 400 ppm of GA3 in the light/dark condition. Treatment with KNO3 did not significantly...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Drought and salt stress; Gibberellic acid; Light; Temperature; Sowing depth.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062014000400002

Iluminação artificial no desempenho de leitões na fase de creche - doi: 10.4025/actascianimsci.v33i4.10828
Provedor de dados: 2
Autores: Sousa Júnior, Vilmar Rodrigues de; Universidade Federal dos Vales do Jequitinhonha e Mucuri; Abreu, Paulo Giovanni de; Embrapa Suínos e Aves; Coldebella, Arlei; Embrapa Suínos e Aves; Lopes, Leticia dos Santos; Embrapa Suínos e Aves; Lima, Gustavo Júlio Mello Monteiro de; Embrapa Suínos e Aves; Sabino, Luana Araújo; Universidade Federal dos Vales do Jequitinhonha e Mucuri.
Objetivou-se com este trabalho avaliar o desempenho produtivo dos animais influenciados por programas de luz na fase de creche. O experimento foi realizado na Embrapa Suínos e Aves. Os tratamentos foram associados à iluminação da sala, sendo em cada sala aplicado um tratamento diferente: Programa LN – Iluminação natural (controle); Programa 16L:8E – Programa de iluminação artificial de 16 horas diárias de luz e 8 horas de escuro, mais iluminação solar vinda das janelas; Programa 23L:1E – Programa de iluminação artificial de 23 horas diárias de luz e 1 hora de escuro, mais iluminação solar vinda das janelas. As variáveis consumo de ração e ganho de peso diário foram coletadas diariamente na primeira semana e a cada sete dias após este período. Em todas as...
Tipo: Pesquisa de campo; testes
Palavras-chave: Desmame; Consumo; Leitões  luz weaning; Weight gain; Piglets; Light.
Ano: 2011
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/10828

High temperatures and absence of light affect the hatching of resting eggs of Daphnia in the tropics
Provedor de dados: 42
Autores: Paes,Thécia A.S.V.; Rietzler,Arnola C.; Pujoni,Diego G.F.; Maia-Barbosa,Paulina M.
Temperature and light are acknowledged as important factors for hatching of resting eggs. The knowledge of how they affect hatching rates of this type of egg is important for the comprehension of the consequences of warming waters in recolonization of aquatic ecosystems dependent on dormant populations. This study aimed at comparing the influence of different temperature and light conditions on hatching rates of Daphnia ambigua andDaphnia laevis resting eggs from tropical environments. The ephippia were collected in the sediment of three aquatic ecosystems, in southeastern Brazil. For each lake, the resting eggs were exposed to temperatures of 20, 24, 28 and 32 °C, under light (12 h photoperiod) and dark conditions. The results showed that the absence of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cladocera; Diapause; Ephippium; Light; Temperature; Tropical aquatic ecosystems.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000100179

Effect of light and temperature on seed germination in Tibouchina mutabilis (Vell.) Cogn. (Melastomataceae)
Provedor de dados: 49
Autores: Simão,Edson; Takaki,Massanori.
The effect of light and temperature on Tibouchina mutabilis seed germination was analyzed by isothermic incubations in the range of 10 to 40 °C, with 5 °C intervals under both continuous white light (32.85 µmolm-2s-1) and darkness and alternating temperatures (15-20; 15-25; 15-30; 15-35; 20-25; 20-30; 20-35; 25-30; 25-35 and 30-35 °C) under both photoperiod of 12 hours and continuous darkness. The seeds of T. mutabilis need light to trigger the germination and no germination was observed in darkness. The range of optimum temperatures for germination was between 25 to 30 °C and the 20-25 °C alternating temperatures. These results indicate that T. mutabilis behaves as a pioneer species and daily alternating temperatures did not change the light sensitivity...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Light; Phytochrome; Seed germination; Tibouchina.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032008000200006

Effects of light and temperature on seed germination in Cecropia hololeuca Miq. (Cecropiaceae)
Provedor de dados: 52
Autores: Godoi,Simone; Takaki,Massanori.
Seeds of Cecropia hololeuca were submitted to regimes of constant and alternating temperatures, associated with photoperiods of white light, "shade light" and continuous darkness under controlled conditions in laboratory. Seeds did not germinate at constant temperatures of 10°C to 20°C and above 35°C. Seeds only germinated in the darkness when the temperature was alternated. "Shade light" inhibited germination. We concluded that the regime of alternating temperatures suppressed the light effects on seed germination of this species.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cecropia hololeuca; Germination; Alternating temperature; Phytochrome; Light.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000200004

Phytochrome and temperature control of seed germination in Muntingia calabura L. (Elaeocarpaceae)
Provedor de dados: 52
Autores: Leite,Idalina T. de A.; Takaki,Massanori.
The temperature range of germination of seeds of Muntingia calabura L. was 15-35° C and the optimum temperature at 35° C where more seeds germinated at short period. The fluence response curves demonstrated the involvement of phytochrome in the control of germination through the low fluence response. The effect of photoperiod showed that the species need long daily exposures to white light and that shade light inhibited completely seed germination, confirming as pioneer species that colonized only large gaps in the forest.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Seed germination; Phytochrome; Light; Temperature; Muntingia calabura.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132001000300012

Spore Germination and Protonemal Development of Dolichomitriopsis diversiformis
Provedor de dados: 52
Autores: Liu,Shibiao; Wei,Hua; Peng,Xiaolie; Li,Jing.
ABSTRACT Dolichomitriopsis diversiformis is an endemic and threatened moss in eastern Asia. In vitro culture and light microscopic observation were employed to study its developmental process from spore germination to the formation of young gametophyte, as well as effects of light and temperature on its spore germination and protonemal development. Microscopic observations revealed that its spores were positively photoblastic with exosporous germination, and sporelings were classified as the bryum-type. Light and dark conditions were compared to understand their effects on spore germination. In 24 h continuous illumination, all spores germinated in both 20 ℃ and 25 ℃. In contrast, in darkness at 20 ℃ from one to 30 days, spores did not germinate. However,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dolichomitriopsis diversiformis; Spore; Protonema; Light; Temperature.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132016000100202

Effects of light and nutrients on different germination phases of the Cosmopolitan moss Bryum argenteum Hedw. (Bryaceae)
Provedor de dados: 52
Autores: Silva,Adaíses Simone Maciel da; Pôrto,Kátia Cavalcanti; Simabukuro,Eliana Akie.
The influence of light and nutrients on the different germination phases of Bryum argenteum spores was studied. The following treatments were used: distilled water and nutrient solution under light (12 h) and continuous darkness. The spores germinated when exposed to light, independent of both medium used. Under darkness, the spores swelled and became chlorophyllous. In the presence of nutrient solution, the germination occurred earlier (after two days) when compared to the distilled water (after more than three days). Nutrients were needed to complete the last germination phase in the majority of spores and to provide the protonemal growth.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bryophyte; Physiology; Germination; Protonema; Light; Nutrients.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000400003

Spore germination of Gleichenella pectinata (Willd.) Ching (Polypodiopsida-Gleicheniaceae) at different temperatures, levels of light and pH
Provedor de dados: 52
Autores: Santos,Eunice Pereira Gonçalves dos; Lehmann,Débora Rosana Marques; Santos,Marisa; Randi,Áurea Maria.
This study investigated the effects of different temperatures (25 and 30 ± 2 ºC), light levels (62, 42, 22 and 5% of natural light), and pH (4.0, 4.5, 5.0, 5.5, 6.0 and 6.7) on the spore germination of Gleichenella pectinata. To accomplish this, the spores were surface sterilized and sown in bottles containing mineral medium. The spores of G. pectinata are monolets and the perispore surface can show large and irregular deposits. During germination, filamentous gametophytes with and without developing rhizoids were observed. Only gametophytes which presented developed rhizoids were able to reach the heart-shaped developmental stage. Based on the collection, the rate of and gametophyte development were generally very low. The relative germination rates were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gleichenella pectinata; Germination; Light; PH; Temperatures.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000600007

Seed germination in Miconia theaezans (Bonpl.) Cogniaux (Melastomataceae)
Provedor de dados: 52
Autores: Godoi,Simone; Takaki,Massanori.
The effects of light and temperature were studied on the seeds of Miconia theazeans by isothermic and alternating temperature incubations. The optimum temperature for seed germination was determined by final percentage and germination rates as located in the range of 27.5 to 30 °C and by germination kinetics at the range of 19.5 to 30 °C. The germination was dependent on diffusion processes. The minimum and maximum temperatures were 12.5-15°C and 32.5-35°C, respectively. The seeds showed strong light dependence for germination with the necessity of daily 4-6 h white light irradiation for the maximum induction of germination. However, under 30-20 °C alternating temperatures, daily 2 hours white light was enough to induce germination and attained maximum...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Light; Seed germination; Temperature.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000400002

Natural preference of zebrafish (Danio rerio) for a dark environment
Provedor de dados: 56
Autores: Serra,E.L.; Medalha,C.C.; Mattioli,R.
The zebrafish (Danio rerio) has been used as a model in neuroscience but knowledge about its behavior is limited. The aim of this study was to determine the preference of this fish species for a dark or light environment. Initially we used a place preference test and in a second experiment we applied an exit latency test. A two-chamber aquarium was used for the preference test. The aquarium consisted of a black chamber and a white chamber. In the first experiment the animal was placed in the aquarium and the time spent in the two compartments was recorded for 10 min. More time was spent in the black compartment (Wilcoxon matched-pairs signed-rank test, T = 7, N1 = N2 = 18, P = 0.0001). In the second experiment the animal was placed in the black or white...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Zebrafish Danio rerio behavior preference dark; Light.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001200016

Use of photocatalytic reduction to hasten preparation of culture media for saccharolytic Clostridium species
Provedor de dados: 58
Autores: Fukushima,Romualdo S.; Weimer,Paul J.; Kunz,Daniel A.
Cysteine is the preferred reducing agent used in the preparation of culture media for the growth of many strictly anaerobic microorganisms; however, redox potential reduction of cysteine is very slow, making it inconvenient if the medium is needed immediately or in large quantity. The time required to reduce culture medium containing resazurin (an indicator of reducing conditions) was dramatically shortened when the medium, after being injected with the reducing agent cysteine, was irradiated with incandescent light from a halogen lamp. Light intensity had an effect upon reduction time: tubes kept in the dark took more than 12 h to achieve the desired degree of anaerobiosis (measured spectrophotometrically by the bleaching of the indicator, resazurin)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anaerobiosis; Culture medium; Cysteine; Light; Resazurin.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822003000100006

Environmental physiology of the bananas (Musa spp.)
Provedor de dados: 61
Autores: Turner,David W.; Fortescue,Jeanie A.; Thomas,Dane S.
The bananas are thought to be particularly sensitive to changes in the environment. This review considers some historical and recent investigations into the response of the leaf, root and reproductive system to the environment. Monteith's analysis of the response of plants to intercepted radiation is appropriate for analyzing the productivity of bananas and plantains. The banana is sensitive to soil water deficits, and expanding tissues such as emerging leaves and growing fruit are among the first to be affected. As soil begins to dry, stomata close and leaves remain highly hydrated, probably through root pressure. Productivity is affected because of the early closure of stomata. We find the common belief that bananas use large amounts of water does not...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Crop yield; Leaf system; Light; Photoperiod; Photosynthesis; Reproductive system; Root system; Temperature; Water supply.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400013