87 research outputs found

    Bioaccumulation of titanium dioxide nanoparticles in green (Ulva sp.) and red (Palmaria palmata) seaweed

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    A bioaccumulation study in red (Palmaria palmata) and green (Ulva sp.) seaweed has been carried out after exposure to different concentrations of citrate-coated titanium dioxide nanoparticles (5 and 25 nm) for 28 days. The concentration of total titanium and the number and size of accumulated nanoparticles in the seaweeds has been determined throughout the study by inductively coupled plasma mass spectrometry (ICP-MS) and single particle-ICP-MS (SP-ICP-MS), respectively. Ammonia was used as a reaction gas to minimize the effect of the interferences in the 48Ti determination by ICP-MS. Titanium concentrations measured in Ulva sp. were higher than those found in Palmaria palmata for the same exposure conditions. The maximum concentration of titanium (61.96 ± 15.49 ÎŒg g−1) was found in Ulva sp. after 28 days of exposure to 1.0 mg L−1 of 5 nm TiO2NPs. The concentration and sizes of TiO2NPs determined by SP-ICP-MS in alkaline seaweed extracts were similar for both seaweeds exposed to 5 and 25 nm TiO2NPs, which indicates that probably the element is accumulated in Ulva sp. mainly as ionic titanium or nanoparticles smaller than the limit of detection in size (27 nm). The implementation of TiO2NPs in Ulva sp. was confirmed by electron microscopy (TEM/STEM) in combination with energy dispersive X-Ray analysis (EDX)The authors wish to thank the fnancial support of Ministerio de EconomĂ­a y Competitividad (project INNOVANANO, reference RT2018-099222-B-100), European Union (INTERREG Atlantic Area, project NANOCULTURE, reference EAPA590/2018), and Xunta de Galicia (Grupo de Referencia Competitiva, grant number ED431C 2022/29)S

    CE0504

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    Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report.Acoustic surveys on northern blue whiting (Micromesistius poutassou) stocks have been carried out since the early 1970s by the Institute of Marine Research (IMR), Bergen. In the early 1980s a coordinated acoustic survey approach was adopted, with both Russia and Norway participating to estimate the size of the stock. The acoustic survey programme is carried out for fishery management purposes, results are presented annually at the ICES led Northern Pelagic and Blue Whiting Fisheries Working Group and from this catch advice is determined for the following year. The highly migratory nature of this stock and its components require a large geographical area to be surveyed during a relatively short spawning window. Acoustic surveys are routinely carried out on specific spawning and pre-spawning aggregations of blue whiting. This can allow for high concentrations of fish to be surveyed in a relatively small geographical and often well defined area, if the timing is synchronised. This survey was conducted as part of a collaborative survey coordinated by the Institute of Marine Research, Bergen, Norway, using the vessel the RV “G.O. Sars”. Also participating were the RV “Fridtjof Nansen” (PINRO, Russia), RV “Atlantniro” (Russia), RV “Tridens” (RIVO, Netherlands) and the RV “Magnus Heinason” (Faroes). The total combined area surveyed in 2005 covered from the Faroe Islands in the north (62Âș of longitude) to the southern coast of Ireland (49Âș N), area coverage to the west extended from 2Âș -20Âș of latitude. The Irish component of the survey was made up of transects covering some 2,228 nautical miles. In addition to the collection of acoustic data fishing hauls were carried out to determine the make up of fish marks recorded by the equipment and to assess the length, weight, age, sex and maturity of the stock. Oceanographic data was collected using a number of spaced hydrograhic stations where salinity and temperature of the water column was recorded at depths of up to 1200 m

    CE0606

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    Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report.Acoustic surveys on the blue whiting (Micromesistius poutassou) stock in the north east atlantic have been carried out since the early 1970s by the Institute of Marine Research (IMR), Norway. In the early 1980s a coordinated acoustic survey approach was adopted, with both Russia and Norway participating to estimate the size of the combined stock. The acoustic survey programme is carried out for fishery management purposes and is continued to date. Results of this annual spawning stock assessment combined with juvenile surveys and commercial catch at age data are presented annually at the ICES led Northern Pelagic and Blue Whiting Fisheries Working Group. Ultimately, from this combined scientific data, management and catch advice is determined for the following year. The highly migratory nature of the combined stock requires a large geographical area to be surveyed during a protracted spawning period. Consequently Acoustic surveys are routinely carried out on specific spawning and post-spawning aggregations of blue whiting. To facilitate a more coordinated spatio-temporal approach to spawning stock assessment, several nations became involved in the PGNAPES coordinated survey programme in 2004. Ireland is one of these nations involved in this annual survey. The 2006 survey was part of an International collaborative survey coordinated by the Institute of Marine Research, Bergen, Norway, using the vessel the RV “G.O. Sars”. Also participating were the RV “Atlantniro” (Russia), RV “Tridens” (RIVO, Netherlands) the RV “Magnus Heinason” (Faroes) and RV “Celtic Explorer” (Ireland). The total combined area surveyed in 2006 covered from the Faroe Islands in the north (62°of longitude) to the southern coast of Ireland (51° N), area coverage to the west extended from 4°-18° of latitude. The Irish component of the survey was made up of transects covering some 2,632 nautical miles (Figure 1). In addition to the collection of acoustic data, fishing hauls were carried out to determine the make up of fish marks recorded by the equipment and to assess the length, weight, age, sex and maturity of the stock. Oceanographic data was collected using a number of spaced hydrograhic stations where salinity and temperature of the water column was recorded at depths down to 800m

    CE04

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    Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report.In the Celtic Sea and ICES Division VIIj, to the south and southwest of Ireland, herring is an important commercial species and currently Ireland is the only country targeting this species in this area. Herring in this region comprise both autumn and winter spawning components. Commercial fishing has targeted the fish during spawning times, though in most recent years fish have been targeted during the summer feeding phase too. In VIIj, fishing has traditionally taken place in October, and concentrated in the bays and inlets. In contrast, fishing in VIIaS has mainly been in December to January, though in VIIg the fishery traditionally takes place from November to January. The protracted spawning period of herring and the overlap between the two spawning socks in this area (October to February) means that it is difficult to design a survey that covers all spawning fish in one specific survey. The stock structure and discrimination of herring in this area is not fully understood. It is known that fish in the eastern Celtic Sea recruit from nursery areas in the Irish Sea and tagging studies have shown linkages between these areas also. For the purpose of stock assessment and management these areas have been combined since 1982. A project is currently underway to describe stock structure and discrimination of herring around Ireland. The results of this project may have implications for the design of this survey and for the stock assessment. For a period in the 1980’s, egg and larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989, and the current survey is the 15th in the series. In addition to the survey track a small component (Baginbun) was intensively surveyed using acoustic and multibeam mapping techniques. The Baginbun area is located east of Waterford Harbour in ICES division VIIaS. Baginbun has supported a large winter fishery for many years and is one of the most important and well known winter spawning areas on the south coast. This year for the first time the RV Celtic Explorer was to survey the area. This allowed a more extensive degree of coverage in the time allocated, the survey was further complemented with a number of hydrographic transects concentrating along the bays in the west and southwest and also along the southern coastline

    New insights into ocean sunfish (mola mola) abundance and seasonal distribution in the northeast atlantic

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    The ocean sunfish, Mola mola, is the largest teleost fish in the world. Despite being found in all oceans of the world, little is known about its abundance and factors driving its distribution. In this study we provide the first abundance estimates for sunfish in offshore waters in the northeast Atlantic and the first record of extensive sunfish presence in these waters year-round. Abundance estimates and predictive distributions for sunfish in approximately 300,000 km(2) of the northeast Atlantic were derived from large scale offshore aerial surveys in 2015-2016 using distance sampling techniques. Generalized additive models of sunfish density were fitted to survey data from 17,360 km of line transect effort resulting in minimum abundance estimates of 12,702 (CI: 9,864-16,357) in the summer (Density = 0.043 ind/ km(2)) and 8,223 individuals (CI: 6,178-10,946) (Density = 0.028 ind/ km(2)) in the winter. Density surface models predicted seasonal shifts in distribution and highlighted the importance of the mixed layer depth, possibly related to thermoregulation following deep foraging dives. The abundance estimate and estimated daily consumption of 2,600 tonnes of jellyfish in the northeast Atlantic highlights the need to re-assess the importance of this species in the pelagic ecosystem, and its role in top-down control of jellyfish blooms

    Using tagging data and aerial surveys to incorporate availability bias in the abundance estimation of blue sharks (Prionace glauca).

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    There is worldwide concern about the status of elasmobranchs, primarily as a result of overfishing and bycatch with subsequent ecosystem effects following the removal of top predators. Whilst abundant and wide-ranging, blue sharks (Prionace glauca) are the most heavily exploited shark species having suffered marked declines over the past decades, and there is a call for robust abundance estimates. In this study, we utilized depth data collected from two blue sharks using pop-up satellite archival tags, and modelled the proportion of time the sharks were swimming in the top 1-meter layer and could therefore be detected by observers conducting aerial surveys. The availability models indicated that the tagged sharks preferred surface waters whilst swimming over the continental shelf and during daytime, with a model-predicted average proportion of time spent at the surface of 0.633 (SD = 0.094) for on-shelf, and 0.136 (SD = 0.075) for off-shelf. These predicted values were then used to account for availability bias in abundance estimates for the species over a large area in the Northeast Atlantic, derived through distance sampling using aerial survey data collected in 2015 and 2016 and modelled with density surface models. Further, we compared abundance estimates corrected with model-predicted availability to uncorrected estimates and to estimates that incorporated the average time the sharks were available for detection. The mean abundance (number of individuals) corrected with modelled availability was 15,320 (CV = 0.28) in 2015 and 11,001 (CV = 0.27) in 2016. Depending on the year, these estimates were ~7 times higher compared to estimates without the bias correction, and ~3 times higher compared to the abundances corrected with average availability. When the survey area contains habitat heterogeneity that may affect surfacing patterns of animals, modelling animals' availability provides a robust alternative to correcting for availability bias and highlights the need for caution when applying "average" correction factors

    He ara hou ka tƫ mai: NZ institutions of higher learning unpacking demands and facilitating change

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    The Virtual Worlds Working Group began with the DEHub research consortium in November 2009. In December 2010, New Zealand joined the VWWG. This paper highlights the current work of the NZ based members of the group and presents the work of 23 authors at 11 institutes of higher education in New Zealand. The scope of the work covered is diverse, and a number of platforms have been used. Virtual worlds enable educators to provide realistic simulations, engaging role-plays, immersive and genuine tasks, and social interaction that encourages group collaboration, and highlights the ability that virtual worlds have to transform both teaching and learning

    He ara hou ka tƫ mai: New Zealand institutions of higher learning unpacking demands and facilitating change

    No full text
    The Virtual Worlds Working Group began with the DEHub research consortium in November 2009. In December 2010, New Zealand joined the VWWG. This paper highlights the current work of the NZ based members of the group and presents the work of 23 authors at 11 institutes of higher education in New Zealand. The scope of the work covered is diverse, and a number of platforms have been used. Virtual worlds enable educators to provide realistic simulations, engaging role-plays, immersive and genuine tasks, and social interaction that encourages group collaboration, and highlights the ability that virtual worlds have to transform both teaching and learning

    Amygdala–medial prefrontal cortex connectivity relates to stress and mental health in early childhood

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    Early life stress has been associated with disrupted functional connectivity between the amygdala and medial prefrontal cortex (mPFC), but it is unknown how early in development stress-related differences in amygdala-mPFC connectivity emerge. In a resting-state functional connectivity (rs-FC) analysis with 79 four- to seven-year-old children, we found a significant correlation between more adverse experiences and weaker amygdala-mPFC rs-FC. We also found that weaker amygdala-mPFC rs-FC was associated with higher levels of aggressive behavior and attention problems. These findings suggest that the impact of stress on emotional circuitry is detectable in early childhood and that this impact is associated with mental health difficulties. Connectivity in this circuit may be useful as a marker for mental health risk and for tracking the efficacy of early interventions
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