281 research outputs found

    Standard length, dry weight and swim bladder percentage gas of Cyclothone species from the IDEADOS and BATHYPELAGIC cruises in Northeast Atlantic Ocean and Mediterranean Sea

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    This dataset contains the values of standard length, dry weight and percentage of gas in Cyclothone spp. swim bladder collected during the Bathypelagic cruise (from 24th May to 23rd June 2018) and IDEADOS cruise (from 12th to 29th July 2010). Samples were obtained with MOCNESS-1 m² (with a 0.2 mm mesh size) zooplankton net during day and night hauls carried out from the surface to 700-800 m during IDEADOS cruise, and to 1800 m in the Bathypelagic cruise. Fish for size frequency distribution were preserved in 5% buffered formalin, and those for weight measurements were frozen at 20°C, and then dry weight (DW, ±0.01 g) and standard length (SL, ±0.01 mm) were measured at the land-based laboratory. The percentage of area with fat tissue (%FT) in Cyclothone spp. swim bladders was linearly regressed against standard length (mm). The maximum percentage area with gas (%GAS) was then estimated as 100-%FT

    Swimbladder properties of Cyclothone spp. in the northeast Atlantic Ocean and the Western Mediterranean Sea

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    Non-migratory bristlemouth fishes (Cyclothone spp.) are the most abundant vertebrates on Earth and play an important role in the biological carbon pump by remineralizing organic carbon in deep ecosystems. Acoustic data and net sampling are often used in combination to estimate fish and zooplankton biomass, but this procedure may be subject to several sources of error when applied to mesopelagic species. For instance, the allocation of echoes to species has often been biased by not considering Cyclothone spp. due to the use of nets targeting larger fish. Furthermore, the acoustic properties of the target organisms must be well understood to convert acoustic density into numerical density. The characteristics of a fish’s swimbladder are the most relevant features necessary to assess its acoustic properties. This study provides information on the swimbladder properties of six Cyclothone species inhabiting the meso- and bathypelagic layers in the North Atlantic Ocean and Mediterranean Sea, including swimbladder location within the body, fat tissue content, morphology, morphometry (only available for C. braueri and C. pseudopallida), and fish body-mass density (only available for C. braueri, C. pseudopallida, C. pallida, and C. pygmaea). The studied species showed a functional physoclistous swimbladder, with well-developed gas glands and rete mirabile and numerous capillaries in the case of the shallower species C. braueri and C. pseudopallida (mainly distributed from 400 to 600 m depth), and a fat-invested swimbladder in species with deeper vertical distribution (C. livida, C. microdon, C. pallida, and C. pygmaea). The fat content in the swimbladder (C. pallida and C. microdon) increased with depth and latitude, reducing the space in the swimbladder that could contain gas. Changes in swimbladder size and volume during growth were analyzed for shallower species, where swimbladder volume and equivalent radius followed negative allometric growth in relation to body length. Finally, values of body-mass density (ρ) and gas content required for neutral buoyancy (VG) were estimated for C. braueri and C. pygmaea collected between 350 and 550 m (ρ = 1.052–1.072 g·cm−3, VG = 2%–4%; ρ = 1.052–1.062 g·cm−3, VG = 3.6%), and for C. pallida and C. pseudopallida sampled in the 450–700 m layer (ρ = 1.052–1.062 g·cm−3, VG = 2.6–3.1%; ρ = 1.052–1.062 g·cm−3, VG = 2.8%–3.25%). Results in this study highlight the change in scattering behavior of Cyclothone species from gas-bearing organisms (those that contain gas in their swimbladder) in the upper mesopelagic zone to the fluid-like scattering (with fat-filled swimbladders) of the deeper and northern individuals. The data presented in this manuscript are important for parametrizing acoustic backscattering models built to estimate the echo of Cyclothone species, although further work is needed, particularly for individuals with partially invested swimbladders with an irregular fat-free shape

    Swim bladder measurements of Cyclothone species from the BATHYPELAGIC cruise to the Northeast Atlantic Ocean

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    This dataset contains the values of swim bladder length, height, width, angle, volume, equivalent spherical radius and aspect ratio in Cyclothone spp. measured during the Bathypelagic cruise (from 24th May to 23rd June 2018). Samples were obtained with MOCNESS-1 m² (with a 0.2 mm mesh size) zooplankton net during day and night hauls carried out from the surface to 1800 m depth. MOCNESS samples were preserved in 5% buffered formalin. Standard length (SL, ±0.01 mm) and swim bladder (Sw, ±0.001 mm) on each specimen were measured at the land-based laboratory. A stereo microscope fitted with an ocular micrometer was used to obtain the swim bladder length height, width, and swim bladder angle (θ). The longitudinal axis was set as the reference line for the angle (θ =0) with positive values over the reference line. Swim bladder volumes were approximated using the formula for a prolate spheroid, the equivalent spherical radius was estimated following the equation of Strasberg (1953) and the aspect ratio was calculated as the ratio of the height to the longitudinal semi-axis

    Standard length, weight, body mass-density and swim bladder measurements data of Cyclothone species from the IDEADOS, BATHYPELAGIC and SUMMER cruises in Northeast Atlantic Ocean and Mediterranean Sea

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    Size, weight, body-mass density and swim bladder measurements of Cyclothone species were analysed during the IDEADOS (Mediterranean Sea, July 2010), Bathypelagic (North Atlantic, May-June 2018) and SUMMER (Mediterranean Sea and North Atlantic, September-October 2020), and cruises. Specimens used to analyse size and weight were collected with a Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS-1 m²), fitted with nets of 0.2 mm mesh size. Hauls were carried out between the surface and 700-800 m, in IDEADOS and SUMMER cruises, and up to 1800 m in Bathypelagic survey. Measures of body mass-density were obtained during the SUMMER cruise from specimens collected using the “Mesopelagos” midwater trawl. Finally, measures of swim bladder length, height, width, angle, volume, equivalent spherical radius, and aspect ratio were measured from specimens collected during the Bathypelagic cruise

    Body mass-density of Cyclothone species from the SUMMER cruise in Northeast Atlantic Ocean and Mediterranean Sea

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    This dataset contains the values of standard length, wet weight, and body mass-density of Cyclothone spp. measured during the SUMMER cruise (from 30th September to 18th October 2020). Samples were obtained with the “Mesopelagos” midwater trawl during day and night hauls carried out from the surface to 700-800 m depth. The Mesopelagos net consists of graded-mesh netting starting with 30 mm and ending with 4 mm. The specimens collected were immediately identified and measured (standard length, SL). Body-mass densities (ρ) of Cyclothone braueri, C. pseudopallida, C. pygmaea and C. pallida were determined on board via a density-bottle method (Greenlaw, 1977; Mikami et al., 2000)

    Linear and multivalent PEGylation of the tobacco mosaic virus and the effects on its biological properties

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    Plant virus-based nanoparticles (VNPs) offer a bioinspired approach to the delivery of drugs and imaging agents. The chemical addressability, biocompatibility, and scalable manufacturability of VNPs make them a promising alternative to synthetic delivery platforms. However, VNPs, just like other proteinaceous or synthetic nanoparticles (NPs), are readily recognized and cleared by the immune system and mechanisms such as opsonization and phagocytosis. Shielding strategies, such as PEGylation, are commonly used to mitigate premature NP clearance. Here, we investigated polyethylene glycol (PEG) coatings on the tobacco mosaic virus (TMV), which was used as a model nanocarrier system. Specifically, we evaluated the effects of linear and multivalent PEG coatings at varying chain lengths on serum protein adsorption, antibody recognition, and macrophage uptake. Linear and multivalent PEGs of molecular weights 2,000 and 5,000 Da were successfully grafted onto the TMV at ≈ 20%–60% conjugation efficiencies, and the degree of cross-linking as a function of PEG valency and length was determined. PEGylation resulted in the modulation of TMV–macrophage interactions and reduced corona formation as well as antibody recognition. Linear and multivalent PEG 5,000 formulations (but not PEG 2,000 formulations) reduced α-TMV antibody recognition, whereas shorter, multivalent PEG coatings significantly reduced α-PEG recognition—this highlights an interesting interplay between the NP and the PEG itself in potential antigenicity and should be an important consideration in PEGylation strategies. This work provides insight into the PEGylation of VNPs, which may improve the possibility of their implementation in clinical applications

    Performance of the CMS cathode strip chambers with cosmic rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 mu m to 243 mu m. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Alignment of the CMS muon system with cosmic-ray and beam-halo muons