25 research outputs found
Optimized localization analysis for single-molecule tracking and super-resolution microscopy
We optimally localize isolated fluorescent beads and molecules imaged as diffraction-limited spots, determine the orientation of molecules, and present reliable formulae for the precisions of various localization methods. For beads, theory and experimental data both show that unweighted least-squares fitting of a Gaussian squanders one third of the available information, a popular formula for its precision exaggerates beyond Fisher's information limit, and weighted least-squares may do worse, while maximum likelihood fitting is practically optimal
Characterisation of the physicochemical qualities of a typical rural-based river: ecological and public health implications
Die Erhebung und Zerlegung einer gemeinsamen StraĂźenbenutzungsgebĂĽhr fĂĽr schwere Nutzfahrzeuge
Unemployment Benefits, Activation and the Interaction between Levels of Government: Experiences with Moral Hazard in Multi-Tiered Labour Market Governance Systems
Fish density and target strength distribution of single fish echoes in varying light conditions with single and split beam echosounding and trawling
Effects of seawater pCO2 and temperature on shell growth, shell stability, condition and cellular stress of Western Baltic Sea Mytilus edulis (L.) and Arctica islandica (L.)
Acidification of the World’s oceans may directly impact reproduction, performance and shell formation of marine calcifying organisms. In addition, since shell production is costly and stress in general draws on an organism’s energy budget, shell growth and stability of bivalves should indirectly be affected by environmental stress. The aim of this study was to investigate whether a combination of warming and acidification leads to increased physiological stress (lipofuscin accumulation and mortality) and affects the performance [shell growth, shell breaking force, condition index (Ci)] of young Mytilus edulis and Arctica islandica from the Baltic Sea. We cultured the bivalves in a fully-crossed 2-factorial experimental setup (seawater (sw) pCO2 levels “low”, “medium” and “high” for both species, temperature levels 7.5, 10, 16, 20 and 25 °C for M. edulis and 7.5, 10 and 16 °C for A. islandica) for 13 weeks in summer. Mytilus edulis and A. islandica appeared to tolerate wide ranges of sw temperature and pCO2. Lipofuscin accumulation of M. edulis increased with temperature while the Ci decreased, but shell growth of the mussels only sharply decreased while its mortality increased between 20 and 25 °C. In A. islandica, lipofuscin accumulation increased with temperature, whereas the Ci, shell growth and shell breaking force decreased. The pCO2 treatment had only marginal effects on the measured parameters of both bivalve species. Shell growth of both bivalve species was not impaired by under-saturation of the sea water with respect to aragonite and calcite. Furthermore, independently of water temperatures shell breaking force of both species and shell growth of A. islandica remained unaffected by the applied elevated sw pCO2 for several months. Only at the highest temperature (25 °C), growth arrest of M. edulis was recorded at the high sw pCO2 treatment and the Ci of M. edulis was slightly higher at the medium sw pCO2 treatment than at the low and high sw pCO2 treatments. The only effect of elevated sw pCO2 on A. islandica was an increase in lipofuscin accumulation at the high sw pCO2 treatment compared to the medium sw pCO2 treatment. Our results show that, despite this robustness, growth of both M. edulis and A. islandica can be reduced if sw temperatures remain high for several weeks in summer. As large body size constitutes an escape from crab and sea star predation, this can make bivalves presumably more vulnerable to predation—with possible negative consequences on population growth. In M. edulis, but not in A. islandica, this effect is amplified by elevated sw pCO2. We follow that combined effects of elevated sw pCO2 and ocean warming might cause shifts in future Western Baltic Sea community structures and ecosystem services; however, only if predators or other interacting species do not suffer as strong from these stressors