CESAM

Santiago do Cacém, Portugal
Santiago do Cacém, Portugal
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Gomez-Gesteira M.,Environmental Physics Laboratory | deCastro M.,Environmental Physics Laboratory | Dias J.M.,CESAM
Journal of Geophysical Research: Oceans | Year: 2015

SST trends measured in the Somalia region during the southwest monsoon season over the period 1982-2013 have shown the existence of a warming-cooling dipole. The positive spot, with a warming trend on the order of 0.37°C dec-1, is centered around 5.1°N-50.3°E and the negative one, with a trend on the order of -0.43°C dec-1, around 11.1°N-52.2°E. The migration of the Great Whirl (GW) over the last three decades at a speed of -0.3°C dec-1 in longitude and -0.6°C dec-1 in latitude was considered as the possible origin of the SST dipole. The displacement of the GW produces changes in the geostrophic currents which, in turn, generate changes in the amount of advected water from and to coast. © 2015. American Geophysical Union.


Santos F.,University VigoOurense Spain | Dias J.M.,CESAM
Journal of Geophysical Research: Oceans | Year: 2016

La Guajira upwelling system has shown a moderate cooling (∼-0.05°C dec-1) over the period 1982-2014 for the months with strong upwelling (JFM). This contrasts with the general warming observed for most of the Caribbean region (∼0.25°C dec-1) over the same period. Cooling is in good agreement with the upwelling increase (∼0.04 m2s-1dec-1) observed in the region during winter months, although the position of the peaks in upwelling and SST trends does not coincide exactly due to the presence of the Caribbean Coastal Undercurrent. © 2016. American Geophysical Union. All Rights Reserved.


Ventura S.P.M.,University of Aveiro | Gurbisz M.,Dublin City University | Ghavre M.,Dublin City University | Ghavre M.,Engineering and Materials Science Center | And 7 more authors.
ACS Sustainable Chemistry and Engineering | Year: 2013

A new class of low bacterial and algal toxicity imidazolium and pyridinium halide ionic liquids (ILs), produced by a short synthesis from substituted mandelic acid derivatives is disclosed. Melting points for most of the ILs were above or close to 100 °C; however, one imidazolium example has a glass transition temperature below room temperature (RT; -3.3 °C). The series of 8 ILs enables an investigation of toxicity on modifying the heterocycle, aromatic ring substitution, ester group, and proximity of cation to aromatic ring present within mandelic acid constituent. Two pyridinium salts, methyl 2-(3,4-methylenedioxyphenyl)-2-pyridinium acetate, bromide salt and methyl 2-(3,4-methylenedioxyphenyl)-2-(2-pyridiniumacetoxy)acetate, bromide salt have low toxicity to all bacteria strains (including Vibrio fischeri), and freshwater green algae (C. Vulgaris and P. subcapitata) screened. All eight pyridinium and imidazolium ILs have low toxicity to Gram-positive (B. subtilis) and Gram-negative (E. coli, P. fluorescens, P. putida (CP1), and P. putgida (KT 2440)) bacteria strains, although a significant range in IC50 values was obtained. Mandelate derived ILs have EC50 (C. Vulgaris and P. subcapitata) values 103-107 higher (less toxic) than other C14-C18 ionic liquids previously reported. © 2013 American Chemical Society.


Hilario A.,CESAM | Johnson S.B.,Monterey Bay Aquarium Research Institute | Cunha M.R.,CESAM | Vrijenhoek R.C.,Monterey Bay Aquarium Research Institute
Deep-Sea Research Part I: Oceanographic Research Papers | Year: 2010

Frenulates are the most poorly known members of the family Siboglinidae (Polychaeta: Canalipalpata). These thread-like worms occur in reducing marine sediments worldwide, but they are often overlooked in benthic samples or too poorly preserved for adequate taxonomic evaluations. We report on a remarkable diversity of frenulates that were recently sampled from 13 mud volcanoes (350-3902 m deep) in the Gulf of Cadiz, off southern Iberia. Sampled with benthic coring devices, the bodies of these long tubiculous worms were often broken or incomplete, making them difficult to identify morphologically. Consequently, we employed DNA taxonomic methods to assess their diversity. Mitochondrial cytochrome-c-oxidase subunit 1 (COI) sequences distinguished 15 evolutionary lineages inhabiting the Gulf of Cadiz. Only four of the lineages could be assigned to currently recognized Atlantic species; the remaining 11 may be new to science. This remarkable diversity of frenulates in a small geographical region is unprecedented and is hypothesized to result from environmental heterogeneity associated with the bathymetric and geochemical settings of these mud volcanoes. © 2009 Elsevier Ltd. All rights reserved.


Catry P.,Eco Ethology Research Unit | Granadeiro J.P.,Servico do Parque Natural da Madeira | Ramos J.,CESAM | Phillips R.A.,University of Coimbra | Oliveira P.,Natural Environment Research Council
Journal of Ornithology | Year: 2011

It has long been known that birds change their behaviour, reproductive performance and survival as they mature, including in the first few years after recruitment into the breeding population. However, and contrasting with the description of patterns of actuarial and reproductive senescence in later years, there are surprisingly few studies documenting changes in behaviour in old individuals. Such studies are important, as birds provide particularly interesting models for studying the biology of senescence. It has been suggested that, unlike mammals, birds may remain physically fit until an advanced age, yet this has limited empirical support. In this paper, we used activity (immersion) loggers to show that old (>26 years) Cory's Shearwaters Calonectris diomedea are less active when foraging at sea, spend more time resting on the water and have a smaller number of take-offs and landings during darkness, when compared to experienced mid-aged individuals (13-20 years old). Old individuals also tended to have reduced immune response against an experimental challenge using phytohaemagglutinin. These results are in line with observed reductions in activity levels with age in a wide range of non-avian taxa, and may suggest that old seabirds are physically less fit than younger individuals. Alternatively, old birds might simply be more experienced and their reduction in activity might reflect a strategic regulation of investment in different activities. Our study illustrates the potential for gaining insights into avian aging patterns and processes by looking into the behaviour of model organisms. We therefore encourage more research focusing on behavioural parameters that may reflect variations in physical condition or strategic choices, during both the breeding and non-breeding seasons. © 2010 Dt. Ornithologen-Gesellschaft e.V.


Catry P.,Eco Ethology Research Unit | Almeida A.,Eco Ethology Research Unit | Lecoq M.,Eco Ethology Research Unit | Granadeiro J.P.,CESAM | And 2 more authors.
Polar Biology | Year: 2011

The Falkland skua Stercorarius antarctica antarctica is a poorly known seabird. Demographic studies at the largest known colony of this taxon revealed a sharp population decline (47%) in just 5 years, between 2004 and 2009. The decline seems to be linked with a chronic low breeding success in the recent years and is consistent with a situation of virtually zero recruitment. The ultimate causes of the decline are, as of yet, unknown, but plausible explanations are examined and discussed. The reported population trends should be the cause of some concern, and more research and monitoring are desired. © 2011 Springer-Verlag.


Sequeira F.,Institute Telecomunicacoes IT Aveiro | Duarte D.,Institute Telecomunicacoes IT Aveiro | Rudnitskaya A.,CESAM | Rudnitskaya A.,University of Aveiro | And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

We report the development of a low cost plastic optical fibre (POF) sensor for ammonium detection using molecularly imprinted polymers (MIP's). The cladding of a 1 mm diameter PMMA fiber is removed, in which is grafted a molecular imprinted polymer (MIP), by radical polymerization with thermal initiation, that act as a selective sensing layer. For the polymerization, 2,2'-Azobis(2-methylpropionamidine)dihydrochloride (AAPH) is used as initiator, methacrylic acid (MAA) as a monomer, ethylene glycol dimethacrylate (EDMA) as a cross-linker, ammonium chloride (NH4Cl) as a template and 30% of ethanol in water as a solvent. The sensing method consists of an intensity based scheme. The response to different concentrations of ammonium solutions in water has been evaluated at room temperature. Solutions with (0 - 0.6) M concentration, with the corresponding refractive indexes varying between 1.3325 - 1.3387, at 25°C were used. The response of the fiber with the original cladding, and after cladding removal has been monitored and compared to the response given by the developed sensor. The response is very fast, less than 1 minute and reversible, which allows the continuum use of the sensor. Further developments are focused in optimization of MIP grafting procedure and sensor performance, in order to increase sensitivity. © 2016 SPIE.

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