5,186 research outputs found
INTERACTION BETWEEN SEABIRDS AND THE SPANISH SURFACE LONGLINE FISHERY TARGETING SWORDFISH IN THE SOUTH ATLANTIC OCEAN (SOUTH OF 25ºS) DURING THE PERIOD 2010-2014
A total of 92 sets (132,268 hooks) targeting swordfish between years 2010-2014 in the South Atlantic (Lat ≥ 25ºS) were analyzed. Various baits were used for night setting with monofilament longlines. No interaction with seabirds was detected and the interaction was therefore nil. The night setting, low levels of lighting during fishing operations and the type of fishing conducted were identified as the most important factors to explain the lack of interaction with seabirds. Observations of seabirds were also made during the study. Most sightings occurred during daytime sailing. During some operations when vessels were setting or hauling there were sporadic sightings of the spectacled petrel (Procellaria conspicillata) and the occasional albatross, although no interaction with fishing operations occurred. The species most often seen was the spectacled petrel (Procellaria conspicillata), with groups at over 150 individuals. Other species observed were Calonectris diomedea, various types of storm petrels, and other species such as Hydrobates leucorhous, Thalassarche chlororhynchos, Diomedea exulans and very rarely Thalassarche melanophrys
Selección de nido y biologÃa reproductiva del Chorlitejo Patinegro Charadrius alexandrinus en playas de la costa oeste de Portugal
Aims: The nest-site selection and breeding biology of Kentish Plover Charadrius alexandrinus were studied
on sandy beaches of the Portuguese West coast.
Methods: Nest-site characteristics were compared with those of random points and between successful and
unsuccessful nests. Breeding parameters (timing of laying, nesting success and egg size) were examined on
sandy beaches and these data combined with a literature review to provide a comparison of Kentish Plovers’
breeding parameters between natural (sandy beaches, saline lakes) and man-made coastal habitats (salinas and
fish-farms).
Results and Conclusions: Three temporal peaks of breeding activity were distinguished: end of April, mid
May and end of June. Most nests were located less than 100 meters from the nearest active nest. The dimen-
sions (breadth and volume) of the eggs from late clutches were significantly smaller than those from eggs of
early and intermediate clutches. Nesting success was 32% (12.3% using the Mayfield method). There were
significant differences in nesting success between the four studied beaches (56% of all clutches produced
chicks in Gala while only 18% of all clutches produced chicks in Costinha). Despite the lower success of in-
termediate clutches no significant difference in nesting success was found between early, intermediate and late
clutches. There was a higher probability of finding nest-sites near objects and in areas with a higher cover of
sparse vegetation and objects than were random points. Successful nests were placed farther from the nearest
mammal footprint, were closer to the nearest vehicle sandmark and had a lower cover of shells and pebbles
than did unsuccessful nests. Nesting success was highly variable for both natural and man-made coastal ha-
bitats and affected mainly by predation and flooding. In terms of conservation it seems important to maintain
habitat diversity for Kentish PloversObjetivos: Se estudia la selección de nido y la biologÃa reproductiva del Chorlitejo Patinegro en playas de la
costa oeste de Portugal.
Métodos: Las caracterÃsticas del emplazamiento de nidos tanto exitosos como fracasados se comparan con las
caracterÃsticas de puntos tomados al azar. Se analizaron variables descriptoras de la reproducción tales
como, fecha de puesta, éxito y tamaño de los huevos. Asà mismo, se utilizaron los datos obtenidos además de
datos procedentes de la bibliografÃa para realizar una comparación de la reproducción en hábitats naturales
(playas y lagos salinos) y en hábitats artificiales (salinas y piscifactorÃas).
Resultados y conclusiones: Se distinguieron tres máximos temporales durante la reproducción: finales de
abril, mediados de mayo y finales de junio. La mayor parte de los nidos se situaron a menos de 100 metros de
otro nido ocupado. Los huevos de las puestas tardÃas fueron significativamente más pequeños (anchura y vo-
lumen) que los huevos procedentes de puestas tempranas o intermedias. El éxito reproductivo fue del 32%
(12,3% utilizando el método de Mayfield). Se encontraron diferencias significativas en el éxito de los nidos en-
tre las cuatro playas estudiadas (el 56% de las puestas produjeron pollos en Gala mientras que solo el 18% de
las puestas produjeron pollos en Costinha). A pesar del bajo éxito de las puestas intermedias no se encontraron
diferencias significativas entre las puestas tempranas, intermedias o tardÃas. Los nidos se situaron con una ma-
yor probabilidad en la proximidad de objetos o en zonas con una menor cobertura de vegetación en compara-
ción con los puntos tomados al azar. Los nidos exitosos se situaron en los lugares más alejados de huellas de
mamÃferos, estuvieron más cerca de lugares donde se encontraron huellas de vehÃculos y tuvieron una menor cobertura de piedras y/o conchas que los nidos fracasados. El éxito reproductor fue muy variable tanto en los
hábitats naturales como en los artificiales, y fueron afectados fundamentalmente por depredación e inundación.
En relación a la conservación del Chorlitejo Patinegro, parece importante conservar hábitats diverso
Engaging children in geosciences through storytelling and creative dance
Natural sciences have traditionally been disseminated in outreach activities as formal, one-way presentations. Nevertheless, innovative strategies are being increasingly developed using arts, gaming, and sketching, amongst
others. This work aimed at testing an alternative and innovative way to engage non-expert audiences in ocean and coastal
geology through a combination of scientific concept explanations and creative dancing. An informal education activity focusing on ocean dynamics was designed for 10-yearold students. It combines coastal science concepts (wind,
waves, currents, and sand), storytelling techniques (narrative
arc), and creative dance techniques (movement, imaginative
play, and sensory engagement). A sequence of six exercises
was proposed, starting with the generation of offshore ocean
waves and ending with sediment transport on the beach during storm/fair-weather conditions. Scientific concepts were
then translated into structured creative movements, within
imaginary scenarios, and accompanied by sounds or music.
The activity was performed six times with a total of 112 students. It was an inclusive activity given that all students in the
class participated, including children with several mild types
of cognitive and neurological impairment. The science and
art activity aroused emotions of enjoyment and pleasure and
allowed for effective communication between scientists and
school community. Moreover, the results provide evidence of
the activity’s effectiveness in engaging children and developing their willingness to further participate in similar activities.PTDC/MAR-EST/1031/2014/ IF/00354/201/ 57/2016/CP1361/CT0002 and DL 57/2016/CP1432/CT0001info:eu-repo/semantics/publishedVersio
Modelo de previsão da deformação permanente de fundações de vias-férreas com recurso a uma rede neuronal artificial
The prediction of the permanent deformation in the subgrade and its reliability is one of the main concerns of the Railway Infrastructure Managers, as it can influence the reduction of the maintenance costs of the track in service. This study proposes a novel methodology for predicting permanent deformation based on a parametric study performed using a hybrid approach that includes the short and long term performance. The conducted study allowed the construction of a robust database used in this study to forecast the permanent deformation. The database feeds the neural network model, whose performance was evaluated using different metrics: MAE, MSE, RMSE, standard deviation, and regression coefficient. The model was tested and validated based on experimental results. The obtained results demonstrate that the developed model is rapid and efficient in accurately predicting the permanent deformation induced by the passage of trains. The model has the potential to be implemented in a computational decision support system for railway track maintenance and management.A previsão da deformação permanente na fundação e respetiva fiabilidade é uma das principais
preocupações dos gestores das Infraestruturas Ferroviárias, pois pode influenciar os custos de manutenção da
via em serviço. Este artigo propõe uma nova metodologia relativa à previsão da deformação permanente com
base num estudo paramétrico realizado usando uma abordagem hÃbrida e que inclui o desempenho a curto e
longo prazo. O estudo realizado permitiu a construção de uma base de dados robusta que foi utilizada neste
estudo para prever a deformação permanente. A base de dados alimenta um modelo da rede neuronal, cujo
desempenho foi avaliado com base em diferentes métricas: MAE, MSE, RMSE, desvio padrão e coeficiente de
regressão. O modelo foi testado e validado com base em resultados experimentais. Os resultados obtidos
mostram que o modelo desenvolvido é rápido e eficiente para prever com precisão a deformação permanente
induzida pela passagem dos comboios. O modelo tem o potencial para ser implementado num sistema
computacional de apoio de decisão para manutenção e gestão de linhas ferroviárias.Este trabalho foi parcialmente realizado no âmbito do In2Track3, um projeto de investigação do Shift2Rail. Este trabalho foi também parcialmente financiado pela FCT/MCTES através de fundos nacionais (PIDDAC) no âmbito da Unidade de I&D Institute for Sustainability and Innovation in Structural Engineering (ISISE), sob a referência UIDB/04029/2020. Adicionalmente, contou com o apoio financeiro de Base Funding -UIDB/04708/2020 do CONSTRUCT - Instituto
de I&D em Estruturas e Construções - financiado por fundos nacionais através do FCT/MCTES
(PIDDAC)
Nanoparticle biocoating to create ATP-powered swimmers capable of repairing proteins on the fly
In this study, we combine nanotechnology and biotechnology to design a biocompatible propulsion system based on the molecular chaperone Hsp90, a heat-shock protein (Hsp) that, in the presence of adenosine 5'-triphosphate (ATP), undergoes nanoscale conformational changes while trapping and renaturing other proteins. We show how, subjected to ATP availability in the medium, Hsp90-functionalized particles significantly enhance their diffusion motion, being able to achieve ballistic motion, while keeping the ability to restore the activity of surrounding heat-inactivated proteins. This biomechanics-based propulsion mechanism represents a promising strategy for the design of self-propelled nanodevices capable of performing sophisticated tasks in live biological contexts that include sensing the environment, recognizing and capturing, folding, and restoring defective proteins on the fly. In the short term, Hsp90-driven nanodevices could be applied to improve industrial processes that require enzymatic catalysis and high temperatures. But in the medium to long term, this bioactive coating could be used in the design of nanomachines that, like mini-robots, navigate the complex body cavities of biological tissues, deliver therapies and/or remove misfolded proteins in disorders such as Alzheimer's or Parkinson's disease.Acknowledgments: The authors acknowledge the financial support from the Spanish Instituto de Salud Carlos iii, and the European Union FEDER funds under Projects ref. PI22/00030, PI19/00349, from the Spanish Ministerio de Ciencia e Innovacion under project PID2020-119242RB-I00 and the European Union H2020-MSCA-RISE-2019 PEPSA-MATE project. ARR and MARD acknowledge financial support from IDIVAL (PREVAL19/04) and the Xunta de Galicia (2017- ED481A/322) respectively. We also acknowledge IDIVAL projects INNVAL19/12 and INNVAL21/1
Biomass size-spectra of macrobenthic assemblages along water depth in Antarctica
Several biomass size spectra of benthic assemblages were constructed along a water depth gradient on the southern coast of Livingston Island (South Shetland Islands, Antarctica). The size-spectrum for shallow bottoms (200 m) zones showed unimodal spectra with biomass peaks in the 1-2 and 0.5-1 g weight ranges respectively. Filter-feeders also affected the larger size classes at intermediate depths, whereas they were almost absent in deeper waters. The slope of the normalized size-spectrum at shallower bottoms (-0.76) was different from those of intermediate (-1.25) and deeper (-1.31) zones. This clearly indicated 2 contrasting faunal strategies: a biomass increase with size in shallow waters, whereas the biomass decreased with size in deep waters. Estimates of total secondary production were calculated using allometric equations published in the literature. Results indicated a decrease of total secondary production along water depth, with 15 g C m-2 yr-1 in shallow waters, 9 g C m-2 yr-1 at intermediate bottoms and 8 g C m-2 yr-1 at deep bottoms. The pattern of the biomass size spectrum for shallower waters suggested that there was a predictable and regular supply of food, which allowed accumulation of biomass in the larger size classes corresponding to filter-feeder organisms. Conversely, the concentration of biomass in smaller size classes of the spectra for intermediate and deeper waters pointed to more unpredictable and fluctuating food conditions arriving from the overlying layer to the deeper sea floor. Sufficient evidence exists in the literature to indicate that a tight pelagic-benthic coupling was causing biological enhancement of a suspension-feeding macrofauna at shallow bottoms, and that below 100 m depth the effects of the coupling were rather weak.Versión del editor2,483
Breeding biology of a winter-breeding procellariiform in the North Atlantic, the Macaronesian shearwater Puffinus lherminieri baroli
The breeding success of burrow-nesting seabirds may be influenced by both nest site characteristics and oceanographic conditions influencing food availability at sea. In this study we describe the breeding biology of the winter-breeding Macaronesian shearwater (Puffinus lherminieri baroli), including nest site characteristics and interspecific competition. We also evaluate the possible effects of changing oceanographic conditions on breeding phenology and breeding success. The study was carried out over two breeding seasons on two islands in the North Atlantic Ocean, Cima Islet and Selvagem Grande. Oceanographic characteristics differed between years. On a regional scale, the North Atlantic Oscillation (NAO) index was low and negative in 2011, and on a local scale, birds used areas with significantly lower values of chlorophyll a concentration and significantly higher values of sea surface temperature anomalies. Hatching success was higher in 2012 than in 2011. At both colonies, egg cracking was the main cause of hatching failure, but in 2011 several eggs on Selvagem Grande were deserted. In 2012 birds laid earlier and chicks had longer wings and were heavier. At both colonies, nests that were deeper, were sheltered from prevailing winds and had small chambers and a soil substrate had a higher probability of being used successfully by the birds. Nests occupied solely by Macaronesian shearwaters were much deeper and had less volume than nests shared with other species. Our study suggests that the breeding success of Macaronesian shearwaters is strongly related to nest site characteristics and that at-sea environmental conditions exert a strong influence on reproductive parameters, with birds breeding in a poor year (evaluated in terms of lower marine productivity) laying much later and their chicks growing at a slower rate than in a good year. The influence of nest site characteristics and environmental conditions may be very important for understanding the breeding ecology of Procellariiformes and may help explain the negative population trend of Macaronesian shearwaters
Investigadores del IEO participan en la elaboración de una monografÃa sobre el Gran Ecosistema Marino de la Corriente de Canarias
CientÃficos de la Universidad de Vigo y el IEO descubren una nueva especie de crustáceo en el talud continental de Mauritania
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