RV POSEIDON Cruise Report POS420 COWACSS Biological observation and sampling of cold-water corals to investigate impacts on climate change

Trondheim – (Kristiansund) – Kiel 08. – (25.) – 30.09.201

Smoothed particle hydrodynamics for modelling cold-water coral habitats in changing oceans

The importance of the growth, proliferation and longevity of reef-forming cold-water corals is paramount as they support various complex bio-diverse habitats and provide many essential ecosystem services. These cold-water coral reefs consist of layers of living coral tissue that grow on top of large masses of coral skeleton. Here, the Goldilocks Principle is used to simulate growth in optimal conditions and model how cold-water corals engineer their habitat to survive and prosper. A computational fluid dynamics model is created based on the Smoothed Particle Hydrodynamics method, a mesh-free Lagrangian numerical method. The SPH solver is written in the C++ programming language and parallelised with OpenMP to improve its efficiency and reduce the execution times. The solver is validated against analytical and numerical solutions and the growth model is then validated against in situ data of real cold-water coral colonies. The numerical results suggest that the longevity of cold-water corals depends on how well they can manage their energetic reserves when exposed to sub-optimal prey-catching conditions

Smoothed particle hydrodynamics for modelling cold-water coral habitats in changing oceans

The importance of the growth, proliferation and longevity of reef-forming cold-water corals is paramount as they support various complex bio-diverse habitats and provide many essential ecosystem services. These cold-water coral reefs consist of layers of living coral tissue that grow on top of large masses of coral skeleton. Here, the Goldilocks Principle is used to simulate growth in optimal conditions and model how cold-water corals engineer their habitat to survive and prosper. A computational fluid dynamics model is created based on the Smoothed Particle Hydrodynamics method, a mesh-free Lagrangian numerical method. The SPH solver is written in the C++ programming language and parallelised with OpenMP to improve its efficiency and reduce the execution times. The solver is validated against analytical and numerical solutions and the growth model is then validated against in situ data of real cold-water coral colonies. The numerical results suggest that the longevity of cold-water corals depends on how well they can manage their energetic reserves when exposed to sub-optimal prey-catching conditions

A comparative investigation of the efficacy of CO2 and high power diode lasers for the forming of EN3 mild steel sheets

A comparative investigation of the effectiveness of a high power diode laser (HPDL) and a CO2 laser for the forming of thin section EN3 mild steel sheet has been conducted. The buckling mechanism was identified as the laser forming mechanism responsible for the induced bending. For both lasers it was found that the induced bending angles increased with an increasing number of irradiations and high laser powers, whilst decreasing as the traverse speed was increased. Also, it was apparent from the experimental results that the laser bending angle was only linearly proportional to the number of irradiations when the latter was small due to local material thickening along the bend edge with a high number of irradiations. Owing to the mild steel’s greater beam absorption at the HPDL wavelength, larger bending angles were induced when using the HPDL. However, under certain conditions the performance of the CO2 laser in terms of induced bending angle was seen to approach that of the HPDL. Nevertheless, similar results between the two lasers were only achieved with increasing irradiations, thus it was concluded that the efficacy of the HPDL was higher than that of the CO2 laser insofar as it was more efficient. From graphical results and the employment of an analytical procedure, the laser line energy range in which accurate control of the HPDL bending of the mild steel sheets could be exercised efficiently was found to be 53 J mm-1 < P/v < 78 J mm-1, whilst for the CO2 laser the range was 61 J mm-1 < P/v < 85 J mm-1

Hidden impacts of ocean acidification to live and dead coral framework

Cold-water corals, such as Lophelia pertusa, are key habitat-forming organisms found throughout the world's oceans to 3000 m deep. The complex three-dimensional framework made by these vulnerable marine ecosystems support high biodiversity and commercially important species. Given their importance, a key question is how both the living and the dead framework will fare under projected climate change. Here, we demonstrate that over 12 months L. pertusa can physiologically acclimate to increased CO2, showing sustained net calcification. However, their new skeletal structure changes and exhibits decreased crystallographic and molecular-scale bonding organization. Although physiological acclimatization was evident, we also demonstrate that there is a negative correlation between increasing CO2 levels and breaking strength of exposed framework (approx. 20–30% weaker after 12 months), meaning the exposed bases of reefs will be less effective ‘load-bearers’, and will become more susceptible to bioerosion and mechanical damage by 2100

Effect of pulse-current-based protocols on the lithium dendrite formation and evolution in all-solid-state batteries

Understanding the cause of lithium dendrites formation and propagation is essential for developing practical all-solid-state batteries. Li dendrites are associated with mechanical stress accumulation and can cause cell failure at current densities below the threshold suggested by industry research (i.e., >5 mA/cm2). Here, we apply a MHz-pulse-current protocol to circumvent low-current cell failure for developing all-solid-state Li metal cells operating up to a current density of 6.5 mA/cm2. Additionally, we propose a mechanistic analysis of the experimental results to prove that lithium activity near solid-state electrolyte defect tips is critical for reliable cell cycling. It is demonstrated that when lithium is geometrically constrained and local current plating rates exceed the exchange current density, the electrolyte region close to the defect releases the accumulated elastic energy favouring fracturing. As the build-up of this critical activity requires a certain period, applying current pulses of shorter duration can thus improve the cycling performance of all-solid-solid-state lithium batteries.publishedVersio

Insulin Detemir Reduces Weight Gain as a Result of Reduced Food Intake in Patients With Type 1 Diabetes

Insulin detemir lacks the usual propensity for insulin to cause weight gain. We investigated whether this effect was a result of reduced energy intake and/or increased energy expenditure

Differences in bioactivity between human insulin and insulin analogues approved for therapeutic use- compilation of reports from the past 20 years

In order to provide comprehensive information on the differences in bioactivity between human insulin and insulin analogues, published in vitro comparisons of human insulin and the rapid acting analogues insulin lispro (Humalog®), insulin aspart ( NovoRapid®), insulin glulisine (Apidra®), and the slow acting analogues insulin glargine (Lantus®), and insulin detemir (Levemir®) were gathered from the past 20 years (except for receptor binding studies). A total of 50 reports were retrieved, with great heterogeneity among study methodology. However, various differences in bioactivity compared to human insulin were obvious (e.g. differences in effects on metabolism, mitogenesis, apoptosis, intracellular signalling, thrombocyte function, protein degradation). Whether or not these differences have clinical bearings (and among which patient populations) remains to be determined