1,117 research outputs found
CV19015
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
Immunocytochemical localization of the neuron-specific form of the c-src gene product, pp60c-src(+), in rat brain
Neurons express high levels of a variant form of the c-src gene product, denoted pp60c-src(+), which contains a 6 amino acid insert in the amino-terminal half of the c-src protein. We have determined the localization of pp60c-src(+) in neurons using an affinity-purified anti-peptide antibody, referred to as affi-SB12, that exclusively recognizes this neuron-specific form of the c-src gene product. Using affi-SB12, we examined the distribution of pp60c-src(+) by immunoperoxidase staining of sections through adult rat brains, pp60c-src(+) was widely distributed in rat brain and appeared to be differentially expressed in subpopulations of neurons. The majority of immunoreactive neurons was found in the mesencephalon, cerebellum, pons, and medulla. Telencephalic structures that contained substantial populations of pp60c-src(+)-immunoreactive neurons included layer V of the cerebral cortex and the ventral pallidum. Within individual neurons, pp60c-src(+) immunoreactivity was localized to the cell soma and dendritic processes, while labeling of axons and nerve terminals (puncta) was not as readily detected. Dense accumulations of immunoreactive axons were rare, being most prominent in portions of the inferior and superior olive, and in the spinal trigeminal nucleus. While the regional distribution of pp60c-src(+) immunoreactivity does not correlate with any specific neuronal cell type or first messenger system, this unique pattern of expression of pp60c-src(+) suggests the existence of a previously uncharacterized functional organization within the brain. Furthermore, the localization of this neuron-specific tyrosine kinase in functionally important areas of the nerve cell, namely, dendritic processes, axons, and nerve terminals, suggests that pp60c-src(+) may regulate pleiotropic functions in specific classes of neurons in the adult central nervous system
Comparison and Uncertainty Quantification of Two-Fluid Models forBubbly Flows with NEPTUNE_CFD and STAR-CCM+
International audienceThe nuclear industry is interested in better understanding the behavior of turbulent boiling flowsand in using modern computational tools for the design and analysis of advanced fuels and reactorsand for simulation and study of mitigation strategies in accident scenarios. Such interests serve asdrivers for the advancement of the 3-dimensional multiphase Computational Fluid Dynamicsapproach. A pair of parallel efforts have been underway in Europe and in the United States, theNEPTUNE and CASL programs respectively, that aim at delivering advanced simulation tools thatwill enable improved safety and economy of operations of the reactor fleet. Results from acollaboration between these two efforts, aimed at advancing the understanding of multiphaseclosures for pressurized water reactor (PWR) application, are presented. Particular attention is paidto the assessment and analysis of the different physical models implemented in NEPTUNE_CFDand STAR-CCM+ codes used in the NEPTUNE and the CASL programs respectively, forapplication to turbulent two-phase bubbly flows. The experiments conducted by Liu and Bankoff(Liu, 1989; Liu and Bankoff 1993a and b) are selected for benchmarking, and predictions from thetwo codes are presented for a broad range of flow conditions and with void fractions varyingbetween 0 and 50percent. Comparison of the CFD simulations and experimental measurements revealsthat a similar level of accuracy is achieved in the two codes. The differences in both sets of closuremodels are analyzed, and their capability to capture the main features of the flow over a wide rangeof experimental conditions are discussed. This analysis paves the way for future improvements ofexisting two-fluid models. The benchmarks are further leveraged for a systematic study of thepropagation of model uncertainties. This provides insights into mechanisms that lead to complexinteractions between individual closures (of the different phenomena) in the multiphase CFDapproach. As such, it is seen that the multi-CFD-code approach and the principled uncertaintyquantification approach are both of great value in assessing the limitations and the level of maturityof multiphase hydrodynamic closures
The COVID-19 pandemic and children’s engagement with learning in rural Sierra Leone
The COVID-19 pandemic caused worldwide educational disruption. This paper addresses a gap in the literature relating to the impact of the pandemic on learning experiences of children in rural communities in the Global South, particularly in earlier years of schooling. Children in these communities are at considerable disadvantage in comparison to their urban peers due to poor school infrastructure and challenges in recruitment and retention of teachers. Drawing on a mixed-methods study of primary school children, their teachers and families in rural Sierra Leone, both during and immediately after school closures, the paper highlights how primary schools and their communities responded to the pandemic and how this influenced children’s engagement with their learning. While national planning focused on pandemic control measures and provision of some remote learning support, findings highlight challenges for poor rural communities in accessing basic learning supports and the consequent disruption to children’s education
Improved Understanding of the Ball-Pen Probe through Particle-In-Cell Simulations
Ball-pen probes (BPP)have been deployed in the SOL of numerous tokamak experiments and low-temperature magnetised plasmas to make direct measurements of the plasma potential and electron temperature. Despite strong empirical evidence for the success of the BPP it lacks a theoretical underpinning of its collection mechanism. In this paper we investigate the capability of the probe to measure the plasma potential by means of particle-in-cell simulations. The BPP is found to float at a potential offset from the plasma potential by a factor TₑαBPP. By simulating BPPs and Langmuir probes, excellent agreement has been found between the measured electron temperature and the specified source temperature. The transport mechanism for both ions and electrons has been determined.E×B drifts are observed to drive electrons and ions down the tunnel. This mechanism is sensitive to the diameter of the prob
CV17017
This report provides the main results and findings of the fifteenth annual underwater television 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, fishing, CTD and other ecosystem data. In 2017 a total of 40 UWTV stations were successfully
completed, 31 on the Aran Grounds, 5 on Galway Bay and 4 on Slyne Head patches. The mean burrow density observed in 2017, adjusted for edge effect, was medium at 0.29
burrows/m². The final krigged burrow abundance estimate for the Aran Grounds was 343 million burrows with a CV (or relative standard error) of 3 %. The final abundance estimate
for Galway Bay and Slyne Head was 25 and 11 million burrows with CVs of 7% and 3% respectively. The total abundance estimates have fluctuated considerably over the time
series. The 2016 combined abundance estimate was 32% lower than in 2015 and at 379 million and is below the MSY Btrigger (540 million). Using the 2017 abundance estimate and
updated stock data implies catch of 551 tonnes and landings of 513 tonnes in 2018 when MSY approach is applied (assuming that discard rates and fishery selection patterns do not
change from the average of 2014–2016). Virgilaria mirabilis was the only sea-pen species observed on the UWTV footage. Trawl marks were present at 20% of the Aran stations surveyed
Transcript of The Dory Derby Accident
This story is an excerpt from a longer interview that was collected as part of the Launching through the Surf: The Dory Fleet of Pacific City project. In this story, Don Grotjohn recounts an accident that occurred during a Dory Derby competition
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