| 1. |
- Araujo, R., et al.
(författare)
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PHENOTYPIC DIFFERENTIATION AT SOUTHERN LIMIT BORDERS: THE CASE STUDY OF TWO FUCOID MACROALGAL SPECIES WITH DIFFERENT LIFE-HISTORY TRAITS
- 2011
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Ingår i: Journal of Phycology. - : Wiley. - 0022-3646. ; 47:3, s. 451-462
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Tidskriftsartikel (refereegranskat)abstract
- Marginal populations are often geographically isolated, smaller, and more fragmented than central populations and may frequently have to face suboptimal local environmental conditions. Persistence of these populations frequently involves the development of adaptive traits at phenotypic and genetic levels. We compared population structure and demographic variables in two fucoid macroalgal species contrasting in patterns of genetic diversity and phenotypic plasticity at their southern distribution limit with a more central location. Models were Ascophyllum nodosum (L.) Le Jol. (whose extreme longevity and generation overlap may buffer genetic loss by drift) and Fucus serratus L. (with low genetic diversity at southern margins). At edge locations, both species exhibited trends in life-history traits compatible with population persistence but by using different mechanisms. Marginal populations of A. nodosum had higher reproductive output in spite of similar mortality rates at all life stages, making edge populations denser and with smaller individuals. In F. serratus , rather than demographic changes, marginal populations differed in habitat, occurring restricted to a narrower vertical habitat range. We conclude that persistence of both A. nodosum and F. serratus at the southern-edge locations depends on different strategies. Marginal population persistence in A. nodosum relies on a differentiation in life-history traits, whereas F. serratus , putatively poorer in evolvability potential, is restricted to a narrower vertical range at border locations. These results contribute to the general understanding of mechanisms that lead to population persistence at distributional limits and to predict population resilience under a scenario of environmental change.
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| 2. |
- Araujo, R., et al.
(författare)
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The role of disturbance in differential regulation of co-occurring brown algae species: Interactive effects of sediment deposition, abrasion and grazing on algae recruits
- 2012
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Ingår i: Journal of Experimental Marine Biology and Ecology. - : Elsevier BV. - 0022-0981. ; 422-423, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Disturbance is an important structuring factor in intertidal communities. This study aimed at experimentally testing the effects of three important sources of disturbance to intertidal rocky habitats (abrasion, sediment deposition and herbivory) on the survivorship and growth of embryos of canopy forming fucoid species (Fucus vesiculosus and Fucus serratus). Natural levels of sediment deposition and herbivore density were characterized and the temporal variation of populations of both species was followed. The experimental study showed that the survivorship of F. serratus embryos was negatively affected by herbivory but growth was enhanced in the presence of abrasion and herbivores. F. vesiculosus suffered the interactive negative effects of the three sources of disturbance tested, although abrasion was the most important factor affecting mortality rates of embryos. Conversely, none of the tested sources of disturbance significantly affected growth of embryos. These results highlight the importance of disturbance events in regulating species interactions which might be particularly relevant for population dynamics and persistence at the geographical borders of species' distribution. (C) 2012 Elsevier B.V. All rights reserved.
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| 3. |
- Sciarretta, A., et al.
(författare)
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A control benchmark on the energy management of a plug-in hybrid electric vehicle
- 2014
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Ingår i: Control Engineering Practice. - : Pergamon Press. - 0967-0661 .- 1873-6939. ; 29, s. 287-298
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Tidskriftsartikel (refereegranskat)abstract
- A benchmark control problem was developed for a special session of the IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling (E-COSM 12), held in Rueil-Malmaison, France, in October 2012. The online energy management of a plug-in hybrid-electric vehicle was to be developed by the benchmark participants. The simulator, provided by the benchmark organizers, implements a model of the GM Voltec powertrain. Each solution was evaluated according to several metrics, comprising of energy and fuel economy on two driving profiles unknown to the participants, acceleration and braking performance, computational performance. The nine solutions received are analyzed in terms of the control technique adopted (heuristic rule-based energy management vs. equivalent consumption minimization strategies, ECMS), battery discharge strategy (charge depleting-charge sustaining vs. blended mode), ECMS implementation (vector-based vs. map-based), ways to improve the implementation and improve the computational performance. The solution having achieved the best combined score is compared with a global optimal solution calculated offline using the Pontryagins minimum principle-derived optimization tool HOT.
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