149 research outputs found

    CV20017

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    This report provides the main results and findings of the fifteenth annual underwater television survey on the ‘Smalls grounds’ ICES assessment area; Functional Unit 22. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. A total of 40 UWTV stations were surveyed successfully (high quality image data), carried out over an isometric grid at 4.5nmi or 8.3km intervals. The precision, with a CV of 8%, was well below the upper limit of 20% recommended by SGNEPS (ICES, 2012). The 2020 abundance estimate was 33% lower than in 2019 and at 750 million is below the MSY Btrigger reference point (990 million). Using the 2020 estimate of abundance and updated stock data implies catch in 2021 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 1238 and 1560 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2017–2019). One species of sea pens was recorded as present at the stations surveyed: Virgularia mirabilis. Trawl marks were observed at 48% of the stations surveyed

    Dominance of unicellular cyanobacteria in the diazotrophic community in the Atlantic Ocean

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    ABSTRACT: The horizontal and vertical distribution of representatives of diazotrophic unicellular cyanobacteria was investigated in the subtropical northeast Atlantic Ocean (28.87 to 42.00°N; 9.01 to 20.02°W). Samples from stations encompassing different water conditions (from oceanic oligotrophic waters to upwelling areas and a temperature range of 13.1°C to 24.2°C) were size fractionated and analyzed for nifH by a nested polymerase chain reaction (PCR) and by tyramide signal amplification–fluorescence in situ hybridization (TSA-FISH) using probe Nitro821. In samples from the surface, mixed-layer depth, and deep chlorophyll maximum waters, most (> 50%) of the nifH recovered was from the 0.2–3 µm fraction and was consistent with TSA-FISH counts. The < 3 µm Nitro821-positive cells were more abundant than the larger cells, and the proportion of single cells was larger than that associated with particulate matter or with larger cells. Phylogenetic analysis of representative samples revealed that most of the sequences belong to diazotrophic unicellular cyanobacteria Group A (UCYN-A or Candidatus Atelocyanobacterium thalassa). N2 fixation in the 0.2–3 µm fraction, putatively representing the activity of UCYN-A, contributed more than 50% of the total N2 fixation. There was a positive relationship of this putative UCYN-A abundance and activity with temperature, and a negative relationship with dissolved O2. The dominance of these putative UCYN-A organisms in nitrate-rich upwelling filament regions suggests that the activity of this group of organisms may not be strongly controlled by the availability of fixed N

    CV20019

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    This report provides the main results of the 2020 underwater television survey on the ‘Labadie, Jones and Cockburn Banks’ ICES assessment area; Functional Unit 2021. The 2020 survey was multi-disciplinary in nature collecting UWTV, and other ecosystem data. A total of 97 UWTV stations were completed at 6nm intervals over a randomised isometric grid design. The mean burrow density was 0.102 burrows/m2 compared with 0.06 burrows/m2 in 2019. The 2020 geostatistical abundance estimate was 1020 million, a 65% increase on the abundance from 2019, with a CV of 5%, which is well below the upper limit of 20% recommended by SGNEPS 2012. Low to medium densities were observed throughout the ground. Using the 2020 estimate of abundance and updated stock data implies catch in 2021 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 1682 and 1710 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2017–2019). One species of sea-pen (Virgularia mirabilis) were recorded as present at the stations surveyed. Trawl marks were observed at 36% of the stations surveyed

    CV20017

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    This report provides the results of the eighth underwater television on the ‘Porcupine Bank Nephrops grounds’ ICES assessment area; Functional Unit 16. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. In total 65 UWTV stations were successfully completed in a randomised 6 nautical mile isometric grid covering the full spatial extent of the stock. The mean burrow density observed in 2020, adjusted for edge effect, was 0.17 burrows/m². The final krigged abundance estimate was 1264 million burrows with a CV of 4% and an estimated stock area of 7,130 km2. The 2020 abundance estimate was 25% higher than in 2019. Using the 2020 estimate of abundance and updated stock data implies catches between 2653 and 3290 tonnes in 2021 that correspond to the F ranges in the EU multiannual plan for Western Waters (assuming that all catch is landed). Four species of sea-pen; Virgularia mirabilis, Funiculina quadrangularis, Pennatula phosphorea and the deepwater sea-pen Kophobelemnon stelliferum were observed during the survey. Trawl marks were also observed on 22% of the stations surveyed

    CV19015

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    This report provides the main results and findings of the fourteenth annual underwater television survey on the ‘Smalls grounds’ ICES assessment area; Functional Unit 22. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. A total of 41 UWTV stations were surveyed successfully (high quality image data), carried out over an isometric grid at 4.5nmi or 8.3km intervals. The precision, with a CV of 9%, was well below the upper limit of 20% recommended by SGNEPS (ICES, 2012). The 2019 abundance estimate was 30% higher than in 2018 and at 1121 million is below the MSY Btrigger reference point (990 million). Using the 2019 estimate of abundance and updated stock data implies catch in 2020 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 2247 and 2820 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2016–2018). One species of sea pens were recorded as present at the stations surveyed: Virgularia mirabilis. Trawl marks were observed at 57% of the stations surveyed

    CV20016

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    This report provides the main results and findings of the nineteenth annual underwater television survey on the Aran, Galway Bay and Slyne head Nephrops grounds, ICES assessment area; Functional Unit 17. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. In 2020 a total of 44 UWTV stations were successfully completed, 34 on the Aran Grounds, 5 on Galway Bay and 5 on Slyne Head patches. The mean burrow density observed in 2020, adjusted for edge effect, was medium at 0.29 burrows/m². The final krigged burrow abundance estimate for the Aran Grounds was 359 million burrows with a CV (Coefficient of Variance; relative standard error) of 4%. The final abundance estimate for Galway Bay was 27 million and for Slyne Head was 7 million, with CVs of 13% and 4% respectively. The total abundance estimates have fluctuated considerably over the time series. The 2020 combined abundance estimate (394 million burrows) is 20% lower than in 2019, and it is below the MSY Btrigger reference point (540 million burrows). Using the 2020 estimate of abundance and updated stock data implies catches between 443 and 508 tonnes in 2021 that correspond to the F ranges in the EU multi annual plan for Western Waters, assuming that discard rates and fishery selection patterns do not change from the average of 2017–2019. Virgularia mirabilis was the only sea-pen species observed on the UWTV footage. Trawl marks were present at 7% of the Aran stations surveyed

    CV19017

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    This report provides the results of the seventh underwater television on the ‘Porcupine Bank Nephrops grounds’ ICES assessment area; Functional Unit 16. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. In total 65 UWTV stations were successfully completed in a randomised 6 nautical mile isometric grid covering the full spatial extent of the stock. The mean burrow density observed in 2019, adjusted for edge effect, was 0.14 burrows/m². The final krigged abundance estimate was 1010 million burrows with a relative standard error of 5% and an estimated stock area of 7,130 km2. The 2019 abundance estimate was 9.5% lower than in 2018. Using the 2019 estimate of abundance and updated stock data implies catches between 2127 and 2637 tonnes in 2020 that correspond to the F ranges in the EU multi annual plan for Western Waters (assuming that all catch is landed). Four species of sea-pen; Virgularia mirabilis, Funiculina quadrangularis, Pennatula phosphorea and the deepwater sea-pen Kophobelemnon stelliferum were observed during the survey. Trawl marks were also observed on 31% of the stations surveyed

    Prioritizing otological surgery during the COVID-19 Pandemic

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    The initial cases of pulmonary infection with the novel corona virus SARS-CoV-2, causing COVID-19, occurred in Wuhan, Hubei Province, China in December 2019 and January 2020 (1). The spread through human-to-human transmission has led to a pandemic with disastrous consequences all over the world. The exponential rate of transmission and no existing vaccine has been a great challenge for all health care systems. A strategy to flatten the curve of transmission was put forward to adjust to the capacities of hospitals and particularly the intensive care units. Governments implemented isolation and social distancing upon societies either with laws or with strong recommendations

    Procedimiento de calibración automática mediante el método de "tapado- destapado"

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    La calibración de piranómetros  requiere trazabilidad para brindar datos  confiables. Un método preciso consiste en la calibración de este tipo de instrumental valiéndose de un pirheliómetro para realizarlo. El procedimiento de calibración, determinado por la norma ISO 9846:1993, requiere tapar y destapar el piranómetro bajo calibración con el objetivo de medir la radiación solar global y difusa que recibe. El presente artículo describe un mecanismo automático que permite efectuar el proceso entero, que, en principio, puede lograr mejores  resultados  que los  que brinda el procedimiento manual habitualmente empleado.Pyranometer calibration requires traceability to provide reliable data. A precise method consists in the calibration of this type of instrument using a pyrheliometer to perform it. The calibration procedure, determined by the ISO 9846 standard, requires covering and uncovering the pyranometer under calibration in order to measure the global and diffuse solar radiation received. This article describes an automatic mechanism that allows the entire process to be carried out, which, in principle, can be achieving better results than those normally used by the manual procedure.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

    Longitudinal variability of size-fractionated N-2 fixation and DON release rates along 24.5 degrees N in the subtropical North Atlantic

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    Dinitrogen (N-2) fixation and dissolved organic nitrogen (DON) release rates were measured on fractionated samples (\u3e10 mu m and m) along 24.5 degrees N in the subtropical North Atlantic. Net N-2 fixation rates (N-2 assimilation into biomass) ranged from 0.01 to 0.4 nmol N L-1 h(-1), and DON release rates ranged from 0.001 to 0.09 nmol N L-1 h(-1). DON release represented approximate to 14% and approximate to 23% of \u3e10 mu m and (assimilation into biomass plus DON release), respectively. This implies that by overlooking DON release, N-2 fixation rates are underestimated. Net N-2 fixation rates were higher in the east and decreased significantly toward the west (r(s)=-0.487, p=0.002, and r(s)=-0.496, p=0.001, for the \u3e10 mu m and fractions, respectively). The sum of both fractions correlated with aerosol optical depth at 550 nm (AOD 550 nm) (r(s)=0.382, p=0.017) and phosphate (PO43-) concentrations (r(s)=0.453, p=0.018), suggesting an enhancement of diazotrophy as a response to aerosol inputs and phosphorus availability. In contrast, DON release was constant among size fractions and did not correlate with any of these variables. We also compared N-2 fixation rates obtained using the N-15(2) dissolved and bubble methods. The first gave average rates 50% (49% 39) higher than the latter, which supports the finding that previously published N-2 fixation rates are likely underestimated. We suggest that by combining N-2 fixation and DON release measurements using dissolved N-15(2), global N-2 fixation rates could increase enough to balance oceanic fixed nitrogen budget disequilibria
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