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| Van Sebille, Erik; Wilcox, Chris; Lebreton, Laurent; Maximenko, Nikolai; Hardesty, Britta Denise; Van Franeker, Jan A.; Eriksen, Marcus; Siegel, David; Galgani, Francois; Law, Kara Lavender. |
| Microplastic debris floating at the ocean surface can harm marine life. Understanding the severity of this harm requires knowledge of plastic abundance and distributions. Dozens of expeditions measuring microplastics have been carried out since the 1970s, but they have primarily focused on the North Atlantic and North Pacific accumulation zones, with much sparser coverage elsewhere. Here, we use the largest dataset of microplastic measurements assembled to date to assess the confidence we can have in global estimates of microplastic abundance and mass. We use a rigorous statistical framework to standardize a global dataset of plastic marine debris measured using surface-trawling plankton nets and coupled this with three different ocean circulation models... |
| Tipo: Text |
Palavras-chave: Marine debris; Ocean circulation; Model comparison. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00309/42053/41349.pdf |
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| Hanna,Lauren L. Hulsman; Garrick,Dorian J.; Gill,Clare A.; Herring,Andy D.; Sanders,James O.; Riley,David G.. |
| The objectives of this study were to 1) compare four models for breeding value prediction using genomic or pedigree information and 2) evaluate the impact of fixed effects that account for family structure. Comparisons were made in a Nellore-Angus population comprising F2, F3 and half-siblings to embryo transfer F2 calves with records for overall temperament at weaning (TEMP; n = 769) and Warner-Bratzler shear force (WBSF; n = 387). After quality control, there were 34,913 whole genome SNP markers remaining. Bayesian methods employed were BayesB ( π = 0.995 or 0.997 for WBSF or TEMP, respectively) and BayesC (π = 0 and π), where π is the ideal proportion of markers not included. Direct genomic values (DGV) from single trait Bayesian analyses were compared... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bayesian inference; Crossbred cattle; Genomic prediction; Model comparison. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572014000500005 |
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| Brook, Barry W; Northern Territory University; barry.brook@ntu.edu.au; Burgman, Mark A; University of Melbourne; m.burgman@botany.unimelb.edu.au; Frankham, Richard; Macquarie University; rfrankha@rna.bio.mq.edu.au. |
| Population viability analysis (PVA) is used in conservation biology to predict extinction probabilities for threatened species. Previous studies have revealed large differences between the predictions of PVA modeling packages, but these comparisons included a range of nonstandard factors. A standardized comparison of five PVA packages (GAPPS, INMAT, RAMAS Metapop, RAMAS Stage, and VORTEX) was conducted on six examples (two mammals, two birds, one reptile, and a hypothetical bird/mammal-like life history). The individual-based packages (GAPPS and VORTEX) predicted a consistently higher risk of extinction than their matrix-based counterparts (INMAT and the RAMAS programs). This arose as only the former considered the effect of demographic stochasticity in... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Demographic stochasticity; Extinction risk; Individual-based models; Matrix-based models; Model comparison; Parameter estimation; Population viability analysis; Sex ratio. |
| Ano: 2000 |
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| Maerz, Joeran; Verney, Romaric; Wirtz, Kai; Feudel, Ulrike. |
| Modeling suspended particulate matter (SPM) dynamics is essential to calculate sediment transport budgets and to provide relevant knowledge for the understanding of biogeochemical cycles in coastal waters. Natural flocs are characterized by their size, shape, structure and density that determine their settling velocity and therefore their vertical as well as horizontal transport. During transport, several processes, in particular aggregation and fragmentation, alter these particle properties. In the present study, we compare two different 0D modeling approaches for flocculation processes, a size class-based (SCB) model and a distribution-based (DB) model that follows the first moment of the particle distribution function. The study leads to an improved... |
| Tipo: Text |
Palavras-chave: Suspended particulate matter (SPM); Flocculation/aggregation; Size class-based model; Distribution-based model; Tidal dynamics; Model comparison. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00027/13870/11064.pdf |
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| Zhu, Ying; Goodwin, Barry K.; Ghosh, Sujit K.. |
| The objective of this study is to evaluate the risk associated with major agricultural commodity yields in the United States. We are particularly concerned with the nonstationary nature of the yield distribution, which arises primarily as a result of technological progress and changing environmental conditions over time. In contrast to common two-stage methods, we propose an alternative parametric model that allows the moments of yield distributions to change with time. Several model selection techniques suggest the proposed time-varying model outperforms more conventional models in terms of in-sample goodness-of-fit, out-of-sample predictive power, and the prediction accuracy of insurance premium rates. |
| Tipo: Journal Article |
Palavras-chave: Crop insurance; Model comparison; Time-varying distribution; Crop Production/Industries; Risk and Uncertainty. |
| Ano: 2011 |
URL: http://purl.umn.edu/105549 |
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