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| Registros recuperados: 76 | |
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| Chevillot, Xavier; Pierre, Maud; Rigaud, Arthur; Drouineau, Hilaire; Chaalali, Aurelie; Sautour, Benoit; Lobry, Jeremy. |
| For decades, global climate change has directly and indirectly affected the structure and function of ecosystems. Abrupt changes in biodiversity have been observed in response to linear or sudden modifications to the environment. These abrupt shifts can cause long-term reorganizations within ecosystems, with communities exhibiting new functional responses to environmental factors. Over the last 3 decades, the Gironde estuary in southwest France has experienced 2 abrupt shifts in both the physical and chemical environments and the pelagic community. Rather than describing these shifts and their origins, we focused on the 3 inter-shift periods, describing the structure of the fish community and its relationship with the environment during these periods. We... |
| Tipo: Text |
Palavras-chave: Ecosystem state; Fish diversity; Estuary; Generalised linear mixed models; GLMM; Time series; Shift; Inter-shift periods. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00334/44567/44282.pdf |
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| Atoui., A.; Brahim, M.; Sammari, Ch.. |
| Dans le cadre d’un programme national concernant l’étude de la circulation des eaux dans le littoral tunisien nous avons installé des courantomètres et des houlographes marégraphes dans le golfe de Gabès et notamment à l’Est de Djerba, en face de Ras-Taguermess et au niveau d’El Kantara. L’analyse harmonique des séries temporelles de niveau d’eau au niveau de Ras Taguermess et El-Kantara montre la dominance des composantes de la marée semi-diurne avec prédominance de la composante semi-diurne (M2) de période 12 h 25 mn. L’analyse en composantes principales où en fonction orthogonale empirique (EOF) des courants de la marée montre qu’au niveau d’El- Kantara la vitesse des courants est de 45 cm.s-1 et que sa direction est de 29° par rapport à l’Est ;... |
| Tipo: Journal Contribution |
Palavras-chave: Coastal waters; Current velocity; Harmonic analysis; Tidal currents; Time series; Water circulation; Water currents; Water levels. |
| Ano: 2009 |
URL: http://hdl.handle.net/1834/4618 |
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| Celec,Peter. |
| Cyclic variations of variables are ubiquitous in biomedical science. A number of methods for detecting rhythms have been developed, but they are often difficult to interpret. A simple procedure for detecting cyclic variations in biological time series and quantification of their probability is presented here. Analysis of rhythmic variance (ANORVA) is based on the premise that the variance in groups of data from rhythmic variables is low when a time distance of one period exists between the data entries. A detailed stepwise calculation is presented including data entry and preparation, variance calculating, and difference testing. An example for the application of the procedure is provided, and a real dataset of the number of papers published per day in... |
| Tipo: Journal article |
Palavras-chave: Chronobiology; Time series; Method; ANORVA; Analysis of rhythmic variance; Circaseptan; Cycle; Rhyth. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000500007 |
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| Solic, M; Krstulovic, N; Marasovic, I; Baranovic, A; Pucherpetkovic, T; Vucetic, T. |
| Time series (> 20 years) of bacterioplankton, phytoplankton and zooplankton abundances and of phytoplankton production in the Adriatic Sea were analysed. Multivariate methods were used to extract the main patterns of year-to-year changes in abundances (Principal Component Analysis), and to discriminate between years and sites (Multidimensional Scaling). Increasing long-term trends were established for planktonic abundances and phytoplankton production in both coastal and open sea areas, presumably as a result of eutrophication processes. In the open sea, natural factors (water exchange between the Mediterranean and Adriatic Seas, and temperature) were dominant in controlling year-to-year fluctuations of plankton. On the other hand, long-term... |
| Tipo: Text |
Palavras-chave: Plankton; Time series; Natural factors; Man-induced factors. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20386/18053.pdf |
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| Matabos, Marjolaine; Cuvelier, D.; Brouard, J.; Shillito, B.; Ravaux, J.; Zbinden, M.; Barthelemy, D.; Sarradin, Pierre-marie; Sarrazin, Jozee. |
| Identifying the factors driving community dynamics in hydrothermal vent communities, and in particular biological interactions, is challenged by our ability to make direct observations and the difficulty to conduct experiments in those remote ecosystems. As a result, we have very limited knowledge on species’ behaviour and interactions in these communities and how they in turn influence community dynamics. Interactions such as competition or predation significantly affect community structure in vent communities, and video time-series have successfully been used to gain insights in biological interactions and species behaviour, including responses to short-term changes in temperature or feeding strategies. In this study, we combined in situ and ex situ... |
| Tipo: Text |
Palavras-chave: Abyss Box; Biological interactions; Deep-sea observatory; Eiffel Tower edifice; Feeding behaviour; Experimental research; Video imagery; Time series; Lucky Strike; Mid-Atlantic Ridge; 37 degrees 17 ' N; 32 degrees 16.3 ' W. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00266/37714/35732.pdf |
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| Amaro,André L. N.; Yanagi Junior,Tadayuki; Yanagi,Sílvia de N. M.; Ferraz,Gabriel A. E S.; Campos,Alessandro T.. |
| Abstract The aim of the present research was to propose a bioclimatic mapping to classify the thermal comfort and discomfort of rural workers within the state of Minas Gerais, considering historical and future scenarios. Monthly historical series (1976-2014) of minimum, mean and maximum temperature-humidity index (THI), determined through the values of air temperature (minimum, mean and maximum) and relative humidity from 48 weather stations located in the state of Minas Gerais were used to analyze the trends through Mann-Kendall and linear regression assays. The bioclimatic mapping of human comfort, obtained via geostatistical analysis, was developed as a function of the minimum, medium and maximum THI for the historical period (1976-2014) and future... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Human; Biometeorology; Human thermal comfort; THI; Time series. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000200173 |
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| Koranteng, Ka; Mcglade, Jm. |
| Using time series analyses, some physical parameters of the continental shelf waters of the Gulf of Guinea were examined. Analysis of coastal sea surface temperatures from Ghana and Ivory Coast, and offshore sea surface temperatures from the Gulf of Guinea clearly shows spatial and inter-annual patterns of cooling in coastal waters of West Africa. The behaviour of the decomposed trend of coastal and offshore sea surface temperatures, sub-surface: temperature measured at 100 m depth off Ghana and salinity showed that the observational period (1963-1992) could be divided into three climatic periods: the period before 1972, from 1972 to 1982, and the period after 1982. In the first period, sea surface temperature at both coastal and offshore areas and bottom... |
| Tipo: Text |
Palavras-chave: Environnement marin; Afrique de l'Ouest; Séries temporelles; Marine environment; West Africa; Time series. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00322/43363/42852.pdf |
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| Barraquand, F.; Picoche, C.; Maurer, Daniele; Carassou, L.; Auby, Isabelle. |
| Phytoplanktonic communities maintain a high diversity in a seemingly homogeneous environment, competing for the same set of resources. Many theories have been proposed to explain this coexistence despite likely competition, such as contrasted responses to temporal environmental variation. However, theory has developed at a faster pace than empirical evaluation using field data, which requires inferring drivers of community dynamics from observational time series. Here, we combine autoregressive models with a data set spanning more than 20 years of phytoplankton counts every two weeks, together with nutrients and physical variables. By comparing models dominated by nutrients or physical variables (hydrodynamics and climate), we first explore which abiotic... |
| Tipo: Text |
Palavras-chave: Competition; Diatoms; Dinoflagellates; Hydrodynamics; Interactions; MAR; Mutualism; Network; Population dynamics; Seasonality; Time series. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57257/59285.pdf |
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| Grassi, Kelly; Poisson-caillault, Emilie; Bigand, André; Lefebvre, Alain. |
| In the framework of ecological or environmental assessments and management, detection, characterization and forecasting of the dynamics of environmental states are of paramount importance. These states should reflect general patterns of change, recurrent or occasional events, long-lasting or short or extreme events which contribute to explain the structure and the function of the ecosystem. To identify such states, many scientific consortiums promote the implementation of Integrated Observing Systems which generate increasing amount of complex multivariate/multisource/multiscale datasets. Extracting the most relevant ecological information from such complex datasets requires the implementation of Machine Learning-based processing tools. In this context, we... |
| Tipo: Text |
Palavras-chave: Clustering; Pattern discovery; Time series; Multi-Level Spectral Clustering; English Channel. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75481/76326.pdf |
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| Registros recuperados: 76 | |
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