32181 research outputs found
Sort by
Study and measures to reduce marina inlet sedimentation in Blankenberge and beach erosion in Wenduine, Belgium
Get PDFAn awkward fishing expedition
Get PDFWe report the case of a patient, among a group of five, in a small outbreak of histamine fish poisoning (HFP). The epidemic character of the ailment led us to the correct diagnosis. In this case, the diagnosis was also associated with a Kounis syndrome (KS). Literature concerning this subject is reviewed, reporting recent physiopathological data
Cis de strandjutter: Minder blauw op het strand
Get PDFMysterieuze zachte blauwe balletjes met een diameter van ongeveer 1,5 cm. Ik vind ze regelmatig in de vloedlijn, soms meerdere samen. Andere strandwandelaars vinden ze ook. Iedereen reageert verbaasd als ze horen waar de balletjes vandaan komen
Expanding the toolbox for cryopreservation of marine and freshwater diatoms
Get PDFDiatoms constitute the most diverse group of microalgae and have long been recognised for their large biotechnological potential. In the wake of growing research interest in new model species and development of commercial applications, there is a pressing need for long-term preservation of diatom strains. While cryopreservation using dimethylsulfoxide (DMSO) as a cryoprotective agent is the preferred method for long-term strain preservation, many diatom species cannot be successfully cryopreserved using DMSO. Therefore, in this study, we studied cryopreservation success in six different diatom species, representing the major morphological and ecological diatom groups, using a range of DMSO concentrations and Plant Vitrification Solution 2 (PVS2) as an alternative cryoprotectant to DMSO. In addition, we tested whether suppressing bacterial growth by antibiotics accelerates the post-thaw recovery process. Our results show that the effects of cryoprotectant choice, its concentration and the addition of antibiotics are highly species specific. In addition, we showed that PVS2 and antibiotics are useful agents to optimize cryopreservation of algae that cannot survive the traditional cryopreservation protocol using DMSO. We conclude that a species-specific approach will remain necessary to develop protocols for diatom cryopreservation and to increase their representation in public culture collections
Cross-disciplinarity in the advance of Antarctic ecosystem research
Get PDFThe biodiversity, ecosystem services and climate variability of the Antarctic continent and the Southern Ocean are major components of the whole Earth system. Antarctic ecosystems are driven more strongly by the physical environment than many other marine and terrestrial ecosystems. As a consequence, to understand ecological functioning, cross-disciplinary studies are especially important in Antarctic research. The conceptual study presented here is based on a workshop initiated by the Research Programme Antarctic Thresholds - Ecosystem Resilience and Adaptation of the Scientific Committee on Antarctic Research, which focussed on challenges in identifying and applying cross-disciplinary approaches in the Antarctic. Novel ideas and first steps in their implementation were clustered into eight themes. These ranged from scale problems, through risk maps, and organism/ecosystem responses to multiple environmental changes and evolutionary processes. Scaling models and data across different spatial and temporal scales were identified as an overarching challenge. Approaches to bridge gaps in Antarctic research programmes included multi-disciplinary monitoring, linking biomolecular findings and simulated physical environments, as well as integrative ecological modelling. The results of advanced cross-disciplinary approaches can contribute significantly to our knowledge of Antarctic and global ecosystem functioning, the consequences of climate change, and to global assessments that ultimately benefit humankind
Effect of settled diatom-aggregates on benthic nitrogen cycling
Get PDFThe marine sediment hosts a mosaic of microhabitats. Recently it has been demonstrated that the settlement of phycodetrital aggregates can induce local changes in the benthic O2 distribution due to confined enrichment of organic material and alteration of the diffusional transport. Here, we show how this microscale O2 shift substantially affects benthic nitrogen cycling. In sediment incubations, the settlement of diatom‐aggregates markedly enhanced benthic O2 and NO3- consumption and stimulated NO2- and NH4+ production. Oxygen microprofiles revealed the rapid development of anoxic niches within and underneath the aggregates. During 120 h following the settling of the aggregates, denitrification of NO3- from the overlying water increased from 13.5 μmol m−2 h−1 to 24.3 μmol m−2 h−1, as quantified by 15N enrichment experiment. Simultaneously, N2 production from coupled nitrification‐denitrification decreased from 33.4 μmol m−2 h−1 to 25.9 μmol m−2 h−1, probably due to temporary inhibition of the benthic nitrifying community. The two effects were of similar magnitude and left the total N2 production almost unaltered. At the aggregate surface, nitrification was, conversely, very efficient in oxidizing NH4+ liberated by mineralization of the aggregates. The produced NO3- was preferentially released into the overlying water and only a minor fraction contributed to denitrification activity. Overall, our data indicate that the abrupt change in O2 microdistribution caused by aggregates stimulates denitrification of NO3- from the overlying water, and loosens the coupling between benthic nitrification and denitrification both in time and space. The study contributes to expanding the conceptual and quantitative understanding of how nitrogen cycling is regulated in dynamic benthic environments
Lagrangian ocean analysis: fundamentals and practices
Get PDFLagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. Over several decades, a variety of tools and methods for this purpose have emerged. Here, we review the state of the art in the field of Lagrangian analysis of ocean velocity data, starting from a fundamental kinematic framework and with a focus on large-scale open ocean applications. Beyond the use of explicit velocity fields, we consider the influence of unresolved physics and dynamics on particle trajectories. We comprehensively list and discuss the tools currently available for tracking virtual particles. We then showcase some of the innovative applications of trajectory data, and conclude with some open questions and an outlook. The overall goal of this review paper is to reconcile some of the different techniques and methods in Lagrangian ocean analysis, while recognising the rich diversity of codes that have and continue to emerge, and the challenges of the coming age of petascale computing
Book of abstracts – 53<sup>rd</sup> European Marine Biology Symposium. Oostende, Belgium, 17-21 September 2018
Get PDFA dynamic testing platform for anti-fouling coatings
Get PDFThe ships’ hull seems to be an excellent transport vehicle for marine plants and animals from onelocation to another. This so-called “hull fouling” has important ecologic and economicconsequences on the environment. Firstly, when these non-indigenous species are able to settle in their new environment, they are able to disrupt the local marine ecosystem and even to destroy local species. Secondly, biofouling generates a substantially increased frictional resistance of the ship’s hull during sailing. An increased frictional resistance of hulls causes a rise in fuel consumption and a waste of time and money when ships have to be cleaned and/or recoated. Yet even a light slime layer has been shown to increase fuel consumption by 8% or more and a heavy slime formation can result in a fuel consumption