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| Registros recuperados: 63 | |
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| FERNANDES,FRANCISCO S.; GODOY,WESLEY A.C.; RAMALHO,FRANCISCO S.; GARCIA,ADRIANO G.; SANTOS,BÁRBARA D.B.; MALAQUIAS,JOSÉ B.. |
| ABSTRACT Population dynamics of aphids have been studied in sole and intercropping systems. These studies have required the use of more precise analytical tools in order to better understand patterns in quantitative data. Mathematical models are among the most important tools to explain the dynamics of insect populations. This study investigated the population dynamics of aphids Aphis gossypii and Aphis craccivora over time, using mathematical models composed of a set of differential equations as a helpful analytical tool to understand the population dynamics of aphids in arrangements of cotton and cowpea. The treatments were sole cotton, sole cowpea, and three arrangements of cotton intercropped with cowpea (t1, t2 and t3). The plants were infested with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aphids; Cotton; Cowpea; Dynamics; Mathematical models. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000100311 |
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| FRIEL,DAVID. |
| In neurons, depolarizing stimuli open voltage-gated Ca2+ channels, leading to Ca2+ entry and a rise in the cytoplasmic free Ca2+ concentration ([Ca2+]i). While such [Ca2+]i elevations are initiated by Ca2+ entry, they are also influenced by Ca2+ transporting organelles such as mitochondria and the endoplasmic reticulum (ER). This review summarizes contributions from the ER to depolarization-evoked [Ca2+]i responses in sympathetic neurons. As in other neurons, ER Ca2+ uptake depends on SERCAs, while passive Ca2+ release depends on ryanodine receptors (RyRs). RyRs are Ca2+ permeable channels that open in response to increases in [Ca2+]i, thereby permitting [Ca2+]i elevations to trigger Ca2+ release through Ca2+-induced Ca2+ release (CICR). However, whether... |
| Tipo: Journal article |
Palavras-chave: Dynamics; Sympathetic neurons; Endoplasmic reticulum; Ryanodine receptors. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000400024 |
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| Qi-Hua,Liu; Xiu,Wu; Tian,Li; Jia-Qing,Ma; Xue-Biao,Zhou. |
| As an indispensable environment element for crop growth, air temperature has brought challenge for the sustainable development of rice (Oryza sativa L.) production. Elevated air temperature led to great loss in rice grain yield in many districts suffering from heat stress due to the greenhouse effect worldwide, which has received more and more attention from researchers. A field experiment was conducted to investigate impacts of high air temperature (HAT) after rice heading stage on dynamics of SPAD values, soluble sugar, soluble protein, and malondialdehyde (MDA) contents of flag leaves, and grain yield attributes. The results showed that HAT significantly reduced SPAD values, soluble sugar and protein contents, seed-setting rate, number of filled grains... |
| Tipo: Journal article |
Palavras-chave: Physiological parameters; Dynamics; Yield attributes. |
| Ano: 2013 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392013000200001 |
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| Cavender-Bares, Jeannine; Department of Ecology, Evolution and Behavior, University of Minnesota; Institute on Environment, University of Minnesota; cavender@umn.edu; Polasky, Stephen; Department of Applied Economics, University of Minnesota; Department of Ecology, Evolution and Behavior, University of Minnesota; Institute on Environment, University of Minnesota; polasky@umn.edu; King, Elizabeth; Biological Sciences, Odum School of Ecology, University of Georgia; Warnell School of Forestry and Natural Resources, University of Georgia; egking@uga.edu. |
| Achieving sustainability, i.e., meeting the needs of current populations without compromising the needs of future generations, is the major challenge facing global society in the 21st century. Navigating the inherent trade-offs between provisioning, regulating, cultural, and supporting ecosystem services, and doing so in a way that does not compromise natural capital needed to provide services in the future, is critical for sustainable resource management. Here we build upon existing literature, primarily from economics and ecology, to present an analytical framework that integrates (1) the ecological mechanisms that underpin ecosystem services, (2) biophysical trade-offs and inherent limits that constrain management options, (3) preferences and values... |
| Tipo: Peer-Reviewed Insight |
Palavras-chave: Dynamics; Ecosystem services; Efficiency frontier; Management constraints; Preferences; Stakeholders; Time lags; Trade-offs. |
| Ano: 2015 |
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| Walker, Brian; CSIRO Sustainable Ecosystems; Brian.Walker@csiro.au; Steffen, Will; ; Will.Steffen@dwe.csiro.au. |
| Global change is the net effect of individual and interactive effects of changes in land use, atmospheric composition, biological diversity, and climate. A synthesis of the past six years' activities of the Global Change and Terrestrial Ecosystems project of the IGBP (International Geosphere-Biosphere Programme) deals with global change effects as ecosystem responses and living with global change. Ecosystem responses are considered in terms of changes in function and vegetation composition/structure. Field experiments of elevated CO2 effects on aboveground biomass show, on average, a positive effect on biomass, ranging from -20% to +80%. Some early predictions of CO2 effects (C3 vs. C4 plants, N-fixers, C:N in litter) are not generally supported, and it... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Agriculture; Biomes; Carbon dioxide; Climate; Dynamics; Ecosystem functioning; Global change; Impacts; Land use; Terrestrial biosphere; Vegetation changes.. |
| Ano: 1997 |
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| Guillon, Erwan; Menot, Lenaick; Decker, Carole; Krylova, Elena; Olu, Karine. |
| The high biodiversity found at cold seeps, despite elevated concentrations of methane and hydrogen sulfide, is attributed to multiple sources of habitat heterogeneity. In addition to geological and geochemical processes, biogenic habitats formed by large symbiont-bearing taxa, such as bivalves and siboglinid tubeworms, or by microbial mats drive the biodiversity of small-sized fauna. However, because these habitat-forming species also depend on geochemical gradients, the respective influence of abiotic and biotic factors in structuring associated macrofaunal communities is often unresolved. The giant pockmark Regab located at 3200 m depth on the Congo margin is characterized by different fluid-flow regimes, providing a mosaic of the most common biogenic... |
| Tipo: Text |
Palavras-chave: Cold-seep; Macrofauna; Diversity; Dynamics; Vesicomyid clams; Gulf of Guinea. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00361/47210/47165.pdf |
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| Gerin, R.; Poulain, P. -m.; Taupier-letage, Isabelle; Millot, C.; Ben Ismail, S.; Sammari, Cherif. |
| Within the framework of the EGITTO/EGYPT programs, the spatial structure and the temporal variability of the surface circulation in the eastern basin of the Mediterranean Sea was studied with satellite-tracked drifters. A total of 97 drifters drogued to 15-m nominal depth were released between September 2005 and March 2007, regularly along ship-of-opportunity routes in the Sicily Channel and within specific structures during dedicated campaigns in the Levantine sub-basin. This study complements previous ones in the former and in the Ionian, but it is the first one in the latter. After editing and low-pass filtering, the drifter trajectories were used to estimate pseudo-Eulerian statistics: mean current, variance ellipses, mean and eddy kinetic energies. A... |
| Tipo: Text |
Palavras-chave: Lagrangian drifters; General circulation; Undrogued drifters; Sea; Variability; Features; Basin; Model; Dynamics. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00204/31480/29891.pdf |
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| Vialard, Jerome; Shenoi, S. S. C.; Mccreary, J. P.; Shankar, D.; Durand, F.; Fernando, V.; Shetye, S. R.. |
| A new observational record of upper-ocean currents at 15 degrees N on the western coast of India is dominated by intraseasonal (55 - 110 day) variations of alongshore currents, whereas sea level at the same location has a clear seasonal signal. These observations can be interpreted within the framework of linear wave theory. At 15 degrees N, the minimum period for planetary waves is similar to 90 day, meaning that intraseasonal energy is largely trapped at the coast in the form of poleward-propagating Kelvin waves, while lower-frequency signals associated with the annual cycle can radiate offshore as planetary waves. This dynamical difference results in a steeper offshore slope of sea level at intraseasonal timescale, and thus stronger geostrophic... |
| Tipo: Text |
Palavras-chave: Variability; Dynamics; Circulation; Currents. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00185/29631/27993.pdf |
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| Leckler, Fabien; Ardhuin, Fabrice; Peureux, Charles; Benetazzo, Alvise; Bergamasco, Filippo; Dulov, Vladimir. |
| The energy level and its directional distribution are key observations for understanding the energy balance in the wind-wave spectrum between wind-wave generation, nonlinear interactions, and dissipation. Here, properties of gravity waves are investigated from a fixed platform in the Black Sea, equipped with a stereo video system that resolves waves with frequency f up to 1.4 Hz and wavelengths from 0.6 to 11 m. One representative record is analyzed, corresponding to young wind waves with a peak frequency fp = 0.33 Hz and a wind speed of 13 m s−1. These measurements allow for a separation of the linear waves from the bound second-order harmonics. These harmonics are negligible for frequencies f up to 3 times fp but account for most of the energy at higher... |
| Tipo: Text |
Palavras-chave: Circulation; Dynamics; Waves; Oceanic; Observational techniques and algorithms; Remote sensing. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00284/39524/38017.pdf |
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| Broche, P; Devenon, Jean-luc; Forget, P; De Maistre, Jc; Naudin, Jj; Cauwet, G. |
| The complicated dynamic processes occurring when fluvial waters mix with marine waters control the nature and the fluxes of materials exported tay rivers to the sea. Understanding these processes is of primary importance in evaluating budgets. In wide-open estuarine situations these processes take place under the influence of an intense turbulence induced by tides. Conversely, the Rhone waters spread into the Mediterranean Sea in the form of an easily distinguishable buoyant plume often extending far offshore from the mouth of the river. The aim of this study is to describe the dynamic and hydrological fields on the basis of eulerian VHF radar mapping of surface currents coupled with lagrangian in situ physical or geochemical measurements. This paper... |
| Tipo: Text |
Palavras-chave: Panache fluvial; Radar VHF; Rhône; Dynamique; River plume; VHF radar; Rhone; Dynamics. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00325/43636/43229.pdf |
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| Registros recuperados: 63 | |
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