| 1. |
- Grandin, Karl, et al.
(author)
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Nuclear Energy
- 2010
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In: AMBIO. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 39:Suppl. 1, s. 26-30
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Journal article (peer-reviewed)abstract
- Nuclear energy can play a role in carbon free production of electrical energy, thus making it interesting for tomorrow’s energy mix. However, several issues have to be addressed. In fission technology, the design of so-called fourth generation reactors show great promise, in particular in addressing materials efficiency and safety issues. If successfully developed, such reactors may have an important and sustainable part in future energy production. Working fusion reactors may be even more materials efficient and environmental friendly, but also need more development and research. The roadmap for development of fourth generation fission and fusion reactors, therefore, asks for attention and research in these fields must be strengthened.
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| 2. |
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| 3. |
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| 4. |
- Jagers, Peter, 1941, et al.
(author)
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Population-size-dependent, age-structured branching processes linger around their carrying capacity
- 2011
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In: Journal of Applied Probability. - 0021-9002. ; 48A, s. 249-260
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Journal article (peer-reviewed)abstract
- Dependence of individual reproduction upon the size of the whole population is studied in a general branching process context. The particular feature under scrutiny is that of reproduction changing from supercritical in small populations to subcritical in large ones. The transition occurs when population size passes a critical threshold, known in ecology as the carrying capacity. We show that populations either die out directly, never coming close to the carrying capacity, or else they grow quickly towards the latter, subsequently lingering around it for a time that is expected to be exponentially long in terms of a carrying capacity tending to infinity.
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| 5. |
- Jagers, Peter, 1941, et al.
(author)
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Stochasticity in the adaptive dynamics of evolution: the bare bones
- 2011
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In: Journal of Biological Dynamics. - : Informa UK Limited. - 1751-3758 .- 1751-3766. ; 5:2, s. 147-162
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Journal article (peer-reviewed)abstract
- First a population model with one single type of individuals is considered. Individuals reproduce asexually by splitting into two, with a population size dependent probability. Population extinction, growth and persistence are studied. Subsequently results are extended to such a population with two competing morphs.Results are applied to a simple model, where morphs arise through mutation. The movement in trait space of a monomorphic population and its possible branching into polymorphism are discussed. This is a first report.It purports to display the basic conceptual structure of a simple exact probabilistic formulation of adaptive dynamics.
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| 7. |
- Sagitov, Serik, 1956, et al.
(author)
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Coalescent approximation for structured populations in a stationary random environment
- 2010
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In: Theoretical Population Biology. - : Elsevier BV. - 0040-5809 .- 1096-0325. ; 78:3, s. 192-199
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Journal article (peer-reviewed)abstract
- We establish convergence to the Kingman coalescent for the genealogy of a geographically - or otherwise - structured version of the Wright-Fisher population model with fast migration. The new feature is that migration probabilities may change in a random fashion. This brings a novel formula for the coalescent effective population size (EPS). We call it a quenched EPS to emphasize the key feature of our model - random environment. The quenched EPS is compared with an annealed (mean-field) EPS which describes the case of constant migration probabilities obtained by averaging the random migration probabilities over possible environments.
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| 8. |
- Sagitov, Serik, 1956, et al.
(author)
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Evolutionary branching in a stochastic population model with discrete mutational steps
- 2013
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In: Theoretical Population Biology. - : Elsevier BV. - 0040-5809 .- 1096-0325. ; 83, s. 145-154
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Journal article (peer-reviewed)abstract
- Evolutionary branching is analysed in a stochastic, individual-based population model under mutation and selection. In such models, the common assumption is that individual reproduction and life career are characterised by values of a trait, and also by population sizes, and that mutations lead to small changes ϵ in trait value. Then, traditionally, the evolutionary dynamics is studied in the limit ϵ→0. In the present approach, small but non-negligible mutational steps are considered. By means of theoretical analysis in the limit of infinitely large populations, as well as computer simulations, we demonstrate how discrete mutational steps affect the patterns of evolutionary branching. We also argue that the average time to the first branching depends in a sensitive way on both mutational step size and population size.
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| 9. |
- Vatutin, V.A., et al.
(author)
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A Decomposable Branching Process in a Markovian Environment
- 2012
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In: International Journal of Stochastic Analysis. - : Hindawi Limited. - 2090-3332 .- 2090-3340. ; :Article ID 694285
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Journal article (peer-reviewed)abstract
- A population has two types of individuals, with each occupying an island. One of those, where individuals of type 1 live, offers a variable environment. Type 2 individuals dwell on the other island, in a constant environment. Only one-way migration is possible. We study then asymptotics of the survival probability in critical and subcritical cases.
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