Life goes on : Oblada melanura (Linnaeus, 1758) (Perciformes, Sparidae), the saddled seabream, expands its distribution range westwards to the Azores

A group of 10 individuals of the saddled seabream, Oblada melanura (Linnaeus, 1758), was photographed at Lajes do Pico Bay, on Pico Island, Azores. This finding represents a significant westward expansion of the known range of this species and may be linked to global warming. A call is therefore made for a monitoring program of the coastal fish fauna of the Azores which would improve the understanding of the effects of climate change and other anthropogenic stressors on marine communities.info:eu-repo/semantics/publishedVersio

Manipulation of Magnetic Skyrmions by Superconducting Vortices in Ferromagnet-Superconductor Heterostructures

Dynamics of magnetic skyrmions in hybrid ferromagnetic films harbors novel physical phenomena and holds promise for technological applications. In this work, we discuss the behavior of magnetic skyrmions when coupled to superconducting vortices in a ferromagnet-superconductor heterostructure. We use numerical simulations and analytic arguments to reveal broader possibilities for manipulating the skyrmion-vortex dynamic correlations in the hybrid system, that are not possible in its separated constituents. We explore the thresholds of particular dynamic phases, and quantify the phase diagram as a function of the relevant material parameters, applied current and induced magnetic torques. Finally, we demonstrate the broad and precise tunability of the skyrmion Hall-angle in presence of vortices, with respect to currents applied to either or both the superconductor and the ferromagnet within the heterostructure

Provenance does matter: links between winter trophic segregation and the migratory origins of European robins

Amongst migratory species, it is common to find individuals from different populations or geographical origins sharing staging or wintering areas. Given their differing life histories, ecological theory would predict that the different groups of individuals should exhibit some level of niche segregation. This has rarely been investigated because of the difficulty in assigning migrating individuals to breeding areas. Here, we start by documenting a broad geographical gradient of hydrogen isotopes (δ2H) in robin Erithacus rubecula feathers across Europe. We then use δ2H, as well as wing-tip shape, as surrogates for broad migratory origin of birds wintering in Iberia, to investigate the ecological segregation of populations. Wintering robins of different sexes, ages and body sizes are known to segregate between habitats in Iberia. This has been attributed to the despotic exclusion of inferior competitors from the best patches by dominant individuals. We find no segregation between habitats in relation to δ2H in feathers, or to wing-tip shape, which suggests that no major asymmetries in competitive ability exist between migrant robins of different origins. Trophic level (inferred from nitrogen isotopes in blood) correlated both with δ2H in feathers and with wing-tip shape, showing that individuals from different geographic origins display a degree of ecological segregation in shared winter quarters. Isotopic mixing models indicate that wintering birds originating from more northerly populations consume more invertebrates. Our multi-scale study suggests that trophic-niche segregation may result from specializations (arising in the population-specific breeding areas) that are transported by the migrants into the shared wintering grounds

Peixes marinhos de Santa Maria.

V Expedição Científica do Departamento de Biologia – Santa Maria e Formigas 1990.0s peixes constituem um elemento conspícuo da fauna marinha açoreana e, como tal, é relativamente elevado o número de publicações dedicadas a este grupo. Apesar disso, não existe nenhum inventário da ictiofauna de Santa Maria. Procurando contribuir para superar esta lacuna, apresenta-se neste artigo a lista das 42 espécies de peixes colectadas em Santa Maria durante a Expedição Cientifica "Santa Maria e Formigas 1990", bem como dos respectivos nome vulgar (n.v.) e local de captura. A lista das espécies ictiológicas colectadas nas Formigas integrará um relatório separado, inteiramente consagrado a estes Ihéus, enquanto a lista completa de todas as espécies colectadas durante a referida Expedição foi já publicada noutro local (Arruda et al., in press). Todos os exemplares colectados serão depositados nas colecções do Museu Carlos Machado, em Ponta Delgada

Electron-Electron Bound States in Maxwell-Chern-Simons-Proca QED3

We start from a parity-breaking MCS QED$_{3}$ model with spontaneous breaking of the gauge symmetry as a framework for evaluation of the electron-electron interaction potential and for attainment of numerical values for the e-e bound state. Three expressions are obtained for the potential according to the polarization state of the scattered electrons. In an energy scale compatible with Condensed Matter electronic excitations, these three potentials become degenerated. The resulting potential is implemented in the Schrodinger equation and the variational method is applied to carry out the electronic binding energy. The resulting binding energies in the scale of 10-100 meV and a correlation length in the scale of 10-30 Angs. are possible indications that the MCS-QED$_{3}$ model adopted may be suitable to address an eventual case of e-e pairing in the presence of parity-symmetry breakdown. The data analyzed here suggest an energy scale of 10-100 meV to fix the breaking of the U(1)-symmetry. PACS numbers: 11.10.Kk 11.15.Ex 74.20.-z 74.72.-h ICEN-PS-01/1

A importância da microscopia electrónica no estudo taxonómico do recife algal fóssil da Prainha.

XXXVIII Reunião Anual da Sociedade Portuguesa de Microscopia Electrónica e Biologia Celular. Ponta Delgada, Açores, 5-7 de Dezembro de 2003