4,416 research outputs found

    Spin wave vortex from the scattering on Bloch point solitons

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    The interaction of a spin wave with a stationary Bloch point is studied. The topological non-trivial structure of the Bloch point manifests in the propagation of spin waves endowing them with a gauge potential that resembles the one associated with the interaction of a magnetic monopole and an electron. By pursuing this analogy, we are led to the conclusion that the scattering of spin waves and Bloch points is accompanied by the creation of a magnon vortex. Interference between such a vortex and a plane wave leads to dislocations in the interference pattern that can be measurable by means of magnon holography

    Temporal patterns in acoustic presence and foraging activity of oceanic dolphins at seamounts in the Azores

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    Ā© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Cascao, I., Lammers, M. O., Prieto, R., Santos, R. S., & Silva, M. A. Temporal patterns in acoustic presence and foraging activity of oceanic dolphins at seamounts in the Azores. Scientific Reports, 10(1), (2020): 3610, doi:10.1038/s41598-020-60441-4.Several seamounts have been identified as hotspots of marine life in the Azores, acting as feeding stations for top predators, including cetaceans. Passive acoustic monitoring is an efficient tool to study temporal variations in the occurrence and behaviour of vocalizing cetacean species. We deployed bottom-moored Ecological Acoustic Recorders (EARs) to investigate the temporal patterns in acoustic presence and foraging activity of oceanic dolphins at two seamounts (Condor and Gigante) in the Azores. Data were collected in Marchā€“May 2008 and April 2010ā€“February 2011. Dolphins were present year round and nearly every day at both seamounts. Foraging signals (buzzes and bray calls) were recorded in >87% of the days dolphin were present. There was a strong diel pattern in dolphin acoustic occurrence and behaviour, with higher detections of foraging and echolocation vocalizations during the night and of social signals during daylight hours. Acoustic data demonstrate that small dolphins consistently use Condor and Gigante seamounts to forage at night. These results suggest that these seamounts likely are important feeding areas for dolphins. This study contributes to a better understanding of the feeding ecology of oceanic dolphins and provides new insights into the role of seamount habitats for top predators.This research was supported by the FundaĆ§Ć£o para a CiĆŖncia e a Tecnologia (FCT), Azores 2020 Operational Programme and the Fundo Regional da CiĆŖncia e Tecnologia (FRCT), through research projects TRACE (PTDC/MAR/74071/2006), MAPCET (M2.1.2/F/012/2011), FCT-Exploratory (IF/00943/2013/CP1199/CT0001), WATCH IT (Acores-01-0145-FEDER-000057) and MISTIC SEAS II (GA11.0661/2017/750679/SUB/ENV.C2), co-funded by FEDER, COMPETE, QREN, POPH, European Social Fund (ESF), the Portuguese Ministry for Science and Education, and EU-DG/ENV. The Azores 2020 Operational Programme is funded by the community structural funds ERDF and ESF. Funds were also provided by FCT to MARE, through the strategic project UID/MAR/04292/2013. MAS was supported through a FCT Investigator contract funded by POPH, QREN, ESF and the Portuguese Ministry for Science and Education (IF/00943/2013). IC was supported by a FCT doctoral grant (SFRH/BD/41192/2007) and RP by a FCT postdoctoral grant (SFRH/BPD/108007/2015). We thank the field and crew teams for assisting with the many deployments and recoveries of the EARs. Special thanks to Norberto Serpa for helping with mooring design, Ken Sexton and Michael Richlen for their roles in manufacturing the EARs, Sergio Gomes for building the battery packs, and Lisa Munger for adapting Triton for EAR data analysis

    Etograma de Parablennius sanguinolentus parvicornis (Valenciennes in Cuvier & Valenciennes, 1836) (Pisces: Blenniidae) dos AƧores

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    No presente artigo concentramo-nos no etograma qualitativo de Parablennius sanguinolenrus parvicomis. O etograma inclui a descriĆ§Ć£o de cerca de quarenta padrƵes de comportamento ilustrados por desenhos baseados cm registos vĆ­deo e fotografias. Os aspectos mais distinctivos do etograma, em contraste com outras espĆ©cies intertidais, sĆ£o: i) a capacidade dos indivĆ­duos para nadarem distĆ¢ncias superiores a 1 metro sem contacto com o rundo. ii) a formaĆ§Ć£o, pelo macho parental, de uma clareira em frente e Ć  volta da entrada do ninho. iii) a incidĆŖncia de padrƵes de comportamento com elevaĆ§Ć£o do corpo em relaĆ§Ć£o ao fundo (altamente conspĆ­cuo na nataĆ§Ć£o sinal, mas tambĆ©m presente em muitas das actividades em que a nataĆ§Ć£o Ć© utilizada como modo de locomoĆ§Ć£o).ABSTRACT: This paper describes the ethogram of Parablennius sanguinolentus parvicomis. The ethogram includes the description of around forty patterns of behaviour illustrated by drawings mostly prepared from video recordings and photographs. The most distinctive features of the ethogram, by contrast with other common intertidal species, are: i) the capacity of the individuals to swim distances over 1 metre al one go, ii) the formation of a clearing in front of or around the nest entrance by the parental male, iii) the incidence of patterns or behaviour that elevate the body in relation to the bottom (highly conspicuous in signal swimming, but a150 present in all sets of activities in which swimming is used as a mode of locomotion)

    Notas sobre os hĆ”bitos alimentares e comportamento predatĆ³rio do mero, Epinephelus marginatus (Lowe, 1834) (Pisces: Serranidae) nos AƧores

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    Entre 1992 e 1995, foram colhidos e examinados 57 exemplares de E. marginatus da ilha Terceira. Os seus comprimentos totais variaram entre 60 e 138 cm com duas categorias de tamanho. O coeficiente de vacuidade observado foi de 44,0% para exemplares de mĆ©dio porte e 31,3% para grandes exemplares. As presas predominantes foram o polvo comum e peixes. Duas posturas de caƧa diferentes foram observadas e sĆ£o descritas.ABSTRACT: Between 1992 and 1995, 57 individuals of E. marginatus were collected near Terceira Island. Their sizes ranged from 60 to 138 cm, total length, with two size categories. Stomach contents were analysed. Vacuity coefficient was 44,0% for medium size specimens and 31,3% for large specimens. Octopus and fishes were the dominant prey. Two different hunting postures were also observed and described

    Atomistic Simulation of Intrinsic Defects and Trivalent and Tetravalent Ion Doping in Hydroxyapatite

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    Atomistic simulation techniques have been employed in order to investigate key issues related to intrinsic defects and a variety of dopants from trivalent and tetravalent ions. The most favorable intrinsic defect is determined to be a scheme involving calcium and hydroxyl vacancies. It is found that trivalent ions have an energetic preference for the Ca site, while tetravalent ions can enter P sites. Charge compensation is predicted to occur basically via three schemes. In general, the charge compensation via the formation of calcium vacancies is more favorable. Trivalent dopant ions are more stable than tetravalent dopants

    Duas novas ocorrĆŖncias de Ziphiidae (Cetacea) nos AƧores e actualizaĆ§Ć£o da lista de espĆ©cies de cetĆ”ceos

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    Os arrojamentos ocorridos em 1989, dum zĆ­fio, Ziphius cavirostris G. Cuvier, 1823, na ilha de Santa Maria, e duma baleia de bico-de-Gervais, Mesoplodon europaeus (Gervais, 1855) na ilha do Faial, representam os primeiros registos destas espĆ©cies paro o ArquipĆ©lago dos AƧores. As medidas externas dos dois espĆ©cimes e a craniometria de M. europaeus sĆ£o apresentadas. Fornece-se tambĆ©m uma lista actualizada das 22 espĆ©cies de cetĆ”ceos registados para as Ć”guas dos AƧores, embora a presenƧa de 3 delas seja actualmente duvidosa.ABSTRACT: Two standings in 1989 of a Cuvierā€™s Beaked Whale, Ziphius cavirostris G. Cuvier, 1823, on the Island of Santa Maria, and of a Gervaisā€™ Beaked Whale, Mesoplodon europaeus (Gervais, 1855), on the Island of Faial, represent the first records of these species in the Azores archipelago. Body measurements of both specimens and the skull biometry of M. europaeus are presented. An updated checklist or 22 cetaceans recorded from the Azorean waters is also presented, although the presences of 3 of them are actually dubious

    D. JoĆ£o de Castro Bank, a shallow water hydrothermal-vent in the Azores: checklist of the marine molluscs.

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    D. JoĆ£o de Castro Bank (DJC) is a shallow seamount with hydrothermal activity located between the islands of Terceira and SĆ£o Miguel, Azores (Portugal). Due to its remote location, few investigators have worked in the area. Thirty-three species of marine molluscs are recorded as new for DJC which brings the total number of species to 42 for this specific area. Common micro-mollusc species known for the Azores (e.g.: the sublittoral species Alvania poucheti and Setia subvaricosa) are not present, and possible reasons for this are discussed

    Table Grapes: There Is More to Vitiviniculture than Wineā€¦

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    Table grapes are fruits intended for fresh human consumption due to their sensory attributes and nutritional value. The objective of this chapter is to review the existing knowledge about table grapes, including a description of different varieties, with particular emphasis on the new highly appreciated seedless varieties. Following an introductory note on the world distribution and production of table grapes, also considering the impact of climate change, selected varieties of table grapes will be characterized in terms of their physiology, postharvest features, and consumer preferences. A morphological description of each variety, with emphasis on grape skin, grape rachis and grape cluster will be included. A final note on the drying of table grapes into raisins, and the most appropriate varieties for drying, will be given. The major changes occurring throughout the growth, development, and ripening phases of table grapes production will be discussed, regarding both physical (skin color and skin and pulp texture) and chemical (phenolic compounds, sugar content and acidity) parameters, as well as growth regulators

    Marine Fishes of the Azores : annotated checklist and bibliography : a catalogue of the Azorean marine ichthyodiversity

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    A list of the marine fishes of the Azores is presented. The list is based on a review of the literature combined with an examination of selected specimens available from collections of Azorean fishes deposited in museums, including the collection of fish at the Department of Oceanography and Fisheries of the University of the Azores (Horta). Personal information collected over several years is also incorporated. The geographic area considered is the Economic Exclusive Zone of the Azores. The list is organised in Classes, Orders and Families according to Nelson (1994). The scientific names are, for the most part, those used in Fishes of the North-eastern Atlantic and the Mediterranean (FNAM) (Whitehead et al. 1989), and they are organised in alphabetical order within the families. Clofnam numbers (see Hureau & Monod 1979) are included for reference. Information is given if the species is not cited for the Azores in FNAM. Vernacular names are always both presented in Portuguese (Azorean names) and English. Synonyms, misspellings and misidentifications found in the literature in reference to the occurrence of species in the Azores are also quoted. The 460 species listed, belong to 142 families; 12 species are cited for the first time for the Azores. Details are given for 23 other species cited for the first time for the Azores in the Red Book of Portuguese Vertebrates (ICN 1993). Fifty-four ambiguous and/or exceptional occurrences are included in an appendix. A second appendix contains the remaining corrections to the checklist of fish included in ICN (1993). The paper concludes with a synthesis and an annotated indexed bibliography of the marine fishes of the Azores. Most references are available through the library of the Department of Oceanography and Fisheries of the University of the Azores.The publication of the present work was funded by the Junta Nacional de InvestigaĆ§Ć£o CientĆ­fica e TecnolĆ³gica (JNICT)- Lisboa. The research was made possible through grants received from Secretaria Regional da Agricultura e Pescas-Horta (AƧores), INVOTAN- Lisboa, FundaĆ§Ć£o Calouste Gulbenkian- Lisboa, FundaĆ§Ć£o Luso-Americana para o Desenvolvimento- Lisboa. The work was developed at the Departamento de Oceanografia e Pescas of the Universidade dos AƧores
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