24 research outputs found
Discard sampling of Dutch bottom-trawl fisheries in 2009 and 2010
In the European Union, the collection of discard data is enforced through the Data Collection Regulation or Framework (DCR/DCF) of the European Commission (EC). To comply with this ruling, approximately ten trips of discard-intensive beam-trawlers are being monitored annually since 1999 (Helmond and Overzee, 2010). In 2009, revisions to the DCF (2008/949/EG), required member states to increase sampling intensity to i) improve the precision of their estimates and ii) the number of sampled métiers. To meet this requirement within an affordable budget, the Institute for Marine Resources and Ecosystem Studies (IMARES, part of Wageningen University and Research) set up a collaborative project between the Dutch fishing industry and the research institute to recruit a ‘reference fleet’ of vessel owners willing to participate in a self-sampling programme. This programme complemented the existing observer programme. In the observer programme, vessels were selected quarterly from a pool of available vessels, whereas in the self-sampling programme, trips were pre-determined from a reference fleet of participating vessels. Missing and/or wrong information precluded the inclusion of 17% and 13% of all self-sampled trips in 2009 and 2010. In total, 9 and 10 observer, and 63 and 132 valid self-sampling trips were completed in 2009 and 2010, respectively. For these remaining valid self-sampled trips, procedures were developed to test whether data quality was comparable with i) other self samples from the reference fleet and ii) comparable observercollected data (i.e. temporally and spatially overlapping trips). In addressing i), there were no unusual patterns in the length frequencies of self-sampled discards of European plaice (Pleuronectes platessa), common dab (Limanda limanda), grey gurnard (Eutrigla gurnardus), and whiting (Merlangius merlangus) in 2009 and2010. In addressing ii), no significant differences in the discard rates of plaice between the two programmes were found. There was no evidence that sampling may have been biased at the vessel level, justifying the decision to present all discard estimates independent of the programme type. While in both programmes the majority of observations were done onboard beam-trawl vessels with mesh sizes ranging between 70 and 99 mm, in the self-sampling programme data from four additional beam- and otter-trawl métiers with two 70-99 and 100-119 mesh size ranges and other target species assemblages (i.e mixed crustaceans and/or demersal fish) were collected. This lead, apart from a considerable increase in sampling effort for some métiers, to an increase in the temporal and spatial spread of sampling. Samples from previously unsampled northern and eastern parts of the North Sea were available. The spatial distribution of sampling locations matched that of the total effort of the fleet for intensively-sampled métiers. In all but two métiers, combined fish and benthos discards exceeded the volume of landings. In contrast, large-mesh beam- and otter trawls (100-119 mm) landed on average more than they discarded. The majority of discards was comprised by benthic (invertebrate ) species such as common starfish (Asteria rubens); sand star (Astropecten irregularis); swimming crab (Liocarcinus holsatus); and serpent star (Ophiura ophiura). Most frequently discarded fish species of no commercial value included: dragonet (Callionymus lyra); grey gurnard (Eutrigla gurnardus); scaldfish (Arnoglossus laterna); and solenette (Buglossidium luteum). Among commercially-valuable fish, common dab (Limanda limanda) and European plaice (Pleuronectes platessa) were the most frequently discarded species
Optimization of combined temozolomide and peptide receptor radionuclide therapy (PRRT) in mice after multimodality molecular imaging studies
Background: Successful treatments of patients with somatostatin receptor (SSTR)-overexpressing neuroendocrine tumours (NET) comprise somatostatin-analogue lutetium-177-labelled octreotate (177Lu-TATE) treatment, also referred to as peptide receptor radionuclide therapy (PRRT), and temozolomide (TMZ) treatment. Their combination might result in additive effects. Using MRI and SPECT/CT, we studied tumour characteristics and therapeutic responses after different (combined) administration schemes in a murine tumour model in order to identify the optimal treatment schedule for PRRT plus TMZ. Methods: We performed molecular imaging studies in mice bearing SSTR-expressing H69 (humane small cell lung cancer) tumours after single intravenous (i.v.) administration of 30Â MBq 177Lu-TATE or
Host genetic effects on HIV-1 replication in macrophages
Sebastiaan Bol ging op zoek naar humane eiwitten die hiv-vermenigvuldiging ondersteunen of remmen, met name in macrofagen. Deze cellen leven lang, gaan niet dood als gevolg van hiv-infectie en zijn - doordat ze zich veelal in weefsels bevinden - lastig bereikbaar voor hiv-remmers. Hierdoor vormen hiv-geïnfecteerde macrofagen één van de belangrijke barrières voor het genezen van mensen met hiv. Bol infecteerde macrofagen van honderden gezonde donoren met hiv en zocht naar verbanden tussen de mate waarin het virus zich vermenigvuldigde en variaties in het DNA (SNPs) van de betreffende proefpersonen. Hij identificeerde SNPs die coderen voor twee eiwitten die wellicht betrokken zijn bij hiv-replicatie in macrofagen. De SNP in één daarvan lijkt ook geassocieerd met ziektebeloop
Observations of changes in residual gas and surface composition with discharge cleaning in PLT
Hydrogen discharge cleaning of the PLT vacuum vessel has been studied by mass spectroscopy of desorbed gases and surface analysis of exposed samples. Several modes of vessel conditioning have been studied to date: (1) a high power discharge cleaning (PDC) mode, with a peak power density to the vessel wall P/sub s/ approximately 0.6 w/cm/sup 2/ and a peak electron temperature T/sub e/ approximately 100 ev; (2) low power (Taylor-type) discharge cleaning (TDC) with P/sub s/ approximately 0.05 w/cm/sup 2/ and T/sub e/ equal to or less than 5 eV. The predominant residual gases produced during PDC are CH/sub 4/ (1-5 x 10/sup -6/ torr) and CO (1-10 x 10/sup -7/ torr), whereas TDC produced primarily H/sub 2/O (1-2 x 10/sup -6/ torr) and CH/sub 4/ (1-10 x 10/sup -7/ torr). In situ surface analysis of hydrocarbon-covered stainless steel has shown significant decreases in carbon coverage occurring after 10/sup 3/-10/sup 4/ pulses of either cleaning mode. Observed changes in oxygen coverage are more difficult to interpret because of the presence of the nascent oxide layer on the stainless steel substrates
Discard sampling of Dutch bottom-trawl fisheries in 2009 and 2010
In the European Union, the collection of discard data is enforced through the Data Collection Regulation or Framework (DCR/DCF) of the European Commission (EC). To comply with this ruling, approximately ten trips of discard-intensive beam-trawlers are being monitored annually since 1999 (Helmond and Overzee, 2010). In 2009, revisions to the DCF (2008/949/EG), required member states to increase sampling intensity to i) improve the precision of their estimates and ii) the number of sampled métiers. To meet this requirement within an affordable budget, the Institute for Marine Resources and Ecosystem Studies (IMARES, part of Wageningen University and Research) set up a collaborative project between the Dutch fishing industry and the research institute to recruit a ‘reference fleet’ of vessel owners willing to participate in a self-sampling programme. This programme complemented the existing observer programme. In the observer programme, vessels were selected quarterly from a pool of available vessels, whereas in the self-sampling programme, trips were pre-determined from a reference fleet of participating vessels. Missing and/or wrong information precluded the inclusion of 17% and 13% of all self-sampled trips in 2009 and 2010. In total, 9 and 10 observer, and 63 and 132 valid self-sampling trips were completed in 2009 and 2010, respectively. For these remaining valid self-sampled trips, procedures were developed to test whether data quality was comparable with i) other self samples from the reference fleet and ii) comparable observercollected data (i.e. temporally and spatially overlapping trips). In addressing i), there were no unusual patterns in the length frequencies of self-sampled discards of European plaice (Pleuronectes platessa), common dab (Limanda limanda), grey gurnard (Eutrigla gurnardus), and whiting (Merlangius merlangus) in 2009 and2010. In addressing ii), no significant differences in the discard rates of plaice between the two programmes were found. There was no evidence that sampling may have been biased at the vessel level, justifying the decision to present all discard estimates independent of the programme type. While in both programmes the majority of observations were done onboard beam-trawl vessels with mesh sizes ranging between 70 and 99 mm, in the self-sampling programme data from four additional beam- and otter-trawl métiers with two 70-99 and 100-119 mesh size ranges and other target species assemblages (i.e mixed crustaceans and/or demersal fish) were collected. This lead, apart from a considerable increase in sampling effort for some métiers, to an increase in the temporal and spatial spread of sampling. Samples from previously unsampled northern and eastern parts of the North Sea were available. The spatial distribution of sampling locations matched that of the total effort of the fleet for intensively-sampled métiers. In all but two métiers, combined fish and benthos discards exceeded the volume of landings. In contrast, large-mesh beam- and otter trawls (100-119 mm) landed on average more than they discarded. The majority of discards was comprised by benthic (invertebrate ) species such as common starfish (Asteria rubens); sand star (Astropecten irregularis); swimming crab (Liocarcinus holsatus); and serpent star (Ophiura ophiura). Most frequently discarded fish species of no commercial value included: dragonet (Callionymus lyra); grey gurnard (Eutrigla gurnardus); scaldfish (Arnoglossus laterna); and solenette (Buglossidium luteum). Among commercially-valuable fish, common dab (Limanda limanda) and European plaice (Pleuronectes platessa) were the most frequently discarded species
Attainment of high confinement in neutral beam heated divertor discharges in the PDX tokamak
The PDX divertor configuration has recently been converted from an open to a closed geometry to inhibit the return of neutral gas from the divertor region to the main chamber. Since then, operation in a regime with high energy confinement in neutral beam heated discharges (ASDEX H-mode) has been routine over a wide range of operating conditions. These H-mode discharges are characterized by a sudden drop in divertor density and H/sub ..cap alpha../ emission and a spontaneous rise in main chamber plasma density during neutral beam injection. The confinement time is found to scale nearly linearly with plasma current, but it can be degraded due to either the presence of edge instabilities or heavy gas puffing. Detailed Thomson scattering temperature profiles show high values of Te near the plasma edge (approx. 450 eV) with sharp radial gradients (approx. 400 eV/cm) near the separatrix. Density profiles are broad and also exhibit steep gradients close to the separatrix
Assessing multiple novel tracers to improve the understanding of the contribution of agricultural farm-waste to diffuse water pollution
A study was undertaken on drained and undrained 1 ha grassland lysimeters to assess the effectiveness of multiple novel tracing techniques in understanding how agricultural slurry waste moves from land to water. Artificial fluorescent particles designed to mimic the size and density of organic slurry particles were found to move off the grassland via inter-flow (surface + lateral through-flow) and drain-flow. Where both pathways were present the drains carried the greater number of particles. The results of the natural fluorescence and delta C-13 of water samples were inconclusive. Natural fluorescence was higher from slurry-amended lysimeters than from zero-slurry lysimeters, however, a fluorescence decay experiment suggested that no slurry signal should be present given the time between slurry application and the onset of drainage. The delta C-13 values of >0.7 mm and 0.7 mm delta C-13 in water from the drain-flow pathways was higher from the lysimeter which had received naturally enriched maize slurry compared to the lysimeter which received grass slurry indicating a contribution of slurry-derived material. Values of <0.7 mm delta C-13 from the same pathway, however, produced counter intuitive trends and may indicate that different fractions of the slurry have different delta C-13 values
PDX experimental results in FY82
This report presents a detailed summary of the major experimental results of PDX in FY82 and represents the efforts of the entire PDX group. Topics covered include ..beta..-scaling and fishbone studies, fluctuations, disruptions, impurities and impurity transport, power handling, limiter conditioning, edge studies, plasma fueling, counter-injection, and diagnostic development. A less detailed version will appear as the FY82 PDX contribution to the PPPL Annual Report