| 1. |
- Orejas, C, et al.
(författare)
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Cold-water corals in aquaria: advances and challenges. A focus on the Mediterranean
- 2019
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Ingår i: Mediterranean Cold-Water Corals: Past, Present and Future. - : Springer. - 2213-719X. - 9783319916071
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Bokkapitel (refereegranskat)abstract
- Knowledge on basic biological functions of organisms is essential to understand not only the role they play in the ecosystems but also to manage and protect their populations. The study of biological processes, such as growth, reproduction and physiology, which can be approached in situ or by collecting exemplars and rearing them in aquaria, is particularly challenging for deep-sea organisms such as cold-water corals (CWCs). Present experimental work and monitoring of deep-sea populations is still a chimera. Only a handful of research institutes or companies have been able to install in situ marine observatories in the Mediterranean Sea or elsewhere, which facilitate for a continuous monitoring of deep-sea ecosystems. Hence, today’s best way to obtain basic biological information on these organisms is (1) working with collected samples and analysing them post-mortem and / or (2) cultivating corals in aquaria in order to monitor biological processes and investigate coral behaviour and physiological responses under different experimental treatments. The first challenging aspect is the collection process, which implies the use of oceanographic research vessels in most occasions, since these organisms inhabit areas between ca. 150 m to more than 1,000 m depth, and specific sampling gears. The next challenge is the maintenance of the animals on board (in situations where cruises may take weeks) and their transport to home laboratories. Maintenance in the home labs is also extremely challenging since special conditions and set ups are needed to conduct experimental studies to obtain information on the biological processes of these animals. The complexity of the natural environment from which the corals were collected cannot be exactly replicated within the laboratory setting; a fact which has led some researchers to question the validity of work and conclusions drawn from such undertakings. It is evident that aquaria experiments cannot perfectly reflect the real environmental and trophic conditions where these organisms occur, but: (1) in most cases we do not have the possibility to obtain equivalent in situ information and (2) even with limitations, they produce relevant information about 117 the biological limits of the species, which is especially valuable when considering potential future climate change scenarios. This chapter includes many contributions from different authors and it intends to be both, a practical “handbook” for conducting CWC aquaria work, while at the same time, to offer an overview on the CWC research conducted in Mediterranean labs equipped with aquaria infrastructure. Experiences from Atlantic and Pacific laboratories with extensive experience with CWC work have also contributed to this chapter, as their procedures are valuable to any researcher interested in conducting experimental work with CWC in aquaria. It was impossible to include contributions from all labs in the world currently working experimentally with CWCs in the laboratory, but at the conclusion of the chapter we attempt, to our best of our knowledge, to supply a list of laboratories with operational CWC aquaria facilities.
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| 2. |
- Purser, Jennifer A., et al.
(författare)
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Repeatability and reproducibility of the ISO/TS 19700 steady state tube furnace
- 2013
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Ingår i: Fire Safety Journal. - : Elsevier BV. - 0379-7112. ; 55, s. 22-34
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Tidskriftsartikel (refereegranskat)abstract
- The ISO/TS 19700 steady state tube furnace is designed to measure the yields of combustion products, and in particular toxic combustion products, under a range of different specified decomposition conditions occurring in full-scale compartment fires. In order to establish the repeatability and reproducibility of the method, a Round Robin inter-laboratory study and statistical analysis has been carried out involving three laboratories. Pre-existing data from a fourth laboratory have also been considered where appropriate. Samples of different polymers (PMMA, LDPE, PA6.6 and rigid PVC) were tested under two fire conditions: well-ventilated flaming at 650 °C and post-flashover under-ventilated flaming at 825 °C, with each laboratory performing three replicate runs on each polymer under each condition. The results showed good agreement between laboratories and against calculated stoichiometric maxima, demonstrating satisfactory levels of repeatability and reproducibility for key combustion gases. These included O2 consumption, and the yields of CO2, CO, HCN and HCl. A number of amendments to the standard have been recommended as a result of minor procedural issues arising during preliminary work.
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| 3. |
- Fedriani, R., et al.
(författare)
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Measuring the ionisation fraction in a jet from a massive protostar
- 2019
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- It is important to determine if massive stars form via disc accretion, like their low-mass counterparts. Theory and observation indicate that protostellar jets are a natural consequence of accretion discs and are likely to be crucial for removing angular momentum during the collapse. However, massive protostars are typically rarer, more distant and more dust enshrouded, making observational studies of their jets more challenging. A fundamental question is whether the degree of ionisation in jets is similar across the mass spectrum. Here we determine an ionisation fraction of ~5–12% in the jet from the massive protostar G35.20-0.74N, based on spatially coincident infrared and radio emission. This is similar to the values found in jets from lower-mass young stars, implying a unified mechanism of shock ionisation applies in jets across most of the protostellar mass spectrum, up to at least ~10 solar masses.
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| 4. |
- Allers, E., et al.
(författare)
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Resistance of Lophelia pertusa to coverage by sediment and petroleum drill cuttings
- 2013
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Ingår i: Marine Pollution Bulletin. - 0025-326X. ; 74:1, s. 132-140
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Tidskriftsartikel (refereegranskat)abstract
- In laboratory experiments, the cold-water coral Lophelia pertusa was exposed to settling particles. The effects of reef sediment, petroleum drill cuttings and a mix of both, on the development of anoxia at the coral surface were studied using O2, pH and H2S microsensors and by assessing coral polyp mortality. Due to the branching morphology of L. pertusa and the release of coral mucus, accumulation rates of settling material on coral branches were low. Microsensors detected H2S production in only a few samples, and sulfate reduction rates of natural reef sediment slurries were low (<0.3 nmol S cm−3 d−1). While the exposure to sediment clearly reduced the coral’s accessibility to oxygen, L. pertusa tolerated both partial low-oxygen and anoxic conditions without any visible detrimental short-term effect, such as tissue damage or death. However, complete burial of coral branches for >24 h in reef sediment resulted in suffocation.
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| 5. |
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| 6. |
- Dorschel, Boris, et al.
(författare)
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The International Bathymetric Chart of the Southern Ocean Version 2
- 2022
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- The Southern Ocean surrounding Antarctica is a region that is key to a range of climatic and oceanographic processes with worldwide effects, and is characterised by high biological productivity and biodiversity. Since 2013, the International Bathymetric Chart of the Southern Ocean (IBCSO) has represented the most comprehensive compilation of bathymetry for the Southern Ocean south of 60 degrees S. Recently, the IBCSO Project has combined its efforts with the Nippon Foundation - GEBCO Seabed 2030 Project supporting the goal of mapping the world's oceans by 2030. New datasets initiated a second version of IBCSO (IBCSO v2). This version extends to 50 degrees S (covering approximately 2.4 times the area of seafloor of the previous version) including the gateways of the Antarctic Circumpolar Current and the Antarctic circumpolar frontal systems. Due to increased (multibeam) data coverage, IBCSO v2 significantly improves the overall representation of the Southern Ocean seafloor and resolves many submarine landforms in more detail. This makes IBCSO v2 the most authoritative seafloor map of the area south of 50 degrees S.
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| 7. |
- Gissi, Emanuele, et al.
(författare)
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Transparency vs magic numbers : The development of stair design requirements in the Italian Fire Safety Code
- 2017
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Ingår i: Fire Safety Journal. - : Elsevier BV. - 0379-7112. ; 91, s. 882-891
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Tidskriftsartikel (refereegranskat)abstract
- Practitioners may face difficulties in the interpretation of fire codes since they often present so called "magic numbers", i.e. numbers available in the codes which are listed for providing the design of building fire safety, for which the derivation and justification are not explained. The present paper discusses the need for a transparent regulatory approach, in which legislators publicly justify each of the choices made during the development of the fire codes. This approach has been used for the first time during the development of the Italian Fire Safety Code DM03/08/15, where the process adopted for the development of the code requirements has been publicly released in parallel with the code itself. This is deemed to facilitate the interpretation of the fire code, avoiding mis-use and preventing criticism on lack of transparency. To address this issue, the Italian legislators have conducted a process of reconstructing the assumptions adopted for the definition of magic numbers in other International codes (i.e., British Standard 9999) in order to identify suitable specifications for the national context under consideration. This includes the performance of a series of calculations rather than a mere historical examination of their basis. As a first attempt towards an increased transparency in fire code development at an International level, this paper publicly summarizes the process adopted by the Italian legislators for the development of the new Italian fire code, focusing on the exemplary case of the calculations performed for the definition of the requirements concerning stair design (i.e. vertical evacuation). This is presented by comparing the deemed-to-satisfy provisions of the Italian code with the ones given in the British Standard 9999. The process of developing fire codes is discussed together with the benefits associated with transparency in the assumptions adopted for their definition.
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| 8. |
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| 9. |
- Larsson, Ann I., 1965, et al.
(författare)
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Tolerance to long-term exposure of suspended benthic sediments and drill cuttings in the cold-water coral Lophelia pertusa
- 2013
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Ingår i: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X. ; 70:1-2, s. 176-188
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Tidskriftsartikel (refereegranskat)abstract
- The cold-water coral Lophelia pertusa was exposed to suspended particles (<63 mu m) for 12 weeks. Skeletal growth was significantly lower under exposure concentrations of similar to 25 mg l(-1) than similar to 5 mg l(-1) and there was a trend of lower growth rates when exposed to water-based drill cuttings than to natural benthic sediment. Polyp extension was less in corals exposed to higher material concentrations, which provides a possible explanation for observed skeletal growth differences between particle concentrations. Particle exposure had no significant impact on respiration or proportions of tissue and fatty acids in corals. The volume of additional cleaning mucus released by exposed corals was low and release did not significantly affect coral energy expenditure. Our results indicate that L. pertusa polyps can deal comparatively well with enhanced particle deposition rates and suspended matter concentrations. However, a small pilot experiment indicated that coral larvae might be particularly vulnerable to high particle concentrations. (c) 2013 Elsevier Ltd. All rights reserved.
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| 10. |
- Purser, A., et al.
(författare)
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The influence of flow velocity and food concentration on Lophelia pertusa (Scleractinia) zooplankton capture rates
- 2010
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Ingår i: Journal of Experimental Marine Biology and Ecology. - 0022-0981. ; 395:1-2, s. 55-62
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Tidskriftsartikel (refereegranskat)abstract
- Lophelia pertusa is the most significant framework building scleractinian coral in European seas, yet the reproductive strategy, longevity, growth and food capture rates for the species remain poorly understood. In this study an experimental investigation into the ability of L pertusa to capture zooplankton from suspension was conducted. By direct ROV sampling approximately 350 L pertusa polyps were collected from the Tisler reef, Norway and maintained under temperature controlled conditions in recirculating flumes. These polyps were subdivided into three replicate groups of similar to 120 polyps and maintained in waters with flow velocities of 2.5 cm s(-1) or 5.0 cm s(-1). Suspended Artemia sauna nauplii food concentrations of between 345 and 1035 A. sauna l(-1) were introduced. L pertusa net capture rates were assessed by monitoring the reduction in suspended A. sauna concentration in each flume over 24 h. Maximum net capture rates were higher in flumes with a 2.5 cm s(-1) flow regime, at 73.3 +/- 2.0 A. salina polyp(-1) h(-1) (mean +/- SD) than those with 5 cm s(-1) flow (19.8 +/- 11.8 A. sauna polyp(-1) h(-1)). Maximum net capture rates were lower in flumes with A. sauna densities of <690 A. salina l(-1) than in flumes with higher food densities under comparable flow velocities. The maximum net capture rates observed represent maximum carbon capture rates of 66.4 +/- 2.0 mu g C polyp(-1) h(-1) and 17.9 +/- 10.7 mu g C polyp(-1) h(-1) under 2.5 and 5 cm(-1) s(-1) flow speeds respectively. The results of this study indicate that L pertusa captures zooplankton more efficiently under slower flow velocities. (C) 2010 Elsevier B.V. All rights reserved.
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