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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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Garcia,Diogo Anastácio; Pereira,Idalmo Garcia; Fonseca e Silva,Fabyano; Rosa,Guilherme Jordão de Magalhães; Pires,Aldrin Vieira; Leandro,Roseli Aparecida. |
The objective of this study was to evaluate the use of probit and logit link functions for the genetic evaluation of early pregnancy using simulated data. The following simulation/analysis structures were constructed: logit/logit, logit/probit, probit/logit, and probit/probit. The percentages of precocious females were 5, 10, 15, 20, 25 and 30% and were adjusted based on a change in the mean of the latent variable. The parametric heritability (h²) was 0.40. Simulation and genetic evaluation were implemented in the R software. Heritability estimates (ĥ²) were compared with h² using the mean squared error. Pearson correlations between predicted and true breeding values and the percentage of coincidence between true and predicted ranking, considering the 10%... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Beef cattle; Early pregnancy; Genetic parameters; GLMM; Link function. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982012000100008 |
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Mahevas, Stephanie; Trenkel, Verena; Doray, Mathieu; Peyronnet, Arnaud. |
Several factors affect trawl catchability: (i) gear and vessel technical characteristics, (ii) anthropogenic factors, and (iii) biological factors. The objectives of this study were to assess the relative contribution of each factor to variations in hake (Merluccius merluccius) landings by the French trawler fleet operating on the shelf of the northern Bay of Biscay (ICES Subdivision VIIIa). Using generalized linear models, the impact of technical and anthropogenic factors was evaluated using landings per unit effort (lpue) obtained from logbooks. Variations in hake lpue were explained primarily by anthropogenic factors. For studying the biological components of catchability, the results of a scientific trawl survey in July 2006 involving three similar... |
Tipo: Text |
Palavras-chave: Accessibility; Beam trawl; Catchability; Fishing power; GLMM; Spatial distribution. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00021/13244/10287.pdf |
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Vogel, Camille; Kopp, Dorothee; Morandeau, Fabien; Morfin, Marie; Mehault, Sonia. |
In the English Channel and Southern Bight, French demersal trawlers target a mix of demersal species including whiting (Merlangius merlangus). The discard ban to be implemented in January 2016 motivated fishermen to look for technical measures to reduce unwanted catches of undersized individuals (<27 cm). From 2008–2014, 18 different gear configurations were tested for bycatch reduction on board fleets of vessels of 16–20 m and 20–24 m. Selective devices tested included grids, square mesh panels (SMP), square mesh cylinders (SMC), various combinations of these devices and large mesh trawls. Using the catch comparison method, our results focus on six devices that proved efficient to reduce catches of undersized whiting, equally divided between the two... |
Tipo: Text |
Palavras-chave: Square mesh; Sorting grids; Fishing gear technology; Merlangius merlangus; Catch comparison; GLMM. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00384/49553/50079.pdf |
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Garcia,D.A.; Pereira,I.G.; Silva,F. Fonseca e; Pires,A.V.; Pessoa,M.C; Oliveira,R.A.M. |
Utilizaram-se os modelos lineares generalizados com as funções de ligação probit e logit na avaliação da prenhez precoce, e observaram-se os efeitos na variabilidade genética e na seleção de reprodutores quando diferentes idades são adotadas na definição dessa característica. A prenhez precoce foi estudada aos 15 (PP15) e 21 meses (PP21). Correlações entre os valores genéticos preditos e a porcentagem de touros em comum, considerando 10% dos touros com maiores valores genéticos (TOP10), entre a classificação dos modelos com função de ligação logit e probit e em cada modelo entre PP15 e PP21, foram calculadas. As herdabilidades para PP15 e PP21 foram próximas entre os modelos, exceto para PP15 utilizando a função de ligação probit. Aquelas entre os modelos... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gado de corte; GLMM; Herdabilidade; Função de ligação; Precocidade. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352012000300020 |
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