Recursos de colección

Repositorio da Universidade dos Açores (8.750 recursos)

O Repositório Institucional da Universidade dos Açores desenvolvido no âmbito do projecto RCAAP.

DCA - Artigos em Revistas Internacionais / Articles in International Journals

Mostrando recursos 1 - 20 de 77

  1. Morphology and Mixing State of Aged Soot Particles at a Remote Marine Free Troposphere Site : Implications for Optical Properties

    China, Swarup; Scarnato, Barbara; Owen, Robert C.; Zhang, Bo; Ampadu, Marian T.; Kumar, Sumit; Dzepina, Katja; Dziobak, Michael P.; Fialho, Paulo; Perlinger, Judith A.; Hueber, Jacques; Helmig, Detlev; Mazzoleni, Lynn R.; Mazzoleni, Claudio
    The radiative properties of soot particles depend on their morphology and mixing state, but their evolution during transport is still elusive. Here we report observations from an electron microscopy analysis of individual particles transported in the free troposphere over long distances to the remote Pico Mountain Observatory in the Azores in the North Atlantic. Approximately 70% of the soot particles were highly compact and of those 26% were thinly coated. Discrete dipole approximation simulations indicate that this compaction results in an increase in soot single scattering albedo by a factor of ≤2.17. The top of the atmosphere direct radiative forcing...

  2. Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory : a case study with long range transported biomass burning plumes

    Dzepina, Katja; Mazzoleni, Claudio; Fialho, Paulo; China, Swarup; Zhang, Bo; Owen, R. Chris; Helmig, Detlev; Hueber, Jacques; Kumar, Sumit; Perlinger, Judith A.; Kramer, Louisa; Dziobak, Michael P.; Ampadu, Marian T.; Olsen, Seth C.; Wuebbles, Donald J.; Mazzoleni, Lynn R.
    Free tropospheric aerosol was sampled at the Pico Mountain Observatory located at 2225 m above mean sea level on Pico Island of the Azores archipelago in the North Atlantic. The observatory is located ~ 3900 km east and downwind of North America, which enables studies of free tropospheric air transported over long distances. Aerosol samples collected on filters from June to October 2012 were analyzed to characterize organic carbon, elemental carbon, and inorganic ions. The average ambient concentration of aerosol was 0.9 ± 0.7 μg m−3. On average, organic aerosol components represent the largest mass fraction of the total measured...

  3. The application of a multi-wavelength Aethalometer to estimate iron dust and black carbon concentrations in the marine boundary layer of Cape Verde

    Fialho, Paulo; Cerqueira, Mário; Pio, Casimiro; Cardoso, João; Nunes, Teresa; Custódio, Danilo; Alves, Célia A.; Almeida, S. M.; Almeida-Silva, M.; Reis, M. A.; Rocha, F.
    The two-component model (Fialho et al., 2006) was used to decouple the contributions of black carbon (BC) and iron oxides, present in dust, to the aerosol attenuation coefficient, measured with a multiwavelength Aethalometer. The model results were compared with the elemental carbon (EC) and iron concentrations determined in the laboratory from the analysis of aerosol particles collected with conventional samplers. The comparison was based on one year of data obtained at Praia, Santiago Island, Cape Verde, after side by side operation of the aerosol monitoring instruments. The linear regression equation that best describes the relationship between BC concentrations, derived from...

  4. Wet deposition of particulate carbon to the Central North Atlantic Ocean

    Custódio, Danilo; Cerqueira, Mário; Fialho, Paulo; Nunes, Teresa; Pio, Casimiro; Henriques, Diamantino
    Elemental carbon (EC) and water-insoluble organic carbon (WIOC) concentrations were measured in wet-only precipitation samples collected on Terceira Island (Azores, Portugal) between December 2009 and October 2010, to investigate temporal variations, source regions and wet deposition fluxes. The global volume-weighted average (vwa) concentrations were 134 ± 19 μgC L(-1) for WIOC and 15.0 ± 1.6 μgC L(-1) for EC, which fall within the range of values that have been found in the European background atmosphere. The WIOC concentration exhibited a temporal variation over the study period with a minimum in winter (vwa 88 ± 16 μgC L(-1)) and a maximum...

  5. Are underwater archaeological parks good for fishes? Symbiotic relation between cultural heritage preservation and marine conservation in the Azores

    Garcia, Catarina; Barreiros, João P.
    The Underwater Archaeological Parks (UAP) of the Azores are a cultural heritage protection initiative and an opportunity to promote fruition between archaeological sites and biodiversity. Respecting UNESCO’s “Convention on the Protection of the Underwater Cultural Heritage” principles, the UAPs were classified for the first time in 2005 and are unique in the Portuguese context. Due to the autonomy that this ultra-peripheral European Region has in terms of cultural heritage management, this structure arises from a specific law in 2005 formulated by initiative of the Azores Regional Government. At the same time, the archipelago’s marine biodiversity richness has become one of...

  6. New insights into the systematics of North Atlantic Gaidropsarus (Gadiformes, Gadidae): flagging synonymies and hidden diversity

    Barros-García, David; Bañón, Rafael; Arronte, Juan Carlos; Fernández-Peralta, Lourdes; García, Ramón; Iglésias, Samuel Paco; Sellos, Daniel Y.; Barreiros, João P.; Comesaña, Ángel Sebastián; De Carlos, Alejandro
    Gaidropsarus Rafinesque, 1810 is a genus of marine fishes, commonly known as rocklings, comprising 14 living species and showing a high ecological diversity from the intertidal zone to the deep sea. The systematics of this group has been controversial due to a general lack of representative specimens and the conservative morphology exhibited. A multidisciplinary approach combining the analysis of meristic data and the DNA barcode standard was applied in a species delimitation approach. Individuals representing eight valid and three unnamed species were collected, morphologically identified and archived in several museum collections. Comparison of DNA sequences shows complex results, furthering the...

  7. New insights into the systematics of North Atlantic Gaidropsarus (Gadiformes, Gadidae): flagging synonymies and hidden diversity

    Barros-García, David; Bañón, Rafael; Arronte, Juan Carlos; Fernández-Peralta, Lourdes; García, Ramón; Iglésias, Samuel Paco; Sellos, Daniel Y.; Barreiros, João P.; Comesaña, Ángel Sebastián; De Carlos, Alejandro
    Gaidropsarus Rafinesque, 1810 is a genus of marine fishes, commonly known as rocklings, comprising 14 living species and showing a high ecological diversity from the intertidal zone to the deep sea. The systematics of this group has been controversial due to a general lack of representative specimens and the conservative morphology exhibited. A multidisciplinary approach combining the analysis of meristic data and the DNA barcode standard was applied in a species delimitation approach. Individuals representing eight valid and three unnamed species were collected, morphologically identified and archived in several museum collections. Comparison of DNA sequences shows complex results, furthering the...

  8. First record of the cubera snapper, Lutjanus cyanopterus (Actinopterygii: Perciformes: Lutjanidae), from the Azores (NE Atlantic) and possible extension range for the West Atlantic

    Ribeiro, Pedro; Gonçalves, João M.; Chavan, Govindraj; Fricke, Ronald; García-Mederos, Antonio M.; Tuset, Victor; Barreiros, João P.
    BACKGROUND. A lutjanid recently captured in Flores Island represents the first documented record of a snapper for the Azores Islands. Since this specimen was not made available to us besides photographs and a muscle sample, a genetic study approach was necessary in order to accurately describe and discuss this somewhat unexpected occurrence. The main objective of this paper was to explain and discuss the presence of this single specimen in this part of the north-eastern Atlantic. MATERIALS AND METHODS. The specimen was caught by spear fishers on 30 July 2014 off Flores Island. We analysed all available photographs and a sample...

  9. First record of the cubera snapper, Lutjanus cyanopterus (Actinopterygii: Perciformes: Lutjanidae), from the Azores (NE Atlantic) and possible extension range for the West Atlantic

    Ribeiro, Pedro; Gonçalves, João M.; Chavan, Govindraj; Fricke, Ronald; García-Mederos, Antonio M.; Tuset, Victor; Barreiros, João P.
    BACKGROUND. A lutjanid recently captured in Flores Island represents the first documented record of a snapper for the Azores Islands. Since this specimen was not made available to us besides photographs and a muscle sample, a genetic study approach was necessary in order to accurately describe and discuss this somewhat unexpected occurrence. The main objective of this paper was to explain and discuss the presence of this single specimen in this part of the north-eastern Atlantic. MATERIALS AND METHODS. The specimen was caught by spear fishers on 30 July 2014 off Flores Island. We analysed all available photographs and a sample...

  10. Deep-sea seven-arm octopus hijacks jellyfish in shallow waters

    Rosa, Rui; Kelly, Jesse T.; Lopes, Vanessa M.; Paula, José R.; Gonçalves, João M.; Calado, Ricardo; Norman, Mark D.; Barreiros, João P.
    Pelagic octopods have secondarily left the seafloor and evolved a holopelagic existence. One of the most striking adaptations among a suite of related pelagic octopod families (superfamily Argonautoidea) is their associations with gelatinous zooplankton (jellyfishes and salps). Here, we report a unique interaction between a male octopod (Haliphron atlanticus) and a jellyfish (Pelagia noctiluca) at the sea surface. The oral-to-oral surface orientation of this encounter and sizes of the animals seem not to fit the explanations of camouflage, shelter, and/or transportation for the octopod or “weapons stealing” strategies observed to date in other pelagic octopods. While maneuvering the jelly, H....

  11. Deep-sea seven-arm octopus hijacks jellyfish in shallow waters

    Rosa, Rui; Kelly, Jesse T.; Lopes, Vanessa M.; Paula, José R.; Gonçalves, João M.; Calado, Ricardo; Norman, Mark D.; Barreiros, João P.
    Pelagic octopods have secondarily left the seafloor and evolved a holopelagic existence. One of the most striking adaptations among a suite of related pelagic octopod families (superfamily Argonautoidea) is their associations with gelatinous zooplankton (jellyfishes and salps). Here, we report a unique interaction between a male octopod (Haliphron atlanticus) and a jellyfish (Pelagia noctiluca) at the sea surface. The oral-to-oral surface orientation of this encounter and sizes of the animals seem not to fit the explanations of camouflage, shelter, and/or transportation for the octopod or “weapons stealing” strategies observed to date in other pelagic octopods. While maneuvering the jelly, H....

  12. Unusual presence of Coryphaena hippurus Linnaeus, 1758 (Perciformes: Coryphaenidae) under an offshore oil platform in Southern Brazil

    Sinopoli, Mauro; Battaglia, Pietro; Barreiros, João P.
    OBJECTIVE: To study the food habits of a sample of the dolphinfish (Coryphaena hippurus) around the Petrobrás PXIV oil platform located off Southern Brazil. Methods: We examined the stomach contents of 28 adult dolphinfish caught around this platform between 2000 and 2001. RESULTS: Results highlighted a diet consisting mainly of pelagic fish, although cephalopods and crustaceans are also present. A large amount of clupeids found in the stomachs could be due to baits used by fishermen that do fish around the platform. CONCLUSIONS: In this research we discuss the possibility of this occurrence being related to trophic opportunistic behavior. This could be...

  13. Unusual presence of Coryphaena hippurus Linnaeus, 1758 (Perciformes: Coryphaenidae) under an offshore oil platform in Southern Brazil

    Sinopoli, Mauro; Battaglia, Pietro; Barreiros, João P.
    OBJECTIVE: To study the food habits of a sample of the dolphinfish (Coryphaena hippurus) around the Petrobrás PXIV oil platform located off Southern Brazil. Methods: We examined the stomach contents of 28 adult dolphinfish caught around this platform between 2000 and 2001. RESULTS: Results highlighted a diet consisting mainly of pelagic fish, although cephalopods and crustaceans are also present. A large amount of clupeids found in the stomachs could be due to baits used by fishermen that do fish around the platform. CONCLUSIONS: In this research we discuss the possibility of this occurrence being related to trophic opportunistic behavior. This could be...

  14. Description of an eye barotrauma in scuba diving with clinical discussion

    Barreiros, Pedro; Haddad Jr., Vidal; Barreiros, João P.
    In this paper we report and discuss a scuba diving accident caused by compression of the mask at a depth of 9.1 m resulting in conjunctiva haemorrhage of both eyes in a 21-year-old male. After five weeks and benefiting from immediate post-accident medical attention and medication followed by ophthalmologic examinations the patient recovered with no chronic effects neither in vision nor in the eyes.

  15. Differential survival and reproduction in colour forms of Philaenus spumarius give new insights to the study of its balanced polymorphism

    Silva, Sara E.; Rodrigues, Ana S. B.; Marabuto, Eduardo; Yurtsever, Selçuk; Borges, Paulo A. V.; Quartau, José A.; Paulo, Octávio S.; Seabra, Sofia G.
    1. Colour polymorphisms are common across animals and are often the result of complex selection regimes. Philaenus spumarius (Linnaeus) (Hemiptera, Aphrophoridae) shows a widely studied dorsal colour polymorphism with several described phenotypes whose variation in their occurrence and frequency, as well as their maintenance across time, have been reported. Several selective influences have been suggested to play a role, but the mechanisms underlying the maintenance of this polymorphism are still poorly understood. 2. To explore the adaptive significance of the colour polymorphism of P. spumarius, an experiment was conducted in captivity under semi-natural conditions to measure survival, reproductive success, and duration...

  16. Comparative phylogeography of endemic Azorean arthropods

    Parmakelis, Aristeidis; Rigal, François; Mourikis, Thanos; Balanika, Katerina; Terzopoulou, Sofia; Rego, Carla; Amorim, Isabel R.; Crespo, Luís C.; Pereira, Fernando E. A.; Triantis, Kostas A.; Whittaker, Robert J.; Borges, Paulo A. V.
    BACKGROUND: For a remote oceanic archipelago of up to 8 Myr age, the Azores have a comparatively low level of endemism. We present an analysis of phylogeographic patterns of endemic Azorean island arthropods aimed at testing patterns of diversification in relation to the ontogeny of the archipelago, in order to distinguish between alternative models of evolutionary dynamics on islands. We collected individuals of six species (representing Araneae, Hemiptera and Coleoptera) from 16 forest fragments from 7 islands. Using three mtDNA markers, we analysed the distribution of genetic diversity within and between islands, inferred the differentiation time-frames and investigated the inter-island...

  17. Modeling directional spatio-temporal processes in island biogeography

    Carvalho, José C.; Cardoso, Pedro; Rigal, François; Triantis, Kostas A.; Borges, Paulo A. V.
    A key challenge in island biogeography is to quantity the role of dispersal in shaping biodiversity patterns among the islands of a given archipelago. Here, we propose such a framework. Dispersal within oceanic archipelagos may be conceptualized as a spatio-temporal process dependent on: (1) the spatial distribution of islands, because the probability of successful dispersal is inversely related to the spatial distance between islands and (2) the chronological sequence of island formation that determines the directional asymmetry of dispersal (hypothesized to be predominantly from older to younger islands). From these premises, directional network models may be constructed, representing putative connections...

  18. Why Flightless Birds are 'Condemned' to Lay Eggs

    Barreiros, João P.
    Letter To Editor

  19. Invasions changing marine biodiversity

    Barreiros, João P.
    Letter To Editor

  20. Zoo animals and humans killed because of human negligent behavior

    Barreiros, João P.; Haddad Jr., Vidal
    Letter to Editor

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