The impact of breeding Yellow-Legged Gulls on vegetation cover and plant composition of Grey Dune habitats

The establishment of large populations of yellow-legged gull Larus michahellis in coastal and urban areas can lead to strong changes in vegetation cover and composition through creating physical disturbance in the vegetation and impacting the soil quality through defecation. In this study, we evaluated the effects of breeding yellow-legged gull populations on tall and short vegetation cover and plant species composition in old (occupied for 13 years) and new (occupied for 3 years) colony sites in grey dunes of the Algarve, southern Portugal. In each site, sampling plots were used to measure the percentage of vegetation cover in areas with and without breeding gulls. In the old colony site, the cover by tall vegetation was substantially reduced and the cover by short vegetation substantially increased in the areas where gulls are breeding in comparison with the adjacent areas. In the new colony sites, there were only minor differences. The increase in cover of short vegetation in the breeding area of the old colony site was mostly by nitrophilous species (Paronychia argentea and Malcolmia littorea) and should be explained by the decrease in vegetation cover of tall plant species and by feces deposition. Tall and slow-growing species Suaeda maritima and Helichrysum italicum covers were negatively affected. Our results showed that yellow-legged gulls affected vegetation cover and composition of grey dunes after 3 years of consecutive breeding, and this should be considered in the management of these habitats where breeding yellow-legged gulls are increasing.info:eu-repo/semantics/publishedVersio

Covariance Matrix Adaptation Pareto Archived Evolution Strategy with Hypervolume-sorted Adaptive Grid Algorithm.

Real-world problems often involve the optimisation of multiple conflicting objectives. These problems, referred to as multi-objective optimisation problems, are especially challenging when more than three objectives are considered simultaneously. This paper proposes an algorithm to address this class of problems. The proposed algorithm is an evolutionary algorithm based on an evolution strategy framework, and more specifically, on the Covariance Matrix Adaptation Pareto Archived Evolution Strategy (CMA-PAES). A novel selection mechanism is introduced and integrated within the framework. This selection mechanism makes use of an adaptive grid to perform a local approximation of the hypervolume indicator which is then used as a selection criterion. The proposed implementation, named Covariance Matrix Adaptation Pareto Archived Evolution Strategy with Hypervolume-sorted Adaptive Grid Algorithm (CMA-PAES-HAGA), overcomes the limitation of CMA-PAES in handling more than two objectives and displays a remarkably good performance on a scalable test suite in five, seven, and ten-objective problems. The performance of CMA-PAES-HAGA has been compared with that of a competition winning meta-heuristic, representing the state-of-the-art in this sub-field of multi-objective optimisation. The proposed algorithm has been tested in a seven-objective real-world application, i.e. the design of an aircraft lateral control system. In this optimisation problem, CMA-PAES-HAGA greatly outperformed its competitors

Implicações de alterações sazonais e anuais da produtividade oceânica na consistência espacial e temporal da distribuição marinha em cagarras de Cabo Verde (Calonectris edwardsii)

Dissertação de Mestrado em Ecologia apresentada à Faculdade de Ciências e TecnologiaA abundância e a previsibilidade dos recursos alimentares para os predadores marinhos são altamente influenciadas pelas mudanças anuais das condições oceanográficas, mas, em geral, são menores nos ecossistemas tropicais do que nos temperados. No entanto, fenómenos de afloramento em determinadas áreas costeiras permitem a multiplicação e emergência de muitas espécies. As aves marinhas são predadores marinhos de topo que têm sido usados para avaliar a saúde do ecossistema e compreender as alterações nos ambientes marinhos. As variações na disponibilidade de recursos podem causar alterações na ecologia espacial e trófica das aves marinhas. Diferentes estratégias podem ser adotadas em diferentes fases do ciclo reprodutivo e em diferentes anos com diferentes condições ambientais. No entanto, parece haver alguma consistência entre anos nos locais de procura de alimento, o que tem implicações importantes para a conservação de aves marinhas e de outros predadores de topo com uma distribuição espacial semelhante.Recolhemos dados para analisar a ecologia espacial (dispositivos GPS) e trófica (análise de isótopos estáveis) de uma ave marinha tropical - cagarra de Cabo Verde (Calonectris edwardsii) - durante as fases de incubação e alimentação das crias de seis anos consecutivos (2013-2018, n=15 ind. por cada período e ano). Pretendemos perceber como é que as variações da produtividade marinha em redor da colónia podem influenciar o comportamento de procura de alimento desta espécie. Os resultados mostraram que a batimetria e a temperatura da superfície do mar foram as variáveis ambientais que melhor explicaram a escolha dos locais de alimentação pelas aves. Tal como esperávamos, houve uma forte alteração nas estratégias de procura de alimento das cagarras cabo-verdianas entre as fases do ciclo reprodutivo (da incubação para a alimentação das crias). As aves adotaram uma estratégia bimodal de procura de alimento, fazendo viagens mais longas à costa Ocidental de África durante a incubação, onde a produtividade marinha é muito alta, e viagens mais curtas em redor da colónia durante a alimentação das crias. Assim, esta espécie diminuiu as suas assinaturas de δ13C desde a incubação para a alimentação das crias, aumentou o nível trófico das suas presas e diminuiu a sobreposição entre os nichos tróficos. Houve algumas alterações significativas nas estratégias de procura de alimento entre anos. Nos anos com valores mais baixos do índice NAO, correspondendo a uma menor produtividade marinha, as aves viajaram mais para a costa africana e gastaram menos tempo na procura de alimento. No entanto, ao contrário do que previmos, a consistência nos habitats de procura de alimento foi maior. Tal como em anos de menor produtividade marinha, elas viajaram mais para a costa de África e apresentaram maiores assinaturas de δ13C. O oposto aconteceu durante os anos de valores mais altos do índice NÃO, ou seja, anos mais produtivos, mas houve algumas exceções. Em anos de condições ambientais mais precárias, as aves aumentaram o nicho trófico desde a incubação para a fase de alimentação das crias e, aparentemente, procuraram por recursos mais diversificados para alimentá-las. Em anos de boas condições ambientais, as aves mostraram ser mais especialistas. Concluímos que os indivíduos realizaram importantes alterações no seu nicho espacial e trófico entre anos como resposta a alterações das condições ambientais.As cagarras de Cabo Verde sofreram ameaças ambientais e antropogénicas. Embora alguns esforços já tenham sido feitos, através da monitorização e do rastreamento destas aves podemos definir áreas marinhas protegidas (AMPs) e avaliar as variações anuais do uso dessas mesmas áreas.The abundance and predictability of food resources for marine top predators is highly influenced by annual changes in oceanographic conditions, but, overall, is lower in tropical than in temperate ecosystems. However, upwelling phenomena in certain coastal areas allow multiplication and resurgence of many prey species. Seabirds are marine top predators that have been used to assess the health of the ecosystem and understand changes in marine environments. Variation in resource availability can cause changes in the spatial and trophic ecology of seabirds. Different strategies can be adopted at different phases of the breeding season and in different years with different environmental conditions. However, there seems to be some inter-annual consistency in foraging sites, which has important implications for the conservation of seabirds and other top predators with a similar spatial distribution.We collected data to analyse the spatial (GPS-loggers) and trophic (stable isotope analysis) ecology of a tropical seabird - Cape Verde shearwater (Calonectris edwardsii) -during both the incubation and chick-rearing phases of six consecutive years (2013-2018, n=15 ind. for each period and year). We intend to understand how variations in marine productivity around the colony can influence foraging behaviour of this species. The results showed that bathymetry and sea surface temperature were the environmental variables that best explained the choice of foraging sites by birds. As we expected there was a strong alteration on the foraging strategies of Cape Verde shearwaters among breeding phases (incubation to chick-rearing). Birds adopted a bimodal pattern of foraging strategies making longer trips to the West African coast during incubation, where marine productivity is very high, and making shorter trips around the colony during the chick-rearing to provisioning their chicks. Thus, this specie decreased their δ13C signatures from incubation to chick-rearing, increased the trophic level of their prey and decreased the overlap between trophic niches. There were some significant changes in foraging strategies among years. In years with lower NAO index values, corresponding to a lower marine productivity, birds travelled more to the African coast and spent less time in foraging. However, contrary to what we predicted, the consistency in foraging habitats was greater. Similarly to years of lower marine productivity they travelled more to the coast of Africa presented larger δ13C signatures. The opposite happened during years of higher NAO index values, i.e. the more productive years, but there were with some exceptions. In years of poorer environmental conditions birds increased the trophic niche from the incubation to the chick-rearing period, and apparently searched for more diversified items to feed their chicks. In years of good environmental conditions birds were more specialised. We concluded that individuals made important shifts on their spatial and trophic niche among years, as a response to changes in environmental conditions. The Cape Verde shearwaters have suffered environmental and anthropogenic threats. Although some efforts have already been made, by monitoring and tracking these birds we can define marine protected areas (MPAs) and assess annual variations in the use of these areas

Containment measures

OBSOLETE (project finished) - Description of containment measures during COVID'19 lockdown, in the context of SIlent Cities project. Please request access to Silent Cities if neede

Guidelines for the use of flow cytometry and cell sorting in immunological studies

International audienceThe classical model of hematopoiesis established in the mouse postulates that lymphoid cells originate from a founder population of common lymphoid progenitors. Here, using a modeling approach in humanized mice, we showed that human lymphoid development stemmed from distinct populations of CD127(-) and CD127(+) early lymphoid progenitors (ELPs). Combining molecular analyses with in vitro and in vivo functional assays, we demonstrated that CD127(-) and CD127(+) ELPs emerged independently from lympho-mono-dendritic progenitors, responded differently to Notch1 signals, underwent divergent modes of lineage restriction, and displayed both common and specific differentiation potentials. Whereas CD127(-) ELPs comprised precursors of T cells, marginal zone B cells, and natural killer (NK) and innate lymphoid cells (ILCs), CD127(+) ELPs supported production of all NK cell, ILC, and B cell populations but lacked T potential. On the basis of these results, we propose a "two-family" model of human lymphoid development that differs from the prevailing model of hematopoiesis